JointUNDP/World Bank Public Disclosure Authorized EnergySector Management Assistance Program
Activity CompletionReport No. 074A/87 Public Disclosure Authorized
Country: GHANA
Activity: SAWMILLRESIDUES UTILIZATION STUDY (VOLUMEI - TECHNICALREPORT)
OCTOBER1988 Public Disclosure Authorized Public Disclosure Authorized
Reportof theJoint UNDP/Wdd Bank Energy Sector Management Assistance Program Thisdocument has a restricteddistnbution. Its contents may not be disclosedwithout authorizationfrom tne Government,the UNDPor the WorldBank. ENERGYSECTOR MANAGEMENT ASSISTANCE PROGRAM
PURPOSE
The Joint UNDP/WorldBank Entrgy SectorManagement Assistance Program (ESMAP) was started in 1983 as a companion to the Energy Assessment Program, establishedin 1980. The AssessmentProgram was designed to identify and analyee the most serious energy problems in developingcountries. ESMAP was designedas a pre-invesetmentfacility, partly to assist in implementingthe actions recommended in the Assessments. Today ESMAP carries out pre-investmentactivities in 45 countriesand providesinstitutional and policy advice to developing country decision-makers.The Program aims to supplement,advance, and strengthenthe impact of bilateraland multilateralresources already available for technicalassistance in the energy sector. The reports produced under the ESMAP Program provide governments,donors, and potentialinvestors with informationneeded to speed up projectprepar- ation and implementation. ESMAP activities fall into two major groupings:
- Energy Efficiencyand Strategy,addressing the institutional, financial,and policy issues of the energy sector, including designof sectorstrategies, improving energy end-use, defining investmentprograms, and strengtheningsector enterprises; and
- Household,Rural, and RenewableEnergy, addressingthe tech- nical, economic, financial,institutional and policy issues affecting energy supply and demand, including energy from traditionaland modern sources for use by rural and urban householdsand rural industries.
FUNDING
The Program is a major internationaleffort supportedby the UNDP, the World Bank, and bilateralagencies in a number of countries includingthe Netherlands,Canada, Switzerland,Norway, Sweden, Italy, Australia,Denmark, France, Finland, the UnitedKingdom, Ireland, Japan, New Zealand,Iceland, and the USA.
INQUIRIES
For further.information on the Programor to obtain copies Af the completedESMAP reportslisted at the end of this document,contact:
Divisionfor Globaland OR EnergyStrategy, Management InterregionalProjects and AssessmentDivision UnitedNations Development Industryand EnergyDepartment Programme World Bank One UnitedNations Plaza 1818 H Street,N.W. New York, N.Y. 10017 Washington,D.C. 20433 GHANA
SAIWILLRESIDUES UTILIZATION STUDY
VOLUMEI - TECHNICALREPORT
OCTOBER1988 AB8C - Architectural and Engineering Services ATP - African Timber and Plywood (Ghana) Ltd. BRRI - Buildingand Road ResearchInstitute CIDA - CanadianInternational Development Agency eCw - ElectricityCorporation of Ghana EEC - EuropeanEconomic Community EBP - ExportRehabilitation Program FAO - Food and AgricultureOrganization FD - Forestry Department FPIB - ForestProducts Inspection Bureau FPRI - ForestProducts Research Institute GIHOC - Ghana IndustrialHolding Corporati"n COG - Government of Ghana CRC - Ghana Railway Commission CTMB - Ghana TimberMarketing Board CWA - ClikstenWest Afica Ltd. IIED - Interna' nal Institutefor Environmentand Development MIN - 1limTim_r Co., Ltd. MLNR - Ministryof Lands and NaturalResource ODA - OverseasDevelopment Administrition PNDC - ProvisionalNational Defense Council SIPI. - Subri IndustrialPlantations Ltd. STC - StateTransport Corporation STP - SpecializedTimber Products Ltd. TDRI - TropicalDevelopment Research Institute TEDB - TimberExport Development Board TVLC - Takoradi Veneer and LumberCo., Ltd. VRA - Volta River Authority
ABBUEVITIE a - annum Abs - absclute ADO - Automotive Diesel Oil CIP - Cost, Insurance and Freight cm - centimeter C&E - Constructionand Equipment DCF - Discounted Cash Flow DM - Deutsche Mark 1IRR - Economic Internal Rate of Return FAS - Free Aboard Ship PFl1 - Financial Internal Rate of Return FOB - Free on Board fUa - from and at CJ - gigajoule GWh - gigawatt-hour h - hour ha - hectare Ha - Mercury HHV - HigherHeating Value hl - hectaliters HP - horsepower IDO - Industrial Diesel Oil IFO - Inland Fuel Oil Igal - Imperial gallon in - inch kg - kilogram kJ - kilojoule km - kilometer kPa - kilopascal kVA - kilovolt-ampere kV - kilowatt kWh - kilowatt-hour 1 - liter LHV - Lower HeatingValue LRMC - Long Run Marginal Cost m - meter N - million MCaI - megacalorie mcdb - moisture content, dry basis icwb - moisturecontent, wet basis MD1 - Medium Density Fiberboard min - minute NJ - megajoule mm - millimeter Mo - month MW - megawatt M.T. - metric tonne NPV - Met Present Value OD - oven dry O&M - Operations and Maintenance RFO - RosidualFuel Oil RWE - Round Wood Equivalent SCF -S tandard Conversion Factor SWE - Sol8iWood Equivalent t - metric tonne TC - turtogenerator toe - tonnes of oil equivalent tonne - metric tonne USD - U.S. Dollar WTP - Willingness-to-Pay yr - year micY ANDFURL BQUIVALES
cumcY
1 VI$ - 150 Cedi
COUVERSONFACTORS
1 MJ 948 Etu 239 Kcal * 0.278 kWh
mcwb LHV HHV Fuel () (NJ/kg) (NJ/kg)
Sawmill Residues 36 11.9 20.0 Fuelwood. air-tried 30 13.1 20.0 Sawdust Briquettes 5 18.9 20.0 Charcoal 5 29.0 30.2 CrudeOil -- 43.3 Gas Oil (ADO) 43.3 45.5 Industrial Diesel Oil (IDO) 42.1 44.6 Inland Fuel Oil (IFO) 40.1 42.8 Residual Fuel Oil (RPO) 39.8 42.5 Electricity - 3.6 a/ a/ NJ/kVh Costs of Utiization...... 46 Technical/InfrastructureConstraints to Residues Utilization ...... 47 Water Spray Lubricdtionof Saw Blades*...... 47 OutsideStorage of Sawdust...... 47 Boiler/FurnaceConfiguration...... 47 BoilerEfficiency...... e...... * *7
V. POTENTIALON-SITE ALTERNATIVES FOR IMPROVINGAND/OR INCREASINGUSE OF WOOD INDUSTRYRESIDUES AS FUEL...... 48 Summary...... 48 On-SiteUtilization...... 50 Backgroun...... 50 SawmillProcess ...... 50 Cogenerationat Grid ConnectedMills...... 57 Cogenerationat Non Grid ConnectedMills...... 64 ResidueHandling and CombustionEfficiency Improvements...... 83 ~~~~~~~~~~~~~~~83 Backgrounds** **#*o ...... e...... 83 Saw Guide and SawdustStorage Improvements*...... 84 FurnaceModifications for SawdustCombustion ..... 0... 85 Boiler/FurnaceEfficiency Improvements...... 85
VI. POTENTIALOFF-SITE ALTERNATIVES FOR IMPROVINGAND/OR INCREASINGUSE OF WOOD INDUSTRYRESIDUES AS FUEL...... 86 Summary...... 86 Off-SiteUtilization...... 88 Background ...... e.... ,****oo 88 Substitutionof Sawdustfor Oil FuelsConsumption.....*. 88 Financialand EconomicAnalysis...... 88 Substitutionof Sawdustfor FuelwoodConsumption*.... 0.. 90 Financialand EconomicAnalysis...... 91 Off-SiteConversion Alternatives e...... 92 Background...... 92 ImprovedCharcoal Production...... 93 Present.e00 ...... 93 ImprovedMethods ...... 96 Financialand EconomicAnalysis of Improved CharcoalOptions ...... o *.. 106 SawdustBriquetting ..... 109
ProposedPlants...... 117 CharcoalBriquettes ...... 124 Background...... 124 ProductionOptions/Economics...... 125
VII. CONCLUSIONSAND REOOMENDATIONSFOR INCREASEDAND,OR IMPROVEDUTILIZATION OF WOOD INDUSTRYRESIDUES...... 128 Suuunary...... *.*...... ~128 On-SiteDirect Utilization...... 128 TABLE OF CONTS
EXECUTIVE SMAY...... i
TM INTRODUCTION 1
Sackopeo ...... ,...... 3 Scopeof Suy3 Organizationof Report...Be p ...... o rt..000 e0e 4
II. TUE GHANAIANWOOD PROCESSINGINDDUSTRY ...... oo...... o.... 6 SectorPerformance...... 6 Type, Capacityand Locationof Wood Processing Facilitiest ...... ieooooooeee*o.....o.o..o.... 10 IndustrialTimber Production.ootucti...oo.o. oono... o.... 13 Wood IndustryTrends Affecting Residues Disposition.... 15 Trend to GreaterValue-Addedue-Atd..oeoo.oed.o. ooooo 15 Trend TowardExploitation of SecondarySpecies.ooooos 16
III. SUPPLYOF WOOD INDUSTRYRESIDUESo.oo...... o.o...... o.o. 17 s.umry...... 1? Sources,Types and Characteristicsof Residuestues.o.... 17 Location of Residues...... i ...... d u es.... 21 ForestResidueso...... *.**...... oo 21 WoodProcessing Residuesi.dou esooo...oo.o.o.oo.o...o.22 Quantities Producedod...... 0.0.00.0... .0000 .0 0000..0 23 Existing Sto 00.000...... 0.c k p i le.... 25 Reliabilityof Supplies p p o.....l oo..o...o..o.... ie.oo... 26 Presentand ProjectedSurplus r p lu..o...... o.o.os...... 27 PresentSurpluso...... o ...... eo.o ..oo 27 FutureSurplusr p l us...... 29
IV. DEMANDFOR WOOD PROCESSINGINDUSTRY RESIDUES..*...... o 31 Summry...... 31 On-siteEnergy Uses and Disposalo....oo.o.o.ooo...o..o 31 Steam and ProcessHeeatoooo...o...... 31 Cogenerationo.oo*oooo*o,ooooo00 0 34 Charcoal Production..oood. u c ...... t i ...... on... 36 D ispo sal..o..oooooooo....oo ooooooooo... o....oo....oo 37 Off-siteEnergy Usesoosooooes...o.oos..o..ooooo..o..oooo 37 Industrialand Co_mercialHeat Raising sing**...o.oo..37 Domestic Cooking.ooki.n .ooo.o.o...ooo . .oo..e...g 38 CharcoalProductionoo...... 0...0...0..0 38 Briuti qgooou e t t i ngooooo*o***ooo*38 Energyvs. Non-EnergyUses... ses...... 0..0..38 SecondaryManufacturing and Export p.o rt...... o...39 CottageIndustry Woodworking...... o.o..oo...... 39 Particleand Fiber Board Productiono.o..o.ooo.o..o.oo39 Summaryof PresentResidues Utili zation...... 39 SawmillProcess Heat...... *.***.,**,0.9...... 000 128 Cogenerationo...... 0.0..o.o...... 131 DirectUtilization in the IndustrialSector...... 132 ResidueSubstitution for Oil Fuels...... 132 ResidueSubstitution for Fuelwood...... 133 ConversionAlternativeso ...... o.o...eo...oo..o..o 133 ImprovedCharcoal Making...... 133 SawdustBriquetting.....0.o...0.o.00oq.e.eO.*0o.0.... .133 BriquetteCarbonization...... 134 NationalInvestment Implications...... 134 Total InvestmentPotential...... 134 Competitionfor ResidueResources...... 135 ResidueUtilization Priorities...... 136 Uncertaintiesand Risk Factors...... 138 Healthof the Wood ProcessingIndustryoo.. 00.0 ...00.. 138 Locationof Wood ProcessingFacilities...... 138 Wood Supply/Demand...... 138 Oil Prices ...o...e.o..o...oo..4*o*o*ooooooo* 138 ElectricityCosts.o000* * oo...... 139 Inveatment Recommendations.. .o.....o o...... t39 SawmillProcess Beat...... 139 Sawdust Briquettingo...... 0000000000000000 139 TechnicalAssistance Recommendations...... 140 Pilot/DemonstrationProjects .o....o...... o...o.ooo. 140 ImprovedSolid Residues Carbonization ...... 0 0..... 140 Briquette Carbonization. 0 0 0.000o0.00.0o0...... o 141 PolicyRecommendations....o...... 141 Sawmill Process Heato...... 0.0...... 142 Residue Conversiono...... 142 Areas for FurtherInvestigation...... s 142
TABLES 2.1 Value Estimatesfor IndustrialForest Products in Export and Domestic Trade.o.. o...... e...... *o.*o 9 2.2 IndustrialTimber Processing Facilities, 1986...... 10 2.3 Distributionof Sawmillsby Size of Production,1986.... 11 2.4 Distributionof Productionby SawmillSize, 1986...... 12 2.5 AnnualCut from HighForest...... 14 2.6 ProjectedDistribution of the IndustrialHardwood Timber Harvest...o.v.s.... .o...... 0.0..0..0 14 3.1 Densitiesand MoistureContents of Selected Ghanaian Woods...... s 18 3.2 MoistureContent of TypicalSaw TimberSpecies Mix ...... 19 3.3 Fuel Characteristicsof SelectedGhanaian Woods...... 20 3.4 NominalCharacteristics of Wood Processing Industry Residues ...... 21 3.5 SawmillResidue Production, 1986...... 23 3.6 CombinedMill ResidueProduction, 1986...... 25 3.7 Wood ProcessingIndustry Residue Production, 1986 ...... 25 3.8 SurplusSawdust Concentrations.... *.0 *...... 0 0 .....o 29 3.9 PlannedAdditions to Wood ProcessingFacilities UtilizingMill Residuefor ProcessHeat Generation... 30 4.1 Wood ProcessingFacilities Utilizing Kill Residue for ProcessHeat Generation,1986...... 32 4.2 Wood ProcessingFacilities Utilizing Mill Residue for Co-Generationof Steamand Power,1986...... 35 4.3 Wood ProcessingIndustry Disposition of Residues by Region,1986...... 40 4.4 End-Usesof Wood ProcessingIndustry Residues by !.ype,1986...... 42 4.5 Disposi..onof Wood ProcessingIndustry Residues by End-Use,96...... 4 5.1 Matrixof TechnicalOptions for Improvingand/or IncreasingOn-Site Residue Utilization .. 60*-*4000.. 49 5.2 Wood ProcessingFacilities Visited by Miss9ion**on..... 50 5.3 SecondarySpecies Requiring Kiln Drying..o..oo...0..g 52 5.4 Summaryof Capitaland AnnualOperating Costs for SawmillProcess Heat Unit ProductionModel.oo..o... 54 5.5 PotentialGross Contributionto ForestIndustry Value Added throughLumber Kiln Dryingoo ing...... 56 5.6 FinancialAnalysis Results, Swmill ProcessHeat Unit Production Motl 57 5.7 EconomicAnalysis Results, Sawmill Process Heat Unit ProductionMoee l 57 5.8 Summaryof IncrementalCapital and AnnualOperating Costs for STP CogenerationAlternative 2...... 60 5.9 Summaryof IncrementalCapital and AnnualOperating Costs for STP CogenerationAlternative 3...... 62 5.10 PinancialAnalysis Results, Grid Connected Co-GenerationModels (STP).... 63
5.11 EconomicAnalysis Results, Grid Connected Co-GenerationModels (8TP ) 64 5.12 HIM CogenerationOptions Decision Matrix..0*0*...... 0 67 5.13 Mim Area ElectricalDemand and Consumption,1985...5.... 69 5.14 Utilizationof Residuesat MIM 70 5.15 CharcoalSales Prices,Mim TimberCo 70 5.16 Summaryof Capitaland AnnualOperating Costs for MIM CogenerationAlternatives...... o...... ee... 19 5.17 Net PresentCost of MIM Alternativeswith No Grid ExtensionAssumed ...... 81 5.18 KIM Alternative3A vs. IA Financialand Economic Analysis Beet 81 ...... 5.19 KIM Alternative5B vs. Base Case B Financialand EconomicAnalysis Results...... 83 6.1 Matrixof TechnicalOptions for Improvingand/or IncreasingOff-Site Residue Utilization...... 87 6.2 Industriesand InstitutionsVisited to Evaluate Potentialfor DirectUtilization of Wood Residue..... 89 6.3 FinancialAnalysis Results, Oil to Sawdust-FiredBoiler Conerson...... 90 6.4 EconomicAnalysis Results, Oil to Sawdust-FiredBoiler Conversion...... ~ ...... 90 6.5 FinancialAnalysis Results, Fuelwood to Sawdust-Fired Boil'rConversion...... 91 6.6 EconomicAnalysis Results, Fuelwood to Sawdust-Fired BoilerConversion...... *...... 00.0.000...... 92 6.7 Earth Mound CharcoalKilns, Ruia s i 96 6.8 Mill ResidueCharcoal Marketing, Kumasi...... 96 6.9 Comparisonof CharcoalKnl n s 99 6.10 Summaryof AnnualizedCapital and OperatingCosts of CharcoalProduction Alternatives...... 100 6.11 Financial/EconomicAnalysis Results, Beehive Brick Kiln CharcoalingImprovement...... 108 6.12 ChaowusLtd. BriquettingMachine Specificationsations*** 110 6,13 ChaowusLtd. BriquetteFuel Characteristicsoo0.00...0000 111 6.14 EstimatedSawdust Briquette Demand m a nt...... 113 6.15 Financialand EconomicCosts of Fuelwoodl...... o.113 6.16 Briquettesvs. FuelwoodComparison in Bread Bakingt Accraccra...... 115 6.17 Briquettesvs. FuelwoodComparison in Brick Manufacturing,Cape Coast... 115 6.18 Briquettesvs. InlandFuel Oil ComparisontAccraa...... 126 6.19 Characteristicsof ProposedSawdust Briquette ManufacturingPlants..l a n ts...... 0118 6.20 Summaryof Capitaland AnnualOperating Costs for ProposedBriquetting Plantsa.n t.s...... o...... 129 6.21 Summaryof BriquetteProduction and Transport FinancialCosts...... 121 6.22 FinancialAnalysis Results, Proposed Sawdust Briquetting lns 121 6.23 EstimatedWood Balance,1986-20008..... 122 6.24 EconomicAnalysis Results, Proposed Sawdust BriquettingPlants ...... 123 7.1 Net EconomicContribution to ExportLumber Unit Value throughKiln Dr y i n g 129 7.2 SawmillProcess Heat InvestmentPotentia1...... 130 7.3 Total InvestmentPotential for Increasedand/or ImprovedUtilization of Wood IndustryResidues...... 134 7.4 Net Benefit/ResidueResource Ratio for EnergyUses in Kumasi 135 7.5 ResidueEnergy Utilization Priorities ...... 136 7.6 ResidueUtilization Profiles for Kumasim.... 137
FIEURES 2.1 TimberExport Volumes, 1976-1986; 1990 (Projected)...... 7 2.2 TimberExport Values, 1976-1986; 1990 (Projected)...... 8 2.3 Distributionof SawmillCapacity by Size, 1986...... 12 3.1 SawmillResidual Fractions vs. Recovery Fraction,1985 ..... 24 3.2 SurplusResidues by Type, 1986...... 28 3.3 SurplusResidues by Region,1986 ...... 28 4.1 ResidueUtilization by Region,1986 ...... 41 4.2 ResidueEnd-Us by Type, 1986...... 43 4.3 ResidueDisposition by End-Use,1986 ...... 45 5.1 STP Ltd. Schematic- Alternative1...... 53 5.2 STP Ltd. Schematic- Alternative2...... 59 5.3 STP Ltd. Schematic- Alternative3...... 61 5.4 MIM ComplexDaily Load Profile ...... 66 5.5 Mim TimbersLtd. Schematic- Base Case A/ Alternative 1A...... 72 5.6 Mim TimbersLtd. Schematic- Alternative2A ...... 74 5.7 Mim TimbersLtd. Schematic- Alternative3A...... 76 5.8 Him TimbersLtd. Schematic- Alternative4A...... 77 6.1 TypicalEarth Mound CharcoalProduction...... 94 6.2 TropicalDevelopment Research Institute (TDRI) Steel CharcoalKiln ...... 98 6.3 Clay/MetalCharcoal Kiln (SubriSemi-Mobile Kiln)...... 101 6.4 MissouriCharcoal Kiln (SubriRiver Project)...... 103 6.5 Casamance Charcoal Kiln...... 105 6.6 BeehiveBrick CharcoalKiln...... 107 6.7 ContinuousBriquette Charcoaling Machine...... 126
BIILIOGRAPHY
MAP IBRD 20619: Chana Wood Processingand Other IndustrialCenters EXECUTIVKSUNKARY
1. Ghana harvested1.07 million m3 (roundwood equivalent)of i3dustrialhardwood timber in 1986and consumedor exportedabout 600,000 m of timberproducts or logs. The difference,which can be considered as wood industryresidues, had an energyvalue of 94,000 toe. About three-quartersof theseresidues were utilizedat varyingefficiencies in the domestic sector and in the wood processingsector itself. The remaining23 percent,with 22,000 toe energy value, found no usage. Efficientuse of these residuesas a sourceof energy,especially in the wood processing industry,could have a significantimpact on the financialhealth and foreignexchange earnings of the sector. This sector accountedfor 6.2 percentof GDP in 1985 and approximately6.4 percentof total exportearnings in 1986. Convertedsurplus residues, after accountingfor mill consumption,could significantlycontribute to the energy demands of the commercialand householdsectors. These possibilitiesand the investmentrequirements necessary to realizethem are discussedbelow.
SectorPerformance (Chapter II)
2. Improvingthe performanceof the Ghana forestryindustry has been the primary target of the Export RehabilitationProgram (ERP) financedby creditsfrom IDA, the OverseasDevelopment Adminstration and the CanadianInternational Development Agency. As a result,productivity in the sectorhas demonstratedmarked gains since1984 after experiencing a sharp drop in output duringthe period 1976-1983. At present,only about 55 percentof wood industryprocessing capacity is utilized. In the short term,further gains in capacityutilization are unlikelydue to forestresource constraints. Total timberharvest is expectedto remain close to the 1986 level throughthe end of the century. However,two industrytrends have been identifiedthat have implicationsfor residue productionand consumption:
(a) increasesin the levelof domesticprocessing for highervalue- added;and
(b) a shift to higher productionof secondary(non-traditional) species.
The primaryeffects of thesetwo trendswill be to changethe quantity, type and characteristicsof the residuesgenerated as well as most likely increasethe on-siteutilization of residuesas a resultof increased needs for processheat.
Supplyof Wood IndustryResidues (Chapter III)
3. Types. Wood industryresidues can be bruadlyclassified into two major categories:solids (slabs, edgings, offcuts, veneer wastes and cores);and fines (sawdust,planer shavings and sanderdust). Solids - ii -
accounted for 79 percent of the residues produced while sawdust accounted for the remaining 21 percent. Table 1 presents a summary of the distributionof residuesby type.
Table 1: PRODUCTIONOFWOOD INDUSTRY RESIDUES, 1986 (3 SUE)
Slabs & veneer EdgIngs Offcuts Sawdust Waste Cores Total
quantity 213,175 66,747 93,269 34,723 26,698 434,612
Percent 49% 1% 21% 9% 6% 100%
4. Location. The production of wood industry residues is primarilyconcentrated in a few major wood processingcenters. In fact, 66 percentof the total residueproduction is concentratedwithin an 8 km radius in the Kumasi area. An additional23 percent is distributed between three' other centers:Takoradi (9X); Mim (9Z); and Akim-rda (5X). The remaining 11 percent is scattered amongst eight other locations.
5. Future Supply. So long as the wood industrycontinues its recovery,total residueproduction is expectedto remain fairly stable though the types and characteristicsof the residues could change slightly. Increases in the level and quality of processing and shifts to harvesting of more secondary species will be the primary factors influencing change in the characteristics of the residues. On the whole, it is expected that effects will be counterbalancing and that the energy value of residueswill also remainfairly stable.
6. Surplus Residues. Only 23 percent of wood industry residues are presentlynot utilized. The total surplus residues have an energy potential of 27,000 toe or equivalent to 13 percent of the 1985 industrial woodfuel consumption. Green (wet) sawdust is the only residue in abundant surplus accounting for 84 percent of the total available surplus residues. Ninety percent of all sawdust produced is not utilized and present disposal costs are estimatedat approximatelyUS$80,000 to 125,000per year. This does not accountfor the potentialenvironmental damageas a resultof burning(smoke) or dumping(leaching).
Demandfor Wood ProcessingIndustry Residues (Chapter IV)
7. End Uses. Table 2 providesa summaryof the 1986 end-use of wood proceisingindustry residues. At presentonly 23 percentof the residues are consumed for on-site process heat generation or cogeneration.Approximately 32 percentis used off-sitefor firewoodor - iii -
charcoal productionwhile 22 percent is used for non-energypurposes (e.g.local furniture,fencing, etc.).
8. On-SiteUse. There are 21 wood processing facilitiesthat have wood-wastefired boilersfor generationof steam and processheat. Almost all are combinationmills producingsawn timber,plywood and/or veneer. These mills generallyconsume 50 to 60 percentof their wood residues. There are four mills that have cogenerationequipment installed on-site. However, only one currently operates in a cogenerationmode; the othershave eitherexperienced equipment problems or have not completedtheir installation. When cogenerating,these mills could consumemost of their residuesto meet their heat and electricity requirements.At present,only two major millsare not connectedto the grid.
Table2: END-USESOF WOODPROCESSING INDUSTRY RESIDUES, 1986 Cm SUE)
Fuel for MtIl Firewood/ Non-Energy Surplus PracessHeat/Cogeneration Charcoal Production Purposes Residues Total
Solids 92,235 136,468 96,341 16,177 341,343
Flues 6,674 3,195 - 83,400 93,269
Total 99,031 139,663 96,341 99,577 434,612 (23S) (32%)a/ (22%) (23%) (100%) a/ includes3% on-sitecharcoal production at MIN.
9. Off-SiteUse. More thanhalf of the wood industryresidues are used off-site;29 percentis for energyand 22 percentfor non-energy purposes. Of the residuesutilized off-site for energy,about 28 percent is used directlyas firewoodfor food preparationin the commercialand householdsectors. The majority,70 percent,is convertedto charcoalin primitiveearth mound kilns. The resultingoutput represents 2 percent of the total charcoalproduction in Ghana. Only 2 percentis sawdust which is convertedto briquettesat a privateplant in Oda for sale to bakersand brickmakers.Of more than60 industrialsites surveyed in the vicinity of the wood processingindustries, only one is a regular consumer of unprocessedsawmill residues. Other industriesusing woodfuelsobtain their firewoodfrom the naturalforests at competitive prices. With the exceptionof a minoramount of sawdustfor briquetting, no other sawdustis presentlyused off-sitefor energy. - iv -
On-siteOptions for ResidueUtilization (Chapter V)
10. Opportunitiesexist not only to utilize surplussawdust but also to improvethe presentuse cf solid residuesso as to obtain the maximum economic benefit from all residues produced. The most economicallyattractive on-site options for improvingand/or increasing residueutilization are:
(a) Steamgeneration to meet processheat needs for kiln dryingand wood treatment;
(b) Improvedsaw blade guide and sawduststorage/handling systems to reducewater contentin the sawdustresidue and increasethe net energyavailable; (c) Furnacemodifications to enable substitutionof sawdust for solidresidues; and (d) Furnaceimprovements for greatercombustion efficiency.
Investmentsin cogenerationsystems proved to be marginalat best and are not recommended.Table 3 summarizesthe estimatedfinancial and economic IRRs for the major investment.Detailed discussions and evaluationsof each are presentedin ChapterV and highlightedbelow.
Table3: SUMMARYOF ESTIMATEDFINANCIAL AND ECONOMICIRR FOR ON-SITE RESIDUEUTILIZATION OPTIONS
OPTION FIRR EIRR
Saw.illProcess Heat 27-56S 30-52S
Cogeneratlonat SrId ConnectedMills Negative 4%8
Cogenerationat Non-gridConnected Mills (MIN)o/ Negative <12%
oZ ComparisonIs againstthe optionof gridextension costs.
11. SawmillProcess Heat. Resultsof the analysison the possible uses for residuesat a typicallarge sawmillpoint to the potentialfor significanteconomic gain from oa-sitegeneration of processheat for wood treatmentand kiln drying. Major economicbenefits are derived from: v
(a) Highervalue-added through export of kiln driedproducts; and
(b) Increasedrange of economicallyexploitable species through log sterilizationand lumberdrying. Financialand economicIRR exceeding30 percentare possible. National investmentrequirements in the rangeof US$ 7.4 to 13.8 millionwould be required(depending on the levelof value-addedprocessing as3umed) with resultingnet annualeconomic benefits in the range of US$ 2.7 to 4.5 millionrespectively.
12. SawdustUtilization: Benefits could be maximizedif provisions are made to utilize surplussawdust as a fuel at mills. This would entail incorporationof measuresto improvethe fuel qualityof sawdust such as more efficientsawblade guide systems and shelteredsawdust handlingand storagesystems. Retrofitcosts are minor comparedto other sawmillcapital investments. Additionally, provisions must be made to installboilers with appropriatecombustion systems for direct sawdust utilization.
13. Coseneration.Almost all large sawmillsin Ghana are connected to the nationalgrid and thereforereceive the benefitof low cost hydro- power. The marginal financialcost of residue fueled cogenerated electricityat these large mills is estimated at 5.6 to 7.1 US cents/kWh. With presentindustrial tariffs set in the range of 3.5 US cents/kWh,there are no financialincentives for mill ownersto undertake investmentsin cogeneration.Lack of financialincentives is not the onlv barrier. Marginaleconomic costs of residuefueled cogeneration is estimatedat 5.8 to 7.6 US cents/kWhwhich is still higher than the presentestimated marginal cost of 5.2 US cents/kWhfor grid systemelec- tricity. In the shortterm at least,residue fueled cogeneration at saw- mills cannotbe supported.In the longerterm however,the marginalcost of grid systemelectricity is expectedto rise as all low cost hydropower sites in Ghana have been fully exploited. Based on data in a recent system expansionstudy for VRA by Acres International,an estimateof LRNC for electricityin the range of 8 US cents/kWhis not unrealistic. Given this scenario,residue fueled cogeneration could be competitive. It must be pointedout, however,that the totalpotential power from this sourcewould likelynot amountto more than 20 MW whereasthe Acres study indicatesa need to bringon between200 to 400 MW by the mid 1990s.
14. Two large mills are presentlylocated off-grid. One, African Timberand PlywoodLtd. (AT&P)located in Samreboi,is not expectedto be connectedto the nationalgrid in the foreseeablefuture. Its options for electricityare either diesel generation or residue fueled cogeneration. AT&P is presentlyundergoing renovation with Bank of Scotland financingand expects to cogenerateits electricitywhen it recommencesoperation in 1988. Clearly,in this case residue fueled cogenerationis more economicthat dieselgeneration. The other mill, Mim TimberCo, Ltd. (MIM) located47 kM from Sunyani,is scheduledto be connectedto the grid in 1989 when VRA undertakesa US$2.2million grid - vi -
extension. To date, constructionhas not yet begun on the extension.An anslysisof the least-costelectricity supply optionat MIM, assuming grid extensionto be uncommitted,confirms that grid extensionis the best choice. A 1.2 MW base/intermediateload residue-fueledcogeneration plant coupled with existing diesels for peaking power results in marginally cheaper electricity when grid extension costs are considered.A US$2.1million investment is requiredfor the cogeneration plant yieldingan economicIRR of only 12 percent. A recommendationfor a cogenerationplant cannot be stronglysupported given the additional managementand risk factorsassociated with operatingthe cogeneration plant,the financialdisincentives for MIN management,and the fact that socialbenefits to the surroundingarea are not fullyprovided.
Off-siteOptions for ResidueUtilization (Chapter VI)
15. Severaloptions are availablefor improvingand/or increasing the off-site utilizationof wood industryresidues. As indicated earlier,over 70 percentof the residuesused off-sitefor energy are convertedto charcoalin primitive,inefficient earth mound kilns. Over 89 percent of the total Sawdust productionis unutilized. And, the presentknown demandfor s'wdustbriquettes exceeds the supply. Given these facts,four key optionswere investigatedin detail:
(a) Direct utilizationof sawdust in industrial/commercialoil- firedor wood-firedcombustion systems; (b) Improvedcharcoal producti,n techniques; (c) Increasedsawdust briquetting capacity; and (d) Introductionof briquettecarbonization techniques.
A summaryof the estimatedfinancial and economicIRR for the first three optionsis presentedin Table 4. Detaileddiscussions and evaluationsof a range of these optionsare presentedin ChapterVI and highlighted below.
Table4: SUMMARYOF ESTIMATEDFINANCIAL AND ECONOM'C iRR FOR OFF-SITERESIOtE UTILIZATION OPTIONS
OPTION FIRR EIRR Conversionof Industrial/Comercial Negative Negative Oil-firedCombustion Systems
Conversionof Industrial/Commercial 11-23%a/ 32-42%a/ Wood-firedSystems
ImprovedCharcoal Production 300% 500% Techniques
IncreasedSawdust Briquetting Capacity Negative-19%b/ 9-19%b/
I/ Representsthe IRR from two of the most attractive candidates. b/ Variabledepending on scaleof project. - vii
16. Substitutionfor Oil Fuels. The economicsof substituting unprocessedsawdust. or solid residues for oil fuels (RFO/IFO) in industrial/comercialcombustion systems in Ghana are unfavorable. Evaluationof a wide range of possibleindustrial/ccmmercial candidates indicatedthat petroleumprices would have to rise above US$ 30/bblin 1986 dollarsbefore savingsfrom fuel costs could amortizethe capital costsrequired for conversion.Alternately, capital costs would have to declineby 40 to 100 percentin order to yieldfavorable returns. One of the primary reasonsfor the negati-e economicsis the fact that most potentialindustrial/commercial candidates have low utilizationfactors associatedwith theircombustion equipment and thereforea relativelylow base from which fuel savingscan be derived.
17. Substitutionfor Fuelwood. The economic potential for substituting unprocessed sawdust for fuelwood consumption in industrial/commercialcombustion equipment is limited. Conversionof most fuelwood combustionequipment to utilize sawdust is generally feasiblerequiring modifications to the grateand feed systems. However, haulagecosts for sawdustand the low financialcosts of fuelwoodlimit the possible candidatesto those in the immediatevicinity of the sawmills.
18. ImprovedCharcoal Making. Almostall charcoalproduction from sawmillresidues is producedby the traditional"earth mound" method. The conversionefficiency of most of these charcoalingoperations was found to be extr ,elylow. The earthmound techniqueis generallyused in forest and land clearing operationsbecause it requires little equipmentand can move with the resource. Sawmillresidues provide an excellentopportunity to utilizeimproved charcoaling techniques, thereby potentia11ydoubling the outputof charcoalderived from these residues withoutincreasing residue consumption.
19. After evaluatingseveral improved charcoaling techniques, it was determinedthat Beehivebrick kilns and Casamancekilns were the most technicallyand economicallyattractive options for charcoalingsawmill residuesin Ghana. If all residuespresently carbonized in only the Kumasiarea were convertedin Beehivebrick kilns, charcoal output would increaseby 4,400 tonnes/yror equivalentto an 80 percentincrease over the present charcoal productionfrom residues. The estimatedtotal investmentrequired to achieve this improvementis US$ 110,000which would yield an economicrate of returnnear 500 percent. Clearly,a programto improvecharcoal production from sawmillresidues should be high on the agenda.
20. SawdustBriguetting. Loose sawdustis cumbersometo manage, transportand use and as statedearlier has limitedoff-site potential. When briquetted,the sawdustcan be effectivelytranspor'-i, stored and utilized. The potential for sawdust briquetteshas already been establishedin Ghana with the operationof a 2,000 tonne/yrplant in Oda. Presentdemand greatly exceeds supply. Totalestimated demand from just the bakers and brick manufacturersin the main urban areas is in - viii -
excess of 45,000 tonnes/yrwhich is about equal to the quantityof briquettesthat could be producedif all surplussawdust were to be briqu4tted. 21. Evaluationof three differentcapacity screw press sawdust briquettingplants indicatesthat definiteeconomies of scale exist with respect to this technology. A 14,000 t/yr plant in Kumasi is economicallyattractive with financialand economicIR estimatedat 19 percent. A plant of this scalewould consumejust over half the surplus sawdust in the Kumasi area yet meet only one-thirdof the potential demand for briquettesfrom the bakersand brick manufacturers.Total investmentfor the plant is US$780,000,of which 24 percentis local costs. 22. Briguette Carbonization. While sawdust briquettesare an acceptablefuel-wood substitute in the commercialsector, they would face difficultiespenentrating the household market where charcoal and charcoalstoves predominate. Sawdustbriquettes produced by the heat extrusionscrew press systemsused in Chana couldbe carbonizedeither in separatekilns or in a carbonizationtunnel appended to the last stage of the briquettingmachine. Carbonizationby the kiln methodis provenand is practicedin Japan and Taiwan. The carbonizationtunnel is still experimentalbut it has potentiallysignificant energy efficiency advantages. Assuminga 32 percentyield of briquettesto charcoaland accountingfor capitaland operatingcosts resultsin charcoalbriquette costs in the range of US$ 80 to 125/tonne. With charcoalFOB export value estimated at US$115 and charcoal prices in Takoradi of US$132/tonne,the possibilityfor a viable charcoalbriquette market exists. However,the relativelyexperimental nature of this technology requiresfollow-up investigation before actual investmentsin this area are undertaken.
Conclusions(Chapter VII)
23. Investments. Investmentsin sawmillprocess heat generation, sawdustbriquetting and improvedcarbonization systems provide the most attractiveoptions for improvingand/or increasingthe use of wood industryresidues. Total potentiallevels of investmentexceed US$8 millionwith economicrates of returnranging from 19 to 46 percentper sub-project. If a high level of log treatmentand kiln drying is assumed,total investmentsin just processheat equipmentcould approach US$14 million. A summary of the total investmentpotential and associatedresidue consumption is presentedin Table 5. - ix -
Table 5: TOTAL INVESTMENTPOTENTIAL FOR INCREASEDAND/OR IMPROVEDUTILIZATION OF WOODINDUSTRY RESIDUES
Investment Annual Residue Investent Location Amount EliR NPV Consumption
Sawmill US$7.4 N Process National at present wood 46S USS20.4 N up to 80,000 m3 Heat Industry output
Sawdust Briquetting Kumasi USS0.78 N 19% US$0.50 M 27,000 m3 Plant
Improved Charcoaling of Residues Nationala/ up to USS0.11M 490% USS1.11N 64,000 m3 a/ Amounts given are for Investmentfor improvedutilization of all residues presently carbonIzed in Kumasl.
24. Competition for Residues. Options for residue utilization are mutually exclusive to the extent that they might compete for the same residue resource in terms of type and location. The primary source of competition would likely occur for sawdust in Kumasi if both maximum process heat generation and sawdust briquetting were promoted. The total sawdust production in Kumasi would not necessarily be sufficient under this scenario. Valuation of residue use for various options provides a basis for prioritization. The resulting residue utilization priorities are presented in Table 6. They indicate that sawdust should be used first at the mill boilers to the extent determined by process heat demand and technical feasibility of sawdust combustion. Solid residues should be used only to meet additional demand not met by sawdust. RemainirZ sawdust should be briquetted if available in sufficient quantities to realize necessary economies of scale. Remaining solid residues should be converted only in efficient charcoal kilns such as the Beehive brick kiln. An analysis of the situation in Kumasi based on this prioritisation would allow for construction of the 14,000 t/yr briquetting plant. x
oable 6: RESIDUEENERGY UTILIZATION PRIORITIES
PriorityRanking Utilization
1 Combustsawdust on-site for process heat generatlon/cogeneration,
2 Combust solid residueson-site for process heat generatlon/cogeneration.
3 Convert solid residuesto charcoal In efficientkiIns.
4 Convert sawdust to briquettes.
5 Utilize solid residuesas firewood.
Recommendations (Chapter VII)
25. Investments. As a result of this investigation the following key investment recommendations can be stated:
(a) Primary attention should be focused on investments to promote the on-siteutilization of sawmillresidues for generationof process heat used in value-added processing;
(b) Attention should also be focused on the possibility of investments in the 14,000 t/yr briquetting plant in Kumasi;
(c) Any investment in increasing residue utilization should incorporate technical assistance and resources to minimize water contamination of sawdust through improved saw blade guides and storage and handling systems;
(d) Financing should be provided to institute a program to convert all sawmill residue charcoaling operations to improved methods;
(e) If donor funding is made available, a small briquette carbonization project should be instituted to demonstrate the technical and economic feasibility of this option.
26. Policies. Government policies on residue utilization can have a major effect on the ultimate disposition of waste wood resources. With appropriate policies of fuels pricing, tax/fee levels, regulation, and market information dissemination the government can guide the development and use of this indigenous resource. Specific policy recommendations are - xi -
discussedin Chapter7. Key policiesrecommended to improveresidue utilizationinclude:
(a) Market developmentand informationdissemination relating to exportopportunities for kiln driedand treatedlumber;
(b) Differentialtaxation on value-addedforest products, and phasedextension of log exportban to widergroup of marketable species (with attendantincrease in requirementsfor lumber treatmentand drying);
(c) Institutionof permit/feesystems for wood residuedumping and a ban on open residueincineration; and
(d) Provisionof domestic loan financingand trainingschemes, possiblyfrom NationalEnergy Board resources,for improved charcoalingof wood industryresidues.
27. FurtherInvestigation. Logging residues constitute more than 1.0 millionmJ/yr of waste wood with an energypotential of more than double that availablefrom the wood processingindustry residues. To date only a small fractionof these residuesare recovered.Clearly, an investigationinto the logistics and economics of recoveringthis potentiallymore significantsource of indigenousenergy is needed to complementany effortsto improveand/or increase the utilizationof wood residues. Subjectsto be addressedinclude methods of carbonizingwaste wood from timber operationsin the forest,incentives that would be required to induce a shift of traditionalcharcoal-making into the loggingareas and presenttechnical, institutional and infrastructural constraintsto wide scale charcoalingof forestresidues. I. INTRODUCTION
Back!round
1.1 The Joint UNDP/WorldBank Energy Sector AssessmentProgram conducteda comprehensivereview of the Ghana energysector in October, 1985. The resultsof this reviewwere containedin a finalreport issued in November,1986, entitled,Ghanas Issues and Options in the Energy Sector. The assessmentdetermined that, in 1985,energy end-uses in the economy were suppliedprimarily by biomass fuels (i.e.,woodfuels and agriculturalresidues), 72 percent, and importedpetroleum, about 24 percent. Only 4 percentof end-useenergy demand was met by electricity obtainedprimarily from two largehydropower plants on the Volta River.
1.2 While forestresources are ample in Ghana,they are subjectto significantover-exploitation especially for meetingthe large woodfuel needs of the rural and urban populations. The Bank/UNDP Energy Assessmentconcluded that this resourcecould be seriouslydepleted by. the early 1990s if deforestationpressures are not eased. Similarly unsettlingis the fact that in 1985 importedpetroleum absorbed 26 percentof the foreignexchange earnings of Ghana. The Assessmentstates that even if petroleumprices were to remainat two-thirdsof their 1985 levelsand Ghana succeededin increasingexports, petroleum imports would still accountfor nearly20 percentof foreignexchange earnings unless expansionof indigenousenergy sources were to becomeviable. In helping identifypossible options to improvethe energysituation in Ghana, the Assessmentidentified the nearly 1.2 milliontonnes/year of wood wastes generatedin loggingand sawmillingas a potentiallyimportant source of indigenousenergy. The Assessmentestimated that recoveryand efficient use of these residuescould reducethe offtakefrom the naturalforests by at least10 percent,or 0.8 milliontonnes/yr. 1/
1.3 Given the conclusionsof the Ghana Energy Assessment,the Bank'sEnergy Sector Management Assistance Program (ESMAP) is executinga seriesof studiesto assistthe Governmentof Ghana (GOG) to exploitthe potentialof its wood wastes. The first undertaken,as representedby this report, was a study of the feasibilityfor increasing,and/4r. improvingthe use of sawmilland wood processingindustry residues. 'he study was co-financedby the CanadianInternational Development Agency (CIDA)and was initiatedin June 1986. A reconnaissancemission to Ghana fieldedin that month identifiedthe main issuesto be addressedin the study. In addition,two Ghanaianconsultants were engagedto conducta completesurvey of wood processingindustry residue production and energy consumptionpatterns and also to identifyand surveypotential commercial
1/ Ghana: Issuesand Optionsin the EnergySector, Report No. 6234-GH, World Bank,November, 1986. -2-
and industrialwood energy consumers.2/ An ESMAP missionfollowed in October 1986, consistingof a mission leader,energy economist,wood industry/residuespecialist, biomass conversion specialist and biomass combustion/energyapplicat-,ns engineer. 3/ The data collectedby both the local consultantsand the ESMAP mission have been extensively evaluatedand the resultsare documentedin this report.
Objectives
1.4 The main objectivesof this study are to identifyand evaluate technicallyand economicallyfeasible opportunities for improvingand/or increasingthe use of wood processingindustry residues as an energy source. In this context,the specificissues evaluated include:
(a) The rate of production,availability and locationof different types of wood industry residues, and the characteristics determiningtheir energy potential;
(b) The technicaland economicpotential of differentopportunities for utilizationof the residuesboth at the site of residue productionas well as externally;
(c) The infrastructure,social and policy constraintspresently inhibitingthe increaseduse of wood industryresidues as an energysource; and
(d) The technicalassistance and investmentrequirements necessary to realisethe economicallyfeasible potential of Ghana'swood industryresidues.
1.5 On the basis of the evaluationof the above issues,the final objectiveof this ESMAP study is to formulatea comprehensivestrategy and follow-upprogram to promote,where economic,the increasedand
2/ "Surveyof Wood ResidueGeneration and Utilizationin Ghana,"Essel Ben Hagan (Consultant)and Martin Ben-Dzam (Consultant- Wood IndustriesSpecialist), Ru-Tek Consultantsand IndustriesLtd., Kumasi,Ghana.
3/ This report is based on the findingsof a missionwhich visited Ghana from October17 to November7, 1986. The missionmembers were Messrs.Matthew Mendis (MissionLeader), Charles Feinstein (Energy Economist),Brian Hickman (Consultant- Wood Industry-Residues), Peter Neild (Consultant- BiomassConversion), and Philip Trees (Consultant- BiomassCombustion/Energy Applications). The report was authoredby Messrs.Mendis and Feinstein. Secretarialsupport was providedby VernetMason. - 3 -
efficient use of Ghana's wood industryresidues. In this regard, particularemphasis is placedon:
(a) Identifying and evaluating potential pilot/demonstration projects which would help establish the effectivenessand viabilityof increasedand/or efficient residue utilization;
(b) Defining investmentrequirements for a program to increase utilizationof surplus residues both at wood processing facilitiesas well as in other commercialand industrial enterprises;
(c) Defining appropriate policy instruments and organizational/.nstitutionalmeasures required to supportthe recommendedprogram; and
(d) Identifyingareas for furtherinvestigation and/or development whichwill help promoteefficient use of wood residues.
Scopeof Study
1.6 This study focuses only on the wood processingindustry resi,ues. It does not considerforest residues produced in the process of loggingor land clearing. Of the total estimated1.2 milliontonnes of wood residuesproduced in Ghana annually,wood processingindustry residuesaccount for approximately342,000 tonnes or about 28 percent. However,this representsthe most readilyaccessible and inexpensively obtainedportion. The forestresidues, while constitutinga significant quantity, require additionalresources to collect and transport to potentialmarkets. At presentsome unknownportion of these residuesis collectedand convertedto charcoalto supplythe more luv ive urban markets. Aspectsfor increasingthe recoveryof forest -,a,while worthyof furtherinvestigation, are not coveredin this -
1.7 In conductingthis study, over 90 percent - the wood processingindustries were directlysurveyed to establishpresent and projectedpatterns of residueproduction, consumption and disposal. In addition,surveys of energyconsumption patterns at major industrialand comercial enterprisesin the vicinityof the wood processingareas were also conducted to help identify opportunitiesfor wood residue consumption.The studyalso investigatedpresent means for conversionof residues to either charcoal or sawdust briquettesfor transport to distant markets. In the case of charcoal,on-site observations were carriedout to characterizecharcoaling operations including conversion efficiencies,productivity and economics,with the intentof identifying methods for improvingcharcoal conversion. A detailedanalysis of the sawdust briquettingoperation in Oda, one of only a few commercially operatingplants in Africa,was also undertakento assessthe scope for similarbriquetting plants elsewhere in Ghana. -4-
1.8 The study consideredthe inputsof over sixteenGOG agencies either directlyor indirectlyrelated to the forestry,wood processing and energy sectors. These inputswere essentialin understandingthe organizationaland institutionalinfluences on residue utilization. Informationon sectorperformance and trendswas ottainedto assist in the evaluation. Finally, fuelwood and charcoal prices at the wholesale/retaillevels were surveyedat the major urban markets to ensure incorporationof current energy price informationin the subsequentevaluations.
Organizationof Report
1.9 The report is structuredto providea clear pictureof the overallpotential and investmentrequirements necessary to improveand/or increasethe use of wood industryresidues as an economicallyattractive energysource in Ghana. ChapterII providesa briefprofile of the Ghana wood processing sector including past, present and projected performance. Emphasisis placedon industrytrends affecting residue productionand disposition,especially as it relatesto processingfor greatervalue added and exploitationof secondaryspecies. ChapterIII presentsinformation on the supplyof wood industryresidues including sources,types, characteristics,locations, quantities, stockpiles and surpluses. ChapterIV containsthe demandside of the pictureoutlining presenton-site and off-siteuses includingenergy versus non-energy uses for the residues.
1.10 Potentialoptions for improvingand/or increasingthe use of wood industryresidues as a fuel are coveredin ChapterV for optionsat the mill sites and ChapterVI for off-siteoptions. Both genericand specificcase studiesare evaluatedto determinetechnical, financial and economicfeasibility. In the case of on-siteoptions, emphasis is given to use of residuesfor processheat generationand to cogenerationof electricity. Economicsof cogenerationat both grid and non grid connected mills are evaluated. Residue handling and combustion efficiency improvementsto increase the quality and usefulnessof residuesare also investigated.Off-site options considered included: substitutionof sawdustfor petroleumand fuelwoodconsumption; improved charcoalproduction; sawdust briquetting; and briquettecharcoaling. In all cases, detailedcost estimatesfor implementingthe proposedoption are developedas a precursorto the financialand economicassessment. Key organizationaland institutionalfactors that couldalter the results are identified.
1.11 Conclusionsregarding increased and/or improved utilization of wood residuesare summarizedin ChapterVII. Economicallyattractive options identifiedin ChaptersV and VI are extrapolatedto determine their national potential. Possibilitiesof cross competitionfor residuesare accountedfor by prioritizingthe alternativeutilizations using a benefits/scarceresources ratio. Total nationalrequirements to implement all economicallyattractive options are then estimated. Uncertaintiesand risks associatedwith investmentsin this sectorare brieflydiscussed. Lastly,the chapterpresents recommendations for key investmentsand technicalassistance. Pilot projectsto demonstrate technicaland economicfeasibility of optionsunfamiliar to Ghana are identifiedalong with pro,ectedcosts. Policyrecommendations to help promote the economicallyattractive options for improving and/or increasingresidue utilization are presentedat the conclusionof the report. - 6 -
II. TMEGCHEtAI VOODPROCESSING INDVSTRY
SectorPerformance
2.1 In parallelwith the generaldecline in the country'seconomic situation,the Ghana forestproduct sector experienced a sharp drop in outputduring the period1976-1983. However,due largelyto changesin Governmentof Ghana (COG) policiesand increaseddonor assistance,the wood industryhas demonstrateda substantialrecovery since reachinga low point four years ago. A twelve year summary of the value of industrialforest productvalues is given in Table 2.1. Forestryand logging contributed5.9 percent of the 1984 GDP; 1985 figures are estimatedat 6.2 percent of the total, or about 7 percent if the manufacturingwood industryis included.4/
2.2 Exportperformance is showngraphically in Figures2.1 and 2.2. The strength of the present recoverycan be gauged by noting that estimated1986 forestproduct exports of US$ 48.0 millionrepresent a 65 percentincrease over comparablefigures for 1985,or a performancewhich has not been achievedin absoluteterms since 1978. The drop in export growth rates representedby the 1990 projectionsreflect limitations on supply of the most readilymarketable species, as will be discussed later.
2.3 The COG has receivedcredits for forestryrehabilitation and developmentfrom IDA totallingUS$25.9 million for: (a) the Export RehabilitationProject (Credit 1435/SP9-GH),and (b) the Export RehabilitationTechnical Assistance Project (Credit 1436-GH),and has also receivedcredits granted by the OverseasDevelopment Administration (ODA) and the CanadianInternational Development Agency (CIDA). The ExportRehabilitation Program (ERP) concentrateson the establishmentof quick-disbursingIDA credits to the forest industry to (a) finance purchaseof equipment,materials and spare parts to enablean increase in productionand exports,and (b) restructurethe timber marketing organizationswhich would enablethe forest industryto exportwith a minimumamount of Govermentcontrol. A total of sixty-twomills have receivedcredit assistance under IDA. In addition,the ERP has provided two Government-ownedindustries with technical assistance. ERP assistancehas been targettedat removingbottlenecks in order to restore basic log extractionand primaryproductive capacity.
4/ Draft Forest Sector Review, West Africa Projects Department, AgricultureDivision, World Bank. -7-
Figure2.1: TIMBEREXPORT VOLUMES, 1976-1986; 1990 (PROJECTED)
1486 368
.6 77 78 79 88 81 82 83 84 8S58687 88 89 98 Year 23 Logs z Lumber a/ World Bank projection. b/ Lumber includessecondary wood productssuch as profiles,flooring and furniturecomponents. Sources TEDS; World Bank. Figuie2.2: TIMBER EXPORTVALUES, 1976-1986; 1990 (PROJECTED)
538 ~28
* ______- - U 76 7778 79 8881 828384 8586 8788 89913 Year a Logs E3 Lumber al World Bank projection. b/ Lumber includes secondary wood products such as profiles, flooring, and furniturecomponents. Sources TUB; World Bank. Table 2.1: VALUE ESTIMATESFOR INDUSTRIALFOREST PRODUCTS IN EXPORTAND DOMESTICTRADE (Millionsof CurrentUS Dollars)
Est. Year 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1964 1985 1986
Rcorded Exports 78.5 78.8 91.4 72.6 63.8 44.5 41.3 20.4 15.3 14.8 18.7 29.1 48.0
Domestic warket 29.3 34.6 61.8 111.1 64.9 63.6 64.4 49.0 46.9 27.6 30.3 49.5 -
TOTAL 107.8 113.4 153.2 183.7 128.7 108.1 105.7 69.4 62.2 42.4 49.0 79.6 -
Source: World Bank, TEDS. - 10 -
Type, Capacityand Locationof Wood ProcessingFacilities
2.4 The wood processingindustry in Ghana consists,for the most part, of primaryproducers such as sawmills,plymills, veneer plants, and combinationsthereof. A small amountof secondarymanufacturing exists producingsmall items such as mouldings,broom handles, parquet flooring and knock-downfurniture components. Some 72 of the active mills in Ghana are straightsawmills, i.e. performing log break-downand producing sawn timbersfor domesticconsumption and export. An additional21 mills produce rotary veneer/plywood(principally for the domestic market) and/or sliced veneers (primarilyfor export). The plywoodand veneer mills are nearly always sited next to a sawmill;if not physically locatedin the same complex,then commonownership and managementassure the input log supply. For this reason,sawmill facilities which include plywoodor veneer lines will be referredto as combinationmills. The number and regionaldistribution of the industrialtimber processing facilitiesis shown in Table 2.2. Not includedin the compilationare approximately12 forest mills (so-called"bush mills") which are scatteredmostly within the high forestzone surroundingKumasi and which employ gasoline-enginedmini-saws. Their small output and remote possibilityof residuesrecovery preclude study considerationand were thus not surveyed.
Table2.2: INDUSTRIALTIMBER PROCESSING FACILITIES, 1986
Rotary Veneer/ Sliced Region Sawmills PlywoodMIIls VeneerMills
Ashanti 43 4 7 BrongAhafo 8 - 1 a/ Central 3 Eastern 6 1 2 Western 12 4 2
Total 72 9 12
a/ On-sitebut not operational. Source: Ru-Tek.
2.5 Based on the GOG's Ministryof Land and Natural Resources (NLIR)guidelines, sawmills can be classifiedas large,medium or small accordingto theirannual saw log inputcapacity: - 11 -
Classification AnnualSaw Log Input (m3)
Large >10,000
Medium 5,000- 10,000
Small 5,OOO
Ghana sawmillshave been classedin Table 2.3 accordingto their size of estimated 1986 actual production. The Ashanti region, comprising43 sawmillsalmost all of which are locatedwithin an 8 km radiusof each other in the Kumasi area, is the dominantwood processingzone. The Western region is of second significancein terms of log volumes processed and is clustered around the centers of Sekondi-Takoradi, Samreboi,and Sefwi-Wiawso.The wood industryof the Brong Ahafo region is dominatedby the state-ownedMim Timber Co. Ltd., the largestsingle sawmillin Ghana, while the mills in the Easternregion are locatedin Akim-Oda and Nkawkaw. The three wood processing facilitiesof the Centralregion are situatedin Dunkwaand Cape Coast.
Table 2.3: DISTRIBUTIONOF SAWMILLSBY SIZE OF PROOUCTION,1986
Millswith Annual Production of a/ Regilon <5000 m3 5000-10000m3 >10,000u3 Total
Ashanti 14 11 18 43 BrongAhafo 6 - 2 8
Central 2 - 1 3 Eastern 3 1 2 6 Western 3 2 7 12 Total 28 14 30 72
a/ Sizeclasses according to saw log Input. Source:Ru-Tek.
2.6 Large sawmillshaving lO,OOO m3 or greater annual log input capacity account for 72.6 percent of the total installed sawmill capacity,as shown in Figure 2.3. The five largestsawmills in Ghana accountfor 25 percentof the total installedsawmill capacity.
2.7 Estimated actual 1986 industrial timber processingmirrors installedcapacities and pointsto the dominanceof the large sawmillsin - 12 -
primaryproduction and, hence,residue production. As shown in Table 2.4, productionat the large class sawmillsin the Ashanti,Western and Centralregions account for nearlythree-fourths of the total in those areas,while in BrongAhafo the fractionexceeds 80 percent. Only in the Easternregion does the share from large mills slip, and then only to 61.7 percent.
IndustrialTimber Production
2.8 Industrialtimber harvesting occurs almost exclusivelyin the high forest zone which coversone-third (8.2 millionha) of the total Ghana land area of 23.9 millionha. Practicallyall existingforest is under concession. The concessionshave not been rationalizedwhich resultsin certainmills experiencinga shortageof raw materialinput and having to operate in others' concessions,often at considerable distancefrom the mill. Presentknowledge of standingwood volumesis incompleteand dates back to PAO surveysof 1980-1982. The Overseas DevelopmentAdministration is presentlycarrying out a new resource inventoryin the high forestzone and preliminaryfindings are expected to be availablein 1987.
Figure2.3: DISTRIBUTIONOP SAWMILLCAPACITY BY SIZE,1986
- < 5.000 m3/yr Oman (12.2%)
135,0000U,000 -
>xm3/ys mm >i/yr168,005,6~18000 ./y
(72.6%)5
FIGURESMg LOG INPUT IN M3/YM
Source: NLNR. - 13 -
Table 2.4: DISTRIBUTIONOF PROOUCTIONBY SAWMILL SIZE, 1986 (Percentageof TotaI Product ion)
Millswith Annual Production of a/
Region < 5000 SOOO-10,000m3 > 10,000 o3
Ashanti 12.8 12.5 74.7
Western 7.4 17.8 74.8
Eastern 19.4 18.9 61.7
Central 27.1 - 72.9
Brong Ahafo 18.3 -- 81.7
a/ Size classesaccording to saw log input. Source: Ru-Tek.
2.9 Approximately 180 species occur in the Chanaian forest, of which a minority have commercial economic value. Silviconsult Ltd. has classified the species into three groups according to their degree of commercialization. 5/ Group A comprises 40 species presently considered commercial and for which doii,estic and export markets exist. Group B contains 20 species presently considered marginally commercial. However, these species are considered potentially commercial and are likely to be increasingly exploited in the near future as markets are developed. Group C contains the remaining species which grow to a utilizable size. A listing of Group A and B species by botanical and trade names is given in Annex 3.
2.10 Fourteen of the 40 species in Group A species are consie red highly desirable and are banned from export in log form. These so-called "primary" species are indicated in Annex 3. The remaining species are considered "secondary" and when harvested are often unrecorded as to species by the Forest Products Inspection Bureau (FPIB). Thus an accurate breakdown of annual cut by species is not possible at present. A geieral comparison of the estimated 1985 commercial roundwood production to the Silviconsult recommended annual allowable cut has been made in Table 2.5. The comparison reveals that he recommended annual allowable cut for the primary species of 185,000 ma was already exceeded
5/ The Forest Department Review and the Requirements of the Forest Products Inspection Bureau and the Timber Export Development Board (Draft Report), Silviconsult, Bjarred, Sweden, September 1985. - 14 -
Table2.5: ANNUALCUT FROMHIGH FORESTIN RESERVES
1985 SliviconsultAnnual EstimatedRWE AllowableCut Productionbl Recommendation SpeciesGroup (millionm ) (mIllilonm3)
GroupA 0.523 0.719 of which 14 primary (0.225) (0.185) of which26 secondary (0.298) (0.534)
Group8 0.004 0.386
Unallocatedby speciesa/ 0.400 -
TOTAL 0,927 1.105
a/ Unrecordedas to species. b/ 1966RWE productestimated at 1.065millIon m 3 . Source: WorldBank, Sliviconsult; TE0O; Mission estimates.
2.11 Table 2.6 depictsthe presentand projectedfuture distribution of the industrialhardwood timber harvest. Figuresfor 1986 estimate that exportsitz log form accountedfor 18.8 percentof the total harvest of ',065,000e , and 37.1 percentof the roundwoodequivalent (RaE) of total exports. As is reflectedin the projections,by 1986 the total hardwood timber harvest had essentiallyreached the Silviconsult recommendationfor annualallowable cut. Harvestprojections thus assume adoptionof a sustainedyield resource management strategy. Increasesin the total harvestwould be dependenton substantialproduction occurring in the high forestareas outsidereserves and in the estimated52,000 ha of timber plantations. However, neither of these resources is systematicallymanaged at present.
Table2.6: PROJECTEDDISTRIBUTION OF THE INDUSTRIALHAROWOOD TINDER HARVEST (thousandm3 )
ProductExports Log RWE of RWE Totel Lumbera/ Veneers Plywood Exports Exports Domestic Harvest
1986 110 29 1 200 539 526 1,065 1990 124 33 2 251 589 511 1,100 1995 176 28 10 180 589 511 1,100 2000 210 20 30 80 555 545 1,100 a/ Includessecondary wood productssuch as profiles,flooring, and furniture components. Source: WorldBank. - 15 -
Wood IndustryTrends Affecting Residues Disposition
2.12 Two trends in local wood processinghave been identified through data analysisand industrydiscussions as having potentially significantimpacts on residuesproduction and utilization.These are (a) a trend to furtherdomestic processing for highervalue-added, and (b) a shiftto higherproduction of secondaryspecies. Each is expected to be a gradualtrend occurring over the next five to fifteenyears. The primaryeffects to be examinedin succeedingchapters include changes in the amounts,types and characteristicsof the variousresidues generated, as well as changesin the demandfor theseresidues within the mills as a resultof increasesin processing.
Trend to GreaterValue-Added
2.13 Unless new inventoryestimates and resultantmanagement plans indicatethat a higherlevel of harvestingis sustainable,production and sectorrevenues will face a constraintin log availability.A shift to greatervalue-added per unit log harvestedis thereforeanticipated in order to maintaingrowth in export value in 1990 and beyond. Specific manifestationsof the trendinclude:
(a) Greaterprocessing of logs into exportlumber, so that export in log form is eventuallyphased out past the turn of the century;
(b) higherproduct recovery through improved sawmilling techniques and machineryand installationof more re-sawequipment;
(c) increased secondary manufactureof wood products such as mouldings (profile boards), fiooring, broom handles and furniturecomponents.
2.14 The rapidityof this shiftwill be governedby:
(a) Pace of modernizationand expansion of wood processing facilities;
(b) Success in developmentof expanded markets for sawn and secondarymanufactured wood products;
(c) Pace of improvementof transport,handling and shipping infrastructurefor timberproducts;
(d) Rate of depletion of commerciallyvaluable timbers, and resultant rise in economic pressures within the sawmill industry;
(e) Political factors, such as a near ban on log exports as proposedin the LagosPlan of Actionfor the Year 2000; and - 16 -
(f) Governmentpolicies such as industrialtimber stump&ge fee levelsand value-addedtaxation.
Trend TowardExploitation of SecondarySpecies
2.15 As noted, the wood processingindustry is already facing constraintson the availabilityof the readily exportablefourteen primaryspecies. These limitationsare most evidentin the Ashantiand Brong Ahafo regions,and sawmillsrelying on logs from these areas will be forced to move to processingof secondaryspecies or face declining log throughputs.Mill managersin Kumasireport having to go 240 km one- way to log the high demand redwoodspecies, approaching the limits of economiclogging given the high transportand loggingroad construction costs. The productionmanager at Mim TimberLtd. forseesa 30-50 percent reductionin primaryspecies throughput with a correspondingincrease in secondaryspecies production over the next five to ten years,while the managerof SpecializedTimber Productsin Kumasienvisions a virtually completeshift at his mill in the long run.
2.16 A number of barrierson increasedsales of secondaryspecies, especiallyin exportmarkets, presently exist:
(a) Uncertaintyas to the resourcebase and totalavailability of secondaryspecies. Many overseascustomers are unwillingto acceptlesser known speciesunless a regularsupply is assured for ten years.
(b) Perishability.Many of the secondaryspecies are subjectto attack by staining and rotting fungi unless specialized treatmentand dryingmeasures are incorporated.
(c) Lack of knowledgeamong processorsand customersof species working propertiesand uses. The Porest ProductsResearch Institute(PPRI) has primaryresponsibility for investigating and reportingon thesecharacteristics.
(d) Conservatismof industryand variablemarket tastes. Market demands are dictated by the uncertainwhims of "changing fashion,"and the current "in" phase of whitewoodsis of uncertainduration.
The TimberExport Development Board (TEDB)is chargedunder PNDC Law 123 with the responsibility"to developmarkets for and promotethe sale and exportof lesserknown timberspecies." While by far the greaterpart of secondaryspecies exports have been in log form, significantexports in productform are expectedto beginby 1990. - 17 -
III. SUPPLYOF WOODINDUSTRY RESIDUES
Summary
3.1 Estimatedtotal wood processingindustry residue production amountedto 434,612m 3 SWE in 1986, and was composedof slabs/edgings (49%), sawdust(21X), offcuts (15%), veneer wastes (9%) and cores (6%). In their green condition,the residueshave an averagedensity of 786 kg/mr at a nominalmoisture content of 36 percent(wet basis),implying a net energy value of 94,000 toe. Major concentrationsof residue productionoccurring in the Kumasiand Sekondi-Takoradiareas coincide with locationsof major non-woodprocessing industries. Other locations where residuesare foundhost littleor no non-woodprocessing industrial activity.
3.2 So long as the wood industrycontinues its upward trend of rehabilitationas in the last threeyears, it can be safelyassumed that the supplyof residualsis reliable.Log throughputlevels will continue to hold the greatestinfluence on the productionlevels of residues. Net effectsof trendsto increasingproduct recovery, secondary manufacture and secondaryspecies exploitation on the suitabilityand reliabilityof wood processingresidues as a fuel is not expectedto be significant.
3.3 Sawdust is the only wood processingresidue presently in abundantsurplus amounting to some 83,400mi SWE with a net energyvalue of 18,000toe. Ninetypercent of all sawdustproduced is unutilisedat present. Surplusesof solid residuestotallinj 15,000 m SWE are primarilyfound at the isolatedsawmill of Mim TimberCo.
Sources,Types and Chares-eristicsof Residues
3.4 The residuesproduced by the saw, ply, veneer and secondary manufacturingoperations consist of:
(a) Slabsand edgings,including slicer boards and bark strips;
(b) offcuts;
(c) sawdust,including planer shavings;
(d) veneerwaste (bothgreen and dry), includingdry plywoodtrim; and
(e) cores (bouls).
The residuesare largely in the green condition,although some dried veneer,dry trim and sawdustis presentin the veneerand plymills,and - 18 -
some dried offcuts,sawdust and planer shavingsis availablein the sawmillsand secondarymanufacturing plants. The densityand moisture contentof the residuesare significantwhen estimatingtheir tonnage and associatedenergy value.
3.5 Table 3.1 containsthe densitiesand greenmoisture contents of many of the more commonwood speciesfound in Chana. The densitiesare given in the green and oven dry conditions.The densitiesand moisture contentsare shownfor the averagegreen condition and are not indicative of changesin these propertiesdue to handlingor manufacture.Changes in propertiescan be expecteddue to: (a) The additionof water due to excessive sawguide lubrication; (b) addition of water due to precipitationwhen residues are stored in uncovered stockpiles; (c) natural drying in storage;or (d) forced drying in manufacturing processesor fuel dryingfacilities.
Table3.1: DENSITIESAND MOISTURECONTENTS OF SELECTEDGHANAIAN NOOS
Green Green Moisture Moisture Densities Content Content Oven Dry (kg/) _ Green (kg/n) (Dry Basis) (Wet Basis) Species Low Avg High Low Avg High (%) (N)
African Walnut 440 560 640 750 825 900 47.3 32.1 Afromosia - 650 - 950 1,050 1,200 61.5 38.0 Ayan 570 710 860 900 950 1,000 33.8 25.3 Bublnga 600 750 880 1,000 1,050 1,100 40.0 28.6 Candellei - 650 - 900 930 950 43.0 30.0 Ceiba 200 260 400 600 700 850 169.0 62.8 Cordia 160 230 290 700 750 80 226.0 69.3 DOnta 660 720 770 700 750 800 31.9 24.2 Edinam - 520 - - 9O0 - 73.0 42.2 Eusri - 500 - 800 825 850 65.0 39.4 Guarea 550 600 700 8a0 900 1,000 50.0 33.3 Hyedus 660 750 880 1,000 1,050 1,100 40.0 28.6 Kyenkyen - 430 - 700 750 80o 74.7 42.8 Kyere 460 500 570 900 925 950 85.0 45.9 Mahogany 420 490 570 650 725 800 48.0 32.4 Mekore 510 590 690 850 9D0 950 52.5 34.4 MNnsonia 540 600 650 850 950 1,000 58.3 36.8 Odum 480 600 670 990 1,045 1,100 74.1 42.6 Sopele 490 620 720 690 890 1,065 43.5 30.31 Utile 450 590 700 750 825 900 39.8 28.5 Wawa 250 350 520 530 590 650 68.6 40.7
Source: Vaa.nfurh/Scheiber Holzatias, Veb Fachbuchverlag, Leipzig, 1974; Mission estimates. - 19 -
3.6 The utilizationof mixed wood specieswithin the mills may resultin the accumulationof speciesmixtures or surgesof one or two species. There is an advantageto mixingspecies when the mixtureis to be used as fuel in the greencondition as the low moisturecontent (m.c.) fuelswill assistthe higherm.c. fuels to burn, and an averagedensity fuel will occupy less space and ease the fuel conveyingand furnace problemswhich may attendvery low densityfuels, or very wet fuels. The anticipatedshift to secondaryspecies indicates a trend toward less dense and wetterspecies. In the shortterm, this trendwill not be seen in certainconcessions such as AfricanTimber and Plywood(Ghana) Ltd. (AT6P)and ClikstanWest AfricaLtd. (CWA). An evaluationof the average moisturecontent of green residuesand the anticipatedshift in about five years has been calculatedfor certainmills surveyed. The analysis is based on their presentand futurespecies mix and a-pearsin Table 3.2. The increasein wet basismoisture content of approximately1.5-2.5 percentat some processingsites would have the effectof reducinglower heatingvalues (LHV) 6/ of undriedresidues by 2.8-4.7percent.
Table3.2: MOISTURECONTENT OF TYPICALSAW TIMBERSPECIES MIX CS)
1986 Est. 1991 wet Dry Dry Wet Mill Basis Basis BasEs Basis
SpecializedTimber Prod. 61.1 38.2 - -
A.G. Timbers 49.5 32.9 - -
A,E. Saoud 57.0 36.3 - -
HIM TioberCo. 52.3 34.3 58.5 36.9
Gliksten (W.A.) Ltd. 46.9 31.9 46.9 31.9
TVLC: Plywood 66.7 40.0 70.6 41.4
TVLC: Timber 52.8 34.5 56.5 36.1
TVLC: Combineda/ 45.4 31.2 48.5 32.5
a/ Includes dried residuals. Source: Mission estimates.
6/ The LHV representsthe energycontent of a fuel after the heat of water vaporizationis deducted. - 20 -
3.7 The effecton the aggregatemoisture content of usinga portion of dried fuel is evidentfrom the data for "TVLC Combined"when the figures are comparedto the plywood and timber green mixed species inputs. The averagemoisture content has been significantlyreduced by incorporatingthe driedcomponents.
3.8 The higher heatingvalues (HHV) 7/ of Ghanaianhardwoods are difficultto find in the literature,but the figuresin Table 3.3 are availablefor the elevenspecies shown.
Table3.3: FUELCH^ACTERISTICS OF SELECTEDGHANAIAN WOODS
Higher Percent Ash Species Heating Value, 00 Volatile Content (NJ/kg) (S) (S)
Wawa 20.17 82.9 1.3
Esa (Celtis) 19.22 81.1 2.1
Ekki 20.61 80.4 0.3
Kyeokyen 19.12 80.9 2.9
Sapele 19.66 81.3 1.0
Doha"s 20.35 81.0 O.S
Danta 20.22 81.2 1.3
Odum 20.24 75.2 2.7
Kane 20.77 82.2 1.0
Celba 18.59 81.7 3.2
Otie 19.19 76.4 3.6
Sources BMI; P-E International.
3.9 Estimated useful average characteristicsfor Ghana wood processingindustry residues are summarizedin Table3.4.
7/ The MMV representsthe oven-dryor calorificheat of a fuel. - 21 -
Table3.4: NOMINALCHARACTERISTICS OF WOODPROCESSING INDUSTRY RESIDUES
OvenDry Density 503 kg/03
Green Molsture Content 36% (vet basis)
GreenDensity 786 kg/m3
Volatiles 81.3%
Ash Content 1.6%
Higher Heating Value 20.0 MJ/kg (ovendry)
LowerHeating Value 11.9MJ/kg (at36% mcwb)
Source:Mission estimates.
3.10 Other important physical characteristics of sawdust and veneer wastes found in Ghana should be noted. Due to the abnormally deep cuts made in the large diameter logs and cants in Ghana, feed speeds are low, and therefore the sawdust is very finely divided. If not overly wetted down, this fine sawdust is easily air conveyed and is a very combustible fuel. It can present a disadvantage in a furnace in that it can become entrained in the combustion gases and carried up the stack, causing high emission levels and fly ash problems. Therefore, a furnace approporiate to the combustion of fine sawdust should be used.
3.11 Veneer wastes found at the combination mills come in long and thin sheets, tend to curl, are flexible, and tend to bulk up to large volumes. These "as clipped" residuals are therefore difficult to handle and convey mechanically and labor-intensive manual methods are commonly employed.
Location of Residues
Forest Residues
3.12 Residues from forest operations are available when the trees are felled and are approximately equal to the volume of roundwood extracted. Butt and top logs, branchwood and non-sawlog material left i the forest from commercial logging thus amounts to some 1.1 million m - 22 -
annually,or 860,000 t/yr green weight. An unknownamount of these residues makes up part of the estimated8.6 million t/yr national woodfuelsgross supply,8/ but the greaterportion remains in the forest to rot over a periodof time. Mim TimbersLtd. is presentlythe only mill making use of some forest residues;Afrormosia branches of 40 cm diameter and larger are fed to ScanstyleLtd. for processinginto furnit3reparts. IiJghfinancial haulage costs of ipproximately1,500 Cedi/m (US$ 10/mJ) for a typical 150 km haul limit greater utilization.Assisted through a US$3.5million FAO project,the Forestry Departmenthas experimentedwith mobilemetal kilns in the Subri River basin as a means of efficienton-site carbonization of forestresidues. The kilns'high cost and difficultyin movingthem from loggingsite to site along with the potentialforest fire hazardshave thus far severely limitedtheir application.However, the COG has createda corporation, Subri IndustrialPlantations Ltd. (SIPL),for large scale clearingand reforestationwithin the Subri forestreserves. Aided by US$ 16 million financingfrom the AfricanDevelopment Bank, SIPL plans to cut 4,000 ha during the first five years followingstart-up. Estimatedyields per hectareare:
Commercialtimber -- 86 m3
Carbonizablewood 160 .3 Residaalfirewood 164 m3
Charcoal supply to the Sekondi-Takoradiarea is thus expected to be boostedby 11,500t/yr, and for firewood,131,000 m 3/yr. Althoughworthy of furtherexamination, potential forest residue utilization is beyond the scopeof the presentstudy.
Wood ProcessingResidues
3.13 Concentrationsof residuesoccur in parallel with saw and combinationmill activity. In the case of mills locatedin the Sekondi- Takoradi area and, to a lesser extent, the Kumasi area, these concentrationscoincide with locationsof major non-wood processing industries.The Akim-Oda,Nkawkaw and Dunkwaareas host only minor non- wood processingindustrial activity, and in the isolatedcompany towns of Him, Sefwi-Wiawsoand Samreboithe mills representvirtually the sole source of non-agriculturalemployment.
8/ GhanaEnergy Assessment. - 23 -
QuantitiesProduced
3.14 Informationon residue productionis based on a direct survey of the 66 mills listed in Annex 2. Residue volumeswere elicited by questioningmill managementon productionfigures and estimatednumbers of carts or loads per day of each of the residue types. The data gatheredat any one mill, however,may be very subjectiveand affectedby the vagaries of question interpretation,experience, mood, and time availabilityof the interviewee. The survey data has thereforebeen utilizedas follows. Data derived from the sawmillquestionnaires has been plotted on Figure 3.1 which shows fractions of slabs/edgings, offcuts and sawdust as ordinates plotted against the lumber recovery factor as abscissa. Fitting the curves to this plot resultsin a more statisticallypowerful method to determinethe sawmillresiduals.
3.15 The averagerecovery factor (weightedby productionlevel) was determinedfor each region in Ghana and the annual residual volume determinedby type as shown in Table 3.5. All volumesrepresent solid wood equivalent(SUE) volumesand can be convertedto oven dry or green weightsusing the nominalcharacteristic values in Table 3.4.
Table3.5: SAWMILLRESIWUE PRODUCTION, 1986
Weighted Log Slabs/Edgings Offcuts Sawdust Total Average Inpt FrectionVoaliu Fraction VolVe Voiure Resiues Resgion Recovery (mJ) (a') uJ) (m') (a)
Ashanti 0.423 348,599 0.331 115,386 0.104 36,254 48,804 200,444 BrongAhafo 0.434 19,400 0.322 6,247 0.100 1,940 2,716 10,903 central 0.485 22,644 0.284 6,341 0.086 1,947 3,170 11,548 Eastern 0.451 32,549 0.310 10,090 0.096 3,125 4,557 17,772 Western 0.585 72,668 0.216 15,696 0.064 4.651 10,174 30,521
495,860 153,850 47,91769,421 271,188 Overall WeightedAverage Lumber Recovery: 0.453
Note: All volumesexpressed In solid woodequivalents (SWE). Source: Mission estimates.
3.16 The data from the plymill, veneer mill and combined mill questionnairescannot be evaluated by similar methodologydue to dissimilaritiesbetween mills and the small number of mills (twelve) fallinginto these categories. Therefore,the residualsfrom this group of mills was taken at face value from the questionnaires.The residues from these mills are summarized in Table 3.6. Again, all volumes representsolid wood equivalents. - 24 -
Figure 3,18 SAWMILLRESIDUAL FRACTIONS VS. RECOVERYFRACTION, 1985
...... - /1 * * 158
: -1S -'1-
SS 1--1 1 Itl":t I1--~~
3 ~ ~~~~ !,W H-Fcs
t~~~~~FtAt t0JS- - 25 -
Table 3.6: COMBINEDMILL. RESIDUE PRODUCTION, 1986 a/ Im3SWE)
Slabsa Sawdust Veneer Edgings Offcuts Shavings Waste Cores Total
59,325 18,830 23,848 34,723 26,698 163,424
af Includesplywood and veneermills. Source: Ru-Tek.
3.17 The total wood processing industry residues are the sum of the volumes given in Tables 3.5 and 3.6 and are shown in Table 3.7. Slabs and edgings are the most abundantly produced residues at 213,175 m3 SWE, representing 49 percent of the estimated 1986 total residuals production of 434,612 m3 SWE. Sawdust at 21 percent and offcuts at 15 percent follow in terms of abundance, while veneer waste and cores are relatively less common at 9 and 6 percent respectively. In their green condition, the total residue production has an energy value of 94,000 toe or 4 percent of fuelwood primary energy production in Ghana.
Table 3.7: WOODPROCESSING INDUSTRY RESIOUE PRODXCTION, 1986 iM SWE)
Slabs& Veneer Mills Edgings Offcuts Sawdust Waste Cores Total
Sawmills 153,850 47,917 69,421 - - 271,188
Combined 59,325 18.830 23.848 34723 26698 163.424
Total 213,175 66,747 93,269 34,723 26,698 434,612
Industry Percentages 49% 15% 21% 9% 6% 100%
Source: Misslonestimates.
Existing Stockpile
3.18 The wood processing facilities in and adjacent to Kumasi and Takoradi commonly have depressed areas land-filled with sawdust. Such stockpiles become contaiminated with dirt and water and inevitably bio- degrade with time and are generally not a satisfactory fuel source. The - 26 -
use of sawdust residues stockpiledout-of-doors in depressionsand ravinesas an energysource is not recom_ended.The operatingcosts to recoversuch residues,to processthem to removecontaminants and to dry them in rotary dryers, and the high capital costs of the necessary ancillary fuel-handlingequipment, are usually prohibitive. Capital facilitiesshould only be plannedbased upon a confirmedongoing supply of sawdust residue which can then be handled following practices appropriateto the process.
Reliabilityof Supplies
3.19 So long as the wood industrycontinues its upward trend of rehabilitationas in the last three years, it can be assumedthat the supplyof residualsis reliable. Supply of residualsfor on-siteuse would, of course,be assuredas the mills controlthe utilizationof their own residues. OnRoingsupply of residuesfor off-siteuses could be assuredby contractualarrangements with producers.
3.20 Effectsof the earliernoted wood productsindustry trends on the reliabilityof residuevolumes and characteristicscan be summarized as follows.
(a) Greaterprocessing of logs into export lumber. Increasesin the volumeof logs convertedinto sawn productswill have the obvious effect of increasingthe volumes of slab/edging, offcut,and sawdustresiduals which are a directby-product of the log break-downand cuttingoperations. (b) Higherproduct recovery. Mill improvementsincreasing recovery tend to reducethe amountof residues. Examplesare: reduced kerf diminishessawdust volumes% improvededging practices reducesedgings volumes; greater sawing accuracy increases the number of boardsproduced; accurate charging reduces round-up losses;improved clipping reduces veneer clips; more accurate lay-upreduces dry trim, etc. As demonstratedin Figure3.1, the effecton sawmillresidues is strongestas regardsslabs and edgings,and weakestwith sawdust.
(c) Increasedsecondary manufacture. Secondarymanufacture may increasesome residuesand diminishothers. If small cuttings are recoveredfrom edgingsand offcuts,these residueswill reduce while sawdustand shavingsincrease. If additional mouldingsare produced,edgings may reduce and sawdustand shavingsincrease. As wood pieces for secondarymanufacture must be kiln-dried,the shift is towarddrier and more finely dividedfuels and away from largersection residues.
(d) Increased secondary species exploitation. As previously calculated,larger proportionsof the less dense and wetter - 27 -
specieswill reducegreen residuecalorific values modestly. However,the kiln-dryingrequirements of many of the lesser- known species,to be discussedin Chapter6, will increasethe proportionof dry residues. In addition,the suitabilityof a numberof these speciesfor rotaryveneer production will also producemore dry residuals.
The effectsof these trendswill be most evidentin the largeroperations where capital is availableto be investedin upgradingand converting plants. The smallermills will continueto produceresidues as they do today. Log throughputlevels will continue to hold the greatest influenceon the productionlevels of wood industryresidues. Other effects are, to some extent,counterbalancing, and their overall net effecton the suitabilityand reliabilityof wood processingresidues as a fuel is not expectedto be significanton an industry-widebasis.
Presentand ProjectedSurplus
PresentSurplus
3.21 Sawdust is the only wood processingresidue psesently in abundantsurplus in Ghana,amounting in 1986 to some 83,400m solid wood equivalentor 65,500tonnes. Ninetypercent of all sawdustproduced is unutilizedat present,which accountsfor 8S percent of all surplus residues. At its nominalmoisture content of 36 percent(wet basis),the surplus sawdusthas a net energy value of 18,000toe. Suqjplusesof slabs/edgings,offcuts and veneerwastes amounting to 13,900m are found aS the isolatedsawmill of Nim TimberCo. Ltd.,with the balanceof 2,270 m of slabs/edgingsfound at other remotemills. Residualvolumes by type are graphedin Figure3.2.
3.22 The regional distributionof the residue surplus is shown graphicallyin Figure3.3.
3.23 Significantconcentrations of surplus sawdust exist in the followingfive centers in the estimatedamounts given in Table 3.8. Kumasicontains 63 percentof all surplussawdust and 69 percentof the exploitableconcentrations. - 28 -
Figure 3.2: SURPLUSRESIDUES BY TYPE, 1986
90 W~7 8' 78
0~6
P ~40-
209- o ~10 0~~ Slabs/ Offcuts Sawdust Veneer Cores Edgings Wastes
Figure 3.3: SURPLUSRESIDUES BY REGION, 1986 610-
3 ' . 050
* 40t
>~10
Ashanti Brong Central Eastern Western Ahafo 3 Sawdust 3 Other - 29 -
Table 3.8: SURPLUSSAWDUST CONCENTRATIONS
Center m3SWE % of Total Surplus Sawdust
Kumasl 52,600 63
Mim 9,500 11
Sokondl-Takoradi 9,200 11
Nkawkaw 2,500 3
Ounkwa 2,500 3
91
Source: Missionestimates.
Future Surplus
3.24 IJnder a "business as usual" scenario (i.e. assuming no new investment in improved residues utilization), the composition and distribution of surplus residuals would not be expected to change drastically, with sawdust continuing to be the main unutilized residue. Quantities of sawdust will be most sensitive to log throu*hput levels. A specific exception to this pattern is found at Cliksten Wea Africa Ltd. in Sefwi-Viawso, where the anticipated shut-down of cogneration operations will free an *nknown proportion of the sawdust presently used as boiler fuel (2,575 mJ in 1986). Similarly, solid residues not used for woodfuel by the surrounding community will be surplus. 9/
3.25 Plans outlined by mill managers indicate a trend to increased use of wood residues for mill process heat generation, as depicted in Table 3.9. The additional heat demands will divert some off-site use of solid residues back to the mills. A decline in surplus sawdust volumes will occur to the extent that sawdust is utilized in mill boilers.
9/ The anticipated re-start of African Timber and Plywood Ltd. is not expected to affect surplus as the mill plans to use all its residues for cogeneration. - 30 -
Table3.9: PLANNEDADDWITIOS TO WOODPROCESSING FACILITIESUTILIZING MILL iRSIDUE FORPROCESS HEAT GENERATION
MiII Mill Type Descrlptlon
SpecializedTimber Products, Ltd. S Installationof cogenerating 70 t/hr at 20 Kumasi barboiler and 480 kVA turbine-generator duefor completion In 1987,plus associated steampits and 6 x I5Om3klIns.
Nim TlmbersLtd. S/P/V Plansto expandpresent klIn capacityof imim 240m3 to IX 0 .3 wIthS years.
HardwoodTimber Products, Ltd. S 3 x 100m3 kilnscurrently Idle due to high Takoradi operationalcost of oil-firedboilers. Will convertto wood-firedboilers In mid-1987.
WesXernTimbers Ltd. S 4 x 70 3 kilnsto be installedIn 1987. Takoradi Boileron-site awaiting Installation.
JohnSitar Co. Ltd. S/P/V Plansto Install12 x 25 .3 kilns,steam Takoradi pits,2 x veneerdryers, and 2 x boilers.
ScanstyleFurniture Ltd. F Currentkiln capacity of 350m3 to be Miii Increasedby28% In 1987.
PokuTransport Industrial P/V Plansto Install2 x locomotivetype ComPlexLtd. boilers. Kumasi
Du-PaulWood Treatment Co. Ltd. S Newsawmill to be completedIn 1987.WiII Takoradi utilizeprocess heot for kiln drying of lumberfor moulding line.
A. E. SaoudLtd. S Newsoamill under construction will Kumasi include1 x 15t/hr boiler.
Note: 1. Milltypes: S a Sawmill P a Plywood V a Veneer F a Furnitureparts Source:Ru-Tek; Mission estimates. - 31 -
IV. DUIAnD101KOOD PROCESSINGINDUSTRY ESIDUES
Summary
4.1 About 27 percent of the 1986 total residue productionwas consumed within the mills themselves,primarily for process heat generation. The largestfraction of residues,50 percent,was utilized outside the mill complexesfor both energy and non-energyuses. The balance,or 23 percent,was surplusand was disposedof by burningor dumping. With the exceptionof Mim TimberCo. in Brong Ahafo,virtually all solid residues are utilized. The Ashanti region is the major consumerof wood processingby-products, both for on- and off-siteuses.
4.2 The use of slabs and edgings for firewood and charcoal productionis the largestend-use of wood residuesat 31 percentof total residueproduction. Fuel for mill processheat/cogneration, other (non- energy)uses, and unusedsurplus evenly split the remainder. The chief non-energyuse of residuesis as a raw materialfor cottageindustry woodworking.
On-siteEnergy Uses and Disposal
4.3 Approximately118,000 m3 (27 percent)of the wood processing residues produced in 1986 were consumedon-site, i.e. at the mills themselves.Nearly 84 percentof this consumptionwas for internalsteam and processheat raisingpu poses, includingcogeneration of steam and electricity.About 10,750m of the on-sitetotal was carbonizedat the Mim Timber Co. Ltd. plant, the only mill in Ghana engaging in this activity. The balance o)f on-site consumptionwas for non-energy purposes.
Steamand ProcessHeat
4.4 As depictedin Table 4.1, 21 mill facilitieshave wood-waste fired furnace/boilersfor the generationof steam and processheat. The heat thus raisedis utilizedin:
(a) Steam/conditioningpits for preparationof veneer blocksand for sterilizationof log speciessubject to spore and fungus infestation;
(b) rotaryand slicedveneer dryers;
(c) dry-kilnasfor the drying of wood stocks for secondary manufacture,manufactured components and exportlumber. - 32 -
The majorityof mills in this categorypresently combust 50-60 percent of their total residues. Almostall the mills utilizingprocess heat are combinationmills, indicatingprocess heat demand in the straight sawmillsis quitelow.
Table4.1: WOODPROCESSING FACILITIES UTILIZING MILL RESIDUEFOR PROCESS HEAT GENERATION, 1986
Residue Ut Ilized for No. of Process Wood-fired Boller Residue Heat Soilers/ Date MIII GeneratedGeneration Nameplate of Nameof MlII Type (m3SWE) (*3SWE) Ratings Manufacture
ASHANTIREGION PokuTransport Industrial ComplexLtd. Veneer/PlymlIl P/V 7,281 4,611 (1) 465 MW 1978 Kumasl at 20 bar
Poku Transport & Sawmills Ltd. Kumesi S 4,866 a/ (1) 720 MCaI/hr 1982
Logs and Lumber Ltd, Kumasi S/P/V 25,365 14,744 (3) 1S t/hr (1) 1972 3 t/hr (2) 1982 EJIsu Forest Products Ltd. Kumasi S/V 6,250 3.425 (1) Hot Water 1977 Boiler FyneLimited Kumasi S/V 6,658 4,019 (1) 6 t/hr 1982 at 3 bars WoodComplex Kassl Ltd. Kumasl 5 7,349 a/ (1) 12 t/hr 1978
AtwimaTimbers Ltd. Kumasl S 15,761 9,797 (1) 10 t/hr 1978
LumberProcessing Ltd. Kumasi P/V 11,080 6,023 (3) 4 t/hr 1977 each NaJa David Veneer S Plywood Kumasl P/V 13,035 7,085 (1) 18 t/hr 1977
WoodIndustries Ltd. Kumasl S 5,760 a/ (1) 10 t/hr 1975
A. 0. TimbersLtd. Kumasi S/V 14,240 7,204 (1) 20 t/hr 1975 - 33 -
ERONGAHAFO lEGION Mlm TimberCompany Ltd. Mi, S/P/V 45,377 3,173 (1) 6.5 t/hr 1979 at 23 bars ScanstyleLtd. Mim F 4,473 1,200 (3) Hot Water 1969 Boiler
CENTRALREGION InternationalHardwood Ltd. Ounkwa S/F 8,750 6,073 (1) 20 t/hr at 5 bars 1957
EASTERNREGION NovotexLtd. Nkawkaw S/P/V 2,101 368 (1) 15 bars 1976
Oda Wood ComplexLtd. Akim Oda S/P/V 12,661 7,881 (1) 5653.3 1982 x 103 kJ/hr
WESTERNREGION A.T. 6 P. b/ Samrebol S/P 20,700 20,700c/ (4) 7.5 t/hr 1948 each GilkstenW. A. Ltd. Safwl-Wlawso S/P/V 12,79M 12,793cl (4) 15 bar 1950
T.V.L.C., Takoradi S/P 4,740 2,220 (1) 10 bar 1972
GhanaPrime Wood ProductsLtd. Takoradi S/P 10,806 8,096 (1) 10 bar 1972
BiblanlIndustrial Complex Ltd. Biblani S 1,474 319 (2) 5 bar 1974
TOTALSd/ 221,360 99,031
/ Boilernot In use, but operatlonal. b/ Mill not In operaticnsince February, 1986. 1985estimate. cf Co-generation of steam and power. d/ Totals do not IncludeA.T. 6 P. Note: 1. Hili types: S a Sawmill P a Plywood V u Veneer F a Furniture parts PB a Perticle board Source: Ru-Tek. - 34 -
Cogeneration
4.5 Table 4.2 shovs that four wood processingfacilities have turbo-generatorsor steam enginesto enableuse of high pressuresteam for electricitygeneration. Three are state-owned: Mim Timber Co., African Timber and Plywood,and GlikstenWest Africa. The fourth, SpecialisedTimber Products,is a privateentity. Only GlikstenWest Africa Ltd. is currentlyoperative in a cogenerationmode, as explained below.
4.6 ClikstenWest Africa Ltd. CUA presentlyburns all of its residuals,including hogged offcuts and cores, in four 1950 vintage locomotive-typeboilers raising an averageof 3.5 t/hr of steam at 15 bars. The steam is passed through 625 kVA and 437.5 kVA turbo- generators. No recordsof power productionare kept, however plant demand is met throughsupplementation from a 690 kVA dieselset. The nationalgrid passeswithin 1 km of the mill. An 800 kVA transformeris on-siteand mill managementhopes to connectto the grid in 1987 as soon as financing for the required second 800 kVA transformercan be arranged. At that time,local electricity production will ceaseand GWA will combustwastes only to meet processheat demands.
4.7 SpecializedTimber Products Ltd. Installationof a 6.4 t/hr at 28 bar boilerand 480 kVA back-pressureturbine at this new sawmillis in progressand will be completedin the firsthalf of 1987. The five year old equipmentwas acquiredfrom a Germanmill for US$ 540,000installed, approximatelya 60 percentsavings over comparablenew units. The mill plans to combustessentially all of its residuesand therebymeet 80 percentof its electricalenergy demand plus the beat load from six 150 a kilnasand two steam pits. Accordingto the mill manager,the chief motivationfor the investmentis to obtaina degreeof independencefrom the ECC grid supplywhich was judgedtoo prone to interruption.The STP managementestimates the value of lost productiondue to electricsupply faults in 1986 at Cedi 5 million(US$ 33,000). Synchronizationfor a power purchase/sell-backarrangement has been investigated,but it was concludedby STP that lack of VRA/ECGstandards negate this option. Table 4.2: WOODPROCESSING FACILITIES UTILIZING WILL iESIDUEFOR 00-GENERATIONOF STEAMAND POWER,1986
Nb eplate Nameplate Rssidue Capacity of CapacIty of Total utilized Steam Engine/ DIesel Installed Rasidue for Turbine Gen- GeneratIng Generation Generated Co-Generation erating Sets Sets Caeacity Nameof Mill (3 SWE/yr) (03 SWE/vr) (&VA) (kVA) (kVA)
Gliksten West Africa Ltd., a/ Sefwl-Wiawso 12,793 12,793 1,062.5 690 1,752.5
Specialized Timber Products Co. Ltd., b/ Kumasi 20,736 20,736 480 NationalGrid 480
Mim TimberCo. Limited,Hli 45,377 0 420 c/ 3,126 3,S46
A.T. S P. Ghana Llmited,d/ Samreboi 20,700 20,700 3,750 850 4,600
s/ To be connectedto nationalgrid In 1987. Presentcondition of boilersIs poor. b/ Projectiononly. Equipmentinstallation to be completedIn 1987. c/ Steamengine presently not operational. d/ Mill not In operationsince February, 1986. Estimatesare for 1985. e/ 3 x 1250kVA turbine-generators;1 - fair condition;2 - poor condition. Source: Ru-Tek;Mission estimates. - 36 -
4.8 Mim Timber Co. Ltd. Steam raisingequipment at Mim comprises two boilers,one wood-firedunit rated at 6.5 t/hr and 23 bars, and the other a 1 t/hr fuel oil-firedunit rated and 10 bars. A secondwood- fired boiler, a 2 t/hr at 7 bar locomotivetype, is slated for installationin 1987. High pressuresteam from the large wood waste boiler is designedto feed a 420 kVA steamengine-generator iiatalled in 1980. However, during operation in the first year, lube oil contaminationof the feedwaterresulted in damage to the boiler. The steam engine has not been operatedsince 1981 becausethe condensate cannot be recycleddue to lube oil contaminationand there is a water supplyshortage at Him duringthe 5 to 6 month dry seasonwhich will not permitopen cycle operation.At present,only 7 percentof the residues are combustedfor processheat; the balanceis sold as firewood(18Z), charcoaled(24Z) or burnt off in a fire pit (52Z). Thus totalelectrical demandsfor the mill, the Scanstylefurniture factory, Mim Agro Ltd. and the surroundingcommunity of 2.2 MW peak and 6.4 GWt.are met entirelyby dieselgeneration. A 47 km Sunyanito Mimgrid extension is proposedfor 1989 at a capitalcost of US$ 2.2 million(before firancing), financed by the EuropeanInvestment Bank.
4.9 AfricanTimber and Plywood(Ghana) Ltd. The largecapacity ATP sawmillhas been shut down since February,1986 and the plywood line since mid-1984because of financialand operationaldifficulties. A recently signed US$ 38 million financingagreement with the Bank of Scotlandprovides for mill rehabilitationand operationunder a five year manAgementcontract with MarktraceProjects Ltd. The ATP power house containsfour 1948 manufacture7.5 t/hr boilers,of which possiblytwo are in operablecondition. These feed three 1,250kVA turbo-generators; only one is consideredserviceable. Plans are to refurbishthe boiler house under the supervisionof the manufacturer,Babcock and Wilcox (UK) Ltd. At such time when the mill complex returns into production, essentiallyall its residueswill be utilized for steam and power generation.The nationalgrid is 28 km away, but there are presentlyno plans for its extensionto Samreboi.
CharcoalProduction
4.10 Thirty-onepercent of the solidresidues produced at Mim Timber Co. Ltd. were convertedinto charcoalat the mill in large earth mound kilns. Total charcoalproduction in 1986 is estimatedat 865 tonnes, which translatesto an apparentconversion efficiency on a dry weight basis of 13.9 percent. Sixty percentof the charcoalthus producedis sold to mill workersat 30 Cedis per 40 kg sack; the balanceis sold to outsidersat variousprices and leads to a average sale price of 64 Cedis/sack. As productioncosts are calculatedby Mim Ltd. at 45 Cedis/sack(assuming a zero opportunityvalue of the residues),net mill income is 19 Cedis/sack. If charcoal consumptionpatterns follow estimatedurban averagesof 140 kg/person/year,then 6,180 personsmeet theirdomestic cooking needs from the residue-derivedcharcoal. - 37 -
Disposal
4.11 Almost all solid residues(i.e. slabs/edgings,offcuts, and cores) which are not consumed at the mills are sold for off-site consumption. The main exceptionis Mim, where nearly 15,000 m* of slabs/edgingsand offcutswere burnedin an open fire pit as a means of disposal. 4.12 Sawdustis dumpedaway in land depressionsor ravinesnear the mills using 5 m3 tractor-trailersand bulldozers. Dependingon land availability,the sawdustmay be burnt in large piles. Financialcosts of equipment,operations and labor for sawdustdisposal range from US$ 1,000 to 8,000 per annum per mill, with the latterfigure pertaining,to the largestmills. Environmentalcosts and fire hazards are likely significantlygreater. HardwoodTimber Products Ltd. of Takoradidumps sawdust in city areas under city council permit, to the voiced displeasureof nearbyresidents. A sawdustpile spontaneouslycombusted on the premisesthe week before the mission'svisit. In Kumasi, land filling around the Ahinsan-Kaaseindustrial area is no longer being allowed by the landowners. A large capacity mill complex, A.E. Saoud/LumberProcessing Ltd., had a seriousfire accidenttwo years ago as a resultof sawdustdisposal by burning.
Off-siteEnergy Uses
4.13 The largestfraction (50 p-rcent),or some 217,000m 3 , of the 1986 processingresidues found their way to gses away from the mill complexes. Energyuse consistedof 124,000mn of slabs/edfingsbeing sold for firewoodand charcoalproduction, plus about 2,800m of sawdust processedinto briquettes.The principalapplication of this energywas for food preparationin bakeries,local restaurantsand households. However,the sawdustbriquettes are being adoptedfor use in brickmaking kilns.
Industrialand CommercialHeat Raising
4.14 Of 61 industrialsites surveyedpreliminarily for energyuse, only one, AsokwaBrick and Tile Co. Ltd. in the CentralRegion, is a regularconsumer of unprocessedsawmill residues. Ankaful Brick and Tile Co. Ltd. is a regularuser of sawdustbriquettes. Other industries utilizingwoodfuels, which includesoap and palm oil producers,brick factoriesand gold mines,obtain firewood from the naturalforest.
4.15 Bakeries,small restaurants("chop bars") and fish smokers locatedwithin a 10 km radiusof the major wood processingcenters are major consumersof slabs/edgingsfor use as firewood.Sale pricesat the sawmillgate are about 400-500Cedi/tonne (US$ 3/tonne)in Kumasiand 600 Cedi/tonne(U8$ 4/tonne) in Takoradi. In addition,about two dozen publicboarding schools in theseareas use from 60 to 450 tonnes/yreach for institutionalcooking. - 38 -
DomesticCooking
4.16 The balanceof residuesconsumed directly as firewocSib used in householdsfor lomesticcooking on simple,inefficient stoves, often of the "three stone" variety. However, charcoal is the preferred domesticfuel in urbanareas, exceeding firewood consumption by nearly10 to 1 on a grossenergy basis. 10/
CharcoalProduction
4.17 An estimated60 percentof the slabs/edgingssold as fuelwood in Kumasi,and 80 percentin Akim-Oda,are carbonizedby charcoalmakers working within a few kilometersof mill sites. Very little residue charcoalingactivity takes place near the mills in Sekondi-Takoradi,and the town's main source of charcoal supply is from the forest areas surroundingTarkwa. The solid residuesare carbonizedin so-called "earthmound" kilns, although in many cases the top coveringiF actually sawdust. In the Kumasiarea in 1986, approximately64,000 m of slabs and edgingswere converteeto 5,400 tonnesof charcoalwith a calorific value of 3,750 toe. An estimated300 personswere employed in this activityat 50 sites, earningamounts ranging from 100-300cedis per person-day.
Briguetting
4.18 There is one briquetteplant presentlyoperating in Ghana, ChaowusLtd. in Akim-Oda. The plant is ownedand operatedby a Taiwanese entrepreneurand has been in productionfor approximatelyone and one- half years. Presentactual production rate of 1,100 t/yr is only half stated capacity due to operationalinefficiencies. Chaowus obtains sawdustat no chargefrom Akim-Odaarea sawmills,using their own 7 tonne truck to haul the sawdustto the plant. Total sawdustdemand, includinI amounts combustedto heat the sawdustdrier, is approximately2,800 m SUE at the currentbriquette production rate. The plant thus consumes about 60 percent of the sawdust produced in Akim-Oda.
Energy vs. Non-Energy Uses
4.19 It is axiomaticthat wood processingresidues should be put to their hihest and best use consistentwith economics. Approximately 95,000m of residueswere put to non-energyuses which will be reviewed brieflyfor comparisonwith value in energyuses. In the case of offcuts and veneercores, non-energy applications are the dominantutilization, accountingfor the dispositionof 77 percentof the formerand 96 percent of the latter.
10/ "Report of Pilot Survey on Puelwoodand CharcoalConsumption in Accra", Governmentof Ghana National Energy Board, October 1985. Table 4.3: VOWDROCESSINB IISSSRTY DISPO6ITION OF RESIOUES6Y tMEBlon, 1906 t0m SW)
UtilIzed Inldn thm Wilts UtIlied Outside1tb Wills _w1 us Slabs Swdust Vener Slabs Saedust e Slabs vener ReolcnAlI I tdgings Offeuts ShavIngs Waste Cores Totals Edgings Offeuts Slavings Wast Coe Totals Edgings Otfeuts Snudunt Wste Totals
Swnelils 14,400 3,760 - - - 18,160 100,966 52,494 390 - - 133,870 - - 46,414 - 48,414 Combined UD#DOO 3,8 3_418 28.398 - 45.201 5jj0 2.6? _ - 20,467 28.393 - - 4,197 - 4,197 Totals 24,400 7,145 3,418 26,396 _ 63,361 106,045 35,361 390 - 20,46? 162,263 - - 52,611 - 52,611 kron Alasto SnWlls _ - - - - - 6,247 1,940 - - - 8,187 - _ 2,716 - 2,716 Ccblned 10,739 ILI73 - - 13,912 8,054 - - - 8,054 8,055 4.603 94 1,249 23,411 Totals 10.739 3,173 - - 13,912 14,301 1,940 - - - 16.241 8,055 4.603 12,220 1,249 26,127 >
Se I I s 2,663 1,423 209 - _ 4,295 1,498 524 - _ - 2,022 2,270 - 2,961 - 5,231 Combne ------Totals 2,663 1,423 209 - _ 4,295 1,496 524 - - - 2,022 2,270 - 2,961 - 5,231 Eastrn semi I I - - - - - 10,090 3,125 693 - - 13,908 - - 3,864 - 3,864 Combined 5.37 1.503 - 3.091 - 9-971 - - 2,112 - 2.678 4.790 - - 378 376 Total s 5,377 1,503 - 3,091 - 9,971 10,090 3,125 2,805 - 2,676 18,698 - - 4,242 4,242 "esterm ellils 5 1,334 1,205 - - 2,539 14,362 3,446 - _ _ 17,606 - - tO,174 - 10,174 CobIned 12,041 5,299 3,047 1.985 3.553 23.925 ------1,192 - 1,192 Totals 13,375 4,504 3,047 1,985 3,553 26,464 14,362 3,446 - _ _ 17,608 - - 11,366 - 11,366
Industry otals 56,544 17,748 6,674 33,474 3,553 118,003 146,296 44,396 3,195 - 23,145 217,032 10,325 4,603 83,400 1,249 99,577
Soure: mI ssIan estieates. - 39 -
SecondaryManufacturins and Export
4.20 Approximately8,200 m3 of solidresidues were furtherprocessed within the mills to yield marketableproducts such as flooring,tool handles,broomsticks, fencing materials and wooden crates. Offcutsof high value speciessuch as Afrormosiaand Hyeduaare ripped into strips for export,while cores (bouls)are slicedlengthwise and reassembledfor strip shipping. These remanufacturingoperations are usually highly profitable.
CottageIndustry Woodworking
4.21 In additionto the industrialscale productionof knock-dawn furnitureparts, there is a large and activecottage industry centered aroundthe sawmillsbased on the reworkingof offcuts. These 3 to 10 man carpentry/furniture operations typically employ small band and circular saws to producelow cost structuraltimber, chairs, tables, beds, chests, toys, etc. for domesticconsumption. It is prima facie evidentthat a good deal of employment,value and incomeis being generatedby these artisanactivies. Particleand Fiber BoardProduction
4.22 NovotexLtd. in Nkawkawfeeds most of its slabs/edgingsand offcutsto a domesticgrade particleboard plant which is part of the complex. About 1,350m of solid residueswere utilizedin this ashion in 1986; the balanceof the raw materialinput for the 8,000 m board productionwas extractedfrom the forestand hogged. WesternTimbers Ltd. of Takoradi,the MLUR and SCM Engineeringof West Germany are jointly investigatingthe feasibilityof producing medium density fiberboard(MDF). The highestgrade can coztainup to 20 percentsawdust and has an exportvalue of about US$300/m FOB. Other gradesroughly compete with domesticplywood and are composedof up to 50 percent sawdust. Althoughthe mill managerasserts that MDF is in high demandas an exportproduct, the high cost of shippingsuch a dense productand the currentworld surplusof MDF manufacturingcapacity will likelydim the economicprospects of such a venture. Nevertheless,should the scheme prove successfulit shouldbe considereda highervalue use for on-site sawdustresidues than as fuel.
Summaryof PresentResidues Utilization
4.23 The 1986 utilizationof wood processingresidues is brokendown by regionin Table4.3 and displayedgraphically in Figure4.1. As to be expectedfrom residueproduction statistics, the Ashantiregion is the major consumerof wood processingby-products both for on- and off-site uses. However, the Western region utilizesa greater share of its residueswithin the mills,due in largepart to the higherproportion of facilities equipped with boilers for process heat raising and cogeneration. - 41 -
Figure 4.1: RESIDUEUTILIZATION BY REGION, 1986
250
150
lee
p4 50 0
Ashanti Brong Central Eastern Western Ahafo gg3In-Mil1 Use 3Outside Mill JUse H Surplus - 42 -
4.24 The end-useof residuesis arrangedby residuetype in Table 4.4 and Figure4.2. The use of slabsand edgingsfor fuelwoodis the largestsingle employment of wood residuesat 31 percentof the total residueproduction. Fuel for mill processheat/cogeneration, other (non- energy)uses, and unusedsurplus evenly split the remainder.
Table4.4: END-USESOF NOMDPROCESSING INDUSTRY RESIDUESBYTYPE, 1986 (a' SWE)
Fuelfor Furniture, MIIIProcess Flrewood/ Fencing, Surplus/ iHeat/Cogeneration CharcoalProd. Export& Other Unused
Slabs/ 48,746 134,918 19,186 10,325 b/ Edgings (49%) (97%) (20%) (10%)
Offcuts 9,046 1,550 51,548 4,603 cl (9%) (1%) (54%) (S )
Sawdust 6,674 3,195", - 83,400 (7%) (2%) (84%)
VeneerWaste 33,474 - - 1,249c/ (34%) (1S)
cores 1,091 - 25,607 - (1I) (26%)
Totals 99,031 139,633 96,341 99,577 (100%) (100%) (100%) (100%)
Industry Percentages 23% 32% 22% 23%
a/ 2,805m3 SWEfor sawdust briquette production atChaowus Ltd., Akio-Oda. b' 8,05S.3 SUE burnedIn firepit at MimTimbers Ltd., Rim. c/ BurnedIn fire pit at HimTIlbers Ltd. Source:Mission estimates. - 43 -
figure4.2t USIDUE MM-USE BY TYPE, 1986
140 w~1310 1ao 110 90
0 ~80 50 0D 40 5 30 0 ~20 le 0 Mdl Fuel FLrewood/ Other Surplus/ Charcoal Unused 3g Slabs/ Offcuts E Sawdust dWste Cores Edgkngs Wae - 44 -
4.25 Table 4.5 and Figure4.3 re-organizethis informationby end- uses of the residues.
Table4.5: DISPOSITIONOF NOD PROMCSSINGINDUSTRY RESIDUESBY END-USE,196 (U SWE)
Veneer Slabs/Edgings Of fcuts Sawdust Waste Cores
Fuel for W111Process 48,746 9,046 6,674 33,474 1,091 Heat/Cogeneratlon (23%) (14S) (7%) (96%) (%)
Firewood/Charcool 134,918 1,550 3,195 - - Production (63%) (2%) (3%)
Furniture,Fencing, 19,186 51,548 - - 25,607 Exportl Other (9%) (77%) (96%)
Surplus/ 10,325 4,603 83,400 1,249 - Unused (S0 (7%) (90%) (4%)
Totals 213,175 66,747 93,269 34,723 26,698 (100%) (100%) (100%) (100%) (100%)
Source: MIssionestimates, - 45 -
Figure 4.31 RESIDUEDISPOSITION SY ND-USE, 1986
220 200 3 2180 gV) g160 148 120 100 80 a' 60 9-40 *3o 1134e20 - Slabs/ Offcuts Sawdust Veneer Cores Edgings Wastes S MillFuel Fi rewood / Oth.r X Surplus - 46 -
The figures indicatethat residues are utilized or disposed of as followgs Residue Utilizationor Disposal
Slabs/edgings Primarilysold for charcoalproduction or firewood.Burned to raise steamfor process heatingof dryersand conditioningvats at combinationmills. Some minor secondary manufacture.Very minor use for particle boardmanufacture. Offcuts Primarilysold to furnituremanufacturers and carpenters.Some use as fuel at combinationmills and cogenerationsites and for charcoalproduction. Very minor use for particleboard manufacture.
Sawdust Usuallydisposed of by dumpingor open burning. Minoruse to raisesteam at combinationmills and for briquette productionin Akim-Oda.
Veneerwaste Burnedto raise steamat combinationmills.
Cores Re-sawnfor export. Sold for domestic consumption.Minor use as hoggedboiler fuel at GWA and for charcoalproduction.
The types end locationsof surplusresidues are discussedin ChapterV.
Costsof Utilization
4.26 In Chanaianmills most residuesare collectedby hand,although sawdustmay be handledby chainconveyors or pneumaticsystems in some of the largerplants. Slabs,edgings and trim blocksare normallyplaced on hand carts or collectedin trailersfor transportout of the mill area. Sawdustis most frequentlytransported to an adjacentpile for landfill or burning. These practiceshave costs associatedwith the labor of collectionand for tractor/truckoperations and maintenance.These costs are essentiallythe same whetherthe residuesare to be sold, dumped, burnedor utilizedto fuel an on-sitethermal plant. The deliveredcost associatedwith off-siteuse is thereforetransport to the point of consumption.
4.27 Additionalcosts would be associatedwith mechanizedfuel handlingat the thermalplant. For example,fuel silos,their unloaders, and fuel distributionconveyors may be requiredat the thermal plant which would need to be justifiedby labor savings or the value of - 47 -
continuityof operation. If air conveyingof sawdustand shavingsis utilized,there may be an increasein horsepowerto redirectthe the fuel up into a fuel silo. Determinationof the incrementalhorsepower is site specificand would resultin an incrementalincrease in powercosts which shouldbe consideredin the economicevaluation of the specificproject.
Technical/InfrastructureConstraints to ResiduesUtilization
4.28 A number of technicaland organizationalconstraints cause sawdust residuesto go unutilized,thus divertingsolid residuesfrom alternativeuses into use as boiler fuel. Rxisting technical shortcomings,as discussedbelow, result in inefficientcombustion of the solid residuefuels.
Water SprayLubrication of Saw Blades
4.29 Numerousmills employwater spray for the lubricationof band and circularsaw bladesused in log break-down.The water is sprayedin excessiveamounts, at some millsvisited being applied on the sawbladeby a garden hose resultingin most of the water simplysplashing off the blade and excessivelywetting the sawdust. The over 70 percentmoisture content(wet basis)of the sawdustmakes it very difficultor impossible to combustwithout expensivepre-drying, and is one cause of the low utilizationof sawdust as a boilerfuel. OutsideStorage of Sawdust
4.30 Want of demand for the fuel and lack of covered storage facilitiescauses the waste sawdustto be storedout-of-doors, exposed to the elements. Rainwateradds to the moisturecontent and difficultyof burning. Boiler/FurnaceConfiguration
4.31 Predominantlyfiretube wood-burning boiler/furnaces utilized throughoutGhana are designedto burn solidwood fuels. The large grate holes and insufficientairflow for suspensionresult in sawdustfuels fallingthrough the grate. Propersupport of sawdustcombustion would in most cases require consid-rablemodification of grates and air feed systems.
BoilerEfficiency
4.32 At some of the wood-firedboiler sites visited,reported wood consumptionand calculatedheat loadsimply boiler efficiencies as low as 15 percent. The evidentexcess combust5 n air results from missing furnace doors and inadequate control of tramp air volume and distribution. - 48 -
V. POTENTIALON-SITE ALTEREATIVRS FOR INPROVINCAND/OR INCREASINGUSE OF MOOD INDUSTRYRESIDUES AS FUEL
Summary
5.1 Increasedprocess heat requirementsand cogenerationoptions could technicallyutilize all of the presentresidue surplus,while technical improvementsin current residue handling, storage and utilizationsystems could make virtually100 percentof the currently wasted sawdustsuitable as a boilerfuel. However,actual improvements and increasesin the use of the availableresidues will be dependenton the financialcosts and economicsof doing so when comparedto other availablealternatives.
5.2 This chapter outlinesthe componentsof the most promising technicaloptions, discussesthe possible technicalconstraints and estimatesthe capitaland operatingcosts requiredfor implementation.A financialand economicevaluation of each optionis presentedfollowing the technicaldiscussions. The alternativesare developedbased on actualsites and conditionsobserved during the fieldwork ratherthan on genericplants based on averageconditions in Ghana. The selectionof actualsites makes the analysispotentially useful. However,the results must be carefullyevaluated if the conclusionsare to be generalized acrossthe sector.
5.3 Severaloptions for improvingandlor increasing the on-siteuse of wood industryresidues in Ghana were identifiedduring the field mission. The most promisingoptions at the mill sites included:
(a) Steam generationto meet increasingprocess heat needs for kiln dryingand wood treatment;
(b) Cogenerationto meet both electricityand process heat requirements;
(c) Improvedsawblade lubrication systems and sawduststorage to reduce the water contentin the sawdustresidue and increase the net energyavailable;
(d) Furnacemodifications to enabledirect combustion of sawdust; and
(e) Furnace improvementsfor greater combustionefficiency in existingboiler equipment.
The first four options have the potential of increasingoverall utilizationof residueswhile the last, if implemented,may have the oppositeeffect. A summarymatrix of the technicallyfeasible options for improvingand/or increasingthe on-siteuse of wood residuesand their potentialimpacts is presentedin Table 5.1. Table 5.1 MATRIXOF TECHNICALOPTIONS FOR IMPROVINBAND/OR INCIEASINSON-SITE R£SIDUEUTILIZATION
Impact on Residues Options Primary Taroets Utilization Renuireuents Benefits
value added for Steam generatlon Nedium to large scale Increase In on-site Capital for additional Increased and potential for Increased mills facing declining demand for solid boiler and kiln drying export lumber commercializationof secondary processing and Inputs of primary species residues and possibly equipment. potential for kiln drying or desiring additional sawdust, species. Also revenues through Increased reduced disposal costs If sawdust lumber processing. Is used.
for electricity Cogeneratlon Large scale mills with Increase In on-site Capital for high Lower expenditures high process heat demands, demand for solid pressure boilers and especially if generated by diesel. residues and possibly turbo-generatlon Also, potential for reduced residue sawdust. equIpment, dlsposal costs.
efficiency of on-site Sawdust handling Mills that utilize Reduced on-site con- Technical assistance, Increased higher revenues from and storage residues for o,% *te sumptionof solid Improvedsaw blade combustion, surplus solid Improvements. energy, residues and potential cooling systems to from sales of off-site sales. reduce excess water In solid residues, lower costs for residue, Improvedstorage disposal of sawdust. and handling facilities.
from the sale of Furnace MillIswith wood-burning Increase In on-site Technical assistance, Revenues solid residues. Modification furnaces unable to burn demand for sawdust, boiler rehabilatlonand surplus sawdust and where there conversion and possibly Is a ready market for additional residue solid residues. handing equIpment.
Increasedefficiency of on-site Furnace Mills with In-efficient Reduced on-site con- Technical assistance higher revenues efficiency wood-burningfurnaces, sumptlonof residues for Improved combustion, sales of surplus residues. Improvements end potential for combustionprocess from Increasedoff-site control. sal.-.of solid residues. - 50 -
On-SiteUtilization
Background
5.4 Opportunitiesfor improving or increasing the on-site utilizationof wood residueswere extensivelyinvestigated through pre- missionon-site surveys of more than 90 percentof the wood processing industriesin Ghana. This was then followedup by a secondset of visits to 13 facilitieswhich accountfor about 50 percentof the total wood processingcapacity in Ghana. A list of the facilitiesvisited is presentedin Table 5.2.
Table 5.2: WOODPROCESSING FACILITIES VISITED BY MIlSION
Ashanti Rei.on
Specializee TimberProducts Ltd. (STP) Kumasi A, G. TImbers Ltd. Kumasi A. E. Saoud Ltd. Kumasi
Eastern Reglon
Oda Plywood and Veneer Co. Ltd. Oda
Brona Ahafo Region
Him Tirber CompanyLtd., (K14) Him Scanstyle Furniture Ltd. Mim
Western Region
African Timber and Plywood Ltd. (ATUP) Sasrebol Gliksten West Africa Ltd. (GWA) Sefwi-Wlawso Hardwood Tlmer Ltd. TUkoradi Takoradi Veneer and Lumber Co. Ltd. (TVLC) Takoradi Western Tlmbers Ltd. Takoradi John Bitar Co. Ltd. Sekondi ProsteaGoldfields Ltd. Prestea
SawmillProcess Heat
5.5 The most extensiveon-site use of wood residuesis for process heat needs, primarilyfor steamingvats, veneerand plyboarddrying and lumberkiln drying. Total 1986 on-sit residueutilization for process hgat amountedto approximately99,000 m% (includingapproximately 13,000 m' used in cogeneration).There is a definitetrend toward increased on- - 51 -
site processheat demand. This trend is drivenby: (a) the need for more on-sitekiln drying and treatmentof lumberprimarily due to the increasedreliance on "secondary"species in the BrongAhafo and Ashanti regions(due to a depletionof primaryspecies) and (b) the desireof the producersto obtain more added value for exportedwood products. The option to establishor increasekiln dryingand steamingvat capacityis primarilylimited to t~e largescale mills with log throughputcapacities in excess of 10,000m per year.At presentonly a minor percentageof the export lumberoutput is kiln dried. Assumingan increasein kiln dryingto 60 percentof the exportlumber would result in an increasein the on-site demand for residuesby as much as 48,000 m per year representing48 percentof the totalpresently surplus residues. If 100 percentof tiseexport lumber were kiln dried,the tot& residuedemand for kiln dryingwould increaseby an estimated80,000 m per year or 80 percentof the availablesurplus.
5.6 SawmillProcess Heat Unit ProductionModel. The Specialised TimberProducts Ltd. (STP)mill in Kumasiis selectedas the model used to evaluatethe technicaland economicpotential of increasedon-site residueutilization for sawmillprocess heat. The primaryobjective at STP is to installa boiler to providesteam for sterilizingvats and drying kilns which are required if the mill is to be capable of processingsecondary species and thereby increaseits annual output. More generally,kiln-drying serves to add value to the export lumber. About 90 percentof the mill'sproduction is for export. At present,STP has no on-sitesteam generationcapacity. The mill currentlyoperates one shifta day with the rysultantlog inputlevel of 43,000ma/yr. STP has a capacityof 70,000m /yr with a two shiftoperation but it is not yet able to operate two shiftsa year due to the shortageof primary specieslogs for input.
5.7 STP has no concessionsand has to purchaseall of its logs. Presentlog throughputconsists of 70 percentWawa and 15 percentUtile, with the remaining15 percentcomposed of Afromosia,Mansonia, Odum and ienri. STP plans to producea greatervariety of secondaryspecies and is currentlyinstalling kiln capacityto do so. A combinationof anti- stain and anti-rottreatment is requiredin order to rendera numberof the secondary species whitewoodscommercially viable. The drying requirementsof the varioussecondary species is the focus of on-going investigation;a partiallisting of theserequirements is given in Table 5.3. STP is also installingsteaming vats to sterilizemold sporesin susceptiblewhitewood logs. - 52 -
Table5.3: SECONDARYSPECIES REQUIRING KILN DRYING
Species Group Present Uses
Aprokuma IV Light carpentry work; moulding
Emire lb Exterior Jolnery, flooring, plywoodand moulding
Kyonkyon lIb Vcneer and plywood
Kyere IV Veneerand plywood
Ofram III InteriorJoinery, moulding, plywood,furniture
Otle 11I Plywoodface/core, light construction,moulding and Interiorfittings
Wawaa/ lb LightJoinery, plywood, veneers, boxesand crates,mouldings
a/ Dryingrequired for mouldings. Source:Mim Timbers;P4E International;TEDS.
STP currently purchases their electricity from the grid but is proceeding with a cogeneration installation. The cogeneration option at STP is not considered in this section but will be addressed later. Only the direct process heat requirements are investigated here.
3.8 3 Infrastructure Requirements. STP plans to install 6 dry kilns of 150 m capacity each plu% two log steaming vats. It is estimated that 3.7 tonnes/hr of 5.3 kg/cm' gauge saturated steam will be required to supply the steaming vats and kiln driers. To satisfy this steam requirement, a sawdust/waste wood-fired boiler and new boiler room will be required. Condensate steam would be collected and returned to a feedwater tank. Wood residues would be manually fed to the furnace with oversize pieces being manually cut-up to suit the furnace requirements. The boiler is assumed to operate continuously for 50 weeks/yr. Fuel requirements are estimated at 11,000 tonnes/yr of wood residues averaging 38 percent mcwb. Total wood residue production at the mill is estimated to be 48 3 ercent of the log throughput which is equal to 22,800 tonnes/yr (70,000 m x 0.48 x 0.420 bone dry tonnes/m? / 0.62). Of the 22,800 tonnes/yr residue, approximately 30 percent is sawdust equivalent to 6,840 tonnes/yr. The remaining 15,960 tonnes/yr residues are made up of edgings, off-cuts, slabs and rejects. A schematic diagram of the proposed alternative is presented in Figure 5.1 as STP Alternative 1. - 53 -
Figure5.1: STP LTD. - SCHEMATIC- ALTERNATIVE1
FLASHSTEAM Alternative 1 09th 1.2t/h VT
FUEL BOILER | _ CONDENSATE fUEL N (S.3kgIcmlgauge 3..l RECEIVER 11000ta saturated) @38%mcwb
l '~~~~~~~IN
FEEDWATER 2 8Vh TANK
MAKE-UPWATER 0.9t/h
5.9 Kiln Throughput. Kiln throughputis derived in Annex 5 as 19,500,3 per annum based on a redwood/whitewoodmix slightlydifferent from that plannedat STP but which mirrorsthe nationalaverage export cut. It is assumedthat kiln dried lumberoutput will consistof: 29 percentof one inch whitewoodsrequiring 10 days dryingtime; 29 percent of two inch whitewoodsrequiring 14 days dryingtime; and 42 percentof redwoods requiringand average of 21 days drying time. The kiln throughputrepresents 55 percentof the mill total lumber production, which is consistentwith the expressedplans of the STP managerto dry half of his production.
5.10 Costs. A summaryof the estimatedc- ;ndannual operating costs for the on-siteprocess heat model is pt_S___ id in Table 5.4. The constructionand equipment(C&E) costs are separatedout to reflectthose costs associatedwith the boilerand the kilnsand vats. Total C&K costs for the boiler including pipeworks, valves, ducts, electrical, instruments,spares etc., are US$333,000while those for the kiln. and vats are US$350,000. The total installedcapital costs for the entire projectis estimatedat US$1.28million. Detailsof the cost estimate are presentedin Annex 5. - 54 -
Table5.4: SiJWMARY OF CAPITALAND ANNUAL OPERATING COSTS FOR SAWMILLPROCSS HEAT UNIT PRODUCTIONMOCEL
Local Costs Foreign Costs Total Item VO00 USS) (000 USOS) ('000USS)
Capital Costs Construction ofIlers S0.0 12.0 62.0 KIls/Vats 15.0 5.0 20.0 65.0 17.0 82.0
Equipment Boilers 271.0 271.0 KiIn/Vats 330.0 330.0 601.0 601.0
Transport Chares a/ 59.3 58.3 117.6 Engineering,Installation 181.1 297.5 478.6 and Contingencies TotalCapital Costs 305.4 973.8 1279.3
Annual OpWratingCosts Labor 9.7 9.7 Power 21.9 21.9 e &M 15.0 15.0 Consumablesb/ 6.7 lS.0 21.7 ContingencIes 6.8 - 6.8 TotalAnnual Operating Costs 60.1 15.0 75.1
a/ Includes International freight and Insurance, local portcharges and bankfees. b/ Includes lost revenues from reduced slab sales.
5.11 Total annualoperating costs are estimatedat US$75,100with the largestsingle component being electricpower requirementsfor the pumps, blowersand kiln air circulationfans. Only US$15,000of the total is expectedto be foreigncosts. Details of the annualoperating costs are presentedin Annex 5.
5.12 Benefits. Air-dryingmakes essentiallyno contributionto productvalue added becausethe lumberwill never reachthe 10-12percent moisturecontent (dry basis)required in the Europeanmarket. Local kiln dryingcan replace8uropean kiln dryingand potentiallycapture the value gain. The gross contributionto forest industryvalue added through lumberkiln drying is calculatedin Table 5.5 and the resultingannual benefit streamsdisplayed in Annex 5. The percentagevalue added for kiln-driedlumber is based on estimatesmade by mill managers and exporters,which rangedfrom 15 to 30 percentfor redwoodsand 10 to 15 percent for whitewoods. The redwoodestimates include a 3 percent benefitdue to reducedmill-to-port transport costs; however, according to mill managers, drying has no effect on the transport economics of the - 55 -
less dense whitewoods.The medianfigures thus obtained,22.5 and 12.5 percent respectively,are consistent with current export price differentialsquoted for kiln-driedvs. undriedlumber. For example,the October 18, 1986 "GhanaTimber Export Market Report" issued by TEDB gives average U.K. pricesper POB m3 for FAS SwieteniaMahogany of US$605for kiln-dried and US$515for shippingdry, a 17.5 percent gain. This does not include the estimated3 percentof gross value savingsin trucking costs due to the lighter weight of the kiln-drywood. Additional benefitsnot capturedin Table 5.5 includethe lower defectrate when shippingkiln-dried, and the lower loggingcosts associatedwith the relativelymore plentiful secondaryspecies which may be rendered exportable through drying.
5.13 Financial Analysis. Results of the financialanalysis are given in Annex 5 and summarized in Table 5.6. It shows the model investmentin kiln-dryingcapacity to be highly favorablefrom the entrepreneurialviewpoint. Financial rates of returnare acceptableover the range of estimatedvalue-added percentages, the variableexhibiting the strongestinfluence on rates of returnin the sensitivityanalysis. Discountedpayback times of 2 to 5 years are appropriatelyshort for the wood productsindustry, which faces rapidlychanging market conditions for its products. Europeanagency commissions, the TEDB exportlevy and miscellaneousGOG exportcharges bave been nettedout from the benefit streams. The financialcost per m of productdrying is derivedin Annex 5 as $16.60for redwoodsand $9.48for whitewoods.The redwoodfigure is consistentwith estimatesmade in the World Bank Draft ForestrySector Review (Annex VII) of $15.00-18.00/m3,kiln drying costs in Western Europeof $25.00/p and up, and estmatesmade by Ghanaianmill managers of $15.00-25.001Ie. .6sew,4mv wissu IMuw ISOi" 5f6 ae".- P0.1,91 *50O 400600A 6"40V i,smON z t 0 6je.430#60600b4e4 Pe"5 Otdj Aq p*,4..dwA s..4l- 4.4 Si "ooem, - -.-.mwt , 4P_ "
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slit _ai i-I*io e*-$a Oei aur leds-egs es-an es-st a C-s ii *50 *I C *-01 'cii *c .s t u-s S'cZ n-il SC * c-s xes-r e." 1S-sU i a-ca cc us a n-i a *swqa s-ass *.ce sis sica e ii,a s-as *'- s-s es-4n esaa -st N sla. C c-s* * iS *l | * g * g XX~~~~~Z&imt s IS :z% 41.C 40lb xes ". 211.1 a S ali tSt S" _ i-ac.sc-in-I c-ins a~~~~SCSu-s9 jes.iS i-am; c-gist aac. es-rn xstn Xs, a J,mess e.g1si 614 55ew5% s-tel u-aa s-eartt.*Za sat, u-ic isis s-cm a-era es-rn es-a X-m*es-si a 4-%Q cl tait "I tisi c c-sc *%i-f t'-is uS st uSSS s-scs C--r fis ses esa ess t t-Ssg Xc4 fra. ci t *'ss c * _q.u s-usez zeca_ _e s _1it i.a S%cc1tel n-1ss s-.s slat i-sit ese. war _ess S i1si Oee lea sn See C frb ses a-ca _tm _r .s _- _-r a-_ esr es-a. _____es_-t N * .a c- * sc X a>wt sin c * ------* ------* ------#* ------v.43 01 0wa-- ozS * ------SeU 4A 6- 11 -1-A 403 $~-MA - -1- Pw6-wwqw:`%-e -1 so
8NIAMONuN1 V3V1 N0fl0W4J(13M1 3nlVA AVitiWI 1SMOS Q±wouIuAIWii SSOuelVuN3L0cd :~S* etqs± - 57 -
Table5.6: FINANCIALANALYSIS RESULTS, SAWMILL PROCESS HEAT UNITPRODUCTION MOCEL
Value-Added NPV FIRR DiscountedPayback (S) (S) (years)
Low Case 1,487,890 27 <5
MediumCase 2,833,580 42 <3
High Case 4,180,270 56 2
5.14 EconomicAnalysis. Economicanalysis results are given in Annex 5 and Table 5.7 and show returnswhich exceedthose found in the financialanalysis. The 4 percentcommission paid to overseasagents has been considereda real resourcecost and has been netted out from the benefitstream; other export fees are domestictransfer payments and have been disregardedfor the evaluationfrom a socialviewpoint. Electricity costs, charged at the marginal ECG industrialtariff rate in the financialanalysis, are charged at the full marginal grid cost in the economicanalysis.
Table5.7: ECONOMICANALYSIS RESULTS, SAWMILL PROCESS HEAT UNITPROOUCTION NOCEL
Value-Added NPV FIRR DiscountedPayback (S) (S) (years)
Low Case 1,664,890 30 <5
MediumCase 3,167,390 46 <3
High Case 4,670,670 62 2
Cogenerationat Grid ConnectedMills
5.15 The potentialfor on-sitecogeneration of electricitymay be enhanced given the increasingdemand for on-site process heat. At present,none of the sawmillsin Ghana that have accessto the national grid generateor cogeneratetheir electricity. There are severalfactors that have influencedthis development. The primary reason was the relativelylow cost of grid electricityin the past. Electricitytariffs have increasedby nearly400 percentsince mid-1983. Even with these increases,grid electricityis still relativelyinexpensive averae,ing - 58 -
about 4.96 cedis/kWh(3.31 US cents/kWh)for a large sawmillunder the industrialtariff. Under the presentcircumstances, it is unlikelythat small scale cogenerationsystems will be competitive. However, the possibilityfor cogenerationof electricityat mills with log input capacitiesabove 40,000 m' and with high processheat and electricity demaridsis worth investigating.One such mill in the Kumasiarea, STP, is presentlyundertaking such a projectutilizing a 5 year old 480 kVA (384 kW) cogenerationsystem purchased from a sawmillin West Germanyat an installedcost of US$540,000.
5.16 There are only 6 millswith capacitiesabove 40,000 m 3 and with accessto the grid. All of these millsare locatedin the Kumasiarea. With the exceptionof STP, none are contemplatinginstalling cogeneration equipmentalthough three of these mills currentlyhave process heat generatingequipment installed. The total on-siteresidue consumption possible,assuming all of the six mills were to eventually install cogenerationsystems to utilizeall their residues,would accountfor 110,000m /yr of residueconsumption equal to 40 percentof the total supplyin the Kumasiarea.
5.17 ProjectDescription. The STP mill in Kumasiis again selected to evaluatethe technicaland economicpotential of cogenerationat grid conectedmills. The objectivein this case is to meet all processheat needs and to generateas much of the mill'selectricity requirements as possibleconsuming all residuesproduced. Surpluselectricity generated during the off-shiftscould potentiallybe sold to the grid. An evaluationof this prospectwill be discussed later based on the resultingmarginal costs of the cogeneratedelectricity.
5.18 Processheat demandat STP is estimatedto be 3.7 tonnes/hrfor the kiln driersand steamingvats. The investmentand operatingcosts for the associatedboiler, kiln driersand steamingvats were outlinedin the previoussection. They are restated,net of costs of the dry kilns and steamingvats, as STP Alternative1 in Annex 6. In this analysisonly the incremental investmentsand operating costs for generating electricityare relevantto the decisionto investin cogeneration.Two alternativesare consideredfor the marginal analysis. The first incorporatesa back pressureand a condensingturbine with the exhaust steam from the back pressureturbine satisfying the processheat load. The secondalternative incorporates only a condensingturbine with the processheat loadssupplied directly by expandingthe high pressuresteam through a pressurereducing valve. Brief descriptionsof both these alternativesfollow.
5.19 STP Alternative 2. In this option,c 8.5 tonne/hr sawdust/wood-wastefueled boiler generating 28 kg/cm gauge, 315 °C steam is required. The steam is su.pliedto a 288 kW backpressure turbogenerator(TG) exhaustingat 5.3 kg/cm2 and a 575 kW condensing turbogenerator.An average load factor of 80 percent plus 13 days scheduleddowntime is assumedfor all systems. Steamexhausted from the backpressureTG is designedto satisfythe heat loadsof the kiln driers - 59 -
and steamingvats estimatedat 3.7 tonnes/hrsteam. An averageof 3.1 tonnes/hrof wet steam exhaustingfrom the condensingTC will pass througha condenserwith the condensatebeing returned,along with the condensatefrom the vats and kilns,to the boilerfeedwater tank. The condenserheat is to be rejectedthrough a mechanicaldraft cooling tower. A schematicdiagram of the proposedalternative is presentedin Figure5.2.
Pigure5.2: STP LTD. - SCH8MATIC- ALTERNATIVE2 f LASHSTfEAM Alternative2 09tEhA
BOILER PRESSURETG FUEL (28kg/cm2gauge 6.8Vh _ 1 . t 22,600Va 31Sa CONDENSING @38%mcwb TG WWCONDENSATE
t~~~~~~~~~~_t 3 RECEIVER 6.8 Vth COOLING OOWERU
FEEDWATER 3 Wh TANK Q 8
MAKE-UPWATER 0.9tSh 5.20 Wood residueswould be receivedat the the boiler plant from the sawmill. Oversizedresidues would be screenedand hoggedand placed in a storagebin. Sawdustresidues will be mechanicallyconveyed to the furnace. The boilerand TC units are assumedto operate3 shiftsa day for 350 days/yr. Averagepower generation is 690 Kw vhichwould meet all of the mill'srequirements when it is in operationplus allow surpluses to be sold back to the grid. Total residueconsumption by the boileris estimatedto be 22,800 tonnes/yrwith averagemoisture content of 38X mcwb. This is equivalentto all the residuesproduced on site whey the mill is operatingat its projectedmaximum capacityof 70,000m log throughput.
5.21 Costs. A summaryof the estimatedincremental capital and operatingcosts for institutingthis cogenerationoption at STP is presented in Table S.8. A detailed breakdown of the total and incrementalcosts is given in Annex6. The incrementalcosts reflectthe need for a largercapacity and higherpressure boiler, the additionof backpressureand condensingTOe, condenserand coolingtower systemsand - 60 -
larger buildingstpipes, valves,tanks. etc. that are associatedwith this option. Total incrementalC&8 costsamount to US$814,000with total incrementalinvestment costs equaling US$1,740,000.
Table5.8s SU#4ARYOF INCREMENTALCAPITAL AND ANNUAL OPERATING COSTSFOR STP CGEiNERATIOt ALTERNATIVE 2
Local Costs Foreign Costs Total Itemn (o000 USS) '000 US$) ('000 USS) IncrementalCapital Costs Construction 29.0 8.0 37.0 EquIpment 777.0 777.0 Transport Chargesa/ 76.7 75.4 152.1 Engineernlg,Installation andContinogncles 284.5 489.7 774.2 TotalIncremental Capital Costs 390.2 1350.1 1740.3 IncrementalAnnual Operating Costs Labor 0.9 0.9 o &m 28.0 28.0 Consumablesb/ 29.6 28.0 57.6 Contingenclies 8.6 8.6 TotalIncremental Annual 67.1 28.0 95.1 OperatingCosts
a/ IncludesInternational freight and Insurance,local port charges and bank fees. b/ Includeslost revenues from reduced slab and offcut sales.
5.22 The total incrementaloperating costs are estimated at US$95,100. This reflectsthe need for additionalsupervisory labor to operatethe largerhigh pressureboiler and higheroperating, maintenance and consumablecosts associated with the boiler,turbogenerator and water treatmentsystems. In addition,slabs and offcutsavailable for sale in the Alternative1 scenarioare combustedin this alternative,and are accountedfor as a cost. Detailsof the estimatedoperating costs are presentedin Annex6.
5.23 Benefits. The primaryincremental benefit of this option is the cost savingsfrom on-sitepower generation and revenuesfrom the sale of surpluselectricity. It is estimaL.:dthat a totalof 4.55 GWh/yr(net of internalparasitic consumption) will be generatedunder this option. Assuming a buy/sell value equivalentto the average cost for grid electricityat STP of 3.31 US cents/kWhresults in a potentialannual financial benefit of US$150,290.Other benefits include increased reliabilityin electricitysupply (assumes grid as back up) and elimination of environmentalcosts (non-quantified)of sawdust disposal. The value of lost productiondue to supplyinterruptions was put at US$30,000per year by the STP management,but was riotincluded in - 61 -
the analyseson the assumptionthat ECG reliabilitywill continueto improve.
5.24 STP Alternative3. This optionalso calls for a 8.5 tonne/hr, 28 kg/cm2 gauge,315 'C steam boilerfueled by sawdustand waste wood. The boileroperates at an average80 percentload factorproducing 6.7 tonnes/hrof steam. An average3.5 tonnes/hrof high pressuresteam is suppliedto a 650 kW condensingturbine Yhile 3.3 tonnes/hris expanded at a pressurereducing station to 6 kg/cm gauge to meet the processheat l.oadsof the plant. The wet steamexhaust from the TG passesthrough a condenserwith the condensatebeing returnedto the boiler feedwater tank. Condenserheat is dissipatedby means of a mechanicaldraft cooliagtower. Condensatefrom the kilns and vats is also recycledto the boiler feedwatertank. The primaryadvantage of this design when comparedto STP Alternative2 is that powergeneration is independentof the plant'sneed for processsteam. Fluctuationsin the processheat loads of the plant will, in Alternative2, requireeither a reductionin power output or a dumpingof the exhaust steam from the backpressure TO. In Alternative3, excesssteam due to a drop in the processheat load could be channeledto the TG to generateadditional electricity. A schematicdiagram of the proposedalternative is presentedin Figure5.3.
Figure 5.3: STP LTD. - SCHEMATIC- ALTERNATIVE3
DESUPERHEATING SPRAYWATERFLSSTA Alternative 3 04 FlASHSTEAMl
PRV 6.8t/h 3.3t/h12th BOILER FUEL (28kg/cm?gauge 22,800Va 31/aC) @38%mcwb -S20kW COOLING OWER CONDENSATE 6.8 t 3h COOLING RECEIVER
FEL 1'W4TER FELt 3.51/hNO~~~~~~~~~~~~TER ~~~~~2.8 t/h TANK E
I MAKE-UPWATER 0.5Vh 5.25 Wood residuerequirements, processing, handling, storage and deliveryare similarto STP Alternative2. The boilerand TG unit are assumedto operate3 shifts/dayfor 350 days/yr. The maximumpossible power generationwould be 650 kW which would occur if the condensingTC were operatedat full capacity. However,the averagepower outputat 80 - 62 -
percentload would be only 520 kW. All wood residuesgenerated on-site would be consumedby the boiler.
5.26 Costs. A summary of the incrementalcapital and annual operati,ngcosts when comparedto STP Alternative1 is presentedin Table 5.9. The incrementalC&E costs amount to US$740,000while the total incrementalcapital costs are equal to US$1,587,900.Incremental annual operatingcosts are equal to US$90,700which is primarilydue to the additionalcosts for operation,maintenance, consumables and lost residue sales. Details of both the capital and annual operatingcosts are presentedin Annex6.
Table 5.9: SUNMARYOF INCFREKNTALCAPITAL AND ANNUAL OPERATING COSTSFOR STP 00-GENERATION ALTERNATIVE 3
Local Costs Foreign Costs Total Item ('000 USS) ('000 USS) ('000 USS)
Increwntal Capitol Costs Construction 21.0 6.0 27.0 EquIpment 713.0 713.0 TransportCharges I/ 70.4 69.2 139.6 Engineering, Installation and Contldgencles 259.9 448.4 708.3
Total IncrementalCapital 351.3 1236.6 1587.9 Costs
Incremental Annual Operating Costs Labor 0.9 0 & M 26.0 26.0 Consumablesb/ 29.6 26.0 55.6 Contingencies 8.2 - 8.2
Total Incremental Annual 64.7 26.0 90.7 Operating Costs
a/ Includes Intersatlonal freight arJ Insurance, local port charges and bank fees. b/ Includes lost revenues fromreduced slab and offcut sales.
5.27 Benefits. The primaryincremental benefit of this option is the cost savingsfrom on-sitepower generationand revenuesfrom the sale of surpluselectricity. It is estimwtedthat a total of 3.21 Gth/yr (net) will be generatedunder this option. Assuminga buy/sellvalue equivalentto the averagecost for grid electricityat STP of 3.31 US cents/kWh results in a potential annual financial benefit of - 63 -
US$1O6,11O.Other benefitsare similarto those discussedunder STP Alternative2.
5.28 FinancialAnalysis of STP Alternatives. Financialanalysis results are derived in Annex 6 and sumarized in Table 5.10. The analysisshows that whileAlternative 2 io the more ieasibleof the two options,there are inadequatefinancial incentives for projectadoption by mill owners. Eitherthe averageindustrial electricity tariff would have to rise to approximately7 US cents/kWh,or the incrementalcapital cost of the installationwould have to drop by 76 percent. In this context,it shouldbe notedthat the secondhand-equipment actually being installedby STP was obtainedat substantialdiscount relative to the new equipmentconsidered in thesemodels.
Table5.10: FINANCIALANALYSIS I£SULTS, GRID CONNECTEDCOGENERATION MMOELS (STP)
Alternative2 Alternative3
NPV S(1,320,460) S(1,470,630)
FIRR Undef. Undef.
CapitalCost SwitchingValue -76S --
MarginalCost of Electricity Generated 7.1 UStAkWh 9.3 UStAkWh
5.29 EconomicAnalysis of STP Alternatives.Details of the economic analysisof Alternatives2 and 3 are givenin Anex 6 and summaryresults presentedin Table5.11. Alternative2 is againthe favoredoption, but at a marginal generationcost of 7.6 US cents/kWhthe electricity producedis not competitivewith the marginalcost of grid hydropowerof 5.2 US cents/kWh. Equivalencewould not be establishedunless the economiccost of the requiredincremental investment were to drop by 49 percent. In the economicevaluation, the valueof slabs and offcutshas been raisedto reflectthe replacementvalue of theirclosest substitute, forestwood.
Cogenerationat Non Grid ConnectedHills
5.30 At presentall exceptthree of the majorsawmills are connected to the nationalgrid. )f the three non grid connectedmills, only one, Cliksten West Africa Ltd. (GWA) in Sefwi-Wiawso,is presently cogeneratingelectricity and steamwhen the plant is in operation. In addition, electricityis generatedwith diesels to meet some plant requirementsand the domesticrequirements of mill personnel. However, - 64 -
the nationalgrid now passeswithin one kilometerof the mill and present plans are to connectto the grid sometimethis year. GWA has initiated procurementof the transformersto make the connection.Once connected to the grid, GOA plansto stop cogeaeratingsteam and electricityand to use its residuesfor the generationof its steamrequirements only. The secondmill with the capacityto cogenerateis AfricanTimber and Plywood (Ghana)Ltd. (AT&P)in Samreboi. However,the plymillat AT&P has been shut down since 1984 and the sawmillwas shut down in early 1986. The mill is presentlyundergoing a major rehabilitationeffort that is being financedexternally. Once complete:it is expectedthat the mill will use its residuesto cogenerateall its electricityrequirements. There are presentlyno plans to bring the nationalgrid, which is 28 km away, to AT&P.
Table5.11: ECONOMICANALYSIS RESULTS, GRID CONNECTEDCOGENERATION MODELS (STP)
Alternative2 Alternative3
NPV S(836,000) S(1,185,120)
FIRR Undef. Undef.
CapI.slCost SwitchingValue -49%
MarginalCost of Electricity 7.6 USt/kWh 10.1USt/kWh Generated
5.31 The Mim TimberCo. (NIM)is the only major operatingmill which presentlygenerates all its electricitywith dieselfuel. MIM had a 420 kVA steam engine/generatorinstalled in 1980 but ceasedto operate the steam engineshortly thereafter because engine lube oil was contaminating the condensatewhich was subsequent'ydamaging the boiler. MIM is 47 kM from Sunyaniwhere the nationalgrid will pass and VRA's presentplans are to extend the grid to MIN in 1989 at a estimatedcapital cost of US52.2million. The total 1985 electricaldemand at MIM, the adjacent Scanstylefurniture factory, Nim Agro Ltd. and the surroundingcommnunity was 2.2 MW peak and 6.4 Gwh per yea , all met by dieselgeneration. KIM presentlygenerates over 45,400 m of wood residuesof which only 7 percent is used to meet its processheat needs. Of the balance,18 percentis sold as firewood,24 percentis convertedto charcoaland 52 '1' percent is burnt in open pits or disposedin landfills. The residues presently burnt or disposed could, if converted at a 10 percent efficiency,supply approximately 7.7 Gwh/yrof electricity. - 65 -
5.32 HIM Alternatives.Tne cituationat HIN is uniquebecause of the proposedgrid extension. Financialjustification for extensionof the grid to MIM has been based on the projectedconsumption of electricityby the MIM complex (mill, furniturefactory and domestic consumption).If the grid is extendedto MIM, the alternativeagainst which cogeneratedelectricity must competeis grid electricity.However, if the grid is not extended to KIM, the alternativeis diesel generation. To date, there seem to be conflictingviews as to the investmentcommitment for the grid extension.The GeneralManager of VIA has indicatedthat the investmentdecision is final and that the gKid will be extendedregardless of MIM's ultimatedecision. If this is the case, the investmentfor grid extensionmust be consideredexogenous in the economicevaluation of the cogenerationoptions. On the other hand, it is possiblethat extensionof the grid could be postponedand the associatedinvestment saved if cogenerationat MIM is economicallymore attractivethan grid electricity.In this case, the investmentfor grid extensionmust be incorporatedinto the economicevaluation of the cogenerationoptions.
5.33 Evaluationof the cogenerationoptions is furthercomplicated by the fact that the electricityload profileat NIM has a wide variation (see Figure5.4). After the plannedmill modernizationand installation of a new mouldingline and additionalkilns withintwo years,the, MIM complex(excluding Mim Agro) will have a 2.2 NW peak demand,an average demendof 1.4 NW (basedon a weightedaverage operating period of 4,800 hr/yr) and a continucusbase load of 450 kW. Conversely,the steam processheat demandis relativelyconstant averaging 7.1 tonnes/hrduring plant operationand 4.4 tonnes/hrat all other times. Given these circumstances,several alternatives exist for design of a cogeneration option.One optionis to build a cogenerationplant which providesall process beat and baselintermediateload electricitywhile either generatingpeak demandwith dieselor, dependingon the grid extension assumption,obtaining it from the grid. A secondoption is to designa cogenerationplant that can meet all electricitydemand includingpeak demand. A third option is to design a cogenerationplant thAt will consumeall availablewood residues,provide all procesFheat needs and generateelectricity in a mannermost efficientlymatched to the procesa heat demand profile while allowing the plant to either purchase electricityfrom the grid duringperiods of deficitand sell it to the grid during periods of surplus. Another option might be to expand througha backpressureTG only that steam which is needed for process heat while'purchasing remaining electricity requirements from the grid. Five distinct options have thus been identified for detailed evaluation.However, the economicsof two of the optionsare also tested under the assumptionthat the inves.mentfor the grid extensionis a sunk cost. A summaryof all the optionsconsidered in this evaluationis presentedin Table5.12. MIM COMPLEX DAILYLOAD PROFILE
Power (xOO kW)
28 ~--1 -~ it------i------l f
l F ~~PeakPeriod
10 ......
'0 - -:L->% --- \\&4 t - --;S7V\o C -
0 6 10 is 20 24 Time of Day - 67 -
Table 5.12: 1IlMCOGENERATION OPTIONS OECISION MATRIX
AssumeNo Grid Extension AssumeGrld Extension (Real Resource Cost) (Sunk-Cost)
Base Case A 100%Diesel Generation Process Heat Boller
Option #1 A Base Casei Extend Grid No on-SiteGeneration No On-Site Generation ProcessHeat Boller ProcessHeat Boiler
Option12 A 2.C6M Wood-firtdCo-Generation Diesel Back-up
OptIon 13 A 1.2 #W Wood-firedBase LoadCo-Generation Diesel Peak LoadGeneration
Optloa 14 A ExtendGrid 260 KM wood-firedCo-Generatlon
Optionff A Optionff 8 ExtendGrid 1.21W Wood-firedCo-Generation 1121W Wood-firedCo-GeneratIon
5.34 Project Description. Nim Timber Co. Ltd., the largest a1.igle wood processing plant in Ghana, is a well managed state owned mill located in the Brong Ahafo region. The mill production facilities include a sawmill which produces sawn timber and veneer flitches, a veneer slicing plant, a moulding plant and six lumber dry kilns. Adjacent to the mill is Scanstyle Him Ltd., the largest knock-down furniture factory in Ghana. Also in the vicinity of the mill is Kim Agro Co. Ltd., a collection of privately owned farms.
5.35 At present, all electricity in the Mim area is generated by diesel engines. The primary producers of electricity are Mim Timbers, Kim Agro, and Scanstyle. Kim Timbers has a total installed diesel capacity of 3,126 kVA, Scanstyle has 600 kVA and Kim Agro, 640 kVA. In 1985, Nim Timbers generated approximately 5.1 Glh of electricity and consumed 424,055 Imperial gallons (Igal) of diesel fuel and 11,250 Igal of lubricating oil. At the same time Him Agro generated 6.5 KWh and consumed 43,800 Igal of diesel oil and 2,080 Igal of lubricating oil, while Scanstyle generated 6.0 KWh burning approximately the same oil - 68 -
quantitiesas at Mim Agro. Given diesel costs of 130 Cedis/Igaland lubricatingoil at 809 Cedis/Igal,the fuel and lubricationcosts alone for generatingelectricity at Mim was about US$526,00Oor equivalenttc U88.3C/kwh. Mim Timberssupplies some electricityto Scanstyle,to the residencesof the managementof both Mim Timbersand Nim Scanstyleand for some social servicesin Mim Town. A summary of the Him area electricaldemand and consumptionfor 1985 is shownin Table 5.13.
5.36 Steam is raisedin two facilitiesat Mim Timbers. The first is an oil-firedCleaver Brooks firetube boiler which supportsthe existing six lumber dry kilns; the second is a Lambionwood-fired furnace and Sillar& Jamarthigh pressureboiler originally designed to providesteam to the now inoperativeSpillingwerke steam engineand for the steaming vats and veneerdriers. The Sillar& Jamarthas a maximumcapacity of 6.5 tonnes/hrof 23 kg/cm2 gauge steamwhile the CleaverBrooks is rated at 1 tonne/hrat 10 kg/cm2. A thirdKewanee-designed, Korean made wood- fired locomotivestyle boiler is on site but has Pot been installed. This boileris ratedat 2 tonnes/hrsteam at 10 kg/cm.
5.37 Him Timbers has limitedconcessions and has nearly depleted most of the economicallyavailable primary species. The management recognizesthat operationsmust startshifting to processmore secondary species if the mill is to continue to operate at near productive capacity. Mim managementpredicts a dramaticdownward shift in the mills processingof primary species within the next 5 to 10 years. To accomodatethis shift,Mim Timbersis planningto add more kiln drying facilitiesand steamingvats. Management estimates that an additional32 kilns will be required. Managementis also emphasizingmore secondary processingand plans to enlargethe mouldingplant. MIM's main sawmill is aging and is expectedto be replacedin two to threeyears. - 69 -
Table 5.13: MIN AREAELECTRICAL DEMAND AND CONSUMPTION, 1905
PowerDemand Installed Peak Use Copacity Demand (lcW) (kW)
SavoIIIa/ 1,400
KiInsb/ 25
Veneerm I1 300
Mouldingplant c/ 152
Shops 150 Combined: 1600kW Offices 50
Watersupply 92
Comunity 300
Him Scanstyle - 300
Min Agro 300
Total 2,200
Consumption(kWh/year)
Him Complexgeneration d/ 5,147,000
Scanstylegeneration 600,000
Him Agro 650.000
ApproximateTotal 6,400,000 a/ Future replacementsawmill anticipated to have approximatelythe samedemand and consumptionas existing. b/ Kilnsanticipated to Increaseto 32 fromcurrent 6. Increaseof 140 Kd anticipated. c/ Mouldingplant anticipatedto Increasefrom 152 to 450 kw with expansionof capacity. I/ Includes360,000 kWh/year sold to Scanstyle.
Source: Mim TimberCo. - 70 -
5.38 Mim Timbershas a processingcapacity of 90,000m 3/yr of log throughput. In yq86,Mim processed81,000 mi of logs and, as a result, produced45,400 m of wood resi ues. The averagebone dry densityof the wood was estimatedat 590 kg/m witb an averagemoisture content of 34 percentmcwb. With the shift to secondaryspecies it is estimatedthat the averagebone dry densitywill declineto 510 kg/m and the average moisturecontent will increaseto 37 percentmcwb. A summaryof the use of residuesin 1985 and 1986 is given in Table5.14.
Table 5.14: UTILIZATIONOf RESIDUESAT HIM
1985 1986 (a3/yr) CS) (C3/yr) (t)
Boller Fuel 3,021 7.2 3,173 7.0
SoldCmmerclally 7,355 17.5 8,054 17.7
CharcoalProduction 9,807 23.3 10,739 23.7
Disposal by Burning 21.868 S200 23411 51.6
Totes 42,051 100.0 45,377 100.0
Source:Ru-Tek..
The Mim managementindicated that firewoodand charcoalwere sold only to meet the needs of the Mi community.Firewood was sold at 2000 cedis per tipper truck (about5 mi) and 80 percentof the charcoalwas sold at subsidizedprices to employeeswhile 20 percentwas sold to dealersat 180 cedis per sack (about40 kg). The sale pricesfor charcoalare given in Table 5.15.
Table 5.15: COAL SALESPRICES, HIM TIMBER00.
Produ.jtoo Share Consuer (C*qdtaS*ck)
10 Jr. & Sr. Staff 0 60 Other Staff 30 10 Scanstyle 100 20 Charcoal Dealers 180
Source: Nim Tlwer Co. - 7) -
5.39 The Mim area presentsan ideal situationto investigatethe potentialfor cogenerationbecause of: electricityand process heat requirements;wood residueavailability; management support at the mill; presenthigh costs of dieselgeneration; and presentisolation from the national grid. A brief descriptionand evaluationof the various alternativesthat are consideredfollows.
5.40 MIM Base Case A. This base case is definedto be 100 percent dieselpower generationwith all processheat requirementsgenerated with waste wood. The nationalgrid is assumednot to be extended. Future electricityconsumption, excluding Him Agro, is estimatedto grow to 6.7 GWh/yr mainly due to the additionof kiln capacity,expanded moulding plant and replacementsawmill. This representsa 0.9 GWh/yrincrease or 16 percent over the 1985 consumptionlevel. An annual average power consumptionof 1,406 kW and a peak of 2,200 kW is expected. This includesa 300 kW load from Scanstyle. Electricityproduction will continuewith existingdiesel capacitywith one-eighthof the diesel capacitybeing replaced annually.
5.41 Followinginstallation of 26 dry kilns additionalto the current6, totalprocess heat demandis expectedto average7.1 tonnes/hr with peak demand reaching 10.1 tonnes/hr. In order to meet the additionalprocess heat requirements,a 1.6 tonne/hr,10.6 kg/cm gauge saturatedsteam wood fueledboiler will be installedto complementthe existingwood fueledSillar & Jamartand Kewaneeboilers. These three boilers will have sufficientcapacity to meet the peak processheat demand from the kilns, steamingvats, veneerdriers and veneer plant. Condensatewould be collectedand retur-4to a boilerfeedwater tank. A new reinforcedconcrete building to house the new boileris required. It is proposedthat the new boilerbe manuallyfired to minimisecapital expenditureand utilizethe low cost labor. The estimatedwood residue requirementbetween the three boilersis 18,700tonnes/yr averaging 34 percentmcwb. This residueis availableon-site. A schematicdiagram of the processheat plant is presentedin Figure5.5. - 72 -
Figure 5.5: HIMTIMBERS LTD. - SCUEMATIC- BASE CASEA/ALTERNATIVE IA
SILLAR& JAMART NEW LOW PRESSURE KEWANEELOCOMOTIVE BOILER BOILER BOILER (23 kg/cm2gauge, 3250C) (10.6 kg/cm' gauge) (10.6 kg/cm2 gauge) s.ltVh (<6.St/h) -1.6) V/h 2Vth (2Vth) j ~~~~~PRV 2.4th (3.3th).4t/h (4.9th)
16kg/cm 2 gauge 0.5 kg/cm2 gauge Veneer Dryer - 2.7 tVh(3.2 t/h) 32 Kilns - 3.2th (5 4 t/h) Veneer Plant Steaming Vats - 1.2 th (1. Sth) Total - 2.7 t/h (3.2th) Total - 4.4 t/h (6.9 tVh)
5.42 HIM AlternativelA/KIM Base Case B. This alternativerequires that only the processheat plant be built and that all electricitywill be purchasedfrom the nationalgrid. The diesel generatorswill be mothballedwith a base load capacitymaintained for standbyemergency power. Given the assumptionthat the grid extensionis not committed, this alternativeis termed Alternative1A and the cost of the grid eztensienmust be incorporatedin the economicanalysis. For the purpose of ecoiomic evaluation, this alternativeis considered"KIM Base Case B" when the investmentfor the nationalgrid extensionis assumedcommitted (i.e.a sunk cost). All aspectsof the processheat plantare similarto that outlinedin "Base Case A". A schematicdiagram of this alternative is presentedin Figure5.5. - 73 -
5.43 MIN Alternative2A. This optionrequires that all electricity and processheat be generatedwith wood residues,and that the diesel generatorsbe maintainedonly for emergencyback-up power. It is difficultto designa systemthat can operateefficiently throughout the load profilebecause of the wide variationbetween the base, intermediate and peak power loads at Mim (see Figure5.4). The least cost solution from an equipmentstandpoint would call for one singlecondensing TG set rated at 2.4 to 2.6 MU to handlethe net 2.2 MW peak demand. However, operatinga large turbineat below ratedcapacity a majorityof the time would incur serious operatingefficiency penalties. Prom an energy efficiencystandpoint, the designwould dictateselecting two or three smallerTG sets with the possibilityof one or two being back-pressure turbinesexhausting steam for use in the veneerdriers, kilns and vats. The final design of the systemwould need to be based on a careful evaluationof turbinecosts and efficiencycurves and the availability and opportunitycosts of the input fuel (i.e.,wood residues). For purposesof this analysis,the 2 turbinearrangement is chosento derive a conservativecosting and to allow maximumkWh productionper tonne of residues. Full condensing capabilityis provided for efficiency purposes,but turbinebleeds are providedto satisfykiln needs for low pressuresteam At the final design stages the possibilityof one condensingand one back-pressureturbine would be evaluatedbefore making finalhardware choices.
5.44 Another issue that has to be addressedat the final design stages is whetheror not a sufficientwater supplyis availableduring the dry seasonto allow the use of water cooledcondensers even with a coolingtower. It is estimatedthat a 2.4 MS plant with condenserand mechnicaldraft coolingtower will requireup to 1000 1/min of water to satisfyall plant needs at full load. It is possiblethat an air cooled condenseris the best choicefor this site with an operatingpenalty of increasingthe turbineexhaust pressure by 3.4 kPa (1 in. Hg Abs) to a value of about 13.5 kPa (4 in. Hg Abs). The financialimpact is not clear at this time as the river supplyis at least 1 km away and the potentialneed for additionalpiping and pumpingcapacity will impactany cost analysis. It is assumedthat the five monthdry seasonhas a severe impacton water availabilitysuch that the air-cooledcondenser is chosen for this analysisas the safe choice.
5.45 For this option,a new 24.5 tonne per hour, 23 kg/cm2 gauge, 3250C wood/wood-wasteburning boiler is required to supplementthe existinghigh pressureSillar & Jamartboiler. A 24.5 tonne per hour boiler is requireddue to the relativelylow steam temperature(325'C) being used in the power cycle. Dependingon the efficiencyof the turbinescommercially available, the steam rate per kWh could be higher than that used in this analysis(i.e. greater than 9.6 kg steam per kWh) and an even largerboiler could be required. In this schemethe Kewanee low pressureboiler is not neededand shouldbe sold to recoveras much capitalas possible. The higherpressure boilers would supplysteam to the turbineat a minimumrate of 9.6 kg steam per kWh. The total boiler capacityrequired is based on bleed steambeing unavailableat all times - 74 -
and the boilersbeing capable of supplyingall kiln, vat, and dryer steam needs. The kilns and vats would normallybe suppliedby turbinebleeds and supplementedby boiler steam only on an as-neededbasis. All condensatewould be collectedfor returnto the boilerfeed water system.
5.46 A new reinforcedconcrete or othersuitable type buildingwould be providedas an extensionto the existingboiler house. It is proposed to providea simplemechanized fuel feed systemconsisting of a small front-end loader, a screen, a hogger and storage bin, and robust conveyorsto feed the furnace. Oversizematerial wouid be rejectedand would requiremanual size reductionbefore being re-fed. Fuel storage would consistof an enclosedpart of the new buildingwhere the front-end loader could operate. A schematicdiagram of this alternativeis presentedin Figure5.6.
Figure5.6: MIM TIMBERSLTD. - SCHEMATICALTERNATIVE 2A
NeW NoH p4*l3 F a a t (23k*%Ws'ug3)5 (23 3,a~.s2 l6.0t/h(24.5t/h) 4.4t/hj(6.St/h)
13.3t/h 1400kW 0 t/h designbase " (20.9t/h) (2200kW)
VheWuovp *2.7tih(S.Zt")2 KiIfl *).2Vbh(.4tAl)
______teamiungVs"U*2vh(lStA* *Z.IUh 3.Z tPh Tomg 44 th(6.9 UN'
~~1~~IL~COt4VSA?UII 4TM "rEegattum
*AVW8g (~4a"VW) .
5.47 This optionwould not requirethe continuedoperation of the existing diesel generators except in an emergency. Therefore, synchronizinggear has not been includedin the cost estimates. The wood-firedplant would produce6.01 millionkWh per year net to users, and 34,,000t/yr of steam supplyto the kilns,vats, and veneer dryer. This will requireup to 38,800tonnes per year of wood residuesat an averagemcwb of 34 percent. Parasiticpower requirementsare estimated at 10 percent of gross output and lossesat 8 percent. The annual - 75-
capacityutilization factor for the plantwould be about 31 percentwith an assumedplant avai.abilityof 88 percent(*6 weeks per year with 3 weeks of scheduleddown time and 3 weeks of unscheduleddown time). The 31 percentutilization factor is low primarilydue to the large capacity required(1.4 MW above intermediateload) to cover a peak demand that accountsfor only 13 percentof the totalpower produced.11/
5.48 MIM Alternative3A. This optionrequires that wood be used to produceall of the power needed to satisfythe base and intarmediate loads,and that peakingbe suppliedby the existingdiesels. As the base load plus intermediateload resultsin a maximumdemand of 1 NW, a 1.2 MW condensingTG set is proposedwith a turbinebleed providedto supply kiln and vat steam. As an optionfor finaldesign, the efficiencycurves for two 600 MY turbinesand one 1200 kW turbineshould be comparedusing load demandprofiles to find the optimumsolution. Also for final design purposes,the possibilityof a back-pressureturbine wiLh only partial capacityfor condensingsupplemented by the condensingability of the kilnsand vats shouldbe evaluated.
5.49 In this option,a new 13 tonne per hour boileris requiredat the steam conditionsof the existingSillar & Jamartboiler. The new boiler capacityis determinedassuming a steam rate per kWh at 9.6 kg plus 10.1 tonnesper hour capacityneeded fur processsteam. The boiler size might have to be increaseddepending on the actual steam rates commerciallyavailable for boilersin this size.
5.50 Followingthe same designdirection as in Alternative2A, an air cooledcondenser is selectedto help reducethe water consumption.A 1.2 NM plant using a condenserand cooling tower would require 500 1/min. The existinglow pressureKewanee boiler is not neededin this optionand its sale is recommended.Similar boiler house additions, wood fuel storage,processing and feed systemsare requiredas specifiedfor Alternative2A, but scaleddown to matchplant capacities.A schematic diagramof this alternativeis presentedin Figure5.7.
11/ If this plant were connectedto the grid and the grid could accept the excess capacityduring non-peak hours, the plant could supply 9.50 millionkWh per year to the grid based on an 881 availability factorand a 10 hour per day non-peakperiod plus two days per week when the mill is shutdown. As a power plant at this size can produce up to 400 kWh per tonne of wood fuel at 34t mcwb, an additional23,750 tonnes per year, at a minimum,of wood fuel would be requiredfor a total annual waste wood require,antof up to 62,550 tonnes. This is approximately23,000 tonnes more than the totalresidues produced at KIM. - 76 -
Figure5.7: MIM TIMBERSLTD. - SCHEMATIC-ALTE*MATIVE3A
fEdWWIS PIS5MrASLA JOMAA likelwmqnn (nkW PLM 10.Ot/h (13.lt/h) 4.4t/ (6.5t/h)
7.3t/h 770kW 0 th designb (9.5/h) (1000kV) is _ 'Wreyw 0.5 IWm VT w Ouw *?tAV * I2%ZE"iln *)*th (S.4 VAW P1N
t~F tml . TOW .44 h (6.95t
Se,*Avvgp 9*w (fUimw.j eret - e
5.51 In this option,the powerplant would supplyup to 5.25 million kWh per year net to users satisfyingthe base and intermediateloads. The dieselrequirement would be for 1.2 MW of capacitybut would produce only 833,000kWh per yes, peakingload. Additionaldiesel serviceof 617,000kWh for scheduledand non-scheduledsteam plant outagescan be predicted. Synchronizinggear is includedin the plant costingto allow paralleloperations, although the optionof operatingisolated equipment should be reviewed. The estimatedcombined availability/utilization factor for the steam plant is about 50 percentassuming 10 percent parasiticrequirement and 8 percentlosses. The estimatedwood residue requirementfor this optionis estimatedto be 35,000tonnes per year at 34 percentmcwb. - 77 -
5.52 MIM A'ternative4A. In this option,a new 3.8 tonne per hour 12/, 23 kg/cp, 325C wood-firedboiler along with a back-pressure turbinewould be provided. The existingSillar & Jamartboiler would also be retained. The system would allow for only back-pressure turbogenerationof up to 440 kW of electricityand enable the turbine exhaustto satisfythe low pressureprocess heat loads of the kilnsand vats. The veneerdryer load would be satisfiedby boiler steam. The steam rate for the turbinewould be about 16.4 kg per kWh. Given steam requirementsin the plant,it is estimatedthat the cogenerationsystem would generatepower at an averageof 270 kW with an availabilityfactor of 88 percent. Thus, total electricitygenerated would equal 2.09 millionkWh per year.
5.53 A new reinforcedconcrete, or suitablesubstitute, building to house the new equipmentis requiredas an extensionto the existing boilerhouse. It is proposedto hand-firethe new boilerto minimizethe overallcost and to utilizethe low cost labor available. A schematic diagramof this proposedalternative is shown in Figure5.8.
Figure 5.8: MIM TIMBERS LTD. - SCHEMATIC- ALTERNATIVE4A
3.2t/h(3.6t/h) 3.7t/h (6.5tih)
4.4t/h 270kW (6.9t/h)l 0.2t/h (2.7t/h) (423kW)
Vmw Ow *LltA0blO 33D*tKilns cown~~~~~~~o ma co'oes.salI______~, StesosmfiVON 2t1(.SA.1f tO OqJg ToWl **.7t270Zt Toa *4.4 tAh(4t9
w m"umS)-to TO OAtS
12/ A 3.8 tonne per hour boilerwith superheatand high steampressure might not be co_merciallyavailable. A 4 to 6 tonne per hour unit might be the only commercialoption, hence the expensewill be high for the capacityneeded. - 78 -
5.54 This option would require the continuedoperation of the existingdiesel generators to providethe balanceof power requirements until connectionof the mill to the grid. The boilerwould consumeup to 19,000 tonnesof wood it 34 percentmcwb. Dieselgeneration initially and grid electricityeventually would be requiredfor 4.61 millionkWh per year. Synchronizinggear is includedto allow paralleloperation, althoughisolating systems must be evaluatedas an alternative.
5.55 HIM Alternative5A!5B. This 1.2 MW optionis technicallythe same as Alternative#3A, exceptthat the grid extensionis assumedto be undertakenand power can be fed in both -. ctions(i.e. MIM can feed the grid surpluspower during the non-peak10 hours per day). The capital cost for the steam plant will remainthe same as in case 03A at US43.06 million for the 1.2 MW condensingsteam turbine-generatorset, new boiler,building and appropriateauxiliaries. In this case, the single turbineoption is definitelythe least cost solutionand most efficient route becausethe power plant is assumedto operateat a constantoutput of 1.0 MW.
5.56 It can be assumedthat the ne% wood-firedsteam power system could supply up to 5.25 millionkWh per year to satisfymost of the complex'sbase and intermediateload. The additional617,000 kWh per year neededdue to scheduledand unscheduledpower plantoutages would be provided by the grid along with an additional833,000 kWh per year requiredfor peaking. The totalof 1.45 millionkWh coverspeaking plus acLeduledand non-scheduledoutages of the wood steam plant. Assuming the power plantoperates at full capacity(net output of 1.0 MW) 24 hours per day, 7 days a week, 46 weeks per year, then the total outputof the plant would be 7.73 GWh/yr. Thus,2.48 GWh/yrwill be availablefor sale back to the grid. Accountingfor the 1.45 GWh/yrpurchased from the grid for peakingrequirements and power plant outagesresults in a net supply to the grid of 1.03 GWh/yr.
5.57 At a 34 percentmcwb, wood fuels in a steamplant of 1.2 MW can producebetween 350 and 385 kWh per tonne of fuel. Thus, to providethe additional2.48 millionkWh to the grid will requirean additional7,100 tonnesof wood (basedon 350 kWh/t). As the plant will requireup to 33,000 tonnes for its ewn annualneeds, the additionalgent:ation for grid feedbackwill increasethe total annualfuel wood needs to about 40,000 tonnesper year, which is slightlygreater than the total wood residuesgenerated at the mill. Approximately1,000 tonnes/yrof readily availablelogging residues would have to be hauled to the plant from forestareas about 100 milesaway.
5.58 Costs. Estimatedfinancial capital and annualoperating costs are presentedin Table 5.16 for the base case and each of the MIM cogenerationalternatives that were analyzed. Component-levelcostings are contained in Annex 7. Capital requirementsfor the various cogenerationalternatives range from US$1.6to 5.2 million. The capital costs do not includecosts of addingkiln or steamingvat capacityor any other costs not directlyrelated to the electricityand processheat generatingplants. Table 5.16: SUWSAYOF CAPITAL AM AMiAL OPERTIsB COSTS FOtRWIN COIENZMTION ALTERIUUTIVES(0000 US$)
3SK OMSECASE A ALTERNATIVEIAASf CAi- B ALTSATIVE 0A ALTERIATIVE 3A ALTERATIVE 4A ALTERNATIVE Local Foreign Local Foreign Local foreign Local Foreign Local Foreign Local Foreign Costs Total Costs Costs Total Item costs Costs Totel Costs Costs Total Costs Costs Total Costs Costs Total Costs
Capital Costs 66.0 17.0 83.0 82.0 20.0 102.0 o Construction 27.0 7.0 34.0 27.0 7.0 34.0 101.0 25.0 126.0 82.0 20.0 102.0 1425.0 - 790.0 710.0 -- 1425.0 1425.0 o Equipment - 385.0 365.0 -- 385.0 38.0 - 2420.0 2420.0 - 1425.0 o Tranort .7 278.9 78.0 76.6 154.6 140.7 138.2 278.9 Chrge 8 38.0 37.4 75.5 38.0 37.4 75.5 238.9 234.7 473.6 1138.2 o Engilneering. festal lotion 631.9 484.3 767.7 t5.O & Contingencies155.0 264.0 419.0 155.0 264.0 419.0 830.4 1337.2 2167.6 484.3 76?.7 1252.0 212.4 419.5
Total Capital 1659.5 3057.9 Costs 913.5 913.5 5187.2 3057.9
Differentialfre .746.0 +2144.4 ase Case 0.00 +4273.7 +2144.4
Annual Operating Costs 9.5 - 9.5 o Labor 12.2 1-2.2 8.6 - 8.6 10.5 - 10.5 12.2 - 12.2 9.5 - 9.5 - 159.5 - 159.5 -35.6 -35.6 oPo b/ - - - 231.8 231.8 - - _- 173.8 25.0 - 25.0 53.0 53.0 o 0 A W 75.3 304.2 c/ 379.5 15.0 - 15.0 87.2 18.0 105.2 66.1 107.7 - 25.0 25.0 29.4 63.0 92.4 o Constsbles - 461.3 d/ 461.3 -- 15.0 15.0 29.4 127.0 156.4 14.4 149.6 164.0 - - 21.9 - - 11.9 O Contingancles - - 85.3 - 27.1 - - 27.2 -- - 35.0
Total Annual 240.9 131.2 OperatIng Costs 938.3 297.5 299.3 385.0
Oltfewnttsl fro -697.4-- -807.1 Dfe crt f ------439.0- -553.3 - -
DIncludes International freight and lnurance local port cbrge and bank fee. / Includes costs for grid pr purchas. S/ Includes anal costs for reptceat of dil gerator capaity. d/ includes annui cests for dIesol fuel. - 80 -
5.59 Financial/EconomicEvaluation of Mim Alternatives.Selection of the most economicallydesirable NIM alternativemay be dependenton whether grid extensionis considereda real resourcecost or a sunk cost. In order to provide investmentguidance relevantunder both assumptions,the followingdecision-making procedure is adopted:
(a) Evaluateall alternativesunder the assumptionthat the grid extensionhas not beenmade and thereforeis not a sunk cost.
(b) Choosethe best alternative.
(c) If the alternativeselected in (b) does not involve grid extension,then recommendthis alternative.
(d) Otherwise,re-evaluate the optionsunder the assumptionthat the grid extensionis a sunk cost and recommendinvestment in the best alternative.
5.60 Cost MinimizationUnder Assumptionof No Grid Extension. Each of the MIM alternativesis designedto providethe same levelof service to the Mim areat (a) Meet the processheat demand for the steam vats, veneerdryer and 32 kilns to be in place withintwo years;and (b Meet the electricpower and energydemands of the upgradedsawmill facility, ScanstyleLtd. and the surroundingcommunity of 2.2 MW peak and 6.7 GWh/yr. Since benefits have been equalized,a net present cost minimizationprocedure was employedto rank alternativesfor study in greaterdetail. The net presentvalue of each alternative,considering only the cost side, was computedas shown in Annex 7 using baseline assumptionsover a 15 year projectlife at a 10 percentdiscount rate. Crid extension costs incurred in Alternatives1A, 4A and 5A were annualizedover a 40 year lifetime. All financialNPV calculations assume that the grid extensioncosts are not borne by MIM. Resultsof this comparisionare shown in Table 5.17.
5.61 As expected, grid extension (Alternative1A) is clearly preferableto total dieselgeneration (Base Case A) from both financial and economicviewpoints. Given averageindustrial tariff levels of about 3.5 US cents/kWh grid extension is also the least-costamong all alternativesconsilered financially. However, the economicperspective is the more relevaatone for nationalplanning purposes, especially since MIM is state-ownei. Alternative3A, a residue-firedbase/intermediate load unit with diesel peaking,is the least-costoption when economic pricingis applied. Alternative2A is costlybecause of the poor load factor achieved by the peaking wood-firedturbogenerator, while the comparisonwith Alternative5A impliesthat dieselsare a cheapersource of peakingpower than the grid extension. - 81 -
Table5,17: I'T PRESENTOOST OF MINALTERNATIVES WITHNO GRID EXTENSION ASSUIIED
Not Present Cost ('000USS) AIternati"e Financial Economic
Base CaseA 8,051 7,318
IA 3,176 6,486
2A 7,463 7,387
3A 5,986 5,928
4A 3,492 6,471
SA 4,056 6,365
5.62 Alternative3A Vs. 1A MarginalCost Analysis. A marginalcost analysiswas performedby subtractingthe costs of AlternativeIA from 3A. The avoidedgrid extensionand grid electricitycosts then become economicbenefits of the incrementalinvestment in Alternative3A over and above processheat requirements.Details of th- marginalanalysis are found in Annex 7 and suanarizedin Table 5.18.
Table5.18: INIALTERNATIVE 3A VS. IA FINANCIALAND ECONOMIC ANALYSIS RESULTS
FInancial Economic
Not Present Value $(2,965,760) S293,180
IRR Undef. 12S
Discounted PaybackTime 12 years
CapItal Oost Switching Value > -100% *14%
DraskevenGrid Electricity Price US 9.3 cents/Wh US 4.6 cents/kWh
5.63 Interpretationof the resultsis straightforwardexcept for the case of the breakevenvalues. They representthe marginal cost of electricitygenerated in Alternative3A when avoidedgrid extensioncosts - 82 -
are taken into account. In the financialcase, the tariffcharged at MIM for grid electricitywould have to rise from the eCC tarifffigure of US 3.5 cents/kWhto US 9.3 cents/hihfor KIM to realizea savings from Alternative3A. MIM does not "see" the grid extensioncosts of US 3.6 cents/kWh. In the economicevaluation, the effectivecost of electricity at KIM is US 4.6 cents/kWh,cheaper than the estimatedgrid hydropower generationcost of US 5.2 cents/kWh.However, the investmentof US$2.14 millionto obtainthis savingsyields a economicrate of returnof only 12 percent. This returnis not sufficientto compensatefor the risk and additionalmanagement burden of the wood/dieselhybrid. Grid extension is thereforerecommended.
5.64 The effect of demand growth in the Mim area has not been quantifiedin this simplifiedanalysis. It is expectedthat growthin energydem&ad in the shortrun will be for nighttimecommunity uses. The increasedenergy consumptioncould be accomodatedat very low marginal costs simplyby burningmore residuesin the cogenerationsystem during off-peakhours. In the longerterm, however, it can be expectedthat (a) on-site residue availabilitywill become a constraint as total electricityconsumption increases to 20 percentabove the 6.7 GWh/yr figureused in the baselineanalysis, and (b) growthin demandwill occur duringthe on-peakhours when the sawmillis operatingwhich nust be met by high-costdiesel generation. At the same time, demandgrowth lowers the unit costs of the grid extension. The long term picture thus supportsthe grid extensionrecommendation.
5.65 Cost MinimizationUnder Assumptionof Grid Extension. If the grid is consideredto be extended(i.e. a sunk cost)Alternatives 2 and 3 can be immediatelydismissed as peakingpower requirementscan be most economicallyhandled by the grid. On the basisof the cost minimization results in paragraph5.60, Alternatives4 and 5 are comparablein economic attractiveness. Alternative5 was selected for closer examinationas it offers the potentialfor greaterrtsidue utilization and on-siteelectricity production.
5.66 Alternative5B vs. Base Case B harginalCost Analysis. A marginalcost analysiswas performedby subtractingthe costs of Base Case B from Alternative5B. Costs includethe opportunityvalues of the charcoaland firewoodbeing consumedin the cogenerationsystem. In addition,for maximumpower productionapproximately 1,000 tonnes/yrof loggingresidues would have to be hauledfrom the forestat a cost of about US$10/tonne. Benefitsare the avoidedcosts of grid electricity plus amounts sold back to the grid due to on-site generation.13/ Detailsof the marginalanalysis are found in Annex 7 and summarizedin Table5.19.
13/ Electricitysold to the grid is assumedto have the same financial and economicvalue as that purchasedfrom the grid. - 83 -
5.67 The resuits show that the economiccost of the electricity produced is approximatelythe same or slightly higher than hydro generatedpower. An optimizedsystam in which residue consumption exactlymatched on-site residue availability could shave 10-20mills off these costs, an insignificantquantity at this level of investment consideration. Financialincentives for investmentby Mim would not exist unless the cost of the marginalinvestment were to drop by 49 percentor the electricitytariff to MIM were raisedby 60 percent.
Table 5.19: MIN ALTERNATIVE5B VS. BASE CASE B FilNANCIAIAND ECONOMICANALYSIS RESULTS
Financial Econ=mIc
NetPresent Value S(139,310) S(24,270)
lRR os 8S
DiscountedPayback Time
Capital Cost SwitchingValue -49t -9S
MarginalCost of US 5.6 cents/kwh US 5.8 cents/Kwh ElectricityGenerated
ResidueHandling and CombustionEfficiency Improvements
Background
5.68 The Missionnoted a numberof low-costimprovements to residue handling,storage and utilisationsystems which, if implemented,could significantlyincrease the energyvalue of the residues. In particular, sawdustis greatlyunderutilised as an on-siteenergy fuel, accounting for only 7 percent of mill process heat-raisingdue to introduced moistureand inabilityto properlycombust in commonlyfound mill boiler furnaces. Substitutionof surplussawdust for solid residuesin mill boilerswould free up slabs,edgings and offcutsfor alternativeenergy and non-energyuses, creatingadditional value. SufficientsuXplus sawdustexists to potentiallyreplace virtually all of the 58,900a' SUE of solidresidues burned for mill processheat/cogeneration.
5.69 Whilecosts for these improvementsare comparativelysmall, the motivationfor theirimplementation will be primarilyfelt at millswhere increasingprocess heat or cogenerationneeds result in a tighteningin the total residue supply/demandbalance. Detailed costings and cost/benefitcomparisons have thereforenot been carried out for the - 84 -
individualimprovements. Rather, their costs have been factoredinto the overall investmentrequirements of the variousprocess heat generation and cogenerationschemes reviewed above, and in certainof the off-site substitutionoptions evaluated in Chapter6. Saw Guide and SawdustStorage Improvements
5.70 Dramaticimprovements to saw guidesover the last fifteenyears have permittedmany benefitsto accrueto the sawmillingindustry. These includereductions in saw kerf, improvedsawing accuracy and improved smoothnessof sawn surfaces,all of which lead to increasedlumber recovery. Spin-offadvantages of the above are reductionsin sawdust volumesgenerated, and the productionof finer and drier sawdust. These spin-offsease sawdustconveying problems and improveits qualityas a fuel or as a feedstockfor briquettingplants.
5.71 Low Volume Water Application. Reductionsin the amount of waterutilized to lubricatesaws with existingsaw guidescan be obtained throughsimple measures to controlthe volumesand to apply it to the saws efficiently.The simplestand leastcostly method of the above is to introducethe saw waterdirectly and accuratelyonto the saw via spray nozzlesand to turn off this water when the blade is not in the cut. Dependingon water qualityit may be necessaryto introducefilters to clean the water suppliedso that it does not plug the nozzles. Such sprays could be added for less than US$50 per bandmillor circular headriginstallation (or aboutUS$100 if filtrationis necessary).
5.72 The best methodto reducewater consumptionis to introduceit into a milledgroove located within the saw guide. This methoddeposits a film of water directlyon the saw blade which is to be preferredto sprayingor splashingit onto the bladewhich allows most of the water to bounce off the surface. The costs to converta 3,300 m bandmillto quick-changeguides would be approximatelyUS$2,700 for completeguide assembliesand would requiretwo man-dayslocal labor to perform the field installation.A guide resurfacingmachizc costs about US$700. An exampleof such guidesis shownin Annex8.
5.73 Also included in Annex 8 are sketches from U.S. Patent 3,623,520for circularand bandsawguide apparatus which clearlyshow the methodologyof introducingwater to the guides. This informationis useful to anyone consideringconverting his own equipment. Typical sellingprice for guide arms for circularedgers for sawingwood up to 300 m thick is about US$370 each. Two guide arms are requiredper saw. Maintenanceequipment consistingof a babbit melting pot (electric),moulds and a guide surfacingmachine with jigs would cost aboutUS$1,100. It is estimatedthat this equipmentcould be producedin Ghanaat 25 percentof the U.S. costs.
5.74 ADO Application. Alternatively,diesel oil (ADO) can be applied to blade surfaces using a felt oil applicator. One such installationobserved at WesternTimbers Ltd. utilizedlocally devised - 85 -
bandsawguides made of Ekki wood, a very dense secondaryspecie. ADO consumptionwas reportedas 0.5 Igal/day. Hlowever,ADO applicationmay staincertain whitewoods.
5.75 SawdustStorage Improvements, Of course,sawguide improvements are uselessas an energy enhancingmeasure if excessivewater is re- introducedinto sawdustthrough exposure to the elements. The obvious remedy is to constructi,mple shalters to preventrainwater from soaking the residue&.
FurnaceModifications for SawdustCombustion
5.76 Un-wetted,fine-grained sawdust is a readilycombustible fuel providedthe propertype of furnacegrate and combustionair circulation systemsare employed. As most sawmillfurnaces currently found in Ghana are primarilydesigned to burn solid fuels,modifications are required for sawdustsubstitution. Both the extentof the requiredretrofits and specific and depend on the installed equipment base. General requirementscomprise:
(a) Installation of pin-hole (in small furnaces) or inclined/steppedgrates for propercombustion support. Use of solidfuel grates,such as bar or large-holetypes, result in a large portion of the sawdust falling unburned through the grate.
(b) Increasein forced/induceddraft airflowto providefor sawdust suspension.In some cases,an increasein fan size/horsepower will be sufficient. Other installationswill require re- workingof the ductingand air circulation.
Given relativelylow labor cc-ts,manual systemsfor sawdustfeed into the furnaceare appropriatefor all but the largestinstallations.
Boiler/FurnaceEfficiency Improvements
5.77 Measuresto improveoverall efficiency of wood combustionare also very site-specific,however, several generic suggestionsare warranted. For any firewoodburning installation, the greatestproblem is overstokingof the furnaceso that the boilerattendants do not have to add wood so often. This resultsin great fuel/airimbalances such that incompletecombustion produces many gaseous unburnedhydrocarbon products(with significant calorific value) that are blown ou. the stack and lost. The remedylies in both operatortraining and properboiler attendant supervision. Efficienciescan be doubled, and sometimes tripled,by learningand implementingproper stoking techniques.
5.78 The secondmajor correctableproblem is excessair infiltration through missing fire doors, doors that are installedbut left open, broken or missingair controldampers, and missinggaskets, unpatched cracks,etc. Theseare all easilycorrectable and produceat least 25-30 percentsavings with minimalinvestment. - 86 -
VI. POTSWTIALOFF-SITS FLURIYTIVRSFORINPROVING AND/Ot IUGRISIUnGTuB u OVODOEF IUDUSTRYRESIDUES AS FMUL
Summary
6.1 Off-siteoptions for utilizationof residueswere extensively evaluatedby the Nissioj. Of the total mill residuesproduced in 1986, 29 percentor 124,000m /yr was used off-sitefor firewoodor to produce charcoal and about 2,800 m of sawdust was processed into fuel briquettes.At present,most of the solidresidues are utilizedfor food preperationin bakeries,chop bars and householdswhile the sawdust briquettesare used primarilyby co_mercialbakeries and more recentlyin bricknakingkilns. As was pointedout in Chapter3, sawdustis the only residue in significant surplus for increasing off-site residue utilization. The primary technical option for off-site direct utilization is modificationof existing oil-fired or wood-fired industrial/conercial combustionsystems to utilizethe surplussawdust.
6.2 At present,the majorityof off-siteresidue utilization is accomplishedonly after conversionprimarily of the solid residuesto charcoaland, more recently,small quantitiesof sawdustto briquettes. Within this context,three possibletechnical options exist to improve and/orincrease the indirectoff-site use of mill residues:
(a) Improvedcharcoal production techniques;
(b) Increasedsawdust briquetting capacity; and
(c) Introductionof briquettecarbonization techniques.
6.3 A sumary matrix of the technicallyfeasible options for improvingand/or increasingthe off-siteuse of wood residuesand their potentialimpacts is presentedin Table 6.1. The sawdustbriquetting option technicallyhas the best potentialfor increasingthe use of presentlysurplus residues. Improvedcharcoal making could increasethe supply of residue-derivedcharcoal ',)y over 80 percent. Very little potentialexists for increasingthe directutilization of surplussawdust residuesprimarily because of technicaland economicconstraints. Brief descriptionsof the key technicallyfeasible options are presentedin tnis chapter alongwith schematicdiagrams, equipment and operatingcost estimates and financial/economicanalyses. The alternativesare developedbased on actualsites and conditionsobserved during the field work rather than on generic plants based on average conditionsin Ghana. The selectionof actual sites makes the analysispotentially useful. However, the results must be carefullyevaluated if the conclusionsare to be generalizedacross the sector. Table 6.1: MATRIXOF TECHNICALOPtIONS FOR IWtIN6 AjR INZASINB OFF-SITERESIWE UTILIZATION
Impact on Residues Ottions Prlmary Tara.ts Utilizatlon Requirement anef Its
Direct Utilization
Conversion of Commercial/industrial Increased off-site demand Technical assistance and Savings from costs of Imported existing ol1-fired boilers In the vicinity for unprocessed residues, capital for conversion of fuels or highcost solid wood- Industrlal/comercIaiof the majorwood especially sawdust, oil-fired combustion fuels, boilers, processing centers, equipment.
Conversion
Improved charcoal Independent charcoal Increased charcoal supply Capital for Improved Increased efficiency and production, makers using earth/ from converted solid charcoal making system, productIvity ia charcoal making, sawdust moundcher- residues, technical assistance Improvedand more consistent coalingtechnique, and training, charcoal quallty, increased revenues to charcoal makers.
Sawdust briquetting Production from sur- Dmand for sawdust which Capital for construction Beneficial use for presently plus sawdust available Is presently only residue and operation of briquet- discarded restaues. Revenues at the wood processing In abundant surplus. ting factorles and to briquette producers and centers adjacent to assistance for expansion reduced disposal costs Industrial and urban of briquette market. to mills. Potential for centers, prlmartly economic use of residues Kumasi,Takoradi and in distant markets. Increased Akim Oda. combustion efficiencyf when comparedto wet sawdust.
Briquette Product) n from sur- Demandfor sawdustwhich Same as above Including Samers above Including higher carbonization plus sawdust to Is presently only residue additional capital for value for charcoal. provide an additional In abundant supply. construction and operat- supply source of char- Ionof a briquette coal for the domestic carbonization process, sector. - 88 -
Off-SiteDirect Utilization
BackRround
6.4 Off-site opportunitiesfor direct residue utilizationwere consideredby the Mission in the industrial,commerical and household sectorsof the economy. Of the total residuesutilized off-site, about 30 percentis used directlyas firewoodprimarily for food preparationin the commercialand householdsectors. Hardly any mill residuesare presentlyutilized directly in the industrialsector for processheat. The Missionvisited twenty non-wood processing industries in the Kumasi, Accra/Tema,Takoradi, Prestea and Cape Coast areas covering food, beverage and agricultural product processing, brick and tile manufacturing, paper recycling, textiles, golo refining, and institutionalservices. These industriescan be dividedin to two main categoriesaccording to their present fuel use: oil consumersand fuelwoodconsumers. A list of the industriesand institutionsvisited and the type of fuel they presentlyuse is shown in Table 6.2. Detailed informationon theirpattern of fuel useageis containedin Annex 9.
Substitutionof Sawdustfor Oil Fuels Consumption
6.5 Industries that presently utilize oil fuels for steam generationor directheat are generallynot readilyadaptable to direct firingof sawdustor solid residues. In all cases examined,the costs for modificationsand additionalequipment required would not justifythe savingsrealized from substitutingfor petroleumfuels, primarily due to the small scale,low utilizationfactors and type of equipmentbeing used in Chanianindustries. In addition,the currentlow financialprice of US$101 per tonne of fuel oil and economicprice of US$76 per tonne (Accra/TemaFOB export value) makes competitionwith oil firing difficult. Engineeringdesigns and costingsfor conversionat three sites are discussedin Annex 10.
Financialand EconomicAnalysis
6.6 Detailedfinancial and economicanalyses may be found in Annex 10. None of the fuel oil substitutionprojects studied were viablefrom either analysisviewpoint. Resultsof DCP analysesat three sites are summarizedin Tables6.3 and 6.4. Calculatedbreakeven values indicate that oil priceswould have to rise above US$30/barrel(in 1986 dollars) for these peojectsto show positivereturns. - 89 -
Table 6.2: INiSTRIES ANDINSTITUTIONS VISITED TO EVALUATE POTENTIALFOR DIRECT UTILIZATION OF WOODRESIDUE
Facility Location Fuel Used
Kumasi Breweries Ltd. Kumasi RFO
Gulness GhanaLtd. Kumasi Elec,ORF0
Komfo AnokyeTeaching Hospital AL
Appiah MenkaComplex Ltd, Kumasi Wood
Ashanti Ol MillsLtd. Kuasi Wood/PalmWaste
Cocoa Processing CompanyLtd. (WAN) Takoradi IFO
Cocoa Processing CompanyLtd. (CPC) Takoradi ADO
GI0OCPaper Conversion Co. Ltd. Takoradi Paper Waste/ADO cermic CoordetroGhana Ltd. Taiorad a/
Prestea Goldfields Ltd. Prestea Wood
Lever Brothers GhanaLtd. Teme FO
FoodSpecialities GhanaLtd. Toem IBO
GhanaToxtiles Manufacturing Co. Tmeo IFO
TomeTextiles Ltd. Tema IFO
GIHOCBrick & TileLtd. Acca iDOhlood
Ankaful Brick Ltd. Cape Coast Wood/Briquettes oa Plant under constructIon. Information on fuel use could not be obtained. - 90 -
Table 6.3: FINANCIALANALYSIS RESULTS, OIL TOSAWDUST-FIRED BOILER CoNVERSION
kPV I RR coapital Cost SwitchingValue Site (S) (5) (5)
Kumsl BreweriesLtd. (1,023,120) Undef. -62
CocosProcessing Co. Ltd. (WAN) (432,890) Undef. -41
LeverBros. Ghana Ltd. (2,297,340) Undef. -98
Source: Annex 10.
Table6.4 ECONOMICANALYSIS RESULTS, OIL TO SAWDUST-FIREDBOILER CONVERSION
Capital Cost site NPV IRR SwitchingValue (S) (S) (5)
KumaslBrewerIes Ltd. (1,143,000) Undof. -72
CocooProcessing Co. Ltd. (VAN) (491,870) Undef. -44
LeverBros. Ghana Ltd. (3,628,330) Undef. -100
Source: Annex10.
Substitutionof Sawdustfor PuelwoodConsumption
6.7 Industriesand comercialoperations that currentlyuse forest- dervied fuelwood could utilize the solid residues from the wood processingindustries if thesewere available. However,most are unable to use the sawdust directlywhich is the residue that is primarily availablein surplus. Many of thesecandidates, especially the bakeries, brick factories and fish smokers, could easily convert to using sawdustbriquettes. In fact, most would prefer the briquettesover fuelvood. A discussionof this aspect is presentedlater in this chapter.
6.8 Many of the wood consumingindustries visited had smallLambion type furnaceswhich couldbe converted,with someminor modifications,to directfiring of sawdust. However,the scaleof plantoperations in most cases was such that potentialwood savingswere generallynot sufficient - 91 -
to recover the capital investmentrequired to install the required furnace modificationsand sawdust handling bUd storage systems. A discussionof the technicaland economicparame;ers considered at some of the sitesvisited is presentedin Annex 11.
Financialand EconomicAnalysis
6.9 Financialand economicanalysis details for some of the more favorablesites are shown in Annex 11 and summarizedin Tables6.5 and 6.6. The AppiahMenkah Complex project is marginalfrom the investor's standpoint,while the conversionof the Prestea GoldfieldsLtd. ore roasteris a feasible,though small, undertaking. Neither entity faces the long-runcost of fuelwoodproduction, and thereforethe rates of return to these conversionsare boostedby about 20 percentagepoints when economicpricing is applied.
Table6,5: FINANCIALANALYSIS RESULTS, FIJELWOOO TO SAWDUST-FIlED BOILERCOWNERSION
CapItalCost Site NPV IRR SwitchingValue (5) (N) (5)
Applah-Nsnkahcomplex Ltd. 5,730 11 +5
Presteosoldflelds Ltd. 20,470 23 --
Source: Annex11.
Table6.6.: ECONOMICANALYSIS RESULTS, FUELNOOD TO SAWDUST-FIRED BOILERCONVERSION
CapitalCost SIte NPV IRR SwitchingValue (5) (N) (S)
Applah-MinkahComplex Ltd. 90,370 32 +92
PresteaGoldflelds LSt. 54,990 42 -
So_rce; Annex 11. - 92 -
Off-SiteConversion Alternatives
BackRround
6.10 A large portion of the the solid wood residuesthat are used off-site for energy is first converted to charcoal while all of the sawdust used for energy off-site is first converted to solid briquettes. Charcoal conversion is accomplished primarilyin traditional "earth mound" kilns operated by independentcharcoal makers working adjacentto or withina coupleof kilometersof the mills that supplythe residue. The conversionerf.ciency of most of these charcoaling operationswas found to be cxtroaelylow, in the range of 11 to 20 percent(charcoal yield on a dry weightbasis). The averageconversion efficiencyaround the Kumasi area is estimatedat approximately16 percent,based on estimatesof solid residuesconsumed and charcoal produced. Charcoalmaking techniquesare availablethat could inurease the conversionefficiency to 25 to 30 percent resultingin a near doublingof the charcoalsupplied from wood residuets.
6 11 The potentialsupply of surplussawdust is estimatedat 83,400 ;I SWE or 65,500tonnes. Over 60 percentof this surplusis locatedin the Kumasi area. As was indicatedearlier in this chapter,the use of unprocessedsawdust in the industrialsector is limiteddue to economic constraints.At presentonly about 2,800m 3 of sawdustis used off-site for energy,and the sawdustmust first be briquettedprior to acceptance by consumers. There is presentlyonly one briquettingplant in Ghana, locatedin Oda, and it is owned and operatedby a privateentrepreneur. This factoryhas a maximumcapacity of 2,200 t/yr but presentlyproduces at the rate of 1,100 t/yr. It is unableto meet the total demand for briquettesfrom the bakersand brickmakersalone which is estimatedat 45,000tJyr or equivalentto over 100 percentof the surplussawdust. 6.12 Given the above, two technicaloptions immediatelypresent themselvesfor furtherevaluation: improved charcoal making techniques, and increasedsawdust briquettingcapacity. In addition,the large demandand relativelyhigh price paid for charcoalmakes the possibility of converting sawdust to charcoal briquettes also potentially interesting. In fact, the possibilityis presentlybeing consideredby the owner of the Oda briquettingplant. This section briefly investigatesthese three optionsoutlining the technicalpossibilities, associated investment,operating costs and financial and economic returns. - 93 -
Improved Charcoal Production
Present Method
6.13 Earth Mound. Almost all charcoal produced from -sawmill residues in Ghana is produced by the traditional "earth mound" method although in most cases the top covering is actually sawdust. The main advantage of the mound system is that it requires no capital investment. The primary disadvantages are that earth mound kilns are hard to control, are susceptible to the elements and have generally very low yields with unpredictable charcoal quality.
6.14 Slabs, edgings and, in some cases, bouls are obtained from sawmills by independent charcoal makers who purchase the residues by the "trailer" or "tractor" load from middlemen. The size, shape and characteristics (moisture content, density, percent bark) of the mill residues vary considerably. In most cases, the charcoal makers simply horizontally stack the residues in an appropriately sized area which might be slightly depressed. Vo cutting, pre-drying or sorting of the residues is practiced and species are mixed indiscriminately. The mounds are generally rectangular in shape with the initial foundations of the stack built so as to permit some air flow under the stack. Thereafter, the wood is stacked as tightly as possible with the top of the mound sloped slightly, about 10 degrees. Once complete, the mound of stacked wood is then covered with dirt and sawdust. In some cases, green vegetation (normally grass), if availatle, is first placed over the stack prior to covering with the dirt and sawdust. The sawdust is also obtained from the nearby sawmills and is used because it is light, easy to shovel and is obtained for a small transport cost. However, the sawdust is not a good covering material because it is porous and allows air to infiltrate the mound causing local flare-ups which not only reduce charcoal production but could destroy the entire mound if unchecked. These flare-ups are extinguished either by covering the area with fresh sawdust or by dousing it with water and then covering it with sawdust. A sketch of a typical charcoal mound observed in Ghana is presented in Figure 6.1.
6.15 Total time per cycle of charcoal production varied from two weeks to a month for some of the larger mounds. In the case of the larger mounds, harvesting of charcoal begins as early as 10 days after ignition of the mound and continues for three more weeks. In such cases, the yield and quality of the charcoal vary ccasiderably with the progress of time. In all cases, the charcoal makers had to live at the site of their charcoal making operations. Most operations were family run with women and children involved in the various operations. - 94 -
Figure6.1s TYPICALMOUND CHARCOAL PRODUCTION
When dirt is used for the covering,then a mat of reedsare often used to keep the charcoalclean. ExhaustVents
Pile of wood
InletVents Inlet> Vents X t ^ *.''m ~~~~~~DirtCoveringor Sawdust
- Fire Starting Channel - 95 -
6.16 Observationsfrom the productionof residuecharcoal at three typicalsites in the Kumasi area is presentedin Table 6.7. Site #1 represens a smalloperation run primarilyby womenwho operateonly one mound at a time. Site #2 is a more typicalsmall family operation with two to threemounds in varyingstages of operation.Site #3 representsa relativelylarge operatorwith stockpilesof wood residuesbeing air dried prior to carbonization.This type of operatoris an exception ratherthan the rule. Not surprisingly,site #3 has the highestcharcoal yield per unit of wood input and the highestreturn to labor. Site #2, which is more typical,has a charcoalyield of 16 percentwith a labor productivityof 12.6 t/man-yr. Site #1 was strictlya "hand-to-mouth" operationwith the revenuesof the previouscharcoal operation required to financethe deliveryof the next batch of slabs and edgings,which when deliveredwere stackedfor charcoalingthus reducingthe time for air drying.In this case the charcoalyield was observedto be 11 percent on a dry basis. The technicalcharacteristics of the charcoalproduced at each of these sitesis presentedin Annex 12.
Table6.7: EARTH"FNM CHARCOALKILNS, KUMASI
Observation Site#1 Site_ 2 S;te#3
Input wood(m3) 10 46 58
Costof woodInput (Cedi) 4,500 22,000 21,300
Output charcoal (tonnes) 0.6 3.5 6.1
Yield, dry weight basis (S) a/ 11 16 20
Charcoal salesprice (Cedilkg) 8.3 11.4 6.7
Gross sales revenue (Cedi) 7,500 40,000 40,300
Grossprofit (Cedi) 3,000 18,000 19,000
LaborInput (man-days) 30 100 60
Returnto labor(CediMan-day) 100 180 317
Laborproductivity (t/man-year) 7.2 12.6 36.6
a/ Yieldscalculated based on 50SWawa/50 redwood Input wood mIx havingan averagedry density of 510kg/m 3. Source: Missionestimates. - 96 -
6.17 ProductionCosts. Total financialproduction costs at a typicalearth mound operationwere estimatedat 8.6 Cedis/kg(US$57.61) of charcoalproduced. A yieldof 16 percent(dry weight basis) and labor productivityof 17 tonnes of charcoal per man-year were used in determiningtypical productioncosts. The resultingestimates and underlyingassumptions used to derive the financial and economic productioncosts are presentedin Annex 13.
6.18 Marketing. Prices received by the charcoalmakers varied dependingupon the qualityof the charcoaland the locationrelative to the retailmarkets in town. A typicalmarketing pattern is detailedin Table 6.8. Charcoalis wholesaledin sacks weighingbetween 35 to 40 kg/sack. Final consumers apparentlymeasure purchase quantitiesin volumetricterms, as the less dense residue-derivedcharcoal sells for a 12 percent premiumon a weight basis over the heavier forest-derived charcoalfrom the high forest/savannahtransition zone.
Table6,8: MILL RESIDUECHARCOAL MARKETING, KUMASI
CedIAkg wholesaleprice 8.6 Transport to market 1.1 Retailer's margin 1.7 Retailprice 11.4 Source: Missionestimates,
ImprovedMethods
6.19 Options. The qualityof the charcoalrequired for domestic consumptionis generallynot extremelyhigh. Volatilecontents in the range of 20-30 percentare desirablein order to allow easy ignitionand some flammability(Earthscan). Given this criteria, carbonization temperaturesin the range of only 300 to 400 °C are requiredwith resultingtheoretical charcoal yields of 30-50percent (dry weightbasis) in laboratotyretorts. Actualyields in fieldoperated kilns would be in the range of 20-30percent.
6.20 Several improved charcoalingmethods with resultinghigher yields are availableand are in use throughoutthe world. All of the improvedmethods have one factor in common in that they requiresome capitalinvestment in equipmentand some trainingof operatorsto utilize the kilns efficiently. In addition,some kilns require significant preprationof raw wood such as cuttingdue to size limitationand drying to mazimizeyields. A brief evaluationof some of the most promising improvedcharcoeling methods, within the contextof residuesfrom Ghana sawmills,is presentedin this section. The improvedmethods considered are: - 97 -
(a) TDRIt"GhanaMini" metal kilns;
(b) Subriclay-metal (Posse) kiln;
(c) Missourikiln;
(d) Casamancekiln; and (e) Beehivebrick kiln.
The first three optionshave been operatedexperimentally in Ghana and data on their costs and operatingcharacteristics were obtainedfor analysis. The last two optionsare charcoalingtechniques that have been gainingwidespread use in other developingcountries but have not been introducedin Ghana to date. A briefdiscussion of each,ofthese options is presentedbelow along with associatedcapital and operatingcosts.
6.21 TDRI/ChanaMini Metal Kilns. The typicalTDRI metal kiln consistsof two interlockingcylindrical sections and a conicalcover. The cover is providedwith four equallyspaced steam releaseports which may be closedoff with plugsas required. The kiln is supportedon eight air inlet/outletchannels, arranged radially around the base. During charring,four smoke stacks are fitted onto alternateair channels. Total volume of the kiln is approximately7 m3. Wood used in the kiln shouldbe air dried for a minimumof 3 weeksand sizedfrom 450 to 600 mm long and 200 mm in diameter.Wood with a lengthor diametergreater than specifiedshould be split beforeuse (TDRI).A sketchof the TDRI metal kiln is shown in Figure6.2.
6.22 The Ghana Mini very closelyresembles the TDRI metal kiln with the exceptionthat it has only one cylindricalsection and is slightly smaller in total volume. Both the TDRI and Ghana Mini have been demonstratedin Ghana. A TDRI kiln is being operatedusing sawmill residues at a sawmill in Kumasi while several Ghana Minis are in operationat the Subri River Projectwhere forest residuesare being carbonized.
6.23 The total cycle time for loading,carbonization and unloading of the metal kilns is approximatelythree days. Labor requirementsare estimatedat one person per kiln. Charcoalyield is estimatedat 27 percenton a dry weightbasis. A summaryof the characteristicsof the metal kiln in comparisonto other improvedkilns is presentedin Table 6.9. The annualizedcapital and operatingcosts for convertingin metal kilns all of the mill residuespresently converted to charcoalin the Kumasiarea is sumnarizedin Table 6.10. Detailsof theseestimates and underlyingassumptions are given in Annex 13. - 98 -
Figure6.2: TROPICALDEVHWPMN RESEARCHINSTIUTE (TDRI) (U.K.) ST8 CHARCOALKILM
_ ~~~~~~~~~~2250mmO._
~~ > _ _ > > ~~~~3 piecesN each "Ring"i can be rolled through 11! the Foreqsfiro
"IN. 4-Vents & Vent Lids
4 - Vents
4 - stacks (are slid over 4 of the vents, then after 1 1/2 days are lifted off and slid on the other 4 - vents.) 999 -
Table6.9: COWARISONOF CHARCOALKILNS
Weight Cycle CapitalCost Estimated Volume Rocoverya/ Time Local Imported Total Life No, TypeKilon 3 of space 5 (days) (Codi) (SU.S.) (5U,S,) (years)
1 Hound 15 to 200 16 7-30 - - Nil N/A
2 TORI 7,2 27 3 90,000 850 1,450 S
3 GhanaMini 6.8 27 3 82,000 740 1,280 5
4 MIssouri 220 18 b/ 21 3,607,000 9,220 33,260 5 30/
5 Clay/Metal 11,2 20 5 43,000 550 840 3
6 Casamance 30-100 25 4-7 - 50 S0 2
7 Brick (Beehive) 5b 30 7-8 280,000 300 2,170 3
a Weightof charcoaldivided by the ovendry weightof wood used. b/ Actual performanceaverae of 10 fIrlngs;kIln doors were warped. et IdeaI recovey. source:mIssion estimates. - 100 -
Table6.10: SUM6ARYOF ANNUALIZEDCAPITAL AND OPERATINGCOSTS OF CIURCOALPRt2OCTION ALTERNATIVES
SUmRI ALTERNATIVE MOUND TDRIMETAL CLAY-METAL CASAMANCE BRICKSEEHIVE FIn Econ Fin Econ Fin Econ Fin Econ Fin Econ
Capital (Sx103 ) - - 53.9 51.3 45.4 43.6 4.0 3.7 43.7 39.7
WoodInput a/ 196.6 417.8 196.6 417.8 196.6 417.8 196.6 417.8 196.6 417.8 (Sxl03)
Labor (SM103) 114.5 100.7 50.8 44.7 73.4 64.6 81.2 71,4 32.4 30.3
Malntenance - - 33.8 30.7 6.8 6.3 - - 9.8 8.6 (SX105)
Total (Sx103 ) 311,1 518.5 335.1 544.5 322.2 532.3 281.8 492.9 282.5 496.4
Charcoal Productionb/ (Tonnes/yr) 5,400 8,850 6,400 8,200 9,800
Unit Costs (5/Tonne) 57.6 96.0 37.9 61.5 50.3 83.2 34.4 60.1 28.8 50.7
Cedis/kg 8.6 5.7 7.5 5.2 4.3 a/ All alternatives are assumedto convert 64,000 m3 SWE/yrof wood. Woodcosts are estimated at 450 Cedis/tonne at the s"wmiil gate. The cost of wood delivered to the charcoalers averages at 600 CedIs/tonne. b/ Charcoal production varies as a function of conversion efficiency.
6.24 SubriClay-I4etal Kiln. The Subri clay/metAlkiln is basically an improvedpit kiln with metal pipes for ductingand a steel roof for coveringof the pit. The walls of the pit are made of poundedclay to help reinforcethem. The dimensionsof the kiln vary but are generally rectangularwith pit depth of no more than 2 meters. The primary advantageof the clay/metalkiln is that it is less costlythan the TDRI type kiln. It is considereda semi-mobilekiln requiringonly the transportof the metal parts and the diggingof a new pit each time the charcoalingoperation is to be moved. A sketchof a typicalSubri clay- metal kiln is presentedin Figure6.3. - 101 -
Figure6.3: CLAY/METALCHARCOAL KILN (SUBRISEMI-MOBILE KILN)
Clay & Dirt Packed in the ends beforefiring.
/ FiringWindow /------_4Steel sheets 2thk x 1200 00 ~x 2400 Ig.
WoodenPegs
3 Ducts/sideApprox. 130 x 200 size
Clay sealing betweensteel sheets
1800 Approx. - 102 -
6.25 The Subri clay-metalkiln can be dimensionedto take long pieces of wood unlike the TDRI circularkiln. The pit type kiln is easierto load, seal and managethan the mound type. Its performanceis less vulnerableto the elementsand it does not requirethe same vigilant attention as a mound operation. However, the pit kiln requires considerableinitial excavation and is only justifiedwhen the kiln is to be repeatedlyused. The walls of the pit are susceptibleto collapse presentinga hazardto those that have to work in the pit. The walls also absorba lot of the condensatesand leach them back especiallyif there is heavy rainfallwhich can also cause an accumulationof water in the pit. 6.26 The pit type kiln tendsto producea relativelyhigher portion of partiallycarbonized pieces of wood. It takesapproximately five days for a completecarbonization cycle primarilydue to the longercooling periodrequired. The high insulationproperties of this type of kiln allow for higher carbonizationtemperatures and therefore "higher quality"charcoal (i.e. highercarbon and lower volatilecontent). The averageefficiency of the Subri clay-metalkilns operatedin Ghana were around20 percentchercoal yield on a dry basis. A comparisonof the key characteristicsof this kiln with other improvedkilnas considered is presented in Table 6.9. A summnaryof the annualizedcapital and operatingcosts for convertingin clay-metalkilns all of the mill residuespresently converted to charcoalin the Kumasiarea is presented in Table 6.10. Detailsof theseestimates and underlyingassumptions are given in Annex 13.
6.27 MissouriKiln. Tse Missourikiln is a high volume concrete kiln with steel doors. The kiln was developedin the UnitedStates for large charcoalmaking operations. It is a permanentstructure requiring a large capitalinvestment. The kiln is generallyrectangular in shape with a vaulted roof and can vary greatly in size with larger ones reaching12 m long, 7 m wide and 4 m high. The kiln usuallyhas four chimneyson eitherside thatare made of metal. The primaryadvantage of the kiln is its scale which allows the use of mechanicalloading and unloadingtherby reducing labor costs. It is also designedto operatein cold weather and to withstandthe extremedifferences in temperature betweenthe innerand outerwalls of the kiln. If operatedproperly, the kiln can achieveyields of 30 percentor more. A sketchof a Missouri kiln is shown in Figure6.4.
6.28 A Missourikiln was constructedand operatedat the Subri River project in Ghana. However,the kiln is not in operationnow becauseof severalproblems experienced due to the warpingof the steel doors and crackingof the concretewalls and roof. While the Missouri kiln has a potentiallyhigh yield it requiresa 3 weeks cycle time for charcoalproduction, a high level of mechanizationand carefulprocess control. In addition,the Missourikiln is highlycapital intensive. A comparisonof the key characteristicsof this kiln is presentedin Table 6.9. Productioncost for charcoalwere not determinedfor this type of kiln because it was judged to be technicallyinappropriate for applicationin Ghana. - 103 -
Figure 6.4: MISSO0UI CHARCOALKILN (SUBBI RIVER PROJECT)
t, C; Steel Stacks
:h ~~~~~~~Reinforced 0. ( g @ X ConcreteWalls 0 ~~~~~~~~~~~~~~~&Roof
Steel Doors aw d~~~~~~~~~~ - 104 -
6.29 CasamanceKiln. The Casamaucekiln is an improvedtype of earth mound kiln developedin Senegal.The kiln is generallycircular in shape and has a capacityof 30 - 100 m3 with a diameterof 6 - 10 m. It resemblesthe Sweedishmound kiln but the wood is stackedhorizontally rather than vertically. The kiln is builtup of radiallyplaced logs. The initiallayer has substantialgaps betweenlogs to allowcirculation of air. The sucessivelayers are builtaround a centralvertical post to create a dome shape. A circumferentialventilation chamber is created aroundthe outsideof of the kiln at groundlevel by leaningshort sticks against the stack. The pile must then be coveredwith a layer of vegetationand earth. A lightinghole in the center is created by removingthe centerpost. A particularfeature of the Casamancekiln is that it can incorporatea chimneyattached to the side of the kiln to condensethe pyrolitictars producedduring the devolatilizationphase of the process. The chimneyis usallymade of weldedoil drums or steel pipe of similardimension. A sketchof a typicalCasamance kiln is shown in Figure6.5.
6.30 Provisionsfor collectionand storageof the condensibletars must be incorporatedif a chimneyis used with the kiln. The recoveryof these tars is often cited as an advantageof the Casamancekiln. Mowever,their use is ratherlimited, primarily as a wood preservative, while their disposalcould be a major environmentalproblem. If the temperaturein the chimneyfalls below 100 eC, the resultingcondensate is primarily water, contaminatedby acetic and other pyroligneous acids. The useable tars and oils are too dilutedto be economically recovered.Therefore, the use of a chimneyfor tar collectionrequires good design and skill when operatingin order to realizethe benefits from tar collection.It ip estimatedthat 40 litersof liquidsand tars can be collectedper 100 ml (stacked)of wood carbonized.
6.31 The main advantagesof the Casamancekiln when comparedto a traditionalearth mound kiln is the shorter cycle time and the potentiallyhigher efficiency. Total cycle time is estimatedto take 4 - 5 days with charcoalyields of 20-25percent on a dry weightbasis. The primarydisadvantage of the Casamancekiln is the skillrequired to build and operate che kiln, the importanceof proper sealingof the kiln and the need for good air circulationin the kiln to obtain the expected yields. Considerablecutting and sizingof wood may be requiredin the case of sawmillresidues, given the importanceof kiln construction. Finally,if tar recoveryis incorporated,provisions for collectionand storageof the tars must be provided,increasing the capitalcost of the operation. A comparisonof the key characteristicsof the Casamancekiln is presentedin Table 6.9. A summaryof the annualizedcapital and operating costs for convertingin Casamancekilns all of the mill residuespresently converted to charcoalin the Kumasiarea is presented in Table 6.10. Detailsof theseestimates and underlyingassumptions are given in Annex13. - 105 -
Figure 6.5: CA8AIA CE CHACOALIKILN
ff, , -- ,s--
I' . - __
I ,. * ......
tt _, -- _ '"-'^
'-- -- "
* - "
I~ b - 106 -
6.32 BeehiveBrick Kilns. The Beehivebrick kiln is Most widely used in Brazil. Thesekilns can vary in size from 10 to 100 m with the most typicalaveraging 50 m3. The 50 m3 kilnshave a circularbase of about 5 m in diameter,a cylindricalwall 2 m high with a dome roof about 2.5 m above the base. In general,the kilnsare designedwith two doors diametricallyopposite each other,one for chargingand a smaller one for unloading.Four to six brickchimneys, evenly spaced around the kiln, are connectedto the base of the kiln. Severalbrick-sized air inletsare maintainedat the base of the cylindricalwall and in the dome for controlof air flow. These air inletsare openedor pluggedup as requiredduring the charcoalingprocess. Once constructed,the brick surfacemust be plastered,usally with mud, to seal the kiln. A sketch of a typicalBeehive kiln is shownin Figure6.6.
6.33 The primaryadvantage of the brick Beehivekiln is that once constructedit requiresa low laborinput, produces a consistentquality charcoaland has a relativelyhigh efficiency. A 50 m3 kiln has an averagecycle time of 7-8 days and requiresone trainedlaborer to load, operateand discharge.However, if the wood piecesare large (above2 m in lengthand 0.5 m in diameter)additional labor would be requiredfor wood preparation.The averageyield is reportedat 30 percenton a dry weightbasis, some 80 percenthigher than that obtainedfrom earthmound kilns. Given the refactorynature of brick kilns, carbonizationat higher temperaturescan be achieved resulting in "high quality" charcoal. In Brazil,most of the charcoalproduced in brick kilns is used by the steel industry. The quality of the charcoal can be controlledto meet less stringentdomestic needs by reducingair input duringthe heatingphase with the beneficialresult of higheryields. A comparisonof the key characteristicsof the Beehivekiln is given in Table 6.9. A summaryof the annualizedcapital and operatingcosts for convertingin brick beehivekilns all of the mill residuespresently convertedto charcoalin the Kumasi area is presentedin Table 6.10. Detailsof theseestimates and underlyingassumptions are givenin Annex 13.
Financialand EconomicAnalysis of ImprovedCharcoal Options
6.34 It would be expected that stationarytype kilns would be favored in circumstanceswhere wood for carbonizationis available essentiallyon-site, in the form of sawmillresidues, rather than in forest areas distant from populationconcentrations and points of consumption. The results of the financial/economicanalyses are in accord with this expectation,with the Bethivebrick kiln having the lowestcost of charcoalproduction both on a financialand an economic basisat US$28.83and US$50.46per tonne,respectively. It is followed by the Casamancekiln with productioncosts calculatedas 19 percent (financial)and 19 percent(economic) higher than the Beehivekiln, and then the TDRI metal kiln at 31 and 22 percenthigher. The traditional earthmound kiln occupieslast place,having an economiccost of charcoal productionsome 90 percenthigher than the Beehivetype. - 107 -
Fisure 6.6: BEEHIVEBRICK CHARCOALKILN
IL -I 8I - 108 -
6.35 A switch in charcoalingregimes for the sawmill residues presentlycarbonized in the Kumasi area can be viewed in cost/benefit terms. However,whereas the "beforeproject" scenario is clearlythe existingearth mound method,choice of a new and improvedmethod must take a numberof socialvariables into account. The capitalrequirements of Beehivekilns are beyondthe means of the traditionalcharcoalers; by necessity,brick kiln operationwill be either contractedto private entrepreneurssited on or adjacentto the millsor a side businessof the mill ownersthemselves. Beehive kilns would requireabout 50 workersfor their operationand displaceabout 300 traditionalcharcoal makers, or a net employmentloss of 250 persons. Adoptionof the best low capital alternative,Casamance kilns, would result in a net displacementof about 100 persons.
6.36 Civen the very high financial/economicreturns which will be demonstrated,either the brickor Casamancekiln typemay be suitablefor introduction. The Beehive kiln type was chosen for more detailed cost/benefitanalysis.
6.37 FinancialAnalysis. The financialanalysis of Beehive vs. earth mound kilns is containedin Annex 13 and summarizedin Table 6.11. Using the going wholesaleprice for earth mound-producedresidue charcoalof 8.6 Cedi/kggives a rate of returnof 292 percentand simple paybacktime of 4 months,indicating that the proposedimprovement should be readilytaken up by the privatesector. The gains resultprimarily from the superiorcharcoal yield and efficiencyof labor utilization comparedto the traditionalmethod.
Table6.11: FINANCIAL/ECONOMICANALYSIS RESULTS, BEEHIVEBRICK KILN CHARDOALING IMPROVEMENT
Financial Economic
NPV 5694,769 S 1,110,261
IRR 292% 490%
SimplePayback Time 4 months 2 months - 109 -
6.38 Economic Analysis. Details and results of the economic analysisare also displayedin Annex 13 and Table 6.11. The economic evaluationdiffers from the financialperspective mainly in the cost associatedwith the input wood residues. Given that residue-derived charcoalis replacingforest-derived charcoal at the margin,the cost of residuesfor carbonizationis adjustedupwards to reflectthe additional economicopportunity cost of forestwood consumptionof US$5.00/tonne. As the conversionefficiency of mound kilns on a wet weight basis is estimatedat about 10.6 percent,over 9 tonnesof wet residuesgo into the makingof each tonne of residuecharcoal. A charcoaleconomic value of US$96.02/tonneresults after adjustment for domestic currency overvaluationis included. Using the economicvalue of charcoalthus furtherincreases the attractivenessof the proposedintervention from an economy-widestandpoint.
SawdustBriguetting
ExistingPlants
6.39 There is one briquetteplant presentlyoperating in Ghana, ChaowusLtd. in Akim-Oda.The plant is ownedand operatedby a Taiwanese entrepreneurand has been in productionfor approximatelyone and one- half years. Two screwpress briquettemachines are employedwith a rated productioncapacity of 150 kg/hr of dried sawdustbriquettes each or 7.2 t/day if operatedcontinuously. Present actual production rate of 1,100 t/yr is only half statedcapacity due to operationalinefficiencies. In particular,the pressesare idle for one ouJt of three shiftsper day due to lack of sawdustdrying capacity. The plantoperates six days per week and employs24 men, 6 of them skilledor semi-skilled.
6.40 SawdustSupply. The plant obtainssawdust at no charge from Akim-Odaarea sawmills,using theirown 7 tonnetruck to haul the sawdust to the plantwhere it is dumpedin a largepile outsidethe entrancedoor to the enclosedplant building. Two laborersthen reloadthe sawdust into the truck at intervalsdetermined by the briquette production rate. The truckthen backs into the infeedend of the buildingand dumps the sawdust on the floor. Two men shovel this sawdustonto a small vibratingscreen which filtersout lumps,stones, sticks, etc.
6.41 SawdustDrying. A short screw conveyorelevates the sawdust from below the screen and feeds it into a piped air stream at the entranceto a vertical"flash tube" dryer. The dryer is heatedby the combustiongases of a rudimentarysloping-grate furnace fed by hand with firewoodand broken briquettes. Gas temperatureat the inlet to the vertical section of the dryer is nominally200 eC to a maximum of 250 'C. The dryer is supposedto reducethe wood moisturecontent to 10 percentmoisture content (wet basis). However,in the wet seasonsthe dryer cannot remove enough water so the plant must run a "graveyard shift" drying sawdust and not producingbriquettes. The pre-dried - 110 -
sawdustis then storedand is re-driednrior to briquettingduring the followingtwo shifts. Followingthe flash tube dryer the sawdust is separatedfrom the dryinggas flow in a cyclone. The sawdustfalls out of the bottom of the cycloneinto a meteringbin. Many glowingembers carriedover from the firewoodfurnace find theirway to the meteringbin causingoccasional flare-ups. The gases exhaustfrom the cycloneupward in to the upper part of the buildingresulting in significantdust emissionswithin the workplace.
6.42 BriquetteExtrusion. The sawdustfeeds out of the meteringbin to each of the two screw extruders. Each screw is one piece with a surfaceof welded-onhard stellitewhich needs to be replacedevery 2 to 3 days; the weldingoperation takes about 30 minutes. The briquettesare extrudedcontinuously through a die but they butt into a deflectorplate and are brokenoff at prescribedintervals. The briquettescould be made to any specifiedlength. Specificationsof the briquettingmachinery, as obtainedfrom the manufacturer'sbrochure copied in Annex 14, are given in Table 6.12. Total plant power demandis calculatedas 38.1 kU, with electrical consumptionaveraging 110 kWh per tonne of briquettes produced.
Table 6.12: CHAOWUSLTD. ORIQUETTINgMACHINE SPECIFICATIONS
Manufacturer: Ming-YI Iron WorksCo. Ltd, Taiwan
Screw Presses: 2 x IS HP each at 1,150 rpm
Briquetting Capacity: 2 x 150kg/hr each
Pre-heoaters: 2 x 2 kVAecn
FormingMuff Heaters: 2 x 4 kVAeach
Pre-WeotTemperature: 200-220*C
6.43 BriquetteCharacteristics. The 450 mm long briquetteproduced is cylindricalin shape, approximately55 mm in diameter with 4 triangularkeys approximately4 mm high spacedequally around the outside diameter and running longitudinallyalong the outer surface. The continuoushole in the center is 22 -m in diameter. The briquetteis extremely dense, hard and strong. Measured briquette fuel characteristicsare shown in Table 6.13.
6.44 BriquetteMarketing. The 1.6 kg briquettesare bundled in packagesof 10 and sold at pricesranging from 60 to 80 Cedis/bundle, with the average delivered price in the Accra/Tema area of 70 Cedis/bundlecorresponding to US$ 29.17/tonne.Delivery is made by the - I1I -
Chaowus Ltd. tip truck. The majorityof the product is sold to the Accra/Temabakers' unions; Ankaful Brick Ltd. in Cape Coast has recently convertedfrom firewoodto briquettesto fire its two brick kilns and consumes5 tonnesper week. The acceptanceof the briquettesh&s created a demand that exceedsthe supplycapability of Chaowus,and --the bakers are not happywith the plant'sinability to provideenough briquettes.
Table6.13: CHAOWUSLTD. BRIQUETTE FUEL CHARACTERISTICS
Density,oven dry 1,281kg/0 3
MoistureContent, dry basis 4.9$
MoistureContent, wet basis 5.1$
Densityat 5.1%mcwb 1,350kg/0
VolatilesContent 0.9%
HighHeating Value 20.1NJ/kg
LowerHeating Value (9 5.1% mcwb) 18.9NJ/kg
Source:Annex 12; Mission estimates.
6.45 Sug8ested Operational Improvements. Given the evident unsatisfieddemand, plant economicscould be substantiallyenhanced if productionbottlenecks could be eliminated. The followingsuggestions were made to the Chaowus management at Akim-Oda as a means to improving plant efficiency and output:
(a) Move the outfeed storage pile to the inside of the plant to avoid the problemof the sawdustbeing rained upon. The unused space in the buildingwould allow for this storage.
(b) Move the dryerfurnace to increasethe burningtime betweenthe furnaceoutlet and the sawdustintroduction and therebyreduce the problemof carry-overof burningembers.
(c) Insulatethe flashtube dryer,even if only with a sand-filled sheetmetal cylinder around each of the two flash tube runs.
(d) Move the dryer cycloneto the centerof the meteringbin to eliminatethe necessityof a worker climbingthe ladderand plowingthe sawdustin the bin towardsthe screwat the far end of the bin. - 112 -
(e) Extend the dryer cycloneexhaust pipe so the exhaustgases (smoke)are emittedoutside instead of insidethe plant. MarketPotential
6.46 Supply. The supply of sawdust briquetts in Ghana is theoreticallyconstrained by the availabilityof s3urplussawdust. Total surplussawdust in 1986 is estimatedat 83,400m3. If all of this is convertedto briquettes,this would be equivalentto approximately47,000 tonnes/yr of briquetteswith an energy value of 22,140 toe/yr or equivalent to 11 percent of the total non-residentialfuelwood consumptionin 1985. If sawdusthaulage costs are to be avoided, productionof briquettesmust occur in localitiescontaining significant concentrationsof surplussawdust. The areas havingsurplus sawdust in excess of 2,500 m /yr were given in Table 3.8. Of the 83,400m of surplusin 1986, 52,600m is locatedin the Kumasiarea. A littleover 9,000 @ is found both at Nim and at Sekondi-Takoradi.Approximately 2,500 m is foundat Nkawkawand Dunkwa. These five areasaccount for 91 percentof the total surplussawdust, equivalent to a potentialof 43,000 tonnesof briquettes.
6.47 Demand. The primaryuse of sawdustbriquettes would be to substiFute for fuelwood consumptionmainly in the industrial and commercialsectors where the premiumqualities of the briquettesare valued. To date, the briquettesproduced by the Chaowusplant in Oda have been primarilyconsumed by commercialbakers and at a few brick kilns. Other potential users include fish smokers, chop bars, institutionalkitchens, and other small commercialfuelwood consumers. While use of briquettesis possiblein the householdsector, it is unlikelyto be widely used domesticallydue to unfamilaritywith the product,the tendencyfor smoking(compared to charcoal)and flameless combustionof the briquettes,and the expected higher cost of the briquettes. It is also unlikelythat large industrialconsumers of fuelwoodwould be a major sourceof demand for briquettesunless the briquettesare equal or less in price,on an energyadjusted basis, than bulk costs for fuelwood. Conversionto use of briquettesin industrial boilersand furnacescurrently using fuel oil would be uneconomicfor the same reasons that conversion to firing with unprocessedsawdust, discussedearlier, is uneconomic.
6.48 The potentialdemand for briquettesfrom the bakersand brick manufacturersalone, locatedonly in the main urban areas,is estimated to be 45,000tonnes per year. The basis for this estimateis presented in Table 6.14. The potentialdemand from the bakers and brick manufacturersalone exceedsthe potentialsupply of briquettesby 2,000 tonnes per year. If the fuelwoodconsumption of fish smokersand chop bars were added,the potentialdemand for briquetteswould increaseto over 500,000tonnes/yr.
6.49 Willingnessto Pay. Informationobtained from the present users of briquettes,the bakers and brick manufacturers,indicated a - 113 -
strong preference for the briquettes based on a number of technical reasons. The main advantages of the briquettes were their uniform quality, higher heat (due to lower moisture content) and cleaner burning properties (less smoke and ash). The primary disadvantage cited by current users was the reliability of supply. Most users of the briquettes indicated a willingness to pay a 10 to 20 percent premium (on an energy equivalent basis) over their cost of fuelwood.
Table6.14: ESTIMATEDSAWDUST BRIQUETTE DEMAND
Rat$ of Estimated Number TotalFuelwood Briquette Briquette of a/ Consumption to Fuelvood Demand Application Producers ('000 t/yr) Consumption ('000 t/yr)
BreadBaking 6,575 52.6 2:3 35 Brick/TileManufacture 38 19.8 1:2 10
a/ Fuelvoodusers In urban areas only. Sources "Reporton PilotSurvey on Fuelwoodand Charcoal Consumption In Accra," Governmentof GhanaNational Energy Board, October 1985; Mission estimates.
6.50 The market price for fuelwood varies throughout Ghana, depending in part on the distance of the market from the source of fuelwood supplies. A summary of wholesale fuelwood costs in major urban centers is presented in Table 6.15. The highest prices occur in the Accra/Tema area where financial costs are US$25/t and economic costs are US$27/t.The equivalent economic cost per unit of energy is 19.2 US cents/GJ. The Sekondi/Takoradi and Cape Coast areas represent the next highest areas for fuelwood with financial and econimic costsin the range of US$16/t and of US$19/t, respectively. The Kumasi area has financial and economic costs of fuelwood estimated at US$10/t and US$14/t respectively.
Table 6.15: FINANCIALAND ECONOMIC COSTS OF FUELMOOD
Area Financial Costs EconomicCosts (USS/t)a/ (USS/t)a/ (USS/GJ)
Accra/Tewo 25 27 1.93 Kumsi 10 14 1.00 Sekondi-Takoradi 16 19 1.36 Capecoast 14 17 1.21
a/ Bas. on air-driedweight typically 30% mceb. Source:Mission estimates. - 114 -
6.51 Estimatesof the "willingnessto pay" or breakevenprice for briquettes consumed by bakers in the Accra/Tema area and brick manufacturersin the Cape Coastarea are presentedin Table 6.16 and 6.17 respectively. In the case of the bakers, the breakevenprice is US$37.50/tof briquettes.However, interviews with severalof the bakers indicateda willingnessto pay of up to a 20 percentpremium for the higher quality characteristicsof the briquettesincluding ease of handlingand storage,faster ignitionand heatin8of ovens,consistent fuel characteristicsresulting in more predictablequality of baked productand less foulingof ovens due to bettercombustion of briquettes and lower residueash. Assuminga conservative10 percentpremium over the energy equivalentbreakeven price with fuelwoodresults in a unit value of US$41.67per tonneof briquettes.14/
6.52 The breakevenprice for briquettesconsumed by the brick manufacturersin Cape Coast is considerablyhigher than that for the bakersin Accra/Tema.At present,the brickmakers are payingUS$33.33/t for briquettesfrom Oda deliveredto theirplant in Cape Coast. However, the use of briquetteshave severaloperational advantages which resultin a net financialbenefit to the brickmakers of approximatelyUS$27.92/t of briquettesused or an equivalentwillingness to pay for briquettesof US$61.25/t. The most significantbenefits are reducedlabor costs and increasedyields of finishedbricks per kiln firing. Labor requirements were reducedby over two-thirdsprimarily by eliminatingthe splitting and choppingof fuelwoodand reducingthe mass of materialneeding to be stored and conveyed. Also, because of the higher and more uniform temperatureof the heat generatedby the briquettes,the yield of acceptablebricks increased by some 25 percent. With fuelwoodfiring the the yield was lower primarilydue to tverfiringof bricks near the furnaceand underfiringof bricksat the top of the kiln. A comparison of the costs and benefitsassociated with fuelwoodand briquetteuse by the brick makers is presentedin Table 6.17. In additionto these two quantifiablefinancial benefits, the brick manufacturersindicated that the laborersprefered to work with the briquettesbecause of theireasier handlingcharacteristics. The smallersize of the briquettesallows them to be placed completelyinside the furnacearea and therebyreduce the amountof heat escapingat the mouth of the furnace. With firewood,the temperaturenear the furnacewas extremelyuncomfortable causing the laborersto pitch the firewoodfrom a distanceinto the furnace. This pitchingof the firewoodcaused noticable damage to the furnacedoors and kiln.
14/ Figureobtained from bids of 100 Cedi per 16 kg bundleof briquettes in biddingsimulations with bakers. - 115 -
Table 6.16: BRIQUETTESVS. FUELWOODCOIIPMISON IN BREADBAKING, ACCRA
Fu.lwood Briquettes
Fuel Input/45 kg sack flour a/ 48 kg 32 kg
Cost of Fuel Input/45 kg sack flour 180 Cedis 120 Cedis
Fuel Financial Cost/tonne 3,750Cedis 3,750 Cedis
Net Briquette FinancialBenefit/ 45 kg Sack Flour 60 Cedis
Net Briquette Financial Benefit/tonne 1,875 Cedi/t ireakeven Price: 3.750 Cedi/t Willingness to Pay + Benefit: 1,875 Cedi/t of Consumer Total: 5,625 Cedl/t (USS37.50/t) a/ Basedon Inputs required per 45 kg sack of flour, Source: Mission estimates.
Table 6.17: BRIQJETTESVS. FUELWOODCOMPARISON IN BRICKMANiFACTURING, CAPE COAST
Fuelwood Briquettes
Fuel Input a/ 9.5 t (I' GJ LiV) 4.8 t (91 GJ iJV) Cost of Fuel bl 1,789 Cedi/t 5,000Cedi/t Total Cost of Fuel Input 17,000 Cedi 24,000 Cedi Firing Time 3 days 1.5days Cycle Time 7 days I days Firing Labor 27 man-days 9 man-days Cost of LaborInput 6,000 Cedi 1,900Cedi BrickRecovery 3,900bricks 4,900 bricks Valueof RecoveredBricks C/ 89,700 Cedi 112,700 Cedi Net Briquette FinancialBenefit/Firing - 20,100 Cedi Net Briquette Financial Benefit/Tonne - 4,188 Cedi/t (US$27.92/t) Oreakeven Price: 5,000 Cedi/t Willingnessto Pay + Benefit: 4.188 Cedi/t of Consumer Total: 9,188 Cedi/t (USS61.25/t) a/ Based on single firing of 5,200 bricks b/ Prices for fuel delivered to brIckmaker. cS/ 23.0 Cedi/brick sales price. Source: Mission estimates. - 116 -
6.53 In estimatingbriquette consumers' willingness to pay, it is relevantto considerwhether presentfuelwood consumers would be better off if they were to use petroleumfuels as a substitutefor firewood instead of briquettes. This comparison has been calculated for briquettesvs. inlandfuel oil, the most economicpetroleum fuel in small scale heat raisinginstallations, and is presentedin Table 6.18.
Table 6.18: BRIQUETTESVS. INLANDFUEL OIL COMPARISON,ACCRA
IFO Briquettes
Heat Value (MJ/kg) 42.8 18.9
FinancialCost (USS/Tonne) 111 49.02 a/
EconomicCost (USS/Tonne) 86 37.98 a/
a/ Breakevenvalues on a unitenergy basis. Source:Mission estimates.
The comparison shows that briquettescould cost the consumer up to US$4S.02/tonneand still be cheaperto use than IFO, thus supportingthe US$41.67/tonnewillingness to pay figurefor briquettes. On an economic basis, the opportunity cost of IFO consumptionof US$37.98 (FOB Accra/Tema)is below the opportunitycost of briquette consumption estimatedas:
FinancialWTP : $41.67/tonne SCF adjustment : x 0.88 $36.67/tonne Plus: Opportunitycost of fuelwoodconsumption : $ 5.00/tonne Adjustmentfor 3:2 ratio: x 1.50 (fuelwood:briquettes) $ 7.50/tonne
Total EconomicWTP : $44.17/tonne
However,given the small scale of the individualbakery operationsand the investmentrequirements for IFO combustionretrofit, oil-firing has not been consideredas the next best opportunitywhen computingbriquette substitutionbenefits. The economic analyses have therefore used US$44.17as the unit benefitvaluation. - 117 -
6.54 The sawdustbriquettes have combustioncharacteristics that are more akin to low grade domesticcharcoal than firewood. The possibility of substitutingbriquettes for charcoalconsumption in some cases should be investigated.If briquetteswere acceptedas a charcoalsubstitute, the willingnessto pay for briquetteswould approach US$55/t in Accra and US$85/tin Takoradi(based on financialcosts for charcoaladjusted for heatingvalues).
ProposedPlants
6.55 The operatiouof the ChaowusLtd. sawdustbriquetting plant in Oda has providedseveral important pieces of informationrelating to the feasibility,design and operationof such plants and the subsequent marketingand use of sawdustbriquettes in Ghana. The evalLtion of the operations of the Oda plant indicatedthe possibilityof several improvementsto increasethe overall productivityof the plant while simultaneouslyreducing plant operatingcost. The Oda plant has also demonstratedthe viabilityof operatingthe briquettingequipment in Ghana. The successof the Oda plant has led ChaowusLtd. to consider constructinga largerbriquetting plant in Kumasi. The exact statusof this proposalis unknownat this stage.
6.56 Three briquettingplants of varing sizes and locationsare proposedto evaluatethe economicsof briquetteproduction. The smallest plant,with a capacityof 3,500 t/yr briquetteoutput, is consideredto be located in Takoradi. The plant will requireabout 6,700 m /yr of sawdustwhich is about two-thirdsof the surplussawdust available in the Sekondi-Takoradiarea. The other two plantsare consideredlocated in the Kumasiarea with the Kumasi-Aplant havinga capacityof 7,000 t/yr briquette output and the Kumasi-S plant having a capacity of 14,000t/yr. The sawdustrequirements of the largerplant are estimated at 27,000 m3, slightlymore than 50 percentof the surplus sawdust available in Kumasi. Characteristicsof three proposed plants are presentedin Table 6.19. - 1l8 -
Table6.19: CHARACTIUSTICSOF PROPOSEDSAWDUST BRIQUETTEMANUFACTURING PLANTS
No. Rated Assumed Plant of Output/ Output/ Output/ Plant Sawdust Plant Screw Press Press Year o/ Consumption/Yearb/ Location Presses (kg/hr) (kg/hr) (tonnes) (tonnes) (m'SWE)
Takoradi 4 150 120 3,500 4,878 6,207
Kumasi-A 10 150 120 7,000 9,758 12,415
Kumaesl-B 20 150 120 14,000 19,515 24,828
a/ Based on 3 shift, 6 day/week operation 50 weeks/year with 80Y plant availability factor. bl Based an Input sawdust at 36%mcwb and 786 kg/M3, and output brI quettes at 8% mcwb. Amountsdo not IncludeInternal plant sawdust consumption for sawdust drier. So.ree7 Mission estimates.
6.57 Costs. A summary of the capital investment and annual operating costs for the three proposed briquetting plants evaluated is presented in Table 6.20. A detailed breakdown of these costs and supporting equipment manufacturer's quotation are given in Annex 14. The capital investment required for the 3,500 t/yr briquette plant in Takoradi is estimated to be almost US$300,000. The investment requirements for the 7,000 t/yr Kumasi-A plant is expected to be US$460,000 and for the larger 14,000 t/yr plant, US$780,000. Annual operating costs range from US$68,000 for the Takoradi plant to US$143,000 for the large Kumasi plant. Economies of scale are apparent in both the investment and annual operating costs. A four fold increase in the capacity of the plant results in only a two and two-thirds increase in the capital investment and only a doubling of the annual operating costs.
6.58 Estimates of transporting the briquettes to the market are also presented in Table 6.20. The estimates represent expected costs of transporting all the briquettes to consumers in the Accra/Tema area where fuelvood prices are highest. The briquettes from the Takoradi plant are assumed to have an average one-way transport distance of 240 km while those produced in Kumasi have a transport distance of 285 km.
6.59 Table 6.21 summarizes the factory gate and delivered financial costs for briquettes produced at the three proposed plants. Again, the economies of scale are evident in the factory gate production cost estimates. Briquettes produced at the 3,500 t/yr plant in Takoradi have a financial breakeven cost of US$32.53. Those produced at the larger plants in Kumasi decrease in cost to US$22.13/t at tbe 7,000 t/yr plant Table 6.20: SAWR OF CAPITALAND NmL oPEERA?T-comTS OOSTS FOR FPOSED WliquETTtilSPLAiTS
TAKORADI KWASI-A KIdMSI LocealCosts Foreign Cost Total Local Costs Foreign Costs Total Local Costs Foreign Costs Total Item (lOwO uSS) ( 000 iiS S (I'00Uts* S) (0005 uS O)O iiS)S000 ( uS S) (OM00tiS * tooo us S) (1011 toS S)
Capital Costs Construction 51.6 13.0 64.6 64.3 15.0 79.3 116.9 28.0 144.9
Equiplnt - 121.0 121.0 - 224.0 224.0 - 307.0 387.0
Transport Charges I/ 12.3 16.0 28.3 22.8 29.6 52.4 39.4 51.1 90.5
Engaineeinog Installation 10.8 67.8 76.6 13.9 90.t 104.6 26.9 130.2 1572 and ontingencies
Total Capital Costs 292,5 440.3 Moed
Annual Operating Costs Laor 12.0 - 12.0 t4,g - 14.0 23.2 - 23.2
POWr 27.8 - 27.8 23.7 _ 23.7 41.3 - -
0 a 14 7.7 12.9 20.6 14.2 II'5 31.7 23.1 34.9 56.0
Cons4mbles 0.4 1.1 1.5 0.9 2.0 3.7 I.i 5.3 ?.l
Continoencies - 6.2 - - 7.4 - - 13.0
Total Annual Operating Costs 68.1 61.3 142.6 iriquette Traeort Costs 533. 127.7 2r5.4 a/ Includesinternational freightad insurane, local port chargs and bak fees. - 120 -
and US$18.95at the 14,000 t/yr plant. Transportationcosts add an additionalUS$15.36/t to the briquettesproduced in Takoradiwhile it takes US$18.24/tto transportbriquettes from Kumasito the Accra/Tema market. However,the possibilityexists of marketingthe briquettes closerto the proposedfactories as transportcosts add significantlyto the deliveredcosts of the briquettes.The economicsof this marketing aspectare discussedlater.
6.60 FinancialAnalysis. The estimatedwillingness to pay of the bakersof US$41.67/tonnehas been takenas the marginaldemand price for purposes of the financial cost/benefitevaluation. Results are summarizedin Table 6.22 and detailsof the analysismay be found in Annex 14. The Takoradiplant is shown to be an infeasibleinvestment, and the smallerof the two Kumasi-situatedplants is only marginally profitable.The Kumasi-Bplant is able to exploiteconomies of scale to the extentsufficient to show a 19 percentfinancial rate of return. Per the critical parameteranalysis, the profitabilityof the Kumasi-B investmentis maintainedunder varying assumptionsof capital cost, briquettingmachine lifetime,and briquettedemand price. Sawdustis assumed to be availablefor the cost of haulage: Given the lack of alternativemarkets for surplussawdust, it is unlikelythat the supply price will rise sufficientlyto significantlyimpact briquetting profitability.
6.61 The effect of marketingthe briquettesat plant gate was explored by (a) netting out all briquettetransport costs and (b) downwardadjusting the assumedbriquette demand price to reflectlower fuelwoodprices in the areas surroundingthe factories. This analysis was performedfor the Takoradiand Kumasi-Bplants and is presentedin Table 6.22 and Annex 14. The gains in reducedtransport costs from local marketingdo not offset the loss in revenuesfrom the assumed lower briquetteprices of US$26.40/tand US$16.50/tin Takoradiand Kumasi, respectively. The results suggestAccra-Tema, with approximately75 percentof the urban populationof Ghana,as the primarymarket for the sawdustbriquettes. This is in accordancewith generalexperience with charcoal: Woodfuelshaving a higherenergy content per unit weighttend to have a comparativeadvantage in urban markets distant from wood sources. More limitedmarkets may be found among Takoradiand Kumasi users willing to pay a substantialpremium for the superiorcombustion characteristicsof the briquettescompared to firewood. Plans of the Chaowusmanagement to marketbriquettes in the Northernregion do not appear feasiblegiven the long transportdistances and probablelow willingness/abilityto pay of the consumers. - 121 -
Table 6.21s SUMARY OF BRIQUETTEPRODUCTION AND TRANSPORTFINANCIAL COSTS
Plant Annual Capacity ProductionCosts TransportCosts Total Delivered (t/yr) (US$/t) (USS/t) (USS/t)
Takoradl 3,500 32.53 15.36 47.89
Kumasi - A 7000 22.13 18.24 40.37
Kumasi - B 14,000 18.95 18.24 37.19
Table 6.22: FINANCIALANALYSIS iESULTS, PROPOSED SAWDUST 8RI3QtETTINGPLANTS
Takoradi Kumasl-A Kumasl-i (3,500t/yr) (7,000t/yr) (14,000t/yr)
Marketed in Accra/Tema
NMPV (204,800) 553,860 S498,240
FIBR Undef. 12% 19%
Capital Cost SwitchingValue -50% +8% +445
BriquettorLife SwitchingValue 20 yr 8 yr 4 yr
DiscountedPayback Time 20 yr 16 yr 7 yr
Briquetteireakeven Price 547.89 $40.37 537.19
Marketedat Plant
NPV ($202,020) -- ($327,350)
FIRR Undef. -- 2%
Capital Cost SwitchingValue -47% -28%
BriquettorLife SwitchingValue 20 yr -- 20 yr
DiscountedPayback Time 20 yr - 20 yr
BriquetteBreakoeven Price S 32.53 518.95 - 122 -
6.62 As depicted in Table 6.23 nationalwood demand is forecast under a trend-basedscenario to rise at 3.6 percentper annum. Financial analysisresults were thereforetested under the assumptionthat wood supply is approximatelyfixed, leadingto a real price increaseof the briquettesof 3 percent/yror 81 percenthigher in 20 years. Under this scenarioall three plantsare feasible,having an FIU of 14, 22 and 28 percentrespectively.
Table6823: ESTIMATEDWOOD EALANCE, 1986-2000
1986 1990 1995 2000 (miliIonm3 RUE)
Fuelwoodconsumption 12.0 13.4 15.4 17.6 Industrial woodconsumption a/ 1.S 1.5 2.0 2.0
Total 13.5 14.9 17.4 19.6
WoodIncrement b/ 17.6 16.9 16.6 16.0
Balance 4.1 2.0 (0.8) (3.6)
a/ Industrial wood consumptionIncludes only the portion of wood utilizedfor Industrialmanufacture and energygeneration. b/ increwent flgure Is taken from a working documentprepared In connectlon with Bank report: Ghana: Issues and Cotions in the EnergySector, May 1986(Report No. 6234-&il). Source: World Bank.
6.63 EconomicAnalysis. The estimatedeconomic willingness to pay of the bakersof US$44.17/thas been taken as the marginalbenefit for the economiccost/benefit evaluation. Resultsare summarizedin Table 6.24 and details of the analysisare given in Annex 14. Similar conclusionsas to the desirabilityof the proposedinvestments follow from the economicanalysis as from the financialperspective. The main differencesin the financialand economicbenefit streams are due to varyingelectricity tariffs charged to the variouslysized plants. The Takoradiplant is assumedto fall under the ECO "Commercial.- Less than 100 kVA maximumdemand" tariff which gives a higheraverage cost per kWh than the estimatedeconomic LRMC of supply. In the case of the larger Kumasi plants, both qualifyingfor special industrialtariffs, the situationis reversed;the economiccost of electricityexceeds the financialcost. - 123 -
Table 6.24: ECONONICANALYSIS RESULTS, PROPOSEDSAWDUST BRIQUE9TTINS PLANTS
Takoradi KumasI-A Kumasi-B (3,500 t/yr) (70000t/yr) (14,000 t/yr)
Marketed In Accra/Toma
NPV ($11,200) 599,100 S500,330
EIRR 9S 13S 191
Capital Cost Switching Value -3% +15% +48%
Briquettor Life Switching Value 13 yr 7 yr 4 yr
Discounted PaybackTime 20 yr 13 yr <7 yr
Briquette Breakeven Value S44.64/t S42.60/t S40.07/t
Marketedat Plant
iNPV 73,710 - $163,520
EIRI 14% - 13%
Capital Cost Switching Value +19% - +16%
Briquettor Life Switching Value 6 yr - 7 yr
DiscountedPayback Time 13 yr -- 13 yr
BrIquette ireakeven Value S28.32/t -- $20.69/t
6.64 Local marketingfor briquettesis more attractivein the social cost/benefitanalysis than under pure private market assumptions, especiallyin the case of the Takoradiplant. However,it is stillmore sociallyprofitable to marketthe Kumasi-Bplant output in the Accra-Tema area than in Kumasi.
6.65 As in the financialanalysis, assumptions about the futurerate of woodfuelsprice inflationhave a substantialeffect on the economic analysisresults. Economicinternal rates of returnincrease to 21, 24 and 29 percentrespectively when the value of briquettesinflates at 3 percent real per annum. - 124 -
CharcoalBriquettes
Background 6.66 There are a numberof methodsthat have been proposedfor the productionof charcoal briquettes.Essentially there are two major differencesbetween methods: one is to carbonizethe sawdust before briquettingit; while the other is to briquettethe sawdust before carbonizingit. In the first method, the loose sawdustis normally carbonizedin a continuousretort. The resultingchar is collected, cooledin a water quenchtank, mixed with an organicbinder and extruded into briquettes.The briquettesare then stacked on steel carts and pushedinto a dryingkiln which is fueledby the hot pyrolysisgases from the retort. This processis used in North Americato producecharcoal briquettes from sawdust for the barbecue market. The resulting briquettesare costlyprimarily due to the use of starchbinders.
6.67 Alternately,it is technicallypossible to convertto charcoal the sawdust briquettesthat are producedby the heat extrusionscrew press briquettingmachines presently used at the Chaowusplant in Oda and proposedfor the briquettingplants evaluated earlier. Similarly produced briquettesare routinelyconverted to charcoalin plants in Japan and Taiwan. The sawdust briquette,because of the high pressure and temperatureunder which it is initiallyproduced, is sufficientlybonded to maintain its integrityduring the charcoalingprocess. Uniform carbonizationis aided by the fact that the briquetteis hollow in the middle.The charcoaledbriquette looks much like the sawdustbriquette exceptit is blackand has a roughand somewhatirregular surface.
6.68 For carbonization,the briquettesare placed in small, four wheelenclosed steel carts. The cartshave lidswhich are tightlysealed to eliminatethe additionof air whichwould ignitethe briquettesduring carbonization.The carts are fed througha "hot tunnel"in a continuous train. The tunnelis heatedby an externalsource: either electricity, firewoodor fossilfuels. The carts pass throughthe tunnelat a speed sufficientto allow carbonization.After the carts exit the tunnelthey are allowed to cool before the charredbriquettes are taken out and bagged. In some operationsin Japan, the sawdust briquettesare carbonizedin batchmode. The briquettesare piledon a steelbase and a steel dome is lowered over the pile to seal it. Externalheat is providedfor carbonizationand the charredbriquettes are allowedto cool prior to raisingof the steeldome.
6.69 It is estimatedthat the theoreticalmaximum -recovery for charcoal with 15 percent volatiles from sawdust briquettes is approximately42 percent on a dry weightbasis. This recoveryrate is based on actualtests with briquettesobtained from the Chaowusplant in Oda. A more practicalrecovery rate for an industrialkiln type operation is estimatedat approximately32 percent. Recoveryrates would vary dependingon the actualquality of charcoalrequired. Higher quality - 125 -
charcoal(i.e., lower volatilecontents) would have lower recoveryrates and vice versa.
ProductionOptions/Economics
6.70 ChaowusLtd. indicatedthat a plant producing4 tonne/dayof charcoalusing the steel cart methodwould requirea capitalinvestment of approximatelyUS$100,000. No estimateson operatingcosts were available. However,assuming two additionalunskilled laborers per shift,annual O&M costsof 5 percentof capitaland energycosts of about US$10/tonneof charcoalresults in an estimatedproduction cost for the briquettes of $29/tonne in addition to the cost of producing the briquettes. Takingthe financialproduction cost at the Takoradiplant of US$32.53 and accountingfor conversionto charcoalat 32 percent resultsin a overallcharcoal briquette production cost of approximately US$137/tonneof charcoal. This is slightlyhigher than the financial cost of forestderived charcoal in the Takoradimarket of US$132/tonne and considerablyhigher than the priceof US$80/tonnefor charcoalin the distantAccra/Tema market. If charcoalis producedfrom briquettesat the large Kumasi-Bbriquetting plant, the estimatedproduction cost for charcoalbriquettes drops, due to the lower productioncoat for sawdust briquettes,down to US$92/tonne. Again, this is higher than the financialprice of wood charcoalin the Kumasimarket of US$66/tonne.
6.71 The Mission's consultants,after evaluating the sawdust briquettingprocess, have proposedan alternatemeans for continuous productionand carbonizationof the briquettes. The proposedsystem, shown in Figure6.7, requirescoupling a tunnelkiln at the exit of the briquettemachine. The hot, freshlyproduced sawdust briquettes would immediatelyenter a sealedtunnel kiln which is heatedby pyrolysisgases recovereddownstream of the kiln. The length of the kiln would be dimensionedto allow sufficientcarbonization time and the temperatureof the kiln controlledto achieve the desirablechatZoal quality. The consultantshave estimatedthat the capital cost for a 7 tonne/day charcoal production capacity would be approximatelyUS$125,000. Additionallabor and energycosts would be minimaldue to the couplingof the kiln directlyto the outputof the briquettingmachines and the use of the pyrolysisgases for heatingthe kilns. However,equipment O0M costs would be higherdue to the mechanizednature of the process. For the purposesof this analysisit is assumedto be 10 percentwhich is likelyto be an upper limit. With theseassuptions, the productioncost of charcoalfrom the sawdustbriquettes is approximatelyUS$16/tonne. Given the productioncost of sawdustbriquettes at the proposedTakoradi plant,the resultingcost of charcoalbriquettes would be approximately US$124/tonne.The cost of the charcoalbriquettes produced in Takoradi is marginallybelow the {inancialprice for charcoalin the Takoradi market. The productioncost of charcoalbriquettes from the Kumasi-B plant is estimatedat US$79/tonnewhich is still higher than the financialprice for charcoalin the Kumasimarket. op.icr l J+o nri
'J~t t VEC49 420 clenf
: |6_^N1evf2O z it \/2sb;~+cnsc| >w m zr |E eslc >' t \LOle*> Volsrne: tominbup"CW^ au
I czv irl
ns~~~~~~~~~~~ 1t.nn1
.~~~~~~~~~~~~~~~~~~~Tp coiR*tiS,thrw bt;4iclldi.6 qdb4tin ;un Co9TJbBICZA 4SoSoOETTE cld*2cooL:tJq ic4I - 127 -
6.72 The continuoussawdust briquette carbonizing process proposed by the consultantshas not been demonstratedon a commercialscale. Also, as indicatedearlier, the demandfor sawdustbriquettes is greaterthan the potentialsupply. Civen both these facts and the marginaleconomics of convertingbriquettes to charcoalit would be unadvisableto seriously considerthe commercialproduction of charcoalbriquettes in Ghana. - 128 -
VII. flOES AND COECLUJICSFOM INCREASEDAND/OI INPROVED UTILIZATIONOF VOOD INDUSTRYURSIDUES
Su _ ry
7.1 Investmentsin sawmill processheat generationand sawdust briquettinghave been identifiedwhich could economicallyutilize the bulk of the 18,000toe energycontained in the presentsawdust surplus. Total potentiallevels of investmentexceed US$8 millionwith economic rates of return rangingfrom 19 c:o46 percentper sub-project.Actual levelsof investmentfor sawmillprocess heat are dependenton the market for treatedand dried lumberand the level of presentlyunused boiler capacity. The investmentswill maximizeeconomic benefits if provisions are made to utilize sawdustas a residue fuel insofaras possible. Needed improvementsinclude upgradedsawblade guides, better sawdust handlingand storage,and furnace grate and airflow systemsenabling directsawdust combustion. A briquettingplant investmentis contingent upon significantunused sawdust quantitiesremaining in Kumasi after amounts for on-sitecombustion are subtractedout. Unutilizedsawdust will continueto be found at smallermill sites havingno processheat demand, while both solid residuesand sawdustwill be significantly underutilizedat Nim TimberCo. and ClikstenVest AfricaLtd.
7.2 Solid residuesnot findingtheir way intohigh valuenon-energy uses should be carbonizedby the most efficientmeans practicable. Beehivebrick kilns are recommendedfor charcoalproduction from sawmill residues. Total investmentrequirements for carbonizingin brick kilns all residuespresently charcoaled in Kumasiis estimatedat US$110,000 with economicrates of returnfrom 300 to more than 500 percent.
On-SiteUtilization
SawmillProcess Heat
7.3 Resultsfrom analysisof a typicallarge sawmillpoint to the potentialfor significanteconomic gains from increasingon-site use of residuesfor processheat generation. Major economicbenefits to be derivedinclude:
(a) Highervalue-added through export of kiln-driedproducts, thus increasingforeign exchange earnings in the forestrysector;
(b) Increasedrange of economicallyexploitable species through log sterilizationand lumberdrying, thus reducinglogging pressure on progressivelyscarce primary species and maintainingsawmill capacityutilization. - 129 -
Financial and economic rates of return exceeding 30 percent are possible for the requiredinvestments in boilerequipment, steaming vats and dry kilns. The potentialnet economiccontribution per unit of exportsis estimatedin Table7.1.
Table7.1: NETECONOMIC CONTRIBUTION TOEXPORT LUMBER UNITVALUE TROUG KILN DRYING(S/r 3)
Redwoods Whitewoods
ValueAdded 55.05 21.00
Drying Cost 19.18 10.96
Net Contribution 35.87 10.04
Source: Annex 5.
7.4 Investmentpotentials and resultingeffects on sectorearnings and residue utilizationare summarizedin Table 7.2 for three export scenarios. For purposesof illustratingpotentials, all exportlumber is assumedto be kiln-dried.Scenario A is based on currentexport output and shows a annualnet economiccontribution of US$2.7million from an investmentof US$7.4million. In this case, the economicnet present value over the estimated15 year life of the investmentwould amountto US$20.4million. ScenariosB and C illustratethe effectsof long-term trends toward increasedlog processingand improvedproduct recovery occurringin conjunctionwith industrymodernization. Estimateshave been derived by applyingscaling factors to the sawmillprocess heat model discussedin Chapter5.
7.5 Estimatesof scale of investmentpotential and benefitsfrom this residue use are, by necessity,proximate. The scope for mill process heat utilizationwill be primarilyexport market-driven,and accurateforecasts of Europeanacceptance of kiln-driedGhanaian products would requirea greaterlevel of understandingof the lumbertrade than covered by the Mission. In addition to marketing intelligence, complementaryinputs are required to assure quality control,proper packaging,and shippinginfrastructure.
7.6 On the basis of statisticscompiled on presenton-site residue consumption,it would appearthat there existssubstantial unused boiler capacityat a numberof the combinationmill sites. Observationsmade at mills visitedconfirm this view; in many instancesoperating pressures indicatedsteam outputsof 40 to 60 percentof boilercapacity. In this circumstance,required investments would be lowerdue to the pre-existing boiler capacity, and rates of return to the incrementalkiln/vat investmentswould be higher. Table 7.2: SAWNILLP0CES HEAT INVESTEIT POTENTIAL
Net Unit Contribution Potential Project Export to Forest Product Net Annual Estimated Estimated Annual Lumber Output Economic Value Economic Investmnt RequIrement Rquirmet Reldue 3 ( 000 *3) (S/0 ) Contribution for 100%Kiln-Drying for 100%Kiln-Drying Sconario Redwood -itewood Redwood Whitewood (million S) (million S) ( 000 t/6) (000 m3 /Vr)
A. 1985 Projected 66 33 35.87 10.04 2.7 7.4 63 80 (66%) (34S)
B. ScenarioA plus all export logs converted to 74 100 35.87 10.04 3.7 11.S go 133 export lumber (42S) (58%) a-
C. Scenario B plus Improvedproduct 89 121 35.87 10.04 4.5 13.8 120 162 recovery (42%) (s%a) e/ Based on estimated 587/i 3 for redwoods and SSO/m for whitewoods. Source: Table 5.5; Mission estimates. - 131 -
7.7 Future investmentsin on-siteprocess heat generationwill maximizeeconomic benefits if provisionsare made to utilizesawdust as a residuefuel insofaras practicable.As discussedin Chapter5, this will entail improvementsin sawblade guides, sawdust handling and storage,and installationof boilerswith appropriatelydesigned grates and airflowsystems to enabledirect sawdust combustion. These features are incorporatedin modernsawmill boiler/furnace systems, but wouldhave to be retrofittedto the majorityof existinginstallations. The present financialopportunity cost to sawmillowners of combustingsolid residues insteadof sawdustin their boilersis low. The effectivecost is the sales value of slabs and edgingsfor firewoodat about US$3-4per green tonne. As the economicvalue of solid residuesas a substitutefor forestwood or as a feedstockin efficientstationary charcoal kilnas is considerablyhigher, tax/regulationincentives may be warranted to promotethe on-siteutilization of sawdustinstead of the solidresidues.
Cogeneration
7.8 Grid ConnectedMills. Almostall large sawmillsin Ghana are connectedto the nationalgrid, and thereforereceive the benefitof low cost hydropower, The mission estimatesthat electricitycould be producedat these mills in residue-firedturbogenerators operating in a cogenerationmode for approximately5.6 to 7.1 US cents per kWh. With presentindustrial tariffs set in the rangeof 3.5 US cents/kWh,there is no financialincentive for mill ownersto make the investmentsthat would be required. While one mill (SpecialisedTimber Products Ltd.) in Kumasi is in the process of installinga 480 kVA boiler/turbine,the circumstancesare atypicalas the cogenerationequipment was acquiredat considerablediscount on the second-handmarket.
7.9 Mill ownerswishing to sell excess self-generatedelectricity to the grid could be offereda tariffin which sell rates exceed buy rates. However,the economics(i.e. from a nationalenergy planning perspective)are unfavorable. Based on an analysisperformed at two sites, the marginal economic cost of residue fueled electricity generationof 5.8 to 7.6 US cents/kWhis higher than the estimated marginalgrid cost of the present1,072 MW hydro-basedsystem of 5.2 US cents/kWh. In the short-termat least,sawmill cogeneration investments cannotbe recommended.
7.10 Taking the longerterm view, it is well establishedthat the low cost hydropowersites are fully exploited,and that additionsto hydro capacitywill entailhigher marginal costs. The least cost hydro expansionunit, the site at Bui as identifiedby Acres Internationalfor VRA, is costed at 7.9 US cents/kWh. Other expansionalternatives examinedby Acres includecoal-fired and oil-firedthermal generation. The preliminaryevaluation made herein indicatesthat sawmill-based cogenerationwould be competitivewith the alternativesjust mentioned. The availabilityof off-shorenatural gas and the ultimatecosts of electricitygenerated from this sourceremain to be defined. - 132 -
7.11 Projectionsmade by Acres forecasta need to bring 200-400MW of generationcapacity on-line in the mid-1990's. While wood residue electricitymay be the least-costexpansion alternative at that time, it should be pointedout that the total installedboiler/turbine capacity required to combusthalf of the residuespresently produced in Ghana would not amountto 20 MW. A decisionwhether to pursuethe wood residue alternativein light of its small contributionrelative to the national electricitypicture is beyondthe scopeof the presenteffort, but should be consideredby nationalenergy policy/planners. 7.12 Mon Grid ConnectedMills. Two large mills are locatedoff- grid. The AfricanTimber and Plywoodmill in Samreboiis well suitedfor cogeneration,and privatefinancing has recentlybeen securedto renovate its nearly40 year old powerhouse.The situationat Mim TimberCo. Ltd. is unique in that a US$2.2 million grid extensionis planned, but constructionhas not yet begun. A searchfor the least-costelectricity supply option confirmsgrid extensionas the best choice. A 1.2 MW base/intermediateload residue-firedcogeneration plant coupledto the existingdiesels for peakingpower appearsto be a marginallycheaper alternativewhen grid powerand extensioncosts are considered.However, the requiredUS$2.14 million extra investmentfor electricitygeneration capacityyields an economicinternal rate of returnof only 12 percent. Considerationof risk and managementburden of the wood/dieselhybrid systemleads to the grid extensionconclusion.
7.13 The same 1.2 MW cogenerationplant, when connectedto the grid and operated in a base load mode, could produce electricityat a 10 percenthigher cost than the presenthydro system. A decisionto invest in this project should be made using the same rationaleas outtinedin paragraphs7.10 and 7.11. In addition,the considerations should include the potentialcontribution to network stabilityfrom distributedpower productionfed-in at a grid endpoint.
DirectUtilization in the IndustrialSector
ResidueSubstitution for Oil Fuels
7.14 The economicsof substitutingunprocessed sawdust for fuel oils (RFO/IFO)in industrialheat-raising applications are unfavorable.Ghana is a net exporterof these fuels from the Tema refineryand the low FOB pricesreceived on the world petroleumproducts market are reflectedin their opportunitycost of consumption.Petroleum prices would, in most cases,have to rise above US$30/barrelin 1986 dollarsbefore the capital costs of conversioncould be amortizedby the fuel savings. The economicsof substitutionfor the highercost gas oil were not evaluated as the small scale of installationsburning this fuel make economic conversionunlikely. In any event,switch-over to InlandFuel Oil is the more probableeconomic course of actionin this instance. - 133 -
ResidueSubstitution for Fuelwood
7.15 The scope for substitutingunprocessed sawdust for fuelwoodin commercial/industrialboilers is limited.The greatestpotential exists at sites close to sawmilloperations where transportand handlingcosts can be minimized. Neverthless,economic benefits are small and are furtherlimited by the smallscale of coumercialoperitions which combust firewood. Boilerefficiencies observed at many of these sites suggest that significantsavings in fuelwood consumptioncould be achieved throughlow cost furnaceimprovements and operationalprocedures.
ConversionAlternatives
Improved Charcoal Making
7.16 Between 25 to 30 percent of all solid residues produced by the mills goes into charcoalmaking where it is carbonizedusing the same inefficientearth mound technologyas found in the Transitionzone and other traditionalcharcoal making areas. As the wood residuesare available from a stationarysource, higher efficiencycarbonization technologiescan be appliedleading to an increasein charcoalyield of over 80 percent. If all solid residuespresently carbonized in Kumasi, the area accounting for approximately60 percent of all residue productionin Ghana,were convertedin Beehivebrick kilns an increasein charcoaloutput of 4,400 tonnes/yrwould result. A capitalinvestment of US$110,000would be requiredwith an economicrate of returnnear 500 percent. Three-quartersof the capitalrequirement is for localcosts.
SawdustBriquetting 7.17 Evaluationof three differentcapacity screw press sawdust briquetteplants demonstrates that definiteeconomies of scaleexist with respectto this conversiontechnology. It is estimatedthat production in Kumasi at the 14,000tonnes of briquettesper annum level could be profitablymarketed to bakers and brick factoriesin the Accra/Tema area. A plant of this scale would consumejust over half the surplus sawdustavailable in Kumasi yet meet only a third of the demand for briquettesamong urban bakersand brick makers alone. Total briquette demandin this sub-sectoris estimatedat 45,000t/yr. Jue to the higher heat value and superiorburning characteristics of the briquettes,a minimumof 21,000t/yr of fuelwoodwould be saved. Total investmentfor the briquetteplant is estimatedas US$780,000. Under the assumption that consumerswould be willingto pay a 10 percentpremium over the energy contentadjusted price of fuelwoodfor the briquettes'ease of handlingand combustionbenefits, the investmentyields an economicrate of returnof !9 percent.
7.18 Costs for transportof sawdustbriquettes to the Accra/Tema pointsof coasumptionexceed the briquetteproduction cost in the largest - 134 -
size plant investigated.Only road transporthas been consideredin the project evaluation. However, when the Central railroad line is rehabilitated,transport costs could drop by perhaps 25 percent. The resulting drop in the delivered cost in Accra/Tema of nearly US$5.00/tonnewould substantiallyimprove the economics of sawdust briquetting.
BriquetteCarbonization
7.19 A carbonizationtunnel appended to the last stage of the sawdust briquette productionline could carbonize the briquettesat relativelylow cost. Charcoal FOB export value of US$115/tonneand Takoradimarket pricesexceeding this figuresuggest that a viablemarket exists for briquettecharcoal. However,the expectedcharcoal yield of 32 percent or less in a commercialprocess means that the charcoal briquetteproduction cost would be a minimumof three times the sawdust briquettecost of US$32/tonnein small scale plants. As the suggested carbonizationprocess is experimental,investments in ciharcoalbriquette productionare not proposedat this time. Follow-upinvestigations are requiredto definethe technologyand economics.
NationalInvestment Implications
TotalInvestment Potential
7.20 If capital is not consideredto be a constraint,the decision rule is to accept all projectsgiving a rate of returngreater than the opportunitycost of capital of 10 percent assumed in this study. Investmentsmeeting this criteriaare sumarized in Table 7.3. In view of the low levels of capacityutilization presently found in Ghanaian industry,rehabilitation investments will be foundthe most profitable.
Table 7.3: TOTALINVESTMENT POTENTIAL FOR INCREASED AND/OR IMPROVED UTILIZATIONOF WOOD INDUSTRY RESIDUES
Investment AnnualResidue Investment Location Amount EIRR WV Consumption SeamiII USS7.4M Promess National at present wood 46% USS20.4M Up to 80,000 m3 Heat Industryoutput Sawdust BriquettingKumasi US$0.78M 19% US$0.50M 27,000m3 Plant
Improved Residues Nationala/ up to USS0.11N 490% USS1.11M 64,0OOm3 Carbonization
a/ Amountsgiven are for investmentfor improvedutilization of all residues presentlycarbonized in Kumasi. - 135 -
Competititionfor ResidueResources
7.21 Schemesfor residueutilization are mutuallyexclusive to the extent that they competefor the same residueresource in terms of type and location. The primarycompetition for residueresources would occur for sawdjstin the Kumasiarea. Total sawdustproduction in Kumasi of 56,400 m , almost all of which is presentlyin surplus,wuuld not be sufficientto providefor the consumptionin both maximumsawmill process heat utilizationand sawdust briquettingunless solid residues were substitutedin the firstapplication.
7.22 In order to providea tool for prioritizingresidue resource utilization,a net benefits/scarceresources ratio was computed for a number of alternativeresidue uses. As explainedin Squireand Van der Tak, the B/R ratio is a transformationof the NPV criterionand is anlogousto the (Benefits- OperatingCosts)/(Capital Cost) ratio used for project ranking whea there is a capital budget constraint (Gittinger'sNet Benefit-InvestmentRatio). If the denominator is expressed in the value of consumptionnumeraire, a unitless ratio results. Conparisonscan be made more immediatelyrecognizable if the ratios are computedper tonne of residueas is shown in Table 7.4. In this case, the values represent breakeven residue worth, or the willingnessto pay at which the residueutilization investment has a zero up,.
Table 7.4: NETBENEFIT/RESIDUE RESOURCE RATIO FOR ENERGY USES IN KUMASI (S/tcmqe)a/
on-Site Boller Charcoalc/ Briquette dV Fuel bV Firewood Feedstock Feedstock
Financial Solid Residues 23 (36) 3 10 0
Sawdust 23 (36) 0 Not Examined 3
Economic SolidResidues 21 (41) 8 18 0
Sawdust 21 (41) 0 NotExamined 3
a/ ResidueInputs have beennormalIzed to green tonnes, b/ Figures In parenthesesare breakevenvalues derived from NPV analysisof sawmill prOCessheat model. Figures to the leftare based on breakevenvalues with RFO on a net energyequlvalent basis. c/ Assumesuse Inthe highest yielding alternative charcoal production method, I.e. eehIvebrick kiln, operating at Kumaslsawmills. d/ Basedon Kumasl-Bplant marketing production In Accra/Teo.m - 136 -
ResidueUtilization Priorities
7.23 Interpretationof Table 7.4 gives the followingpriorities for the utilizationof residuesfor energypurposes in cases where there are alternativeuses for the same residue:
Table7.5: RESIDUEENERGY UTILIZATION PRIORITIES
Priority Ranking Utilizatlon
1 Combustsawdust on-site for process heat generatlon/cogeneration
2 Combustsolid residues on-sIte for processheat generatlon/cogeneration
3 Convertsolid residues to charcoalIn efficientkilns
4 Convertsawdust to briquettes
5 Utilizesolid residues as firewood
7.24 The followingconclusions are drawn from the above ranking:
(a) Sawdust should be used in sawmill boilers to the extent determinedby demand for processheat and technicalfeasibility of sawdustcombustion. Solid residuesshould be used to meet the balanceof heat demand.
(b) Remainingsawdust should be briquettedif it existsin amounts sufficientto allow briquettingon an economicscale; such a situationexists in Kumasi.
(c) Remaining solid residues will be most profitably used if convertedin efficientcharcoal kilns such as the Beehivebrick kiln.
The effect of these prescriptionsis illustratedin Table 7.6, which gives a sample "before and after' residue utilizationpattern. The reasonablenessof the underlyingassumptions needs to be tested through examinationof the exportmarket for dried lumberand the existingdrying capacity. - 137 -
Table 7.6s RESIDUEUTILIZATION PROFILES FOR KUMASI ('000m 3 SWE)
Veneer Solids Waste Sawdust
1986 Pattern
Mill BoilerFuel 25.1 28.4 3.4
Charcoal Production 63.6 - -
Firewood 42.4
Non-Energy 62.2 - 0.4
Surplus -52.6
193.3 28.4 56.4
PotentialFuture Pattern
Mill BollerFuel a/ 33.1 28.4 29.0
CharcoalProduction b-
Firewood
Briquetting - - 27.0
Non-Energy b- 0.4
Surplus - _
I/ Assumptions: 70S of export lumber from Kumasi. 60%of export lumber dried. 75%of new process heat demandmet by sawdust. b/ Charcoal/Non-Energy split not profiled.
7.25 Non-energyuses for residueswere brieflyreviewed in Chapter 4. The basic conclusionis that non-anergyuses for solid residuessuch as re-manufacturefor exportor cottageindustry use shouldbe considered of higher value than energy uses. Prospectsfor utilizationof large amountsof sawdustfor the productionof fiber board are not favorable due to the present world market situationfor this product,and non- energyuses for sawdusthave not enteredinto the estimations. - 138 -
Uncertaintiesand Risk Factors
Healthof the Wood ProcessingIndustry
7.26 West Africa held 30 percent of the world tropicalhardwood trade in the early 1960s, of which Ghana was a major player. The downwardslide which characterizedthe Ghanaianwood productsindustry in the period 1975-1983 has reduced Ghana's role to one of relative insignificanceon a world scale; at the same time, upward potential exists through recaptureof lost export markets. While the present industryrecovery is vigorous,a seriousdownturn could jeopardizethe wood residueutilization investments planned on the basis of a healthy level of wood processing activity. An investment in a sawdust briquettingplant, as a case in point, might cease to be viable if residueproduction were to fall off drastically.A preferencefor export of logs insteadof productswould similarlyreduce residue production, but with negativeimplications for domesticincome and employment.
Locationof Wood ProcessingFacilities
7.27 The locationof the wood resourcebase has shiftedover time as the most easilyexploitable areas are logged. Coupledwith the on-going grid extensionprogram and transportnetwork improvements, there is some incentivefor wood processingindustries to locatein areas closerto the timber resource. Residue productionwould become less physically concentratedin areas like Kumasi,although the changeswould occur only slowly over a long time and would not be expectedto affect the basic viabilityof investments.
Wood Supply/Demand
7.28 The sustainabilityof wood productionfor industrialand fuel uses and its balancewith demandhave been taken as given in most of the residue utilizationanalyses. Increasingwood scarcitywould have the effect of raising the importanceof obtaining value-addedfor wood products,carbonizing wood residuesefficiently and sawdustbriquetting, and therebyraise the returnsto these activities. Investmentviability could be threatenedto the extent that wood resourceshortages lead to a declinein residueavailability.
Oil Prices
7.29 The assumeddownside potential for petroleumprices is not so great as to make fuel oil more economicthan on-sitewood residuesfor sawmillprocess heat raising. On the oppositeside, a rise in oil prices increasesthe value of wood residuesas a fuel to the extent that wood and petroleumare substitutablefuels. - 139 -
ElectricityCosts
7.30 Electricitycosts have been assumed to increasein line with the general rate of inflationas per the Acres generationplanning study. However, long run marginalcosts can be expectedto evolve in relation to demand growth as the current hydro capacity becomes strained. More or less rapid electricitydemand growthwill advanceor retard, respectively,the timeframein which residue-firedcogeneration may become competitivewith other electricitysources as discussedin paragi;ph 7.11.
InvestmentRecommendations
SawmillProcess Heat
7.31 Priority investment attention should be focused on the utilizationof sawmill residuesfor on-sitegeneration of processheat for lumber dryingand treatment. Complementaryefforts will be required to determine:
(a) target export markets for treated and kiln-driedlumber and neededpromotion efforts;
(b) speciesdemand and dryingrequirements;
(c) qualitycontrol requirements;
(d) packagingand shippinginfrastructure requirements; and
(e) marketing structures through which output from smaller exporters can be passed through larger mills for further processing.
The TimberExport Development Board shouldserve as the coordinatingbody for these informationgathering efforts.
SawdustBriguetting
7.32 Second priorityinvestment consideration should be given to a 14,000t/yr sawdustbriquetting plant in Kumasi. It is anticipatedthat financingcould be raisedfrom privatesector sources. Investmentshould proceedonly in conjunctionwith:
(a) assurancesfor long-termsawdust supply from cooperatingmills; and
(b) briquettemarket promotion efforts. - 140 -
The briquettemarketing effort could be undertakenwith the assistanceof a qualified local consulting organization engaged to perform a substantialportion of the marketsurvey and evaluationwork.
TechnicalAssistance Recommendations
7.33 Future investmentsin sawmill boiler/kilncapacity expansion shouldincorporate the followingtechnical assistance components in order to maximizeeffective residues utilization:
(a) Saw blade guide improvements;
(b) Residueshandling and storageimprovements;
(c) Furnacemodifications for sawdustcombustion; and
(d) Boilerefficiency improvements.
These measureswill maximizethe utility of sawdustas a boiler fuel, thus freeing solid residues for other energy or non-energypurposes. Boiler efficiencyimprovements, among others, at non-wood processing sites are being addressedunder the on-going ESMAP IndustrialEnergy EfficiencyImprovement project. Coordinationof these effortswith any sawmillenergy efficiency upgrades is required.
Pilot/DemonstrationProjects
ImprovedSolid Residues Carbonization
7.34 A component in improved charcoal making from solid sawmill residues is recommendedfor inclusion in the proposed ESMAP Ghana CharcoalProduction Improvement project. Kumasi is a highly suitable area for the introductionof efficientBeehive brick kilns. Such kilns can be constructedeither at or adjacentto the sawmillsusing locally availablematerials and can be operatedby charcoalersretained by the sawmill. Alternatively,private developers could be awarded exclusive contractsfor the purchaseand carbonizationof the surplussolid residue output at each sawmill. The main ESMAP input will be to provide assistance to determine the appropriate organizationalstructure, identifyinterested sawmill operators or local entrepreneurs,and draft suitableagreements. Specifically the projectcomponent will:
(a) Provide and present detailed informationas to the expected financial returns to the adoption of improved residue carbonization regimes, including capital, material, and trainingrequirements and charcoalyields; - 141 -
(b) Survey and evaluatelocal sawmilloperators and entrepreneurs for their interest and capabilities in improved residue charcoalproduction;
(c) Demonstrate the constructionand operation of the brick (Beehive) kiln on or adjacent to a suitable sawmill, and comparewith the presentmethod;
(4) Determine the most viable organizationof production,i.e. either directly managed by sawmill operators or by entrepreneurs;
(e) If the resultsof (b)-(t)indicate contractual arrangements as being preferable,assist in the drafting, negotiationand finalizationof fixed term renewablecontracts for the purchase and utilizationof sawmillwastes;
(f) Provide technical details as to design, constructionand operationof the brick (Beehive)kilns;
(g) Developa cadreof trainedpersonnel, possibly at FPRI, capable of assistingand trainingothers in the construction,operation and maintenanceof the brick kilns;and
(h) Identifyfollow-on training requirements and financingneeds.
BriquetteCarbonization
7.35 Dependingon donor interest,the technologyand economicsof producingcharcoal from sawdustbriquettes could be investigatedthrough a pilot/demonstrationproject. The existingbriquette factory in Oda is suggestedas a demonstrationsite. The Chaowusplant owner has already begun examining available processes and machinery for briquette carbonization,which would have multi-countryapplication if proved feasible.
PolicyRecommendations
7.36 Governmentpolicies on residue utilizationcan have a large effect on the ultimate dispositionof the waste wood resource. The policyinstruments of fuelspricing and tax/subsidylevbls may be used to direct investment into economically desirable forms of residue utilization,while regulationcan be appliedto prohibitcertain wasteful practices. Lack of informationamong producersand consumersis another type of market failure which can be rectified through government intervention. Specificpolicy recommendationsfor each of the residue utilizationsthat have been identifiedas economicallydesirable are given below. When applicable,cross referencesto corroboratingBank reportrecommendations are indicatedin parentheses. - 142 -
SawmillProcess Heat
7.37 Utilizationof residues,especially sawdust, in sawmillprocess heat applicationsmay be promotedby:
(a) Improvedcoordination between FPRI and TEDB concerningspecies characteristics,uses and treatment requirements, and widespreaddissemination of researchresults to producersand overseasagents (Ghana Forestry Sector Review).
(b) Increasedflow of marketingintelligence from TEDB to producers concerningtreated and kiln-driedproduct export opportunities.
(c) Establishment of kiln-dried lumber quality control and packagingguidelines, and provisionof port infrastructurefor containerizedcargo handling(Ghana Forestry Sector Review).
(d) Differentialtaxation on value-addedforest products (Chana ForestrySector Review).
(e) Phasedextension of log exportban to largernumbers of species (with attendant increase in log sterilizationand product drying requirements)as they become commerciallyaccepted (GhanaForestry Sector Review).
(f) Institutionof permit/feesystems for sawdustdumping and a ban on open sawdustincineration.
ResidueConversion
7.38 Conversionof residuesto more economicallyuseful forms may be promotedby: Provisionof domestic loan financing,which may include the National Energy Board Energy Fund or the NationalBoard for Small Scale Industries;in the case of residue charcoaling operations,loans shouldonly be made to suitablyqualified and trainedentrepreneurs.
Areas for FurtherInvestigation
7.39 An investigationinto economicoptions for the utilizationof logging residues is recommendedand has been incorporatedas a major componentof the proposedESNAP Ghana CharcoalProduction Improvement project. In detail,the componentwills - 143 -
(a) Developa methodto carbonizewaste wood from timberoperations in the forest; this includes a technical and economic assessment,logistic requirements, and timber companies'and Government'sinputs and requirements;
(b) Identify the manpower requirements to carry out these activities,and determinehow and to what extent these can be met by charcoalersfrom the Transitionzone;
(c) Determine the training needs and potential incentivesfor traditionalcharcoalers to start operating in the timber extractionareas;
(d) Determinethe regulatory,economic and social requirementsto be met to reduce traditionalcharcoaling operations in the Transitionzone, and enable charcoalproduction in the timber extractionareas;
(e) Design an appropriateenergy pricing and tax policy to support (d);
(f) Preparea scheduledand costedplan of action. - 144 -
BIBLIOGRAPHY
1. Ghana: Issuesand Optionsin the EnergySector, Report No. 6234-GH, World Bank, November1986.
2. Draft Ghana ForestrySector Review, West AfricaProjects Department, AgricultureDivision, World Bank, 1986.
3. "Surveyof Wood ResidueGeneration and Utilizationin Ghana,"Final Report,Ru-Tek Consultants and IndustriesLtd., Kumasi,Ghana, November1986.
4. "GhanaSawmill Residues Utilization Study," Report X7280/1, Sandwell Swan WoosterInc., Vancouver,January 1987.
5. The ForestDepartment Review and the Requirementsof the Forest ProductsInspection Bureau and the TimberExport Development Board (DraftReport), Silviconsult, Bjarred, Sweden, September 1985.
6. "Reporton Pilot Surveyon Puelwoodand CharcoalConsumption in Accra,"Government of Ghana NationalEnergy Board, October, 1985.
7. EEC Trade PromotionProject "Ghanaian Timber Marketing Study," P-E InternationalOperations Ltd. for Ministryof Financeand Economic Planning,London, 1981.
8. Ghana GenerationPlanning Study, Acres InternationalLtd., Toronto,January 1985.
9. "EconomicAppraisal Report on Rehabilitationof Centraland Eastern Lines,"RITES, New Delhi,October 1986.
10. "TimberExport Development Board Law," P.N.D.C.L.123, Provisional NationalDefence Council of Ghana,October 1985.
11. "GhanaTimber Export Market Report," Issue No. 11, TimberExport DevelopmentBoard, Takoradi, Ghana, October 1986.
12. "GhanaHardwoods," Ghana TimberMarketing Board, Takoradi, Ghana.
13. "Reporton ExportPermits," Forest Products Inspection Bureau, Takoradi,Ghana, October 1986.
14. "CharcoalProduction in Steel and Brick Kilns - TechnologyTransfer in Ghana,"Building and Road ResearchInstitute, Kumasi, Ghana.
15. Ghana: TowardsStructural Adjustment, Report No. 5854-GH,World Bank, October1985. - 145 -
16. Wagenfurh/ScheiberHolzatlas, Veb Fachbuchverlag,Leipzig, 1974. 17. "Productionof Bricksby Hand MouldingMethod at the Asakwa Brick Factory,"Building and Road ResearchInstitute, Kumasi, Ghana.
18. "3000 kW Power Plant Fired by Wood Waste: PreliminaryPlanning for Mim TimberCo. Ltd.,"Spilling Consult AG, Wohlen,Switzerland, June 1977.
19. "CharcoalProduction in DevelopingCountries," Swedforest ConsultingAB for SIDA, Stockholm,March 1983.
20. CharcoalMaking in DevelopingCountries, Technical Report No. 5, Karthscan/IIED9London, 1986. B U KINA F ASO~ --
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Country Project Date Number
Energy Effieiency end Strategy Africa Regional Participants' Reports - Regional Power Seminar on Reducing Electric System Losses in Africa 8B88 087188 8angladesh Power System Efficiency Study 2185 031/85 Sotsvna Pump Electrification Prefeasibility Study 1/86 047/86 Review of Electricity Service Connection Policy 7t87 071/87 Tuli Block Farms Electrification Prefeaibility Study 7/87 072/87 Burkina Technical Assistance Program 3/86 052/86 Burundi Presentation of Energy Projeuts for the tourtb Five-Year Plan (1983-1987) 5185 036/85 Review of Petroleum Import and Distribution Arrangements 1/84 012/84 Costa Rica Recmeended Technical Assistance Projects 11184 027/84 Ethiopia Power System Efficiency Study 10/85 045/85 The Gambia Petrol -j Supply Management Assistace 4/85 035/85 Chana Energy Rationalization in the Industrial ectct of Ghana 6/88 084/88 Guinea- Recommended Technical Assistance 8! sau Projects in the Electric Power Sector 4/8S 033/85 Indonesia Energy Efficiency Improvement in the Brick, Tile and Lime Industries on Java 4/87 067/87 Power Generation Efficiency Study 2/86 050/86 Jamaica Petroleum Procurement, Refining, and Distribution 11/86 061/86 Kenya Power System Efficiency Report 3184 014/84 Liberia Power System Efficiency Study 12/87 081/87 Recommended Technical Assistance Projects 6/85 038/85 Madagasear Power System Efficiency Study 12/87 075/87 Malaysia Sabah Power System Efficiency Study 3/87 068/87 Mauritius Power System B ficiency Study 5/87 070/87 Panama Power System Loss Reduction Study 6/83 004/83 Papuea new nergy Sector Institutional Review: Proposals Gunea for Strengthening the Department of Minerals and Energy 10/84 023/84 Power Tariff Study 10/84 024/84 Senegal Assistance Given for Preparation of Documents for Energy Sector Donors' leeting 4/86 056/86 Seychelles Electric Power System Efficiency Study 8/84 021/84 Sri Lanka Power System Loss Reduction Study 7/83 007/83 Syria Electric Power Efficiency Study 9/88 089/88 Sudan Power System Efficiency Study 6/84 018/84 Managemen Assistance to the Miaistry of Eegy and wining 5/83 003/83 Togo Power System Efficiency Study 12/87 078/87 WoodRecovery in the Nangbeto Lake 4/86 055/06 Uganda Energy Efficiency in Tobacco Curing Industry 2/86 049/86 Institutional Strengthening in the Energy Sector 1/85 029/85 Zambia energy Sector Institutional Review 11/86 060/86 Zimbabwe Power Sector Hanagement Assistance Projects Background, Objectives, and ork Plan 4/85 034/85 Power Systpu Loss Reduction Study 6/83 005/83
Household, Rural ,ad Renevable Energy surundi Peat Utiization Project 11/85 046/85 Improved Charcoal Cookstove Strategy 9/85 042/85 Cote Improved Siomasa Utilization-Pilot Projects dlIvoire Using Agro-Industrial Residues 4/87 069/87 Ethiopia Agricultural Residue Briquettings Pilot Project 12/86 062/86 Bagasse Study 12/86 063/86 The Cambia solar Water seating Retrofit Project 2/85 030/85 Solar Photovoltaic Applications 3/85 032/85 Clobal Proceedings of the ESMP Eastern & Southern Africa Household Energy Planning Seminar 6/U8 085/88 Jamaica FIDC Sawmill Residues Utilization Study 9/88 088 Charcoal Production Project 9/88 090/88 Kenya Solar Water Heating Study 2/87 It6/87 Urban woodfuel Developeent 10/87 076t87 Malawi Technical Assistance to Improve the Efficiency of Fuelwood Use In the Tobacco Industry 11/83 009/83 Mauritlus Bsagasse Power Pc Atial 10/87 077/87 Niger Household Energy Conservation and Substitution 12/87 0o2/87 Improved Stoves Project 12/87 080/87 Peru Proposal for a Stove Dissemtnation Program in the Sierra 2/87 064/87 Rvanda Improved Charcoal Cookstove Strategy 8/86 059/86 Improved Charcoal Production Tecbaiques 2/87 065/87 Senegal Industrial Energy Conservation Project 6/85 037/85 Sri Laoka Industrial Energy Conservation: Fea6ibility Studies for Selected Industries 3/86 054/86 Sudan Wood Energy/Forestry Project 4/88 073/88 Tanzania Woodfuel/Forustry Project 8a88 086/88 Thailand Accelerated Dissemination of Im;roved Stoves and Charcoal Kilns 9/87 079/87 Rural Energy Issues and Options 9/85 044/85 Northeast Region Village Forestry and Woodfuel Pre-Investment Study 2/88 083/88 Uganda Fuelvood/Forestry Feasibility Study 3t86 053/86