Utilization of Biodegradable Wastes As a Clean Energy Source in the Developing Countries: a Case Study in Myanmar

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Article Utilization of Biodegradable Wastes as a Clean Energy Source in the Developing Countries: A Case Study in Myanmar

Maw Maw Tun 1,2,* , Dagmar Juchelková 1,* , Helena Raclavská 3 and Veronika Sassmanová 1 1 Department of Power Engineering, VŠB-Technical University of Ostrava, 17. listopadu 15, 70833 Ostrava-Poruba, Czech Republic; [email protected] 2 Department of Energy Engineering, Czech Technical University, Zikova 1903/4, 166 36 Prague, Czech Republic 3 Centre ENET, VŠB-Technical University of Ostrava, 17. listopadu 15, 70833 Ostrava-Poruba, Czech Republic; [email protected] * Correspondence: [email protected] (M.M.T.); [email protected] (D.J.); Tel.: +420-773-287-487 (M.M.T.) Received: 12 October 2018; Accepted: 12 November 2018; Published: 16 November 2018

Abstract: Nowadays, waste-to-energy has become a type of renewable energy utilization that can provide environmental and economic beneﬁts in the world. In this paper, we evaluated the quality of twelve biodegradable waste samples from Myanmar by binder laboratory heating and drying oven at 105 ◦C. The calculation methods of the Intergovernmental Panel on Climate Change (IPCC) and Institute for Global Environmental Strategies (IGES) were used for the greenhouse gas emission estimation from waste disposal at the open dumpsites, anaerobic digestion, and waste transportation in the current situation of Myanmar. Greenhouse gas (GHG) emission and fossil fuel consumption of the improved biodegrade waste utilization system were estimated and both were found to be reduced. As a result, volume and weight of the biodegradable wastes with 100% moisture reduction were estimated at approximately 5 million cubic meters per year and 2600 kilotonnes per year, respectively, in 2021. The total GHG emissions in the current situation amounted to approximately 1500 and 1800 Gigagrams of CO2-eq per year in 2019 and 2021, respectively, while the total GHG emission avoidance from a sustainable approach amounted to 3500 and 4000 Gigagrams of CO2-eq per year, respectively. The study aimed at highlighting the utilization of biodegradable wastes as a clean energy source in developing countries.

Keywords: renewable energy source; biodegradable waste; waste quality; greenhouse gas emission; sustainable approach

1. Introduction Nowadays, waste has become a local and global issue related to society, wild species, and the environment. Waste generation in developing countries has been increasing along with the growing population, increasing per capita waste generation and economic growth. Without an effective and efﬁcient solid waste management program, the waste generated from various human activities, both industrial and domestic, can result in health hazards and have a negative impact on the environment [1]. The urban population in most Asian developing countries in 2012 might be increased by around 50% in 2025 [2]. Since waste generation rates are closely related to the population and per capita waste generation of a country, the Asian developing countries might have signiﬁcantly increased waste generation rates during 2012–2025 (Figure1).

Energies 2018, 11, 3183; doi:10.3390/en11113183 www.mdpi.com/journal/energies Energies 2018, 11, 3183 2 of 20

EnergiesEnergies 20182018,, 1111,, xx 22 ofof 2020

300300 200200 250 250 160160 200200 120120 150150 8080 100100 Kilotonnes per dayper Kilotonnes Kilotonnes per dayper Kilotonnes

Inhabitants (millions) Inhabitants 40 Inhabitants (millions) Inhabitants 5050 40

00 00

PopulationPopulation 20122012 PopulationPopulation 20252025 SolidSolid WasteWaste GenerationGeneration 20122012 SolidSolid WasteWaste GenerationGeneration 20252025

FigureFigure 1. 1. TotalTotal poppopulation populationulation and and solid solid waste waste generation generation in in the the selected selected developing developing Asian Asian countries countries duringduring 2012 2012–20252012––20252025 [2,3 [[2,32,3]].]..

AccordingAccording toto thethethe World WorldWorld Bank BankBank 2012 20122012 Report ReportReport [2 [2],],[2], the thethe amount amountamount of of municipalof municipalmunicipal solid solidsolid wastes wasteswastes (MSW) (MSW)(MSW) of the ofof thecitiesthe citiescities around aroundaround the world thethe worldworld might mightmight reach 2.2reachreach billion 2.22.2 tonnesbillionbillion per tonnestonnes year per byper 2025 yearyear and byby waste20252025 and generationand wastewaste ratesgenerationgeneration might ratesdoublerates mightmight over doubledouble the next overover two thethe decades nextnext twotwo in developing decadesdecades inin countries. developingdeveloping The countries.countries. country-specific TheThe countrycountry waste--specificspecific composition wastewaste compositioniscomposition mainly influenced is is mainly mainly by consumption influenced influenced by by patterns, consumption consumption educational patterns, patterns, and living educational educational standards, and and household living living standards, standards, income, householdandhousehold economic income income development.,, andand economic economic Generally, development. development. compared Generally,Generally, to the developed comparedcompared countries,to to the the developeddeveloped most developing countries,countries, mostcountriesmost developingdeveloping have greater countriescountries organic havehave greater fractionsgreater organicorganic of their fractionfraction MSWss of composition,of theirtheir MSWMSW composition,composition, being over 50% beingbeing of overover the total.50%50% ofFigureof thethe total.total.2 shows FigureFigure the 22 comparisonshowsshows thethe ccomparisonomparison of waste composition, ofof wastewaste compositioncomposition collection,, collectioncollection efficiency efficieffici andencyency per andand capita perper waste capitacapita wastegenerationwaste generation generation in Asian inin developing Asian Asian developing developing countries countries countries as per the as as World per per the theBank World World 2012 ReportBankBank 2012 2012 [2] and Report Report the scholars [2] [2] and and [ 4thethe] It scholarsisscholars observed [4] [4] thatItIt is is the observed observed MSW in that that most the the of the MSW MSW Asian in in most developingmost of of the the countries Asian Asian developing developing is mainly composed countries countries ofis is organic mainly mainly composedwaste,composed with ofof around organicorganic 55%, waste,waste, followed withwith byaroundaround other 55%,55%, (16%), followfollow papereded (17%), byby otherother plastic (16%),(16%), (11%), paperpaper and (17%),(17%), glassand plasticplastic metal (11%),(11%), (1%) andonand average. glassglass andand The metalmetal collection (1%)(1%) efficiencyonon average.average. and TheThe per collectioncollection capita waste efficiencyefficiency generation andand of perper these capitacapita developing wastewaste generationgeneration countries are ofof theselowerthese developingdeveloping than 70% and countriescountries 1.5 kg perareare capitalowerlower than perthan day, 770%0% respectively. andand 11.5.5 kkgg perper capitacapita perper dayday,, respectivelyrespectively..

100100 22

8080 1.61.6

6060 1.21.2

4040 0.80.8 efficiency (%) efficiency efficiency (%) efficiency Kg per capita per day per capitaper Kg 2020 0.40.4 day per capitaper Kg

00 00 Waste composition (wt. %) & Collection Collection &%) (wt. composition Waste Waste composition (wt. %) & Collection Collection &%) (wt. composition Waste

OthersOthers MetalMetal GlassGlass PlasticPlastic PaperPaper OrganicOrganic CollectionCollection EfficiencyEfficiency PerPer CapitaCapita WasteWaste GenerationGeneration

Figure 2. FigureFigure 2.2. ComparisonComparison of of waste waste composition composition,composition,, collection collection efficiency efﬁciencyefficiency and and per per capita capita waste waste generation generation in in Asian developing countries [2,4]. AsianAsian developingdeveloping countriescountries [2,4[2,4]]..

Energies 2018, 11, 3183 3 of 20

Due to the higher organic fraction and higher moisture content of the MSW, thermal waste treatment is not suitable for energy recovery without additional fuel supply in the developing countries [5,6]. In addition, due to the high investment costs of waste-to-energy technologies, the developing countries commonly use open dumping and landfilling as their principal waste disposal methods [2,7]. However, the negative impacts of waste disposal at open dumpsites and landfills significantly affect the environment [8,9] and public health due to the environmental pollution from the greenhouse gas emissions generated from anaerobic digestion of biodegradable wastes to the atmosphere [10] and landfill leachate impact on the groundwater [11], hygienic issues for waste service workers and the residents residing near the landfilling areas, and the likelihoods of spreading the diseases carried by insects and bacteria to the residents [12]. Further, accelerating waste generation rates in most developing countries could potentially encounter the limited land area for waste disposal at open dumpsites and landfills [13–15]. Nowadays, there is a growing interest in the utilization of renewable energy sources, including biomass, due to the environmental concerns of fossil fuel energy consumption [16]. Currently, the biofuel production from renewable sources is a major challenge in research [17]. Methods of hydrogen generation from waste products have been developed [16]. MSW incineration plants have been advantageous to developed countries for energy recovery and reduction of the mass and volume of initial bulk wastes, despite their drawbacks [13,18]. When incinerated, waste is reduced by 80–85% by weight and by 95–96% by volume [19]. However, waste fuel for energy recovery should ideally have a high heating value and low content of moisture and ash. Therefore, the aim of MSW drying is the modification of the waste’s characteristics to increase its low heating value and allow easier removal of glass, metals, and other inert materials [20]. Hence, energy-oriented conversion technologies for the improvement of the waste quality by drying might have the potential to increase the heating values of raw waste materials [20,21] as well as to reduce the bulk volume of the wastes [22] and waste odour [23] and to facilitate a storage [22] and transportation [24]. In addition, the dried waste materials could offer other significant benefits such as reduced dependency on fossil fuel [23], reduced environmental impacts from the landfills [25], and mitigation of global warming [26]. Therefore, a drying process could probably become a future potential waste pre-treatment option with environmental and economic benefits in developing countries which have higher solar radiation and availability of reliable energy sources from industries, such as waste heat. Among the Asian developing countries, Myanmar was chosen to be a representative country to highlight the utilization of biodegradable wastes as a clean energy source by improving their quality. This was because most cities of Myanmar generally practice the separation of waste into two categories—bio-solid wastes (dry wastes) and biodegradable wastes (wet wastes). The separation of the biodegradable wastes from the generated wastes could easily enable the quality of the biodegradable wastes to be separately improved by drying for use as a future potential energy source.

2. Background of the Study Myanmar is one of the developing countries in South East Asia. It is composed of seven states and seven divisions. It covers approximately an area of 677,000 square kilometres. Myanmar has a total population of over 53 million residents in 2018. The population of Myanmar might be trending around 56.32 million in 2020 [27]. Around 35% of the population resides in an urban area in 2018. The per capita gross domestic product of Myanmar is approximately 1400 US dollars. In Myanmar, the provision of waste collection services, management activities, and initiation of 3Rs (Reduce, Reuse, and Recycle) practices are extensively undertaken by responsible organizations independently [28]. Regarding the research studies [29–31], waste collection methods in Myanmar include door to door waste collection, bell ringing block collection to the household, collection of waste from kerbside bins, collection at street dump yards, collection at a temporary storage system, and sweeping waste from the road. The collection efﬁciency of the major cities like Yangon and Mandalay was higher than 80% in 2017 [31]. However, the overall collection efﬁciency of the country is Energies 2018, 11, 3183 4 of 20 Energies 2018, 11, x 4 of 20 comparativelyrate of Myanmar lower accounted than that of for the approximately major cities, at 11 around,500 tonnes 45% [ 2 per]. The day, total with waste 6230 generation tonnes rate of the of Myanmarbiodegradable accounted wastes for per approximately day in 2017 (Figure 11,500 tonnes 3). This per rate day, will with reach 6230 more tonnes than of the15,000 biodegradable tonnes per wastesday, with per around day in 20179000 (Figuretonnes 3of). the This biodegradable rate will reach wastes more thanper day 15,000 by tonnes2021, according per day, withto the around World 9000Bank tonnes 2012 Report of the biodegradable[2]. wastes per day by 2021, according to the World Bank 2012 Report [2].

20,000 0.75

16,000 0.7

12,000 0.65

Tonnes day per Tonnes 8,000 0.6 Kg per capita per day per capita perKg

4,000 0.55 2017 2018 2019 2020 2021 Year Others (Recyclables & Non-Recyclables) Biodegradable Wastes Total Solid Waste Generation Per Capita Waste Generation Figure 3.3. TheThe contributioncontribution of biodegradable wastes in the total solid waste generation in Myanmar Myanmar.. Note: TheThe contributioncontribution of of biodegradable biodegradable wastes wastes in thein the total total solid solid waste waste generation generation was estimated was estimated based onbased the Worldon the BankWorld 2012 Bank Report, 2012 regardingReport, regarding the waste the composition waste composition and the total and solid the wastetotal solid generation waste ofgeneration Myanmar. of The Myanmar. data were The considered data were only considered until 2021, only since until waste 2021, composition since waste may composition change with may the developmentchange with the of thedevelopment economy and of the living econom standardsy and ofliving people standards in Myanmar. of people in Myanmar.

Due to to the the higher higher organic organic fraction fraction in in the the MSW MSW composition, composition, higher moisture content of of the the organic wastes,wastes, high capital cost ofof waste-to-energywaste-to-energy technologies,technologies, and insufficientinsufficient budget for MSW management, Myanmar Myanmar simply simply uses use opens open dumping dumping or uncontrolled or uncontrolled landfilling landfilling as the as principal the principal waste disposalwaste disposal method, method, like the like similar the similar situations situations of other of developing other developing countries countries (Figure 4(Figure). However, 4). However despite, thedespite landfills the instrumentedlandfills instrumented with the proper with the liner proper and leachate liner and collection leachate systems, collection it may system not eliminates, it may not the rainwatereliminate percolationthe rainwater that percolation impacts on leachatethat impacts production on leachate quality production and quantity quality [32]. Leachateand quantity treatment [32]. representsLeachate treatment one of the represents most relevant one problemsof the most in relevant the field problems of waste treatment in the field [33 of]. waste Currently, treatment landfilling [33]. accountsCurrently, for landfilling approximately accounts 85% of for the approximately total waste disposal 85% of in the Myanmar total waste (approximately disposal in 9800 Myanmar tonnes per(approximately day out of 11,500 9800 tonnes perper dayday inout 2017). of 11 One,500 incinerationtonnes per day plant in with 2017). a capacityOne incineration of 60 tonnes plant of wasteswith a capacity per day hasof 60 been tonnes built of for wastes waste-to-energy per day has in been Yangon built [ 34for]. waste The plant-to-energy generates in Yangon 700 kilowatts [34]. The of electricalplant generates power 700 daily. kilowatts In addition, of electrical an anaerobic power digesterdaily. In has addition, been built an anaerobic for power digester generation has frombeen 30built tonnes for power of waste generation per day in from Mandalay 30 tonnes [31]. of 3-Rs waste activities per day have in beenMandalay widely [31]. practiced 3-Rs activities in Yangon have and Mandalay,been widely but prac theticed recycling in Yangon sector and is still Mandalay, in the development but the recycling stage. Aboutsector is 5% still (86 in tonnes) the development of the total collectedstage. About wastes 5% in(86 Yangon tonnes) could of the be total recycled collected daily wastes [31,35 ],in but Yangon it accounts could forbe onlyrecycled 2%, daily compared [31,35 to], thebut totalit accounts waste generationfor only 2%, of compared the entire to country. the total Since waste there generation is still a of lack the of entire sufficient country. data Since about there the currentis still a waste lack of disposal sufficient methods data about of the the entire current country, waste the disposal data were methods approximately of the entire derived country, from thethe researchdata were data approximately [7,31]. The contribution derived from of wastethe research disposal data methods [7,31]. in The Myanmar contribution is presented of waste in Figuredisposal4. “Others”methods refersin Myanmar to reuse is activities, presented animal in Figure feedings, 4. “O illegalthers” dumping,refers to reuse open activities, burning,etc. animal feedings, illegal dumping, open burning, etc.

Energies 2018, 11, 3183 5 of 20 Energies 2018, 11, x 5 of 20

13% 2% Landfilling 1% 1% Incineration

Anaerobic Digestion

83% Recycling

Others

Figure 4. 4. ComparisonComparison of of waste waste disposal disposal methods methods by percentage by percentage of daily of daily treated treated municipal municipal solid waste solid (MSW)waste (MSW by weight) by weight in Myanmar in Myanmar [7,31]. [7,31].

Currently, alongalong withwith economiceconomic development,development, populationpopulation growth,growth, andand rapidrapid urbanizationurbanization andand industrialization,industrialization, the the most most immediate immediate environmental environmental issues issues related related to MSW to MSW have have accelerated accelerated the need the forneed sustainable for sustainable waste management waste management in the major in citiesthe major of Myanmar cities of [36 Myanmar]. Exploring [3 the6]. possibilitiesExploring the of wastepossibilities fuel as of a cleanwaste energyfuel as sourcea clean becomesenergy source a potential becomes means a potential to gain environmentalmeans to gain environmental and economic beneﬁtsand economic from thebenefits waste from management the waste in management the developing in the countries. developing In Myanmar, countries. the In majorMyanmar, fraction the ofmajor MSW fraction composition of MSW is composition constituted by is organicconstituted or biodegradable by organic or waste.biodegradable Hence, ifwaste. the biodegradable Hence, if the wastebiodegradable could be wasteutilized could as an be energy utilized source, as an the energy environmental source, the pollution environmental from the pollution waste disposal from the at openwaste dumpsites disposal at and open fossil dumpsites fuel consumption and fossil fuel could consumption be avoided. could The pre-treatment be avoided. T ofhe biodegradable pre-treatment wastesof biodegradable by drying wastes could play by drying a key could role in play reducing a key their role in moisture reducing content their moisture and improving content their and qualityimproving for combustion.their quality for Therefore, combustion. the objectives Therefore, of the the objectives study were of the toestimate study were the to biodegradable estimate the wastebiodegradable quality by waste drying quality as a wayby drying of pre-treatment, as a way of topre estimate-treatment, the to amount estimate of GHGthe amount emissions of GHG and avoidanceemissions from and the avoidance waste disposal from the at landﬁlls waste disposal and utilization at landfills of biodegradable and utilization wastes, of and biodegradable to propose awastes, sustainable and to approach propose a to sustainable the waste approach management to the for waste a sustainable management energy for systema sustainable in Myanmar. energy Thesystem presented in Myanma resultsr. The could presented also be used results for could the assessment also be used of biodegradablefor the assessment waste of management biodegradable in otherwaste developingmanagement countries. in other developing countries.

3. Materials and Methods 3.1. Collection of the Samples 3.1. Collection of the Samples The data related to waste generation and waste composition were collected from the World The data related to waste generation and waste composition were collected from the World Bank 2012 Reports [2], published research papers [7,31,35], and report papers [34]. The average Bank 2012 Reports [2], published research papers [7,31,35], and report papers [34]. The average composition of the MSW in Myanmar accounted for 54% organic waste, 16% plastic waste, 8% paper, composition of the MSW in Myanmar accounted for 54% organic waste, 16% plastic waste, 8% 7% glass, 8% metal, and 7% others [2]. In Myanmar, wet wastes and dry wastes are collected separately, paper, 7% glass, 8% metal, and 7% others [2]. In Myanmar, wet wastes and dry wastes are collected mostly in Yangon [28,29]. The wet wastes in Yangon account for organic wastes, composed of food separately, mostly in Yangon [28,29]. The wet wastes in Yangon account for organic wastes, wastes and green leaves, while the dry wastes include plastics, papers, glass, metals, and others [35]. composed of food wastes and green leaves, while the dry wastes include plastics, papers, glass, Of these, wet wastes (mostly food waste and green leaves) were considered for drying for optimization metals, and others [35]. Of these, wet wastes (mostly food waste and green leaves) were considered of the biodegradable waste quality in this study. Twelve samples were prepared to estimate the for drying for optimization of the biodegradable waste quality in this study. Twelve samples were quality improvement of the biodegradable wastes by drying. These samples amounted to 500 g. prepared to estimate the quality improvement of the biodegradable wastes by drying. These The composition ratio of the biodegradable waste samples (food wastes: green leaves/garden samples amounted to 500 g. The composition ratio of the biodegradable waste samples (food wastes: leaves) were considered to be 80:20, based on the research studies about the waste composition green leaves/garden leaves) were considered to be 80:20, based on the research studies about the in Yangon [37,38] in order to cover the variations of the biodegradable waste composition in most waste composition in Yangon [37,38] in order to cover the variations of the biodegradable waste composition in most cities of Myanmar. Table 1 presents the biodegradable waste samples of Myanmar for evaluating their quality by drying.

Energies 2018, 11, 3183 6 of 20 cities of Myanmar. Table1 presents the biodegradable waste samples of Myanmar for evaluating their quality by drying.

Table 1. The properties of the biodegradable waste samples of Myanmar.

Description Quantity Number of samples 12 Total amount of each sample (g) 500 Composition ratio 80:20 (Food wastes: Green leaves/Garden wastes) Density (kg/m3) 274 ± 50 Moisture content (%) 80 ± 4 LHV (MJ/kg) 4 ± 1 LHV: lower heating value.

3.2. Methods

3.2.1. Assessment of the Moisture Contents of the Samples The moisture contents of the samples were assessed by Mettler Toledo HG63 Halogen Moisture Analyzer (Type: HG63). Standard drying was used to dry the samples, with the switch off criterion of one milligram per 50 s and drying temperature of 105 ◦C.

3.2.2. Assessment of the Moisture Reduction, Weight Reduction, Volume Reduction, and Heating Value Increase of the Samples The samples were dried by binder laboratory hating and drying oven (BINDER: FED 400; Capacity: 1000 mm width × 800 mm height × 500 mm depth) at a drying temperature of 105 ◦C for 5 h with an air fan speed of 80%. The drying temperature of 105 ◦C was chosen together with five hours of drying time to efficiently evaluate the changes in the quality of the different samples during the drying process. The moisture reduction, weight reduction, and volume reduction of the samples were recorded at different times. The initial lower heating values and final lower heating values of the samples were approximately estimated based on the following Equations (1) and (2) [39]:

n Wi (100 − MCi) LHVinitial = ∑ × × Ei (1) i=1 Davg 100 W (100−MC ) n j × j ∑j=1 Davg 100 LHV = LHV × (2) ﬁnal initial ( − ) n Wi × 100 MCi ∑i=1 Davg 100 where

LHVinitial and LHVﬁnal are the initial lower heating values and ﬁnal lower heating values of the samples (megajoules per kilogram (MJ per kg)), respectively.

Davg is the average dry mass of the biodegradable wastes in mass (kg) (assumed as 0.2 kg, based on the fact that the total weight and the moisture content of the biodegradable wastes are 1 kg and 80%, respectively).

Wi is the initial weight of a waste component i in the total initial weight of the waste composition (kg).

Wj is the final weight of a waste component j in the total final weight of the waste composition (kg). MCi and MCj are the initial and final moisture content of the waste component i and j (%). Ei is the energy content of a waste component i (MJ per kg). Energies 2018, 11, 3183 7 of 20

n is the total number of the waste types in the total waste composition.

The energy contents of food wastes and green leaves are in the range of 3489–6979 MJ per kg and 2326–18,608 MJ per kg, respectively [40]. The average energy content and moisture content of the biodegradable waste samples were approximately considered as 3.5 MJ per kg and 80% [40], respectively, for ease of estimation.

3.2.3. GHG Emissions and Avoidance from Anaerobic Digestion of the Biodegradable Wastes Based on the IGES GHG calculation methods [41], the GHG emissions and avoidance from anaerobic digestion were estimated as described in the Equation (3).

NGHGAD = ADemission − ADavoidance " # CBiogas × PCH4 × ECCH4 × EFCO2 (3) = [(ECH4 × DM × 1000 × GWPCH4)] − +(GHGLFavoidance)

where

NGHGAD is the net GHG emission/avoidance from anaerobic digestion (kg CO2 per tonne of organic waste).

ADemission is the GHG emissions from the treatment of anaerobic digestion (kg CO2 per tonne of organic waste).

ADavoidance is the GHG avoidance due to the energy recovery from anaerobic digestion and due to avoidance of landﬁlling of the equivalent amount of organic wastes used for anaerobic digestion (kg CO2 per tonne of organic waste). ECH4 is the emissions of CH4 due to leakages (kg of CH4 per kg of dry matter) (assumed as 2 kg of CH4 per tonne of dry organic wastes). DM is the dry matter percentage in the inﬂuent (%) (assumed as 20%). is the conversion factor to calculate dry matter content per tonne of organic waste.

GWPCH4 is the global warming potential of CH4 (21 kg CO2 per kg of CH4). 3 3 CBiogas is the collected amount of biogas (m per ton of organic waste) (assumed as 592 m per tonne of dry mass).

PCH4 is the percentage of CH4 in biogas (%) (assumed as 60%). 3 3 ECCH4 is the energy content of CH4 (MJ per m ) (assumed as 37 MJ per m ). EFCO2 is the emission factor of CO2 by combustion of liquid petroleum gas (LPG) (kg of CO2 per MJ) (assumed as 0.063 kg of CO2 per MJ). Despite having two possible substitutions from biogas into thermal energy or from biogas into electricity, it was assumed that LPG consumption was substituted by using biogas as the thermal energy source.

GHGLFavoidance is the GHG avoidance from landﬁlling of the equivalent amount of organic wastes calculated as per the Equation (4) below. The considerations for the GHG emissions from fossil fuel consumption for operation activities during anaerobic digestion were not included for ease of estimation.

3.2.4. GHG Emission from Waste Disposal of Biodegradable Wastes at Open Dumpsites The Intergovernmental Panel on Climate Change (IPPC) calculation method was used for estimation of GHG emissions to the atmosphere from biodegradable waste disposal at open dumpsites or landfills. The IPCC default method is considered more suitable to be applied in this study because the method is simple, and calculations only require an input of a limited set of parameters, for which Energies 2018, 11, 3183 8 of 20 specific quantities and data of a country are not available [42]. By the IPCC default method, the methane emissions from open dumpsites and landfills can be calculated as follows [35,42]:

16 CH Emission = MSW × MSW × MCF × DOC × DOC × F × − R × (1 − OX) . (4) 4 T F F 12

where

CH4 Emission is methane emission from landﬁll in gigagrams per year. MSWT is the total solid waste generation (Gg per year). MSWF is the fraction of solid waste disposed of, on the wet weight bis. MCF is the methane correction factor (0.6 as a recommended value of IPCC for uncategorized landﬁll). DOC is the degradable organic carbon in MSW (0.1042, derived from IPCC default DOC values).

DOCF is the fraction of DOC that can decompose (fraction) (0.5 as a default value of IPPC). F is a fraction of CH4 in generated landﬁll gas (0.5 as a default value of IPPC). R is the recovered methane (Gg per year) which is zero for open dumpsites with no gas collection system. 16/12 is the molecular weight ratio of methane to carbon, and OX is the oxidation factor, which is zero for open dumpsites as a recommended value of IPCC.

3.2.5. GHG Emission from Transportation The GHG emissions from fossil fuel based-transportation of wastes to ﬁnal disposal sites can be estimated as follows [35,41]: F GHG = × E × EF. (5) T W where

GHGT is GHG emissions from transportation (kg CO2 per tonne of transported waste). F is the total amount of fossil fuel consumption per month, (Diesel in litres and Natural gas in kg). W is the total amount of waste transported per month (tonnes per month). E is the energy content of fossil fuel (36.42 MJ per litre for diesel and 37.92 MJ per kg for natural gas).

EF is the CO2 emission factor of the fuel (0.074 kg CO2 per MJ for diesel and 0.056 kg CO2 per MJ for natural gas).

The fuel consumption for waste transportation towards the open dumping and landﬁlls in all the cities of Myanmar was approximately derived from the waste transportation data of Yangon city. In Yangon city, 128,704 L of diesel and 900 L of gasoline were used for transporting 46,500 tonnes of the collected wastes per month in 2012 [29].

3.2.6. Fossil Fuel Savings and GHG Emissions/Avoidance from Fossil Fuel Consumption and Utilization of the Biodegradable Wastes The amount of fossil fuel that could be saved by the utilization of the biodegradable wastes was estimated by the following equation: Eb FFS = Wb × (6) Eff where

FFS is the amount of fossil fuel that could be saved by utilization of the biodegradable wastes (kilotonnes per year). Energies 2018, 11, 3183 9 of 20

Wb is the amount of the biodegradable wastes (kilotonnes per year). Eb is the energy content of the biodegradable wastes (MJ per kg) (assumed as 3.5 MJ per kg of the biodegradable waste).

Eff is the energy content of the fossil fuel (MJ per kg) (assumed as 30 MJ per kg of black coal).

The GHG emissions from fossil fuel consumption were estimated based on the Equation (7):

GHGF = EF × EMF (7)

where

GHGF is the total estimated amount of greenhouse emissions from fossil fuel consumption (Gg of CO2-eq per year). EF is the total estimated quantity of the energy content of fossil fuel (GJ per year). EMF is the total estimated amount of CO2 emission from fossil fuel consumption (kg of CO2 per GJ).

For ease of estimation, black coal was considered as a fossil fuel, and its CO2 emission from fossil fuel consumption was considered as 92.4 kg of CO2 per GJ [43]. The energy content of fossil fuel was approximately considered to be the equivalent quantity of the energy content of the biodegradable wastes. Biodegradable wastes were considered to be the biomass without the GHG emissions from its consumption [43].

3.2.7. GHG Emission Avoidance from Avoiding Waste Disposal at Open Dumpsites The GHG emission avoidance from the biodegradable waste disposal at open dumpsites could occur when all the biodegradable wastes are assumed to be theoretically used as a clean energy source without any disposal at open dumpsites. Thus, the GHG emission avoidance from avoiding the biodegradable waste disposal at open dumpsites is approximately estimated to equal the amount of GHG emissions from landﬁlling the equivalent amount of waste.

3.2.8. GHG Emission Avoidance from the Utilization of Biodegradable Wastes The GHG emission avoidance from the utilization of biodegradable wastes could occur when the equivalent amount of fossil fuel energy could be avoided by utilizing the equivalent amount of energy from the improved biodegradable wastes. Thus, the amount of GHG emission avoidance from the utilization of biodegradable wastes is approximately estimated to equal the amount of the GHG emissions from the equivalent amount of fossil fuel consumption.

4. Results and Discussion

4.1. Properties of Biodegradable Waste Samples before and after Drying Table2 presents the results of the initial and final values of mass, volume, moisture, and heating values of the improved biodegradable waste samples at 105 ◦C in 5 h. It was observed that the initial and final moisture contents of the biodegradable wastes were in the range of approximately 80 ± 4% and 15 ± 8%, respectively. Meanwhile, the initial and final lower heating values of the biodegradable wastes were in the range of approximately 4 ± 1 MJ per kg and 15 ± 1 MJ per kg. Energies 2018, 11, 3183 10 of 20

Table 2. Properties of the biodegradable waste samples of Myanmar before and after drying at 105 ◦C for 5 h.

Biodegradable Waste Properties Sample Initial Mass Initial Final Initial Final Initial Final Final No. Mass Reduction Volume Volume Moisture Moisture LHV LHV Mass (g) (g) (%) (10−6 m3) (10−6 m3) (%) (%) (MJ/kg) (MJ/kg) 1 500 110 78 1100 500 82.00 4.00 3.15 16.80 2 500 166 67 1800 1300 79.11 15.20 3.66 14.84 3 500 145 71 1850 1050 83.15 11.00 2.95 15.58 4 500 144 71 1550 1100 71.20 10.80 5.04 15.61 5 500 182 64 1700 1300 77.42 18.40 3.95 14.28 6 500 224 55 1300 900 84.73 26.80 2.67 12.81 7 500 250 50 2000 1800 81.96 32.00 3.16 11.90 8 500 157 69 1800 900 79.11 13.40 3.66 15.16 9 500 206 59 2350 1300 80.00 21.20 3.50 13.79 10 500 180 64 1675 900 73.73 9.63 4.60 15.81 11 500 129 74 2500 1500 85.44 11.24 2.55 15.53 12 500 131 74 2288 1375 79.44 5.58 3.60 16.52 500 ± 0 169 ± 42 66 ± 8 1826 ± 8 1160 ± 342 80 ± 4 15 ± 8 4 ± 1 15 ± 1 LHV: lower heating value.

Table 3. The values of correlation, sample size, and p values of different variables related to moisture reduction.

Weight Volume Heating Value Description Reduction Reduction Increase Correlation Coefﬁcient 0.99 0.87 0.94 Moisture Sample Size 12 12 12 Reduction p value 0.00000 0.00021 0.00000

The effect of moisture reduction on weight reduction, volume reduction, and heating value increase of the biodegradable waste samples is shown in Figure5a–c, respectively. It was observed that the moisture reduction signiﬁcantly affected the weight reduction, volume reduction, and heating value increase of the biodegradable waste samples as stated by [39]. Likewise, about 50% moisture reduction from the biodegradable wastes might provide approximately 40% weight reduction from the initial weight of the wastes, 25% volume reduction from the initial volume of the wastes, and 210% heating value increase from the initial heating value of the wastes, respectively. As a result, regarding the achievable percentages of the moisture reduction, the biodegradable waste quality might be increased. The moisture reduction of the wastes could also save a reasonable amount of the GHG emissions from the waste transportation to the open dumpsites due to the reduced volume and weight of the wastes. Energies 2018, 11, x 10 of 20

4.2. The Effect of Moisture Reduction on Weight Reduction, Volume Reduction, and Heating Value of the Biodegradable Wastes of Myanmar Statistical data analysis was performed on the variables related to the moisture reduction of the biodegradable waste samples. To examine the strength and direction of the linear relationship between the variables, Pearson correlation was calculated for each pair of the variables (Table 3). Pearson correlation coefficient can range in value from −1 to 1 (absolute value of −1 or 1 indicates a perfect linear relationship, while the values close to 0 indicates no linear relationship between the variables). The significance of the correlation coefficient was determined by comparison of the p-value to the significance level of 0.05. The correlation was significant (p-value was below the significance level of 0.05) in the following pairs of variables: the moisture reduction and weight reduction; the moisture reduction and volume reduction; and the moisture reduction and heating value increase. The effect of moisture reduction on weight reduction, volume reduction, and heating value increase of the biodegradable waste samples is shown in Figure 5a–c, respectively. It was observed that the moisture reduction significantly affected the weight reduction, volume reduction, and heating value increase of the biodegradable waste samples as stated by [39]. Likewise, about 50% moisture reduction from the biodegradable wastes might provide approximately 40% weight reduction from the initial weight of the wastes, 25% volume reduction from the initial volume of the wastes, and 210% heating value increase from the initial heating value of the wastes, respectively. As a result, regarding the achievable percentages of the moisture reduction, the biodegradable waste quality might be increased. The moisture reduction of the wastes could also save a reasonable amount of the GHG emissions from the waste transportation to the open dumpsites due to the reduced volume and weight of the wastes.

Table 3. The values of correlation, sample size, and p values of different variables related to moisture reduction.

Weight Volume Heating Value Description Reduction Reduction Increase Correlation Coefficient 0.99 0.87 0.94 Moisture Sample Size 12 12 12 Reduction Energies 2018, 11, 3183 p value 0.00000 0.00021 0.00000 11 of 20

80 50 y = 0.8209x - 0.2333 y = 0.4315x + 3.0403 60 R² = 0.9913 40 R² = 0.762

30 40 20 20

Weight Weight Reduction (%) 10 Volume Volume Reduction (%)

0 0 0 20 40 60 80 100 0 20 40 60 80 100 Moisture Reduction (%) Moisture Reduction (%)

Energies 2018, 11, x (a) (b) 11 of 20

500 y = 4.2255x - 3.9019 400 R² = 0.8917

300

200

100 Heating Heating Value Increase (%) 0 0 20 40 60 80 100 Moisture Reduction (%) (c)

Figure 5. Effect of moisture reduction on (a)) weightweight reduction,reduction, (b)) volumevolume reduction,reduction, and (c) heatingheating value increase ofof thethe biodegradablebiodegradable wastewaste samples.samples.

4.3. GHG Emission/Avoidance from Biodegradable WasteWaste DisposalDisposal andand BiodegradableBiodegradable WasteWaste UtilizationUtilization Figure6 6 shows shows thethe totaltotal estimatedestimated weightweight ofof thethe biodegradablebiodegradable wasteswastes beforebefore andand afterafter theirtheir moisture reduction. The total estimatedestimated biodegradable waste generation in Myanmar amounted to approximately 2200 kilotonnes per year in 2017, projecting towards 3200 kilotonnes per year in in 2021. 2021. In Figure Figure6 , 6, three three scenarios scenarios were were considered: considered: 50%, 80%, 50%, and 80% 100%, and moisture 100% moisture reduction reduction for the reduction for the ofreduction the weight of the of weight biodegradable of biodegradable wastes. Itwastes. was observed It was observed that regarding that regarding 50%, 80%, 50%, and 80% 100%, and of100% the moistureof the moisture reduction, reduction, the total the estimated total estimated amount amount of the reduced of the weightreduced of weight the biodegradable of the biodegradable wastes in Myanmarwastes in Myanmar might account might for account 900, 1500, for 900, and 1500, 1800 and kilotonnes 1800 kilo pertonnes year, per respectively, year, respectively in 2017,, trending in 2017, aroundtrending 1300, around 2100, 1300, and 2100 2600, and kilotonnes 2600 kilotonnes per year, per respectively, year, respectively in 2021., in Likewise,2021. Likewise, regarding regarding 50%, 80%,50%, and 80% 100%, and moisture 100% moisture reduction, reduction, the total estimated the total estimatedquantity of quantity the reduced of the volume reduced amounted volume to approximatelyamounted to approximately 2, 3, and 4 million 2, 3 cubic, and meters4 million per cubic year, meters respectively, per year in 2017, respectively and 3, 4, and, in 52017 million and cubic 3, 4, metersand 5 million per year, cubic respectively, meters per in year 2021,, respectively compared to, in the 2021, estimated compared initial to volumethe estimated of the biodegradableinitial volume wastesof the biodegradable (Figure7). wastes (Figure 7).

Weight Reduction- 100%MCR 2021 Weight Reduction- 80%MCR Weight Reduction- 50%MCR Weight Reduction-0%MCR 2019 Year Weight-100%MCR

Weight-80%MCR

2017 Total Weight-50%MCR

Total Weight -4000 -2000 0 2000 4000 Kilotonnes per year

Figure 6. The total estimated weight of the biodegradable wastes before and after moisture reduction.

Energies 2018, 11, x 11 of 20

500 y = 4.2255x - 3.9019 400 R² = 0.8917

300

200

100 Heating Heating Value Increase (%) 0 0 20 40 60 80 100 Moisture Reduction (%) (c)

Figure 5. Effect of moisture reduction on (a) weight reduction, (b) volume reduction, and (c) heating value increase of the biodegradable waste samples.

4.3. GHG Emission/Avoidance from Biodegradable Waste Disposal and Biodegradable Waste Utilization Figure 6 shows the total estimated weight of the biodegradable wastes before and after their moisture reduction. The total estimated biodegradable waste generation in Myanmar amounted to approximately 2200 kilotonnes per year in 2017, projecting towards 3200 kilotonnes per year in 2021. In Figure 6, three scenarios were considered: 50%, 80%, and 100% moisture reduction for the reduction of the weight of biodegradable wastes. It was observed that regarding 50%, 80%, and 100% of the moisture reduction, the total estimated amount of the reduced weight of the biodegradable wastes in Myanmar might account for 900, 1500, and 1800 kilotonnes per year, respectively, in 2017, trending around 1300, 2100, and 2600 kilotonnes per year, respectively, in 2021. Likewise, regarding 50%, 80%, and 100% moisture reduction, the total estimated quantity of the reduced volume amounted to approximately 2, 3, and 4 million cubic meters per year, respectively, in 2017 and 3, 4, Energies 2018and, 511 million, 3183 cubic meters per year, respectively, in 2021, compared to the estimated initial volume 12 of 20 of the biodegradable wastes (Figure 7).

Weight Reduction- 100%MCR 2021 Weight Reduction- 80%MCR Weight Reduction- 50%MCR Weight Reduction-0%MCR 2019 Year Weight-100%MCR

Weight-80%MCR

2017 Total Weight-50%MCR

Total Weight -4000 -2000 0 2000 4000 Kilotonnes per year

Figure 6. The total estimated weight of the biodegradable wastes before and after moisture FigureEnergies 6. 2018The, 11 total, x estimated weight of the biodegradable wastes before and after moisture reduction.12 of 20 reduction. Energies 2018, 11, x 12 of 20 15

1510

105

-50

-10-5 Million cubic metres per yearper metres cubic Million 2017 2019 2021 -10 Total Volume Volume-50%MCR

Million cubic metres per yearper metres cubic Million Volume-80%MCR2017 2019 Volume-100%MCR2021 Volume Reduction-0%MCR Volume Reduction-50%MCR Total Volume Volume-50%MCR Volume-80%MCR Volume-100%MCR Figure 7. The totalVolume estimated Reduction-0%MCR volume of biodegradable wastesVolume before Reduction-50%MCR and after moisture reduction. Figure 7. The total estimated volume of biodegradable wastes before and after moisture reduction. Standard deviation for the volume of the biodegradable wastes is ±18%;± MCR: Moisture reduction. StandardFigure deviation 7. The total for theestimated volume volume of the of biodegradable biodegradable wastes wastes before is 18%;and after MCR: moisture Moisture reduction reduction.. StandardThe total deviation amount forof biodegradablethe volume of the wastes biodegradable in 2017 accountedwastes is ±18%; for approximatelyMCR: Moisture reduct2300 kilotonnesion. The total amount of biodegradable wastes in 2017 accounted for approximately 2300 kilotonnes per per year, providing around 8000 Terajoules of energy resources per year (Figure 8). In 2021, the year, providingquantityThe total of around the amount energy 8000 of resources Terajoulesbiodegradable from of energywastes the biodegradable in resources 2017 accounted perwaste year sfor was approximately (Figure estimated8). In at 2021,2300 approximately kilotonnes the quantity of the energyper11,000 year, resources Terajoules providing from per aroundyear. the biodegradable As 8000 a result, Terajoules it could wastes of save energy was400 kilotonnes resources estimated perof at fossil year approximately fuel (Figure if the 8). biodegradab In 11,000 2021, Terajoulesthele per year.quantitywastes As acould result, of the be energyefficiently it could resources saveutilized. 400 from kilotonnes the biodegradable of fossil waste fuel ifs was the biodegradableestimated at approximately wastes could be 11,000 Terajoules per year. As a result, it could save 400 kilotonnes of fossil fuel if the biodegradable efﬁciently utilized. wastes could be efficiently utilized. 4000 16,000

40003000 16,000 12,000 3000 2000 12,000 8,000 20001000 8,000 4,000

1000 yearper Terajoules Kilotonnes per year per Kilotonnes 0 4,000 Terajoules per yearper Terajoules Kilotonnes per year per Kilotonnes -10000 0 2017 2018 2019 2020 2021 -1000 Year 0 Biodegradable2017 Wastes2018 Fossil2019 Fuel Savings2020 2021Energy Resources Year Figure 8. EstimatedBiodegradable energy resourcesWastes from Fossil the biodegradableFuel Savings wastesEnergy and Resources fossil fuel savings.

Standard deviation of the energy resources from the biodegradable wastes is ±20%. FigureFigure 8. Estimated 8. Estimated energy energy resources resources from fromthe biodegradable the biodegradable wastes wastes and and fossil fossil fuel fuel savings. savings Standard. deviationStandardAs ofshown the deviation energy in Figure resourcesof the9, the energy GHG from resources emissions the biodegradable from from the biodegradablethe biodegradable wastes iswastes±20%. wastes is ±20%. were estimated based on the biodegradable waste disposal at open dumpsites, anaerobic digestion, and waste transportationAs shown fromin Figure the collection9, the GHG points emissions to the from open the dumpsites. biodegradable It was wastes observed were that estimated the total based net onamount the of biodegradable GHG emissions waste from disposalopen dumping, at open anaerobic dumpsites, digestion anaerobic, and waste digestion transportation, and waste was transportationestimated at approximately from the collection 1200 points Gg of COto the2-eq open per dumpsites. year in 2017. It was The observed total net that amount the total of GHG net amountemissions of wouldGHG emissions probably fromincrease open by dumping, 40% in 2021, anaerobic regarding digestion the current, and waste situation. transportation However, was if a estimatedsustainable at approach approximately could be 1200 taken Gg by of pre CO-2treating-eq per the year biodegradable in 2017. The wastes total net by amount drying methods of GHG emissionsand utilizing would them probably, there would increase be byseveral 40% majorin 2021, benefits regarding, such the as currentthe avoidance situation. of biodegradableHowever, if a sustainablewaste disposal approach at open could dumpsites, be taken the by energy pre-treating sources thefrom biodegradable the biodegradable wastes wastes, by drying the avoidance methods andof fossil utilizing fuel consumption,them, there would and reducedbe several waste major transportation benefits, such cost as thedue avoidance to the reduced of biodegradable weight and wastevolume disposal of the at initial open dumpsites, bulk biodegradable the energy wastes. sources The from comparison the biodegradable of GHG wastes, emission/avoidance the avoidance ofbetween fossil fuelthe currentconsumption, situation and and reduced a sustainable waste transportationapproach to the cost waste due management to the reduced of Myanmarweight and is volume of the initial bulk biodegradable wastes. The comparison of GHG emission/avoidance between the current situation and a sustainable approach to the waste management of Myanmar is

Energies 2018, 11, 3183 13 of 20

As shown in Figure9, the GHG emissions from the biodegradable wastes were estimated based on the biodegradable waste disposal at open dumpsites, anaerobic digestion, and waste transportation from the collection points to the open dumpsites. It was observed that the total net amount of GHG emissions from open dumping, anaerobic digestion, and waste transportation was estimated at approximately 1200 Gg of CO2-eq per year in 2017. The total net amount of GHG emissions would probably increase by 40% in 2021, regarding the current situation. However, if a sustainable approach could be taken by pre-treating the biodegradable wastes by drying methods and utilizing them, there would be several major beneﬁts, such as the avoidance of biodegradable waste disposal at open dumpsites, the energy sources from the biodegradable wastes, the avoidance of fossil fuel consumption, and reduced waste transportation cost due to the reduced weight and volume of the initial bulk biodegradable wastes. The comparison of GHG emission/avoidance between the current Energies 2018,, 11,, xx 13 of 20 situation and a sustainable approach to the waste management of Myanmar is presented in Figure 10. presentIt can beed seen in Figure that the 10. total It c netan estimatedbe seen that GHG the emission total net avoidance estimated from GHG biodegradable emission avoidance wastes would from amount to around 3500 Gg of CO -eq per year in 2019 and 4000 Gg of CO -eq per year in 2021, biodegradable wastes would amount2 to around 3500 Gg of CO22--eq per year in2 2019 and 4000 Gg of respectively (Figure 10). CO22--eq per year in 2021,, respectively (Figure 10).

2000

1500

1000 eq per yearper eq eq per yearper eq - - 2 2 500

0 Gg of CO of Gg Gg of CO of Gg -500-500 2017 2018 2019 2020 2021 Waste Disposal at Landfills Anaerobic Digestion Waste Transportation Waste Transportation Figure 9. Total estimatedestimated greenhousegreenhouse gasgas (GHG)(GHG)) emissionsemissions from biodegradable wastewaste disposal in the current situationsituation ofof Myanmar.Myanmar..

2000 Current Situation A Sustainable Approach

1000

-1000-1000 eq peryear eq peryear - - 2 2 -2000-2000

-3000-3000 Gg Gg ofCO Gg Gg ofCO -4000-4000

-5000-5000 2017 2018 2019 2020 2021 GHG Emission from Waste Disposal at Open Dumpsites GHG Emission from Waste Transportation (x1/10) GHG Avoidance from Anaerobic Digestion GHG Avolidance from Biomass Energy from Biodegradable Wastes Reduced GHG from Waste Transporation (x 1/10) FossilFossil FuelFuel EmissionEmission AvoidanceAvoidance GHG Emission from Avoiding Waste Disposal at Open Dumpsites

Figure 10. Comparison of GHGGHG emission/avoidanceemission/avoidance from from the the waste waste disposal of biodegradable waste between the current situationsituation andand aa sustainablesustainable approachapproach toto wastewaste managementmanagement ininin Myanmar.Myanmar..

5. Recommendations Growing population, economic development, rapid urbanization,, and increasing per capita waste generation are boosting the waste generating rates in developing countries. Meanwhile, biodegradable waste accounts forfor a significant part of their MSW and has become the major problem forfor the the MSW MSW management.management. Figure Figure 11 11 showsshows the the projectprojected biodegradable waste generation trends and available solar energy resources inin the the selected selected Asian Asian developing developing countries. countries. The The projected projected biodegradable waste generation trends in these developing countries were derived from the World Bank 2012 Report [2] regarding waste composition and total solid waste generation. It was seen that Pakistan, Indonesia,, and Vietnam would be the most significant contribution of the biodegradable wastes among the countries, ranging from around 30–55 kilotonnes per day in 2012 to 35–75 kilotonnes per day in 2020. The solar energy resource depends on the locations and areas of the country since the country with a larger area of land could generally have a higher solar energy resource. Therefore, Myanmar,, with an approximate area of 677,000 square kilometres,, accounts for approximately 2000 Terawatt--hour per year.

Energies 2018, 11, 3183 14 of 20

5. Recommendations Growing population, economic development, rapid urbanization, and increasing per capita waste generation are boosting the waste generating rates in developing countries. Meanwhile, biodegradable waste accounts for a signiﬁcant part of their MSW and has become the major problem for the MSW management. Figure 11 shows the projected biodegradable waste generation trends and available solar energy resources in the selected Asian developing countries. The projected biodegradable waste generation trends in these developing countries were derived from the World Bank 2012 Report [2] regarding waste composition and total solid waste generation. It was seen that Pakistan, Indonesia, and Vietnam would be the most signiﬁcant contribution of the biodegradable wastes among the countries, ranging from around 30–55 kilotonnes per day in 2012 to 35–75 kilotonnes per day in 2020. The solar energy resource depends on the locations and areas of the country since the country with a larger area of land could generally have a higher solar energy resource. Therefore, Myanmar, with an approximate area of 677,000 square kilometres, accounts for approximately 2000 Terawatt-hour

Energiesper 2018 year., 11, x 14 of 20

80,000 6000

60,000 4500

40,000 3000 TWh per year per TWh

Tonnes per dayper Tonnes 20,000 1500

0 0

Biodegradable Wastes 2016 Biodegradable Wastes 2018 Biodegradable Wastes 2020 Solar Energy Source FigureFigure 11. Projected 11. Projected biodegradable biodegradable waste waste generation generation and solar and solarenergy energy resource resourcess in Asian in Asian developing developing countriescountries [2,44 []2. ,44].

Nowadays,Nowadays, there there are already are already several several ways ways to handle to handle biodegradable biodegradable waste waste,, such such as composting, as composting, anaerobicanaerobic digestion digestion,, and and landfills landﬁlls with with gas gas recovery recovery systems. systems. However, However, modern modern waste waste disposal disposal methodsmethods,, such such as biodrying as biodrying and andbiostabilization biostabilization,, are still are stillin development. in development. Therefore, Therefore, a comparison a comparison of of the majorthe major waste waste disp disposalosal methods methods for biodegradable for biodegradable waste waste is presented is presented in Table in Table 4. 4.

Energies 2018, 11, 3183 15 of 20

Table 4. Comparison of the major waste disposal methods for biodegradable wastes [2,41,45,46].

Waste Economic Benefits Waste Working GHG Types of Wastes Separation Disposal Cost Energy Potential Possibility of (Viewed from Benefits Environmental Disposal Skills and Emissions/Leachate GHG Avoidance Treated Work (USD per (kWh per tonne) Resource Recovery of the Environment and Impact Methods Technologies Production tonne) Public Health) - Avoidance - Combustion of wastes Mixed MSW of landfilling - Fossil fuel (Biodegradable - Avoidance of fossil Comparatively Incineration Needed 40–200 [2] 585 Yes Highly needed High consumption for Wastes + Other fuel consumption due lower operation activities Combustible Wastes) to energy recovery - Methane emissions - Avoidance Food wastes/Green due to the leakage of landfilling Anaerobic leaves 730–1300 (for dry Comparatively Highly needed 20–150 [2] Yes Highly needed High - Fossil fuel - Avoidance of fossil Digestion (Biodegradable ton of food waste) consumption for fuel consumption due lower Wastes) operation activities to energy recovery - Avoidance of Food wastes/Green - Fossil fuel chemical leaves Comparatively Composting Highly needed 5–90 [2] - Yes Needed High consumption for fertilizer usage (Biodegradable operation activities - Avoidance lower Wastes) of landfilling - Emissions due to anaerobic digestions of - Avoidance of fossil Mixed MSW the wastes and fuel consumption due Landfilling (Biodegradable No needed 10–100 [2] 105 No Needed High leachate production to energy recovery High Wastes + Others) - Fossil fuel (only for landfill consumption for gas recovery) operation activities - Emissions due to Mixed MSW Open anaerobic digestion of (Biodegradable No needed 2–10 [2] - No No needed Low - Very high Dumping waste and Wastes + Others) leachate production Note: Waste disposal cost might vary with the country groups: developing countries and developed countries. The values in the table were collected from two groups of these countries. Energies 2018, 11, 3183 16 of 20

In Myanmar, the majority of the cities are currently practicing a waste separation system involving two categories—bio-solid waste and biodegradable waste. Currently, 30 tonnes of organic waste are being treated by anaerobic digestion process in Mandalay, and 60 tonnes of mixed waste are being incinerated in Yangon city. However, the majority of the generated waste from the cities of Myanmar are disposed of at open dumpsites, making up approximately 85% of the total. There is also a reasonable amount of waste being illegally dumped, such as waste disposal at nearby streets, illegal dumpsites, open burning, streams, rivers, etc. As a result, there have been GHG emissions and leachate production that negatively affect the environment annually. Environmental issues are also closely related to public health issues, not only from the hygienic perspective, but also from the other important perspectives, such as spreading of diseases, water pollution, soil pollution, air pollution, etc. Therefore, the consequences of doing little or even nothing to address waste management could be very costly to society and the economy overall [47]. Figure 12 illustrates a sustainable approach to waste management in Myanmar. As a sustainable approach, biodegradable waste needs to be managed very well and considered as a significant issue of municipal solid waste management. Anaerobic digestion for the treatment of biodegradable wastes is significantly advantageous to biogas production. Similarly, the composting process, which is less costly and easy to operate locally, is also well-suited to the pre-treatment of biodegradable wastes and the production of compost for agriculture use. Moreover, as a pre-treatment option of the biodegradable wastes for a clean energy source, drying of biodegradable waste is also a possibility for reducing the moisture content of bulky waste and increasing the heating values of waste for incineration. The energy source for drying could be derived from solar energy or the waste heat disposed from the industries. If the quality of biodegradable waste could be improved, the improved raw materials could be efficiently utilized for waste-to-energy (combustion and biogas production) conversion, refuse-derived fuel, sanitization of wastes, and transport of the waste without any negative impacts on the health of the waste collectors. Since Myanmar has average solar radiation of approximately 18 Megajoules per square meter per day [48], it is reasonably suitable for drying of the biodegradable waste. In addition, waste heat could be applied for the drying process during the night or during the seasons with low solar radiation, such as the raining season. The amount of the biodegradable waste for the potential small drying units accounts for approximately 200 kg of biodegradable waste. The energy required for drying depends on the moisture content of the biomass, the available heat source, the sizes of the biomass materials, the types of dryer (such as direct, indirect, or combined), and the energy recovery option. The energy required to dry one kilogram of biodegradable waste is in the range of approximately 2000–5000 kilojoules per kilogram, assuming it to be similar to drying biomass with 50–60% moisture content [49]. However, there might be some drawbacks of using dryers, such as the costly design of the solar dryer, land use and storage for drying, and people’s perception of the odour coming from the drying process if it takes place near or inside the city. These drawbacks could be overcome if the local governments would conduct several surveys about land availability and people’s perceptions and cooperate with the local technological universities and research institutions for sustainable waste management solutions. Technological universities and research institutions could create locally available green technologies from laboratory and pilot scale to industrial scale. In addition, more research on the costs and benefits of drying for a waste fuel source should be conducted, regarding the available heat sources, different seasonal profiles, locally accessible technologies, different drying methods, and seasonal waste composition and properties, etc. As the overall benefits, the drying process for the improvement of biodegradable waste quality by using solar radiation or waste heat could bring no “additional” cost of energy sources for drying and could reduce dependency on fossil fuels in developing countries. Besides, such a process could solve several issues related to the sanitization of biodegradable waste and the health risks of the waste workers or waste collectors, reduction of the transportation cost, and reduction of greenhouse gas emissions from the waste transportation sector, as well as the business-as-usual fossil fuel consumption. Energies 2018, 11, 3183 17 of 20 Energies 2018, 11, x 17 of 20

Figure 12. 12.A A sustainable sustainable approach approach to waste to waste management management for a sustainable for a sustainable energy system energy in systemMyanmar: in (new)Myanmar: refers (new) to the refers proposed to the pretreatment/waste proposed pretreatment/waste disposal methods. disposal methods.

6. ConclusionsHowever, there might be some drawbacks of using dryers, such as the costly design of the solar dryer,Nowadays, land use and the storage majority for drying of waste, and disposal people’s in perception Myanmar of isthe by odour landfilling. coming from Recycling the drying and waste-to-energyprocess if it takes technologies place near are or insidein the development the city. These stage. drawbacks To be able could toutilize be overcome energy from if the waste, local governmentsthe study estimated would theconduct improvement several surveys of biodegradable about land waste availability quality byand drying. people The’s perception quantity ofs and the cooperatereduced volume with the and local weight technological of the biodegradable universities wastes and with research 100% moistureinstitutions reduction for sustainable were estimated waste managementat 5 million cubic solutions. meters perTechnological year and 2600 universities kilotonnes and per researchyear, respectively, institutions in 2021. could The create greenhouse locally availablegas emissions green in technologies the current from situation laboratory amounted and pilot to approximately scale to industrial 1500 andscale. 1800 In addition, Gigagrams more of research on the costs and benefits of drying for a waste fuel source should be conducted, regarding CO2-eq per year in 2019 and 2021, respectively, while the greenhouse gas emission avoidance from the available heat sources, different seasonal profiles, locally accessible technologies, different a sustainable approach amounted to 3500 and 4000 Gigagrams of CO2-eq per year, respectively. Althoughdrying methods waste-to-energy, and seasonal has becomewaste composition a type of renewable and properties, energy etc. utilization, a quick transition from openAs dumping the overall to costlybenefits, waste-to-energy the drying process technologies for the improvement might be hard of inbiodegradable a developing waste country quality like byMyanmar. using solar However, radiation a locally or wast accessiblee heat could sustainable bring approachno “additional” to waste cost management, of energy sources such as for drying drying for andoptimization could reduce of biodegradable dependency wasteon fossil quality fuels and in developing utilizing improved countries. waste Besides, for energy, such a could process probably could solvebecome several a future issues method related ofcreating to the sanitization a clean energy of biodegradable source from waste waste in theand future the health of Myanmar risks of and the wasteother developingworkers or countries.waste collectors, reduction of the transportation cost, and reduction of greenhouse gas emissions from the waste transportation sector, as well as the business-as-usual fossil fuel Authorconsumption. Contributions: Conceptualization, D.J., M.M.T., H.R. and V.S.; Methodology, M.M.T., D.J., H.R. and V.S.; Resources, M.M.T.; Formal Analysis, M.M.T. and D.J.; Investigation, M.M.T., D.J. and H.R.; Supervision, D.J. and H.R.; Writing Original Draft Preparation, M.M.T.; Writing review & editing, M.M.T., D.J., H.R. and V.S. 6. Conclusions Funding: The research was funded by the Ministry of Education, Youth and Sports of the Czech Republic and the project:Nowadays, CZ.02.1.01/0.0/0.0/ the majo 16_019/0000753.rity of waste disposal in Myanmar is by landfilling. Recycling and Acknowledgments:waste-to-energy technologiesThe author wouldare in the like development to express his specialstage. To sincere be able gratitude to utilize to Ministry energy offrom Education, waste, Youththe study and Sportsestimated of the the Czech improvement Republic and of Ministry biodegradable of Education waste of Myanmarquality by for drying. giving himThe an quantit opportunityy of the to reducedstudy in the volume Czech Republic. and weight of the biodegradable wastes with 100% moisture reduction were estimatedConflicts of at Interest: 5 millionThe cubic authors meters declare per no year conflict and of 2600 interest. kilotonnes per year, respectively, in 2021. The greenhouse gas emissions in the current situation amounted to approximately 1500 and 1800 Gigagrams of CO2-eq per year in 2019 and 2021, respectively, while the greenhouse gas emission avoidance from a sustainable approach amounted to 3500 and 4000 Gigagrams of CO2-eq per year, respectively. Although waste-to-energy has become a type of renewable energy utilization, a quick transition from open dumping to costly waste-to-energy technologies might be hard in a developing country like Myanmar. However, a locally accessible sustainable approach to waste management,

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