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Home , Electrolytic cell, Electrolytic process, Sodium hydroxide

Eco-profiles of the European Plastics Industry

SODIUM

A report by

I Boustead

for

Plastics Europe

Data last calculated

March 2005

naoh 1

IMPORTANT NOTE

Before using the data contained in this report, you are strongly recommended to look at the following documents:

1. Methodology

This provides information about the analysis technique used and gives advice on the meaning of the results.

2. Data sources

This gives information about the number of plants examined, the date when the data were collected and information about up-stream operations.

In addition, you can also download data sets for most of the upstream operations used in this report. All of these documents can be found at: www.plasticseurope.org.

Plastics Europe may be contacted at

Ave E van Nieuwenhuyse 4 Box 3 B-1160 Brussels

Telephone: 32-2-672-8259 Fax: 32-2-675-3935

naoh 2 CONTENTS

ELECTROLYSIS OF ...... 4

PRODUCT TREATMENT...... 8

PARTITIONING ...... 8

SODIUM CHLORIDE ...... 8 EMISSIONS ...... 8 STEAM INPUT TO THE CELL ...... 9 HC L INPUT TO THE CHLORINE CELL ...... 9 NAOH INPUT TO THE CHLORINE CELL ...... 9 SULPHURIC INPUT ...... 9 EMISSIONS FROM THE CHLORINE CELL ...... 9 CHLORINE EMISSIONS FROM THE CHLORINE CELL ...... 9 ELECTRICITY USE IN THE CHLORINE CELL ...... 10 ECO-PROFILE OF ...... 10

naoh 3 OF BRINE

Over 90% of all industrial chlorine is produced by electrolysis, a process in which an electric current is passed through a brine . An important by- product of this process is sodium hydroxide. In its simplest form an is as shown in Figure 1. Two plates, or , are inserted into a brine solution and connected to a DC power supply. The connected to the negative terminal is called the and the electrode connected to the positive terminal is called the . When the current passes, chlorine gas is liberated at the anode, hydrogen gas is liberated at the cathode and the is gradually converted from to sodium hydroxide.

The net result of the reaction can be written as:

NaCl(aq) + H 2O(l) = NaOH(aq) + ½H 2(g) + ½Cl 2(g)

All of the products of this reaction are marketable and so should be as pure as possible - hence one reason for the initial purification of the brine.

Quite apart from the poor energy efficiency of the simple cell, it possesses a number of other disadvantages which call for a more sophisticated design. Principal amongst these are:

(a) It is difficult to collect the hydrogen and chlorine gases,

(b) It is difficult to keep the hydrogen and chlorine gases apart. This could cause serious problems because they could react explosively with each other to form .

(c) The electrolyte is a mixture of sodium chloride and sodium hydroxide which would need further treatment to separate the marketable sodium hydroxide.

(d) Cells operate at elevated and hot sodium hydroxide solution will dissolve chlorine.

(e) The simple cell is not a continuous process.

(f) Once a significant proportion of the sodium chloride has been converted to the hydroxide, the cell is operating with dilute of NaCl, which makes it inefficient.

naoh 4 - + chlorine cathode anode

hydrogen

brine

NaOH

Figure 1. Simple electrolytic cell.

One of the first methods employed to overcome some of these problems was the diaphragm cell shown schematically in Figure 2. It differs from the simple cell of Figure 1 in that the anode and cathode are separated by a permeable membrane (originally made from porous pot). The level of electrolyte in the anode chamber is maintained at a slightly higher level than that in the cathode chamber by allowing fresh brine to trickle in at the same rate as it runs out through the diaphragm. The net result is a continuous flow of electrolyte from anode to cathode chamber but the electrolytic reaction is identical to that in the simple cell.

The diaphragm cell overcomes most of the problems of the simple cell. Hydrogen and chlorine are produced in separate chambers, sodium hydroxide cannot diffuse into the anode chamber to react with the chlorine because of the continuous flow of brine through the diaphragm, the anode is presented with a constant concentration of sodium chloride so producing chlorine at a constant rate and, finally, the process is continuous.

naoh 5 hydrogen chlorine - +

brine

NaCl+NaOH

Figure 2. Schematic diagram of a diaphragm cell.

From an operational viewpoint, the brine used in diaphragm cells must be carefully purified. It is especially important that the concentrations of Mg ++ and Ca ++ are minimised because the presence of sodium hydroxide will cause these two impurities to precipitate. This often occurs in the diaphragm itself and blocks the pores.

In modern diaphragm cells the diaphragm is usually made of asbestos, the cathode is usually a steel wire mesh and the are usually titanium. The diaphragm will usually last 3 to 4 months before it needs replacement. The membrane cell is based on the same principle as the diaphragm cell but the membrane is usually based on cellulosic fibres.

One of the main commercial disadvantages of the diaphragm cell is the production of a mixture of sodium chloride and sodium hydroxide rather than pure sodium hydroxide. This problem is overcome in the cell (sometimes called the cell) illustrated schematically in Figure 3.

This cell relies on the property of mercury, a liquid at room temperatures, to dissolve sodium metal to form an amalgam which remains liquid until the sodium concentration reaches 2.5wt%. In the mercury cell, mercury flows slowly across the steel of the cell and electrical contact is made through the base. A stream of clean mercury is fed in at one end of the cell and liquid amalgam is extracted at the other. Similarly, saturated brine is fed into one end of the cell and depleted brine is extracted at the other; this maintains a constant concentration of brine within the cell.

This type of cell requires to additional external facilities; some means of decomposing the amalgam and some means of regenerating the brine.

The amalgam can be readily decomposed with hot water and since the process is separate from the electrolytic cell, the sodium hydroxide is pure and can be

naoh 6 obtain at commercial concentrations at this stage. Furthermore, since the hydrogen liberated during the decomposition is outside of the electrolytic cell, there is no possibility of any reaction between hydrogen and chlorine.

saturated brine depleted brine anode

amalgam outlet mercury inlet

cathode

Figure 3. Schematic diagram of a mercury cell. See text for explanation.

During passage through the cell, the brine concentration is reduced by 10%- 15% of its initial value. The brine is regenerated by passing it through a suspension of solid sodium chloride. However, because of the continuous recycling, it is important that the resaturation plant also incorporates a further purification operation to prevent the build-up of impurities.

In the sample of producers examined in this report, 68% were operating mercury cells, 12% were operating diaphragm cells and the remaining 20% operated membrane cells. The mix of products also varied from one operator to another. Most producers manufactured chlorine, sodium hydroxide and hydrogen. One producer however made no chlorine; all of it was converted to . The quantities of hydrogen recovered for further use was variable, ranging from one producers who vented the whole of the hydrogen output to the atmosphere to one producer who recovered almost the whole stoichiometric amount. All operators of mercury cells also produced sodium hypochlorite. Smaller quantities of hypochlorite were produced by the operators of membrane cells but very little hypochlorite was manufactured by the operators of diaphragm cells. The production of the different products by the various routes are summarised in Table 1.

naoh 7 Table 1. Production of chlorine, sodium hydroxide, hydrogen and sodium hypochlorite in thousands of tonnes by the different production routes in the sample of plants examined. NaOH and NaOCl are expressed as 100% chemical and not as solution mass. Production from Chlorine Sodium Hydrogen Sodium plants operating: hydroxide hypochlorite Mercury cells 5007 6386 189 374 Membrane cells 1836 2045 51 125 Diaphragm cells 949 1063 27 3 Totals 7792 9494 267 502

PRODUCT TREATMENT

Most chlorine is dried using concentrated sulphuric acid and then compressed. A small proportion ( ≈ 5% of the sample examined) was liquefied.

Sodium hydroxide from mercury cells is usually produced as a 50% solution. That produced in both membrane and diaphragm cells is treated to remove residual sodium chloride and is concentrated. A small proportion ( ≈ 4% of the sample examined) produced solid sodium hydroxide.

None of the plants examined reported any treatment for the hydrogen produced. In many instances this hydrogen was burned in the steam plant to generate process steam and, occasionally, electricity for use in the electrolysis plant.

PARTITIONING

Sodium chloride

In the present work, sodium chloride has been partitioned between chlorine, sodium hydroxide and, where appropriate, sodium hypochlorite and hydrogen chloride on the basis of the stoichiometric demand. Any excess inputs of sodium chloride have been attributed to the relevant products in proportion to their stoichiometric demands.

Water emissions

Those water emissions associated with NaCl and its purification have been attributed to chlorine, sodium hydroxide and, where appropriate, sodium hypochlorite and hydrogen chloride on the basis of the quantities of sodium chloride attributed to each of these products. Water emissions, which could not

naoh 8 be directly attributed to sodium chloride, e.g. mercury emissions, were partitioned between the products on a simple mass basis.

Steam input to the chlorine cell

In an earlier report, 1 the steam input to chlorine cells was all attributed to sodium hydroxide on the assumption that this was the primary reason for this input. From the present data, however, it is clear that this is not so. Many plants which reported separately the NaOH concentration stage also reported steam inputs to the cell itself. The steam input to the chlorine cell has therefore been partitioned across all products on a simple mass basis.

HCl input to the chlorine cell

Any HCl input to the cell electrolyte will be completely dissociated and will therefore provide an additional source of chloride ions in the electrolyte. It has therefore has been attributed to the production of chlorine.

NaOH input to the chlorine cell

Any NaOH input to the cell has been attributed solely to the production of NaOH on the assumption that it will be recovered along with the NaOH generated within the .

Sulphuric acid input

An input of 98% sulphuric acid is used for chlorine drying and so has all been attributed to the chlorine output.

Hydrogen emissions from the chlorine cell

Hydrogen emissions from the cell refer to the losses of hydrogen to the atmosphere. These emissions have therefore all been attributed to the production of hydrogen.

Chlorine emissions from the chlorine cell

Chlorine gas emissions from the cell refer to the loss of chlorine to the atmosphere. These emissions have therefore all been attributed to the production of chlorine.

1 I Boustead. Ecoprofiles of the European polymer industry: Report 6: . A report for APME’s technical and Environmental Centre, Brussels. April 1994.

naoh 9 Electricity use in the chlorine cell

The allocation of electricity to the different products from the chlorine cell has been the subject of much discussion over the years. Almost all methods that have been proposed have their proponents and opponents and no single method meets with universal approval. In the present work electricity input is partitioned over all marketable or usable products on a simple mass basis. This is the method that has traditionally been used in almost all work to date.

ECO-PROFILE OF SODIUM HYDROXIDE

The data given here refer to a concentrated solution of sodium hydroxide and refer to the mass of hydroxide, not the mass of solution. Table 2 shows the gross or cumulative energy to produce 1 kg of electrolytic hydrogen and Table 3 gives this same data expressed in terms of primary fuels. Table 4 shows the energy data expressed as masses of fuels. Table 5 shows the raw materials requirements and Table 6 shows the demand for water. Table 7 shows the gross air emissions and Table 8 shows the corresponding equivalents of these air emissions. Table 9 shows the emissions to water. Table 10 shows the solid waste generated and Table 11 gives the solid waste in EU format.

Table 2 Gross energy required to produce 1 kg of sodium hydroxide. (Totals may not agree because of rounding) Fuel type Fuel prod'n Energy content Energy use Feedstock Total & delivery of delivered in energy energy energy fuel transport (MJ) (MJ) (MJ) (MJ) (MJ) Electricity 7.81 4.05 0.07 - 11.93 fuels 0.15 1.11 0.03 <0.01 1.29 Other fuels 0.39 8.11 0.03 0.29 8.82 Totals 8.35 13.27 0.13 0.29 22.04

naoh 10 Table 3 Gross primary fuels required to produce 1 kg of sodium hydroxide. (Totals may not agree because of rounding) Fuel type Fuel prod'n Energy content Fuel use Feedstock Total & delivery of delivered in energy energy energy fuel transport (MJ) (MJ) (MJ) (MJ) (MJ) Coal 1.63 2.02 <0.01 0.23 3.88 Oil 0.72 1.44 0.12 <0.01 2.27 Gas 1.53 7.44 <0.01 <0.01 8.98 Hydro 0.57 0.43 <0.01 - 1.00 Nuclear 3.67 1.81 <0.01 - 5.48 Lignite <0.01 <0.01 <0.01 - <0.01 Wood <0.01 <0.01 <0.01 0.06 0.06 Sulphur <0.01 <0.01 <0.01 0.01 0.01 Biomass (solid) 0.04 0.03 <0.01 <0.01 0.07 Hydrogen <0.01 0.48 <0.01 - 0.48 Recovered energy <0.01 -0.45 <0.01 - -0.45 Unspecified <0.01 <0.01 <0.01 - <0.01 Peat 0.01 0.01 <0.01 - 0.01 Geothermal 0.06 0.03 <0.01 - 0.08 Solar <0.01 <0.01 <0.01 - <0.01 Wave/tidal <0.01 <0.01 <0.01 - <0.01 Biomass (liquid/gas) 0.02 0.01 <0.01 - 0.03 Industrial waste 0.02 0.01 <0.01 - 0.03 Municipal Waste 0.05 0.02 <0.01 - 0.07 Wind 0.02 0.01 <0.01 - 0.03 Totals 8.35 13.27 0.13 0.29 22.04

Table 4 Gross primary fuels used to produce 1 kg of sodium hydroxide expressed as mass. Fuel type Input in mg Crude oil 50000 Gas/condensate 170000 Coal 140000 Metallurgical coal 32 Lignite 12 Peat 1600 Wood 6300

naoh 11 Table 5 Gross raw materials required to produce 1 kg of sodium hydroxide. Raw material Input in mg Air 22000 Animal matter <1 Barytes 31 Bauxite <1 Bentonite <1 Biomass (including water) 11000 Calcium sulphate (CaSO4) <1 Chalk (CaCO3) <1 Clay <1 Cr <1 Cu <1 Dolomite 1 Fe 80 Feldspar <1 Ferromanganese <1 Fluorspar <1 Granite <1 Gravel <1 Hg 2 Limestone (CaCO3) 11000 Mg <1 N2 710 Ni <1 O2 2 Olivine 1 Pb 1 Phosphate as P2O5 <1 Potassium chloride (KCl) 2 Quartz (SiO2) <1 Rutile <1 S (bonded) <1 S (elemental) 1400 Sand (SiO2) 81 Shale <1 Sodium chloride (NaCl) 990000 Sodium nitrate (NaNO3) <1 Talc <1 Unspecified <1 Zn <1

Table 6 Gross water consumption required for the production of 1 kg of sodium hydroxide. (Totals may not agree because of rounding) Source Use for Use for Totals processing cooling (mg) (mg) (mg) Public supply 430000 - 430000 River canal 6 640 640 Sea 34 550 580 Well <1 <1 <1 Unspecified 3000000 6600000 9600000 Totals 3400000 6600000 10000000

naoh 12 Table 7 Gross air emissions associated with the production of 1 kg of sodium hydroxide. (Totals may not agree because of rounding) Emission From From From From From From Totals fuel prod'n fuel use transport process biomass fugitive (mg) (mg) (mg) (mg) (mg) (mg) (mg) dust (PM10) 350 83 2 110 - - 540 CO 740 150 23 1 - - 910 CO2 440000 680000 3800 570 -5800 - 1100000 SOX as SO2 2900 1900 34 <1 - - 4800 H2S <1 - <1 <1 - - <1 mercaptan <1 <1 <1 <1 - - <1 NOX as NO2 1300 1700 34 10 - - 3000 NH3 <1 - <1 <1 - - <1 Cl2 <1 <1 <1 <1 - - <1 HCl 46 13 <1 <1 - - 59 F2 <1 <1 <1 <1 - - <1 HF 2 <1 <1 <1 - - 2 hydrocarbons not specified 510 110 10 <1 - <1 640 aldehyde (-CHO) <1 - <1 <1 - - <1 organics <1 <1 <1 <1 - - <1 Pb+compounds as Pb <1 <1 <1 <1 - - <1 Hg+compounds as Hg <1 - <1 <1 - - <1 metals not specified elsewhere 1 1 <1 <1 - - 2 H2SO4 <1 - <1 <1 - - <1 N2O <1 <1 <1 <1 - - <1 H2 28 <1 <1 260 - - 290 dichloroethane (DCE) C2H4Cl2 <1 - <1 <1 - <1 <1 vinyl chloride monomer (VCM) <1 - <1 <1 - <1 <1 CFC/HCFC/HFC not specified <1 - <1 <1 - - <1 organo-chlorine not specified <1 - <1 <1 - - <1 HCN <1 - <1 <1 - - <1 CH4 11000 230 <1 65 - <1 12000 aromatic HC not specified elsewhere <1 - <1 <1 - <1 <1 polycyclic hydrocarbons (PAH) <1 <1 <1 <1 - - <1 NMVOC <1 - <1 <1 - - <1 CS2 <1 - <1 <1 - - <1 methylene chloride CH2Cl2 <1 - <1 <1 - - <1 Cu+compounds as Cu <1 <1 <1 <1 - - <1 As+compounds as As - - - <1 - - <1 Cd+compounds as Cd <1 - <1 <1 - - <1 Ag+compounds as Ag - - - <1 - - <1 Zn+compounds as Zn <1 - <1 <1 - - <1 Cr+compounds as Cr <1 <1 <1 <1 - - <1 Se+compounds as Se - - - <1 - - <1 Ni+compounds as Ni <1 <1 <1 <1 - - <1 Sb+compounds as Sb - - <1 <1 - - <1 ethylene C2H4 - - <1 <1 - - <1 oxygen - - - <1 - - <1 asbestos - - - <1 - - <1 dioxin/furan as Teq - - - <1 - - <1 benzene C6H6 - - - <1 - <1 <1 toluene C7H8 - - - <1 - <1 <1 xylenes C8H10 - - - <1 - <1 <1 ethylbenzene C8H10 - - - <1 - <1 <1 styrene - - - <1 - <1 <1 propylene - - - <1 - - <1

naoh 13 Table 8 Carbon dioxide equivalents corresponding to the gross air emissions for the production of 1 kg of sodium hydroxide. (Totals may not agree because of rounding) Type From From From From From From Totals fuel prod'n fuel use transport process biomass fugitive (mg) (mg) (mg) (mg) (mg) (mg) (mg) 20 year equiv 1200000 700000 3900 4600 -5800 <1 1900000 100 year equiv 710000 690000 3900 2100 -5800 <1 1400000 500 year equiv 530000 680000 3900 1000 -5800 <1 1200000

naoh 14 Table 9 Gross emissions to water arising from the production of 1 kg of sodium hydroxide. (Totals may not agree because of rounding). Emission From From From From Totals fuel prod'n fuel use transport process (mg) (mg) (mg) (mg) (mg) COD 1 - <1 3 5 BOD <1 - <1 <1 <1 Pb+compounds as Pb <1 - <1 <1 <1 Fe+compounds as Fe <1 - <1 <1 <1 Na+compounds as Na <1 - <1 23000 23000 acid as H+ 1 - <1 1 3 NO3- <1 - <1 <1 <1 Hg+compounds as Hg <1 - <1 <1 <1 metals not specified elsewhere <1 - <1 6 7 ammonium compounds as NH4+ 1 - <1 1 2 Cl- <1 - <1 32000 32000 CN- <1 - <1 <1 <1 F- <1 - <1 <1 <1 S+sulphides as S <1 - <1 <1 <1 dissolved organics (non- <1 - <1 <1 <1 suspended solids 34 - 4 3400 3400 detergent/oil <1 - <1 <1 <1 hydrocarbons not specified <1 <1 <1 <1 <1 organo-chlorine not specified <1 - <1 17 17 dissolved chlorine <1 - <1 <1 <1 phenols <1 - <1 <1 <1 dissolved solids not specified <1 - <1 16000 16000 P+compounds as P <1 - <1 3 3 other nitrogen as N <1 - <1 3 4 other organics not specified <1 - <1 <1 <1 SO4-- <1 - <1 4700 4700 dichloroethane (DCE) <1 - <1 <1 <1 vinyl chloride monomer (VCM) <1 - <1 <1 <1 K+compounds as K <1 - <1 <1 <1 Ca+compounds as Ca <1 - <1 100 100 Mg+compounds as Mg <1 - <1 <1 <1 Cr+compounds as Cr <1 - <1 <1 <1 ClO3-- <1 - <1 280 280 BrO3-- <1 - <1 <1 <1 TOC <1 - <1 1 1 AOX <1 - <1 <1 <1 Al+compounds as Al <1 - <1 <1 <1 Zn+compounds as Zn <1 - <1 <1 <1 Cu+compounds as Cu <1 - <1 1 1 Ni+compounds as Ni <1 - <1 1 1 CO3-- - - <1 150 150 As+compounds as As - - <1 <1 <1 Cd+compounds as Cd - - <1 <1 <1 Mn+compounds as Mn - - <1 <1 <1 organo-tin as Sn - - <1 <1 <1 Sr+compounds as Sr - - <1 <1 <1 organo-silicon - - - <1 <1 benzene - - - <1 <1 dioxin/furan as Teq - - <1 <1 <1

naoh 15 Table 10 Gross solid waste associated with the production of 1 kg of sodium hydroxide. (Totals may not agree because of rounding) Emission From From From From Totals fuel prod'n fuel use transport process (mg) (mg) (mg) (mg) (mg) Plastic containers <1 - <1 <1 <1 Paper <1 - <1 <1 <1 Plastics <1 - <1 1100 1100 Metals <1 - <1 <1 <1 Putrescibles <1 - <1 <1 <1 Unspecified refuse 600 - <1 <1 600 Mineral waste 25 - 38 6800 6900 Slags & ash 8600 1300 15 2800 13000 Mixed industrial -990 - 1 380 -610 Regulated chemicals 730 - <1 200 930 Unregulated chemicals 560 - <1 2200 2700 Construction waste <1 - <1 <1 <1 Waste to incinerator <1 - <1 <1 <1 Inert chemical <1 - <1 780 780 Wood waste <1 - <1 130 130 Wooden pallets <1 - <1 <1 <1 Waste to recycling <1 - <1 <1 <1 Waste returned to mine 26000 - 1 6 26000 Tailings 1 - 1 7 9 Municipal solid waste -6600 - - <1 -6600 Note: Negative values correspond to consumption of waste e.g. recycling or use in electricity generation.

naoh 16 Table 11 Gross solid waste in EU format associated with the production of 1 kg of sodium hydroxide. Entries marked with an asterisk (*) are considered hazardous as defined by EU Directive 91/689/EEC Emission Totals (mg) 010101 metallic min'l excav'n waste 350 010102 non-metal min'l excav'n waste 27000 010306 non 010304/010305 tailings 2 010308 non-010307 powdery wastes 2 010399 unspecified met. min'l wastes 98 010408 non-010407 gravel/crushed rock 76 010410 non-010407 powdery wastes <1 010411 non-010407 potash/rock salt 3400 010499 unsp'd non-met. waste 1 010505*oil-bearing drilling mud/waste 710 010508 non-010504/010505 chloride mud 560 010599 unspecified drilling mud/waste 600 020107 wastes from forestry 130 050106*oil ind. oily maint'e sludges <1 050107*oil industry acid tars <1 050199 unspecified oil industry waste 22 050699 coal pyrolysis unsp'd waste 29 060101*H2SO4/H2SO3 MFSU waste <1 060102*HCl MFSU waste <1 060106*other acidic MFSU waste <1 060199 unsp'd acid MFSU waste <1 060204*NaOH/KOH MFSU waste <1 060299 unsp'd base MFSU waste 2 060313*h. metal /sol'n MFSU waste 3100 060314 other salt/sol'n MFSU waste <1 060399 unsp'd salt/sol'n MFSU waste 1100 060404*Hg MSFU waste 7 060405*other h. metal MFSU waste 1 060499 unsp'd metallic MFSU waste 720 060602*dangerous sulphide MFSU waste <1 060603 non-060602 sulphide MFSU waste 3 060701*halogen electrol. asbestos waste 220 060702*Cl pr. activated C waste <1 060703*BaSO4 sludge with Hg 6 060704*halogen pr. and sol'ns 1300 060799 unsp'd halogen pr. waste 700 061002*N ind. dangerous sub. waste <1 061099 unsp'd N industry waste <1 070101*organic chem. aqueous washes <1 070103*org. halogenated solv'ts/washes <1 070107*hal'd still bottoms/residues <1 070108*other still bottoms/residues <1 070111*org. chem. dan. eff. sludge <1 070112 non-070111 effluent sludge <1 070199 unsp'd organic chem. waste <1 070204*polymer ind. other washes <1 070207*polymer ind. hal'd still waste <1

continued over …..

naoh 17 Table 11 - continued Gross solid waste in EU format associated with the production of 1 kg of sodium hydroxide. Entries marked with an asterisk (*) are considered hazardous as defined by EU Directive 91/689/EEC

070208*polymer ind. other still waste <1 070209*polymer ind. hal'd fil. cakes <1 070213 polymer ind. waste plastic <1 070214*polymer ind. dan. additives <1 070216 polymer ind. silicone wastes <1 070299 unsp'd polymer ind. waste <1 080199 unspecified paint/varnish waste <1 100101 non-100104 ash, slag & dust 9900 100102 coal <1 100104*oil fly ash and boiler dust <1 100105 FGD Ca-based reac. solid waste <1 100113*emulsified hyrdocarbon fly ash <1 100114*dangerous co-incin'n ash/slag <1 100115 non-100115 co-incin'n ash/slag 170 100116*dangerous co-incin'n fly ash <1 100199 unsp'd themal process waste 200 100202 unprocessed /steel slag 24 100210 iron/steel mill scales 2 100399 unspecified waste <1 100501 primary/secondary zinc slags <1 100504 zinc pr. other dust <1 100511 non-100511 Zn pr. skimmings <1 101304 lime calcin'n/hydration waste <1 130208*other engine/gear/lub. oil <1 150101 paper and cardboard packaging <1 150102 plastic packaging <1 150103 wooden packaging <1 150106 mixed packaging <1 170107 non-170106 con'e/brick/tile mix <1 170904 non-170901/2/3 con./dem'n waste <1 190199 unspecified incin'n/pyro waste <1 190905 sat./spent ion exchange resins 780 200101 paper and cardboard <1 200108 biodeg. kitchen/canteen waste <1 200138 non-200137 wood <1 200139 plastics 1100 200140 metals <1 200199 other separately coll. frac'ns -1600 200301 mixed municipal waste <1 200399 unspecified municipal wastes -6000 Note: Negative values correspond to consumption of waste e.g. recycling or use in electricity generation.

naoh 18