Background_BAT-ELV

Draft background document

Assessments of technological developments:

Best available techniques (BAT) and limit values

Prepared by:

Katja Kraus (Chair, Germany)

Stefan Wenzel (Germany)

Grace Howland (Canada)

Ute Kutschera (Austria)

Stanislaw Hlawiczka (Poland)

André Peeters Weem (The Netherlands)

Chuck French (United States of America)

Submitted to the Task Force on Heavy Metals

UNECE Convention on Long-range Transboundary Air Pollution

April 06, 2006

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2

Introduction

1. The Task Force on Heavy Metals reviewed technological developments with regard to emissions from stationary sources for those heavy metals (HM) listed in annex I to the Protocol. This report compiles background information on technological developments for each source category of annex II to the Protocol, including:

-

- a compilation of recent developments in best available techniques (BAT) in relation to annex III to the Protocol; a compilation of current emission limit values (ELVs) in relation to annex V to the Protocol as well as for source categories identified in annex II and HM indicated in annex I for which no ELV is specified in annex V.

2. The report is structured according to the technical information given in annex III to the

Protocol. The following table gives an overview of the chapters of the report and their correspondence to the sector description and technical information in annex III and the source categories of annex II to the Protocol.

Sector

(chapter of the report)

Technical information according to annex III to the Protocol

Source categories according to annex II to the Protocol

Combustion of fossil fuels in utility and industrial boilers

Combustion of fossil fuels in utility and industrial boilers: coal and fuel oil fired boilers, not including gas turbines and stationary engines, and not including the use of waste as a fuel, are considered.

1: Combustion installations with a net rated thermal input exceeding 50 MW

Primary iron and steel industry

Primary iron and steel industry: the processing of ferrous metal ores together with the primary iron and steel industry are considered. The production of mercury and gold as well as the roasting and sintering of non-ferrous metal ores are regarded within the primary and secondary non-ferrous metal industry.

2: Metal ore (including sulfide ore) or concentrate roasting or sintering installations with a capacity exceeding 150 tonnes of sinter per day for ferrous ore or concentrate, and 30 tonnes of sinter per day for the roasting of copper, lead or zinc, or any gold and mercury ore treatment.

Secondary iron and

Secondary iron and steel industry: the secondary iron and steel industry insteel industry cluding electric arc furnaces (EAF) are considered.

3: Installations for the production of pig-iron or steel (primary or secondary fusion, including electric arc furnaces) including continuous casting, with a capacity exceeding 2.5 tonnes per hour.

Iron foundries

Iron foundries: iron foundries, not including steel and temper foundries, are considered.

4: Ferrous metal foundries with a production capacity exceeding 20 tonnes per day.

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Sector

(chapter of the report)

Primary and secondary non-ferrous metal industry

Technical information according to annex III to the Protocol

Primary and secondary non-ferrous metal industry: the processing of nonferrous metals and their ores is considered.

Cement industry

Cement industry: the production of cement clinker in fossil fuel fired kilns, not including the use of waste as a fuel, is considered.

Source categories according to annex II to the Protocol

5: Installations for the production of copper, lead and zinc from ore, concentrates or secondary raw materials by metallurgical processes with a capacity exceeding 30 tonnes of metal per day for primary installations and 15 tonnes of metal per day for secondary installations, or for any primary production of mercury.

6: Installations for the smelting (refining, foundry casting, etc.), including the alloying, of copper, lead and zinc, including recovered products, with a melting capacity exceeding 4 tonnes per day for lead or 20 tonnes per day for copper and zinc.

7: Installations for the production of cement clinker in rotary kilns with a production capacity exceeding 500 tonnes per day or in other furnaces with a production capacity exceeding 50 tonnes per day.

Glass industry

Chlor-alkali industry

Glass industry: the production of glass using lead in the process, including the recycling of lead containing glass, is considered.

8: Installations for the manufacture of glass using lead in the process with a melting capacity exceeding 20 tonnes per day.

Chlor-alkali industry: the chlor-alkali production by the mercury, diaphragm and membrane cell electrolysis process is considered.

9: Installations for chlor-alkali production by electrolysis using the mercury cell process..

Municipal, medical and hazardous waste incineration

Municipal, medical and hazardous waste incineration: the incineration of municipal, medical and hazardous waste is considered.

10: Installations for the incineration of hazardous or medical waste with a capacity exceeding 1 tonne per hour, or for the co-incineration of hazardous or medical waste specified in accordance with national legislation.

11: Installations for the incineration of municipal waste with a capacity exceeding 3 tonnes per hour, or for the co-incineration of municipal waste specified in accordance with national legislation.

3. The following acronyms are used throughout the document:

BAT Best available techniques

BF Blast furnace

BOF Basic oxygen furnace

BREF Best available technique reference document

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CFA Circulating fluidized-bed absorber

EAF Electric arc furnace

ELV Emission limit values

ESP Electrostatic precipitator

FF Fabric filter

FGD Flue gas desulfurization

IGCC Integrated gasification combined-cycle

PM Particulate matter

SCR Selective Catalytic Reduction

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I. COMBUSTION OF FOSSIL FUELS IN UTILITY AND INDUSTRIAL BOILERS

Sector description and BAT according to annex III of the Protocol

4. This category covers the combustion of fossil fuels in utility and industrial boilers. Annex II limits the coverage to combustion installations with a net rated thermal input exceeding 50 MW.

According to annex III, BAT are considered for coal and fuel oil fired boilers.

5. The combustion of biomass and peat are not currently taken into account in annex III but may be a relevant source of heavy metal emissions. Therefore, additional information is given for these installations. The co-incineration of waste in combustion installations is treated within the category municipal, medical and hazardous waste incineration.

6. According to annex III, BAT to reduce emissions of heavy metals, except mercury, include the reduction in fuel use and the combustion of natural gas or alternative fuels with a low heavy metal content, the use of ESPs or FFs. Further emission reduction may be achieved by

IGCC power plant technology, the beneficiation (washing or bio-treatment) of coal, and the application of techniques to reduce emissions of nitrogen oxides, sulfur dioxide and particulates.

No BAT for mercury removal is identified in annex III.

BAT according to other references

7. About half of the electricity generated worldwide is produced from different fossil fuels, with 30 % being generated from coal. The combustion process leads to the generation of emissions to air which are considered to be one of the major sources of air pollution. The emission of heavy metals results from their presence as a natural component in fossil fuels and are mostly released as compounds in association with particulates. Therefore, BAT to reduce the emissions of heavy metals is generally the application of high performance PM removal devices such as ESPs or FFs. However, mercury is at least partly, and up to 90 % present in the vapour phase and its collection by PM control devices is highly variable. For ESPs or FFs operated in combination with FGD techniques, an average removal rate of 75 % and of 90 % in the additional presence of high dust SCR can be obtained for mercury, depending on the temperature of the filter system and the characteristics of the combusted coal, e.g., char/carbon content, chlorine content, etc..

8. BAT for preventing releases of PM from the unloading, storage and handling of solid and liquid fuels and also additives such as lime and limestone are:

-

- using loading equipment that minimises the height of fuel drop to the stockpile using water spray systems for stockpiles, where applicable

-

-

-

- covering stockpiles grassing over long-term storage areas of coal for lignite, the direct transfer via belt conveyors or trains from the mine to the storage area placing transfer conveyers in safe areas aboveground so that they are not damaged

-

- using cleaning devices for conveyer belts using enclosed conveyers with well designed extraction and filtration equipment on transfer points

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-

-

- rationalising transport systems using good design and construction practices and adequate maintenance for lime and limestone, having enclosed conveyers, pneumatic transfer systems and silos with well designed extraction and filtration equipment on transfer points

Combustion of coal and lignite

9. For the fuel pretreatment of coal and lignite, blending and mixing of fuels are part of BAT, in order to ensure stable combustion conditions and to thus reduce peak emissions. Switching fuel to a fuel with a better environmental profile can also be regarded as BAT. If coal cleaning is carried out prior to combustion, data from the U.S. Department of Energy indicate that typically 10-50 % of the mercury in coal can be removed by in the cleaning process alone. The same sources indicate that removal of cadmium and lead can reach even 80%.

10. For the combustion of coal and lignite, pulverized combustion, fluidized bed combustion as well as pressurized fluidized bed combustion and grate firing are all BAT for new and existing plants. Grate firing should preferably only be applied to new plants with a rated thermal input below 100 MW. Pressurized gasification in an IGCC plant is a high efficiency technology that reduces emissions from large scale power production based on solid fuels. Power plants based on coal gasification have been in operation in the USA since 1983 (Kingsport, Tennesssee) and IGCC installations have been in use in the USA since 1995 (Polk, Florida) and in the Netherlands since 1994 (Buggenum). Since then several more installations have been commissioned in the USA and Europe (For more information see: http://www.clean-energy.us).

11. For PM removal of off-gases from coal- and lignite-fired new and existing combustion plants, BAT is the use of an ESP or a FF, where a FF normally achieves emission levels below

5 mg/m³. Furthermore, the best levels of mercury control are generally achieved by emission control systems (e.g. FGD plus particulate control device) that use FFs. Cyclones and mechanical collectors alone are not BAT, but they can be used as a pre-cleaning stage. BAT associated emission levels for PM are lower for combustion plants over 100 MW th

, especially over

300 MW th

, because the wet FGD technique which is already a part of the BAT conclusion for desulfurization also reduces PM.

12. All solid fuels such as coal and lignite have a certain concentration of trace elements such as heavy metals. Basically most of the heavy metals evaporate in the combustion process and condensate later onto the surface of the PM (i.e. fly ash). Therefore, BAT to reduce the emissions of most heavy metals from flue-gases of coal- and lignite-fired combustion plants is to use a high performance ESP (PM removal rate >99.5%) or a FF (PM removal rate >99.95%, achieving PM emission concentrations below 5 mg/m³). With mercury in particular, the capture efficiencies of these systems heavily depend on the speciation of the mercury in, and the fly ash content of, the flue gas. Therefore, for some plants using high performance ESP or FF, the capture of mercury on fly ash can be enhanced by switching or blending the combusted coals to achieve a higher carbon/char, higher chlorine, or lower mercury content in the combusted coal or by introducing carbon/activated carbon into the flue upstream of the ESP or FF.

13. Mercury has a high vapour pressure at the typical control device operating temperatures, and its collection by PM control devices is highly variable. Taking into account that spray dryer

FGD scrubbers and wet lime/limestone scrubbers are regarded as BAT for the reduction of sulfur dioxide for larger combustion plants, relatively low mercury emission levels are achieved.

For the reduction and limitation of mercury emissions, the best levels of control are generally obtained by emission control systems that use FFs and ESPs, where high efficiency ESPs

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show good removal of mercury (bituminous coal) at temperatures below 130 °C. It appears that little mercury can be captured in hot-side ESPs (installed upstream of the air heater). [The best levels of control are generally obtained by emission control systems / Recommended control measures are generally those] that use FFs. However, life time of FFs is very dependent upon the working temperature and their resistance to the chemical attack by corrosive elements in exhaust gases.

14. Dry FGD systems are already equipped to control emissions of sulfur dioxide and PM.

Wet FGD systems are typically installed downstream of an ESP or FF. Wet limestone FGD scrubbers are the most commonly used scrubbers on coal-fired utility boilers. These FGD units are expected to capture more than 90 per cent of the ionic mercury (Hg 2+ ) in the flue gas entering the scrubber. Consequently, existing wet FGD scrubbers may lower mercury emissions between 20 and 80 %, depending on the speciation of mercury in the inlet flue gas. Improvements in wet scrubber performance in capturing mercury depend primarily on the oxidation of elemental mercury (Hg 0 ) to ionic mercury. This may be accomplished by (i) the injection of appropriate oxidizing agents or (ii) the installation of fixed oxidizing catalysts upstream of the scrubber to promote oxidation of elemental mercury to water soluble species (such as Hg 2+ ).

An alternative strategy for controlling mercury emissions from wet FGD scrubbing systems is to inject sorbents upstream of the PM control device. Wet scrubbers installed primarily for mercury cost between $76,000 and $174,000 per pound of mercury removed.

15. For FFs or ESPs operated in combination with FGD techniques, such as wet limestone scrubbers, spray dryer scrubbers or dry sorbent injection, an average removal rate of 75 % or

90 % in the additional presence of SCR can be obtained. The reduction rate when firing subbituminous coal or lignite is considerably lower and ranges from 30 – 70%. The lower levels of mercury capture in plants firing sub-bituminous coal and lignite are attributed to the low fly ash carbon content and the higher relative amounts of gaseous mercury in the flue gas from the combustion of these fuels.

16. Additional mercury control can be achieved by injection of a sorbent (carbon- and/or calcium-based) prior to the flue gas treatment system. The used carbon and attached waste products are captured by existing PM controls, such as ESPs or FFs. The U.S. test programs have shown mercury removals of 50 to over 95 percent, depending on the carbon feed rate. The

U.S. Environmental Protection Agency (EPA) estimates it would cost between $ 67,700 and

$ 70,000 per pound to achieve a 90 % control level. A recent presentation at the Air Quality V conference by the United States Department of Energy (DOE) noted that the preliminary economic analysis of field testing data indicates that good progress is being made to reducing the indicated costs by 25 -50%. Factors likely to influence the effectiveness and cost-effectiveness of activated carbon include: flue gas temperature (to preferably be below 150 °C); the amount of carbon injected; PM control equipment design; the amount, concentration, and species of mercury in the flue gas; the contact between the carbon and mercury (efficient distribution is needed for the carbon to absorb the mercury); the type of carbon used (e.g., activated carbon that is chemically impregnated with sulfur, iodide, chloride or calcium hydroxide may be more effective by 25 – 45% than non-impregnated activated carbon, particularly when most of the mercury is in elemental form) (U.S. EPA, 2000).

17. Alternatively to carbon injection, the flue gas can be distributed throughout a carbon filter bed. Carbon filter bed technology is assumed by U.S. EPA to remove 80 – 90% of the mercury in flue gas at two large (generic) individual facilities at a cost of $ 33,00 to $ 38,000 per pound of mercury removed.

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18. Depending on the plant and coal used, periodic monitoring of Hg at frequency of at least every third year up to continuous monitoring is recommended to confirm the effectiveness of a chosen BAT. Continuous monitoring of Hg allows for the possibility of maximizing the capture efficiency of a chosen BAT over short periods of time. Total Hg emissions need to be monitored in addition to the speciation of the mercury, i.e., concentration of the elemental, ionized mercury and the Hg present as part of the particulate matter. A mass balance approach is recommended where the mercury in the coal and ash are monitored as well as the emissions from the stack and all analyses are done by accredited laboratories.

19. The least costly retrofit options for the control of mercury emissions from units with ESP or FF are believed to include:

-

The modification of dry FGD systems by the use of appropriate sorbents for the capture of mercury and other air toxics is considered to be the easiest retrofit problem to solve.

-

-

Injection of a sorbent upstream of the ESP or FF. Cooling of the stack gas or modifications to the ducting may be needed to keep sorbent requirements at acceptable levels;

Injection of a sorbent between the ESP and a pulse-jet FF retrofitted downstream of the

ESP. This approach will increase capital costs but reduce sorbent costs;

-

Installation of a semi-dry CFA upstream of an existing ESP used in conjunction with sorbent injection. It is believed that CFAs can potentially control mercury emissions at lower costs than those associated with the use of spray dryers.

20. Preliminary annual costs of mercury controls using powdered activated carbon (PAC) injection have been estimated based on recent pilot-scale evaluations with commercially available adsorbents. These control costs range from 0.03 to 0.4 US cents/kWh, with the highest costs associated with plants having hot-side ESPs. For plants representing 89 % of current capacity and using controls other than hot-side ESPs, the costs range from 0.03 to

0.2 US cents/kWh. Assuming a 40 % reduction in sorbent costs by the use of a composite lime-

PAC sorbent for mercury removal, cost projections range from 0.02 to 0.2 US cents/kWh, with higher costs again being associated with plants using hot-side ESPs.

Combustion of liquid fuels

21. For PM removal from off-gases from new and existing liquid fuel-fired combustion plants,

BAT is the use of an ESP or a FF. Cyclones and mechanical collectors alone are not BAT, but they can be used as a pre-cleaning stage. BAT associated emission levels for PM are lower for combustion plants over 300 MW th

because the FGD technique that is part of the BAT conclusion for desulfurization also reduces particulate matter.

22. Liquid fuels, especially heavy fuel oil, typically contain heavy metals, in particular vanadium and nickel. Basically most of the heavy metals evaporate in the combustion process and condensate later in the process on the surfaces of the PM (e.g. fly ash). The ESP is the most used technique for PM removal from off-gases from heavy fuel oil firing. The FF is also an applied technique but less important because of the elevated risk of fire, which is reduced if the

FF is applied in combination with FGD. Therefore, BAT to reduce the emissions of PM and heavy metals are the use of high performance ESPs (reduction rate >99.5%) or, taking into account the risk mentioned above, a FF (reduction rate >99.95%). Wet scrubbers installed primarily for mercury cost between $ 76,000 and $ 174,000 per pound of mercury removed.

23. Periodic monitoring of heavy metals is BAT. A frequency of every year up to every third year, depending on the kind of liquid fuel used, is recommended. Total mercury especially needs to be monitored and not only the part bound to PM.

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Combustion of biomass and peat

24. For the pretreatment of biomass, in particular for wood, classification based on the size and the contamination are BAT, in order to ensure stable combustion conditions, to reduce the amount of unburned fuel in the ash, and thus to reduce peak emissions. In case the wood used is contaminated, it is BAT to know the type of contamination of the wood and an analytical knowledge of the contaminants for each load that arrives to the power plant.

25. For the combustion of biomass and peat, pulverized combustion, fluidized bed combustion as well as spreader stoker grate-firing technique for wood and the vibrating, water-cooled grate for straw-firing are BAT. Pulverized peat combustion plants are not BAT for new plants.

26. For PM removal from off-gases from biomass- and peat-fired new and existing combustion plants, BAT is the use of FF or an ESP. When using low sulfur fuels such as biomass, the potential for reduction performance of ESPs is reduced with low flue-gas sulfur dioxide concentrations. In this context, the FF, which leads to PM emissions around 5 mg/m³, is the preferred technical option to reduce PM emissions. Cyclones and mechanical collectors alone are not

BAT, but they can be used as a pre-cleaning stage.

27. Biomass and peat have certain concentrations of trace elements such as heavy metals.

Basically most of the heavy metals evaporate in the combustion process and condensate later onto the surface of the PM (fly ash). Therefore, BAT to reduce the emissions of heavy metals from flue-gases of biomass- and peat-fired combustion plants is to use a FF (reduction rate

>99.95%) or a high performance ESP (reduction rate >99.5%), where the FF should be seen as the first choice for PM removal.

Emerging techniques

28. Research so far has indicated that the most cost-effective approach to mercury control may be an integrated multi-pollutant (sulfur dioxide, nitrogen oxides, PM, and mercury) control technology.

29. Recent data suggests that new designs of ESPs can achieve 99.8% PM reductions.

30. The wet scrubber efficiency for mercury removal can be increased by

-

Adding lime or limestone: It has been assumed that if lime or limestone is added to the scrubber to increase the percentage of sulfur dioxide removed, the same percentage increase in the amount of oxidized mercury removed would occur (about 18%). For units with existing scrubbers, cost estimates range from $ 62,000-$ 258,000 per pound, with a reduc-

-

- tion potential of 30 pounds/year.

Improving the liquid-to-gas ratio. In two separate pilot studies, increasing the liquid-to-gas ratio from 40 gal/1000 acf to 125 gal/1000 acf increased the removal efficiency of oxidized mercury from 90 percent to 99 percent.

Wet FGD Tower Design. Research has shown that tray tower or open spray tower designs can be effective in removing oxidized mercury from boiler flue gas. The tray tower design removed from 85 to 95 percent of the total mercury (where the composition of the flue gas was mostly oxidized mercury). The open spray tower design removed from 70 to 85 percent of the total mercury.

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-

Injection of activated carbon impregnated with additives increasing adsorption capacity.

Apart from sulfur, iodide, chloride or calcium compounds other impregnating agents can be used like noble metals, titanium and selenium.

31. Low-NO x

technologies are also likely to reduce mercury emission in the exhaust gases due to the lower operating temperatures. However, while some sources indicate that a reasonable reduction can be achieved, other preliminary results of staged combustion in atmospheric fluidized bed combustion (AFBC) units indicated that low-NO x

had little effect on trace element emissions.

32. Reburning: This control technology for nitrogen oxides leads to an increased fly ash carbon content and thus enhances the mercury adsorption capacity of fly ash. While increased mercury capture has been shown to occur with increased fly ash carbon, this phenomenon has not been used in commercial practice for the control of mercury emissions, and it should be considered a potential control option that might be available in the future.

Combustion of coal and lignite

33. Simultaneous control of sulfur dioxide, nitrogen oxides and mercury: This flue-gas treatment system, which is under demonstration in the U.S., is a gas-phase oxidation process to simultaneously capture up to 99 % of the nitrogen and sulfur oxides as well as basic vapors and heavy metals (100 % of mercury). Capture rates of up to 99 % sulfur dioxide and 98 % nitrogen oxides were demonstrated at laboratory level over a wide range of temperatures found in flue-gases. Engineering cost estimates for the construction of a full scale 500 MW power plant installation is 30-50 % lower in capital costs and with 1/6 th operating costs compared to limestone/SCR. Further advantages of the system are: no lime/limestone is used, no carbon dioxide emissions, no catalysts are used, reagent is recycled, proven co-product technologies, system can be retrofitted on most plants.

Combustion of liquid fuels

34. Fuel cell applications are expected to be a future technique for clean liquid fuels. At the moment, the size of the pilot plants is small compared to large combustion plants.

Combustion of biomass and peat

35. IGCC: Pressurized gasification in an IGCC is one of the high efficiency technologies which could reduce emissions from large scale power production based on solid fuels. Peat is an ideal fuel for gasification because of its high volatile content. A demonstration plant for biomass-fired IGCC is under construction in Sweden. The gasification of straw has only been tested successfully when done together with coal.

Emission Limit Values

36. Annex V of the Protocol includes an ELVs for PM emissions for solid and liquid fuels of

50 mg/m³ (referring to 6% O

2

and 3% O

2

in the flue gas, respectively). For the heavy metals covered by the Protocol no ELV is specified.

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37. The following table gives an overview on current ELVs implemented by the Parties. Information was compiled using Parties’ responses to question 44 of the 2004 questionnaire on

Strategies and Policies for Compliance Review and additional information by national experts.

For comparison, the table also includes BAT associated emission levels as indicated in the respective European BREF document.

Table I-1 ELVs for combustion of fossil fuels in utility and industrial boilers

All values are expressed in mg/Nm³ referring to standard conditions (273.15 K, 101.3 kPa, dry gas) and do not cover start-up and shutdown periods except stated otherwise. Application ranges normally refer to thermal energy input. BAT associated emission levels from the respective BREF document are not considered as ELVs and are given for comparison; they are indicated in italic letters.

Country / reference

ELV Remarks

ELVs for PM emissions

Annex V of the Protocol

> 50 MW

Austria > 50 MW

> 50 MW

> 50 MW

Belgium > 50 MW

> 50 MW

Bulgaria < 500 MW

> 500 MW

Canada > 25 MW el

Czech

Republic

< 500 MW

> 500 MW

50-100 MW

> 100 MW

Finland > 50 MW

50 solid (6% O2) and liquid (3% O2) fuels; continuous (daily) and discontinuous measurements (hourly average)

50 solid fuels (6%O

2

, wood 13% O

2

)

35 liquid fuels except light fuel oil (3% O

2

)

30 light fuel oil (3% O

2

) continuous (daily) and discontinuous measurements (half-hourly average)

150 solid and liquid fuels, existing installations built before 01/07/87

(Flanders only)

50 solid and liquid fuels, all other installations discontinuous (Flanders only, each value) or continuous measurements (daily average).

100 solid fuels (6% O2)

50

50 liquid fuels (3% O2)

5 gaseous fuels 3%O2

Existing installations.: monthly and yearly mean, new installations. Hourly and daily mean values.

20-25 0.095 kg/MWh net energy output (approximately 9 ng/J heat input); combustion of solid, liquid, or gaseous fuel; new installations, 6% O2

50 liquid fuels, existing installations

100

50 solid fuels, existing installations

50 solid and liquid fuels, new installations

30

5 gaseous fuels, new and existing installations

50/30 6%/3% O2; existing installations as of 01/01/2008

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Germany

Netherlands

Slovakia

>50 MW 20 all installations; solid and liquid fuels except light fuel oil; daily average; for light fuel oil: soot level 1

20 daily average

50

Slovenia

Belgium

50-500 MW

≥ 500 MW

> 50 MW

50-100 MW

> 100 MW

100

50

For coal burning (6 % O2), existing installations

50 liquid fuels (3% O2); existing installations

50 coal burning (6 % O2) and liquid fuels (3% O2); new installations

30 as of 01/01/2008

Switzerland

United

States of

America

50 all installations if mass flow > 0.5 kg/h

17 For new utility boilers > 25 MW, the PM ELV = 6.4 ng/J (which is equivalent to 17 mg/m 3 at 6% O

2

), or sources can

35 meet a 99.9% reduction.

For new industrial boilers > 3 MW, the PM ELV = 13 ng/J (which is equivalent to 35 mg/m 3 at 6% O

2

)

82 For existing industrial coal-fired boilers > 3 MW, the PM ELV =

30.3 ng/J (which is equivalent to 82 mg/m 3 at 6% O

2

)

BAT (BREF) 50-100 MW 5-30

50-100 MW 5-20 all fuels, existing installations all fuels, new installations

100-300 MW 5-25

100-300 MW 5-20 coal and lignite and liquid fuels; existing installations all fuels: new installations; biomass and peat: also existing installations

> 300 MW

> 300 MW

5-20

5-10 all fuels: existing installations; biomass and peat: also new installations coal and lignite and liquid fuels; new installations solid fuels: 6% O

2

, liquid fuels: 3% O

2

ELVs for cadmium emissions

0.2 all installations if total load ≥ 1 g/h; common ELV for Cd, Hg, Th and their compounds; discontinuous measurements.

Denmark > 5 MW

France > 20 MW

Germany

Switzerland

United

States of

America

Belgium

> 50 MW

0.1 hard coal; hourly average, 10% O2

0.05 new and existing installations (as of 01/01/2008); common ELV for Cd, Hg, Tl: 0.1

0.05 all installations; liquid fuels except light fuel oil; discontinuous measurements; half hour average

0.1 all installations if mass flow > 0.5 g/h

1.1 ELV for Total Selected Metals (i.e., 8 metals including lead and cadmium) for existing industrial boilers is 0.001 lb/million Btu

(about 0.43 ng/J) or about 1.1 mg/m 3 .

ELVs for lead emissions

5 all installations if total load ≥ 25 g/h; common ELV for Sb, Pb, Cr,

Co, Cu, Mn, Pt, V, Sn and their compounds. Discontinuous measurements.

13

Denmark > 2/5 MW

France > 20 MW

Germany > 50 MW

Switzerland

United

States of

America

Belgium

Denmark > 2/5 MW

France > 20 MW

Germany > 50 MW

Switzerland

United

States of

America

5 heavy fuel oil > 2 MW; hard coal > 5 MW; common ELV for Ni, V,

Cr, Cu, Pb; hourly average (10% O2)

1 new and existing installations (as of 01/01/2008)

0.5 all installations; liquid fuels except light fuel oil; discontinuous measurements; half hour average

5 all installations if mass flow > 25 g/h

1.1 ELV for Total Selected Metals (i.e., 8 metals including lead and cadmium) for existing industrial boilers is 0.001 lb/million Btu

(about 0.43 ng/J) or about 1.1 mg/m 3 .

ELVs for mercury emissions

0.2 all installations if total load ≥ 1 g/h; common ELV for Cd, Hg, Th and their compounds. Discontinuous measurements.

0.1 heavy fuel oil > 2 MW; hard coal > 5 MW; hourly average (10%

O2)

0.05 new and existing installations (as of 01/01/2008); common ELV for Cd, Hg, Tl: 0.1

0.03 all installations; solid fuels; daily average

0.2 all installations if mass flow > 1 g/h

0.01 Mercury ELV for existing industrial boilers is 9 lb/trillion Btu

(about 0.004 ng/J) heat input or about 0.01 mg/m 3 .

References

EC 2001

Ambient air pollution by mercury - Position Paper. European Communities, 2001.

EIPPCB 2005

Integrated Pollution Prevention and Control: Reference Document on Best Available Techniques for Large Combustion Plants. European IPPC Bureau, Sevilla: May 2005.

U.S. EPA 2000

Great Lakes Binational Toxics Strategy: Draft Report for Mercury Reduction Options. United

States Environment Protection Agency, September 2000.

UNECE 2002

Control of Mercury Emissions from Coal-Fired Electric Utility Boilers. United Nations Economic

Commission for Europe, Economic and Social Council, July 2002.

UNEP (2002)

Global Mercury Assessment. United Nations Environmental Programm Chemicals, 2002.

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U.S. EPA, 2004

National Emission Standards for Hazardous Air Pollutants for Industrial/Commercial/Institutional Boilers and Process Heaters: Final Rule. 13 September 2004.

U.S. EPA, 2006

New Source Performance Standard (NSPS) for Utility Boilers. April 2006.

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II. PRIMARY IRON AND STEEL INDUSTRY

Sector description and BAT according to III of the Protocol

38. This category covers the processing of ferrous metal ores or concentrates with a capacity exceeding 150 tonnes of product per day, and installations for the production of pig iron or steel, including continuous casting, with a capacity exceeding 2.5 tonnes per hour. According to annex III, BAT are considered for sinter and pellet plants, blast furnaces (BF) and basic oxygen furnaces (BOF) with subsequent casting, that typically constitute an integrated steel work.

The secondary iron and steel industry including electric arc furnaces (EAFs) is considered within the secondary iron and steel industry, while the production of mercury and gold and other processing of non-ferrous metals is considered within the primary and secondary non-ferrous metal industry.

1

39. According to annex III, FFs should be used whenever possible; reducing the PM content to less than 20 mg/m³ (hourly average). If conditions make this impossible, ESPs and/or highefficiency scrubbers may be used, reducing the PM content to 50 mg/m³. Many applications of

FFs can achieve much lower values. When using BAT as described in annex III in the primary iron and steel industry, the total specific emission of PM directly related to the process can be reduced to the following levels:

-

Sinter plants 40 - 120 g/Mg

-

-

Pellet plants 40 g/Mg

BF 35 - 50 g/Mg

-

BOF 35 - 70 g/Mg.

Direct reduction and direct smelting are under development and may reduce the need for sinter plants and blast furnaces in the future.


40. [The most relevant emissions of the iron and steel industry are those to air.] In integrated steelworks, sinter plants and steelworks dominate the overall emissions for most atmospheric pollutants including heavy metals. Although big efforts have been made to reduce emissions, the contribution of the sector to the total emissions to air is considerable for a number of pollutants, especially for PM, some heavy metals and PCDD/F.

41. The reduction and capture of fugitive emissions is important since fallout and reentrainment (e.g., from nearby roadways and parking lots) may contribute significantly to heavy metal loading on the surrounding area and beyond. An emission limit for a control system exhaust becomes meaningless if a significant percentage of emissions are not captured by the control system in the first place.

1 The coverage is in accordance with the technical information given in annex III of the Protocol, whereas the category description as given in annex II would cover different activities.

16

42. Although the blast furnace route is the main process for iron production, several other production routes for pig iron are currently being developed and one technique is already applied commercially (Corex) These so-called "smelting reduction" techniques invariably use coal instead of coke as the main fuel. Some of the new techniques also replace pellets and sinter by pulverised iron ore. Two main types of alternative ironmaking which can be considered as proven types of alternative ironmaking are following:

-

Direct reduction (DR) involves the production of solid primary iron from iron ores and a reducing agent (e.g. natural gas). The solid product is called Direct Reduced Iron (DRI) and is

- mainly applied as feedstock in EAFs producing steel. The direct reduction process has been commercialised since the 1970's and a variety of processes have been developed.

The DR/EAF technology combination is a complete replacement of the traditional iron sintering/coke oven/BF/BOF steelmaking route.

Smelting reduction (SR) involves combining iron ore reduction with smelting (cf. blast furnace) in a reactor, without the use of coke. The product is liquid pig iron, which can be treated and refined in the same way as pig iron from the BF. Today, only one variant of SR is commercially proven (Corex), but a number of variants are in an advanced state of development.

These processes are alternatives to the coke oven/BF route and possibly with other direct iron smelting processes will replace BFs as they become noneconomic. However, no information is available with regard to emissions of heavy metals.

Processing of ferrous metal ores

43. Use of conventional controls to lower mercury emissions does not prevent mercury pollution permanently because it collects the mercury and transfers it to scrubber water which is then recycled back to the beneficiation (extraction) process. However, some mercury that is scrubbed out of the gas flows into the tailing basin, attaches to solids and settles out in the basin. There is little biological activity in the solids that settle, therefore re-volatilization of mercury should not occur.

44. One option is to make plant area modifications to increase mercury rejection to the tailing and reduce the recycling effect of mercury in the beneficiation process. This option calls for modifying the ore concentrating process to increase the mercury rejection to the tailing and for routing the scrubber water outside of the process to reduce the recycling effect of mercury in the beneficiation process. Increases in mercury separation in the iron concentration process will most likely come from improving the weight recovery of iron through additional stages of grinding and flotation. Flotation as well as increased sulfide levels in the ore may also increase the amount of mercury that is rejected to the tailing.

Sinter plants

45. For sinter plants, the following techniques or combination of techniques are considered as

BAT with regard to heavy metals and PM emissions for both new and existing installations: a) Waste gas PM removal by application of:

-

Advanced ESP (moving electrode ESP, ESP pulse system, high voltage operation of

ESP …) or

-

-

ESP plus FF or

Pre-PM removal (e.g. ESP or cyclones) plus high pressure wet scrubbing system.

Using these techniques PM emission concentrations < 50 mg/Nm3 are achieved in normal operation. In case of application of a FF, PM emissions of 10-20 mg/Nm3 are achieved. b) Minimization of heavy metal emissions by:

17

-

-

Use of fine wet scrubbing systems in order to remove water-soluble heavy metal chlorides, especially lead chloride(s) with an efficiency of > 90% or a FF with lime addition;

Exclusion of PM from last ESP field from recycling to the sinter strand, dumping it on a secure landfill (watertight sealing, collection and treatment of leachate), possibly after water extraction with subsequent precipitation of heavy metals in order to minimize the quantity to dump. c) Recirculation of a part of the waste gas, if sinter quality and productivity are not significant affected.

46. Total costs of implementing FFs for one representative sinter plant are 3000 to 16000

Euro p.a..

47. It is recommended that an environmental performance indicator for the sintering operation be less than 150 grams of PM per tonne of sinter produced for existing iron sinter plants and

100 grams of PM per tonne of sinter produced for modified or new iron sinter plants.

48. Best environmental practices for the minimization of emissions from the sinter strand operation include

- enclosure and/or hooding, where appropriate, with emission controls, of the sinter strand operations that are potential sources of fugitive emissions;

- operating practices that minimize fugitive emissions that are not amenable to enclosure or hooding;

Pelletisation plants

49. For pelletisation plants, the following techniques or combination of techniques are considered as BAT with regard to heavy metals and PM emissions for both new and existing installations: Efficient removal of PM from the induration strand waste gas, by means of:

-

Scrubbing or

-

Semi-dry desulfurization and subsequent PM removal (e.g. gas suspension absorber

(GSA)) or any other device with the same efficiency.

Achievable removal efficiency for PM: >95%; corresponding to achievable concentration of <

10 mg PM/Nm³.

Blast furnaces

50. For BF, the following techniques or combination of techniques are considered as BAT with regard to heavy metals and PM emissions for both new and existing installations: a) Hot stoves: emission concentration of PM <10 mg/Nm3 (related to an oxygen content of

3%) can be achieved b) BF gas treatment with efficient PM removal: Coarse PM is preferably removed by means of dry separation techniques (e.g. deflector) and should be reused. Subsequently fine PM is removed by means of:

- a scrubber or

- a wet ESP or

- any other technique achieving the same removal efficiency;

A residual PM concentration of < 10 mg/Nm 3 is possible. c) Cast house PM removal (tap-holes, runners, skimmers, torpedo ladle charging points);

Emissions should be minimized by covering the runners and evacuation of the mentioned emission sources and purification by means of FF or ESP. PM emission concentrations of

18

1-15 mg/Nm3 can be achieved. Regarding fugitive emissions 5-15 g PM/t pig iron can be achieved; thereby the capture efficiency of fumes is important. d) Fume suppression using nitrogen (in specific circumstances, e.g. where the design of the casthouse allows and nitrogen is available).

Basic oxygen steelmaking and casting

51. For oxygen steel making including hot metal pre-treatment, secondary metallurgical treatment and continuous casting, the following techniques or combination of techniques are considered as BAT with regard to heavy metals and PM emissions for both new and existing installations: a) PM abatement from hot metal pre-treatment (including hot metal transfer processes, desulfurisation and deslagging), by means of:

-

Efficient capture and exhaust;

-

Subsequent purification by means of FF or ESP.

PM emission concentrations of 515 mg/Nm³ are achievable with FF and 20-30 mg/Nm³ with ESP. b) BOF gas recovery and primary PM removal, applying:

-

-

Suppressed combustion and

Dry ESP (in new and existing situations) or

-

Scrubbing (in existing situations).

Collected BOF gas is cleaned and stored for subsequent use as a fuel, if economical feasible or with regard to appropriate energy management. In some cases, it may not be economical or, with regard to appropriate energy management, not feasible to recover the BOF gas. In these cases, the BOF gas may be combusted with generation of steam.

Collected PM should be recycled as much as possible. [Note the usually high zinc content of the PM.] Special attention should be paid to the emissions of PM from the lance hole.

This hole should be covered during oxygen blowing and, if necessary, inert gas injected into the lance hole to dissipate the PM. c) Secondary PM removal, applying:

-

Efficient capture and exhaust during charging and tapping with subsequent purification by means of FF or ESP or any other technique with the same removal efficiency. Capture efficiency of about 90% can be achieved. Residual PM content of 515 mg/Nm³ in

-

- case of FF and of 20-30 mg/Nm3 in case of ESP can be achieved.

Efficient evacuation during hot metal handling (reladling operations), deslagging of hot metal and secondary metallurgy with subsequent purification by means of FF or any other technique with the same removal efficiency. For these operations emission factors below 5 g/t liquid steel are achievable.

Fume suppression with inert gas during reladling of hot metal from torpedo ladle (or hot metal mixer) to charging ladle in order to minimize fume/PM generation.

52. It is recommended that an environmental performance indicator for PM for the BOF steelmaking process would be a maximum of 60 grams per tonne of molten steel for new or modified BOFs and ancillary equipment and a maximum of 90 grams per tonne of molten steel for existing BOFs.


Blast furnaces

19

53. Next to the developments in ironmaking (DR and SR), there is a tendency towards continuous processes instead of batch processes. The shift from ingot casting to continuous casting in the 1980's is a representative example of this. In future, batch steelmaking (e.g. (Linz-

Donawitz-converter, EAF) will probably be replaced by continuous steelmaking processes.

Basic oxygen steelmaking and casting

54. The use of new reagents in the desulfurisation process might lead to a decrease in PM emissions and a different (more useful) composition of the generated PM. The technique is under development.

55. Several foaming techniques at pig iron pre-treatment and steel refining are already available, absorbing the PM arising from the hot metal processing.


56. Annex V o f the Protocol includes an ELV for PM of 50 mg/m³ for sinter plants and for BFs, and of 25 mg/m³ for pellet plants for grinding and drying and for pelletizing or alternatively of

40 g/Mg of pellets produced. For BOFs as well as for the heavy metals covered by the Protocol no ELVs are specified.




Table II-1 ELVs for primary iron and steel production

All values are expressed in mg/Nm³ referring to standard conditions (273.15 K, 101.3 kPa, dry gas) and do not cover start-up and shutdown periods except stated otherwise. BAT associated emission levels from the respective BREF document are not considered as ELVs and are given for comparison; they are indicated in italic letters.

Country / reference

ELV Remarks



50 sinter plants

25 pellet plant: grinding, drying, pelletizing; alternatively 40 g/Mg pellets

50 BFs continuous (daily) and discontinuous measurements (hourly average)

20

Austria 2

Belgium

Bulgaria

Czech

Republic

Germany

Netherlands

Slovakia

Switzerland

United

States of

America

50 sinter plants, melting and casting of pig iron, converter, vacuum, electro slag remelting

20 production iron and steel continuous (daily) and discontinuous measurements (half-hour average); gaseous or liquid fuels 3%O2 (heat furnace 5%O2), solid fuels 6% O2

150 all installations if mass flow ≤ 500 g/h

50 all installations if mass flow > 500 g/h discontinuous or continuous (daily average) measurements

10 BFs: furnace charging

50 Sintering of metallurgic ores, blast furnaces

50 steel industry and coke-making gas; existing installations

10 BFs; new installations

30 production of steel used elsewhere; new installations

100 agglomerization, pelletization; existing installations

25/50 agglomerization, pelletization; new installations

100 iron production; existing installations

50 iron production; new installations

20 all installations except BFs (general requirement)

10 BFs (3% O2) continuous (daily) and discontinuous measurements (half-hour average)

40-75 Roasting / sintering installations;

5-50 production of pig iron and steel;

8 hour average

50


23 Sinter plants: new installations

31 Sinter plants: existing installations

6.8 BFs: new installations

23 BFs: existing installations

23 to 68 BOFs: ELVs are in this range for various operations at BOFs at new and existing installations.

2 the regulation is currently under revision, with the aim to reach an adjustment to the state of the art

21

BAT (BREF)

Austria

Belgium

France

Germany

Switzerland

Austria

Belgium

Denmark

France

Germany

Switzerland

Austria

<50 sinter plant

10-20 sinter plant using FF

<10 pelletisation plant

<10 BFs: BF gas

1-15 BFs: cast house PM removal

20-30 hot metal pre-treatment (including hot metal transfer processes, desulfurisation and deslagging) using ESP

5-15 hot metal pre-treatment using FF

20-30

BOFs using ESP

5-15

BOFs using bag filter additionally: hot metal handling (reladling operations), deslagging of hot metal and secondary metallurgy < 5 g/t liquid steel


0.2 production iron and steel; common ELV for Cd, Hg, Tl; discontinuous measurements (half-hour average)

0.2 all installations if mass flow ≥ 1 g/h; common ELV for Cd, Hg, Th and their compounds; discontinuous measurements.

0.05 BOF, sinter plants; if mass flow Cd+Hg+Tl > 1 g/h; additional com mon ELV of 0.1 mg/Nm³

0.05 all installations (general requirement); alternatively < 0.15 g/h common ELV for Cd and As and their compounds, Benzo(a)pyren, water soluble Co compounds, Cr(VI) compounds; continuous (daily) and discontinuous measurements (half-hour average)



5 production iron and steel; common ELV for Pb, Cr (exc. CrVI),

Cu, Mn, V, Sn; discontinuous measurements (half-hour average)

5 all installations if mass flow ≥ 25 g/h; common ELV for Sb, Pb,

Cr, Co, Cu, Mn, Pt, V, Sn and their compounds; discontinuous measurements.

1 all installations if mass flow > 5 g/h; hourly average

1 BOF, sinter plants; if mass flow Pb and its compounds > 10 g/h

0.5 all installations except sinter plants (general requirement);

1 sinter plants: sintering belt common ELV for Pb, Co, Ni, Se, Te and their compounds; continuous (daily) and discontinuous measurements (half-hour average)



0.2 production iron and steel; common ELV for Cd, Hg, Tl; discontinuous measurements (half-hour average)

22

Belgium

Denmark

France

Germany

Switzerland

0.2 all installations if mass flow ≥ 1 g/h; common ELV for Cd, Hg, Th and their compounds. Discontinuous measurements.

0.1 all installations if mass flow > 1 g/h; hourly average

0.05 BOF, sinter plants; if mass flow Cd+Hg+Tl > 1 g/h; additional com mon ELV of 0.1 mg/Nm³

0.05 all installations (general requirement); alternatively < 0.25 g/h continuous (daily) and discontinuous measurements (half-hour average)


References

EC 2001

Economic Evaluation of Air Quality Targets for Heavy Metals. European Commission, Entec

UK Limited, January 2001.

EIPPCB 2001

Integrated Pollution Prevention and Control: Best Available Techniques Reference Document on the Production of Iron and Steel. European IPPC Bureau, Sevilla: December 2001.

U.S. EPA 2000

Great Lakes Binational Toxics Strategy: Draft Report for Mercury Reduction Options. United

States Environment Protection Agency, September 2000.

U.S. EPA, 2003

National Emissions Standard for Hazardous Air Pollutants (NESHAP) for Integrated Iron and

Steel Industry. United States Environment Protection Agency, May 20, 2003.

Lemmon 2004

Further Development of Emission Standards for the Iron and Steel Sector. William Lemmon and Associates Ltd., Cheminfo Services Inc. (Report prepared for: Environment Canada).

Draft, November 2004

23

III. SECONDARY IRON AND STEEL INDUSTRY


58. This category covers the secondary production of iron or steel (secondary fusion), including electric arc furnaces (EAFs), with a capacity exceeding 2.5 tonnes per hour, for which BAT are considered according to annex III. The production of pig-iron or steel is considered within the primary iron and steel industry.

3

59. According to the BAT description in annex III, the efficient collection of all emissions by installing doghouses or movable hoods or by total building evacuation is important. For all PMemitting processes in the secondary iron and steel industry, PM removal in FFs, which reduces the PM content to less than 20 mg/m 3 , shall be considered as BAT. When BAT is used also for minimizing fugitive emissions, the specific PM emission (including fugitive emission directly related to the process) will not exceed the range of 0.1 to 0.35 kg/Mg steel. There are many examples of clean gas PM content below 10 mg/m3 when FFs are used. The specific PM emission in such cases is normally below 0.1 kg/Mg.


60. Processing of secondary raw materials such as iron and steel can be a significant source of mercury emissions, and emission control technologies are often necessary. In this case the origin of the mercury may be from both natural impurities as well as from the intentional use of iron/steel scrap containing mercury (e.g. switches, air-bag activators etc.) that end up in iron/steel scrap.

61. Pollution prevention techniques are very effective at reducing mercury emissions from secondary steel production processes. For example, mercury-bearing components in steel scrap can be removed prior to shipping the scrap to a secondary iron & steel facility. The mercury can then be recovered at a mercury recycling facility. Although removal of mercury switches from end-of-life automobiles is mandated in all the European Union, this general pollution prevention technique should still be considered as BAT. Also, there may be opportunities to remove additional mercury-bearing components from other products prior to recycling in secondary iron & steel facilities.

62. For EAF steelmaking, the following techniques or combination of techniques are considered as BAT with regard to heavy metals and PM emissions for both new and existing installations: a) PM collection efficiency:

-

-

-

With a combination of direct off gas extraction (4th or 2nd hole) and hood systems or dog-house and hood systems or total building evacuation


24

98% and more collection efficiency of primary and secondary emissions from EAF are achievable. b) Waste gas PM removal by application of:

-

Well-designed FF achieving less than 5 mg PM/Nm3 for new plants and less than 15 mg PM/Nm3 for existing plants, both determined as daily mean values.

The minimisation of the PM content correlates with the minimisation of heavy metal emissions except for heavy metals present in the gas phase like mercury.

63. It is recommended that the pollution prevention techniques be included as a best environmental practice include:

-

Develop and implement operating practices to prevent or minimize the contaminants in the steel scrap or other raw materials;

-

-

Develop and implement operating practices to prevent or minimize the presence of mercury in the scrap

Enclose the filter PM collection and discharge and carry out transfer and disposal in an environmentally sound method.

64. It is recommended that an environmental performance indicator for the EAF steelmaking process would be a maximum of 60 grams per tonne of molten steel for new or modified EAFs and a maximum of 120 grams per tonne of molten steel for existing EAFs.


65. In recent years a number of new furnace types have been introduced, that might be realised at industrial scale, and that show advantages with regard to heavy metals and PM emissions:

-

Comelt EAF: integrated shaft scrap preheating and a complete off gas collection in each

-

- operating phase.

Contiarc furnace: waste gas and PM volumes are considerably reduced, and the gas-tight furnace enclosure captures all primary and nearly all secondary emissions.

Direct reduction (DR) involves the production of solid primary iron from iron ores and a reducing agent (e.g. natural gas). The solid product is called Direct Reduced Iron (DRI) and is mainly applied as feedstock in EAFs. The direct reduction process has been commercialised since the 1970's and a variety of processes have been developed. The use of DRI in

EAF steelmaking is forecast to continue to grow in the near future. The major driving forces

- for DRI production are the need for virgin material in the EAF steelmaking process to produce higher quality steel and the increasing price of steel scrap offset by increased natural gas prices.

The use of liquid iron might be a further option.


66. Annex V of the Protocol includes an ELV for particulate emissions of 20 mg/m³ for EAF.

For other related processes and for the heavy metals covered by the Protocol no ELVs are specified.




25

Table III-1 ELVs for secondary steel production


Country / reference

ELV Remarks



Austria 4

Belgium

Bulgaria

Czech

Republic

Germany

Slovakia

Switzerland

United

States of

America

BAT (BREF)

Austria

Belgium

France

20 EAF > 2.5 t/h; continuous (daily) and discontinuous measurements (hourly average)

20 EAF, induction, ladle furnace

50 converter, vacuum melting, electro slag remelting continuous (daily) and discontinuous measurements (half-hour average), gaseous or liquid fuels 3%O2 (heat furnace 5%O2), solid fuels 6% O2

20 EAF; discontinuous or continuous (daily average) measurements

20 EAF

50 EAF < 2.5 t/h, new installations

20 EAF > 2.5 t/h, new installations

5 EAF

20 all installations (general requirement) continuous (daily) and discontinuous measurements (half-hour average)

50


12 EAF: ELV for new installations, based on regulation finalized in

1984 and applies to facilities built after 1984 (U.S. EPA, 1984).

< 15

< 5

EAF, existing installations, daily mean

EAF, new installations, daily mean


0.2 production of iron and steel; common ELV for Cd, Hg, Th; discontinuous measurements (half-hour average)


0.05 EAF if mass flow Cd+Hg+Tl > 1 g/h; additional common ELV of

0.1 mg/Nm³

4 the regulation is currently under revision, with the aim to reach an adjustment to the state of the art

26

Germany

Switzerland

Austria

Belgium

Denmark

France

Germany

Switzerland

Austria

Belgium

Denmark

France

Germany

Switzerland




5 production of iron and steel; common ELV for Pb, Cr (exc. CrVI),

Cu, Mn, V, Sn; discontinuous measurements (half-hour average)


Cr, Co, Cu, Mn, Pt, V, Sn and their compounds. Discontinuous measurements.


1 EAF if mass flow Pb and its compounds > 10 g/h

0.5 all installations (general requirement); common ELV for Pb, Co, Ni, Se, Te and their compounds; continuous (daily) and discontinuous measurements (half-hour average)



0.2 production iron and steel; common ELV for Cd, Hg, Th; discontinuous measurements (half-hour average)



0.05 EAF if mass flow Cd+Hg+Tl > 1 g/h; additional common ELV of

0.1 mg/Nm³



References

EIPPCB 2001

Integrated Pollution Prevention and Control: Best Available Techniques Reference Document on the Production of Iron and Steel. European IPPC Bureau, Sevilla: December 2001.

Lemmon 2004

Further Development of Emission Standards for the Iron and Steel Sector. William Lemmon

27

and Associates Ltd., Cheminfo Services Inc. (Report prepared for: Environment Canada).

Draft, November 2004

Lourie & Love 2002

Mercury Use in Switches in Canada and Estimating the Release of Mercury from these

Sources at Electric Arc Furnaces, prepared for CCME by Lourie & Love Inc., March 2002

UNEP 2002


U.S. EPA, 1984. New Source Performance Standard (NSPS) for Secondray Iron and Steel

(Electric Arc Furnaces). 40 Code of Federal Regulations (CFR) Part 60, Subpart AAa. October 31, 1984

28

IV. IRON FOUNDRIES


68. This sector covers ferrous metal foundries with a capacity exceeding 20 tonnes per day.

According to annex III, BAT are considered for cupola and induction furnaces that are operated in iron foundries. Electric arc furnaces (EAFs) are treated within the secondary iron and steel industry.

69. Rotary furnaces are not currently taken into account in annex III but may be a relevant source of heavy metal emissions. Therefore, additional information is given for these installations.

70. According to annex III, the efficient collection of all emissions by installing doghouses or movable hoods or by total building evacuation is important. Emission reduction with ESPs, FFs, the latter also combined with pre-PM removal, dry absorption or chemisorption, or venturi scrubbers can reduce PM concentrations to 20 mg/m3, or less. For existing smaller installations, these measures may not be BAT if they are not economically viable.


71. For the foundries industry, emissions to air are the key environmental concern. The foundry process generates (metal-laden) mineral dusts, acidifying compounds, products of incomplete combustion and volatile organic carbons. PM is a major issue, since it is generated in all process steps, in varying types and compositions. PM is emitted from metal melting, sand moulding, casting and finishing. Any PM generated may contain metal and metal oxides. In the foundry process, emissions to air will typically not be limited to one (or several) fixed point(s).

The process involves various emission sources (e.g. from hot castings, sand, hot metal). A key issue in emission reduction is not only to treat the exhaust and off-gas flow, but also to capture it.

72. For iron foundries, the following techniques or combination of techniques (Points 72 through 82) are considered as BAT with regard to heavy metals and PM emissions. The BAT associated emission level for PM, after collecting and PM removal from exhaust gases, for all types of furnaces (cupola, induction, and rotary furnace) and mouldings (lost mould and permanent mould) as well as finishing operations is 5-20 mg/m³ (daily average, standard conditions).

Fugitive emissions

73. BAT is to minimize fugitive emissions arising from various non-contained sources in the process chain, by using a combination of the following measures. The emissions mainly involve losses from transfer and storage operations and spills.

- avoid outdoor or uncovered stockpiles, but where outdoor stockpiles are unavoidable, to use sprays, binders, stockpile management techniques, windbreaks, etc.

29

-

-

-

-

- cover skip and vessels vacuum clean the moulding and casting shop in sand moulding foundries clean wheels and roads keep outside doors shut carry out regular housekeeping

74. Additionally, fugitive emissions may arise from the incomplete evacuation of exhaust gas from contained sources, e.g. emissions from furnaces during opening or tapping. BAT is to minimize these fugitive emissions by optimizing capture and cleaning. For this optimization one or more of the following measures are used, giving preference to the collection of fume nearest to the source:

- hooding and ducting design to capture fume arising from hot metal, furnace charging, slag

- transfer and tapping applying furnace enclosures to prevent the release of fume losses into the atmosphere

- applying roofline collection, although this is very energy consuming and should only be applied as a last resort.

Cupola furnace melting of cast iron

75. The amount of PM and exhaust gases resulting are directly related to the amount of coke charged per tonne of iron. Therefore, all measures that improve the thermal efficiency of the cupola will also reduce the emissions from the furnace. For the operation of cupola furnaces,

BAT is all of the following, to: a) use divided blast operation (2 rows of tuyères) for cold blast cupolas b) use oxygen enrichment of the blast air, in a continuous or intermittent way, with oxygen levels between 22 and 25 % (i.e. 1 % - 4 % enrichment) c) minimize the blast-off periods for hot blast cupolas by applying continuous blowing or long campaign operation. Depending on the requirements of the moulding and casting line, duplex operations must be considered

- apply good melting practice measures for the furnace operation

-

-

Operating the furnace in its optimum regime as much as possible

Avoiding excess temperatures

-

-

-

-

Uniform charging:

Minimising air losses

Avoiding “bridging” in the cupola

Utilising good lining practice d) use coke with known properties and of a controlled quality e) clean furnace off-gas by subsequent collection, cooling and PM removal. BAT for PM removal is to use a bag filter or wet scrubber.

Induction furnace melting of cast iron and steel

76. For the operation of induction furnaces, BAT is all of the following, to:

- apply measures to increase furnace efficiency through shorter melting times and reduced

- downtime. use a hood, lip extraction or cover extraction on each induction furnace to capture the fur-

-

- nace off-gas and to maximise off-gas collection during the full working cycle use dry flue-gas cleaning keep PM emissions below 0.2 kg/tonne molten iron.

Rotary furnace melting of cast iron

30

77. For the operation of rotary furnaces, BAT is all of the following, to:

- use techniques to optimize furnace operation and to increase the melting efficiency.

- collect the off-gas close to the furnace exit, apply post combustion, cool it using a heatexchanger and then to apply dry PM removal.

Lost mould casting

78. For green sand moulding, BAT for green sand preparation is to enclose all the unit operations of the sand plant (vibrating screen, sand PM removal, cooling, mixing operations) and to remove PM from the exhaust gas.

79. For chemically-bonded sand mould and core-making, all type of binders are determined as BAT if they are applied according to good practice measures, which mainly involve process control and exhaust capture measures to minimize emissions.

80. Pouring, cooling and shake-out generate emissions of PM. BAT is to:

- enclose pouring and cooling lines and to provide exhaust extraction, for serial pouring lines,

- and enclose the shake-out equipment, and to treat the exhaust gas using wet or dry PM removal.

Permanent mould casting

81. BAT for sand preparation in permanent mould casting is to enclose all the unit operations of the sand plant (vibrating screen, sand PM removal, cooling, mixing operations) and to dedust the exhaust gas.

82. BAT for used sand management in permanent mould foundries is to enclose the decoring unit, and to treat the exhaust gas using wet or dry PM removal.

Finishing of castings

83. For abrasive cutting, shot blasting and fettling, BAT is to collect and treat the finishing offgas using a wet or dry system. If an Argon-Oxygen Decarborization (AOD) converter is used for steel refining, BAT is to extract and collect the exhaust gas using a roof canopy.


84. Use of low cost combustible materials in cupola melting: In order to reduce the consumption of coke, techniques have been developed to allow the use of high calorific value solid waste (tyres, plastic pieces, etc.) together with lower grade coke as a fuel. However, the application of alternative fuels will cause a change in the flue-gas composition; leading to higher amounts of PM for disposal, possibly with a higher content of pollutants and an increased risk of dioxins, polycyclic aromatic hydrocarbons (PAHs) and heavy metals.


85. Annex V of the Protocol does not specify any ELV for this category.

31




Table IV-1 ELVs for iron foundries


Country / reference

ELV Remarks


Austria

Belgium

Germany

Netherlands

Switzerland

United

States of

America

BAT (BREF)

Austria

Belgium

20 Induction, EAF, cupola with furnace top extraction; heat treatment; core prod. ≥0.5 kg/h

50 other furnaces; plants of sand regeneration, mould production, cleaning and fettling (>25 kg/h)

5% O2 for heat treatment furnaces; continuous (daily) or discontinuous measurements (half-hour average)

20 foundries discontinuous or continuous (daily average) measurements

20 all installations (general requirement) continuous (daily) and discontinuous measurements (half-hour average)

5 daily average or half hourly average for discontinuous measurements


4.6 Cupola or electric arc furnace: new installations

13.8 Cupola furnace: existing installations

2.3

11.5

Electric induction furnace or scrap pre-heater: new installations

Electric arc furnace, electric induction furnace or scrap preheater: existing installations

4.6 Pouring area or pouring station: new installations

23 Pouring area or pouring station: existing installations

5-20 daily average; additionally PM emissions < 0.2 kg/tonne molten iron for induction furnaces


0.2 common ELV for Cd, Tl; 5% O2 for heat treatment furnaces; discontinuous measurements (half-hour average)

0.2 all installations if mass f low ≥ 1 g/h; common ELV for Cd, Hg, Th and their compounds. Discontinuous measurements.

32

France

Germany

Netherlands

Switzerland

Austria

Belgium

Denmark

France

Germany

Netherlands

Switzerland

Austria

Belgium

Denmark

France

Germany

Netherlands

Switzerland

References

0.05 foundries; if mass flow Cd+Hg+Tl > 1 g/h; additional common

ELV of 0.1 mg/Nm³


0.05 If mass flow of Cd is > 0.25 mg/m3



5 common ELV for Pb, Zn, Cr, Cu, V, Sn; 5% O2 for heat treatment furnaces; discontinuous measurements (half-hour average)




1 foundries; if mass flow Pb and its compounds > 10 g/h

0.5 all installations (general requirement); common ELV for Pb, Co, Ni, Se, Te and their compounds; continuous (daily) and discontinuous measurements (half-hour average)

0.5 If mass flow of Pb is > 2.5 mg/m3



0.1 common ELV for Hg, Be; 5% O2 for heat treatment furnaces; discontinuous measurements (half-hour average)



0.05 foundries; if mass flow Cd+Hg+Tl > 1 g/h; additional common

ELV of 0.1 mg/Nm³


0.05 If mass flow of Hg is > 0.25 mg/m3


33

EIPPCB 2005

Integrated Pollution Prevention and Control: Reference Document on Best Available Techniques in the Smitheries and Foundries Industry. European IPPC Bureau, Sevilla: May 2005.

U.S. EPA, 2004. National Emission Standards for Hazardous Air Pollutants for Iron and Steel

Foundries: Final Rule, 69 Federal Register 21905. United States Environmental Protection

Agency. 22 April 2004.

34

V. PRIMARY AND SECONDARY NON-FERROUS METAL INDUSTRY


87. This category covers the primary and secondary production of non-ferrous metals. With respect to the heavy metals of concern, according to annex II consideration is limited to the production of copper, lead, zinc and mercury. For the production from ore, concentrates or secondary raw materials of copper, lead, and zinc by metallurgical processes, the coverage is limited to installations with a capacity exceeding 30 tonnes of metal per day for primary installations and 15 tonnes of metal per day for secondary installations. For installations for the smelting, including alloying, of these metals, including recovered products, the coverage is restricted to installations with a melting capacity of more than 4 tonnes per day for lead and 20 tonnes per day for copper and zinc. According to annex III, BATs are also considered for the primary production of gold.

5

88. Secondary aluminium production is not currently taken into account but may be a relevant source of heavy metal emissions. Therefore, additional information is given for these sector.

89. Large amounts of mercury are currently brought out of use as a result of ongoing and anticipated substitution of mercury-based chlor-alkali production in Europe and North America.

Use of mercury is declining, at both global and EU levels, yet some significant uses remain.

The main global uses are gold mining, batteries and the chlor-alkali industry, together accounting for over 75% of consumption. As a pro-active contribution to a proposed globally organized effort to phase out primary production of mercury and to stop surpluses re-entering the market, the European Commission intends to propose an amendment to Regulation (EC) No. 304/2003 to phase out the export of mercury from the European Community by 2011. In North America, to reduce supply, the US Government decided in 2004 to place a large quantity of previously stockpiled mercury into long-term storage (at least 40 years) to prevent it from entering the market (U.S. DNSC, 2004).

90. According to annex III, BAT in this sector are the following: a) For mercury production, soot from the condensers and settling tanks should be removed, treated with lime and returned to the retort or furnace. For efficient recovery of mercury the following techniques can be used:

-

-

-

-

-

-

Measures to reduce PM generation during mining and stockpiling, including minimizing the size of stockpiles;

Indirect heating of the furnace;

Keeping the ore as dry as possible;

Bringing the gas temperature entering the condenser to only 10 to 2 0°C above the dew point;

Keeping the outlet temperature as low as possible; and

Passing reaction gases through a post-condensation scrubber and/or a selenium filter.


35

PM formation can be kept down by indirect heating, separate processing of fine grain classes of ore, and control of ore water content. PM should be removed from the hot reaction gas before it enters the mercury condensation unit with cyclones and/or ESPs. b) For gold production by amalgamation, similar strategies as for mercury can be applied.

Gold is also produced using techniques other than amalgamation, and these are considered to be the preferred option for new plants. c) For the production of non-ferrous metals from sulphitic ores, FFs should be used when appropriate. A PM content of less than 10 mg/m3 can be obtained. The PM should be recycled in-plant or off-site. Before being fed to an SO3 contact plant, the off-gas must go through a thorough PM removal (< 3 mg/m3) and could also require additional mercury removal thereby also minimizing heavy metal emissions. d) For primary lead production, first experiences indicate that there are interesting new direct smelting reduction technologies without sintering of the concentrates. These processes are examples of a new generation of direct autogenous lead smelting technologies which pollute less and consume less energy. e) Secondary lead is mainly produced from used car and truck batteries,. This BAT should include one melting operation in a short rotary furnace or shaft furnace. Oxy-fuel burners can reduce waste gas volume and flue PM production by 60%. Cleaning the flue-gas with

FFs makes it possible to achieve PM concentration levels of 5 mg/m3. f) For primary zinc production, pressure leaching may be an alternative to roasting and may be considered as a BAT for new plants depending on the concentrate characteristics.

Emissions from pyrometallurgical zinc production in Imperial Smelting (IS) furnaces can be minimized by using a double bell furnace top and cleaning with high-efficiency scrubbers, efficient evacuation and cleaning of gases from slag and lead casting, and thorough cleaning (< 10 mg/m3) of the CO-rich furnace off-gases. g) In general, processes should be combined with an effective PM collecting device for both primary gases and fugitive emissions. PM concentrations below 5 mg/m3 have been achieved in some cases using FFs.


91. The main environmental issues for the production of most non-ferrous metals from primary raw materials include the potential emission to air of PM and metals/metal compounds. The pyrometallurgical processes are potential sources of PM and metals from furnaces, reactors and the transfer of molten metal. The production from secondary raw materials is also related to the off-gases from the various furnaces and transfers that contain PM and metals.

92. In the majority of cases these process gases are cleaned in FFs and so the emissions of

PM and metal compounds such as lead are reduced. Gas cleaning using wet scrubbers and wet ESPs is particularly effective for process gases that undergo sulfur recovery in a sulfuric acid plant. In some cases where PM is abrasive or difficult to filter, wet scrubbers are also effective. The use of furnace sealing and enclosed transfers and storage is important in preventing fugitive emissions.

Materials handling and storage

93. The techniques that are used depend to a large extent on the type of material that is being used. BAT to prevent releases of PM and heavy metals from raw material handling are:

-

Transfer conveyors and pipelines placed in safe, open areas above ground so that leaks can be detected quickly and damage from vehicles and other equipment can be prevented.

36

-

-

-

-

Where required, sealed delivery, storage and reclamation systems can be used for dusty materials and silos can be used for day storage. Completely closed buildings can be used for the storage of dusty materials and may not require special filter devices.

Sealing agents (such as molasses and PVA) can be used where appropriate and compatible to reduce the tendency for material to form PM.

Where required enclosed conveyors with well designed, robust extraction and filtration equipment can be used on delivery points, silos, pneumatic transfer systems and conveyor transfer points to prevent the emission of PM.

Rationalized transport systems can be used to minimize the generation and transport of PM within a site.

Fume and gas collection

94. Emissions to air arise from the storage, handling, pre-treatment, pyrometallurgical and hydrometallurgical stages. Transfer of materials is particularly important. Data provided has confirmed that the significance of fugitive emissions in many processes is very high and that fugitive emissions can be much greater than those that are captured and abated. In these cases it is possible to reduce environmental impact by following the hierarchy of gas collection techniques from material storage and handling, reactors or furnaces and from material transfer points. Potential fugitive emissions must be considered at all stages of process design and development. The hierarchy of gas collection from all of the process stages is:

-

-

-

Process optimization and minimization of emissions;

Sealed reactors and furnaces;

Targeted fume collection;

95. With regard to PM and heavy metals emissions, important gas collection measures are:

-

The use of sealed furnaces or other process units to prevent fugitive emissions, allow heat

- recovery and the collection of process gases.

The use of semi-sealed furnaces where sealed furnaces are not available.

-

-

-

The minimization of material transfers between processes.

Where such transfers are unavoidable, the use of launders in preference to ladles for molten materials.

In some cases the restriction of techniques to those that avoid molten material transfers may prevent the recovery of some secondary materials that would then enter the waste

-

-

-

- stream. In these cases the use of secondary or tertiary fume collection is appropriate so that these materials can be recovered.

Hooding and ductwork design to capture fume arising from hot metal, matte or slag transfers and tapping.

Furnace or reactor enclosures may be required to prevent release of fume losses into the atmosphere.

Where primary extraction and enclosure are likely to be ineffective, then the furnace can be fully closed and ventilation air drawn off by extraction fans to a suitable treatment and discharge system.

Roofline collection of fume is very energy consuming and should be a last resort.

Removal of mercury

96. Mercury removal is necessary when using raw materials that contain the metal. Mercury appears as an impurity of copper, zinc, lead, and nickel ores. The element is also present in the gold ores. The following techniques are considered to be BAT.

-

The Boliden/Norzink process with the recovery of the scrubbing solution and production of mercury metal.

37

-

-

-

-

Bolchem process with the filtering off the mercury sulfide to allow the acid to be returned to the absorption stage.

Outokumpu process.

Sodium thiocyanate process.

Activated Carbon Filter. An adsorption filter using activated carbon is used to remove mercury vapor from the gas stream as well as dioxins.

97. For processes where mercury removal from the gases is not practicable the two processes to reduce the mercury content in sulfuric acid produced during the production of non-ferrous metals are considered to be BAT.

-

Superlig Ion Exchange process.

-

Potassium iodide process.

The emissions associated with the above processes are related to any residual mercury that will be present in the acid that is produced, the product specification is normally < 0.1 ppm

(mg/l) and is equivalent to ~ 0.02 mg/Nm3 in the cleaned gas.

98. Formation of particles of chloride and sulfate salts was considered to be an important removal mechanism for mercury in the FGD process. This would be promoted by high Cl content in the coal and for mercury sulfate, and by low temperatures combined with the catalytic effect of activated carbon.

-

-

The relatively low temperatures found in wet scrubber systems allow many of the more volatile trace elements to condense from the vapor phase and thus to be removed from the flue gases. In general, removal efficiency for mercury ranges from 30 to 50%.

In summary, the overall removal of mercury in various spray dry systems varies from about

35 to 85%. The highest removal efficiencies are achieved from spray dry systems fitted with downstream FFs.

99. Mercury releases and health hazards from artisanal gold mining activities may be reduced by educating the miners and their families about hazards, by promoting certain techniques that are safer and that use less or no mercury and, where feasible, by putting in place facilities where the miners can take concentrated ores for the final refining process.

Abatement of PM and heavy metals emissions

100. BAT for the abatement of PM and heavy metals emissions are the following:

-

Fume collection systems used should exploit furnace or reactor sealing systems and be designed to maintain a reduced pressure that avoids leaks and fugitive emissions, where applicable. Systems that maintain furnace sealing or hood deployment should be used. Ex-

-

- amples are through electrode additions of material, additions via tuyeres or lances and the use of robust rotary valves on feed systems. The use of an intelligent system capable of targeting the fume extraction to the source and duration of any fume is more energy efficient.

Overall for PM and associated metal removal, FFs (after heat recovery or gas cooling) can provide the best performance provided that modern wear resistant fabrics are used, the particles are suitable and continuous monitoring is used to detect failure. Modern filter (e.g. membrane filter) offer significant improvements in performance, reliability and life and therefore offer cost savings in the medium term. They can be used in existing installations and can be fitted during maintenance. They feature bag burst detection systems and online cleaning methods.

For sticky or abrasive dusts, wet electrostatic precipitators or scrubbers can be effective provided that they are properly designed for the application.

38

-

BAT for gas and fume treatment systems are those that use cooling and heat recovery if practical before a FF except when carried out as part of the production of sulfuric acid. The gas cleaning stage that is used prior to the sulfuric acid plant will contain a combination of dry ESP, wet scrubbers, mercury removal and wet ESP.

BAT for gas collection and abatement for the various process stages regarding to PM and heavy metals are summarized in the following table:

Materials handling and storage. Correct storage, handling and transfer. PM collection and

FF if necessary.

Grinding, drying.

Sintering/roasting, Smelting,

Converting, Fire refining

Process operation. Gas collection and FF.

Gas collection, gas cleaning in FF, heat recovery.

Slag treatment. Gas collection, cooling and FF.

Thermal refining. Gas collection and FF.

Electrode baking, graphitisation Gas collection, condenser and ESP, afterburner or alumina scrubber and FF.

Metal powder production

Melting and casting.

Gas collection and FF.

Gas collection and FF.

101. FFs are not BAT for the recovery of non-ferrous metals from sulfur-bearing concentrates due to the potential for condensation of sulphuric acid on the baghouse filter media particularly during temporary outages and operation at gas temperatures below the acid gas dew point.

The ESP is the preferred dust abatement method for these processes. It will tolerate short periods of condensation without plugging/blinding as occurs immediately even with modern fabric filters (e.g., membrane filter bags).

102. When BAT are used, the associated emission level for PM, depending on its characteristics, for FF and alumina scrubber is 15 mg/Nm³, and for wet ESP or ceramic filter < 5 mg/Nm³

(daily average, standard conditions).

103. The concentration of heavy metals is linked to the concentration of PM and proportion of the metals in the PM. The metal content of PM varies widely between processes. In addition, for similar furnaces there are significant variations in metal content due to the use of varying raw materials. It is considered that low concentrations of heavy metals are associated with the use of high performance, modern abatement systems such as a membrane FF provided the operating temperature is correct and the characteristics of the gas and PM are taken into account in the design. As a total PM retention of more than 99.75 % can be achieved with the use of ESPs and FFs, the contents of heavy metals, including mercury on particles in the flue gas can be reduced by at least 95.0 to 99.0 %.

Production of copper and its alloys from primary and secondary raw materials

104. Process selection for primary copper smelting: Depending on the raw materials available,

BAT are:

-

The continuous processes from Mitsubishi and Outokumpu/Kennecott are considered to be

BAT for the smelting and converting stage. The Mitsubishi system also treats copper secondary raw material and scrap. The Mitsubishi and Outokumpu processes are derivatives of the Canadian INCO flash furnace which was the first continuous smelting process for copper and nickel. The INCO flash furnace has distinct advantages for certain concentrate chemistry and is also BAT.

39

-

-

-

Similar environmental performance, using concentrate blends from various sources, can be achieved using the Outokumpu Flash Smelting Furnace, and for smaller throughputs the

ISA Smelt furnace. These furnaces are used in combination with the Peirce-Smith (or similar) converter.

The combination of partial roasting in a fluid bed roaster, electric furnace matte smelting and Peirce-Smith converter offers advantages for the treatment of complex feed materials allowing recovery of other metals contained in the concentrate like zinc and lead.

The use of the Outokumpu Flash Smelting Furnace for direct smelting to blister copper us-

- ing specific concentrates with a low iron content or very high grade concentrates (low slag fall).

The Noranda, El Teniente converter and Contop furnaces may also achieve the same environmental performance as those listed above, given good gas collection and abatement systems. The INCO flash furnace may also have advantages but operates with 100% oxygen resulting in a narrow operating window.

Gases from the primary smelting and converting processes should be treated to remove PM and volatile metals.

105. Process selection for the production of copper from secondary raw materials: For the production of copper from secondary raw materials the variation in feed stock and the control of quality also has to be taken into account at a local level and this will influence the combination of furnaces, pre-treatment and the associated collection and abatement systems that are used.

BAT are BF, mini-smelter, TBRC, Sealed Submerged EAF, ISA Smelt, and the Peirce-Smith converter. The submerged EAF is a sealed unit and is therefore inherently cleaner than the others, provided that the gas extraction system is adequately designed and sized. The electric furnace is also used for secondary material. For high grades of copper scrap without organic contamination, the reverberatory hearth furnace, the hearth shaft furnace and Contimelt process are considered to be BAT in conjunction with suitable gas collection and abatement systems.

106. Process selection for primary and secondary converting: If batch operated converters such as the Peirce-Smith converters (or similar) are used they should be used with total enclosure or efficient primary and secondary fume collection systems. The hooding systems should be designed to allow access for the ladle transfers while maintaining good fume collection. This can be achieved by the use of a system of intelligent control to target fume emissions automatically as they occur during the cycle. The blowing cycle of the converter and the fume collection system should be controlled automatically to prevent blowing while the converter is rolled out.

Additions of materials through the hood or tuyeres should be used if possible. The ISA Smelt furnace can be operated batch-wise, where smelting is carried out in a first stage followed by conversion in a second stage, and is also considered as BAT.

107. Process selection for other processes stages: BAT are:

-

The drying of concentrate etc in directly fired drum and flash dryers, in fluid bed and steam

- dryers.

Slag treatment by electric furnace slag cleaning, slag fuming, crushing/grinding and slag

-

- flotation.

Fire refining in rotary or tilting reverberatory furnaces. Anode casting in pre-formed moulds or in a continuous caster.

Electrolytic copper refining by optimized conventional or mechanized permanent cathode

- technology.

The hydro-metallurgical processes using the electro-winning process are considered to be

BAT for oxidic ores and low grade, complex and precious metal free copper sulfide ores.

40

108. Gas collection and abatement: Fume production from secondary raw materials can be minimized by the choice of the furnace and abatement systems. Secondary fume collection is needed in the case of some batch converters and for the ventilation of tap-holes, launders etc.

BAT for gas collection and abatement for the various process stages with regard to PM and heavy metals are summarized in the following table:

Raw materials handling. Correct storage, handling and transfer. PM collection and FF.

Raw materials thermal pre-treatment

Primary smelting

Correct pre-treatment. Gas collection and FF.

Process operation and gas collection, gas cleaning followed by gas cooling/final cleaning (normally followed by sulfuric acid plant)

Secondary smelting

Primary converting Process operation and gas collection, gas cleaning (followed by sulfuric acid plant)

Secondary converting Process operation and gas collection, cooling and cleaning by

FF. scrubbing if necessary

Fire refining

Process operation and gas collection, cooling and cleaning by

FF. scrubbing if necessary

Melting and casting.

Pyro-metallurgical slag treatment


FF or scrubber


FF.


FF.

109. The BAT associated emission level for PM is 15 mg/Nm³ (daily average). For secondary smelting and converting, primary and secondary fire refining, electric slag cleaning and melting, it can be reached using high performance FFs. For secondary fume collection systems and drying processes, FF with lime injection (for sulfur dioxide collection/filter protection) are BAT.

Production of aluminium from secondary raw materials

110. Process selection for secondary aluminium smelting: The smelting and melting processes that are considered to be BAT are the Reverberatory furnace, Tilting rotary furnace, Rotary furnace, Meltower Induction furnace, depending on the feed materials, with the following features:

-

-

-

-

The use of a sealed charging carriage or similar sealed feeding system if possible.

The use of enclosures or hoods for the feeding and tapping areas and targeted fume extraction systems if practical

The use of coreless-induction furnaces for relatively small quantities of clean metal

The use of fabric or ceramic filters for PM removal.

111. Process selection for other processes stages: BAT for holding or de-gassing is the fume collection from furnaces and launders, cooling, and FF if necessary.

112. Gas collection and abatement: BAT for gas and fume treatment systems are those that use cooling and heat recovery if practical before a FF. FF or ceramic filters that use modern high performance materials in a well constructed and maintained structure are applicable. The use of or the recycling of skimmings and filter dusts, if it is possible, is considered to be part of the processes. BAT for gas collection and abatement for the various process stages are summarized in the following table:

41

Raw materials handling. PM prevention and correct storage. PM collection and

FF.

Raw materials pre-treatment Correct pre-treatment. Gas collection and FF.

Secondary smelting Process operation, gas collection and efficient PM removal.

Holding and refining

Salt slag and skimmings treatment processes

Process operation and gas collection/cleaning

Process operation and gas collection/treatment

113. The BAT associated emission level for PM is 1-

5 mg/Nm³ (daily average) for materials pre-treatment (including swarf drying), melting and smelting of secondary aluminium and holding and de-gassing molten metal, using a high performance FF.

Production of lead and zinc from primary and secondary raw materials

114. Process selection for primary lead smelting: Depending on the raw materials available,

BAT are:

Applied technique

Kaldo process TBRC (Totally enclosed)

Raw material

Pb concentrate and secondary (most grades)

ISF and New Jersey Distillation Zn/Pb concentrates

QSL Pb concentrate and secondary material

Kivcet furnace

Kaldo Furnace

Cu/Pb concentrate and secondary material

Pb concentrate and secondary material

ISA Smelt Furnace

Blast Furnace

Pb concentrate and secondary material complex lead bearing primary and secondary material

Gases from the sintering, roasting and direct smelting processes should be treated to remove

PM and volatile metals.

115. Process selection for secondary lead smelting: Depending on the raw materials available, processes that are BAT are: The blast furnace (with good process control), ISA Smelt/Ausmelt, the electric furnace and the rotary furnace. The submerged arc electric furnace is used for mixed copper and lead materials. It is a sealed unit and is therefore inherently cleaner than the others, provided that the gas extraction system is adequately designed and sized. The electric furnace is used for secondary material containing sulfur and is connected to a sulfuric acid plant. When only clean lead and clean scrap is used, also melting crucibles and kettles is BAT.

116. Process selection for lead refining: Processes would be used with efficient primary and if necessary, secondary fume collection systems. Temperature control of the refining kettles is articularly important to prevent lead fume and indirect heating is more effective in achieving this.

117. Process selection for primary and secondary zinc production: No specific process is BAT provided that for any process good process control, gas collection and abatement systems are used.

42

118. Gas collection and abatement: The ISF process need to use wet scrubbing so that the gases are cooled prior to use as a fuel. BAT for gas collection and abatement for the various process stages are summarized in the following table:

Raw materials handling. Correct storage, PM collection and FF.

Correct pre-treatment. Gas collection and FF. Raw materials pre-treatment

(mechanical decoating/stripping; thermal decoating)

Primary raosting and smelting, sintering

ISF

Process operation, gas collection, gas cleaning, cooling and sulfuric acid plant

Wet scrubbing (to cool gas) prior to use as low calorific value gas

Secondary smelting

Thermal refining

Melting, alloying, casting and

PM production

Slag fuming and Waelz kiln processes

Process operation and gas collection, cooling and FF

Process operation, gas collection, cooling and FF

Process operation, gas collection, cooling and FF

Process operation, gas collection, cooling and FF or wet

ESP if wet quenching is used.

119. The BAT associated emission level for PM is 1-

5 mg/Nm³ (daily average). This can be achieved using a high performance FF for the melting of clean material, alloying and zinc PM production. Temperature control of melting kettles or vessels is needed to prevent volatilisation of metals. For materials pre-treatment, secondary smelting, thermal refining, melting, slag fuming and Waelz kiln operation, this can be achieved using a high performance FF or wet ESP (A wet ESP may be applicable to gases from slag granulation or wet gas quenching).

Production of gold

120. Process selection: No specific process is considered as BAT. The use of the copper route for smelting precious metals has a lower potential for the emission of lead to all environmental media and should be used if the combination of raw materials, equipment and products allows it.

121. Gas collection and abatement: Secondary fume collection is needed in the case of some furnaces. The use of or the recycling of acids, slags, slimes and filter dusts are considered to part of the processes. In the case of high content of mercury in the ore it is necessary to use an activated carbon adsorber bed. BAT for gas collection and abatement for the various process stages are summarized in the following table:

Raw materials handling. Correct storage. PM collection and FF if necessary.

Raw materials pre-treatment Correct pre-treatment. Gas collection and FF.

Roasting and smelting Process operation, gas collection, cooling and FF; scrubbing if necessary

Selenium roasting

Dissolution and chemical refining

Process operation, gas collection, cooling and PM removal, scrubbing and wet ESP

Process operation and gas collection with oxidising scrubber

Thermal refining (Miller process)

Process operation, gas collection, scrubbing and wet ESP

Melting, alloying and casting Process operation, gas collection, cooling and FF

43

Slag treatment and cupelling Process operation, gas collection, cooling and FF.

122. The BAT associated emission level for PM for materials pre-treatment (including incineration), roasting, cupelling, smelting, thermal refining, and melting for precious metal recovery is

15 mg/Nm³ (daily average). This can be achieved using a high performance FF or ceramic filter.

Production of mercury

123. Materials handling and storage In addition to the generic BAT for materials handling and storage, because of the vapour pressure of mercury, storage of the product in sealed and isolated flasks is considered to be BAT.

124. Process selection for mercury production: [The BAT to produce mercury is the production of mercury from secondary raw materials]. Only in situations were waste mercury cannot be obtained the production of primary mercury from cinnabar can be regarded as BAT. For primary mercury production from cinnabar the use of a Herreschoff furnace is BAT. For other production either from gas treatment systems for other non-ferrous metals or from secondary raw materials it is not possible to conclude that a single production process is BAT.

125. Gas collection and abatement: BAT for gas and fume treatment systems are those described for mercury removal. For PM forming process stages a FF is considered to be BAT.

BAT for gas collection and abatement for the various process stages are summarized in the following table:

Ore grinding and conveying. PM collection and FF.

Handling secondary material Enclosed handling, scrubbing of ventilation gases

Primary or secondary roasting Mercury condenser and mercury scrubber system.

Product handling Enclosed filling station, scrubbing of ventilation gases.

The performance of the scrubber based processes are uncertain for fine mercury particles and it is concluded that further investigation of the techniques in this application is needed before

BAT can be confirmed and associated emissions given.

126. The BAT associated emission level for PM from ore grinding, roasting, distillation and associated processes for primary production of mercury is 15 mg/Nm³ (daily average). This can be achieved using a FF, while a wet ESP may be applicable to gases from slag granulation. [Because the primary production is not regarded as BAT, the BAT associated emission levels are based on the production of secondary mercury.] Mercury emissions to air from secondary production and production from base metals associated with the use of BAT in the mercury sector are of 0.02 mg/Nm³ (daily average), what can be achieved by a mercury scrubber

(Boliden, thiosulphate etc).


127. The application of selenium filter is proposed as a dry media process, which can be applied at both steel and non-ferrous metal smelters. Mercury removal of above 90 % has been achieved through this technique reducing the mercury concentrations to be low 0.01 mg/m³.

Selenium filters are recommended for the removal of mercury from the flue gas stream upstream of the acid plant in non-ferrous metal smelters. For copper production, the estimates of

44

the annualized cost indicate a range from 1990 US$ 10.0 to more than 50.0 per tonne of copper. In the case of lead smelters this cost is about 50 % lower.

128. The mercury reduction of a selenium scrubber is about 90 –95%, resulting in mercury concentrations of about 0.2 mg/m³. However, at low incoming Hg concentrations the removal efficiency can be less than 90 %.

129. For the Odda chloride process, mercury concentrations of the treated gases are 0.05-0.1 mg/m³.

Production of copper and its alloys from primary and secondary raw materials

130. Bath smelting can offer low cost installations because of the potential high reaction rates in modern plant coupled with sealed or semi-sealed furnaces. Plant reliability needs to be proven in the long term.

131. ISA Smelt for reduction/oxidation is not industrially proven but is emerging.

132. The use of hydro-metallurgical processes is also emerging and they are suitable for mixed oxidic/sulfidic ores that contain low concentrations of precious metals. Some processes are being developed for concentrates and PM treatment based on leaching for example leachsolvent extraction-electro-win (L:SX:EW) processes.

133. Developments in other industrial sectors may also be seen as emerging for copper production processes. Particular developments are:

-

The use of modern fabrics for bag filters mean that more effective and robust fabrics (and housing design) can allow bag life to extended significantly, improving performance and re-

- ducing costs at the same time.

The use of intelligent damper controls can improve fume capture and reduce fan sizes and hence costs. Sealed charging cars or skips are used with a reverberatory furnace at a secondary aluminium smelter and reduces fugitive emissions to air significantly by containing emissions during charging.

Production of aluminium from secondary raw materials

134. Reuse of filter PM from secondary aluminium production: PM and fume from a rotary furnace is treated with sodium bicarbonate and activated carbon as the scrubbing medium to remove chlorides produced by the salt flux and sodium chloride is formed. The PM is then collected in a FF and can be included with the salt charged to the furnace.

135. Catalytic filter bags.

Production of lead and zinc from primary and secondary raw materials

136. Leaching processes based on chloride for zinc and lead recovery are reported as being at the demonstration stage.

45

137. The injection of fine material via the tuyeres of a blast furnace has been successfully used and reduces the handling of dusty material and the energy involved in returning the fines to a sinter plant.

138. Control parameters such as temperature are used for melting furnaces and kettles and reduce the amount of zinc and lead that can be fumed from a process.

139. Furnace control systems from other sectors may be available for the blast furnace and

ISF.

140. The EZINEX process is based on ammonia/ammonium chloride leaching followed by cementation and electrolysis. It was developed for the direct treatment of EAF dusts and one plant is operational. It may be used for richer secondary zinc feed.

141. The Outokumpu Flash Smelting Furnace has been used on a demonstration basis for the production of lead by direct smelting. The use of Waelz kilns for this purpose has also been reported. The literature contains many other potential examples that have not yet been developed beyond the pilot scale.

142. For the lead sulfide process, a mercury removal efficiency of 99.0 % has been measured, resulting in mercury emission concentrations of 0.01-0.0

5 mg/Nm³.

143. The BSN process treats pelletised PM from EAF by drying and clinkering followed by the reduction, volatisation and re-oxidation to produce ZnO.

Production of gold

144. The 'J' process is not operated in Europe but can operate with a lower inventory of gold compared with other gold refining processes. It uses a re-generable iodine solution to dissolve impure gold (< 99.5%). The gold is reduced by potassium hydroxide, separated, washed and dried to a powder containing 99.995% gold. Liquor from the reduction stage is fed to an electrolytic cell where soluble impurities and any unreduced gold iodide are deposited on the cathode and removed for recovery in a precious metals circuit. The solution is then transferred to an electrolytic diaphragm cell fitted with inert electrodes. Iodine solution produced in the anode compartment and KOH solution produced in the cathode compartment are recycled

145. A process has been designed to treat a pyrite concentrate that contains microscopic gold particles (< 1 µm) to produce a gold ore, a lead/silver concentrate and a zinc concentrate

Production of mercury

146. A process integrated with primary mercury production is being developed to recover mercury that is removed from processes that are substituting other materials for mercury. This development will include the abatement of fine mercury particles and this technique will be available for primary mercury production.


46

147. Annex V of the Protocol includes an ELV for PM for the production of copper and zinc, including Imperial Smelting furnaces, of 20 mg/m³, and of 10 mg/m³ for the production of lead.

No ELV is specified for the heavy metals covered by the Protocol, nor for the production of mercury or gold.




Table V-1 ELVs for the primary and secondary non-ferrous metal industry


Country / reference

ELV Remarks



Austria 6

Belgium

Bulgaria

Germany

Netherlands

20 production of copper and zinc, including Imperial Smelting furnaces

10 production of lead continuous (daily) and discontinuous measurements (hourly average)

20 > 5 MW (electric furnace > 3MW);

10 production of Pb and Zn, > 1MW

6% O

2

solid, 3% O

2 liquid and gaseous fuels; continuous (daily) and discontinuous measurements (half-hour average)

10 primary lead production and melting

20 primary production and melting of other non-ferrous metals continuous measurements, daily average.

20 production of copper and zinc

10 production of lead

5 production of non-ferrous unrefined metals, roasting, smelting or sintering of non-ferrous metal ores

5 melting, alloying or refining of non-ferrous metals (non-ferrous metal foundries with a production capacity of > 20 t/d or > 4 t/d for lead and cadmium) continuous (daily) and discontinuous measurements (half-hour average)

1-5 prod. of copper, lead, zinc, gold and mercury; daily average

6 The regulation is currently under revision, with the aim to reach an adjustment to the state of the art

47

Netherlands

Switzerland

Austria 7

Belgium

Denmark

France

Germany

Switzerland

United

States of

America

BAT (BREF)

Austria

Belgium

France

Germany

Netherlands


Primary Copper Smelting: Nonsulfuric acid PM limit of 6.2 mg/dscm for flash smelting furnaces, slag cleaning vessels and batch converters

1-5 prod. of copper, lead, zinc, gold and mercury; daily average


0.05 additionally common ELV for Cd, Hg, Be, Tl < 0.2 mg/m³; discontinuous measurements (half-hour average)


0.05 primary and secondary production of lead, zinc and aluminium; if mass flow Cd+Hg+Tl > 1 g/h; additional common ELV of 0.1 mg/Nm³





5 Common ELV for Pb, Zn, Cr (except for Cr-VI), Cu, Mn, V, Sn; discontinuous measurements (half-hour average)




1 primary and secondary production of lead, zinc and aluminium; if mass flow Pb and its compounds > 10 g/h

0.5 all installations (general requirement);

1 sinter plant: sintering belt

1 prod. of non-ferrous unrefined metals except lead

2 production of lead

1 lead refining common ELV for Pb, Co, Ni, Se, Te and their compounds; continuous (daily) and discontinuous measurements (half-hour average)


7 The regulation is currently under revision, with the aim to reach an adjustment to the state of the art

48

Switzerland

United

States of

America

Austria

Belgium

Canada

Denmark

France

Germany

Netherlands

Switzerland

1 Production of lead battery


Primary Lead Smelting: 500 grams of lead per megagram of lead metal produced

Secondary Lead Smelting: Lead limit of 2.0 mg/dscm for all furnace types (blast, reverberatory, rotary and electric).


0.1 Sum Be and Hg, additionally common ELV for Cd, Hg, Be, Tl <

0.2 mg/m³; discontinuous measurements (half-hour average)

0.2 all installations if mass flow ≥ 1 g/h; common ELV for Cd, Hg, Th and their compounds. Discontinuous measurements. existing primary zinc, lead and copper smelters: 2 g Hg/tonne total production of finished metals (as of 2008) new and expanding primary zinc, nickel and lead smelters: 0.2 g

Hg/tonne production of finished zinc, nickel and lead new and expanding primary copper smelters: 1 g Hg/tonne of finished copper atmospheric emissions; for new installations additional mercury offset program to en sure no “net” emission increases occur: a new facility will recover and retire an amount of mercury equivalent to their annual emissions.


0.05 primary and secondary production of lead, zinc and aluminium; if mass flow Cd+Hg+Tl > 1 g/h; additional common ELV of 0.1 mg/Nm³




References

CEC 2005

Community Strategy Concerning Mercury. Commission of the European Communities,

COM(2005) 20 final

CCME 2000

Canada-wide Standards for Mercury Emissions. Canadian Council of Ministers of the Environment, Quebec, June 5-6, 2000

49

EC 2001

Ambient air pollution by mercury - Position Paper. European Communities, Luxembourg, 2001.

EIPPCB 2001

Integrated Pollution Prevention and Control: Reference Document on Best Available Techniques in the Non Ferrous Metals Industries. European IPPC Bureau, Sevilla: December 2001.

UNEP 2002

Global Mercury Assessment. United Nations Environment Programme, UNEP Chemicals, Geneva, December 2002.

50

VI. CEMENT INDUSTRY


149. This category covers installations for the production of cement clinker in rotary kilns with a production capacity exceeding 500 tonnes per day, or in other furnaces with a production capacity exceeding 50 tonnes per day. According to annex III, BAT are considered for fossil fuel fired kilns. The co-incineration of waste in cement kilns is treated within the waste incineration category.

150. According to annex III, in terms of energy demand and emission control opportunities, rotary kilns with cyclone preheaters are preferable for clinker production. For heat recovery purposes, rotary kiln off-gases are conducted through the preheating system and the mill dryers (where installed) before being dedusted, and the collected PM is returned to the feed material. Based on annex III, less than 0.5% of lead and cadmium entering the kiln is released in exhaust gases . The high alkali content and the scrubbing action in the kiln favour metal retention in the clinker or kiln PM. The emissions of heavy metals into the air can be reduced by, for instance, taking off a bleed stream and stockpiling the collected PM instead of returning it to the raw feed. However, in each case these considerations should be weighed against the consequences of releasing the heavy metals into the waste stockpile. Another possibility is the hotmeal bypass, where calcined hot-meal is in part discharged right in front of the kiln entrance and fed to the cement preparation plant. Alternatively, the PM can be added to the clinker. Another important measure is a very well controlled steady operation of the kiln in order to avoid emergency shut-offs of the ESPs. It is important to avoid high peaks of heavy metal emissions in the event of such an emergency shut-off. To reduce direct PM emissions from crushers, mills, and dryers, FFs are mainly used, whereas kiln and clinker cooler waste gases are controlled by FFs or ESPs. With ESP, PM can be reduced to concentrations below 50 mg/m3.

When FF are used, the clean gas PM content can be reduced to 10 mg/m3 (273 K, 101.3kPa, dry gas).


151. The selected process has a major impact on the energy use and air emissions from the manufacture of cement clinker. For new plants and major upgrades the BAT for the production of cement clinker is considered to be a dry process kiln with multi-stage preheating and precalcination. The associated BAT heat balance value is 3000 MJ/tonne clinker. It is expected that all the non-dry kilns will convert to the dry method when they are renewed

152. The BAT for the manufacturing of cement with regard to PM and heavy metals emissions includes the following general primary measures:

-

A smooth and stable kiln process, operating close to the process parameter set points, is beneficial for all kiln emissions as well as the energy use.

-

-

Minimising fuel energy use

Careful selection and control of substances entering the kiln can reduce emissions. When practicable selection of raw materials and fuels with low contents of sulfur, nitrogen, chlorine, metals and volatile organic compounds should be preferred.

51

153. Fugitive emission sources mainly arise from storage and handling of raw materials, fuels and clinker and from vehicle traffic at the manufacturing site. A simple and linear site layout is advisable to minimize possible sources of fugitive PM. Proper and complete maintenance of the installation generally has the indirect result of reducing fugitive PM by reducing air leakage and spillage points. The use of automatic devices and control systems also helps fugitive PM reduction, as well as continuous trouble-free operation.

154. Some techniques for fugitive PM abatement are:

-

Open pile wind protection. Outdoor storage piles of dusty materials should be avoided, but when they do exist it is possible to reduce fugitive PM by using properly designed wind barriers.

-

-

-

Water spray and chemical PM suppressors. When the point source of PM is well localised a water spray injection system can be installed.

Paving areas used by lorries, road wetting and housekeeping.

Mobile and stationary vacuum cleaning. During maintenance operations or in case of trou-

-

- ble with conveying systems, spillage of materials can take place. To prevent the formation of fugitive PM during removal operations, vacuum systems should be used.

Ventilation and collection in FFs. As far as possible, all material handling should be conducted in closed systems maintained under negative pressure. The suction air for this purpose is then de-dusted by a FF before emitted into the atmosphere.

Closed storage with automatic handling system. Clinker silos and closed fully automated raw material storage are considered the most efficient solution to the problem of fugitive PM generated by high volume stocks. These types of storage are equipped with one or more

FFs to prevent fugitive PM formation in loading and unloading operations.

155. The BAT for reducing PM emissions are the combination of the above described general primary measures and: h) Minimization/prevention of PM emissions from fugitive sources i) Efficient removal of PM from point sources by application of:

-

-

Electrostatic precipitators with fast measuring and control equipment to mini-mise the number of carbon monoxide trips

FFs with multiple compartments and ‘burst bag detectors’

156. [In contrast to the BAT description in the HM Protocol,] The BAT emission level for PM associated with these techniques is 20-

30 mg/m³ on a daily average basis. This emission level can be achieved by electrostatic precipitators and/or FFs at the various types of installations in the cement industry. The best installations achieve emission lev els below 10 mg/m³ (273 K,

101.3 kPa, 10% oxygen, dry gas).

157. [Heavy metal emissions from cement production are not considered to be as much of a priority except Hg, although they are still of concern.] In general, available information indicates that there is no major difference in heavy metal emissions between the different process types

(e.g. wet or dry kilns), or between kilns burning different fuels (e.g. conventional fuels or waste derived fuels). This is because it is the raw material input and not the process type which has the greater effect on heavy metal emissions. Mercury is primarily introduced into the kiln with raw-materials (usually about 90% of the mercury is in the material input) with generally a minor amount (about 10%) coming from the fuels.

158. The best way to reduce heavy metal emissions is to avoid using feed materials with a high content of volatile metals such as mercury. Mercury can build up over time in the cement kilns PM, which is usually returned to the kiln system. When high build-ups occur in the PM, emissions may increase. This can be remedied by discarding the cement kiln PM rather than

52

returning it to the raw [meal/material]. As metals are often bound to PM, particulate abatement methods will help to reduce HM emissions.


159. Fluidised bed cement manufacturing technology: This process is expected to reduce heat use by 10-12%.

160. A way to minimize mercury emissions is to lower the exhaust temperature. When high concentrations of volatile metals (especially mercury) occur, adsorption on activated carbon is an option.

161. The energy content of emissions can be reduced further by replacing clinker in cement by slag from the production of iron (BOF slag) (For more information: http://www.ecocem.ie and http://www.epa.gov/epaoswer/non-hw/procure/products/cement.htm).


162. The Protocol on Heavy Metals includes an ELV for particulate emissions for the production of cement of 50 mg/m³ (273 K, 101.3 kPa, dry gas).. No ELV is specified for the heavy metals covered by the Protocol.




164. All values are expressed in mg/Nm³ referring to standard conditions (273.15 K, 101.3 kPa, dry gas) and do not cover start-up and shutdown periods except stated otherwise.

Table VI-1 ELVs for the cement industry


Country / reference

ELV Remarks


Austria 8


50 continuous (daily) and discontinuous measurements (hourly average)

50 10% O2; continuous (daily) and discontinuous measurements

(half-hour average)

8 The regulation is under revision, with the aim to reach an adjustment to the state of the art.

53

Belgium

Bulgaria

Czech

Republic

Germany

Netherlands

Slovakia

Switzerland

United

States of

America

BAT (BREF)

Austria

Belgium

France

Germany

Switzerland

Austria

Belgium

Denmark

France

Germany

Netherlands

Switzerland

150 all installations if mass flow ≤ 500 g/h

50 all installations if mass flow > 500 g/h continuous measurements, daily average.

50

50

20 10% O

2; continuous (daily) and discontinuous measurements

(half-hour average)

15 8 hour average

50


The ELV for new and existing installations = 0.15kg of PM per Mg of feed (dry basis) to kiln, based on continuous basis.

20-30 10 % O2, daily average


0.1 discontinuous measurements (half-hour average)

0.2 all install ations if mass flow ≥ 1 g/h; common ELV for Cd, Hg, Th and their compounds. Discontinuous measurements.

0.2 common ELV for Cd, Ti, Hg

0.05 10% O

2

; alternatively < 0.15 g/h common ELV for Cd and As and their compounds, Benzo(a)pyren, water soluble Co compounds, Cr(VI) compounds; continuous (daily) and discontinuous measurements (half-hour average)



1 common ELV for Pb, Co, Ni, As; discontinuous measurements

(half-hour average)

5 all instal lations if mass flow ≥ 25 g/h; common ELV for Sb, Pb,



5 common ELV for Sb, Cr, Cu, Sn, Mn, Pb, V, Zn

0.5 10% O

2

; common ELV for Pb, Co, Ni, Se, Te and their compounds; continuous (daily) and discontinuous measurements

(half-hour average)

1 8 hour average



54

Belgium

Denmark

France

Germany

Netherlands

Switzerland



0.2 common ELV for Cd, Ti, Hg

0.05 10% O

2

; alternatively < 0.25 g/h; continuous (daily) and discontinuous measurements (half-hour average)

0.05 8 hour average


References

EC 2001

Economic Evaluation of Air Quality Targets for Heavy Metals. European Commission, Entec

UK Limited, January 2001.

EC 2001a


EIPPCB 2001

Integrated Pollution Prevention and Control: Reference Document on Best Available Techniques in the Cement and Lime Manufacturing Industries. European IPPC Bureau, Sevilla: December 2001.

U.S. EPA, 1999

National Emission Standards for Hazardous Air Pollutants for Portland Cement Manufacturing

Industry; Final Rule, 64 Federal Register 31898. United States Environmental Protection

Agency. 14 June 1999.

55

VII. GLASS INDUSTRY


165. This category covers installations for the manufacture of glass using lead in the process with a melting capacity exceeding 20 tonnes per day. According to annex III, BAT are considered for the production of glass using lead in the process, including the recycling of lead containing glass.

166. Lead is used in fluxes and colouring agents in the frit industry, in some special glasses

(e.g. coloured glasses, CRT funnels) and domestic glass products (lead crystal glasses). External cullet is an important source of metal contamination particularly for lead.

167. According to annex III, PM emissions stem mainly from batch mixing, furnaces, diffuse leakages from furnace openings, and finishing and blasting of glass products. They depend notably on the type of fuel used, the furnace type and the type of glass produced. Oxy-fuel burners can reduce waste gas volume and flue PM production by 60%. The lead emissions from electrical heating are considerably lower than from oil/gas-firing. During the melting cycle using discontinuous furnaces, the PM emission varies greatly. The PM emissions from crystal glass tanks (<5 kg/Mg melted glass) are higher than from other tanks (<1 kg/Mg melted soda and potash glass). Some measures to reduce direct metal-containing PM emissions are: pelleting the glass batch, changing the heating system from oil/gas-firing to electrical heating, charging a larger share of glass returns in the batch, and applying a better selection of raw materials

(size distribution) and recycled glass (avoiding lead-containing fractions). Exhaust gases can be cleaned in FFs, reducing the emissions below 10 mg/m3. With electrostatic precipitators 30 mg/m3 is achieved.


168. Related to the category description, the production of container glass, flat glass, domestic glass, special glass and frits may be of concern, due to the potential use of lead oxides as raw material or the use of cullet that may comprise lead containing glasses. The BAT described in this subsection are primarily based on the European BAT reference (BREF) document

(EIPPCB, 2001) and are valid for the production of all these types of glass mentioned if not stated otherwise.

Materials Storage and Handling

169. Bulk powder materials are usually stored in silos, and emissions can be minimized by using enclosed silos, which are vented to suitable PM abatement equipment such as FFs.

Where practicable collected material can be returned to the silo or recycled to the furnace.

Where the amount of material used does not require the use of silos, fine materials can be stored in enclosed containers or sealed bags. Stockpiles of coarse dusty materials can be stored under cover to prevent wind born emissions. Where PM is a particular problem, some installations may require the use of road cleaning vehicles and water damping techniques.

56

170. Where materials are transported by above ground conveyors some type of enclosure to provide wind protection is necessary to prevent substantial material loss. These systems can be designed to enclose the conveyor on all sides. Where pneumatic conveying is used it is important to provide a sealed system with a filter to clean the transport air before release. To reduce PM during conveying and "carry-over" of fine particles out of the furnace, a percentage of water can be maintained in the batch, usually 0 - 4 %.

171. An area where PM emissions are common is the furnace feed area. The main techniques for controlling emissions in this area are:

-

-

Batch moisture.

Slight negative pressure within the furnace (only applicable as an inherent aspect of opera-

-

-

- tion).

Provision of extraction, which vents to a filter system, (common in cold top melters).

Enclosed screw feeders.

Enclosure of feed pockets (cooling may be necessary).

172. In potentially very dusty areas such as batch plants the buildings can be designed with the minimum of openings and doors, or PM curtains can be provided where necessary. In the furnace buildings it is often necessary to ensure a degree of natural cooling and so vents etc are provided. It is important to ensure a good standard of house keeping and that all PM control measures (seals, extraction etc.) are properly functioning.

173. Areas of the process where PM is likely to be generated (e.g. bag opening, frit batch mixing, FF PM disposal, etc) can be provided with extraction which vents to suitable abatement plant. This can be important at smaller installations where a higher degree of manual handling takes place. All of these techniques are particularly relevant where more toxic raw materials are handled and stored, e.g. lead oxide.

PM and heavy metals

174. In general, BAT for controlling PM emissions from furnaces in the glass industry is the use of either an ESP or FF, operating where appropriate, in conjunction with a dry or semi-dry acid gas scrubbing system. The BAT emission level for PM associated with these techniques is

5 - 30 mg/Nm³ which generally equates to less than 0.1 kg/tonne of glass melted. Values in the lower part of the range given would generally be expected for bag filter systems. In some cases, the application of BAT for metals emissions may result in lower emission levels for PM.

Secondary PM abatement represents BAT for most glass furnaces, unless equivalent emissions can be achieved with primary measures.

175. Glass manufacturing facilities in the US typically control PM emissions using an ESP, or a

FF using acid and temperature resistant filters. Acid gases are controlled using a Dry Injection

FF/ Dry Lime Scrubber combination, or a wet scrubber. U.S. EPA has found that ESPs are most effective for reduction of heavy metals in furnace gases. ESPs achieve about 95% reduction in fine PM and metal fumes, and can easily handle the high temperature gases from furnaces. Although generally a FF is expected to achieve at least 99% efficiency for removal of

PM, this level is not achieved at the high temperatures and fine PM characteristic of the glass manufacturing industry. However, a FF can be engineered to achieve similar results (e.g., fitted with high-temperature resistant, acid gas resistant filters).

176. In general in this sector, BAT is considered to be raw material selection to minimize emissions of heavy metals, combined with acid gas scrubbing and PM abatement, where appropri-

57

ate. The emission level associated with BAT for metals including lead (As, Co, Ni, Se, Cr, Sb,

Pb, Cu, Mn, V, Sn) is <5 mg/ Nm³.

Domestic Glass

177. In general and where it is economically viable, predominantly electrical melting is considered BAT for lead crystal, crystal glass and opal glass production, since this technique allows efficient control of potential emissions of volatile elements. Where crystal glass is produced with a less volatile formulation, other techniques may be considered when determining BAT for a particular installation.

Downstream processes

178. For the production of container glass, the main potential source of emissions from downstream processes is hot end coating treatment. A number of techniques can be used to treat emissions. Hot end treatment fumes may also be treated with the furnace waste gases in a common acid gas/PM abatement system. The emission level associated with BAT is < 20 mg/Nm3 for PM.

179. For flat glass processing, a number of techniques can be used to treat downstream emissions. The emission levels associated with BAT are < 20 mg/Nm3 for particulates and <5 mg/Nm³ for metals including lead (As, Co, Ni, Se, Cr, Sb, Pb, Cu, Mn, V, Sn).

180. Potential emissions from downstream processes in the domestic glass sector consist mainly of PM and acid gas fumes from lead crystal and crystal glass production. For potentially dusty activities BAT is considered to be cutting under liquid where practicable, and if dry cutting or grinding is carried out then extraction to a bag filter system. The emission level associated with BAT for particu lates is <10 mg/Nm³, and for metals including lead (As, Co, Ni, Se, Cr, Sb,

Pb, Cu, Mn, V, Sn) is <5 mg/Nm³.

181. For the production of special glass, the emissions associated with downstream processing can be very variable and a wide range of primary and secondary techniques can be used. For potentially dusty activities BAT is considered to be PM minimisation by cutting, grinding or polishing under liquid, or where dry operations are carried out extraction to a bag filter system. The emission level associated with BAT for particulates as well as for metals including lead (As, Co, Ni, Se, Cr, Sb, Pb, Cu, Mn, V, Sn) is <5 mg/Nm³.

182. In frits production, the only likely emission from downstream processes is PM and BAT is considered to be the use of a bag filter system. The emission levels associated with BAT are considered to be 5 - 10 mg/Nm3 for particulate and <5 mg/Nm3 for metals (As, Co, Ni, Se, Cr,

Sb, Pb, Cu, Mn, V, Sn).


183. The Plasma Melter makes use of the electrical conductivity of molten glass and operates with negligible PM emissions. It is however not expected to be a viable technique for melting within the foreseeable future.


58

184. Annex V of the Protocol includes an ELV for lead emissions for the production of glass of

5 mg/m³. No ELV is specified for particulate emissions nor for the emissions of cadmium and mercury.




Table VII-1 ELVs for the glass industry


Country / reference

ELV Remarks

Austria

Belgium

Germany


50 O

2

reference: 8% flame heated tanks; 13% day tanks; actual O

2

electric furnaces; 21% Oxy fuel melting ; continuous (daily) and discontinuous measurements (half-hour average)

50 continuous measurements, daily average.

20 melting capacity >20 t/d;

8% O2 for flame-heated glass melting furnaces, 13% O2 for flameheated pot furnaces and day tanks, special provisions for oxygen fuel fired and electrically heated glass melting tanks; continuous (daily) and discontinuous measurements (half-hour average)

Netherlands

Switzerland

5-30 equates to < 0,1 kg/tonne of glass melted


United

States of

America

BAT (BREF)

0.1-0.13 g PM per

Kg glass produced

The ELVs for lead glass manufacturing installations built after

1980 are 0.1 g PM per kg glass produced (0.1 g/Kg) for furnaces with gaseous fuel and 0.13 g/Kg for furnaces with liquid fuel (U.S.

EPA, 1980).

5-30 furnaces; equates to < 0.1 kg/tonne of glass melted;

< 20 downstream processes: container glass, flat glass

< 10 downstream processes: domestic glass

5-10 downstream processes: frits

8 Vol% O2 continuous melters, 13 Vol% O2 discontinuous melters (except oxy-fuel fired systems)


Austria 0.1 O

2


2

electric furnaces; 21% Oxy fuel melting ; discontinuous measurements (halfhour average)

59

Belgium

France

Germany

Netherlands

Switzerland


Austria

Belgium

Denmark

France

Germany

0.2 special glass

5 other glass; common ELV for Cr, Vi, Pb, Cd, Sb, Ni, Co, Se, V; discontinuous measurements.

0.05 if mass flow Cd+Hg+Tl > 1 g/h; additional common ELV of 0.1 mg/Nm³

0.05 other glass, alternatively < 0.15 g/h

0.5 container glass, common ELV for Cd and As and their compounds, Benzo(a)pyren, water soluble Co compounds, Cr(VI) compounds

0.2 ELV for Cd only; if cadmium compounds are used as colouring agents for quality reasons and Cd mass flow < 0.5 g/h;

Melting capacity >20 t/d; 8% O2 for flame-heated glass melting furnaces, 13% O2 for flame-heated pot furnaces and day tanks, special provisions for oxygen fuel fired and electrically heated glass melting tanks; continuous (daily) and discontinuous measurements (halfhour average)




5 continuous (daily) and discontinuous measurements (hourly average)

5 Common ELV for Cd, As, Co, Ni, Se, Sb, Pb, Cr, Cu, Mn; O

2


2

electric furnaces; 21% Oxy fuel melting ; discontinuous measurements (half-hour average)

5 special glass

5 other glass; common ELV for Cr, Vi, Pb, Cd, Sb, Ni, Co, Se, V; discontinuous measurements.


3 CRT funnels

1 other glass if mass flow Pb and its compounds > 5 g/h

0.5

3 if lead is required for product quality common ELV for Pb, Co, Ni, Se, Te and their compounds;

0.8 ELV for Pb and its compounds only; container glass using foreign cullet; additionally common ELV for Pb, Co, Ni, Se, Te and their com pounds < 1.3 mg/Nm³

Melting capacity >20 t/d; 8% O2 for flame-heated glass melting furnaces, 13% O2 for flame-heated pot furnaces and day tanks, special provisions for oxygen fuel fired and electrically heated glass melting tanks; continuous (daily) and discontinuous measurements (half-hour average)

60

Netherlands

Switzerland

BAT (BREF)

Belgium

Denmark

France

Germany

Netherlands

Switzerland



< 5 Common BAT level for As, Co, Ni, Se, Cr, Sb, Pb, Cu, Mn, V, Sn; furnaces and down stream processes; at 8 % O2 by volume for continuous melters and 13 % O2 by volume for discontinuous melters (except oxy-fuel fired systems)




0.05 basic oxygen furnace if mass flow Cd+Hg+Tl > 1 g/h; additional com mon ELV of 0.1 mg/Nm³

0.05 melting capacity >20 t/d;; alternatively < 0.25 g/h

8% O2 for flame-heated glass melting furnaces, 13% O2 for flame-heated pot furnaces and day tanks, special provisions for oxygen fuel fired and electrically heated glass melting tanks; continuous (daily) and discontinuous measurements (half-hour average)



References

EIPPCB 2001

Integrated Pollution Prevention and Control: Reference Document on Best Available Techniques in the Glass Manufacturing Industry. European IPPC Bureau, Sevilla: December 2001.

U.S. EPA, 1980

New Source Performance Standard (NSPS). United States Environmental Protection Agency.

60 Code of Federal Regulations (CFR) Subpart CC. Standards of Performance for Glass

Manufacturing Plants. 1980.

61

VIII. CHLOR-ALKALI INDUSTRY


186. This category covers installations for chlor-alkali production by electrolysis using the mercury cell process.

187. The use of mercury-cell technology has been declining in Europe and North America over the past few decades, as many such plants have shut down or been converted to non-mercury processes. Moreover, European and North American producers are committed to not building any new mercury-cell facilities. In addition, North American and European regulations do not allow the construction of these facilities. The total phase-out of the mercury process for chloralkali production by the year 2010 was recommended by the Commission for the Protection of the Marine Environment of the North-East Atlantic (OSPARCOM) in its PARCOM decision 90/3 of 14 June 1990, which was reviewed in 1999-2001 without any changes.

188. According to BAT as described in annex III, with regard to emissions into air, mercury diffusely emitted from the cells to the cell room are particularly relevant. Preventive measures and control are of great importance and should be prioritized according to the relative importance of each source at a particular installation. In any case specific control measures are required when mercury is recovered from sludges resulting from the process. The following measures can be taken to reduce emissions from existing mercury process plants:

-

-

-

Process control and technical measures to optimize cell operation, maintenance and more efficient working methods;

Coverings, sealings and controlled bleeding-off by suction;

Cleaning of cell rooms and measures that make it easier to keep them clean; and

-

Cleaning of limited gas streams (certain contaminated air streams and hydrogen gas).

Based on annex III, these measures can cut mercury emissions to values well below 2.0 g/Mg of Cl2 production capacity, expressed as an annual average. There are examples of plants that achieve emissions well below 1.0 g/Mg of Cl2 production capacity. The membrane process results in no direct mercury emissions. Moreover, the global energy balance shows a slight advantage for membrane cell technology in the range of 10 to 15% and a more compact cell operation. It is, therefore, considered as the preferred option for new plants. PARCOM decision

90/3 of 14 June 1990 of the Commission for the Prevention of Marine Pollution from Landbased Sources (OSPARCOM) recommends that existing mercury cell chlor-alkali plants should be phased out as soon as practicable with the objective of phasing them out completely by

2010. As a result of PARCOM decision 90/3, existing mercury-based chlor-alkali plants were required to meet the level of 2 g of Hg/Mg of Cl2 by 31 December 1996.


189. The selected process technology has a major impact on the energy use and emissions from the manufacture of chlor-alkali. BAT for the production of chlor-alkali is considered to be membrane technology. Non-asbestos diaphragm technology can also be considered as BAT.

62

190. Mercury releases from chlor-alkali operations can be entirely eliminated only by converting to a non-mercury process such as the membrane cell process. Conversion to membrane cell technology is considered as BAT in the BREF document for chlor-alkali production under the IPPC Directive. Conversions and closures of mercury-cell chlor-alkali plants are being carried out faster in some OSPARCOM countries than in others.

191. Among OSPARCOM countries and in the EU there has been considerable discussion about the possible impacts the re-marketing of the mercury from decommissioned chlor-alkali facilities will have on the global mercury market. In 1999 all West European chlor-alkali producers presented the authorities with a voluntary commitment, one clause of which commits them not to sell or transfer mercury cells after plant shutdown to any third party for re-use. Euro

Chlor signed an agreement with the stateowned Miñas de Almadén of Spain. This agreement stipulates that Miñas de Almadén will accept all surplus mercury from western European chlorine producers, under the condition that it displaces, ton for ton, mercury that would otherwise have been newly mined and smelted to satisfy legitimate uses. As a pro-active contribution to a proposed globally organised effort to phase out primary production of mercury and to stop surpluses re-entering the market, the Commission intends to propose an amendment to Regulation (EC) No. 304/2003 to phase out the export of mercury from the Community by 2011. In

North America, to reduce supply, the US Government decided in 2004 to place a large quantity of previously stockpiled mercury into long-term storage (at least 40 years) to prevent it from entering the market (U.S. DNSC, 2004).

192. During the remaining life of mercury cell plants, all possible measures should be taken to protect the environment as a whole including: a) Minimizing mercury losses to air by:

- use of equipment and materials and, when possible, a lay-out of the plant (for example,

-

-

- dedicated areas for certain activities) that minimize losses of mercury due to evaporation and/or spillage good housekeeping practices and good maintenance routines collection and treatment of mercury-containing gas streams from all possible sources, including hydrogen gas. Sulfur impregnated activated charcoal was used by ICI Cornwall for the hydrogen filters. reduction of mercury levels in caustic soda

Based on available data, the best performing mercury cell plants are achieving total mercury losses to air, water and with products in the range of 0.2-0.5 g Hg per tonne of chlorine capacity as a yearly average, and with regard to air emissions 0.21-0.32 g Hg/Mg Cl2, as shown in the following table [BREF].

Air emissions from cell room g Hg/tonne chlorine capacity

0.2-0.3

0.0003-0.01 process exhausts, including Hg distillation unit untreated cooling air from Hg distillation unit hydrogen gas

0.006-0.1

<0.003 b) Minimizing current and future mercury emissions from handling, storage, treatment and disposal of mercury-contaminated wastes by:

- implementation of a waste management plan drawn up after consultation with the ap-

-

-

-

- propriate authorities minimizing the amount of mercury-containing wastes recycling the mercury contained in wastes when possible treatment of mercury-contaminated wastes to reduce the mercury content in the wastes stabilization of residual mercury-contaminated wastes before final disposal.

63

c) Decommissioning carried out in a way that prevents environmental impact during and after the shutdown process as well as safeguarding human health

193. Major points of mercury emission generation in the mercury cell process of chlor-alkali production include: byproduct hydrogen stream, end box ventilation air, and cell room ventilation air. Typical devices/techniques for removal of mercury in these points are:

- gas stream cooling to remove mercury from hydrogen stream,

-

- mist eliminators, scrubbers, and

- adsorption on activated carbon and molecular sieves.

The installation of the above mentioned devices can remove mercury with the efficiency of more than 90 %.

194. However, most mercury losses from chlor-alkali facilities are fugitive. Relevant preventive measures include:

-

-

Equipment cool-down before opening for invasive maintenance;

Consolidation of maintenance actions to minimize the number of invasive maintenance

-

-

-

- events;

Draining mercury from components before they are opened or keeping the internal mercury covered with cooling water or installing a hood to capture mercury vapour;

Capital investment in larger-capacity decomposers that require less invasive maintenance;

Improving the purity of brine so as to prevent build-up of mercury wastes that require invasive maintenance;

Use of longerlasting metallic anodes that necessitate less invasive maintenance; DSA’s

-

- were used in Canada: Dimensionally Stable Anodes (DSA) replaced graphite (carbon) anodes that were the cause of many chlorinated organic substances released

Capital investment in new elongated cells with air pollution prevention features like internal mechanical arms that can accomplish some maintenance actions that formerly required invasive maintenance.

Complete enclosure of the cell room with all cell room air ventilated to a control device (cell room under negative pressure) was one control technique proposed for the ICI Cornwall plant in 1994. The control device would be a charcoal/sulfur filter

195. All plants in the OSPAR region comply with the limit value of 2 g Hg/t Cl2 for air emissions in PARCOM Decision 90/3, and it is clear that in many plants, air emissions continue to fall. However, a wide range in actual values from 0.14 to 1.57 g Hg/t Cl2 is shown [OSPAR

2003].


196. Fundamental research programmes related to mercury technology are not being developed since it is very unlikely that any new mercury plants will be built. The only recent improvements in mercury cells concern the anode geometry with the aim of improving gas release in order to decrease electrical energy usage and increase anode coating life.


197. Annex V of the Protocol includes an ELV for mercury for new chlor-alkali plants of 0.01 grams of mercury per metric tonne of chlorine production capacity (i.e. 0.01 g mercury/tonne

Cl2). However, no ELVs for mercury emissions from existing plants are specified in the Protocol. Instead, the Protocol requires Parties to evaluate ELVs for existing chlor-alkali plants within

64

two years after the date of entry into force of the Protocol. A separate summary of emission limit values and control for the chlor-alkali industry with regard to mercury emissions from existing plants was submitted to WGSR at its 37th session in 2005 (EB.AIR/WG.5/2005/2 annex I).




Table VIII-1 ELVs for the chlor-alkali industry

All values are expressed in g Hg/Mg Cl2 production capacity except stated otherwise. BAT associated emission levels from the respective BREF document are not considered as ELVs and are given for comparison; they are indicated in italic letters.

Country / reference

ELV Remarks


0.01 new installations, total plant emissions Annex V of the Protocol

Belgium

Canada

Czech

Republic

Finland

France

Germany

Netherlands

Slovakia

Sweden

Switzerland

1.5 new installations;

2 existing installations; additionally ELV of 0.2 mg/Nm 3 if mass flow



1 g/h phase out of mercury cell process by 2010

5 existing installations, emissions from cell room

0.1 existing installations, emissions from hydrogen gas

0.1 existing installations, emissions from end boxes

0.1 existing installations, emissions from retorts/Hg recovery additionally ELV of 1.68 kg Hg/day for total plant emissions

0.01 new installations

2 existing installations phase out of mercury cell process by 2010

ELV of 0.05 mg Hg/Nm 3 if mass flow Cd+Hg+Tl > 1 g/h; additional commo n ELV of 0.1 mg/Nm³

1 existing installations;

1.2 existing installations if alkali lye and dithionite or alcoholates are produced simultaneously in one facility; emissions from cell room and end boxes

1.5 phase out of mercury cell process by 2010

1.5 phase out of mercury cell process by 2010

ELV of 0.2 mg/m³ for all installations if mass flow > 1 g/h

65

United

States of

America

BAT (BREF)

OSPARCOM

0.0 ELV for total mercury emissions for new installations

0.076 ELV for mercury from hydrogen streams and end box ventilation systems for existing installations with end box ventilation based on 52 week average of Cl

2

produced (not capacity);

0.033 ELV for mercury from hydrogen streams for existing installations without end box ventilation based on 52 week average of Cl2 produced.

For cell rooms, no numerical ELV is specified; however, stringent workplace standards are required to minimize emissions from cell rooms or, as an alternative, facilities can implement a cell room monitoring program. Cell room ventilation emissions of below 1,3 kg/d may be assumed when the operator carries out the work practice standards.

Also, for all mercury recovery facilities with oven type thermal recovery units, total mercury emissions are not to exceed 23 mg per normal cu bic meter (mg/Nm³) from each unit vent; and for non-oven type mercury thermal recovery units, emissions are not to exceed 4 mg/Nm³.

0.21-0.32 existing installations, total plant emissions (air, water and products)

0.14-1.57 measured emissions in existing installations; reported emissions for 2003, phase out of the mercury process for chlor-alkali production by 2010

References

CEC 2005

Community Strategy Concerning Mercury. Commission of the European Communities,

COM(2005) 20 final

EC 2001


EIPPCB 2001

Integrated Pollution Prevention and Control: Reference Document on Best Available Techniques in the Chlor-Alkali Manufacturing industry. European IPPC Bureau, Sevilla: December

2001.

OSPAR 2004

OSPAR Implementation Report Dec. 90/3: Overview Assessment of Implementation of

PARCOM Decision 90/3 on Reducing Atmospheric Emissions from Existing Chlor-Alkali Plants

- Update 2004. OSPAR Commission, 2004.

OSPAR 2005

Mercury Losses from the Chlor-Alkali Industry in 2003. OSPAR Commission, 2005.

66

UNEP 2002


U.S. DNSC, 2004.

Mercury Management Environmental Impact Statement. United States Defense National

Stockpile Center (DNSC). 30 April 2004. 69 Federal Register 23733, 4/30/04.

U.S. EPA, 2003

NESHAP for Mercury Emissions from Mercury Cell Chlor-Alkali Plants; Final Rule 68 Federal

Register 70904 - 70946, United States Environment Protection Agency. December 19, 2003.

67

IX. MUNICIPAL, MEDICAL AND HAZARDOUS WASTE INCINERATION


199. This sector covers installations for the incineration of hazardous or medical waste with a capacity exceeding 1 tonne per hour and for the incineration of municipal waste with a capacity exceeding 3 tonnes per hour, as well as installations for the co-incineration of municipal, medical and hazardous waste.

According to annex III, besides emissions abatement measures waste management strategies and alternative waste treatment methods are also considered.

200. There are wastes that are neither classified as hazardous, municipal or medical wastes, depending on national legislation (e.g., non-hazardous industrial wastes, sludge etc.), and thus are not currently taken into account according to annex II. These wastes may be incinerated as well as co-incinerated in other industries, therefore potentially constituting a relevant source of heavy metal emissions. Therefore, additional information is given for these type of wastes. Furthermore, there are other thermal waste treatment methods (e.g. pyrolysis) that are not currently taken into account in annex II but may be a relevant source of heavy metal emissions.

Therefore, additional information is given for these processes as well.

201. According to annex III, particular actions should be taken both before and after incineration to reduce the emissions of mercury, cadmium and lead. BAT for reducing PM is considered to be FFs in combination with dry or wet methods for controlling volatiles. ESPs in combination with wet systems can also be designed to reach low PM emissions, but they offer fewer opportunities than FFs especially with precoating for adsorption of volatile pollutants. When

BAT is used for cleaning the flue gases, the concentration of PM will be reduced to a range of

10 to 20 mg/m3; in practice lower concentrations are reached, and in some cases concentrations of less than 1 mg/m3 have been reported. The concentration of mercury can be reduced to a range of 0.05 to 0.10 mg/m3 (normalized to 11% O2). Heavy metals are found in all fractions of the municipal waste stream (e.g. products, paper, organic materials). Therefore, by reducing the quantity of municipal waste that is incinerated, heavy metal emissions can be reduced. This can be accomplished through various waste management strategies, including recycling programmes and the composting of organic materials. In addition, some UNECE countries allow municipal waste to be landfilled. In a properly managed landfill, emissions of cadmium and lead are eliminated and mercury emissions may be lower than with incineration.

[According to the EU-landfill directive 1999/31 EU (version 20/11/2003) only pre-treated waste may be landfilled in the EU-member states and specific requirements have to be fulfilled (e.g.

C-content). Under special conditions (e.g. low ph) heavy metals may be mobilized and washed out from the landfills. Considering the integrated emissions, it can not generally be stated, that the emissions from landfills are lower than those from incineration.]


202. [In some countries / for BAT and in the Waste incineration Directive of the EU, too] no differentiation is made between municipal, hazardous and medical waste in terms of applied techniques or achievable emission limits (as all types of waste are often incinerated in the same installation).

68

203. The only relevant primary techniques for preventing emissions of mercury into the air are those that prevent or control, if possible, the inclusion of mercury in waste. In some countries mercury-containing components are separated out of the solid waste stream and managed or recycled properly. Removing mercury from the waste stream before it enters the incinerator is much more cost-effective than capturing mercury later from flue gases using emissions control devices. Once present in the waste stream, mercury contributes to the need for emission controls on incinerators, special disposal of incinerator residues, landfill leachate treatment etc.

204. Lower emissions of mercury from municipal waste combustors and medical waste incinerators can be achieved through product substitution. Although this is potentially applicable to a wide range of components, batteries have received the greatest attention because of their significant contribution to total mercury content in municipal and medical wastes. The applicability of the product substitution to other areas should be based on technical and economic feasibility.

205. Non-technical measures for preventing and controlling mercury releases from waste streams are:

- prohibit mercury in product waste and in process waste from being released directly to the environment, by means of an effective waste collection service; and

- prohibit mercury in product waste and in process waste from being mixed with less hazardous waste in the general waste stream, by ensuring separate collection and treatment.

206. In general, BAT is:

- to establish and maintain quality controls over the waste input,

- in order to reduce overall emissions, to adopt operational regimes and implement procedures (e.g. continuous rather than batch operation, preventative maintenance systems) in

- order to minimize as far as practicable planned and unplanned shutdown and start-up operations, the optimization and control of combustion conditions

207. Mercury emissions from municipal waste incinerators occur in two main forms: elemental mercury and ionic mercury. Elemental mercury is not readily removed by conventional emission control devices (such as ESPs, FFs, scrubbers). However, ionic mercury is captured relatively well by some of these devices. Also, some mercury-specific technologies can capture elemental mercury (such as sorbent injection). Therefore, in order for elemental mercury to be effectively controlled, it either has to be transformed into ionic mercury (which can then be removed by a suitable conventional device) or mercury-specific capture technologies must be applied. In the presence of chloride ions and at combustion chamber temperatures above

850°C a considerable part of mercury is present as HgCl2 in municipal waste incinerators.

208. Between 30 % and 60 % of mercury is retained by high efficiency ESPs or FFs and FGD systems capture further 10 to 20 %.

209. The following technologies may be used to filter out mercury from waste incinerators and combustors:

-

Carbon filter beds have been developed for use as a final cleaning stage in waste incinerators and utility boilers to remove volatile heavy metals (e.g., mercury). Cost effectiveness studies indicate $513 –$1,083 per pound mercury removed using carbon filter beds on

- waste incinerators.

Wet scrubbing systems are available in different designs and can be used to control metals.

A 90 percent reduction of mercury is possible with a wet scrubber when a wet scrubber with

69

-

- additives is used. Cost-effectiveness for this technology is estimated to be $1,600 –$3,320 per pound of mercury removed and on medical waste incinerators, $2,000-$4000 per pound.

Selenium filters have been developed to remove elemental mercury. Selenium filters are effective on flue gas streams with inlet mercury concentrations of up to 9 mg/m³.

Activated carbon injection prior to the ESP or FF: test programs have shown mercury removals of 50 to 95 percent. The cost of removing mercury from MWCs using activated carbon injection is estimated to be $211 –$870 per pound and from Medical Waste Incinerators, $2,000-$4000 per pound.

According to the U.S. EPA, the techniques should reduce emissions of mercury by 80 percent.

210. BAT is the use of an overall flue-gas treatment system that, when combined with the installation as a whole, generally provides for the operational emission levels listed in the following table for rele ases to air associated with the use of BAT (in mg/Nm³): noncontinuous measurements

1/2 hour average daily average

Total PM 1-20 1-5 In general the use of FFs give the lower levels within these emission ranges. Effective maintenance of

PM control systems is very important. Energy use can increase as lower emission averages are sought. Controlling PM levels generally reduces metal emissions too.

Mercury and its compounds(as

Hg)

Total cadmium and thallium

(and their compounds expressed as the metals) sum other metals

<0.05 0.001-0.03 0.001-0.02 Adsorption using carbon based reagents is generally required to achieve these emission levels with many wastes - as metallic Hg is more difficult to control than ionic

Hg. The precise abatement performance and technique required will depend on the levels and distribution of Hg in the waste. Some waste streams have very highly variable Hg concentrations

– waste

0.005-0.05 pretreatment may be required in such cases to prevent peak overloading of flue-gas treatment system capacity.

See comments for Hg. The lower volatility of these metals than Hg means that PM and other metal control methods are more effective at controlling these substances than Hg.

0.005 - 0.5 Techniques that control PM levels generally also control these metals

70

211. If re-burn of flue gas treatment residues is applied, then suitable measures should be taken to avoid the re-circulation and accumulation of Hg in the installation.

212. For the control of Hg emissions where wet scrubbers are applied as the only or main effective means of total Hg emission control:

- the use of a low pH first stage with the addition of specific reagents for ionic Hg removal, in combination with the following additional measures for the abatement of metallic (ele-

-

- mental) Hg, as required in order to reduce final air emissions to within the BAT emission ranges given for total Hg activated carbon injection, activated carbon or coke filters,

213. For the control of Hg emissions where semi-wet and dry FGT systems are applied, the use of activated carbon or other effective adsorptive reagents for the adsorption of Hg, with the reagent dose rate controlled so that final air emissions are within the BAT emission ranges given for Hg.

214. Selective catalytic reduction (SCR) for control of nitrogen oxides also reduces mercury emissions as a co-benefit.

215. Most Parties require discontinuous monitoring of mercury emissions only, while some consider continuous monitoring as BAT; proven systems for continuous measurements of mercury are available on the market.

Co-incineration of waste and recovered fuel in cement kilns

216. The use of suitable wastes as raw materials can reduce the input of natural resources, but should always be done with satisfactory control on the substances introduced to the kiln process.

217. The use waste fuels may increase the input of metals into the process. As the metals entering the kiln system are of varying volatility and because of the high temperature, the hot gases in the cement kiln system contain also gaseous metal compounds. Balance investigations show that there is low retention of elements with high volatility in the clinker, resulting in an accumulation of these substances in the kiln system.

218. Volatile components in material that is fed at the upper end of the kiln or as lump fuel can evaporate. These components do not pass the primary burning zone and may not be decomposed or bound in the cement clinker. Therefore the use of waste containing volatile metals

(mercury, thallium) or volatile organic compounds can result in an increase of the emissions of mercury, thallium or VOCs when improperly used.

219. In general, the BAT for cement kilns apply.

Co- incineration of waste and recovered fuel in combustion installations

220. Certain waste derived fuels may be co-combusted in regular combustion installations such as power plants together with conventional fuels. These secondary fuels include materials like e.g. animal by-products, organic acids, solvents, packing materials and plastics, fuels de-

71

rived from waste (recovered fuels), sludge, tires, agricultural residues, demolition wood etc.

Waste derived fuels are mainly solid or liquid with a significant amount of ash. For this reason co-combustion is more or less limited to the application in coal-fired boilers and fluidized bed combustion systems.

221. In general, the BAT for combustion installations apply.

222. Co-incineration in large combustion plants should not cause higher emissions. Large combustion plants, designed and operated according to BAT, operate effective techniques and measures for the removal of PM, including partly heavy metals, and other emissions. In general, these techniques can be seen as sufficient and can, therefore, also be considered as BAT for the co-combustion of secondary fuel. The rationale as to which wastes can be used for cocombustion is based of the specifications of the conventional fuel normally burned in the specific plant and its associated measured emission levels. If the range of impurities of the waste, in particular the content of heavy metals, lies within the same range as that from the normally used conventional fuel, the fuel specific BAT applies also for the co-combustion of this secondary fuel. The first BAT choice in this respect is also the careful selection of the type and mass flow of the secondary fuel, together with limiting the percentage of the secondary fuel that can be co-combusted. With regard to heavy metals, this encompasses to avoid Hg entering as an elevated component of the secondary fuel and, when there are large quantities of secondary fuel with high concentrations of heavy metals (especially Hg), to use gasification of the secondary fuel and cleaning of the product gas. However, according to the waste used, the cocombustion of secondary fuel can lead to increased emissions of heavy metals, in particular mercury. In this case the adaptation of flue-gas cleaning systems and the additional injection of activated carbon with an associated reduction rate of 70 – 85 % for mercury is BAT.

223. It is expected that in future, due to the extra experience being gained with pretreatment and abatement techniques, the degree of co-incineration will be increased above the level of

10 % on a thermal basis.


224. The PECK combination process for municipal solid waste treatment: Before re-circulating to the grate, fly ashes collected in the boiler and ESP are mixed with dewatered sewage sludge and fed to a pelletiser. The resulting dry pellets are treated in a fluidized bed reactor, where chlorination and evaporation of the metals take place at 900 °C. The evaporated metals leave the fluidized bed reactor together with the flue-gas. By a partial quench the heavy metals are condensed and filtered afterwards. The depleted fly ash, the re-circulate, is removed from the evaporation reactor and fed back through a buffer silo to the grate. The filtered heavy metal concentrate is then transported to the zinc and lead refining industry. Heavy metals like zinc, lead, cadmium and copper are concentrated in the output flows hydroxide sludge, ferrous and copper scrap. The heavy metals flow via the mineral product and the purified flue-gas are negligible. The process has been developed for municipal solid wastes but could in principle be applied to other wastes.

225. Heavy metal evaporation process: Fly ash is heated to around 900 ºC in an atmosphere enriched with hydrochloric acid. The heavy metals are volatilized as chlorides and then condensed on a filter where they concentrate to such an extent that re-cycling may be possible.

The remaining fly ash is thus cleaned and may be used for construction. When sited on an existing incineration site the flue-gases evolved may be treated in the existing FGT system, and

72

the HCl may be drawn from a wet scrubber. The process has not been demonstrated on a commercial scale plant.

226. Hydro-metallurgical treatment + vitrification: In this process hydrometallurgical treatment allows the removal of heavy metals and salts. The subsequent vitrification of the fly ash produces a slag which may be used for construction. The process is reported to be applicable to several ash compositions and to have been demonstrated on a semi-industrial scale.


227. Annex V of the Protocol includes ELVs for particulate emissions of 10 mg/m³ for hazardous and medical waste incineration and of 25 mg/m³ for municipal waste incineration, and for mercury emissions of 0.05 mg/m³ for hazardous waste incineration and of 0.08 mg/m³ for municipal waste incineration. No ELVs are specified for co-incineration, for lead and cadmium emissions and for the emissions of mercury from medical waste incineration. Instead, the Protocol requires Parties to evaluate ELVs for mercury-containing emissions from medical waste incineration within two years after the date of entry into force of the Protocol. A separate summary of emission limit values and control for medical waste incineration with regard to mercury emissions was submitted to WGSR at its 37th session (EB.AIR/WG.5/2005/2 annex II).

228. The following table gives an overview on current ELVs implemented by the Parties. Infor mation was compiled using Parties’ responses to question 44 of the 2004 questionnaire on



Table IX-1 ELVs for municipal, medical and hazardous waste incineration


Country / reference

ELV Remarks


Austria


10 hazardous and medical waste incineration

25 municipal waste incineration

11% O2; continuous (daily) and discontinuous measurements

(hourly average)

10 waste incineration (solid fuels: 11% O2, liquid fuels: 3% O

2

)

10-20 coincineration in cement kilns (≤ 40% thermal input, 10% O

2

) and coincineration in combustion installations ≤ 100 MW (≤ 40% thermal in put); sliding scale ELV (≤ 40% thermal input)

10-15 co-incineration in combustion installa tions > 100 MW (≤ 40% thermal input); sliding scale ELV (≤ 40% thermal input) continuous measurements, daily average

73

Belgium

Bulgaria

Czech

Republic

Germany

Netherlands

Slovakia

Switzerland

United

States of

America

BAT (BREF)

Austria

10 municipal, medical and hazardous waste incineration; continuous measurements, daily average.

10 hazardous waste incineration, 11% O2, daily average.

10 waste incineration, daily average

10 waste incineration (11% O2, waste oil and pyrolysis gas: 3% O2), co-incernation in combustion installations (< 25% thermal input, solid fuels: 6% O2, liquid and gaseous fuels: 3% O2), coincernation in cement and lime kilns (> 60% thermal input, 11%

O2, waste oil and pyrolysis gas: 3% O2; on demand: sliding scale

ELV of 1020 mg/m³ depending of the amount of co-incinerated waste), co-incernation in other installations (> 25% thermal input)

20 co-incernation in cement kilns (< 60% thermal input, 10% O2), in existing combustion installations and if no desulfurication is necessary (< 25% thermal input, solid fuels: 6% O2, liquid and gaseous fuels: 3% O2) and in other installations (< 25% thermal input); continuous measurements; daily average

5 municipal, hazardous and medical waste incineration, 8 hour average

50 waste incineration, < 1 t/h

30 waste incineration, 1-3 t/h

20 waste incineration, > 3 t/h

10 waste incineration, 11% O2

17 Municipal Waste Combustors (MWCs), new installations (11%

O

2

)

19 MWCs, existing installations > 9.5 tonnes/hr (11% O

2

)

50 MWCs, existing installations 1.4 to 9.5 tonnes/hr (11% O

2

)

2.4 to 24

21 to 57

Range for 5 types of hazardous waste combustors, new facilities.

Range for 5 types of hazardous waste combustors, existing facilities.

24 Medical Waste incinerators: new installations > 90.9 kg/hr (11%

O

2

)

24 Medical Waste Incinerators: existing installations > 227 kg/hr

(11% O

2

).

1-5 waste incineration, daily average


0.05 waste incineration and co-incineration ≤ 40% thermal input (solid fuels: 11% O2, liquid fuels: 3% O

2

, cement kilns: 10% O2); halfhour average

74

Belgium

Bulgaria

Czech

Republic

Denmark

France

Germany

Netherlands

Slovakia

United

States of

America

BAT (BREF)

Austria

Belgium

Czech

Republic

0.05 Flanders: Municipal, medical and hazardous waste incineration; common ELV for Cd, Tl; continuous (daily) and discontinuous measurements

0.2 Walloon: Municipal waste incineration (17% O2), medical waste incineration (9% O2)

0.5 Walloon: waste oil incineration

0.05 hazardous waste incineration, 11% O2, daily average.

0.1 combustion of waste oils

0.05 municipal waste incineration, discontinuous measurements

0.05 municipal, medical and industrial waste incineration; common

ELV for Cd, Tl

0.05 incineration and co-incernation of waste (> 25% thermal input, >

60% for cement and lime kilns); common ELV for Cd and Tl and their compounds; common ELV for Cd and As and their compounds, Benzo(a)pyren, water soluble Co compounds, Cr(VI) compounds; common ELV for Cd, As, Co, Cr and their compounds, Benzo(a)pyren; discontinuous measurements; 11% O2, waste oil and pyrolysis gas: 3% O2, cement kilns: 10% O2, solid fuels: 6% O2, liquid and gaseous fuels: 3% O2; minor coincineration covered to sector-specific regulations

0.05 municipal, hazardous and medical waste incineration, common

ELV for Cd, Th; 8 hour average

0.2 waste incineration; common ELV for Hg, Tl, Cd

0.03 MWCs, existing installations > 9.5 tonnes/hr (11% O

2

)

0.07 MWCs, existing installations 1.4 to 9.5 tonnes/hr (11% O

2

)

0.028 Medical Waste incinerators: new installations > 90.9 kg/hr (11%

0.113

O

2

)

Medical Waste Incinerators: existing installations > 227 kg/hr

(11% O

2

).

0.005-0.05 waste incineration, common BAT value for Cd, Tl and their compounds; discontinuous measurements



2

, cement kilns: 10% O2); common ELV for Pb and 9 other HM; half-hour average

0.5 Flanders: Municipal, medical and hazardous waste incineration; common ELV for Sb, As, Pb, Cr, Co, Cu, Mn, Ni, V, Sn; continuous (daily) and discontinuous measurements

5 Walloon: common ELV for Pb, Cr, Cu, Mn; municipal waste incineration (17% O2), medical waste incineration (9% O2), waste oil incineration

1 combustion of waste oils

75

Denmark

France

Germany

Netherlands

Slovakia

United

States of

America

BAT (BREF)


Austria

Belgium

Bulgaria

0.5 municipal waste incineration; common ELV for As, Pb, Sb, Cr,

Co, Cu, Mn, Ni, V, discontinuous measurements

0.5 municipal, medical and industrial waste incineration; common

ELV for Sb, As, Pb, Cr, Co, Cu, Mn, Ni, V

0.5 incineration and co-incernation (> 25% thermal input, > 60% for cement and lime kilns) of waste; common ELV for Sb, As, Pb, Cr,

Co, Cu, Mn, Ni, V, Sn and their compounds; discontinuous measurements; 11% O2, waste oil and pyrolysis gas: 3% O2, cement kilns: 10% O2, solid fuels: 6% O2, liquid and gaseous fuels: 3% O2; minor co-incineration covered to sector-specific regulations

0.5 hazardous and medical waste incineration,

1 municipal waste incineration common ELV for HM incl. Pb; 8 hour average

5 waste incineration; common ELV for Pb, Cu, Mn

0.31 MWCs, existing installations > 9.5 tonnes per hour (11% O2)

1.2 MWCs, existing installations 1.4 to 9.5 tonnes per hour (11% O2)

0.05 Medical Waste incinerators: new installations > 90.9 kg/hr (11%

0.85

O2)

Medical Waste Incinerators: existing installations > 227 kg/hr

(11% O2).

0.005-0.5 waste incineration, common BAT value for other metals except

Hg, Cd, Tl and their compounds; discontinuous measurements


0.05 hazardous waste incineration

0.08 municipal waste incineration

11% O2; continuous (daily) and discontinuous measurements

(hourly average)


2

, cement kilns: 10% O2); continuous (daily) and discontinuous measurements (half-hour average)

0.05 Flanders: municipal, medical and hazardous waste incineration; continuous (daily) and discontinuous measurements

0.2 Walloon: common ELV for Pb, Cr, Cu, Mn; municipal waste incineration (17% O2), medical waste incineration (9% O2)

0.05 hazardous waste incineration, 11% O2, daily average.

76

Canada

Czech

Republic

Denmark

France

Germany

Netherlands

Slovakia

Switzerland

United

States of

America

BAT (BREF)

0.02 municipal and medical waste incineration except conical waste combusters; new or expanding facilities of any size and existing facilities except medical waste incineration < 120 Tonnes/year

0.05 hazardous waste incineration; new or expanding facilities of any

0.07 size;

Sewage sludge incineration; new or expanding facilities of any size;

0.04 medical waste incineration < 120 Tonnes/year; existing facilities

0.05 hazardous waste incineration; existing facilities

0.07 Sewage sludge incineration; existing facilities

11% oxygen

0.08 municipal waste incineration

0.1 medical waste incineration

0.05 co-incineration in cement plants and combustion installations

0.05 municipal waste incineration; discontinuous measurements

0.05 municipal, medical and industrial waste incineration

0.03 incineration of waste (11% O2, waste oil and pyrolysis gas: 3%

O2), co-incernation in cement and lime kilns (10% O2), coincernation in combustion installations (solid fuels: 6% O2, liquid and gaseous fuels: 3% O2), co-incernation in other installations

0.05 co-incernation in cement kilns (< 60% thermal input), if Hg due to raw materials; 10% O2 continuous measurements; daily average

0.05 municipal, hazardous and medical waste incineration, 8 hour average

0.2 waste incineration; common ELV for Hg, Tl, Cd

0.1 waste incineration, 11% O2

0.39 Medical Waste incinerators (11% O

2

)

0.06 MWCs, existing installations (11% O

2

)

0.005 to 0.09 Range for 5 types of hazardous waste combustors (11% O

2

)

0.001-0.02 waste incineration, daily average

References

CCME 2000

Canada-wide Standards for Mercury Emissions. Canadian Council of Ministers of the Environment, Quebec, June 5-6, 2000

EC 2001


77

EIPPCB 2005

Integrated Pollution Prevention and Control: Reference Document on the Best Available Techniques for Waste Incineration. European IPPC Bureau, Sevilla: July 2005.

EPA 2000

Draft Report for Mercury Reduction Options. United States Environment Protection Agency,

September 2000.

UNEP 2002

Global Mercury Assessment. United Nations Environmental Programme Chemicals, 2002.

78

Background_BAT-ELV

Draft background document

Assessments of technological developments:

Best available techniques (BAT) and limit values

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Best available techniques (BAT) and limit values

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