United Nations Environment Programme

Transcription

1 United Nations Environment Programme UNEP(DTIE)/Hg/INC.3/CRP.8 31 October 2011 English only Intergovernmental negotiating committee to prepare a global legally binding instrument on mercury Third session Nairobi, 31 October 4 November 2011 Agenda item 3 Preparation of a global legally binding instrument on mercury Submission by the Government of Norway on processes using mercury, particularly catalysts in the production of polymers and chemicals Note by the secretariat The secretariat has the honour to provide, in the annex to the present note, a submission prepared by the Government of Norway on processes using mercury, particularly catalysts in the production of polymers and chemicals. It has been reproduced as submitted and has not been formally edited. K

2 Annex Submission by the Government of Norway on processes using mercury, particularly catalysts in the production of polymers and chemicals PROCESSES: Catalysts in the production of polymers and chemicals Norway Introduction Mercury is used intentionally in several industrial processes including chlor-alkali production with mercury technology, VCM production with mercury-dichloride as catalyst and in the production of chemicals and polymers with mercury compounds as catalysts. This document focuses on the need for phase out of mercury compounds used as catalysts in the production of polymers and chemicals, and in particular the polyurethane production. More detailed information on the different processes, health and environmental risks and mercury-free alternatives are included in the appendix to this document. The use of mercury compounds as catalysts in the production of polymers and chemicals and the need for regulation The use of mercury compounds as catalysts in the production of polymers and chemicals should be phased out. Technical and economically feasible alternative methods without the need for mercury technology exist. 2.1 Polyurethane production Organic mercury compounds have for a long time been used as catalysts for polyurethane materials. The mercury-based products are used both for the professional market and for consumer products. Polymer production is an application where the use of mercury is still significant, despite considerable substitution with mercury free alternative processes. Numerous applications for mercury-catalysed polyurethanes are in use today, for example in gaskets and seals, as encapsulant for electronic assemblies, in film and television props, in vibration dampers, for clear polyurethane on labels, water resistant coatings and concrete sealants, for boat repair and repair on conveyor belts, in rollers on swivel chairs and roller skates and in shoe soles. Mercury catalysts have also been used in polyurethane flooring. In 2008 it was estimated that metric tons/year of mercury catalyst was used globally in polyurethane applications, see UNEP Toolkit (Jan 2011). This corresponds to over 100 tons of mercury. The total amount of mercury used in polyurethane globally equals the uses of mercury in other product groups like lighting and electrical and electronic devices. Since the mercury catalyst is incorporated into the products, the final product formed contains the same amount of mercury. The mercury ends up in a wide variety of products. Main releases are assumed to be from formulation and processing (large number of sites) service life and the waste phase. Once emitted, mercury enters the complex biogeochemical cycle. Technically and economically feasible mercury-free alternative catalysts exist for most applications and developments of alternatives for the remaining products are ongoing. The total costs of converting to systems using non-mercury catalysts are competitive to the costs of a typical system using mercury catalyst. If waste disposal costs and costs related to health and environmental 2

3 hazards are taken into account the benefits of replacing mercury technology with non-mercury alternatives outweighs the costs. Inclusion of this process in Annex D Part I (option 1) will ensure the final phase out of mercury uses in polyurethane production. 2.2 Production of chemicals Some other processes may use mercury catalysts. Examples are sodium methylate production and acetaldehyde production with mercury-sulphate. Alternative, non-mercury processes are available. Vinyl acetate production and the production of pigments are other examples, the extent of such production today is not known except for the uses of a mercury process in the production of sodium methylate. Mercury-free technology exists for the sodium methylate production, and immediate phase-out is feasible. In addition, with the severe accidents caused in Minamata and Kazakhstan in mind, the production of acetaldehyde and other chemicals with mercury compounds as catalysts should be prohibited to prevent any future use of the processes. Annex D in the New daft text (UNEP(DTIE)/Hg/INC.3/3) In order to prevent all production of chemicals and polymers with mercury compounds as catalysts, these processes should be included in Annex D if the positive list approach is taken. No allowable-use exemptions are deemed necessary for the phase out of the uses of mercury catalysts in the production of chemicals. However, for the uses in polyurethane a short phase out period should be allowed. For more information, please confer the appendix to this document. The list in Annex D could be as outlined in the New draft text or amended as proposed below: Part I, option 1 Manufacturing process not allowed under Article 7 Allowable-use exemption [Expiration date] 1. Chlor-alkali production [describe allowable-use exemption] [31 December 2020] [Acetylene-based] vinyl chloride monomer production[*] 2. [3. Production processes of chemicals and polymers in which mercury or mercury compounds are used as catalysts] 3. [4. Artisanal and small-scale gold mining] Mercury catalysts in polyurethane production [20xx] [20xx] 5 years after entry into force of the convention [20xx] 3

4 APPENDIX Information on different processes for the production of polymers and chemicals where mercury compounds are used as catalysts, including information on health and environmental risks and mercury-free alternatives 1 Polyurethane production Organic mercury compounds have commonly been used as catalyst in the production of twocomponent polyurethanes (PU). The catalyst is used for hardening or curing the polyurethane materials. The use of the catalysts for polyurethanes differs from the use of catalysts in the production of monomers (e.g. VCM) in the way that the catalyst in the polyurethanes is incorporated into the final product. In the past mercury was extensively used as a catalyst to promote a large range of polymer reactions. The mercury uses for these applications have declined, but mercury is still extensively used in the production of polyurethane elastomers, coatings, sealants and adhesives (so-called CASE applications). The mercury compounds are in particular used for polyurethane elastomers (flexible plastics) that can be cast into complex shapes, or sprayed onto a surface as insulation, corrosion protection, etc. The polyurethane products are used for a wide range of end-products including rollers, flooring, gaskets, encapsulation of electronic components, shoe soles, shock absorption and repair of industrial installations. The main mercury compounds currently used are phenyl mercury compounds, first of all phenylmercury neodecanoate. The mercury content in the final polyurethane product is %. It is estimated that tonnes of mercury catalyst may be used globally in PU elastomer applications. If one assumes that the mercury catalyst is added to a system at an average of %, then approximately 55,000-65,000 tonnes of PU elastomers are catalyzed globally with mercury each year. Assuming that the global market for PU elastomers is 1.6 million tonnes, this suggests that around 4% of that global market uses mercury catalysts. This represents over 100 tonnes of annual mercury consumption worldwide. The mercury catalyst remains in the final product. For the end user it is not possible to know whether the PU contains mercury or not. The products eventually end up in landfills. No treatment of the mercury will be performed since at the waste stage it is not possible to know which PU products that contain mercury or not. The mercury in the products eventually ends up in the environment where the phenylmercury compounds degrade to elemental and inorganic mercury. The polymers manufactured with mercury processes therefore contribute to the anthropogenic global mercury pollution. The mercury enters the complex biogeochemical mercury cycle and undergoes long range transport. When this mercury is methylated, e.g. in sediments, the result is biomagnification in food-chains and toxic effects in humans and ecosystems. 1 Text mainly reproduced from UNEP Toolkit (Jan 2011) and Norwegian proposal to prohibit the manufacture and uses of phenylmercury substances in Europe (2010/2011). 4

5 Mercury-free alternatives and benefits and costs when replacing mercury technology Most of the production of the polyurethane production today takes place with non-mercury catalysts. In Europe approximately 95% of the polyurethane production uses alternative catalysts like bismuth, zinc and zirconium carboxylate, titanium chelates and tertiary amines. The industry is working to find mercury-free alternatives for the remaining applications, for example for subsea uses. The ongoing work on the proposal to prohibit the use of mercury technology in Europe revealed that all use of mercury-containing catalysts can be replaced within a transition period of 5 years. A shorter transition period will lead to increased costs due to reduced quality of products. Alternatively derogations might be given leading to increased administrative costs. The main cost of restricting the use of these substances will be the cost of finding and developing suitable alternatives. Because there is no benefit estimates which are fully transferable to the emission reductions estimated, the net benefit of the restriction has not been calculated. However, the lowest estimate of the benefits presented, outweighs the estimated costs of the restriction by a large margin. Bearing all the uncertainties in mind we believe that this merit the conclusion that the benefits of the restriction proposed can be expected to outweigh the costs. We think this can be convertible to the global scale. Sodium methylate production Sodium methylate, NaOCH 3, is widely used in industry and laboratories and is of commercial importance in making biodiesel, pharmaceuticals, perfumes, metallic soap, dyes and organic intermediate. Sodium methylate can be made as a by-product in the manufacture of chlorine using a mercury chlor-alkali cell. Mercury-free alternatives and benefits and costs when replacing mercury technology Sodium methylate and other alkali metal alcoholates can be made by reacting an alkali metal chloride with an alcohol under the influence of direct current. This process is mercury free and uses less energy than the mercury process. This process requires a modest financial investment and dominates the word market. One manufacturing process uses raw materials such as caustic soda and methanol. In addition to sodium methylate solution, new plants can produce sodium methylate powder, which is used in the transesterification of oils for the food industry. Utilizing caustic soda and methanol rather than mercury-cell based chlorine and sodium metal, is much more desirable for the food industry and biodiesel producers seeking to sell their refined glycerin into the food, beverage, pharmaceutical and nutraceutical markets. Acetaldehyde production Mercury-sulphate (HgSO 4 ) can be used in the production of acetaldehyde, although alternative, non-mercury processes are available. Earlier in the twentieth century mercury was used for acetaldehyde production in the USA and other countries. This process is no longer used in the U.S, and is probably not used any longer in many other countries. No information is available with regard to the use of mercury for producing acetaldehyde in other countries. 5

6 The potential releases of mercury from this type of facility were well illustrated in the mercury pollution tragedy that occurred in 1950s-1960s in Minamata Bay Japan. For 20 years, a chemical plant had been making acetaldehyde, which is used to make plastics, drugs, and perfume. As part of its normal operations, the plant dumped waste products, including large amounts of mercury, into Minamata Bay. Many people died or suffered permanent disabilities as a result of this pollution. In 1968, the plant stopped using mercury in its manufacturing process and stopped dumping waste into the bay. Another incident occurred in Kazakhstan, where accidental release of mercury from an acetaldehyde plant in the Karaganda region of central Kazakhstan has resulted in serious contamination of the surrounding region and in particular the River Nura (reference: Management of Mercury Pollution of the River Nura, research at University of Southhampton, United Kingdom. Mercury-free alternatives replacing mercury technology No information on current uses of the process using the mercury technology has been found. The liquid-phase oxidation of ethylene using a catalytic solution of palladium and copper chlorides was first used commercially in the USA in 1960 and more than 80% of the world production of acetaldehyde in recent years has been made by this process. The remainder is produced by the oxidation of ethanol and the hydration of acetylene. Acetaldehyde is produced by a limited number of companies over the world. The total production of acetaldehyde in the USA in 1982 amounted to 281 thousand metric tons. Total acetaldehyde production in Western Europe in 1982 was 706 thousand metric tons, and the production capacity was estimated to have been nearly 1 million metric tons. In Japan, the estimated production in 1981 was 323 thousand metric tons. Other production of chemicals with mercury compounds as catalysts Vinyl acetate can be produced using mercury salts as a catalyst. Mercury sulphate (II) has been used as catalyst in production of the cube (1-amino anthrachion) colours (/pigments), with an annual consumption of several metric tons of mercury with catalyst until No information on current uses of the processes has been found. 6