Burying mercury

07 October 2002 00:00  [Source: ICB]

A new European Commission report predicts that the phase-out of the mercury-cell process in the chlor-alkali industry will lead to a surplus of 12 000-15 000 tonne of mercury becoming available. Martin Todd investigates the fate of the decommissoned mercury

The phase-out of the mercury-cell process in the European chlor-alkali industry continues apace and will go on for at least another decade, according to a recent European Commission report, Mercury from the Chlor-Alkali Industry. The report assesses various options for the surplus mercury, which will be generated by mercury-cell phase-out within the European chlor-alkali industry. All decommissioned installations have re-used the residual mercury in other remaining chlor-alkali units or sold it on the open market.

Industry estimates

Euro Chlor, the chlor-alkali industry federation, estimates that 50% of mercury-cell capacity will convert to membrane technology by 2010 and the remainder by 2020.

Around 34 mercury-based chlorine plants have been shut down or converted, in recent years, and the remaining 47, which account for 54% of west European chlorine capacity in 11 member state countries, will be gradually converted as mercury-cells reach the end of their economic lives. But the high cost of conversion, which has been estimated at E3.1bn ($3.0bn), could become an issue. The conversion or phase-out of the remaining units will result in 12 000-15 000 tonne of decommissioned mercury becoming available on the market.

However, the Commission report says the precise timetable for the phase-out will depend on how national authorities implement the IPPC directive, and whether or not the recommended phase-out of mercury cells as envisaged by OSPAR Decision 90/3 is followed. According to the Commission, some member countries are seen to be firm about an early phase-out, while others have yet to indicate their most likely cause of action.

If there was to be forced phase-out earlier than 2020, says the Commission, problems would arise, as the market would not be able to absorb the amounts of mercury that would become available through decommissioning. In this scenario the mercury would have to be put into storage.

Emission reductions

The European chlor-alkali sector has reduced mercury emissions/tonne of chlorine produced by 72% and implemented six voluntary measures designed to meet PARCOM marine convention regulations and objectives. Industry observers say that the phase-out of mercury-based chlor-alkali plants represents a step forward for the environment, in that it will significantly reduce mercury emissions and energy consumption in the sector.

In terms of dealing with decommissioned mercury, Euro Chlor and the largest European mercury mining company Minas de Almaden has developed an approach that would return mercury to mercury mines, leaving unmined mercury in the ground.

The contractual agreement states that surplus mercury from west European chlor-alkali plants will be placed on the market. The agreement concerns up to 1000 tonne of mercury in any year. If more than this becomes available in any year, the conditions of the agreement are to be revised.

According to the Commission, Almaden has mercury sales of 700-1300 tonne/year. By the end of 2002, it is estimated that more than 1300 tonne of decommissioned mercury will be transferred to Almaden. In 2000 only 354 tonne of mercury went from the industry to the Spanish mine.

At least 600 tonne/year of decommissioned mercury is expected to be released as chlor-alkali plants convert to alternative technologies. The Commission report suggests that such amounts would avoid a mercury supply imbalance on global markets and minimise the disruption of market prices, which have declined due to regulatory pressures. However, it is unclear what will be the impact of larger quantities of decommissioned mercury coming on to the merchant market.

'Euro Chlor communications manager Peter Whippy states: 'We feel that this approach reflects the true spirit of sustainable development, since it takes into account the triple bottom line,' that is, incorporating environmental, economic and social factors.

As well as re-use, the Commission report identifies intermediate storage for an unknown period of time until a strategy for re-use and or safe disposal is available or definitive storage. However, the Commission notes that 'appropriate methods are not fully developed and the costs are relatively high', in terms of definitive storage. Developing an approach that incorporates definitive storage, could affect the competitiveness of the chlor-alkali industry on global markets.

Euro Chlor executive director Barrie Gilliatt notes: 'This approach reduces atmospheric emission to air from smelting during new mining and avoids E180m-330m of extra costs to the conversion bill faced by the chlor-alkali industry.'

East European chlor-alkali producers recently met with Euro Chlor to discuss mercury management techniques and best practice within the industry. According to the Commission, there are 10 chlor-alkali plants in eastern Europe, covering EFTA and European Union accession countries. Three are based in Poland; the Czech republic and Romania have two plants each, while Hungary, Slovakia and Bulgaria each have one chlor-alkali unit each. It is estimated that decommissioning these units would make another 2000 tonne of mercury available to the market. Euro Chlor officials explain the arrangement that has been made with its EU members to return surplus mercury to Minas de Almaden mine in Spain.

Encouragement

Gilliatt states: 'The Commission report encourages producers in accession countries to follow the same scheme as our EU members. The producers we have contacted [in eastern and central Europe] are evaluating the situation, but we are optimistic that they too will recognise the benefits of pursuing this voluntary initiative by our industry.'

According to one industry observer, when the PARCOM marine convention regulators recommended that emissions from mercury-cell chlor-alkali plants be reduced and production be eventually phased out, little thought was given to the environmental fate of the 12 000-15000 tonne of mercury that would become surplus from EU plants converting to alternative technologies. Now we have a coherent strategy, which will go a long way to tackling the problems of removing mercury from the chlor-alkali industry. While there is little disagreement on the path that is being followed, the speed the industry travels along that path is still being debated.

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