§ Mr. EvansTo ask the Secretary of State for Trade and Industry what her assessment is of the effectiveness of emissions scrubbers in removing mercury pollutants from power station emissions. [97522]
§ Mr. WilsonThere are a number of factors which affect the effectiveness of scrubbers removing mercury emissions. Around 40–60 per cent. of the mercury produced during coal combustion is in the elemental70W vapour form and the type of wet scrubbers used on coal-fired plant (eg flue gas desulphurisation (FGD) used for sulphur dioxide control) are not effective in removing this form of mercury from the flue gas. Of the remaining mercury, which is in an oxidised form, wet emissions scrubbers have been shown to be effective. In summary, it is estimated that about 50 per cent. of mercury produced is removed by wet scrubbers. There is no information on dry scrubbers although there is research being carried out on this.
A study on the monitoring and control of trace elements from coal-fired power generation is about to be let within the DTI's Cleaner Coal Technology Programme and this will include mercury emissions, their measurement, and their effects, and will cover the emerging legislative and policy issues.