DEVELOPMENT OF MERCURY CONTROL TECHNOLOGY FOR COAL-FIRED SYSTEMS

摘要

The results and conclusions to date from the Argonne research on dry sorbents can be summarized as follows: 1. Lime hydrates, either regular or high-surface-area, are not effective in removing elemental mercury. 2. Mercury removals are enhanced by the addition of activated carbon. 3. Mercury removals with activated carbon decrease with increasing temperature, larger particle size, and decreasing mercury concentration in the gas. 4. Chemical pretreatment (e.g., with sulfur or CaCl_2 can greatly increase the removal capacity of activated carbon. 5. Chemically treated mineral substrates have the potential to be developed into effective and economical mercury sorbents. 6. Sorbents treated with different chemicals respond in significantly different ways to changes in flue-gas temperature.Preliminary results from the wet scrubbing research include: 1. No removal of elemental mercury is obtained under normal scrubber operating conditions. 2. Mercury removal is improved by the addition of packing or other techniques to increase the gas-liquid contact area. 3. Stainless steel packing appears to have beneficial properties for mercury removal and should be investigated further. Beneficial synergisms with polysulfide solutions have been observed. 4. Oxidizing additives may be used in conjunction with wet scrubbing to greatly enhance removals. Selectivity is required to avoid excessive additive consumption from competing reactions.