Mercury removal from geothermal exhaust gas by sulfur-impregnated and virgin activated carbons

摘要

Sulfur-impregnated and virgin activated carbons have been used in a laboratory scaled fixed-bed reactor to investigate their capability of removing mercury vapours form a gas mixture containing H_2S, O_2 and moisture that is representative of the exhaust gas emissions of the geothermal power plants of the Monte Amiata field in Italy. The observed deposition of sulfur from H_2S oxidation on the carbonaceous matrix increases the mercury scavenging capacity of the commercial sulfur-impregnated activated carbon and makes virgin activated carbon capable of adsorbing mercury vapours by the formation of HgS contextually to the deposition of sulfur, achieving a mercury adsorption capacity comparable to the commercial sulfur-impregnated activated carbon.