abstract |
A method for removal of mercury from a gaseous stream containing the mercury, hydrogen and/or CO, and hydrogen sulfide and/or carbonyl sulfide in which a dispersed Cu-containing sorbent is contacted with the gaseous stream at a temperature in the range of about 25° C. to about 300° C. until the mercury concentration in the gaseous stream after contacting the sorbent exceeds a predetermined breakthrough level, signaling a spent sorbent. Arsenic, cadmium and selenium present in the gaseous stream may also be captured along with the mercury. The spent sorbent is then contacted with a desorbing gaseous stream at a temperature equal to or slightly higher than the temperature at which the mercury adsorption is carried out, producing a regenerated sorbent and an exhaust gas comprising released mercury. The released mercury in the exhaust gas is then captured using a high-capacity sorbent, such as sulfur-impregnated activated carbon, at a temperature less than about 100° C. The regenerated sorbent may then be used to capture additional mercury from the mercury-containing gaseous stream. The process may be carried out at pressures in the range of about 1 bar to about 200 bar. |