Similar to the process using amines, flue gas is exposed to an ammonium carbonate solution at about 35 °F that absorbs the CO2 to form ammonium bicarbonate. Heating the mixture causes the bicarbonate to revert to the carbonate form, which is recycled, while the CO2 is captured. Data reported in May from an Alstom ammonia project at We Energies' power station in Pleasant Prairie, Wis., showed that 88–90% of the CO2 emitted was captured at greater than 99% purity.
by Ann M. Thayer |
July 13, 2009