Coal gasification gas cleanup

Coal gasification integrated with combined cycle power generation (IGCC) is an alternative technology to utilize coal for electric power generation. IGCC technology has a higher efficiency and lower sulphur emissions than that of conventional power generation by coal combustion. Under gasification conditions, part of the coal S and N is converted to H2S and NH3, which have to be removed from the product gas before its combustion in the gas turbine. Sorbents can be used to capture H2S at the reactor temperature, or at a lower temperature after the product gas is partially cooled. Controlled combustion of coal gas can convert NH3 to N2. Equilibrium calculations provide valuable information on gas cleanup as a function of operating conditions of the selected gasifier technology and the type of sorbent being used.