Reductant Gases for Flue Gas Desulfurization Systems.

摘要

The report gives results of a study of the use of coal or residual-oil gasification to produce a hydrogen/carbon monoxide-rich gas for use as a reductant for regenerable flue gas desulfurization (FGD) processes. Two different reduction systems are considered:one for the type of FGD process that produces a concentrated SO2stream;the other,for the type that uses a liquid-phase Claus reactor. Detailed data on the composition of the raw gas from several gasifiers are analyzed. To supplement the data on trace constituents in the gas,thermodynamic calculations were made to determine the equilibrium gas-phase concentrations for a typical coal and typical gasification conditions. Mass transfer was calculated to determine the extent to which certain gaseous species could be removed by water-washing of the gas. The effects of the remaining trace constituents on the components of the reduction systems are analyzed. Additional research on trace constituents and their effects are recommended. The capital and operating costs for reductant systems based on gasification of coal and residual oil are estimated and compared with those for reduction systems based on natural gas.