Review of Ammonia and Hydrogen Cyanide Concentrations in Low and Medium-Btu Coal Gases.

摘要

Measurements by various investigators of NH sub 3and HCN concentrations in the off-gases from the Mond, Riley-Morgan,Lurgi,Koppers-Totzek,Hygas and Synthane coal gasifiers are summarized. The equilibrium concentrations of NH sub 3at the gasifier bed and outlet temperatures,and the concentrations of NH sub 3 +HCN assuming complete conversion of coal-bound nitrogen were calculated and compared with the observed concentrations. It was concluded that at present the best method of estimating NH sub 3 +HCN levels in gasifier off-gases is to subtract byproduct ash,char and tar nitrogen from the coal nitrogen and assume complete conversion of the balance to NH sub 3 +HCN. Low temperature cleanup produces low/medium-Btu gas containing 1to 10ppm V NH sub 3and 1to 100ppm V HCN. high temperature NH sub 3and HCN removal has not been demonstrated. (ERA citation 04:032015)