Simulation of Pittsburgh No. 8 bituminous Coal Gasifier
Department of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), No. 424, Hafez Avenue, 15914, Tehran, Iran
This paper presents process simulation of moving-bed coal gasifier. The system of differential equations for the mass and energy balances is solved by using Runge-Kutta method in Matlab. This Simulation is used to predict profiles of temperature and concentration. The simulation results were compared with experimental data relevant to Westfield plant in Scotland successfully. Also, the effect of operating parameters on composition of product gas and conversion of solid was investigated. Carbon conversion increased with decreasing of steam-oxygen ratio or with increasing of inlet gas temperature and oxygen mole fraction in air as feed. A dry ash gasifier would have to be larger than steam-oxygen ratio of 7 to operate below the ash fusion temperature. The possibility of reducing the ratio of steam to oxygen by maintaining the ash state was investigated. Dry ash gasifier with Pittsburgh No. 8 coal as feed could achieve carbon conversion efficiency of 99.68% at steam-oxygen ratio of 9 and H2 and CO increased with decreasing of steam-oxygen ratio.