Hydrodynamic and gasification studies of sawdust in a pressurized circulating fluidized bed

Abstract

The present research is focused on the hydrodynamics and gasification studies of a pressurized circulating fluidized bed (PCFB) gasifier considering saw dust as a bed inventory. The operating pressure range of the PCFB gasifier is maintained in between 1 to 4 bar and the suspension density, syngas composition, lower heating value (LHV), gas yield, carbon conversion efficiency (CCE) and cold gas efficiency (CGE) were calculated and presented in this paper. The suspension density increases with rise in operating pressure and decreases with rise in superficial velocity. The concentration of CH4 in the syngas was found to be increasing with rise in bed pressure and is found to be 4.78 % at 4 bar. However, no significant effect of operating pressure on H2 concentration is observed and is found to vary between 8.3 to 7.95 %. The CO concentration increases up to 2 bar pressure and decreases gradually afterwards. The LHV, gas yield, CCE and CGE has a positive response to the rise in operating pressure and found maximum at 4 bar. The CCE and CGE of the PCFB gasifier are increased by 57 % and 58 %, respectively when the operating pressure is changed from 1 to 4 bar.