Catalytic coal gasification in an internally circulating fluidized bed reactor with draft tube

Abstract

Australian subbituminous coal loaded with the single and mixed catalysts of the alkali and transition metal salts [K2CO3, Ni(NO3)(2), K2SO4, Ni(NO3)(2 +) K2SO4] was gasified in an internally circulating fluidized bed (0.3 m-I.D. x 2.7 m-high) with a draft tube (0.1 m-ID x 0.9 m-high) at atmospheric pressure. Air and steam as the reactant gases were introduced into the draft tube and annulus regions in the bed separately. The effects of reaction temperature (750-900 degrees C), O-2/coal ratio (0.3-0.5) and steam/ coal ratio (0.3-0.8) on compositions, gas yield, calorific value of the product gas, and carbon conversion in the catalytic and non-catalytic coal gasifications have been determined. Coal gasification in the newly developed internally circulating fluidized bed with a draft tube produces higher calorific value gas (12 MJ/m(3)) with higher catalytic reaction rate and selectivity compared with the other types of gasifiers. (C) 1998 Elsevier Science Ltd. All rights reserved.