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

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.