Steam gasification of coal with salt mixture of potassium and nickel in a fluidized bed reactor

Australian coal loaded with a mixed catalyst of K2SO4+Ni(NO3)(2) has been g asified with steam in a fluidized bed reactor of 0.1 in inside diameter at atmospheric pressure. The effects of gas velocity (2-5 U-g/U-mf), reaction temperature (750-900 degreesC), air/coal ratio (1.6-3.2), and steam/coal ra tio (0.63-1.26) on gas compositions, gas yield and gas calorific value of t he product gas and carbon conversion have been determined. The product gas quality and carbon conversion can be greatly improved by applying the catal yst; they can also be enhanced by increasing gas velocity and temperature. Up to 31% of the catalytic increment in gas calorific value could be obtain ed at higher temperatures. In the experimental runs with variation of steam /coal ratio, the catalytic increments were 16-38% in gas calorific value, 1 4-57% in carbon conversion, 5-46% in gas yield, and 7-44% in cold gas effic iency. With increasing fluidization gas velocity and reaction temperature, the unburned carbon fi-action of cyclone fine for catalytic gasification de creased 4-18% and 13-16%, respectively, compared to that for non-catalytic gasification.