Kinetic model and prediction for coal hydrogasification

Abstract

Coal hydrogasification is a key component of zero emission coal (ZEC) power generation system which discharges little CO2 and other pollutants at a thermal efficiency close to 70%. In addition, coal hydrogasification itself has many advantages. A hydrogasification kinetic model including ten homogeneous reactions and four heterogeneous reactions is established in this work and is validated against experiment data available in literatures. The validated model is then used to predict the effects of different reaction conditions including the reaction temperature T, the reaction pressure pt, the H2/coal mass ratio U and the reaction time t on coal hydrogasification properties. The results indicate that coal hydrogasification is facilitated by the increased pt and t. When T is not higher than 1273 K, the gasification process is promoted with T increment. Increasing U can promote the coal hydrogasification process on the whole. When U is larger than 0.5, however, the coal conversion ratio (xcoal) will slightly decrease with U increment.