Gasification of Seven Coals in Carbon Dioxide at Elevated Temperatures and High Heating Rates: Unification Approach of Reactivity.

Abstract

Studies on coal gasification in CO 2 at elevated temperatures and high heating rates are necessary to develop IGCC technology. Coal gasification is a very complicated phenomenon, which makes a generalized understanding and description of gasification reactivity of a coal highly important. With a unique fluidized bed, the reactivity of seven coals was investigated at elevated temperatures and high heating rates. A modified random pore model was proposed to unify the gasification reactivity of coals obtained by us. It was identified that the coal reactivity can be unified with a master curve described by the new model for all the coals, temperatures and heating rates examined in this work. This model can also satisfactorily unify the experimental gasification data in literature. The modified random pore model can predict the experimental data with an error within about 5%. The error of the prediction by the modified random pore model is about one-third smaller than that of the prediction by the random pore model. It is recommended as a sub-model for simulation of coal gasification in practical gasifiers.