Analysis of Coal Gasification Reactivity, Kinetics, and Mechanism with Iron-Based Catalyst from Coal Liquefaction.

Abstract

In this work, the effect of an iron-based catalyst from coal liquefaction on coal gasification was studied. Two catalyst loading methods and three catalyst loading contents were taken into consideration. Besides, the carbon structure, surface morphology, and element distribution of coal char and gasified semi-char were investigated, and the interactions between the catalyst and internal minerals of coal were studied. The results showed that the coal char prepared by wet impregnation had higher reactivity than that prepared by a dry mixing method. From the perspective of improving the coal reactivity, the optimal addition method should be wet impregnation with a 2% catalyst. The model-free and model-fitting methods were applied to study the catalytic gasification kinetics. The iron-based catalyst would be broken during wet impregnation, and the catalyst fragments could stick to the surface of coal char, resulting in higher reactivity. The graphitization of char increased with the addition of the iron-based catalyst. This can imply that the carbon structure cannot effectively represent the gasification reactivity in the presence of the iron-based catalyst. The Iron-based catalyst can accelerate the gasification rate alone and can also provide higher catalytic activity with the internal minerals of coal.