Chapter 32 - Reactivity of Heat-Treated Coals

Abstract

This chapter presents approaches to measure gasification rates and explains how rates that are found to be widely different for coal-derived chars depend on measurable properties of the chars. Interest in coal gasification has suddenly been revived, initially because of interest in the production of synthetic natural gas and lately also because of the realization that industry will again need low and medium Btu gas produced from coal. The interest not only encompasses the coals of the eastern United States but also, in a most significant way, focuses on the western subbituminous and lignite deposits. Interest in the western coals is stimulated by their high reactivity and their abundance. The heat treatment of coals invariably results in the production of some kind of coke or char. The structure of a char and, hence, its reactivity are influenced in a complex manner by a number of variables, such as heating rate, maximum heat treatment temperature, soak time at maximum temperature.