Steam Gasification Reactivity of Flash Hydropyrolysis Char

Abstract

In order to investigate the steam gasification reactivity of char from flash hydropyrolysis of coal, Loy Yang coal (Australpyroian brown coal) and Manvers coal (British bituminous coal) were pyrolyzed, using a small-scale pilot reactor of entrained flow type, in an atmosphere of hydrogen gas of 70 atm at 860-960°C. The gasi-fication reactivity of hydropyrolysis chars was measured at 800°C-1200°C using a thermo-balance and was compared with that of pyrolysis chars. In addition, to -ly study the relationship between the coal pyrolysis conditions and the gasification reactivity of generated char, the coal was pyrolyzed using a heated grid reactor, while varying the heating rate, the kind of atmospheric gases and pressure.
Thus the following findings have been obtained. The steam gasification reactivity of hydropyrolysis char was higher than that of pyrolysis char. The difference in the reactivity of both type of char is affected by the type of raw coal. The gasification reactivity of char from British bituminous coal was strongly affected by the reaction conditions and atmosphere during char production; the reactivity of the char which was generated under the condition of heating rate being 500°C/sec or more was high; the reactivity of the char generated in a high pressure hydrogen atmosphere was higher than that of the char generated in an inert atmosphere. Regarding influence of coal pyrolysis conditions on char reactivity, heating rate has greater effects than atmospheric gases or pressure.