Review of advance on coal pyrolysis mechanism

Bingbiao Yang and Li Wang

Abstract

Coal pyrolysis is a key technologies to clean coal utilization, which contributes to energy saving and environmental protection. This paper reviews the update findings of coal pyrolysis, which involves various factors. They affects the physical and chemical properties of coal char, coal gasification reactivity, and pyrolysis furnace structure. These findings show that inert atmosphere reduces the initial reactive char gasification. Hydrogen atmosphere increases chemical reactivity of coal char, methane atmosphere mixed with steam promotes the nitrogen emission. Pressurized pyrolysis makes C/H mole ratio of coal char increasing and the specific surface area decreasing, and limits volatiles separated out. Higher temperature is conducive to the coal char conversion, heating rate is helpful to the trace elements release and improves the reactivity of ash melting char. It found that temperature, pressure, and heating rate have mutual effects. In future studies, it is desirable to obtain coal char with high carbon content and excellent reactivity.