Gasification reactivity and characteristics of coal chars and petcokes

Abstract

Gasification reactivity and characteristics of three coal chars and two petcokes were investigated in detail. The temperature programmed reaction technique were used to test the gasification reactivity. The characteristics of the various chars were analyzed by XRD, SEM, N2 adsorption technique and FT-IR. As expect, the coal chars and petcokes showed significantly different gasification reactivity. The reactivity of the two petcokes was much poorer than that of the three coal chars. The gasification reactivity of the coal char increased with the decreasing of coal rank. The gasification reactivity was closely related to the characteristics of samples. It was found that the lower degree of graphitization, less compact surface and more developed pore structure corresponded to higher gasification reactivity of chars. These characteristics of the carbon structure was more favorable to gas diffusion, and hence resulted in high gasification reactivity. In addition, coal char contained more oxygen-containing functional groups and active components such as Ca/Mg/Fe/K/Na compounds, which all had promoting effect on gasification reaction.