Strength and Gasification Reactivity of Coke Prepared by Blending a Ca/C Composite and Coal

Abstract

In this study, a calcium/carbon composite (Ca/C) was prepared from porous CaO by the water vapor swelling method; its pores were filled with tar-derived carbonaceous material to produce high-strength and highly reactive coke. The properties of coke prepared by blending the Ca/C composite and caking-coal were then investigated. The mesopores in the swelling Ca disappeared and the crushing strength was developed by filling tar-derived carbonaceous material into the porous Ca. Thus, a Ca/C composite could be produced by the abovementioned method, wherein the tar-derived carbonaceous material and Ca species were in close proximity. When the Ca/C composite was blended into the caking-coal, the strength of the coke obtained increased by up to 50% of Ca/C blending, which made it possible to produce high-strength coke. On examining the C structure of the prepared coke by X-ray diffraction, that of the original coke was found to be almost unchanged by adding the Ca/C composite. Conversely, the Ca/C blended-coke showed higher CO₂ gasification reactivity than the original coke prepared from caking-coal. Based on the CO₂ gasification reactivity test of the demineralized coke, it was clear that an increase in the gasification reactivity of the Ca/C blended-coke depended upon the catalytic effect of Ca. Thus, this method helped produce high-strength and highly reactive coke.