Effects of the Catalyst and Reaction Conditions on the Integrated Process of Coal Pyrolysis with CO2Reforming of Methane†

Abstract

Our previous works showed that the tar yield of coal pyrolysis can obviously be improved by integrated CO{sub 2} reforming of methane to coal pyrolysis in a fixed-bed reactor consisting of an upper catalyst layer and a lower coal layer. In this work, the effects of catalyst supports (MgO, Al{sub 2}O{sub 3}, SiO{sub 2}, and NaY) and reaction conditions on tar and water yields, CH{sub 4} conversion in pyrolysis of Chinese Pingshuo coal, and the carbon deposition on different catalysts were investigated. The results indicated that the catalyst support has an important effect on the integrated process and MgO is the best among the studied supports. A higher tar yield, lower water yield, and lower carbon deposition can be obtained with Ni/MgO as the catalyst. The tar yield increases with the increase of the pyrolysis temperature, holding time, CO{sub 2}/CH{sub 4} ratio, and CH{sub 4} flow rate, respectively, while the char yield decreases with an increasing pyrolysis temperature. 22 refs., 7 figs., 1 tab.