Promoting effect of biomass ash additives on high-temperature gasification of petroleum coke: Reactivity and kinetic analysis

The effect of biomass ash (rice straw ash (RSA) and cotton straw ash (CSA)) on the gasification reactivity and the evolution of physicochemical structure of petcoke char was investigated. The catalytic effect of CSA was significantly higher than that of RSA, and the catalytic effect of biomass ash was enhanced at lower gasification temperature and for higher blending ratio of biomass ash. The promoting effect of biomass ash was related to the increase of active AAEM content, the decrease of order degree of carbon structure and the development of surface structure in char gasification after biomass ash addition, which was more significant for CSA, at lower temperature and for higher blending ratio. Moreover, the shrinking core model was suitable for char gasification, and the additions of RSA and CSA reduced the activation energy of petcoke char gasification from 199.84 kJ mol(-1) to 159.85 kJ mol(-1) and 62.75 kJ mol(-1), respectively. (C) 2020 Energy Institute. Published by Elsevier Ltd. All rights reserved.