文献类型：期刊文献

英文题名：A new active site/intermediate kinetic model for K2CO3-catalyzed steam gasification of ash-free coal char

作者：Wu, Xuantao[1];Tang, Jia[1];Wang, Jie[1]

机构：[1]E China Univ Sci & Technol, Dept Chem Engn Energy, Key Lab Coal Gasificat & Energy Chem Engn, Minist Educ, Shanghai 200237, Peoples R China

年份：2016

卷号：165

起止页码：59

外文期刊名：FUEL

收录：;EI(收录号：20154401452732);WOS:【SCI-EXPANDED(收录号:WOS:000364655000008)】；

基金：The research work is funded by the Natural Science Foundation of China (Grant Nos. 21076081 and 21376080).

语种：英文

外文关键词：Coal char; Catalytic gasification; Kinetic model; Potassium carbonate

摘要：Experimental results showed that the K2CO3-catalyzed steam gasification of ash-free char had two distinct characteristics of gas evolution. One was a broad maximum of gasification rate versus carbon conversion at a higher carbon conversion as a result of the sustained catalytic activity. Another was the variations of gas composition with carbon conversion arising from the complex reaction pathways. No model was reported to describe both characteristics in the literature. In this work, a new kinetic model was formulated in terms of an active site/intermediate mechanism with an assumption of the variations of effective carbon concentration with carbon conversion. The mechanism involved three potassium species and four reaction pathways for the catalyst cycle and gas release. The model was associated with five parameters including four rate constants and a catalysis factor, and it manifested a capability of predicting accurately the profiles of both gasification rate and gas composition over the entire range of carbon conversion. All four rate constants estimated from the modeling followed the Arrhenius equations with the reasonable activation energies. Moreover, the model could predict the formation, growth and decline of three potassium species during the gasification. The modeling result would deepen the understanding of the chemical processes of K2CO3-catalyzed steam gasification of char. (C) 2015 Elsevier Ltd. All rights reserved.