Comparison of kinetic models for isothermal CO2 gasification of coal char–biomass char blended char
来源期刊：International Journal of Minerals Metallurgy and Materials2015年第4期
论文作者：Hai-bin Zuo Wei-wei Geng Jian-liang Zhang Guang-wei Wang
文章页码：363 - 370
摘 要：This study investigated the isothermal gasification reactivity of biomass char(BC) and coal char(CC) blended at mass ratios of 1:3, 1:1, and 3:1 via isothermal thermogravimetric analysis(TGA) at 900, 950, and 1000°C under CO2. With an increase in BC blending ratio, there were an increase in gasification rate and a shortening of gasification time. This could be attributed to the high specific surface area of BC and the high uniformity of carbon structures in CC when compared to those in BC. Three representative gas–solid kinetic models, namely, the volumetric model(VM), grain model(GM), and random pore model(RPM), were applied to describe the reaction behavior of the char. Among them, the RPM model was considered the best model to describe the reactivity of the char gasification reaction. The activation energy of BC and CC isothermal gasification as determined using the RPM model was found to be 126.7 k J/mol and 210.2 k J/mol, respectively. The activation energy was minimum(123.1 k J/mol) for the BC blending ratio of 75%. Synergistic effect manifested at all mass ratios of the blended char, which increased with the gasification temperature.
Hai-bin Zuo1，Wei-wei Geng1，Jian-liang Zhang2，Guang-wei Wang2
1. State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing2. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing
摘 要：This study investigated the isothermal gasification reactivity of biomass char(BC) and coal char(CC) blended at mass ratios of 1:3, 1:1, and 3:1 via isothermal thermogravimetric analysis(TGA) at 900, 950, and 1000°C under CO2. With an increase in BC blending ratio, there were an increase in gasification rate and a shortening of gasification time. This could be attributed to the high specific surface area of BC and the high uniformity of carbon structures in CC when compared to those in BC. Three representative gas–solid kinetic models, namely, the volumetric model(VM), grain model(GM), and random pore model(RPM), were applied to describe the reaction behavior of the char. Among them, the RPM model was considered the best model to describe the reactivity of the char gasification reaction. The activation energy of BC and CC isothermal gasification as determined using the RPM model was found to be 126.7 k J/mol and 210.2 k J/mol, respectively. The activation energy was minimum(123.1 k J/mol) for the BC blending ratio of 75%. Synergistic effect manifested at all mass ratios of the blended char, which increased with the gasification temperature.
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