Simulation of high-temperature steam-only gasification of woody biomass with dry-sorption CO2 capture

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• 作者：Ehsan Mostafavi ; Jennifer H. Pauls ; C. Jim Lim and Nader Mahinpey
• 刊名：The Canadian Journal of Chemical Engineering
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：94
• 期：9
• 页码：1648-1656
• 全文大小：732K
• ISSN：1939-019X

文摘

Over the last few decades, research on the abatement of carbon dioxide (CO₂) gas has gained momentum, due to its increasing atmospheric levels. This study investigated high-temperature steam-only gasification of woody biomass for the production of high-purity hydrogen integrated with CO₂ capture in a moving-bed gasifier. Extensive process modelling and simulation were performed using the superior solid handling features of the Aspen Plus process simulator software. After validating the model with experimental data from a demonstration plant available in the open literature, a reversible carbonation-calcination reaction of calcium oxide (CaO) with CO₂ was added to the system. Sensitivity analyses were conducted to verify the predictive accuracy of the model. The effects of steam-to-carbon (S/C) ratio on the resulting gas composition were thoroughly studied to delineate the complex process of gasification. Beyond the mitigation of CO₂ emissions, the introduction of a CaO-based sorbent in the process simulation significantly enhanced hydrogen production by simultaneously promoting the forward water-gas shift reaction and reducing tars through increased tar-cracking reactions. The results show that hydrogen of a higher purity was produced with the inclusion of dry-sorption CO₂ capture in the gasification process. Moreover, the addition of the sorbent increased the higher heating values (HHV) by 3 times and improved the cold gas efficiency by 34 %.