A comprehensive study on pyrolysis kinetics of microalgal biomass
A comprehensive study on pyrolysis kinetics of microalgal biomass
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DOI：
10.1016/j.enconman.2016.10.077
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发表时间：
2017-01-01
影响因子：
10.4
通讯作者：
Chen, Wei-Hsin
中科院分区：
文献类型：
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作者：
Bach, Quang-Vu;Chen, Wei-Hsin
微藻生物质热解生产生物燃料已引起广泛关注。然而，详细的降解机制和动力学的过程还没有得到充分的探讨。采用热重法研究了小球藻ESP-31的非等温热解过程。从单反应到七个平行反应的动力学模型，对热解实验数据进行拟合，找出最佳热解模型。结果表明，微生物与木质纤维素生物质的热解行为有所不同，这是由于二者组成的内在差异所致。总的来说，动力学建模过程表明，增加反应的数量提高了模型拟合质量。曲线拟合结果表明，由三个或三个以下反应组成的模型不适用于微球热解。四反应模型考虑了碳水化合物、蛋白质、脂类等的热解，可用于模拟热降解过程，但不能准确预测肩峰和小峰的热降解。推导的七反应模型进一步将碳水化合物和蛋白质的分解过程分为两个阶段，并很好地解释了热降解过程。该模型表明，脱挥发分峰归因于蛋白质I和碳水化合物II的联合降解。七反应模型的拟合质量最高，因此推荐用于预测微球热解过程。(C)2016爱思唯尔有限公司版权所有
Pyrolysis of microalgal biomass for biofuels production has attracted much attention. However, detailed degradation mechanism and kinetics of the process have not been fully explored yet. In this study, a non isothermal pyrolysis of microalga Chlorella vulgaris ESP-31 is thermogravimetrically investigated. Several kinetic models, from a single reaction to seven parallel reactions, are tested to fit the experimental pyrolysis data for finding out the optimal pyrolysis model. The results show that the pyrolysis behavior of the microalga is somewhat different from that of lignocellulosic biomass, stemming from the inherent difference in their compositions. Overall, the kinetic modeling processes show that increasing the number of reactions improves the model fit quality. Curve fitting results indicate that the models consisting of three and less than three reactions are not suitable for microalga pyrolysis. The four-reaction model, via considering the pyrolysis of carbohydrate, protein, lipid and others, can be employed for modeling the thermal degradation; however, it cannot precisely predict the thermal degradation of the shoulder and the small peak. The conducted seven-reaction model further partitions the decomposition processes of carbohydrate and protein into two stages, and explains the thermal degradation well. The model indicates that the devolatilization peak is attributed to the combined degradation of Protein I and Carbohydrate II. The seven-reaction model offers the highest fit quality and is thus recommended for predicting the microalga pyrolysis processes. (C) 2016 Elsevier Ltd. All rights reserved.