Catalytic mechanism study on the gasification of depolymerizing slag in supercritical water for hydrogen production
Catalytic mechanism study on the gasification of depolymerizing slag in supercritical water for hydrogen production
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DOI：
10.1016/j.ijhydene.2020.06.061
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发表时间：
2020-07
影响因子：
7.2
通讯作者：
Cui Wang;C. Zhu;Wen Cao;Wenwen Wei;H. Jin
中科院分区：
文献类型：
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作者：
Cui Wang;C. Zhu;Wen Cao;Wenwen Wei;H. Jin
超临界水气化技术可以实现生物质、煤等有机物高效转化为富氢气体。但在较低温度下的非催化气化效率不高。此外，催化气化反应机理复杂。因此，如何提高催化效率，掌握催化机理是一个具有挑战性的课题。本文对解聚渣在不同催化剂催化下的超临界水气化进行了实验研究，并对催化机理进行了分析。结果表明，K2 CO 3的催化机理是促进木质纤维素的溶胀和水解，增加酚类中间体的生成量。Ru/Al 2 O3表现出一些不同的催化性能。它促进水解产物的加氢反应、开环反应和碳-碳键的断裂，从而提高气化程度和气化效率。此外，由于两种催化剂促进了不同的气化阶段，因此二元催化剂表现出良好的协同效应，催化活性高于任何单一催化剂。在K2 CO 3和Ru/Al 2 O3协同催化下，气化效率和氢气产率分别提高了13.22 mmol g− 1和66.46%。
Supercritical water gasification technology can realize efficient conversion of biomass, coal and other organics into hydrogen rich gas. But the efficiency of non-catalytic gasification at relative low temperature is not high. Besides, as for catalytic gasification, catalysis mechanism is complex. Thus how to improve efficiency and master the catalysis mechanism is a challenging issue. In this thesis, supercritical water gasification of depolymerizing slag experiments with the catalysis of different kinds of catalysts are conducted and the catalysis mechanism is analyzed. The results indicate that catalyst mechanism of K2CO3is that it can promote the swelling and hydrolysis of lignocellulose and increase the amounts of phenolic intermediates. Ru/Al2O3presents some different catalytic properties. It facilitates hydrogenation reaction of hydrolysis products, ring-opening reaction and the cleavage of carbon-carbon bonds then enhances gasification degree and increases gasification efficiency. Moreover, the binary catalyst displays a good synergic effect and the catalytic activity is higher than that of any single catalyst since these two catalysts promote various gasification stages. The gasification efficiency and hydrogen yield increase 13.22 mmol g−1and 66.46% respectively with the synergic catalyst of K2CO3and Ru/Al2O3.