Structured ZSM-5/SiC foam catalysts for bio-oils upgrading
Structured ZSM-5/SiC foam catalysts for bio-oils upgrading
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DOI：
10.1016/j.apcata.2020.117626
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发表时间：
2020-06
期刊：
影响因子：
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通讯作者：
Xiaoxia Ou;Chunfei Wu;Kaiqi Shi;C. Hardacre;Jinsong Zhang;Yilai Jiao;Xiaolei Fan
中科院分区：
文献类型：
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作者：
Xiaoxia Ou;Chunfei Wu;Kaiqi Shi;C. Hardacre;Jinsong Zhang;Yilai Jiao;Xiaolei Fan
采用前驱体分散-二次生长法制备了负载于SiC泡沫上的ZSM-5沸石涂层，并将所得结构化ZSM-5/SiC泡沫催化剂用于生物油催化改质（即甲醇和苯甲醚模型化合物的脱氧）的概念验证研究。通过在80 °C下热固化沸石前体，在SiC泡沫上产生具有晶间孔隙的ZSM-5涂层。与使用ZSM-5颗粒的填充床相比，使用SiC泡沫作为沸石载体显著改善了传输现象，解释了结构化ZSM-5/SiC泡沫催化剂实现的相对良好的催化性能。与ZSM-5颗粒相比，ZSM-5/SiC泡沫催化剂在工艺的初始阶段显示出100.0%的甲醇转化率（在8 h-1的重时空速（WHSV）下）和100.0%的苯甲醚转化率（在WHSV =5 h-1下），而在相同条件下，ZSM-5颗粒仅获得约3%。通过对新鲜催化剂和待生催化剂的表征数据的对比分析，解释了ZSM-5/SiC和ZSM-5颗粒催化剂的失活机理。利用泡沫SiC负载ZSM-5的过程强化显著改善了整体气固传质，从而减轻了负载型ZSM-5外表面碳沉积造成的孔堵塞。
ZSM-5 zeolite coating supported on SiC foams was prepared by a precursor dispersion-secondary growth method and the resulting structured ZSM-5/SiC foam catalyst was used for the proof-of-concept study of catalytic bio-oils upgrading (i.e.deoxygenation of the model compounds of methanol and anisole) in reference to ZSM-5 catalyst pellets. A layer of ZSM-5 coating with inter-crystal porosity on SiC foams was produced by curing the zeolite precursor thermally at 80 °C. The use of SiC foam as the zeolite support significantly improved transport phenomena compared to the packed-bed using ZSM-5 pellets, explaining the comparatively good catalytic performance achieved by the structured ZSM-5/SiC foam catalyst. In comparison with the ZSM-5 pellets, the ZSM-5/SiC foam catalyst showed 100.0% methanol conversion (at the weight hourly space velocity, WHSV, of 8 h–1) and 100.0% anisole conversion (at WHSV =5 h−1) at the initial stage of the processes, while only about 3% were obtained for the ZSM-5 pellets, under the same conditions. Based on the comparative analysis of the characterisation data on the fresh and spent catalysts, the deactivation mechanisms of the ZSM-5/SiC and the ZSM-5 pellet catalysts were explained. The process intensification using SiC foam to support ZSM-5 improved the global gas-to-solid mass transfer notably, and hence mitigating the pore blocking due to the carbon deposition on the external surface of supported ZSM-5.