Probing deactivation by coking in catalyst pellets for dry reforming of methane using a pore network model  

作　　者：Yu Wang Qunfeng Zhang Xinlei Liu Junqi Weng Guanghua Ye Xinggui Zhou 

机构地区：[1]State Key Laboratory of Chemical Engineering,School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China

出　　处：《Chinese Journal of Chemical Engineering》2023年第3期293-303,共11页中国化学工程学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (22078090 and 92034301);the Shanghai Rising-Star Program (21QA1402000);the Natural Science Foundation of Shanghai (21ZR1418100);the Open Project of State Key Laboratory of Chemical Engineering (SKL-ChE-21C02)。

摘　　要：Dry reforming of methane(DRM) is an attractive technology for utilizing the greenhouse gases(CO_(2) and CH_(4)) to produce syngas. However, the catalyst pellets for DRM are heavily plagued by deactivation by coking, which prevents this technology from commercialization. In this work, a pore network model is developed to probe the catalyst deactivation by coking in a Ni/Al_(2)O_(3) catalyst pellet for DRM. The reaction conditions can significantly change the coking rate and then affect the catalyst deactivation. The catalyst lifetime is higher under lower temperature, pressure, and CH_(4)/CO_(2) molar ratio, but the maximum coke content in a catalyst pellet is independent of these reaction conditions. The catalyst pellet with larger pore diameter, narrower pore size distribution and higher pore connectivity is more robust against catalyst deactivation by coking, as the pores in this pellet are more difficult to be plugged or inaccessible.The maximum coke content is also higher for narrower pore size distribution and higher pore connectivity, as the number of inaccessible pores is lower. Besides, the catalyst pellet radius only slightly affects the coke content, although the diffusion limitation increases with the pellet radius. These results should serve to guide the rational design of robust DRM catalyst pellets against deactivation by coking.

关 键 词：Deactivation by coking Dry reforming of methane Pore network model Diffusion limitation Catalyst pellet 

分 类 号：TE665.3[石油与天然气工程—油气加工工程] TQ426[化学工程]