石油化工高等学校学报2011，Vol.24Issue(5)：1-5,5.DOI:10.3696/j.issn.1006-396X.2011.05.001
重油在催化剂中的有效扩散系数及扩散受阻因子
Effective Diffusion Coefficient and Restricted Diffusion Factor of Heavy Oil in Catalysts
摘要
Abstract
Through the measured effective diffusion coefficient of Dagang vacuum residue supercritical fluid extraction and fractionation (SFEF) fractions in FCC catalysts and SiO2 model catalysts the restricted diffusion factor was calculated. The restricted diffusion factor in FCC catalysts is less than 1 and it is 2~3times larger in large pore catalyst than in the conventional FCC catalyst. The results show that the diffusion of SFEF fractions in the two FCC catalysts is restricted by the pore. When the average molecular diameter is less than 1. 8 nm, the diffusion of SFEF fractions in SiO2 model catalyst which average pore diameter bigger than 5. 6 nm is unrestricted. The diffusion is restricted in the catalyst pores of less than 8 nm for SFEF fractions which diameter more than 1. 8 nm. The tortuosity factor of SiO2 model catalyst was obtained to be 2. 87, within the range of empirical value. The effective diffusion coefficient of the SFEF fractions in SiO2 model catalyst was two orders of magnitude bigger than that in FCC catalyst with the same average pore diameter. It indicates that besides the ratio of molecular diameter to the pore diameter A, the effective diffusion coefficient is also closely related to the pore structure of catalyst. Because SiO2 model catalyst has uniform pore size, the diffusion coefficient can be precisely correlated with pore size of catalyst, so it is a good model material for catalyst internal diffusion investigation.关键词
渣油/FCC催化剂/SiO2模型催化剂/有效扩散系数/扩散受阻因子Key words
Residue/ FCC catalyst/ SiO2 model catalyst/ Effective diffusion coefficient/ Restricted diffusion factor Corresponding author.分类
能源科技引用本文复制引用
刘子媛,陈胜利,董鹏,葛秀军,孙昱东..重油在催化剂中的有效扩散系数及扩散受阻因子[J].石油化工高等学校学报,2011,24(5):1-5,5.基金项目
国家重点基础研究发展规划'973'计划项目(2004CB217808) （2004CB217808）
国家杰出青年科学基金项目(20725620). （20725620）
