【摘要】 在脉冲微反装置上,以4种C₈烷烃异构体为探针分子,系统地考察了它们在晶粒大小不同的zSM-5分子筛上的裂化反应行为。实验数据用Thiele模数加以关联,并求出效率因子,从而得知晶粒内扩散对反应的影响。还考察了分子筛的外表面、酸性、大晶粒分子筛的硅铝比分布以及反应物的不可逆吸附。研究结果表明.烃类裂化反应受到分子筛晶粒内扩散的影响,且其程度随着反应温度的升高而增大,随着支链的增加而增加。更多还原

【Abstract】 The catalytic cracking characteristics of four C₈ paraffin isomers on ZSM-5 molecular sieves were studied with a pulse microreactor. ZSM-5 Molecular sieves with sirniliar physicochernical properties but different crystal sizes were chosen to investigate the effects of the intracrystal diffusion. In association with diffusion, the outer surface, acid properties, the distribution of SiO₂/Al₂O₃ ratio and the irreversible adsorption of reactants were studied. The results show that the cracking of hydrocarbons is affected by the intracrystal diffusion, the influence is increased with temperature and branching degree of the reactants.更多还原