超临界苯烃化催化反应中焦前物分子扩散模型的研究

Study on Diffusion Model of Multi-Aromatics in Supercritical Fluid Benzene-Alkylation Process

摘要: 通过超临界相和液相条件下苯烃化反应的实验研究和催化剂的测试分析，发现Ｙ型分子筛催化剂的失活是由于副反应的存在，在催化剂表面上生成了多环大分子生物（称为焦前物）。实验结果表明，超监介反应可以抑制催化剂的结焦，超临界相催化剂活性与液相催化剂活性相比在四倍以上。本文研究超临界流体中的分子扩散传质行为，以并四苯、并五苯和并六苯为焦前物的代表物，建立超监蛤苯烃化反应过程中焦前物粗硬球分子扩散模型。

Abstract: The results of benzene-alkylation process have been compared between supercriti-cal condition and liquid condition,The dcactivation on Y-zeolite catalyst is owing to the accumulation and further reation of multi-aromatics on the catalyst surface. Research results show that supercritical reaction technology is a good method for improving catalyst coked-deactivation process, because the activativity-life of catalyst in supercritical benzene-alkylation process is four times longer than that in liquid condition. Based on the theory of molecular fluid dynamics,the coke precursor diffusion behavior is further studied.In this paper the Rough Hard Sphere model is proposed,and coke precursor diffusion coefficient with Tetracen,Pentacen and Hexacen acting as simulation substances is calculated.