Butylation of toluene:: Influence of zeolite structure and acidity on 4-tert-butyltoluene selectivity

被引：17

作者：

Pai, Shivanand ^{[1
]}

Gupta, Upendranath ^{[1
]}

Chilukuri, Satyanarayana ^{[1
]}

机构：

[1] Natl Chem Lab, Catalysis Div, Pune 411008, Maharashtra, India

来源：

JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL | 2007年 / 265卷 / 1-2期

关键词：

toluene; large pore zeolites; butylation; 4-t-butyltoluene; acidity;

D O I：

10.1016/j.molcata.2006.09.046

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Vapour phase alkylation of toluene with tert-butyl alcohol was studied over the large pore zeolites H beta, HY and HMCM-22. The influence of the acidity, reaction temperature, run duration, feed rate (WHSV) and molar ratio of the reactants on conversion of toluene and selectivity for 4-tertbutyl toluene was studied. Among the isomers formed during the reaction, the para-isomer was the predominant one, followed by the meta-isomer, while no ortho-isomer was found in the products due to steric factors. 4-tert-Butyl toluene selectivity decreases at higher temperatures, while going through a maximum in the 413-433 K temperature range. Zeolite HY with a high silica to alumina ratio (SiO2/Al2O3 = 80), that has strong acidity, but lower acid site density, possesses high activity for toluene conversion, high alkylation selectivity and also high para-selectivity. The improved para-selectivity of high silica HY zeolite is attributed to the low isomerization activity that results in the suppression of the secondary isomerization of 4-tert-butyl toluene. Both alkylation and selectivity are higher with feed mixtures containing a lower fraction of tert-butyl alcohol. (c) 2006 Elsevier B.V. All rights reserved.

引用

页码：109 / 116

页数：8

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