02067nas a2200229   4500008004100000022001400041245010500055210006900160260007300229300001200302490000800314520122600322653002101548653001201569653001501581653002401596653001201620100001901632700002301651700003301674856013001707       2007                        eng d  a1381-116900aButylation of toluene: influence of zeolite structure and acidity on 4-tert-butyltoluene selectivity0 aButylation of toluene influence of zeolite structure and acidity  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR  a109-1160 v2653 a<p>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.</p>10a4-t-butyltoluene10aAcidity10abutylation10alarge pore zeolites10aToluene1 aPai, Shivanand1 aGupta, Upendranath1 aChilukuri, Satyanarayana, V.  uhttps://library.ncl.res.in/content/butylation-toluene-influence-zeolite-structure-and-acidity-4-tert-butyltoluene-selectivity