Alkylation of Benzene with Linear Oiefins over Zeotile Based Catalysts

Abstract

Liquid phase alkylation of benzene with 1-decene as a model reaction was performed over series of zeolites catalysts, containing 30% Al2O3 as a binder, in a fixed bed reactor. Among the various zeolite catalysts, Zeolite-Y having SAR of 12 was found to be the most active and it showed better conversion and required 2-phenyl isomer content in the product. In the lab scale reactor, we have screened alkylation of benzene with 1-decene at various temperatures, 100-150 oC, molar feed ratios (benzene:1-decene) 5-20, zeolite SAR 9-30 and WHSV 1-2 gh-1 under N2 pressure of 10 kg/cm2, to achieve maximum olefin conversion, appropriate 2-phenyl isomer selectivity with less formation of heavier alkylates. The optimum reaction conditions of 130 oC, benzene/olefin molar ratio of 15, WHSV 1.5 gh-1 and time on stream 7 h, the highly active Zeolite-Y (HY-12) showed more than 85% of olefin conversion with 30% 2-phenyldecane selectivity. Based on the out come of lab scale studies, the more active and stable HY-12 was further evaluated in pilot plant using the olefin feeds having mixture of C10-C14 (commercially used alkylation feed for LAB manufacturing). The conversion of olefin reaches almost 100% with 2-phenyl isomer selectivity of 21-23% over HY-12. The formation of heavier alkylates was observed to certain extent over the period of reaction time. Magnesium and Zinc exchanged H–Y zeolites were prepared by simple ion exchange methods with the scope of controlling heavier alkylate formation. The Magnesium exchanged HY-12 sample retain the catalytic activity as similar to HY-12 with significant improvement in reduction of heavier alkylate formation. Introduction of zinc results in lower olefin conversion with fast deactivation of catalyst.