Alkylation of bromobenzene with allyl acetate over zeolites: Influence of zeolite factors and reaction conditions on activity and selectivity

The influence of zeolite factors such as pore geometry (viz. H-USY, H-BEA, H-MOR, H-ZSM-5) and SUM ratio and reaction conditions such as feed flow rate (liquid hourly space velocity, LHSV = 57.6, 115, and 230 h(-1)), feed composition (molar ratio: allyl acetate/bromobenzene = 1/10, 1/20, 1/40, 1/100, and 11150) and reaction temperature (130, 150, and 170 degrees C) in the alkylation of bromobenzene with ally] acetate has been investigated. The activity and selectivity in allyl acetate to alkylated products conversion are found to be strongly influenced by the zeolite factors. Catalysts with smaller pore sizes deactivate faster due to faster pore blocking by side products. H-USY zeolites deactivate the slowest and produce the largest amount of alkylation products. The distribution for the total alkylation products (consisting of allyl bromobenzene (ABB), cis- and trans-propenyl bromobenzene (PBB) and dialkylated product (DAP)) lies around 50% over the whole allyl acetate conversion range with H-USY. H-MOR and H-ZSM-5 produce practically no primary alkylation products, but rather a large amount of side products of the alkylating agent. The conversion of ally] acetate decreases with increasing liquid hourly space velocity and allyl acetate concentration in the feed. At high concentration of allyl acetate, the formation of light components is high. Higher reactor temperatures lead to higher initial catalyst activity, but also faster deactivation and lower selectivity for alkylation products. (c) 2006 Elsevier B.V. All rights reserved.