Optimization of Process Parameters for Isopropylation of Toluene over Modified Zeolite using Response Surface Methodology

Abstract

Vapor-phase isopropylation of toluene with isopropanol has been investigated in a fixed-bed flow reactor under atmospheric pressure using N₂ carrier gas over Cerium modified 13X zeolite catalyst. The main product of this alkylation reaction was p-cymene followed by meta-isomer, while ortho-cymene was negligibly formed. Response surface methodology was used to study the combined effects of temperature, reactant molar ratio and space time on the conversion of toluene and selectivity of cymene. The isopropylation reaction was optimized using Box-Behnken design over the temperature range of

433–553 K, feed molar ratios of toluene to isopropanol between 0.5 and 6 and the space time conditions varied between 8 and 28 kg h/kg mol. It was found that mid-range values of process parameters maximized conversion of toluene and selectivity of cymene.