Alkylation of benzene with dodecene. The activity and selectivity of zeolite type catalysts as a function of the porous structure

LAB (Linear Alkyl Benzene) isomers were obtained by the alkylation of benze ne with 1-dodecene over FAU, BEA and EMT zeolites in the presence of decane as solvent. The initial activities were compared by fitting the kinetics early data wit h a pseudo first order law in dodecene. These were in agreement with those determined from the slope of the conversion versus time curve at zero conve rsion. The activity and stability were discussed in terms of the residual Na+ cont ent, Si/Al ratio and porous structure of the catalysts. The selectivity to the most desired 2-phenyl dodecane isomer was found to increase with increa sed porous constraints. Yields in the preferred isomer over BEA catalysts w ere very close to those provided by the FAU open structure catalysts in spi te of a much lower conversion over BEA catalysts. Deactivation affected not only the alkylation reaction, but the isomerisation of the olefin as well, over BEA catalysts. (C) 1999 Elsevier Science B.V. All rights reserved.