Linear alkylation of benzene over mesoporous aluminosilicate molecular sieves

Abstract

Linear alkyl benzenes (LAB), which are valuable industrial chemicals used in the manufacture of detergents are usually mixtures of C₁₀-C₁₃ alkyl benzenes obtained by alkylation of benzene with long chain olefins (Cio to C₁₃) over Friedel-Crafts type catalysts such as AlCl₃, BF₃, H₂SO⁴, anhydrous HF etc. (1). An important by-product obtained during the production of LAB is HAB (heavy alkyl benzenes), which is a valuable source of synthetic lube oils for special lubrication purposes. The alkylation of benzene with long chain olefins has been reported over ZSM-12 (2) and over a number of medium and wide pore zeolites (3). Hexagonal mesoporous silica (HMS) supported AlCl₃ gives enhanced selectivity for the formation of the 2-isomer (4). In the present work the alkylation of benzene with a commercial olefin mixture (C₁₀-C₁₃) over mesoporous Al-MCM-41 is reported.