Disproportionation and transalkylation of alkylbenzenes over zeolite catalysts

Disproportionation and transalkylation are important processes for the interconversion of mono-, di-, and tri-alkylbenzenes. In this review, we discuss the recent advances in process technology with special focus on improvements of para-isomer selectivity and catalyst stability. Extensive patent search and discussion on technology development are presented. The key criteria for process development are identified. The working principles of para-isomer selectivity improvements involve the reduction of diffusivity and the inactivation of external surface. In conjunction with the fundamental research, various practical modification aspects particularly the pre-coking and the silica deposition techniques, are extensively reviewed. The impact of para-isomer selective technology on process economics and product recovery strategy is discussed. Furthermore, perspective trends in related research and development are provided. (C) 1999 Elsevier Science B.V. All rights reserved.