Development of a green LAB process: alkylation of benzene with 1-dodecene over mordenite

Abstract

This work examines the linear alkylbenzene (LAB) production reaction by alkylation of benzene with 1-dodecene over a commercial mordenite, containing 30% Al₂O₃ as a binder, in a fixed bed reactor. The effects of various steam pretreatments on the properties of mordenite were studied in the LAB reaction and characterized by means of temperature programming desorption of ammonia. It was found that with steam pretreatment at 10.7 kPa partial pressure, the mordenite catalyst has a maximum acidity and activity, selectivity of 98% LAB product with 67% 2-phenyl isomer and stability beyond 600 hours operation. In the proposed reaction pathway, the isomer selectivity and catalytic stability were attributed to the result of product shape selectivity from zeolite pore structures and the comparative reaction rate of isomerization and alkylation of 1-dodecene, in which alkylation was catalyzed by strong acid sites. The extent to which external (liquid–solid) and internal (pore diffusion) mass transfer affects the main reaction was also carefully examined. Furthermore, in benzene enriched feeds, the LAB reaction was found to be first order with respective to 1-dodecene, with an apparent activation energy of 17 kcal mol⁻¹.