Synthesis of linear alkylbenzene catalyzed by Hβ-zeolite

For the alkylation of benzene with long-chain olefins, Hbeta-zeolite catalyst not only has the advantages of high selectivity to 2-phenyl isomers with no corrosive or environmental problems, but it also can be regenerated repeatedly. The characterization of the coke shows that the deactivation of catalysts is caused by a jam of bulkier molecules, such as naphthalene, indane and linear alkylbenzenes, which are too big to move quickly in the intracrystalline pores of the catalysts. These bulkier molecules deposit in intracrystalline pores and then in larger pores. The aromatic compounds in raw olefins must be removed because they can deactivate the catalyst quickly; the moisture in the reactants should be 20-30 ppm. The deactivated catalyst can be regenerated by benzene washing at higher temperature. New species, such as alkylbenzene with short chains, naphthalene, indane, biphenyl, condensed ring compounds and unsaturated compounds, are formed by cracking and cyclization in the regeneration process. (C) 2002 Elsevier Science B.V. All rights reserved.