Abstract: This invention relates to a vapor phase process for the production of an alkyl styrene by the catalytic dehydrogenation of tertiary butylethylbenzene in the presence of catalysts containing iron oxides under conditions which minimize the undesirable thermal degradation of the raw material and the product while maintaining good yield and selectivity with low production of by-products. Specifically, it has been discovered that these desired results may be obtained by conducting the subject reaction at relatively low temperatures of between about 1000.degree. F. and about 1100.degree. F. and by maintaining a low partial pressure (i.e., not greater than about 0.5 psi) of the alkyl ethylbenzene in the reaction mixture. The desired partial pressure of the alkyl ethylbenzene is obtained by carrying out the catalytic reaction at a pressure of between about 1 psia and about 30 psia with steam as a diluent, the weight ratio of steam to alkyl ethylbenzene being between about 3 and about 30.

Abstract: The present invention provides an alkylation process which is highly selective towards the production of para-tertiarybutylethylbenzene in high yield and in high para isomer content, while minimizing the development of unwanted by-products and impurities during the alkylation reaction. In accordance with the process, a feed stream mixture comprising the olefin alkylating agent and a molar excess of an aromatic hydrocarbon substrate is introduced into the inlet of a reactor zone and through a bed of active zeolite alkylation catalyst under alkylation conditions such that substantially all of the olefin reacts with the aromatic substrate to produce a mixture comprising the alkylated product and unreacted aromatic compound. This mixture is continuously withdrawn from the reactor zone as reactor effluent, after which the effluent is split into a product stream and recycle stream.