title: Evaluation of the Parameters and Conditions of Process in the Ethylbenzene Dehydrogenation with Application of Permselective Membranes to Enhance Styrene Yield.
abstract: Styrene is an important monomer in the manufacture of thermoplastic. Most of it is produced by the catalytic dehydrogenation of ethylbenzene. In this process that depends on reversible reactions, the yield is usually limited by the establishment of thermodynamic equilibrium in the reactor. The styrene yield can be increased by using a hybrid process, with reaction and separation simultaneously. It is proposed using permselective composite membrane to remove hydrogen and thus suppress the reverse and secondary reactions. This paper describes the simulation of a dehydrogenation process carried out in a tubular fixed-bed reactor wrapped in a permselective composite membrane. A mathematical model was developed, incorporating the various mass transport mechanisms found in each of the membrane layers and in the catalytic fixed bed. The effects of the reactor feed conditions (temperature, steam-to-oil ratio, and the weight hourly space velocity), the fixed-bed geometry (length, diameter, and volume), and the membrane geometry (thickness of the layers) on the styrene yield were analyzed. These variables were used to determine experimental conditions that favour the production of styrene. The simulation showed that an increase of 40.98% in the styrene yield, compared to a conventional fixed-bed process, could be obtained by wrapping the reactor in a permselective composite membrane.
authors.affiliation: School of Petroleum Engineering, Tiradentes University, 300 Murilo Dantas Avenida, 49032-490 Aracaju, SE, Brazil.
authors.forename: Paulo Jardel P
authors.initials: PJ
authors.lastname: Araújo
authors.affiliation: Institute for Research and Technology (ITP), Tiradentes University (UNIT), 300 Murilo Dantas Avenida, 49032-490 Aracaju, SE, Brazil.
authors.forename: Manuela Souza
authors.initials: MS
authors.lastname: Leite
authors.affiliation: College of Chemical Engineering, State University of Campinas, 500 Albert Einstein Avenida, 13083-852 Campinas, SP, Brazil.
authors.forename: Teresa M Kakuta
authors.initials: TM
authors.lastname: Ravagnani