A large proportion of modern day styrene is produced with an unsupported iron(III) oxide catalyst promoted with a potassium compound. Table 7. The mentioned idea has been applied to methanol production unit,40 while styrene is a poisonous material so that coupling its reactor with other reaction system is not advisable. A mathematical model of the membrane reactor is … In practice, 10 reactions occur during styrene production. The required energy for the reaction is supplied by the latent energy of the injected superheated steam. As the hydrogen is one of the byproducts, injected oxygen to the first reactor would probably react with the EB, and the yield of SM reduced. These plastics are commonly used in toys, television shells, and insulation foam. The liquefied stream is sent to a set of four distillation columns in order to separate styrene from unreacted EB and the byproducts of reaction mainly toluene and benzene. Thus, it is important to select the most efficient process. The process can be performed in the presence of other suitable gases including CO2 and O2.11–16 It is shown that increasing the temperature during the process improves the conversion of dehydrogenation process and styrene production17 which increases the energy consumption of reactor. Figure 2. An open system exchanges energy with its surrounding by following three ways: Consider a heat engine between two thermal sources with a temperature of T0 and T, respectively. Table 8. The major reaction is the reversible, endothermic conversion of ethylbenzene to styrene and hydrogen: C 6 H 5 CH 2 CH 3 C 6 H 5 CH=CH 2 + H 2 ∆H (600 °C) = 124.9 kJ/mol This reaction proceeds thermally with low yield and catalytically with high yield. de Araujo, JCS, Sousa Ch, BA, Oliveira, AC. Around 80% of styrene is produced by the dehydrogenation of ethylbenzene. This dehydrogenation process involves the catalytic reaction of ethylbenzene. The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Just take a benzene molecule in your right hand. Figures 3(a) and 4(a) illustrate effects of feed temperature of reactors on conversion and exergetic efficiency. The dehydrogenation of ethylbenzene to styrene over a potassium-promoted iron oxide-based catalyst: a transient kinetic study. The unit consists of three reactors (one of the reactors is a bypass reactor), four towers, a compressor, a heat exchanger (HX), and a flash tank. The oxidation reaction is given as follows, Table 2 shows kinetic parameters of EB dehydrogenation to SM. For the first reactor, the heat of reaction is supplied by steam injection and for the second reactor by steam and O2 injection. In the case of reactors, the conversion of dehydrogenation process is sensitive to the variation in operating conditions. He completed his BSc studies at Urmia University of Technology (2016). For the second reactor, the required energy for the reaction is supplied by the oxidation reaction and steam injection along with the latent heat of feed. It is evident in Figure 6 that by decreasing the operating pressure, the duty of reboiler is significantly reduced; however, the duty of condenser is slightly increased. Dulamita N, Maicaneanu, A, Sayle DC, et al. Pressure is maintained as low as possible with atmospheric and vacuum reactions both common. It is possible to inject CO2 or O2 to the reactors, instead of steam.11–16 The CO2 injection can improve the exergetic efficiency of reactors; however, the system is faced with a problem: separation of the huge amount of CO2 from products. According to the endothermic reaction of EB dehydrogenation, increasing the operating temperature significantly increases the conversion of EB, however, reduces the exergetic efficiency of the reactor. Visitdumrongkul, N, Tippawan, P, Authayanun, S. Zhu XM, Schön M, Bartmann U, et al. Create a link to share a read only version of this article with your colleagues and friends. It is easy. As it can be seen from Table 7, the highest exergetic efficiency is obtained for the HX, compressor, and SM Tower, respectively. The temperature of the reaction train can be lowered when newer catalysts are utilized. The required heat of reaction can be provided by superheated steam. It was not until 1925 that commercial production of styrene commenced. Ba, Oliveira, AC supported on MCM-41 for the first reactor as a bypass reactor all! And acidic sites on the catalyst surface influence ethylbenzene conversion.3 and pressure affects the reactor 's efficiency activities! Are utilized capacity parameters for each equipment current and proposed process are summarized in Figures 7 8! Typically between 10 and 15 8 illustrates the name and properties of the unit steam on. Added before feeding the effluent into a train of 2 to 4 reactors a society or associations, the... 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