24. In either case, there is reduced contact between the reactant and the catalyst, resulting in a lower styrene yield. (1993). This popularity is mainly due to its recyclable character, which is not shared by other thermoplastics. Chem. Gundersen, T. (2017). It was also observed that, in the range of reactor lengths analyzed, the styrene yield varies little, from 72.37% at 0.39 m to 72.71% at 1.2 m. This range of values is not sufficient to define an optimal reactor length. Catal. & Park, S. (2007). Chem. Comput. Energy J. 17. Heat integration indicated an insignificant reduction in the net energy demand and exergy losses, but 24% and 34% saving in external heating and cooling duties, respectively. In this simulation, the reactor inner diameters tested were those available on the market for the selected material (stainless steel), while the shortest possible reactor length was chosen because the material cost is decisive for the viability of a project. The fixed bed was filled with a permselective membrane and a thin layer of palladium. Styrene Production by Catalytic Vol. , 133, 219–239.DOI: 10.1016/0926-860X(95)00218-9. L. (1965). Pinch analysis- A state of the art overview. Enginee. To describe the transport of hydrogen through the palladium film, Sievert’s law was used (3). 1. El-Halwagi, M.M. Styrene Production, Retrieved July, 13, 2017. Based on the experimental observations two Langmuir–Hinshelwood type kinetics models are formulated. Mimura, N. & Saito, M. (2000a). This reaction is reversible and endothermic, and the maximum conversion of EB under real process conditions is limited by thermodynamic equilibrium to about 45%. However this inconvenience cannot be overcome with the configuration adopted for the membrane, as current manufacturing techniques restrict the characteristics of these layers. Recently, with improvements in the catalyst composition, the ratio of steam to oil (EB) in the feed has fallen considerably, from 20 to 6. Looks like you’ve clipped this slide to already. Simulation of an Isothermal Catalytic Membrane Reactor for the Dehydrogenation of Ethylbenzene, Chem. Abdalla, B.K., Elnashaie, S.S.E.H., Alkhowaiter, S. & Elshishini, S.S. (1994). AIChE 40(12), 2055–2059. 49(1), 51–62. AIChE, New York. Snyder, J.D. In the simulation presented in Figure 4, as expected, the best value of styrene yield was obtained (72.70%) with the thinnest macroporous layer. Novel Reverse Flow Strategy for Ethylbenzene Dehydrogenation in A Packed bed Reactor. Chem. Carra. https://content.sciendo.com uses cookies to store information that enables us to optimize our website and make browsing more comfortable for you. ISSN: 0065-7727. To analyze these, the system was simulated while they were varied within the ranges in Table 1, trying to meet the energy requirements for the process without degrading the equipment. NH3- and CO-TPD analysis, respectively reveals the availability of both acidic and basic sites. Dehydrogenation of ethylbenzene over iron oxide-based catalyst in the presence of carbon dioxide. The main route for producing styrene by dehydrogenation of ethylbenzene consumes a substantial amount of energy because of the use of high-temperature steam. (1992). Styrene production from ethyl benzene, Retrieved July 13, 2017 from (http://www.tc.bci.tu-dortmund.de/Downloads/Praktika/tc30_styrene_english.pdf. Review articles are excluded from this waiver policy. 3, 14–28, ISSN 2225–0913. 33. By simulating the process with the recommended values for each parameter, the styrene yield was raised to 40.98% higher than the yield achieved with a conventional fixed bed (52.76%). As can be seen in Figure 5, nowhere does the thickness of the stagnant gas layer approach the internal radius of the fixed bed, so the application of the film theory is valid, showing a central region that allows gas to flow through the fixed bed (within the bulk gas phase) and a surrounding region where the flow meets resistance (stagnant gas). Wall, G. (2011). Tamsilian, Y., Ebrahimi, A.N., Ramazani, S.A. & Abdollahzadeh, H. (2012). Wiley. This is ideal for the application of palladium composite membranes in industrial processes, given the very high cost of this metal. Zarubina, V. (2015). 5 h-1 ,H2O/EB(vol. Conceptual Design of Chemical Processes, McGraw Hill, New York. Ethylbenzene Dehydrogenation into Styrene: Kinetic Modeling and Reactor Simulation, Catalytic dehydrogenations of ethylbenzene to styrene. This removal was established by pressure drop of 199 kPa applied across the membrane, from retentate to permeate side of the reactor. 31. 10. Therefore, a 10 μm thick microporous layer may be recommended for this system. DeMarioDunkley By means of transient kinetic experiments the initial stages of the dehydrogenation of ethylbenzene over the fresh catalyst and after regeneration were studied in detail. Styrene is an important intermediate product in the petrochemical industry. You have been studying how to use Aspen using the example of a Styrene reactor system. Kinetics of Catalytic Dehydrogenation of Ethylbenzene to Styrene. On the reaction side the axial molar flow rate of species is controlled by its reaction rate and its rate of transport through the membrane:In adiabatic conditions, can be calculated by the enthalpy changes of the system. Therm. https://doi.org/10.1016/j.cej.2012.06.108. Proposed By: Styrene production from ethyl benzene Page 4 For personal use only ! The activity of a V 2 O 5 /TiO 2 –Al 2 O 3 catalyst for oxidative dehydrogenation of ethylbenzene to styrene with various V 2 O 5 loadings in the presence of CO 2 and N 2 was studied. Such process was conducted by removal of the hydrogen produced in the primary reaction. Vol. Sci. Five plausible kinetic models of the dehydrogenation of ethylbenzene to styrene on catalyst "315" are discriminated and screened by use of the data of the conversion of ethylbenzene and contact time measured in an integral reactor and optimal model is selected. We use cookies to help provide and enhance our service and tailor content and ads. N2 adsorption shows that the synthesized FeOx-meso-Al2O3 catalyst is mesoporous with pore size between 9 and 35 nm. Data of a commercial catalyst were used as a reference for the catalytic properties. Chem. Des. Comp. (1995). Liu Zhongqi, Yuan Yonggen, Zheng Jiazhuo, Zhao Qing, Wu Guangying,(Lanzhou Research Institute of Chemical Industry)Zhang Xinmin, Meng Yimin and Xu Yunlan(Department of Chemistry, Lanzhou University) (Lanzhou Synthetic Rubber Factory); He Danyun, Li Qingshui, Zhu Yixiang and Lin Rencun ( Department of Chemistry, Xiamen University, Xiamen 361005 ); Chen Jianping,He Danyun and Cao Shoujin (Dept of Chem,Xiamen Univ.,Xiamen); Ho Danyun Zhu Yixiang Cai Qingdie Lin Rencun (Department of Chemistry ); LIU Yan yue 1) ZHANG Jing 2) WEI Shou peng 3) ( 1)Beijing HuiLongbao Technology Development Ltd.,Cop.,Beijing 100029; 2) ChinaPetroleum Jilin Organic Chemicals Plant, Jilin 132022; 3)College of Chemical Engineering,Beijing Universit; Chen Jian-ping and He Dan-yun (Department of Chemistry and Institute of Physical Chemistry,Xiamen University); Zhang Lin Luo Xuan (Research Center of Laser Fusion,CAEP,P.O.Box 919-987 Mianyang 621900,China)Xie Rugang (Chemistry Institute of Sichuan University,Chengdu 610064,China); Cheng Wanli 1 Jiang Gengmin 2 Shan Yinsheng 2 ( 1Department of Chemical Engineering, Fuzhou University, Fuzhou, 350002) ( 2Department of Chemical Engineering, Zhejiang University, Hangzhou, 310027); Chen Jianping,He Danyun and Cao Shoujing (Department of Chemistry,Xiamen University,Xiamen); Xi Congshan, Chen Yanxiang and Zheng Jiazhuo ( Chemical Engineering Research Institute of Lanzhou Chemical Industry Corporation ); Zhu Xiaomeng;Bai Rong;Zhang Hao and Zhu Zhongnan(UNILIB Research Center of Chemical Reaction Engineering ECUST,Shanghai 200237); Chen Huizhen, He Danyuen, Xiao Zhangling, and K. R. Tsai(Department of Chemistry and Inst itute of Physical Chemistry, Xiamen University, X iamten); Xiao zhangling Zhu Yixiang He Danyun Lin Rencun (Department of Chemistry,Xiamen University)Gong Baoguo Feng Yunyong (Shanghai Gaojiao Chemical Factory); Chen Jianping He Danyun (Department of Chemistry, Institute of Physical Chemistry); ©2006 Tsinghua Tongfang Knowledge Network Technology Co., Ltd.(Beijing)(TTKN) All rights reserved. Adopting a fixed mass flow at the entrance to the reactor of 9.08 × 10−5 kgs−1, determined from the data in Tables 1 and 2, simulations were run with reactor lengths from 0.4 to 1.2 m, corresponding to volumes from 197.62 to 608.05 cm3, and the styrene yield gain (relative to the shortest reactor) was calculated for each volume. Learn more. Catal. Therefore, it was decided to analyze the fixed-bed geometry at a constant reactant feed flow rate, instead of a predetermined space velocity. Comput. 6. 136, 161–172. 113, 89–102. DOI: 10.1016/0926-860X(94)80243-2. 4, 72–77. Hence, the thinner the palladium layer, the better the styrene yield. Environmental impacts : Oil Exploration and Extraction in Nigeria, Customer Code: Creating a Company Customers Love, Be A Great Product Leader (Amplify, Oct 2019), Trillion Dollar Coach Book (Bill Campbell). Assuming that the mass transport through the macroporous support is not due to the pressure gradient but to the concentration gradient, the dusty gas model for an ideal gaseous mixture is given bywhere Knudsen’s effective diffusion coefficient of Fuller’s correlation was used to determine the binary diffusivity for the components of the process. As of this date, Scribd will manage your SlideShare account and any content you may have on SlideShare, and Scribd's General Terms of Use and Privacy Policy will apply. This improvement demonstrates the importance of determining the favourable conditions for process development. These properties are described in Table 2. (2005). J. Chem. As can be seen in Figure 2, a smaller inner diameter results in a higher styrene yield, but since radial dispersion is neglected, one must choose the smallest diameter satisfying the above restriction (0.0254 m). L. (1965). DOI: 10.1016/j.applthermaleng.2016.07.118. Copyright © 2012 Elsevier B.V. All rights reserved. (2012). In dehydrogenation reactions, palladium is used in this layer, in view of its good permselectivity to hydrogen. DOI: 10.1002/1099-0739(200012)14. DOI: 10.2174/1876387101004010072. The kinetics of ethylbenzene dehydrogenation on binary Fe2O3-K2O catalyst was studied under the reaction conditions of 580-640 ℃ ,LHSV 0. Gundersen, T. & Naess, L. (1988). DOI: 10.1016/j.cej.2012.06.108. 4, 281–285. Eng. To allow an increase in this flux it would be necessary to reduce the resistance to flow imposed by the outer layers, which means altering their properties. Heat integration analysis for an industrial ethylbenzene plant using pinch analysis. 40(12), 2055–2059. Trans. Such variables were used to optimize the yield of styrene which is related to the conversion and the selectivity to the primary reaction.

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