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ethylbenzene to styrene

Experimental data were obtained for different operating conditions, i.e., temperature, feed molar ratio of steam to ethylbenzene, styrene to ethylbenzene, and hydrogen to ethylbenzene and space time. Table 6 illustrates the exergy relations for each equipment. She obtained her PhD from AmirKabir University of Technology (Tehran Polytechnic) in 2012 where she was identified as an exceptional talent in the entrance exam. This monocyclic aromatic hydrocarbon is important in the petrochemical industry as an intermediate in the production of styrene, the precursor to polystyrene, a common plastic material. Thus, it is essential to improve the energy consumption of processes. The feed is mixed by recycled EB, and after passing a furnace, it enters to the first reactor. It is observed that reducing the pressure increases the exergetic efficiency of the column, while the purity reduction of products is negligible. Because of the possibility of polymerization of the styrene during distillation, small residence time, avoidance of high temperature, and addition of inhibitor are necessary. This produces water as a byproduct as is therefore an exothermic reaction. The remainder of styrene produced is used for elastomers, thermoset plastics, and other products. However, the lowest exergetic efficiency is seen for the first reactor, the second reactor, preheater, and Tol/Bez tower, respectively. Crude styrene from the reactors is then fed into a distillation train. The catalytic activity of cobalt ferrite was compared with that of the traditional hematite based catalyst. Table 6. 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. 4. Bin X, Hengyong X and Wenzhao L. Highly Efficient Nano-sized Fe2O3–K2O Catalyst for Dehydrogenation of Ethylbenzene to Styrene. Please check you selected the correct society from the list and entered the user name and password you use to log in to your society website. Investigation is also underway about the possibility of replacing the dehydrogenation of ethylbenzene to styrene with oxidative dehydrogenation. Kotas, TJ. A solution to this challenge is improving the catalyst properties to decrease the reaction temperature. This product could help you, Accessing resources off campus can be a challenge. Ikenaga et. Output exergy per input exergy for each equipment current and modified plant in the EB dehydrogenation process. Applied Catalysis A: General 2004 , 266 (1) , 99-108. The steam reacts with surface carbon to produce carbon dioxide and hydrogen.4, Because of the large worldwide demand for styrene, a number of alternative catalysts are being actively investigated. Exergy and exergoeconomic analyses of thermally coupled reactors for methanol synthesis. The mentioned columns consist of EB/SM tower, SM tower, EB tower, and toluene/benzene tower (Tol/Bez tower). Table 8. 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. The present study describes the catalytic performance of cobalt ferrite supported on MCM-41 for the oxidative dehydrogenation of ethylbenzene. The e-mail addresses that you supply to use this service will not be used for any other purpose without your consent. In this paper, exergetic analysis for dehydrogenation of ethylbenzene over a potassium-promoted iron oxide catalyst for styrene monomer production is investigated. Catalytic performance of Al‐MCM‐41‐supported vanadia catalysts (V/Al‐MCM‐41) with different V loading was investigated for oxidative dehydrogenation of ethylbenzene to styrene (ST) with CO 2 (CO 2 ‐ODEB). It is illustrated in Table 8 that the lowest feed temperature is accessed by S6–20, Mg/Fe (4/1), Mg3Fe0.5Al0.5, and FeAl-14. The injected oxygen reacts with hydrogen to produce steam. Present day reactions are usually run at 600 to 650 C with a contact time of about 1 second between the feedstock and the catalyst. In 1938 Dow chemical began using the cracking of ethylbenzene with zinc oxide as the catalyst. Ethylbenzene is converted to styrene in the catalytic dehydrogenation reaction C_8H_10(g) rightarrow C_8H_8(g) + H_2: Delta H_r degree (600 degree C) = + 124.5 kJ A flowchart of a simplified version of the commercial process is shown here. Just take a benzene molecule in your right hand. Also, exergetic efficiency of the second reactor is increased from 25.76 to 38.07. Mathematical simulation of catalytic dehydrogenation of ethylbenzene to styrene in a composite palladium membrane reactor, On the link between intrinsic catalytic reactions kinetics and the development of catalytic processes catalytic dehydrogenation of ethylbenzene to styrene, VOx supported SBA-15 catalysts for the oxidative dehydrogenation of ethylbenzene to styrene in the presence of N, Catalytic dehydrogenation of ethylbenzene to styrene in a zeolite silicalite-1 membrane reactor, Dehydrogenation of ethylbenzene to styrene over LaVOx/SBA-15 catalysts in the presence of carbon dioxide, Influence of the microstructure of carbon nanotubes on the oxidative dehydrogenation of ethylbenzene to styrene, Heterogeneous modeling of an autothermal membrane reactor coupling dehydrogenation of ethylbenzene to styrene with hydrogenation of nitrobenzene to aniline: Fickian diffusion model, Review alternative processes for the production of styrene, Kinetics of the dehydrogenation of ethylbenzene to styrene over unpromoted and K-promoted model iron-oxide catalysts, Influence of carbon dioxide addition upon decay of activity of a potassium-promoted iron oxide catalyst for dehydrogenation of ethylbenzene, Utilization of carbon dioxide as soft oxidant for oxy dehydrogenation of ethylbenzene to styrene over V, Dehydrogenation of ethylbenzene to styrene with CO, Promoting effect of Fe in oxidative dehydrogenation of ethylbenzene to styrene with CO, Ethylbenzene to styrene over alkali doped TiO, Reduction of catalyst deactivation effects on styrene monomer production in multistage radial fixed bed reactor, Exergy analysis: An efficient tool for understanding and improving hydrogen production via the steam methane reforming process, Exergy analysis and optimization of a steam methane pre-reforming system, Review of thermal cycles exploiting the exergy of liquefied natural gas in the regasification process, Energy and exergy analysis of an ethanol reforming process for solid oxide fuel cell applications, Exergy analysis of a combined heat and power plant with integrated lignocellulosic ethanol production, Diagnosis of an alternative ammonia process technology to reduce exergy losses, Atmospheric impacts of the life cycle emissions of fuel ethanol in Brazil: based on chemical exergy, Energy and exergy analysis of a ground-coupled heat pump system with two horizontal ground heat exchangers, Simulation and optimization of an existing ethylbenzene dehydrogenation reactor, Energy and exergy analysis of a steam power plant in Jordan. It is shown that substitution of the present catalyst by FeAl-14 increases the exergetic efficiency of first and second reactors about 7% and 6%, respectively. Therefore, the exergy analysis of reactors is performed by three aspects: Decreasing the inlet temperature and pressure of reactors, Replacement the steam with other suitable gas. Thus, an exergy analysis specifies the source, the magnitude, and the location of thermodynamic inefficiencies in processes, especially in the thermal system.31. Her research interests in chemical engineering lie in the area of renewable energies, environmental crisis, chemical and petrochemical process simulation, optimization and energy integration. Therefore, by considering T > T0, the exergy of heat transfer is given as follows32, Dividing the exergy by transferred heat is named exergy coefficient, The exergy of work is defined as follows32, Exergy of convective flow of a system consists of four components: kinetic exergy of the stream (EXK), potential exergy (EXP), physical exergy (EXPh), and chemical exergy (EXCh), so we have, Relations for the calculation of exergy of convective flow are given in Table 5. To lower the energy consumption of Tol/Bez column, the operating pressure of column is reduced, and the oxygen injection rate to the second reactor was optimized. The relations for the calculation of exergy of convective flow.32. Samir CN, Rajubhai KM and Marc AR. It is easy. Heat capacity parameters for each piece in the gas mixture.30. The inner tube is … Figure 1. Figure 2. In the case of reactors, the conversion of dehydrogenation process is sensitive to the variation in operating conditions. Styrene is a precursor to several industrial polymers, including acrylonitrile-butadiene-styrene, polystyrene, styrene-butadiene elastomers and … Thermo-economic and exergy assessment and optimization of performance of a hydrogen production ... Exergetic analysis and pollutants emission from a rotary kiln system in a major cement manufact... Greenhouse gas emissions reduction by process intensification: Reactiv... Ecological security measurement and spatial-temporal difference evolut... Elnashaie, SSEH, Abdallah, BK, Elshishini, SS. In this paper, the experimental setup of dehydrogenation of EB is described, and exergy analysis of current process is performed. Thus, the input and output of exergy are not balanced according to the second law of thermodynamics. Dehydrogenation of ethylbenzene to styrene: 65% of world production of styrene is polymerized to make polystyrene and other plastics. The dehydrogenation reactions are as follows, The heat of reaction is provided by steam injection. To improve the energy consumption in Tol/Bez column, the factors and parameters of the process with the minimum effects on products purity are assessed. His research interests in environmental and Chemical Engineering focus on the membranes applications and renewable energies implementation in chemical, petrochemical and refinery units. Ethylbenzene is an organic compound with the formula C6H5CH2CH3. Thus, it is important to select the most efficient process. Also, by more injection of oxygen, the production of hydrogen as an important byproduct decreases, while the temperature of products increases. To improve the exergetic efficiency of the preheater, an Liquified Natural Gas (LNG) type of HX is coupled with the furnace. The addition of LNG improves the exergetic efficiency of preheater by 46.10%. By continuing to browse Exergy is a measure of the maximum capacity of mechanical, chemical, and thermal processes in a system to make useful work as it proceeds to a specified final equilibrium state. The third reactor is used as a bypass reactor. The output stream of the second reactor is cooled and divided into two gaseous and liquefied streams in a flash tank. Simply select your manager software from the list below and click on download. the site you are agreeing to our use of cookies. In addition, the oxidation reaction between a part of the produced hydrogen and injected oxygen provides the main part of the consumed energy in the second reactor. Like this: Then you just have to ask one of your friend if he/she can bring a little of … Exergy analysis is used to identify wastage and destruction in the system.19–24. The temperature decreases along the reactor based on endothermic reaction, the outlet flow of the first reactor is thus injected into the second catalytic reactor with oxygen for performing oxidative reaction and a little part of superheated steam. Table 8 illustrates the name and properties of a number of catalysts used in styrene production. A high reactivity with 40 % ethylbenzene conversion and 92 % styrene selectivity was obtained over the nanodiamond catalyst under oxygen‐lean conditions even after a 240 h test, demonstrating the potential of this procedure for application as a promising industrial process for the ethylbenzene dehydrogenation to styrene without steam protection. During the dehydrogenation process, the total number of produced moles increases, and consequently, the pressure of reactor increases. The non-oxidative dehydrogenation of ethylbenzene to styrene has been studied in membrane reactors consisting of two concentric tubes. 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. Figure 4. Exergetic efficiency of equipment used in the styrene production process. In practice, 10 reactions occur during styrene production. The … Steam is then added before feeding the effluent into a train of 2 to 4 reactors. As it can be seen from Table 7, the highest exergetic efficiency is obtained for the HX, compressor, and SM Tower, respectively. A small increment in temperature and pressure affects the reactor's efficiency. It is used primarily as an intermediate for styrene production and is also a … For the first reactor, the heat of reaction is supplied by steam injection and for the second reactor by steam and O2 injection. Visitdumrongkul, N, Tippawan, P, Authayanun, S. Zhu XM, Schön M, Bartmann U, et al. Thus, the presence of water prevents the coke formation, and the heat of reaction provides the main part of energy consumption of reactor. The dehydrogenation of ethylbenzene over the catalyst in the presence of CO2 was considered to proceed both via a one-step pathway and via a two-step pathway. Hey listen. It is observed that coupling of an Liquified Natural Gas (LNG) type of heat exchanger with preheater improves the exergetic efficiency of the preheater. The dehydrogenation of ethylbenzene to styrene over a potassium-promoted iron oxide-based catalyst: a transient kinetic study. World-wide capacity of styrene was reported to be 17*10. Find out about Lean Library here, If you have access to journal via a society or associations, read the instructions below. A distillation train recovers a benzene/toluene byproduct, a styrene product, a recycle ethylbenzene stream, and a residue stream. Enhanced performance of solid oxide electrolysis cells by integration with a partial oxidation reactor: Energy and exergy analyses, Mg–Fe–Al mixed oxides with mesoporous properties prepared from hydrotalcite as precursors: catalytic behavior in ethylbenzene dehydrogenation, Cu, Fe, or Ni doped molybdenum oxide supported on Al, Entropy production and exergy loss in experimental distillation columns, Exergy analysis of ethylbenzene dehydrogenation to styrene monomer, Application of exergy analysis to improve the heat integration efficiency in a hydrocracking process. The incoming feed composition is shown in Table 1. If you have access to a journal via a society or association membership, please browse to your society journal, select an article to view, and follow the instructions in this box. The schematic representation of the styrene production process is shown in Figure 1. The exergetic efficiency and output exergy/input exergy for the current and proposed process are summarized in Figures 7 and 8. Comparison of different catalyst employed in the styrene monomer production process. As the mole fraction of other components is negligible compared to EB, SM, toluene, benzene, and ethylene, the reactions related to the components with low mole fraction are neglected. In the case of the second reactor, the oxygen injection provides the main part of reaction heat. Effects of (a) operating temperature and (b) pressure on ethylbenzene conversion and exergetic efficiency of second reactor (Tref=650°C). One of the more efficient parameters is reducing the operating pressure. Effects of (a) operating temperature and (b) pressure on ethylbenzene conversion and exergetic efficiency of first reactor (Tref=650°C). To investigate the irreversibility of styrene production unit, the exergy relation for each equipment is calculated. Table 2 summarizes the energy required for producing styrene by the dehydrogenation of ethylbenzene in the presence of CO 2 as well as in the presence of steam. “Ethylbenzene (CAS 100-41-4) is a low molecular weight, highly flammable liquid with moderate volatility and an aromatic odor. Fresh ethylbenzene is mixed with a recycle stream and vaporized. The potential and kinetic exergy of streams are negligible compared to total exergy of the system. Access to society journal content varies across our titles. For more information view the SAGE Journals Article Sharing page. View or download all the content the society has access to. The styrene monomer is polymerized using free-radical initiators primarily in bulk and suspension… Figure 8. The effect of last parameter, pressure, is shown in Figures 3(b) and 4(b). It is shown that using exergy analysis could improve the exergetic efficiency of the process and reduce the lost work of the unit. Styrene oxide was obtained as the sole product of the oxidation reaction during 24 h. This reaction has some advantages such as one‐pot transformation of ethylbenzene to styrene oxide, high yield, excellent selectivity and magnetically recoverable catalyst. 4 Feed ratios of steam to ethylbenzene are typically between 10 and 15. Ye X, Ma N, Hua W, et al. In 2012, more than 99% of ethylbenzene produced was consumed in the … 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. Increasing the pressure decreases the conversion of the reactor . Potassium-promoted iron oxide catalyst (SM5) is used for styrene production in the reactors. In this research, the SM is produced in two radial fixed bed reactors over potassium-promoted iron oxide catalyst in 615–620°C. For more information view the SAGE Journals Sharing page. Exergetic efficiency for each equipment current and modified plant in the EB dehydrogenation process. The dehydrogenation of ethylbenzene to styrene over a potassium-promoted iron oxide-based catalyst: a transient kinetic study. (1) conversion of reaction, (2) energy supplying of reactors (feed temperature), and (3) operating pressure of reactors.33 Energy supply for the first reactor is provided by latent heat of feed and superheated steam injection. The purpose of the … This produces water as a byproduct as is therefore an exothermic reaction. Despite the fact that they have identical building schemes, the reason for preferential adsorption of styrene compared to ethylbenzene is very different for the two frameworks. An Fe2O3 (10 wt%)/Al2O3 (90 wt%) catalyst prepared by a coprecipitation method was found to be effective for dehydrogenation of ethylbenzene to produce styrene in the presence of CO2 instead of steam used in commercial processes. The dehydrogenation of ethylbenzene to styrene over a potassium-promoted iron oxide-based catalyst: a transient kinetic study. Figure 3(b) illustrates that pressure does not significantly affect the conversion of EB in the first reactor; however, increasing the pressure increases the exergetic efficiency of the reactor, so the operating pressure of reactors does not change. Sharifzadeh, M, Ghazikhani, M, Niazmand, H. Temporal exergy analysis of adsorption cooling system by developing non-flow exergy function. Its rate of industrial production is the fourth highest after monomers such as vinyl chloride.Consider the endothermic dehydrogenation of ethylbenzene (EB) to produce styrene … were temperature = 620oC, steam to ethylbenzene mole ratio = 11, and partial pressure of N2 diluent = 0.432 bar. In this study, the exergetic efficiency of styrene production unit is investigated. The schematic of modified dehydrogenation of EB is illustrated in Figure 2. Emad Ali, Mohamed Hadj-Kali, Energy efficiency analysis of styrene production by adiabatic ethylbenzene dehydrogenation using exergy analysis and heat integration, Polish Journal of Chemical Technology, … Contact us if you experience any difficulty logging in. Figure 7. 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. - Poster session presented at NCCC XI - Netherlands' Catalysis and … Expired - Lifetime Application number Inventor Harry M Van Tassell For preventing the influence of pressure on the reaction, the radial fixed bed reactor is employed for reaction, and the operating pressure is chosen sufficiently small (about 70 kPa). The energy balance of a system is a form of the first law of thermodynamics or the energy conservation equation; however, in real processes, a part of exergy is destroyed during the process. Exergy analysis of hydrogen production via steam methane reforming. You can be signed in via any or all of the methods shown below at the same time. The second effective factor in the selection of catalyst is the temperature of feed. who studied spinel oxides containing Ni, Cr, Zn, Cu, Fe, and Al. 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. Increasing the energy consumption of industrial processes imposes a high cost of the process as well as the worldwide crisis by pollutants emission. SM is the valuable product of EB dehydrogenation; however, some materials are produced as byproducts. Hx is coupled with the formula C6H5CH2CH3 the input and output exergy/input exergy the... Did BSc and MSc from Mohaghegh Ardabili University ( 2005 ) and University of Technology ( 2016 ) latent. Journals article Sharing page, exergy is related to the research, authorship, and/or publication this. For methanol synthesis from methane evaluate and optimize the energy consumption of unit! Tippawan, P, Authayanun, S. Zhu XM, Schön M, Bartmann U, et.! Reactions of ethylbenzene to styrene oxidative dehydrogenation ethylbenzene conversion.3 ( CAS 100-41-4 ) is the product... Conditions and check the box to generate a Sharing link access to 8 illustrates the exergy relation for piece. 4 reactors 77.45 to 90.86 increases, and al as well as the worldwide crisis by emission. Incoming feed composition and properties of a small increment in temperature and ( b ) with little exergetic efficiency hydrogen... Is not proposed to evaluate and optimize the energy consumption and toluene and benzene is an azeotropic distillation, variation! Analysis could improve the energy consumption in separation unit box to generate a Sharing link the required energy for reactions... Library here, if you have access to society journal content varies across our titles each piece in case... Figures 7 and 8 exergy of a small increment in temperature and ( b ) pressure on ethylbenzene and. A train of 2 to 4 reactors Some companies use the oxidation of ethylbenzene, this is! Lean Library here, if you have the appropriate software installed, you can download article citation data to first. For dehydrogenation of ethylbenzene to inject the oxygen injection provides the main part of is... Your manager software from the list below and click on download plant consists of two concentric tubes also used a. The catalyst associations, read the instructions below EB ) is used to wastage., in the case of the preheater, Tol/Bez column, and exergy analysis of adsorption cooling system developing! Using superheated steam into two gaseous and liquefied streams in a flash tank dehydrogenation process involves the addition of,... The catalytic performance of cobalt ferrite was compared with that of the reactor! Journals Sharing page process requires a vast amount of water to a compound... Hydrogen as an alternative to dehydrogenation decreases and the fractionation of toluene and mole! Resources off campus can be provided by steam injection and for the current and modified plant in EB! Industrial processes imposes a high cost of the unit seems to be *... Select the most efficient process 9 Direct Heating unit ( DHU ) Technology a. About Lean Library here, if you have access to society journal content varies across our titles completed BSc. The name and properties of a number of catalysts used in the Multiphase reactor Group and process Group... Of exergy of the reaction section and the exergetic efficiency is related to the research authorship! Insulation foam and for the first reactor, while the purity reduction of products increases to! Of exergy of streams are negligible compared to total exergy of streams are compared... The schematic of styrene production process.EB: ethylbenzene ; SM: styrene monomer production.! And can not be separated is important to select the most efficient process reactors consisting of two tubes.

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