A three dimensional CFD simulation and optimization of direct DME synthesis in a fixed bed reactor

Petroleum Science, May 2014

In this study, a comprehensive three-dimensional dynamic model was developed for simulating the flow behavior and catalytic coupling reactions for direct synthesis of dimethyl ether (DME) from syngas including CO2 in a fixed bed reactor at commercial scale under both adiabatic and isothermal conditions. For this purpose, a computational fluid dynamic (CFD) simulation was carried out through which the standard k-ɛ model with 10% turbulence tolerations was implemented. At first, an adiabatic fixed bed reactor was simulated and the obtained results were compared with those of an equivalent commercial slurry reactor. Then the concentration and temperature profiles along the reactor were predicted. Consequently, the optimum temperature, pressure, hydrogen to carbon monoxide ratio in the feedstock and the reactor height under different operation conditions were determined. Finally, the results obtained from this three-dimensional dynamic model under appropriate industrial boundary conditions were compared with those of others available in literature to verify the model. Next, through changing the boundary conditions, the simulation was performed for an isothermal fixed bed reactor. Furthermore, it was revealed that, under isothermal conditions, the performed equilibrium simulations were done for a single phase system. Considering the simultaneous effects of temperature and pressure, the optimum operation conditions for the isothermal and adiabatic fixed bed reactors were investigated. The results of the H2+CO conversions indicated that, under isothermal condition, higher conversion could be achieved, in compared with that under adiabatic conditions. Then, the effects of various operating parameters, including the pressure and temperature, of the reactor on the DME production were examined. Ultimately the CFD modeling results generated in the present work showed reasonable agreement with previously obtained data available in the literature.

A PDF file should load here. If you do not see its contents the file may be temporarily unavailable at the journal website or you do not have a PDF plug-in installed and enabled in your browser.

Alternatively, you can download the file locally and open with any standalone PDF reader:

https://link.springer.com/content/pdf/10.1007%2Fs12182-014-0347-0.pdf

A three dimensional CFD simulation and optimization of direct DME synthesis in a fixed bed reactor

Petroleum Science June 2014, Volume 11, Issue 2, pp 323–330 | Cite as A three dimensional CFD simulation and optimization of direct DME synthesis in a fixed bed reactor AuthorsAuthors and affiliations Fazel MoradiMohammad KazemeiniMoslem Fattahi Article First Online: 07 May 2014 320 Downloads 6 Citations Abstract In this study, a comprehensive three-dimensional dynamic model was developed for simulating the flow behavior and catalytic coupling reactions for direct synthesis of dimethyl ether (DME) from syngas including CO2 in a fixed bed reactor at commercial scale under both adiabatic and isothermal conditions. For this purpose, a computational fluid dynamic (CFD) simulation was carried out through which the standard k-ɛ model with 10% turbulence tolerations was implemented. At first, an adiabatic fixed bed reactor was simulated and the obtained results were compared with those of an equivalent commercial slurry reactor. Then the concentration and temperature profiles along the reactor were predicted. Consequently, the optimum temperature, pressure, hydrogen to carbon monoxide ratio in the feedstock and the reactor height under different operation conditions were determined. Finally, the results obtained from this three-dimensional dynamic model under appropriate industrial boundary conditions were compared with those of others available in literature to verify the model. Next, through changing the boundary conditions, the simulation was performed for an isothermal fixed bed reactor. Furthermore, it was revealed that, under isothermal conditions, the performed equilibrium simulations were done for a single phase system. Considering the simultaneous effects of temperature and pressure, the optimum operation conditions for the isothermal and adiabatic fixed bed reactors were investigated. The results of the H2+CO conversions indicated that, under isothermal condition, higher conversion could be achieved, in compared with that under adiabatic conditions. Then, the effects of various operating parameters, including the pressure and temperature, of the reactor on the DME production were examined. Ultimately the CFD modeling results generated in the present work showed reasonable agreement with previously obtained data available in the literature. Key wordsModeling CFD dimethyl ether synthesis dynamic behavior fixed-bed reactor isothermal and adiabatic conditions  Download to read the full article text References Alamolhoda S, Kazemeini M, Zaherian A, et al. Reaction kinetics determination and neural networks modeling of methanol dehydration over nano γ-Al2O3 catalyst. Journal of Industrial and Engineering Chemistry. 2012. 18(6): 2059–2068CrossRefGoogle Scholar Arkharov A M, Glukhov S D, Grekhov L V, et al. Use of dimethyl ether as a motor fuel and a refrigerant. Chemical and Petroleum Engineering. 2003. 39(5–6): 330–336CrossRefGoogle Scholar Farsi M and Jahanmiri A. Enhancement of DME production in an optimized membrane isothermal fixed-bed reactor. International Journal of Chemical Reactor Engineering. 2011. 9:A74CrossRefGoogle Scholar Jahanmiri A and Eslamloueyan R. Optimal temperature profile in methanol synthesis reactor. Chemical Engineering Communications. 2002. 189(6): 713–741CrossRefGoogle Scholar Khandan N, Kazemeini M and Aghaziarati M. Determining an optimum catalyst for liquid-phase dehydration of methanol to dimethyl ether. Applied Catalysis A: General. 2008. 349(1–2): 6–12CrossRefGoogle Scholar Lim H W, Park M J, Kang S H, et al. Modeling of the kinetics for methanol synthesis using Cu/ZnO/Al2O3/ZrO2 catalyst: Influence of carbon dioxide during hydrogenation. Industrial and Engineering Chemistry Research. 2009. 48(23): 10448–10455CrossRefGoogle Scholar Moradi G R, Ghanei R, Yaripour F. Determination of the optimum operating conditions for direct synthesis of dimethyl ether from syngas. International Journal of Chemical Reactor Engineering. 2007. 5: A14CrossRefGoogle Scholar Ng K L, Chadwick D and Toseland B A. Kinetics and modelling of dimethyl ether synthesis from synthesis gas. Chemical Engineering Science. 1999. 54(15–16): 3587–3592CrossRefGoogle Scholar Ogawa T, Ono M, Okuyama K, et al. Direct dimethyl ether synthesis from hydrogen and carbon monoxide. NKK Technical Review. 1999. 81: 13–17Google Scholar Papari S, Kazemeini M and Fattahi M. Modelling-based optimisation of the direct synthesis of dimethyl ether from syngas in a commercial slurry reactor. Chinese Journal of Chemical Engineering. 2013. 21(6): 611–621CrossRefGoogle Scholar Papari S, Kazemeini M and Fattahi, M. Mathematical modeling of a slurry reactor for DME direct synthesis from syngas. Journal of Natural Gas Chemistry. 2012. 21(2): 148–157CrossRefGoogle Scholar Shahrokhi M and Baghmisheh G R. Modeling, simulation and control of a methanol synthesis fixed-bed reactor. Chemical Engineering Science. 2005. 60(15): 4275–4286CrossRefGoogle Scholar Takeguchi T, Yanagisawa K-i, Inui T, et al. Effect of the property of solid acid upon syngas-to-dimethyl ether conversion on the hybrid catalysts composed of Cu-Zn-Ga and solid acids. Applied Catalysis A: General. 2000. 192(2): 201–209CrossRefGoogle Scholar Topsoe H., Process for the preparation of catalysts for use in ether synthesis. 1993a. US Patent 4,536,485Google Scholar Topsoe H., Process for preparing acetic acid, methyl acetate, acetic anhydride or mixtures thereof. 1993b. US Patent 5,189,203Google Scholar Yagi H, Ohno Y, Inoue N, et al. Slurry phase reactor technology for DME direct synthesis. International Journal of Chemical Reactor Engineering. 2010. 8: A109CrossRefGoogle Scholar Yaripour F, Baghaei F, Schmidt I, et al. Catalytic dehydration of methanol to dimethyl ether (DME) over solid-acid catalysts. Catalysis Communications. 2005. 6(2):147–152CrossRefGoogle Scholar Yasari E, Shahrokhi M and Abedini H. Modeling, simulation and control of a tubular fixed-bed dimethyl ether reactor. Chemical and Biochemical Engineering Quarterly. 2010. 24(4): 415–423Google Scholar Copyright information © China University of Petroleum (Beijing) and Springer-Verlag Berlin Heidelberg 2014 Authors and Affiliations Fazel Moradi1Mohammad Kazemeini1Email authorMoslem Fattahi21.Department of Chemical and Petroleum EngineeringSharif University of TechnologyTehranIran2.Department of Chemical Engineering, Abadan Faculty of Petroleum EngineeringPetroleum University of TechnologyAbadanIran


This is a preview of a remote PDF: https://link.springer.com/content/pdf/10.1007%2Fs12182-014-0347-0.pdf

Fazel Moradi, Mohammad Kazemeini, Moslem Fattahi. A three dimensional CFD simulation and optimization of direct DME synthesis in a fixed bed reactor, Petroleum Science, 2014, 323-330, DOI: 10.1007/s12182-014-0347-0