Modeling Temperature and Pressure Effects on Hot Spot Formation in Fischer-Tropsch Fixed Bed Reactor

Document Type : Research Paper

Authors

1 1. Research Institute of Petroleum Industry (RIPI), Tehran, Iran

2 Chemical Engineering School, Iran University of Science and Technology, Tehran

Abstract

Fischer-Tropsch process is one of the developing processes in the world, and especially in Iran, for the conversion of synthesis gas into paraffin and olefinic products. The purpose of this study was to investigate the effect of feed temperature and pressure on hot spot formation by means of reactor simulation. The simulation of GTL process fixed bed reactor is carried out by Matlab software package using computational fluid dynamics. Also, the kinetics proposed for Fischer-Tropsch process in the literature has been compared. Two-dimensional modeling was performed and flow regime within the reactor was considered laminar. The finite volume method was used to solve the equations. The results of the process modeling suggest that hot spot formation is more possible in bed primary section because of reaction concentration. Increasing reactor temperature resulted in an enhancement of reactant conversion and product yield. Raising feed temperature causes hot spot temperature to increase. According to the modeling results, the optimum temperature and pressure are equal to 570 K and 20 bar respectively. It was also found that increasing pressure and consequently temperature increased C7+ product yield, which in turn will increase the production of linear hydrocarbons.

Keywords

References

مراجع
[1] احمدی مروست م.، سنتز فیشر ـ تروپش به کمک کاتالیست دو عامل آهن ـ زئولیت: بررسی سینتیک واکنش ها و مدل سازی راکتور، رساله دکتری مهندسی شیمی، دانشگاه صنعتی امیرکبیر، 1384.
[2]. Akhtar A., Pareek V. K., and Tade M. O., “Modern trends in CFD simulation: application to GTL technology”, journal of chemical products and process modelling. Vol. 1, pp. 2-30, 2006.
[3]. Martin J. Keyser Raymond C., Everson and Rafael L., and Espinoza., “Fischer-tropsch kinetic studies with cobalt-manganese oxide catalysts”, Ind. Eng. Chem. Res.39, 48-54, 2000.
[4]. Burtron H. and Davis., Fischer–tropsch synthesis: overview of reactor development and future potentialities, center for applied energy research, University of Kentucky, 2540 Research Park Drive, Lexington, KY 40511, USA, 2005.
[5]. Andrey A., Troshko and FranzZdravistch., “CFDmodeling of slurry bubble column reactors for Fisher–Tropsch synthesis”, journal of Chemical Engineering Science,64, pp. 892 – 903, 2009.
[6]. Anthony G. Dixon Michiel Nijemeisland and Hugh Stitt., “CFD simulation of reaction and heat transfer near the wall of a fixed bed”, International Journal Of Chemical Reactor Engineering, Vol. 1, Article A22, 2003.
[7]. Egbert S. Lox and Gilbert F. Froment., “Kinetics of the fischer-tropsch reaction on a precipitated promoted iron catalyst”, 2. Kinetic Modeling,. journal of Ind.Eng. Chem. Res. 32, pp. 71-82, 1993.
[8]. Mazzone L.C.A. and Fernandes F.A.N., “Modeling of fischer-tropsch synthesis in a tubular reactor”, journal of Latin American Applied Research,m 36: pp. 141-148, 2006.
[9]. Esteban Duran J., Mohseni M., Taghipour F., “Modeling of annular reactors with surface reaction using computational fluid dynamics (CFD)”, journal of Chemical Engineering Science 65 pp. 1201–1211, 2010.
[10]. Andrei Y. Khodakov, Wei Chu and Pascal Fongarland., “Advances in the development of novel cobalt fischer-tropsch catalysts for synthesis of long-chain hydrocarbons and clean fuels”, Journal of Chem. Rev. 107, pp. 1692:1744,2007.
[11]. Yang J., Liu Y., Chang J., Yi-Ning Wang, Bai L., Xu Y. Y., H. W. Y. W. Li, Xiang, and B. Zhong, Detailed kinetics of fischer-tropsch synthesis on an industrial Fe-Mn catalyst, Ind. Eng. Chem. Res. 42, pp. 5066-5090, 2003.
[12]. Chemical engineering module model Llibrary, Porous Reactor with Injection Needle, page 528 ,Current Density Distribution in a Solid Oxide Fuel Cell, page 683.
[13]. Maxwell Equations S., Hsu H. W. and Bird R. B., Multicomponent diffusion problems, AIChE J. ,6,387-453.
Journal of Petroleum Research
Volume 24, Issue 78 - Serial Number 78
September and October 2014
Pages 127-137

Files

Share

How to cite

Statistics