SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2015, Vol. 23 ›› Issue (10): 1627-1633.DOI: 10.1016/j.cjche.2015.07.025

• 催化、动力学与反应工程 • 上一篇    下一篇

Numerical simulation of fixed bed reactor for oxidative coupling of methane over monolithic catalyst

Zhao Zhang, Ziqi Guo, Shengfu Ji   

  1. State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
  • 收稿日期:2014-10-14 修回日期:2015-07-17 出版日期:2015-10-28 发布日期:2015-11-27
  • 通讯作者: Shengfu Ji
  • 基金资助:

    Supported by the National Basic Research Program of China (2005CB221405).

Numerical simulation of fixed bed reactor for oxidative coupling of methane over monolithic catalyst

Zhao Zhang, Ziqi Guo, Shengfu Ji   

  1. State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
  • Received:2014-10-14 Revised:2015-07-17 Online:2015-10-28 Published:2015-11-27
  • Supported by:

    Supported by the National Basic Research Program of China (2005CB221405).

摘要: A three-dimensional geometric modelwas set up for the oxidative coupling of methane (OCM) fixed bed reactor loaded with Na3PO4-Mn/SiO2/cordierite monolithic catalyst, and an improved Stansch kinetic model was established to calculate the OCMreactions using the computational fluid dynamicsmethod and Fluent software. The simulation conditions were completely the same with the experimental conditions that the volume velocity of the reactant is 80 ml·min-1 under standard state, the CH4/O2 ratio is 3 and the temperature and pressure is 800 ℃ and 1 atm, respectively. The contour of the characteristic parameters in the catalyst bed was analyzed, such as the species mass fractions, temperature, the heat flux on side wall surface, pressure, fluid density and velocity. The results showed that the calculated valuesmatchedwell with the experimental values on the conversion of CH4 and the selectivity of products (C2H6, C2H4, CO,CO2 and H2) in the reactor outlet with an error range of ±4%. The mass fractions of CH4 and O2 decreased from 0.600 and 0.400 at the catalyst bed inlet to 0.445 and 0.120 at the outlet, where the mass fractions of C2H6, C2H4, CO and CO2 were 0.0245, 0.0460, 0.0537 and 0.116, respectively. Due to the existence of laminar boundary layer, the mass fraction contours of each species bent upwards in the vicinity of the boundary layer. The volume of OCM reaction was changing with the proceeding of reaction, and the total moles of products were greater than reactants. The flow field in the catalyst bed maintained constant temperature and pressure. The fluid density decreased gradually from 2.28 kg·m-3 at the inlet of the catalyst bed to 2.18 kg·m-3 at the outlet of the catalyst bed, while the average velocity magnitude increased from 0.108 m·s-1 to 0.120 m·s-1.

关键词: Numerical simulation, Fixed bed reactor, Computational fluid dynamics, Oxidative coupling of methane, Monolithic catalyst

Abstract: A three-dimensional geometric modelwas set up for the oxidative coupling of methane (OCM) fixed bed reactor loaded with Na3PO4-Mn/SiO2/cordierite monolithic catalyst, and an improved Stansch kinetic model was established to calculate the OCMreactions using the computational fluid dynamicsmethod and Fluent software. The simulation conditions were completely the same with the experimental conditions that the volume velocity of the reactant is 80 ml·min-1 under standard state, the CH4/O2 ratio is 3 and the temperature and pressure is 800 ℃ and 1 atm, respectively. The contour of the characteristic parameters in the catalyst bed was analyzed, such as the species mass fractions, temperature, the heat flux on side wall surface, pressure, fluid density and velocity. The results showed that the calculated valuesmatchedwell with the experimental values on the conversion of CH4 and the selectivity of products (C2H6, C2H4, CO,CO2 and H2) in the reactor outlet with an error range of ±4%. The mass fractions of CH4 and O2 decreased from 0.600 and 0.400 at the catalyst bed inlet to 0.445 and 0.120 at the outlet, where the mass fractions of C2H6, C2H4, CO and CO2 were 0.0245, 0.0460, 0.0537 and 0.116, respectively. Due to the existence of laminar boundary layer, the mass fraction contours of each species bent upwards in the vicinity of the boundary layer. The volume of OCM reaction was changing with the proceeding of reaction, and the total moles of products were greater than reactants. The flow field in the catalyst bed maintained constant temperature and pressure. The fluid density decreased gradually from 2.28 kg·m-3 at the inlet of the catalyst bed to 2.18 kg·m-3 at the outlet of the catalyst bed, while the average velocity magnitude increased from 0.108 m·s-1 to 0.120 m·s-1.

Key words: Numerical simulation, Fixed bed reactor, Computational fluid dynamics, Oxidative coupling of methane, Monolithic catalyst