Using a membrane reactor for the oxidative coupling of methane: simulation and optimization

An oxidative coupling of methane (OCM) is a promising process to convert methane into ethylene and ethane; however, it suffers from the relatively low selectivity and yield of ethylene at high methane conversion. In this study, a membrane reactor is applied to the OCM process in order to prevent the deep oxidation of a desirable ethylene product. The mathematical model of OCM process based on mass and energy balances coupled with detailed OCM kinetic model is employed to examine the performance of OCM membrane reactor in terms of CH4 conversion, C2 selectivity, and C2 yield. The influences of key operating parameters (i.e., temperature, methane-to-oxygen feed ratio, and methane flow rate) on the OCM reactor performance are further analyzed. The simulation results indicate that the OCM membrane reactor operated at higher operating temperature and lower methane-to-oxygen feed ratio can improve C2 production. An optimization of the OCM membrane reactor using a surface response methodology is proposed in this work to determine its optimal operating conditions. The central composite design is used to study the interaction of process variables (i.e., temperature, methane-to-oxygen feed ratio, and methane flow rate) and to find the optimum process operation to maximize the C2 products yield.

[1]  G. Wozny,et al.  Oxidative coupling of methane in a fluidized bed reactor: Influence of feeding policy, hydrodynamics, and reactor geometry , 2011 .

[2]  Z. Stansch,et al.  Comprehensive Kinetics of Oxidative Coupling of Methane over the La2O3/CaO Catalyst , 1997 .

[3]  Zhonglai Wang,et al.  Scale up and stability test for oxidative coupling of methane over Na2WO4-Mn/SiO2 catalyst in a 200 ml fixed-bed reactor , 2008 .

[4]  Sangtae Kim,et al.  Diffusion and surface exchange coefficients in mixed ionic electronic conducting oxides from the pressure dependence of oxygen permeation , 1998 .

[5]  Gabriele Clarizia,et al.  Integrated membrane operations in the ethylene oxide production , 2012, Clean Technologies and Environmental Policy.

[6]  Malcolm L. H. Green,et al.  The relationship between the structure and the performance of Na-W-Mn/SiO2 catalysts for the oxidative coupling of methane , 2002 .

[7]  Yaghobi Nakisa,et al.  Modeling the oxidative coupling of methane: Heterogeneous chemistry coupled with 3D flow field simulation , 2009 .

[8]  Zongping Shao,et al.  Investigation of the permeation behavior and stability of a Ba0.5Sr0.5Co0.8Fe0.2O3−δ oxygen membrane , 2000 .

[9]  N. Mostoufi,et al.  Kinetic modeling of oxidative coupling of methane over Mn/Na2WO4/SiO2 catalyst , 2009 .

[10]  Haihui Wang,et al.  Oxidative coupling of methane in Ba0.5Sr0.5Co0.8Fe0.2O3−δ tubular membrane reactors , 2005 .

[11]  Y. S. Lin,et al.  Optimum operation of oxidative coupling of methane in porous ceramic membrane reactors , 2003 .

[12]  Amornchai Arpornwichanop,et al.  Investigation of a Dual-bed Autothermal Reforming of Methane for Hydrogen Production , 2011 .

[13]  J. Lunsford.  CATALYTIC CONVERSION OF METHANE TO MORE USEFUL CHEMICALS AND FUELS: A CHALLENGE FOR THE 21ST CENTURY , 2000 .

[14]  J. Kuipers,et al.  Integrated autothermal oxidative coupling and steam reforming of methane. Part 1 : Design of a dual-function catalyst particle , 2012 .

[15]  K. Omata,et al.  Oxidative coupling of methane using a membrane reactor , 1989 .

[16]  J. Kuipers,et al.  Integrated autothermal oxidative coupling and steam reforming of methane. Part 2: Development of a packed bed membrane reactor with a dual function catalyst , 2012 .

[17]  Zongping Shao,et al.  Performance of a mixed-conducting ceramic membrane reactor with high oxygen permeability for methane conversion , 2001 .

[18]  Subhash Bhatia,et al.  Oxidative coupling of methane (OCM) in a catalytic membrane reactor and comparison of its performance with other catalytic reactors , 2009 .

[19]  S. Bhatia,et al.  Modeling of catalytic reactor for oxidative coupling of methane using La2O3/CaO catalyst , 2002 .

[20]  K. Yoon,et al.  Oxidative coupling of methane over calcium chloride-promoted calcium chlorophosphate , 2001 .

[21]  Design and demonstration of an experimental membrane reactor set-up for oxidative coupling of methane , 2013 .