Analysis of oxidative coupling of methane in membrane reactors

Abstract

Abstract In order to increase the efficiency of the Oxidative Coupling of Methane (OCM) process, in this work, a new feeding policy structure for an alternative operation mode of the Packed Bed Membrane Reactor (PBMR) is proposed. In Fixed Bed Reactors (PFR), C 2 yield and selectivity still can not fulfill the industrial requirements. Moreover, when the available manipulating parameters (such as oxygen partial pressure or membrane permeability) in a PFR or even in a conventional PBMR are used to improve the selectivity, it leads to a sharp decrease in yield and methane conversion. In this work, a comparison of the OCM process efficiency for these three types of reactors is presented. For this purpose, a mathematical model of each reactor is used. In particular, the effect of oxygen concentration in different structures has been investigated. It can be shown that the efficiency of the OCM process in terms of selectivity and yield performance can be improved by using the proposed PBMR. Moreover, considerable improvement in C 2 yield (at some selectivity performances around 5 %) is achieved by using the proposed structure in comparison to the conventional PBMR. Besides, injecting the methane into the shell side of the proposed PBMR structure is deemed to be another possibility of this structure towards the improvement of the process flexibility and efficiency. Based on this, a network of membrane reactors, which includes the proposed and the conventional PBMR structures, is able to improve the economical and industrial considerations in points of selectivity, one-pass yield and methane conversion for OCM process.