Ethylene Production from Oxidative Coupling of Methane in Solid Oxide Electrochemical Cells

Abstract

The oxidative coupling of methane (OCM) to ethylene is a potentially more economical and environmentally benign approach for ethylene production compared to conventional high temperature thermal cracking of natural gas. The OCM reaction is typically conducted in packed bed flow reactors under thermal conditions in the presence of a heterogeneous catalyst. However, due to the intrinsic thermodynamic and kinetic constraints, the existing catalytic systems operated in packed bed reactors have not yet met the techno-economic requirements for the commercialization of this process. As an alternative, membrane reactors that selectively conduct the oxygen ions (O2-) could potentially offer significantly higher methane conversion and C2 product selectivity compared to conventional packed bed reactors. The lower partial pressure of oxygen and the distinct nature of oxygen species available for methane oxidation in the membrane reactor could effectively suppress the kinetics of the chemical transformations leading to the combustion products. In this context, solid oxide electrochemical cells (SOEC), specifically based on oxygen ion conducting membranes, are excellent platforms for conducting the OCM reaction. Here we demonstrate the development of novel SOECs integrated with a series of advanced OCM catalysts to achieve highly efficient ethylene production.