hide
Free keywords:
Water splitting; Methane coupling; Equilibrium limitation; Oxygen permeable membrane; Perovskite
Abstract:
The equilibrium limitations of water splitting and the coupling of methane to C-2 hydrocarbons (ethane + ethylene) were simultaneously overcome by using a perovskite Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) oxygen-permeable membrane reactor. Oxygen produced from thermal water splitting was transported through the BSCF membrane and consumed in the coupling of methane. The BSCF membrane consists of an about 70 mu m thick dense BSCF layer on an about 0.8 mm thick porous BSCF layer as support. By applying the membrane reactor concept instead of a fixed bed reactor without oxygen supply, the methane conversion and C-2 yield increased from 3.7% to 26% and 3.1% to 6.5% at 950 degrees C, respectively. In both experiments, the supported 2 wt.% Mn-5 wt.% Na2WO4 catalyst was used at 950 degrees C. Simultaneously, about 9% of the H2O injected was converted to hydrogen with a production rate of about 3.3 cm(3) min(-1) cm(-2) at 950 degrees C which is higher than 1 m(3) (STP) H-2 m(-2)h(-1). (c) 2011 Elsevier B.V. All rights reserved
