Autothermal reforming of ethanol in dense oxygen permeation membrane reactor

摘要

Perovskite-type Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) material was synthesized by the combined EDTA-citric acid complexing method and the disk-type BSCF dense membrane reactor (DMR) was constructed for H2 production by ethanol oxidative steam reforming reaction. The autothermal reaction conditions in the DMR were obtained through optimizing the ethanol oxidative steam reforming reaction (EOSR). The results showed that the hydrogen yield decreases (3.5-3.2 mol/mol(EtOH)) with the net heat of reaction Q decreases from 0 to -257 j/mol(EtOH) because the oxygen permeation flux for the membrane increases with temperature. The hydrogen production is 3.5 mol/mol(EtOH) at autothermal temperature of 750 degrees C and the oxygen permeation flux of the dense ceramic membrane reactor is 6.5 ml(STP)/cm(2) min. The activation energy for oxygen permeation was 46.4 kJ/mol under the air/Ar gradient, as compared to about 20.1 kJ/mol under EOSR reaction, respectively. The BSCF DMR performed stably under the autothermal reaction condition was stable for at least 180 h. These results indicate the BSCF membrane holding the high oxygen permeation flux, the excellent phase reversibility and the good stability under the highly reducing atmosphere, shows great application potential for H-2 production via the autothermal reaction. (C) 2015 Elsevier B.V. All rights reserved.