Enhanced stability of membrane reactor for thermal decomposition of CO2 via porous-dense-porous triple-layer composite membrane

A triple-layer composite membrane with porous-dense-porous structure was proposed to develop a high performance membrane reactor. The triple-layer composite membrane consists of a porous Sr0.7Ba0.3Fe0.9Mo0.1O3−δ (SBFM) layer, a dense 0.5 wt% Nb2O5-doped SrCo0.8Fe0.2O3−δ (SCFNb) layer and a porous La0.8Sr0.2MnO3−δ-yttria stabilized zirconia (LSM/YSZ) layer. The porous layers can effectively reduce the corrosion of the reactive atmosphere to the membrane, while the dense layer permeated oxygen effectively. Compared with single layer dense SCFNb membrane reactor, the triple-layer composite membrane reactor can be operated for more than 500 h. At the temperature of 900 °C, the CO2 conversion can reach 20.58% with the CH4 conversion, CO selectivity and O2 flux being about 84%, 97% and 2.13 mL (STP) cm−2 min−1, respectively. The porous-dense-porous structure can successfully combine the high oxygen permeation and stability of the membrane reactor.