Steam-promoted CO2 flux in dual-phase CO2 separation membranes

Abstract Steam dissolving into molten carbonates through the formation of hydroxide ions could contribute to the permeation of CO 2 in dual-phase membranes under certain conditions. In this work, ceria (CeO 2 ) supported dual-phase membranes was fabricated and the effect of steam on the transport properties has been investigated by means of flux measurements. The results show an approximate 30% increase of the CO 2 flux when 2.5% steam is introduced to the feed side, while an approximate 250–300% increase of the CO 2 flux is observed when introducing the same amount of steam to the sweep side. These phenomena and transport mechanisms are explained by the theory of ambipolar permeation of CO 2 via various combinations of charged species.