Technico‐economical assessment of MFI‐type zeolite membranes for CO 2 capture from postcombustion flue gases

A detailed survey of the effect of moisture on the CO 2 /N 2 permeation and separation performance of Mobile Five (MFI) zeolite membranes in view of downstream postcombustion CO 2 capture applications in power plants and incinerators is presented. The membranes, displaying a nanocomposite architecture, have been prepared on α‐alumina tubes by pore‐plugging hydrothermal synthesis at 443 K for 89 h using a precursor clear solution with molar composition 1 SiO 2 :0.45 tetrapropylammonium hydroxide:27.8 H 2 O. The synthesized membranes present reasonable permeation and CO 2 /N 2 separation properties even in the presence of high water concentrations in the gas stream. A critical discussion is also provided on the technico‐economical feasibility (i.e., CO 2 recovery, CO 2 purity in the permeate, module volume, and energy consumption) of a membrane cascade unit for CO 2 capture and liquefaction/supercritical storage from standard flue gases emitted from an incinerator. Our results suggest that the permeate pressure should be kept under primary vacuum to promote the CO 2 driving force within the membrane. © 2011 American Institute of Chemical Engineers AIChE J, 58: 3183–3194, 2012