Liquid Membrane Immobilized in Durable Inorganic Matrix for CO2 Separation

In this work, we will report a new liquid/inorganic membrane product concept for CO2 separation. A liquid fluid of selective CO2 absorption properties is immobilized in a thin, inorganic substrate sheet (20~50um) of graded pore structures. CO2 selectively absorbs into the liquid fluid in the feed side, the absorbed species diffuse across the liquid film under a partial pressure gradient of CO2, and CO2 desorbs in the permeate side. The inorganic matrix provides mechanical strength and membrane surface area. Compared to the absorption process, CO2 continuously absorbs and desorbs in the same spot during membrane separation. Thus, energy and capital costs associated with regeneration in the conventional absorption process can be saved. Compared to the conventional membrane, the proposed membrane provides combined performance attributes of high membrane area packing density, low cost, and durability. CO2 permeance obtained with the proposed hybrid membrane is among the highest in the literature.