US Patent 7938890 Separating gas using immobilized buffers

A layered structure can be formed having immobilized or segregated pH buffering groups that can be used to separate carbon dioxide or other gases. The pH buffering groups can be immobilized within a matrix, confined within a gel, or segregated by a semi-permeable membrane. The pH buffering groups can be configured to increase the efficiency of the system by maintaining a desirable pH profile within the cell and to permit the flow of the carbon-containing ions within the system while controlling diffusion of protons and/or hydroxyl ions.