▎ 摘　　要

NOVELTY - A membrane comprises a base, a support layer comprising a gas permeable polymer arranged on the base, and a selective polymer layer arranged on the support layer. The selective polymer layer comprises a selective polymer matrix. The support layer has carbon dioxide permeance of at least 25000 GPU at 57 degrees C and ambient pressure. USE - Membrane used for separating gas such as carbon dioxide, hydrogen sulfide and hydrogen chloride from feed gas stream (all claimed). ADVANTAGE - The membrane is selectively permeable to acidic gas and has excellent carbon dioxide and nitrogen selectivity and high performance. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) manufacture of the membrane, which involves depositing the support layer on a base and depositing a selective polymer layer on the support layer. The selective polymer layer comprises a selective polymer matrix. The support layer, comprises a gas permeable polymer, hydrophilic additive, solvent, and pore forming agent; and (2) separating of gas (G1) from a feed gas stream, which involves contacting the membrane with the feed gas stream comprising the gas (G1) under conditions effective to afford transmembrane permeation of the gas.