Separation Membrane Unit And Separation Apparatus

A separation membrane unit that selectively separates carbon dioxide gas from a supply gas containing the carbon dioxide gas and nitrogen gas, the separation membrane unit comprising:

• a porous plate having a first surface and a second surface opposite to each other, and in which a plurality of through holes extending from the first surface toward the second surface are formed;
• and a separation membrane including a porous body disposed on the first surface and a resin layer disposed on the porous body and selectively permeating the carbon dioxide gas contained in the supply gas toward the porous body,
• wherein when the carbon dioxide gas permeability of the separation membrane is defined as A, 500,000 GPU≥A≥1,000 GPU is satisfied,
• when the average thickness of the separation membrane is defined as T1, 200 μm≥T1≥10 μm is satisfied;
• when the average diameter of the plurality of through holes on the first surface is D1, T1/D1≥0.02 is satisfied, and
• when the nitrogen gas permeability of the separation membrane is defined as B and the gas permeability of the porous plate is defined as C, 1>(B+C)/(A+C)≥0.8 is satisfied.