A numerical study in a carbon dioxide membrane permeator

A numerical analysis of countercurrent permeators having different types of membranes is presented for natural gas purification with a sweep gas on the permeate side. Two kinds of membranes are studied: a homogeneous silicon membrane and an asymmetric cellulose acetate membrane. A mathematical formulation and calculation procedure using numerical methods to solve material and transport equations is presented for each membrane for predicting the membrane area required to purify a natural gas containing CO₂ to a desired level of purity. It has been found that the asymmetric cellulose membrane requires less membrane area than the silicon membrane for the same degree of separation. The structure of the asymmetric cellulose acetate membrane allows reduced membrane area compared to the silicon membrane under the same operating conditions.