Natural gas purification from acid gases using membranes: A review of the history, features, techno-commercial challenges, and process intensification of commercial membranes

Acid gas removal from natural gas is an indispensable treatment process that is required to boost the produced gas quality prior to its utilization. There has been a prodigious number of advances made in the development of technically-reliable membranes. As a result, the use of membrane units has increased in natural gas treatment plants, particularly for acid gas removal. Apart from explaining separation fundamentals, this paper covers the development history, application record, separation capability, pretreatment requirements and the operational limitations of the well-recognized commercial membranes. Furthermore, the paper discusses process intensification of membrane units, i.e., the optimization of the membrane unit design to yield the targeted separation at the minimum cost, and at the least physical/environmental footprints. The paper clarifies that the advantages offered by the membrane technology may not necessarily qualify it for adoption in onshore applications. However, the membrane technology is definitely the preferred solution in offshore applications.