Nitrogen removal from natural gas.
Before entering distribution pipelines, natural gas needs to have to be in line with the specification for caloric value. Nitrogen does not have any caloric value, so high nitrogen content in sales gas makes it difficult to reach the minimum caloric value level. Removal of nitrogen from natural gas is being done via cryogenic technologies (extreme cooling). These technologies have high energy consumption. Because of the lack of alternative technologies, cryogenic technologies are often used.
Membrane technology should be able to offer an attractive alternative, but there are no membranes in the market that have a high selectivity of nitrogen over hydrocarbons. Without this high selectivity it is not possible to achieve an economically feasible separation.
Feed gas = Raw natural gas
Retentate gas = Purified natural gas, mainly CH4
Permeate gas = N2