GPSA · Solution-Diffusion · Permeability
Understand gas separation membranes, permeability, and CO2/N2 removal
Membrane systems use the solution-diffusion mechanism where faster-permeating components (CO2, H2S, H2O) pass through a polymeric membrane preferentially over methane. The feed/permeate pressure ratio should exceed 10:1 for optimal separation driving force per GPSA guidelines.
Stage cut (θ) is the ratio of permeate to feed flow. Typical single-stage CO2 removal uses a 15-25% stage cut. Higher stage cuts increase CO2 removal but also increase methane loss to the permeate stream, reducing hydrocarbon recovery.
Selectivity (α) is the CO2/CH4 permeability ratio — higher selectivity means better separation with less methane loss. Typical membrane flux is 0.5-2.0 scf/ft²·day·psi, and membrane area requirements are calculated from the target purity and recovery.
It designs membrane separation systems for gas treating applications including CO2 removal and nitrogen rejection.
The calculator supports CO2 removal and N2 rejection from natural gas streams using membrane separation technology.
Membrane separation is used for gas treating to remove contaminants like CO2 and excess nitrogen to meet pipeline quality specifications.