Review of Membranes for Helium Separation and Purification

Abstract

Membrane gas separation has potential for the recovery and purification of helium, because the majority of membranes have selectivity for helium. This review reports on the current state of the research and patent literature for membranes undertaking helium separation. This includes direct recovery from natural gas, as an ancillary stage in natural gas processing, as well as niche applications where helium recycling has potential. A review of the available polymeric and inorganic membranes for helium separation is provided. Commercial gas separation membranes in comparable gas industries are discussed in terms of their potential in helium separation. Also presented are the various membrane process designs patented for the recovery and purification of helium from various sources, as these demonstrate that it is viable to separate helium through currently available polymeric membranes. This review places a particular focus on those processes where membranes are combined in series with another separation technology, commonly pressure swing adsorption. These combined processes have the most potential for membranes to produce a high purity helium product. The review demonstrates that membrane gas separation is technically feasible for helium recovery and purification, though membranes are currently only applied in niche applications focused on reusing helium rather than separation from natural sources.

Recent developments in polyetherimide membrane for gas separation

“…Helium is found during the production of natural gas from petroleum reservoirs. The concentration of helium ranges from 0.03 to 4.05 mol% . Conventionally, helium is separated using cryogenic distillation, but the process is energy intensive.…”

Silicon carbide filters and porous membranes: A review of processing, properties, performance and application

“…As CH 4 concentration is likely to be very low at the back end of the natural gas processing plant, currently there is limited number of publications for He/N2 permselectivity using SiC membranes and best results are 21. This separation factor is moderate though superior to polymeric membranes as reported by Scholes and Ghosh [106] based on poly(trimethylsilylpropyne) (~2), polyethylene (~7.8) and poly (ethylene-copropylene) (<6.5). Nevertherless, He/N2 permselectivity of several polymeric membranes such as aromatic polyimide (74) [107] and inorganic membranes such as silica cobalt membrane (~1000) [108].…”

Polyetherimide-Montmorillonite Nano-Hybrid Composite Membranes: CO2 Permeance Study via Theoretical Models

“…Hence, the gas molecules mobility across polymer phase depends on both thermodynamic and kinetic properties of penetrant gas [19]. Subsequently, the gas permeation in polymer matrix depends on both diffusion (D) and solubility (S) coefficients as explained by Fickian diffusion as given in Equation (1) [20].…”