(586c) Membrane Based Acid Gas Separation: Past, Present and Future
Membrane based CO2 separation was discovered and practiced as early as 1980s. The overall membrane adoption rate for these type of separation was lower due to several challenges related to pretreatment and unknown process design expertise for membrane systems. The overall experience in early adoption of membrane was mixed bag with some installations were successful while others did not make mark due to lack of process design and inadequate pretreatment. The early adoption of CO2 and H2S removal membrane started for Enhanced Oil Recovery (EOR) applications where high CO2 feed gas streams were uneconomical to treat using conventional technologies like Hot potassium carbonate and Amine treating. Gas membrane system provided an economical solution to remove CO2 and recover maximum hydrocarbon in the product gas. The higher CO2 recovery with higher purity improved overall CO2 EOR processing economics.
Gas separation membrane adoption has increased over last 30 years and has shown significant adoption in offshore CO2 removal projects. The high CO2 natural gas producing assets around the world require more compact and light weight separation technology which membrane technology is a clear winner. The offshore CO2 removal membrane systems must be more agile to address offshore processing challenges with higher up time availability. The new FPSOs and fixed platforms requires bulk CO2 to be removed offshore followed by onshore treatment of gas for LNG or midstream gas processing. The current challenge for offshore is that membranes are still little less competitive for low CO2< 10% streams compared to amine system. This is due to pretreatment and recycle compression for higher hydrocarbon recoveries. However for large CO2 removal applications, membrane is still a preferred option.
The future for gas processing CO2 removal membranes is around applications which are usually not economically feasible for gas membranes, like low CO2< 10% removal applications, membranes with limited pretreatment and remove CO2 and H2S more effectively with maximum hydrocarbon retention. The approach of current membranes in combination with other technologies, hybrid approach, could address some of these applications more cost effectively than standalone membranes solution. However new age of nano composite with highly cross linked polymer membranes can limit the size of pretreatment and provide long term benefits. Also, digital integration of membrane performance and real time advisory tool can provide higher visibility of membrane performance and optimization making membranes more viable with higher adoption rate for onshore and offshore gas processing applications.