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VIDEO : The working principle of Evonik ’ s SEPURAN ® membranes Gas separation membranes work on the principle of selective permeation through a membrane surface . The driving force for permeation of the gas through the membrane is the difference between the partial pressures of the gas on the retentate side ( the interior of the hollow fibre ) and the permeate side ( the exterior of the hollow fibre ).
Product diversification
If viewed as a proof of concept , SEPURAN ® Green could not have been more successful . Following its launch in 2010 / 2011 , Evonik began exploring opportunities in more traditional markets . Despite facing competition from well-established players , the company ’ s membrane portfolio was soon diversified to cover other gases such as helium ( SEPURAN ® Noble ), nitrogen ( SEPURAN ® N2 ), and natural gas ( SEPURAN ® NG ).
“ Knowing that entering existing markets would be more challenging , we pushed ourselves to develop innovative products at the cutting edge of membrane technology ,” says Mr . Baumgarten . “ For instance , our membranes have exceptional efficiency in nitrogen generation and enable particularly selective separation of sour gases from natural gas . And in helium , we bring such an extraordinary selectivity to the market that cryogenic technologies can be replaced with a membrane / PSA combination , which is an extremely efficient way to extract helium from natural gas . Contributions like these have helped us not only to establish ourselves as a truly relevant player in all gas separation markets , but also to pave the way for the green gas economy .”
SEPURAN ® Noble for H 2 recovery
A further step in this direction was marked by the launch of the SEPURAN ® Noble membrane for hydrogen recovery in 2018 . The first uses of membranes to recover hydrogen from ammonia and methanol plants date to the 1980s , making hydrogen one of the first applications for industrial gas separation membranes . The highly selective and efficient SEPURAN ® Noble membrane is capable of extracting hydrogen at a concentration level of more than 90 %. However , certain hydrogen applications such as fuel cells require a hydrogen purity of up to 99.9999 %. To make this achievable , Evonik has partnered with Linde Engineering . Together , they have developed a product that combines two mature , state-ofthe-art technologies : Linde ’ s PSA process and Evonik ’ s membrane technology .
Earlier this year , Linde started up a demonstration plant in Dormagen , Germany , to showcase how hydrogen can be separated from natural gas stream using HISELECT ® powered by Evonik ’ s membrane technology . In Mr . Baumgarten ’ s view , this new technology has the potential to become a major accelerator for the hydrogen sector .
12 Hydrogen Tech World | Issue 6 | October 2022