10 years SEPURAN® Green

In 2011, Evonik introduced a new membrane technology for even more efficient biogas upgrading. Ten years later, SEPURAN® Green membranes are considered the globally recognized quality standard in biogas upgrading-with more than 700 reference plants around the globe. 


SEPURAN® Green stands for a hollow-fibre membrane technology for efficient upgrading of biogas to high purity biomethane. Since the product launch of SEPURAN® Green in 2011, Evonik has worked with selected partners to develop its membrane technology into a new quality standard in biogas upgrading. The Group is thus making an important contribution in the decentralized provision of biomethane as a climate-friendly energy source.

"With Evonik's innovative strength, we have shaped a global technology leader for membrane-based gas separation in less than ten years and decisively shaped the global biogas market," emphasizes Dr. Goetz Baumgarten, head of the Membranes Innovation Growth Field at Evonik. "In close cooperation with our partners such as Envitec Biogas, Tecno Project Industriale, Hitachi Zosen Inova, Bright Biomethane, and Prodeval, we are setting new standards in terms of biogas plant efficiency, methane yield, or running performance, and establishing our membrane technology as the new quality standard on the market."


  • Know-how in polymer chemistry
  • Patented 3-step membrane process
  • Strategic partnerships with plant partners

At the heart of SEPURAN® Green membrane technology are polymer-based hollow-fibre membranes made from the high-performance plastic polyimide developed in-house. Evonik is the world's only backward-integrated manufacturer of highly selective gas separation membranes. The specialty chemicals company draws on its many years of expertise in polymer chemistry and adjusts the properties of the membranes as early as the development stage of the starting material, the high-performance plastic, to produce particularly selective and robust membranes that can withstand extreme pressures and temperatures.

Evonik has developed and patented a 3-stage process for biogas upgrading that makes optimum use of the separation properties of SEPURAN® Green membranes. In the gas separation process developed by Evonik, binary gas mixtures such as raw biogas, which consists mainly of biomethane and carbon dioxide, can be separated particularly efficiently and cost-effectively. In addition to higher yields and lower equipment and energy costs-no second compressor is needed-the membrane process does not require additional purification, so the enriched gas can be fed directly into the natural gas grid. 

SEPURAN® Green membranes can be perfectly integrated into the plant concepts of the plant partners. The plant partners can thus deliver a turnkey, highly efficient and reliable plant at competitive conditions.


Alongside solar and wind technology, biomethane is an important building block in the renewable energy mix. For years, Europe, with France as the pioneer, has played a leading role in biogas production on an international scale. In the meantime, many other European countries such as Italy, Belgium or the Netherlands, but also the large economies of the USA and China, are relying on the climate-friendly energy source biomethane.

Biogas is produced by fermenting biomass-an organic substance from waste such as liquid manure and sewage sludge, for example, or from renewable raw materials. The particularly selective SEPURAN® Green hollow-fibre membrane from Evonik easily and efficiently converts raw biogas, which consists of the energy carrier biomethane plus carbon dioxide, into high-purity biomethane. The climate-friendly energy carrier can consequently be used as a fuel or to generate electricity and heat. The membranes are made of a high-performance plastic specially developed by Evonik that is highly resistant to pressure and temperature.

Compared with other biogas upgrading processes such as pressurized water scrubbing, pressure swing adsorption, or amine scrubbing, Evonik's membrane technology has significant advantages: It requires comparatively little energy and does not need any auxiliary materials or chemicals. It produces no waste or wastewater that would otherwise have to be treated and disposed of.

Bio-LNG - a climate-friendly fuel

Biogas can be easily upgraded to biomethane and used locally in liquid (bio-LNG) form as a climate-friendly fuel. The decentralized provision of Bio-LNG shortens the transport distances of the fuel as well as reduces transport costs. The use of regionally available substrates makes it possible to provide the fuel from the region for the region. Furthermore, new jobs are created along the local value chain.

The defossilization of transport in general and heavy-duty transport in particular is an important approach to achieving the German government's climate target - i.e. reducing German greenhouse gas emissions by 55 percent by 2030 compared with 1990.

"Biomethane, as an established and available renewable fuel alternative, can become one of the key technologies for the climate-friendly transport turnaround in Germany when it comes to defossilization of transport. The technology is already being used successfully in numerous commercial vehicles," says Volker Wehber, head of the global SEPURAN® Green business at Evonik.


Evonik's success story in the field of renewable gas treatment began 10 years ago with SEPURAN® Green. In addition to biogas membranes, today's membrane product portfolio includes gas separation technologies in the field of process gases, helium treatmenthydrogen extraction and natural gas processing. The specialty chemicals company is also working on the development of a new type of membrane that can make the production of green hydrogen economically viable. With its innovative membrane technology, Evonik has been making an important contribution to sustainable gas economy for years.