Evonik’s SEPURAN® Green Membranes – The Heart of the Biogas Plant

The market entry of Evonik into the biogas upgrading industry in 2011 revolutionized the market and set new technology standards. The introduction of highly selective SEPURAN® Green membranes in combination with a patent-protected 3-stage membrane process allowed for high methane yields and high product purities with optimized energy consumption – all while using only a single compressor. With more than 150 references in North America and over 1,000 references globally, Evonik is the industry leader in biogas membrane upgrading.

With Evonik’s patented biogas upgrading process, the best results of the membranes’ separation properties can be realized. Through a skillful connection of SEPURAN® Green membranes , it is possible to obtain methane yields of over 99.5% from crude biogas. Evonik’s biogas upgrading patent includes a 3-stage membrane design that requires only one compressor, thus minimizing OPEX over the lifetime of the project.

At the core of the separation process are innovative hollow fiber membranes from Evonik’s SEPURAN® Green brand. These consist of a high-performance polymer, developed by Evonik, that can withstand high pressure and high temperatures. The innovative hollow fiber technology is highly robust for the lifespan of the plant. Evonik membranes are stable from day one and have been proven to last for over a decade. The high selectivity membranes enable the production of high-purity biomethane with superior methane recovery, plus outstanding uptime.

According to BiogasWorld’s Intelligence Report 20221, membrane technology is by far the number one technology choice by system integrators worldwide, based on installed capacity as well as the number of units. Membranes are reliable, very simple to operate and have no moving parts. This combination of attractive benefits leads to low maintenance and low OPEX cost. To align with ever-increasing demand in the growing biogas market, Evonik has announced expanded production yet again to position SEPURAN® Green membranes to lead the biogas industry into the future.

SEPURAN® Green Membrane Benefits:

• Lower energy consumption through recycling rates of 30 – 40%;
• Very high selectivity and high purity;
• Simple to operate and efficient;
• Continuous separation process;
• H2S Tolerance up to 3%;
• Operational ease and low maintenance with no rotating parts;
• Reliability, start-up in seconds and high (95%) onstream time;
• Flexible in feed gas variations and flows, turndown ratio down to 20%;
• Membrane lifetime of more than 10 years;
• RNG project cost saving, very low methane loss (<0.5%), low fugitive emissions, low initial capital outlay and low operational costs.