Compact Membrane Systems (CMS), a pioneer in innovative separations technology, has completed the first pilot demonstration of Optiperm biogas. Optiperm biogas targets the separation of methane from carbon dioxide with fewer stages and less compression than existing membrane solutions, addressing the biogas market. CMS completed its first pilot demonstration and has proven membrane stability and achieved 90% methane purity with a single stage membrane unit.
Courtesy of CMS
Optiperm biogas reduces the stages, compression, and pretreatment needed to upgrade biogas streams. The lower operating pressure (2-3 bara) makes the upgrading process more energy efficient than current high pressure membrane solutions. The fluoropolymer nature of the membranes provides stability in H2S, and resistance to common poisons like hydrogen, water vapor, and CO. The technology is scalable and can produce economically viable biogas upgrades for small, medium, and large streams. Optiperm biogas permeates the carbon dioxide, water, and hydrogen sulfide, leaving upgraded methane in the retentate.
Working with Dickinson College Energy Projects Manager Matt Steiman, a spiral wound module system was installed at the Dickinson College Farm in late 2020. During the pilot installation, Optiperm biogas demonstrated stability and verified the performance that was measured in CMS laboratory testing. The unit took feed directly from the digester with no pretreatment and operated at a feed pressure of 2.7 bara. The feed contained 56-60% methane with balance carbon dioxide, 300 ppm H2S and was saturated with water vapor.
In a single stage, Optiperm biogas achieved:
Stable performance for 2 months
90% methane product
90% methane recovery
80% carbon dioxide in permeate stream
8x H2S reduction (from 300 ppm to 37 ppm)
The next steps include scale-up of the membrane modules for commercial use.