Biogas from waste won’t go to waste

ETI creates sustainable biogas purification process 



By: Taylor Baseheart, Communications Manager for The Water Council


Wastewater treatment facilities go through a multistep process to clean and dispose of our organic wastes. “Anaerobic Digestion,” one of the last steps of treatment, involves using oxygen free tanks that grow naturally occurring micro-bacteria to safely break down these wastes and ultimately help protect our environment. During the digester process, biogas is produced comprised of methane and carbon dioxide. But what if you could repurpose this biogas and create a more sustainable and useable energy supply? Enter Energy Tech Innovations (ETI). 

A 2018 Pilot Program winner, ETI is working on commercializing a new biogas water wash purification method that is readily adaptable at wastewater facilities and is expected to be at least 30% cheaper to produce clean renewable natural gas (RNG) as compared to other commercially available systems.  

“This is a biogas purification process where nothing goes to waste,” stated Bryan Johnson, the founder of ETI. “RNG is produced from the purified methane on one output side and the separated carbon dioxide on the other output side of the process which has beneficial wastewater treatment uses as well.”

The benefits include offsetting the cost of purchased natural gas as well as the potential to utilize the separated carbon dioxide in wastewater treatment processes (for alkalinity/pH buffering and can aid in phosphorus removal).   

As a previous BREW graduate cohort company, ETI was able to work with Professor Jin Li from the University of Wisconsin – Milwaukee’s Department of Civil and Environmental Engineering as part of a contracted outreach study program where Professor Li directed process validation modeling work on ETI’s water wash purification process. Ultimately, much of this work effort resulted in a master’s thesis written by Md Abul Bashar who recently graduated this summer from UW-Milwaukee. 

With Pilot Program funds from The Water Council and supporters, Fund for Lake Michigan (FFLM), Milwaukee Metropolitan Sewerage District (MMSD) and Wells Fargo, ETI is working with a manufacturer on site to assemble the biogas purification and are close to completion. The next step will be piloting their process at the Jones Island Water Reclamation Facility later this summer and early fall timeframe. Stay tuned for more updates.  

For more information about ETI and their technology, please visit 


Pilot Program Partners