Opus 12 and Southern California Gas Co. (SoCalGas) have demonstrated a new process to convert the carbon dioxide in raw biogas to methane in a single electrochemical step, a critical improvement in the science of upgrading biogas to pipeline quality natural gas, and a simpler method of converting excess renewable electricity into storable natural gas.
The research is part of SoCalGas' development of technologies known as power-to-gas (P2G), a method of storing excess renewable energy. Because gases can be easily stored for long periods of time using existing infrastructure, power-to-gas technology has distinct advantages over storing renewable electricity in batteries.
Opus 12 is a clean-energy startup incubated in the prestigious Cyclotron Road program at Lawrence Berkeley National Lab and a portfolio company of Evok Innovations, a cleantech fund established by the BC Cleantech CEO Alliance, Cenovus Energy and Suncor Energy to accelerate commercialization of solutions to the most pressing environmental and economic challenges facing the oil and gas sector.
Opus 12 used a new type of polymer electrolyte membrane (PEM) electrolyzer to convert carbon dioxide to methane, showing that instead of wasting the carbon dioxide in raw biogas it can be converted to methane using renewable electricity.
Raw biogas is mostly methane, but also contains about 30 to 40 per cent carbon dioxide, which is typically vented to atmosphere in a biogas production facility. While other power-to-gas systems convert water into hydrogen and oxygen using renewable electricity, Opus 12's method would likely be implemented adjacent to biogas production so it can make use of a greenhouse gas that would otherwise contribute to climate change.
"This groundbreaking innovation holds the potential to simplify storing renewable electricity in the form of zero-carbon renewable natural gas that can be used for home heating, water heaters, or clean trucks to transport goods," Yuri Freedman, SoCalGas senior director of business development, said in a statement.
"Southern California has ideal conditions for this type of solution, with significant biogas resources and high penetration of renewable electricity," said Nicholas Flanders, Opus 12's chief executive officer. "SoCalGas has identified this regional advantage, and with their scale and expertise in P2G and biogas, the company has been the ideal partner for this project."
The feasibility study was the first phase of research that will also explore new catalysts, modifying the catalyst layer formulation, and other ways to enhance the system's methane conversion performance.