SoCalGas, PG&E and Opus 12 demonstrate conversion of CO2 into RNG

By Southern California Gas Co. | June 23, 2020

Southern California Gas Co. (SoCalGas), Pacific Gas and Electric Company (PG&E), and Opus 12 on June 22 announced they have demonstrated further advancement of a new electrochemical technology that converts the carbon dioxide content in raw biogas to pipeline-quality renewable natural gas, a critical improvement in the science of upgrading waste emissions to renewable gas. The single-step process is designed to use renewable electricity, and thus also provides a way for long-term storage of excess wind and solar power. The 12-month research and development effort was funded by SoCalGas and PG&E and builds on the success of an initial feasibility study in 2018

Raw biogas is produced from the anaerobic breakdown of waste from sources like landfills, sewage, and dairy farms. It contains roughly 60 percent methane (the main component of natural gas), and 40 percent carbon dioxide. While current biogas upgrading technology removes the carbon dioxide from biogas, this new technology captures the carbon dioxide and converts it into additional renewable fuel.

The new demonstration shows that improved catalyst activity could speed reactions by five times and nearly double conversion efficiency, making the technology commercially competitive with other new biogas upgrading methods. The core technology was scaled up and tested using commercially available electrolyzer hardware. The next step will be to test this technology for longer periods at an existing biogas facility.

"This cutting-edge method of using renewable electricity to convert carbon dioxide in biogas to renewable natural gas in a single-step process is significant to SoCalGas," said Yuri Freedman, SoCalGas' senior director of business development. "As we work to meet California's ambitious climate goals, emissions-reducing innovations like these will help us protect the environment by providing a reliable carbon-neutral fuel."

"PG&E is deeply committed to meeting California's bold vision for a sustainable energy future in a reliable and cost-effective manner for customers.  We continue to work toward advancing innovation that provides new possibilities in our quest to reduce greenhouse gas emissions and find alternative sources of carbon-neutral fuel. We are very proud to be part of this collaboration with Opus 12 and SoCalGas," said PG&E's Manager of Innovation and Research and Development, Francois Rongere.

"We achieved significant advances in reaction rate and demonstrated the scalability of our approach by moving from lab scale to commercial-grade components," said Dr. Etosha Cave, Opus 12 co-founder and chief science officer. "We look forward to continuing to work with our partners at SoCalGas and PG&E toward a field demonstration of this technology."

"Our vision for deploying this technology in California is to recycle CO2 emissions from industry and agriculture before they reach the air, and create valuable products such as renewable natural gas and feedstocks for everyday materials, chemicals, and even liquid fuels. They are compatible with existing infrastructure, and when produced with renewable electricity, these products will have significantly lower lifecycle emissions than conventional products."

Opus 12, a clean-energy startup with its origins at Stanford University and the prestigious Cyclotron Road program at Lawrence Berkeley National Lab, has created a new proprietary Polymer Electrolyte Membrane (PEM) electrolyzer that uses electricity to convert water and carbon dioxide into renewable natural gas in one step. The technology differs from those that use microorganisms.

The research is part of SoCalGas' and PG&E's respective development of cutting-edge technologies for storing excess renewable energy. Because gases can be easily stored for long periods of time using existing infrastructure, these technologies have distinct advantages over storing renewable electricity in batteries.