Sothern California Gas (SoCalGas), Pacific Gas and Electric Company (PG&E) and Opus 12 have joined forces to advance an electrochemical technology that converts the carbon dioxide (CO2) content in raw biogas to pipeline-quality renewable natural 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 twelve-month R&D effort was funded by SoCalGas and PG&E.

Raw biogas is produced from the anaerobic breakdown of waste from sources like landfills, sewage, and dairy farms. It contains roughly 60% methane, and 40% CO2. 

While current biogas upgrading technology removes the CO2 from biogas, the new technology captures the CO2 and converts it into additional renewable fuel. 

“This cutting-edge method of using renewable electricity to convert CO2 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.”

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 electrolyser hardware. The next step will be to test this technology for longer periods at an existing biogas facility.

“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,” said Francois Rongere, PG&E’s Manager of Innovation and Research and Development.

“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.” 

“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,” explains Etosha Cave, Opus 12 Co-Founder and Chief Science Officer.

“They are compatible with existing infrastructure, and when produced with renewable electricity, these products will have significantly lower lifecycle emissions than conventional products.”