Southern California Gas (SoCalGas), Pacific Gas and Electric Company (PG&E), and clean-energy startup Opus 12 have teamed up to advance an electrochemical technology designed to convert the carbon dioxide (CO2) content in raw biogas to pipeline-quality renewable natural gas.

Developed by Opus 12, the single-step Polymer Electrolyte Membrane (PEM) electrolyzer is designed to use electricity to convert water and CO2 into renewable natural gas.

The technology, which is claimed to be different from those that use microorganisms, provides a way for long-term storage of excess wind and solar power.

The twelve-month research and development effort, which is backed by funding from SoCalGas and PG&E, follows successful completion of initial feasibility study in 2018.

SoCalGas business development senior director Yuri Freedman said: “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.”

As per the new demonstration, improved catalyst activity could speed reactions by five times and could d nearly double conversion efficiency. This makes the technology commercially competitive with other new biogas upgrading methods.

Core technology to undergo testing at existing biogas facility

The core technology, which has been tested using commercially available electrolyzer hardware, will now undergo testing for longer periods at an existing biogas facility.

Opus 12 co-founder and chief science officer Dr Etosha Cave said: “We achieved significant advances in reaction rate and demonstrated the scalability of our approach by moving from lab scale to commercial-grade components.

“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.”

Last year, SoCalGas and the Pacific Northwest National Laboratory (PNNL) have secured $300,000 in funding from the US Department of Energy (DOE) for a carbon capture and utilisation (CCU) project in California, US.