Biomethanation: A Unique and Sustainable Approach to Renewable Natural Gas
Recorded: June 28, 2018, 1:00 PM - 2:00 PM
Research looks at process to use solar or wind energy to provide food for microorganisms to turn into storable renewable electricity
The Department of Energy’s National Renewable Energy Laboratory (NREL) is working on a “Power to Gas” (P2G) experiment to make a renewable form of natural gas, using solar/wind energy, water, carbon dioxide (CO2), and tiny microbes called archaea.
As one of the largest natural gas distributors in the US with over 21 million customers in a state that encourages low-carbon fuels and where there is more available solar and wind power than can be sold, Southern California Gas Co (SoCalGas) heard of Electrochaea’s work and was intrigued. They reached out to the Department of Energy’s NREL to work on a pilot project here in the US.
For the project, NREL designed, built and operate a 250-kilowatt electrolyzer system that uses solar and wind power to split water into hydrogen and oxygen. The hydrogen and carbon dioxide are move into NREL’s 25-foot tall pilot bioreactor under pressure, where it is fed to the archaea to produce methane. Methane, the primary ingredient of natural gas, can be stored in the already existing natural gas pipeline systems for later conversion into electricity as needed.
"This is a viable, albeit two-step, approach for energy storage for renewables," said Kevin Harrison, NREL's principal investigator on the project. He and Nancy Dowe, a fermentation microbiologist at NREL, spent time with Electrochaea researchers in Copgenhagen and Munich prior to the project.
"It's a really interesting project for me," Dowe said. "I really like the biology element because the biocatalysts are completely renewable. You can keep these cultures going as long as you're supplying them CO2, hydrogen, and whatever nutrients they need. It's a self-replicating catalyst, and it's exciting to use biology as an energy storage solution."
Michael Jacobson, Ph.D.
Bryan Swistock, James Andrew Clark