New way to cut gas emissions studied
UC Berkeley researchers say they have found a better way to make natural gas power plants emit less carbon dioxide, a tool they hope can help fight climate change even while California tries to shift to renewable energy.
Working with the fossil fuel giant ExxonMobil, the Berkeley researchers identified a new technique that they say can catch about 90% of the planetwarming carbon dioxide emitted from a gasburning plant and is six times more effective than the method currently used. Their findings appear in an edition of the journal Science that comes out Friday.
The technique studied by the researchers uses a porous, honeycomblike material to capture carbon dioxide and lowtemperature steam to flush it out, after which the gas would likely be stored underground. That’s different from the current, more expensive and energyintense approach of bubbling gas through organic molecules in water and heating it to higher temperatures. ExxonMobil funded the research.
The findings from Berkeley and ExxonMobil come amid increasingly urgent efforts to reduce greenhouse gas emissions worldwide. California in particular has set some aggressive climate change goals, in
cluding vowing to procure 100% of its energy from carbonfree sources by 2045. Various local governments in the state have also sought to ban or restrict the use of natural gas in new buildings.
Though it emits far less carbon dioxide than coal, natural gas is still a fossil fuel that various clean energy advocates would like the state to ditch — and quickly. For now, however, it remains a key part of the energy grid, responsible for more than a third of California’s power mix as of 2018. Nationwide, natural gas is the primary fossil fuel that utilities burn to generate electricity, according to the U.S. Energy Information Administration.
“Natural gas is going to be, for quite some time yet, a major source of electricity in California,” said Jeffrey Long, a UC Berkeley chemistry professor and senior author of the research paper. “It’s just impossible to supply the power needs of the state without using natural gas for the next many years. This kind of technology can lessen the impact of natural gas power production on climate change.”
Michael Wara, a Stanford University climate and energy policy expert, said that finding a way to cut costs from carbon capture projects — as the new research says it has — is important. In an an email, he called it a “precursor to seeing projects that cut emissions in California, including at power plants but more likely at industrial facilities where fossil fuels are hard to substitute for.”
ExxonMobil said it has been working with Long and his team for eight years to improve carbon capture techniques. Spokeswoman Sarah Nordin said in an email that ExxonMobil officials collaborate with academic researchers “as part of our commitment to finding meaningful and scalable solutions to meet global energy demand, while also minimizing the environmental impacts of energy use, including the risks of climate change.”
Still, some environmentalists think that, in California at least, state officials are better off focusing on policies that boost the use of solar and wind power.
“Research and innovation on the carbon capture side is worth pursuing, but it’s really hard to understand how the environment benefits from a system that still depends on fossil fuel extraction,” said Evan Gillespie, western region director for the Sierra Club’s Beyond Coal campaign. “Generally speaking, what’s been good for ExxonMobil has been bad for the environment.”
Regardless of what happens with the carbon capture technique identified by the researchers, California’s push to abandon fossil fuels entirely will almost certainly continue unabated.
The state has already made major strides reducing greenhouse gas emissions from its electric power sector, and former Gov. Jerry Brown sought to take the state even further than its 100% renewable goal in 2045. Starting in 2046, he envisioned that California would start taking more carbon dioxide from the atmosphere than it emitted each year.
And in February, the California Energy Commission approved new codes allowing several Bay Area cities to limit natural gas use in new buildings. San Francisco is now considering its own natural gas ban for newly constructed homes and businesses.