Guest essay by Eric Worrall
A new paper claims the vast artificial airflow created by the world’s air conditioners could be harnessed to suck CO2 out of the atmosphere, by adding or retrofitting a CO2 absorber and converter to air conditioners. But critics see a few problems with the concept.
Could Air-Conditioning Fix Climate Change?
Researchers propose a carbon-neutral “synthetic oil well” on every rooftop
By Richard Conniff on April 30, 2019
A paper published Tuesday in the Nature Communications proposes a partial remedy: Heating, ventilation and air conditioning (or HVAC) systems move a lot of air. They can replace the entire air volume in an office building five or 10 times an hour. Machines that capture carbon dioxide from the atmosphere—a developing fix for climate change—also depend on moving large volumes of air. So why not save energy by tacking the carbon capture machine onto the air conditioner?
This futuristic proposal, from a team led by chemical engineer Roland Dittmeyer at Germany’s Karlsruhe Institute of Technology, goes even further. The researchers imagine a system of modular components, powered by renewable energy, that would not just extract carbon dioxide and water from the air. It would also convert them into hydrogen, and then use a multistep chemical process to transform that hydrogen into liquid hydrocarbon fuels. The result: “Personalized, localized and distributed, synthetic oil wells” in buildings or neighborhoods, the authors write. “The envisioned model of ‘crowd oil’ from solar refineries, akin to ‘crowd electricity’ from solar panels,” would enable people “to take control and collectively manage global warming and climate change, rather than depending on the fossil power industrial behemoths.”
“This is a wonderful concept—it made my day,” says David Keith, a Harvard professor of applied physics and public policy, who was not involved in the new paper. He suggests that the best use for the resulting fuels would be to “help solve two of our biggest energy challenges”: providing a carbon-neutral fuel to fill the gaps left by intermittent renewables such as wind and solar power, and providing fuel for “the hard-to-electrify parts of transportation and industry,” such as airplanes, large trucks and steel- or cement-making. Keith is already targeting some of these markets through Carbon Engineering, a company he founded focused on direct air capture of carbon dioxide for large-scale liquid fuel production. But he says he is “deeply skeptical” about doing it on a distributed building or neighborhood basis. “Economies of scale can’t be wished away. There’s a reason we have huge wind turbines,” he says—and a reason we do not have backyard all-in-one pulp-and-paper mills for disposing of our yard wastes. He believes it is simply “faster and cheaper” to take carbon dioxide from the air and turn it into fuel “by doing it an appropriate scale.”
…Read more: https://www.scientificamerican.com/article/could-air-conditioning-fix-climate-change/
The abstract of the paper;
Climate change represents an existential, global threat to humanity, yet its delocalized nature complicates climate action. Here, the authors propose retrofitting air conditioning units as integrated, scalable, and renewable-powered devices capable of decentralized CO2 conversion and energy democratization.Read more: https://www.nature.com/articles/s41467-019-09685-x
Turning every high-rise residential or office building air conditioner into a miniature flammable petroleum refinery which vents electrolysis oxygen. What could possibly go wrong?
Update (EW): Added more detail to the final paragraph