“The bottom line is that air capture will only make sense from an energy efficiency and cost point of view once the world’s electric grid is completely decarbonized.”—Mike Desmond, American Physical Society Committee
That was the conclusion of a study earlier this year by a group of scientists from the American Physical Society studying cost effectiveness of carbon capture and sequestration (CCS) Now another study by MIT published in the Proceedings of the National Academy of Sciences confirms that conclusion saying that CCS proposals are not realistic because their costs would vastly exceed those of blocking emissions at the source by available scrubbing technologies at power generating plants that burn fossil fuels.
This second study by Howard Herzog, a senior research engineer at the MIT Energy Initiative and MIT civil and environmental engineering postdoctoral candidate Kurt Zenz House with help from researchers at C12 Energy in Berkeley, Calif., and at Stanford University found that the current realistic cost of carbon capture is more likely about $1000 per tonne.
The technical problem with removing carbon dioxide from the air is that it requires processing about 300 times more air per ton of CO2 removed due to differences in CO2 concentration compared to scrubbing exhaust gases. That is as carbon dioxide is diluted in the atmosphere it is necessary to process a lot more air to get the same reduction in CO2 as you would by scrubbing the exhaust gases at the power plant stack at a cost that is at least an order of magnitude higher that scrubbing.
And then there is this, in order to process all that hot air to remove the carbon dioxide you’d need power to run the equipment which would almost certainly be fossil fueled so you might end up with a net increase in emissions.
The bottom line for utilities is stick to scrubbers at the plant. The bottom line for the scientists was decarbonize. The bottom line for the rest of us—-go tell China about your study results then get real, people!
- New Study Says Carbon Capture will not be cost-effective for the foreseeable future (nextbigfuture.com)
- Gosh! Decarbonizing the atmosphere may be costly and impractical (junkscience.com)
- MIT Energy Initiative: The Future of the Electric Grid (bespacific.com)
- Capturing CO2 Too Costly to Combat Climate Change? (news.sciencemag.org)
- Large-Scale Carbon Capture and Storage: Feasibility, Permanence and Safety Issues Remain Unresolved (thinkprogress.org)