'Partial capture' of carbon dioxide cleans coal, costs less, say researchers at MIT

With many states requiring or considering requiring coal-fired power plants to capture at least 90 percent of their carbon-dioxide emissions, and Congress considering likewise, the high cost of full capture means that few new power plants are being built in the U.S. Research at the Massachusetts Institute of Technology says an intermediate carbon-capture step may provide a way to stimulate construction of coal plants, and help existing plants move to a full-capture system later.

Nancy Stauffer of the MIT Energy Initiative writes, "Depending on the type of plant, carbon capture alone can increase the initial capital cost by 30 to 60 percent and decrease plant efficiency so that the cost per kilowatt-hour rises. That high cost would reduce — or possibly eliminate — the hours the plant will be called on to run." Plus, no one knows exactly how full capture programs work for a large-scale power plant.

"Our approach — 'partial capture' — can get CO₂ emissions from coal-burning plants down to emissions levels of natural gas power plants," said Ashleigh Hildebrand, a graduate student in chemical engineering and the Technology and Policy Program. This step would still capture a significant portion of carbon emissions, but would reduce the initial cost of implementing the program, provide higher plant efficiency than full capture programs, and allow power plants to test carbon capture programs on a smaller scale before moving to a full capture program. (Read more)