The largest plant for burning oxygen is 10 megawatts; the plant in Meredosia would be 200 megawatts and the first of a commercial scale, officials involved in the project said.

Under the new structure, the original FutureGen coalition would still manage the sequestration portion of the project and would arrange experiments with different types of coals to gain experience that could be useful around the world.

The oil-fired plant belongs to Ameren, which is based in St. Louis. It has not run much in recent years and has not generated any power since 2009, said a spokeswoman, Susan Gallagher. The plant operates in the competitive Illinois market, and any profit or loss would fall to Ameren shareholders and not its customers, she said.

Some of the oxygen will be supplied by the French energy company Air Liquide, which relies on a conventional technology, chilling the air until the oxygen turns to a liquid at 297 degrees below zero Fahrenheit. The energy required to accomplish that has always been considered a drawback to the technology.

Mr. Rogers said the project would also test a membrane that could sort oxygen from nitrogen without consuming much energy. And a plant burning oxygen would not need to use much energy to clean up other pollutants, like nitrogen oxides, which cause smog, and mercury, he said.

Babcock & Wilcox will do the engineering. The project is expected to capture 90 percent of the carbon dioxide, or 1.3 million tons a year.

Two other efforts to capture carbon dioxide from coal burning are under way. Duke Energy is building a coal-fired plant in Edwardsport, Ind., that will cook coal into a gas that is a mixture of hydrogen and carbon monoxide. Tentative plans call for it to be outfitted with equipment that sorts out the carbon dioxide and burns the hydrogen, although there is no firm commitment yet to do that.