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Prairie State must cut carbon emissions to avoid closure. The U of I has a plan to help

The Prairie State Energy Campus in Marissa, Illinois in April 2021. The plant is Illinois' biggest single source of greenhouse emissions according to federal data.
Derik Holtmann
Belleville News-Democrat
The Prairie State Energy Campus in Marissa, Illinois in April 2021. The plant is Illinois' biggest single source of greenhouse emissions according to federal data.

Editor’s note: This story was originally published by the Belleville News-Democrat, a news partner of St. Louis Public Radio.

Unless a coal-fired power plant in southwestern Illinois manages to make dramatic reductions in its carbon emissions, it will be forced to close within the next 23 years.

Kevin O’Brien, director of the Illinois Sustainable Technology Center at the University of Illinois, has been working on designing a plan to capture carbon at Prairie State Energy Campus, the biggest emitter of greenhouse gases in Illinois, according to federal data. In 2020, the plant’s stacks sent forth nearly 12 million tons of the heat-trapping gases that contribute to devastating climate change.

The state’s new clean energy law, the Climate and Equitable Jobs Act, requires Prairie State Energy Campus to be 100% carbon-free by the end of 2045. It mandates a 45% reduction by Jan. 1, 2035. If the company falls short, it must retire one or more units or further reduce emissions by 45% by mid-2038.

The stacks spew water, carbon dioxide and nitrogen, with carbon dioxide making up about 10 to 12% of emissions.

If Prairie State succeeds, it could save hundreds of jobs as Illinois phases out fossil fuel energy over the next 23 years. Employees at Prairie State are banking on it.

Dustin Wathen, a manager for both the plant and the surface coal mine at the Prairie State campus, says he has to be able to answer three questions for his employees: Do they need to start looking for a job now? How is Prairie State going to try to sustain their jobs? What happens if they might be forced to change jobs?

“What would be most helpful is we keep this plant running,” said Wathen, who oversees 20 employees and several contractors.

To produce the Front End Engineering and Design (FEED) study, the university partnered with three private companies: Mitsubishi Heavy Industries America, Inc., Kiewit Corporation, and Sargent and Lundy. The effort began in February 2020 and was completed December 31, 2021.

Prairie State didn’t say if it will put the plan in place, but said additional work would be needed if it does.

“Analysis of the results of the FEED study are ongoing, and while the FEED study provides many of the necessary elements for advancing carbon capture, additional engineering work, financial evaluation, and state and federal regulatory/legislative initiatives are still necessary,” Prairie State spokeswoman Alyssa Harre said in an email.

Rather than sending the polluting gas up the stacks, new technology would pull off the gases and pipe them to a capture facility, where the carbon dioxide would be separated from the nitrogen. The nitrogen would be routed back to the stack and emitted, while the carbon dioxide would be contained. The current plan, O’Brien said, is to “inject it geologically” and store it underground. It could also potentially be used to grow algae for animal feed, soil enhancers or biofuel.

The technology could redirect up to 90 or 95% of the carbon dioxide emissions.

The engineering design will be used at a cement plant in Ste. Genevieve, Missouri, through a U.S. Department of Energy grant, the St. Louis Post-Dispatch reported. The plant might use a design that turns the gas into liquid, which would be injected deep underground below a layer of impenetrable rock.

Underground sequestering has been used at the Archer Daniels Midland ethanol plant in Decatur using millions in federal tax dollars. But the project hadn’t met its goals as of late 2020, according to a review by the Midwest Center for Investigative Reporting. The ADM facility was the second heaviest emitter of carbon dioxide in Illinois in 2020 at about 4.5 million tons.

It’s unclear if storing carbon dioxide underground might work at Prairie State or if it will use the university’s plan at all. If it did, it would become a “major workforce development” opportunity, O’Brien said.

There’s a business incentive for capturing carbon, O’Brien said. Tax credits can amount to $50 per ton captured, and the value of those credits could increase.

“That financial piece has made it very attractive to retrofit these facilities,” O’Brien said. “They realize that under the current atmosphere, they’re really going to need to explore that if they’re going to want to remain long term.”

The Department of Energy has also taken an interest in the potential at Prairie State, O’Brien said.

A grant from the department helped pay for the $14.7 million engineering design project, and Prairie State chipped in $3.75 million.

Prairie State argues its plant already uses technology that makes it one of the most efficient facilities with some of the lowest polluting emissions compared to other plants, but it will have to do much more if it wants to remain open under Illinois law. O’Brien says there are ways to make it happen.

“Taking an existing asset and trying to utilize that asset even more is a critical factor in terms of moving forward,” O’Brien said.

Kelsey Landis is a reporter with the Belleville News-Democrat, a news partner of St. Louis Public Radio.

Kelsey Landis is an Illinois state affairs and politics reporter for the Belleville News-Democrat, a news partner of St. Louis Public Radio.