An environmental group is warning that a proposed pipeline network that would carry carbon emissions to underground storage in Illinois and North Dakota could also extend the life of fossil fuel power plants in the Upper Midwest.
The recently announced projects would immediately benefit ethanol producers, but the Sierra Club says they might also offer a regulatory or economic lifeline to coal-fired power plants in the region under future federal emissions policies.
The pipelines and storage sites, still in very early planning stages, are being promoted as a solution for ethanol refineries. But Andy Knott of the Sierra Club’s Beyond Coal Campaign said, “we certainly have a concern” that later on carbon capture could encompass coal plant emissions.
If the federal government should impose a carbon emissions reduction policy, carbon capture and storage could help a power plant “to clear that bar,” said Jeremy Fisher, senior advisor for strategic research and development for the Sierra Club’s environmental law program.
Secure underground storage sites abound in the Midwest, most notably in North Dakota, Nebraska and Illinois, according to Brad Crabtree, vice president for carbon management at the Great Plains Institute. One of them has been in operation since 2017, when ethanol manufacturer Archer Daniels Midland began injecting about one million tons of CO2 each year thousands of feet underground directly beneath its plant in Decatur, Illinois.
More Midwestern projects are planned. Using a similar approach, a partnership of Battelle and Catahoula Resources envisions burying waste CO2 from Nebraska’s 25 ethanol plants in nearby saline reservoirs.
Two pipelines, announced in the past few months, would deliver CO2 from Midwestern ethanol plants to salty storage beds located deep underground in North Dakota and Illinois. Navigator CO2 Ventures and the investment firm BlackRock are planning a 1,200-mile pipeline to collect carbon dioxide from “industrial sources” in North Dakota, Minnesota, Nebraska, Iowa and Illinois and stashing it underground in Illinois. A tentative route angles from northwest to southeast Iowa. It would pass fairly close to three of the state’s four largest coal-burning power plants: the George Neal Energy Center and the Louisa and Ottumwa generating stations.
Early this year, the Iowa-based Summit Agricultural Group created a subsidiary, Summit Carbon Solutions, that has binding offtake agreements with 31 ethanol producers in the Dakotas, Minnesota, Nebraska and Iowa, said company president Justin Kirchhoff. The compressed liquid will be moved through a 2,000-mile pipeline to North Dakota. The route has not yet been defined.
The company claims it can store 10 million tons of CO2 yearly — and cut carbon waste from ethanol plants in half. Kirchhoff expects enough continued efficiency gains in farming and fermentation that, within a decade, ethanol could be carbon neutral.
With the North Dakota saline beds capable of containing all of the country’s emissions for some 50 years, Kirchhoff anticipates eventually reaching out to fertilizer plants and possibly steel and cement factories as well. The economics of carbon capture and sequestration at coal-fired plants aren’t there yet, he said, but could be if President Joe Biden and Congress proceed with hiking the carbon-storage tax credit from $50 to $85 per ton.
The economics of gathering and sequestering CO2 from ethanol plants are good and only going to get much, much better, according to Kirchhoff. Besides the $50-a-ton federal tax credit, states with low-carbon fuel standards pay a hefty premium for ethanol, as high as $200 per ton of CO2 sequestered, Crabtree said. The standards impose a yearly ceiling on total allowable CO2 emissions from transportation fuels. Along with that is a price schedule that assigns a higher price for fuel with lower carbon intensity.
California, Oregon and Washington have those standards in place. Kirchhoff said Canada, New York, Colorado, New Mexico and Minnesota are all considering similar policies.
Although long-term storage of carbon dioxide to date mostly has been in spent oil and gas fields in Texas and elsewhere, there is basically no chance it would return to the surface of the saline fields of the Upper Midwest, according to both Crabtree and Daniel Sanchez, an engineering professor at the University of California-Berkeley. Sanchez studies engineered biomass and bioenergy systems that remove CO2 from the atmosphere.
The key, according to John Tombari, Battelle’s commercial director of carbon capture and storage, is to find sites with porous sandy soils thousands of feet down, where CO2 can settle into the spaces between grains of sand, topped by a layer of tight and impenetrable clay. The same high pressure that has kept oil and gas underground for millions of years would apply to liquified CO2, he said. In perhaps thousands of years, the liquid would begin to harden into rock.
If all of the ethanol-generated carbon dioxide were stashed underground, it would shave about 1% from total transportation emissions nationwide, Sanchez said. Transportation is the single largest category of emissions.
A pipeline network could serve other industrial sources of carbon dioxide. The manufacture of fertilizer, steel and cement all generate substantial amounts of CO2. There’s one distinct advantage to ethanol, however. The CO2 it produces is pure, meaning it requires nothing but a good push from a pump to get it into a pipeline. CO2 emissions from the manufacture of fertilizer are only slightly less pristine, according to Kirchhoff. But the prodigious carbon dioxide output from cement and steel manufacturing requires more clean-up, meaning costs are higher.
Another possible source of CO2, at least in theory, is coal-fired power plants, of which the Midwest has plenty. Some clean-energy advocates worry that a carbon capture system, even if established initially for ethanol and other industrial producers, might eventually start removing carbon emissions from power plants. They fear that the technology, especially supported by sufficient tax incentives, could change the emissions math enough to allow coal-fired plants to operate for much longer than they would otherwise.
“We’ve seen a number of instances in which coal plants that are otherwise slated for retirement have had the process slowed or halted because third parties believe that subsidies for CCS [carbon capture and sequestration] will rise to the extent that post-combustion capture becomes cost effective,” said the Sierra Club’s Fisher. He cited the San Juan Generating Station in New Mexico and Coal Creek in North Dakota as examples.
While it hasn’t developed a position on the use of CCS in the ethanol industry, Sierra Club is unequivocally opposed to operating carbon capture at coal plants. The technology is costly and energy- and water-intensive, said Laurie Williams, a senior attorney for the Sierra Club.
Fisher said carbon capture likely would increase a plant’s emissions of nitrous oxides and particulates, and might cause groundwater pollution issues.
“A CCS project would both have to pay for itself and make up the premium required to make an uneconomic plant economic,” Williams said. “For example, MidAmerican’s coal plants in Iowa are old, expensive, and should be retired and replaced with low-cost renewable energy that we know works well today.”
MidAmerican spokesperson Geoff Greenwood said the company continues “to investigate carbon capture, utilization and sequestration where it makes sense as part of a net zero transition.”
In North Dakota, the recent sale announcement for the Coal Creek Station power plant quoted the buyer’s president, Stacy Tschider, saying, “Carbon capture and storage is vital to continued operation of Coal Creek Station and will be an important step toward Gov. Doug Burgum’s goal for the state to reach carbon neutrality by 2030.”
Crabtree, a capture-and-storage enthusiast who takes a middle road on using them with coal plants, contends that the concerns that CCS will keep old and inefficient coal plants online longer is “misplaced.” Carbon capture and sequestration is quite costly, he said, and companies “won’t make that investment in plants that are old or inefficient or don’t have sufficient pollution controls.”
As for newer, cleaner and more efficient coal and gas-fired plants, he said, CCS “has to be an option. President Biden has set a goal of net zero by 2035. There is no way we can meet that goal without carbon capture on the most modern and efficient power plants operating today.”