Scrubbing the Skies

Is clean coal fact or fantasy?

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By Zack Fishman


For more than half of its 150-year history, the Urbana-Champaign campus of the University of Illinois has relied heavily on Abbott Power Plant for on-site electricity and steam generation. Today, the university receives three-quarters of its power needs from the aged brick building, a structure that would blend well with the classic campus architecture if not for its towering twin chimneys spouting steam.

Yet Abbott’s reliability might soon become a liability for the campus, which has pledged to eliminate all on-campus carbon dioxide emissions by 2050. Despite being promoted as efficient, safe, and EPA compliant, the plant produces significant carbon dioxide emissions by burning natural gas and coal, constituting 61% of the university’s direct carbon output. The U of I is looking for a way to phase out its dirty power and, in 2015, university researchers proposed implementing a technology that could nearly eliminate its emissions: carbon capture and storage (CCS).

CCS technology turns fossil fuel plants into largely clean energy sources. The technology takes many forms, but its standard operation involves removing CO2 from a power plant’s smokestack and injecting the gas thousands of feet underground for permanent storage. CCS has existed for decades but remains stuck in research and development limbo, seeing relatively little action at the large scale. Implementation at Abbott, according to its supporters, would prove CCS viable for wider deployment.

The initiative to clean up Abbott was spearheaded by Kevin O’Brien, Director of the Illinois Sustainable Technology Center (ISTC), a division of the campus’ Prairie Research Institute. The sustainable energy expert and his team was funded in 2015 by the U.S. Department of Energy (DOE) to study the plant, where they “learned a great deal about how to retrofit this technology on a traditional working power plant,” O’Brien wrote in an email.

But building equipment that can pull greenhouse gases such as CO2 from the air is challenging because of the molecule’s highly stable, neutrally charged nature. CO2 can only be captured by being either reacted into a more easily captured compound or physically separated from other gases, while the final collection of gas must be nearly pure for later transportation and storage. The process is inevitably energy-intensive and expensive.

ISTC’s proposed solution would have employed CO2-bonding chemicals to capture 90% of Abbott’s greenhouse gas emissions and then release it into a diverted stream, to be sent away for underground storage.

O’Brien’s 2016 proposal for further funding ultimately fell through; no CCS project was funded by the DOE that year. “This occurred during the transition to the Trump administration when clarity on administration priorities was not yet established,” ISTC Communications Director Jim Dexter said. The group failed to receive funding for a similar plan in 2017. O’Brien now leads a carbon capture project at a power plant in Springfield, Illinois. For now, Abbott will remain dirty, and campus will need to find another way to go carbon-free.


‘Fantastic Geology’

A model of the carbon capture and storage process. Credit: Global CCS Institute

This is much more than a local story. ISTC’s inability to secure necessary funding is a plot line familiar to that of many other CCS projects — and one that may have global consequences in climate change mitigation. A 2018 special report from the Intergovernmental Panel on Climate Change (IPCC) states that the world must completely eliminate CO2 emissions by 2050 to avoid the greatest environmental and societal harms — a gargantuan task, considering the world’s annual (and accelerating) production of 37.1 billion tons of the greenhouse gas. Out of the four outlined pathways to achieve a carbon-free 2050, three rely on significant deployment of CCS. That’s a high bar of expectation for a chronically underdeveloped technology.

Many obstacles stand in the way of meaningfully implementing carbon capture, which captures only 0.1 percent of today’s global emissions. The technology is largely unknown to the public and remains poorly funded relative to both fossil fuel and renewable energy systems. Its operation costs are currently too expensive to be commercially viable. Advocates say sufficient research and development could elevate CCS as a key factor in combating climate change; opponents claim it is a money sink that diverts investment from more effective renewable energy infrastructure. Whether carbon capture will play a key role in stopping climate change is uncertain, but the debate over its implementation is crucial to saving the planet from an intolerably hot and polluted future.

Greater success for CCS in the field can be found in Decatur, Illinois, 50 miles southeast of the Urbana-Champaign campus. The Illinois State Geological Survey (ISGS), another division of the Prairie Research Institute, has been involved in one of the first successful storage sites in the United States. The ISGS-affiliated Midwest Geological Sequestration Consortium (MGSC), alongside agriculture business giant Archer Daniels Midland (ADM), initiated a storage project in 2011 that captured 1 million tons of CO2 from ADM’s nearby ethanol plant and injected the gas more than a mile underground. ADM — the top employer in Decatur, a Fortune 500 company and a top-100 polluter in the U.S. — reopened the operation in 2017 at full capacity and will store another 5 million tons by 2022, equivalent to the annual emissions of nearly 200,000 cars.

Sallie Greenberg, ISGS Associate Director and a co-Principal Investigator at the MGSC, said the Illinois Basin underlying most of the state has “fantastic geology” for carbon dioxide storage. Within the basin, a thick layer of porous sandstone is prime filled with highly compressed CO2, and capped by dense shale rock, which prevents the gas from seeping to the surface. Trapped by the shale, the CO2 is permanently stored in the sandstone. MGSC has monitored the injection site for leaks — CO2 erupting from the surface could contaminate groundwater and even suffocate people — and found it to be safe. According to the Global CCS Institute, the underground storage space of the United States is sufficient to safely sequester the world’s CO2 production for centuries.

The CCS facility in Decatur, Ill. Photo Credit: Herald & Review

Storing greenhouse gas deep in the ground is far from a new practice. Since the early 1970s, enhanced oil recovery has been used to significantly increase yields of crude oil by injecting CO2 deep into oil fields. Producing the black gold is a great economic incentive for CCS research but obviously undercuts its purpose for emission reductions. More than a billion tons of CO2 have been stored with enhanced oil recovery, but an increasing number of sequestration projects, such as in Decatur, are storing carbon without producing oil.

Greenberg also foresees greater interest in geological storage due to a change in the 45Q tax credit, which now gives a tax break of up to $50 per ton of stored CO2 to companies that choose to pursue sequestration.

“It has made the possibility of carbon storage more viable because industry and investors can start to see how you could both do a project and cover the cost of a project by getting tax credits,” she said, noting increased interest from industries that historically have not engaged with carbon sequestration. “I think it’s likely the next round of projects will be industrial plants or other ethanol plants like ADM.”


Direct Air Capture: The New Frontier

Successful or not, industrial projects like the power plant and storage sites in Illinois represent only one, official side of the CCS development world. Another plays by its own set of rules: a carbon capture “Wild West” inhabited not by public university researchers but risk-taking entrepreneurial leaders seeking to make CO2 capture affordable through market-based products. These businesses often rely on private investment more than government funding, and they capture CO2 straight from ambient, “normal” air rather than from a smokestack — a technique dubbed “direct air capture” (DAC).

Swiss company Climeworks is one of the biggest players in the direct air capture (DAC) arena. Surrounded by rich green fields outlined by the Alps, its Zurich plant features a towering array of large fans — resembling jet engines — overlooking the idyllic view. The fans take in enormous quantities of air and capture most incoming CO2 with a patented filter. Climeworks sells the pure gas for a variety of uses, from geological storage to greenhouses to beverage companies.

Unlike traditional CCS, DAC could potentially power a future of negative emissions, in which more CO2 is removed from the atmosphere than is emitted. Louise Charles, spokeswoman for Climeworks, elaborated on its importance. “By using our direct air capture technology to both serve markets in need of CO2 and also remove CO2 safely and permanently from the atmosphere by storing it underground,” she wrote in an email, “we facilitate a sustainable way to reach negative emissions — and to reach the Paris climate goals.”

One option for reducing greenhouse gas buildup in the atmosphere is storing it deep underground. Lab experiments confirm that carbon dioxide is effectively trapped when injected into basalt formations. Photo Credit: U.S. Department of Energy

But Climeworks’ technology must extract from ambient air the relatively sparse CO2, which is 400 times less concentrated than in smokestacks. As a result of such technical challenges, removing one ton of CO2 currently costs the company $600 to $800, a prohibitively high cost for large-scale employment. Charles projected the price to decline to $100 per ton in the future, citing Climeworks’ “detailed cost roadmap” and some modeling inspired by solar panels.

“The price of a solar panel per watt in 1975 was roughly $100 but it has declined to 37 cents at the end of 2017 (a factor of 275 over 43 years) because of economies of scale and tech development,” she said. “We expect similar for DAC.”

Other companies exist in this private CCS space. Carbon Engineering, a Canadian company, has recently claimed in a published report that its cost to perform DAC can be as low as $94 per ton of CO2, while Icelandic company CarbFix injects CO2 into underground basalt rocks on the premise that 95 percent of the gas reacts into permanent stone within two years.

Although these groups seem to be gaining significant traction — Carbon Engineering recently received $68 million in private funding, an all-time high for a DAC company — their success will be limited by the surrounding policies. Carbon taxes, which set a cost to emitting CO2, would highly incentivize businesses to invest in these companies’ services. But carbon taxes and similar pricing policies are only sporadically implemented worldwide, with none currently found in the U.S.

“If carbon pricing mechanisms were in place, it would definitely play in our favor long-term,” Charles said. “It is important for these regulations to allow negative emission technology including DAC to flourish.” She said Climeworks will still be able to conduct business without widespread carbon pricing, albeit with limits in its growth.

The comparison between industrial CCS and entrepreneurial DAC is a challenging one to make, and it is difficult to declare one or the other as the better approach. Do we want the technology to rely primarily on public or private funding? Do we store CO2 in the ground or turn it into fuel? Should we try to reduce power plant pollution for the following decades or implement negative emissions for the following centuries?


Is CCS a “false hope?” 

For many people, scientists and activists alike, the answer to these questions is “none of the above.”

Greenpeace has used particularly colorful language in its opposition to CCS, variously calling carbon capture a “false hope,” a “scam,” and a “corporate boondoggle.” Its news releases might overemphasize the risk of underground leaks, but environmental groups also express legitimate complaints over the tech’s excessive costs and inability to compete in today’s electricity markets.

These concerns are echoed by two University of Michigan researchers, Dr. Sarang Supekar and Professor Steve Skerlos, in a 2015 article published in The Conversation. The two mechanical engineers calculated that carbon capture equipment would consume between 45 percent and 60 percent of a coal plant’s own power generation, which would significantly increase the cost of already struggling coal-powered electricity. To Supekar and Skerlos, renewables are simply cheaper and more reliable. (The analysis has stirred some controversy: another group of scientists called the study’s findings flawed and its numbers exaggerated. The Michigan researchers fired back with their own claims of incorrect analysis.)

Michael Bernard, who writes about low-carbon technologies online, also thinks CCS siphons money away from wind and solar energy, and he crunched some numbers to demonstrate his point. In his analysis, he concluded that if the money spent on large-scale carbon capture projects since 1972 had instead been spent on wind energy, 43 percent more CO2 emissions would have been avoided. Furthermore, because solar and wind energy annually displace 35 times the emissions that CCS projects have in their 40-plus-year lifetimes, he dismissed the technology as “a rounding error in global warming mitigation.”

The technologies Bernard compares are on an unequal playing field in regards to development — CCS is less mature than wind and solar, so money spent on it produces less efficient results — but he makes clear that he would rather commit to renewable energy generation than gamble on slow-moving tech.

At the center of that gamble is much uncertainty. The cost to capture CO2 in the future is uncertain. Its relative value compared with renewable energy sources is likewise uncertain. Whether carbon taxes will be passed, and where — again uncertain. CCS’s lack of technological maturity exacerbates these problems. Dozens of variations are being developed in the CCS space, but none yet can be deployed on a wide scale.

Equipment used for a Carbon Capture program, which is developing novel solvents for better capturing carbon dioxide from coal-powered plants. Photo Credit: U.S. Department of Energy

Researchers and corporate interests alike compete for millions in R&D funding to prove their CCS invention is the winning formula, but a plethora of imperfect choices makes it difficult to throw support behind any of them. And given the stakes of any decision about CCS tech — where to spend billions of dollars toward the goal of saving the planet — the uncertainty is doubly daunting, even prohibitive to many.

Briefly putting aside the bitter argument over its economic feasibility, CCS provides several enticing benefits. Carbon-neutral gasoline sourced from the air could cleanly accommodate any non-electric cars of the future. “Clean coal” may be more politically viable in the short term than a call for the fossil fuel industry’s extinction. And negative emissions in a 100 percent renewable world could further mitigate the disasters of climate change after all the fossil fuel plants have been closed. But for anything to happen, the stars — financial, technological, and political — must align. It’s an alignment that may never come to pass.

Choosing a side in the carbon capture debate at a critical time in CCS development is challenging. But Greenberg, who supports further CO2 storage research and implementation, believes in the importance of continuing the dialogue even with those with who oppose the technology.

“I think there are as many different perspectives as there are people, and what is important is a robust and integrated stakeholder engagement process around a project or around a subject like carbon storage,” she said. “That process has to have room for people who agree and people who disagree.”

About the Author …

Zack Fishman is from Park Ridge, Ill. He received a B.S. in Engineering Physics with a minor in Mathematics and the Certificate in Environmental Writing in May 2019. While at Illinois, he wrote for the Daily Illini and the Green Observer. He is pursuing a M.S. in Science Journalism at Northwestern University. This article was researched and written for ESE 498, the CEW capstone course, in Spring 2019.