A demonstration project in Illinois is the first in the U.S. to begin pumping over a million metric tons of man-made liquid CO2 into permanent underground storage. The Midwest Geological Sequestration Consortium announced this week that its project in Decatur, Ill., had begun injecting carbon dioxide into sandstone formations 7,000 feet below ground.
Carbon dioxide capture and sequestration is a key strategy for combating the industrial emissions that contribute to global warming. In this case, the carbon dioxide is a byproduct of ethanol production in a nearby plant run by Archer Daniels Midland. The project is a joint project by the Illinois State Geological Survey (ISGS) of the Prairie Research Institute, ADM and the U.S. Department of Energy Office of Fossil Energy.
Robert J. Finley, leader of the project and director of the Advanced Energy Technology Initiative at the ISGS at the University of Illinois, was excited to talk about it, saying: “In the Midwest, and specifically here in Illinois, we’re beginning to document that the geology is very suitable for the storage of carbon. The production of biofuels from crop products can be a very effective way to reduce the carbon footprint of our liquid fuels because you’re taking that liquid CO2 and putting it in the ground.”
Making ethanol, then, becomes a carbon pump. Plants such as corn fix CO2 that is taken from the air. Then, during the production of ethanol for fuel, the CO2 is released and captured, dehydrated and compressed into a liquid, then run through a short pipeline and directly into the ground.
Finley points out that, as a demonstration project, working with an ethanol plant has distinct advantages. With a coal-fired power plant, for example, much of the expense of a sequestration project involves separating the CO2 from the other gases in the smokestack emissions, which are about 12% to 14% carbon dioxide. The fermentation tanks in ethanol production, however, produce about 99.9% carbon dioxide, which is then easily gathered at low cost at the rate of about 1,000 metric tons per day.
“The research that we’re doing is very much on the subsurface geologic environment, to make sure that we can do this safely and effectively, and that we can monitor the CO2,” says Finley. “So we’re using our research dollars to answer these important questions about safety and effectiveness, and we don’t have to use our Department of Energy-funded dollars to just try to get our flow of CO2.”
The Illinois project is one of seven regional partnerships studying sequestration around the country, and the first to use a man-made CO2 source. The project takes advantage of the massive Mt. Simon Sandstone, which is below several layers of shale that serve as a cap to keep the liquid in place. The storage capacity of Mt. Simon is estimated at 11 to 151 billion metric tons.
Establishing that million-metric ton projects are feasible is important because a medium-sized 500 MW coal-fired power plant produces about 3 million metric tons of CO2 per year, and are a key target for sequestration projects.
Finley points out that the Decatur project is not related to the troubled FutureGen project, which sought to build an advanced coal-to-gas power plant in Illinois and sequester its emissions, then was revised to refit a Meredosia plant after Obama took office. That project has been plagued by cost overruns, and major partners have pulled out at various points of the project. He does say, however, that some of the technology that would be used to do that sequestration, and the actual sandstone formation used, would be the same.
The Decatur experiment is expected to continue injecting CO2 for the next three years, and has drawn significant interest from other scientists and industrial concerns around the world.
[For the record, Dec 2, 2011, 11:45 AM: This post has been corrected. The photograph and photographer were miscredited, and the original text failed to identify the Illinois State Geological Survey of the Prairie Research Institute as a partner in the consortium.]
-- Dean Kuipers
Photo: The Midwest Geological Sequestration Consortium verification well in Decatur, Ill. The project is the first to sequester 1 million metric tons of man-made CO2 in limestone formations below ground. Credit: Daniel Byers for the Midwest Geological Sequestration Consortium