CHICAGO — A landmark Energy Department project to bury carbon dioxide produced by humans has begun as workers sunk a huge drill bit into Illinois ground this week, signaling continued support for a climate change mitigation strategy that has fallen out of favor in many circles.
The start of drilling marks the launch a geological sequestration project that will deposit a million metric tons of carbon dioxide into the ground by 2012.
While that’s nothing compared to the several billion tons of CO2 that humans emit yearly, it’s the geology of the site that makes the development exciting. The CO2 will be piped into a geological formation that underlies parts of Illinois, Indiana and Kentucky that could eventually hold more than 100 billion tons of CO2.
"This is going to be a large-scale injection of 1 million metric tons, one of the largest injections to date in the U.S." project manager Robert Finley said here at the American Association for the Advancement of Science meeting Sunday.
While the Department of Energy and private industry have been pushing to create cheaper renewable energy and investigating increased nuclear-power options to reduce carbon emissions, carbon capture and sequestration remains an attractive idea. It would allow regions of the country like the southeast, which don’t have Texas or California-level wind or solar resources, to continue burning coal without contributing to climate change.
To do that, many technological issues will need to be solved. Last year, the Bush administration canceled the DOE’s most expensive carbon capture and sequestration project, FutureGen, and some utility executives have questioned whether storing CO2 will actually make sense. The Intergovernmental Panel on Climate Change estimated that as much as 30 percent of the energy created by a coal plant would have to be spent on just pulling the CO2 out of its flue gas.
But new materials for more selectively capturing CO2 from gas mixes continue to be created in labs like Omar Yaghi’s at UCLA and at Georgia Tech under Chris Jones. Those innovations could make the capture part of "carbon capture and sequestration" easier than it currently is. Add in a carbon tax of some form and fossil-fuel power plant operators would have the incentive to start capturing a lot of carbon dioxide. Then, they’ll just need somewhere to put it.
The DOE thinks the United States has more than enough underground closet space.
Mt_simon_slide "What we found in the U.S. with the research that we’ve done over the last 10 years is that there is a significant potential to store CO2 … in these very large reservoirs that are underground," said John Litynski, who works in the fossil-fuel-centered National Energy Technology Laboratory’s Sequestration Division.
But most current sequestration projects use the carbon dioxide to squeeze more oil and gas out of depleted fields. Those fields probably won’t cut it for much larger amounts of CO2. For that, we’ll have to turn to huge reservoirs deeper underground. That’s why the Illinois demonstration project is so important. It will test a formation called the Mt. Simon sandstone, allowing scientists to track in near real-time what happens when they start putting large amounts of compressed carbon dioxide 6,500 feet below the surface.
"We have numbers for what we think the capacity is in the U.S., but the only way to prove that is to actually drill a well," said Litynski.
Drilling a 6,500-foot well doesn’t come cheap — the Illinois Basin project has an million price tag. It’s a collaboration between the DOE and industrial partners including Archer Daniels Midland, which is providing the land for the test site and will serve up CO2 from its ethanol fermenters. A group of scientists centered at the Illinois State Geological Survey known as the Midwest Geological Carbon Sequestration Consortium are leading the research.
They’ll collect enormous amounts of data about how the CO2 plume moves through the pores in the sandstone. The Mt. Simon formation is particularly attractive because of a series of fortuitous events that have placed three layers of impermeable rock — known as "cap rock" — between the sandstone and the surface. Finley thinks that makes the project a very good bet to succeed in keeping CO2 buried away for what amounts to forever in human timescales.
But the audience at the AAAS meeting who watched the researchers present their sequestration evidence weren’t wholly convinced. They gave the presenters a rougher time than one normally sees at this meeting, where most questions are softballs. One audience member noted that the Mt. Simon project was sequestering 10,000 times less CO2 than we’d have to put into the ground each year to offset human emissions.
It’s the expense and time needed to scale up the tech that leads renewable energy advocates to complain that money used to make coal cleaner should instead be spent scaling up wind power or installing
