CO2 To Go Underground

21 October 2012
Published in Energy
Written by  Ross Chambless
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CO2 To Go Underground Kimo, Flicker Creative Commons

About 66 percent of Utah's total carbon dioxide emissions are coming from coal-fired power plants. Geophysicists, engineers and geologists are hard at work, trying to figure out how they can safely capture the CO2 after the coal is burned and store it underground. Yet, as Ross Chambless reports, who exactly will take responsibility for the CO2 after it's pumped underground is still unclear

Here, just south of Green River Utah is Crystal Geyser, an example of how CO2 naturally wants to leak to the surface, bubbling up cold water along with it. Someone drilling for oil here in the 1930s drilled through a natural CO2 aquifer, about 800 meters under the ground.

Knowing that CO2 is naturally stored beneath the ground, scientists are now studying how to inject the gas deep into the earth as a way to reduce global warming. In a humming University of Utah laboratory, Brian McPherson, associate professor of civil and environmental engineering, shows me a small pocket sized card showing the geological layers of time bellow the ground. "We are looking at the Jurassic time period for most, which is 175 million years ago." That's where he plans to inject CO2 being emitted from Utah's coal fired power plants.

McPherson has been leading a regional partnership since 2003 to locate the best places in Utah and other western states where CO2 could safely be injected and stored permanently. "Lets see...three kilometers, 30 degrees per kilometers, that's 90 degrees plus 10 degrees, so about 100 degrees Celsius so a little over 200 degrees Fahrenheit." Using sophisticated gas compression equipment they simulate with stone samples the actual conditions the CO2 will experience.

"What we think is going to happen is that there will be chemical changes, some structural mechanical changes, but what we would like to do is develop the ability to engineer those changes. McPherson is carrying out 120 million dollars of research mostly funded by the department of energy. The federal government is now investing in dozens of projects across the US to match carbon capture and sequestration efforts in other countries.

However, skeptics like the Sierra Club and others say the possibility of CO2 leaking could make it dangerous. But, McPherson believes the chances of such leaks are minimal. He says the technology of injecting gases like CO2 or natural gas has actually been well developed in the last 30 years by the oil and gas industry for the purpose of oil exploration or storing natural gas underground. "It's effectively the same technology just applied with a different type of gas and perhaps greater rates. So we will store a lot more CO2 than typically stored in a natural gas storage site. That's the difference. The testing that were carrying on and the commercial plans are for much deeper storage. Natural gas storage sites typically a few thousand feet, a couple thousand feet maybe. We are going to go very deep 5-10,000 feet you know 1-2 miles deep."

But there is one pending issue that unsettles carbon capture and storage researchers like McPherson. "Liability. The science and the technology, I think we have that under control. When it comes to carbon capture and storage specifically, the very open ended question is the liability, who will take responsibility for that CO2 when it is put deep into the subsurface."

"Were exploring the liability issues, we don't have answers to those yet." Diane Neilson, the governor's energy advisor says the state is now determining permits and regulations for drilling projects and CO2 injection tests, but that state governments the federal government and energy companies will have to develop a regulatory framework, and quickly. "I think the uncertainty about who takes responsibility will slow the process. The lack of a regulatory framework will slow the process. I think even in the testing time frame when we're setting those parameters, the inability of a state or federal government or the company doing the work to step forward and assume the responsibility will cause concern."

Ultimately, retrofitting existing power plants means energy costs for everyone will be more expensive. Individual coal power plants may incur higher operating cost upward 20-50% according to McPherson and others. With most of the expense coming from developing the chemical processes involved with capturing the CO2. Those who question the viability of CO2 sequestration say this will expose the true cost of coal energy and that the valuable funds should instead go towards energy efficiency and renewable energy projects.

Still McPherson says carbon capture and storage can be done relatively quickly and may not cost so much. "On the other hand if a carbon tax or cap and trade system is instigated then that will spread those costs across many different sectors as apposed to just the electricity rate payer. I suspect it will lead to like another incremental cost increase at the gas pump so to speak."

For now McPherson's university research team is prepared to move forward with Utah's first commercial size testing. Partnering with engineers from headwaters clean carbon services, a large oil and gas development company based in Utah. Their plan is to start injecting 1 million tons of compressed CO2, about the size of New York's empire state building every year for four years at a location in central Utah.

This story originally aired 3/23/09

UPDATE: McPherson and his team received a 5 million dollar grant in September 2010 from the U.S. Department of Energy to identify possible CO2 capture locations.

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