This summer, researchers from UT Austin’s Bureau of Economic Geology will test one means of so-called geologic carbon sequestration by pumping carbon dioxide into a formation deep beneath Liberty County to study its ability to permanently and safely store this most abundant of greenhouse gases.

The three thousand tons of CO2 for the project will be generated at a Gulf Coast refinery in a processing unit that produces CO2 for commercial purposes. Then the CO2 will be trucked in pressurized tanks to a newly drilled well near the town of Dayton. Over a period of several weeks, the CO2 will be injected in liquid form 5,500 feet down into the Frio Formation, a saline brine formation unfit for human consumption and far below aquifers used for drinking water.

“Based on years of research, we believe saline formations like the Frio can permanently sequester carbon dioxide with little or no environmental impact and this small-scale pilot project will test our research,” said Susan Hovorka, senior researcher at University of Texas Austin’s Bureau of Economic Geology and head of the Frio project. Researchers will use instruments placed in an existing well nearby to monitor the movement of the CO2 and any physical changes in the formation for several months until the system stabilizes, after which the injection well will be plugged and abandoned.

Hovorka helped found the Bureau’s Gulf Coast Carbon Center, to assess candidate reservoirs from Texas to Mississippi for carbon sequestration. “From a geological standpoint, the Gulf Coast area offers significant opportunities for carbon storage because it has thick saline formations capped by hundreds of feet of shale that should prevent CO2 from escaping,” said Hovorka.

The Department of Energy estimates saline formations, which underlie much of the United States, could store an estimated 500 billion metric tons of CO2, an amount greater than fifty times estimated annual CO2 emissions worldwide from human activity. As large as that estimate sounds, it could be overly conservative. “The storage potential of these reservoirs is enormous with the Frio, alone, probably capable of storing 200 billion metric tons of carbon dioxide,” says Hovorka.

The Gulf Coast, like much of Texas, also has an abundance of oil and gas reservoirs that could store vast amounts of carbon dioxide with the added benefit of recovering oil and natural gas displaced by the injected gas. Millions of tons of CO2 have been injected into oil fields in West Texas over the past twenty years to prolong the productive life of reservoirs. Large-scale commercial sequestration projects are now operating in Saskatchewan, Canada and in the North Sea where CO2 created in the processing of natural gas is re-injected into reservoirs.

The need to find solutions to global warming caused by increasing atmospheric CO2 is accelerating carbon sequestration research across the country. The DOE is currently evaluating carbon storage potential in deep saline formations in Ohio and West Virginia, and is conducting sequestration field tests in depleted oil fields in New Mexico and Wyoming. DOE researchers are also studying deep, unmineable coal seams in the eastern United States for CO2 storage. To make sequestration a viable solution to climate change, the CO2 to be stored must be captured from large sources such as power plants and refineries that would otherwise release it into the atmosphere.

“The Houston area could be well-positioned for a future carbon sequestration industry because it has its numerous refineries and petrochemical plants that generate large amounts of carbon dioxide in close proximity to geological carbon sinks,” said Mike Moore, Managing Partner of Houston-based Falcon Environmental Services, which is developing CO2 sequestration projects in Texas. CO2 could be captured from the exhaust gases of boilers, heaters and process units at these industrial sites, and from the area’s fossil fuel power plants, compressed to liquid form and piped short distances to injection wells.

The high cost of compressing, transporting, and injecting CO2 is a major challenge to establishing viable sequestration projects.

“At present, enhanced oil and gas recovery offers the only economic payback for sequestering carbon dioxide, so opportunities are relatively limited. Storage in saline reservoirs does not generate a return and deep coal seams remain somewhat unproven,” said Moore.

However, Moore said the economics of carbon sequestration could change dramatically if states or the federal government impose caps on CO2 emissions. That could foster an expansion of emission allowance trading and give value to sequestered CO2 as emission reduction credits. At least one Canadian power producer is already purchasing CO2 credits from oil producers in Texas to meet its future greenhouse emissions targets.

More information about carbon sequestration and the Frio Project is available at www.gulfcoastcarbon.org. Pat Spillman is an environmental attorney who lives and works in Houston.