New projects to explore 'breakthrough' ideas for capturing, storing carbon gases

Pittsburgh, PA - One of the "breakthroughs" singled out by President Bush and others that could dramatically reduce the threat of global climate change is carbon sequestration - the capture and storage of greenhouse gases that otherwise would be expelled from energy facilities.

Already, carbon sequestration is one of the fastest growing areas of research in the U.S. Department of Energy. Now, as part of this effort, the department is preparing to add three new projects to its research portfolio.

One project, if successful, will add a new option for capturing carbon gases that could significant reduce the high costs and severe energy penalties that have hindered past approaches. The other two projects will explore ways to store carbon dioxide safely and essentially permanently, again without imposing excessive costs on the energy consumer.

The three projects were selected in a broad competition run by the Energy Department's National Energy Technology Laboratory. They were submitted by:

• University of Texas at Austin, Austin, TX. Researchers is the University's Department of Chemical Engineering will develop an alternative solvent that captures more carbon dioxide while using 25 to 50 percent less energy than conventional, state-of-the-art MEA (monoethanol amine) scrubbing, another CO2-removal method. Using less energy allows coal plants to produce more electricity while capturing and storing CO2. By expanding on bench-scale system modeling and pilot-scale experiments, the university will develop and validate a process model to optimize solvent rate, stripper pressure and other parameters. Because gas/liquid contact and CO2 mass transfer would be enhanced, capital costs may be reduced.

  Total project cost: $728,007; DOE share: $461,849; applicant share: $266,158; project duration: 3 years. Contact: Gary T. Rochelle, 512-471-7230

• University of Massachusetts, Lowell, MA, which proposes to study in a laboratory a deep-ocean CO2-sequestration method that blends liquid CO2, water and finely ground limestone into an emulsion that could be pumped into the ocean for long-term storage. Because this emulsion would weigh more than seawater, it would sink to the deep ocean. This would make it possible to CO2 at shallower depths than current directed-injection techniques. Soluble calcium bicarbonate, food for aquatic organisms, would be formed and stored in the ocean indefinitely. The emulsion would be analyzed in-situ through windows to study its structure, droplet size and stability for one year. In the second year, an emulsion of liquid CO2, water and a possibly a surfactant will be investigated as it flows through a pipe. The optimal mix of reagents to produce a stable emulsion will be determined.

  Total project cost: $267,840; DOE share: $206,290; applicant share: $61,550; project duration: 2 years. Contact: Dr. Anastasios Angelopoulos, 978-934-3667

• University of Kentucky Research Foundation, Lexington, KY. The University proposes to displace natural gas from black Devonian shales and use these organic-rich rocks to store CO2. Studies have shown that CO2 is preferentially adsorbed by gaseous coals in deep, unminable coal seams in very much the same manner that gas is naturally stored in these coals. In fact, CO2 displaces methane molecules two to one. The study will determine whether a similar phenomena takes place in Devonian black shales, which serve as both a source and a trap for natural gas. This project will analyze CO2 adsorption along with natural gas production, and determine which shales offer the best sequestration potential. At the end of the project, data will be available through publications and Web-based systems.

  Total project cost: $532,966; DOE share: $364,453; applicant share: $168,513; project duration: 2 years. Contact: Jeff Kurz, 859-257-4498