DOE studies sequestration

The Department of Energy (DOE) will spend almost $25 million to co-fund eight new exploratory projects that will study methods to capture and store carbon gases.

The research will explore ‘carbon sequestration,’ a promising class of technologies that removes global warming gases from the exhausts of power plants or from the atmosphere itself, and then securely stores them in underground geologic formations or in terrestrial vegetation such as forests. Most of the projects will focus on carbon dioxide, but one will collect natural gas from a landfill before it can escape into the air.

The eight projects emerged from a nationwide competition that attracted 62 proposals from private companies, universities, local governments, and environmental organizations. The chosen proposals were generated by BP, Alstom Power, Praxair, Consol, Dakota Gasification, Advanced Resources International, The Nature Conservancy, and Yolo County, California.

The Energy Department’s Office of Fossil Energy, which will oversee the research, has set a goal of developing sequestration approaches that cost $10 or less per ton of carbon – equivalent to adding only 0.2 cents per kilowatt-hour to the average cost of electricity. Currently, only a limited number of sequestration options are available, and most can cost as much as 30 times more than the department’s goal.

The private sector participants have offered to fund an average of 40 percent of total project costs, well above the 20 percent minimum cost-sharing that the US Energy Department required. Exact funding for the projects will be determined in final negotiations between DOE and the companies involved.

The new projects were in the following categories: Separation and Capture, Sequestration in Geological Formations, Terrestrial Ecosystems and Advanced Concepts.

Separation and Capture

BP Corporation, Anchorage, Alaska, will head a seven-member international team to demonstrate the feasibility of capturing carbon dioxide (CO2) from a variety of fuel types and combustion sources and storing it in unmineable coal seams and saline aquifers.

Alstom Power, Windsor, CT, will test a way to produce concentrated CO2 by firing oxygen (rather than air) in an advanced boiler. The company will also evaluate ways to use the CO2 to produce saleable byproducts, such as enhanced oil recovery. The first phase would include small-scale testing, and if it is successful, a second phase will be a pilot test of the concept.

Praxair, Tonawanda, NY, will develop a novel ‘oxy-fuel’ boiler – a new boiler design that incorporates a membrane to separate oxygen from the air, which is then used for combustion. Because it produces a concentrated CO2 exhaust, it could reduce the complexity of CO2 capture, reduce the cost of carbon sequestration, and offer increased thermal efficiency and reduced pollution.

Sequestration in Geological Formations

Consol Research & Development, South Park, PA, will demonstrate a coal bed methane production technology known as ‘slant-hole’ drilling to drain natural gas from unmineable coal seams, then use the gas production holes for sequestering CO2.

Dakota Gasification Company, Bismarck, ND, will use new reservoir mapping and predictive tools to develop a better understanding of the behaviour of CO2 in a geologic formation, including the way it moves through reservoir rocks, the quantity that can be stored in a reservoir, and how long the CO2 could be expected to remain trapped in the underground formation.

Advanced Resources International, Arlington, VA., will study the way CO2 is trapped naturally in US deposits and determine if the knowledge can be adapted for sequestration applications.

Terrestrial Ecosystems

The Nature Conservancy, Arlington, VA, will develop and implement various forestry sequestration projects and refine the tools and methods for measuring their long-term carbon storage potential.

Advanced Concepts

Yolo County Planning and Public Works Department, CA, will demonstrate full-scale application of a new waste landfill ‘bioreactor’ approach that was tested at a smaller scale in an earlier DOE project. Methane emitted from degrading wastes in the landfill will be trapped by special membranes on the surface and transported to collection points. Methane is an even more potent greenhouse gas than CO2.

Carbon sequestration is an important field of study because it offers a way to address global climate issues,’ said Secretary Abraham. ‘This becomes especially significant as we craft energy and environmental strategies that draw upon all of our available energy resources, sustain economic growth, and, at the same time, respond to concerns about the long-term health of our planet.’