PROGRAM AREA OVERVIEW --

9. CAPTURE, SEQUESTRATION, AND UTILIZATION OF CARBON

The world is becoming increasingly concerned about the greenhouse effect, and CO₂ emission is a significant contributor to it. Hence, the capture and permanent sequestration of CO₂ has become a major world wide goal. In the United States, the capture and sequestration of CO₂ is expected to be an important element of any strategy implemented to reduce the emission of this greenhouse gas to the atmosphere. Grant applications are sought only in the following subtopics:

a. Advanced Technologies for Monitoring, Mitigation, and Verification— Monitoring, mitigation, and verification (MM&V) is defined as the capability to measure the amount of CO₂ stored at a specific sequestration site, monitor the site for leaks or other deterioration of storage integrity over time, and verify that the CO₂ is stored in a way that is permanent and not harmful to the host ecosystem. MM&V can be divided into three broad categories – subsurface, soils, and above-ground – each having its own set of needs.

Subsurface MM&V involves tracking the fate of CO₂ within the geologic formations underlying the earth and identifying possible migration to the surface. This category also includes developments to mitigate leakage, should it occur. For subsurface MM&V, grant applications are sought for technologies/approaches for monitoring and verifying subsurface sequestration options. Approaches of interest include surface-to-borehole seismic, micro-seismic, cross-well electromagnetic, electrical resistance tomography, CO₂ tracers, surface leak detection, and mineralization concepts for leakage mitigation.

Soils MM&V involves tracking carbon uptake and storage in the first several feet of topsoil and identifying potential leakage pathways into the atmosphere from the underlying geologic formation. For soils MM&V, grant applications are sought for low cost technologies that are capable of measuring carbon at one-tenth of the cost and time required to analyze samples using current methods. Systems must have a minimum detection limit of 0.1 percent carbon in soil, with an accuracy and precision of measurement of +10%. The soil carbon must be measured at a minimum within the top 30 cm, with measurement at 100 cm below the surface desired. The system can either take in situ measurements or incorporate soil sampling (soil core) techniques for later analysis. Soil sampling devices that are capable of measuring other soil properties (such as bulk density and the concentrations of soil nutrients -- e.g., phosphorus, nitrates-nitrogen, potassium, magnesium, calcium, and iron) along with the carbon will be considered to have an advantage. Because the measurement of soil bulk density may be required to determine the mass of carbon in a sample, approaches that also can improve existing methods for measuring the bulk density of soil are of interest. In field or in-situ measurement technologies are needed to reduce the cost and time of measurement to one-tenth of current methods. For bulk density measurements, the minimum detection limit should be 0.1g/cm³, with accuracy and precision of +10%.

Above-ground MM&V refers to terrestrial sequestration and involves the quantification of above-ground carbon stored in vegetation. For above-ground MM&V, grant applications are sought to develop new technologies for measuring the carbon stored in above ground vegetation on carbon sequestration projects, as well as to verify the permanence of the carbon storage. The technology must be able to reduce the costs of measuring above ground carbon stored in biomass by a factor of 10, compared to the cost of current field methods. Technologies that use remote sensing are of particular interest because they offer the most immediate potential. For trees, current methods use the diameter at breast height for estimating the amount of biomass, and subsequently the amount of carbon. New remote sensing applications may need to use other relationships such as crown diameter and height of the vegetation to estimate carbon content. Because many sequestration projects also offer the potential for forest products, technologies that are capable of providing quantitative estimates of the forest products that exist in a particular location have an advantage over those that only measure carbon storage.

b. Advanced Separation and Capture Techniques for CO₂—Significant research and development is currently being pursued for new technologies to separate and capture CO₂ from both fuel and flue gas streams. This subtopic seeks separation/capture technologies for fuel and flue gas streams, gasification processes, and oxycombustion.

Aqueous amine absorption is the state-of-the-art technology for post-combustion CO₂ capture from flue gas. However, amine absorption has a number of drawbacks, including significant capital and operating costs. Therefore, grant applications are sought to develop alternative technologies that can substantially lower the cost of CO₂ separation from the flue gas. Among the candidate technologies, some data has already been developed for membrane separations and solid adsorbents (reference 4); therefore, these technologies are of interest along with technologies that optimize amine absorption processes. Grant applications should demonstrate familiarity with both current commercial technologies and ongoing research, discuss how the presence of minor flue gas components would affect the proposed technology, and account for the effect of flue gas conditions such as flow rate and temperature.

In a gasification processes, a carbonaceous fuel is thermally decomposed in the absence of oxygen to form a hydrogen-rich “synthesis gas” that can be converted to electrical energy through a variety of means (e.g., combustion turbine, electrochemical cell, or combined cycle). The state-of-the-art for CO₂ capture from synthesis gas is a process involving a liquid glycol solvent. The glycol is highly effective and can be used to capture both CO₂ and H₂S. However, the CO₂ is released at near atmospheric pressure and requires compression from 14-20 psi up to 2,000 psi, resulting in considerable increases in cost. Therefore, grant applications are sought to develop new technologies that can more cost effectively capture CO₂ from synthesis gas. Research areas of interest include physical sorbents, membranes, and other separation processes.

With oxycombustion, the fuel is burned in oxygen rather than air, resulting in a highly pure CO₂exhaust that requires no separation. Unfortunately, no commercial oxygen combustion power plants are currently in operation, due mainly to the high cost of oxygen. Another barrier to oxygen combustion is energy loss due to the large quantity of CO₂ exhaust that must be recycled to the oxygen boiler to maintain combustion temperatures at a level that is compatible with boiler materials. Grant applications are sought to develop technologies to overcome these barriers to oxycombustion. Research areas of interest include oxygen transport membranes, circulating fluidized bed designs without recycle, and chemical looping.

c. Non-Carbon Dioxide (Non-CO₂) Greenhouse Gas Reduction—Until recently, efforts to understand and reduce the level of greenhouse gases have focused on carbon dioxide sequestration, more efficient use of carbon fuels, and lower carbon-content fuels. Recent publications by Hansen, et al., have shed new light on the importance of non-CO₂ contribution to greenhouse effects. Therefore, grant applications are sought to develop technology that could significantly reduce the escape to the atmosphere of two of these non-CO₂ gases: methane (CH₄) and nitrous oxide (N₂O). Areas of interest include the reduction of these emissions from oil and gas exploration and production, coal mines, landfills, refineries, rice cultivation, enteric fermentation, fertilizer utilization, manure, residue burning, biomass production and use, and other sources.

d. Breakthrough Technologies—Over the past two years the DOE’s Sequestration Program has been working with the National Research Council/National Academy of Sciences in an effort to bolster the high-risk/high reward portion of the research portfolio. Accordingly, “Breakthrough Concepts” R&D is focused on the pursuit of revolutionary and transformational sequestration approaches with the potential for low cost, permanence, and large global capacity. Grant applications are sought for concepts/technologies that have the potential to provide “leap frog” performance and cost improvements compared to existing technologies. Areas of interest include: (1) the development of new chemical or biochemical processes that utilize captured CO₂ from power plants or coal gasification plants as a feedstock to produce value-added products – these processes should have the potential to utilize up to 100 million metric tons of CO₂as a feedstock and be economically viable without parasitic energy losses; (2) ExampleCO₂conversion (via photosynthesis processes, biological processes, or mineralization processes, etc.) to either useful products, as discussed above, or stable solids that enhance geologic sequestration; (3) chemical looping, where oxygen for combustion is delivered to the fuel via a redox agent rather than by direct air or gaseous oxygen; and (4) novel soil amendments that increase the rate at which carbon can be returned to soil.

References:

Subtopic a: Advanced Technologies for Monitoring, Mitigation, and Verification

1. Carbon Sequestration Technology Roadmap and Program Plan – 2004, U.S. DOE National Energy Technology Laboratory (NETL), April 29, 2004. (Full-text available at: http://www.netl.doe.gov/coal/Carbon%20Sequestration/pubs/SequestrationRoadmap4-29-04.pdf )

2. Vine, E. and Sathaye, J., The Monitoring, Evaluation, Reporting, and Verification of Climate Change Mitigation Projects: Discussion of Issues and Methodologies and Review of Existing Protocols and Guidelines, prepared for U.S. Environmental Protection Agency, Berkeley, CA: Lawrence Berkeley National Laboratory, December 1997. (Full text available at: http://yosemite.epa.gov/oar/globalwarming.nsf/content/ResourceCenterPublicationsReferenceMERVCReportMethods.html)

3. Soil Survey Laboratory Methods Manual—The Soil Survey Analytical Continuum: Soil Survey Investigations Report No. 42 – Version 3.0, U.S. Department of Agriculture-National Resources Conservation Service/National Soil Survey Center, January 1996. (Full text available at: ftp://ftp-fc.sc.egov.usda.gov/NSSC/Lab_Methods_Manual/ssir42.pdf)

Subtopic b: Advanced Separation and Capture Techniques for CO₂

4. Carbon Dioxide Capture from Power Stations, Technical Report, London: International Energy Agency (IEA) Greenhouse Gas Programme, 1994. (ISBN: 1 898373 15 9) (Full text available at: http://www.ieagreen.org.uk/sr2p.htm)

5. Carbon Sequestration Technology Roadmap and Program Plan – 2004, U.S. DOE NETL, April 29, 2004. (Full-text available at: http://www.netl.doe.gov/coal/Carbon%20Sequestration/pubs/SequestrationRoadmap4-29-04.pdf )

6. U.S. DOE NETL Carbon Sequestration – Core R&D: CO₂ Capture Web page. (URL: http://www.netl.doe.gov/coal/Carbon%20Sequestration/index.html. In the circular menu, select “Core R&D” and then “Capture”.)

Subtopic c: Carbon Dioxide (Non-CO₂) Greenhouse Gas Reduction

7. Hansen, J. E. and Sato, M., “Trends of Measured Climate Forcing Agents,” Proceedings of the National Academy of Sciences, U.S.A., 98(26):14778-14783, December 18, 2001. (ISSN: 0027-8424)

8. Hansen, J. E., “The Forcing Agents Underlying Climate Change: An Alternative Scenario for Climate Change in the 21st Century,” Testimony to U.S. Senate Committee on Commerce, Science and Transportation, May 1, 2001. (Full text available at: http://commerce.senate.gov/hearings/0501han.PDF)

9. Houghton, J. T., et al., eds., Climate Change 2001, 4 vols., produced by Intergovernmental Panel on Climate Change, Cambridge, UK: Cambridge University Press, August 2001. (ISBN: 0521807670) (Full text available at: http://www.ipcc.ch/)

10. U.S. Methane Emissions from 1990 – 2020: Inventories, Projections, and Opportunities for Reductions, U.S. Environmental Protection Agency, Office of Air and Radiation, 1999. (Full text available at: http://yosemite.epa.gov/oar/globalwarming.nsf/UniqueKeyLookup/SHSU5BUT5X/$File/methane_emissions.pdf)

11. Carbon Sequestration Technology Roadmap and Program Plan – 2004, U.S. DOE NETL, April 2004. (Full-text available at: http://www.netl.doe.gov/coal/Carbon%20Sequestration/pubs/SequestrationRoadmap4-29-04.pdf)

Subtopic d: Breakthrough Technologies

12. Carbon Sequestration Technology Roadmap and Program Plan – 2004, U.S. DOE NETL, April 29, 2004. (Full-text available at: http://www.netl.doe.gov/coal/Carbon%20Sequestration/pubs/SequestrationRoadmap4-29-04.pdf )

13. U.S. DOE NETL Carbon Sequestration – Core R&D: Breakthrough Concepts Web page. (URL: http://www.netl.doe.gov/coal/Carbon%20Sequestration/index.html. In the circular menu, select “Core R&D” and then “Breakthrough Concepts”.)

14. Lal, R., et al., The Potential of U.S. Cropland to Sequester Carbon and Mitigate the Greenhouse Effect, Lewis Publishers, August 1, 1998. (ISBN: 157504112X)

15. Sixth International Conference on Carbon Dioxide Utilization, Breckenridge, CO, September 9-14, 2001, Preprinted Abstracts, 2004. (Full text available at: http://www.nrel.gov/docs/gen/fy01/30717.pdf)

16. Ayers, W. M., ed., Catalytic Activation of Carbon Dioxide, American Chemical Society Symposium Series, 1988. (ISBN: 0-8412-1447-6).

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