Basic Research Needs for Geosciences - Energetics Meetings and ...

APPENDIX 1: TECHNICAL PERSPECTIVES RESOURCE DOCUMENTTECHNOLOGY AND APPLIED RESEARCH AND DESIGN NEEDS FORGEOLOGICAL CARBON SEQUESTRATIONINTRODUCTIONIn the global energy system, fossil fuels currently comprise 85% of all energy supply.Combustion of these fuels releases greenhouse gases to the atmosphere, chiefly CO 2 . Every year,~27 Gt of man-made CO 2 enter the atmosphere (7.3 Gt C), nearly all of it from fossil fuelcombustion. Concerns have increased about the risks of greenhouse gas emissions and attendantclimate change impacts. This has prompted renewed focus on reducing emissions throughefficiency improvement, renewable energy supplies, and nuclear fission. Still, even with newcarbon-free sources of energy, reduction in worldwide emissions may not decrease as much ashoped because fossil energy use will continue and grow. Providing a technology foundation forreduced carbon or carbon-free economic energy development for the rest of the world is anotherhighly worthwhile objective for research in this area.Carbon sequestration is the long-term isolation of carbon dioxide from the atmosphere throughphysical, chemical, biological, or engineered processes. Geological carbon sequestration appearsto be one of the more promising options for major greenhouse gas reduction in the next 20–50years, particularly when coupled with improvements in energy efficiency, renewable energysupplies, and nuclear power. The basis for this interest includes several factors:• The potential capacities are large based on initial estimates. Formal estimates for globalstorage potential vary substantially, but are likely to be between 800 and 3300 Gt of C (3000and 10,000 Gt of CO 2 ), with significant capacity located reasonably near large point sourcesof the CO 2 .• Geological carbon sequestration can begin operations with demonstrated technology. Carbondioxide has been separated from large point sources for nearly 100 years, and has beeninjected underground for over 30 years.• Testing of geological carbon sequestration at intermediate scale is feasible. In the U.S.,Canada, and many industrial countries, large CO 2 sources like power plants and refineries lienear prospective storage sites. These plants could be retrofitted and begin CO 2 injectiontoday, though it is important to keep in mind the scientific uncertainties and unknowns.As the concepts for geological carbon sequestration are proven to be reliable for current powerplant technology, improved power plant designs, such as the integrated gasification combinedcycle approach to clean coal power generation, are expected to be able to bring downsequestration costs dramatically by incorporating the requirements for sequestration in the powerplant design from the beginning rather than treating it as an add-on technology.To achieve substantial greenhouse gas reductions, geological storage needs to be deployed at alarge scale (Friedmann 2006), there must be minimal leakage from the underground storagereservoirs back to the atmosphere, and there must be minimal impact on other uses of thesubsurface environment and the resources it contains. With regard to scale, 600 large pulverizedcoal plants (~1000 MW each) will produce 1 Gt C/y (3.7 Gt CO 2 /y) requiring sequestration. Thisis 3600 times the injection of Statoil’s Sleipner project (Pacala and Socolow 2004), which hasAppendix 1 • 4Basic Research Needs for Geosciences: Facilitating 21 st Century Energy Systems