"I have spent the last ten years researching the need, the feasibility, and the technology of capturing and disposing of carbon dioxide in the context of zero emission. The White House announcement is a major step in the right direction, but we must not limit ourselves to incremental improvements in current technology," says Lackner. "I would further propose that industry and academic research take on the challenge of developing ultra-efficient, zero-emission power plants that integrate both fuel cell technology and hydrogen production with safe and permanent carbon sequestration. This is a great opportunity to develop zero emission energy from nearly inexhaustible, low cost-energy resources, and assure sustainable energy worldwide for generations. Without maintaining some reliance on fossil fuels, a zero-emissions plant for hydrogen power alone would be too expensive to succeed. Incrementalism cannot capture the imagination of the public, and in the end would deliver an inferior and more expensive product. The world cannot afford to abandon fossil fuels, but the technology that ultimately succeeds will be radically different from today's."
Dr. Klaus Lackner, Columbia University's Ewing Worzel Professor of Geophysics, points out that the transition to President Bush's hydrogen economy, although important, does not alone eliminate climate change concerns. When hydrogen is made, more energy is consumed than is eventually returned in a fuel cell. By far, the cheapest sources of energy for making hydrogen are fossil fuels like coal and natural gas. Without the introduction of carbon dioxide capture and disposal, a transition to a hydrogen economy would likely aggravate rather than reduce the environmental impact from greenhouse gas emissions.
Lackner has researched new technologies, some in the developmental stage, that could capture all carbon dioxide, either at the point of emission from power plants or from the air, and dispose of it safely and permanently. These approaches, according to Lackner, would make fossil energy use sustainable for at least another century.
Lackner's research on carbon dioxide capture could entirely eliminate this greenhouse gas from the atmosphere at relatively little cost to consumers:
Carbon Dioxide Capture from the Air
Capturing carbon dioxide emissions from the air could be accomplished by letting wind carry air over an absorber that pulls out carbon dioxide. This could be achieved, Lackner argues, through a variety of methods, including blowing air over limewater, which will remove the air's carbon dioxide and produce limestone.
"The volume of air that needs to be processed is surprisingly little when compared to the volumes required for harnessing wind energy, a process already used across the globe," said Lackner. "Windmill installations used to harness wind energy need to be several hundred times larger than carbon dioxide collectors that capture the carbon dioxide from a similarly sized power plant. Yet, windmills are technically and economically viable."
Research by Lackner and his colleagues at the Los Alamos laboratories has shown that recycling the resulting absorber material is also affordable. They estimate that the cost of trapping carbon dioxide from air could eventually be less than 25 cents per gallon of gas, with the potential for better and cheaper methods in the future.
Carbon Dioxide Capture from Power Plants
The capture of carbon dioxide directly from power plants could be accomplished through new plant designs. Lackner is currently working through the Zero Emission Coal Alliance with industry to develop a plant design that could generate hydrogen or electricity from coal without any emissions to the atmosphere. In it, lime captures waste carbon dioxide and generates heat for additional hydrogen production. The lime is recovered with leftover heat from electricity production. The plant would combine carbon dioxide capture with 70-percent efficiency in converting energy in coal into electricity.
"Even though the overall process is novel, the building blocks are well known in refining and clean-coal technologies," said Lackner. "Costs for future plants have been estimated at about 4.5 cents per kilowatt-hour."
For disposing of captured carbon dioxide, Lackner advocates underground injection, a low-cost procedure whose effectiveness has been proven in enhanced oil recovery. Although underground injection will become more difficult as demand for repositories increases, he contends that an alternative method of disposal is available. Magnesium silicates can be used to react with carbon dioxide to form magnesium carbonate (limestone) and silica (quartz), which can be disposed of safely and permanently.
"With proper public and private sector support, implementation of these new technologies could start today," said Lackner. "This track of action would allow for the research and development time that will certainly be needed to make renewable energy resources a viable energy option."
Klaus Lackner is a research scientist at The Earth Institute at Columbia University, the world's leading academic center for the integrated study of Earth, its environment, and society. The Earth Institute builds upon excellence in the core disciplines -earth sciences, biological sciences, engineering sciences, social sciences and health sciences -and stresses cross-disciplinary approaches to complex problems. Through its research training and global partnerships, it mobilizes science and technology to advance sustainable development, while placing special emphasis on the needs of the world's poor.