Computing steps up to capture,
keep carbon dioxide underground
Posted January 25, 2012
Producing electricity to power our homes and businesses while also reducing carbon dioxide emissions remains difficult. Fossil fuels provide most electricity in the United States. Coal-burning plants produce nearly three quarters of the nation’s power, simultaneously spewing carbon dioxide into the atmosphere.
Even with innovations in renewable energy, reaching a goal to reduce U.S. carbon dioxide emissions to levels 20 percent below 1990 levels by 2020 will require developing safe, effective ways to capture and store the CO2 fossil fuels release as they burn.
Many of the ideas underlying carbon capture and sequestration are either in laboratory tests or pilot studies. Using traditional scale-up processes to commercialize new research ideas in the power industry has historically taken 20 to 30 years, says David Miller, a technical team lead for the Carbon Capture Simulation Initiative at the DOE’s National Energy Technology Laboratory (NETL) in Morgantown, W.Va.
DOE supports several computational projects to accelerate this process. Researchers use supercomputers to speed designs for new materials that sponge up carbon dioxide and systems that facilitate its large-scale capture. Other scientists use computation to better understand the geological and physical processes and lay the groundwork for approaches that will sequester gas underground.
Grabbing the carbon dioxide
As power plants burn coal, heat converts boiler water to steam, which spins turbines and generates power. The primary combustion product is carbon dioxide, part of a mixture of gases that includes nitrogen and water vapor.
To store only carbon dioxide from this combustion process, researchers need materials that sponge it up while letting other gases escape. At the same time, they’d like to reuse these absorbent materials, so they also need ones that eventually release the carbon dioxide through processes such as heating.
A variety of materials structured with nano-sized gaps are possible candidates for carbon dioxide collection, including crystalline porous substances, zeolites and metal organic frameworks, says Maciej Haranczyk of Lawrence Berkeley National Laboratory. Such materials aren’t easy to synthesize in a laboratory, so researchers would like to focus on specific structures with promising features.