Washington, D.C. — The successful bench-scale test of a novel carbon dioxide (CO2) capturing sorbent promises to further advance the process as a possible technological option for reducing CO2 emissions from coal-fired power plants.
The new sorbent, BrightBlack, was originally developed for a different application by Advanced Technology Materials Inc. (ATMI) , a subcontractor to SRI for the Department of Energy (DOE)-sponsored test at the University of Toledo. Through partnering with the Office of Fossil Energy’s National Energy Technology Laboratory (NETL) and others, SRI developed a method to use the ATMI sorbent to capture CO2. The high-capacity sorbent is regenerated easily at moderate thermal temperatures, making the process less energy-intensive than typical, amine-based CO2-capture processes.
Concern over the impact of greenhouse gas emissions and increasing CO2 concentrations in the atmosphere are driving the search for low-cost and efficient technologies to capture and store or utilize CO2 produced from sources such as power plants. Since a typical 500‑megawatt plant emits 2 to 3 million tons of CO2 per year, capturing CO2 from flue gas holds great potential for reducing overall release of the greenhouse gas into our atmosphere.
NETL and hundreds of technology developers from industry and academia are working together to meet the challenge of devising low-cost, efficient CO2 capture technologies for new and existing pulverized coal power plants. The program goal for DOE’s Emissions and Capture Program is to develop CO2 separation and capture technologies that can achieve at least 90 percent CO2 removal at no more than a 35 percent increase in the cost of energy services.
In the SRI process, CO2 is absorbed in a bed of sorbent pellets and desorbed in a separate reactor that regenerates the sorbent and cycles it back to the absorber. As the test run began, the observed CO2‑capture efficiency was as high as 95 percent and the captured CO2 purity was 95 to 100 percent. Through 7,000 absorption-regeneration cycles, and a total of 130 hours of operation, the sorbent showed little-to-no mechanical or chemical degradation. “SRI’s carbon capture process, which includes both the sorbent and unique process design, looks promising for future applications,” said Andrew O’Palko, the NETL project manager.
As SRI nears completion of the project, they will analyze the test results in detail to determine total system performance and estimated economic benefits. This information will be used for the next steps in scaling-up the sorbent and process: designing a larger, pilot-scale unit of 0.5 megawatts or more in preparation for potential future testing at an operating pulverized-coal boiler.
In addition to researching and developing methods to capture CO2, such as this new solvent, NETL researchers and their technology-development partners also are working on ways to safely and permanently store captured CO2 in underground formations or use it in practical and economic ways, such as in enhanced oil recovery or the creation of products.