A typical 500 MW coal-fired power plant emits 2 million to 3 million tons of CO2 per year, so the successful bench-scale test bodes well for the sorbent’s use as a means to reduce GHGs, according to DOE.
Advanced Technology Materials Inc., subcontractor to non-profit research institute SRI for the DOE-sponsored test at the University of Toledo, originally developed the sorbent, called BrightBlack, for a different application. SRI partnered with DOE’s National Energy Technology Laboratory and others to develop a method to use the sorbent to capture CO2 in a less-energy-intensive process, compared to the typical, amine-based CO2-capture processes.
In the SRI process, a bed of sorbent pellets absorbs CO2, which is then desorbed in a separate reactor that regenerates the sorbent and cycles it back to the absorber.
The tests showed 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, according to NETL scientists.
SRI’s next step will be to scale up the sorbent and process, designing a larger, pilot-scale unit of 0.5 MW or more in preparation for potential future testing at an operating pulverized-coal boiler.
In addition to researching and developing methods to capture CO2, 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.
North America’s geological formations have the capacity to store 500 years of CO2 emissions, according to an atlas produced in May by the United States, Canada and Mexico.
A report published in April by the International Energy Agency and Global CCS Institute said there has been “limited progress” made by committed governments in reviewing opportunities for carbon capture systems in industry since 2011.
In July 2011, American Electric Power shelved plans to build one of the nation’s first carbon capture and storage facilities, terminating its agreement with the DOE.