Available Technology

CO2 Separation from Low-Temperature Flue Gases

The Department of Energy’s National Energy Technology Laboratory (NETL) is seeking collaborative research and licensing partners interested in implementing United States Patent Number7,842,126, titled "Co2 Separation from Low-Temperature Flue Gases." Disclosed in this patent are novel methods for processing carbon dioxide (CO2) from combustion gas streams. Researchers at NETL are focused on the development of novel sorbent systems that can effectively remove CO2 and other gases in an economically feasible manner with limited impact on energy production cost. The current invention will help in reducing greenhouse gas emissions by using an improved, re-generable aqueous amine and soluble potassium carbonate sorbent system. This novel solvent system may be capable of achieving CO2 capture from larger emission streams at lower overall cost.
Patent Abstract: 
Sequestration of CO2 produced from coal-fired electric power generating facilities and other stationary sources is an essential part of the U.S effort to mitigate greenhouse gas emissions. With increased global warming due to the presence of greenhouse gases, the capture and permanent sequestration of CO2 is a high priority. Post-combustion capture of CO2 poses a significant engineering challenge due to low CO2 concentration and pressure, trace impurities, and CO2 compression requirements. The NETL-patented technology couples kinetic rate enhancements of amine-based sorbents with phase separation of CO2 and chemical regeneration of the amine sorbent. The CO2 is absorbed into an amine-bearing solution containing dissolved sodium or potassium carbonate. The dissolved CO2 reacts with the carbonate to form the corresponding bicarbonate, which precipitates from solution. The separated bicarbonate solid is then heated to release CO2 and regenerate the carbonate reagent – avoiding the need to heat bulk amine solution. An alternate embodiment of this process uses CO2-loaded amine solutions to promote rapid carbonation of solid streams with significant carbonation potential (e.g., waste cement, CaO-bearing fly ash). Through this carbonation, CO2 is sequestered as a stable mineral carbonate, and the CO2 capture capacity of the amine solution is chemically regenerated.
This novel solvent system represents an alternative pathway to achieve high CO2 capture efficiency with modest regeneration energy requirements -Mineral carbonate additives are chemically stable and relatively non-corrosive -This technology is potentially applicable for CO2 capture from utility emission streams at moderate overall cost
Patent Number: 
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