Development of an Electrochemical Process for High Efficiency CO2 Separation and Concentration Using Quinone Carriers

76035-As the U.S. becomes increasingly dependent on foreign energy sources, environmental concerns with CO2 emissions may stifle increased development of domestic coal energy. The prominent methods of carbon dioxide capture, using pressure and temperature swing processes, have thermodynamic limitations that result in low efficiencies and unacceptable added energy costs. New technologies, which are not reliant on pressure and temperature swing processes, are needed to reduce the costs associated with the direct capture of CO2. This project will develop quinine-based CO2 carriers and demonstrate a process for electrochemical CO2 separation-pumping from post combustion gas streams, providing a final product concentration of 99% from an initial 1% concentration in the source stream. Phase I will determine the electrochemical CO2 pumping performance with d-CNQ (a model carrier) in simulated post combustion flue gas streams containing typical amounts of oxygen, sulfur dioxide, and nitric oxide. Temperature dependence, oxygen sensitivity, carrier stability, solubility, and CO2 binding constants of the baseline quinone will be determined, and a continuous bench-top system will be demonstrated. Commercial Applications and Other Benefits as described by the awardee: The technology should have extensive application for sequestering CO2 in coal fired power plants, resulting in potential energy cost savings of more than $2 billion/year by 2012. Other potential applications include low-cost separation of CO2 from acid gas wells, enabling new options for developing natural gas resources, and pre-combustion CO2 separation from coal or biomass gasification streams in the production of fuels and chemicals.