CO2 Separation Membrane for Incipient Flue Gas

There are increasingly greater legislative, social, and environmental factors motivating reductions in the emission of man-made carbon dioxide and other greenhouse gases to the atmosphere. Fossil fuel power plants collectively produce the largest fraction of man-made carbon dioxide emissions. The cost of separating carbon dioxide from the flue gas of power plants is prohibiting the application of carbon capture and sequestration methods for lowering the emission of carbon dioxide into the atmosphere. The conventional carbon dioxide separation methods consume about 10 to 30 times more energy than the theoretical minimum requirement and have infrastructure costs that rivals that of the power plant itself. A new approach is needed to retrofit existing fossil fuel power plants for cost effective carbon capture and sequestration. An energy efficient approach is separating carbon dioxide from the flue gas while it is still at high temperature and pressure and has the energy gradients to drive its own separation. Passive membrane separation of carbon dioxide from flue gas at the incipient conditions improves heat and mass transfer to lower the energy costs of carbon dioxide capture. A carbon dioxide separation membrane technology that can operate on the flue gas does not presently exist due to the challenging conditions of 250 – 600 °C, residual oxygen, and water vapor. A new passive separation membrane technology is, however, being proposed that has the potential to sustainably operate in these extreme conditions. Related fields of research have recently revealed that an inorganic liquid may have the chemical properties required to separate carbon dioxide from the flue gas while it is still hot and pressurized. Existing approaches will be applied to retain the liquid in porous structural materials using capillary action to fabricate the membrane. The interactions of the inorganic liquid with carbon dioxide will be measured to verify the potential for practical separation rates. A new carbon dioxide separation membrane technology will be developed that has the potential to make carbon capture and sequestration cost effective. The application of this membrane technology to new and existing fossil fuel power plants will significantly lower carbon dioxide emissions in the United States. Commercial Application and Other Benefits: The proposed membrane technology has the potential to facilitate a reduction in the United States’ carbon dioxide by 10 – 20 % by avoiding 10’s of billion $ per year carbon dioxide separation costs. A significant reduction in carbon dioxide emissions is expected to have a positive effect on the environment.