Reference #: 00815
Background:
The technical approach to reduce CO2 emissions is simply to avoid the emissions to the atmosphere by capturing and storing it at either the pre-combustion or post-combustion stage. At either stage, CO2 has to be separated from either a reducing fuel stream (pre-combustion) or an oxidizing flue gas stream (post-combustion) into a highly concentrated form, from which CO2 can then be further compressed into a liquid form and stored via geologic sequestration. The technologies available for CO2 separation include mechanical scrubbing and poly-amine solvent-based physical adsorptions. The former is mainly used in separating CO2 from CH4 (or natural gas) and the latter is widely employed in CO2 separation in flue and fuel gas streams of power plants. Unfortunately, both methods are energy-intensive and cost-prohibitive for large-scale commercial applications. Therefore, developing a cost-effective and separation-efficient CO2 capture technology is scientifically interesting but industrially demanding.
Invention Description:
Dr. Huang has invented a novel mixed carbonate ion and electron conducting membrane that is capable of electrochemically separating CO2 from a flue gas mixture. The mixed conducting membrane is comprised of two phases. The first phase is the electron-conducting porous metal, and the second phase is the carbonate ion conducting molten carbonates that are held in the pores of the porous metal substrate by the capillary force. The realization of CO2 separation is also assisted by reactant gases such as H2 and CO. The chemical reactor built upon the mixed conducting membrane and assisted by the reactant gases produces two stream lines: one is the CO2-free flue gas and the other is the mixture of CO2 and H2O. A fraction of the latter is also recycled to regenerate the needed reactant gas via a coal gasification reactor and a steam methane reforming reactor for the subsequent CO2 separation. The majority of the effluent then undergoes a physical condensation of H2O to achieve a pure stream of CO2 as the product.
Potential Applications:
The invented technology can be potentially be applied to separate and capture CO2 in flue gas produced from existing coal-fired power plants.
Advantages and Benefits:
• No secondary conception needed
• Cost-effective method to reduce CO2 emissions
• Separation-efficient method to reduce CO2 emissions