Carbon Dioxide Separation from Flue Gas By Phase Enhanced Absorption. Report for July 1, 2004 to June 30, 2007.

Hu, L.

Technical Information Center Oak Ridge Tennessee

关键词: Flue gas;    Carbon dioxide;    Separation processes;    Enhanced absorption;    Potassium carbonates;   

RP-ID  :  DE2009945929

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

A new process, phase enhanced absorption, was invented. The method is carried out in an absorber, where a liquid carrier (aqueous solution), an organic mixture (or organic compound), and a gas mixture containing a gas to be absorbed are introduced from an inlet. Since the organic mixture is immiscible or at least partially immiscible with the liquid carrier, the organic mixture forms a layer or small parcels between the liquid carrier and the gas mixture. The organic mixture in the absorber improves mass transfer efficiency of the system and increases the absorption rate of the gas. The organic mixture serves as a transportation media. The gas is finally accumulated in the liquid carrier as in a conventional gas-liquid absorption system. The presence of the organic layer do not hinder the regeneration of the liquid carrier or recovery of the gas because the organic layer is removed by a settler after the absorption process is completed. In another aspect, the system exhibited increased gas-liquid separation efficiency, thereby reducing the costs of operation and maintenance. Our study focused on the search of the organic layer or transportation layer to enhance the absorption rate of carbon dioxide. The following systems were studied, (1) CO2-water system and CO2-water-organic layer system; (2) CO2-Potassium Carbonate aqueous solution system and CO2-Potassium Carbonate aqueous solution-organic layer system. CO2-water and CO2-Potassium Carbonate systems are the traditional gas-liquid absorption processes. The CO2-water-organic layer and CO2-Potassium Carbonate-organic layer systems are the novel absorption processes, phase enhanced absorption. As we mentioned early, organic layer is used for the increase of absorption rate, and plays the role of transportation of CO2. Our study showed that the absorption rate can be increased by adding the organic layer. However, the enhanced factor is highly depended on the liquid mass transfer coefficients for the CO2-water-organic layer system. For the CO2-Potassium Carbonate aqueous solution-organic layer system, the enhanced factor is not only depended on the liquid mass transfer coefficients, but also the chemical reaction rates.