Zeolite vs MOF Membranes For Carbon Dioxide Separation: Which Is Best?

Carbon dioxide separation from light gases is a very important environmental and energy issue. The state-of-the-art process for the purification of CO2 from gases uses amine adsorption , which is a complex , and costly approach. Membrane separation technology is far less expensive and requires less energy consumption. Feasibility studies demonstrate that membranes are a technically and economically viable option for CO2 capture from flue gas and natural gas treatment. This presentation focuses on two type of families of membranes that have shown promise to separate carbon dioxide from light gases: traditional zeolites , and emerging metal organic frameworks. Zeolite (inorganic crystalline structures with uniform-sized pores of molecular dimensions) membranes have highly desirable separation properties such as molecular sieving ability , high thermal , mechanical , and chemical stability. The molecular sieving ability of zeolite membranes has been exploited for a vast number of relevant gas mixture separations , including CO2 separation from N2 and CH4. Although zeolite membranes can separate CO2 from light gases , the development of superior performance membranes for gas mixture separations requires novel materials with fundamentally different structural , compositional , adsorption and transport properties than those of zeolites. In this respect , metal organic frameworks , have emerged as a novel type of microporous crystalline materials which combine highly desirable properties , such as uniform micropores , high surface areas , and exceptional thermal and chemical stability , making them ideal candidates for gas mixture separation applications. Several MOF compositions , in membrane form have demonstrated to be effective for separating CO2 from other gases. In this presentation , the advantages and limitations of relevant zeolite and MOF membrane compositions for CO2 separation are discussed. Finally , representative examples of zeolite vs MOF membranes for CO2 separation are compared to answer the question: which is best?