Homogenization of the Dense Composite Membranes for Carbon Dioxide Separation

A possible approach to the carbon dioxide removal from flue gases is application of the dense composite membrane (matrix: polymer material; dispersed phase: zeolite powder). This type of membrane is based on a solution-diffusion mechanism. Carbon dioxide is dissolved in the membrane bulk, and then diffuses to the permeate side. A successful membrane should have high permeability of the carbon dioxide and low permeability for all other gasses commonly present in the combustion process (oxygen, nitrogen, hydrogen...). The main challenge is to provide good contact between long and usually hydrophobic polymer chains and relatively small, but electrically charged, zeolite particles. Two different polymers and four different zeolites were tested for this purpose. As the polymer bulk material, different co-polymers of ethylene-oxide and phthalimide were used. Five different zeolite powders in combination with two different potential additives were tested.