Design And Preparation Of Novel Composite Molecular Sieve And Their Gas Adsorption And Separation Properties

As a kind of porous aluminosilicate material with crystalline morphology, molecular sieve hasthe advantages of uniform pore size, large specific surface area, good thermal stability and greatadsorption capacity. So it has been widely used in numerous fields of gas adsorption and separation,liquid purification, catalytic cracking. The preparation and performance test of new functionalizedmolecular sieve have always been a hot topic, especially the gas adsorption and separationproperties.Based on a review on the research background, present situation, the preparation andapplication of porous material, we prepared a novel composite molecular sieve by using themethod of ion exchange to deal with5A molecular sieve with the organic solvent impregnated. Weexamined and optimized all kinds of preparation conditions including the impregnation solvent, ionexchange time and temperature, thus greatly improved the gas adsorption and separationperformance. Research results show that the molecular sieve after benzene processing hashigh carbon dioxide/nitrogen separation performance. The detailed research work is outlined asfollows:(1) The5A molecular sieve was impregnated with four different organic solvents comparedwith the untreated molecular sieve, then reacted with the ion exchange liquid for different lengthsof time and novel molecular sieves were got. We examined the effects of impregnationsolvents, ion exchange time, ion exchange temperature, solution concentration and otherreaction conditions on the gas adsorption and separation performance.(2) The SEM, TEM, XRD and other methods were used to characterize the morphology,structure and composition of as-prepared molecular sieve, and the results are consistent withthe expected experimental design. (3) Using specific surface area analyzer and high pressure gas adsorption instrument, weresearch the gas adsorption properties of as-prepared molecular sieve of single componentgas carbon dioxide, nitrogen and methane.The results showed that, carbon dioxide adsorption of molecular sieve with the organicsolvent impregnated reduced slightly, but nitrogen adsorption capacity is greatly reducedcontrast to untreated molecular sieve. So the molecular sieve has high carbon dioxide/nitrogen separation performance. And gas adsorption properties of molecular sieve are closelyrelated to the ion exchange time, ion exchange temperature and other factors.