Abstract
A triple-port automatic high-pressure volumetric sorption analyzer was set up for sorption measurements over the temperature range of (273.15-368.15) K and pressures up to 10 MPa. The main function of this apparatus is to rapidly screen porous materials for the separation of a specific gas mixture by measuring adsorption isotherms. Measurements with empty sample containers were carried out to evaluate potential systematic errors. Validation measurements on commonly studied cases (CO(2) adsorption on Zeolite 4A, ZIF-8, and Zeolite 13X) were performed, and the excellent agreement with results of literature indicates the high reliability of the measurement system. A comprehensive uncertainty analysis was carried out to determine the uncertainty of measurement results and to propose future improvements of the system. Later, the measurement system was applied to screen suitable materials for the separation of refrigerant blends, which are composed of six pure refrigerants (R-32, R-125, R-1234yf, R-134a, R-1234ze-(E), and R-290). The studied porous materials include six metal-organic framework samples, five zeolite samples, and one activated carbon sample. The results show that all zeolite samples investigated (Köstrolith 3AK, 3ABFK, 3ABFK-(HSD), 4AK, and 4ABFK) exhibit a higher adsorption capacity for R-32 than for the other five refrigerants, with Köstrolith 4ABFK showing the highest selectivity. This makes it possible to use any of these zeolite samples to separate R-32 from the R-410A blend (a mixture of R-32 + R-125, to be phased down in the European Union) or even separate R-32 from the mixtures composed of any of these six refrigerants. The other studied porous samples do not yield any promising results for the refrigerant blend separation.