Development, construction, and operation of a multisample volumetric apparatus for the study of gas adsorption equilibrium

The construction of a simple volumetric adsorption apparatus is highlighted. The setup is inexpensive and provides a clear demonstration of gas phase adsorption concepts. The topic is suitable for undergraduate chemistry and chemical engineering students. Moreover, this unit can also provide quantitative data that can be used by young researchers to screen the adsorption capacity of different adsorbent materials for various gases. A Labview-based interface was developed to allow the students to perform automated data acquisition and unit control. The laboratorial setup permits the simultaneous measurement of gas adsorption equilibrium on two adsorbent samples, up to 20 bar over a wide temperature range (303-1373 K). The quality of the obtained data was validated by comparison with adsorption isotherms recorded on a high-precision gravimetric apparatus. For this purpose, adsorption equilibria of carbon dioxide (CO₂) at 303 and 353 K and nitrogen (N₂) at 323 K were recorded on a commercial sample of metal-organic framework MIL-53(Al) as well as on activated carbon. The recorded data were in good agreement with the data obtained by gravimetry, which suggests the validity of the data produced using the new setup.