Characterizing Adsorbents for Gas Separations | AIChE

Characterizing Adsorbents for Gas Separations

Porous adsorbents such as zeolites and activated carbons are widely used in industrial gas separations. In order to select a material for a given separation, and to subsequently design and optimize a process, each adsorbent must be thoroughly characterized. Key performance parameters include working capacity, heats or enthalpies of adsorption, and selectivity, each of which can be determined using established laboratory techniques. Although commercial instruments are widely available for this purpose, gas adsorption, particularly at higher pressures, can be challenging to measure accurately, and so careful attention must be paid to potential sources of error. Furthermore, despite the maturity of adsorption technology for producing and purifying industrial gases, considerable scope still exists for further advances in both measurement techniques and instrumentation.

This white paper introduces the information required to characterize the performance of adsorbents for gas separations and describes the main measurement techniques, together with some of the measurement pitfalls. Areas in which further work is required are also highlighted, and advantages and disadvantages of each technique discussed. The aim is to provide useful, practical information for anyone interested in characterizing adsorbents for gas separations. A reference list is also provided for further reading on the topic.