Journal Article

Determination of binary CO2/H2 adsorption isotherms and kinetics over porous organic cage CC3 via zero-length column technique

Rownaghi, Ali A., Moreno, Jimmy D. L., Rezaei, Fateme, Newport, Kyle

2024

Overview

Understanding the dynamics of mixed-gas adsorption is essential for industrial-scale adsorptive separations. Also, obtaining binary adsorption isotherms is essential to gain a better understanding of adsorbate-adsorbent interactions in multicomponent gas mixtures. Porous organic cages (POCs) are highly porous, crystalline materials, with a small average pore window that make them promising candidates for separation applications. In this work, we utilized zero-length column (ZLC) technique to not only determine the kinetics of CO 2 /H 2 separation over CC3 but also obtain the binary adsorption isotherms. The ultracrystalline diffusivities of 1.49 × 10 –4 and 8.31 × 10 –5 cm 2 .s -1  were estimated from the ZLC desorption profiles for unary CO 2 and H 2 gases at 293 K, respectively, whereas in binary CO 2 /H 2 mixture, these diffusion values were reduced by 18 and 19 times, respectively. Moreover, our results indicated that the adsorption capacities estimated from binary runs diminished by approximately 36.0% and 33.6% for CO 2 and H 2 , respectively, relative to the unary runs. The findings of this investigation highlight the importance of the ZLC technique in providing valuable insights on mixture adsorption equilibrium and dynamics without the need for tedious and complex experiments.

• Publisher: Springer US,Springer Nature B.V
• Subject: Adsorbents / Adsorption / Adsorptivity / Carbon dioxide / Chemistry / Chemistry and Materials Science / Diffusion models / Engineering Thermodynamics / Equilibrium / Experiments / Gas mixtures / Gases / Heat and Mass Transfer / Industrial Chemistry/Chemical Engineering / Isotherms / Kinetics / Porous materials / Separation / Surfaces and Interfaces / Thin Films / Zero length column