Single and Multicomponent Sorption of CO₂, CH₄ and N₂ in a Microporous Metal-Organic Framework

Abstract

Single and multicomponent fixed-bed adsorption of CO₂, N₂, and CH₄ on crystals of MOF-508b has been studied in this work. Adsorption equilibrium was measured at temperatures ranging from 303 to 343 K and partial pressures up to 4.5 bar. MOF-508b is very selective for CO₂ and the loadings of CH₄ and N₂ are practically temperature independent. The Langmuir isotherm model provides a good representation of the equilibrium data. A dynamic model based on the LDF approximation for the mass transfer has been used to describe with good accuracy the adsorption kinetics of single, binary and ternary breakthrough curves. It was found that the intra-crystalline diffusivity for CO₂ is one order of magnitude faster than for CH₄ and N₂.

Keywords:

• CO₂ separation
• dynamic simulation
• fixed bed
• dynamic
• metal-organic framework
• multi-component adsorption
• natural gas

Notes

b, Binary experiment; t, Ternary experiment.