Comparative investigation on the correction factors of hydrogen permeability on CNTs-Mixed matrix membrane

Abstract

This paper discusses different important gas permeation models such as âMaxwellâ, âBruggemanâ, âLewis-Neilsonâ, and âPalâ models to predict âMixed Matrix Membranesâ (MMMs) performance. The main parameter considered and discussed is the permeability of Hydrogen on Carbon Nanotubes (CNTs)-MMM. For evaluation of the theoretical models, experimental data of permeability for H₂ were compared to the theoretical models. The results revealed that, the existing models are not appropriate for evaluation of the permeability of the carbon nanostructure-based MMMs. Therefore, correction factors are needed to fit the selective permeability of carbon nanostructure-based MMMs for selective separation of various gaseous such as H₂ or CO₂. This correction factor robustly depends on the morphology of carbon nanostructures, the defect, kind and amount of metal/metal oxide nanoparticles, doped on carbon substrate and functional groups in the carbon matrix. Hence, to be in a good agreement with experimental data for separation of H₂ from CO₂, the correction value was estimated to -0.0022 for single-walled carbon nanotubes (SWCNTs), -0.0032 for pure multi-walled carbon nanotubes (MWCNTs), -0.0044 for carbon nanofibers (CNFs).