Equilibrium and kinetic modeling of hydrogen adsorption on several Activated Carbon and Metal-Organic Framework adsorbents

Abstract

This study investigates the equilibrium and kinetic modeling of hydrogen gas adsorption on five activated carbon adsorbents (AX-21, AUK, FAS-3, PAU-700, and FAS-2008) and three Metal-Organic Framework (MOF) adsorbents (IRMOF-1, CO₂(m-dobdc), and Ni₂(m-dobdc)). Equilibrium modeling was conducted using the Langmuir and Sips isotherm models. According to the Langmuir model, within the pressure range of 0–5 MPa, the FAS-3 adsorbent exhibited the highest adsorption capacity among the activated carbons, while AX-21 showed superior performance in the 5–10 MPa range. For the MOF adsorbents, Ni₂(m-dobdc) demonstrated the highest adsorption capacity. The Sips isotherm model also identified Ni₂(m-dobdc) as the leading adsorbent for hydrogen adsorption across all tested materials. For kinetic modeling, the linear driving force (LDF) model was initially validated for CH₄/He adsorption on an MOF adsorbent and subsequently applied to hydrogen adsorption studies on the other adsorbents. The breakthrough curve for Ni₂(m-dobdc) exhibited a lower slope within the 0–600s timeframe, indicating greater mass transfer resistance and delayed breakthrough compared to other adsorbents. Overall, the Ni₂(m-dobdc) adsorbent demonstrated superior performance in both equilibrium and kinetic modeling for hydrogen gas adsorption.