Unary and Binary Dynamic Column Breakthrough Experiments with Carbon Dioxide and Nitrogen Imaged by X-ray Computed...

Area of Science:

• Materials Science
• Chemical Engineering
• Physical Chemistry

Background:

• The digital adsorption (DA) method combines adsorption experiments with X-ray computed tomography (XCT).
• Previous applications focused on strongly adsorbing CO2 in unary systems.
• Extending DA to weakly adsorbing N2 and binary CO2-N2 systems presents unique challenges.

Purpose of the Study:

• To adapt and validate the DA method for weakly adsorbing N2 and binary CO2-N2 systems.
• To investigate the influence of X-ray attenuation by the bulk phase for different adsorbates.
• To assess the DA method's capability in describing dynamic adsorption processes.

Main Methods:

• Equilibrium adsorption isotherm measurements using DA on activated carbon and zeolite 13X at 294.15 K (0.1–9 bar).
• Unary dynamic column breakthrough (DCB) experiments with N2.
• Binary CO2-N2 DCB experiments complemented by a 1D DCB model.

Main Results:

• X-ray attenuation considerations are crucial for weak adsorbates and at high pressures for strong adsorbates.
• DA method, with a correction factor, accurately describes transient N2 adsorption under equilibrium-controlled conditions.
• Binary DCB experiments captured dynamic adsorption behavior, including gas uptake rates and thermal roll-up effects.

Conclusions:

• The DA method is successfully extended to weakly adsorbing N2 and binary CO2-N2 systems.
• XCT provides valuable insights into dynamic adsorption phenomena.
• The DA method, when carefully applied, is a powerful tool for studying complex adsorption processes.