CO₂ Desorption Performance from Imidazolium Ionic Liquids by Membrane Vacuum Regeneration Technology

Area of Science:

• Chemical Engineering
• Materials Science

Background:

• Solvent regeneration is crucial for post-combustion CO2 capture and utilization (CCU).
• High-purity CO2 is essential for technical valorization.
• Conventional amine-based absorbents have limitations in CO2 capture processes.

Purpose of the Study:

• To evaluate the membrane vacuum regeneration (MVR) process for solvent regeneration in CCU.
• To assess the performance of physical and physico-chemical absorbents, specifically the ionic liquid [emim][Ac].
• To develop and validate a mathematical model for the MVR process in a hollow fiber membrane contactor (HFMC).

Main Methods:

• Desorption tests using polypropylene hollow fiber membrane contactors (PP-HFMC).
• Development of a two-dimensional, pseudo-steady-state mathematical model for the MVR process.
• Model validation using experimental CO2 absorption-desorption data under varying vacuum pressures and temperatures.

Main Results:

• The ionic liquid [emim][Ac] demonstrated suitability as an alternative absorbent.
• MVR efficiency significantly increased from 3% at 500 mbar to 95% at 40 mbar vacuum pressure.
• Sensitivity analysis of Henry's constant and chemical interaction parameters provided insights into process behavior.

Conclusions:

• MVR is a highly effective technology for CO2 solvent regeneration in CCU.
• The developed mathematical model accurately predicts MVR performance.
• The study contributes to understanding and optimizing CO2 capture and utilization processes.