Modeling, Simulation, and Membrane Wetting Estimation in Gas-Liquid Contacting Processes Including Shell-Side...

Area of Science:

• Chemical Engineering
• Environmental Science
• Separation Processes

Background:

• Biogas upgrading is crucial for utilizing methane (CH4) as a renewable energy source.
• Carbon dioxide (CO2) removal is a key step in biogas purification.
• Membrane contactors offer a promising technology for gas-liquid separations.

Purpose of the Study:

• To assess mass transfer models for CO2 removal in a gas-liquid membrane contactor.
• To optimize operating conditions for efficient CO2 capture and CH4 recovery.
• To develop a predictive correlation for CO2 removal based on experimental data.

Main Methods:

• Experiments were conducted in a 3 M Liqui-Cel MM-1.7 × 5.5 membrane module.
• An aqueous solution of 0.25 M diethanolamine (DEA) was used as the solvent.
• Gas and liquid flow rates were systematically varied to evaluate CO2 removal and CH4 recovery.

Main Results:

• CO2 removal efficiencies exceeding 67% and reaching 100% were achieved.
• Optimal biogas and solvent flow rates were identified for maximum performance.
• A correlation was developed to interpolate CO2 removal based on flow rates.
• Wetting values were found to be dependent on liquid flow rate and less sensitive to gas flow rate.

Conclusions:

• The study validates mass transfer models and provides insights into membrane wetting phenomena.
• The developed correlation aids in predicting CO2 removal efficiency for biogas upgrading.
• The choice of shell-side correlation significantly impacts the analysis of mass transfer and wetting.