Tailoring Low-Cost Granular Activated Carbons Intended for CO₂ Adsorption

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Physical adsorption using activated carbons is a key method for separating carbon dioxide (CO2) from flue gas and biogas.
• Developing efficient and cost-effective adsorbents is crucial for industrial CO2 capture applications.

Purpose of the Study:

• To prepare granular activated carbons from coconut shells for CO2 adsorption.
• To optimize CO2 adsorption performance on a volume basis using practical and cost-effective methods.

Main Methods:

• Systematic screening of chemical activation (H3PO4, ZnCl2) and physical activation (CO2) parameters.
• Preparation of granular activated carbons from coconut shell biomass.
• Evaluation of CO2 adsorption capacity on both mass and volume bases.

Main Results:

• Achieved high volumetric CO2 uptakes of 2.67 mmol/cm³ at 1.0 bar and 1.17 mmol/cm³ at 0.15 bar.
• Developed activated carbons with a favorable combination of gravimetric CO2 uptake and bulk density.
• Obtained performance comparable to KOH-activated carbons but with fewer restrictions.

Conclusions:

• Cost-effective granular activated carbons from coconut shells demonstrate high volumetric CO2 adsorption performance.
• The developed materials offer a promising alternative for industrial CO2 capture technologies.
• This work advances CO2 adsorption as a viable method for reducing greenhouse gas emissions.