CO₂ capture by microporous carbon based on Brazil nut shells.

Area of Science:

• Materials Science
• Environmental Science
• Chemical Engineering

Background:

• Rising carbon dioxide (CO2) emissions from human activities intensify the greenhouse effect and drive climate change.
• Urgent need for effective CO2 capture technologies to mitigate climate change.
• Porous carbon materials from lignocellulosic waste offer a sustainable and cost-effective solution for CO2 capture.

Purpose of the Study:

• To synthesize activated carbon from Brazil nut biomass residues for CO2 capture.
• To investigate the efficacy of physical and chemical activation methods in producing porous carbon.
• To evaluate the CO2 adsorption performance of the synthesized materials.

Main Methods:

• Synthesis of activated carbon from Brazil nut lignocellulosic residue using physical and chemical activation.
• Characterization of porous structure using N2 adsorption-desorption isotherms.
• Measurement of CO2 adsorption capacity at different temperatures and pressures.

Main Results:

• Both physical and chemical activation yielded microporous carbon structures.
• Chemical activation resulted in higher surface areas (1421–2730 m²/g) compared to physical activation (912 m²/g).
• The chemically activated sample (BS6-K1) demonstrated superior CO2 adsorption (3.8 and 6 mmol/g at 25°C and 0°C, respectively), attributed to a high volume of ultramicropores.

Conclusions:

• Activated carbon synthesized from Brazil nut residues is a viable precursor for CO2 capture materials.
• The developed material offers a sustainable and efficient alternative for CO2 mitigation technologies.
• The high CO2 adsorption capacity is linked to the material's specific microporous structure.