Carbon Dioxide Adsorption over Activated Biocarbons Derived from Lemon Peel

Area of Science:

• Materials Science
• Environmental Science
• Chemical Engineering

Background:

• Rising atmospheric carbon dioxide (CO2) concentrations pose a significant threat to global ecosystems.
• Porous carbons from biobased waste offer a sustainable pathway for CO2 capture.
• Industrial CO2 emissions require effective mitigation strategies.

Purpose of the Study:

• To develop highly porous carbons from lemon peel waste for selective CO2 adsorption.
• To optimize the synthesis process for enhanced CO2 capture capacity.
• To evaluate the applicability of the Radke-Prausnitz equation for gas-solid adsorption.

Main Methods:

• Two-step synthesis: temperature pretreatment (500 °C) followed by KOH chemical activation (850 °C).
• Varied KOH-to-carbon ratios to determine optimal pore structure.
• CO2 adsorption capacity measurements at 0 °C and 100 kPa.
• Analysis of pore size distribution and specific surface area.

Main Results:

• Activated biocarbon achieved a specific surface area of 2821 m²/g and a total pore volume of 1.39 cm³/g.
• Optimal CO2 adsorption capacity of 5.69 mmol/g was recorded at 0 °C and 100 kPa.
• Micropore volume and distribution were crucial for high adsorption performance.
• The Radke-Prausnitz equation accurately modeled the gas-solid adsorption equilibrium.

Conclusions:

• Lemon peel waste can be converted into highly effective porous carbons for CO2 capture.
• The developed biocarbon demonstrates significant potential for mitigating industrial CO2 emissions.
• The Radke-Prausnitz equation provides a valuable tool for understanding and predicting gas-solid adsorption.