From Green to Black Gold: Highly Microporous Carbons from Pistachio Shells by a Controlled Physical Activation...

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Growing generation of pistachio shell waste.
• Increasing demand for high-surface-area carbon materials.
• Need for sustainable and cost-effective synthesis methods.

Purpose of the Study:

• To develop highly microporous carbons from pistachio shells.
• To optimize the physical activation process using carbon dioxide (CO2).
• To explore different pre-treatment strategies for enhanced porosity.

Main Methods:

• Biomass pre-treatment of pistachio shells.
• Hydrothermal carbonization for enhanced aromatization and mineral removal.
• Benign CO2 physical activation process.
• Tuning microstructure, mineral content, and particle morphology.

Main Results:

• Synthesis of highly microporous carbons with BET surface areas up to 3300 m²/g and pore volumes up to 1.6 cm³/g.
• Hydrothermal carbonization proved most effective for porosity generation.
• Increased activation temperature reduced operation time without compromising pore development.
• Optimized strategies for pore structure, energy consumption, and product yield.

Conclusions:

• Pistachio shells are a viable precursor for high-quality microporous carbons.
• CO2 activation combined with specific pre-treatment offers an efficient and sustainable route.
• The developed methods provide integral strategies for biomass-based carbon production.