Valorization of Crab Shells as Potential Sorbent Materials for CO₂ Capture

Area of Science:

• Materials Science
• Environmental Science
• Chemical Engineering

Background:

• Conventional porous adsorbents like zeolites, silicas, metal-organic frameworks (MOFs), and porous carbons are widely used for CO2 capture.
• Crab shell waste presents an underutilized, sustainable resource with inherent porosity and nitrogen-bearing groups suitable for CO2 adsorption.

Purpose of the Study:

• To investigate the potential of crab shells as sustainable solid adsorbents for CO2 capture.
• To enhance the CO2 adsorption properties of crab shells through selective deproteinization and demineralization treatments.
• To analyze the impact of these treatments on the textural properties, CO2 adsorption capacity, and speciation.

Main Methods:

• Selective deproteinization and demineralization of crab shells.
• Characterization of textural properties (e.g., surface area).
• Solid-state Nuclear Magnetic Resonance (NMR) spectroscopy for atomic-scale speciation analysis.
• Measurement of CO2 adsorption capacity at standard conditions (1 bar, 298 K).

Main Results:

• Optimized crab shell samples achieved a surface area of 36 m²/g.
• The best-performing sample demonstrated a CO2 adsorption capacity of 0.31 mmol/g.
• Adsorption capacity and surface area showed significant gains (∼3.5 and 2 times, respectively) compared to pristine crab shells.

Conclusions:

• Treated crab shells are effective and sustainable solid adsorbents for CO2 capture.
• Fishing industry waste can be transformed into valuable, eco-friendly materials for carbon capture applications.
• This approach offers a cost-effective and renewable alternative to conventional adsorbents.