Wood-Inspired Ultrafast High-Performance Adsorbents for CO₂ Capture

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Amine-based solid adsorbents face challenges in adsorption kinetics and long-term stability for carbon dioxide (CO2) capture under regeneration conditions.
• Existing adsorbents struggle with efficiency and durability, hindering practical CO2 removal applications.

Purpose of the Study:

• To develop a novel CO2 adsorbent with enhanced adsorption kinetics, high capacity, and excellent stability.
• To utilize a biochar derived from natural wood as a carrier for organic amines, inspired by its ordered pore structure and thermal conductivity.

Main Methods:

• Preparation of a biochar carrier from natural wood with a highly ordered pore structure and excellent thermal conductivity.
• Impregnation of the biochar carrier with organic amines to create advanced CO2 adsorbents.
• Evaluation of adsorption working capacity, long-term cycle stability under harsh conditions (120 °C, 100% CO2), adsorption kinetics, and regeneration heat.

Main Results:

• The prepared biochar-based adsorbent exhibited a high adsorption working capacity of 4.23 mmol CO2·g-1.
• The adsorbent maintained stable performance over 30 adsorption-desorption cycles under harsh conditions.
• Ultra-fast adsorption kinetics were observed, with a reaction rate constant 37 times higher than traditional silica.
• A low regeneration heat of 1.64 MJ·kg-1 (CO2) was achieved, crucial for practical applications.

Conclusions:

• Biochar-based adsorbents derived from natural wood offer a promising solution for efficient and stable CO2 capture.
• The hierarchical structure of the biochar enhances adsorption kinetics and overall adsorbent performance.
• These findings pave the way for more practical and cost-effective CO2 capture technologies.