Optimization of Particle Size Blending and Binder Content in Coconut Shell-Based Activated Carbon Monoliths for Methane Adsorption

This study examined the effects of particle size blending and hybrid binder content on the structural properties and methane adsorption behavior of coconut shell-based activated carbon monoliths. Monoliths were prepared using activated carbon particles with two size ranges (212–250 µm and 26–53 µm), blending ratios of 1:9, 3:7, 5:5, and 7:3, and a hybrid binder containing styrene–butyl acrylate (SBA) and carboxymethylcellulose (CMC). Morphology and elemental composition were analyzed by SEM-EDS, specific surface area and pore structure were evaluated by BET analysis, and surface properties were examined by XPS. Structural density and compressive strength were also measured. Among the tested samples, M50ML showed the highest structural density (0.544 g/cm3), compressive strength (27.5 MPa), and methane uptake (3.06 mg/g). This result was related to improved packing by particle size blending while maintaining microporosity. These results indicate that particle size blending and binder content significantly affected the structural properties and methane adsorption behavior of the prepared monoliths.