Influence of Impregnation of Sodium Carbonate Catalyst on Physicochemical Properties of Biochar †

Biochar (BC) has been a viable resource in producing functionalised carbonaceous materials beneficial in soil fertility, environmental remediation, and energy recovery. In this study, the influence of Na₂CO₃ on the pyrolytic conversion of green pea peels to BC was examined to assess BC’s yield and physicochemical characteristics. Experiments were conducted in batch processes at a constant temperature of 500 °C by wet impregnation using 0%, 10%, 20%, and 30% (w/w) ratios of Na₂CO₃ catalyst to biomass weight. Characterisations of the produced BC materials were conducted by bomb calorimetry, SEM, BET, FTIR, and XRD. Accordingly, catalyst incorporation by pretreatment resulted in a decrease in yield while increasing the porous development. The specific surface area at a constant temperature increased from 1.006 to 17.7 m² g⁻¹, and the pore diameter decreased from 173.1 to 9.283 nm. The oxygenated functional groups negatively correlated with the increase in the amount of catalyst, whereas the calorific values of the synthesised materials increased from 20.313 kJ g⁻¹ to 25.479 k Jg⁻¹ when the catalyst impregnation ratio was enhanced from 0% to 30%, indicating that BC produced from catalysed processes demonstrates better energy recovery potential.