Preparation of Granular Biochar from Citrus Pomace

Citrus pomace is a major by-product of citrus processing; however, its utilization remains limited because of its high moisture content and low pH.In this study, granular biochar was produced by first fabricating binderfree granules using the natural binding components of citrus pomace, followed by carbonization.Citrus tree pruning residues were blended with the pomace to control moisture content and to improve granule formability and carbonization characteristics.The proposed granulation-carbonization process produced biochar with a uniform particle size and shape, which markedly improved carbonization uniformity and product consistency compared with conventional biochar prepared from irregular biomass.The quality of the resulting biochar was evaluated based on its pH and elemental characteristics, including the H/C and O/C atomic ratios, confirming that high-quality biochar can be produced through the proposed process.In addition, the granular biochar generated fewer fines, thereby improving production yield and handling properties.Incorporating inorganic additives further demonstrated the potential to produce functional biochar with adjustable pH and nutrient-supplying capability.Overall, the proposed production process provides an effective strategy for the high-value utilization of citrus processing residues, and the resulting granular biochar offers considerable potential as an environmentally friendly soil amendment.