VALORIZATION OF PALM KERNEL SHELL BIOCHAR AND BOILER ASH INTO SOLID ORGANIC FERTILIZER: DEVELOPMENT AND QUALITY EVALUATION

Abstract

Palm oil processing generates substantial solid waste that remains underutilized despite its significant potential as a renewable biomass resource. Among these residues, palm kernel shells and boiler ash are particularly promising due to their complementary nutrient profiles, with high organic carbon (C) and potassium (K) contents, respectively. This study aims to develop and evaluate a solid organic fertilizer derived from these materials and to assess its chemical quality in accordance with SNI 7763:2024 standards. The research involved optimization of three fertilizer formulations using different proportions of palm kernel shell biochar and boiler ash, followed by comprehensive chemical and nutrient analyses. The results demonstrate that the optimal formulation yields a nutrient-enriched fertilizer containing nitrogen (N) 0.82%, phosphorus (P) 4.355%, potassium (K₂O) 3.97%, magnesium (MgO) 3.44%, organic carbon (C) 15.41%, iron (Fe) 7283.8 ppm, and zinc (Zn) 589 ppm. All parameters meet the quality requirements specified in SNI 7763:2024, indicating the product's suitability as a solid organic fertilizer. These findings highlight the potential of palm oil biomass waste as a value-added resource for sustainable fertilizer production, contributing to circular agro-industrial development, waste valorization, and environmental sustainability.

Keywords: Biochar; Boiler Ash; Palm Kernel Shell; Slow-Release Fertilizer.