Environmental, Energy, and Economic Evaluation of Conventional and Dry Ice Cleaning Technologies in Malaysian Palm Oil Mill☆

Palm oil mills are pivotal to Malaysia’s palm oil industry, producing both crude palm oil (CPO) and palm kernels, and are increasingly influenced by environmental and regulatory frameworks such as the Roundtable on Sustainable Palm Oil (RSPO) and Malaysia Sustainable Palm Oil (MSPO). This study evaluates cleaning technologies in Malaysian palm oil mills by comparing conventional and dry ice cleaning methods, with a particular focus on three dimensions of sustainability: environmental impact, energy efficiency, and cost. The dry ice cleaning method demonstrated superior environmental performance, achieving lower mean values of biochemical oxygen demand (BOD) and total suspended solids (TSS) by 17.01% and 14.30%, respectively. However, conventional cleaning consumed significantly less energy (17.37 MJ m⁻2) than dry ice cleaning (58.37 MJ m⁻2), representing a 70.24% reduction in energy use. Cleaning costs were also reduced by 28.67%. Based on on-site observations, the dry ice cleaning method has the potential to improve workplace safety by effectively removing residues that could cause slip hazards or fire risks. These findings provide practical insights for stakeholders in optimizing and selecting appropriate mill cleaning technologies.