Powering pineapple industry with pineapple residues - A circular bioenergy strategy for Costa Rica

Costa Rica's pineapple industry produces millions of tons of agricultural residues annually, with pineapple leaves often managed through environmentally harmful open-field burning. This study develops a novel and scalable circular bioenergy strategy that transforms pineapple leaves into compressed renewable natural gas (CRNG) and renewable power, while supporting pineapple cold-chain logistics. The integrated system co-locates anaerobic digestion (AD), CRNG fueling infrastructure, and refrigerated fruit storage at strategically optimized depot sites. Using geographic information systems (GIS), multi-objective optimization (MOO), process modeling and simulation to obtain mass and energy balances, and environmental impact evaluation, a systems-level analysis was conducted across five production sections. The system processes approximately 7.52 million metric tons of pineapple leaves annually, producing 39,530 metric tons of CRNG, 688,504 metric tons of dry pulp, and 5.59 million metric tons of digestate. Energy recovery from CRNG and pulp combustion totals 15.34 billion MJ/year, resulting in a net energy surplus of 10.66 billion MJ/year, enabling the system to fully power its operations and supply additional energy for external use. The environmental impact analysis suggests substantial environmental benefits compared to open burning, including the reduction of 81,211 metric tons of CO2-equivalent emissions, elimination of 14,927 metric tons of particulate matter, and prevention of 2,316 metric tons of acidifying gases and 70,619 metric tons of smog-forming emissions annually, based on the processing of 7.52 million metric tons of pineapple leaves. This integrated approach not only improves energy resilience and rural sustainability but also serves as a replicable model for tropical agricultural systems seeking technically viable, logistically optimized, and environmentally superior solutions for large-scale residue management.