Sustainable ethyl levulinate production from oil palm empty fruit bunch: Integrated techno-economic analysis and life cycle assessment

Abstract

Environmental concerns regarding non-renewable energy sources have driven a critical shift towards sustainable bio-based chemical production methods. Among these, the conversion of oil palm empty fruit bunch (EFB) to ethyl levulinate (EL) offers a low-toxic, biodegradable, high-performance fuel additive. This study established a multi-dimensional feasibility framework to evaluate the three conversion pathways using Aspen Plus simulation: a three-step conversion of cellulose-derived glucose via 5-hydroxymethylfurfural (5-HMF) and levulinic acid (LA) to EL (Route 1), and two furfural-based configurations valorising the hemicellulose fraction via furfuryl alcohol (Route 2) or intermediate LA production (Route 3). To determine the optimal design, a multi-criteria sustainability index (SI) was developed by integrating technical yield with economic profitability from techno-economic analysis (TEA) and environmental impact from life cycle assessment (LCA). Route 2 achieved an SI of 1 across the entire weighting space. This streamlined two-step furfural pathway achieved a technical yield of 23.5 wt% EL, an annual profit of RM 100.37 million, and a global warming potential (GWP) impact score of 4.98 tonnes of CO 2 -eq/tonne EL. Its dominance is driven by reduced complexity, lower capital investment, and decreased utility-related emissions. Although Route 3 yielded 23.0 wt% EL, its intensive energy requirements resulted in a higher GWP of 17.93 tonnes CO 2 -eq/tonne EL. Route 1 remained the least competitive overall, though it became more competitive than Route 3 only when environmental weighting exceeds approximately 32–88%. Process simplification effectively aligns technical, economic, and environmental objectives, thereby providing a robust model for the Malaysian circular bioeconomy.