Life cycle assessment of the production processes for high-value biomass derivatives HMF and FDCA

The production of high-value-added products from biomass is a key strategy for advancing carbon neutrality. This approach not only reduces dependence on fossil resources but also enhances the economic value and utilization efficiency of renewable materials. 5-hydroxymethylfurfural (HMF) and 2,5-furan dicarboxylic acid (FDCA) are potential candidates for producing high-value-added chemicals via carbon-neutral pathways. This study conducts life cycle assessment (LCA) in accordance with ISO 14,040/44 standards, defining the functional unit as 1 ton of straw (for HMF production) and 284.34 kg of HMF (for FDCA production). Results show HMF_straw outperforms HMF_fructose in all categories, reducing 87.73 kg CO₂ eq and 7.87 kg 1,4-DB eq per unit product. HMF_fructose has 23.46%-27.83% higher aquatic/sediment ecotoxicity. Sensitivity analysis indicates that replacing the existing power structure (60% coal-fired power + 40% renewable energy) with 100% renewable energy can reduce global warming potential GWP by 74.56%. Replacing dichloromethane (DCM) with γ-valerolactone (GVL) reduces HT by 63.36%. Crystallization for FDCA is more sustainable than distillation, reducing abiotic depletion, acidification, human toxicity and photochemical oxidation by 50.22%-59.02%, and ~ 20% in fossil energy and global warming potential. The results confirm that straw is an environmentally viable feedstock for HMF production, crystallization represents more sustainable pathway for FDCA synthesis, and optimizing the power structure alongside solvent substitution can significantly reduce environmental impacts. This provides quantifiable reference criteria for green optimization in biomass chemical processes.