Environmentally friendly process design for furan-based long-chain diester production aiming for bio-based lubricants†

Increasing environmental issues and depletion of fossil resources highlight the need to develop sustainable lubricant production technologies. This study endeavored to produce various biomass-derived furan diesters and evaluate their physical properties against conventional lubricants. Among the synthesized furan diesters, the THFDM-C18 diester, produced via the esterification of THFDM and oleic acid, was identified as a promising candidate for base oils due to its broad applicability as well as environmentally benign properties. Based on our experimental results, which include the hydrogenation of HMF to 2,5-tetrahydrofuran dimethanol (THFDM) using Ru/Al₂O₃ (achieving a 95.6% yield of THFDM) and subsequent esterification with C18-fatty acids to produce the THFDM-C18 diester using Amberlyst-15 (achieving a 91.0% yield of the THFDM-C18 diester), a simulation model was developed, which showed 62 metric tons per day of the THFDM-C18 diester. Life cycle assessment (LCA) results indicated that this process reduces CO₂ emissions by 35.0% compared to fossil fuel-based synthetic lubricant production (9.84 vs. 15.15 kg CO₂ eq.). The techno-economic analysis (TEA) revealed a minimum selling price (MSP) of 4.92 USD per kg, with MEG and oleic acid prices being the major cost factors. These findings highlight the potential of biomass-derived lubricants as sustainable alternatives to conventional petroleum-based products and emphasize the importance of further research to enhance process efficiency and reduce costs.