High-efficiency recovery, regeneration and recycling of 1-ethyl-3-methyli-midazolium hydrogen sulfate for levulinic acid production from sugarcane bagasse with membrane-based techniques

Ionic liquids have been proven efficient and environmental medium for producing platform chemical levulinic acid. Lack of high-efficiency, stable and low-cost recovery strategy with complex electrolyte form restricts the further scale-up of ionic liquids for platform chemicals production. Membrane-based techniques including ultrafiltration (UF) and bipolar membrane electrodialysis (BMED) were employed for the high-efficiency recovery, regeneration and recycling of 1-ethyl-3-methylimidazolium hydrogen sulfate [Emim][HSO4] for levulinic acid production from sugarcane bagasse. UF-BMED treatment works based on the interception of macromolecule biomass degradation products by UF treatment with regional recovery of Emim+ and SO42- by BMED treatment. Effect of major parameters on [Emim][HSO4] recovery performance was determined. Recovery ratio for Emim+ and SO42- approached 95.4% and 95.9%. Energy consumption of specific [Emim][HSO4] recovery was closed to 5.8 kWh/kg. Insight gained from this study suggests a high-efficiency and economical strategy for platform chemicals production with green solvent ionic liquids.

Automated summary

Ionic liquids are an efficient and environmentally friendly medium for producing platform chemical levulinic acid. Membrane-based techniques, such as ultrafiltration (UF) and bipolar membrane electrodialysis (BMED), are used for high-efficiency recovery, regeneration, and recycling of [Emim][HSO4], achieving recovery ratios of 95.4% for Emim+ and 95.9% for SO42-.