Controllable recovery and regeneration of bio-derived ionic liquid choline acetate for biomass processing via bipolar membrane electrodialysis-based methodology

Ionic liquid recovery and recycling via electrodialysis in biomass processing: An economical assessment

Extravagant price and lack of high-efficiency recovery technology limited scale-up utilization of ionic liquids. Ionic liquids recovery with electrodialysis-based techniques has caught wide concern due to membrane-based characteristic. Economical assessment for electrodialysis-based ionic liquid recovery and recycling in biomass processing was performed by determining influence of equipment-related and financial-related factors with sensitivity analysis for each factor. Overall recovery cost of 1-ethyl-3-methylimidazolium acetate, choline acetate, 1-butyl-3-methylimidazolium hydrogen sulphate and 1-ethyl-3-methylimidazolium hydrogen sulfate varied within 0.75-1.96 $/Kg, 0.99-3.00 $/Kg, 1.37-2.74 $/Kg and 1.15-2.89 $/Kg when factors changed within investigated range. Fold of membrane cost, factor of membrane stack cost, factor of auxiliary equipment cost, factor of annual maintenance cost and annual interest rate of loan were positively related with recovery cost. While percentage of annual elapsed time and loan period were negatively correlated with recovery cost. Economical assessment confirmed economic efficiency of electrodialysis for ionic liquids recovery and recycling in biomass processing.

High-efficiency recovery and regeneration of choline-polyol deep eutectic solvent for biorefinery via bipolar membrane electrodialysis and ultrafiltration

Deep eutectic solvents (DES) have been widely studied for interesting solvent properties in resources utilization and green conversion of energy. Complex composition of DES and lack of recovery techniques restricts their further scale-up application. Exploring efficient recovery and regeneration methodology of DES in biorefinery could be beneficial for low-carbon circular bioeconomy. Recovery and regeneration of choline-polyol DES (choline chloride-ethylene glycol, ChCl-EG) after biomass pretreatment was studied using bipolar membrane electrodialysis (BMED) with ultrafiltration (UF). UF-BMED treatment worked based on the interception of macromolecular degradation products in pretreatment liquor and regional recovery of Ch⁺, Cl^- with EG. Influence of major parameters on DES recovery performance was studied with emphasis. Maximum recovery ratio of DES reached 97.4% and minimum specific energy consumption of DES recovery approached 6.0 kW·h/kg. Cognition gained from this research revealed an efficient technique for DES recycling after biorefinery.