Regional recovery and controllable regeneration of brønsted acidic deep eutectic solvent in biomass fractionation via bipolar membrane electrodialysis

Abstract

Brønsted acidic deep eutectic solvent (DES) has got more and more focus in biomass-related studies and applications due to a few novel specialties. High-efficiency recycling approach and theory was necessary before scale-up utilization of Brønsted acidic DES in biomass processing. Regional recovery and controllable regeneration of Brønsted acidic DES oxalic acid-ethylene glycol (OA-EG) was studied in biomass fractionation by designing bipolar membrane electrodialysis (BMED)-based methodology. Dominating parameters controlling DES recovery were studied with emphasis. Recovery ratio of OA (90.6 %-97.8 %) and EG (94.3 %-98.0 %), current efficiency (89.3 %-94.7 %), transport rate of OA (29.3–458.7 mmol/(m2·min)) with total energy consumption (0.110–0.832 kW·h) and specific energy consumption (3.1–17.7 kW·h/kg) of DES recovery were studied to assess the BMED-based methodology. Reusability of regenerated Brønsted acidic DES was confirmed by repeated corncob fractionation and recovery experiments. Recovery cost of deep eutectic solvent OA-EG with BMED was estimated to be 0.5 %-5.2 % of its purchasing cost from supplier and 4.3 %-51.2 % of its industrial purchasing cost according to the economic appraisal. Perception acquired from this study revealed an efficient, low-cost and sustainable approach for Brønsted acidic DES recycling in biorefinery