abstract
An efficient process for the production of furfural from xylan by using acidic deep eutectic solvents (DESs), which act both as solvents and catalysts, is developed. DESs composed of cholinium chloride ([Ch]Cl) and malic acid or glycolic acid at different molar ratios, and the effects of water and gamma-valerolactone (GVL) contents, solid/liquid (S/L) ratio, and microwave heating are investigated. The best furfural yields are obtained with the DES [Ch]Cl:malic acid (1:3 molar ratio)+5 wt % water, under microwave heating for 2.5 min at 150 degrees C, a S/L ratio of 0.050, and GVL at a weight ratio of 2:1. Under these conditions, a remarkable furfural yield (75 %) is obtained. Direct distillation of furfural from the DES/GVL solvent and distillation from 2-methyltetrahydrofuran (2-MeTHF) after a back-extraction step enable 89 % furfural recovery from 2-MeTHF. This strategy allows recycling of the DES/GVL for at least three times with only small losses in furfural yield (>69 %). This is the fastest and highest-yielding process reported for furfural production using bio-based DESs as solvents and catalysts, paving the way for scale-up of the process.
keywords
LIGNOCELLULOSIC BIOMASS; HEMICELLULOSE; XYLOSE; POLYSACCHARIDES; DERIVATIVES; HYDROLYSIS; CHEMISTRY; LIGNIN; MEDIA; DES
subject category
Chemistry; Science & Technology - Other Topics
authors
Morais, ES; Freire, MG; Freire, CSR; Coutinho, JAP; Silvestre, AJD
our authors
Groups
G4 - Renewable Materials and Circular Economy
G5 - Biomimetic, Biological and Living Materials
Projects
acknowledgements
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the FCT/MCTES and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. The research leading to reported results has received funding from FCT through the projects DeepBiorefinery (PTDC/AGR-TEC/1191/2014) and MultiBiorefinery (POCI-01-0145-FEDER-016403), and through C.S.R.F. Researcher contract (CEECIND/00464/2017). E.S.M. acknowledges FCT for the Ph.D. grant SFRH/BD/129341/2017. The NMR spectrometers used are part of the National NMR Network (PTNMR) and are partially supported by Infrastructure Project No. 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC.