Combined effect of hot water and deep eutectic solvent (DES) pretreatment on a lignocellulosic biomass mixture for improved saccharification efficiency

• Published in: Bioresource technology reports 2022-02, Vol.17, p.100986, Article 100986
• Main Authors: Gundupalli, Marttin Paulraj, Anne Sahithi, S.T., Jayex, Elizabeth Panakkal, Asavasanti, Suvaluk, Yasurin, Patchanee, Cheng, Yu-Shen, Sriariyanun, Malinee
• Format: Article
• Language: English
• Subjects: Cellulose; Deep eutectic solvent; Hot water; Lignocellulose; Saccharification
• ISSN: 2589-014X; 2589-014X
• DOI: 10.1016/j.biteb.2022.100986

The combined effect of hot water (HW) and deep eutectic solvent (DES) on the solubilization of hemicellulose and lignin present in a lignocellulose mixture (rice straw, napier grass, and sugarcane bagasse in a 1:1:1 ratio) was investigated. The selected DES for present study included choline chloride (ChCl) with urea (U), glycerol (G), and lactic acid (LA) at a molar ratio of 1:2 w/w. The selection of different lignocellulosic biomass was made taking into account the similar percentage of hemicellulose and lignin. The hot water and DES pretreatment was performed with biomass loading of 1:10 w/v, 121 °C, 40 min. and 130 °C, 95 min, and 150 rpm, respectively. The HW-ChCl-LA resulted in 4.51-fold increase in cellulose digestibility at 72 h (20.63 ± 0.68% to 93 ± 3.62%). The FTIR spectrum for pretreated solids showed significant changes in the wavelength related to hemicellulose and lignin. [Display omitted] •Individual and combined effect of HW and DES on mix solids was studied.•Maximum delignification of 76.3% for HW-ChCl/LA was achieved.•Increase in delignification and results in higher glucose yield during saccharification.•Glucose yield for HW-ChCl/LA treated mix solids during saccharification was 94.5 wt%.•Combining pretreatment methods of different nature can benefit the biorefineries.