S. S. Shashkina, Sergey Nikolaevich Evstaf'ev
The results of the study presented the possibility of using deep eutectic solvent based on triethylamine hydrochloride as a method of preliminary treatment of wheat straw for enzymatic hydrolysis. Thermal treatment in triethylamine hydrochloride / oxalic acid medium was conducted in the temperature range 80–110 °С. Fractionation of the products mixture allowed to isolate cellulose, hemicelluloses and lignin fractions. The results of composition analysis as well as IR-spectra of technical cellulose indicate the intensive processes of delignification and hemicellulose hydrolysis during the treatment. The maximum degree of delignification (94.5%) was obtained at the temperature of 110 °C, while total cellulose content in the technical cellulose was 91.2% dry mass. It was found that treatment of wheat straw in triethylamine hydrochloride / oxalic acid medium is efficient as a preparation step for enzymatic hydrolysis. The maximum yield of reducing sugars (27% dry mass) was achieved by 48 h enzymatic hydrolysis of technical cellulose, isolated at 110 °C, which is three times higher than the yield of sugars from untreated straw.