OPTIMIZATION OF PRODUCTION CONDITIONS OF AMORPHOUS CELLULOSE WITH A HIGH ENZYMATIC HYDROLYZABILITY

Abstract

In this paper, a method for producing amorphous cellulose (AC) was studied by treatment of initial cellulosic materials (MCC and mixed paper waste paper) with a cold solvent, containing 7% NaOH and 12% urea, at different solvent to cellulose (R) ratios, ml/g. Using X-ray diffraction, it was found that after treatment of MCC with the solvent at R = 3, the crystalline modification (CM) of CI of the initial cellulose is converted to CM CII, having a low crystallinity degree. In the case, where the initial cellulose is treated with the solvent at R ≥ 5, a completely amorphous cellulose (AC) is formed. Due to its high hydrolyzability, the AC with concentration of 50 g/L is converted into glucose almost completely within 48 hours under the action of the CTec-3 enzyme preparation at a dose of 30 mg/g dry substrate. The obtained AC sample can be used as an amorphous standard in the study of enzymatic hydrolysis of various types of cellulose and lignocellulose. It was found that the most beneficial enzymatic saccharification of AC is carried out at increased concentration of the cellulosic substrate, 150 g/L. Due to the high cost of MCC, it is preferable to use low-cost cellulosic raw material, such as mixed waste paper, for the industrial production of AC and glucose.