Efficient saccharification of wheat straw pretreated by solid particle-assisted ball milling with waste washing liquor recycling

• Published in: Bioresource technology Vol. 347; p. 126721
• Main Authors: Liu, Xiao-le, Dong, Chengyu, Leu, Shao-Yuan, Fang, Zhen, Miao, Zheng-diao
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2022
• Subjects: Ball milling; Biomass; Cellulase; Cellulose; Enzymatic hydrolysis; Hydrolysis; Pretreatment; Solid particle; Triticum; Wheat straw; Ball milling; Solid particle; Pretreatment; Enzymatic hydrolysis; Wheat straw
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2022.126721

Wheat straw was ball milling pretreated with NaOH particles for enzymatic hydrolysis. [Display omitted] •NaOH particles added during BM showed the best synergistic interaction effect.•NaOH-BM treatment decreased CrI and D50 by 1.1 and 6.9 - fold in 1 h, respectively.•Reducing-end concentration of cellulose increased by 3.8 times from 12.5 - 60.2 μM.•Glucose yield (82.4%) with 4 h NaOH BM treatment was 3.1 - fold that of raw straw.•Washing liquor was recycled for the re-treatment, reaching 99.4% glucose yield. Wheat straw was pretreated using ball milling (BM) promoted by solid particles (NaOH, NaCl, citric acid). NaOH showed the best synergistic interaction effect, due to the breakage of β-1,4-glycosidic bonds among cellulose molecules by the alkali solid particles induced by BM. NaOH-BM pretreatment decreased the straw crystallinity from 46% to 21.4% and its average particle size from 398.3 to 50.6 μm in 1 h. After 4 h milling, the reducing-end concentration of cellulose increased by 3.8 times from 12.5 to 60.2 μM, with glucose yield increased by 2.1 times from 26.6% to 82.4% for 72 h enzymatic hydrolysis at cellulase loading of 15 FPU/g dry substrate. The pretreatment washing liquor was recycled for the re-treatment of partially pretreated biomass at 121 °C for 30 min, resulting in 99.4% glucose yield by enzymatic hydrolysis. BM assisted with alkali particles was an effective approach for improving biomass enzymatic saccharification.