Mild fractionation of sugarcane bagasse into fermentable sugars and β-O-4 linkage-rich lignin based on acid-catalysed crude glycerol pretreatment

Morteza Hassanpour; Mahsa Abbasabadi; Lalehvash Moghaddam; Fubao Fuelbiol Sun; Leigh Gebbie; Valentino Setoa Junior Te'o; Ian M O'Hara; Zhanying Zhang

doi:10.1016/j.biortech.2020.124059

Mild fractionation of sugarcane bagasse into fermentable sugars and β-O-4 linkage-rich lignin based on acid-catalysed crude glycerol pretreatment

Bioresour Technol. 2020 Dec:318:124059. doi: 10.1016/j.biortech.2020.124059. Epub 2020 Sep 2.

Authors

Morteza Hassanpour¹, Mahsa Abbasabadi², Lalehvash Moghaddam¹, Fubao Fuelbiol Sun³, Leigh Gebbie², Valentino Setoa Junior Te'o², Ian M O'Hara¹, Zhanying Zhang⁴

Affiliations

¹ Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology, 2 George St, Brisbane, Qld 4000, Australia; School of Mechanical, Medical and Process Engineering, Science and Engineering Faculty, Queensland University of Technology, 2 George St, Brisbane, Qld 4000, Australia.
² Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology, 2 George St, Brisbane, Qld 4000, Australia; School of Biology & Environmental Science, Science and Engineering Faculty, Queensland University of Technology, 2 George St, Brisbane, Qld 4000, Australia.
³ Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
⁴ Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology, 2 George St, Brisbane, Qld 4000, Australia; School of Mechanical, Medical and Process Engineering, Science and Engineering Faculty, Queensland University of Technology, 2 George St, Brisbane, Qld 4000, Australia. Electronic address: jan.zhang@qut.edu.au.

PMID: 32911367
DOI: 10.1016/j.biortech.2020.124059

Abstract

Acid-catalysed crude glycerol (ACG) pretreatment was carried out at 110 °C and 130 °C for mild fractionation of sugarcane bagasse into fermentable sugars and high-quality lignin. ACG pretreatment at 110 °C led to sugar yields of 71%-74%, comparable to those with acid-catalysed reagent-grade glycerol (AG). ACG pretreatment removed more lignin (53%-75%) than AG pretreatment (38%-49%), likely due to the presence of organic impurities in ACG. Hence, 28% more lignin was recovered from ACG pretreatment hydrolysate than with the AG pretreatment. NMR analysis revealed that recovered lignin was modified by glycerol through etherification of β-aryl ethers and esterification of hydroxycinnamic acids, which prevented lignin condensation and led to the generation of β-O-4 linkage-rich lignin at mild conditions (110 °C for 3 h and 5 h). This study suggests that crude glycerol is a suitable low-cost solvent for mild fractionation of lignocellulosic biomass into fermentable sugars and high-quality lignin for value-adding applications.

Keywords: Biodiesel; Biorefinery; Delignification; Lignocellulose; NMR; Organosolv.

MeSH terms

Cellulose
Glycerol
Hydrolysis
Lignin*
Saccharum*
Sugars

Substances

Sugars
Cellulose
Lignin
bagasse
Glycerol