Improvement of enzymatic saccharification by simultaneous pulping of sugarcane bagasse and washing of its cellulose fibers in a batch reactor

• Published in: Biotechnology journal 2023-08, Vol.18 (8), p.e2200542-n/a
• Main Authors: Nogueira, Bruno L., Secchi, Argimiro R., Machado, Fabricio, Rodrigues, Carime V. S., Gambetta, Rossano, Rodrigues, Dasciana S.
• Format: Article
• Language: English
• Subjects: lignocellulosic biomass; organosolv fractionation; pretreatment; sugarcane bagasse
• ISSN: 1860-6768; 1860-7314
• DOI: 10.1002/biot.202200542

A modification of the conventional batch organosolv process is proposed in a way where the solid biomass remains inside a basket, physically separated from the liquid phase, with the vapor promoting the fractionation of the biomass and the extracted compounds and fragments being washed down to the liquid phase. The modified organosolv process applied to sugarcane bagasse (SB‐M) delivers a rich cellulosic solid phase that after enzymatic hydrolysis leads to a hydrolyzed with approximately 100 g L−1 of glucose. At the same enzymatic hydrolysis conditions, the conventional organosolv process (SB‐C) delivers a hydrolyzed with 80 g L−1 of glucose, while the autohydrolysis process (SB‐A) leads to 55 g L−1 of glucose. These different results are related to the cellulose content: SB‐M (70%), SB‐C (57%), e SB‐A (44%), as well the reduced lignin content in the SB‐M. The novelty of this study is the confirmation that it is possible to degrade lignin from sugarcane bagasse and simultaneously remove its fragments from the cellulose fibers in a batch reactor containing an internal basket. This study describes a simple and rapid protocol for the isolation of the main components of lignocellulosic biomass (cellulose, hemicellulose, and lignin), which may lead to the study of new catalysts for the chemical transformation of these components separately or simultaneously to the step of pretreatment. Graphical and Lay Summary The modified organosolv process proposed in this study has advantages compared to other pretreatment processes, such as the elimination of the fiber washing step after pretreatment, the possibility to use heterogeneous catalysts in the liquid phase for the simultaneous conversion of lignin or hemicellulose, allows obtaining hydrolysates with high purity and concentration of glucose, and removal of inhibitors from pretreated biomass.