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Title: Comparison of two acid hydrotropes for sustainable fractionation of birch wood

Source: ChemSusChem. 13(17): 4649-4659.

Author(s)Cai, Cheng ; Li, Jian ; Hirth, Kolby ; Huber, George W.; Lou, Hongming ; Zhu, J. Y.

Publication Year: 2020  View PDF »

Category: Journal Articles

Abstract: This study reports on acomparative study of acid hydrotropic fractionation (AHF) of birch wood using maleic acid (MA) and p-toluenesulfonicacid (p-TsOH). Under the same level of delignification, lignin dissolved by MA is much less condensed with ahigher content of ether aryl b-O-4 linkages. Lignin depolymerization dominated in MA hydrotropic fractionation (MAHF) and resulted in asinglelower molecular weightpeak, in contrast to the competitive depolymerizationand repolymerization in p-TsOH AHF with abimodal distribution. The less condensed MA-dissolved lignin facilitated catalytic conversion to monophenols. Carboxylationofresidual lignin in fractionated cellulosic water-insoluble solids (WISs) enhanced enzymatic saccharification by decreasing nonproductive cellulase binding to lignin. At alow cellulase loading of 10 FPUg@1 glucan, sac- charification of WIS-MT120 from MAHF at 120°C was 95% compared with 48% for WIS-PT85 from p-TsOH AHF at 85°C under the same level of delignification of 63%. Residual lignin carboxylation also facilitated nanofibrillation of WIS for producing lignin-containing cellulose nanofibrils (LCNFs) through an enhanced lignin lubrication effect, which substantially decreases fibrillation energy.LCNFs from only one pass of microfluidization of WIS-MT120 have the same morphologyasthose from WIS-PT85 after three passes. MA also has a lower solubility and higherminimal hydrotropic concentration,which facilitated acid recovery. MAisU.S. Food and Drug Administration (FDA)approved as an indirect food additive, affording significant advantages compared with p-TsOH for biorefinery applications.

Keywords: Maleic acid hydrotrope fractionation (MAHF); lignin esterification (carboxylation); 2D NMR; enzymatic hydrolysis; lignin containing cellulose nanofibrils (LCNF)

Publication Review Process: Formally Refereed

File size: 1,008 kb(s)

Date posted: 11/03/2020

This publication is also viewable on Treesearch:  view
RITS Product ID: 10058
Current FPL Scientist associated with this product
Zhu, JunYong
Research General Engineer

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