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Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53726-2398
Phone: (608) 231-9200
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Title: Acid hydrotropic fractionation of switchgrass at atmospheric pressure using maleic acid in comparison with p-TsOH: Advantages of lignin esterification

Source: Industrial Crops and Products

Author(s)Su, Chen ; Hirth, Kolby ; Liu, Zhulan ; Cao, Yunfeng ; Zhu, J.Y.

Publication Year: 2021  View PDF »

Category: Journal Articles

Abstract: Switchgrass was fractionated using maleic acid (MA) as an acid hydrotrope in comparison with p-toluenesulfonic acid (p-TsOH) at atmospheric pressure. MA achieved more rapid and greater maximal dissolution of lignin and hemicelluloses (88 % and 63 %, respectively) than did p-TsOH (73 % and 55 %, respectively). MA esterified (carboxylated) the dissolved acid hydrotropic lignin (AHL) as evidenced by 2D 1 H-13C HSQC NMR analysis, which improved AHL antioxidant ability compared with AHL from p-TsOH that is not carboxylated. MA also carboxylated the lignin and cellulose in the fractionated cellulosic water-insoluble solids (WIS), which significantly improved WIS enzymatic digestiblity for sugar production than did p-TsOH with the same level of delignification. It also improved the lignin lubrication effect to facilitate mechanical fibrillation of WIS into lignocellulosic nanofibrils. MA is an FDA-approved indirect food additive (21CFR175-177) with lower acidity and solubility than p-TsOH, which substantially benefits recycling and decreasing environmental impacts to achieve sustainability.

Keywords: Maleic acid fractionation; lignin esterification; lignin-containing cellulose nanofibrils (LCNFs); antioxidant activity; structural characteristic

Publication Review Process: Formally Refereed

File size: 6,144 kb(s)

Date posted: 03/17/2021

This publication is also viewable on Treesearch:  view
RITS Product ID: 10128
Current FPL Scientist associated with this product
Zhu, JunYong
Research General Engineer

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