How Alkyl Chain Length of Alcohols Affects Lignin Fractionation and Ionic Liquid Recycle During Lignocellulose Pretreatment

Sawant, Manali
Tan, Jared
Canlas, Christian G.
Sun, Ning
Zhang, Wei
Renneckar, Scott
Prasomsri, Teerawit
Shi, Jian
Persil Çetinkol, Özgül
Singh, Seema
Simmons, Blake A.
George, Anthe
Alcohols of increasing alkyl chain length were investigated as precipitants in an ionic liquid (IL) pretreatment system. Switchgrass samples pretreated by 1-ethyl-3-methylimidazolium acetate were characterized after the use of different alkyl chain lengths of alcohols as antisolvents. The resulting IL-pretreated switchgrass (PSG) samples were characterized by enzymatic hydrolysis, cross polarization/magic angle spinning (CP/MAS) C-13 nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), and 2D NMR spectroscopy. Glucan digestibilities of PSG samples were similar to 80 % after 72 h at 5 mg protein g(-1) glucan regardless of the antisolvent used. The use of 1-octanol as an antisolvent, with 10 % water to allow for use of wet biomass, enabled a partial lignin fractionation and multiphase separation for the IL recycle without compromising the chemical structure of the carbohydrates and lignin from the PSG. Lignin fragments were observed in the IL after pretreatment by gel permeation chromatography (GPC). After separation, both the IL and the octanol antisolvent were reused for switchgrass pretreatment and precipitation for an additional 3 cycles. The PSG samples derived from recycled IL were rapidly hydrolyzed, and a high glucan digestibility of 80 % was obtained even at a low enzyme loading of 5 mg protein g(-1) glucan. 2D NMR analysis of residual solids of PSG post-enzymatic hydrolysis revealed that lignin in these residual solids was depolymerized. This strategy enables an ease in separation of pretreated lignocellulosic solids, reduced water use, and recycle of both IL and the antisolvent.


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Ionic liquids (ILs) are low-melting organic salts that consist entirely of ions. During the last decade, they have found numerous applications because of their unique properties such as wide liquid range, nonflammability and negligible vapor pressure at ambient temperatures [1-3]. The properties of ILs can be tuned by changing the constituent ions. In recent years, unlike commonly known alkyl substituted ILs a new class of ILs called Tunable Aryl Alkyl Ionic Liquids (TAAILs) has drawn attention [4-6]. By re...
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Özdemir, Melek; Şahin, Ertan (null; 2018-04-27)
Ionic liquids (IL) are ionic, salt-like materials and composed of an organic cation and anion. Different types of anions and cations can be used to modify the chemical and physical properties of the IL. Phosphonium, ammonium, sulfonium, imidazolium, picolinium, pyridinium, pyrrolidinium, thiazolium, oxazolium and pyrazolium cations are widely used cations in the synthesis of ionic liquids, while hexafluorophosphate and tetrafluoroborate are the most prominent anions used in IL synthesis [1]. A series of tun...
Modified Hantzsch Reaction in the Presence of Chiral Organic Catalysts
Magerramov, A. M.; Guseinov, E. Z.; Akhmedov, I. M.; Tanyeli, Dj.; Kurbanova, M. M. (2016-05-01)
Modified Hantzsch reaction in three- and four-component system in the presence of new chiral organic catalysts was investigated and the advantages of this reaction in three- component system compared to four-component one were demonstrated, the influence of catalysts on the dynamics and stereochemistry of the reaction was elucidated. The enantiomeric excess of the main reaction product was evaluated with HPLC, its structure was proved by X-ray diffraction analysis.
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Özdemir, Melek; AKTAN, EBRU (2019-03-15)
A series of new 1-aryl-3,5-dimethylpyrazolium based tunable protic ionic liquids/salts ([Ph(R)Hpz][X], R: -H, -Cl, -Br, -CH3, -OCH3, X: chloride [Cl-] and tetrafluoroborate (BF4-) have been synthesized through acid-base neutralization reactions between 1-aryl-3,5-dimethy1-1H-pyrazoles and the corresponding inorganic acids. The chemical structure of the salts was confirmed by FTIR, H-1 NMR, C-13 NMR, elemental analysis, and F-19 NMR (3a-3e) and the crystal structure of the two salts (2a and 3d) was also eluc...
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Enayat, Shabnarn; Banerjee, Sreeparna (2009-09-01)
Leaves, bark and catkins of Salix aegyptiaca L were extracted into solvents of increasing polarity from cyclohexane (non-polar), butanol, ethanol and water (polar) and analysed for their antioxidant capacity, total phenol and flavonoids. The highest antioxidant activity (19 mu g/ml IC50 for inhibition of DPPH radical activity), total phenolic content (212 mg gallic acid equivalents/g of dried extract) and total flavonoid (479 mg catechin equivalents/g of dried extract) was observed in the ethanolic extract ...
Citation Formats
N. SATHITSUKSANOH et al., “How Alkyl Chain Length of Alcohols Affects Lignin Fractionation and Ionic Liquid Recycle During Lignocellulose Pretreatment,” BIOENERGY RESEARCH, pp. 973–981, 2015, Accessed: 00, 2020. [Online]. Available: