Engineering topics
Publications and source records attributed to Dutta, Tanmoy.
The present invention provides for novel protic ionic liquids (PIL) or phosphate-based ionic liquid (PBIL) useful for lignocellulosic processing described herein. The novel protic ionic liquids are capable of pretreatment of lignocellulosic biomass over a wide range of pH.
Disclosed herein are lignin-derived ionic liquids and methods for preparing them. The methods include forming a reaction mixture comprising a lignin-derived starting material, a carbonyl compound, and an amine; maintaining the reaction mixture under conditions sufficient to form a lignin-derived aminophenol; and converting the lignin derived aminophenol to the lignin-derived ionic liquid. Monomeric phenols, oligomeric phenols, and polymeric phenols can be used as lignin-derived starting materials.
Methods and compositions are provided for synthesizing ionic liquids from lignin. Methods and compositions are also provided for treating lignin with ionic liquids.
Disclosed herein are methods for preparing sugar compositions. The methods include: i) forming a mixture including polysaccharide biomass and an ionic liquid solution, wherein the ionic liquid solution contains water and an ionic liquid, and the ionic liquid contains a) a cation and b) a sugar acid anion or a ketoacid anion; ii) maintaining the mixture under conditions sufficient to dissolve at least a portion of the polysaccharide present in the polysaccharide biomass; iii) adding at least one glycoside hydrolase to the mixture; and iv) maintaining the mixture containing the glycoside hydrolase under conditions sufficient to hydrolyze at least a portion of the dissolved polysaccharide, thereby forming the sugar compositions. The sugar compositions contain at least one monosaccharide or oligosaccharide. New sugar-based ionic liquids are also described.
Methods and compositions are provided for ionic liquid processing of biomass.
The present invention provides for a method for dissolving and/or depolymerizing lignin comprising: (a) providing a composition comprising lignin, (b) contacting the composition with a strong hydrogen donor, such as a polyol, to form a first solution, (c) incubating the first solution at a temperature equal to or less than 100° C., whereby at least 20% by weight of the lignin is dissolved, (d) optionally introducing an oxidation agent to the first solution to form a second solution, wherein the temperature of the second solution is equal to or less than 100° C., whereby lignin is depolymerized, and (e) optionally introducing an anti-solvent to the second solution to precipitate the depolymerized lignin.
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Lignin is the primary contributor to the high cost of biofuel-production from lignocellulosic biomass. Here, in order to study lignin removal and the release of aromatic monomers, we applied hydrocracking and ionic liquid pretreatments on Arabidopsis thaliana biomass from both wild type (WT) and a mutant (CAD cxd) defective in two cinnamyl alcohol dehydrogenase genes involved in the lignin biosynthetic pathway. For Arabidopsis WT, our results highlight that pretreatments reduce average molecular weight of lignin by about 65% and decrease the content of β-O-4 linkages between lignin monomers. For Arabidopsis CAD mutant, an opposite effect is evidenced. Fewer differences were observed on depolymerization and molecular structure of lignin, which indicates that (8-O-4), (8-5), and (8-8) linkages observed in CAD mutant make lignin more resilient to pretreatment than wild-type lignin. Finally, our study shows the potential of hydrocracking pretreatment technology for extracting valuable aldehyde monomers such as vanillin and syringaldehyde from biomass.
Abstract Background In this work, three pretreatments under investigation at the DOE Bioenergy Research Centers (BRCs) were subjected to a side-by-side comparison to assess their performance on model bioenergy hardwoods (a eucalyptus and a hybrid poplar). These include co-solvent-enhanced lignocellulosic fractionation (CELF), pretreatment with an ionic liquid using potentially biomass-derived components (cholinium lysinate or [Ch][Lys]), and two-stage Cu-catalyzed alkaline hydrogen peroxide pretreatment (Cu-AHP). For each of the feedstocks, the pretreatments were assessed for their impact on lignin and xylan solubilization and enzymatic hydrolysis yields as a function of enzyme loading. Lignins recovered from the pretreatments were characterized for polysaccharide content, molar mass distributions, β-aryl ether content, and response to depolymerization by thioacidolysis. Results All three pretreatments resulted in significant solubilization of lignin and xylan, with the CELF pretreatment solubilizing the majority of both biopolymer categories. Enzymatic hydrolysis yields were shown to exhibit a strong, positive correlation with the lignin solubilized for the low enzyme loadings. The pretreatment-derived solubles in the [Ch][Lys]-pretreated biomass were presumed to contribute to inhibition of enzymatic hydrolysis in the eucalyptus as a substantial fraction of the pretreatment liquor was carried forward into hydrolysis for this pretreatment. The pretreatment-solubilized lignins exhibited significant differences in polysaccharide content, molar mass distributions, aromatic monomer yield by thioacidolysis, and β-aryl ether content. Key trends include a substantially higher polysaccharide content in the lignins recovered from the [Ch][Lys] pretreatment and high β-aryl ether contents and aromatic monomer yields from the Cu-AHP pretreatment. For all lignins, the 13 C NMR-determined β-aryl ether content was shown to be correlated with the monomer yield with a second-order functionality. Conclusions Overall, it was demonstrated that the three pretreatments highlighted in this study demonstrated uniquely different functionalities in reducing biomass recalcitrance and achieving higher enzymatic hydrolysis yields for the hybrid poplar while yielding a lignin-rich stream that may be suitable for valorization. Furthermore, modification of lignin during pretreatment, particularly cleavage of β-aryl ether bonds, is shown to be detrimental to subsequent depolymerization.