Conversion of carbohydrates and lignocellulosic biomass into 5-hydroxymethylfurfural using AlCl3·6H2O catalyst in a biphasic solvent system

2012 ◽  
Vol 14 (2) ◽  
pp. 509-513 ◽  
Author(s):  
Yu Yang ◽  
Chang-wei Hu ◽  
Mahdi M. Abu-Omar
2016 ◽  
Vol 18 (21) ◽  
pp. 5756-5763 ◽  
Author(s):  
Ali Hussain Motagamwala ◽  
Wangyun Won ◽  
Christos T. Maravelias ◽  
James A. Dumesic

We demonstrate the design of a solvent system for efficient production and enhanced separation of carbohydrates from lignocellulosic biomass.


2014 ◽  
Vol 16 (8) ◽  
pp. 3819-3829 ◽  
Author(s):  
Charles M. Cai ◽  
Nikhil Nagane ◽  
Rajeev Kumar ◽  
Charles E. Wyman

A monophasic reaction strategy is proposed that couples metal halides with a highly tunable co-solvent system employing renewable THF to significantly enhance co-production of furfural and 5-HMF from biomass.


2018 ◽  
Author(s):  
◽  
Zhu Chen

Lignocellulosic biomass, which is mainly composed of cellulose, hemicellulose, and lignin, is a promising feedstock for producing renewable chemicals and fuels. To make lignocellulosic biomass-based refinery (biorefinery) competitive with petroleum refinery, maximizing the utilization of the three major components is critical. This requires the efficient fractionation of lignocellulose into different streams amenable to further upgrading. To this end, this work investigated the use of quaternary ammonium salt-based green solvents for lignocellulose fractionation and upgrading into renewable chemicals. First, a platform solvent system based on choline chloride and ethylene glycol was developed for switchgrass fractionation. Tailor-made lignin can be produced by using this platform solvent system, while the delignification and cellulose digestibility were not compromised. Highly concentrated sugar hydrolysate from pulp (cellulose) streams can be obtained via high solid loading enzymatic hydrolysis. The hemicellulose streams can be facilely upgraded into furfural via a novel biphasic system-acetone and aqueous choline chloride: ethylene glycol (ChCl:EG). Secondly, switchgrass can be fractionated effectively at high solid loading using either aqueous ChCl:EG or a series of ternary deep eutectic solvents. The cellulose stream can be converted into highly concentrated hydrolysate for high titer platform chemical production via fermentation. The hemicellulose and lignin streams can also be converted into other value-added products via other upgrading pathways. Thirdly, aqueous ChCl can also be a good solvent for switchgrass fractionation at mild conditions. The resultant lignin presented a very similar structure to native lignin, and thus, a great potential to be valorized into different products. The hemicellulose and cellulose streams can also be converted into valuable chemicals via biological and chemical routes. Lastly, a one-pot process capable of directly converting the untreated lignocellulosic biomass into furfural, digestible cellulose pulp and high purity lignin was developed. Furfural can be produced with high yield, while cellulose and lignin with appealing properties can be obtained via a one-pot process.


1972 ◽  
Vol 70 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Mario A. Pisarev ◽  
Noe Altschuler ◽  
Leslie J. DeGroot

ABSTRACT The process of secretion of the thyroid hormone involves several steps: pinocytosis of thyroglobulin, fusion of the colloid droplets with the lysosomes, digestion of thyroglobulin by a cathepsin, dehalogenation of tyrosines and release of thyronines into the blood stream. The present paper describes a double isotope technique for studying the first two steps. Thyrotrophin (TSH) administration to rats increased the radioactivity present in all fractions, specially in the 15 000 × g pellet. When the subcellular distribution of acid phosphatase was determined, the highest specific activity was found in this fraction, thus indicating the presence of lysosomes. The content of radioactive materials in the 15 000 × g pellet was analyzed by trichloroacetic acid precipitation and by ascending paper chromatography using n-butanol:ethanol:ammonium hydroxide (5:1:2;v/v) as solvent system. The results obtained showed that 90% of the radioactivity was protein bound and strongly suggest that this material is thyroglobulin.


2014 ◽  
Vol 21 (1) ◽  
pp. 11-15
Author(s):  
Daiva Kazlauskienė ◽  
Guoda Kiliuvienė ◽  
Palma Nenortienė ◽  
Giedrė Kasparavičienė ◽  
Ieva Matukaitytė

By conducting the toxicological analysis it is meaningful to determine the analytical system that could identify simultaneously several medicinal preparations quickly and precisely. The purpose of this work was to create and validate the method of thin-layer chromatography that would be suitable to separate the components of antidepressant mixture (amitriptyline hydrochloride, paroxetine hydrochloride, sertraline hydrochloride, fluvoxamine maleate and buspirone hydrochloride) and to identify them. The system was validated with regard to the sensitivity, repetition of data, resistance and particularity. The solvent systems with potential of high separation of components in their mixture were created: acetonitrile, methanol, ammonia solution 25 percent (85:10:5); acetonitrile, methanol, ammonia solution 25 percent (75:20:5); dichlormethane, 1,4-dioxane, ammonia solution 25 percent (50:45:5); dichlormethane, 1,4-dioxane, ammonia solution 25 percent (42:55:3); trichlormethane, 1,4-dioxane, ammonia solution 25 percent (25:70:5); trichlormethane, 1,4-dioxane, ammonia solution 25 percent (60:36:4). One of the most suitable solvent systems for separation of the analyzed mixture (sertraline, amitriptyline, paroxetine, buspirone, fluvoxamine) was determined – acetonitrile, methanol, ammonia solution 25 percent (85:10:5). When this solvent system was used, the average Rf values of the analyzed compounds differed the most. Validation was conducted – the relative standard deviation (RSD, percent) of the average Rf value of the analyzed compounds varied from 0,6 to 1,8 percent and did not exceed the permissible error of 5 percent. The sensitivity of methodology was determined by assessing the intensity of the mixture’s spots on the chromatographic plate. The detection limit of buspirone was 0,0012 µg; sertraline – 0,0008 µg; amitriptyline – 0,0004 µg; fluvoxamine – 0,0004 µg; paroxetine – 0,0008 µg. The resistance of results to the changed conditions – it was determined that when the amounts of the solvents acetonitrile and methanol were increased or decreased to two milliliters, the average Rf values of the analyzed compounds did not change statistically significantly


Author(s):  
Autumn Flynn ◽  
Kelly McDaniel ◽  
Meredith Hughes ◽  
David Vogt ◽  
Nathan Jui

A photocatalytic system for the dearomative hydroarylation of benzene derivatives has been developed. Using a combination of an organic photoredox catalyst and an amine reductant, this process operates through a reductive radical-polar crossover mechanism where aryl halide reduction triggers a regioselective cyclization event, giving rise to a range of complex spirocyclic cyclohexadienes. This light-driven protocol functions at room temperature in a green solvent system (aq. MeCN), without the need for precious metal-based catalysts or reagents, or the generation of stoichiometric metal byproducts.


2018 ◽  
Vol 17 (6) ◽  
pp. 1385-1398 ◽  
Author(s):  
Deepak K. Tuli ◽  
Ruchi Agrawal ◽  
Alok Satlewal ◽  
Anshu S. Mathur ◽  
Ravi P. Gupta ◽  
...  

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