Lignins hydrolyzed

So-called accessory enzymes are also required for hydrolysis of hemicellulose in native plant tissue. These enzymes include a variety of acetyl xylan esterases (EC 3.1.1.72), acetyl esterases (EC 3.1.1.6), and esterases, such as feruloyl acid esterase (EC 3.1.1.73),178 that hydrolyze lignin glycoside bonds. They also include classes for cleavage of specific hemicellulose side chains, such as a-L-arabinofuranose, glucuronic acid, and 4-O-methyl-glucuronic acid groups. 

Phenols. Phenol has been condensed with furfural Mn presence of hydroxylamine hydrochloride and the condensate has been sulfonated in petroleum oil at 70-80 °C for 7-8 h and 3% hydrolyzed lignin has been added to give KFFUR-1,2 resin with a total capacity of 2.S-2.9 meq/g at 1 1 mole ratio and 3.5 meq/g at 2 1 mole ratio of phenol to furfural. In a similar way,/>-phenolsulfonic acid can be polymerized with furfural in the mole ratios 1 2 and 1 3 to give KFFUR-1,2,3 with a static exchange capacity of 3 meq/g for calcium chloride and 3.5-4.0 meq/g for sodium hydroxide. The mechanical properties and exchange capadty of this resin can be improved by conducting the polycondensation in a magnetic field... 

Furthermore, a procedure is known [79] in which activated lignin (hydrolyzed lignin treated at 200-230°C) is used as a contact Cl impregnated into a PE-based polymer blend with benzoic acid. The resultant hose is brought into contact with a dicyclohexilamine melt. Film extruded from this blend filled by the activated lignin becomes a VCl carrier as a result of interactions between benzoic acid and cyclohexilamine. 

Organosolvent H H H Yes Yes H Yes Hydrolyzes lignin and hemicellulose E>ifBcult solvent recovery... 

Acid Detergent Fiber. The ground sample is heated for 1 h under reflux in a solution of 2% cetyltrimethyl ammonium bromide [57-09-0] in IN sulfuric acid [7664-93-9]. The acid hydrolyzes and dissolves the nonceUulosic polysaccharides. The insoluble residue, relatively free of hemiceUuloses and containing aU the ceUulose and lignin, is filtered, dried, and corrected for ash to give the ADF value. 

Lignin is a high-molecular, mainly three-dimensional aromatic substance, that, in contrast to polysaccharides, can be hydrolyzed only in small partitions [16] ... 

Wood chips can also be utilized as such to produce bioethanol. The cellulose and hemicellulose material is hydrolyzed in the presence of acids (H2SO4, HCl, or HCOOH) or enzymes to yield glucose and other monosaccharides [16]. Lignin is separated by filtration as a solid residue and the monosaccharides are fermented to ethanol, which, in turn, is separated from water and catalyst by distillation. Ethanol can be used not only as energy source but also as a platform component to make various chemicals, such as ethene and polyethene. Today green acetaldehyde and acetic acid from wood-derived bioethanol is manufactured by SEKAB Ab, at the Ornskoldsvik Biorefinery of the Future industrial park. 

The data from these first two batch tests indicated that poly(lignin-g-(l- amidoethylene)) hag properties which make it a potentially effective drilling mud additive. The tests show that poly(lignin-g-(l-amidoethylene)) and its hydrolyzed derivatives act as a high temperature thinner and as a filtrate control agent. The... 

Harris, Sherrard and Mitchell (38) have found that methylation of the lignin in the wood, is not complete, until the wood has been hydrolyzed. After hydrolysis all the hydroxyl groups present in the lignin can be methylated. This has been taken to indicate that lignin is chemically combined to the carbohydrate portion of the wood. 

Bergius (2) Also known as Beigius-Willstater-Zechmeister. A process for extracting sugar from wood by hydrolyzing the cellulose with concentrated hydrochloric acid. Lignin remains undissolved. Developed in the 1920s. 

Alternatively, lignocellulose can also be hydrolyzed to liberate the lignin and de-polymerize the polysaccharides to sugars. The sugars can subsequently be converted into various fuel and chemical components via chemical or biological routes. 

Various processes have been developed for hydrolyzing lignocellulose to its major constituents, i.e., to sugars and (partly) depolymerized lignin. The lignin is usually precipitated from the aqueous solution and either used as chemical feedstock or burned as process fuel. The aqueous sugar solution is then applied for fermentation to ethanol after neutralization and purification. 

Lignin contains phenolic and a few carboxylic acid groups it therefore dissolves in sodium hydroxide. Soda pulping is based on this fact. Here, at the high temperatures used, ester bonds arc hydrolyzed, and some of the carbohydrate-lignin ether bonds are split. Cold caustic soda is used for semichemical processes. 

Naturally lignins that have been modified by chemical reactions, e.g. condensed or sulfonated by pulping, are far less susceptible to biological decay than natural lignins, because the weak, readily hydrolyzable benzyl aryl ether bonds or the readily oxidisable benzyl alcohols of guaiacyl-glycerol units have been sulfonated or transformed by condensation reactions into strong carbon-carbon bonds. 

Complex phenolics Coumarins, phenolic quinones, lignins, flavonoids, stilbenes, hydrolyzable tannins, condensed (or catechin) tannins, phenolic lipids... 

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