A method for synchronously extracting xylooligosaccharides and lignosulfonate from neutral sulfite pretreated plant fiber waste liquid

Abstract

The invention discloses a method for synchronously extracting xylooligosaccharide and lignosulfonate from waste liquor of plant fibers pretreated by neutral sulfite. The method includes steps of 1), separating solid from liquor in the waste liquor obtained when the plant fibers are pretreated by the aid of the neutral sulfite and removing solid residues to obtain clear solution; 2), diluting the solution obtained at the step 1), carrying out chromatography on the solution by the aid of anion exchange resin, eluting the solution by the aid of deionized water at the eluent flow rate of 1-2 BV / h under the control and eluting 1-2 column volumes of the solution to obtain xylooligosaccharide solution; 3) eluting the anion exchange resin used at the step 2) by the aid of aqueous solution with NaOH and NaCl at the flow rate of 1-3 BV / h, eluting 3-6 column volumes of the anion exchange resin to obtain the lignosulfonate; 4), respectively desalting solution obtained at the step 2) and solution obtained at the step 3) by means of nano-filtration to obtain high-purity xylooligosaccharide products and lignosulfonate products. The aqueous solution with the NaOH and the NaCl is used as eluent.

Description

technical field [0001] The invention relates to a method for synchronously preparing xylooligosaccharides and lignosulfonate from plant fiber waste liquid pretreated by neutral sulfite, and to an anion exchange chromatography method for synchronous separation and recovery of neutral sulfite pretreatment Process of xylooligosaccharides and lignosulfonates in plant fiber waste liquid. Background technique [0002] Xylooligosaccharides, also known as xylooligosaccharides, are functional polymeric sugars formed by combining 2-10 xylose molecules with β-1,4 glycosidic bonds. Compared with soybean oligosaccharides, fructooligosaccharides, and isomaltose oligosaccharides commonly used by people, it has unique advantages, and it can selectively promote the proliferation activity of intestinal bifidobacteria. A daily intake of 0.7 grams per person has a significant effect. At the same time, it can also promote the absorption of calcium, reduce the content of cholesterol in the body...

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Problems solved by technology

Patent CN102493251A invented a method for extracting high-purity sugar liquid from red liquor, using ultrafiltration and nanofiltration membrane systems to remove different molecular weight lignosulfonates in papermaking red liquor, and using ion exchange resin and electrodialysis to remove red liquor Anions and cations in the sugar solution are finally obtained, but lignosulfonate extraction is not involved

Patent CN103468834A discloses a method for preparing xylooligosaccharides from plant fibers with neutral sulfite pretreatment. It pulverizes agricultural and forestry waste rich in hemicellulose and adds it to neutral sulfite aqueous solution. 8.0, 140-170°C, fully mixed and reacted for 10-60 minutes; the aqueous solution of xylo-oligosaccharides mainly rich in polymerization degree of 2-6 can be obtained, but a large amount of lignosulfonate formed in it has not been extracted synchronously

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