Xylose and xylitol separately purified in same ion exchanger

US4239922A · kind A · utility

Assignee

• Benckiser-Knapsack GmbH · DE

Inventors

• Theodor Riehm · Heidelberg, DE
• Theodor Auel · Ilvesheim, DE
• Wilhelm Spatz · Ober-Kainsbach, DE

Key dates

• Filing date: Jun 13, 1979
• Grant date: Dec 16, 1980
• Expiry date: Jun 13, 1999

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07B2200/07
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for producing polyalcohols such as xylite from deciduous wood wherein the wood is hydrolyzed with dilute mineral acid to produce a sugar solution which is deionized and decolorized in an ion exchanger and hydrogenated to produce a polyalcohol solution which is also decolorized and deionized by ion exchange and from which pure polyalcohol is thereafter separated by crystallization, further comprising dispensing with neutralization of the acid in the sugar solution after hydrolysis, deionizing and decolorizing both the sugar solution and the polyalcohol solution in the same ion exchanger, eluting acetic acid taken up by the ion exchanger from the polyalcohol solution and displacing polyalcohol solution from the exchanger with the acid containing sugar solution, washing the ion exchanger with water only after ion exchange of the sugar solution, removing the bulk of the acetic acid from the sugar solution by evaporating the sugar solution to a higher concentration than the concentration customarily utilized for hydrogenation, and rediluting the sugar solution prior to hydrogenation with the exchanger wash water.