Xylose recovery from annual plants - esp. straw, by treating with base and then with mineral acid

摘要

Recovery of xylose (I) from annual plants, esp. straw, comprises first treating with sufficient alkali hydroxide to liberate and neutralise acetic acid bound-up in the straw. The solid residue is then treated with an inorganic acid. Pref. the hydroxide is 1.1-1.2 moles per mole acetic acid and the straw is esp. derived from wheat, rye, barley, oats or rice. (I) is used in the food industry, and its reduction prod. Xylitol is a sweetener for diabetics. Complete removal of acetic acid and N-contg. crystallisation inhibitors is achieved without affecting the pentosans and yields of (I) are =26%. Lignin can be easily extracted from the reaction residue (it is thermoplastic and very reactive, useful e.g. for making dyes and antiparasitic agents) leaving a further residue from which cellulose can be recovered.