Separation And Purification Of Xylose Mother Liquor By Ion-exchange Chromatography

Xylose is an important chemical material, which can be used as non-calorie sweeteners infood and beverage. The most important usage of xylose is as raw material to produce xylitol.xylose has been produced nearly 40 years in china. The xylose mother liquor is produced aftercrystallization of xylose. In recent years, how to reasonably use xylose mother liquor has beenpaid much attention by manufacturers because the mother liquor contains xylose and arabinosewith high concentrations and high economic value. In this paper, the separation of the motherliquor is investigated to obtain xylose and arabinose by using two ion-exchange resins.When the mother liquor was kept for about 3~4 months, two layers will be formed. The twolayers were investigated: the upper liquor was concentrated and the lower one washed bymethanol and ethanol. The following conclusions were obtained: crystal xylose cannot be formedin the concentrated top layer solution, and raw crystal xylose can be formed by washing thebottom layer solution with methanol and ethanol.In this paper, separation and purification of the mother liquor was studied systematicallyusing two selected ion exchange resins. The optimal separation conditions were determined.According to the results of single factor tests, the optimal separation conditions for ion exchangeresin 1 are as follows: volume fraction of the mother liquor 83%,operating temperature 40℃,elution speed 2ml/min, injection volume 15ml. Under the optimal conditions, arabinose can beobtained with a purity of 83.5%, and recovery of 59.6%. The optimal separation conditions forion exchange resin 2 are as follows:operating temperature 40℃, elution speed 2ml/min,injection volume 15ml. Under the optimal conditions, the recovery of xylose is 36.8%, and therecovery of arabinose is 48.8 %. Finally, the separation process with the combination of the two ion exchange resins wasinvestigated based on the above study. The mother liquor is successfully separated, the recoveryof xylose is 14.7% and that of arabinose is 17.2%. The results indicated that xylose andarabinose can be separated from xylose mother liquor.