The Synthesis Of Xylitol By Electrochemistry

Corncob is a kind of cheap renewable resource. The synthesis of xylitol by electrochemistry from corncob could be a cheaper alternative to the traditional chemical process, since it is a simple process, with great specificity and low energy requirements. This paper presented a detail study of the synthesis of xylitol.In this paper, hemicellulose of corncob was hydrolyzed into xylose while sulphuric acid was used as the catalyzer. In order to a maximal yield of deoxidize sugar and xylose, the value range of influence factors, such as the ratio of solid to liquid, concentration of sulphuric acid, hydrolysis temperature and reaction time, was obtained through single factor experiments of hydrolysis. On the basis of perpendicular design experiment, the optimal hydrolysis conditions were mass ratio of liquid to solid 4:1, concentration of sulphuric acid 3.0%, hydrolysis temperature 120℃and reaction time 2h. Under the condition, 10.51% xylose yield was obtained. When the hydrolysis conditions were mass ratio of solid to liquid 4:1, concentration of sulphuric acid 3.0%, hydrolysis temperature 120℃and reaction time 4h, deoxidize sugar had a maximal yield and hemicellulose had good utilization.This paper has also studied the direct electricity decomposition method which prepares xylitol by electrolytically reduction of xylan, and studied the electrosynthesis method for deoxidizing the xylose to xylitol in cathode. Electrolyte, electroanalysis temperature, the effects of reaction time and the initial concentration of xylose had significant effects on xylitol production. The influence both of acid hydrolysis and electroanalysis condition on the acquiring rate of xylitol has been investigated. The optimum parameters of manufacturing process have been obtained as follows—the hydrolysis temperature 120℃, electroanalysis temperature 60℃, vitriol concentration 2%, duration 4h and the acquiring rate is 73.61%.This paper developed an effective and economical xylitol process by electroche-mistry using corncob hemiecellulosic hydrolysate instead of xylose. The technology is of important social value and apparent economic value.