Pure xylose prodn - by hydrolysis of hemicellulose - contg materials

摘要

Hemicellulose-contng. material is treated with 0.2-10% H2SO4 at 90-140 degrees C. for 4-14 hrs. The resulting hydrolysate is neutralised, pref with CaOH)2, CaSO4 is filtered off; the soln. is concentrated and treated with methanol, whereby pure xylose crystallises out. Under these conditions, other pentoses and hexoses are decomposed or converted into furfurol and hydroxymethyl-furfurol, which is distilled off. Xylose produced can be used in the tobacco-, paint- and leather-industries, and also (opt. in the form of xylite) as a sugar substitute for diabetics.