| abstract |
Xylose is produced from residues of annuals by (a) extracting soluble and solubilizable undesired substances from the residues countercurrently with an aqueous acid solution, (b) pressing the extracted residues to remove as much as possible of the proportion of undesired substances, (c) moistening the pressed residues with an acid solution which contains xylose; (d) hydrolyzing the pentosans present in the residues by increasing the temperature of the acidified moistened residues, (e) terminating the hydrolysis by decreasing the temperature of the hydrolyzed residues, (f) extracting the pentoses from the hydrolyzed residues with water, (g) purifying and concentrating the xylose solution obtained, and, if desired, (h) winning xylose by crystallization. |