Process of hydrolyzing wood in preparing crystalling glucose

Claim 1

IN THE PROCESS OF PREPARING CRYSTALLINE GLUCOSE BY PREHYDROLYZING A VEGETABLE CELLULOSIC MATERIAL WITH A DILUTE MINERAL ACID, SEPARATING THE TREATED RESIDUE, HYDROLYZING THE RESIDUE WITH COLD CONCENTRATED HYDROCHLORIC ACID, DISTILLING OFF THE BULK OF SAID CONCENTRATED HYDROCHLORIC ACID, DILUTING THE REMAINING SYRUP AND HEATING THE THUS OBTAINED SUGAR SOLUTION IN A FINAL HYDROLYSIS STEM FOR THE PRODUCTION OF GLUCOSE, THE IMPROVEMENT WHICH COMPRISES HEATING THE CELLULOSIC MATERIAL IN THE PREHYDROLYSIS STEP WITH A MEMBER OF THE GROUP CONSISTING OF DILUTE SULFURIC ACID AND DILUTE HYDROCHLORIC ACID AT TEMPERATURES OF ABOUT 120 TO 140* C. UNTIL THE MONOSACCHARIDES CONTAINED IN SAID CELLULOSIC MATERIAL HAVE BEEN SUBSTANTIALLY DISSOLVED, AND ADJUSTING IN SAID FINAL HYDROLYSIS STEP THE SUGAR SOLUTION TO A SUGAR CONCENTRATION OF ABOUT 10 TO 15 PER CENT BY WEIGHT, AND TO A HYDROCHLORIC ACID CONCENTRATION OF ABOUT 0.4 TO 1 PER CENT, AND HEATING THE SOLUTION AT A TEMPERATURE OF ABOUT 110 130* C. FOR A TIME SUFFICIENT TO CONVERT THE POLYSACCHARIDES CONTAINED IN SAID SOLUTION SUBSTANTIALLY INTO GLUCOSE.