Hydrolysis of wood with concentrated hydrochloric acid

Claim 1

IN THE HYDROLYSIS OF WOOD WITH CONCENTRATED HYDROCHLORIC ACID, THE STEPS WHICH COMPRISE PROVIDING A PLURALITY OF SEPARATE STATIONARY COLUMS OF LIGNIN-CONTAINING PREHYDROLZED CELLULOSIC MATERIAL, SAID COLUMNS BEING CONNECTED IN SERIES TO FORM A SACCHARIFICATION UNIT, INTRODUCING CONTINUOUSLY CONCENTRATED HYDROCHLORIC ACID CONTAINING ABOUT 40% BY WEIGHT OF HCI IN SAID UNIT TO HYDROLYZE THE CELLULOSE TO SUGAR, SAID CONCENTRATED HYDROCHLORIC ACID FORMING IN SAID UNIT A ZONE OF FRESH CONCENTRATED HYDROCHLORIC ACID AND IN FRONT THEREOF IN THE DIRECTION OF FLOW A ZONE OF ACID SUGAR SOLUTION, INTERMITTENTLY WITHDRAWING SAID ACID SUGAR SOLUTION AT A POINT SPACED BY THE LENGTH OF AT LEAST ONE COLUMN FROM THJE POINT OF ADMISSION OF SAID CONCENTRATED HYDROCHLORIC ACID, INTRODUCING CONTINOUSLY WATER INTO SAID UNIT AT A POINT REARWARDLY OF THE ADMISSION OF SAID CONCENTRATED HYDROCLORIC ACID FOR REMOVING HYDROCLORIC ACID FROM THE RESIDUAL LIGNIN, SAID WATER FORMING A WASHING ZONE AND IN FRONT THEREOF IN THE DIRECTION OF FLOW A ZONE OF DILUTE HYDROCLORIC ACID, INTERMITTENTLY ADVANCING IN THE DIRECTION OF FLOW THE ADMISSION OF SAID CONCENTRATED HYDROCLORIC ACID AND SAID WATER AND THE WITHDRAWAL OF SAID ACID SUGAR SOLUTION, CONTINOUSLY WITHDRAWING A PORTION OF SAID DILUTE HYDROCHLORIC ACID AT A POINT LOCATED BETWEEN THE POINTS OF ADMISSION OF SAID WATER AND OF SAID CONCENTRATED HYDROCHLORIC ACID, AND ADJUSTING THE ADMISSIONS AND WITHDRAWALS OF THE LIQUID SO AS TO MAINTAIN A SUBSTANTIAL EQUILIBRIUM BETWEEN THE AMOUNTS OF WITHDRAWN AND INTRODUCED HC1 AND A SUBSTSNTISLLY UNIFORM CONCENTRATION IN SAID ZONES DURING THEIR ADVANCE THROUGH THE UNIT.