Patent ID: 8895275

Claim:
A method for producing an aqueous sugar solution from cellulosic materials, comprising: mixing ground cellulosic materials with a superacid to form a mixture, wherein the superacid is free of periodic acid, wherein the superacid is partially concentrated perchloric acid, wherein the perchloric acid is present in a concentration of 60% to 72%; heating the mixture for not more than 5 minutes, wherein the heating is conducted at a temperature range of 60° C. to 70° C.; chilling the heated mixture in ice to produce a chilled mixture; neutralizing the chilled mixture with an alkali to yield a salt precipitate wherein the alkali is selected from the group consisting of potassium hydroxide, rubidium hydroxide, caesium hydroxide, calcium hydroxide, calcium oxide, and combinations thereof; filtering the salt precipitate off to obtain the aqueous sugar solution; and treating the salt precipitate with sulfuric acid to yield a sulfate salt and perchloric acid, wherein the sulfate salt is selected from the group consisting of potassium sulfate, rubidium sulfate, caesium sulfate, and calcium sulfate.