GB311695A - Improvements relating to the saccharification of wood and other cellulosic materials - Google Patents

Abstract

311,695. Distilleries des Deux-SÞvres. May 14, 1928, [Convention date]. Glucose.-Completely dried cellulosic material, either pure or mixed with other products, is treated with anhydrous or highly concentrated 'formic acid in the presence of a small quantity of catalyst acids or salts such as sulphuric, hydrochloric, phosphoric, sulphurous, benzenesulphonic or toluenesulphonic acid, or chloride of zinc, calcium or iron or bisulphates, and the formates obtained are hydrolyzed directly in a sufficiently concentrated formic medium, by the progressive addition of a small quantity of water whilst assisting the reaction by stirring and heating. The hydrolysis is completed by boiling the sugars and dextrins in aqueous solution in the presence of a mineral acid, with or without pressure. The cellulose if in the form of wood may be given a preliminary treatment with dilute solutions of mineral acids to convert it more or less thoroughly to hydro-cellulose and convert pentosans into pentoses which may be eliminated and converted into furfurol. Examples are given of the treatment of paper pulp and sawdust. The formic acid is recovered by distillation in the presence of a liquid forming therewith an azeotropic mixture, or by distillation in the presence of an alcohol giving with the formic acid a volatile formate, which is subsequently saponified, or by bringing the formic acid into aqueous solution with the sugars, and extracting it by methodical exhaustion in counter current by means of solvents insoluble or but. slightly soluble in water.