Patent ID: 8492125

Claim:
A method for dissolving cellulose, the method comprising: providing a cellulosic raw material, subjecting the cellulosic raw material to an enzymatic treatment process by contacting the cellulosic raw material with a cellulase preparation comprising at least one endoglucanase, mixing the cellulosic raw material after the enzymatic treatment with an aqueous solution, an alkali metal hydroxide and a zinc salt in order to obtain an aqueous intermediate product containing the cellulosic raw material of at least 3.5 wt.-%, the alkali metal hydroxide between 3.5 wt.-% and 7 wt.-% and the zinc salt, the aqueous intermediate being a slurry or dispersion containing undissolved cellulose, freezing the aqueous intermediate product to a solid state at a subzero temperature dependent on the alkali metal hydroxide concentration of the aqueous intermediate product, and melting the resultant frozen solid state intermediate product and causing the undissolved cellulose to dissolve due to melting.