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1. (WO2018219638) PROCESS FOR THE PRODUCTION OF A NANOCELLULOSE MATERIAL TECHNICAL FIELD

Pub. No.:    WO/2018/219638    International Application No.:    PCT/EP2018/062543
Publication Date: Fri Dec 07 00:59:59 CET 2018 International Filing Date: Wed May 16 01:59:59 CEST 2018
IPC: C08B 1/00
C08B 15/02
D21C 9/00
D21H 11/18
Applicants: SAPPI BIOCHEMTECH B.V.
Inventors: ENGLISH, Robert
HEATON, John
Title: PROCESS FOR THE PRODUCTION OF A NANOCELLULOSE MATERIAL TECHNICAL FIELD
Abstract:
A process for the production of a non-derivatized nanocellulose material from a cellulosic fibrous material, comprising the steps of providing a suspension of cellulosic fibrous material in a continuous phase of a non-aqueous process liquid comprising a swelling agent and a processing solvent;allowing the cellulosic fibrous material to swell such as to form a suspension of swollen cellulosic fibrous material in a continuous phase of non-aqueous process liquid;optionally refining said suspension of swollen cellulosic fibrous material in a continuous phase of non-aqueous process liquid to increase the fineness of the swollen cellulosic fibrous material;removing the swelling agent from the rocess liquid such as to form a suspension of cellulosic fibrous material in a continuous phase of processing solvent; subjecting the swollen and optionally refined cellulosic fibrous material to high-shear comminution such as to release of the non-derivatized nanocellulose material from the swollen and optionally refined cellulosic fibrous material and such as to form a dispersion of non-derivatized nanocellulose material in a continuous phase of a processing solvent; contacting the dispersion of non-derivatized nanocellulose material in a continuous phase of a processing solvent with a supercritical fluid such as to remove the processing solvent and isolate the non-derivatized nanocellulose material, wherein the supercritical fluid is preferably supercritical carbon dioxide or ammonia;characterized in that the swelling agent is a low- transition-temperature mixture (LTTM) and in particular a deep eutectic solvent and said low- transition-temperature mixture and in particular said deep eutectic solvent is soluble in the processing solvent and wherein the processing solvent is non-solubilizing for the cellulosic fibrous material and the non-derivatized nanocellulose material.