Process for making partly-hydrolyzed cellulose using compressed cellulosic materials
AssigneeNoram Engineering and Constructors Ltd.
InventorsJames M. Lockhart, James T. Wearing, Ali Gulamhusein, Evan J. Hobenshield, Durk Devries
Life of this patent
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Abstract
A method and apparatus for contacting and reacting fine cellulosic material with acid to produce partly-hydrolyzed cellulose, in which the cellulose is compressed to form higher density material, resulting in reduced consumption of acid and increased uniformity of reaction times. Cellulosic material, such as ground wood pulp, is compressed to reduce the interstitial spaces therein. The compressed material is contacted with an acid, such as sulfuric acid, which is allowed to wick into the interstitial spaces and react with the cellulose to produce partly-hydrolyzed cellulose.
Claims37
A method of reacting cellulosic material with acid to produce cellulose crystallites, comprising the steps of:
- (a) providing dry cellulosic material;
- (b) compressing the cellulosic material to produce a compressed cellulosic material;
- (c) contacting the cellulosic material with an acid solution, before, during or after step (b), wherein the weight ratio of the acid solution to the cellulosic material is 1.5:1 or greater;
- and
- (d) allowing the compressed cellulosic material to absorb and react with the acid, to produce cellulose crystallites.
A method of reacting cellulosic material with acid to produce cellulose crystallites, comprising the steps of
- (a) providing cellulosic material;
- (b) compressing the cellulosic material to reduce interstitial spaces therein and produce a compressed cellulosic material;
- (c) contacting the compressed cellulosic material with an acid solution;
- and
- (d) allowing the acid solution to wick into the interstitial spaces in the compressed cellulosic material and react with the cellulosic material, to produce cellulose crystallites.
(canceled)
An apparatus for reacting cellulosic material with acid to produce cellulose crystallites, comprising:
- (a) a means for feeding cellulosic material into the apparatus at an input zone thereof;
- (b) a means for compressing the cellulosic material to reduce interstitial spaces therein and form compressed cellulosic material;
- (c) a means for contacting the compressed cellulosic material with an acid downstream of the means for compressing, for wicking of the acid into the interstitial spaces in the compressed cellulosic material;
- (d) a means for extracting air from the compressed cellulosic material;
- (e) a means for holding the compressed cellulosic material and absorbed acid during reaction therebetween to form cellulose crystallites;
- and
- (f) a means for releasing the cellulose crystallites from an output zone of the apparatus.
An apparatus for reacting cellulosic material with acid to produce cellulose crystallites, comprising:
- (a) a conveyer;
- (b) a means for feeding cellulosic material onto the conveyer;
- (c) rollers or shoe presses for compressing the cellulosic material on the conveyer to form a layer of compressed cellulosic material;
- (d) a means for applying acid to the compressed cellulosic material layer for absorption of the acid into the compressed cellulosic material;
- and
- (e) a means for holding the layer of compressed cellulosic material and absorbed acid during reaction therebetween to form cellulose crystallites.
A method of reacting cellulosic material with acid to produce cellulose crystallites, comprising the steps of:
- (a) providing cellulosic material;
- (b) compressing the cellulosic material to reduce interstitial spaces containing gas therein and produce a compressed cellulosic material;
- (c) contacting the compressed cellulosic material with an acid solution;
- and
- (d) allowing the acid solution to be conveyed into the interstitial spaces in the compressed cellulosic material and react with the cellulosic material, to produce cellulose crystallites.
Dependencies are inferred from the claim text.