Noram Engineering and Constructors Ltd.

The University of British Columbia

James M Lockhart

J David Genders

Peter Symons

James Theodore Wearing

James Allen Olson

Dominic Mark Martinez

Ali Gulamhusein

Evan J Hobenshield

Durk Devries

Ario Madani

Ian Alistair Frigaard

Davood Farajisarir

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.

Process for making partly-hydrolyzed cellulose using compressed cellulosic materials

A method of recovering purified partly-hydrolyzed cellulose particles from a composition comprising agglomerated partly-hydrolyzed cellulose particles and an acid, using electrodialysis. The invention addresses the problem of reducing the acid to very low levels while avoiding the high capital and operating costs, high water usage and large filtration surface area or dilution time requirements of the prior art processes. Following dilution, concentration by centrifuging or settling, and/or dialysis of the composition, the composition is treated in an electrodialysis cell to remove ions, such as free sulfate from sulfuric acid. The method may include having an anion exchange resin in the feed compartment of the electrodialysis cell, adding a base to the receiving solution in the electrodialysis cell, and a second step of electrodialysis of the purified partly-hydrolyzed cellulose particles.

Purification process for partly-hydrolyzed cellulose

Particles are separated from a source viscoplastic fluid by flowing streams of the viscoplastic fluid and a destination fluid in parallel streamed relationship inside a rotating cylindrical annulus by using baffles to introduce each fluid independently at an inlet lower end of the annulus and for separating the upper streams consisting of an un-yielded source and destination flow proximate the radially innermost side of the annulus, a bulk axial flow in a more central region and a yielded layer destination flow adjacent the radial outermost side of the annulus which contains the particles that have separated. Inlet and outlet baffles are provided at each end of the vertically oriented device to maintain the flows discrete on entry and to maintain the separated flows discrete on exit so as to facilitate removal of the component flows from the fractionator.

Method and apparatus for continuously fractionating particles contained within a viscoplastic fluid

A method of recovering purified partly-hydrolyzed cellulose () from a composition () comprising partly-hydrolyzed cellulose and an acid, such as sulfuric acid. A base () having a cation that forms a precipitate with the anion of the acid is added to the composition. For example, a base such as barium hydroxide is added to form a sulfate precipitate. The precipitate () is then separated from the partly-hydrolyzed cellulose (), thus reducing its acid content. The method may include additional steps of centrifugation () of the composition, breaking-up agglomerations () in the composition after precipitation, and dialysis ().

Growing community of inventors

Vancouver, Canada

James M Lockhart