Method for separating the non-inked cellulose fibers from the inked cellulose fibers in cellulosic materials

• US 5,843,764 A
• Filed: 01/18/1995
• Issued: 12/01/1998
• Est. Priority Date: 05/21/1993
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Energy Systems, Inc. (AES Corporation)
• Original Assignee: Martin Marietta Energy Systems, Inc.
• Inventors: Woodward, Jonathan
• Primary Examiner(s): Wityshyn, Michael G.
• Assistant Examiner(s): PRATS, FRANCISCO CHANDLER
• Application Number:
  US08/375,200
• Time in Patent Office: 1,413 Days
• Field of Search: 435/277, 435/278, 435/209, 435/99
• US Class Current: 435/277
• CPC Class Codes: D21C 5/005 Treatment of cellulose-containing material with microorganisms or enzymes
• CPC Class Codes: D21C 5/025 De-inking
• CPC Class Codes: Y02W 30/64 Paper recycling

Abstract

A method for enzymatically separating the non-inked cellulose fibers from the inked cellulose fibers in cellulosic materials. The cellulosic material, such as newsprint, is introduced into a first chamber containing a plastic canvas basket. This first chamber is in fluid communication, via plastic tubing, with a second chamber containing cellobiase beads in a plastic canvas basket. Cellulase is then introduced into the first chamber. A programmable pump then controls the flow rate between the two chambers. The action of cellulase and stirring in the first chamber results in the production of a slurry of newsprint pulp in the first chamber. This slurry contains non-inked fibers, inked fibers, and some cellobiose. The inked fibers and cellobiose flow from the first chamber to the second chamber, whereas the non-inked fibers remain in the first chamber because they are too large to pass through the pores of the plastic canvas basket. The resulting non-inked and inked fibers are then recovered.

Claims

1. A method for separating non-inked cellulose fibers from inked cellulose fibers in cellulosic materials comprising the steps of:

introducing cellulosic material into a first vessel, the cellulosic material comprising cellulose, the cellulose comprising non-inked cellulose fibers and inked cellulose fibers;

reacting the cellulosic material with cellulase to form a slurry, the reaction causing the cellulosic material to separate into non-inked cellulose fibers and inked cellulose fibers, the slurry comprising non-inked cellulose fibers, inked cellulose fibers, and cellobiose;

transferring the slurry through a first retaining means in the first vessel to retain the non-inked cellulose fibers in the first vessel;

transferring the slurry from the first vessel into a second vessel, the slurry comprising individual inked cellulose fibers, the first vessel being in fluid communication with the second vessel, the second vessel containing cellobiase;

transferring the slurry through a second retaining means in the second vessel for retaining the inked cellulose fibers in the second vessel;

recovering the non-inked cellulose fibers; and

recovering the inked cellulose fibers.

2. A method in accordance with claim 1, further comprising the additional step of size reducing the cellulosic material prior to introduction into the first vessel.

3. A method in accordance with claim 1, wherein the first vessel is agitated.

4. A method in accordance with claim 1, wherein the second vessel is agitated.

5. A method in accordance with claim 1, wherein the step of transferring the slurry into the second vessel is accomplished by means of a pump, the pump being in fluid communication with the first vessel and the second vessel.

6. A method in accordance with claim 1, wherein the first retaining means comprises a porous material.

7. A method in accordance with claim 6, wherein the porous material contains a plurality of pores extending therethrough.

8. A method in accordance with claim 7, wherein the pores permit inked cellulose fibers to migrate therethrough.

9. A method in accordance with claim 1, wherein the cellulosic material is paper.

10. A method in accordance with claim 1, wherein the cellulosic material is newsprint.

11. A method in accordance with claim 1, wherein the second retaining means comprises a porous material.

12. A method in accordance with claim 11, wherein the porous material contains a plurality of pores extending therethrough.