IP Library Granted Patent US 7,582,213
Granted Patent B2
US 7,582,213 · App. 11/435,221 · Granted Sep 1, 2009

Cellulose fiber-based filters

Assignees: Regents of the University of Minnesota; Agricultural Utilization Research Institute
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Quick Facts
Patent No.
US 7,582,213
App. No.
11/435,221
Granted
Sep 1, 2009
Kind
B2
Abstract

The present invention comprises an improved method for refining cellulose that produces a highly refined cellulosic material. The method comprises soaking raw material in a mild NaOH using reduced temperatures and pressures, and refining the material with a plate refiner so that a waste water stream is reduced in volume and has a pH within a range of 8 to 9. The present invention also comprises a HRC gel having a lignin concentration of at least about one (1)% by weight, and a water retention capacity of about 25 to at least about 56 g H 2 O/g dry HRC.

Claims (5)

1. A filter comprising a highly refined cellulose having a lignin concentration of at least 1% by weight, and a water retention capacity of at least about 20 g H 2 O/g dry HRC.

2. The filter of claim 1 wherein the highly refined cellulose has a Langmuir surface area of at least about 7 m 2 /g.

3. The filter of claim 1 wherein the highly refined cellulose has an average pore diameter of at least about 5 angstroms.

4. A method for filtering comprising exposing a liquid to the filter of claim 1 .

5. A method for filtering comprising passing a liquid or a gas through the filter of claim 1 .

Assignments (1)
SECURITY AGREEMENT Recorded Apr 2, 2010
From: FIBERSTAR, INC.
To: JANDO, INC.; FAULKS, DON
Reel/Frame 024170/0726 →
Continuity (3)
Continuation 1030325600 · Nov 25, 2002
Division 0943294500 · Nov 3, 1999
Related Publication 20060204631A1 · Sep 14, 2006