METHODS OF PULP FIBER TREATMENT
In some embodiments, a method may include treating pulp in pulp and paper mills. The methods may include providing a peracetate oxidant solution and generating a reactive oxygen species. The peracetate solution may include peracetate anions and a peracid. In some embodiments, the peracetate solution may include a pH from about pH 10 to about pH 12. In some embodiments, the peracetate solution has a molar ratio of peracetate anions to peracid ranging from about 60:1 to about 6000:1. In some embodiments, the peracetate solution has a molar ratio of peracetate to hydrogen peroxide of greater than about 16:1. The peracetate oxidant solution may provide enhanced treatment methods of bleaching, brightening, and delignifying pulp fibers involving the use of peracetate oxidant solutions.
1 . A method of treating pulp, comprising:
contacting pulp with a parent oxidant solution;
mixing the pulp with the parent oxidant solution; and
generating a reactive oxygen species.
2 . The method of claim 1 , wherein the parent oxidant solution is a peracetate oxidant solution.
3 . The method of claim 1 , further comprising heating the pulp to a temperature from between about 50° C. to about 95° C.
4 . The method of claim 3 , wherein the heating accelerates the generation of reactive oxygen species from the parent oxidant solution.
5 . The method of claim 1 , further comprising delignifying the pulp.
6 . The method of claim 1 , further comprising extracting lignin from the pulp.
7 . The method of claim 1 , further comprising brightening the pulp.
8 . The method of claim 1 , further comprising bleaching the pulp.
9 . The method of claim 8 , further comprising replacing a chlorine stage.
10 . The method of claim 1 , further comprising reducing a waste water stream.
11 . The method of claim 1 , wherein the pulp consists of a suspension of cellulose fibers in water.
12 . The method of claim 1 , wherein the pulp comprises a pulp consistency from 0.1 to 20% pulp fiber.
13 . The method of claim 2 , wherein the peracetate oxidant solution comprises peracetate anions and a peracid, wherein the peracetate oxidant solution has a pH from about 7 to about pH 12, and wherein the peracetate oxidant solution has a molar ratio of peracetate anions to peracid ranging from about 60:1 to about 6000:1.
14 . The method of claim 13 , wherein a peracetate anion to hydrogen peroxide molar ratio is greater than about 16:1.
15 . The method of claim 1 , wherein the reactive oxygen species generated is a singlet oxygen.
16 . The method of claim 1 , wherein the generating of the reactive oxygen species reduces the kappa number of the pulp.
17 . The method of claim 1 , wherein contacting the pulp with the peracetate oxidant solution reduces odors and microbial count.
18 . The method of claim 1 , wherein contacting the pulp comprises contacting the pulp at any stage of a pulp treatment process.
19 . The method of claim 1 , wherein contacting the pulp comprises contacting the pulp before, during, and/or after a pulping stage.
20 . The method of claim 1 , wherein contacting the pulp comprises contacting the pulp before, during, and/or after a delignification stage.
21 . The method of claim 1 , wherein contacting the pulp comprises contacting the pulp before, during and/or after a washing stage.
22 . The method of claim 1 , wherein mixing the pulp comprises an effective pH range from between about pH 6 to about pH 11.
23 . The method of claim 2 , further comprising sequentially dosing the pulp with the peracetate oxidant solution.
24 . The method of claim 23 , wherein sequentially dosing the pulp comprises increasing delignification, bleaching and/or brightening efficacy.
25 . The method of claim 1 , further comprising measuring an oxidation-reduction potential to monitor and control peracetate oxidant solution dose level.
26 . The method of claim 1 , further comprising reducing corrosion in a pulp mill.
27 . The method of claim 1 , further comprising reducing AOX formation in a pulp mill.
28 . The method of claim 1 , wherein contacting the pulp comprises contacting the pulp anywhere in a pipe, in-line mixing apparatus, mixed tank, blending unit, circulated sump, recirculating water system and/or inlet or outlet of a pump.
29 . A method of reducing a microbial load in a pulp slurry, comprising:
contacting pulp slurry containing a population of microbes with a parent peracetate oxidant solution;
mixing said pulp slurry with the parent peracetate oxidant solution; and
generating a reactive oxygen species.
30 . The method of claim 29 , further comprising heating the pulp slurry to within a temperature range between about 50° C. to about 95° C.