BLACK LIQUOR TREATMENT
Compositions and methods for minimizing fouling and/or reducing the viscosity of black liquor in a Kraft pulping process are provided. An exemplary composition includes an anionic sulfate or sulfonate surfactant; an anionic sulfate or sulfonate dispersant; and a nonionic alkoxylated surfactant.
1 . A composition comprising:
an anionic sulfate or sulfonate surfactant;
an anionic sulfate or sulfonate dispersant; and
a nonionic alkoxylated surfactant.
2 . The composition of claim 1 , wherein the anionic sulfate or sulfonate surfactant is selected from sodium xylene sulfonate, di-phenyl sulfonate gemini surfactant, and combinations thereof.
3 . The composition of claim 1 , wherein the anionic sulfate or sulfonate surfactant comprises an alkyldiphenyloxide disulfonate.
4 . The composition of claim 1 , wherein the anionic sulfate or sulfonate dispersant comprises a naphthalene sulfonate condensation polymer or a sodium lignosulfonate.
5 . The composition of claim 1 , wherein the nonionic alkoxylated surfactant is selected from ethylene oxide-propylene oxide (EO/PO) block copolymer surfactants, EO/PO/EO block copolymer surfactants, and linear ethoxylate [castor] oil.
6 . The composition of claim 1 , wherein the nonionic alkoxylated surfactant comprises glycerol initiated EO/PO side chain surfactant.
7 . The composition of claim 1 , wherein:
the anionic sulfate or sulfonate surfactant comprises an alkyldiphenyloxide disulfonate;
the anionic sulfate or sulfonate dispersant comprises a naphthalene sulfonate condensation polymer; and
the nonionic alkoxylated surfactant comprises glycerol branched EO/PO side chain surfactant.
8 . The composition of claim 7 , wherein the composition consists essentially of carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and sodium atoms.
9 . The composition of claim 1 , wherein the composition is free of nitrogen-containing compounds and phosphorus-containing compounds.
10 . The composition of claim 1 , wherein the composition consists essentially of carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and sodium atoms.
11 . A composition comprising:
water; and
active compounds comprising:
0 to 90% by weight of an anionic sulfonate surfactant;
0 to 90% by weight of an anionic sulfonate dispersant; and
0 to 25% by weight of a nonionic ethoxylated surfactant, based on a total weight of the active compounds.
12 . The composition of claim 11 , wherein the composition comprises:
from 40 to 80% by weight of the water; and
from 20 to 60% by weight of the active compounds, based on a total weight of the composition.
13 . The composition of claim 11 , wherein:
the anionic sulfonate surfactant comprises an alkyldiphenyloxide disulfonate;
the anionic sulfonate dispersant comprises a naphthalene sulfonate condensation polymer; and
the nonionic ethoxylated surfactant comprises glycerol branched EO/PO side chain surfactant.
14 . A method for treating a black liquor, the method comprising:
adding an effective amount of a composition to the black liquor; and
minimizing fouling and/or reducing the viscosity of the black liquor, wherein the composition comprises:
an anionic sulfate or sulfonate surfactant;
an anionic sulfate or sulfonate dispersant; and
a nonionic ethoxylated surfactant.
15 . The method of claim 14 , further comprising passing the black liquor through a series of evaporators from a first evaporator to a last evaporator, wherein the effective amount of the composition is added to the black liquor in the last evaporator.
16 . The method of claim 14 , wherein the effective amount of the composition is added to the black liquor when a solids concentration of the black liquor is from 40 to 60% by weight.
17 . The method of claim 14 , wherein the effective amount of the composition is from 25 to 5,000 ppm, based on black liquor solids.
18 . The method of claim 14 , wherein the black liquor has a pH of greater than 12, and wherein the black liquor is at a temperature of greater than 120° C.
19 . The method of claim 14 , wherein:
the anionic sulfate or sulfonate surfactant comprises an alkyldiphenyloxide disulfonate;
the anionic sulfate or sulfonate dispersant comprises a naphthalene sulfonate condensation polymer; and
the nonionic ethoxylated surfactant comprises glycerol branched EO/PO side chain surfactant.
20 . The method of claim 14 , wherein the composition consists essentially of carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and sodium atoms.