Black liquor viscosity reducing and anti-scale agent

Patent metadata

Field	Value
Publication number	US-11905655-B2
Application number	US-202016941931-A
Country	US
Kind code	B2
Filing date	Jul 29, 2020
Priority date	Aug 30, 2019
Publication date	Feb 20, 2024
Grant date	Feb 20, 2024

Abstract

The disclosure provides methods and compositions for reducing the viscosity of black liquor. Also provided are methods of inhibiting deposition of scale and methods of processing black liquor. In some embodiments, the compositions include a carboxylate-containing polymer and an inorganic salt. In some embodiments, the compositions include a carboxylate-containing polymer, an inorganic salt, and a surfactant.

First claim

What is claimed is:

1. A method of reducing a viscosity of a black liquor, comprising:
adding an effective amount of a composition to the black liquor, and
reducing the viscosity of the black liquor, wherein the composition
comprises an inorganic salt and a carboxylate-containing polymer,
wherein the inorganic salt comprises a bisulfite salt, and
wherein the carboxylate-containing polymer is selected from the group consisting of a polyacrylate, polymer comprising sulfonate and a nonionic monomer, a polymer comprising a polyacrylate and a phosphonate, and any combination thereof.

2. The method of claim 1 , wherein the composition further comprises a surfactant.

3. The method of claim 1 , further comprising:
concentrating the black liquor to a solids level of about 40% or more;
transporting the condensed black liquor to a recovery boiler; and
incinerating the condensed black liquor in the recovery boiler.

4. The method of claim 1 , wherein the effective amount is from about 100 ppm to about 10,000 ppm.

5. The method of claim 1 , wherein the viscosity is reduced to an amount between about 15 cP and about 50 cP.

6. The method of claim 1 , wherein the composition is added at a time selected from the group consisting of when the black liquor comprises from about 15% solids to about 20% solids, when the black liquor comprises from about 35% solids to about 45% solids, when the black liquor comprises from about 55% solids to about 65% solids, and any combination thereof.

7. A method of inhibiting scale deposition on a surface of an evaporator, comprising:
adding an effective amount of a composition to a black liquor,
contacting the surface of the evaporator with the black liquor, and
inhibiting scale deposition on the surface, wherein the composition
comprises an inorganic salt, a surfactant, and a carboxylate-containing polymer,
wherein the inorganic salt comprises a bisulfite salt, and
wherein the carboxylate-containing polymer is selected from the group consisting of a polyacrylate, a polymer comprising sulfonate and a nonionic monomer, a polymer comprising a polyacrylate and a phosphonate, and any combination thereof.

8. The method of claim 7 , wherein the scale comprises burkeite.

Assignees

• Ecolab Usa Inc

Inventors

• Pace Luiz Wanderley Bratfisch
• Duggirala Prasad Yogendra

Classifications

• D21C9/008

  Prevention of corrosion or formation of deposits on pulp-treating equipment (D21C9/08, D21H21/02 take precedence) · CPC title

• D21C11/106 Primary

  Prevention of incrustations on heating surfaces during the concentration, e.g. by elimination of the scale-forming substances contained in the liquors · CPC title

• D21C3/226

  Use of compounds avoiding scale formation · CPC title

• D21C11/0092

  Substances modifying the evaporation, combustion, or thermal decomposition processes of black liquor (treatment of solid substances (ash) separated from combustion gases D21C11/066; avoiding scale-forming during evaporation D21C11/106) · CPC title

• D21C11/04

  of alkali lye · CPC title