Formulation and method for inhibiting carbon-based deposits

Patent metadata

Field	Value
Publication number	US-10428429-B2
Application number	US-201515516019-A
Country	US
Kind code	B2
Filing date	Sep 30, 2015
Priority date	Sep 30, 2014
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

There is a formulation and a method for inhibiting carbon-based deposits on metal substrate. The method comprises the use of a formulation comprising at least one oxidizing agent and at least one etchant capable of forming free metal ions from the metal substrate, at least one sequestering agent having a ligand capable of forming a complex with the free metal ions and at least one chelating agent having a ligand capable of complexing with at least one surface metal atom.

First claim

What is claimed is:

1. A formulation for inhibiting carbon-based deposits on a metal substrate, the formulation comprising at least one oxidizing agent and at least one etchant to form free metal ions from the metal substrate, at least one sequestering agent having a ligand selected to form a complex with the free metal ions and at least one chelating agent having a ligand selected to complex with at least one surface metal atom, wherein the at least one etchant comprises 50 to 70 wt % of the formulation, based on the weight of the formulation, the at least one etchant being an acid selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, trifluoromethanesulfonic acid, fluorosulfuric acid, trichloroacetic acid, trifluoroacetic acid and combination thereof, and wherein the at least one sequestering agent comprises 20 to 25 wt % of the formulation, based on the weight of the formulation.

2. The formulation according to claim 1 , wherein the weight ratio of the at least one oxidizing agent to the at least one etchant is 0.2:2 to 0.2:3.

3. The formulation according to claim 1 , wherein the weight ratio of the at least one sequestering agent to the at least one chelating agent is 4:0.1 to 5:0.3.

4. The formulation according to claim 1 , wherein the at least one oxidizing agent comprises 10 to 15 wt % of the formulation, based on the weight of the formulation.

5. The formulation according to claim 1 , wherein the at least one oxidizing agent is selected from the group consisting of peroxides, peroxyacids, peroxyesters, permanganates, mineral acids, nitrates, persulphates, perborates, perchlorates, perchlorites, chlorates, chlorites, percarbonates, derivatives thereof and combinations thereof.

6. The formulation according to claim 1 , wherein the at least one sequestering agent is an amino acid selected from the group consisting of glycine, threonine, aspartic acid, glutamic acid and serine.

7. The formulation according to claim 1 , wherein the at least one sequestering agent is a hydroxycarboxylic acid selected from the group consisting of malic acid, gluconic acid, citric acid, tartaric acid, glycolic acid and lactic acid.

8. The formulation according to claim 1 , wherein the at least one chelating agent comprises 0.5 to 5 wt % of the formulation, based on the weight of the formulation.

9. The formulation according to claim 1 , wherein the at least one chelating agent is selected from the group consisting of ketone, phosphonic acid, sulfonic acid and an optionally substituted heterocyclic compound having at least 3 heteroatoms.

10. The formulation according to claim 1 , wherein the at least one oxidizing agent comprises 10 to 15 wt % of the formulation, and the at least one chelating agent comprises 0.5 to 1.5 wt % of the formulation, wherein the weight percentages of the etchant, the oxidizing agent, the sequestering agent and the chelating agent add up to 100 wt % of the formulation.

11. The formulation according to claim 1 , further comprising a stabilizer, wherein said stabilizer is 1,5-naphthalene disulfonic acid, or a salt thereof.

12. A method for inhibiting carbon-based deposits on a metal substrate, said method comprising:
contacting said metal substrate with a formulation to inhibit carbon-based deposits on said metal substrate, wherein said formulation comprises at least one oxidizing agent and at least one etchant to form free metal ions from the metal substrate, a sequestering agent having a ligand selected to form a complex with the free metal ions and at least one chelating agent having a ligand selected to complex with at least one surface metal atom,
wherein the at least one etchant comprises 50 to 70 wt % of the formulation, based on the weight of the formulation, the at least one etchant being an acid selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, trifluoromethanesulfonic acid, fluorosulfuric acid, trichloroacetic acid, trifluoroacetic acid and combination thereof, and wherein the at least one sequestering agent comprises 20 to 25 wt % of the formulation, based on the weight of the formulation.

13. The method according to claim 12 , wherein the weight ratio of the at least one oxidizing agent to the at least one etchant is 0.2:2 to 0.2:3.

14. The method according to claim 12 , wherein the weight ratio of the at least one sequestering agent to the at least one chelating agent is 4:0.1 to 5:0.3.

15. The method according to claim 12 , wherein the contacting operation is carried out at a pressure between 101 325 Pa to 506 625 Pa.

16. The metal according to claim 12 , wherein the free metal ion is selected from the group consisting of Fe2+, Fe3+, Cr3+, Ni+, Ti+, Ti2+, W+ and W2+.

17. The method according to claim 12 , wherein the at least one surface metal atom is selected from the group consisting of Fe, Cr, Ni, Ti and W.

18. The method according to claim 12 , wherein the surface metal atom is a surface metal ion selected from the group consisting of Fe2+, Fe3+, Cr3+, Ni+, Ti+, Ti2+, W+ and W2+.

19. A metal pipe treated with a formulation for inhibiting carbon-based deposits on a metal substrate, the formulation comprising at least one oxidizing agent and at least one etchant to form free metal ions from the metal substrate, at least one sequestering agent having a ligand selected to form a complex with the free metal ions and at least one chelating agent having a ligand selected to complex with at least one surface metal atom, wherein the at least one etchant comprises 50 to 70 wt % of the formulation, based on the weight of the formulation, the at least one etchant being an acid selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, trifluoromethanesulfonic acid, fluorosulfuric acid, trichloroacetic acid, trifluoroacetic acid and combination thereof, and wherein the at least one sequestering agent comprises 20 to 25 wt % of the formulation, based on the weight of the formulation.

Assignees

• Agency Science Tech & Res

Inventors

• Hong Liang
• Zheng Yuanhuan
• Tay Siok Wei

Classifications

• C10G75/02

  by addition of corrosion inhibitors · CPC title

• C10G9/16

  Preventing or removing incrustation · CPC title

• C23F3/06 Primary

  with acidic solutions · CPC title

• C09K13/06

  with organic material · CPC title

• F16L9/02

  of metal (F16L9/16 - F16L9/22 take precedence) · CPC title