Amorphous Dithiazine Dissolution Formulation and Method for Using the Same

Abstract

Amorphous Dithiazine Dissolution Formulation and Method for using the Same The invention relates a use of an aqueous composition comprising at least one organic peroxide to dissolve amorphous dithiazine.

Claims

1.-23. (canceled)

24. A method Method for dissolving amorphous dithiazine, the method comprising adding an aqueous composition comprising at least one organic peroxide as dithiazine dissolver to the dithiazine-containing system.

25. The method according to claim 24, wherein the aqueous composition comprises 0.1 to 35 wt.-% of the organic peroxide.

26. The method according to claim 24, wherein the aqueous composition further comprises 0.1 to 6 wt.-% of a corrosion inhibitor.

27. The method according to claim 26, wherein the corrosion inhibitor comprises at least one imidazoline and amidoamine, the total concentration of the imidazoline and amidoamine being from 1 to 3 wt.-%.

28. The method according to claim 26, wherein the corrosion inhibitor comprises at least one sulfur synergist, the concentration of the sulfur synergist being from 0.05 to 5 wt.-%.

29. The method according to claim 26, wherein the corrosion inhibitor comprises at least one phosphate ester, the concentration of the phosphate ester being from 0.05 to 5 wt.-%.

30. The method according to claim 26, wherein the corrosion inhibitor comprises at least one a phosphate ester, at least one sulfur synergist and at least one imidazoline and amidoamine.

31. The method according to claim 24, wherein the organic peroxide is peracetic acid.

32. The method according to claim 26, wherein the corrosion inhibitor comprises at least one imidazoline and amidoamine according to the formulae C and D ##STR00017## wherein R.sup.3 is —H, —C.sub.2H.sub.4NH.sub.2, —C.sub.2H.sub.4OH, —(C.sub.2H.sub.4NH).sub.x—C.sub.2H.sub.4NH.sub.2, X is a number from 0 to 200, R.sup.4 is a C.sub.3 to C.sub.29 aliphatic hydrocarbon group.

33. The method according to claim 26, wherein the corrosion inhibitor comprises at least one sulfur synergist selected from the group consisting of the formulae
C.sub.nH.sub.2n+1SH wherein n is a number from 1 to 18;
M.sub.x(S.sub.2O.sub.3).sub.y wherein x=2 and y=1 and M═Li, Na, K, Ag, Cu or NH.sub.4, x=1 and y=1 and M═Mg, Ca, Sr, Cu, Zn, Pb or Fe, x=2 and y=3 and M═Al, Bi or Fe;
M(SCN).sub.x wherein x=1 and M═Li, Na, K, Ag, Cu or NH4, x=2 and M═Mg, Ca, Sr, Cu, Zn, Pb or Fe, x=3 and M═Al, Bi or Fe;
M(HSCH.sub.2COO).sub.x wherein x=1 and M═Li, Na, K, Ag, Cu or NH4, x=2 and M═Mg, Ca, Sr, Cu, Zn, Pb or Fe, x=3 and M═Al, Bi or Fe;
and
S═C(NH).sub.2R.sup.7R.sup.6 wherein R.sup.7 and/or R.sup.6 are independently selected from the group consisting of H, C.sub.1 to C.sub.10 alkyl, C.sub.2 to C.sub.10 alkenyl or C.sub.5 to C.sub.9 aryl groups.

34. The method according to claim 26, wherein the corrosion inhibitor comprises at least one phosphate ester of the formula (12) ##STR00018## wherein R.sub.a, R.sub.b and R.sub.cindependently are selected from H or a hydrocarbon group, which may contain oxygen or nitrogen atoms, with a carbon atom number ranging from 1 to 49.

35. The method according to claim 34, wherein at least one of R.sub.a, R.sub.b and R.sub.c comprises one or more ethoxy groups.

36. The method according to claim 34, wherein at least one of R.sub.a, R.sub.b and R.sub.c comprises an alkyl or alkenyl group.

37. The method according to claim 34, wherein the number of carbon atoms in at least one of R.sub.a, R.sub.b or R.sub.c is from 4 to 30.

38. The method according to claim 24, wherein the aqueous composition further comprises a surfactant.

39. The method according to claim 38, wherein the surfactant has an HLB value of 11 to 16.

40. The method according to claim 38, wherein the concentration of the surfactant is from 1 to 20 wt.-%.

41. The method according to claim 38, wherein the surfactant is selected from the group consisting of a) N-Alkyl-N-acylglucamine ##STR00019## wherein R.sup.14 is a linear or branched, saturated or unsaturated C.sub.5-C.sub.21-hydrocarbon residue, preferably a C.sub.7-C.sub.13-hydrocarbon residue, and R.sup.15 is a C.sub.1-C.sub.4 alkyl residue, preferably methyl. b) a mixture of at least 50 wt.-% of the total amount of N-Alkyl-N-acylglucamines according to formula (20) with R.sup.14 being a C.sub.7-C.sub.9-alkyl residue and at most 50 wt.-% of the total amount of N-Alkyl-N-acylglucamines according to formula (20) with R.sup.14 being a C.sub.11-C.sub.13-alkyl residue, and c) a cyclic N Alkyl-N-acylglucamine of the formulae ##STR00020## whereas in formulae (21), (22) and (23) R.sup.14 is a linear or branched, saturated or unsaturated C.sub.5-C.sub.21-alkyl residue, preferably a C.sub.7-C.sub.13-alkyl residue, and R.sup.15 is a C.sub.1-C.sub.4-alkyl residue.

42. The method according to claim 38, wherein the surfactant is a nonyl phenol ethoxylate according to formula (24) ##STR00021## wherein k is a number from 1 to 20.

43. The method according to claim 24, wherein an organic solvent is present.

44. The method according to claim 43, wherein the solvent is selected from the group consisting of monohydric alkyl alcohols having 1 to 8 carbon atoms, dihydric aliphatic alcohols having 2 to 6 carbon atoms and C.sub.1 to C.sub.4 alkyl ethers of the mono- and dihydric alcohols.

45. The method according to claim 43, wherein the solvent is present in a concentration of 0.1 to 30 wt.-%.

46. The method according to claim 24, wherein water is present in an amount to balance to 100 wt.-%.

Description

EXAMPLES

[0126] If not stated otherwise, references to % or ppm mean wt.-% or weight -ppm throughout this specification.

[0127] In order to clearly and demonstrably illustrate the current invention, several examples have been presented below, these are however, non-limiting and have been specifically chosen to show those skilled in the art, the logic taken to arrive at the final formulations.

Example 1: Dissolver Test Data

[0128] The following work shows the efficacy of dissolution of various substances of the prior art (marked as C for comparative in Table 1) and of the inventive compositions. Static dissolution tests were performed using 10 grams of dissolver solution and 0.5 grams of amorphous dithiazine sample. All tests were performed at 20° C. and were run for 6 hours. The amorphous dithiazine was carefully pre-weighed and then after the test, was dried and prepared accordingly and reweighed thus calculating a weight loss and therefore a dissolution percentage. In all tests the dissolver solution contained 10 wt.-% of the main component in order to match up activity. The main component is the compound mentioned in the column “Dissolver Formulation” in Table 1. The dilution water used was deionized. The test data has been summarized in Table 1.

TABLE-US-00001 TABLE 1 Tests on amorphous dithiazine using current known art and inventive examples Amorphous Dithiazine Amorphous Laboratory Dithiazine Generated Field Sample Temper- (Weight (Weight ature No. Dissolver Formulation Loss %) Loss %) (° C.) 1.0 Hydrogen peroxide 0.0 0.0 20 (comp.) 1.1 Hydrogen peroxide 5.6 5.6 65 (comp.) 1.2 Peracetic acid 100.0 100.0 20

[0129] The performance of the inventive components from Group 1 are noted to yield higher performance than the comparative examples of the prior art.

Example 2: Corrosivity of Tested Amorphous Dithiazine Dissolvers

[0130] In order to test, experimentally, the corrosivity of the instant invention and the other state-of-the-art chemistries, ASTM standard testing was performed (ASTM G31-72 and ASTM D471) on the fluids using a carbon steel (C1018) and stainless steel (SS316L) metallurgy. Tests were run for 24 hours in a static jar test at 40° C. The results can be seen in Table 2 and the clear benefit of the instant invention can be discerned.

[0131] The corrosion inhibitor used was a combination of one component from each of groups 2a, 2b and 2c as mentioned above. It comprised a TOFA-DETA-Imidazoline, thioglycolic acid and an ethoxylated phosphate ester.

TABLE-US-00002 TABLE 2 Corrosivity tests on amorphous dithiazine dissolvers using the current invention and from the prior art Corrosivity (mpy) Corrosivity (mpy) No. Dissolver Formulation C1018 SS316L 2.1 C Hydrogen peroxide >2,000 >2,000 2.2 C Peracetic acid >2,000 >2,000 2.3 Peracetic acid + 5000 ppm 1.82 2.92 of Corrosion Inhibitor 1 2.4 Peracetic acid + 5000 ppm 2.92 4.67 of Corrosion Inhibitor 2

[0132] Corrosion Inhibitor 1 is a proprietary product that contains 25 wt-% of a phosphate ester.

[0133] Corrosion inhibitor 2 is a commercial product that comprises a blend of quinoline quaternary ammonium alkyl amine salts, an alkyl thioamide, and oxyalkylated phenols.

[0134] This result shows that the corrosivity of peracetic acid may be mitigated by a corrosion inhibitor, a phosphate ester being particulary effective.

Example 3: Dissolution of Inventive Formulation Combinations

[0135] The following work shows the efficacy of dissolution of various inventive compositions that incorporate Group 2, 3 and 4 components to show that the presence of a corrosion inhibitor package does not affect the efficacy of dissolution. Static dissolution tests were performed using 10 grams of dissolver solution and 0.5 grams of amorphous dithiazine sample. All tests were performed at 20° C. and were run for 6 hours. The amorphous dithiazine was carefully pre-weighed and then after the test, was dried and prepared accordingly and reweighed thus calculating a weight loss and therefore a dissolution percentage. Like in Example 1 in all tests 10 wt.-% of the main component was used in order to match up activity. The surfactant used was a nonyl phenol ethoxylate and the solvent used was 2-butoxyethanol/water. The water used was deionized. The test data has been summarized in Table 3.

TABLE-US-00003 TABLE 3 Dissolution tests on amorphous dithiazine dissolvers using variations of the instant invention Amorphous Dithiazine Amorphous Laboratory Dithiazine Generated Field Sample (Weight (Weight No. Dissolver Formulation Loss %) Loss %) 3.1 Hydrogen peroxide + 5.6 5.0 2% Corrosion Inhibitor 3.2 Peracetic acid + 100.0 100.0 2% Corrosion Inhibitor 3.3 Hydrogen peroxide + 5.6 5.0 2% Corrosion Inhibitor + 2% surfactant 3.4 Peracetic acid + 100.0 100.0 2% Corrosion Inhibitor + 2% surfactant 3.5 Hydrogen peroxide + 5.3 5.0 2% Corrosion Inhibitor + 10% solvent 3.6 Peracetic acid + 100.0 100.0 2% Corrosion Inhibitor + 10% solvent 3.7 Hydrogen peroxide + 5.2 5.0 2% Corrosion Inhibitor + 2% surfactant + 10% solvent 3.8 Peracetic acid + 100.0 100.0 2% Corrosion Inhibitor + 2% surfactant + 10% solvent