U.S. patent application number 10/164100 was filed with the patent office on 2003-01-16 for method for inhibiting calcium salt scale.
Invention is credited to Loy, Jeremy E., Severtson, Steven John, Thompson, Jacob Owen, Verrett, Sheldon Phillip.
Application Number | 20030010458 10/164100 |
Document ID | / |
Family ID | 23141509 |
Filed Date | 2003-01-16 |
United States Patent
Application |
20030010458 |
Kind Code |
A1 |
Thompson, Jacob Owen ; et
al. |
January 16, 2003 |
Method for inhibiting calcium salt scale
Abstract
Compositions and method for improving inhibition of calcium salt
scale formation under the conditions found in chemical pulp
processes in which an effective amount of selected phosphonates or
phosphonate blends is admixed with the aqueous digester composition
in a chemical pulping process during the digestion stage. The
compositions and method are especially well suited for use in the
Kraft pulping process.
Inventors: |
Thompson, Jacob Owen; (St.
Louis, MO) ; Verrett, Sheldon Phillip; (Olivette,
MO) ; Severtson, Steven John; (Shoreview, MN)
; Loy, Jeremy E.; (Vemon Hills, IL) |
Correspondence
Address: |
LATHROP & GAGE LC
2345 GRAND AVENUE
SUITE 2800
KANSAS CITY
MO
64108
US
|
Family ID: |
23141509 |
Appl. No.: |
10/164100 |
Filed: |
June 5, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60296316 |
Jun 6, 2001 |
|
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|
Current U.S.
Class: |
162/29 ;
162/30.11; 162/48; 252/175; 252/181 |
Current CPC
Class: |
D21C 3/226 20130101;
C02F 5/14 20130101; C02F 5/12 20130101 |
Class at
Publication: |
162/29 ; 252/175;
252/181; 162/30.11; 162/48 |
International
Class: |
C02F 005/02; C02F
005/14; C02F 001/58; C02F 001/66; C02F 001/68 |
Claims
What is claimed is:
1. A scale inhibiting composition for inhibiting calcium salt scale
formation in alkaline aqueous mixtures of chemical pulping
processes, wherein said composition is added to the digester of
said chemical pulping process, said composition comprising an
effective scale inhibiting amount of at least one phosphonate
selected from compounds having the
formula:X.sub.2NCH.sub.2PO.sub.3M.sub.2 (I),compounds having the
formula: 4amine oxides of phosphonates of formula (I), or mixtures
thereof; wherein M is independently selected from hydrogen, alkali
metal, alkaline earth metal or ammonium, X is independently
selected from H, R, or --CH.sub.2PO.sub.3M.sub.2 wherein R is an
alkyl group or --NX.sub.2 substituted alkyl group having 2 to 6
carbon atoms, R' is an alkyl group having 1 to 17 carbon atoms and
R' is optionally branched and optionally unsaturated, and Y is
selected from --PO.sub.3M.sub.2, H or R'; with the proviso that
when said phosphonate is N(CH.sub.2PO.sub.3M.sub.2).sub.3, the
amount of said phosphonate on an active acid basis is greater than
25 ppm based on the weight of total liquor charged to said
digester.
2. The composition of claim 1 wherein M is independently selected
from hydrogen or an alkali metal.
3. The composition of claim 2 wherein M is sodium or potassium when
M is an alkali metal.
4. The composition of claim 1 wherein X is independently selected
from--CH.sub.2PO.sub.3M.sub.2 or R.
5. The composition of claim 4 wherein at least one of X is R and R
is--(CH.sub.2).sub.nNX'.sub.2, wherein n is an integer from 2 to 6
and X' is independently selected from R or
--CH.sub.2PO.sub.3M.sub.2.
6. The composition of claim 4 wherein each X is R and R is
--(CH.sub.2).sub.nNX'.sub.2, wherein n is an integer from 2 to 6
and X' is independently selected from R or
--CH.sub.2PO.sub.3M.sub.2.
7. The composition of claim 1 wherein Y is --PO.sub.3M.sub.2.
8. The composition of claim 7 wherein R' is an alkyl group having 1
to 5 carbon atoms.
9. The composition of claim 1 wherein said phosphonate is at least
one phosphonate of formula (I).
10. The composition of claim 1 wherein said phosphonate is at least
one phosphonate of formula (II).
11. The composition of claim 1 wherein said phosphonate is at least
one amine oxide of phosphonates of formula (I).
12. The composition of claim 1 wherein said phosphonate is a
mixture of at least two phosphonates of formula (I).
13. The composition of claim 1 wherein said phosphonate is a
mixture of at least one phosphonate of formula (I) and at least one
phosphonate of formula (II).
14. The composition of claim 1 wherein said phosphonate is a
mixture of at least two phosphonates of formula (II).
15. The composition of claim 9 wherein said phosphonate is
N(CH.sub.2PO.sub.3M.sub.2).sub.3 and the amount of said phosphonate
on an active acid basis is about 500 to about 1000 ppm based on the
weight of total liquor charged to said digester.
16. The composition of claim 10 wherein said phosphonate is
CH.sub.3C(OH)(PO.sub.3M.sub.2).sub.2.
17. The composition of claim 16 wherein the amount of said
phosphonate on an active acid basis is about 20 to about 200 ppm
based on the weight of total liquor charged to said digester.
18. The composition of claim 9 wherein said phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
).sub.2.
19. The composition of claim 18 wherein the amount of said
phosphonate on an active acid basis is about 10 to about 1000 ppm
based on the weight of total liquor charged to said digester.
20. The composition of claim 9 wherein said phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2-
).sub.2.
21. The composition of claim 20 wherein the amount of said
phosphonate on an active acid basis is about 150 to about 1000 ppm
based on the weight of total liquor charged to said digester.
22. The composition of claim 9 wherein said phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2 and the amount of
said phosphonate on an active acid basis is about 30 to about 1000
ppm based on the weight of total liquor charged to said
digester.
23. The composition of claim 9 wherein said phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2CH.sub.2N(CH.sub.2PO.sub.-
3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2CH.sub.-
2N-(CH.sub.2PO.sub.3M.sub.2).sub.2.
24. The composition of claim 23 wherein the amount of said
phosphonate on an active acid basis is about 10 to about 1000 ppm
based on the weight of total liquor charged to said digester.
25. The composition of claim 12 wherein said phosphonate is a
mixture of:
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2CH.sub.2N(CH.sub.2PO.sub.-
3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2CH.sub.-
2--N(CH.sub.2PO.sub.3M.sub.2).sub.2, and a second phosphonate
selected from N(CH.sub.2PO.sub.3M.sub.2).sub.3,
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH-
.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2,
(M.sub.2O.sub.3PCH.sub.2).- sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2,
or (M.sub.2O.sub.3PCH.sub.2).sub.2N-
CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub-
.3M.sub.2).sub.2.
26. The composition of claim 25 wherein said second phosphonate is
N(CH.sub.2PO.sub.3M.sub.2).sub.3, and the amount of said mixture on
an active acid basis is about 10 to about 1000 ppm based on the
weight of total liquor charged to said digester.
27. The composition of claim 25 wherein said second phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
).sub.2, and the amount of said mixture on an active acid basis is
about 20 to about 1000 ppm based on the weight of total liquor
charged to said digester.
28. The composition of claim 25 wherein said second phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2-
).sub.2, and the amount of said mixture on an active acid basis is
about 80 to about 1000 ppm based on the weight of total liquor
charged to said digester.
29. The composition of claim 25 wherein said second phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, and the amount
of said mixture on an active acid basis is about 10 to about 1000
ppm based on the weight of total liquor charged to said
digester.
30. The composition of claim 12 wherein said phosphonate is a
mixture of
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2-
).sub.2 and
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.s-
ub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2.
31. The composition of claim 30 wherein the amount of said mixture
on an active acid basis is about 50 to about 1000 ppm based on the
weight of total liquor charged to said digester.
32. The composition of claim 12 wherein said phosphonate is a
mixture of
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
).sub.2 and a second phosphonate selected from
(M.sub.2O.sub.3PCH.sub.2).s-
ub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2).sub.2,
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, or
N(CH.sub.2PO.sub.3M.sub.2).sub.3.
33. The composition of claim 32 wherein said second phosphonate is
selected from
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2P-
O.sub.3M.sub.2).sub.2 or N(CH.sub.2PO.sub.3M.sub.2).sub.3, and the
amount of said mixture on an active acid basis is about 30 to about
1000 ppm based on the weight of total liquor charged to said
digester.
34. The composition of claim 32 wherein said second phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, and the amount
of said mixture on an active acid basis is about 20 to about 1000
ppm based on the weight of total liquor charged to said
digester.
35. The composition of claim 13 wherein said phosphonate is a
mixture of a first phosphonate selected from
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2C-
H.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2,
(M.sub.2O.sub.3PCH.sub.2).sub.2NC-
H.sub.2CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.-
2PO.sub.3M.sub.2)CH.sub.2CH.sub.2CH.sub.2N-(CH.sub.2PO.sub.3M.sub.2).sub.2-
,
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.-
2).sub.2 or
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.s-
ub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, and a
second phosphonate selected from
CH.sub.3C(OH)(PO.sub.3M.sub.2).sub.2.
36. The composition of claim 35 wherein said first phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
).sub.2, and the amount of said mixture on an active acid basis is
about 20 to about 1000 ppm based on the weight of total liquor
charged to said digester.
37. The composition of claim 35 wherein said first phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2CH.sub.2N(CH.sub.2PO.sub.-
3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2Ch.sub.2CH.sub.-
2N-(CH.sub.2PO.sub.3M.sub.2).sub.2, and the amount of said mixture
on an active acid basis is about 20 to about 500 ppm based on the
weight of total liquor charged to said digester.
38. The composition of claim 35 wherein said first phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, and the amount
of said mixture on an active acid basis is about 30 to about 1000
ppm based on the weight of total liquor charged to said
digester.
39. The composition of claim 35 wherein said first phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2-
).sub.2 and the amount of said mixture on an active acid basis is
about 30 to about 150 ppm based on the weight of total liquor
charged to said digester.
40. The composition of claim 12 wherein said phosphonate is a
mixture of
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2-
).sub.2 and N(CH.sub.2PO.sub.3M.sub.2).sub.3, and the amount of
said mixture on an active acid basis is about 100 to about 1000 ppm
based on the weight of total liquor charged to said digester.
41. The composition of claim 12 wherein said phosphonate is a
mixture of N(CH.sub.2PO.sub.3M.sub.2).sub.3 and
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.s-
ub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2Ch.sub.2N(CH.sub.2PO.sub.3M.-
sub.2).sub.2, and the amount of said mixture on an active acid
basis is about 50 to about 1000 ppm based on the weight of total
liquor charged to said digester.
42. The composition of claim 1 wherein the pH of said alkaline
aqueous mixture is at least 9.
43. A method for inhibiting calcium salt scale formation in
chemical pulping processes comprising adding an effective scale
inhibiting amount of at least one phosphonate to the alkaline
aqueous mixture in the digester of said chemical pulping process,
wherein said at least one phosphonate is selected from compounds
having the formula:X.sub.2NCH.sub.- 2PO.sub.3M.sub.2 (I),compounds
having the formula: 5amine oxides of phosphonates of formula (I),
or mixtures thereof; wherein M is independently selected from
hydrogen, alkali metal, alkaline earth metal or ammonium, X is
independently selected from H, R, or --CH.sub.2PO.sub.3M.sub.2
wherein R is an alkyl group or --NX.sub.2 substituted alkyl group
having 2 to 6 carbon atoms, R' is an alkyl group having 1 to 17
carbon atoms and R' is optionally branched and optionally
unsaturated, and Y is selected from --PO.sub.3M.sub.2, H or R';
with the proviso that when said phosphonate is
N(CH.sub.2PO.sub.3M.sub.2).sub.3, the amount of said phosphonate on
an active acid basis is greater than 25 ppm based on the weight of
total liquor charged to said digester.
44. The method of claim 43 wherein M is independently selected from
hydrogen or an alkali metal.
45. The method of claim 44 wherein M is sodium or potassium when M
is an alkali metal.
46. The method of claim 43 wherein X is independently selected from
--CH.sub.2PO.sub.3M.sub.2 or R.
47. The method of claim 46 wherein at least one of X is R and R is
--(CH.sub.2).sub.nNX'.sub.2, wherein n is an integer from 2 to 6
and X' is independently selected from R or
--CH.sub.2PO.sub.3M.sub.2.
48. The method of claim 46 wherein each X is R and R is
--(CH.sub.2).sub.nNX'.sub.2, wherein n is an integer from 2 to 6
and X' is independently selected from R or
--CH.sub.2PO.sub.3M.sub.2.
49. The method of claim 43 wherein Y is --PO.sub.3M.sub.2.
50. The method of claim 47 wherein R' is an alkyl group having 1 to
5 carbon atoms.
51. The method of claim 43 wherein said phosphonate is at least one
phosphonate of formula (I).
52. The method of claim 43 wherein said phosphonate is at least one
phosphonate of formula (II).
53. The method of claim 43 wherein said phosphonate is at least one
phosphonate of formula (III).
54. The method of claim 43 wherein said phosphonate is a mixture of
at least two phosphonates of formula (I).
55. The method of claim 43 wherein said phosphonate is a mixture of
at least one phosphonate of formula (I) and at least one
phosphonate of formula (II).
56. The method of claim 43 wherein said phosphonate is a mixture of
at least two phosphonates of formula (II).
57. The method of claim 51 wherein said phosphonate is
N(CH.sub.2PO.sub.3M.sub.2).sub.3 and the amount of said phosphonate
on an active acid basis is about 500 to about 1000 ppm based on the
weight of total liquor charged to said digester.
58. The method of claim 52 wherein said phosphonate is
CH3C(OH)(PO.sub.3M.sub.2).sub.2.
59. The method of claim 58 wherein the amount of said phosphonate
on an active acid basis is about 20 to about 200 ppm based on the
weight of total liquor charged to said digester.
60. The method of claim 51 wherein said phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
).sub.2.
61. The method of claim 60 wherein the amount of said phosphonate
on an active acid basis is about 10 to about 1000 ppm based on the
weight of total liquor charged to said digester.
62. The method of claim 51 wherein said phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2-
).sub.2.
63. The method of claim 61 wherein the amount of said phosphonate
on an active acid basis is about 150 to about 1000 ppm based on the
weight of total liquor charged to said digester.
64. The method of claim 51 wherein said phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2 and the amount of
said phosphonate on an active acid basis is about 30 to about 1000
ppm based on the weight of total liquor charged to said
digester.
65. The method of claim 51 wherein said phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2CH.sub.2N(CH.sub.2PO.sub.-
3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2CH.sub.-
2N-(CH.sub.2PO.sub.3M.sub.2).sub.2.
66. The method of claim 65 wherein the amount of said phosphonate
on an active acid basis is about 10 to about 1000 ppm based on the
weight of total liquor charged to said digester.
67. The method of claim 54 wherein said phosphonate is a mixture
of:
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2CH.sub.2N(CH.sub.2PO.sub.-
3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2CH.sub.-
2--N(CH.sub.2PO.sub.3M.sub.2).sub.2, and a second phosphonate
selected from N(CH.sub.2PO.sub.3M.sub.2).sub.3,
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH-
.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2,
(M.sub.2O.sub.3PCH.sub.2).- sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2,
or (M.sub.2O.sub.3PCH.sub.2).sub.2N-
CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub-
.3M.sub.2).sub.2.
68. The method of claim 67 wherein said second phosphonate is
N(CH.sub.2PO.sub.3M.sub.2).sub.3, and the amount of said mixture on
an active acid basis is about 10 to about 1000 ppm based on the
weight of total liquor charged to said digester.
69. The method of claim 67 wherein said second phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
).sub.2, and the amount of said mixture on an active acid basis is
about 20 to about 1000 ppm based on the weight of total liquor
charged to said digester.
70. The method of claim 67 wherein said second phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2-
).sub.2, and the amount of said mixture on an active acid basis is
about 80 to about 1000 ppm based on the weight of total liquor
charged to said digester.
71. The method of claim 67 wherein said second phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, and the amount
of said mixture on an active acid basis is about 10 to about 1000
ppm based on the weight of total liquor charged to said
digester.
72. The method of claim 54 wherein said phosphonate is a mixture of
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2-
).sub.2 and
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.s-
ub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2.
73. The method of claim 72 wherein the amount of said mixture on an
active acid basis is about 50 to about 1000 ppm based on the weight
of total liquor charged to said digester.
74. The method of claim 54 wherein said phosphonate is a mixture of
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
).sub.2 and a second phosphonate selected from
(M.sub.2O.sub.3PCH.sub.2).s-
ub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2).sub.2,
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, or
N(CH.sub.2PO.sub.3M.sub.2).sub.3.
75. The method of claim 74 wherein said second phosphonate is
selected from
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.-
sub.2).sub.2 or N(CH.sub.2PO.sub.3M.sub.2).sub.3, and the amount of
said mixture on an active acid basis is about 30 to about 1000 ppm
based on the weight of total liquor charged to said digester.
76. The method of claim 74 wherein said second phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, and the amount
of said mixture on an active acid basis is about 20 to about 1000
ppm based on the weight of total liquor charged to said
digester.
77. The method of claim 55 wherein said phosphonate is a mixture of
a first phosphonate selected from
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2C-
H.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2,
(M.sub.2O.sub.3PCH.sub.2).sub.2NC-
H.sub.2CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.-
2PO.sub.3M.sub.2)CH.sub.2CH.sub.2CH.sub.2N-(CH.sub.2PO.sub.3M.sub.2).sub.2-
,
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.-
2).sub.2 or
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.s-
ub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, and a
second phosphonate selected from
CH.sub.3C(OH)(PO.sub.3M.sub.2).sub.2.
78. The method of claim 77 wherein said first phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
).sub.2, and the amount of said mixture on an active acid basis is
about 20 to about 1000 ppm based on the weight of total liquor
charged to said digester.
79. The method of claim 77 wherein said first phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2CH.sub.2N(CH.sub.2PO.sub.-
3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2CH.sub.-
2N-(CH.sub.2PO.sub.3M.sub.2).sub.2, and the amount of said mixture
on an active acid basis is about 20 to about 500 ppm based on the
weight of total liquor charged to said digester.
80. The method of claim 77 wherein said first phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, and the amount
of said mixture on an active acid basis is about 30 to about 1000
ppm based on the weight of total liquor charged to said
digester.
81. The method of claim 77 wherein said first phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2-
).sub.2 and the amount of said mixture on an active acid basis is
about 30 to about 150 ppm based on the weight of total liquor
charged to said digester.
82. The method of claim 54 wherein said phosphonate is a mixture of
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2-
).sub.2 and N(CH.sub.2PO.sub.3M.sub.2).sub.3, and the amount of
said mixture on an active acid basis is about 100 to about 1000 ppm
based on the weight of total liquor charged to said digester.
83. The method of claim 54 wherein said phosphonate is a mixture of
N(CH.sub.2PO.sub.3M.sub.2).sub.3 and
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.s-
ub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.-
sub.2).sub.2, and the amount of said mixture on an active acid
basis is about 50 to about 1000 ppm based on the weight of total
liquor charged to said digester.
84. The method of claim 43 wherein said chemical pulping process is
a Kraft process.
85. The method of claim 84 wherein calcium salt scale is inhibited
in the digester.
86. The method of claim 84 wherein calcium salt scale is inhibited
in the brown stock washing area.
87. The method of claim 84 wherein calcium salt scale is inhibited
in the black liquor recovery area.
88. The method of claim 43 wherein said calcium salt is calcium
carbonate or calcium sulfate.
89. The method of claim 88 wherein said calcium salt is calcium
carbonate.
90. The method of claim 43 wherein the pH of said alkaline aqueous
mixture is at least 9.
91. A method for inhibiting calcium salt scale formation in an
aqueous system in a chemical pulping process having a sufficient
quantity of available calcium cations and anions selected from
carbonate and sulfate susceptible to form said calcium salt scale,
comprising admixing an effective scale inhibiting amount of at
least one phosphonate with said aqueous system in the digester of
said chemical pulping process maintained in a temperature range to
inhibit calcium salt scale formation; and wherein said phosphonate
is selected from compounds having the
formula:X.sub.2NCH.sub.2PO.sub.3M.sub.2 (I),compounds having the
formula: 6amine oxides of phosphonates of formula (I), or mixtures
thereof; wherein M is independently selected from hydrogen, alkali
metal, alkaline earth metal or ammonium, X is independently
selected from H, R, or --CH.sub.2PO.sub.3M.sub.2 wherein R is an
alkyl group or --NX.sub.2 substituted alkyl group having 2 to 6
carbon atoms, R' is an alkyl group having 1 to 17 carbon atoms and
R' is optionally branched and optionally unsaturated, and Y is
selected from --PO.sub.3M.sub.2, H or R'; with the proviso that
when said phosphonate is N(CH.sub.2PO.sub.3M.sub.2).sub.3, the
amount of said phosphonate on an active acid basis is greater than
25 ppm based on the weight of total liquor charged to said
digester.
92. A method for inhibiting calcium salt scale formation in an
aqueous system in a selected chemical pulping process comprising:
(a) determining the calcium salt scale inhibition profiles of
phosphonate concentration and process temperature as a function of
time for phosphonate compositions admixed with the aqueous digester
composition in a chemical pulping process digester, (b) identifying
the calcium salt scale inhibition capability required by said
selected chemical pulping process based on the process operating
conditions of time, temperature and pressure, and the aqueous
digester composition, (c) selecting the appropriate phosphonate
composition and phosphonate use concentration to effectively
inhibit calcium salt scale formation in said selected chemical
pulping process when said phosphonate is admixed with the aqueous
digester composition in said selected chemical pulping process
based on steps (a) and (b), and (d) admixing the selected
phosphonate composition with the aqueous digester composition in
said selected chemical pulping process during the digestion stage
of the chemical pulping process; wherein said selected phosphonate
composition is at least one phosphonate selected from compounds
having the formula:X.sub.2NCH.sub.2PO.sub.3M.sub.2 (I),compounds
having the formula: 7amine oxides of phosphonates of formula (I),
or mixtures thereof; wherein M is independently selected from
hydrogen, alkali metal, alkaline earth metal or ammonium, X is
independently selected from H, R, or --CH.sub.2PO.sub.3M.sub.2
wherein R is an alkyl group or --NX.sub.2 substituted alkyl group
having 2 to 6 carbon atoms, R' is an alkyl group having 1 to 17
carbon atoms and R' is optionally branched and optionally
unsaturated, and Y is selected from --PO.sub.3M.sub.2, H or R';
with the proviso that when said phosphonate is
N(CH.sub.2PO.sub.3M.sub.2).sub.3, the amount of said phosphonate on
an active acid basis is greater than 25 ppm based on the weight of
total liquor charged to said digester.
93. A method for inhibiting calcium salt scale formation in an
aqueous system in a selected chemical pulping process comprising:
(a) identifying the calcium salt scale inhibition capability
required by said selected chemical pulping process based on the
process operating conditions of time, temperature and pressure, and
the aqueous digester composition, (b) selecting the appropriate
phosphonate composition and phosphonate use concentration to
effectively inhibit calcium salt scale formation in said selected
chemical pulping process when said phosphonate is admixed with the
aqueous digester composition in said selected chemical pulping
process based on step (a) and the calcium salt scale inhibition
profiles of phosphonate concentration and process temperature as a
function of time for phosphonate compositions admixed with the
aqueous digester composition in a chemical pulping process
digester, and (c) admixing the selected phosphonate composition
with the aqueous digester composition in said selected chemical
pulping process during the digestion stage of the chemical pulping
process; wherein said selected phosphonate composition is at least
one phosphonate selected from compounds having the
formula:X.sub.2NCH.sub.2PO.sub.3M.sub.2 (I),compounds having the
formula: 8amine oxides of phosphonates of formula (I), or mixtures
thereof; wherein M is independently selected from hydrogen, alkali
metal, alkaline earth metal or ammonium, X is independently
selected from H, R, or --CH.sub.2PO.sub.3M.sub.2 wherein R is an
alkyl group or --NX.sub.2 substituted alkyl group having 2 to 6
carbon atoms, R' is an alkyl group having 1 to 17 carbon atoms and
R' is optionally branched and optionally unsaturated, and Y is
selected from --PO.sub.3M.sub.2, H or R'; with the proviso that
when said phosphonate is N(CH.sub.2PO.sub.3M.sub.2).sub.3, the
amount of said phosphonate on an active acid basis is greater than
25 ppm based on the weight of total liquor charged to said
digester.
94. The composition of claim 13 wherein said phosphonate is a
mixture of N(CH.sub.2PO.sub.3M.sub.2).sub.3, and
CH.sub.3C(OH)(PO.sub.3M.sub.2).sub.- 2, and the amount of said
mixture on an active acid basis is about 30 to about 500 ppm based
on the weight of total liquor charged to said digester.
95. The method of claim 55 wherein said phosphonate is a mixture of
N(CH.sub.2PO.sub.3M.sub.2).sub.3, and
CH.sub.3C(OH)(PO.sub.3M.sub.2).sub.- 2, and the amount of said
mixture on an active acid basis is about 30 to about 500 ppm based
on the weight of total liquor charged to said digester.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a nonprovisional application which
claims the priority of prior provisional application serial No.
60/296,316, entitled "Method for Inhibiting Calcium Salt Scale,"
filed Jun. 6, 2001, which is hereby incorporated by reference into
this application.
FIELD OF THE INVENTION
[0002] This invention relates to compositions and methods for
inhibiting scale formation in aqueous alkaline systems of chemical
pulping processes. More particularly, this invention relates to
compositions and methods for inhibiting formation, deposition and
adherence of calcium salt scale deposits in chemical pulping
process equipment.
BACKGROUND OF THE INVENTION
[0003] Paper is widely used worldwide in commerce and in homes and
has a variety of uses. Pulp making is thus carried out on a large
industrial scale worldwide to produce sufficient quantities of
paper. Accordingly it is highly desirable that such pulp making
operations be carried out in a cost effective, efficient operation
with minimum manufacturing equipment downtime and minimum periods
of reduced pulp making process equipment efficiency.
[0004] The basic steps in industrial pulp making are to convert
plant fiber into chips, convert chips into pulp, (optionally)
bleach the pulp, wash the pulp, and transform the pulp into
suitable paper which can be used in paper products such as writing
paper, newsprint and paper for documents.
[0005] Typically, several chemical pulping processes are used in
industrial pulp making operations. Well known industrial alkaline
chemical pulping processes include the Kraft (or sulfate), soda and
alkaline sulfite processes. The Kraft process makes the strongest
fibers of any pulp producing process and is the most commonly used
pulp making process in part due to its efficient recovery process
for the cooking chemicals. While the present invention has
applicability to any of the above alkaline chemical pulping
processes, it is particularly useful with the Kraft process and, as
such, the Kraft process is described in more detail below.
[0006] Initially, suitable trees are harvested, debarked and then
chipped into suitable size flakes or chips. These wood chips are
sorted with the small and the large chips being removed. The
remaining suitable wood chips are then charged to a digester (which
is a vessel or tank for holding the chips and an aqueous digesting
composition, such tanks can be designed for either batch or
continuous operation).
[0007] Illustratively, in a batch type digester, wood chips and a
mixture of "weak black liquor," the spent liquor from a previous
digester cook, and "white liquor," a solution of sodium hydroxide
and sodium sulfide, that is either fresh or from the chemical
recovery plant, is pumped into the digester. In the cooking process
lignin, which binds the wood fiber together, is dissolved in the
white liquor forming pulp and black liquor.
[0008] The digester is sealed and the digester composition is
heated to a suitable cook temperature under high pressure. After an
allotted cooking time at a particular temperature and pressure
(H-factor) in the digester, the digester contents (pulp and black
liquor) are transferred to a holding tank. The pulp in the holding
tank is transferred to brown stock washers while the liquid (black
liquor formed in the digester) is sent to the black liquor recovery
area, i.e. black liquor evaporators. The black liquor is evaporated
to a high solids content, usually 60-80% solids, using a multiple
effect evaporator, for example. The higher the solids content, the
more difficult it is to pump the black liquor and the more scale
problems the pulp mill will have. One of the most troublesome is
calcium carbonate scale which forms in various areas of the pulp
mill, including the digester, the black liquor evaporator area, and
the brown stock washing area.
[0009] Most commercial paper mills use multiple effect evaporators
(MEE) as the black liquor evaporators. These evaporators generally
range from four to eight effects in length. Generally, undesirable
calcium carbonate scaling occurs in only one or two effects.
Currently, most mills do not use any scale inhibitor but rather
contend with the scale problem by shutting down the black liquor
evaporator section and washing out the calcium carbonate scale with
hot acid, i.e. acid cleaning. This hot acid boil out adversely
affects papermill production and is a concern because the acid used
is corrosive to mill piping and equipment.
[0010] The Kraft cook is highly alkaline, usually having a pH of 10
to 14, more particularly 12 to 14. The digester composition
contains a large amount of sodium sulfide, which is used as an
accelerant to increase the delignification rate of the cook. This
works to release the lignin in the wood chips and thus the
cellulose becomes available as pulp.
[0011] The combination of operating conditions in the Kraft process
is conducive to scale formation and deposition and increases the
propensity of the calcium carbonate scale to form, deposit and
adhere to metallic and other surfaces within which it comes in
contact. Under such process conditions, calcium present in the
water and leached from the wood in the Kraft process can react with
carbonate and produce rather rapid scaling with the deposition of
calcium carbonate scale. Such scale is frequently deposited in the
digester, piping, heat exchangers etc., all of which have surfaces
on which the calcium carbonate can deposit and adhere. Such
deposition builds up over time and can result in undesirable
premature shutdowns downstream on the pulp making manufacturing
line to remove scale deposits by hot acid washing.
[0012] Several patents and a technical article disclose problems of
scaling. In "An Effective Sequestrant For Use In Controlling
Digester Scale," R. H. Windhager, Paper Trade Journal, pp. 42-44,
Nov. 5, 1973, the use of small quantities of mono-aminomethylene
phosphonic acid (ATMP) as a calcium carbonate scale inhibitor in a
digester to inhibit scale deposition from the digester cooking
liquor is disclosed.
[0013] U.S. Pat. No. 4,799,995 (issued to Druce K. Crump et al. on
Jan. 24, 1989) discloses that inhibition of calcium scale under
conditions found in pulp digesters has been accomplished by
employing mixtures of polyamino(polyalkylenephosphonic) acids with
non-ionic surfactants added to the pulp liquor. This U.S. patent
also discloses that phosphonates such as
nitrilotris(methylenephosphonic acid) ("NTMP" or "ATMP"),
1-hydroxyethane-1,1-diphosphonic acid ("HEDP") and sodium
1-hydroxyethane-1,1-diphosphonate ("NaHEDP") are said to have been
commonly used to control scale. However, the '995 patent discloses
that the use of HEDP in black liquor actually promoted scale and
use of diethylenetriamine penta(methylenephosphonic acid) ("DTPMP")
in black liquor without the presence of a nonionic surfactant
resulted in only limited scale reduction. While the '995 patent
discloses the use of nonionic surfactants to improve scale
reduction, it is preferred to avoid the use of surfactants in
chemical pulp processes, particularly in the digester. The
compositions of the present invention when added to an alkaline
chemical pulp process digester are effective at inhibiting calcium
salt scale in chemical pulp processes without the need for a
nonionic surfactant.
[0014] Canadian Patent No. 1,069,800 (Philip S. Davis et al., Jan.
15, 1980) discloses the addition of blends of organophosphonates,
e.g. 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), with
amino-organo phosphonates, e.g. amino tri(methylenephosphonic acid)
(AMP), ethylenediamine tetra(methylenephosphonic acid) (EDTPA) and
hexamethylenediamine tetra(methylenephosphonic acid) (HMDTA), to
black liquor to reduce calcium carbonate scale in a black liquor
evaporator system at a pH above 9. This patent also discloses that
use of individual (single) phosphonates, instead of the disclosed
blends, were not effective at a pH above 9 to inhibit calcium
carbonate crystallization.
[0015] U.S. Pat. No. 4,851,490 (issued to Fu Chen et al. on Jul.
25, 1989) discloses water soluble polymers containing
hydroxyalkyleneaminoalkylene phosphonate functions which are said
to have utility as deposit control agents effective in a number of
water systems such as cooling, boilers, conversion coating, paper
and pulp processing and gas scrubbing.
[0016] U.S. Pat. No. 5,534,157 (issued to Craig D. Iman et al. on
Jul. 9, 1996) discloses a method for inhibiting the formation,
deposition and adherency of scale-forming salts in process waters
at high pH utilizing polyether polyamine methylene phosphonates. At
column 4, lines 35-51 thereof, this U.S. patent discloses that
inhibitors such as HEDP and ATMP are useless as scale inhibitors at
alkaline pH conditions.
[0017] U.S. Pat. No. 5,562,830 (issued to Davor F. Zidovec et al.
on Oct. 8, 1996) discloses a method of inhibiting corrosion and
scale formation and deposition in aqueous systems by adding a
combination of a polyepoxysuccinic acid or salts thereof and a
phosphonocarboxylic acid or salts thereof.
[0018] U.S. Pat. No. 5,552,018 (issued to Johan Devenyns on Sep. 3,
1996) discloses a process in which a peroxyacid is employed to
improve the selectivity of the delignification of a chemical paper
pulp that has already undergone a delignifying treatment in the
presence of chemical reagents, i.e. a Kraft cook. Phosphonates are
disclosed as stabilizers in this process.
[0019] Despite the aforementioned patents and technical article,
enhanced methods and compositions for inhibiting the formation,
deposition and adherence of scale to metallic surfaces particularly
in commercial chemical pulp processing equipment is highly
desired.
SUMMARY OF THE INVENTION
[0020] It is an object of this invention to provide a composition
for inhibiting the formation, deposition and adherence of calcium
salt scale to metallic and other surfaces in the equipment, vessels
and/or piping of a chemical pulp process facility. It is yet
another object of this invention to provide a method for inhibiting
the formation, deposition and adherence of calcium salt scale to
surfaces in the equipment, vessels and/or piping of a chemical pulp
process facility.
[0021] These and other objects are achieved in the invention which
is described in more nonlimiting detail hereinafter.
[0022] According to the invention, a scale inhibiting composition
for inhibiting calcium salt scale formation in alkaline aqueous
mixtures of chemical pulping processes is provided, wherein the
composition is added to the digester of a chemical pulping process,
the composition comprising an effective scale inhibiting amount of
at least one phosphonate selected from compounds having the
formula:
X.sub.2NCH.sub.2PO.sub.3M.sub.2 (I),
[0023] compounds having the formula: 1
[0024] amine oxides of the phosphonates of formula (I), or mixtures
thereof; wherein M is independently selected from hydrogen, alkali
metal, alkaline earth metal or ammonium, X is independently
selected from H, R, or --CH.sub.2PO.sub.3M.sub.2 wherein R is an
alkyl group or --NX.sub.2 substituted alkyl group having 2 to 6
carbon atoms, R' is an alkyl group having 1 to 17 carbon atoms and
R' is optionally branched and optionally unsaturated, and Y is
selected from --PO.sub.3M.sub.2, H or R'; with the proviso that
when the phosphonate is N(CH.sub.2PO.sub.3M.sub.2).sub.3, the
amount of the phosphonate on an active acid basis is greater than
25 ppm based on the weight of total liquor charged to the
digester.
[0025] Further according to the invention, a method for inhibiting
calcium salt scale formation in chemical pulping processes is
provided comprising admixing an effective scale inhibiting amount
of the above composition with the alkaline aqueous mixture in the
digester of the chemical pulping process.
[0026] Still further according to the invention, a method for
inhibiting calcium salt scale formation in an aqueous system in a
chemical pulping process having a sufficient quantity of available
calcium cations and anions selected from carbonate and sulfate to
form said calcium salt scale is provided, comprising admixing an
effective scale inhibiting amount of at least one phosphonate with
the aqueous system in the digester of the chemical pulping process
maintained in a temperature range to inhibit calcium salt scale
formation, wherein the at least one phosphonate is as defined
above.
[0027] Still further according to the invention, a method for
inhibiting calcium salt scale formation in an aqueous system in a
selected chemical pulping process is provided comprising: (a)
determining the calcium salt scale inhibition profiles of
phosphonate concentration and process temperature as a function of
time for phosphonate compositions admixed with the aqueous digester
composition in a chemical pulping process digester, (b) identifying
the calcium salt scale inhibition capability required by said
selected chemical pulping process based on the process operating
conditions of time and temperature, and the aqueous digester
composition, (c) selecting the appropriate phosphonate composition
and phosphonate use concentration to effectively inhibit calcium
salt scale formation in the selected chemical pulping process when
the phosphonate is admixed with the aqueous digester composition in
the selected chemical pulping process based on steps (a) and (b),
and (d) admixing the selected phosphonate composition with the
aqueous digester composition in the selected chemical pulping
process during the digestion stage of the chemical pulping process;
wherein the selected phosphonate composition is as defined
above.
[0028] Still further according to the invention, a method for
inhibiting calcium salt scale formation in an aqueous system in a
selected chemical pulping process is provided comprising: (a)
identifying the calcium salt scale inhibition capability required
by the selected chemical pulping process based on the process
operating conditions of time and temperature, and the aqueous
digester composition, (b) selecting the appropriate phosphonate
composition and phosphonate use concentration to effectively
inhibit calcium salt scale formation in the selected chemical
pulping process when said phosphonate is admixed with the aqueous
digester composition in the selected chemical pulping process based
on step (a) and the calcium salt scale inhibition profiles of
phosphonate concentration and process temperature as a function of
time for phosphonate compositions admixed with the aqueous digester
composition in a chemical pulping process digester, and (c)
admixing the selected phosphonate composition with the aqueous
digester composition in the selected chemical pulping process
during the digestion stage of the chemical pulping process; wherein
the selected phosphonate composition is as defined above.
DETAILED DESCRIPTION OF THE DRAWINGS
[0029] Not Applicable
DETAILED DESCRIPTION OF THE INVENTION
[0030] A first embodiment of the invention relates to a scale
inhibiting composition for inhibiting calcium salt scale formation
in alkaline aqueous mixtures of chemical pulping processes, wherein
the composition is added to the digester of a chemical pulping
process, the composition comprising an effective scale inhibiting
amount of at least one phosphonate selected from compounds having
the formula:
X.sub.2NCH.sub.2PO.sub.3M.sub.2 (I),
[0031] compounds having the formula: 2
[0032] amine oxides of phosphonates of formula (I), or mixtures
thereof; wherein M is independently selected from hydrogen, alkali
metal, alkaline earth metal or ammonium, X is independently
selected from H, R, or --CH.sub.2PO.sub.3M.sub.2 wherein R is an
alkyl group or --NX.sub.2 substituted alkyl group having 2 to 6
carbon atoms, R' is an alkyl group having 1 to 17 carbon atoms and
R' is optionally branched and optionally unsaturated, and Y is
selected from --PO.sub.3M.sub.2, H or R'; with the proviso that
when the phosphonate is N(CH.sub.2PO.sub.3M.sub.2).sub.3, the
amount of the phosphonate on an active acid basis is greater than
25 ppm based on the weight of total liquor charged to the
digester.
[0033] In the phosphonates of the invention, M is preferably
hydrogen or alkali metal, and the alkali metal is preferably sodium
and potassium, X is preferably R or --CH.sub.2PO.sub.3M.sub.2, Y is
preferably --PO.sub.3M.sub.2, and R' is preferably an alkyl group
having 1 to 5 carbon atoms.
[0034] Examples of suitable phosphonates include, but are not
limited to, the phosphonates in Table 1 below. Table 1 below
provides formulas for representative phosphonates of formulas (I)
and (II). The phosphonates in Table 1 are available from Solutia
Inc., 575 Maryville Centre Drive, St. Louis, Mo. under the
trademark Dequest.RTM. phosphonates and are identified by their
Dequest.RTM. phosphonate product number.
1TABLE 1 Dequest Product No. Formula X (or Y) R (or R') n X' M 2000
I 2 --CH.sub.2PO.sub.3M.sub.2 -- -- 6 H 2006 I 2
--CH.sub.2PO.sub.3M.sub.2 -- -- 5 Na, 1 H 2010 II --PO.sub.3M.sub.2
--CH.sub.3 -- 4 H 2016 II --PO.sub.3M.sub.2 --CH.sub.3 -- 4 Na 2041
I 1 R, --(CH.sub.2)nNX'.sub.2 2 2 --CH.sub.2PO.sub.3M.sub.2 8 H 1
--CH.sub.2PO.sub.3M.sub.2 2046 I 1 R, --(CH.sub.2)nNX'.sub.2 2 2
--CH.sub.2PO.sub.3M.sub.2 5 Na, 3 H 1 --CH.sub.2PO.sub.3M.sub.2
2054 I 1 R, --(CH.sub.2)nNX'.sub.2 6 2 --CH.sub.2PO.sub.3M.sub.2 6
K, 2 H 1 --CH.sub.2PO.sub.3M.sub.2 2060 I 2 R
--(CH.sub.2)nNX'.sub.2 2, 2 4 --CH.sub.2PO.sub.3M.sub.2 10 H 2066 I
2 R --(CH.sub.2)nNX'.sub.2 2, 2 4 --CH.sub.2PO.sub.3M.sub.2 7 Na, 3
H
[0035] The formulas and corresponding names of the Dequest
phosphonates listed in Table 1 are shown below.
[0036] Dequest 2000--amino-tris(methylenephosphonic acid)
[0037] N(CH.sub.2PO.sub.3H.sub.2).sub.3
[0038] Dequest 2006--sodium salt of amino-tris(methylenephosphonic
acid)
[0039] Na.sub.5H[N(CH.sub.2PO.sub.3).sub.3]
[0040] Dequest 2010--1-hydroxyethylidene (1,1-diphosphonic
acid)
[0041] CH3C(OH)(PO.sub.3H.sub.2).sub.2
[0042] Dequest 2016--sodium salt of 1-hydroxyethylidene
(1,1-diphosphonic acid)
[0043] Na.sub.4[CH.sub.3C(OH)(PO.sub.3).sub.2]
[0044] Dequest 2041--ethylenediamine tetra(methylenephosphonic
acid)
[0045]
H.sub.8[(O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3-
).sub.2]
[0046] Dequest 2046--ethylenediamine tetra(methylenephosphonic
acid), pentasodium salt
[0047]
Na.sub.5H.sub.3[(O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2-
PO.sub.3).sub.2]
[0048] Dequest
2054--[1,6-hexanediylbis[nitrilobis(methylene)]]tetrakis-ph-
osphonic acid, potassium salt
[0049]
K.sub.6H.sub.2[(O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2P-
O.sub.3).sub.2]
[0050] Dequest 2060--diethylenetriamine-penta(methylenephosphonic
acid)
(H.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3H.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3H.sub.2).sub.2
[0051] Dequest 2066--sodium salt of
diethylenetriamine-penta(methylenephos- phonic acid)
[0052]
Na.sub.7H.sub.3[(O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2-
PO.sub.3)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3).sub.2]
[0053] Another preferred phosphonate of formula (I) is the compound
N,N'-bis(3-aminopropyl)ethylenediamine-hexa(methylenephosphonic
acid), or a salt thereof wherein the salt is sodium, potassium,
ammonium, and the like. When the compound is the sodium salt, the
compound has the formula
Na.sub.xH.sub.y[(O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2CH.sub.2N(CH.sub-
.2PO.sub.3)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3)CH.sub.2CH.sub.2CH.sub.2N(CH-
.sub.2PO.sub.3).sub.2]; wherein x+y is 12, and is designated herein
as 4NHMP. This compound can be prepared according to the procedure
disclosed in Example 1 of U.S. Pat. No. 5,261,491, which is herein
incorporated by reference.
[0054] One preferred phosphonate of formula (I) is a phosphonate
wherein at least one of X is R and R is (CH.sub.2).sub.nNX'.sub.2,
wherein n is an integer from 2 to 6, preferably 2 to 4, and X' is
independently selected from R or CH.sub.2PO.sub.3M.sub.2. Another
preferred phosphonate of formula (I) is a phosphonate wherein each
X is R and R is (CH.sub.2).sub.nNX'.sub.2, wherein n is an integer
from 2 to 6, preferably 2 to 4, and X' is independently selected
from R or CH.sub.2PO.sub.3M.sub.2.
[0055] A more preferred phosphonate of formula (I) is a phosphonate
selected from:
[0056]
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.3N(CH.sub.2PO.sub.3M-
.sub.2)(CH.sub.2).sub.2N(CH.sub.2PO.sub.3M.sub.2)(CH.sub.2).sub.3N(CH.sub.-
2PO.sub.3M.sub.2).sub.2 or
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.-
2N(CH.sub.2PO.sub.3M.sub.2).sub.2.
[0057] A preferred phosphonate of formula (II) is a phosphonate
wherein Y is PO.sub.3M.sub.2 and R is alkyl of 1 to 5 carbons. A
more preferred phosphonate of formula (II) is a phosphonate wherein
Y is PO.sub.3M.sub.2 and R is methyl.
[0058] A preferred amine oxide of the phosphonate of formula (I) is
.sup.-O.rarw..sup.+N--(CH.sub.2PO.sub.3M.sub.2).sub.3.
[0059] Blends of at least two phosphonates independently selected
from the phosphonates of formulas (I), (II) and (III) may be used
according to the invention. It is currently preferred to use a
blend of two phosphonates, with a blend of a phosphonate of formula
(I) with either a phosphonate of formula (I) or formula (II) being
more preferred, and a blend of two phosphonates of formula (I)
being most preferred. The composition of the blends can vary over a
wide range with the percentage of each component ranging broadly
from 1 to 99 wt. %, provided each phosphonate is present in an
amount of at least about 1 wt. %. Preferably, each phosphonate is
present in an amount of at least about 10 wt. %. In the case of a
two component blend, each phosphonate is present preferably in an
amount of about 10 to about 90 wt. %, and more preferably in an
amount of about 20 to about 80 wt. %.
[0060] A series of blends of phosphonates which may be used
according to the invention were prepared for testing. The blends
were prepared as concentrates having 30% total active acid content
and were then diluted to the desired concentration for use. These
blends (as described below) were tested as calcium salt scale
inhibitors in a simulated Kraft cook according to the procedure
described in the Examples. The weight ratios of these various
blends are shown in Table 2 below.
2TABLE 2 WEIGHT RATIO OF RESPECTIVE PRODUCT NO. - BLEND BLEND OF
PHOSPHONATES OF PHOSPHONATES PHOSPHONATES IN BLEND Product 78
D2006/D2066 50/50 Product 79 D2000/D2054 50/50 Product 80
D2006/4NHMP 50/50 Product 81 D2010/D2066A 50/50 Product 82
D2010/D2054 50/50 Product 83A D2016/4NHMP 70/30.sup.1 Product 83B
D2016/4NHMP 25/75.sup.1 Product 84 D2054/4NHMP 50/50 Product 85
D2010/D2000 50/50 Product 86 4NHMP/D2066A 50/50 Product 87
D2054/D2066A 50/50 Product 94 D2046/D2006 50/50 Product 95
D2046/D2016 60/40 Product 96 D2046/D2054 60/40 Product 97
D2046/D2066A 50/50 Product 98 D2046/4NHMP 60/40 .sup.1A 50/50 blend
concentrate having 30% total active acid content does not remain
homogeneous.
[0061] The preferred blends for use in the invention are blends of
a phosphonate selected from
N,N'-bis(3-aminopropyl)ethylenediamine-hexa(met- hylenephosphonic
acid), [1,6-hexanediylbis[nitrilobis(methylene)]]tetrakis-
-phosphonic acid, ethylenediamine tetra(methylenephosphonic acid),
diethylenetriamine-penta(methylenephosphonic acid), or salts
thereof with a phosphonate selected from the phosphonates of
formulas (I) or (II). More preferred are blends of phosphonates
selected from
N,N'-bis(3-aminopropyl)ethylenediamine-hexa(methylenephosphonic
acid),
[1,6-hexanediylbis[nitrilobis(methylene)]]tetrakis-phosphonic acid,
ethylenediamine tetra(methylenephosphonic acid),
diethylenetriaminepenta(- methylenephosphonic acid) or salts
thereof with another phosphonate selected from the phosphonates of
formulas (I) and blends of
N,N'-bis(3-aminopropyl)ethylenediamine-hexa(methylenephosphonic
acid) or salts thereof with a phosphonate selected from the
phosphonates of formula (II).
[0062] An effective amount of phosphonate or mixtures of
phosphonates is employed in making and using the scale inhibiting
composition of this invention. That effective amount depends on the
particular phosphonate(s) employed in practicing this invention and
other factors including, but not limited to, the digester
composition, the operating conditions (i.e. H-factor) of the
digester, the composition and operating conditions in the brown
stock washing area and black liquor recovery area, as well as other
factors and conditions known to those of ordinary skill in the art.
Selection of the effective amount of phosphonate will be readily
apparent to one of ordinary skill in the art after reading this
specification.
[0063] The scale inhibiting composition of the invention include,
but are not limited to, at least one phosphonate of formula (I), at
least one phosphonate of formula (II), at least one amine oxide of
a phosphonate of formula (I), a mixture of at least two
phosphonates of formula (I), a mixture of at least one phosphonate
of formula (I) or an amine oxide of a phosphonate of formula (I)
and at least one phosphonate of formula (II), a mixture of at least
one phosphonate of formula (I) and at least one amine oxide of a
phosphonate of formula (I), or a mixture of at least two
phosphonates of formula (II). Preferably, the scale inhibiting
composition of the invention is at least one phosphonate of formula
(I), a mixture of at least two phosphonates of formula (I), or a
mixture of at least one phosphonate of formula (I) and at least one
phosphonate of formula (II).
[0064] When the scale inhibiting composition of the invention is at
least one phosphonate of formula (I), the phosphonate(s) and the
effective scale inhibiting amount of each is as follows.
[0065] As used herein, the ppm usage level of scale inhibitor is
based on the weight of total liquor charged with the liquor assumed
to have a density of 1 g/mL.
[0066] When the phosphonate is N(CH.sub.2PO.sub.3M.sub.2).sub.3,
the effective scale inhibiting amount of phosphonate on an active
acid basis is about 500 to about 1000 ppm, and preferably about 600
to about 800 ppm, based on the weight of total liquor charged to
the digester.
[0067] When the phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.-
sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, the effective amount of the
phosphonate on an active acid basis is about 10 to about 1000 ppm,
preferably about 20 to about 500 ppm, and more preferably about 30
to about 500 ppm, based on the weight of total liquor charged to
the digester.
[0068] When the phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).-
sub.6N(CH.sub.2PO.sub.3M.sub.2).sub.2, the effective amount of the
phosphonate on an active acid basis is about 150 to about 1000 ppm,
preferably about 200 to about 500 ppm, based on the weight of total
liquor charged to the digester.
[0069] When the phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.-
sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).-
sub.2, the effective amount of phosphonate on an active acid basis
is about 30 to about 1000 ppm, preferably about 40 to about 500
ppm, based on the weight of total liquor charged to the
digester.
[0070] When the phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.-
sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M-
.sub.2)CH.sub.2CH.sub.2CH.sub.2N--(CH.sub.2PO.sub.3M.sub.2).sub.2,
the effective amount of phosphonate on an active acid basis is
about 10 to about 1000 ppm, preferably about 20 to about 500 ppm,
based on the weight of total liquor charged to the digester.
[0071] The preferred phosphonates of formula (I) are
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
).sub.2,
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.-
3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2, or
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2CH.sub.2N(CH.sub.2PO.sub.-
3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2CH.sub.-
2M--(CH.sub.2PO.sub.3M.sub.2).sub.2, more preferably
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
).sub.2 or
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2CH.sub.2N(CH.su-
b.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.su-
b.2CH.sub.2N--(CH.sub.2PO.sub.3M.sub.2).sub.2, and most preferably
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2CH.sub.2N(CH.sub.2PO.sub.-
3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2CH.sub.-
2N--(CH.sub.2PO.sub.3M.sub.2).sub.2.
[0072] When the scale inhibiting composition of the invention is at
least one phosphonate of formula (II), the phosphonate is
preferably CH.sub.3C(OH)(PO.sub.3M.sub.2).sub.2 and the effective
scale inhibiting amount of phosphonate on an active acid basis is
about 20 to about 200 ppm, preferably about 30 to about 100 ppm,
based on the weight of total liquor charged to the digester.
[0073] When the scale inhibiting composition of the invention is at
least one amine oxide of a phosphonate of formula (I), the
effective scale inhibiting amount of amine oxide is the amount on
an active acid basis that is equivalent to the effective amount of
the corresponding phosphonate of formula (I).
[0074] When the scale inhibiting composition of the invention is a
mixture of at least two phosphonates of formula (I), the
phosphonate(s) and the effective scale inhibiting amount of each is
as follows.
[0075] When the first phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.su-
b.2CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.-
sub.3M.sub.2)CH.sub.2CH.sub.2CH.sub.2--N(CH.sub.2PO.sub.3M.sub.2).sub.2,
the second phosphonate is preferably selected from
N(CH.sub.2PO.sub.3M.sub.2).sub.3,
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.-
2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2,
(M.sub.2O.sub.3PCH.sub.2).sub.2-
N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2).sub.2, or
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2. When the second
phosphonate is N(CH.sub.2PO.sub.3M.sub.2).sub.3, the amount of the
mixture on an active acid basis is about 10 to about 1000 ppm,
preferably about 200 to about 500 ppm, based on the weight of total
liquor charged to the digester. When the second phosphonate is
(M.sub.2O.sub.3PCH.sub.2)-
.sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, the amount
of the mixture on an active acid basis is about 20 to about 1000
ppm, preferably about 30 to about 500 ppm, based on the weight of
total liquor charged to the digester. When the second phosphonate
is (M.sub.2O.sub.3PCH.sub.2).su-
b.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2).sub.2, the amount of
the mixture on an active acid basis is about 80 to about 1000 ppm,
preferably about 300 to about 500 ppm, based on the weight of total
liquor charged to the digester. When the second phosphonate is
(M.sub.2O.sub.3PCH.sub.2)-
.sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.-
2PO.sub.3M.sub.2).sub.2, the amount of the mixture on an active
acid basis is about 10 to about 1000 ppm, preferably about 30 to
about 500 ppm, based on the weight of total liquor charged to the
digester.
[0076] When the first phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.su-
b.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, the second phosphonate
is preferably selected from
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6-
N(CH.sub.2PO.sub.3M.sub.2).sub.2,
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2-
CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.-
2).sub.2, or (CH.sub.2PO.sub.3M.sub.2).sub.3. When the second
phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.su-
b.2).sub.2 or N(CH.sub.2PO.sub.3M.sub.2).sub.3, the amount of the
mixture on an active acid basis is about 30 to about 1000 ppm,
preferably about 50 to about 500 ppm, based on the weight of total
liquor charged to the digester. When the second phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2N-
CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub-
.3M.sub.2).sub.2, the amount of the mixture on an active acid basis
is about 20 to about 1000 ppm, preferably about 40 to about 500
ppm, based on the weight of total liquor charged to the
digester.
[0077] When the first phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.s-
ub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2).sub.2, and the second
phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2mixture on an active acid
basis is about 50 to about 1000 ppm, preferably about 100 to about
500 ppm, based on the weight of total liquor charged to the
digester.
[0078] When the first phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.s-
ub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2).sub.2, and the second
phosphonate is N(CH.sub.2PO.sub.3M.sub.2).sub.3, the amount of the
mixture on an active acid basis is about 100 to about 1000 ppm,
preferably about 500 to about 600 ppm, based on the weight of total
liquor charged to the digester.
[0079] When the first phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.su-
b.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.s-
ub.2).sub.2, and the second phosphonate is
N(CH.sub.2PO.sub.3M.sub.2).sub.- 3, the amount of the mixture on an
active acid basis is about 50 to about 1000 ppm, preferably about
150 to about 500 ppm, based on the weight of total liquor charged
to the digester.
[0080] The preferred blends of at least two phosphonates of formula
(I) are blends of
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2CH.sub.2N(C-
H.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2C-
H.sub.2CH.sub.2--N(CH.sub.2PO.sub.3M.sub.2).sub.2 with
N(CH.sub.2PO.sub.3M.sub.2).sub.3,
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.-
2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2,
(M.sub.2O.sub.3PCH.sub.2).sub.2-
N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2).sub.2 or
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2 or blends of
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
).sub.2 with
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2CH.sub.2N(CH.-
sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.-
sub.2CH.sub.2N--(CH.sub.2PO.sub.3M.sub.2).sub.2,
(M.sub.2O.sub.3PCH.sub.2)-
.sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2).sub.2,
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, or
N(CH.sub.2PO.sub.3M.sub.2).sub.3.
[0081] The most preferred blends of at least two phosphonates of
formula (I) are blends of
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2CH.sub.-
2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)--CH.-
sub.2CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2 with
N(CH.sub.2PO.sub.3M.sub.2).sub.3,
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.-
2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2,
(M.sub.2O.sub.3PCH.sub.2).sub.2-
N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2).sub.2, or
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2.
[0082] When the scale inhibiting composition of the invention is a
mixture of at least one phosphonate of formula (I) and at least one
phosphonate of formula (II), the phosphonate(s) and the effective
scale inhibiting amount of each is as follows.
[0083] When the blend is a mixture of a first phosphonate of
formula N(CH.sub.2PO.sub.3M.sub.2).sub.3, and the second
phosphonate of formula CH.sub.3C(OH)(PO.sub.3M.sub.2).sub.2, the
amount of the mixture on an active acid basis is about 30 to about
500 ppm, preferably about 50 to about 300 ppm, based on the weight
of total liquor charged to the digester.
[0084] Preferred blends are mixtures of a first phosphonate
selected from
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
).sub.2,
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.-
3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2,
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2CH.sub.2N(CH.sub.2PO.sub.-
3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2CH.sub.-
2N--(CH.sub.2PO.sub.3M.sub.2).sub.2 or
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH-
.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2).sub.2, and a second
phosphonate selected from CH.sub.3C(OH)(PO.sub.3M.sub.2).sub.2.
[0085] When the first phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.su-
b.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, the amount of the
mixture on an active acid basis is about 20 to about 1000 ppm,
preferably about 30 to about 500 ppm, based on the weight of total
liquor charged to the digester. When the first phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NC-
H.sub.2CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.-
2PO.sub.3M.sub.2)CH.sub.2CH.sub.2CH.sub.2N--(CH.sub.2PO.sub.3M.sub.2).sub.-
2, the amount of the mixture on an active acid basis is about 20 to
about 500 ppm, preferably about 20 to about 150 ppm, based on the
weight of total liquor charged to the digester. When the first
phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2N(CH.sub.2).sub.6N(CH.sub.2PO.sub.3M.sub.2-
).sub.2, the amount of the mixture on an active acid basis is about
30 to about 150 ppm, preferably about 40 to about 80 ppm, based on
the weight of total liquor charged to the digester. When the first
phosphonate is
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2-
)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2).sub.2, the amount of
the mixture on an active acid basis is about 30 to about 1000 ppm,
preferably about 50 to about 500 ppm, based on the weight of total
liquor charged to the digester.
[0086] The most preferred blends of at least one phosphonate of
formula (I) and at least one phosphonate of formula (II) are blends
of
(M.sub.2O.sub.3PCH.sub.2).sub.2NCH.sub.2CH.sub.2CH.sub.2N(CH.sub.2PO.sub.-
3M.sub.2)CH.sub.2CH.sub.2N(CH.sub.2PO.sub.3M.sub.2)CH.sub.2CH.sub.2CH.sub.-
2N--(CH.sub.2PO.sub.3M.sub.2).sub.2 and
CH.sub.3C(OH)(PO.sub.3M.sub.2).sub- .2.
[0087] A second embodiment of the invention relates to a method for
inhibiting calcium salt scale formation in chemical pulping
processes comprising adding an effective scale inhibiting amount of
at least one phosphonate to the alkaline aqueous mixture in the
digester of the chemical pulping process, wherein the at least one
phosphonate is selected from compounds having the formula:
X.sub.2NCH.sub.2PO.sub.3M.sub.2 (I),
[0088] compounds having the formula: 3
[0089] amine oxides of phosphonates of formula (I),
[0090] or mixtures thereof;
[0091] wherein M, X, R, R' and Y are as defined above; with the
proviso that when the phosphonate is
N(CH.sub.2PO.sub.3M.sub.2).sub.3, the amount of the phosphonate on
an active acid basis is greater than 25 ppm based on the weight of
total liquor charged to the digester.
[0092] Further according to the second embodiment of the invention,
the invention is also a method for inhibiting calcium salt scale
formation in an aqueous system in a chemical pulping process having
a sufficient quantity of available calcium cations and anions
selected from carbonate and sulfate susceptible to form said
calcium salt scale, comprising admixing an effective scale
inhibiting amount of at least one phosphonate with the aqueous
system in the digester of the chemical pulping process maintained
in a temperature range of about 110.degree. C. to about 180.degree.
C., preferably about 150.degree. C. to about 175.degree. C., to
inhibit calcium salt scale formation, wherein the phosphonate is as
described above.
[0093] In the practice of the method of this invention in a
chemical pulping process, e.g. a Kraft process, the aqueous
phosphonate composition of the invention is admixed with an
alkaline, aqueous composition in the digester. The aqueous
phosphonate composition of the invention can be added to the
digester using any conventional means known to those of ordinary
skill in the art. In addition, the aqueous phosphonate composition
of the invention can be added directly to the digester composition
or it can be introduced into one of the aqueous feed compositions
being charged to the digester prior to charging of that aqueous
feed composition. The pH in the digester of an alkaline chemical
pulping process is at least 9. In the case of a Kraft process, the
pH in the digester is preferably about 10 to about 14, and more
preferably about 12 to about 14. The aqueous phosphonate
composition of the invention can be added in a batch digester in
any conventional manner known to one of ordinary skill in the art.
For example, in a batch digester operation, the addition of the
aqueous phosphonate composition of the invention can be a bulk
addition at the beginning of the digester cook cycle or during the
digester cook cycle, or it can be added in multiple charges
throughout the digestion cycle or continuously throughout the
digester cook cycle. It is currently preferred to add the aqueous
phosphonate composition of the invention as a bulk charge at or
near the beginning of the digester cook cycle. In the case of a
continuous digester operation, the addition of the aqueous
phosphonate composition of the invention will typically be added
continuously to maintain the effective concentration of
phosphonate.
[0094] The amount of a scale inhibiting composition of this
invention employed is an effective amount which is that amount that
is sufficient to provide an effective scale inhibiting
concentration of phosphonate in the digester over time at which the
formation, deposition and adherence of calcium salt scale,
particularly calcium carbonate or calcium sulfate scale, is
satisfactorily inhibited in the digester, brown stock washers
and/or black liquor recovery area. One of ordinary skill in the art
using this invention will know the acceptable level of calcium salt
scale in the digester, brown stock washing area, and black liquor
recovery area of the particular chemical pulping facility, and will
be able to readily select an appropriate phosphonate and
concentration for addition to the digester to achieve the desired
scale inhibition for the required time based on the disclosure of
this specification. It will be apparent to those of skill in the
art after reading this specification that many factors of the type
which have been mentioned herein and others, will determine the
amount of the phosphonate of the invention needed to achieve the
desired inhibition. The determination of these amounts is within
the ordinary skill of the artisan in this field without undue
experimentation considering the direction provided herein.
[0095] A third embodiment of the invention relates to a method for
inhibiting calcium salt scale formation in an aqueous system in a
selected chemical pulping process comprising (a) identifying the
calcium salt scale inhibition capability required by the selected
chemical pulping process based on the process operating conditions
of time, temperature and pressure, and the aqueous digester
composition, (b) selecting the appropriate phosphonate composition
and phosphonate use concentration to effectively inhibit calcium
salt scale formation in the selected chemical pulping process when
the phosphonate is admixed with the aqueous digester composition in
the selected chemical pulping process based on step (a) and the
calcium salt scale inhibition profiles of phosphonate concentration
and process temperature as a function of time for phosphonate
compositions admixed with the aqueous digester composition in a
chemical pulping process digester, and (c) admixing the selected
phosphonate composition with the aqueous digester composition in
the selected chemical pulping process during the digestion stage of
the chemical pulping process; wherein the selected phosphonate
composition is as defined above for this invention.
[0096] A fourth embodiment of the invention relates to a method for
inhibiting calcium salt scale formation in an aqueous system in a
selected chemical pulping process comprising (a) determining the
calcium salt scale inhibition profiles of phosphonate concentration
and process temperature as a function of time for phosphonate
compositions admixed with the aqueous digester composition in a
chemical pulping process digester, (b) identifying the calcium salt
scale inhibition capability required by the selected chemical
pulping process based on the process operating conditions of time,
temperature and pressure, and the aqueous digester composition, (c)
selecting the appropriate phosphonate composition and phosphonate
use concentration to effectively inhibit calcium salt scale
formation in the selected chemical pulping process when the
phosphonate is admixed with the aqueous digester composition in the
selected chemical pulping process based on steps (a) and (b), and
(d) admixing the selected phosphonate composition with the aqueous
digester composition in the selected chemical pulping process
during the digestion stage of the chemical pulping process; wherein
the selected phosphonate composition is as defined above for this
invention.
[0097] In the third and fourth embodiments of the invention, the
calcium salt scale inhibition profiles of phosphonate concentration
and process temperature as a function of time for phosphonate
compositions admixed with the aqueous digester composition in a
chemical pulping process digester can be determined by conducting
laboratory experiments, such as described herein, or by conducting
larger scale testing. As each chemical pulping process will vary
depending on the type of wood being processed, the specific
operating conditions used, the composition in the digester, and the
like, the specific phosphonate or phosphonate blend and the
required use concentration of same necessary to achieve the desired
scale inhibition will be dependent upon the specific chemical
pulping process. By utilizing the calcium salt scale inhibition
profiles in conjunction with the calcium salt scale inhibition
capability required by the selected chemical pulping process based
on its process operating conditions of time, temperature and
pressure, and the aqueous digester composition, one of ordinary
skill in the art may select the appropriate phosphonate composition
and phosphonate use concentration to effectively inhibit calcium
salt scale formation in the selected chemical pulping process when
the phosphonate is admixed with the aqueous digester composition in
the selected chemical pulping process.
[0098] The invention is further described in the following Examples
which are not intended to limit or restrict the invention. Unless
otherwise indicated all quantities are expressed in weight.
EXAMPLES
[0099] A Kraft cook test was employed in the following examples and
illustrates the use of the compositions of this invention in the
process of this invention. In carrying out these tests, samples
were taken of a composition of the digester at selected times
during the cook. The concentration of total calcium and inhibited
calcium were determined analytically using Atomic Absorption
Spectroscopy (AA). The general procedure described below was
followed. Additionally, the tests were generally carried out at
inhibitor levels of 10, 50, 100 and 500 parts per million (ppm)
active acid based on the amount of total liquor charged to the
digester, for each phosphonate composition tested, and also with no
inhibitor present.
[0100] As used herein, the active acid level is that amount of free
acid which is equimolar to the amount of phosphonate that was
actually added. Unless otherwise specified, use of "%" is on a
weight basis.
Kraft Cook Test
[0101] The Kraft Cook Test used herein was developed to gauge the
performance of scale inhibition of compositions of this invention
in a simulated digester composition wherein calcium is slowly
extracted from the wood chips into the Kraft system. The test was a
standard Kraft cook with a 5:1 liquor to wood ratio in a MK Systems
Inc. minimill laboratory digester. The digester aqueous composition
temperature was ramped from ambient temperature to 180.degree. C.
in one hour and then maintained at 180.degree. C. for an additional
one to two hours. Samples were taken from the digester using a
liquid cooled extractor at various time intervals under high
pressure and temperature during the cook to monitor calcium
concentrations by AA as described in the "Monitoring Calcium
Release During Kraft Cook" section below.
[0102] Drying of Wood Chips:
[0103] Pine wood chips were passed through a 12.5 mm slotted
screen, with the small pins being removed.
[0104] The chips were sorted by hand to remove any bark or knots,
and the wood chips dried at 110.degree. C. for 12 hours. This was
done to reduce variability with moisture and extractives. The wood
chips were stored in a container with desiccant and allowed to cool
to room temperature.
[0105] Preparation of White Liquor/Charge of Digester:
[0106] A liquor to wood ratio of 5:1 was prepared with 18.5%
effective alkali, having a 25% sulfidity and 5 grams per liter of
sodium carbonate. The sodium carbonate introduced into the white
liquor was representative of that which is typically carried over
in the recovery process in a Kraft mill.
[0107] The charge of phosphonate employed was based upon the weight
of total liquor charged to the digester to give the desired
equivalent ppm of active acid in the digester.
[0108] White liquor was prepared according to the following
procedure. Approximately 2 liters of double-deionized water were
transferred to a 4 liter volumetric flask. 322.99 g of 50% sodium
hydroxide, 163.76 g Na.sub.2S.9H.sub.2O, and 20.0 g anhydrous
sodium carbonate were added to the 4 liter flask and dissolved,
enough inhibitor was added to reach the desired concentration, and
double deionized water added to fill to the mark.
[0109] Prior to running the test, the digester was acid cleaned
using a 10% sulfuric acid solution to remove any existing deposits.
After the acid cleaning, the digester was rinsed with distilled
water.
[0110] 800 grams of dried Pine wood chips, prepared as described
above, were added to the wood chip holder. White liquor (4L) and
wood chips were transferred to the digester and the initial
temperature and time recorded.
[0111] Monitoring Calcium Release During Kraft Cook:
[0112] A 5-mL sample was taken for AA analysis and the heating
sequence in the digester was initiated.
[0113] (The AA analysis is done by atomic absorption by flame
photometry using a Perkin Elmer model 100 spectrometer; see
generally, Instrumental Methods of Analysis, Hobart H. Willard,
Lynn L. Merritt, Jr.; John A Dean, 4.sup.th Edition, D. Van
Nostrand Company, Inc. August 1965)
[0114] Quantitatively one milliliter (mL) of the sample was
transferred to a centrifuge tube with 5 mL of 4% HCl solution and
AA was used to determine the calcium content of the sample, i.e.
Total Calcium. The remaining sample was drawn into a 10 mL syringe
and filtered through a 0.45-.mu.m syringe filter. Quantitatively
one mL of the filtrate was transferred to a centrifuge tube with 5
mL of 4% HCl solution and AA was used to determine the calcium
content of the filtrate, i.e. Inhibited Calcium.
[0115] Every 15 minutes for the length of the test, e.g.
approximately 2-4 hours, the liquor in the condenser line was
purged, a temperature measurement was made, and a 5 mL liquor
sample was pulled. The AA analysis procedure as described above was
then repeated. At the end of the test, the calcium content and
temperature data were plotted versus time.
[0116] Each example below was carried out according to the general
procedure recited above. In most examples, the phosphonates were
tested at four concentration levels. All levels are given in parts
per million phosphonate on an active acid basis by weight total
liquor.
[0117] Except as specified herein, chemicals used in the examples
were obtained from Fisher Scientific. Dequest phosphonates, used
individually and in blends in the examples, were obtained from
Solutia Inc. (St. Louis, Mo.). 4NHMP was prepared according to the
procedure described herein.
[0118] Tables 3-96 hereinafter following provide the data for a
series of test runs performed on the digester at various levels of
phosphonates and mixtures of phosphonate. The phosphonate or blend
tested are identified by product name (as defined in Tables 1 and 2
herein) in the header of each Table below. The temperature is in
degrees Celsius. Parts per million (ppm) of calcium is in parts per
million by weight based on total liquor.
Example 1
[0119] Dequest 2006 was tested in the Kraft Cook Test described in
the Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 4-7 below. In addition, a control
experiment with no added inhibitor was run and the results are
given below in Table 3. The data in Table 3 can be used as the
control for Examples 1-8.
3TABLE 3 Kraft Cook with no Inhibitor Inhibited Time, Minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 25 15 17.1 16.6 88 30
37.4 36 133 45 19.4 15 168 60 4.6 2.5 180 75 1.6 0.8 180 90 0.4 0
180 105 0 0 180
[0120]
4TABLE 4 500 ppm Dequest 2006 Inhibited Time, Minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 24 15 20.6 20.9 82 30
37.8 38.2 132 45 53 53 170 60 61.8 59.7 180 75 68.5 66.4 180 90
71.2 71.9 180 105 72.6 71.7 180 120 70.9 64.8 180 150 47.4 47.5 180
180 30.7 31.4 180 240 32.8 22.1 180
[0121]
5TABLE 5 100 ppm Dequest 2006 Inhibited Time, Minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 25 15 19.4 19.9 86 30
36.8 36.2 130 45 49.4 48.5 170 60 61.1 55.3 180 75 60.9 58.9 180 90
22.8 17.4 180 105 12.5 14. 180 120 12 10.7 180 135 9.8 9.5 180 150
6.8 8 180 180 6.6 7 180
[0122]
6TABLE 6 50 ppm Dequest 2006 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 15 14.9 84 30 29.1 29 132
45 39.2 37.6 171 60 54.4 51 180 75 46.2 39.1 180 90 21.9 16.4 180
105 15.4 13.7 180 120 11.8 11.1 180 135 9.2 9.2 180 150 8.9 7.6 180
180 7.6 6.8 180
[0123]
7TABLE 7 10 ppm Dequest 2006 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 24 15 10.1 10.1 88 30 22.7 22.1
134 45 34.5 32.3 174 60 25 13.1 180 75 13.4 5.7 180 90 8.1 5 180
105 6.9 4.7 180 120 6.1 4.4 180
[0124] The data of Example 1 demonstrates that a use level of 500
ppm provided significant improvement in calcium inhibition compared
to lower use levels or the use of no inhibitor. The data also
suggests that a Dequest 2000 and Dequest 2006 use range of about
500 to about 1000 ppm would be effective to inhibit calcium salt
scale according to the invention.
Example 2
[0125] Dequest 2016 was tested in the Kraft Cook Test described in
the Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 8-11 below.
8TABLE 8 500 ppm Dequest 2016 Inhibited Time, Minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 24 15 13.3 13.2 90 30
12.2 6.4 138 45 4.7 3.7 172 60 4.3 4 180 75 5.1 5 180 90 5.5 5.2
180 120 5.5 6.2 180 240 6.5 7.2 180
[0126]
9TABLE 9 100 ppm Dequest 2016 Inhibited Time, Minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 25 15 12.2 11.9 81 30
22.9 22.4 131 45 32.2 32.7 169 60 44 43.9 180 75 54.1 54.7 180 90
59 57.5 180 105 57.9 55.4 180 120 56.4 56.7 180 135 52 48.9 180 150
51.2 48.2 180 180 25.4 21.8 180
[0127]
10TABLE 10 50 ppm Dequest 2016 Inhibited Time, Minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 24 15 13.9 13.3 80 30
28.5 27.7 131 45 40.9 40.7 165 60 64.6 63.3 180 75 80.5 80.6 180 90
85.7 85.9 180 105 89.6 87.9 180 120 88.5 87.8 180 150 84.5 84
180
[0128]
11TABLE 11 10 ppm Dequest 2016 Inhibited Time, Minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 24 15 8.7 8.1 82 30
18.9 18.3 130 45 33.4 32.8 162 60 42 41.7 180 75 39.6 38.4 180 90
22.5 16.8 180 105 13 8.5 180 120 10 6.4 180 135 7.9 5.4 180
[0129] The data of Example 2 demonstrates that use levels of 100
and 50 ppm provided significant improvement in calcium inhibition
compared to use levels of 10 and 500 ppm or the use of no
inhibitor. The data of this example suggests that a Dequest 2010
and Dequest 2016 use range of about 20 to about 200 ppm would be
effective to inhibit calcium salt scale according to the
invention.
Example 3
[0130] Dequest 2054 was tested in the Kraft Cook Test described in
the Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 12-15 below.
12TABLE 12 500 ppm Dequest 2054 Total Calcium, Inhibited Calcium,
Time, Minutes ppm ppm Temperature 0 0 0 24 15 13.4 13.9 82 30 27.8
27.4 120 45 42.8 42.5 160 60 52.5 51 180 75 62.9 61.3 180 90 69.1
67.5 180 105 69.6 69.8 180 120 70.5 69.2 180 150 67.9 67.2 180 180
65.2 64.9 180 240 58.7 57.4 180
[0131]
13TABLE 13 100 ppm Dequest 2054 Total Calcium, Inhibited Calcium,
Time, Minutes ppm ppm Temperature 0 0 0 25 15 9.6 9 88 30 18.8 19.1
133 45 32.5 32.1 168 60 47.6 45.8 180 75 61.8 61.8 180 90 66.1 57
180 105 68.9 67.2 180 120 64.6 64.9 180 135 61.2 60.6 180 150 51.3
50.5 180 180 27.5 26.9 180
[0132]
14TABLE 14 50 ppm Dequest 2054 Total Calcium, Inhibited Calcium,
Time, Minutes ppm ppm Temperature 0 0 0 25 15 16.2 16.1 82 30 30
29.3 128 45 41.9 41.5 160 60 61.1 57.8 184 75 66.2 63.4 180 90 56.9
47 180 105 27.1 20.6 180 120 14.8 11.1 180 135 10.6 9 180 150 7.5
7.3 180 180 5.3 5.3 180
[0133]
15TABLE 15 10 ppm Dequest 2054 Total Calcium, Inhibited Calcium,
Time, Minutes ppm ppm Temperature 0 0.9 0.5 25 15 12.3 12.1 82 30
26.5 26.5 128 45 40.3 37.8 160 60 38.2 34.5 184 75 15.3 10.9 180 90
8.4 7.9 180 105 6 5.6 180 120 4.5 4.1 180 135 3.5 3.5 180 150 2.7
2.5 180 180 2.5 1.5 180
[0134] The data of Example 3 demonstrates that a use level of 500
ppm provided significant improvement in calcium inhibition compared
to 10, 50 and 100 ppm use levels or the use of no inhibitor. The
data of this example suggests that a Dequest 2054 use range of
about 150 to about 1000 ppm would be effective to inhibit calcium
salt scale according to the invention.
Example 4
[0135] Dequest 2060S was tested in the Kraft Cook Test described in
the Examples section at 100, 50 and 10 ppm active acid. The results
are given in Tables 16-18 below.
16TABLE 16 100 ppm Dequest 2060S Total Calcium, Inhibited Calcium,
Time, Minutes ppm ppm Temperature 0 0 0 25 15 1.2 0.6 90 30 9.3 8.7
139 45 25.7 26.3 174 60 39.7 40.3 180 75 56.1 55.5 189 90 65.4 63.1
186 105 68.9 60.2 182 120 76 74.2 180 150 74.2 63.1 180 180 53.2
45.6 180
[0136]
17TABLE 17 50 ppm Dequest 2060S Total Calcium, Inhibited Calcium,
Time, Minutes ppm ppm Temperature 0 0 0 25 15 4.4 4 82 30 20 19 134
45 41 38.8 165 60 61.5 60.5 180 75 82.7 74.7 180 90 91.3 84.2 180
105 88.8 85.6 180 120 87 78.9 180 150 71.4 67.6 180 180 50.6 41
180
[0137]
18TABLE 18 10 ppm Dequest 2060S Total Calcium, Inhibited Calcium,
Time, Minutes ppm ppm Temperature 0 0 0 25 15 7.2 3.9 79 30 21.3
19.9 134 45 41.2 41.2 176 60 64 60.5 180 75 70.9 70 180 90 61 59.2
180 105 52 51.2 180 120 42.6 38.4 180
[0138] The data of Example 4 demonstrates that use levels of 50 and
100 ppm provided significant improvement in calcium inhibition
compared to a 10 ppm use level or the use of no inhibitor. The data
of this example suggests that a Dequest 2060S use range of about 30
to about 1000 ppm would be effective to inhibit calcium salt scale
according to the invention.
Example 5
[0139] Dequest 2066 was tested in the Kraft Cook Test described in
the Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 19-22 below.
19TABLE 19 500 ppm Dequest 2066 Total Calcium, Inhibited Calcium,
Time, Minutes ppm ppm Temperature 0 0 0 24 15 21.3 21.2 84 30 36.6
36.6 134 45 52.5 51.4 170 60 62.8 62.2 180 75 70 69 180 90 72.8
72.8 180 105 75.2 75.3 180 120 76.7 76.7 180 150 76 75.3 180 180
74.3 74.3 180 240 69.8 68.5 180
[0140]
20TABLE 20 100 ppm Dequest 2066 Total Calcium, Inhibited Calcium,
Time, Minutes ppm ppm Temperature 0 0 0 25 15 15.9 15.4 86 30 30.4
29.4 130 45 40.8 40.8 168 60 53.8 52.8 180 75 60.1 59.9 180 90 63.4
60.3 180 105 59.4 57.2 180 120 63 61.7 180 135 58.2 56.2 180 150 55
43.4 180 180 40.9 39.2 180
[0141]
21TABLE 21 50 ppm Dequest 2066 Total Calcium, Inhibited Calcium,
Time, Minutes ppm ppm Temperature 0 0 0 25 0 0 0 24 15 17 16.7 84
30 33.9 32.8 130 45 48.8 48.2 171 60 62.2 60.2 180 75 73.8 65 180
90 76.9 67.4 180 105 75.5 65.7 180 120 70.8 67.2 180 135 65.7 64
180 150 61.1 60.1 180 180 43.8 37.9 180
[0142]
22TABLE 22 10 ppm Dequest 2066 Inhibited Time, Minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 24 15 10.2 4.6 84 30
20.8 20.7 134 45 32.7 31.8 170 60 40.5 40.3 180 75 41.8 40 180 90
33.8 31.8 180 105 24.6 22.3 180 120 16.5 13.9 180 150 9.5 7.4
180
[0143] The data of Example 5 demonstrates that use levels of 50,
100 and 500 ppm provided significant improvement in calcium
inhibition compared to a 10 ppm use level or the use of no
inhibitor. The data of this example suggests that a Dequest 2066
use range of about 30 to about 1000 ppm would be effective to
inhibit calcium salt scale according to the invention.
Example 6
[0144] 4NHMP was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 23-26 below.
23TABLE 23 500 ppm 4NHMP Inhibited Time, Minutes Total Calcium, ppm
Calcium, ppm Temperature 0 0 0 24 15 19.7 19.2 84 30 37.6 37.6 132
45 63.3 61.9 170 60 82.5 80.1 180 75 89.5 89.1 180 90 94.4 93.2 180
105 99.7 96.2 180 120 101.8 99.1 180 150 107 106.4 180 180 102.8
101 180 240 98.7 96.2 180
[0145]
24TABLE 24 100 ppm 4NHMP Inhibited Time, Minutes Total Calcium, ppm
Calcium, ppm Temperature 0 0 0 24 15 13.8 13.8 84 30 29 27.8 132 45
54.1 53.5 170 60 72.2 72.6 180 75 84.5 83.6 180 90 96.5 93 180 105
100.2 98.2 180 120 100.8 97 180 150 94.5 93.6 180 180 86 85.3
180
[0146]
25TABLE 25 50 ppm 4NHMP Inhibited Time, Minutes Total Calcium, ppm
Calcium, ppm Temperature 0 0 0 24 15 14.8 14.6 82 30 30.6 30.1 130
45 57.7 54.1 165 60 75 72.9 180 75 89.8 86.5 180 90 96.5 94.1 180
105 101.2 99.3 180 120 102.8 100 180 150 97.2 97.1 180 180 86.1
86.5 180
[0147]
26TABLE 26 10 ppm 4NHMP Inhibited Time, Minutes Total Calcium, ppm
Calcium, ppm Temperature 0 0 0 24 15 18 12 84 30 36 30 134 45 60 54
180 60 72 72 180 90 78 78 180 105 72 72 180 120 60 60 180 150 48 48
180 180 36 36 180
[0148] The data of Example 6 demonstrates that use levels of 10,
50, 100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of no inhibitor. The data of this
example suggests that a 4NHMP use range of about 10 to about 1000
ppm would be effective to inhibit calcium salt scale according to
the invention.
Example 7
[0149] Dequest 6004 was tested in the Kraft Cook Test described in
the Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 27-30 below.
27TABLE 27 500 ppm Dequest 6004 Inhibited Time, Minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 24 15 26.1 25.1 82 30
38.6 38.6 132 45 53.5 41 169 60 50.6 41.2 180 75 52.2 47.9 180 90
53.5 50.8 180 105 53.8 52.9 180 120 53.5 53.5 180 150 54.5 49.1 180
180 53.1 52.1 180 210 52.3 51.2 180
[0150]
28TABLE 28 100 ppm Dequest 6004 Inhibited Time, Minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 24 15 15.6 15.6 84 30
32.4 32 132 45 45.1 37.5 172 60 52.6 45.8 180 75 59.1 51 180 90
36.6 28.7 180 105 25.9 22.4 180 120 18.8 15.6 180 150 13.8 11.9 180
180 10.7 9.2 180
[0151]
29TABLE 29 50 ppm Dequest 6004 Inhibited Time, Minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 24 15 11.6 11.4 84 30
27.7 27.8 132 45 55.5 52.3 170 60 77.1 70.7 180 75 70.5 58.8 180 90
50.7 39.9 180 105 34.5 24.9 180 120 28 15.6 180 150 19.4 12.3 180
180 17.1 8.1 180
[0152]
30TABLE 30 10 ppm Dequest 6004 Inhibited Time, Minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 24 15 11 10.4 84 30
26.1 24.9 134 45 51.3 50.7 168 60 32.1 20.3 180 75 22.8 10.1 180 90
21.2 9.6 180 105 18.2 8.4 180 120 16.5 7.8 180
[0153] The data of Example 7 demonstrates that use levels of 50,
100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of 10 ppm inhibitor or the use of no
inhibitor. The data of this example suggests that a Dequest 6004
use range of about 50 to about 1000 ppm would be effective to
inhibit calcium salt scale according to the invention.
Example 8
[0154] Dequest 2046 was tested in the Kraft Cook Test described in
the Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 31-34 below.
31TABLE 31 10 ppm Dequest 2046 Inhibited Time, minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 21 15 18 18 80 30 30 30
132 45 48 48 170 60 60 60 176 75 66 60 176 90 54 54 176 105 42 42
176 120 36 36 176 150 30 30 176 180 30 24 176
[0155]
32TABLE 32 50 ppm Dequest 2046 Inhibited Time, minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 21 15 12 12 80 30 36 36
132 45 48 48 170 60 60 60 176 75 72 72 176 90 72 72 176 105 78 78
176 120 78 72 176 150 60 60 176 180 54 48 176
[0156]
33TABLE 33 100 ppm Dequest 2046 Inhibited Time, minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 21 15 18 18 80 30 30 30
132 45 48 48 170 60 60 66 176 75 72 72 176 90 72 72 176 105 78 72
176 120 78 72 176 150 72 66 176 180 60 60 176
[0157]
34TABLE 34 500 ppm Dequest 2046 Inhibited Time, minutes Total
Calcium, ppm Calcium, ppm Temperature 0 0 0 21 15 30 30 82 30 42 42
130 45 60 60 168 60 78 78 178 75 90 90 178 90 102 102 178 105 108
108 178 120 114 108 178 150 120 114 178 180 120 114 178
[0158] The data of Example 8 demonstrates that use levels of 10,
50, 100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of no inhibitor. The data of this
example suggests that a Dequest 2046 use range of about 10 to about
1000 ppm would be effective to inhibit calcium salt scale according
to the invention.
Phosphonate Blends
[0159] A series of blends of phosphonates were made and then tested
as calcium carbonate scale inhibitors in a digester according to
the procedure described above. The compositions of these various
blends are shown in Table 2 above.
Example 9
[0160] A control with no inhibitor was tested in the Kraft Cook
Test described in the Examples section. The results are given in
Table 35 below and can be used as a control for Examples 10-25.
35TABLE 35 Kraft Cook with no Inhibitor Inhibited Time, Minutes
Total Calcium, ppm Calcium, ppm Temperature 0 0 0 25 15 11.5 10.9
82 30 24.8 23.4 128 45 39 38.2 163 60 16.6 14.9 180 75 12.9 10.3
180 90 10.3 6.7 180 105 9.2 7.8 180 120 8.4 7.8 180
Example 10
[0161] Blend 78 was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 36-39 below.
36TABLE 36 500 ppm Blend 78 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 22 15 16 16 80 30 48 48 124 45
78 78 164 60 96 96 176 75 114 114 176 90 114 114 176 105 120 120
176 120 126 120 176 150 126 120 176 180 126 120 176
[0162]
37TABLE 37 100 ppm Blend 78 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 3.3 2.6 82 30 18.8 19.9
128 45 29.7 28.6 163 60 46 43.1 180 75 57.6 53.6 180 90 71.3 67 180
105 73.2 67 180 120 76.4 69.5 180 150 56.8 53.6 180 180 38.8 32.6
180
[0163]
38TABLE 38 50 ppm Blend 78 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 11.2 11.2 82 30 27.2 28.1
128 45 51.4 50.4 163 60 67.1 69.1 180 75 85.6 82.4 180 90 80.8 79.2
180 105 82.1 78.2 180 120 72.5 67.7 180 150 55.9 53 180 180 35.2
33.5 180
[0164]
39TABLE 39 10 ppm Blend 78 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 7.8 7.4 82 30 29.5 28.7
128 45 60.4 57.2 163 60 84.4 80.4 180 75 68.8 60.8 180 90 41.9 32.3
180 105 29.5 19.5 180 120 23.4 15.8 180 150 18.3 12.6 180 180 15.1
10.3 180
[0165] The data of Example 10 demonstrates that use levels of 50,
100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of 10 ppm inhibitor or the use of no
inhibitor. The data of this example suggests that a blend of
Dequest 2000 or 2006 and Dequest 2066 or 2060 in the use range of
about 50 to about 1000 ppm would be effective to inhibit calcium
salt scale according to the invention.
Example 11
[0166] Blend 79 was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 40-43 below.
40TABLE 40 500 ppm Blend 79 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 22 15 24 24 80 30 48 48 124 45
72 72 166 60 90 90 180 75 102 96 180 90 108 102 180 105 114 102 180
120 108 102 180 150 96 90 180 180 84 72 180
[0167]
41TABLE 41 100 ppm Blend 79 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 7 5.4 82 30 20.3 19.6 128
45 42.6 41.9 163 60 62.2 57.2 180 75 78.1 69.8 180 90 89.7 82.1 180
105 93.7 78.8 180 120 93.1 81.5 180 150 68.5 45.9 180 180 44.4 31.3
180
[0168]
42TABLE 42 50 ppm Blend 79 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 25 15 9.3 9.1 82 30 22.9
22.6 128 45 52.4 49.5 163 60 74.7 69.6 180 75 85.1 78.3 180 90 86.4
79.3 180 105 74.1 62.4 180 120 57.6 42.4 180 150 33.9 22.9 180 180
25.6 17.4 180
[0169]
43TABLE 43 10 ppm Blend 79 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 25 15 11.2 11.2 82 30 24.4
23.7 128 45 51.2 45.1 163 60 61.2 55.1 180 75 40.2 15. 180 90 24.1
9.5 180 105 16.3 6.3 180 120 10.5 6.3 180 150 6.6 3.7 180 180 2.7
2.1 180
[0170] The data of Example 11 demonstrates that use levels of 50,
100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of 10 ppm inhibitor or the use of no
inhibitor. The data of this example suggests that a blend of
Dequest 2000 or 2006 and Dequest 2054 in the use range of about 50
to about 1000 ppm would be effective to inhibit calcium salt scale
according to the invention.
Example 12
[0171] Blend 80 was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 44-47 below.
44TABLE 44 500 ppm Blend 80 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 22 15 24 24 80 30 42 42
124 45 72 72 164 60 90 90 179 75 102 102 180 90 108 108 180 105 114
108 180 120 114 102 180 150 114 96 180 180 108 90 180
[0172]
45TABLE 45 100 ppm Blend 80 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 25 15 12.9 11.7 86 30 31.2
29.3 132 45 61 58.7 168 60 89.2 83.8 179 75 104.8 103.7 180 90
113.6 109.8 180 105 112.8 101.7 180 120 103.7 96.1 180 150 76.2
71.3 180 180 50.7 47.6 180
[0173]
46TABLE 46 50 ppm Blend 80 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 25 15 7.7 7.4 86 30 19.4
19.1 132 45 41.7 41.1 168 60 60.8 59.2 179 75 75.4 74.1 180 90 85.4
83.1 180 105 84.8 78.3 180 120 78 70.8 180 150 63.1 55.6 180 180
39.2 33 180
[0174]
47TABLE 47 10 ppm Blend 80 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 25 15 10.3 10.3 86 30 19.5
19.2 132 45 31.2 30.9 168 60 39.2 35 179 75 36.7 33.9 180 90 32.3
31.5 180 105 28.2 26.7 180 120 21.3 19.9 180 150 12.3 11.3 180 180
5.5 4.4 180
[0175] The data of Example 12 demonstrates that use levels of 10,
50, 100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of no inhibitor. The data of this
example suggests that a blend of Dequest 2000 or 2006 and 4NHMP in
the use range of about 10 to about 1000 ppm would be effective to
inhibit calcium salt scale according to the invention.
Example 13
[0176] Blend 81B was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 48-51 below.
48TABLE 48 500 ppm Blend 81B Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 22 15 24 24 80 30 42 42
124 45 42 42 164 60 42 42 180 75 42 42 180 90 42 42 180 105 48 48
180 120 48 48 180 150 48 48 180 180 54 54 180
[0177]
49TABLE 49 100 ppm Blend 81B Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 25 15 7 7.1 82 30 18.8
18.5 128 45 38.5 36.5 163 60 65.6 61.8 180 75 85.7 83.3 180 90
102.3 91.6 180 105 106.5 103.4 180 120 113.1 108.6 180 150 107.9
104.1 180 180 97.1 94.4 180
[0178]
50TABLE 50 50 ppm Blend 81B Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 25 15 6.2 5.8 82 30 15.5
15.2 128 45 34.3 33.6 163 60 56 45.3 180 75 71.2 67.6 180 90 83.5
79.3 180 105 84.2 81.5 180 120 79.3 76.7 180 150 69.6 67.9 180 180
58.9 55.3 180
[0179]
51TABLE 51 10 ppm Blend 81B Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 25 15 11.3 10.9 82 30 23.4
22.4 128 45 45.4 43.7 163 60 54.6 53.3 180 75 54.9 51.9 180 90 49.3
46.4 180 105 38.8 37.8 180 120 30.6 29.6 180 150 12.6 11.6 180 180
4.4 3.7 180
[0180] The data of Example 13 demonstrates that use levels of 50,
100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of 10 ppm inhibitor or the use of no
inhibitor. The data of this example suggests that a blend of
Dequest 2010 or 2016 and Dequest 2066 or 2060 in the use range of
about 30 to about 1000 ppm would be effective to inhibit calcium
salt scale according to the invention.
Example 14
[0181] Blend 82 was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 52-55 below.
52TABLE 52 500 ppm Blend 82 Time, Total Inhibited Minutes Calcium,
ppm Calcium, ppm Temperature 0 0 0 22 15 24 24 82 30 30 30 126 45
18 12 162 60 18 12 180 75 18 18 180 90 24 18 180 105 24 24 180 120
24 24 180 150 24 24 180 180 24 24 180
[0182]
53TABLE 53 100 ppm Blend 82 Time, Total Inhibited Minutes Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 7.3 4.9 82 30 21 18 128 45
40.7 38.5 163 60 59.8 58.8 180 75 78.8 76.2 180 90 98.3 97.3 180
105 109.3 107.9 180 120 108.6 106.6 180 150 94.6 88.2 180 180 76.5
72.5 180
[0183]
54TABLE 54 50 ppm Blend 82 Time, Total Inhibited Minutes Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 9.2 8.9 82 30 21.7 21.4
128 45 46.7 44.9 163 60 62.4 61.8 180 75 77.4 75.2 180 90 92.4 89.3
180 105 99.6 97.1 180 120 94.9 95.9 180 150 90.5 87.4 180 180 82.4
79 180
[0184]
55TABLE 55 10 ppm Blend 82 Time, Total Inhibited Minutes Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 12 12 82 30 30 30 128 45
42 42 163 60 54 54 180 75 42 30 180 90 30 24 180 105 24 18 180 120
18 18 180 150 18 18 180 180 18 12 180
[0185] The data of Example 14 demonstrates that use levels of 50
and 100 ppm provided sigificant improvement in calcium inhibition
compared to the use of 10 or 500 ppm inhibitor or the use of no
inhibitor. The data of this example suggests that a blend of
Dequest 2010 or 2016 and Dequest 2054 in the use range of about 30
to about 150 ppm would be effective to inhibit calcium salt scale
according to the invention.
Example 15
[0186] Blend 83A was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 56-59 below.
56TABLE 56 500 ppm Blend 83A Time, Total Inhibited Minutes Calcium,
ppm Calcium, ppm Temperature 0 0 0 22 15 24 24 82 30 24 24 124 45
18 18 156 60 18 18 176 75 18 18 176 90 18 18 176 105 18 18 176 120
18 18 176 150 24 24 176 180 24 24 176
[0187]
57TABLE 57 100 ppm Blend 83A Time, Total Inhibited Minutes Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 5 4.7 82 30 19 18 128 45
33.1 32.7 163 60 54.9 52.8 180 75 75.7 72 180 90 91.8 90.4 180 105
98.9 98.3 180 120 99.3 96.9 180 150 93.5 88.7 180 180 89.7 84.9
180
[0188]
58TABLE 58 50 ppm Blend 83A Time, Total Inhibited Minutes Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 6.7 6.4 82 30 17.4 17.1
128 45 38.8 36.5 163 60 59.2 59.9 180 75 76.4 75.1 180 90 89.4 88.7
180 105 96.1 93.5 180 120 98.4 97.1 180 150 98.7 96.4 180 180 94.8
92.5 180
[0189]
59TABLE 59 10 ppm Blend 83A Time, Total Inhibited Minutes Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 10.7 10.4 82 30 22.7 22.1
128 45 43.6 42.6 163 60 59.4 58.3 180 75 67.9 63.5 180 90 64.4 63.4
180 105 56.3 52.8 180 120 45 42.3 180 150 25.8 24.8 180 180 14.9
13.5 180
[0190] The data of Example 15 demonstrates that use levels of 50,
100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of 10 ppm inhibitor or the use of no
inhibitor. The data of this example suggests that a blend of
Dequest 2010 or 2016 and 4NHMP in the use range of about 20 to
about 500 ppm would be effective to inhibit calcium salt scale
according to the invention.
Example 16
[0191] Blend 83B was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 60-63 below.
60TABLE 60 500 ppm Blend 83B Time, Total Inhibited Minutes Calcium,
ppm Calcium, ppm Temperature 0 0 0 22 15 18 18 80 30 36 36 124 45
36 36 166 60 36 36 180 75 36 36 180 90 42 42 180 105 42 42 180 120
42 42 180 158 42 42 180 180 42 42 180
[0192]
61TABLE 61 100 ppm Blend 83B Time, Total Inhibited Minutes Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 12 12 82 30 30 30 128 45
54 54 163 60 72 72 180 75 84 84 180 90 108 101 180 105 108 101 180
120 108 101 180 150 108 108 180 180 114 108 180
[0193]
62TABLE 62 50 ppm Blend 83B Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 12.4 11.9 82 30 28.4 28.3
128 45 56.1 54.7 163 60 86.7 83.8 180 75 110.2 107.8 180 90 124.8
123.4 180 105 133.2 129.9 180 120 135.2 128.5 180 158 134.6 132.3
180 180 115.8 104.5 180
[0194]
63TABLE 63 10 ppm Blend 83B Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 18 12 82 30 30 30 128 45
42 42 163 60 54 54 180 75 60 54 180 90 60 60 180 105 60 54 180 120
60 60 180 158 54 54 180 180 42 42 180
[0195] The data of Example 16 demonstrates that use levels of 50,
100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of 10 ppm inhibitor or the use of no
inhibitor. The data of this example suggests that a blend of
Dequest 2010 or 2016 and 4NHMP in the use range of about 20 to
about 500 ppm would be effective to inhibit calcium salt scale
according to the invention.
Example 17
[0196] Blend 84 was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 64-67 below.
64TABLE 64 500 ppm Blend 84 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 22 15 24 24 82 30 48 48 126 45
78 78 164 60 102 102 180 75 120 114 180 90 126 120 180 105 132 126
180 120 132 126 180 150 120 114 180 180 102 102 180
[0197]
65TABLE 65 100 ppm Blend 84 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 6.3 5.9 82 30 19.6 17.3
128 45 42.7 41.7 163 60 53.7 51.7 180 75 81.5 79.5 180 90 94.3 93.2
180 105 106.6 104.3 180 120 110.3 107.9 180 150 99.3 96.9 180 180
59.1 58.8 180
[0198]
66TABLE 66 50 ppm Blend 84 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 6.7 6.4 82 30 17.8 17.4
128 45 42.7 40.4 163 60 57.3 56.6 180 75 73.8 72.8 180 90 84.8 83.8
180 105 89.6 89 180 120 91.2 86.4 180 150 65.7 62.4 180 180 38.8
38.5 180
[0199]
67TABLE 67 10 ppm Blend 84 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 8.3 7.9 82 30 15.8 15.5
128 45 36.5 35.5 163 60 52.3 50.9 180 75 58.8 55.7 180 90 55.3 52.9
180 105 43.4 42.3 180 120 34.4 33.1 180 150 22.1 20.3 180 180 12.7
11.4 180
[0200] The data of Example 17 demonstrates that use levels of 100
and 500 ppm provided significant improvement in calcium inhibition
compared to the use of 10 or 50 inhibitor or the use of no
inhibitor. The data of this example suggests that a blend of 4NHMP
and Dequest 2054 in the use range of about 80 to about 1000 ppm
would be effective to inhibit calcium salt scale according to the
invention.
Example 18
[0201] Blend 85 was tested in the Kraft Cook Test described in the
Examples section at 100 ppm active acid. The results are given in
Table 68 below.
68TABLE 68 100 ppm Blend 85 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 10.5 10.2 82 30 24.3 23.7
128 45 41.1 40.3 163 60 58.5 57.9 180 75 73.9 73.6 180 90 86.8 86
180 105 89.1 89.1 180 120 94.4 94.4 180 150 97.5 94.9 180 180 90.5
89.3 180
[0202] The data of Example 18 demonstrates that a use level of 100
ppm provided significant improvement in calcium inhibition compared
to the use of no inhibitor. The data of this example suggests that
a blend of Dequest 2000 or 2006 and Dequest 2010 or 2016 in the use
range of about 70 to about 200 ppm would be effective to inhibit
calcium salt scale according to the invention.
Example 19
[0203] Blend 86 was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 69-72 below.
69TABLE 69 500 ppm Blend 86 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 22 15 24 24 84 30 36 36 126 45
66 66 166 60 84 84 180 75 96 90 180 90 108 102 180 105 114 108 180
120 114 108 180 150 114 108 180 180 108 102 180
[0204]
70TABLE 70 100 ppm Blend 86 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 4.4 4.1 82 30 16.4 15.9
128 45 34.9 29.9 163 60 44.7 43.9 180 75 57.1 56.8 180 90 69.2 68.3
180 105 73.1 72.3 180 120 73.6 70 180 150 66.4 63.5 180 180 52.1
46.7 180
[0205]
71TABLE 71 50 ppm Blend 86 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 25 15 6.1 5.8 82 30 19.1 18.7
128 45 45.3 44.6 163 60 64.1 63.4 180 75 75.7 74.4 180 90 88 81.6
180 105 89.9 88.3 180 120 87.1 84.8 180 150 57.3 54.3 180 180 33.9
33.6 180
[0206]
72TABLE 72 10 ppm Blend 86 Time, Total Calcium, Inhibited Calcium,
Minutes ppm ppm Temperature 0 0 0 25 15 12 12 82 30 30 30 128 45 42
42 163 60 54 48 180 75 54 54 180 90 54 54 180 105 48 48 180 120 42
42 180 150 30 30 180 180 24 24 180
[0207] The data of Example 19 demonstrates that use levels of 10,
50, 100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of no inhibitor. The data of this
example suggests that a blend of Dequest 2060 or 2066 and 4NHMP in
the use range of about 10 to about 1000 ppm would be effective to
inhibit calcium salt scale according to the invention.
Example 20
[0208] Blend 87 was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 73-76 below.
73TABLE 73 500 ppm Blend 87 Time, Total Calcium, Inhibited Calcium,
Minutes ppm ppm Temperature 0 0 0 22 15 30 30 82 30 48 48 126 45 78
78 163 60 96 96 180 75 114 108 180 90 120 114 180 105 126 120 180
120 132 126 180 158 138 132 180 180 138 132 180
[0209]
74TABLE 74 100 ppm Blend 87 Time, Total Calcium, Inhibited Calcium,
Minutes ppm ppm Temperature 0 0 0 25 15 7.4 7.1 82 30 21.3 20.9 128
45 43.4 41.4 163 60 61.8 59 180 75 83 82.9 180 90 92.6 89.5 180 105
96.5 94.4 180 120 96.8 93.3 180 158 80.2 77.4 180 180 53.8 50
180
[0210]
75TABLE 75 50 ppm Blend 87 Time, Total Calcium, Inhibited Calcium,
Minutes ppm ppm Temperature 0 0 0 25 15 14.7 14.3 82 30 29.8 29.3
128 45 63.2 60.8 163 60 86.2 85.7 180 75 111.6 111.6 180 90 130.4
127.6 180 105 142.2 139.4 180 120 141.3 137 180 158 110.7 101.3 180
180 67.4 60.8 180
[0211]
76TABLE 76 10 ppm Blend 87 Time, Total Calcium, Inhibited Calcium,
Minutes ppm ppm Temperature 0 0 0 25 15 18 12 82 30 36 36 128 45 60
54 163 60 66 60 180 75 42 30 180 90 30 18 180 105 24 18 180 120 18
12 180 158 12 12 180 180 12 6 180
[0212] The data of Example 20 demonstrates that use levels of 50,
100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of 10 ppm inhibitor or the use of no
inhibitor. The data of this example suggests that a blend of
Dequest 2060 or 2066 and Dequest 2054 in the use range of about 50
to about 1000 ppm would be effective to inhibit calcium salt scale
according to the invention. It is believed that the difference
between the data for 50 ppm inhibitor and 100 ppm inhibitor is due
to the wood chips used in the experiments. The advantage of using
100 ppm inhibitor compared to 50 ppm inhibitor is seen in the shape
of the curve as opposed to the height of the curve.
Example 21
[0213] Blend 94 was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 77-80 below.
77TABLE 77 500 ppm Blend 94 Time, Total Calcium, Inhibited Calcium,
Minutes ppm ppm Temperature 0 0 0 21 15 24 24 90 30 42 42 136 45 66
66 174 60 90 84 178 75 102 96 178 90 108 96 178 105 114 108 178 120
114 108 178 150 120 114 178 180 120 114 178
[0214]
78TABLE 78 100 ppm Blend 94 Time, Total Calcium, Inhibited Calcium,
Minutes ppm ppm Temperature 0 0 0 21 15 18 18 80 30 30 30 132 45 48
48 170 60 60 60 176 75 72 66 176 90 78 72 176 105 84 78 176 120 84
78 176 150 84 78 176 180 78 72 176
[0215]
79TABLE 79 50 ppm Blend 94 Time, Total Calcium, Inhibited Calcium,
Minutes ppm ppm Temperature 0 0 0 21 15 18 18 80 30 30 30 132 45 42
42 170 60 60 60 176 75 72 72 176 90 78 78 176 105 78 72 176 120 78
78 176 150 72 60 176 180 42 42 176
[0216]
80TABLE 80 10 ppm Blend 94 Time, Total Calcium, Inhibited Calcium,
Minutes ppm ppm Temperature 0 0 0 21 15 12 12 80 30 30 30 132 45 48
42 170 60 66 54 176 75 66 60 176 90 48 42 176 105 36 30 176 120 30
24 176 150 24 18 176 180 24 12 176
[0217] The data of Example 21 demonstrates that use levels of 50,
100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of 10 ppm inhibitor or the use of no
inhibitor. The data of this example suggests that a blend of
Dequest 2000 or 2006 and Dequest 2046 in the use range of about 30
to about 1000 ppm would be effective to inhibit calcium salt scale
according to the invention.
Example 22
[0218] Blend 95 was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 81-84 below.
81TABLE 81 500 ppm Blend 95 Time, Total Calcium, Inhibited Calcium,
Minutes ppm ppm Temperature 0 0 0 21 15 12 12 82 30 30 30 132 45 48
48 170 60 54 54 177 75 54 54 177 90 60 54 177 105 60 54 177 120 60
60 177 150 66 60 177 180 66 60 177
[0219]
82TABLE 82 100 ppm Blend 95 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 21 15 18 18 80 30 24 24
132 45 42 42 170 60 54 54 176 75 66 66 176 90 72 72 176 105 78 78
176 120 84 84 176 150 84 84 176 180 84 84 176
[0220]
83TABLE 83 50 ppm Blend 95 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 21 15 6 6 80 30 24 24 132
45 42 42 170 60 54 48 176 75 60 60 176 90 66 66 176 105 66 66 176
120 72 72 176 150 72 72 176 180 72 72 176
[0221]
84TABLE 84 10 ppm Blend 95 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 21 15 12 12 80 30 30 30
132 45 48 48 170 60 66 66 176 75 66 60 176 90 42 36 176 105 30 30
176 120 30 24 176 150 24 18 176 180 24 18 176
[0222] The data of Example 22 demonstrates that use levels of 50,
100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of 10 ppm inhibitor or the use of no
inhibitor. The data of this example suggests that a blend of
Dequest 2010 or 2016 and Dequest 2046 in the use range of about 20
to about 1000 ppm would be effective to inhibit calcium salt scale
according to the invention.
Example 23
[0223] Blend 96 was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 85-88 below.
85TABLE 85 500 ppm Blend 96 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 21 15 18 18 88 30 36 36
136 45 54 54 172 60 78 72 174 75 90 84 174 90 96 90 174 105 102 90
174 120 108 96 174 150 108 96 174 180 108 96 174
[0224]
86TABLE 86 100 ppm Blend 96 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 21 15 12 12 80 30 30 30
132 45 48 48 170 60 60 60 176 75 66 66 176 90 72 72 176 105 78 78
176 120 84 84 176 150 84 84 176 180 84 84 176
[0225]
87TABLE 87 50 ppm Blend 96 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 21 15 6 6 80 30 30 30 132
45 48 48 170 60 60 60 176 75 72 72 176 90 78 72 176 105 84 78 176
120 84 84 176 150 72 48 176 180 48 42 176
[0226]
88TABLE 88 10 ppm Blend 96 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 21 15 12 12 80 30 24 24
132 45 48 42 170 60 66 60 176 75 78 78 176 90 78 72 176 105 54 54
176 120 42 36 176 150 30 24 176 180 24 24 176
[0227] The data of Example 23 demonstrates that use levels of 50,
100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of 10 ppm or use of no inhibitor.
The data of this example suggests that a blend of Dequest 2046 and
Dequest 2054 in the use range of about 30 to about 1000 ppm would
be effective to inhibit calcium salt scale according to the
invention.
Example 24
[0228] Blend 97 was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 89-92 below.
89TABLE 89 500 ppm Blend 97 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 21 15 24 24 86 30 36 36
134 45 66 60 172 60 84 78 174 75 96 90 174 90 102 96 174 105 114
108 174 120 114 108 174 150 114 108 174 180 114 108 174
[0229]
90TABLE 90 100 ppm Blend 97 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 21 15 18 18 80 30 30 30
132 45 48 48 170 60 54 54 176 75 60 60 176 90 66 66 176 105 72 72
176 120 72 72 176 150 72 72 176 180 72 72 176
[0230]
91TABLE 91 50 ppm Blend 97 Time, Minutes Total Calcium, ppm
Inhibited Calcium, ppm Temperature 0 0 0 21 15 18 18 80 30 30 30
132 45 48 48 170 60 60 60 176 75 72 72 176 90 72 72 176 105 72 66
176 120 72 72 176 150 66 66 176 180 54 54 176
[0231]
92TABLE 92 10 ppm Blend 97 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 21 15 12 12 80 30 30 30 132 45
48 48 170 60 66 66 176 75 72 66 176 90 60 54 176 105 48 42 176 120
36 30 176 150 30 24 176 180 24 18 176
[0232] The data of Example 24 demonstrates that use levels of 50,
100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of 10 ppm or the use of no
inhibitor. The data of this example suggests that a blend of
Dequest 2060 or 2066 and Dequest 2046 in the use range of about 20
to about 1000 ppm would be effective to inhibit calcium salt scale
according to the invention.
Example 25
[0233] Blend 98 was tested in the Kraft Cook Test described in the
Examples section at 500, 100, 50 and 10 ppm active acid. The
results are given in Tables 93-96 below.
93TABLE 93 500 ppm Blend 98 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 21 15 24 24 84 30 42 42 132 45
60 60 168 60 90 90 180 75 96 96 180 90 102 102 180 105 102 102 180
120 102 102 180 150 102 102 180 180 102 102 180
[0234]
94TABLE 94 100 ppm Blend 98 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 21 15 18 18 80 30 30 30 132 45
42 42 170 60 54 54 176 75 66 66 176 90 66 66 176 105 72 72 176 120
72 72 176 150 72 72 176 180 72 72 176
[0235]
95TABLE 95 50 ppm Blend 98 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 21 15 12 12 80 30 24 24 132 45
42 42 170 60 60 60 176 75 66 66 176 90 72 72 176 105 72 72 176 120
78 78 176 150 72 72 176 180 66 66 176
[0236]
96TABLE 96 10 ppm Blend 98 Inhibited Time, Minutes Total Calcium,
ppm Calcium, ppm Temperature 0 0 0 21 15 12 12 80 30 30 30 132 45
48 48 170 60 66 60 176 75 78 72 176 90 72 72 176 105 66 66 176 120
54 54 176 150 36 36 176 180 24 24 176
[0237] The data of Example 25 demonstrates that use levels of 50,
100 and 500 ppm provided significant improvement in calcium
inhibition compared to the use of 10 ppm or the use of no
inhibitor. The data of this example suggests that a blend of
Dequest 2046 and 4NHMP in the use range of about 20 to about 1000
ppm would be effective to inhibit calcium salt scale according to
the invention.
[0238] The preceding description is for illustration and should not
be taken as limiting. Various modifications and alterations will be
readily suggested to persons skilled in the art. It is intended,
therefore, that the foregoing be considered as exemplary only and
that the scope of the invention be ascertained from the following
claims. It is further intended that each and every claim limitation
be literally construed to include any and all variants which are
insubstantially different from what is literally recited except
variants which are in the prior art.
* * * * *