CA1114978A - Sludge conditioning composition for scale inhibition in water - Google Patents
Sludge conditioning composition for scale inhibition in waterInfo
- Publication number
- CA1114978A CA1114978A CA328,648A CA328648A CA1114978A CA 1114978 A CA1114978 A CA 1114978A CA 328648 A CA328648 A CA 328648A CA 1114978 A CA1114978 A CA 1114978A
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- Prior art keywords
- acid
- water
- copolymer
- maleic anhydride
- organophosphonic
- Prior art date
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-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents
- C02F5/08—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
- C02F5/10—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances
- C02F5/14—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances containing phosphorus
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- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Organic Chemistry (AREA)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Detergent Compositions (AREA)
Abstract
A B S T R A C T
"COMPOSITION AND METHOD FOR SCALE INHIBITION"
When a copolymer of styrene sulphonic acid and maleic anhydride or acid, and an organophosphonic acid especially 1-hydroxyethylidene-1,1-diphosphonic acid, are added to boiler water, the formation of scale is more effectively inhibited by this combination of additives than by the same concentration of either alone.
"COMPOSITION AND METHOD FOR SCALE INHIBITION"
When a copolymer of styrene sulphonic acid and maleic anhydride or acid, and an organophosphonic acid especially 1-hydroxyethylidene-1,1-diphosphonic acid, are added to boiler water, the formation of scale is more effectively inhibited by this combination of additives than by the same concentration of either alone.
Description
'7B
DESCRIPTION
"COMPOSITION AND METHOD FOR SCALE INHIBITION"
The formation of scale and sludge deposits on heating surfaces is the most serious problem encountered in industrial boiler operations. To combat the scale-forming tendency of entrained impurities, -such as calcium and magnesium salts, and iron, the boiler water is generally treated with a precipitating agent and a sludge conditioner, to maintain the sludge in a fluid and thereby prevent it from adhering to the boiler surface. The precipitating agents commonly employed for calcium salts are soda ash (sodium carbonate) and a sodium phosphate, eOg. disodium phosphate, trisodium phosphate, or sodium metaphosphate.
Magnesium is precipitated by the alkalinity of the boiler water as magnesium hydroxide. The resultant precipitate or sludge, which is made non-sticky and easily manageable by the addition of a sludge conditioner, is removed from the boiler through the "blowdown".
t'~lowdown" is the operation of exhausting the water, containing the fluid sludge, from the boiler by letting down the pressure within the boiler rapidLy).
Up to the present, tannins, lignins, starches, polyacrylates and polymethacrylates have been used as sludge conditioners.. However, they have not given compl.etely satis~actory resultsO
While no complete solut:ion to the problem has been found i.n the prior art, we have been fortunate in discoveri.ng an improved sludge-conditioning composition based upon the synergistic action o:f two components, which sati.sfactori.ly controls and prevents the occurrence of scale in a steam generating boil.er and is useful generally for inhibiting depositio}l of scale in aqueous systems~
The compositi.on of the present in~ention - , comprises (a) a cop~olymer of styrene sulphonic acid and A maleic anhydride~)or a water-soluble salt thereof and (b) a water-soluble organophosphonic acid having a carbon to phosphorus bond or a water soLuble salt thereof.
The invention also includes a methcd of inhibiting formation of scale i.n an aqueous medium, particularly water in a boiler, which comprises 20 maintaining in said medi.um from 0.01 to 500 ppm by weight of the above-defined components (a) and (b).
The components can be added sequentially or as a composition.
The most pxeferxed~organophosphonic acid is 25 . l-hydroxyethylidene~ di.phosphonic acid (HEDP for brevity)~ A water-sol.uble salt thereof is also _ ' .
1~14~
preferred.
The preferred general classes of organo-phosphoric acids for use in the invention are those of formulae A, B and C below:
HO \ O ¦ R1 \ O / OH
P _ ---C -- P \ IA) O R O
Il 13 II
(HO) 2=P --C - P=(OH) 2 (B) o o HO ~ / OH
P-CH2 ~ CH2-P
HO . OH
N-R'-N O (C) \11 / \ II OH
HO OH
wherein m is an integer from 1 to 10, Rl is hydrogen, or an alkyl group having from 1 to 4 carbon atoms-R2 is hydroxyl, hydrogen, or an alkyl group having from 1 to 4 carbon atoms, (and where m is 2 to 10, the Rl and R2 symbols do not necessarily have the same meaning in each occurrence ofRl and R2 respectively), R3 is an alkyl group having l to 10 carbon atoms, benzyl or phenyl and R' is an alkylene group having from l to 10 carbon atoms. Mixtures of two or more of any of these acids or water-soluble salts thereof can be used. HEDP falls within formula A.
Other specific illustrations of organophosphonic acids usable in the invention are those mentioned in the Examples hereinafter, including polyalkylene polyamine poly(meth~lene) phosphonic acids and other types of organophosphonic acid not all of which are within formu~ A, B and C above.
Copolymers of styrene sulphonic acid and maleic anhydride are well known and are available commercially. They can be made by the general process of reacting the copolymer of styrene and maleic anhydride dissolved in an inert, organic solvent such as methylene chloride or dichloroethane with a sulphur trioxide-organic phosphorus compound adduct.
The resultant copolymer of styrene sulphonic acid and maleic anhydride, being insoluble in the organic solvent, precipitates from the solution. A process for sulphonating the copolymer of styrene and maleic anhydride employing sulphur tri~xide-organic phosphorus compound adduct is described in United States Patent B 25 No. 3,072,618~fo 7~a ~ l~s~e~ ~n~a~ ~ J963r .
The compolymers of principal interest in this invention have molecular weights in the range of about 800 to 7,000,000. and more preferably about 4,000. The proportion of styrene sulphonic acid units of the polymer is generally from 2 to 98%, more usually and more preferably about 75%, of the copolymer.
The preferred weight ratio of copolymer or salt thereofo water-soluble organophosphonic acid or salt thereof is from 1:10 to 10:1, especially about 1:1.
In use, concentrations of the additive build-up in the boiler water to levels about ten times those in the feed waters. Thus, feed concentrations of about 2 ppm (see Table 2) and 5 ppm (see Table 3) will build up to about 20 and 50 ppm respectively in the boilerO A particularly suitable range of concentrations i~ the boiler is about 0.2-50 ppm, and most preferably about 20 ppm. A broad range, whether for feed water or boiler water, is about 0.01-500 ppm of additive.
~0 ~Lsk~, J~sveD J~ne 20, ~7~
B United States Patent No. 3,671,448~describes inhibiting formation of scale by use of a mixture of an amino alcohol and an organophosphonic acid or salt thereof. Comparative experiments referred to therein show that at both high and low temperatures l-hydroxyethylidene-l,l-diphosphonic acid does not _ ~
.
.
~ C~7a remain effective for very long.
t~ ~`L~ f Q/ ,'~-~e~/ Seff~b~r /3,/9~7 Our United States Patent ~o. 4,048,066~
describes the use for preventing formation of scale of a variety of polymeric additives. including 5 styrene sulphonic acid-maleic anhydride copolymers among themO It does not suggest that these copolymers are advantageous over the many other additives proposed and does not suggest the combination of any of the polymeric additives disclosed with an organophosphonic 10 acid, or salt thereof. As illustrated in Tables
DESCRIPTION
"COMPOSITION AND METHOD FOR SCALE INHIBITION"
The formation of scale and sludge deposits on heating surfaces is the most serious problem encountered in industrial boiler operations. To combat the scale-forming tendency of entrained impurities, -such as calcium and magnesium salts, and iron, the boiler water is generally treated with a precipitating agent and a sludge conditioner, to maintain the sludge in a fluid and thereby prevent it from adhering to the boiler surface. The precipitating agents commonly employed for calcium salts are soda ash (sodium carbonate) and a sodium phosphate, eOg. disodium phosphate, trisodium phosphate, or sodium metaphosphate.
Magnesium is precipitated by the alkalinity of the boiler water as magnesium hydroxide. The resultant precipitate or sludge, which is made non-sticky and easily manageable by the addition of a sludge conditioner, is removed from the boiler through the "blowdown".
t'~lowdown" is the operation of exhausting the water, containing the fluid sludge, from the boiler by letting down the pressure within the boiler rapidLy).
Up to the present, tannins, lignins, starches, polyacrylates and polymethacrylates have been used as sludge conditioners.. However, they have not given compl.etely satis~actory resultsO
While no complete solut:ion to the problem has been found i.n the prior art, we have been fortunate in discoveri.ng an improved sludge-conditioning composition based upon the synergistic action o:f two components, which sati.sfactori.ly controls and prevents the occurrence of scale in a steam generating boil.er and is useful generally for inhibiting depositio}l of scale in aqueous systems~
The compositi.on of the present in~ention - , comprises (a) a cop~olymer of styrene sulphonic acid and A maleic anhydride~)or a water-soluble salt thereof and (b) a water-soluble organophosphonic acid having a carbon to phosphorus bond or a water soLuble salt thereof.
The invention also includes a methcd of inhibiting formation of scale i.n an aqueous medium, particularly water in a boiler, which comprises 20 maintaining in said medi.um from 0.01 to 500 ppm by weight of the above-defined components (a) and (b).
The components can be added sequentially or as a composition.
The most pxeferxed~organophosphonic acid is 25 . l-hydroxyethylidene~ di.phosphonic acid (HEDP for brevity)~ A water-sol.uble salt thereof is also _ ' .
1~14~
preferred.
The preferred general classes of organo-phosphoric acids for use in the invention are those of formulae A, B and C below:
HO \ O ¦ R1 \ O / OH
P _ ---C -- P \ IA) O R O
Il 13 II
(HO) 2=P --C - P=(OH) 2 (B) o o HO ~ / OH
P-CH2 ~ CH2-P
HO . OH
N-R'-N O (C) \11 / \ II OH
HO OH
wherein m is an integer from 1 to 10, Rl is hydrogen, or an alkyl group having from 1 to 4 carbon atoms-R2 is hydroxyl, hydrogen, or an alkyl group having from 1 to 4 carbon atoms, (and where m is 2 to 10, the Rl and R2 symbols do not necessarily have the same meaning in each occurrence ofRl and R2 respectively), R3 is an alkyl group having l to 10 carbon atoms, benzyl or phenyl and R' is an alkylene group having from l to 10 carbon atoms. Mixtures of two or more of any of these acids or water-soluble salts thereof can be used. HEDP falls within formula A.
Other specific illustrations of organophosphonic acids usable in the invention are those mentioned in the Examples hereinafter, including polyalkylene polyamine poly(meth~lene) phosphonic acids and other types of organophosphonic acid not all of which are within formu~ A, B and C above.
Copolymers of styrene sulphonic acid and maleic anhydride are well known and are available commercially. They can be made by the general process of reacting the copolymer of styrene and maleic anhydride dissolved in an inert, organic solvent such as methylene chloride or dichloroethane with a sulphur trioxide-organic phosphorus compound adduct.
The resultant copolymer of styrene sulphonic acid and maleic anhydride, being insoluble in the organic solvent, precipitates from the solution. A process for sulphonating the copolymer of styrene and maleic anhydride employing sulphur tri~xide-organic phosphorus compound adduct is described in United States Patent B 25 No. 3,072,618~fo 7~a ~ l~s~e~ ~n~a~ ~ J963r .
The compolymers of principal interest in this invention have molecular weights in the range of about 800 to 7,000,000. and more preferably about 4,000. The proportion of styrene sulphonic acid units of the polymer is generally from 2 to 98%, more usually and more preferably about 75%, of the copolymer.
The preferred weight ratio of copolymer or salt thereofo water-soluble organophosphonic acid or salt thereof is from 1:10 to 10:1, especially about 1:1.
In use, concentrations of the additive build-up in the boiler water to levels about ten times those in the feed waters. Thus, feed concentrations of about 2 ppm (see Table 2) and 5 ppm (see Table 3) will build up to about 20 and 50 ppm respectively in the boilerO A particularly suitable range of concentrations i~ the boiler is about 0.2-50 ppm, and most preferably about 20 ppm. A broad range, whether for feed water or boiler water, is about 0.01-500 ppm of additive.
~0 ~Lsk~, J~sveD J~ne 20, ~7~
B United States Patent No. 3,671,448~describes inhibiting formation of scale by use of a mixture of an amino alcohol and an organophosphonic acid or salt thereof. Comparative experiments referred to therein show that at both high and low temperatures l-hydroxyethylidene-l,l-diphosphonic acid does not _ ~
.
.
~ C~7a remain effective for very long.
t~ ~`L~ f Q/ ,'~-~e~/ Seff~b~r /3,/9~7 Our United States Patent ~o. 4,048,066~
describes the use for preventing formation of scale of a variety of polymeric additives. including 5 styrene sulphonic acid-maleic anhydride copolymers among themO It does not suggest that these copolymers are advantageous over the many other additives proposed and does not suggest the combination of any of the polymeric additives disclosed with an organophosphonic 10 acid, or salt thereof. As illustrated in Tables
2 and 3 in the Examples hereinafter, compare especially Examples 2 and 4 and Examples 6 and 8. the combination of additives employed in the present invention gives greater scale reduction than is obtainable from the 15 same amount of styrene sulphonic acid-maleic anhydride copolymer alone. 7 The invention and in particular the synergistic effects of the components (a) and (b) is illustrated by the following Examp~es.
-, ' ~
EXAMP
Test: procedure used The tests were carri.ed out in a small labor,ator.-y boiler having three removabl.e tubes. T'he small laboratory boiler used has been described previously in the proceedings of the Fifteenth Annual Water Conference, Engineers Society of Western Pennsylvania, pages 87 102 (1954). Upon completion of a test, an unheated bGi,ler tube was removed from the boile-r, the scale or deposit present on 6 inches (15 cm) of the central lengt'h of the tube was removed (by scrapi.ng), collected and weighedO
The boiler feedwater was prepared by diluting Lake Zurich. Illinois, United States of America tap water with distilled water to 40 ppm total hardness as CaC03, followed by adjustment to a 6 to 1 elemental calcium to magnesium ratio using calcium chlorideO
The above boiler feed was fed to the boilers together with chemical treatment solutions (containing sodium sulphate, sodium sulphite, sodium hydroxide, sodium chloride, treatment agents consisti.ng of phosphate and sludge-conditioning reagents except in blank runs) in a ratio of 3 volumes of feedwater to 1 volume of chemical treatment solution, giving a feedwater of tota,l hardness 30 ppm as CaC03O
All scaling test.s, whether sludge-condi.tioning reagent was present or absent (blank), were carried out in the same way, as follows~ Boiler. blowdown was adjusted to LO% of the boiler feedwat.er, thereby concentrating salts in t.he boiler water by about 1,0 times. Using the feedwater described i.n the previous paragraph, t.he composition of the chemical t.reatment,.
solution was adjusted to gi.ve a boiler water (after the 10 concentrations) of t.he following compositi.ono Sodium Hydroxide as NaOH258 ppm 10 Sodium Carbonate as ~a2C03120 ppm Sodium ChLoride as NaC168L ppm Sodium Sulphite as ~a2S0350 ppm Sodium Sul.phate as ~a~S04819 ppm Silica as SiO2 l.ess than1 ppm 15 Iron as Fe less t'han1 ppm Phosphate as P04 10-20 ppm All scaling tests were run for 45 hours each at a boile:r pressure of 220 psi.g. (1.505 Kg/cm2 gauge)~
The boiler water sludge-conditioning properties of the synergistic mixture of copolymer of styrene sulphonic acid and maleic anhydride and HEDP at 2ppm in the feedwater are ill.ust;rated by Table 2 bel.owc ~ .. . . . . .
.
Example No. Additive 1 Blank (No additi.ve) 2 Copolymer of styrene sulphonic acid and maleic anhydride (3.1 by wt.) having a mol wt, of 4,000 (I)
-, ' ~
EXAMP
Test: procedure used The tests were carri.ed out in a small labor,ator.-y boiler having three removabl.e tubes. T'he small laboratory boiler used has been described previously in the proceedings of the Fifteenth Annual Water Conference, Engineers Society of Western Pennsylvania, pages 87 102 (1954). Upon completion of a test, an unheated bGi,ler tube was removed from the boile-r, the scale or deposit present on 6 inches (15 cm) of the central lengt'h of the tube was removed (by scrapi.ng), collected and weighedO
The boiler feedwater was prepared by diluting Lake Zurich. Illinois, United States of America tap water with distilled water to 40 ppm total hardness as CaC03, followed by adjustment to a 6 to 1 elemental calcium to magnesium ratio using calcium chlorideO
The above boiler feed was fed to the boilers together with chemical treatment solutions (containing sodium sulphate, sodium sulphite, sodium hydroxide, sodium chloride, treatment agents consisti.ng of phosphate and sludge-conditioning reagents except in blank runs) in a ratio of 3 volumes of feedwater to 1 volume of chemical treatment solution, giving a feedwater of tota,l hardness 30 ppm as CaC03O
All scaling test.s, whether sludge-condi.tioning reagent was present or absent (blank), were carried out in the same way, as follows~ Boiler. blowdown was adjusted to LO% of the boiler feedwat.er, thereby concentrating salts in t.he boiler water by about 1,0 times. Using the feedwater described i.n the previous paragraph, t.he composition of the chemical t.reatment,.
solution was adjusted to gi.ve a boiler water (after the 10 concentrations) of t.he following compositi.ono Sodium Hydroxide as NaOH258 ppm 10 Sodium Carbonate as ~a2C03120 ppm Sodium ChLoride as NaC168L ppm Sodium Sulphite as ~a2S0350 ppm Sodium Sul.phate as ~a~S04819 ppm Silica as SiO2 l.ess than1 ppm 15 Iron as Fe less t'han1 ppm Phosphate as P04 10-20 ppm All scaling tests were run for 45 hours each at a boile:r pressure of 220 psi.g. (1.505 Kg/cm2 gauge)~
The boiler water sludge-conditioning properties of the synergistic mixture of copolymer of styrene sulphonic acid and maleic anhydride and HEDP at 2ppm in the feedwater are ill.ust;rated by Table 2 bel.owc ~ .. . . . . .
.
Example No. Additive 1 Blank (No additi.ve) 2 Copolymer of styrene sulphonic acid and maleic anhydride (3.1 by wt.) having a mol wt, of 4,000 (I)
3 HEDP (II)
4 I + II (l:l by wto ) TABLE 2 (continued) Example Amount of Scale Scale NoO Formed, in G:rams Reduction, %
1 Oo 686 None 2 0O090 86a 9 3 0~094 8603 4 OOOOO lOOoO
Experiments were conducted for in-service cleaning of boilers with high-iron scaleO The laboratory boiler was first operated for 24 hours to bui.ld hydroxyapatite type scale on the heat.ing tubes, using a feedwater cont~ining 45 ppm (as CaC03) total hardness, 10 ppm (as Fe) of ferric chloride, and phosphate ionsO
';''B
In 24 hours, the average boiler scale produced on t:he 6-inch (15 cm) centre port-ion of the three heaters was 4.64 grams of hydroxyapatite with a large amount of iron. After the pre-scaling, the laboratory boiler test was continued for 45 hours using a low hardness feedwater (0.6 ppm as CaC03 total hardness) and 5 ppm of the treatment additive being tested. ~o phosphate and iron were addedO The experimental results are tabulated below.
Example No Additive Blank (~o additive) 6 Copolymer of styrene sulphonic acid and maleic anhydride (3:1 by wto) having a moL wt. of 4,000 (I) 7 HEDP (II) --8 I + II (1:1 by wt., iOe. 2.5 ppm of each) TABLE 3 (continuedj Example Amount of Scale Formed Scale ~o. _ (or Removed) in Grams red 0.02 ~one 6 (0.27) 5.8 7 (0.15) 3.2 8 (0.90) 19.4 ~' - . .
;'',' ' ~$~
The synergistic effect of the composition of the invention in preventing scale is evident from Tables 2 and 3.
The following compositions according to this invention would also be synergistically effective in inhibiting formation of scale when tested by the procedure above described.
EX~MPLE 9 Copolymer of sodium styrene sulphonate and maleic anhydride (9 1 by wt.) having a molecular weight of 500 ~ 000 90% and nitrilo tri(methylene phosphonic acid) 10%.
Copolymer of potassium styrene sulphonate and maleic anhydride tlo 5 by wt.) having a molecular weight of 1~200 35% and ethylenediamine tetra(methylene phosphonic acid) 65%~
Copolymer of styrene sulphonic acid and maleic acid ( 2 1 by wt.) having a molecular weight of 6,000 80% and hydroxypropylidene diphosphonic acid 20%o Copolymer of ammonium styrene sulphonate 25 and maleic anhydride (1:15 by wt.) having a molecular weight of 2,000,000 15% and potassium salt of HEDP 85%.
_ 12 -Copolymer of sodium styrene sulphonate and sodium maleate (1:2 by wt.) having a molecular weig~t of 15,000 10% and hexamethylenediamine tetra(methylene phosphonic acid) 90%.
Copolymer of styrene sulphonic acid and maleic anhydride (20:1 by wt.) having a molecular weight of 2,000 75% and sodium salt of diethylenetriamine penta(methylene phosphonic acid) 25%.
Copolymer of sodium styrene sulphonate and maleic anhydride (1:1 by wt.) having a molecular weight of 250,000 20% and aminoethylidene diphosphonic acid 80%. -Copolymer of styrene sulphonic acid and maleic anhydride (8:1 by wt.) having a molecular weight of 9,000 8% and HEDP 92%.
Copolymer of styrene sulphonic acid and maleic anhydride (4:1 by wt.) having a molecular weight of 50,000 70% and n-butylamino di(ethyl phosphonic acid) 30%.
Copolymer of styrene sulphonic acid and maleic 25 acid (3:1 by wt.) having a molecular weight of 3,000 55% and isopropyl phosphonic acid 45%.
?
1114~7B
_ 13 -Copolymer of potassium styrene sulphonate and maleic anhydride (1:8 by wt.) having a molecular weight of 250,000 40% and 2-phosphono-~ut.ane tricarboxylic acid-L,2,4 60%, Copolymer of styrene sulphonic acl.d and maleic anhydri.de (1:2 by wto) havi.ng a molecul.ar weight of 5,000 68%, 2-aminoethyl phosphonic acid 32%.
Copolymer of styrene sulphonic acid and maleic anhydride (5:1 by wto ~ having a molecular weight of 2.500 40%. sodium salt of t.etraethylenepentamine hepta(methylene phosphonic acid) 60%o Copolymer of styrene sulphonic acid and maleic anhydride ~1:9 by weight~ having a molecular weight of 700.000 25% and methylene diphosphoni.c acid 75%O
, ~ .
?
.
1 Oo 686 None 2 0O090 86a 9 3 0~094 8603 4 OOOOO lOOoO
Experiments were conducted for in-service cleaning of boilers with high-iron scaleO The laboratory boiler was first operated for 24 hours to bui.ld hydroxyapatite type scale on the heat.ing tubes, using a feedwater cont~ining 45 ppm (as CaC03) total hardness, 10 ppm (as Fe) of ferric chloride, and phosphate ionsO
';''B
In 24 hours, the average boiler scale produced on t:he 6-inch (15 cm) centre port-ion of the three heaters was 4.64 grams of hydroxyapatite with a large amount of iron. After the pre-scaling, the laboratory boiler test was continued for 45 hours using a low hardness feedwater (0.6 ppm as CaC03 total hardness) and 5 ppm of the treatment additive being tested. ~o phosphate and iron were addedO The experimental results are tabulated below.
Example No Additive Blank (~o additive) 6 Copolymer of styrene sulphonic acid and maleic anhydride (3:1 by wto) having a moL wt. of 4,000 (I) 7 HEDP (II) --8 I + II (1:1 by wt., iOe. 2.5 ppm of each) TABLE 3 (continuedj Example Amount of Scale Formed Scale ~o. _ (or Removed) in Grams red 0.02 ~one 6 (0.27) 5.8 7 (0.15) 3.2 8 (0.90) 19.4 ~' - . .
;'',' ' ~$~
The synergistic effect of the composition of the invention in preventing scale is evident from Tables 2 and 3.
The following compositions according to this invention would also be synergistically effective in inhibiting formation of scale when tested by the procedure above described.
EX~MPLE 9 Copolymer of sodium styrene sulphonate and maleic anhydride (9 1 by wt.) having a molecular weight of 500 ~ 000 90% and nitrilo tri(methylene phosphonic acid) 10%.
Copolymer of potassium styrene sulphonate and maleic anhydride tlo 5 by wt.) having a molecular weight of 1~200 35% and ethylenediamine tetra(methylene phosphonic acid) 65%~
Copolymer of styrene sulphonic acid and maleic acid ( 2 1 by wt.) having a molecular weight of 6,000 80% and hydroxypropylidene diphosphonic acid 20%o Copolymer of ammonium styrene sulphonate 25 and maleic anhydride (1:15 by wt.) having a molecular weight of 2,000,000 15% and potassium salt of HEDP 85%.
_ 12 -Copolymer of sodium styrene sulphonate and sodium maleate (1:2 by wt.) having a molecular weig~t of 15,000 10% and hexamethylenediamine tetra(methylene phosphonic acid) 90%.
Copolymer of styrene sulphonic acid and maleic anhydride (20:1 by wt.) having a molecular weight of 2,000 75% and sodium salt of diethylenetriamine penta(methylene phosphonic acid) 25%.
Copolymer of sodium styrene sulphonate and maleic anhydride (1:1 by wt.) having a molecular weight of 250,000 20% and aminoethylidene diphosphonic acid 80%. -Copolymer of styrene sulphonic acid and maleic anhydride (8:1 by wt.) having a molecular weight of 9,000 8% and HEDP 92%.
Copolymer of styrene sulphonic acid and maleic anhydride (4:1 by wt.) having a molecular weight of 50,000 70% and n-butylamino di(ethyl phosphonic acid) 30%.
Copolymer of styrene sulphonic acid and maleic 25 acid (3:1 by wt.) having a molecular weight of 3,000 55% and isopropyl phosphonic acid 45%.
?
1114~7B
_ 13 -Copolymer of potassium styrene sulphonate and maleic anhydride (1:8 by wt.) having a molecular weight of 250,000 40% and 2-phosphono-~ut.ane tricarboxylic acid-L,2,4 60%, Copolymer of styrene sulphonic acl.d and maleic anhydri.de (1:2 by wto) havi.ng a molecul.ar weight of 5,000 68%, 2-aminoethyl phosphonic acid 32%.
Copolymer of styrene sulphonic acid and maleic anhydride (5:1 by wto ~ having a molecular weight of 2.500 40%. sodium salt of t.etraethylenepentamine hepta(methylene phosphonic acid) 60%o Copolymer of styrene sulphonic acid and maleic anhydride ~1:9 by weight~ having a molecular weight of 700.000 25% and methylene diphosphoni.c acid 75%O
, ~ .
?
.
Claims (13)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A composition for adding to water which comprises (a) a copolymer of styrene sulphonic acid and maleic anhydride or acid, or a water-soluble salt thereof, and (b) a water-soluble organophosphonic acid having a carbon to phosphorus bond or a water-soluble salt thereof.
2. A composition according to claim 1 wherein the organophosphonic acid has the formula A, B or C below:
(A) (B) (C) wherein m is an integer from 1 to 10, R1 is hydrogen, or an alkyl group having from 1 to 4 carbon atoms, R2 is hydroxyl, hydrogen, or an alkyl group having from 1 to 4 carbon atoms, ( and where m is 2 to 10, the R1 and R2 symbols do not necessarily have the same meaning in each occurrence of R1 and R2 respectively). R3 is an alkyl group having 1 to 10 carbon atoms, benzyl or phenyl and R' is an alkylene group having from 1 to 10 carbon atoms.
(A) (B) (C) wherein m is an integer from 1 to 10, R1 is hydrogen, or an alkyl group having from 1 to 4 carbon atoms, R2 is hydroxyl, hydrogen, or an alkyl group having from 1 to 4 carbon atoms, ( and where m is 2 to 10, the R1 and R2 symbols do not necessarily have the same meaning in each occurrence of R1 and R2 respectively). R3 is an alkyl group having 1 to 10 carbon atoms, benzyl or phenyl and R' is an alkylene group having from 1 to 10 carbon atoms.
3. A composition according to claim 1 wherein the organophosphonic acid is 1-hydroxyethyl-idene-1,1-diphosphonic acid.
4. A composition according to claim 1, 2 or 3 in which the weight ratio of copolymer or salt thereof to the water-soluble organophosphonic acid or salt thereof is from 10:1 to 1:10.
5. A composition according to claim 3 consisting essentially of a copolymer of styrene sulphonic acid and maleic anhydride; and 1-hydroxy-ethylidene-1,1-diphosphonic acid.
6. A composition according to claim 1, 2 or 3, in which the copolymer of water-soluble salt thereof contains about 75% by weight of styrene sulphonic acid units and its molecular weight is about 4,000.
7. A composition according to claim 1 in which the organophosphonic acid is 2-phosphono-butane-1,2,4-tricarboxylic acid.
8. A method of inhibiting formation of scale in an aqueous medium, which comprises maintaining in said medium a total of 0.01 to 500 ppm of weight of (a) a copolymer of styrene sulphonic acid and maleic anhydride or acid, or a water-soluble salt thereof, and (b) a water-soluble organophosphonic acid having a carbon to phosphorus bond or a water-soluble salt thereof.
9. A method according to claim 8 which comprises adding components (a) and (b) to the water as a single composition containing these components.
10. A method according to claim 9 wherein the organophosphonic acid is 1-hydroxyethylidene-1,1-diphosphonic acid.
11. A method according to claim 10 in which the composition consists essentially of (a) a copolymer of styrene sulphonic acid and maleic anhydride; and (b) hydroxyethylidene diphosphonic acid, and the components (a) and (b) are maintained in the aqueous medium in a total concentration of about 20 ppm by weight.
12. A method according to claim 8 wherein the components (a) and (b) are introduced into boiler water.
13. A method according to claim 8 or 11 wherein the aqueous medium contains a scale-forming iron salt.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US91571378A | 1978-06-15 | 1978-06-15 | |
| US915,713 | 1978-06-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1114978A true CA1114978A (en) | 1981-12-22 |
Family
ID=25436161
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA328,648A Expired CA1114978A (en) | 1978-06-15 | 1979-05-30 | Sludge conditioning composition for scale inhibition in water |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS551897A (en) |
| CA (1) | CA1114978A (en) |
| DE (1) | DE2923718A1 (en) |
| ES (1) | ES481476A1 (en) |
| FR (1) | FR2431999A1 (en) |
| GB (1) | GB2023121B (en) |
| IT (1) | IT1121786B (en) |
| SE (1) | SE431533B (en) |
Families Citing this family (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| PT71647B (en) * | 1979-08-16 | 1982-01-21 | Calgon Corp | Process for preparing a composition for the control of scale and deposits in gas-liquid separation |
| US4306991A (en) | 1979-09-18 | 1981-12-22 | Chemed Corporation | Scale inhibition |
| CA1151498A (en) * | 1979-10-23 | 1983-08-09 | Dearborn Chemicals Ltd. | Treatment of aqueous systems |
| DE3230291A1 (en) * | 1981-08-18 | 1983-03-03 | Dearborn Chemicals Ltd., Widnes, Cheshire | COMPOSITION FOR PREVENTING KETTLE IN AQUEOUS SYSTEMS |
| US4409192A (en) * | 1982-04-26 | 1983-10-11 | Betz Laboratories, Inc. | Gas scrubbing methods |
| JPS58199877A (en) * | 1982-05-03 | 1983-11-21 | ナルコ・ケミカル・カンパニ− | Composition and method of preventing corrosion of ferrous metal |
| US4581145A (en) * | 1982-09-27 | 1986-04-08 | Dearborn Chemical Company | Composition and method for inhibiting scale |
| CA1207211A (en) * | 1982-09-27 | 1986-07-08 | Dionisio G. Cuisia | Composition and method for inhibiting scale |
| CA1224999A (en) * | 1983-02-16 | 1987-08-04 | Dionisio G. Cuisia | Composition and method for inhibiting scale |
| US4556493A (en) * | 1983-02-16 | 1985-12-03 | Dearborn Chemical Company | Composition and method for inhibiting scale |
| US4576722A (en) * | 1983-02-22 | 1986-03-18 | The Mogul Corporation | Scale and sludge compositions for aqueous systems |
| EP0210590A3 (en) * | 1983-03-07 | 1988-02-17 | Calgon Corporation | Polymeric additives for water |
| GB8311002D0 (en) * | 1983-04-22 | 1983-05-25 | Unilever Plc | Detergent compositions |
| JPS63176871A (en) * | 1987-01-17 | 1988-07-21 | Daihatsu Motor Co Ltd | Lubricating device for transmission |
| DE19514272C2 (en) * | 1995-04-21 | 1997-02-20 | Amtra Aquaristik Gmbh | Means and methods for regulating the hardness and pH of the water in freshwater aquariums |
| EP0785174A1 (en) * | 1996-01-22 | 1997-07-23 | Monsanto Europe S.A./N.V. | Use of triaminophosphonates in cement |
| US6310031B1 (en) | 1999-11-30 | 2001-10-30 | Amway Corporation | Method of inhibiting soil redeposition |
| CN107973425A (en) * | 2017-12-13 | 2018-05-01 | 攀枝花钢城集团瑞天安全环保有限公司 | Composite slow-corrosion scale resistor and preparation method thereof |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3549538A (en) * | 1967-06-22 | 1970-12-22 | Nalco Chemical Co | Scale inhibition and removal in steam generation |
| GB1414918A (en) * | 1973-02-14 | 1975-11-19 | Ciba Geigy Uk Ltd | Treatment of water to prevent the deposition of scale |
| US3890228A (en) * | 1973-04-13 | 1975-06-17 | Chemed Corp | Polyacrylate-polyphosphonic acid treatment in aqueous systems |
| IT1038850B (en) * | 1974-06-10 | 1979-11-30 | Grace W R & Co | PROCESS FOR WATER TREATMENT |
| JPS5175681A (en) * | 1974-12-26 | 1976-06-30 | Chemed Corp | MIZUJUNKANKEINITAISURU HORIAKURIRUSAN HOSUPPONSAN SHORIHO |
| CA1062983A (en) * | 1975-09-08 | 1979-09-25 | Joseph J. Schuck | Copolymers for the control of the formation and deposition of materials in aqueous mediums |
| JPS5827349B2 (en) * | 1975-11-25 | 1983-06-08 | 栗田工業株式会社 | Corrosion prevention composition in aqueous systems |
| SE435456B (en) * | 1976-01-07 | 1984-10-01 | Calgon Corp | COMPOSITION AND PROCEDURE TO CONTROL THE BUILDING OF THE FLAVOR IN GAS WASHER |
| GB1539974A (en) * | 1976-11-10 | 1979-02-07 | Ciba Geigy Ag | Method of inhibiting corrosion and scaling of metals in contact with water |
| US4048066A (en) * | 1976-11-17 | 1977-09-13 | Chemed Corporation | Method of inhibiting scale |
-
1979
- 1979-05-30 CA CA328,648A patent/CA1114978A/en not_active Expired
- 1979-06-11 IT IT23459/79A patent/IT1121786B/en active
- 1979-06-12 SE SE7905174A patent/SE431533B/en not_active IP Right Cessation
- 1979-06-12 FR FR7915042A patent/FR2431999A1/en active Granted
- 1979-06-12 JP JP7314479A patent/JPS551897A/en active Granted
- 1979-06-12 DE DE19792923718 patent/DE2923718A1/en not_active Ceased
- 1979-06-12 ES ES481476A patent/ES481476A1/en not_active Expired
- 1979-06-15 GB GB7920922A patent/GB2023121B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR2431999A1 (en) | 1980-02-22 |
| SE431533B (en) | 1984-02-13 |
| ES481476A1 (en) | 1980-07-01 |
| FR2431999B1 (en) | 1985-05-10 |
| JPS6152760B2 (en) | 1986-11-14 |
| IT1121786B (en) | 1986-04-23 |
| IT7923459A0 (en) | 1979-06-11 |
| GB2023121A (en) | 1979-12-28 |
| SE7905174L (en) | 1979-12-16 |
| DE2923718A1 (en) | 1979-12-20 |
| GB2023121B (en) | 1982-08-25 |
| JPS551897A (en) | 1980-01-09 |
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