CA1087480A - Gas scrubber scale and deposit control - Google Patents
Gas scrubber scale and deposit controlInfo
- Publication number
- CA1087480A CA1087480A CA269,079A CA269079A CA1087480A CA 1087480 A CA1087480 A CA 1087480A CA 269079 A CA269079 A CA 269079A CA 1087480 A CA1087480 A CA 1087480A
- Authority
- CA
- Canada
- Prior art keywords
- polymer
- scale inhibitor
- composition
- water
- carbon atoms
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- 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
-
- 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
- C02F5/145—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 combined with inorganic substances
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/49—Phosphorus-containing compounds
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Water Supply & Treatment (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Hydrology & Water Resources (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Inorganic Chemistry (AREA)
- Polymers & Plastics (AREA)
- Medicinal Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
- Treating Waste Gases (AREA)
- Detergent Compositions (AREA)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
Abstract
A B S T R A C T
Use of a high molecular weight polymer and a scale inhibitor to control deposit build-up in gas scrubbers.
Use of a high molecular weight polymer and a scale inhibitor to control deposit build-up in gas scrubbers.
Description
~37~
BA CK GROUND OF T~E IN VENTIOl~l During recent years, the number of wet scrubber systems installed to remove gaseous and particulate material from waste stack gases has increased tremendously. Additional such systems are on the drawing board now. These wet scrubbers are being used to clear effluent from boiler stacks, incinerator stacks~ lime kilns, foundries, blast furnaces, basic oxygen furnaces (BOF), open hearth unitsJ coke plants, paper mill recovery boilers, pet food manufacturing facilities, electric furnaces (steel and aluminum), smelters~, asphalt plants and many others.
One of the most important features of a scrubber system is the COntaCt cha~lber~, the device used to eFfect transfer of gaseous and/or i~
particulate matter from the gas to the water phase. Most wet scrubber systems involve a venturi, a packed bed, an orifice plate, ~L spray chamber or a turbulent bed. Some systems even use two contact chambers in series, for example, a venturi followed by a spray
BA CK GROUND OF T~E IN VENTIOl~l During recent years, the number of wet scrubber systems installed to remove gaseous and particulate material from waste stack gases has increased tremendously. Additional such systems are on the drawing board now. These wet scrubbers are being used to clear effluent from boiler stacks, incinerator stacks~ lime kilns, foundries, blast furnaces, basic oxygen furnaces (BOF), open hearth unitsJ coke plants, paper mill recovery boilers, pet food manufacturing facilities, electric furnaces (steel and aluminum), smelters~, asphalt plants and many others.
One of the most important features of a scrubber system is the COntaCt cha~lber~, the device used to eFfect transfer of gaseous and/or i~
particulate matter from the gas to the water phase. Most wet scrubber systems involve a venturi, a packed bed, an orifice plate, ~L spray chamber or a turbulent bed. Some systems even use two contact chambers in series, for example, a venturi followed by a spray
2 0 chamber .
. ` .
Venturi or orifice plate scrubbers are generally more efficient for particulate removal while paclced beds, turbulent beds and spray chambers are usually Inore efficient for removing gaseous components such as SO2 and HF.
L~
.- .
.'' ''.
i~ , , . , . - ., ...... . . ~ . , . . . . :
C..1154IA
~8~4~3~
The present invention is directed specifically to those scrubber systems where scaling and deposition problems due to insoluble calcium carbonate, calcium fluoride~, iron o~ide (Fe203)~ silica, manganese oxide~ iron ore fines and slag fines are encountered~ The type problem S which the present invention mi~limizes is that which is found in gas scrubber systems of blast furnace operations where iron ore is being converted or processed to iron having a high carbon content.
In order to assure a complete understanding of the problem to which the present invention is addressed, a brief description of a blast furnace operation is hereafter provided.
In the production of iron, iron ore is fed together with additional ingredients such as dolomite through the top of a blast furnace fired by coke. An air stream is blown upward frorn the bottom of the furnace through the subsequent molten materials~ The carbon of the coke reduces the iron ore (FezO3) to iron metal. The molten iron is tapped from the bottom of the furnace while the slag is tapped from the middle of the furnace. The by..product of the carbon reduction is of course a combination of carbon dioxide and carbon monoxide which reacts with the calcium present to form the troublesome scaleformerA calcium ZO carbonate and other solids: clay, slag, fines, etc.
. ~' .
As can be appreciated~ the air stream blown upward contributes significantly to the impurity content of the flue gas, thus putting an extreme burden on the scrubbing system. The particulate load in the ~ -scrubbing ~nediun~ ranges from about 1, 000 to 2, 000 parts per million 2S because of the particulate load of the flue gas. ~`
-''.
_ 2 - ~
9 ~79L~ C- 1 1 54IA
The scrubbers that are used in blast furnace gas clean~up are often of the Venturi design and treat the off~gases from the furnace.
These gases contain significant quantities of iron oxide~ whose fine particle si~7e allows it to be carried of~ in the gas stream. Also present may be coke fines, to a lesser extent and to some extent, particulate slag materials used, such as silicates and unused dolomitesO
The iron oxide has been subjected to high temperatures within the furnace and may therefore be in a sintered form of low surface activity.
Ho~vever, its fine particle size presents deposition problems in scrub~
bers and delivery lines.
Another example of an operative system is a basic oxygen furnace (BOF) in which the BOF receives molten metal from the blast furnace plus scrap, various alloys to meet specifications, and lime and fluorspar as a flux. Oxygen is introduced through a lance to remove impurities. The oxygen blow can release 4. 4 tons of dust per 220 ton heat. This dust must be removed fro~ the waste gas. The dust con sists o iron o~ide, lime and fluoride.
This particulate and soluble gases are removed from the waste gas in a wet scrubber. In the scrubber water the iron oxide, calcium fluoride and calcium carbonate combine to cause massive deposit build-up on the scrubber system intervals which result in inefficient scrubber operation and high maintenance costs. ~ -Prior art methods, such as the method set forth in U. S. Patent No. 3~ 880, 620, employ scale inhibitorsJ i. e., inorganic and organic phosphates; and low molecular weight polymeric dispersants This ',. ' . ' '
. ` .
Venturi or orifice plate scrubbers are generally more efficient for particulate removal while paclced beds, turbulent beds and spray chambers are usually Inore efficient for removing gaseous components such as SO2 and HF.
L~
.- .
.'' ''.
i~ , , . , . - ., ...... . . ~ . , . . . . :
C..1154IA
~8~4~3~
The present invention is directed specifically to those scrubber systems where scaling and deposition problems due to insoluble calcium carbonate, calcium fluoride~, iron o~ide (Fe203)~ silica, manganese oxide~ iron ore fines and slag fines are encountered~ The type problem S which the present invention mi~limizes is that which is found in gas scrubber systems of blast furnace operations where iron ore is being converted or processed to iron having a high carbon content.
In order to assure a complete understanding of the problem to which the present invention is addressed, a brief description of a blast furnace operation is hereafter provided.
In the production of iron, iron ore is fed together with additional ingredients such as dolomite through the top of a blast furnace fired by coke. An air stream is blown upward frorn the bottom of the furnace through the subsequent molten materials~ The carbon of the coke reduces the iron ore (FezO3) to iron metal. The molten iron is tapped from the bottom of the furnace while the slag is tapped from the middle of the furnace. The by..product of the carbon reduction is of course a combination of carbon dioxide and carbon monoxide which reacts with the calcium present to form the troublesome scaleformerA calcium ZO carbonate and other solids: clay, slag, fines, etc.
. ~' .
As can be appreciated~ the air stream blown upward contributes significantly to the impurity content of the flue gas, thus putting an extreme burden on the scrubbing system. The particulate load in the ~ -scrubbing ~nediun~ ranges from about 1, 000 to 2, 000 parts per million 2S because of the particulate load of the flue gas. ~`
-''.
_ 2 - ~
9 ~79L~ C- 1 1 54IA
The scrubbers that are used in blast furnace gas clean~up are often of the Venturi design and treat the off~gases from the furnace.
These gases contain significant quantities of iron oxide~ whose fine particle si~7e allows it to be carried of~ in the gas stream. Also present may be coke fines, to a lesser extent and to some extent, particulate slag materials used, such as silicates and unused dolomitesO
The iron oxide has been subjected to high temperatures within the furnace and may therefore be in a sintered form of low surface activity.
Ho~vever, its fine particle size presents deposition problems in scrub~
bers and delivery lines.
Another example of an operative system is a basic oxygen furnace (BOF) in which the BOF receives molten metal from the blast furnace plus scrap, various alloys to meet specifications, and lime and fluorspar as a flux. Oxygen is introduced through a lance to remove impurities. The oxygen blow can release 4. 4 tons of dust per 220 ton heat. This dust must be removed fro~ the waste gas. The dust con sists o iron o~ide, lime and fluoride.
This particulate and soluble gases are removed from the waste gas in a wet scrubber. In the scrubber water the iron oxide, calcium fluoride and calcium carbonate combine to cause massive deposit build-up on the scrubber system intervals which result in inefficient scrubber operation and high maintenance costs. ~ -Prior art methods, such as the method set forth in U. S. Patent No. 3~ 880, 620, employ scale inhibitorsJ i. e., inorganic and organic phosphates; and low molecular weight polymeric dispersants This ',. ' . ' '
3 _ `'' .
~ ~ ~ `
~ ~ ~ `
4~ C~ 1 1 54IA
approach has not been completely successful in preventing deposition and has resulted in increased treatment costs and frequent shutdowns for mechanical cleaning.
~ccordingly, it is an ob~ect of this invention to provide a composition and method of effectively preventing deposits in gas s crubber s .
It is a further object of th;s invention to provide a composition and method for preventing deposits in gas scrubbers which is economical and which minimizes the frequency of ~nechanically cleaning scrubber 1 0 equipment.
It is still a further object of this invention to provide a compo-sition and method of preventing deposits in gas scrubbers which is effective over a wide range of pH conditions, These and other objects of this invention are accomplished by 1~ the composition and method of this invention in which from about 0. 01 to about 100 ppm active ingredients, preferably from about .1 to about 10 ppm active ingredients, of a composition comprising a scale :
inhibitor and a high molecular weight polymer is maintained in the :
aqueous scrubbing medium. The ratio of scale inhibitor to high molecular weight polymer may be from about 1:10 to about 10 preferably from about 1:5 to about 5:1~ by weight.
' Suitable threshold scale inhibitors include phosphonates of the general formula:
, ~ ' ~ ' '' _ 4 ~.
, :~ - . . . . :, . . ... . .
C~115a~IA
R\ _ _ N ~ (CH2CH2)X ~ N- _ R
R/ ~ R_ n :
wherein. R is ... ..... .
O
_ CH2 -- P ~ OM
OM
is H, NH~L, alkali metal or combinations thereof;
n i6 0 to 6; and x is 1 to 6; and those of the general formula:
O R C) " I Ir HO _ P ~ C _ P ~ OH
t OH X OH
wherein X is c~ OH or ~ NH2 and R is an alkyl group of frorn 1 to 5 . ~ .., 15 carbon atoms. The most preferred cornpounds, however~, are amino ;
tris ~methylene phosphonic acid) and hydroxyethylidene-lg l-.diphos.~ ... .:phonic acid (HEDP) and water~soluble salts thereof.
' Also useful as threshold scale inhibitors are phosphates such .
as polyphosphates, as for example sodium polyphosphates and phos-Z0 phate esters of the formula:
., N ~ RDPO3M2 ] 3 :',',', ""~, whexein M may be .. H, r. NH2 or a monovalent metal ion and 1~ is an . ~: . -alkylene group having from 1 to 18 carbon atoms. Suitable polyphos- `
phates are disclosed in U. S. Patent Nos. 2, 337, 856, 2, 906, 599 and .:
3~ 213, 017. .~ . . ' , ~ 5 ..
,. .
'. .: " ' '.' ;, . ' : ~ : ' , ',` .' '.. '; " ' ' -.
7~B~ C~1154IA
Suitable high molecular weight polymers include any non..
ionic or anionic water_soluble polymer having a molecular weight of at least 100,000 and preferably at least 1,000,000. Examples of suitable polymers include polyacrylamides such as those set forth in U. S. Patent No. 3,085~j,916, polymers of 2.. acrylamido me'chyl propane sulfonic acid such as those set forth in U. S" Patent No. 3, 709, 816, and sulfonated polystyrenes such as those set forth in U. ~. Patent No. 3, 630, 937.
The invention is further illustrated by the following examples:
10 ppm of a composition comprising a high molecular weight copolymer of 2-acrylamido methyl propane sulfonic acid and acrylamide and a scale inhibitor Camino tris (methylene phosphonate)] in a weight :
ratio of 1:2, 5 was maintained in the water supply to a basic oxygen furnace recycle scrubber syste:m for 13 weeks at which time the .
system was visually inspected and no visible deposition was observed in the pumps, valves or sprays. This is in contrast to heavy fouling ;-~
of pumps, sprays and valves, which resulted in loss of gas washing and cooling efficiencies, thereby causing temporary loss of production, :
that occurred in a two-week period with no treatmentO Previously, ~ :
this system was heavily contaminated with calcium carbonate and -~
contained significant ams:>unts of ferric oxide.
i :
6. 6 ppm of a composition comprising a high molecular weight .
Z5 copolymer of 2.. acrylamido methyl propane sulfonic acid and acrylamide .
':
- 6 _ - : . , 37~D c~ 1 1 54IA
and a scale inhibitor [a~nino tris (methylene phosphonate)] in a weight ratio of 1:2. 5 was maintained in the water supply to a basic oxygen furnace quencher and venturi scrubber system that had a severe build-up of calcium fluoride, iron oxide and calcium carbonate.
After 1600 heats, the system was inspected and the gas ducts~, scupper gratings and nozzles were observed to be clean, ~ 5 ppm of a composition comprising a high molecular weight copolymer of 2.-acrylamido methyl propane sulfonic acid and acrylamide .
and a scale inhibitor Camino tris (methylene phosphonate)] in a weight ratio o 1:2, 5 was maintained in the water supply to a blast furnace scrubber system having heavy iron deposits, which had previously resulted in an increase in the top pressure in the furnace resulting in furnace production loss and shutdown for descaling within one week when a low molecular weight (approximately 1000) polyacrylate and . . ~.
.~ amino tris (methylene phosphonate) were used. After six weeks of . ;
treatment with the high molecular weight polymer/scale inhibitor compositions of this invention, no pressure increase or build_up was .
observed and the system is operating normally.
~.
EXAMPLE 4 :~
` In order to si}nulate conditions in a gas scrubber system, a ~.
synthetic water was prepared which had a pH of 12. 0, a suspended ;:
solids (hydrated ferric oxide) concentration of 2000 mg/l, a sodium hydroxide concentration of 200 mg/l, a sodium bicarbonate concen-tration of 260 mg/l, a calcium concentration of 450 mg/l and a fluoride concentration of 40 mg/l. The water was maintained at a .
7~
temperature of 140+4F. and circulated through the test system at a linear velocity of between 3 and 4 ft. /sec. The test system contained an unheated test section (12 inches long), a heated section (12 inches long), a spray section and a drain section. The inhibitor was added to the synthetic water which was then circulated through the system for five hours at which time the system was shut down and the test sections weighed and the percent inhibition calculated in accordance with the following formula: ~ -rwt. of deposit (inhibited)l % inhibition = 1 - l wt. of deposit (control) ~ x The results of these tests are set forth in Table I.
,, Table I
Weight Gained in Grams ProductConcentration (unheated, heated, %
Test # and Ratio (ppm) drain) Inhibition Control - - 8.21 -8. 325 10. 425 Calgon/ 5, 0 3.29 59. 9 Polymer 1 2. 91 65. 0 1:1 1. 31 87. 4 2 AMP/ 5. 0 0. 88 89. 3 Polymer 1 0. 59 92. 9 1:1 1.16 88.9 3 r~EDP/ 5. 0 1. 67 79. 7 Polymer 1 1.56 81.3 1:1 0 97 90 7 4 Calgon/ 5. 0 0. 50 93. 9 Polymer 2 0. 68 91. 8 1:1 1. 20 88. 5 ~MPj 5. 0 0. 69 91. 6 Polyxner 2 0. 60 92. 8 ` 1:1 1.23 8~.2 -~
' - .
- 8 - ~
''"' ' :, : ~', , , , . . - :, ~7~
Table I (Continued) Weight Gained in Grams ProductConcentration(unheated, heated, %
Test # and Ratio(ppm) drain) Inhibition 6 HEDP/ 5. 0 0. 80 90. 3 Polymer 2 o 55 93 4 1: 1 1. 41 86. 5 .
7 Calgon/ 10. 0 0. 42 94, 9 Polymer 3 0.45 94.6 1:5 1.42 86.4 8 AMP/ 5. 0 8. 35 - 1. 7*
Polymer 3 6.25 24. 9
approach has not been completely successful in preventing deposition and has resulted in increased treatment costs and frequent shutdowns for mechanical cleaning.
~ccordingly, it is an ob~ect of this invention to provide a composition and method of effectively preventing deposits in gas s crubber s .
It is a further object of th;s invention to provide a composition and method for preventing deposits in gas scrubbers which is economical and which minimizes the frequency of ~nechanically cleaning scrubber 1 0 equipment.
It is still a further object of this invention to provide a compo-sition and method of preventing deposits in gas scrubbers which is effective over a wide range of pH conditions, These and other objects of this invention are accomplished by 1~ the composition and method of this invention in which from about 0. 01 to about 100 ppm active ingredients, preferably from about .1 to about 10 ppm active ingredients, of a composition comprising a scale :
inhibitor and a high molecular weight polymer is maintained in the :
aqueous scrubbing medium. The ratio of scale inhibitor to high molecular weight polymer may be from about 1:10 to about 10 preferably from about 1:5 to about 5:1~ by weight.
' Suitable threshold scale inhibitors include phosphonates of the general formula:
, ~ ' ~ ' '' _ 4 ~.
, :~ - . . . . :, . . ... . .
C~115a~IA
R\ _ _ N ~ (CH2CH2)X ~ N- _ R
R/ ~ R_ n :
wherein. R is ... ..... .
O
_ CH2 -- P ~ OM
OM
is H, NH~L, alkali metal or combinations thereof;
n i6 0 to 6; and x is 1 to 6; and those of the general formula:
O R C) " I Ir HO _ P ~ C _ P ~ OH
t OH X OH
wherein X is c~ OH or ~ NH2 and R is an alkyl group of frorn 1 to 5 . ~ .., 15 carbon atoms. The most preferred cornpounds, however~, are amino ;
tris ~methylene phosphonic acid) and hydroxyethylidene-lg l-.diphos.~ ... .:phonic acid (HEDP) and water~soluble salts thereof.
' Also useful as threshold scale inhibitors are phosphates such .
as polyphosphates, as for example sodium polyphosphates and phos-Z0 phate esters of the formula:
., N ~ RDPO3M2 ] 3 :',',', ""~, whexein M may be .. H, r. NH2 or a monovalent metal ion and 1~ is an . ~: . -alkylene group having from 1 to 18 carbon atoms. Suitable polyphos- `
phates are disclosed in U. S. Patent Nos. 2, 337, 856, 2, 906, 599 and .:
3~ 213, 017. .~ . . ' , ~ 5 ..
,. .
'. .: " ' '.' ;, . ' : ~ : ' , ',` .' '.. '; " ' ' -.
7~B~ C~1154IA
Suitable high molecular weight polymers include any non..
ionic or anionic water_soluble polymer having a molecular weight of at least 100,000 and preferably at least 1,000,000. Examples of suitable polymers include polyacrylamides such as those set forth in U. S. Patent No. 3,085~j,916, polymers of 2.. acrylamido me'chyl propane sulfonic acid such as those set forth in U. S" Patent No. 3, 709, 816, and sulfonated polystyrenes such as those set forth in U. ~. Patent No. 3, 630, 937.
The invention is further illustrated by the following examples:
10 ppm of a composition comprising a high molecular weight copolymer of 2-acrylamido methyl propane sulfonic acid and acrylamide and a scale inhibitor Camino tris (methylene phosphonate)] in a weight :
ratio of 1:2, 5 was maintained in the water supply to a basic oxygen furnace recycle scrubber syste:m for 13 weeks at which time the .
system was visually inspected and no visible deposition was observed in the pumps, valves or sprays. This is in contrast to heavy fouling ;-~
of pumps, sprays and valves, which resulted in loss of gas washing and cooling efficiencies, thereby causing temporary loss of production, :
that occurred in a two-week period with no treatmentO Previously, ~ :
this system was heavily contaminated with calcium carbonate and -~
contained significant ams:>unts of ferric oxide.
i :
6. 6 ppm of a composition comprising a high molecular weight .
Z5 copolymer of 2.. acrylamido methyl propane sulfonic acid and acrylamide .
':
- 6 _ - : . , 37~D c~ 1 1 54IA
and a scale inhibitor [a~nino tris (methylene phosphonate)] in a weight ratio of 1:2. 5 was maintained in the water supply to a basic oxygen furnace quencher and venturi scrubber system that had a severe build-up of calcium fluoride, iron oxide and calcium carbonate.
After 1600 heats, the system was inspected and the gas ducts~, scupper gratings and nozzles were observed to be clean, ~ 5 ppm of a composition comprising a high molecular weight copolymer of 2.-acrylamido methyl propane sulfonic acid and acrylamide .
and a scale inhibitor Camino tris (methylene phosphonate)] in a weight ratio o 1:2, 5 was maintained in the water supply to a blast furnace scrubber system having heavy iron deposits, which had previously resulted in an increase in the top pressure in the furnace resulting in furnace production loss and shutdown for descaling within one week when a low molecular weight (approximately 1000) polyacrylate and . . ~.
.~ amino tris (methylene phosphonate) were used. After six weeks of . ;
treatment with the high molecular weight polymer/scale inhibitor compositions of this invention, no pressure increase or build_up was .
observed and the system is operating normally.
~.
EXAMPLE 4 :~
` In order to si}nulate conditions in a gas scrubber system, a ~.
synthetic water was prepared which had a pH of 12. 0, a suspended ;:
solids (hydrated ferric oxide) concentration of 2000 mg/l, a sodium hydroxide concentration of 200 mg/l, a sodium bicarbonate concen-tration of 260 mg/l, a calcium concentration of 450 mg/l and a fluoride concentration of 40 mg/l. The water was maintained at a .
7~
temperature of 140+4F. and circulated through the test system at a linear velocity of between 3 and 4 ft. /sec. The test system contained an unheated test section (12 inches long), a heated section (12 inches long), a spray section and a drain section. The inhibitor was added to the synthetic water which was then circulated through the system for five hours at which time the system was shut down and the test sections weighed and the percent inhibition calculated in accordance with the following formula: ~ -rwt. of deposit (inhibited)l % inhibition = 1 - l wt. of deposit (control) ~ x The results of these tests are set forth in Table I.
,, Table I
Weight Gained in Grams ProductConcentration (unheated, heated, %
Test # and Ratio (ppm) drain) Inhibition Control - - 8.21 -8. 325 10. 425 Calgon/ 5, 0 3.29 59. 9 Polymer 1 2. 91 65. 0 1:1 1. 31 87. 4 2 AMP/ 5. 0 0. 88 89. 3 Polymer 1 0. 59 92. 9 1:1 1.16 88.9 3 r~EDP/ 5. 0 1. 67 79. 7 Polymer 1 1.56 81.3 1:1 0 97 90 7 4 Calgon/ 5. 0 0. 50 93. 9 Polymer 2 0. 68 91. 8 1:1 1. 20 88. 5 ~MPj 5. 0 0. 69 91. 6 Polyxner 2 0. 60 92. 8 ` 1:1 1.23 8~.2 -~
' - .
- 8 - ~
''"' ' :, : ~', , , , . . - :, ~7~
Table I (Continued) Weight Gained in Grams ProductConcentration(unheated, heated, %
Test # and Ratio(ppm) drain) Inhibition 6 HEDP/ 5. 0 0. 80 90. 3 Polymer 2 o 55 93 4 1: 1 1. 41 86. 5 .
7 Calgon/ 10. 0 0. 42 94, 9 Polymer 3 0.45 94.6 1:5 1.42 86.4 8 AMP/ 5. 0 8. 35 - 1. 7*
Polymer 3 6.25 24. 9
5:1 11. 54 -10.7* - ~
9 HEDP/ 0. 1 0. 52 93, 7 ~:
Polymer 3 0. 46 94. 5 :
1:1 1.80 82.7 Calgon/ 10. 0 3. 50 57. 4 Polymer 4 3. 31 60. 2 1:5 4.23 59. 4 11 AMP/ 5.0 5.98 27.2 Polymer 4 5. 38 35.4 5:1 f~. 38 38. 8 12 HEDP/ 0. 1 2.21 73. 1 Polymer 4 1. 80 78. 4 1: 1 1. 53 85. 3 13 Calgon/ 0. 1 0. 34 95. 9 Polymer 5 0. 33 96. 0 1:1 0.60 94.2 14 AMP/ 10. 0 1. 49 81. 9 Polymer 5 1. 40 83. 2 :5 *~'c *~ic HEDP/ 5. 0 2. 68 67. 4 Polymer 5 2. 16 74. 1 5:1 1. 99 80. 9 ~'c Values reflect weight gain greater than control value.
** Weights of drain section were not taken since heavy flocculation resulted in more mechanical entrapment than deposit accumulation. -~
. .
:' 7~
Table I (Continued) Weight Gained in Grams ProductConcentration(unheated, heated, %
Test # and Ratio~ppm) drain~ Inhibition 16 Calgon/ 0. 1 0. 62 92. 4 Polymer 6 0. 61 92. 7 1:1 1.65 84.2 17 AMP/ 10. 0 2. 22 73. 0 Polymer 6 2. 07 75. 1 1:5 2.86 72.6 18 HEDP/ 5. 0 4. 31 47. 5 Polymer 6 3. 80 54. 4 5:1 Z.70 74.1 19 Calgon/ 5. 0 0. 43 94. 8 Polymer 7 0. 51 93. 9 5:1 1. 02 90, 2 AMP/ 0. 1 0. 67 91. 8 Polymer 7 0. 57 93. 2 ~ -1:1 0. 44 95. 8 21 HEDP/ 10.0 0. 66 92. 0 Polymer 7 0. 86 89. 7 1:5 1.14 89.1 22 Calgon/ 5. 0 0. 57 93. 1 Polymer 8 0. 58 93. 0 5:1 1.59 84.7 Z3 AMP/ 0. 1 0. 72 91. 2 Polymer 8 0. 51 93. 9 1:1 1.27 87.8 24 HEDP/ 10. 0 1. 84 77. 6 Polymer 8 1. 70 79. 6 115 ~.64 84.3 :
~L~i~37~ c 11 54IA
Pr oduct De signations Calgon sodium hexametaphosphate AMP amino tris (methylene phosphonic acid) HEDP l-hydroxyethylidene~ diphosphonic acid Polymer 1 49/51 copoly~ner of acrylamide and 2-acrylamido-Z-methyl propane-l-sulfonic acid having a molecular weight of appr oximately 1, 000, 000 Polymer 2 homopolymer of 2-acrylamido-2-methyl propane-l-sulfonic acid having a molecular :
weight of approximately S00, 000 Polymer 3 high molecular weight ~mhydrolyzed poly-acrylamide having a molecular weight of .
approximately 1, 000, 000 Polymer 4 low molecular weight sodium acrylate having a molecular weight of approximately 700-1, 000 Polymer 5 high molecular weight hydrolyzed (15%) polyacrylamide having a molecular weight of appr oximately 1, 00 0, 000 : Polymer 6 low molecular weight hydrolyzed (50%) polyacrylamide having a molecular weight of approxi~nately 8, 000 Polymer 7 sulfonated polystyrene having a molecular weight of approximately 700, 000 Polyrner 8 sulfonated polystyrene having a molecular weight c~f apprwrimately 6, 000-8, 000 '; ~
.
.
~. ~ , .. :' -
9 HEDP/ 0. 1 0. 52 93, 7 ~:
Polymer 3 0. 46 94. 5 :
1:1 1.80 82.7 Calgon/ 10. 0 3. 50 57. 4 Polymer 4 3. 31 60. 2 1:5 4.23 59. 4 11 AMP/ 5.0 5.98 27.2 Polymer 4 5. 38 35.4 5:1 f~. 38 38. 8 12 HEDP/ 0. 1 2.21 73. 1 Polymer 4 1. 80 78. 4 1: 1 1. 53 85. 3 13 Calgon/ 0. 1 0. 34 95. 9 Polymer 5 0. 33 96. 0 1:1 0.60 94.2 14 AMP/ 10. 0 1. 49 81. 9 Polymer 5 1. 40 83. 2 :5 *~'c *~ic HEDP/ 5. 0 2. 68 67. 4 Polymer 5 2. 16 74. 1 5:1 1. 99 80. 9 ~'c Values reflect weight gain greater than control value.
** Weights of drain section were not taken since heavy flocculation resulted in more mechanical entrapment than deposit accumulation. -~
. .
:' 7~
Table I (Continued) Weight Gained in Grams ProductConcentration(unheated, heated, %
Test # and Ratio~ppm) drain~ Inhibition 16 Calgon/ 0. 1 0. 62 92. 4 Polymer 6 0. 61 92. 7 1:1 1.65 84.2 17 AMP/ 10. 0 2. 22 73. 0 Polymer 6 2. 07 75. 1 1:5 2.86 72.6 18 HEDP/ 5. 0 4. 31 47. 5 Polymer 6 3. 80 54. 4 5:1 Z.70 74.1 19 Calgon/ 5. 0 0. 43 94. 8 Polymer 7 0. 51 93. 9 5:1 1. 02 90, 2 AMP/ 0. 1 0. 67 91. 8 Polymer 7 0. 57 93. 2 ~ -1:1 0. 44 95. 8 21 HEDP/ 10.0 0. 66 92. 0 Polymer 7 0. 86 89. 7 1:5 1.14 89.1 22 Calgon/ 5. 0 0. 57 93. 1 Polymer 8 0. 58 93. 0 5:1 1.59 84.7 Z3 AMP/ 0. 1 0. 72 91. 2 Polymer 8 0. 51 93. 9 1:1 1.27 87.8 24 HEDP/ 10. 0 1. 84 77. 6 Polymer 8 1. 70 79. 6 115 ~.64 84.3 :
~L~i~37~ c 11 54IA
Pr oduct De signations Calgon sodium hexametaphosphate AMP amino tris (methylene phosphonic acid) HEDP l-hydroxyethylidene~ diphosphonic acid Polymer 1 49/51 copoly~ner of acrylamide and 2-acrylamido-Z-methyl propane-l-sulfonic acid having a molecular weight of appr oximately 1, 000, 000 Polymer 2 homopolymer of 2-acrylamido-2-methyl propane-l-sulfonic acid having a molecular :
weight of approximately S00, 000 Polymer 3 high molecular weight ~mhydrolyzed poly-acrylamide having a molecular weight of .
approximately 1, 000, 000 Polymer 4 low molecular weight sodium acrylate having a molecular weight of approximately 700-1, 000 Polymer 5 high molecular weight hydrolyzed (15%) polyacrylamide having a molecular weight of appr oximately 1, 00 0, 000 : Polymer 6 low molecular weight hydrolyzed (50%) polyacrylamide having a molecular weight of approxi~nately 8, 000 Polymer 7 sulfonated polystyrene having a molecular weight of approximately 700, 000 Polyrner 8 sulfonated polystyrene having a molecular weight c~f apprwrimately 6, 000-8, 000 '; ~
.
.
~. ~ , .. :' -
Claims (19)
1. A composition useful for controlling deposit build-up in gas scrubbers consisting essentially of a scale inhibitor selected from the group consisting of:
a. phosphonates of the general formula:
wherein R is M is H, NH4, alkali metal or combinations thereof;
n is 0 to 6; and x is 1 to 6;
b. phosphonates of the general formula:
wherein X is -OH or -NH2 and R is an alkyl group of from 1 to 5 carbon atoms; and c. sodium polyphosphates and phosphate esters of the formula:
wherein M may be -H, - NH2 or a monovalent metal ion and R is an alkylene group having from 1 to 18 carbon atoms; and at least one water-soluble polymer selected from the group con-sisting of polyacrylamides, poly(2-acrylamido methyl propane sulfonic acid) and sulfonated polystyrenes, said polymer having a molecular weight of at least 250,000 wherein the ratio of scale inhibitor to polymer is from about 1:10 to about 10:1 by weight.
a. phosphonates of the general formula:
wherein R is M is H, NH4, alkali metal or combinations thereof;
n is 0 to 6; and x is 1 to 6;
b. phosphonates of the general formula:
wherein X is -OH or -NH2 and R is an alkyl group of from 1 to 5 carbon atoms; and c. sodium polyphosphates and phosphate esters of the formula:
wherein M may be -H, - NH2 or a monovalent metal ion and R is an alkylene group having from 1 to 18 carbon atoms; and at least one water-soluble polymer selected from the group con-sisting of polyacrylamides, poly(2-acrylamido methyl propane sulfonic acid) and sulfonated polystyrenes, said polymer having a molecular weight of at least 250,000 wherein the ratio of scale inhibitor to polymer is from about 1:10 to about 10:1 by weight.
2. A composition as in Claim 1, wherein the scale inhibitor is amino tris(methylene phosphonate).
3. A composition as in Claim 1, wherein the polymer is a copolymer of acrylamide and 2-acrylamido methyl propane sulfonic acid or its water-soluble salt.
4. A composition as in Claim 1, wherein the polymer is a polyacrylamide.
5. A composition as in Claim 1, wherein the polymer is sulfonated polystyrene.
6. A composition as in Claim 1, wherein the scale inhibitor is a polyphosphate.
7. A composition as in Claim 6, wherein the poly-phosphate is sodium hexametaphosphate.
8. A composition as in Claim 1, wherein the scale inhibitor is a phosphonate of the formula:
wherein X is - OH or - NH2 and R is an alkyl group of from 1 to 5 carbon atoms, or a water-soluble salt thereof.
wherein X is - OH or - NH2 and R is an alkyl group of from 1 to 5 carbon atoms, or a water-soluble salt thereof.
9. A composition as in Claim 8, wherein the scale inhibitor is hydroxyethylene-1,1-diphosphonic acid or a water-soluble salt thereof.
10. A composition useful for con-trolling deposit build-up in gas scrubbers consisting essentially of amino tris(methylene phosphonate) and a copolymer of acrylamide and 2-acrylamido methyl propane sulfonic acid or its water-soluble salts having a molecular weight of at least 250,000 wherein the weight ratio of phosphonate to polymer is from 1:5 to 5:1.
11. A method of controlling deposit build-up in gas scrubbers which comprises maintaining in the aqueous scrubbing medium at least 0.01 ppm of a composition consisting essentially of a scale inhibitor selected from the group consisting of:
a. phosphonates of the general formula:
wherein R is M is H, NH4, alkali metal or combinations thereof;
n is 0 to 6; and x is 1 to 6;
b. phosphonates of the general formula:
wherein X is -OH or -NH2 and R is an alkyl group of from 1 to 5 carbon atoms; and c. sodium polyphosphates and phosphate esters of the formula:
wherein M may be -H, -NH2 or a monovalent metal ion and R is an alkylene group having from 1 to 18 carbon atoms; and at least one water-soluble polymer selected from the group con-sisting of polyacrylamides, poly(2-acrylamido methyl propane sulfonic acid) and sulfonated polystyrenes, said polymer having a molecular weight of at least 250,000, wherein the ratio of scale inhibitor to polymer is from about 1:10 to about 10:1 by weight.
a. phosphonates of the general formula:
wherein R is M is H, NH4, alkali metal or combinations thereof;
n is 0 to 6; and x is 1 to 6;
b. phosphonates of the general formula:
wherein X is -OH or -NH2 and R is an alkyl group of from 1 to 5 carbon atoms; and c. sodium polyphosphates and phosphate esters of the formula:
wherein M may be -H, -NH2 or a monovalent metal ion and R is an alkylene group having from 1 to 18 carbon atoms; and at least one water-soluble polymer selected from the group con-sisting of polyacrylamides, poly(2-acrylamido methyl propane sulfonic acid) and sulfonated polystyrenes, said polymer having a molecular weight of at least 250,000, wherein the ratio of scale inhibitor to polymer is from about 1:10 to about 10:1 by weight.
12. A method as in Claim 11, wherein the polymer is sulfonated polystyrene.
13. A method as in Claim 11, wherein the polymer is a polyacrylamide.
14. A method as in Claim 11, wherein the polymer is a copolymer of acrylamide and 2-acrylamido methyl propane sulfonic acid or its water-soluble salts.
15. A method as in Claim 11, wherein the scale inhibitor is amino tris(methylene phosphonate).
16. A method as in Claim 11, wherein the scale inhibitor is a phosphonate of the formula:
wherein X is -OH or -NH2 and R is an alkyl group of from 1 to 5 carbon atoms, or a water-soluble salt thereof.
wherein X is -OH or -NH2 and R is an alkyl group of from 1 to 5 carbon atoms, or a water-soluble salt thereof.
17. A method as in Claim 16, wherein -the scale inhibitor is hydroxyethylidene-1,1-diphosphonic acid or a water-soluble salt thereof.
18. A method as in Claim 11, wherein the poly-phosphate is sodium hexametaphosphate.
19. A method as in Claim 11, wherein the scale inhibitor is a polyphosphate.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US64725376A | 1976-01-07 | 1976-01-07 | |
| US647,253 | 1976-01-07 | ||
| US73372376A | 1976-10-26 | 1976-10-26 | |
| US733,723 | 1976-10-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1087480A true CA1087480A (en) | 1980-10-14 |
Family
ID=27095118
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA269,079A Expired CA1087480A (en) | 1976-01-07 | 1977-01-04 | Gas scrubber scale and deposit control |
Country Status (15)
| Country | Link |
|---|---|
| JP (1) | JPS52110288A (en) |
| BR (1) | BR7608838A (en) |
| CA (1) | CA1087480A (en) |
| CH (1) | CH624368A5 (en) |
| DE (1) | DE2700347A1 (en) |
| DK (1) | DK153367C (en) |
| FI (1) | FI763638A (en) |
| FR (1) | FR2337694A1 (en) |
| GB (1) | GB1532391A (en) |
| IE (1) | IE44558B1 (en) |
| IT (1) | IT1121700B (en) |
| LU (1) | LU76525A1 (en) |
| NL (1) | NL185221C (en) |
| NO (1) | NO144619C (en) |
| SE (1) | SE435456B (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2019826B (en) * | 1978-04-28 | 1982-06-23 | Martin Marietta Corp | Process of removing oxides of sulphur from gases sludge resulting from process and product comprising lime or limestone |
| CA1114978A (en) * | 1978-06-15 | 1981-12-22 | Chih M. Hwa | Sludge conditioning composition for scale inhibition in water |
| JPS55109432A (en) * | 1979-02-19 | 1980-08-22 | Kurita Water Ind Ltd | Deodorizing method |
| US4342733A (en) * | 1981-01-09 | 1982-08-03 | Betz Laboratories, Inc. | Method of improving sulfite antioxidant performance in high solids scrubbers |
| DE3230291A1 (en) * | 1981-08-18 | 1983-03-03 | Dearborn Chemicals Ltd., Widnes, Cheshire | COMPOSITION FOR PREVENTING KETTLE IN AQUEOUS SYSTEMS |
| DE3249178T1 (en) * | 1982-01-29 | 1984-09-06 | Dearborn Chemical Co., Lake Zurich, Ill. | Process for suppressing corrosion of iron-based metals |
| CA1207211A (en) * | 1982-09-27 | 1986-07-08 | Dionisio G. Cuisia | Composition and method for inhibiting scale |
| US4469663A (en) * | 1982-10-15 | 1984-09-04 | The Dow Chemical Company | Scale control in flue gas desulfurization |
| CA1258963A (en) * | 1983-03-07 | 1989-09-05 | Bennett P. Boffardi | Synergistic scale and corrosion inhibiting admixtures containing carboxylic acid/sulfonic acid polymers |
| DE3317126C2 (en) * | 1983-05-06 | 1986-07-24 | Mannesmann AG, 4000 Düsseldorf | Process to avoid acid corrosion on continuous casting plants |
| US4671934A (en) * | 1986-04-18 | 1987-06-09 | Buckman Laboratories, Inc. | Aminophosphonic acid/phosphate mixtures for controlling corrosion of metal and inhibiting calcium phosphate precipitation |
| US4872996A (en) * | 1987-03-13 | 1989-10-10 | The Dow Chemical Company | Use of aminophosphonic acids to inhibit scale formation and corrosion caused by manganese in water systems |
| EP0311072A3 (en) * | 1987-10-08 | 1989-06-07 | The B.F. Goodrich Company | Stabilization of metal ions and dispersion of particulates in aqueous systems |
| US10926219B2 (en) | 2015-08-28 | 2021-02-23 | Serionix, Inc. | Gas filters for basic contaminants |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1110365A (en) * | 1965-03-29 | 1968-04-18 | Calgon Corp | Inhibition of scale in saline water evaporators |
| FR1544503A (en) * | 1966-11-16 | 1968-10-31 | Benckiser Gmbh Joh A | Descaler products |
| US3630937A (en) * | 1968-05-06 | 1971-12-28 | Calgon Corp | Sulfonated polystyrene compositions and methods of treating boiler water |
| GB1361857A (en) * | 1970-08-28 | 1974-07-30 | Chemed Corp | Scale-inhibiting composition and method |
| US3663448A (en) * | 1970-09-25 | 1972-05-16 | Calgon Corp | Inhibiting scale deposition |
| US3709816A (en) * | 1971-07-01 | 1973-01-09 | Calgon Corp | Control of alluvial and other deposits in aqueous systems |
| US3806367A (en) * | 1972-06-01 | 1974-04-23 | Bitz Lab Inc | Acrylamido-sulfonic acid polymers and their use as rust and tubercle removing agents |
| FR2198106A1 (en) * | 1972-09-04 | 1974-03-29 | Rhone Progil | Corrosion and scale prevention in cooling systems - using phosphates, zinc salts and acrylic polymers |
| DE2248586A1 (en) * | 1972-10-04 | 1974-04-18 | Drew Chem Corp | METHOD OF SEPARATION OF ACID GASES FROM MIXTURES OF FLUIDS CONTAINING SUCH GASES |
| US3890228A (en) * | 1973-04-13 | 1975-06-17 | Chemed Corp | Polyacrylate-polyphosphonic acid treatment in aqueous systems |
| US3918935A (en) * | 1973-08-13 | 1975-11-11 | Factory Mutual Res Corp | Non-newtonian liquid and method for wet scrubbing stack gases |
| US3880620A (en) * | 1974-06-19 | 1975-04-29 | Betz Laboratories | Method for scrubbing gases derived from blast furnaces |
-
1976
- 1976-12-15 SE SE7614102A patent/SE435456B/en not_active IP Right Cessation
- 1976-12-16 DK DK566776A patent/DK153367C/en not_active IP Right Cessation
- 1976-12-17 FI FI763638A patent/FI763638A/fi not_active Application Discontinuation
- 1976-12-21 NL NLAANVRAGE7614213,A patent/NL185221C/en not_active IP Right Cessation
- 1976-12-23 NO NO764352A patent/NO144619C/en unknown
- 1976-12-30 BR BR7608838A patent/BR7608838A/en unknown
- 1976-12-31 IT IT52856/76A patent/IT1121700B/en active
- 1976-12-31 IE IE2858/76A patent/IE44558B1/en not_active IP Right Cessation
-
1977
- 1977-01-04 GB GB46/77A patent/GB1532391A/en not_active Expired
- 1977-01-04 CA CA269,079A patent/CA1087480A/en not_active Expired
- 1977-01-05 DE DE19772700347 patent/DE2700347A1/en active Granted
- 1977-01-05 LU LU76525A patent/LU76525A1/xx unknown
- 1977-01-05 FR FR7700135A patent/FR2337694A1/en active Granted
- 1977-01-06 CH CH15477A patent/CH624368A5/en not_active IP Right Cessation
- 1977-01-07 JP JP43977A patent/JPS52110288A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| BR7608838A (en) | 1977-10-25 |
| IE44558L (en) | 1977-07-07 |
| FR2337694B1 (en) | 1981-12-24 |
| FI763638A (en) | 1977-07-08 |
| DK153367B (en) | 1988-07-11 |
| NL185221B (en) | 1989-09-18 |
| GB1532391A (en) | 1978-11-15 |
| LU76525A1 (en) | 1977-07-15 |
| DE2700347C2 (en) | 1989-12-28 |
| SE7614102L (en) | 1977-07-08 |
| JPS52110288A (en) | 1977-09-16 |
| FR2337694A1 (en) | 1977-08-05 |
| CH624368A5 (en) | 1981-07-31 |
| DE2700347A1 (en) | 1977-07-14 |
| DK153367C (en) | 1989-01-02 |
| DK566776A (en) | 1977-07-08 |
| IT1121700B (en) | 1986-04-10 |
| NL7614213A (en) | 1977-07-11 |
| NO144619B (en) | 1981-06-29 |
| NO144619C (en) | 1981-10-07 |
| NL185221C (en) | 1990-02-16 |
| IE44558B1 (en) | 1982-01-13 |
| SE435456B (en) | 1984-10-01 |
| NO764352L (en) | 1977-07-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4118318A (en) | Gas scrubber scale and deposit control | |
| CA1087480A (en) | Gas scrubber scale and deposit control | |
| US5683587A (en) | Process for treating industrial wastes | |
| US4640793A (en) | Synergistic scale and corrosion inhibiting admixtures containing carboxylic acid/sulfonic acid polymers | |
| US5961837A (en) | Process for treatment of industrial waste | |
| US5645756A (en) | Hardness suppression in urea solutions | |
| US4552665A (en) | Stabilization of soluble manganese and its reaction products | |
| CA2162518C (en) | Polyether polyamino methylene phosphonates for high ph scale control | |
| EP0210590A2 (en) | Polymeric additives for water | |
| US5124046A (en) | Method for controlling calcium carbonate scaling in high pH aqueous systems | |
| CA1182983A (en) | Gas scrubbing methods | |
| US3880620A (en) | Method for scrubbing gases derived from blast furnaces | |
| US5454954A (en) | Scale control in metal mining circuits using polyether polyamino methylene phosphonates | |
| AU649149B2 (en) | Inhibition of scale formation and corrosion by sulfonated organophosphonates | |
| EP0302651B1 (en) | Method for controlling calcium carbonate scaling in high ph aqueous systems | |
| US5616307A (en) | Boiler operation with decreased NOx and waste water discharge | |
| JPS5811279B2 (en) | Scale prevention treatment method | |
| US5169537A (en) | Water soluble terpolymers and methods of use thereof | |
| US5128427A (en) | Terpolymer from sodium arcylate, sodium salt of amps and allyl ether of glycerol | |
| BE850110A (en) | FIGHT AGAINST SCALE AND DEPOSITS IN GAS WASHERS. | |
| WO1994002410A1 (en) | BOILER OPERATION WITH DECREASED NOx AND WASTE WATER DISCHARGE | |
| JPS6233000B2 (en) | ||
| NL8802315A (en) | Preventing scale deposition in gas washing plants - with scale inhibitor and a water-soluble polymer | |
| JPS61116289A (en) | Method of preventing trouble of adhesion of mist | |
| JPH07194938A (en) | Flue gas desulfurization method for heavy oil boiler |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |