WO2020174607A1 - Procédé pour fournir une protection contre la corrosion à un circuit eau-vapeur - Google Patents

Procédé pour fournir une protection contre la corrosion à un circuit eau-vapeur Download PDF

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WO2020174607A1
WO2020174607A1 PCT/JP2019/007560 JP2019007560W WO2020174607A1 WO 2020174607 A1 WO2020174607 A1 WO 2020174607A1 JP 2019007560 W JP2019007560 W JP 2019007560W WO 2020174607 A1 WO2020174607 A1 WO 2020174607A1
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Prior art keywords
water
steam
amine
film forming
aluminium
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PCT/JP2019/007560
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English (en)
Inventor
Wolfgang Hater
Andre De Bache
Patrick Kraft
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Kurita Water Industries Ltd.
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Priority to PCT/JP2019/007560 priority Critical patent/WO2020174607A1/fr
Priority to JP2021540455A priority patent/JP2022532692A/ja
Publication of WO2020174607A1 publication Critical patent/WO2020174607A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F11/00—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent
    • C23F11/08—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids
    • C23F11/10—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids using organic inhibitors
    • C23F11/14—Nitrogen-containing compounds
    • C23F11/141—Amines; Quaternary ammonium compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/42—Treatment of water, waste water, or sewage by ion-exchange
    • 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
    • C02F5/12—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 nitrogen
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B37/00—Component parts or details of steam boilers
    • F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
    • F22B37/025—Devices and methods for diminishing corrosion, e.g. by preventing cooling beneath the dew point
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B37/00—Component parts or details of steam boilers
    • F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
    • F22B37/04—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler and characterised by material, e.g. use of special steel alloy
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28B—STEAM OR VAPOUR CONDENSERS
    • F28B1/00—Condensers in which the steam or vapour is separate from the cooling medium by walls, e.g. surface condenser
    • F28B1/06—Condensers in which the steam or vapour is separate from the cooling medium by walls, e.g. surface condenser using air or other gas as the cooling medium
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F19/00—Preventing the formation of deposits or corrosion, e.g. by using filters or scrapers
    • F28F19/02—Preventing the formation of deposits or corrosion, e.g. by using filters or scrapers by using coatings, e.g. vitreous or enamel coatings
    • F28F19/06—Preventing the formation of deposits or corrosion, e.g. by using filters or scrapers by using coatings, e.g. vitreous or enamel coatings of metal
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F21/00—Constructions of heat-exchange apparatus characterised by the selection of particular materials
    • F28F21/08—Constructions of heat-exchange apparatus characterised by the selection of particular materials of metal
    • F28F21/081—Heat exchange elements made from metals or metal alloys
    • F28F21/082—Heat exchange elements made from metals or metal alloys from steel or ferrous alloys
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F21/00—Constructions of heat-exchange apparatus characterised by the selection of particular materials
    • F28F21/08—Constructions of heat-exchange apparatus characterised by the selection of particular materials of metal
    • F28F21/081—Heat exchange elements made from metals or metal alloys
    • F28F21/084—Heat exchange elements made from metals or metal alloys from aluminium or aluminium alloys
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/02—Non-contaminated water, e.g. for industrial water supply
    • C02F2103/023—Water in cooling circuits
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2303/00—Specific treatment goals
    • C02F2303/08—Corrosion inhibition

Definitions

  • the present invention relates to a method for providing corrosion protection to a water-steam circuit having both internal surfaces made of aluminium or aluminium alloy and internal surfaces made of steel.
  • aluminium and aluminium alloys in the construction of power plants, in particular in the construction of water-steam-circuits (hereinafter WSC), is gaining in importance.
  • WSC water-steam-circuits
  • aluminium and aluminium alloys are increasingly used in the construction of tubes in air cooled condensers such as Heller towers and jet spray coolers.
  • the use of aluminium and aluminium alloys offers both construction and economic benefits.
  • aluminium and aluminium alloys are more sensitive to corrosion than steel or non-ferrous metals which are commonly used in the construction of components of WSC. Therefore, the means conventionally taken for corrosion protection of conventional WSC constructed of steel cannot be transferred one to one to WSC having components made of aluminium or aluminium alloys. In fact, the means for corrosion protection have to be adequately adapted in order to meet the requirements of aluminium and aluminium alloys. What is more, corrosion products of aluminium may distribute in the WSC and form deposits on the turbine blades. Further complicating the matter is the fact that other components of water-steam-circuits such as boilers may still require to be made of steel for construction reasons, which have other requirement with regard to the optimum corrosion protection.
  • Aluminium is an amphoteric metal.
  • International standards such as standards of the International Association for the Properties of Water and Steam (IAPWS) require that WSC having components made of aluminium or aluminium alloys are operated at pH levels of approximately pH 8.0, e.g. in the range of pH 7.7 to 8.0 (see IAPWS Technical Guidance Document 3 10(2015)).
  • WSC corrosion protection is usually achieved by oxygen treatment (OT) at these pH levels. While oxygen treatment at pH 8.0 and a stationary oxygen concentration of about 50 ppb may provide sufficient protection of both the aluminium and the steel components of WSC during continuous operation, steel components will suffer corrosion under these conditions during shutdown or cycling mode operation, because it is not possible to achieve a stationary oxygen concentration under these conditions.
  • WSC made of steel components are usually subjected to an all-volatile treatment (AVT) at elevated pH level, e.g. at pH of above pH 8.7, preferably at least pH 9.2 and up to 10, according to the VGB guideline VGB-S-010-T00 or IAPWS Technical Guidance Document 3 10(2015), in order to avoid corrosion of the steel surfaces, especially when the plant, and thus the WSC, is operated in cycling mode.
  • AVT all-volatile treatment
  • VGB-S-116-00-2016-04-EN “Conservation of Power Plants” recommends an AVT treatment at elevated pH of 9.2 - 9.5 prior to a wet conservation. Following this regime under cycling mode conditions would mean a frequent change of operating modes which would be extremely difficult to realize, if possible at all.
  • cycling mode i.e. discontinuous operation with frequent short-term stand-by periods (off periods)
  • the WSC will lead to difficult challenges for plant operators, because every time the WSC is turned off and on, the boiler, steam lines, turbine and auxiliary components go through unavoidably large thermal and pressure stresses, which may cause damage.
  • the WSC comprises both components made of steel and components made of aluminium, in particular because of the different demands of aluminium components and the steel components to the quality of the circulating water.
  • Film forming amines have been suggested as feed water additives for providing improved corrosion protection of WSC made of steel or copper components.
  • Film forming amines i.e. long chain alkyl fatty amines and long chain oligoalkylamine fatty amines adsorb to the interior surfaces of WSC components and form a tight protective barrier against corrosive agents.
  • film forming amines sharply increase the protection of aluminium against corrosion at elevated pH levels of at least pH 8.8, e.g. at pH 8.8 to pH 10, in particular at least pH 9.0, e.g. pH 9.0 to 9.6, which is similar to the protection level at neutral or almost neutral pH of approximately pH 8.0.
  • pH 8.8 e.g. at pH 8.8 to pH 10
  • pH 9.0 e.g. pH 9.0 to 9.6
  • the steel parts are almost inert to corrosion because of an insoluble magnetite layer formed on the surface of the internal steel parts.
  • no noticeable transport of aluminium is observed under these conditions.
  • the present invention relates to a method for providing corrosion protection to a water-steam circuit having both internal surfaces made of aluminium or aluminium alloy and internal surfaces made of steel, which method comprises operating the water-steam circuit with water having a pH value, measured at 22°C, in the range of pH 8.8 to 10.0, in particular in the range of pH 9.0 to 9.6, especially in the range of pH 9.2 to 9.6 and containing a film forming amine.
  • the method allows for efficient prevention or reduction of corrosion of the internal surfaces of components made of aluminium or aluminium alloy under conditions which are also beneficial for the corrosion protection of the internal surfaces of components made of steel. Therefore, the method of the present invention facilitates corrosion protection of water-steam circuits containing both components made of steel and components made of aluminium or aluminium allows. Apart from that, the method of the invention also provides efficient corrosion protection of those components, which are made of non-ferrous metals, such as e.g. copper or copper alloys, such as brass, and nickel base alloys. Moreover, no significant transport of aluminium salts of formation of aluminium containing deposits within the water-steam cycle is observed under these conditions. Therefore, the process of the invention can be broadly applied to water-steam circuits under different operating conditions, i.e. under continuous operation but also under cycling mode conditions or for preparing a lay-up for shut down.
  • internal surfaces is understood as those surfaces of the water-steam circuit, which get into contact with the water or the steam circulating in the water-steam circuit und thus are principally subjected to conditions which may cause corrosion.
  • Typical components of water-steam circuits which have internal surfaces, include but are not limited to steam generators, also called boilers, condensers, coolers and pipes connecting the different components. As further components, they may also include feed water tanks, deaerating heaters for removing corrosive gases from the feedwater, economizers and flash tanks. If the water-steam circuit is part of a power plant it will also have one or more turbines for driving generators. Furthermore, a water-steam circuit may also include a pretreatment system for adjusting quality parameters of the water used for operating the water-steam circuit, such as concentration of salts and pH value.
  • steels types frequently used for the construction of components of water-steam circuits may be high alloy steels or low-alloy steels and include, but are not limited to, e.g. martensitic steels, in particular martensitic steels having a chromium content of 9 - 14 %, such as the martensitic steels T/P92 and VM12/VM12-SHC, austenitic steels and ferritic steels, e.g. low alloy ferritic steels such as T/P24, but also nickel base alloys.
  • Typical aluminium materials include in particular pure aluminium having an aluminium content of > 99 % and aluminium alloys such as aluminium-magnesium alloys, aluminium-magnesium-silicon alloys and aluminium-zinc alloys.
  • the average concentration of the film forming amine in the water used for operating the water-steam circuit is preferably in the range from 0.01 to 5.0 mg/kg, in particular in the range from 0.05 to 2.0 mg/kg and especially in the range from 0.1 to 1.5 mg/kg.
  • the film forming amine is dosed to the water used for operating the water-steam circuit in such an amount that at least during operation of the water-steam circuit the above concentrations are achieved.
  • the term “average concentration” is understood as a time average of the concentration, which means that during the operation time of the water-steam circuit the concentration of the film forming amine in the water used for operating the water-steam circuit is on average within the above ranges.
  • the concentration of the film forming amine in the water must not necessarily be in the above range at every point of time, when the water-steam circuit is operated. Rather, it is possible that the concentration may be outside the above ranges for a certain period of time. However, any period where the concentration of the film forming amine is outside the above ranges will usually not exceed 4 h, in particular 2 h. Moreover, during these periods the concentration will usually not exceed 2 times of the upper limit given above and it will not or only shortly, preferably for not more than 4 h, drop to zero.
  • concentration ranges given above refer to the concentration of the film forming amine in those parts of the water-steam circuit, where the water used for operating the water-steam circuit is in the liquid state.
  • concentration of the film forming amine in the water used for operating the water-steam circuit may vary within the water-steam circuit to a certain extent and not be the same at each and every point of the water-steam circuit. However, the deviation will not be very high and generally the average concentration ranges given above are maintained in any part of the water-steam circuit where the water is in the liquid state.
  • Suitable film forming amines for use in the method of the present invention are hydrophobic amines having at least one long chain hydrocarbon radical having preferably from 12 to 22 carbon atoms.
  • Examples include fatty amines and oligoamines wherein at least one long chain hydrocarbon radical having preferably from 12 to 22 carbon atoms is attached to one nitrogen atom of the oligo amine.
  • the film forming amines may bear hydroxyalkyl or oligoalkylenoxide groups attached to the nitrogen atom(s).
  • R 1 -(NR 3 -R 2 ) n -NR 4 R 5 (I) wherein n is 0, 1 or 2;
  • R 1 is a linear or branched, acyclic hydrocarbon group having 12 to 22 carbon atoms, in particular 16 to 20 carbon atoms;
  • R 2 is C 2 -C 4 -alkanediyl, in particular 1,2-ethandiyl or 1,3-propandiyl;
  • groups R 1 include, but are not limited to lauryl (n-dodecyl), myristyl (n-tetradecyl), cetyl (n-hexadecyl), margaryl (n-heptadecyl), stearyl (n-octadecyl), arachidyl (n-eicosanyl), behenyl (n-docosenyl), palmitoleyl (9-hexadecen-1-yl), oleyl(9-hexadecen-1-yl), 11-octadecen-1-yl, 9,12-octadecadien-1-yl and 9,12,15-octadecatrien-1-yl and mixtures thereof, such as tallowalkyl (mixture of linear alkyl which mainly consists of linear C 16 /C 18 alkyl), and cocoalkyl (mixture of linear alkyl, which mainly consists of C 12
  • C 2 -C 4 -alkanediyl is understood to mean a saturated hydrocarbon group having 2, 3 or 4 carbon atoms, which may be linear or branched and which is preferably linear.
  • R 2 is ethanediyl, propanediyl or butanediyl, in particular 1,2-ethanediyl, 1,3-propanediyl or 1,4-butandiyl, and especially 1,3-propanediyl.
  • C 1 -C 4 -alkyl denotes a linear or branched alkyl radical comprising from 1 to 4 carbon atoms, for example CH 3 , C 2 H 5 , n-propyl, CH(CH 3 ) 2 , n-butyl, CH(CH 3 )-C 2 H 5 , CH 2 -CH(CH 3 ) 2 and C(CH 3 ) 3 .
  • R 3 , R 4 and R 5 are preferably hydrogen or -(C 2 H 4 O) p -H.
  • n is preferably 0, 1 or 2.
  • the film forming amines are compounds of the formula (I), where n is 1 or 2, or mixtures comprising at least 80 % by weight, based on the total amount of film forming amine, of one or more compounds of formula (I), where n is 1 or 2.
  • the film forming amines consist to at least 80 % by weight, based on the total amount of film forming amine, of one or more compounds of formula (I), where n is 1 or 2.
  • the amount of compounds of formula (I), where n is 0 does not exceed 20 % by weight of the total amount of film forming amine.
  • R 2 is 1,2-ethanediyl, 1,3-propanediyl or 1,4-butandiyl, and especially 1,3-propanediyl
  • R 3 , R 4 and R 5 are preferably hydrogen or -(C 2 H 4 O) p -H.
  • R 3 , R 4 and R 5 are hydrogen.
  • Examples of particular amines of formula (I) with n being 0 and R 3 , R 4 and R 5 being hydrogen are octadecylamine, oleylamine and tallowamine.
  • compositions of film forming amines which contain at least 80 % by weight, based on the total weight of the film forming amine, of compounds of the formula (I) with n being 1 or 2 are the Duomeen(trademark) brands of AkzoNobel, such as Duomeen(trademark) T, Duomeen(trademark) O and Duomeen(trademark) C, the Triameen(trademark) brands of AkzoNobel, such as Triameen(trademark) T and Triameen(trademark) C, the Dinoram(trademark) brands of Archem, such as Dinoram(trademark) O, and Inipol(trademark) DS.
  • Duomeen(trademark) brands of AkzoNobel such as Duomeen(trademark) T, Duomeen(trademark) O and Duomeen(trademark) C
  • Triameen(trademark) brands of AkzoNobel such as Triameen(trademark) T and Triameen(trademark) C
  • compositions of film forming amines which contain at least 80 % by weight, based on the total weight of the film forming amine, of compounds of the formula (I) with n being 3 and R 3 , R 4 and R 5 being hydrogen are the Tetrameen(trademark) brands of AkzoNobel, such as Tetrameen(trademark) T.
  • R 3 , R 4 and/or R 5 are -(C m H 2m-2 O) p -H while the others of R 3 , R 4 and R 5 are hydrogen.
  • These amines are also termed alkoxylated fatty amines.
  • m is preferably 2.
  • n is preferably 0, 1 or 2.
  • the total number of repeating units C m H 2m-2 O, in particular of groups CH 2 CH 2 O, per molecule is in the range from 2 to 15, in particular in the range from 2 to 6.
  • alkoxylated fatty amines may be mixtures of compounds of the formula (I) having a different number of repeating units C m H 2m-2 O, in particular of groups CH 2 CH 2 O.
  • the total number of repeating units C m H 2m-2 O, in particular of groups CH 2 CH 2 O is understood as the number average of these groups in the alkoxylated fatty amines.
  • Alkoxylated fatty amines are known and commercially available. They can be prepared by common methods, e.g. by reacting a compound of the formula (I), where R 3 , R 4 and R 5 are hydrogen, with at least one C 2 -C 4 -alkylene oxide, in particular with ethylene oxide.
  • R 3 , R 4 and R 5 are hydrogen
  • at least one of the hydrogens R 3 , R 4 and R 5 is replaced by polyether chains -(C m H 2m-2 O) p -H in the resulting product compound.
  • all of the hydrogens R 3 , R 4 and R 5 are replaced by polyether chains -(C m H 2m-2 O) p -H in the resulting product compound.
  • a fatty amine or fatty amine mixture based on natural fatty amines is employed for alkoxylation.
  • n is 0.
  • Amines based on vegetable or animal fat typically comprise a mixture of at least one of the following amines: oleic amine, palmitic amine, stearic amine, myristic amine, linoleic amine, oleyl amine, decyl amine, undecyl amine, dodecyl amine, tridecyl amine, tetradecyl amine, hexadecyl amine, octadecyl amine.
  • fatty amine mixtures based on natural fatty amines are fatty amines derived from tallow, coconut oil, sunflower oil, rape oil, soybean oil or palm kernel oil.
  • cocoamine as Ethomeen C/12, Ethomeen C/15, Ethomeen C/25, Berol 398 or tallowamine as Ethomeen T/12, Ethomeen T/12 LC, Ethomeen T/15, Ethomeen T/25, Ethoduomeen T/13, Ethoduomeen T/22, Ethoduomeen T/25 or oleylamine as Berol 302, Ethomeen O/12, Ethomeen O/12 LC, Ethomeen OV/17, Ethomeen OV/22.
  • Suiatable alkylene oxides for alkoxylation are ethylene oxide (EO), propylene oxide (PO), 1,2-butylene oxide, 2,3-butylene oxide and mixtures thereof.
  • Examples include ethoxylated fatty amines selected from ethoxylated tallow amine, ethoxylated coco amine, ethoxylated soya amine, ethoxylated oleyl amine, ethoxylated decyl amine, ethoxylated dodecyl amine, ethoxylated tridecyl amine, and ethoxylated tetradecyl amine with preference given to ethoxylated tallow amine with 3 to 15 EO, ethoxylated coco amine with 3 to 15 EO, ethoxylated oleyl amine with 3 to 15 EO, ethoxylated dodecyl amine with 3 to 15 EO, ethoxylated tridecyl amine with 3 to 15 EO, ethoxylated tetradecyl amine with 3 to 15 EO, ethoxylated hexadecyl amine
  • Examples of particular amines of formula (I) with n being 0 and R 3 , R 4 and R 5 are hydroxyethyl are commercially available as the Ethomeen T series from Akzo Nobel, such as Ethomeen C/12, Ethomeen C/15, Ethomeen C/25, Ethomeen T/12, Ethomeen T/12 LC, Ethomeen T/15, Ethomeen T/25, Ethomeen O/12, Ethomeen O/12 LC, Ethomeen OV/17, Ethomeen OV/22.
  • a further particular group of embodiments relates to compound mixtures, consisting to at least 80 % of compounds of formula (I), where n is 1 or 2 and least one of R 3 , R 4 and/or R 5 are -(C m H 2m-2 O) p -H, in particular 2-hydroxyethyl, while the others of R 3 , R 4 and R 5 are hydrogen.
  • the total number of repeating units C m H 2m-2 O, in particular of groups CH 2 CH 2 O, per molecule is in the range from 3 to 15, in particular in the range from 3 to 6.
  • the degree of ethoxylation i.e. the sum of p is preferably in the range from 3 to 15 and in particular from 3 to 6.
  • Etoduomeen T series from Akzo Nobel, such as Ethoduomeen T/13, Ethoduomeen T/22, Ethodumeen T/25.
  • Preferred examples of film forming amines for use in the method of the invention include oleyl amine, N-(3-aminopropyl)oleyl amine, mixtures of oleyl amine and N-(3-aminopropyl)oleyl amine, ethoxylated N-(3-aminopropyl)oleyl amine, and mixtures of ethoxylated N-(3-aminopropyl)oleyl amine and ethoxylated oleylamine.
  • film forming amines which comprise at least 80 % of compounds of the formula (I), where n is 1,
  • film forming amines which comprise at least 80 % by weight, based on the total amount of film forming amine, of one or more compounds of the formula (I), wherein n is 1,
  • R 1 is a straight chain hydrocarbon group having 18 carbon atoms
  • R 2 is 1,3-propandiyl
  • R 3 , R 4 and R 5 are hydrogen or all of R 3 , R 4 and R 5 are -(C 2 H 4 O) p -H, where the total number of p, is either 0 or 3 to 15 especially 3 to 6.
  • the concentration of the film forming amine is usually determined periodically or continuously in at least one point of the water-steam-circuit in particular in at least two points of the water-steam-circuit.
  • Suitable points for determining the concentration of the film forming amine are in particular those, where the water is in the liquid state.
  • Preferred points for controlling the concentration of the film forming amine include e.g. - the feed water, i.e. the water which is fed from the feed tank to the water-steam circuit; - the condensate water and - the water of the steam drum, i.e. the water contained in the steam generating part of the boiler.
  • concentration of the film forming amine in the sample is determined by a standard method, e.g. the British standard BS 2690: Part 117:1983, by photometrical methdos as described by K. Stiller et al. Power Plant Chemistry 2011, 13(10), pp. 602-611, M. Lendi et al., Power Plant Chemistry 2014, 16(1), pp. 4-11, EP 562210, or by the colorimetric method described in GB 994 051.
  • concentration of the film forming amine by inline measurements, e.g.
  • any film forming amine which is consumed will be replenished in such amounts that the film forming amine is present in the concentration ranges given above.
  • the film forming amine is dosed to the water used for operating the water-steam circuit in such an amount that at least during operation of the water-steam circuit the above concentrations are achieved.
  • the film forming amine may be added in portions or continuously.
  • the amount or rate of addition will of course depend from the the concentration of the film forming amine determined in the control measurements. In case the water-steam circuit was previously operated without the film forming amine, it is preferred that the amount of film forming amine which is initially added will result only in a low concentration which is close to the lower limit given above and that further additions will be made in order to achieve a preferred concentration range. In particular, an initial overdosage should be avoided.
  • the film forming amine can principally added at any point of the water-steam circuit, in particular at a point, where the water is present in liquid form.
  • Suitable points for addition of the film forming amine are principally known to a skilled person, e.g. from A. Bursik et al., Power Plant Chemistry 2015, 17(6), pp. 342-353 and from IAPWS Technical Guidance Document 8 16(2016), point 8.5 and the references cited therein.
  • Suitable points include any point between the feed water tank and the boiler, such as feedwater pump inlet of the boiler, the deaerating heater (deaerator), in particular the deaerator outlet, the economizer, in particular the feedpump inlets of the low pressure or high pressure economizer circuits, the condenser and into the pipeline to an air cooled condenser, condensate extraction pump and/or drum. It is preferred to add at least a portion of the film forming amine into the condensate, in particular at the condensate discharge pump.
  • the pH level of the water used for operating the water-steam circuit is in the range from pH 8.8 to pH 10 and in particular in the range from pH 9.0 to pH 9.6.
  • the pH ranges given here refer to the pH value as determined at 22°C.
  • the pH is usually determined by an electrochemical method, e.g. by using a commercially available pH meter, which usually includes a glass electrode or a combination thereof with a reference electrode.
  • the procedures for measuring the pH are known and described e.g. in DIN EN ISO 10253:2012-04 (see also point 3.1.3 of IAPWS Technical Guidance Document 2 09(2015)).
  • the pH value of the water used for operating the water-steam circuit is on average within the above ranges.
  • the pH value of the water must not necessarily be in the above range at every point of time, when the water-steam circuit is operated. Rather, it is possible that the pH value may be outside the above ranges for a short period of time.
  • any period where the pH level is outside the above ranges will usually not exceed 1 h, in particular 30 min. to avoid an increase of corrosion.
  • the pH level will usually not deviate by more than 0.2 pH units, in particular not more than 0.1 pH units of the limits given above.
  • the pH level of the water used for operating the water-steam circuit may vary within the water-steam circuit to a certain extent and not be the same at each and every point of the water-steam circuit. However, the deviation will not be very high and generally the above average pH levels are maintained in any part of the water-steam circuit where the water is in the liquid state.
  • the pH level is usually determined periodically or continuously in at least one point of the water-steam-circuit in particular in at least two points of the water-steam-circuit. Suitable points for determining the pH level are in particular those, where the water is in the liquid state. Preferred points for controlling the pH level include e.g. - the feed water, i.e. the water which is fed from the feed tank to the water-steam circuit; - the condensate water and - the water of the steam drum, i.e. the water contained in the steam generating part of the boiler.
  • a sample may be taken and the pH of the sample is determined according a standard procedure as described above, in particular according to the procedure described in DIN EN ISO 10253:2012-04.
  • the base can principally added at any point of the water-steam circuit, in particular at a point, where the water is present in liquid form.
  • Suitable points for addition of the base art those mentioned above for the addition of the film forming amine and include e.g.
  • the feedwater tank any point between the feed water tank and the boiler, such as feedwater pump inlet of the boiler, the deaerating heater (deaerator), in particular the deaerator outlet, the economizer, in particular the feedpump inlets of the low pressure or high pressure economizer circuits, the condenser and into the pipeline to an air cooled condenser, condensate extraction pump and/or drum.
  • the deaerating heater in particular the deaerator outlet
  • the economizer in particular the feedpump inlets of the low pressure or high pressure economizer circuits
  • the further base may be added in portions or continuously.
  • the amount or rate of addition will of course depend from the outcome of the pH measurements.
  • the conductivity of the water used for operating the water-steam circuit at a level of at most 30 ⁇ S/cm, in particular at most 20 ⁇ S/cm or at most 10 ⁇ S/cm.
  • the conductivity values given here refer to the specific conductivity of a sample of the water used for operating the water-steam circuit as determined at 22°C.
  • the conductivity can be determined by standard procedures as described e.g. in DIN EN 27888:1993-11. It is apparent for a skilled person that in some cases it may not possible to measure the pH at 22°C. However, it is not necessary to measure the conductivity at 22°C because a skilled person is familiar with the temperature dependence of conductivity.
  • the conductivity of the water used for operating the water-steam circuit is on average below the above limits.
  • the conductivity of the water must not necessarily below the above limits at every point of time, when the water-steam circuit is operated. Rather, it is possible that the conductivity may be slightly higher than the above limits for a short period of time.
  • any period where the conductivity is higher than the above limits will usually not exceed 4 h, in particular 2 h.
  • the conductivity will usually not exceed 50 ⁇ S/cm, in particular not exceed 30 ⁇ S/cm or 20 ⁇ S/cm.
  • the conductivity of the water used for operating the water-steam circuit may vary within the water-steam circuit to a certain extent and not be the same at each and every point of the water-steam circuit. However, the deviation will not be very high and generally the above limits of conductivity are maintained in any part of the water-steam circuit where the water is in the liquid state.
  • the conductivity is usually determined periodically or continuously in at least one point of the water-steam-circuit in particular in at least two points of the water-steam-circuit.
  • Suitable points for determining the conductivity of the water used for operating the water-steam circuit are those, where the water is in the liquid state.
  • Preferred points for controlling the pH level include e.g. - the feed water, i.e. the water which is fed from the feed tank to the water-steam circuit; - the condensate water and - the water of the steam drum, i.e. the water contained in the steam generating part of the boiler.
  • a sample may be taken and the conductivity of the sample is determined according a standard procedure as described above, in particular according to the procedure described in DIN EN 27888:1993-11.
  • the water circulating in the water-steam circuit may be conducted through a bed of an ion-exchange resin, in particular a mixed bed of an cation exchange resin and an anion exchange resin to remove any ionic impurities.
  • polishing units are also termed polishing units.
  • the condensate is conducted through the polishing unit.
  • the method of the present invention may be applied principally to any water-steam circuit having internal surfaces made of steel and internal surfaces made of aluminium.
  • the method of the present invention is particularly suitable for fulfilling the high demands of water-steam circuits, which are part of a power-plant, including water-steam circuits of fossil power plants, such as coal fired power plants and gas turbine power plants, of biogas power plants, of nuclear power plants and the like.
  • the method of the present invention is especially suitable for fulfilling the high demands of water-steam circuits, which are part of a power-plant, that are operated in cycling mode.
  • cycling mode is understood as discontinuous operation with frequent short-term stand-by periods (off periods).
  • cycling mode is understood similarly and means the operation of electric generating units at varying load levels (power demand), including on/off and low load variations, in response to changes in system load (demand) requirements.
  • power demand power demand
  • the method of the invention allows for efficient and economic corrosion protection under these challenging conditions.
  • Figure 1a shows a Nyquist plot of an electrochemical impedance measurement of an aluminium electrode in deionised water containing 0.2 g/L of NaCl at pH 9.2 and 50°C according to example 1 after a treatment time of 8 h.
  • the polarization resistance derived from the plot is 3.0 k ⁇ cm 2 indicating insufficient formation of a corrosion protection layer.
  • Figure 1b shows a Nyquist plot of an electrochemical impedance measurement of an aluminium electrode in deionised water, containing 0.2 g/L of NaCl and 4 ppm of a film forming amine consisting mainly of N-(3-aminopropyl)oleyl amine, at pH 9.2 and 50°C according to example 1 after a treatment time of 8 h.
  • the polarization resistance derived from the plot is 6.85 k ⁇ cm 2 indicating formation of a corrosion protection layer.
  • Figure 1c shows a Nyquist plot of an electrochemical impedance measurement of an aluminium electrode in deionised water, containing 0.2 g/L of NaCl and 4 ppm of a film forming amine consisting mainly of ethoxylated N-(3-aminopropyl)oleyl amine (3 EO), at pH 9.2 and 50°C according to example 1 after a treatment time of 8 h.
  • the polarization resistance derived from the plot is 6.10 k ⁇ cm 2 indicating formation of a corrosion protection layer.
  • Example 1 Electrochemical Impedance Measurements For electrochemical impedance measurements the following equipment was used - rotating disc Hach EDI 101 with speed control unit CTV101 (500 rpm); - potiometer Autolab PG Stat 12 controlled by nova 1.11 software (Methrom): - Working electrode: Aluminium rod (purit > 99.999 %) having a diameter of 5 mm and a tip surface of 0.196 cm 2 ; - counter electrode: Radiometer platinum; - Origalys Ag/AgCl reference electrode; - 600 mL beaker; - Heating plate; - pH-meter Knick Portamess with temperature compensation unit and a SE102N electrode; - Pt 100 thermometer for temperature control.
  • Working electrode Aluminium rod (purit > 99.999 %) having a diameter of 5 mm and a tip surface of 0.196 cm 2 ; - counter electrode: Radiometer platinum; - Origalys Ag/AgCl reference electrode; - 600 mL beaker; - Heating plate; - pH-
  • the working electrodes were prepared by grinding the Al electrode tip at 150 rpm using a grinder and silicon carbide grinding paper with a grit of P4000 until a plane surface is accomplished. This metal surface is polished to a so called “mirror effect”.
  • Test solutions were prepared as follows: Blank solution: 0.2g (+/- 0.005g) of NaCl p.a. was weighed into a 1L volumetric flask and filled up to 1 L with deionized water. The pH was adjusted with 0.05 mol/L NaOH or 0.05 mol/L HCl depending of the target pH (8.2, 9.2 or 9.7). Sample with film forming amine: A solution of the film forming amine in deionized water having a concentration of the film forming amine of 1000 ppm was prepared. From this solution 4 mL were added to the blank water to the total volume of 1 L. The pH was adjusted with 0.05 mol/L NaOH or 0.05 mol/L HCl depending of the target pH (8.2, 9.2 or 9.7).
  • Film forming amine 1 (FFA 1): A commercial product formulation, wherein the film forming amine essentially consists of N-(3-aminopropyl)oleyl amine.
  • Film forming amine 2 (FFA 2): A commercial product formulation, wherein the film forming amine essentially consists of ethoxylated N-(3-aminopropyl)oleyl amine having a total of three hydroxyethyl groups per molecule.
  • Test setup 400 mL of the test solution mentioned above were filled into 600 mL beaker and the pH was adjusted to the target pH value. In case of test at 50°C the solution was heated up to this temperature on a heating plate. During the trial the temperature was maintained by the heating plate and controlled via a Pt-100 thermometer.
  • the rotating disk working electrode with the aluminum electrode tip, the Pt-reference electrode and the Ag/AgCl reference electrode were placed into the solution as follows: Going from the electrode tip in the middle: 0.03 cm to the left the counter electrode was placed and 4.5 cm on the right the reference electrode was placed. The electrode tip was placed about 90% deep into the solution and the other electrodes are placed about the same height into the solution.
  • the test was started within 2 minutes after the electrode tip had been grinded to avoid any oxidation on the surface and to guarantee the reproducibility of the test.
  • the speed control unit of the rotating disk was started with a rotation speed of 500 rpm.
  • OCP open circuit potential
  • FRA frequency response analyzer
  • the impedance Z( ⁇ ) was calculated, which is a complex number having a real part Z’ and an imaginary part Z’’ which are shown as a Nyquist plot: -Z ⁇ ⁇ vs Z ⁇ or Bode plot. Further reference is made to C. Foret et al., Power Plant Chemistry 2014, 16(5), pp. 284-292, in particular to equations (1) to (4) on page 364. The evaluation of the data can be done either graphical or calculated via nova software or Excel.
  • the FFC apparatus includes a 3-neck 4 L round bottom flask equipped with a nitrogen inlet in one of the sideward necks, a vertical heating tube with a heating mantle connected to the central neck of the round bottom flask, a condenser at the distal end of the heating tube, a return line equipped with a mantle cooler and having means for discharging condensate probe downstream of the mantle cooler and a nitrogen outlet downstream the means for discharging condensate (condensate sampling unit), the return line being connected to the other sideward neck of the round bottom flask.
  • the FFC apparatus also includes a heating bath for heating the round bottom flask.
  • Blank Trial 3 L of ultrapure water and approx. 5mg/L aluminum (as aluminium sulfate) were filled into the 4 L round bottom flask. After 5 min of stirring a sample was taken in order to determine the actual concentration of aluminium in the flask, which was 5.6 mg/L. Then the solution was heated up with maximum heating rate (heating mantle + heating bath). The solution was stirred at 250rpm. After the first condensate flew back into the flask, every hour a sample of the condensate was taken (4h sampling time in total) from the condensate sampling unit and the aluminium concentration in the condensate was determined. No aluminium was found in the condensate. The concentration of aluminium in the flask was still 5.6 mg/L.
  • Trial 1 With 5 ppm Al and 4 ppm Film Forming Amine 1: In a first step, the FFC apparatus was conditioned by heating an aqueous solution of the film forming amine (10 mg/L) at maximum heating rate for 8 h. The solution was discharged from the FFC apparatus. In a second step, 3 L of ultrapure water, approx. 5 mg/L aluminum (as aluminium sulfate) and 4 mg/ ml were filled into the 4l round bottom flask. After 5 min of stirring a sample was taken in order to determine the actual concentration of aluminium and film forming amine in the flask, which was 5.6 mg/L for aluminium and 4.06 mg/L for FFA 1.
  • Trial 2 With 5 ppm Al and 4 ppm Film Forming Amine 1: The test conditions and procedure were equivalent to Trial 1. However instead of adding the aluminium sulfate (approx. 5mg Al/l) in the beginning together with FFA1 into the round bottom flask, it was added after 2h, when FFA1 was already detectable in the condensate at the condensate sampling unit. The heating was continued for 70 hours and samples were taken 1 h, 2 h, 3 h, 4, h, 20 h, 24 h, 48 h and 70 h after the addition aluminium sulfate from the condensate sampling unit. The results are summarized in the following table 2:
  • the concentration of aluminium in samples was determined by inductively coupled plasma optical emission spectrometry (ICP-OES).
  • the concentration of the film forming amine was determined by the Bengalrose method described in K. Stiller et. al. Power Plant Chemistry 2011, 13(10), pp. 602-611

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Abstract

La présente invention concerne un procédé pour fournir une protection contre la corrosion à un circuit eau-vapeur ayant à la fois des surfaces internes en aluminium ou en alliage d'aluminium et des surfaces internes en acier, ledit procédé comprenant le fonctionnement du circuit eau-vapeur avec de l'eau ayant une valeur de pH, mesurée à 22°C, dans la plage de pH de 8,8 à 10,0, en particulier dans la plage de pH 9,0 à 9,6, spécialement dans la plage de pH 9,2 à 9,6 et contenant une amine filmogène.
PCT/JP2019/007560 2019-02-27 2019-02-27 Procédé pour fournir une protection contre la corrosion à un circuit eau-vapeur WO2020174607A1 (fr)

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WO2022172279A1 (fr) 2021-02-15 2022-08-18 Hindustan Petroleum Corporation Limited Composé dioléyle inhibant la corrosion, et formulation d'amine de celui-ci formant un film inhibant la corrosion

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0902232A1 (fr) * 1997-04-28 1999-03-17 Siemens Aktiengesellschaft Procédé pour opérer un dispositif traversé par un fluide et système de préparation d'un fluide
JP2004244683A (ja) * 2003-02-14 2004-09-02 Neos Co Ltd 水溶性金属防食剤
US20140102481A1 (en) * 2012-02-28 2014-04-17 Areva Gmbh Method for conditioning a power-generating circulatory system of a power plant
US20160002793A1 (en) * 2013-03-01 2016-01-07 General Electric Company Compositions and methods for inhibiting corrosion in gas turbine air compressors
JP2016065291A (ja) * 2014-09-25 2016-04-28 伯東株式会社 ボイラ水系システムの腐食抑制剤及び腐食抑制方法
JP2017154049A (ja) * 2016-02-29 2017-09-07 栗田工業株式会社 ボイラ水の水処理方法

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ATE27832T1 (de) * 1983-08-03 1987-07-15 Ouest Union Chim Ind Korrosionsinhibierende zusammensetzung zum schuetzen von metalloberflaechen einer anlage, die wasser als thermisches oder energetisches fluidum verwendet, und verfahren zum schuetzen dieser oberflaeche.
JP4711902B2 (ja) * 2006-03-03 2011-06-29 伯東株式会社 ボイラ腐食抑制方法
JP2019203183A (ja) * 2018-05-25 2019-11-28 オルガノ株式会社 蒸気復水系システムにおけるアルミニウムの腐食抑制方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0902232A1 (fr) * 1997-04-28 1999-03-17 Siemens Aktiengesellschaft Procédé pour opérer un dispositif traversé par un fluide et système de préparation d'un fluide
JP2004244683A (ja) * 2003-02-14 2004-09-02 Neos Co Ltd 水溶性金属防食剤
US20140102481A1 (en) * 2012-02-28 2014-04-17 Areva Gmbh Method for conditioning a power-generating circulatory system of a power plant
US20160002793A1 (en) * 2013-03-01 2016-01-07 General Electric Company Compositions and methods for inhibiting corrosion in gas turbine air compressors
JP2016065291A (ja) * 2014-09-25 2016-04-28 伯東株式会社 ボイラ水系システムの腐食抑制剤及び腐食抑制方法
JP2017154049A (ja) * 2016-02-29 2017-09-07 栗田工業株式会社 ボイラ水の水処理方法

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022172279A1 (fr) 2021-02-15 2022-08-18 Hindustan Petroleum Corporation Limited Composé dioléyle inhibant la corrosion, et formulation d'amine de celui-ci formant un film inhibant la corrosion

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