NZ611109B2 - Aqueous acid cleaning, corrosion and stain inhibiting compositions in the vapor phase comprising a blend of nitric and sulfuric acid - Google Patents
Aqueous acid cleaning, corrosion and stain inhibiting compositions in the vapor phase comprising a blend of nitric and sulfuric acid Download PDFInfo
- Publication number
- NZ611109B2 NZ611109B2 NZ611109A NZ61110912A NZ611109B2 NZ 611109 B2 NZ611109 B2 NZ 611109B2 NZ 611109 A NZ611109 A NZ 611109A NZ 61110912 A NZ61110912 A NZ 61110912A NZ 611109 B2 NZ611109 B2 NZ 611109B2
- Authority
- NZ
- New Zealand
- Prior art keywords
- acid
- vapor phase
- nitric
- corrosion
- stainless steel
- Prior art date
Links
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 title claims abstract description 77
- 238000005260 corrosion Methods 0.000 title claims abstract description 69
- 230000007797 corrosion Effects 0.000 title claims abstract description 69
- 238000004140 cleaning Methods 0.000 title claims abstract description 46
- 239000012808 vapor phase Substances 0.000 title claims abstract description 36
- 239000000203 mixture Substances 0.000 title claims description 71
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 title claims description 50
- 230000002401 inhibitory effect Effects 0.000 title claims description 7
- 239000011260 aqueous acid Substances 0.000 title description 2
- 229910001220 stainless steel Inorganic materials 0.000 claims abstract description 66
- 239000010935 stainless steel Substances 0.000 claims abstract description 60
- 239000002253 acid Substances 0.000 claims abstract description 53
- 150000001412 amines Chemical class 0.000 claims abstract description 45
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 34
- 239000003112 inhibitor Substances 0.000 claims abstract description 21
- 238000000034 method Methods 0.000 claims abstract description 21
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims abstract description 6
- 239000004202 carbamide Substances 0.000 claims abstract description 6
- 229910017604 nitric acid Inorganic materials 0.000 claims description 42
- 238000010186 staining Methods 0.000 claims description 38
- 229910000831 Steel Inorganic materials 0.000 claims description 22
- 239000010959 steel Substances 0.000 claims description 22
- 150000002500 ions Chemical class 0.000 claims description 15
- 239000004094 surface-active agent Substances 0.000 claims description 7
- 230000008569 process Effects 0.000 claims description 4
- 150000001298 alcohols Chemical class 0.000 abstract description 30
- 229910052751 metal Inorganic materials 0.000 abstract description 11
- 239000002184 metal Substances 0.000 abstract description 11
- 238000004519 manufacturing process Methods 0.000 abstract description 5
- 239000000243 solution Substances 0.000 description 37
- 230000009467 reduction Effects 0.000 description 29
- 238000012360 testing method Methods 0.000 description 21
- 239000002689 soil Substances 0.000 description 15
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 14
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 13
- 229910052804 chromium Inorganic materials 0.000 description 12
- 239000011651 chromium Substances 0.000 description 12
- 238000007792 addition Methods 0.000 description 11
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 10
- 229910052698 phosphorus Inorganic materials 0.000 description 10
- 239000011574 phosphorus Substances 0.000 description 10
- 239000012141 concentrate Substances 0.000 description 9
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 8
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 8
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 229910045601 alloy Inorganic materials 0.000 description 7
- 239000000956 alloy Substances 0.000 description 7
- 238000004458 analytical method Methods 0.000 description 7
- 229910052799 carbon Inorganic materials 0.000 description 7
- 229910052759 nickel Inorganic materials 0.000 description 7
- 150000001875 compounds Chemical class 0.000 description 6
- 229910052500 inorganic mineral Inorganic materials 0.000 description 6
- 229910001092 metal group alloy Inorganic materials 0.000 description 6
- 239000011707 mineral Substances 0.000 description 6
- 238000010998 test method Methods 0.000 description 6
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 5
- 230000002378 acidificating effect Effects 0.000 description 5
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 5
- 239000008367 deionised water Substances 0.000 description 5
- 229910021641 deionized water Inorganic materials 0.000 description 5
- 235000013305 food Nutrition 0.000 description 5
- 239000007788 liquid Substances 0.000 description 5
- 229910000734 martensite Inorganic materials 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 229910000975 Carbon steel Inorganic materials 0.000 description 4
- 238000011109 contamination Methods 0.000 description 4
- 229910052742 iron Inorganic materials 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000003466 welding Methods 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 3
- 229910000589 SAE 304 stainless steel Inorganic materials 0.000 description 3
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 3
- 239000000654 additive Substances 0.000 description 3
- 238000005275 alloying Methods 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 238000010923 batch production Methods 0.000 description 3
- 235000013361 beverage Nutrition 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 3
- 238000010924 continuous production Methods 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- -1 ferrous metals Chemical class 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000004615 ingredient Substances 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 239000010936 titanium Substances 0.000 description 3
- 229910052719 titanium Inorganic materials 0.000 description 3
- 239000010963 304 stainless steel Substances 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 2
- 239000000788 chromium alloy Substances 0.000 description 2
- 229910000423 chromium oxide Inorganic materials 0.000 description 2
- 239000003086 colorant Substances 0.000 description 2
- 239000000356 contaminant Substances 0.000 description 2
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 2
- 239000003599 detergent Substances 0.000 description 2
- 239000000975 dye Substances 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000000945 filler Substances 0.000 description 2
- 239000006260 foam Substances 0.000 description 2
- 239000003205 fragrance Substances 0.000 description 2
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 description 2
- 150000007522 mineralic acids Chemical class 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 229910052750 molybdenum Inorganic materials 0.000 description 2
- 239000011733 molybdenum Substances 0.000 description 2
- ZODDGFAZWTZOSI-UHFFFAOYSA-N nitric acid;sulfuric acid Chemical compound O[N+]([O-])=O.OS(O)(=O)=O ZODDGFAZWTZOSI-UHFFFAOYSA-N 0.000 description 2
- 150000007524 organic acids Chemical class 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000002304 perfume Substances 0.000 description 2
- 230000002829 reductive effect Effects 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 239000012085 test solution Substances 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 241000894006 Bacteria Species 0.000 description 1
- 229910052684 Cerium Inorganic materials 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 229910000599 Cr alloy Inorganic materials 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 229910000541 Marine grade stainless Inorganic materials 0.000 description 1
- KFFQABQEJATQAT-UHFFFAOYSA-N N,N'-dibutylthiourea Chemical compound CCCCNC(=S)NCCCC KFFQABQEJATQAT-UHFFFAOYSA-N 0.000 description 1
- FLVIGYVXZHLUHP-UHFFFAOYSA-N N,N'-diethylthiourea Chemical compound CCNC(=S)NCC FLVIGYVXZHLUHP-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 1
- 229910001113 SAE steel grade Inorganic materials 0.000 description 1
- 238000010793 Steam injection (oil industry) Methods 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 125000003277 amino group Chemical group 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 229910000963 austenitic stainless steel Inorganic materials 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 239000003139 biocide Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000004061 bleaching Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000000711 cancerogenic effect Effects 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 231100000315 carcinogenic Toxicity 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 125000002091 cationic group Chemical group 0.000 description 1
- ZMIGMASIKSOYAM-UHFFFAOYSA-N cerium Chemical compound [Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce] ZMIGMASIKSOYAM-UHFFFAOYSA-N 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 235000013351 cheese Nutrition 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000004035 construction material Substances 0.000 description 1
- 235000013365 dairy product Nutrition 0.000 description 1
- 238000005238 degreasing Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000000586 desensitisation Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 239000003651 drinking water Substances 0.000 description 1
- 235000020188 drinking water Nutrition 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000806 elastomer Substances 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 239000000796 flavoring agent Substances 0.000 description 1
- 235000019634 flavors Nutrition 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 239000008233 hard water Substances 0.000 description 1
- 230000002209 hydrophobic effect Effects 0.000 description 1
- 229910001026 inconel Inorganic materials 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- 229910001105 martensitic stainless steel Inorganic materials 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 230000000813 microbial effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000010955 niobium Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000009972 noncorrosive effect Effects 0.000 description 1
- 235000006408 oxalic acid Nutrition 0.000 description 1
- FWFGVMYFCODZRD-UHFFFAOYSA-N oxidanium;hydrogen sulfate Chemical compound O.OS(O)(=O)=O FWFGVMYFCODZRD-UHFFFAOYSA-N 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 125000000963 oxybis(methylene) group Chemical group [H]C([H])(*)OC([H])([H])* 0.000 description 1
- 239000011253 protective coating Substances 0.000 description 1
- 238000011012 sanitization Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
- 230000007480 spreading Effects 0.000 description 1
- 235000000346 sugar Nutrition 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 229910000811 surgical stainless steel Inorganic materials 0.000 description 1
- 239000010966 surgical stainless steel Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 239000002562 thickening agent Substances 0.000 description 1
- 150000003585 thioureas Chemical class 0.000 description 1
- 230000036962 time dependent Effects 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 230000004580 weight loss Effects 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
- C11D1/38—Cationic compounds
- C11D1/42—Amino alcohols or amino ethers
- C11D1/44—Ethers of polyoxyalkylenes with amino alcohols; Condensation products of epoxyalkanes with amines
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
- C11D1/66—Non-ionic compounds
- C11D1/72—Ethers of polyoxyalkylene glycols
-
- C11D11/0041—
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
- C11D3/0005—Other compounding ingredients characterised by their effect
- C11D3/0073—Anticorrosion compositions
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
- C11D3/02—Inorganic compounds ; Elemental compounds
- C11D3/04—Water-soluble compounds
- C11D3/042—Acids
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
- C11D7/02—Inorganic compounds
- C11D7/04—Water-soluble compounds
- C11D7/08—Acids
-
- 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
- C23F11/02—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in air or gases by adding vapour phase inhibitors
-
- 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
- C23F11/04—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in markedly acid liquids
-
- 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
- C23F14/00—Inhibiting incrustation in apparatus for heating liquids for physical or chemical purposes
- C23F14/02—Inhibiting incrustation in apparatus for heating liquids for physical or chemical purposes by chemical means
-
- 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
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
- C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
- C23G1/04—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors
- C23G1/06—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors organic inhibitors
-
- 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
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
- C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
- C23G1/04—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors
- C23G1/06—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors organic inhibitors
- C23G1/061—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors organic inhibitors nitrogen-containing compounds
-
- 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
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
- C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
- C23G1/08—Iron or steel
- C23G1/085—Iron or steel solutions containing HNO3
Abstract
The present disclosure relates to sulfuric/ nitric blended acid cleaners which employ the use of ethoxylated amines and/or ethoxylated alcohols as a corrosion and stain inhibitor in the vapor phase for cleaning metal and other surfaces, particularly stainless steel. Method of use and manufacturing of the same are also disclosed. In one embodiment the cleaner comprises a vapor phase corrosion inhibitor, sulfuric acid, urea and water. f the same are also disclosed. In one embodiment the cleaner comprises a vapor phase corrosion inhibitor, sulfuric acid, urea and water.
Description
AQUEOUS ACID CLEANING, CORROSION AND STAIN TING
COMPOSITIONS IN THE VAPOR PHASE COMPRISING A BLEND OF
NITRIC AND SULFURIC ACID
FIELD OF THE INVENTION
The present invention relates to s acid cleaners for cleaning metal and
other surfaces, particularly stainless steel and for inhibiting both staining and corrosion
in the vapor phase. Method of use and manufacturing of the same are also disclosed.
BACKGROUND
Steel is the c name for a group of ferrous metals, composed principally of
iron, which have considerable durability and versatility. By the proper choice of carbon
content, on of alloying elements, and by le heat treatment, different kinds of
steel can be made for various purposes and the use in ry of all kinds of steel is
now quite expansive.
Stainless steel (SS) is defined as a steel alloy, with a minimum of 11%
chromium content by mass. Stainless steel does not stain, corrode, or rust as easily as
traditional steel. There are over 150 different grades and surface finishes to allow the
stainless steel to suit the environment in which it will be used. Stainless steel’s low
maintenance and relatively low cost make it an ideal base material for many
commercial applications. It is used in cookware, cutlery, hardware, surgical
ments, major appliances, industrial equipment, food and beverage processing
ry equipment, it is also used as a structural alloy for cars and as a construction
material for buildings.
Stainless steels have a passive film of chromium oxide that forms in the
presence of oxygen due to the chromium present in the steel. This layer blocks most
corrosion from spreading into the metal’s internal structure. Higher corrosion resistance
can be ed with chromium additions of 13% by weight up to 26% for harsh
environments. The chromium forms a passive layer of chromium III oxide (Cr203)
when exposed to oxygen. To have their optimum corrosion resistance, ess steel
surfaces must be clean and have an adequate supply of oxygen to maintain this passive
surface layer.
Cleaning of stainless steel includes the removal of various surface inants
to ensure corrosion resistance, to prevent contamination, and to achieve the desired
appearance of the steel. Acid cleaning is a process by which a solution of a mineral or
organic acid in water sometimes in ation with a g agent or detergent or
both, is employed to remove iron and other metallic contamination, light oxide films,
soil and similar contaminants.
Acid cleaning compositions for removing contaminants from stainless steel
lly have the mineral or organic acid in a solution with a pH of less than 7.0. The
compositions can remove both organic and inorganic soils in the same operation. They
also are used to improve corrosion resistance and enhance brightness or gloss of the
base metal surface.
One of the problems which arise in the use of steel is its corrosion, either by the
atmosphere or by the environment in which it is used. The rate of corrosion may vary,
depending on the surrounding conditions and also the composition of the steel. Stainless
steel, especially, is much more ant to corrosion than plain carbon and other steels.
This resistance is due to the addition of chromium and other metals to this alloy,
specifically stainless steel. Although stainless steel has iable resistance to
corrosion, it will still corrode in certain stances and attempts have been made to
prevent or reduce this corrosion. Most acid cleaners also include a corrosion tor of
some sort. For example, in acid media copper sulphate has been used as a ion
inhibitor. However this and other proposed inhibitors are not entirely satisfactory since,
like copper sulphate, they may be ive, introduce an effluent disposal problem
and, moreover, are not entirely effective. For example, when copper containing urea
sulfuric solutions are placed in contact with nickel metal, copper will plate the nickel
surface.
2012/050070
A variety of compounds, including dialkylthioureas, such as diethylthiourea and
dibutylthiourea, are known to reduce the corrosivity of sulfuric acid to carbon steels.
Thioureas are not appropriate for food and beverage ions as some of them have
been found to be carcinogenic and any remnant thioreas compounds are considered
contamination for such surfaces.
The type of acid used has also presented problems in development of acid
cleaners. Many acid cleaners are based upon phosphoric acid due to its diverse
functionality such as a low corrosion profile on many alloys and elastomers, good
mineral lity and good soil suspension properties. Many acid cleaners are also
based on high levels of nitric acid due to its compatibility with a variety of materials as
well as its effectiveness at mineral soil solubility and removal, however, high nitric acid
based cleaners can cause vapor staining and ion to stainless steel due to the
volatile airborne nitrogen oxides.
Phosphoric acid and nitric acid continue to have more strict effluent regulations
due to the orus and nitrate environmental and drinking water issues. It is
therefore an object of this invention to provide a phosphorous free and reduced nitric
acid based cleaning composition which has equal or superior cleaning, corrosion and
vapor stain inhibiting properties as other phosphoric and nitric acid based cleaners on
some varieties of stainless steel, such as the 300 series.
It is also an object of this invention to provide sulfuric/nitric blended acid
ng itions which are used at higher temperatures and which are relatively
noncorrosive and stain inhibiting in the vapor phase to ess steel due to addition of
an ethoxylated amine and/or an lated alcohol.
Other objects, aspects and ages of this invention will be apparent to one
skilled in the art in view of the following disclosure, the examples, and the appended
claims.
2012/050070
SUMMARY OF THE INVENTION
The present invention employs the use of an ethoxylated amine and/or an
ethoxylated alcohol as a corrosion inhibitor for use in sulfuric/ nitric acid blended
cleaning compositions. Applicants have found, surprisingly that the combination of
ethoxylated amines and/or ethoxylated alcohols as a corrosion and stain inhibitors in an
acidic cleaning solution reduce and/or inhibit vapor phase staining and corrosion. The
invention s an aqueous on of a pH of less than 7, which uses an acid as the
cleaning component. Any acid used in an acid cleaning composition may be combined
with an ethoxylated amine and/or ethoxylated alcohol according to the invention, such
as acetic acid, citric acid, oxalic acid, sulfuric acid, and nitric acid all of which are
traditionally used in acid cleaning compositions. In a preferred embodiment, the acid
cleaning solution is a blend of nitric acid and sulfuric acid. The acid cleaning
compositions of the invention retain the anti-corrosive and improve anti-staining
properties of phosphoric acid as well as the cleaning lities while ating
orus and reducing nitric acid to improve the environmental profile while
providing a less expensive t.
Typical sulfuric/ nitric blended acid cleaners contain from about 1 to about 30
weight percent, or about 5 to about 25 weight percent sulfuric acid; from about 1 to
about 25 weight percent, or about 5 to 15 weight percent nitric acid; and about 1 to
about 80 weight percent water. Nitric and sulfuric acid, in combination, constitute at
least about 5 to about 50 weight percent nitric acid and about 1 to about 30 weight
percent sulfuric acid.
According to the invention for a concentrated solution, nitric and sulfuric acid,
in combination, constitute at least about 5 to about 50 weight t nitric acid and
about 1 to about 30 weight percent sulfuric acid. The ethoxylated amine and/or
ethoxylated alcohol then, can be from about 0.05 to about 5 weight percent of the
composition, with the remainder being water, cally about 1 to about 80 weight
percent.
In some embodiments, nitric acid is present in the compositions at at least about
to about 50 weight percent, or about 5 to about 25 weight percent. In other
ments, sulfuric acid is present in the compositions at at least about 1 to about 30
weight percent. It is theorized that the nitric acid protects the surface of the stainless
steel metal from the more corrosive sulfuric acid due to its oxidizing characteristics
allowing the continuous formation of the passive chromium oxide film. This also
makes the composition less expensive and retains the low corrosivity and ng
properties ofphosphoric and nitric containing acid based cleaners. Applicants have
found that addition of a corrosion inhibitor including ethoxylated amines and/or
ethoxylated alcohols work surprisingly well in acidic cleaning compositions to
minimize the staining and corrosion of steel in the vapor phase that is often found in
high nitric acid containing solutions.
The compositions of this invention can be produced by first mixing sulfuric acid
and nitric acid and, optionally water, by either batch or continuous processes, to which
the ethoxylated amine and/or ethoxylated l is later added. While not wishing to
be bound by any theory, it is postulated that the ethoxylated ls as well as other
such ethoxylated surfactants which are intended to be within the scope of the ion,
being less water soluble at higher temperatures, oil out of solution and form an oily
layer on top of the solution that minimizes the e of acidic vapors that e and
stain the stainless steel. Furthermore, it is postulated that the ethoxylated amines
volatilize at high atures and protect the stainless steel surface by forming a
r via adsorption of the amine group to the metal e.
While multiple embodiments are disclosed, still other embodiments of the
present invention will become apparent to those skilled in the art from the following
detailed description, which shows and describes illustrative embodiments of the
invention. Accordingly, the detailed description is to be regarded as rative in nature
and not restrictive.
WO 93372
FIGURES
Figure 1 illustrates the vapor phase ng summary for a 410 stainless steel
corrosion test med at 180 degrees Fahrenheit.
Figure 2 illustrates the vapor phase staining summary for a 410 stainless steel
corrosion test performed at 160 degrees heit.
Figure 3 illustrates the vapor phase ng summary for a 304 stainless steel
corrosion test performed at 180 degrees Fahrenheit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
So that the invention maybe more readily understood, certain terms are first
defined and certain test methods are described.
As used herein, “weight percent,3’ CCwt-%,” “percent by weight,” “% by weight,”
and variations thereof refer to the concentration of a substance as the weight of that
substance divided by the total weight of the composition and lied by 100. It is
understood that, as used here, “percent,” “%,” and the like are intended to be
synonymous with “weight percent,” “wt-%,” etc.
It should be noted that, as used in this specification and the appended claims, the
singular forms “a,” “an,” and “the” include plural referents unless the content clearly
dictates otherwise. Thus, for example, reference to a composition containing “a
compound” es a composition having two or more compounds. It should also be
noted that the term “or” is generally employed in its sense including r” unless the
content clearly dictates otherwise.
As used herein, the term “phosphorus-free” refers to a composition, mixture, or
ingredient that does not contain phosphorus or a phosphorus-containing compound or to
which phosphorus or a phosphorus-containing nd has not been added. Should
phosphorus or a phosphorus-containing compound be t through contamination of
a phosphorus-free composition, mixture, or ients, the amount of phosphorus shall
be less than 0.5 wt.%. More preferably, the amount of phosphorus is less than 0.1 wt-%,
and most preferably the amount of phosphorus is les than 0.01 wt.%.
ing” means to perform or aid in soil removal, bleaching, microbial
population reduction, rinsing, or combination thereof.
The term “about,” as used herein, ing the quantity of an ingredient in the
compositions of the invention or employed in the methods of the invention refers to
variation in the numerical ty that can occur, for example, through typical
measuring and liquid handling ures used for making concentrates or use
solutions; through inadvertent error in these procedures; through differences in the
manufacture, source, or purity of the ingredients employed to make the compositions or
carry out the s; and the like. The term about also encompasses amounts that
differ due to different equilibrium conditions for a ition resulting from a
ular initial mixture. Whether or not modified by the term ,” the claims
include lents to the quantities. All numeric values are herein assumed to be
modified by the term “about,” whether or not explicitly indicated. The term “about”
lly refers to a range of numbers that one of skill in the art would consider
equivalent to the recited value (i.e., having the same function or result). In many
instances, the terms “about” may include numbers that are rounded to the nearest
significant figure.
The recitation of numerical ranges by endpoints includes all numbers subsumed
within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).
In some aspects, the present disclosure s to phosphorous free acid cleaning
compositions which may be used in place of traditional phosphoric and nitric acid
cleaning compositions, which retain the cleaning and anti-corrosive properties while
improving the anti-staining properties of the same and are less expensive to produce.
The compositions will find use in any cleaning situation where phosphoric and nitric
containing acid based cleaners can be used, including, but not limited to, stainless steel.
Stainless steels are generally classified as carbon steels containing at least about
weight percent, y about 5 to about 40 weight percent, and ly about 10 to
about 25 weight t chromium. They may also contain other alloying elements such
as nickel, cerium, aluminum, titanium, copper, or other elements.
ess steels are y classified in three different categories—austenitic,
ferritic, and martensitic steels—which have in common the fact that they n
significant amounts of chromium and resist corrosion and oxidation to a great extent
than do ordinary carbon steels and most alloy steels.
Austenitic stainless steels or 300 series, make up about 70% of stainless steel
production and are the most common alloys of this group. They contain a maximum of
0.25% carbon, a minimum of 16% um and ent nickel and manganese to
retain an austenitic structure at all temperatures from the cryogenic region to the
melting point of the alloy. A typical composition of 18% chromium and 10% nickel,
commonly known as 18/10 stainless, is often used in flatware. AISI types 302, 303,
304, and 316 are several of the more extensively used austenitic stainless steels.
Ferritic stainless steels are highly corrosion-resistant, but less durable than
austenitic grades. They are generally characterized, in part, by the fact that they contain
chromium only (in addition to the other components of carbon steel) or only very minor
amounts of alloying elements. Martensitic stainless steels are not as corrosion-resistance
as the other two classes but are ely strong and tough, as well as highly
machineable, and can be hardened by heat treatment. Martensitic stainless steel contains
chromium (about 12-14%), molybdenum (about ), nickel (about 0-2%), and
carbon (about 0.1-1%) (giving it more hardness but making the material a bit more
brittle). It is quenched and magnetic.
Stainless Steel Grades
The SAE steel grades are the most commonly used grading system in the US for
stainless steel.
300 Series- austenitic chromium-nickel alloys
0 Type 301- highly ductile, for formed products. Also hardens rapidly
during mechanical working. Good weldability. Better wear resistance and fatigue
strength than 304
0 Type 302- same ion ance as 304, with slightly higher
strength due to additional carbon
0 Type 303- free machining version of 304 Via addition of sulfur and
phosphorus
0 Type 304-the most common grade; the classic 18/8 stainless steel
0 Type 304L-same as the 304 grade but contains less carbon to
increase ility and is slightly weaker than 304.
0 Type 304LN—same as 304L, but also nitrogen is added to obtain a
much higher yield and tensile strength than 304L
0 Type 308-used as the filler metal when welding 304
0 Type 309-better ature resistance than 304, also sometimes
used as filler metal when welding dissimilar steels, along with inconel
0 Type 316-the second most common grade (after 304); for food and
surgical stainless steel uses; alloy addition of molybdenum prevents specific forms of
corrosion. It is also knows as marine grade stainless steel due to its increased resistance
to chloride corrosion compared to type 304. 316 is often used for building nuclear
essing .
0 Type 316L-extra low carbon grade of 316, generally used in stainless
steel watches and marine applications due to its high resistance to corrosion. Also
referred to as “A4” in accordance with ISO 3506.
0 Type 316 Ti-includes titanium for heat resistance, therefore it is used
in flexible chimney liners.
0 Type 321-similar to 304 but lower risk of weld decay due to addition
of titanium. See also 347 with addition of niobium for desensitization during welding.
400 Series- ferritic and martensitic chromium alloys
0 Type 405- ferritic for welding applications
0 Type 408- heat ant; poor corrosion resistance; 11% chromium,
8% nickel
0 Type 409- cheapest type; used for automobile exhausts; ferritic (iron/
um only)
0 Type 410- martensitic (high-strength iron/ um). Wear
resistant, but less corrosion ant.
0 Type 416- easy to machine due to additional sulfur
0 Type 420- Cutlery Grade martensitic; r to the Brearley’s
original rustless steel. Excellent polishability.
0 Type 430- decorative, e.g., for automotive trim; ferritic. Good
formability, but with reduced temperature and corrosion resistance.
0 Type 439- ferritic grade, a higher grade version of 409 used for
catalytic converter exhaust ns. Increased chromium for improved high
temperature corrosion/ oxidation resistance.
0 Type 440- a higher grade of cutlery steel, with more , allowing
for much better edge ion when properly heat-treated.
0 Type 446- for elevated temperature service
The acid cleaning compositions of the invention can be used in, including but
not limited to the austenitic stainless steel surfaces mentioned above. The absence of
thiol compounds makes this cleaning composition acceptable for ware washing and
cleaning of other surfaces that come into contact with food.
Clean in Place Procedures
The composition of the invention will also find use in ng mineral soils as
well. In one ment the composition may be used on stainless steel pipes which
need to use acid cleaners to e surfaces including clean in place (i.e., CIP)
applications where the cleaner is passed through the pipes without dissembling
equipment.
Exemplary ries in which the s of the present invention can be
applied include, but are not limited to: the food and beverage industry, e.g., the dairy,
cheese, sugar, and brewery industries; oil processing industry; industrial agriculture and
ethanol processing; and the pharmaceutical manufacturing industry.
In some aspects, the methods of the present invention apply to equipment, e.g.,
industrial equipment, generally cleaned using clean in place cleaning ures.
Examples of such equipment include evaporators, heat exchangers (including tube-in-
tube exchangers, direct steam injection, and plate-in-frame exchangers), heating coils
(including steam, flame or heat er fluid heated) stallizers, pan crystallizers,
spray dryers, drum dryers, membranes and tanks.
tional CIP (clean-in-place) ses are generally well known. The
process includes applying or circulating a water diluted solution of cleaning concentrate
(typically about 0.5-3% by volume) onto the surface to be cleaned. The solution flows
across the surface (3 to 6 feet/ second) to remove the soil. Either new solution is re-
applied to the surface, or the same solution is re-circulated and re-applied to the surface
as required to achieve a clean soil-free surface.
A typical CIP process to remove a soil (including organic, nic or a
mixture of the two components) often includes at least three steps: an initial water rinse
or previously used chemical rinse, an alkaline and/or acid solution wash, and a final
fresh water rinse. Additional steps may include a separate acid or alkaline wash as wall
as a separate sanitizing step. The alkaline solution s the soils and removes the
organic alkaline soluble soils. The acid solution removes any ing mineral soils.
The strength of the alkaline and acid ons, the duration of the cleaning steps and the
cleaning solution temperature are typically dependent on the amount and ty of the
soil. The water rinse removes any residual chemical solution and soils prior to the
equipment being returned on-line for tion purposes.
Ethoxylated Amines and/0r Ethoxylated ls
Amines are reacted with various amounts of ethylene oxide to ethoxylate the
amines and to modify emulsif1cation, surface n, solubility and cationic strength
properties of the base amines. Ethoxylated amines are represented by the formula
(CHZCHZO)XH
(CHZCHZO)yH
where R is the alkyl radical and x+y is 2, 5, 10, 15, or 50. Alkyl groups are
commercially available at 10 to 18 carbon atoms. An example of a commercially
available ethoxylated amine for use in the compositions includes, but is not limited to,
Ethomeen® SV/15, commercially available from AkzoNobel.
Alcohols are treated with ethylene oxide to ethoxylate the alcohol and potassium
hydroxide (KOH), which serves as a catalyst. The reactor is pressurized with en
and heated to about 150 CC. The reaction is shown below: ROH + n C2H4O —>
R(OC2H4)nOH wherein n is 5 to 10. An example of a commercially available
ethoxylated alcohol is l® 25-7 from Air Products.
The present ion employs the use of ethoxylated amines and/or ethoxylated
alcohols as a corrosion inhibitor for use in acid cleaning compositions including sulfuric
acid and/or nitric acid. Typical sulfuric/nitric blended acid cleaners contain from about
1 to about 30 weight percent sulfuric acid, from about 5 to about 50 or from about 5 to
about 25 weight percent nitric acid and about 1 to 80 weight percent water. Nitric and
sulfuric acid, in combination, constitute at least about 1 to about 50 weight percent of
the composition.
In some aspects, ethoxylated amines and/or ethoxylated alcohols are t in
the acid trate compositions at at least about 0.05 to about 5 weight percent. The
ethoxylated amines, ethoxylated alcohols and nitric acid protects the surface of the
metal from the sulfuric acid, it makes the composition less expensive and retains the
low ivity, low staining and cleaning properties of phosphoric containing acid
based cleaners. Applicants have found that on of a corrosion inhibitor including
ethoxylated amines and/or ethoxylated alcohols works surprisingly well in acidic
cleaning compositions.
The compositions of this invention can be produced by first mixing sulfuric acid
and nitric acid and, optionally water, by either batch or continuous processes, to which
the lated amine and/or ethoxylated alcohol is later added. While not wishing to
be bound by any theory, it is postulated that the lated amines and ethoxylated
alchols as well as other such amines and alcohols which are intended to be within the
scope of the invention, coat the surface of the steel to provide a protective coating
which prevents the sulfuric/ nitric blended acid from corroding the same, even in acidic
environments.
Additives
In some aspects, the aqueous solutions in accordance with embodiments of the
invention may also n other components, if this appears to be desirable. In many
cases it is ble to add surfactants in order to age a simultaneous cleaning
and degreasing effect, and to ensure satisfactory wetting of the surfaces being d
with the acid cleaning composition. The desired amount of the surfactants may be added
directly to the ent solution, but it is preferable to add them to the concentrate used
in producing the solution.
In addition to the main components other additives may be added to the
compositions depending upon the soils to be removed, the stainless steel or other
material to be cleaned, the requiring inhibiting affects, the desired final e
properties and the waste disposal requirements and ic considerations. Other
additives may also be included including but not limited to g agents to lower
solution e tension, solvents to aid in the removal of hydrophobic soils, defoamers
to prevent foam or foam buildup on solution surface, thickeners (acid ) to allow
the cleaner to adhere (cling to vertical surface), passivators to protect the surface from
nmental attack, and biocides to control odor problems and kill harmful bacteria.
Dyes and other components may also be added.
The term “surfactant” or “surface active agent” refers to an organic al
that when added to a liquid changes the properties of that liquid at a surface.
Aesthetic enhancing agents such as colorants and perfume are also ally
incorporated into the concentrate composition of the ion. Examples of colorants
useful in the present invention include but are not limited to liquid and powdered dyes
from Milliken Chemical, Keystone, Clariant, Spectracolors, and Pylam.
Examples of perfumes or fragrances useful in concentrate compositions of the
invention include but are not limited to liquid fragrances from J&E Sozio, Firmenich,
and IFF (International Flavors and nces).
It should be understood that the water provided as part of the solution or
concentrate can be relatively free of hardness. It is expected that the water can be
deionized to remove a majority of the dissolved solids in the water. The concentrate is
then diluted with water available at the locale or site of dilution and that water may
contain varying levels of hardness depending upon the locale. Although deionized is
preferred for formulating the concentrate, the concentrate can be formulated with water
that has not been deionized. That is, the trate can be ated with water that
includes dissolved solids, and can be formulated with water that can be characterized as
hard water.
Examples of useful ranges for the basic composition for the acid cleaning
composition of the invention include those provided in Table l, illustrated below:
Ethoxylated Amine and/or 0.05-5 0.05 -5
Ethoxylated Alcohol
1-80 1-60
Urea
Table 1
In an alternate embodiment, the acid cleaning ition can include the
components at the amounts shown as provided in Table 2, illustrated below:
Sulfuric Ac1d
Ethoxylated Amine and/or 0.05-5 0.05-5
Table2
In an another alternate embodiment, the acid cleaning composition can include
the components in the s shown as provided in Table 3, illustrated below:
WO 93372
Nitric Acid 5-50 5-25
lated Amine and/or
Ethoxylated Alcohol
Urea Up to 5%
Surfactant Up to 5%
Table 3
The sulfuric-nitric/ ethoxylated amine and/or ethoxylated alcohol acid
compositions can be produced by the mixture of nitric and sulfuric acid and, optionally
water, by either batch or continuous process with the addition of ethoxylated amines
and/or ethoxylated alcohols and any other ents thereafter.
Generally, during a clean in place s the concentrated formula is d
with water to a specific concentration and heated to the desired temperature and re-
circulated through the sing equipment. Without g to be bound by any
particular theory, it is thought that the ethoxylated amines in the dilute cleaning
solutions effectively inhibit vapor phase corrosion and staining of stainless steel at
temperatures ranging from 40 degrees Fahrenheit to 200 degrees Fahrenheit. It is further
thought that the ethoxylated alcohols in the dilute ng solution effectively inhibit
vapor phase corrosion and staining of stainless steel at temperatures ranging from 40
s Fahrenheit to 160 degrees Fahrenheit.
In some aspects, use of acid cleaners may involve the use of an alkaline
detergent cleaning product and water rinse, either prior to or after application of the acid
cleaner followed by a subsequent water rinse.
The invention has been shown and described herein in what is considered to be
the most practical and preferred embodiment. The applicant recognizes, however, that
departures may be made therefrom within the scope of the invention and that obvious
modifications will occur to a person skilled in the art. The examples which follow are
intended for purposes of ration only and are not ed to limit the scope of the
invention. All references cited herein are hereby incorporated in their entirety by
reference.
EXAMPLES
METAL ALLOY ION TEST METHOD
The following test method describes an accepted, but not exclusive, procedure
for metal alloy corrosion testing based on ASTM Methods such as ASTM G1 and
ASTM G31.
1. Obtain coupons, clean, passivate, measure surface area and weigh the coupons
prior to corrosion tests.
2. Subject the coupons to the corrosive environment for a period of time dependent
on the particular test purpose.
3. At the end of the test, thoroughly rinse the coupons, dry, re-weigh and calculate
the MPY (mil inch per year) according to the following calculation:
a. MPY = (534568 >< grams weight loss)/ (inches2 average surface area ><
hours time >< centimeters3 metal alloy density).
L TEST PROCEDURE FOR PIXEL ANALYSIS FOR STAINED
STAINLESS STEEL COUPONS
1. Scan the coupons using a scanner.
2. Use ImageJ software to create a gray scale ram of the scanned coupon.
3. Calculate the mean of the gray scale histogram for each area on the coupon that
is of interest, i.e. the histogram pixel analysis of a coupon’s vapor phase d area
can be compared to a non-stained histogram of another area or coupon to calculate a
percent difference.
CORROSION TEST S
A vapor phase corrosion test was performed using the metal alloy corrosion test
described above on 410 stainless steel coupons, using an equivalent acidity use solution
to 0.83% HN03 at 180 degrees Fahrenheit. The ess steel coupons were half
immersed into the test solution for 47.5 hours. The level of vapor phase staining was
ined in comparison to an unstained spot on the ess steel coupon using
histogram pixel analysis. A value of “0” indicates an unstained stainless steel coupon
whereas a negative number indicates a more stained stainless steel coupon. The results
can be seen in Figure l and Table 4 below.
Nitric Acid/
Sulfuric Acid
Nitric Acid/
Sulfuric Acid with
an Ethoxylated
Nitric Acid/ 146% increase
Sulfuric Acid with
an Ethoxylated
Stainless steel coupon #l was immersed in a deionized water solution bath and
showed relatively no vapor staining based on the histogram pixel analysis resulting in a
-1% change vs. a non-stained coupon histogram pixel is. Stainless steel coupon
#2 was immersed in a nitric acid solution bath and showed an increased amount of
staining as compared to coupon #l (deionized water). Stainless steel coupon #3 was
immersed in a nitric acid/ sulfuric acid solution bath and showed even more staining as
compared to coupon #l ized water) and coupon #2 (nitric only). Stainless steel
coupon #4 was immersed in a nitric acid/ sulfuric acid solution bath with an added
ethoxylated amine. The stain was slightly greater than coupon #1 (deionized water), but
significantly less than coupon #2 c only) and coupon #3 (nitric/sulfuric).
Comparing the vapor staining ram pixel analysis of coupon #4
(nitric/sulfuric/ethoxylated amine) to coupon #3 (nitric/sulfuric) shows a 65% reduction
in vapor phase staining and corrosion. Without wishing to be bound by any particular
theory, it is thought that the addition of the ethoxylated amine resulted in a decrease in
the vapor phase staining of the nitric/sulfuric acid blend. Lastly, stainless steel coupon
#5 was immersed in a nitric acid/ sulfuric acid solution bath with the addition of an
ethoxylated alcohol. At 180 degrees Fahrenheit, the lated amine was not
effective at inhibiting the vapor phase staining of the nitric/sulfiiric blend. The results
from this test clearly te that an ethoxylated amine is an effective vapor stain and
corrosion inhibitor for a 410 stainless steel surface at a higher temperature range.
A second test was run using the metal alloy corrosion test method described
above to measure the vapor phase staining of a 410 stainless steel coupon with various
test compositions at 160 degrees Fahrenheit. The vapor phase corrosion test was
performed with an equivalent y use on to 0.83% HN03 at 160 degrees
heit. The stainless steel coupons were half immersed in the test solutions for 65
hours. The results of this test are shown in Figure 2 and Table 5 below.
Deionized Water 0. 1 102% Reduction 101 % reduction
Nitric Acid 1.3 124% Reduction 107% reduction
3 Sulfuric Acid 246% Increase N/A
4 Nitric Acid/ ic . N/A 71% reduction
Acid
Nitric Acid/ ic -2.7 49% ion 85% reduction
Acid with an
ethoxylated alcohol
6 Nitric Acid/ Sulfuric -0.4 93% reduction 98% reduction
Acid with an
ethoxylated amine and
an ethoxylated alcohol
Nitric Acid/ ic . 103% reduction 101 % ion
Acid with an
lated amine
Table 5
Stainless steel coupons #1 (deionized) and #2 (nitric only) showed relatively
little to no vapor staining or corrosion based on the histogram pixel analysis. However,
stainless steel coupon #3 (sulfuric only) showed a relatively high level of vapor
staining. Stainless steel coupon #4 (nitric/sulfuric) showed a 71% reduction in staining
and ion in comparison to the stainless steel coupon #3 (sulfuric only). Stainless
steel coupon #5 (nitric/sulfuric/ethoxylated alcohol) was immersed in a e of nitric
acid and sulfuric acid solution with an added vapor phase staining and corrosion
inhibitor, specifically an ethoxylated alcohol. This mixture resulted in a 49% reduction
in vapor staining in comparison to coupon #4 (nitric/ sulfuric) and a 85% reduction in
vapor staining in comparison to coupon #3 (sulfuric only). Stainless steel coupon #6
(nitric/sulfuric/ethoxylate alcohol/ethoxylated amine) was immersed in a e of
nitric acid and sulfuric acid solution with two added corrosion inhibitors, specifically an
ethoxylated amine and an ethoxylated alcohol. Coupon #6 had a 93% reduction in
vapor staining in ison to coupon #4 (nitric/ sulfuric) and a 98% reduction in
staining and corrosion in comparison to coupon #3 (sulfuric only). Finally, stainless
steel coupon #7 (nitric/sulfuric/ethoxylated amine) was immersed in a mixture of nitric
acid and sulfuric acid solution with an added vapor phase staining and corrosion
inhibitor, specifically an ethoxylated amine. Coupon #7 had a 103% reduction in vapor
staining in comparison to coupon #4 (nitric/ sulfuric) and a 101% reduction in vapor to
coupon #3 (sulfuric only). This test illustrates that both an ethoxylated amine and/or an
ethoxylated alcohol are highly effective vapor stain and corrosion inhibitors for 410
stainless steel at temperatures as high as 160 degrees heit.
A third test was run using the metal alloy corrosion test method described above
to measure the vapor phase staining of a 304 stainless steel coupon with various test
compositions at 180 degrees Fahrenheit. The vapor phase corrosion test was performed
with an equivalent y use solution to 0.83% HN03 at 180 degrees Fahrenheit. The
stainless steel coupons were half immersed into the test on for approximately 300
hours. The level of vapor phase staining was ined in comparison to an unstained
spot on the stainless steel coupon using histogram pixel analysis. A value of “0”
indicates an unstained stainless steel coupon whereas a negative number indicates a
more stained stainless steel coupon. The results are shown in Figure 3 and Table 6
De1on1zcd 39 A) reduct1on 17 A) reduct1on
Water
Sulfuric Acid 112% reduction 117% reduction
Nitric Acid/ 26% reduction
Sulfuric Acid
Nitric Acid/ 94% reduction 91% reduction
Sulfuric Acid
with an
ethoxylated
amine
6 Nitric Acid/ -0.5 88% reduction 84% reduction
Sulfuric Acid
with an
ethoxylated
alcohol
Table 6
As can be seen from these s, stainless steel coupon #l (deionized water)
and #3 (sulfuric only) showed relatively little to no vapor staining or corrosion.
However, stainless steel coupon #2 (nitric only) did show mild vapor staining. Stainless
steel coupon #4 (nitric/sulfuric) was immersed in a mixture of nitric acid and sulfuric
acid and showed a 26% reduction in vapor staining in comparison to coupon #2 (nitric
only). Stainless steel coupon #5 (nitric/sulfuric/ethoxylated amine) was immersed in a
mixture of nitric acid and sulfuric acid solution with an added ion inhibitor,
specifically an ethoxylated amine, and showed a 91% reduction in vapor staining in
comparison to coupon #4 (nitric/sulfuric) and a 94% reduction in vapor ng in
comparison to coupon #2 (nitric only). Finally, stainless steel coupon #6
(nitric/sulfuric/ethoxylated alcohol) was immersed in a mixture of nitric acid and
sulfuric acid solution with an added corrosion inhibitor, specifically an ethoxylated
alcohol. Coupon #6 had a 84% ion in vapor staining in comparison to coupon #4
(nitric/sulfuric) and a 88% reduction in vapor staining in comparison to coupon #2
(nitric only). This test illustrates that both an ethoxylated amine and/or an ethoxylated
alcohol are highly effective vapor stain and corrosion inhibitors for 304 ess steel,
particularly at temperatures as high as 180 degrees Fahrenheit.
Obviously, many ations and variations of the ion as hereinbefore
set forth can be made without ing from the spirit and scope thereof, and,
therefore, only such limitations should be imposed as are indicated by the appended
claims.
134516/47
Claims (8)
1. A method of inhibiting vapor phase corrosion and staining on a stainless steel surface in a clean in place process, the method including: (a) applying a vapor phase corrosion inhibited acid cleaning composition to a ess steel surface, the composition including an acid cleaning solution in contact with the stainless steel surface and a vapor phase corrosion inhibitor and up to 4 weight percent (wt. %) urea at a composition temperature range of about 40 degrees Fahrenheit to about 200 degrees Fahrenheit, wherein the corrosion inhibitor is an lated amine having the following formula: where R is an alkyl radical and x+y is 2, 5, 10, 15, or 50.
2. The method of claim 1, wherein the vapor phase corrosion inhibited acid ng ition includes about 0.05 wt. % to about 5 wt. % vapor phase corrosion inhibitor.
3. The method of claim 1, wherein the acid ng solution includes at least one of sulfuric acid diluted with water at a concentration up to 30 wt. % or nitric acid diluted with water at a concentration up to 25 wt. % or mixtures thereof.
4. The method of any one of claims 1 to 3, wherein the vapor phase corrosion inhibited acid cleaning composition includes about 1 wt. % to about 50 wt. % of a sulfuric/ nitric blended acid ng solution in water.
5. The method of claim any one of claims 1 to 4, wherein the vapor phase ion inhibited acid cleaning ition includes about 5 wt. % to about 50 wt. % nitric acid or about 1 to about 30 wt. % sulfuric acid or mixtures thereof.
6. The method of any one of claims 1 to 5, wherein the vapor phase corrosion inhibited acid cleaning composition es about 1 wt. % to about 80 wt. % water.
7. The method of claim 1, wherein the composition is in a concentrated form that may be diluted to a usable cleaning solution concentration.
8. The method of any one of claims 1 to 7, wherein the vapor phase corrosion inhibited acid cleaning composition includes about 0.01 wt. % to about 5 wt. % surfactant.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NZ705321A NZ705321B2 (en) | 2011-01-05 | 2012-01-05 | Aqueous acid cleaning, corrosion and stain inhibiting compositions in the vapor phase comprising a blend of nitric and sulfuric acid |
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US98467011A | 2011-01-05 | 2011-01-05 | |
US12/984,670 | 2011-01-05 | ||
US13/344,119 US8618037B2 (en) | 2011-01-05 | 2012-01-05 | Aqueous acid cleaning, corrosion and stain inhibiting compositions in the vapor phase comprising a blend of nitric and sulfuric acid |
PCT/IB2012/050070 WO2012093372A2 (en) | 2011-01-05 | 2012-01-05 | Aqueous acid cleaning, corrosion and stain inhibiting compositions in the vapor phase comprising a blend of nitric and sulfuric acid |
US13/344,119 | 2012-01-05 |
Publications (2)
Publication Number | Publication Date |
---|---|
NZ611109A NZ611109A (en) | 2015-03-27 |
NZ611109B2 true NZ611109B2 (en) | 2015-06-30 |
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