WO2012090557A1 - 選択還元型触媒、およびそれを用いた排気ガス浄化装置並びに排気ガス浄化方法 - Google Patents
選択還元型触媒、およびそれを用いた排気ガス浄化装置並びに排気ガス浄化方法 Download PDFInfo
- Publication number
- WO2012090557A1 WO2012090557A1 PCT/JP2011/071414 JP2011071414W WO2012090557A1 WO 2012090557 A1 WO2012090557 A1 WO 2012090557A1 JP 2011071414 W JP2011071414 W JP 2011071414W WO 2012090557 A1 WO2012090557 A1 WO 2012090557A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- catalyst
- exhaust gas
- zeolite
- composite oxide
- weight
- Prior art date
Links
- 239000003054 catalyst Substances 0.000 title claims abstract description 241
- 230000009467 reduction Effects 0.000 title claims abstract description 48
- 238000000746 purification Methods 0.000 title claims abstract description 45
- 238000000034 method Methods 0.000 title claims abstract description 43
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims abstract description 185
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 claims abstract description 125
- 239000010457 zeolite Substances 0.000 claims abstract description 125
- 229910021536 Zeolite Inorganic materials 0.000 claims abstract description 122
- 239000007789 gas Substances 0.000 claims abstract description 101
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 72
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 68
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims abstract description 66
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims abstract description 43
- 239000004202 carbamide Substances 0.000 claims abstract description 43
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 34
- 239000000203 mixture Substances 0.000 claims abstract description 31
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 29
- 238000002485 combustion reaction Methods 0.000 claims abstract description 26
- QGLKJKCYBOYXKC-UHFFFAOYSA-N nonaoxidotritungsten Chemical compound O=[W]1(=O)O[W](=O)(=O)O[W](=O)(=O)O1 QGLKJKCYBOYXKC-UHFFFAOYSA-N 0.000 claims abstract description 22
- 229910001930 tungsten oxide Inorganic materials 0.000 claims abstract description 22
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 claims abstract description 20
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 claims abstract description 20
- 229910052742 iron Inorganic materials 0.000 claims abstract description 14
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 12
- 229910021529 ammonia Inorganic materials 0.000 claims abstract description 11
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims abstract description 10
- 235000011114 ammonium hydroxide Nutrition 0.000 claims abstract description 10
- 238000005507 spraying Methods 0.000 claims abstract description 4
- 239000002131 composite material Substances 0.000 claims description 100
- 238000006722 reduction reaction Methods 0.000 claims description 42
- 238000000576 coating method Methods 0.000 claims description 40
- 239000011248 coating agent Substances 0.000 claims description 39
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 32
- 230000007062 hydrolysis Effects 0.000 claims description 24
- 238000006460 hydrolysis reaction Methods 0.000 claims description 22
- 230000003647 oxidation Effects 0.000 claims description 22
- 238000007254 oxidation reaction Methods 0.000 claims description 22
- 238000010531 catalytic reduction reaction Methods 0.000 claims description 17
- 229930195733 hydrocarbon Natural products 0.000 claims description 10
- 150000002430 hydrocarbons Chemical class 0.000 claims description 10
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 9
- 229910002091 carbon monoxide Inorganic materials 0.000 claims description 9
- 239000007864 aqueous solution Substances 0.000 claims description 8
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 claims description 6
- 239000000243 solution Substances 0.000 claims description 5
- MGWGWNFMUOTEHG-UHFFFAOYSA-N 4-(3,5-dimethylphenyl)-1,3-thiazol-2-amine Chemical compound CC1=CC(C)=CC(C=2N=C(N)SC=2)=C1 MGWGWNFMUOTEHG-UHFFFAOYSA-N 0.000 claims description 3
- 239000004215 Carbon black (E152) Substances 0.000 claims description 3
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 claims description 3
- 239000013618 particulate matter Substances 0.000 claims description 3
- 230000001590 oxidative effect Effects 0.000 claims description 2
- 230000003197 catalytic effect Effects 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 62
- 238000006243 chemical reaction Methods 0.000 description 25
- 239000000463 material Substances 0.000 description 23
- 238000005342 ion exchange Methods 0.000 description 19
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 16
- 239000002002 slurry Substances 0.000 description 16
- 230000000694 effects Effects 0.000 description 15
- 229910004298 SiO 2 Inorganic materials 0.000 description 13
- 230000000052 comparative effect Effects 0.000 description 13
- 239000002245 particle Substances 0.000 description 11
- 238000004519 manufacturing process Methods 0.000 description 10
- 229910052751 metal Inorganic materials 0.000 description 10
- 239000002184 metal Substances 0.000 description 10
- 229910000510 noble metal Inorganic materials 0.000 description 9
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 8
- 210000004027 cell Anatomy 0.000 description 8
- 229910052697 platinum Inorganic materials 0.000 description 8
- 229910052684 Cerium Inorganic materials 0.000 description 7
- 239000012298 atmosphere Substances 0.000 description 7
- 239000011230 binding agent Substances 0.000 description 7
- 229910052878 cordierite Inorganic materials 0.000 description 7
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 7
- 239000011148 porous material Substances 0.000 description 7
- 229910052710 silicon Inorganic materials 0.000 description 7
- 238000001179 sorption measurement Methods 0.000 description 7
- WTHDKMILWLGDKL-UHFFFAOYSA-N urea;hydrate Chemical compound O.NC(N)=O WTHDKMILWLGDKL-UHFFFAOYSA-N 0.000 description 7
- 239000002253 acid Substances 0.000 description 6
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 6
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 6
- 238000000354 decomposition reaction Methods 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 6
- 230000001737 promoting effect Effects 0.000 description 6
- -1 urea oxide Chemical compound 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 229910010413 TiO 2 Inorganic materials 0.000 description 5
- 239000000446 fuel Substances 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 239000004071 soot Substances 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 238000010304 firing Methods 0.000 description 4
- 229910052763 palladium Inorganic materials 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 239000010703 silicon Substances 0.000 description 4
- 229910052721 tungsten Inorganic materials 0.000 description 4
- 229910052726 zirconium Inorganic materials 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 3
- OWIKHYCFFJSOEH-UHFFFAOYSA-N Isocyanic acid Chemical compound N=C=O OWIKHYCFFJSOEH-UHFFFAOYSA-N 0.000 description 3
- 229910002651 NO3 Inorganic materials 0.000 description 3
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 3
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 3
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 3
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 3
- 239000000654 additive Substances 0.000 description 3
- 239000012736 aqueous medium Substances 0.000 description 3
- 239000000969 carrier Substances 0.000 description 3
- 150000001768 cations Chemical class 0.000 description 3
- 239000006185 dispersion Substances 0.000 description 3
- 238000006073 displacement reaction Methods 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 238000011068 loading method Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 229910017604 nitric acid Inorganic materials 0.000 description 3
- 229910052761 rare earth metal Inorganic materials 0.000 description 3
- 150000002910 rare earth metals Chemical class 0.000 description 3
- 239000011973 solid acid Substances 0.000 description 3
- 239000007921 spray Substances 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- 229910052717 sulfur Inorganic materials 0.000 description 3
- 239000011593 sulfur Substances 0.000 description 3
- 239000004094 surface-active agent Substances 0.000 description 3
- 229910052723 transition metal Inorganic materials 0.000 description 3
- 150000003624 transition metals Chemical class 0.000 description 3
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 3
- 239000010937 tungsten Substances 0.000 description 3
- 241000269350 Anura Species 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 238000001321 HNCO Methods 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 2
- UGACIEPFGXRWCH-UHFFFAOYSA-N [Si].[Ti] Chemical compound [Si].[Ti] UGACIEPFGXRWCH-UHFFFAOYSA-N 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000006555 catalytic reaction Methods 0.000 description 2
- 210000002421 cell wall Anatomy 0.000 description 2
- 239000006255 coating slurry Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 239000002657 fibrous material Substances 0.000 description 2
- 238000005470 impregnation Methods 0.000 description 2
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 231100000572 poisoning Toxicity 0.000 description 2
- 230000000607 poisoning effect Effects 0.000 description 2
- 239000010970 precious metal Substances 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 241000894007 species Species 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- 238000005979 thermal decomposition reaction Methods 0.000 description 2
- 238000009283 thermal hydrolysis Methods 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- 229910052777 Praseodymium Inorganic materials 0.000 description 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- XHCLAFWTIXFWPH-UHFFFAOYSA-N [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] XHCLAFWTIXFWPH-UHFFFAOYSA-N 0.000 description 1
- 150000001242 acetic acid derivatives Chemical class 0.000 description 1
- 238000005903 acid hydrolysis reaction Methods 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- XLJMAIOERFSOGZ-UHFFFAOYSA-N anhydrous cyanic acid Natural products OC#N XLJMAIOERFSOGZ-UHFFFAOYSA-N 0.000 description 1
- 150000007514 bases Chemical class 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 125000002091 cationic group Chemical group 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- RCFVMJKOEJFGTM-UHFFFAOYSA-N cerium zirconium Chemical compound [Zr].[Ce] RCFVMJKOEJFGTM-UHFFFAOYSA-N 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical compound [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000012013 faujasite Substances 0.000 description 1
- 229910052733 gallium Inorganic materials 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910052680 mordenite Inorganic materials 0.000 description 1
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 1
- 229910052759 nickel Inorganic materials 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
- 150000002823 nitrates Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 238000010979 pH adjustment Methods 0.000 description 1
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000000197 pyrolysis Methods 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 229910052707 ruthenium Inorganic materials 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000011232 storage material Substances 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- 229910001935 vanadium oxide Inorganic materials 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9459—Removing one or more of nitrogen oxides, carbon monoxide, or hydrocarbons by multiple successive catalytic functions; systems with more than one different function, e.g. zone coated catalysts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9404—Removing only nitrogen compounds
- B01D53/9409—Nitrogen oxides
- B01D53/9413—Processes characterised by a specific catalyst
- B01D53/9418—Processes characterised by a specific catalyst for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
- B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
- B01J29/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65
- B01J29/78—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 containing arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
- B01J21/066—Zirconium or hafnium; Oxides or hydroxides thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
- B01J23/24—Chromium, molybdenum or tungsten
- B01J23/30—Tungsten
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
- B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
- B01J29/40—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
- B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
- B01J29/40—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively
- B01J29/42—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively containing iron group metals, noble metals or copper
- B01J29/46—Iron group metals or copper
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
- B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
- B01J29/40—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively
- B01J29/48—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively containing arsenic, antimony, bismuth, vanadium, niobium tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
- B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
- B01J29/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65
- B01J29/7007—Zeolite Beta
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
- B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
- B01J29/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65
- B01J29/72—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 containing iron group metals, noble metals or copper
- B01J29/76—Iron group metals or copper
- B01J29/7615—Zeolite Beta
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/19—Catalysts containing parts with different compositions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/02—Impregnation, coating or precipitation
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/20—Reductants
- B01D2251/206—Ammonium compounds
- B01D2251/2062—Ammonia
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/20—Reductants
- B01D2251/206—Ammonium compounds
- B01D2251/2067—Urea
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/20—Metals or compounds thereof
- B01D2255/206—Rare earth metals
- B01D2255/2065—Cerium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/20—Metals or compounds thereof
- B01D2255/207—Transition metals
- B01D2255/20715—Zirconium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/20—Metals or compounds thereof
- B01D2255/207—Transition metals
- B01D2255/20738—Iron
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/20—Metals or compounds thereof
- B01D2255/207—Transition metals
- B01D2255/20776—Tungsten
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/30—Silica
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/40—Mixed oxides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/40—Mixed oxides
- B01D2255/407—Zr-Ce mixed oxides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/50—Zeolites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/50—Zeolites
- B01D2255/504—ZSM 5 zeolites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/90—Physical characteristics of catalysts
- B01D2255/902—Multilayered catalyst
- B01D2255/9022—Two layers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
- B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
- B01J29/40—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively
- B01J29/405—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively containing rare earth elements, titanium, zirconium, hafnium, zinc, cadmium, mercury, gallium, indium, thallium, tin or lead
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
- B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
- B01J29/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65
- B01J29/7049—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 containing rare earth elements, titanium, zirconium, hafnium, zinc, cadmium, mercury, gallium, indium, thallium, tin or lead
- B01J29/7057—Zeolite Beta
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2066—Selective catalytic reduction [SCR]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Definitions
- the present invention relates to a selective reduction catalyst, an exhaust gas purification device using the selective reduction catalyst, and an exhaust gas purification method. More specifically, the present invention relates to a boiler by spraying urea water or ammonia water as a reducing component to a selective reduction catalyst. Nitrogen oxides contained in exhaust gas from lean combustion engines such as gas turbines, lean burn gasoline engines, diesel engines, etc., from a low temperature to a high temperature, space velocity (also referred to as SV) is a high SV (30 k-60 khr).
- the present invention relates to a selective reduction catalyst that can effectively purify even under ultra-high SV (60 khr ⁇ 1 or more) to ⁇ 1 ), has excellent heat resistance and low pressure loss, and an exhaust gas purifying apparatus and an exhaust gas purifying method using the same.
- Exhaust gas emitted from lean combustion engines contains various harmful substances derived from fuel and combustion air.
- harmful substances include hydrocarbons (HC), soluble organic fractions (also referred to as SOF), soot, carbon monoxide (CO), and nitrogen oxides (NOx).
- HC hydrocarbons
- SOF soluble organic fractions
- SOF soot
- CO carbon monoxide
- NOx nitrogen oxides
- NOx purification technology that uses a catalyst is a selective reduction catalyst that contains NOx-containing exhaust gas in the presence of ammonia (NH 3 ) component, mainly composed of vanadium oxide, zeolite, etc.
- NH 3 ammonia
- a technique for reducing denitration by contacting with a catalyst is known as a selective reduction method or a selective catalytic reduction (hereinafter, also referred to as SCR) method.
- NOx is finally reduced to N 2 mainly by the following reaction formulas (1) to (3).
- the NH 3 / NOx molar ratio should be 1.0, but transient engine operation during operation of the diesel engine obtained when the conditions and, and the space velocity, temperature of the exhaust gas, when the temperature of the catalyst surface are not suitable, the choice but to increase the NH 3 / NOx ratio of the NH 3 component supplied to obtain sufficient denitration performance
- the leaked NH 3 may be referred to as slip or NH 3 slip.
- NH 3 gas may be used as a reducing component, but NH 3 itself has an irritating odor and harmfulness. Therefore, a method has been proposed in which urea water is added as an NH 3 component from the upstream of the denitration catalyst, NH 3 is generated by thermal decomposition or hydrolysis, and this is used as a reducing agent to exhibit denitration performance.
- the reaction formula for obtaining NH 3 by such decomposition of urea is as follows (4) to (6).
- Urea is spray-supplied as urea water from the upstream of the SCR catalyst.
- NH 3 mainly contributes to the reduction and purification of NOx
- the reaction of NOx in the SCR catalyst is affected by the decomposition efficiency of urea. If the decomposition efficiency of urea is low, not only the efficiency of NOx purification is lowered, but also the amount of urea used increases, and there is a possibility that NH 3 slip is induced by unreacted urea.
- Non-patent Document 1 In the purification of NOx by NH 3 component, the reaction is promoted in an atmosphere containing approximately half of NO and NO 2 as in the above formula (3) (Non-patent Document 1).
- NO nitric oxide
- Patent Document 2 In order to efficiently purify NOx, it has been proposed to dispose NO oxidation means in the exhaust gas flow path in order to increase the concentration of the NO 2 component in the exhaust gas (Patent Document 2).
- a method of simultaneously purifying harmful particulate components and NOx with one catalyst system using such NO oxidation means One of them is that an oxidation catalyst, a filter, and an SCR catalyst are arranged in this order in the exhaust gas flow path, and an ammonia component is sprayed before the SCR catalyst (Patent Document 3).
- exhaust gas from gas turbines and gas engines has high temperature and high SV (space velocity), and NO X removal under such conditions is a problem for selective catalytic reduction (SCR) catalysis.
- SCR selective catalytic reduction
- As a catalyst for performing selective catalytic reduction of nitrogen oxides with ammonia at an exhaust temperature of more than about 300 ° C. a first component containing zeolite and a second component composed of each substance or mixture of cerium, iron, copper, etc.
- An SCR catalyst containing an oxygen storage material has been proposed (Patent Document 1).
- the SCR catalyst examples include “cerium mixed washcoat catalyst” using a material containing alumina, mixed zeolite, and Ce / Zr-based oxide, and high NOx removal at a high temperature such as 550 ° C. It is said that efficiency has been obtained.
- the exhaust gas from a diesel engine can vary widely in space velocity from 1 k to 150 khr ⁇ 1 .
- the denitration efficiency of the SCR catalyst is confirmed at a relatively low space velocity of 15 to 25 khr ⁇ 1 , but it is considered that the denitration efficiency is lowered at a relatively high space velocity exceeding that.
- An object of the present invention is to supply urea water or ammonia water as a reducing component to the selective reduction catalyst by spraying, so that it is included in exhaust gas from boilers, gas turbines, lean burn gasoline engines, diesel engines, and other lean combustion engines.
- An object of the present invention is to provide a selective reduction catalyst that can effectively purify nitrogen oxides even under a high SV and has a small pressure loss, an exhaust gas purifying apparatus and an exhaust gas purifying method using the same.
- an SCR catalyst comprising a specific zeolite and a composite oxide having a specific composition consisting of silica, tungsten oxide, ceria, and zirconia as a denitration component. If necessary, a composite oxide (C) composed of titania, silica, and zirconia is used as a urea hydrolysis component, and the catalyst bed temperature is reduced over a wide range of temperatures from 150 ° C. to 580 ° C.
- the present invention has been completed by finding that nitrogen oxide components in exhaust gas exhausted from a lean combustion engine can be purified with high efficiency by urea or aqueous ammonia, and the activity can be maintained even after heat treatment at a high temperature of about 650 ° C. It came to do.
- the selective reduction type for selectively reducing nitrogen oxides by adding urea or ammonia as a nitrogen oxide reducing agent to the exhaust gas discharged from the lean combustion engine.
- the surface of the monolithic support is coated with a catalyst layer containing a zeolite (A) containing at least an iron element and a composite oxide (B) made of silica, tungsten oxide, ceria and zirconia as a denitration component.
- the composite oxide (B) has a composition of silica: 20 wt% or less, tungsten oxide: 1-50 wt%, ceria: 1-60 wt%, and zirconia: 30-90 wt%
- a selective reduction catalyst is provided.
- the composite oxide (B) has a composition of silica: 5 wt% or less, tungsten oxide: 3-30 wt%, ceria: 5-40 There is provided a selective catalytic reduction catalyst characterized in that it is in weight percent and zirconia: 50 to 90 weight percent.
- the catalyst layer further includes a composite oxide (C) composed of titania, silica, and zirconia as a urea hydrolysis component. A selective reduction catalyst is provided.
- the composition of the composite oxide (C) is titania: 70 to 95% by weight, silica: 1 to 10% by weight, and zirconia: 5 to A selective reduction catalyst characterized by being 20% by weight is provided.
- the zeolite (A) is ⁇ -type zeolite (A1) and / or MFI-type zeolite (A2) ion-exchanged with iron.
- a selective reduction catalyst is provided.
- a catalyst is provided.
- the coating amount of the denitration component or urea hydrolysis component constituting the catalyst layer is 20 to 320 g / L.
- a selective reduction catalyst is provided.
- the selective reduction characterized in that the coating amount of the zeolite (A) is 10 to 80% by weight with respect to the whole catalyst layer.
- a type catalyst is provided.
- the coating amount of the composite oxide (B) is 20 to 90% by weight with respect to the entire catalyst layer.
- a selective reduction catalyst is provided.
- the coating amount of the composite oxide (C) is 1 to 30% by weight relative to the entire catalyst layer.
- a selective reduction catalyst is provided.
- the zeolite (A) containing at least an iron element, silica, tungsten oxide, ceria, And a catalyst layer comprising a composite oxide (B) made of zirconia and a composite oxide (C) made of titania, silica, and zirconia is coated in two upper and lower layers.
- the coating amount of the lower layer is 20 to 80% by weight, and the coating amount of the upper layer is 80 to 20% by weight.
- a featured selective reduction catalyst is provided.
- the lower layer comprises zeolite (A) 50 to 90% by weight, composite oxide (B) 10 to 40% by weight, and composite oxide (C).
- a selective catalytic reduction catalyst comprising 1 to 30% by weight is provided.
- the upper layer is 10 to 40% by weight of the zeolite (A), 50 to 90% by weight of the composite oxide (B), and the composite oxide (C).
- a selective catalytic reduction catalyst comprising 1 to 30% by weight is provided.
- an oxidation catalyst having an oxidation function of nitric oxide and hydrocarbons and a filter (DPF) for collecting and removing particulate matter in the exhaust gas passage.
- a spray means for supplying an aqueous urea solution or an aqueous ammonia solution, and the selective catalytic reduction catalyst according to any one of the first to fourteenth inventions are arranged in this order.
- the exhaust gas purified from the lean combustion engine is passed through the oxidation catalyst (DOC) and the filter (DPF) using the exhaust gas purifying apparatus according to the fifteenth aspect of the present invention.
- an exhaust gas purification method characterized by reducing the nitrogen oxide.
- a specific zeolite and a composite oxide having a specific composition composed of silica, tungsten oxide, ceria, and zirconia are included as a denitration component.
- NOx in the exhaust gas can be purified with high efficiency over a wide temperature range from high to high. Further, it can be effectively purified even under a high SV (30 to 60 khr ⁇ 1 ) to a very high SV (60 khr ⁇ 1 or more), excellent in heat resistance, and pressure loss can be reduced.
- the SCR catalyst can be reduced in weight and size, and the problem of mounting space for the exhaust gas purification catalyst device for automobiles can be reduced. In addition, it can meet the demands for lower fuel consumption and higher output.
- FIG. 1 is a graph comparing NOx purification performance with urea using a selective catalytic reduction catalyst of the present invention and comparing with a conventional catalyst.
- FIG. 2 is a graph in which pressure loss is measured using the selective reduction catalyst of the present invention and compared with a conventional catalyst.
- the selective reduction type catalyst of the present invention (hereinafter sometimes referred to as the present catalyst) is a process in which urea oxide or ammonia is added to the exhaust gas discharged from a lean combustion engine as a nitrogen oxide reducing agent.
- a catalyst layer containing a zeolite (A) containing at least an iron element and a composite oxide (B) made of silica, tungsten oxide, ceria and zirconia is used as a denitration component.
- the composite oxide (B) is coated on the surface of the monolithic structure type carrier and has a composition of silica: 20% by weight or less, tungsten oxide: 1-50% by weight, ceria: 1-60% by weight, and zirconia: 30 It is characterized by being -90% by weight.
- the zeolite (A) is a denitration component containing at least an iron element.
- These zeolites can be mentioned. Among them, ⁇ -type zeolite or MFI-type zeolite is preferable.
- the ⁇ -type zeolite preferably used in the present catalyst is classified, for example, as a tetragonal synthetic zeolite whose unit cell composition is represented by the following average composition formula.
- M m / x [Al m Si (64-m) O 128 ] .pH 2 O (Wherein M is a cationic species, x is the valence of M, m is a number greater than 0 and less than 64, and p is a number greater than or equal to 0)
- This ⁇ -type zeolite has a relatively complicated three-dimensional pore structure composed of linear pores having a relatively large diameter and unidirectionally aligned pores and curved pores intersecting with the pores. And diffusion of gas molecules such as NH 3 are easy.
- such a structure has only a linear hole in which mordenite, faujasite, etc. are aligned in one direction, whereas it is a unique structure, and because it is such a complicated hole structure, ⁇ -zeolite is highly effective because it is difficult to cause structural breakdown due to heat and has high stability.
- zeolite needs to have an acid point capable of adsorbing a basic compound such as NH 3 , but the number of acid points varies depending on the Si / Al ratio.
- zeolite with a low Si / Al ratio has a large number of acid sites, but the degree of deterioration is large in durability in the presence of water vapor, and on the contrary, zeolite with a high Si / Al ratio is excellent in heat resistance.
- NH 3 is adsorbed on the acid sites of the zeolite, which becomes active sites to reduce and remove nitrogen oxides such as NO 2, so the one with more acid sites (Si / Al ratio) The lower one is advantageous for the denitration reaction.
- a molar ratio of SiO 2 to Al 2 O 3 (hereinafter abbreviated as SAR) is generally used by component analysis.
- SAR has a trade-off relationship between durability and activity, but considering these, the SAR of zeolite is preferably 15 to 300, more preferably 17 to 60. Such characteristics are also possessed by ⁇ -type zeolite and MFI-type zeolite.
- the zeolite (A) of the present catalyst contains zeolite containing an iron element as a main component. Usually, zeolite has a cation as a counter ion as a solid acid point. As the cation, ammonium ions and protons are generally used.
- an iron element is added as a cation species to the ⁇ -type zeolite used in the present catalyst.
- Fe- ⁇ an iron element added as a cation species to the ⁇ -type zeolite used in the present catalyst.
- Fe- ⁇ an iron element added as a cation species to the ⁇ -type zeolite used in the present catalyst.
- NO is oxidized to NO 2 on the zeolite surface to increase the reaction activity with NH 3
- the framework structure of the zeolite is It is thought that it is stabilized and contributes to the improvement of heat resistance.
- the amount of Fe added to the zeolite is preferably 0.1 to 5% by weight, more preferably 0.5 to 4.5% by weight in terms of Fe 2 O 3 .
- the amount of iron element exceeds 5% by weight in terms of Fe 2 O 3 , the number of active solid acid points cannot be secured and the activity is lowered. If the amount of iron element is less than 0.1% by weight in terms of Fe 2 O 3 , it is not preferable because sufficient NOx purification performance cannot be obtained and exhaust gas purification performance is lowered. In addition, although all of the iron element added as an ion exchange seed may be ion-exchanged, a part thereof may exist in the state of iron oxide.
- the method for supporting the iron element may be an ion exchange method or an impregnation method.
- a metal catalyst component it is desirable that at least a part of the zeolite is ion-exchanged with the metal catalyst component.
- the metal catalyst component may not be completely ion-exchanged, and a part thereof may exist as an oxide.
- Zeolite to which such an iron element is added is commercially available in various grades from the manufacturer, and can be produced as described in JP-A-2005-502451.
- nitrates, acetates, chlorides, etc. containing iron elements may be dissolved in an aqueous solution, and then zeolite may be added and supported by an impregnation method.
- the precipitate obtained by adjusting the pH may be dried and calcined, or immersed in an aqueous solution in which nitrate, acetate, chloride, etc.
- the firing temperature is preferably 300 to 800 ° C, more preferably 400 to 600 ° C.
- a heating means it can carry out by well-known heating means, such as an electric furnace and a gas furnace.
- MFI type zeolite As a zeolite having a three-dimensional pore structure preferable as a zeolite of the present catalyst, for example, MFI type zeolite is also known as an SCR component.
- the Si / Al ratio of the MFI type zeolite is also the same as that of the ⁇ type zeolite described above.
- the MFI type zeolite contains an iron element like the ⁇ type zeolite.
- the MFI-type zeolite containing an iron element may be hereinafter referred to as “Fe-MFI”.
- the zeolite species may be used in combination with one or more of various types of zeolite such as A, X, Y, MOR, CHA, and SAPO.
- the total proportion of the various ⁇ -type zeolites or MFI-type zeolites in the total zeolite is preferably 50 to 100%.
- the zeolite may contain other transition metals, rare earth metals, noble metals, and the like.
- transition metals such as nickel, cobalt, zirconium and copper, and rare earth metals such as cerium, lanthanum, praseodymium and neodymium.
- noble metals such as gold, silver, platinum, palladium, rhodium, iridium, ruthenium and elements such as niobium, tungsten, tantalum, tin, gallium, ceria, cerium-zirconium composite oxide, lanthanum oxide, alumina, silica, zirconia,
- a metal oxide such as vanadia, or a material that can be generally used as a catalyst material, such as an alkali element or an alkaline earth element, can be appropriately added as long as the object of the present invention is not impaired.
- the zeolite (A) preferably contains 50 to 100% by weight, more preferably 60 to 100% by weight of the zeolite containing Fe element with respect to the total amount of zeolite.
- Zeolite containing no iron element also has low activity as an SCR, so it is not desirable to increase the amount of such zeolite.
- Composite oxide (B) is a denitration component of the present catalyst, and is an oxide substantially composed of silica, tungsten oxide, ceria, and zirconia.
- the composition of the composite oxide (B) is preferably 20% by weight or less of silica, 1 to 50% by weight of tungsten oxide, 1 to 60% by weight of ceria, and 30 to 90% by weight of zirconia.
- the silica is 5% by weight or less
- the tungsten oxide is 3 to 30% by weight
- the ceria is 5 to 40% by weight
- the zirconia is 50 to 90% by weight.
- the function of each component in the composite oxide (B) is not clear, but is considered as follows.
- Silica is known to have a high BET specific surface area compared to various metal oxides, and increases the number of active sites by increasing the BET specific surface area in a complex oxide system composed of silica and other elements. There is a possibility to make it.
- Ceria is also known as a NOx adsorption functional material, and in this material system, the NOx adsorption can be promoted to promote the SCR reaction between NH 3 and NOx.
- Zirconia has other components in a thermally stable state. The effect as a dispersion holding material for high dispersion can be expected.
- tungsten oxide is highly acidic and has a large adsorption power for urea and ammonia, which are alkali components. Therefore, the use of tungsten oxide can be expected to improve the denitration performance.
- the role of tungsten (W) is important among the constituent materials, and it is preferable to have a structure in which the interface between cerium (Ce) and W promotes the DeNOx reaction.
- Si / W / Ce / Zr materials constituting the composite oxide (B) are extracted from W / Ce materials excluding Si and Zr, W / Zr materials excluding Si and Ce, and Si.
- the W / Ce material and the W / Zr material are This is because the NOx purification performance of the W / Ce material is higher than that of the / Zr material.
- this composite oxide (B) becomes said composition and structure, it will not be specifically limited by a manufacturing method.
- a starting material having a form of nitrate, sulfate, carbonate, acetate, chloride, etc. containing silicon, tungsten, cerium, and zirconium is dissolved in an aqueous solution at a time, and then mixed, pH Solids obtained by sedimentation or evaporation to dryness may be calcined by adjustment, etc., or after oxides are formed by performing the above treatment on single or multiple metal salts
- the remaining metal salts may be supported at once or sequentially.
- Each element is manufactured by adding all elements at once, or by first producing a core powder from one or several kinds of elements and then loading the remaining elements at once or sequentially, so that each element has an optimal composition.
- the composite oxide (B) contained in can be prepared.
- Composite oxide (C) When the internal combustion engine operates at a high speed or a high load, the exhaust gas becomes high temperature. Usually, at high temperatures, the thermal decomposition and hydrolysis of urea are accelerated without the aid of hydrolysis components, and the denitration reaction is likely to proceed. Further, when the reducing agent is ammonia, the catalyst layer of the present invention may not contain the hydrolysis component composite oxide (C). However, when the reducing agent is urea, for the purpose of accelerating the production of NH 3 at a low temperature and promoting the denitration reaction, the catalyst includes zeolite (A) and composite oxide (B), which are the denitration components.
- the composite oxide (C) as a hydrolysis component of the urea component.
- titania is an essential component, and an oxide containing at least one of zirconia, tungsten oxide, silica, and alumina as necessary (titania, zirconia, tungsten oxide, silica, alumina, a composite oxidation thereof) Can be used.
- These hydrolyzed components are used as composite oxides, but may be used as clusters with one or more kinds of particles selected from the above oxides.
- the heat resistance may be inferior.
- the decomposition performance of urea may be lowered, and the low-temperature activity of the catalyst may be lowered.
- the exhaust gas temperature may exceed 600 ° C. due to combustion of soot. If titania alone is used, the activity may be reduced at such times, and therefore silica or zirconia oxide is contained for the purpose of improving heat resistance.
- the hydrolysis component used in the present catalyst that is, the composite oxide (C) is preferably a composite oxide composed of titania, silica, and zirconia. More preferably, the composition is titania: 70 to 95% by weight, silica: 1 to 10% by weight, and zirconia: 5 to 20% by weight.
- This composite oxide (C) can be produced by a known method. That is, starting materials having forms such as nitrate, sulfate, carbonate, acetate, etc. containing titanium, silicon, zirconium are solubilized in an aqueous solution at a time, and then mixed and precipitated as a precipitate by adjusting pH, etc. The solid obtained by evaporating or evaporating may be calcined, or after the oxide is formed by performing the above-described treatment on a single or plural metal salts, the remaining metal salts are added at once. Or you may carry
- the denitration component of this catalyst is zeolite (A) and composite oxide (B).
- the catalyst it is effective to increase the mixing ratio of the composite oxide (B) in the denitration component.
- the reason is considered that the effect is acquired by the following three elements, for example.
- the pressure loss of the catalyst is lower in the present catalyst containing zeolite (A) and composite oxide (B) than the comparative catalyst in which the denitration component is composed only of zeolite (A). This indicates that the catalyst layer is thin.
- NH 3 is considered to diffuse into the catalyst while repeatedly adsorbing and desorbing from the solid acid sites on the surfaces of various materials contained in the catalyst. It is considered that when the catalyst diffuses more uniformly in the catalyst, the reducing agent spreads over the denitration component in the catalyst, and as a result, the denitration efficiency increases.
- the composite oxide (B) has a higher denitration reaction rate in NH 3 -SCR than the zeolite (A). This is because when the model gas purification performance of NH 3 -SCR is evaluated without converting the material powder into a catalyst, the composite oxide (B) has a higher NOx purification rate than the zeolite (A).
- the denitration component at the high temperature and high SV will be higher if the denitration component is composed only of the composite oxide (B) without using the zeolite (A). Actually this is not the case. The reason may be related to the fact that the composite oxide (B) has a smaller amount of NH 3 adsorption than the zeolite (A).
- Zeolite (A) adsorbed NH 3 amount less complex oxide than (B) alone does not have enough adsorbed NH 3 amount for advancing a sufficient denitration reaction, adsorption amount of NH 3 in the zeolite coexist (A) , And the increase in reaction opportunity with NOx due to re-adsorption of NH 3 desorbed from zeolite (A) to composite oxide (B) is due to the combined use of zeolite (A) and composite oxide (B) It is also considered to be a cause of the synergy effect.
- Monolithic structure type carrier This catalyst has a surface of the monolithic structure type carrier coated with at least a zeolite (A) and a complex oxide (B) denitration component, and further a complex oxide (C) which is a urea hydrolysis promoting component. It is preferable to coat the composition containing.
- the monolithic structure type carrier is not particularly limited, and can be selected from known honeycomb structure type carriers.
- a honeycomb structure type carrier there are a flow-through type carrier and a wall flow type carrier used for a DPF. Both of them can be used in the present invention, but the flow-through type carrier is used from the viewpoint of reducing pressure loss. Is preferred.
- a honeycomb structure type carrier may have any overall shape, and can be appropriately selected according to the structure of the exhaust system to be applied, such as a columnar type, a square column type, or a hexagonal column type.
- the number of holes in the opening can be determined in consideration of the type of exhaust gas to be processed, gas flow rate, pressure loss or removal efficiency, etc.
- the number is preferably about 100 to 1500 per square inch, and more preferably 100 to 900.
- the cell density per square inch is 100 or less, the contact area between the exhaust gas and the catalyst cannot be secured, and a sufficient exhaust gas purification function cannot be obtained. Further, if the cell density per square inch exceeds 1,500, a significant exhaust gas pressure loss occurs.
- the thickness of the cell wall of such a honeycomb structure type carrier is preferably 2 to 12 mil (milliinch), and more preferably 4 to 8 mil.
- the material of the honeycomb structure type carrier includes metals such as stainless steel and ceramics such as cordierite.
- the monolithic structure type carrier used in the present catalyst includes a sheet-like structure knitted from a thin fibrous material, and a felt-like noncombustible structure composed of a relatively thick fibrous material. The body can be used. Although these integrated structure type carriers may increase the back pressure, they have a large amount of supported catalyst components and a large contact area with the exhaust gas, so that they may have a higher processing capacity than other structural type carriers. .
- the amount of coating is a carrier having 100 to 1500 holes per square inch and a cell wall thickness of 4 to 8 mil. If present, the total amount of the catalyst is preferably 30 to 330 g / L, more preferably 35 to 300 g / L.
- the coating amount of the denitration component zeolite (A), composite oxide (B) and urea hydrolysis component composite oxide (C) constituting the catalyst layer is preferably 20 to 320 g / L, ⁇ 300 g / L is more preferable. If the coating amount is too small, the denitration effect of the present invention may not be sufficiently obtained. If the coating amount is too large, the honeycomb holes may be clogged, the exhaust gas back pressure will increase significantly, and the engine performance will deteriorate. There is a fear.
- the coating amount of zeolite (A) is 10 to 80% by weight with respect to the whole catalyst layer, and the coating amount of composite oxide (B) is 20 to 90% with respect to the whole catalyst layer.
- the coating amount of the composite oxide (C) is 1 to 30% by weight with respect to the entire catalyst layer. Within this range, a sufficient amount of denitrification component zeolite (A) and complex oxide (B) are contained with respect to the hydrolysis promoting component complex oxide (C), so that a large denitration effect can be obtained. Can do. More preferably, the coating amount of zeolite (A) is 15 to 70% by weight with respect to the whole catalyst layer, and the coating amount of composite oxide (B) is 30 to 85% with respect to the whole catalyst layer. The coating amount of the composite oxide (C) is 2 to 20% by weight based on the entire catalyst layer.
- the coating amount of zeolite (A) is less than 10% by weight relative to the entire catalyst layer, the denitration performance is insufficient, and if it exceeds 80% by weight, the increase in the denitration performance is small and the cost is high. This is because if the coating amount of the composite oxide (B) is less than 20% by weight or exceeds 90% by weight with respect to the entire catalyst layer, a composite effect with the zeolite (A) containing an iron element cannot be expected. Further, when the coating amount of the composite oxide (C) is less than 1% by weight with respect to the entire catalyst layer, the decomposition performance of urea becomes insufficient, and when it exceeds 30% by weight, the denitration performance is reduced due to the reduction of denitration components. Problems that worsen may arise.
- the present catalyst may be coated in a single layer structure on a monolithic structure type carrier, but can be coated and laminated so as to have a two-layer structure or more. That is, on the surface of the monolithic structure type carrier, zeolite (A) containing at least iron element, composite oxide (B) made of silica, tungsten oxide, ceria and zirconia, and composite oxide made of titania, silica and zirconia It is preferable that the catalyst layer containing the product (C) is coated in two upper and lower layers.
- the reason why the performance is improved by covering and laminating the two-layer structure or more can be considered as follows.
- the NOx purification rate at a relatively low temperature has a higher contribution of the upper layer portion in the catalyst layer than in the high temperature condition due to gas diffusion.
- the contribution of the entire catalyst layer to the NOx purification rate at a relatively high temperature is higher than that at low temperature.
- a mixed layer of a catalyst component having a higher reaction rate that is, a zeolite (A) having a high content ratio of the composite oxide (B) is disposed in the upper layer, and the disadvantage of the upper layer is disposed in the lower layer.
- the lower layer contains zeolite (A) 50 to 90% by weight, composite oxide (B) 10 to 40% by weight, and composite oxide (C) 1 to 30% by weight, More preferably, the upper layer contains 10 to 40% by weight of zeolite (A), 50 to 90% by weight of composite oxide (B), and 1 to 30% by weight of composite oxide (C).
- the coating amount of the lower layer is 20 to 80% by weight of the whole
- the coating amount of the upper layer is preferably 80 to 20% by weight
- the coating amount of the lower layer is 20 to 50% by weight of the whole.
- the coating amount of the upper layer is 80 to 50% by weight of the whole.
- the zeolite containing iron element contained in one layer is preferably 50% by weight or more of the total amount of zeolite in the catalyst, and 80% by weight or more of the zeolite containing iron element. It is preferable that it is 90% by weight or more. Even if the amount of zeolite containing no iron element contained in one layer is large, as long as the amount of zeolite containing iron element contained in one layer contained in another layer is sufficient, the catalyst as a whole as the SCR Can supplement the activity.
- the titania contained in the composite oxide (C) as a hydrolysis promoting component may be present in both the upper layer and the lower layer, but a higher concentration in the upper layer may be preferable.
- urea When urea is supplied into the exhaust gas, urea diffuses from the surface of the SCR catalyst to the inside of the catalyst. However, when titania is contained in the upper layer, it is quickly decomposed into NH 3 and the entire SCR catalyst reaching the lower layer. This is because it is supplied as NH 3 having high reactivity with NOx, and purification of exhaust gas is promoted.
- the catalyst is not particularly limited by its production method, and can be produced by a conventionally known method.
- a catalyst component the zeolite (A), the composite oxide (B), and, if necessary, the composite oxide (C) are prepared.
- these catalyst components and additives such as binders and surfactants as necessary are mixed with an aqueous medium to form a slurry mixture, which is then applied to a monolithic support, dried and fired to integrate the catalyst components.
- a structural catalyst is used.
- the aqueous medium may be used in such an amount that each catalyst component can be uniformly dispersed in the slurry.
- various additives can be added as necessary.
- additives in addition to surfactants used to adjust viscosity and improve slurry dispersibility, acids and alkalis for pH adjustment can be blended, and surfactants, dispersion resins, etc. can be blended. .
- pulverization and mixing by a ball mill or the like can be applied, but other pulverization or mixing methods may be applied.
- the coating method is not particularly limited, but a wash coat method is preferable.
- drying and firing are performed to obtain a monolithic structure type catalyst on which the composition of the present catalyst is supported.
- the drying temperature is preferably 100 to 400 ° C, more preferably 100 to 300 ° C.
- the firing temperature is preferably 400 to 700 ° C, particularly preferably 400 to 600 ° C.
- the drying time is preferably 0.5 to 3 hours, and the firing time is preferably 0.5 to 3 hours.
- a heating means it can carry out by well-known heating means, such as an electric furnace and a gas furnace.
- a plurality of slurry-like mixtures may be prepared and the above operation may be repeated twice. At that time, it may be dried and baked after being coated twice by the wash coat method, or may be dried after being coated by the wash coat method, and dried and baked after coating the second and subsequent layers thereon. Good.
- Exhaust gas purification device The exhaust gas purification device of the present invention includes an oxidation catalyst (DOC) having an oxidation function of nitrogen monoxide and hydrocarbons and a filter (DPF) for collecting and removing particulate matter in an exhaust gas passage. ), A spray means for supplying an aqueous urea solution or an aqueous ammonia solution, and the selective catalytic reduction catalyst are arranged in this order.
- DOC oxidation catalyst
- DPF filter
- Diesel engines have a relatively low exhaust gas temperature compared to gasoline engines due to their structural characteristics, and the temperature is generally room temperature to 700 ° C.
- the exhaust gas temperature is particularly low during start-up and low loads. However, when the temperature of the exhaust gas is low, the temperature of the catalyst does not rise sufficiently, the purification performance is not sufficiently exhibited, and NOx in the exhaust gas is easily exhausted without being sufficiently purified.
- an oxidation catalyst that oxidizes HC and CO in the exhaust gas, and combustible particle components contained in the exhaust gas
- the filter (DPF) which collects is arranged.
- the oxidation catalyst a known platinum or a catalyst mainly composed of activated alumina on which at least one of palladium is supported can be used.
- activated alumina containing La can also be used.
- a catalyst containing ⁇ -type zeolite ion-exchanged with cerium may be used.
- the DOC preferably contains a platinum component or a palladium component as a noble metal component, and the amount of the noble metal component is preferably 0.1 to 4 g / L, preferably 0.5 to 3 g / L in terms of metal. It is more preferable. And the noble metal component is too much becomes a high cost, sometimes not too little Suitable NO 2 / NOx ratio.
- the noble metal component preferably contains 30 to 100 w% platinum in terms of metal, and more preferably 50 to 100 w% platinum. Since light oil used for diesel automobile fuel contains a sulfur component, noble metals in the catalyst component may be poisoned by exhaust gas.
- the precious metal component palladium is known to be prone to sulfur poisoning, whereas platinum is known to be less susceptible to sulfur poisoning. Therefore, it is preferable to use platinum as a main component in the DOC used in the present invention as a noble metal component.
- This SCR catalyst is arrange
- the combustion engine to which the present invention is applied ranges from a small automobile having a displacement of about 1 L to a heavy-duty diesel engine having a displacement of more than 50 L, and exhausted from these diesel engines.
- NOx in the exhaust gas varies greatly depending on its operating state, combustion control method, and the like.
- the SCR catalyst for NOx purification in these diesel engine exhaust gas can also be selected according to the diversity of the diesel engine displacement from about 1L to over 50L.
- the combustible particle components collected by the DPF are then burned and removed, and the DPF function is regenerated. NO 2 may be used for burning soot in the DPF.
- DPFs are coated with an oxidation catalyst for the purpose of promoting this combustion regeneration, and as described above, they are called CSF (Catalyzed Soot Filter).
- CSF Catalyzed Soot Filter
- the DPF includes CSF coated with such an oxidation catalyst.
- a NOx occlusion catalyst may be used in addition to the SCR as in the present method, which is called LNT (Lean NOx Trap).
- LNT Lean NOx Trap
- the NOx occluded in the LNT purifies NOx using HC and CO, which are reducing components in the exhaust gas, as a reducing agent, but this method may be combined with such an LNT.
- the exhaust gas purification method of the present invention uses the exhaust gas purification device described above to allow exhaust gas discharged from a lean combustion engine to pass through an oxidation catalyst (DOC) and a filter (DPF), and in the exhaust gas. After purifying the hydrocarbon component, carbon monoxide, and converting most of the nitric oxide into nitrogen dioxide, it is sprayed with an aqueous urea solution or an aqueous ammonia solution, passed through a selective catalytic reduction catalyst, and nitrogen in the exhaust gas. The oxide is reduced.
- DOC oxidation catalyst
- DPF filter
- the selective catalytic reduction catalyst has a specific component composition, not only under a space velocity lower than 30 khr ⁇ 1, but also from a high SV (30 k-60 HR ⁇ 1 ) to a very high SV (60 khr ⁇ ). (1 or more) can be effectively purified, heat resistance is excellent, and pressure loss can be reduced.
- Urea hydrolysis component i.e., milled using a composite oxide (C) (87 wt% TiO 2/10 wt% ZrO 2/3 wt% SiO 2) was prepared 54 g, to adjust the concentration of water mill given Particle diameter.
- a composite oxide (B) i.e. Si / W / Ce / Zr-based material (1 wt% SiO 2/10 wt% WO 3/23 wt% CeO 2/66 wt% ZrO 2) 679g, then zeolite (A), i.e.
- an integral structure carrier specifically, a honeycomb flow-through cordierite carrier (300 cell 5 mil, ⁇ 9 inch ⁇ 7 inch length) is immersed in a slurry for coating, and the integral structure carrier is obtained by a wash coat method.
- a catalyst component of 280 g per unit volume was coated, preheated at 350 ° C. for 4 hours in an air atmosphere, and then subjected to a baking treatment at 450 ° C. for 1 hour.
- Table 1 shows the catalyst amount per unit volume and the composition of the obtained SCR catalyst (1). In Table 1, the numerical value is the carrying amount [g / L] per unit volume of the honeycomb flow-through cordierite carrier.
- Urea hydrolysis component i.e. providing a composite oxide (C) (87 wt% TiO 2/10 wt% ZrO 2/3 wt% SiO 2) 54 g, was charged into a ball mill to obtain a predetermined particle size.
- C composite oxide
- This coating slurry is immersed in a honeycomb flow-through type cordierite carrier (300 cell 5 mil, ⁇ 9 inch ⁇ 7 inch length) as an integral structure carrier, and 280 g per unit volume of the integral structure carrier by a wash coat method.
- the catalyst component was applied.
- a baking treatment at 450 ° C. for 1 hour was performed.
- Table 1 shows the catalyst amount per unit volume and the composition of the obtained SCR catalyst (2).
- First urea hydrolysis component i.e. providing a composite oxide (C) (87 wt% TiO 2/10 wt% ZrO 2/3 wt% SiO 2) 54 g, was charged into a ball mill to obtain a predetermined particle size.
- C composite oxide
- composite oxide (B) ie Si / W / Ce / Zr-based material (1 wt% SiO 2 / 10 wt% WO 3/23 wt% CeO 2/66 wt% ZrO 2) 232g, are sequentially charged binder 36 g, was slurry for application.
- an integral structure carrier specifically, a honeycomb flow-through cordierite carrier (300 cell 5 mil, ⁇ 9 inch ⁇ 7 inch length) is immersed in a slurry for coating, and the integral structure carrier is obtained by a wash coat method. 280 g of catalyst component was applied per unit volume. Thereafter, a baking treatment at 550 ° C. for 30 minutes was performed in an air atmosphere. The amount of catalyst per unit volume and the composition of the obtained SCR catalyst (3) are shown in Table 1 as in the case of the SCR catalyst (1).
- composite oxide (B) ie Si / W / Ce / Zr-based material (1 wt% SiO 2 / 10 wt% WO 3/23 wt% CeO 2/66 wt% ZrO 2) 232g, are sequentially charged binder 36 g, was slurry for application.
- an integral structure carrier specifically, a honeycomb flow-through cordierite carrier (300 cells, 5 mil, ⁇ 9 inch ⁇ 7 inch length) is immersed in the slurry for coating, and the integral structure carrier is obtained by a wash coat method.
- 112 g of the catalyst component was applied per unit volume.
- a baking treatment at 550 ° C. for 30 minutes was performed in an air atmosphere to obtain a lower layer coated product.
- Upper layer (Top) First urea hydrolysis component, i.e. providing a composite oxide (C) (87 wt% TiO 2/10 wt% ZrO 2/3 wt% SiO 2) 54 g, was charged into a ball mill to obtain a predetermined particle size.
- this slurry for coating (C) was applied to the above-mentioned lower layer coated product by the wash coat method.
- preheating was performed at 350 ° C. for 4 hours in an air atmosphere, followed by baking treatment at 450 ° C. for 1 hour to obtain SCR (4).
- the amount of catalyst per unit volume and the composition of the obtained SCR catalyst (4) are shown in Table 1 as in the case of the SCR catalyst (1).
- comparative SCR catalyst (1) The composite oxide (B) of the SCR catalyst (3) is transferred to a BEA type zeolite (A), and the composite oxide (C) is a titanium-silicon composite oxide (SiO 2 equivalent silicon content; 10 wt. %, BET value; 100 m 2 / g), a comparative SCR catalyst (1) was obtained. About each obtained comparative SCR catalyst, the catalyst amount [g / L] per unit volume and a composition are described in Table 1 similarly to this SCR catalyst (1).
- titanium-silicon composite oxide SiO 2 equivalent silicon content: 10 wt%, BET value: 100 m 2 / g
- an integral structure carrier specifically, a honeycomb flow-through cordierite carrier (300 cell 5 mil, ⁇ 9 inch ⁇ 7 inch length) is immersed in a slurry for coating, and the integral structure carrier is obtained by a wash coat method.
- a catalyst component of 280 g per unit volume was coated and subjected to a baking treatment at 450 ° C. for 1 hour in an air atmosphere.
- the catalyst amount [g / L] per unit volume and a composition are described in Table 1 similarly to this SCR catalyst (1).
- Examples 1 to 4 (Comparative Examples 1 and 2)
- the SCR catalysts (1) to (4) obtained as described above were measured for NOx purification performance and pressure loss under the following measurement conditions.
- the comparative SCR catalysts (1) and (2) were also tested in the same manner and their performance was compared.
- the measurement of pressure loss used the product name: Super Flow made from Colorado Springs. The results are shown in FIGS.
- the present invention can be used for purification technology of NOx generated by lean combustion, for example, for moving objects such as diesel cars, gasoline cars, ships, and stationary applications such as generators.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Combustion & Propulsion (AREA)
- Biomedical Technology (AREA)
- Health & Medical Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Catalysts (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Exhaust Gas After Treatment (AREA)
Abstract
Description
4NO + 4NH3 + O2 → 4N2 + 6H2O …(1)
6NO2 + 8NH3 → 7N2 + 12H2O …(2)
NO + NO2 + 2NH3 → 2N2 + 3H2O …(3)
このような尿素の分解でNH3を得る反応式は、以下の(4)~(6)のとおりである。
NH2-CO-NH2 → NH3 + HNCO (4;尿素熱分解)
HNCO + H2O → NH3 + CO2 (5;イソシアン酸加水分解)
NH2-CO-NH2 + H2O → 2NH3 + CO2 (6;尿素加水分解)
また、スリップするNH3の量が多くなると、触媒に高い酸化能力が要求され、活性種である白金など高価な貴金属を多量に使用する必要があった。
このようなNO酸化手段を利用して、有害微粒子成分、NOxを一つの触媒系で同時に浄化する方法も提案されている。その一つが、排気ガス流路中に酸化触媒、フィルター、SCR触媒をこの順に配置し、SCR触媒の前段でアンモニア成分を噴霧するものである(特許文献3)。
ディーゼル機関からの排気ガスは、特許文献1に記載されているように空間速度が1k~150khr-1と広範に変動しうる。特許文献1では、15k~25khr-1の比較的低い空間速度でSCR触媒の脱硝効率を確認しているが、それを超える比較的高い空間速度では脱硝効率が低下すると考えられる。
また、本発明の第3の発明によれば、第1の発明において、触媒層が、さらに尿素加水分解成分として、チタニア、シリカ、及びジルコニアからなる複合酸化物(C)を含むことを特徴とする選択還元型触媒が提供される。
また、本発明の第4の発明によれば、第3の発明において、複合酸化物(C)の組成が、チタニア:70~95重量%、シリカ:1~10重量%、及びジルコニア:5~20重量%であることを特徴とする選択還元型触媒が提供される。
また、本発明の第5の発明によれば、第1の発明において、ゼオライト(A)が、鉄でイオン交換したβ型ゼオライト(A1)及び/又はMFI型ゼオライト(A2)であることを特徴とする選択還元型触媒が提供される。
また、本発明の第6の発明によれば、第1の発明において、ゼオライト(A)が、鉄元素をFe2O3換算で0.5~5重量%含むことを特徴とする選択還元型触媒が提供される。
また、本発明の第7の発明によれば、第1又は3の発明において、触媒層を構成する脱硝成分又は尿素加水分解成分の被覆量が、20~320g/Lであることを特徴とする選択還元型触媒が提供される。
さらに、本発明の第8の発明によれば、第1の発明において、ゼオライト(A)の被覆量が、触媒層の全体に対して、10~80重量%であることを特徴とする選択還元型触媒が提供される。
また、本発明の第10の発明によれば、第1の発明において、複合酸化物(C)の被覆量が、触媒層の全体に対して、1~30重量%であることを特徴とする選択還元型触媒が提供される。
さらに、本発明の第11の発明によれば、一体構造型担体の表面に、第1~10のいずれかの発明において、少なくとも鉄元素を含むゼオライト(A)と、シリカ、酸化タングステン、セリア、及びジルコニアからなる複合酸化物(B)と、チタニア、シリカ、及びジルコニアからなる複合酸化物(C)を含む触媒層が上下二層に被覆されていることを特徴とする選択還元型触媒が提供される。
また、本発明の第12の発明によれば、第11の発明において、下層の被覆量が全体の20~80重量%であり、上層の被覆量が全体の80~20重量%であることを特徴とする選択還元型触媒が提供される。
また、本発明の第13の発明によれば、第11の発明において、下層がゼオライト(A)50~90重量%、複合酸化物(B)10~40重量%、及び複合酸化物(C)1~30重量%を含むことを特徴とする選択還元型触媒が提供される。
さらに、本発明の第14の発明によれば、第11の発明において、上層がゼオライト(A)10~40重量%、複合酸化物(B)50~90重量%、及び複合酸化物(C)1~30重量%を含むことを特徴とする選択還元型触媒が提供される。
また、本発明の第16の発明によれば、第15発明の排気ガス浄化装置を用いて、希薄燃焼機関から排出される排気ガスを酸化触媒(DOC)とフィルター(DPF)に通過させ、排気ガス中の炭化水素成分、一酸化炭素を浄化するとともに、一酸化窒素の多くを二酸化窒素に転化した後、尿素水溶液またはアンモニア水溶液を噴霧供給して、選択還元型触媒を通過させて排気ガス中の窒素酸化物を還元することを特徴とする排気ガス浄化方法が提供される。
本発明の選択還元型触媒(以下、本触媒ということがある)は、希薄燃焼機関から排出される排気ガスに窒素酸化物の還元剤として尿素またはアンモニアを添加し窒素酸化物を選択的に還元するための選択還元型触媒において、少なくとも鉄元素を含むゼオライト(A)と、シリカ、酸化タングステン、セリア、及びジルコニアからなる複合酸化物(B)を含む触媒層を脱硝成分として、一体構造型担体の表面に被覆してなり、複合酸化物(B)の組成が、シリカ:20重量%以下、酸化タングステン:1~50重量%、セリア:1~60重量%、及びジルコニア:30~90重量%であることを特徴とする。
本発明においてゼオライト(A)は、少なくとも鉄元素を含む脱硝成分であり、例えば三次元の細孔構造を有するβ型、MFI型のゼオライトをはじめ、A、X、Y、MOR、CHA、SAPOなどのゼオライトが挙げられる。中でも好ましいのは、β型ゼオライト、又はMFI型のゼオライトである。
Mm/x[AlmSi(64-m)O128]・pH2O
(式中、Mはカチオン種であり、xは前記Mの価数であり、mは0を越え64未満の数であり、pは0以上の数である)
このβ型ゼオライトは、比較的大きな径を有する一方向に整列した直線的細孔とこれに交わる曲線的細孔とからなる比較的複雑な3次元細孔構造を有し、イオン交換時のカチオンの拡散、およびNH3等のガス分子の拡散が容易である。また、このような構造はモルデナイト、ホージャサイト等が一方向に整列した直線的な空孔のみを有するのに対して、特異な構造であり、このような複雑な空孔構造であるがゆえに、βゼオライトは、熱による構造破壊が生じ難く安定性が高く、自動車用触媒にとって有効な材料である。
本触媒のゼオライト(A)には、鉄元素を含むゼオライトが主成分として含有される。通常、ゼオライトには固体酸点として、カチオンがカウンターイオンとして存在する。カチオンとしては、アンモニウムイオンやプロトンが一般的であるが、本触媒に使用されるβ型ゼオライトにはカチオン種として鉄元素が添加され、以下、本発明では「Fe-β」ということがある。
鉄元素でイオン交換されたβ型ゼオライトによって本発明の作用が向上する理由は定かではないが、ゼオライト表面においてNOをNO2に酸化してNH3との反応活性を高め、ゼオライトの骨格構造が安定化され、耐熱性の向上に寄与していると考えられる。
ゼオライトに対するFeの添加量は、Fe2O3換算で0.1~5重量%が好ましく、0.5~4.5重量%がより好ましい。鉄元素の量がFe2O3換算で5重量%を超えると、活性な固体酸点の数が確保できなくなり活性が下がる。鉄元素の量がFe2O3換算で0.1重量%未満では、充分なNOx浄化性能が得られず排気ガスの浄化性能が低下するので好ましくない。なお、イオン交換種として添加される鉄元素は、その全てがイオン交換されても良いが、その一部が酸化鉄の状態で存在していても良い。
本触媒を他のタイプのゼオライトと併用する場合には、全ゼオライト中、前記各種β型ゼオライト若しくはMFI型ゼオライトのトータルの比率が50~100%であることが好ましい。
また、ゼオライトは、前記鉄元素の他に、他の遷移金属、希土類金属、また貴金属などを含んでいてもよい。具体的には、ニッケル、コバルト、ジルコニウム、銅などの遷移金属、セリウム、ランタン、プラセオジム、ネオジウムなどの希土類金属、などを挙げることができる。
また、金、銀、白金、パラジウム、ロジウム、イリジウム、ルテニウム等の貴金属やニオブ、タングステン、タンタル、スズ、ガリウムなどの元素、セリア、セリウム・ジルコニウム複合酸化物、酸化ランタン、アルミナ、シリカ、ジルコニア、バナジアなどの金属酸化物や、アルカリ元素、アルカリ土類元素など一般に触媒材料として使用可能な材料を、本発明の目的を阻害しない範囲で適宜添加することができる。
複合酸化物(B)は、本触媒の脱硝成分であって、実質的にシリカ、酸化タングステン、セリア、及びジルコニアからなる酸化物である。
複合酸化物(B)中の各成分の機能については、明確ではないものもあるが、おおよそ次のように考えられる。
またセリアは、NOx吸着機能材料として知られており、本材料系においてもNOx吸着を促進することでNH3とNOxのSCR反応を促進でき、ジルコニアは、その他成分を熱的に安定な状態で高分散させる為の分散保持材料としての効果を期待できる。
一方、タングステンの酸化物は、酸性が強く、アルカリ成分である尿素やアンモニアの吸着力が大きいので、タングステンの酸化物を使用することで脱硝性能が高くなるという作用効果を期待できる。
この複合酸化物(B)は、上記の組成、構造になれば、製法によって特に限定されない。一例を示せば、珪素、タングステン、セリウム、ジルコニウムを含む硝酸塩、硫酸塩、炭酸塩、酢酸塩、塩化物等の形態を有する出発原料を一度に水溶液中に可溶させた後、混合し、pH調整等により沈殿物として沈降させるか蒸発乾固させるかして得られた固形物を焼成してもよいし、単一もしくは複数の金属塩に上記処理を行うことにより酸化物を形成させた後、残りの金属塩を一度にまたは逐次に担持してもよい。
一度にすべての元素を加えて製造するか、最初に核となる粉末を単数もしくは数種類の元素から製造した後、残りの元素を一度にまたは逐次に担持させることにより、各々の元素を最適な組成で含有する複合酸化物(B)を調製することができる。
内燃機関が高回転あるいは高負荷で稼動する時には排気ガスは高温となる。通常高温時には加水分解成分の補助が無くとも尿素の熱分解・加水分解が促進され、脱硝反応が進行しやすい。また還元剤がアンモニアの場合、本発明の触媒層に加水分解成分の複合酸化物(C)は含まれないものでもよい。
しかし、還元剤が尿素である場合は、特に低温でのNH3生成を促進し脱硝反応を促進させる目的で、本触媒には前記の脱硝成分であるゼオライト(A)、複合酸化物(B)に加え、尿素成分の加水分解成分として複合酸化物(C)を含有することが望ましい。
このような加水分解成分としては、チタニアを必須成分とし、必要によりジルコニア、酸化タングステン、シリカ、アルミナのうち少なくとも一つを含む酸化物(チタニア、ジルコニア、酸化タングステン、シリカ、アルミナ、これらの複合酸化物)を使用する事ができる。また、これら加水分解成分は、複合酸化物として使用するが上記酸化物の中から選択された1種以上の粒子とのクラスターとして使用しても良く、他に希土類金属成分、遷移金属成分等が添加されていてもよい。
この複合酸化物(C)は、公知の方法で製造できる。すなわち、チタン、珪素、ジルコニウムを含む硝酸塩、硫酸塩、炭酸塩、酢酸塩等の形態を有する出発原料を一度に水溶液中に可溶させた後、混合し、pH調整等により沈殿物として沈降させるか蒸発乾固させるかして得られた固形物を焼成してもよいし、単一もしくは複数の金属塩に上記処理を行なうことにより酸化物を形成させた後、残りの金属塩を一度にまたは逐次に担持してもよい。
本触媒の脱硝成分であるゼオライト(A)と複合酸化物(B)に対する加水分解促進成分である複合酸化物(C)の重量比は、[(C)/((A)+(B))]が、0/100~3/7である。[(C)/((A)+(B))]=1/100~3/7である事が望ましく、1/50~1/5がより望ましい。ゼオライト(A)または複合酸化物(B)の量が多すぎると、還元成分である尿素の分解性能が劣る場合があり、量が少なすぎるとNOxの浄化性能が劣る場合がある。
まず第1には、脱硝成分中の複合酸化物(B)の混合割合を高めることにより、触媒層でのガスの拡散性が向上する可能性がある点である。後述するように触媒の圧力損失は、脱硝成分がゼオライト(A)のみで構成される比較触媒よりも、ゼオライト(A)と複合酸化物(B)を含む本触媒の方が低い。これは触媒層が薄いことを示している。特に低温側では、触媒に含まれる各種材料表面の固体酸点にNH3が吸着・脱離を繰り返しながら、触媒中に拡散していくと考えられる。触媒中により均一に拡散する方が、触媒中の脱硝成分に還元剤がいきわたることとなり、結果的に脱硝効率が上がると考えられる。
また、第2には複合酸化物(B)がゼオライト(A)よりもNH3-SCRにおける脱硝反応の反応速度が高いことも一因であると考えられる。材料粉末を触媒化せず粉末のままで、NH3-SCRのモデルガス浄化性能評価をすると、ゼオライト(A)よりも複合酸化物(B)の方がNOx浄化率が高くなるからである。
なお、この第2の考えに基づけばゼオライト(A)を使用せず、複合酸化物(B)のみで脱硝成分を構成させる方が、高温高SV時の脱硝効率が高くなる筈であるが、実際にはそのようにはならない。その理由として、複合酸化物(B)のNH3吸着量がゼオライト(A)よりも少ないことが関係する可能性がある。ゼオライト(A)よりもNH3吸着量の少ない複合酸化物(B)のみでは脱硝反応を十分に進ませる為のNH3吸着量が足りず、共存させるゼオライト(A)でのNH3の吸着分、およびゼオライト(A)から脱離してくるNH3の複合酸化物(B)への再吸着によるNOxとの反応機会の増加が、ゼオライト(A)と複合酸化物(B)を併用することによるシナジー効果の一因であるとも考えられる。
本触媒は、少なくともゼオライト(A)と複合酸化物(B)脱硝成分を一体構造型担体の表面に被覆しており、さらに尿素の加水分解促進成分である複合酸化物(C)を含む組成物を被覆していることが好ましい。
また、このようなハニカム構造型担体は、その全体形状も任意であり、円柱型、四角柱型、六角柱型など、適用する排気系の構造に応じて適宜選択できる。さらに開口部の孔数についても処理すべき排気ガスの種類、ガス流量、圧力損失あるいは除去効率などを考慮して適正な孔数が決められるが、通常、ディーゼル自動車の排気ガス浄化用途としては、1平方インチ当たり100~1500個程度が好ましく、100~900個であることがより好ましい。1平方インチ当たりのセル密度が100個以下であると、排気ガスと触媒の接触面積を確保する事ができず、充分な排気ガスの浄化機能が得られない。また1平方インチ当たりのセル密度が1500個を超えると、著しい排気ガスの圧力損失が生じる。
なお、本触媒に使用される一体構造型担体としては、ハニカム構造型担体の他にも、細い繊維状物を編んだシート状構造体、比較的太い繊維状物からなるフェルト様の不燃性構造体が使用できる。これら一体構造型担体は、背圧が高まる恐れはあるものの、触媒成分の担持量が大きく、また排気ガスとの接触面積が大きいので、他の構造型担体よりも処理能力を高くできる場合がある。
そして、ゼオライト(A)の被覆量が、触媒層の全体に対して、10~80重量%であること、複合酸化物(B)の被覆量が、触媒層の全体に対して、20~90重量%であること、複合酸化物(C)の被覆量が、触媒層の全体に対して、1~30重量%であることが好ましい。
この範囲であれば加水分解促進成分の複合酸化物(C)に対して、十分な量の脱硝成分ゼオライト(A)、複合酸化物(B)が含まれているため、大きな脱硝効果を得ることができる。より好ましいゼオライト(A)の被覆量は、触媒層の全体に対して、15~70重量%であること、複合酸化物(B)の被覆量が、触媒層の全体に対して、30~85重量%であること、複合酸化物(C)の被覆量が、触媒層の全体に対して、2~20重量%である。
ゼオライト(A)の被覆量が、触媒層の全体に対して、10重量%未満では、脱硝性能が不十分となり、80重量%を超えても脱硝性能の上昇は小さく高コストとなる。複合酸化物(B)の被覆量が、触媒層の全体に対して、20重量%未満もしくは、90重量%を超えると鉄元素を含むゼオライト(A)との複合効果が期待できないためである。また、複合酸化物(C)の被覆量が、触媒層の全体に対して、1重量%未満では、尿素の分解性能が不十分となり、30重量%を超えると脱硝成分の減少により脱硝性能が悪化する問題が生じることがある。
また、本触媒は、一体構造型担体の上に一層構造で被覆してもよいが、二層構造以上となるように被覆し積層することができる。すなわち、一体構造型担体の表面に、少なくとも鉄元素を含むゼオライト(A)と、シリカ、酸化タングステン、セリア、及びジルコニアからなる複合酸化物(B)と、チタニア、シリカ、及びジルコニアからなる複合酸化物(C)を含む触媒層が上下二層に被覆されていることが好ましい。
二層構造以上となるように被覆し積層することで性能が向上する理由は、つぎのように考えることができる。すなわち比較的低温におけるNOx浄化率には、ガス拡散の関係で触媒層の中でも比較的上層部位の寄与が高温条件と比べて高くなる。一方で比較的高温におけるNOx浄化率には、低温条件と比較して触媒層全体の寄与が高くなる。これらの特性を考えた場合に、より反応速度の速い触媒成分、すなわち複合酸化物(B)の含有比率の高いゼオライト(A)との混合層を上層に配置し、下層には上層の不利点を補う為の機能層、すなわちNH3吸着量が少ないという複合酸化物(B)の特性を補う為に上層とは逆にゼオライト(A)比率の高い混合層を下層に配置するのが性能向上に寄与すると考えられる。
具体的に本触媒においては、下層がゼオライト(A)50~90重量%、複合酸化物(B)10~40重量%、及び複合酸化物(C)1~30重量%を含むこと、一方、上層がゼオライト(A)10~40重量%、複合酸化物(B)50~90重量%、及び複合酸化物(C)1~30重量%を含むことがより好ましい。
また下層の被覆量が全体の20~80重量%であり、上層の被覆量が全体の80~20重量%であることが好ましい、更には下層の被覆量が全体の20~50重量%であり、上層の被覆量が全体の80~50重量%であることがより好ましい。このように下層の被覆量に対して、反応速度が速い脱硝成分である複合酸化物(B)をより高濃度で含む上層の被覆量を多くすることで、十分に高い脱硝性能をあげることができる。
本触媒を多層化する場合、一つの層に含まれる鉄元素を含むゼオライトは、本触媒全体のゼオライト量のうち、50重量%以上であることが好ましく、80重量%以上が鉄元素を含むゼオライトであることが好ましく、90重量%以上であることがより好ましい。一つの層に含まれる鉄元素を含まないゼオライトの量が多くても、他の層に含まれる一つの層に含まれる鉄元素を含むゼオライトの量が充分であれば、触媒全体としてSCRとしての活性を補うことができる。
加水分解促進成分として複合酸化物(C)に含まれるチタニアは、上層、下層の両方に存在させても良いが、上層での濃度が高い方が好ましい場合もある。排気ガス中に尿素が供給される場合、尿素は、SCR触媒表面から触媒内部へ拡散して行くが、上層にチタニアが含まれると、いち早くNH3に分解し、下層に至るSCR触媒全体で、NOxとの反応性の高いNH3として供給され、排気ガスの浄化が促進されるからである。
本触媒は、その製造方法によって特に制限されず、従来公知の方法によって製造することができる。
まず、触媒成分として、前記のゼオライト(A)、及び複合酸化物(B)、必要により複合酸化物(C)を用意する。その後、これら触媒成分と必要に応じてバインダーや界面活性剤などの添加剤を水系媒体と混合してスラリー状混合物にしてから、一体構造型担体へ塗工して、乾燥、焼成する事により一体構造型触媒とする。
また、一体構造型担体へ本触媒の成分を複数層形成するには、複数のスラリー状混合物を用意して上記の操作を2回繰り返せばよい。その際、ウォッシュコート法により2回塗工した後に乾燥、焼成してもよく、ウォッシュコート法により塗工した後に乾燥し、その上に二層目以降を被覆した後で乾燥、焼成してもよい。
本発明の排気ガス浄化装置は、排気ガス流路に、一酸化窒素、炭化水素の酸化機能を有する酸化触媒(DOC)と、パティキュレートマターを捕集し燃焼除去するフィルター(DPF)と、尿素水溶液もしくはアンモニア水溶液を供給する噴霧手段と、前記の選択還元型触媒をこの順序で配置したことを特徴とする。
酸化触媒としては、公知の白金、またはパラジウムのうち少なくとも一種が担持された活性アルミナを主成分とする触媒を用いることができる。なおその酸化触媒としては、活性アルミナがLaを含むものを使用することもできる。さらにセリウムでイオン交換したβ型ゼオライトを含有する触媒を用いても良い。
また、この貴金属成分には金属換算で30~100w%の白金を含む事が好ましく、50~100w%の白金を含む事がより好ましい。ディーゼル自動車の燃料に使用される軽油には硫黄成分が含まれているから、排気ガスにより触媒成分中の貴金属が被毒してしまうことがある。一方、貴金属成分のパラジウムは硫黄被毒し易い傾向が知られており、これに対し白金は硫黄被毒し難い傾向が知られている。そのため、本発明に使用されるDOCには貴金属成分として白金を主成分として使用する事が好ましい。
なお、DPFで捕集した可燃性粒子成分は、その後燃焼して除去され、DPF機能が再生される。DPFにおける煤の燃焼にはNO2を使用する場合がある。NO2による煤の燃焼は酸素に比べて穏やかであり、燃焼熱によるDPFの破損を誘発し難い。DPFにはこの燃焼再生を促進する目的で酸化触媒を被覆したものがあり、前記のとおり、CSF(Catalyzed Soot Filter)といわれている。本方法では特に断りの無い限り、DPFは、このような酸化触媒を塗布したCSFを包含するものとする。
また、排気ガス中のNOxを浄化する手段として、本方法のようなSCRとは別にNOx吸蔵触媒を使用する場合があり、LNT(Lean NOx Trap)といわれる。LNTに吸蔵されたNOxは、排気ガス中の還元成分であるHCやCOを還元剤としてNOxを浄化するが、本方法はこのようなLNTと組み合わせても良い。
本発明の排気ガス浄化方法は、前記の排気ガス浄化装置を用いて、希薄燃焼機関から排出される排気ガスを酸化触媒(DOC)とフィルター(DPF)に通過させ、排気ガス中の炭化水素成分、一酸化炭素を浄化するとともに、一酸化窒素の多くを二酸化窒素に転化した後、尿素水溶液またはアンモニア水溶液を噴霧供給して、選択還元型触媒を通過させて排気ガス中の窒素酸化物を還元することを特徴とする。
尿素加水分解成分、すなわち複合酸化物(C)(87重量%TiO2/10重量%ZrO2/3重量%SiO2)54gを用意し、水で濃度を調整しボールミルを用いてミリングして所定の粒子径とした。
複合酸化物(C)のスラリーを攪拌機で攪拌しながら、水、60%硝酸水溶液、複合酸化物(B)、すなわちSi/W/Ce/Zr系材料(1重量%SiO2/10重量%WO3/23重量%CeO2/66重量%ZrO2)679g、次にゼオライト(A)、すなわちFeイオン交換ゼオライト(Feイオン交換量;2.2重量%Fe2O3換算、BEA型、SAR=26)232g、造孔粒子60g、バインダー36gを順次投入して塗布用スラリーとした。
続いて、一体型構造担体、具体的にはハニカムフロースルー型コージェライト担体(300セル5ミル、φ9インチ×7インチ長さ)を塗布用スラリーに浸漬させ、ウォッシュコート法で、一体型構造担体の単位体積あたり280gの触媒成分を被覆し、大気雰囲気下、350℃4時間予備加熱した後に450℃1時間の焼成処理を施した。
得られた本SCR触媒(1)の単位体積あたりの触媒量、並びに組成を表1に記す。なお、表1中、数値はハニカムフロースルー型コージェライト担体の単位体積あたりの担持量[g/L]である。
尿素加水分解成分、すなわち複合酸化物(C)(87重量%TiO2/10重量%ZrO2/3重量%SiO2)54gを用意し、ボールミルに投入し、所定の粒子径とした。
続いて、複合酸化物(C)のスラリーを攪拌機で攪拌しながら、水、60%硝酸水溶液、複合酸化物(B)すなわち、Si/W/Ce/Zr系材料(1重量%SiO2/10重量%WO3/23重量%CeO2/66重量%ZrO2)679g、次にゼオライト(A)、すなわちFeイオン交換ゼオライト(Feイオン交換量;4.0重量%Fe2O3換算、MFI型、SAR=27)232g、造孔粒子66g、バインダー36gを順次投入した。
この塗布用スラリーを一体型構造担体のハニカムフロースルー型コージェライト担体(300セル5ミル、φ9インチ×7インチ長さ)に浸漬させ、ウォッシュコート法で、一体型構造担体の単位体積あたり280gの触媒成分を塗布した。その後に、大気雰囲気下、350℃4時間予備加熱した後に450℃1時間の焼成処理を施した。
得られた本SCR触媒(2)の単位体積あたりの触媒量、並びに組成を表1に記す。
まず尿素加水分解成分、すなわち複合酸化物(C)(87重量%TiO2/10重量%ZrO2/3重量%SiO2)54gを用意し、ボールミルに投入し、所定の粒子径とした。
続いて、このスラリーに、ゼオライト(A)、すなわちFeイオン交換ゼオライト(Feイオン交換量;2.2重量%Fe2O3換算、BEA型、SAR=26)357gと、Feイオン交換ゼオライト(Feイオン交換量;4.0重量%Fe2O3換算、MFI型、SAR=27)321g、次に複合酸化物(B)すなわち、Si/W/Ce/Zr系材料(1重量%SiO2/10重量%WO3/23重量%CeO2/66重量%ZrO2)232g、バインダー36gを順次投入して、塗布用スラリーとした。
続いて、一体型構造担体、具体的にはハニカムフロースルー型コージェライト担体(300セル5ミル、φ9インチ×7インチ長さ)を塗布用スラリーに浸漬させ、ウォッシュコート法で、一体型構造担体の単位体積あたり280gの触媒成分を塗布した。その後、大気雰囲気下、550℃30分の焼成処理を施した。
得られた本SCR触媒(3)の単位体積あたりの触媒量、並びに組成を、本SCR触媒(1)同様に表1に記す。
=下層(Bottom)=
まず尿素加水分解成分、すなわち複合酸化物(C)(87重量%TiO2/10重量%ZrO2/3重量%SiO2)54gを用意し、ボールミルに投入し、所定の粒子径とした。
続いて、このスラリーに、ゼオライト(A)、すなわちFeイオン交換ゼオライト(Feイオン交換量;2.2重量%Fe2O3換算、BEA型、SAR=26)357gと、Feイオン交換ゼオライト(Feイオン交換量;4.0重量%Fe2O3換算、MFI型、SAR=27)321g、次に複合酸化物(B)すなわち、Si/W/Ce/Zr系材料(1重量%SiO2/10重量%WO3/23重量%CeO2/66重量%ZrO2)232g、バインダー36gを順次投入して、塗布用スラリーとした。
その後、一体型構造担体、具体的にはハニカムフロースルー型コージェライト担体(300セル5ミル、φ9インチ×7インチ長さ)をこの塗布用スラリーに浸漬させ、ウォッシュコート法で、一体型構造担体の単位体積あたり112gの触媒成分を塗布した。その後に、大気雰囲気下で、550℃30分の焼成処理を施し、下層塗布品を得た。
=上層(Top)=
まず尿素加水分解成分、すなわち複合酸化物(C)(87重量%TiO2/10重量%ZrO2/3重量%SiO2)54gを用意し、ボールミルに投入し、所定の粒子径とした。
続いて、複合酸化物(C)のスラリーを攪拌機で攪拌しながら、水、60%硝酸水溶液、複合酸化物(B)すなわち、Si/W/Ce/Zr系材料(1重量%SiO2/10重量%WO3/23重量%CeO2/66重量%ZrO2)679g、次にゼオライト(A)、すなわちFeイオン交換ゼオライト(Feイオン交換量;4.0重量%Fe2O3換算、MFI型、SAR=27)232g、造孔粒子66g、バインダー36gを順次投入した。
その後、この塗布用スラリー(C)を上記の下層塗布品にウォッシュコート法で塗布した。こうして、一体型構造担体の単位体積あたり168gの触媒成分を塗布した後に、大気雰囲気下、350℃4時間予備加熱した後に、450℃1時間の焼成処理を施し、SCR(4)を得た。
得られた本SCR触媒(4)の単位体積あたりの触媒量、並びに組成を、本SCR触媒(1)同様に表1に記す。
上記の本SCR触媒(3)の複合酸化物(B)をBEA型のゼオライト(A)に振り替え、また複合酸化物(C)としてチタン-ケイ素複合酸化物(SiO2換算ケイ素含有率;10重量%、BET値;100m2/g)に換えて、比較SCR触媒(1)を得た。
得られた各比較SCR触媒について、単位体積あたりの触媒量[g/L]、並びに組成を、本SCR触媒(1)同様に表1に記す。
加水分解成分としてチタン-ケイ素複合酸化物(SiO2換算ケイ素含有率;10重量%、BET値;100m2/g)54g、Feイオン交換ゼオライト(Feイオン交換量;2.2重量%Fe2O3換算、BEA型、SAR=26)696g、Feイオン交換ゼオライト(Feイオン交換量;4.0重量%Fe2O3換算、MFI型、SAR=27)179g、バインダー71g、および水をボールミルに投入してミリングし塗布用スラリーとした。
続いて、一体型構造担体、具体的にはハニカムフロースルー型コージェライト担体(300セル5ミル、φ9インチ×7インチ長さ)を塗布用スラリーに浸漬させ、ウォッシュコート法で、一体型構造担体の単位体積あたり280gの触媒成分を被覆し、大気雰囲気下、450℃1時間の焼成処理を施した。
得られた各比較SCR触媒(2)について、単位体積あたりの触媒量[g/L]、並びに組成を、本SCR触媒(1)同様に表1に記す。
上記のようにして得た本SCR触媒(1)~(4)について、下記測定条件のもと、NOxの浄化性能と、圧力損失を測定した。また、比較SCR触媒(1)(2)についても、同様に実験し、性能を比較した。なお、圧力損失の測定には、Colorado Springs社製の商品名:Super Flowを使用した。結果を、図1,2に示す。
・エンジン:ディーゼル5Lエンジン
・還元剤成分:32.5重量%尿素水溶液
・尿素水噴霧量:排気ガス中のNH3/NOx比率を1.0に制御
・触媒の熱処理条件:630℃×50時間、10vol%水蒸気含有空気気流中
・触媒の床温度とSV;表2を参照
上記本SCR触媒(1)~(4)を用いた実施例と、比較SCR触媒(1)~(2)を用いた比較例を対比することで、次のことが分かる。
すなわち、本発明の選択還元型触媒、本SCR触媒(1)~(4)は、図1に示すとおり従来タイプの比較SCR(1)(2)と比べて、いずれもNOx浄化性能が優れている。また図2に示すとおり圧力損失が小さく優れている。また、本SCR触媒(4)の性能は本SCR触媒(1)~(3)と比べた場合、最もNOx浄化性能が高いことが分かる。
Claims (16)
- 希薄燃焼機関から排出される排気ガスに窒素酸化物の還元剤として尿素またはアンモニアを添加し窒素酸化物を選択的に還元するための選択還元型触媒において、
少なくとも鉄元素を含むゼオライト(A)と、シリカ、酸化タングステン、セリア、及びジルコニアからなる複合酸化物(B)を含む触媒層を脱硝成分として、一体構造型担体の表面に被覆してなり、複合酸化物(B)の組成が、シリカ:20重量%以下、酸化タングステン:1~50重量%、セリア:1~60重量%、及びジルコニア:30~90重量%であることを特徴とする選択還元型触媒。 - 複合酸化物(B)の組成が、シリカ:5重量%以下、酸化タングステン:3~30重量%、セリア:5~40重量%、及びジルコニア:50~90重量%であることを特徴とする請求項1記載の選択還元型触媒。
- 触媒層が、さらに尿素加水分解成分として、チタニア、シリカ、及びジルコニアからなる複合酸化物(C)を含むことを特徴とする請求項1記載の選択還元型触媒。
- 複合酸化物(C)の組成が、チタニア:70~95重量%、シリカ:1~10重量%、及びジルコニア:5~20重量%であることを特徴とする請求項3記載の選択還元型触媒。
- ゼオライト(A)が、鉄でイオン交換したβ型ゼオライト(A1)及び/又はMFI型ゼオライト(A2)であることを特徴とする請求項1記載の選択還元型触媒。
- ゼオライト(A)が、Fe2O3換算で鉄元素を0.1~5重量%含むことを特徴とする請求項1記載の選択還元型触媒。
- 触媒層を構成する脱硝成分又は尿素加水分解成分の被覆量が、20~320g/Lであることを特徴とする請求項1又は3記載の選択還元型触媒。
- ゼオライト(A)の被覆量が、触媒層の全体に対して、10~80重量%であることを特徴とする請求項1記載の選択還元型触媒。
- 複合酸化物(B)の被覆量が、触媒層の全体に対して、20~90重量%であることを特徴とする請求項1記載の選択還元型触媒。
- 複合酸化物(C)の被覆量が、触媒層の全体に対して、1~30重量%であることを特徴とする請求項1記載の選択還元型触媒。
- 一体構造型担体の表面に、請求項1~10のいずれかに記載の少なくとも鉄元素を含むゼオライト(A)と、シリカ、酸化タングステン、セリア、及びジルコニアからなる複合酸化物(B)と、チタニア、シリカ、及びジルコニアからなる複合酸化物(C)を含む触媒層が上下二層に被覆されていることを特徴とする選択還元型触媒。
- 下層の被覆量が全体の20~80重量%であり、上層の被覆量が全体の80~20重量%であることを特徴とする請求項11記載の選択還元型触媒。
- 下層がゼオライト(A)50~90重量%、複合酸化物(B)10~40重量%、及び複合酸化物(C)1~30重量%を含むことを特徴とする請求項11記載の選択還元型触媒。
- 上層がゼオライト(A)10~40重量%、複合酸化物(B)50~90重量%、及び複合酸化物(C)1~30重量%を含むことを特徴とする請求項11記載の選択還元型触媒。
- 排気ガス流路に、一酸化窒素、炭化水素の酸化機能を有する酸化触媒(DOC)と、パティキュレートマターを捕集し燃焼除去するフィルター(DPF)と、尿素水溶液もしくはアンモニア水溶液を供給する噴霧手段と、請求項1~14のいずれかに記載の選択還元型触媒をこの順序で配置したことを特徴とする排気ガス浄化装置。
- 請求項15に記載の排気ガス浄化装置を用いて、希薄燃焼機関から排出される排気ガスを酸化触媒(DOC)とフィルター(DPF)に通過させ、排気ガス中の炭化水素成分、一酸化炭素を浄化するとともに、一酸化窒素の多くを二酸化窒素に転化した後、尿素水溶液またはアンモニア水溶液を噴霧供給して、選択還元型触媒を通過させて排気ガス中の窒素酸化物を還元することを特徴とする排気ガス浄化方法。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/884,164 US8741240B2 (en) | 2010-12-27 | 2011-09-21 | Selective reduction catalyst, and exhaust gas purification device and exhaust gas purification method using same |
JP2012550753A JP5769732B2 (ja) | 2010-12-27 | 2011-09-21 | 選択還元型触媒、およびそれを用いた排気ガス浄化装置並びに排気ガス浄化方法 |
KR1020137013175A KR20140027062A (ko) | 2010-12-27 | 2011-09-21 | 선택 환원형 촉매, 및 그것을 이용한 배기가스 정화 장치 및 배기가스 정화 방법 |
CN201180059555.8A CN103260752B (zh) | 2010-12-27 | 2011-09-21 | 选择还原型催化剂、以及使用其的废气净化装置和废气净化方法 |
EP11854194.5A EP2659974B1 (en) | 2010-12-27 | 2011-09-21 | Selective reduction catalyst, and exhaust gas purification device and exhaust gas purification method using same |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2010290311 | 2010-12-27 | ||
JP2010-290311 | 2010-12-27 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2012090557A1 true WO2012090557A1 (ja) | 2012-07-05 |
Family
ID=46382682
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2011/071414 WO2012090557A1 (ja) | 2010-12-27 | 2011-09-21 | 選択還元型触媒、およびそれを用いた排気ガス浄化装置並びに排気ガス浄化方法 |
Country Status (6)
Country | Link |
---|---|
US (1) | US8741240B2 (ja) |
EP (1) | EP2659974B1 (ja) |
JP (1) | JP5769732B2 (ja) |
KR (1) | KR20140027062A (ja) |
CN (1) | CN103260752B (ja) |
WO (1) | WO2012090557A1 (ja) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103464142A (zh) * | 2013-10-10 | 2013-12-25 | 西北化工研究院 | 用于氨选择催化还原脱除氮氧化物的催化剂及其制备方法 |
JP2015196116A (ja) * | 2014-03-31 | 2015-11-09 | 株式会社キャタラー | Scr用触媒及び排ガス浄化触媒システム |
JP2015196115A (ja) * | 2014-03-31 | 2015-11-09 | 株式会社キャタラー | Scr用触媒及び排ガス浄化触媒システム |
KR20160045178A (ko) * | 2014-10-16 | 2016-04-27 | 현대자동차주식회사 | 디젤차량의 백연 저감 시스템 |
JP2016513585A (ja) * | 2013-03-14 | 2016-05-16 | ビーエーエスエフ コーポレーション | 選択的な触媒作用の還元触媒系 |
US9387438B2 (en) | 2014-02-14 | 2016-07-12 | Tenneco Automotive Operating Company Inc. | Modular system for reduction of sulphur oxides in exhaust |
JP2017500187A (ja) * | 2013-10-30 | 2017-01-05 | ジョンソン、マッセイ、パブリック、リミテッド、カンパニーJohnson Matthey Public Limited Company | 三元触媒、及びそれの排気システムでの使用 |
US10792614B2 (en) * | 2012-02-06 | 2020-10-06 | Basf Se | Process and apparatus for treatment of gas streams containing nitrogen oxides |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2013005850A2 (en) | 2011-07-01 | 2013-01-10 | Toyota Jidosha Kabushiki Kaisha | Exhaust Purification System for Internal Combustion Engine |
CA2900291A1 (en) * | 2013-03-14 | 2014-10-02 | Basf Corporation | Selective catalytic reduction catalyst system |
EP3212326A1 (en) * | 2014-10-28 | 2017-09-06 | SMH Co., Ltd. | Metathesis catalyst on mixed metal oxide-zeolite support and process for use thereof |
CN104645797B (zh) * | 2015-01-31 | 2017-02-22 | 浙江海洋学院 | 一种油船废气处理及利用废气制惰的装置和工艺 |
KR101791051B1 (ko) | 2015-03-11 | 2017-10-30 | 한화토탈 주식회사 | 다환식 방향족 화합물로부터 btx 함유 단일 고리 방향족 화합물의 전환 방법 |
CN110099732A (zh) | 2016-12-20 | 2019-08-06 | 优美科股份公司及两合公司 | 含有氧化钒和含有铁的分子筛的scr催化剂装置 |
EP3558493A1 (de) * | 2016-12-20 | 2019-10-30 | Umicore AG & Co. KG | Scr-katalysatorvorrichtung enthaltend vanadiumoxid und eisen-haltiges molekularsieb |
GB201705279D0 (en) * | 2017-03-31 | 2017-05-17 | Johnson Matthey Plc | Selective catalytic reduction catalyst |
KR102154586B1 (ko) * | 2019-09-17 | 2020-09-10 | 대영씨엔이(주) | 선택적 촉매 환원 반응의 환원제 분사 시스템 및 방법 |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0538420A (ja) | 1991-01-08 | 1993-02-19 | Agency Of Ind Science & Technol | 窒素酸化物の除去処理方法 |
JP2002502927A (ja) | 1998-02-06 | 2002-01-29 | ジョンソン、マッセイ、パブリック、リミテッド、カンパニー | 排ガス中のNOxの還元機構 |
JP2005502451A (ja) | 2001-09-07 | 2005-01-27 | エンゲルハード・コーポレーシヨン | NOx還元用の水熱的に安定な金属による助触媒作用を受けているゼオライトベータ |
JP2005111436A (ja) * | 2003-10-10 | 2005-04-28 | Valtion Teknillinen Tutkimuskeskus | 窒素酸化物を接触的に除去するための方法とそのための装置 |
JP2005238196A (ja) * | 2004-02-27 | 2005-09-08 | Tokyo Roki Co Ltd | 窒素酸化物浄化用触媒、並びにそれを用いた窒素酸化物の浄化方法及び窒素酸化物浄化装置 |
JP2008049290A (ja) * | 2006-08-25 | 2008-03-06 | Tokyo Roki Co Ltd | 窒素酸化物を浄化する触媒、方法、及び装置 |
WO2009080152A1 (en) * | 2007-12-21 | 2009-07-02 | Umicore Ag & Co. Kg | Method for treating nox in exhaust gas and system therefore |
JP2009262098A (ja) * | 2008-04-28 | 2009-11-12 | Ne Chemcat Corp | 選択還元触媒を用いた排気ガス浄化方法 |
JP2009538736A (ja) | 2007-01-09 | 2009-11-12 | 田中貴金属工業株式会社 | 高温アンモニアscr触媒とその使用方法 |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2907444B1 (fr) * | 2006-10-20 | 2008-12-19 | Rhodia Recherches & Tech | Composition a acidite elevee a base d'oxydes de zirconium,de silicium et d'au moins un autre element choisi parmi le titane,l'aluminium,le tungstene,le molybdene,le cerium,le fer et le manganese |
US8636959B2 (en) * | 2007-05-09 | 2014-01-28 | N.E. Chemcat Corporation | Selective catalytic reduction type catalyst, and exhaust gas purification equipment and purifying process of exhaust gas using the same |
JP5110954B2 (ja) * | 2007-05-09 | 2012-12-26 | エヌ・イーケムキャット株式会社 | 選択還元型触媒を用いた排気ガス浄化触媒装置並びに排気ガス浄化方法 |
GB2450484A (en) * | 2007-06-25 | 2008-12-31 | Johnson Matthey Plc | Non-Zeolite base metal catalyst |
FR2960231B1 (fr) * | 2010-05-19 | 2012-07-20 | Rhodia Operations | Composition a base de cerium, de zirconium et de tungstene, procede de preparation et utilisation en catalyse, notamment pour le traitement des gaz d'echappement |
US9011809B2 (en) * | 2011-03-31 | 2015-04-21 | N.E. Chemcat Corporation | Ammonia oxidation catalyst, exhaust gas purification device using same, and exhaust gas purification method |
-
2011
- 2011-09-21 CN CN201180059555.8A patent/CN103260752B/zh active Active
- 2011-09-21 EP EP11854194.5A patent/EP2659974B1/en active Active
- 2011-09-21 WO PCT/JP2011/071414 patent/WO2012090557A1/ja active Application Filing
- 2011-09-21 US US13/884,164 patent/US8741240B2/en active Active
- 2011-09-21 JP JP2012550753A patent/JP5769732B2/ja active Active
- 2011-09-21 KR KR1020137013175A patent/KR20140027062A/ko not_active Application Discontinuation
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0538420A (ja) | 1991-01-08 | 1993-02-19 | Agency Of Ind Science & Technol | 窒素酸化物の除去処理方法 |
JP2002502927A (ja) | 1998-02-06 | 2002-01-29 | ジョンソン、マッセイ、パブリック、リミテッド、カンパニー | 排ガス中のNOxの還元機構 |
JP2005502451A (ja) | 2001-09-07 | 2005-01-27 | エンゲルハード・コーポレーシヨン | NOx還元用の水熱的に安定な金属による助触媒作用を受けているゼオライトベータ |
JP2005111436A (ja) * | 2003-10-10 | 2005-04-28 | Valtion Teknillinen Tutkimuskeskus | 窒素酸化物を接触的に除去するための方法とそのための装置 |
JP2005238196A (ja) * | 2004-02-27 | 2005-09-08 | Tokyo Roki Co Ltd | 窒素酸化物浄化用触媒、並びにそれを用いた窒素酸化物の浄化方法及び窒素酸化物浄化装置 |
JP2008049290A (ja) * | 2006-08-25 | 2008-03-06 | Tokyo Roki Co Ltd | 窒素酸化物を浄化する触媒、方法、及び装置 |
JP2009538736A (ja) | 2007-01-09 | 2009-11-12 | 田中貴金属工業株式会社 | 高温アンモニアscr触媒とその使用方法 |
WO2009080152A1 (en) * | 2007-12-21 | 2009-07-02 | Umicore Ag & Co. Kg | Method for treating nox in exhaust gas and system therefore |
JP2009262098A (ja) * | 2008-04-28 | 2009-11-12 | Ne Chemcat Corp | 選択還元触媒を用いた排気ガス浄化方法 |
Non-Patent Citations (1)
Title |
---|
CATALYSIS TODAY, vol. 114, 2006, pages 3 - 12 |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10792614B2 (en) * | 2012-02-06 | 2020-10-06 | Basf Se | Process and apparatus for treatment of gas streams containing nitrogen oxides |
JP2016513585A (ja) * | 2013-03-14 | 2016-05-16 | ビーエーエスエフ コーポレーション | 選択的な触媒作用の還元触媒系 |
CN103464142A (zh) * | 2013-10-10 | 2013-12-25 | 西北化工研究院 | 用于氨选择催化还原脱除氮氧化物的催化剂及其制备方法 |
JP2017500187A (ja) * | 2013-10-30 | 2017-01-05 | ジョンソン、マッセイ、パブリック、リミテッド、カンパニーJohnson Matthey Public Limited Company | 三元触媒、及びそれの排気システムでの使用 |
US9387438B2 (en) | 2014-02-14 | 2016-07-12 | Tenneco Automotive Operating Company Inc. | Modular system for reduction of sulphur oxides in exhaust |
JP2015196116A (ja) * | 2014-03-31 | 2015-11-09 | 株式会社キャタラー | Scr用触媒及び排ガス浄化触媒システム |
JP2015196115A (ja) * | 2014-03-31 | 2015-11-09 | 株式会社キャタラー | Scr用触媒及び排ガス浄化触媒システム |
KR20160045178A (ko) * | 2014-10-16 | 2016-04-27 | 현대자동차주식회사 | 디젤차량의 백연 저감 시스템 |
KR101646355B1 (ko) * | 2014-10-16 | 2016-08-08 | 현대자동차주식회사 | 디젤차량의 백연 저감 시스템 |
Also Published As
Publication number | Publication date |
---|---|
JPWO2012090557A1 (ja) | 2014-06-05 |
EP2659974B1 (en) | 2019-06-12 |
US20130230441A1 (en) | 2013-09-05 |
EP2659974A1 (en) | 2013-11-06 |
JP5769732B2 (ja) | 2015-08-26 |
CN103260752A (zh) | 2013-08-21 |
EP2659974A4 (en) | 2014-12-17 |
CN103260752B (zh) | 2015-06-17 |
US8741240B2 (en) | 2014-06-03 |
KR20140027062A (ko) | 2014-03-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5769732B2 (ja) | 選択還元型触媒、およびそれを用いた排気ガス浄化装置並びに排気ガス浄化方法 | |
JP5989214B2 (ja) | アンモニア酸化触媒、およびそれを用いた排気ガス浄化装置並びに排気ガス浄化方法 | |
JP5110954B2 (ja) | 選択還元型触媒を用いた排気ガス浄化触媒装置並びに排気ガス浄化方法 | |
JP5732297B2 (ja) | アンモニア酸化触媒、および排気ガス浄化装置並びに排気ガス浄化方法 | |
JP6040232B2 (ja) | 排気ガス浄化装置 | |
WO2012002052A1 (ja) | 選択還元型触媒を用いた排気ガス浄化装置及び排気ガス浄化方法 | |
EP1985353B1 (en) | Exhaust gas purification catalyst for automobile, exhaust gas purification catalyst system and purifying process of exhaust gas | |
US8636959B2 (en) | Selective catalytic reduction type catalyst, and exhaust gas purification equipment and purifying process of exhaust gas using the same | |
EP2113296A2 (en) | Exhaust gas purification method using selective reduction catalyst | |
JP3204682U (ja) | バイパス流路を用いたコールドスタート対応尿素scrシステム | |
KR20190036543A (ko) | 배기 가스 촉매 및 필터 기재에 대한 촉매 결합제 | |
WO2018025827A1 (ja) | コールドスタート対応尿素scrシステム | |
JP5651727B2 (ja) | 選択還元触媒を用いた排気ガス浄化方法 | |
JP2012152744A (ja) | 排気ガス浄化用選択還元触媒及びそれを用いた排気ガス浄化装置 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 11854194 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2012550753 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2011854194 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 13884164 Country of ref document: US |
|
ENP | Entry into the national phase |
Ref document number: 20137013175 Country of ref document: KR Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |