JP3310926B2 - DeNOx catalyst and method for producing the same - Google Patents
DeNOx catalyst and method for producing the sameInfo
- Publication number
- JP3310926B2 JP3310926B2 JP12871198A JP12871198A JP3310926B2 JP 3310926 B2 JP3310926 B2 JP 3310926B2 JP 12871198 A JP12871198 A JP 12871198A JP 12871198 A JP12871198 A JP 12871198A JP 3310926 B2 JP3310926 B2 JP 3310926B2
- Authority
- JP
- Japan
- Prior art keywords
- vanadium
- titanium
- oxide
- catalyst
- fine particles
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000003054 catalyst Substances 0.000 title claims description 79
- 238000004519 manufacturing process Methods 0.000 title claims description 9
- 239000002245 particle Substances 0.000 claims description 52
- 239000011148 porous material Substances 0.000 claims description 50
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 36
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 29
- 239000010419 fine particle Substances 0.000 claims description 27
- 238000000034 method Methods 0.000 claims description 24
- 229910052720 vanadium Inorganic materials 0.000 claims description 21
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims description 21
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 20
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 20
- 239000002244 precipitate Substances 0.000 claims description 20
- 239000000243 solution Substances 0.000 claims description 20
- 239000006104 solid solution Substances 0.000 claims description 18
- 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 claims description 16
- 238000000975 co-precipitation Methods 0.000 claims description 15
- 229910001935 vanadium oxide Inorganic materials 0.000 claims description 15
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 13
- 239000000203 mixture Substances 0.000 claims description 10
- 239000007864 aqueous solution Substances 0.000 claims description 9
- 229910052721 tungsten Inorganic materials 0.000 claims description 9
- 229910052750 molybdenum Inorganic materials 0.000 claims description 8
- DCKVFVYPWDKYDN-UHFFFAOYSA-L oxygen(2-);titanium(4+);sulfate Chemical compound [O-2].[Ti+4].[O-]S([O-])(=O)=O DCKVFVYPWDKYDN-UHFFFAOYSA-L 0.000 claims description 8
- 229910000348 titanium sulfate Inorganic materials 0.000 claims description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 7
- 239000013543 active substance Substances 0.000 claims description 7
- 239000011733 molybdenum Substances 0.000 claims description 7
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 7
- 239000010937 tungsten Substances 0.000 claims description 7
- 230000001590 oxidative effect Effects 0.000 claims description 6
- XJDNKRIXUMDJCW-UHFFFAOYSA-J titanium tetrachloride Chemical compound Cl[Ti](Cl)(Cl)Cl XJDNKRIXUMDJCW-UHFFFAOYSA-J 0.000 claims description 6
- QKDGGEBMABOMMW-UHFFFAOYSA-I [OH-].[OH-].[OH-].[OH-].[OH-].[V+5] Chemical compound [OH-].[OH-].[OH-].[OH-].[OH-].[V+5] QKDGGEBMABOMMW-UHFFFAOYSA-I 0.000 claims description 5
- 238000003756 stirring Methods 0.000 claims description 4
- 239000012190 activator Substances 0.000 claims description 3
- 150000002500 ions Chemical class 0.000 claims description 3
- 150000003609 titanium compounds Chemical class 0.000 claims description 3
- SOQBVABWOPYFQZ-UHFFFAOYSA-N oxygen(2-);titanium(4+) Chemical class [O-2].[O-2].[Ti+4] SOQBVABWOPYFQZ-UHFFFAOYSA-N 0.000 claims description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims 2
- 239000010936 titanium Substances 0.000 claims 2
- 229910052719 titanium Inorganic materials 0.000 claims 2
- SDJHNUZSGWOXKD-UHFFFAOYSA-N [O-2].[V+5].[O-2].[V+5] Chemical compound [O-2].[V+5].[O-2].[V+5] SDJHNUZSGWOXKD-UHFFFAOYSA-N 0.000 claims 1
- 239000011149 active material Substances 0.000 claims 1
- 229910000476 molybdenum oxide Inorganic materials 0.000 claims 1
- 230000003472 neutralizing effect Effects 0.000 claims 1
- 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 1
- 229910001930 tungsten oxide Inorganic materials 0.000 claims 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 20
- 229910010413 TiO 2 Inorganic materials 0.000 description 13
- 230000000694 effects Effects 0.000 description 13
- 238000010438 heat treatment Methods 0.000 description 10
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 9
- 239000002994 raw material Substances 0.000 description 7
- 239000007789 gas Substances 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 5
- 239000013078 crystal Substances 0.000 description 5
- 238000002441 X-ray diffraction Methods 0.000 description 4
- 238000009826 distribution Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 238000005470 impregnation Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000006386 neutralization reaction Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 239000011882 ultra-fine particle Substances 0.000 description 4
- HGUFODBRKLSHSI-UHFFFAOYSA-N 2,3,7,8-tetrachloro-dibenzo-p-dioxin Chemical compound O1C2=CC(Cl)=C(Cl)C=C2OC2=C1C=C(Cl)C(Cl)=C2 HGUFODBRKLSHSI-UHFFFAOYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 229910021529 ammonia Inorganic materials 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 239000012495 reaction gas Substances 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 150000001805 chlorine compounds Chemical class 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- 229910021551 Vanadium(III) chloride Inorganic materials 0.000 description 1
- 238000000026 X-ray photoelectron spectrum Methods 0.000 description 1
- VEGUWHDSQWYLLI-UHFFFAOYSA-N [O-2].[V+5].[Mo+4] Chemical compound [O-2].[V+5].[Mo+4] VEGUWHDSQWYLLI-UHFFFAOYSA-N 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 1
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 1
- 235000011130 ammonium sulphate Nutrition 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- UNTBPXHCXVWYOI-UHFFFAOYSA-O azanium;oxido(dioxo)vanadium Chemical compound [NH4+].[O-][V](=O)=O UNTBPXHCXVWYOI-UHFFFAOYSA-O 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 238000010531 catalytic reduction reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- GNTDGMZSJNCJKK-UHFFFAOYSA-N divanadium pentaoxide Chemical compound O=[V](=O)O[V](=O)=O GNTDGMZSJNCJKK-UHFFFAOYSA-N 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 230000033116 oxidation-reduction process Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- NFVUDQKTAWONMJ-UHFFFAOYSA-I pentafluorovanadium Chemical compound [F-].[F-].[F-].[F-].[F-].[V+5] NFVUDQKTAWONMJ-UHFFFAOYSA-I 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 230000027756 respiratory electron transport chain Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000002076 thermal analysis method Methods 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 229910001428 transition metal ion Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- HQYCOEXWFMFWLR-UHFFFAOYSA-K vanadium(iii) chloride Chemical group [Cl-].[Cl-].[Cl-].[V+3] HQYCOEXWFMFWLR-UHFFFAOYSA-K 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 229920003169 water-soluble polymer Polymers 0.000 description 1
Description
【０００１】[0001]
【発明の属する技術分野】本発明は排ガス中の窒素酸化
物を従来の触媒よりも低温で浄化できる脱硝触媒及びそ
の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a denitration catalyst capable of purifying nitrogen oxides in exhaust gas at a lower temperature than conventional catalysts and a method for producing the same.
【０００２】[0002]
【従来の技術】ボイラ、ゴミ焼却炉等の排ガス中の窒素
酸化物（ＮＯx ）は環境汚染の原因物質であり、環境浄
化のためのＮＯx 無害化方法としては、通常酸化チタン
（ＴｉＯ2 ）−５酸化バナジウム（Ｖ2 Ｏ5 ）系触媒を
用い、アンモニア（ＮＨ3 ）を還元剤とする接触還元法
が行われている。この方法では、排ガス温度が約２００
℃よりも低くなると脱硝率小さくなるという問題があ
る。最近ゴミ焼却炉や産業廃棄物焼却炉ではダイオキシ
ンの生成が新たな環境問題となっている。ダイオキシン
を除去するためには、その蒸気圧が低くなる約２００℃
以下の低温に排ガス温度を下げる必要がある。そこで、
従来の技術では、約１５０℃程度の低温でダイオキシン
を除去した後、排ガス温度を約２００℃以上に加熱し、
ＴｉＯ2 −Ｖ2 Ｏ5 系触媒で脱硝する方法を用いざるを
得ない。このＶ2 Ｏ5 系触媒の脱硝性能が低温で小さく
なる原因としては、含浸法で製造されているため比表面
積が約５０〜９０ｍ2 ／ｇと小さい触媒しか得られない
ことが考えられる。そこで、触媒の活性を低温でさらに
高くするためには、これよりも比表面積が大きい触媒が
必要となっている。2. Description of the Related Art Nitrogen oxides (NO x ) in exhaust gas from boilers, refuse incinerators and the like are substances causing environmental pollution. As a method for detoxifying NO x for environmental purification, titanium oxide (TiO 2) is usually used. ) used -5 vanadium oxide (V 2 O 5) based catalyst, catalytic reduction of ammonia (NH 3) as a reducing agent is being carried out. In this method, the exhaust gas temperature is about 200
If the temperature is lower than ℃, there is a problem that the denitration rate becomes small. Recently, generation of dioxin has become a new environmental problem in garbage incinerators and industrial waste incinerators. In order to remove dioxin, its vapor pressure drops to about 200 ° C
It is necessary to lower the exhaust gas temperature to the following low temperature. Therefore,
In the conventional technology, after removing dioxin at a low temperature of about 150 ° C., the exhaust gas temperature is heated to about 200 ° C. or more,
A method of denitration with a TiO 2 -V 2 O 5 catalyst has to be used. As the small due denitration performance at a low temperature of V 2 O 5 catalyst, it is considered that the specific surface area of about 50~90m 2 / g and less catalyst obtained only because it is produced by an impregnation method. Therefore, in order to further increase the activity of the catalyst at a low temperature, a catalyst having a larger specific surface area is required.
【０００３】[0003]
【発明が解決しようとする課題】本発明の第一の課題
は、上記技術レベルを考慮して、現用のＴｉＯ2 −Ｖ2
Ｏ 5 系触媒よりも低温度でも脱硝活性が高い高比表面積
の触媒を提供し、環境浄化に役立てようとするものであ
る。通常５価のバナジウムは従来メタバナジン酸アンモ
ニウム（ＮＨ4 ＶＯ3 ）が原料として用いられ、この原
料を用いると含浸法しか触媒にする方法がないので、比
表面積が約５０〜９０ｍ2 ／ｇと小さい触媒しか得られ
ないという問題点があった。これに対し、３価のバナジ
ウムとしては３塩化バナジウム等があり、これは共沈法
により水酸化バナジウム（３価）としてＴｉＯ2 に担持
することが可能であるので、調製条件を適正化すること
により高比表面積の微粒子が得られ、これをさらに酸化
することによりＶ2 Ｏ5 に変える方法、すなわち共沈及
び原子価制御法（共沈後、酸化によりバナジウムの価数
を３価から５価に変える方法）により比表面積が１００
ｍ2 ／ｇ以上の触媒を提供できる可能性がある。本発明
はその比表面積が１００ｍ2 ／ｇ以上の脱硝触媒及びそ
の製法を適用しようとするものである。本発明の第二の
課題は、この共沈法により作製した高比表面積の触媒の
組成や細孔分布を適正にして、低温脱硝活性に優れた触
媒及びその製法を提供しようとするものである。The first object of the present invention
In consideration of the above technical level,Two-VTwo
O FiveHigh specific surface area with higher denitration activity even at lower temperatures than based catalysts
To provide environmentally friendly catalysts to help purify the environment.
You. Normally, pentavalent vanadium is conventionally used as ammonium metavanadate.
Nium (NHFourVOThree) Is used as a raw material
When using a catalyst, there is no way to make the catalyst a catalyst only by the impregnation method.
Surface area is about 50-90mTwo/ G and only a small catalyst
There was no problem. In contrast, trivalent vanadium
There is vanadium trichloride etc., which is coprecipitation method
TiO2 as vanadium hydroxide (trivalent)TwoCarried on
It is necessary to optimize the preparation conditions
Gives high specific surface area fine particles, which are further oxidized.
By doing VTwoOFiveThe way to change, ie co-precipitation
And valence control method (Vanadium valence by oxidation after coprecipitation
The specific surface area is 100
mTwo/ G or more of catalyst may be provided. The present invention
Has a specific surface area of 100 mTwo/ G or more of denitration catalyst and its
It is intended to apply the manufacturing method. The second of the present invention
The challenge is to develop a high specific surface area catalyst produced by this coprecipitation method.
Optimized composition and pore distribution to provide excellent low-temperature denitration activity
It is intended to provide a medium and a method for producing the same.
【０００４】[0004]
【課題を解決するための手段】本発明は上記技術レベル
を考慮して優れた低温脱硝触媒を提供するため、以下の
構成（１）〜（５）よりなるものである。 （１）平均粒径１０ｎｍ以下の酸化チタン超微粒子と平
均粒径１０〜５０ｎｍの酸化チタン微粒子の大小２種の
粒径から構成されるアナターゼ型構造の酸化チタン混合
物を担体とし、酸化バナジウム微粒子又は酸化バナジウ
ムにモリブデン及び／又はタングステンを固溶させた酸
化バナジウム固溶微粒子を活性体として共沈法により３
〜３０重量％担持させた比表面積が１００ｍ2 ／ｇ以上
であることを特徴とする脱硝触媒。 （２）アナターゼ型構造の酸化チタンを担体とし、酸化
バナジウム微粒子又は酸化バナジウムにモリブデン及び
／又はタングステンを固溶させた酸化バナジウム固溶微
粒子を活性体として共沈法により３〜３０重量％担持さ
せた比表面積が１００ｍ 2 ／ｇ以上であり、細孔径１〜
８ｎｍの細孔、又は細孔径が１〜８ｎｍと８〜５０ｎｍ
の大小２種の細孔からなる細孔を全部で０．１ｃｃ／ｇ
以上含有してなることを特徴とする脱硝触媒。 （３）平均粒径１０ｎｍ以下の酸化チタン超微粒子と平
均粒径１０〜５０ｎｍの酸化チタン微粒子の大小２種の
粒径から構成されるアナターゼ型構造の酸化チタン混合
物を担体とし、酸化バナジウム微粒子又は酸化バナジウ
ムにモリブデン及び／又はタングステンを固溶させた酸
化バナジウム固溶微粒子を活性体として共沈法により３
〜３０重量％担持させた比表面積が１００ｍ 2 ／ｇ以上
であり、細孔径１〜８ｎｍの細孔、又は細孔径が１〜８
ｎｍと８〜５０ｎｍの大小２種の細孔からなる細孔を全
部で０．１ｃｃ／ｇ以上含有してなることを特徴とする
脱硝触媒。The present invention comprises the following constitutions (1) to (5) in order to provide an excellent low-temperature denitration catalyst in consideration of the above technical level. (1) Ultrafine titanium oxide particles having an average particle size of 10 nm or less
Two kinds of large and small titanium oxide fine particles having an average particle size of 10 to 50 nm
Titanium oxide mixture with anatase structure composed of particle size
The product is used as a carrier, and vanadium oxide fine particles or vanadium oxide solid solution fine particles in which molybdenum and / or tungsten are solid-dissolved in vanadium oxide are used as active substances by coprecipitation method.
A denitration catalyst characterized by having a specific surface area of not less than 100 m 2 / g supported by ３０30% by weight. (2) Oxidation using titanium oxide of anatase type structure as carrier
Molybdenum and vanadium fine particles or vanadium oxide
// Vanadium oxide solid solution with tungsten solid solution
3 to 30% by weight of particles as active substance by coprecipitation method
The specific surface area is 100 m 2 / g or more,
8 nm pores or pore diameters of 1 to 8 nm and 8 to 50 nm
0.1cc / g of pores composed of two kinds of pores, large and small
A denitration catalyst characterized by containing the above. (3) Ultrafine titanium oxide particles having an average particle diameter of 10 nm or less
Two kinds of large and small titanium oxide fine particles having an average particle size of 10 to 50 nm
Titanium oxide mixture with anatase structure composed of particle size
Material as a carrier, vanadium oxide fine particles or vanadium oxide
Molybdenum and / or tungsten solid solution
Using vanadium fluoride solid solution fine particles as the active substance, 3
Specific surface area supported by ３０30% by weight is 100 m 2 / g or more
, And the pores having a pore diameter of 1 to 8 nm, or pore diameter 1-8
A denitration catalyst comprising a total of 0.1 cc / g or more of pores composed of two large and small pores having a diameter of 8 nm to 50 nm.
【０００５】（４）４塩化チタン又は硫酸チタンを含有
する水溶液に、３〜３０重量％活性体を担持させるのに
必要なバナジウム（３価）又はバナジウム（３価）とモ
リブデン及び／又はタングステンのイオンを含有する溶
液を添加し、さらに水又は水と水溶性アルコールを加
え、溶液中のチタン化合物の濃度が０．５〜０．０５モ
ル／リットルの水溶液になるように調整し、続いてこの
溶液に濃度３〜０．５規定のアンモニア水を徐々に滴下
して中和することにより、酸化チタンとバナジウム水酸
化物又はバナジウム水酸化物固溶体の共同沈澱物を生成
させ、この沈澱を洗浄、乾燥した後、２８０〜５５０℃
の温度で酸化雰囲気中で熱処理して酸化することによ
り、酸化チタンに担持させた酸化バナジウムの価数を３
価から５価に変えることを特徴とする上記（１）〜
（３）いずれかに記載の脱硝触媒の製造方法。 （５）上記（４）記載の製造方法において、４塩化チタ
ン又は硫酸チタンを含有する水溶液に平均粒径１０〜５
０ｎｍの酸化チタン微粒子を加え、攪拌しながら共沈さ
せることにより、共沈により生成した平均粒径１０ｎｍ
以下の酸化チタン超微粒子と添加した平均粒径１０〜５
０ｎｍの酸化チタン微粒子からなる大小２種の酸化チタ
ン混合物を担体として活性体を担持させることを特徴と
する上記（１）〜（３）いずれかに記載の脱硝触媒の製
造方法。(4) Vanadium (trivalent) or vanadium (trivalent) and molybdenum and / or tungsten necessary to support 3 to 30% by weight of an active substance in an aqueous solution containing titanium tetrachloride or titanium sulfate. A solution containing ions is added, water or water and a water-soluble alcohol are further added, and the concentration of the titanium compound in the solution is adjusted to an aqueous solution of 0.5 to 0.05 mol / L. Aqueous ammonia having a concentration of 3 to 0.5N is gradually dropped into the solution to neutralize the solution, thereby forming a coprecipitate of titanium oxide and vanadium hydroxide or a vanadium hydroxide solid solution, and washing the precipitate. After drying, 280-550 ° C
By performing heat treatment in an oxidizing atmosphere at a temperature of oxidizing, the valence of vanadium oxide supported on titanium oxide becomes 3
(1) to (4), characterized in that the valence is changed to pentavalent
(3) The method for producing a denitration catalyst according to any of the above. (5) The method according to the above (4), wherein the aqueous solution containing titanium tetrachloride or titanium sulfate has an average particle size of 10-5.
By adding 0 nm titanium oxide fine particles and co-precipitating with stirring, the average particle diameter generated by co-precipitation is 10 nm.
The following titanium oxide ultrafine particles and the added average particle size of 10 to 5
The method for producing a denitration catalyst according to any one of the above (1) to (3), wherein an activator is carried using a mixture of two kinds of titanium oxides, each of which is composed of 0 nm titanium oxide fine particles, as a carrier.
【０００６】[0006]
【発明の実施の形態】本発明の脱硝触媒及びその製造方
法をまとめて、その数値限定の理由を説明する。なお、
本発明の脱硝触媒はアンモニアを還元剤として用いるこ
とにより脱硝性能を有するものであり、本発明の脱硝触
媒を用いてアンモニアを注入することにより窒素酸化物
を高性能に無害化できる。BEST MODE FOR CARRYING OUT THE INVENTION The denitration catalyst of the present invention and the method for producing the same will be summarized and the reasons for limiting the numerical values will be described. In addition,
The denitration catalyst of the present invention has a denitration performance by using ammonia as a reducing agent. By injecting ammonia using the denitration catalyst of the present invention, nitrogen oxides can be made harmless with high performance.
【０００７】（１）沈澱を作る時の溶液中のチタン化合
物の濃度を０．５〜０．０５モル／リットルにする。溶
液中のＴｉＣｌ4 濃度が０．５モル／リットルより大き
い場合、濃度が濃すぎて沈澱が糊状になり攪拌しにくく
なる等、取扱いにくくなるので、濃度を０．５モル／リ
ットル以下にする必要がある。しかし、濃度が０．０５
モル／リットルよりも小さい場合、溶液が薄いので触媒
を作るのに多量の溶液が必要になり実用的でない。より
好ましいＴｉＣｌ4 濃度は０．０５〜０．３モル／リッ
トルの範囲である。ＴｉＣｌ4 濃度をこの範囲に保つた
めには、水で希釈するが、水とメタノール、エタノー
ル、プロパノール、ポリビニルアルコール、ポリエチレ
ングリコールなどの水溶性アルコールの混合物を用いる
こともできる。アルコールは触媒を高温で調製する時に
分解し、生成した触媒微粒子に細孔を形成させ、比表面
積を大きくする作用を有するからである。アルコールの
添加量は特に制限するものではないが、１０重量％以下
の範囲が好ましい。さらに、ポリビニールアルコール等
の水溶性ポリマーを同じ目的で添加することもできる
が、このような添加物を用いた場合も、本発明の例外と
するものではない。(1) The concentration of the titanium compound in the solution at the time of forming the precipitate is adjusted to 0.5 to 0.05 mol / l. If the concentration of TiCl 4 in the solution is larger than 0.5 mol / l, the concentration is too high, and the precipitate becomes paste-like, and it becomes difficult to stir. There is a need. However, if the concentration is 0.05
If it is smaller than mol / liter, the solution is thin and a large amount of solution is required to make the catalyst, which is not practical. A more preferred TiCl 4 concentration is in the range of 0.05-0.3 mol / l. To maintain the TiCl 4 concentration in this range, the mixture is diluted with water, but a mixture of water and a water-soluble alcohol such as methanol, ethanol, propanol, polyvinyl alcohol, or polyethylene glycol can also be used. This is because alcohol decomposes when the catalyst is prepared at a high temperature, forms pores in the generated catalyst fine particles, and has an effect of increasing the specific surface area. The amount of alcohol added is not particularly limited, but is preferably in the range of 10% by weight or less. Further, a water-soluble polymer such as polyvinyl alcohol can be added for the same purpose, but the use of such an additive is not an exception of the present invention.
【０００８】（２）アンモニア水の濃度を３〜０．５規
定とする。中和に使用するアンモニア水が３規定よりも
濃い場合、滴下したアンモニア水のまわりに沈澱が固ま
って生成するため不均一となり、粗大化して沈澱の比表
面積が小さくなるので、アンモニア水の濃度を３規定以
下とする必要がある。しかし、濃度が０．５規定未満の
場合、多量のアンモニア水を中和のため加える必要があ
り、溶液の体積が増えすぎて実用的でない。アンモニア
水のより好ましい濃度は０．５〜２規定の範囲である。
なお、アンモニア水で中和する時、一度に混ぜると沈澱
が不均質に生成し比表面積が小さくなるので、アンモニ
ア水を徐々に滴下することが高比表面積の触媒を調製す
るためには必要である。(2) The concentration of ammonia water is set to 3 to 0.5 normal. If the ammonia water used for neutralization is more than 3N, the precipitate will solidify around the dropped ammonia water and form, resulting in non-uniformity, coarsening and a decrease in the specific surface area of the precipitate. It is necessary to be 3 or less. However, when the concentration is less than 0.5N, a large amount of aqueous ammonia needs to be added for neutralization, and the volume of the solution is too large to be practical. The more preferred concentration of the aqueous ammonia is in the range of 0.5 to 2N.
In addition, when neutralized with aqueous ammonia, if mixed at once, the precipitate will be formed inhomogeneously and the specific surface area will be small, so it is necessary to gradually add aqueous ammonia to prepare a high specific surface area catalyst. is there.
【０００９】（３）担体に対し、酸化バナジウム又はそ
の固溶体微粒子を活性体として３〜３０重量％担持させ
る。触媒としてバナジウム系酸化物又はその固溶体を用
いる理由は、低温でも脱硝性能の劣化が小さいこと及び
バナジウム酸化物にＭｏ及び／又はＷを固溶させること
により、バナジウムの価数が変化して５価と４価の混合
状態となり、脱硝反応にともなう酸化還元が起こりやす
くなるためである。なお、溶液中のＶ等の遷移金属イオ
ンの濃度は、ＴｉＯ2 に対し何重量％バナジウム系酸化
物を担持させるかという担持量でおのずから決まるもの
である。ＴｉＯ2 担体に対し担持させる触媒の担持量
は、３重量％未満の場合、脱硝性能が低く、また３０重
量％より多くしても脱硝性能が増えることはなく、逆に
触媒粒子の成形性が悪く、触媒の形状を保てないこと、
Ｖ2 Ｏ5 粒子が互いに接触する確率が高くなり、熱処理
により粒成長して比表面積が小さくなる等の不具合が生
じるからである。担体粒子を活性体粒子で覆うために
は、１０重量％程度添加すれば十分であり、本発明の触
媒では担持量が１５重量％になれば１５０℃での脱硝率
は１００％になりほぼ目的を達成しているので、担持量
としては、５〜１５重量％の範囲がより好ましい実施態
様である。活性体の原料としては、ＶＣｌ3 、ＭｏＣｌ
5 、ＷＣｌ6 等の塩化物を用いることができる。ＴｉＯ
2 に担持することにより高比表面積の触媒が得られる
が、その作用としては、Ｖ2 Ｏ5 粒子がＴｉＯ2 粒子に
より均一に分散されているためＶ2 Ｏ5 粒子の粒成長が
防止され、超微粒子からなる高比表面積の触媒が得られ
ることが考えられる。(3) 3 to 30% by weight of vanadium oxide or solid solution fine particles thereof as an active substance is supported on a carrier. The reason for using a vanadium-based oxide or a solid solution thereof as a catalyst is that the valency of vanadium changes due to the fact that the deterioration of the denitration performance is small even at a low temperature and the valence of vanadium is changed by dissolving Mo and / or W in the vanadium oxide. And a tetravalent mixed state, so that oxidation-reduction accompanying the denitration reaction easily occurs. Note that the concentration of transition metal ions such as V in the solution is naturally determined by the amount of the vanadium-based oxide supported on the TiO 2 by weight. When the amount of the catalyst supported on the TiO 2 support is less than 3% by weight, the denitration performance is low, and when the amount is more than 30% by weight, the denitration performance does not increase, and conversely, the moldability of the catalyst particles increases. Bad, not keeping the shape of the catalyst,
This is because the probability that the V 2 O 5 particles come into contact with each other increases, and problems such as a decrease in the specific surface area due to the grain growth due to the heat treatment occur. In order to cover the carrier particles with the activator particles, it is sufficient to add about 10% by weight. In the catalyst of the present invention, when the supported amount becomes 15% by weight, the denitration rate at 150 ° C. becomes 100%, which is almost the target. Therefore, the range of 5 to 15% by weight is a more preferable embodiment. Raw materials for the active substance include VCl 3 , MoCl
5 , chlorides such as WCl 6 can be used. TiO
2 of high specific surface area catalyst is obtained by supporting a but, as its effect, the grain growth of V 2 O 5 particles for V 2 O 5 particles are uniformly dispersed by TiO 2 particles is prevented, It is considered that a catalyst having a high specific surface area composed of ultrafine particles can be obtained.
【００１０】（４）沈澱を洗浄し、乾燥した後、酸化雰
囲気中２８０〜５５０℃の温度で熱処理する。アンモニ
ア水で中和すると多量のＮＨ4 Ｃｌが生成するため、こ
れを洗浄し除去する必要がある。さらに、吸着している
水分を乾燥器中で乾燥して除去する必要がある。得られ
た沈澱は、アナターゼ型のＴｉＯ2 微粒子とＶ（３価）
と他の遷移金属の水酸化物であるので、これを酸化雰囲
気中で２８０〜５５０℃に加熱し、脱水させるとともに
酸化雰囲気中で熱処理し、バナジウムの原子価を３価か
ら５価に変えて、Ｖ（５価）酸化物又はその固溶体にす
る必要がある。２８０℃よりも低温では非晶質の酸化物
が含まれており、さらに触媒が長期間使用により劣化し
た場合、３００℃以上に加熱して触媒を再生する等の必
要が生ずるので、２８０℃よりも低温で触媒を調製して
も低温で調製した効果がなくなるので意味がない。ま
た、５５０℃よりも高温では触媒中の酸化物系超微粒子
が粒成長して、比表面積が小さくなるので脱硝性能が低
くなるためである。より好ましい熱処理温度は３００〜
５００℃である。熱処理時間は特に制限する必要はない
が１〜２時間で十分である。３００℃で２時間熱処理し
て調製した触媒（表３の試料番号１）中のバナジウムの
価数をＸ線光電子スペクトルで解析したところ、バナジ
ウムの価数は主として５価であるが、他に４価と３価の
バナジウムが約１０％混在していることが明らかになっ
た。すなわち、酸化バナジウムとしては、Ｖ2 Ｏ5 以外
に４価と３価のバナジウム酸化物が含まれていても本発
明の例外とするものではない。５価のバナジウムに４価
と３価のバナジウムが混在した状態の方が酸化還元にと
もなう電子の移動が速く、活性が高いという作用を有す
るからである。(4) The precipitate is washed and dried, and then heat-treated at 280-550 ° C. in an oxidizing atmosphere. When neutralized with aqueous ammonia, a large amount of NH 4 Cl is generated, and it is necessary to wash and remove this. Further, it is necessary to remove the adsorbed moisture by drying in a dryer. The obtained precipitate is composed of anatase-type TiO 2 fine particles and V (trivalent).
And other transition metal hydroxides, which are heated to 280-550 ° C. in an oxidizing atmosphere, dehydrated and heat-treated in an oxidizing atmosphere to change the valence of vanadium from trivalent to pentavalent. , V (pentavalent) oxide or a solid solution thereof. At a temperature lower than 280 ° C, an amorphous oxide is contained. Further, when the catalyst is deteriorated by long-term use, it becomes necessary to heat the catalyst to 300 ° C or more to regenerate the catalyst. There is no point in preparing the catalyst at a low temperature because the effect of the preparation at a low temperature is lost. If the temperature is higher than 550 ° C., the oxide-based ultrafine particles in the catalyst will grow and the specific surface area will be small, so that the denitration performance will be low. A more preferred heat treatment temperature is 300 to
500 ° C. The heat treatment time need not be particularly limited, but 1-2 hours is sufficient. When the valence of vanadium in the catalyst (sample No. 1 in Table 3) prepared by heat treatment at 300 ° C. for 2 hours was analyzed by an X-ray photoelectron spectrum, the valence of vanadium was mainly pentavalent, but was 4 It was found that about 10% of trivalent and trivalent vanadium were mixed. In other words, vanadium oxide containing tetravalent and trivalent vanadium oxides other than V 2 O 5 is not an exception to the present invention. This is because a state in which tetravalent vanadium and trivalent vanadium are mixed with pentavalent vanadium has the effect of faster electron transfer and higher activity due to redox.
【００１１】（５）触媒中に細孔径１〜８ｎｍの細孔又
は細孔径１〜８ｎｍと８〜５０ｎｍの大小２種の細孔径
からなる細孔を０．１ｃｃ／ｇ以上含有させる。共沈及
び原子価制御法により得られた触媒の細孔は、その細孔
径が１〜８ｎｍの小さい細孔又は細孔径１〜８ｎｍと８
〜５０ｎｍの大小２種の分布をもった細孔からなり、そ
こに含まれる全細孔は０．１ｃｃ／ｇ以上であることが
吸着試験により判明し、これが低温で脱硝性能が高いと
いう作用をもつことがわかった。細孔径１〜８ｎｍの小
さい細孔は、ＮＯ、ＮＨ3 等の反応ガス分子の吸着を起
こしやすくし低温での反応活性を高めるとともに、細孔
径８〜５０ｎｍの大きい細孔は、ＳＯ2 とＮＨ3 との反
応でできた酸性硫安の付着による細孔の閉塞を遅くする
とともに反応ガス分子の触媒内部への拡散を速くするの
で、低温での反応活性が高くなる作用を有する。これに
対し、従来の含浸法による触媒では、細孔径は約２０ｎ
ｍ前後と大きく、細孔径１〜８ｎｍの微細な細孔が少な
いことが判明した。すなわち、従来法では、担体となる
酸化チタンの粒径は１０ｎｍより大きいので、小さい細
孔があまり存在しないのに対し、本発明の共沈法では、
触媒粒子の粒径が１０ｎｍ以下と小さく、このため微細
な細孔が増えて、活性が向上したと考えられる。本発明
の酸化物触媒では、細孔は主として触媒粒子の間隙に存
在していると考えられる。このため、２種の細孔分布を
持たせるためにはは、大小２種の粒径を持つ酸化物粒子
の混合物を担体として用いる方法が有効である。すなわ
ち、塩化チタン又は硫酸チタンの水溶液に平均粒径１０
〜５０ｎｍの酸化チタン微粒子を加え、攪拌しながらア
ンモニア水を滴下し共沈させるか、粒径の大きい粒子を
加えずに、共沈させた触媒沈澱物を４００〜５５０℃の
高温で熱処理させて触媒粒子を部分的に粒成長させる方
法も用いることができる。(5) The catalyst contains 0.1 cc / g or more of pores having a pore diameter of 1 to 8 nm or pores having two kinds of large and small pore diameters of 1 to 8 nm and 8 to 50 nm. The pores of the catalyst obtained by the coprecipitation and valence control method are small pores having a pore diameter of 1 to 8 nm or pores having a pore diameter of 1 to 8 nm.
It consists of pores having two kinds of large and small distributions of up to 50 nm, and all pores contained in the pores are found to be 0.1 cc / g or more by an adsorption test. It turned out to have. Small pores having a pore diameter of 1 to 8 nm tend to cause adsorption of reaction gas molecules such as NO and NH 3 to enhance reaction activity at a low temperature, and large pores having a pore diameter of 8 to 50 nm contain SO 2 and NH 2. This has the effect of increasing the reaction activity at low temperatures, because it slows the closing of the pores due to the adhesion of acidic ammonium sulfate formed by the reaction with 3, and accelerates the diffusion of the reaction gas molecules into the inside of the catalyst. On the other hand, in the catalyst by the conventional impregnation method, the pore diameter is about 20 n.
m and a small number of fine pores having a pore diameter of 1 to 8 nm. That is, in the conventional method, the particle size of the titanium oxide serving as the carrier is larger than 10 nm, so that there are not many small pores, whereas in the coprecipitation method of the present invention,
It is considered that the particle size of the catalyst particles was as small as 10 nm or less, which increased the number of fine pores and improved the activity. In the oxide catalyst of the present invention, it is considered that the pores mainly exist in the gaps between the catalyst particles. Therefore, in order to provide two kinds of pore distributions, it is effective to use a mixture of oxide particles having two kinds of particle sizes, large and small, as a carrier. That is, an aqueous solution of titanium chloride or titanium sulfate has an average particle diameter of 10%.
５０50 nm titanium oxide fine particles are added and ammonia water is added dropwise with stirring to coprecipitate, or the coprecipitated catalyst precipitate is heat treated at a high temperature of 400 to 550 ° C. without adding large particles. A method of partially growing the catalyst particles can also be used.
【００１２】[0012]
【実施例】以下、具体的な実施例及び参考例をあげ、本
発明の効果を一層明らかにする。EXAMPLES Hereinafter, specific examples and reference examples will be given to further clarify the effects of the present invention.
【００１３】（例１）初めに、ＶＣｌ3 の０．１モル／
リットル濃度の水溶液を調製し、アンモニア水で中和し
沈澱を作製し、適正なアンモニア水の濃度を把握する試
験を行った。アンモニア水の濃度が３規定よりも大きい
場合、中和により沈澱が局所的に生成し、不均質に反応
が起こっているのが認められた。アンモニア水の濃度が
０．５〜２規定であれば、中和により溶液の色が次第に
変化し、均一に沈澱が生成することが観察された。アン
モニア水の濃度が０．１規定よりも薄いと、原料溶液の
数倍の体積のアンモニア水を加える必要があり、実用性
がないことがわかった。(Example 1) First, 0.1 mol / l of VCl 3 was added.
An aqueous solution having a liter concentration was prepared, neutralized with aqueous ammonia to form a precipitate, and a test for determining an appropriate aqueous ammonia concentration was performed. When the concentration of the aqueous ammonia was higher than 3N, a precipitate was locally formed due to the neutralization, and it was recognized that the reaction occurred heterogeneously. When the concentration of the aqueous ammonia was 0.5 to 2N, it was observed that the color of the solution gradually changed due to the neutralization, and a uniform precipitate was formed. When the concentration of the aqueous ammonia is lower than 0.1 normal, it is necessary to add several times the volume of the aqueous ammonia to the raw material solution, which is not practical.
【００１４】（例２）ＶＣｌ3 の０．１モル／リットル
濃度の水溶液を調製し、１規定のアンモニア水で中和し
沈澱を作製した。得られた沈澱は水酸化物であり、熱分
析により加熱すると２００℃でほぼ脱水が終了し、水酸
化物から酸化物に変わった。この酸化物は結晶化度は低
く主として非晶質であり、さらに加熱すると約３００℃
で発熱し、結晶化して結晶質酸化物に変わった。すなわ
ち、結晶質バナジアを得るためには約３００℃以上に加
熱する必要があることが明らかになった。また得られた
酸化物を空気中３００〜３５０℃で１時間熱処理した試
料の結晶構造をＸ線回折により調べた結果、Ｖ2 Ｏ5 で
あることが確認され、３価のＶ化合物を原料としても５
価の酸化物が得られることが判明した。Example 2 A 0.1 mol / liter aqueous solution of VCl 3 was prepared and neutralized with 1N aqueous ammonia to form a precipitate. The obtained precipitate was a hydroxide, and when heated by thermal analysis, dehydration was almost completed at 200 ° C., and the hydroxide was changed to an oxide. This oxide has a low crystallinity and is mainly amorphous.
, And crystallized into a crystalline oxide. That is, it was found that heating to about 300 ° C. or more was required to obtain crystalline vanadia. Further, as a result of examining the crystal structure of a sample obtained by heat-treating the obtained oxide in air at 300 to 350 ° C. for 1 hour by X-ray diffraction, it was confirmed to be V 2 O 5 , and a trivalent V compound was used as a raw material. Also 5
It has been found that a monovalent oxide is obtained.
【００１５】（例３）触媒を担持させるためのＴｉＯ2
微粒子を得るための条件を把握するため、ＴｉＣｌ4 溶
液を１規定のアンモニア水で中和してＴｉＯ2 の沈澱を
作製した。得られた沈澱を３００℃で１時間熱処理した
ＴｉＯ2 担体微粒子の特性を表１に示す。ＴｉＣｌ4 濃
度は０．０５〜０．３モル／リットルの範囲では高比表
面積の触媒が得られ、かつ溶液の取扱いやすさも良好で
あった。表１中のＳ１は硫酸チタンを原料として作製し
たＴｉＯ2 微粒子である。結晶構造はいずれも主として
アナターゼ型であることがＸ線回折により判明した。(Example 3) TiO 2 for supporting a catalyst
In order to grasp the conditions for obtaining the fine particles, the TiCl 4 solution was neutralized with 1N aqueous ammonia to produce a TiO 2 precipitate. Table 1 shows the properties of the TiO 2 carrier fine particles obtained by heat-treating the obtained precipitate at 300 ° C. for 1 hour. TiCl 4 concentration in the range of 0.05 to 0.3 mole / liter catalyst is obtained of high specific surface area, and ease of handling of the solution was also good. S1 in Table 1 is TiO 2 fine particles produced using titanium sulfate as a raw material. X-ray diffraction revealed that all of the crystal structures were mainly of the anatase type.
【００１６】[0016]
【表１】 [Table 1]
【００１７】（例４）ＴｉＣｌ4 の溶液を作製する時、
水と同時にエタノールを加えて、溶液中のエタノール濃
度が１０重量％になるように調整した後、例３と同じ処
理をし、触媒を作製した結果を上記表１の試料Ａ１及び
Ａ２に示す。エタノールを加えて沈澱を作製した後、熱
処理することにより、超微粒子の比表面積が若干増える
ことが認められた。Example 4 When preparing a solution of TiCl 4 ,
After adding ethanol at the same time as the water to adjust the ethanol concentration in the solution to 10% by weight, the same treatment as in Example 3 was performed to prepare a catalyst. The results of preparation of the catalyst are shown in Samples A1 and A2 in Table 1 above. It was confirmed that the specific surface area of the ultrafine particles was slightly increased by heat treatment after adding ethanol to form a precipitate.
【００１８】（例５）ＴｉＣｌ4 の溶液にＶＣｌ3 及び
Ｍｏ、Ｗの塩化物を添加し、水を加えて溶液中のＴｉＣ
ｌ4 濃度を０．２モル／リットルに調整し、１規定のア
ンモニア水で中和し、得られた沈澱を１２０℃で２４時
間乾燥し、さらに３００〜５５０℃で２時間熱処理して
ＴｉＯ2 担持Ｖ2 Ｏ5 系触媒を得た。得られた触媒の比
表面積は後記表３に示すように１００〜３８０ｍ2 ／ｇ
で、従来のもの（比較材）よりも大きかった。これは、
共沈法ではＶ2 Ｏ5 粒子がＴｉＯ2 粒子の間に均一に分
散しているため、Ｖ2 Ｏ5 粒子が接触する確率が減少し
粒成長が抑えられたためと考えられる。これが本発明に
より高比表面積の触媒が得られた原因と考えられる。沈
澱を５５０℃で２時間熱処理した場合、微粒子が粒成長
するので、触媒の比表面積が減少した。また、６００℃
よりも高温に加熱するとＶ2 Ｏ5 固溶体は溶融する危険
性があるので、これ以上高温での熱処理はできない。Ｓ
１、Ｓ２は硫酸チタンを原料として同じ方法で調製した
触媒である。Ｋ１、Ｋ２、Ｋ３は塩化チタンの半分を市
販の平均粒径２０ｎｍの酸化チタン粒子で置換し、共沈
及び原子価制御法により作製した触媒である。ＳＫ１は
硫酸チタンの半分を市販の平均粒径２０ｎｍの酸化チタ
ン微粒子で置換した触媒である。共沈及び原子価制御法
により作製した触媒を３００℃で熱処理すると、細孔径
１〜８ｎｍの微細な細孔が多く存在するが、これを５０
０〜５５０℃で熱処理した場合、大小２種の細孔が存在
していた。表２中の細孔径の表示で２種の数字がある場
合、細孔径分布のピークが２つあることを示す。比較材
は、ＮＨ4 ＶＯ3 を原料として含浸法により調製した従
来法による触媒である。結晶粒径は主として担体である
酸化チタンの粒径により決まるＸ線回折ピークの半値幅
から求めた触媒粒子の平均粒径である。(Example 5) VCl 3 and chlorides of Mo and W are added to a solution of TiCl 4 , and water is added to the solution of TiC 4 in the solution.
l 4 concentration was adjusted to 0.2 mol / liter, and neutralized with 1 N ammonia water, the resulting precipitate was dried 24 hours at 120 ° C., TiO 2 and 2 hours heat treatment at more 300 to 550 ° C. to obtain a supported V 2 O 5 catalyst. The specific surface area of the obtained catalyst was 100 to 380 m 2 / g as shown in Table 3 below.
Therefore, it was larger than the conventional one (comparative material). this is,
It is considered that in the coprecipitation method, since the V 2 O 5 particles are uniformly dispersed between the TiO 2 particles, the probability that the V 2 O 5 particles come into contact is reduced and the grain growth is suppressed. This is considered to be the reason that a catalyst having a high specific surface area was obtained by the present invention. When the precipitate was heat-treated at 550 ° C. for 2 hours, the specific surface area of the catalyst was reduced because the fine particles grew. 600 ° C
If heated to a higher temperature, the V 2 O 5 solid solution may be melted, so that heat treatment at a higher temperature is not possible. S
1, S2 is a catalyst prepared by the same method using titanium sulfate as a raw material. K1, K2, and K3 are catalysts prepared by substituting half of titanium chloride with commercially available titanium oxide particles having an average particle diameter of 20 nm and by a coprecipitation and valence control method. SK1 is a catalyst in which half of titanium sulfate is replaced by commercially available titanium oxide fine particles having an average particle diameter of 20 nm. When the catalyst prepared by the coprecipitation method and the valence control method is heat-treated at 300 ° C., many fine pores having a pore diameter of 1 to 8 nm are present.
When heat treatment was performed at 0 to 550 ° C., two types of pores, large and small, were present. When there are two kinds of numbers in the display of the pore diameter in Table 2, it indicates that there are two peaks in the pore diameter distribution. The comparative material is a conventional catalyst prepared by an impregnation method using NH 4 VO 3 as a raw material. The crystal particle size is an average particle size of catalyst particles obtained from a half-value width of an X-ray diffraction peak mainly determined by a particle size of titanium oxide as a carrier.
【００１９】[0019]
【表２】 [Table 2]
【００２０】（例６）脱硝率の評価は、上記に示した触
媒をガラス管中に充填し、ＮＨ3 とＮＯを含む反応ガス
を空間速度５０００ｈ-1で流し、１５０℃及び１３０℃
で行った。得られた結果を表３に示す。脱硝試験は１５
０℃及び１３０℃で１００時間行ったが、脱硝率の劣化
は２％以内であり、安定であることが確認された。得ら
れた触媒の結晶構造は、Ｘ線回折によりアナターゼ型で
あることが確認された。なお、Ｖ2 Ｏ5 にＭｏＯ3 やＷ
Ｏ3 を微量添加した場合、他の結晶構造の混在物は特に
は観察されなかったので、ＭｏやＷは５〜１０重量％程
度の添加量であれば固溶している可能性が考えられる。
固溶により脱硝性能が向上する傾向があるが、この原因
としては、固溶により欠陥が導入されるので酸素が拡散
しやすくなること、Ｖイオンが４価と５価の価数をもつ
ようになり、酸化還元が起こりやすくなること等が考え
られる。脱硝率の評価に用いたガスの組成は、ＮＯx ：
１００ｐｐｍ、ＮＨ3 ：１００ｐｐｍ、ＳＯ2 ：１０ｐ
ｐｍ、ＣＯ2 ：１０％、Ｈ2 Ｏ：２０％、残部空気であ
る。(Example 6) The denitration rate was evaluated by filling the above-mentioned catalyst into a glass tube, flowing a reaction gas containing NH 3 and NO at a space velocity of 5000 h -1 , at 150 ° C. and 130 ° C.
I went in. Table 3 shows the obtained results. DeNOx test is 15
The test was carried out at 0 ° C. and 130 ° C. for 100 hours, and it was confirmed that the denitration rate was within 2% and stable. The crystal structure of the obtained catalyst was confirmed to be an anatase type by X-ray diffraction. Note that MoO 3 or W is added to V 2 O 5.
When a small amount of O 3 was added, no inclusions of other crystal structures were particularly observed, so it is possible that Mo or W may be in a solid solution if the addition amount is about 5 to 10% by weight. .
There is a tendency for the denitration performance to be improved by the solid solution. This is because defects are introduced by the solid solution, so that oxygen is easily diffused, and V ions have tetravalent and pentavalent valences. It is conceivable that oxidation and reduction easily occur. The composition of the gas used to evaluate the denitration rate was NO x :
100 ppm, NH 3 : 100 ppm, SO 2 : 10 p
pm, CO 2: 10%, H 2 O: 20%, the balance air.
【００２１】[0021]
【表３】 [Table 3]
【００２２】以上の結果、本発明のＴｉＯ2 にＶ2 Ｏ5
又はＶ2 Ｏ5 固溶体を３〜３０重量％担持させた触媒
は、比表面積が従来材の値よりも大きく、従来の触媒で
は性能が低かった１５０℃及びさらに低温の１３０℃で
も高い脱硝率をもつので、低温度領域でも安定して使用
できる脱硝触媒が提供できた。活性体の担持量としては
１０〜１５重量％のものが、１５０℃で脱硝率９５％以
上、１３０℃で９０％以上であり特に高性能であった。As a result, V 2 O 5 was added to TiO 2 of the present invention.
Alternatively, a catalyst in which a V 2 O 5 solid solution is supported by 3 to 30% by weight has a specific surface area larger than that of a conventional material, and has a high denitrification rate even at 150 ° C., which is low in performance of a conventional catalyst, and even at 130 ° C., which is lower temperature. Therefore, a denitration catalyst that can be used stably even in a low temperature range can be provided. The amount of the activated body loaded was 10 to 15% by weight, and the denitration ratio was at least 95% at 150 ° C and at least 90% at 130 ° C, and was particularly high performance.
【００２３】[0023]
【発明の効果】本発明により、従来の触媒よりも低温度
で使用できる高比表面積の脱硝触媒を提供することがで
き、環境浄化に有用な新しい脱硝触媒が提供でき、産業
上の利用価値が高い。According to the present invention, a denitration catalyst having a high specific surface area that can be used at a lower temperature than conventional catalysts can be provided, a new denitration catalyst useful for environmental purification can be provided, and industrial utility value can be obtained. high.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ Ｂ０１Ｊ 37/03 Ｂ０１Ｊ 37/08 37/08 Ｂ０１Ｄ 53/36 １０２Ｃ (72)発明者 水流 靖彦 神奈川県横浜市金沢区幸浦一丁目８番地 １ 三菱重工業株式会社 基盤技術研究 所内 (72)発明者 田浦 昌純 神奈川県横浜市金沢区幸浦一丁目８番地 １ 三菱重工業株式会社 基盤技術研究 所内 (72)発明者 大村 聡 神奈川県横浜市金沢区幸浦一丁目８番地 １ 三菱重工業株式会社 基盤技術研究 所内 (56)参考文献 特開 平４−59054（ＪＰ，Ａ) 特開 平４−271836（ＪＰ，Ａ) 特開 平１−111442（ＪＰ，Ａ) 特開 昭58−210849（ＪＰ，Ａ) 特開 平９−187652（ＪＰ，Ａ) 特開 昭54−66390（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) B01J 21/00 - 38/74 B01D 53/86 B01D 53/94 F01N 3/28 ＷＰＩ（ＤＩＡＬＯＧ)────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. 7 Identification code FI B01J 37/03 B01J 37/08 37/08 B01D 53/36 102C (72) Inventor Yasuhiko Minoru 1-chome, Sachiura, Kanazawa-ku, Yokohama-shi, Kanagawa 8-1 1 Mitsubishi Heavy Industries, Ltd.Basic Technology Research Institute (72) Inventor Masazumi Taura 1-8-1, Koura, Kanazawa-ku, Yokohama-shi, Kanagawa Prefecture 1 Mitsubishi Heavy Industries, Ltd.Basic Technology Research Laboratory (72) Inventor Satoshi Omura Kanazawa, Yokohama-shi, Kanagawa Prefecture 1-8-8 Sachiura-ku, 1 Mitsubishi Heavy Industries, Ltd. Fundamental Technology Research Laboratory (56) References JP-A-4-59054 (JP, A) JP-A-4-271836 (JP, A) JP-A-1-111442 (JP JP-A-58-210849 (JP, A) JP-A-9-187652 (JP, A) JP-A-54-66390 (JP, A) (58) Fields investigated (Int. Cl. 7) B01J 21/00-38/74 B01D 53/86 B01D 53/94 F01N 3/28 WPI (DIALOG)
Claims (5)
粒子と平均粒径１０〜５０ｎｍの酸化チタン微粒子の大
小２種の粒径から構成されるアナターゼ型構造の酸化チ
タン混合物を担体とし、酸化バナジウム微粒子又は酸化
バナジウムにモリブデン及び／又はタングステンを固溶
させた酸化バナジウム固溶微粒子を活性体として共沈法
により３〜３０重量％担持させた比表面積が１００ｍ2
／ｇ以上であることを特徴とする脱硝触媒。An ultrafine titanium oxide having an average particle size of 10 nm or less.
Particles and titanium oxide fine particles having an average particle size of 10 to 50 nm.
Oxidized titanium with anatase-type structure composed of two small particle sizes
Tan mixture as a carrier, the ratio was 3 to 30% by weight carried by coprecipitation of vanadium oxide particles, or vanadium oxide solid solution fine particles is dissolved molybdenum and / or tungsten oxide, vanadium as the active material surface area 100 m 2
/ G or more.
し、酸化バナジウム微粒子又は酸化バナジウムにモリブ
デン及び／又はタングステンを固溶させた酸化バナジウ
ム固溶微粒子を活性体として共沈法により３〜３０重量
％担持させた比表面積が１００ｍ 2 ／ｇ以上であり、細
孔径１〜８ｎｍの細孔、又は細孔径が１〜８ｎｍと８〜
５０ｎｍの大小２種の細孔からなる細孔を全部で０．１
ｃｃ／ｇ以上含有してなることを特徴とする脱硝触媒。 2. A titanium oxide having an anatase structure as a carrier.
And molybdenum fine particles or vanadium oxide
Vanadium oxide with a solid solution of den and / or tungsten
3-30 weight% by coprecipitation method
% Supported specific surface area is 100 m 2 / g or more,
Pores with a pore size of 1 to 8 nm, or pore sizes of 1 to 8 nm and 8 to
A total of fine pores composed of two kinds of fine pores, each having a size of 50 nm, is 0.1
A denitration catalyst comprising at least cc / g.
粒子と平均粒径１０〜５０ｎｍの酸化チタン微粒子の大
小２種の粒径から構成されるアナターゼ型構造の酸化チ
タン混合物を担体とし、酸化バナジウム微粒子又は酸化
バナジウムにモリブデン及び／又はタングステンを固溶
させた酸化バナジウム固溶微粒子を活性体として共沈法
により３〜３０重量％担持させた比表面積が１００ｍ 2
／ｇ以上であり、細孔径１〜８ｎｍの細孔、又は細孔径
が１〜８ｎｍと８〜５０ｎｍの大小２種の細孔からなる
細孔を全部で０．１ｃｃ／ｇ以上含有してなることを特
徴とする脱硝触媒。3. An ultrafine titanium oxide having an average particle size of 10 nm or less.
Particles and titanium oxide fine particles having an average particle size of 10 to 50 nm.
Oxidized titanium with anatase-type structure composed of two small particle sizes
Vanadium oxide fine particles or oxidized
Molybdenum and / or tungsten dissolved in vanadium
Coprecipitation method with activated vanadium oxide solid solution fine particles
The specific surface area supported by 3 to 30% by weight is 100 m 2.
/ G or more, and a total of 0.1 cc / g or more of pores having pore diameters of 1 to 8 nm, or pores of two kinds of large and small pores having pore diameters of 1 to 8 nm and 8 to 50 nm. A denitration catalyst characterized by the following.
水溶液に、３〜３０重量％活性体を担持させるのに必要
なバナジウム（３価）又はバナジウム（３価）とモリブ
デン及び／又はタングステンのイオンを含有する溶液を
添加し、さらに水又は水と水溶性アルコールを加え、溶
液中のチタン化合物の濃度が０．５〜０．０５モル／リ
ットルの水溶液になるように調整し、続いてこの溶液に
濃度３〜０．５規定のアンモニア水を徐々に滴下して中
和することにより、酸化チタンとバナジウム水酸化物又
はバナジウム水酸化物固溶体の共同沈殿物を生成させ、
この沈殿を洗浄、乾燥した後、２８０〜５５０℃の温度
で酸化雰囲気中で熱処理して酸化することにより、酸化
チタンに担持させた酸化バナジウムの価数を３価から５
価に変えることを特徴とする請求項１〜３いずれかに記
載の脱硝触媒の製造方法。4. Ion of vanadium (trivalent) or vanadium (trivalent) and molybdenum and / or tungsten necessary for supporting 3 to 30% by weight of an active substance in an aqueous solution containing titanium tetrachloride or titanium sulfate. Is added, water or water and a water-soluble alcohol are further added, and the concentration of the titanium compound in the solution is adjusted to an aqueous solution of 0.5 to 0.05 mol / L. By gradually dropping and neutralizing ammonia water having a concentration of 3 to 0.5 N to form a coprecipitate of titanium oxide and vanadium hydroxide or a vanadium hydroxide solid solution,
The precipitate is washed and dried, and then heat-treated in an oxidizing atmosphere at a temperature of 280 to 550 ° C. to be oxidized, so that the valence of vanadium oxide supported on titanium oxide is changed from trivalent to 5
The method for producing a denitration catalyst according to any one of claims 1 to 3, wherein the value is changed to a value.
化チタン又は硫酸チタンを含有する水溶液に平均粒径１
０〜５０ｎｍの酸化チタン微粒子を加え、攪拌しながら
共沈させることにより、共沈により生成した平均粒径１
０ｎｍ以下の酸化チタン超微粒子と添加した平均粒径１
０〜５０ｎｍの酸化チタン微粒子からなる大小２種の酸
化チタン混合物を担体として活性体を担持させることを
特徴とする請求項１〜３いずれかに記載の脱硝触媒の製
造方法。5. The method according to claim 4, wherein the aqueous solution containing titanium tetrachloride or titanium sulfate has an average particle size of 1%.
Fine particles of titanium oxide having a particle diameter of 1 to 50 nm were added and co-precipitated with stirring to obtain an average particle size of 1
Ultrafine titanium oxide particles of 0 nm or less and average particle size of 1 added
The method for producing a denitration catalyst according to any one of claims 1 to 3, wherein an activator is supported using a mixture of two kinds of large and small titanium oxides composed of titanium oxide fine particles of 0 to 50 nm as a carrier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12871198A JP3310926B2 (en) | 1997-09-30 | 1998-05-12 | DeNOx catalyst and method for producing the same |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26633997 | 1997-09-30 | ||
| JP9-266339 | 1997-09-30 | ||
| JP12871198A JP3310926B2 (en) | 1997-09-30 | 1998-05-12 | DeNOx catalyst and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11165068A JPH11165068A (en) | 1999-06-22 |
| JP3310926B2 true JP3310926B2 (en) | 2002-08-05 |
Family
ID=26464299
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12871198A Expired - Lifetime JP3310926B2 (en) | 1997-09-30 | 1998-05-12 | DeNOx catalyst and method for producing the same |
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| Country | Link |
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| JP (1) | JP3310926B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8288309B2 (en) | 2009-10-01 | 2012-10-16 | Mitsubishi Heavy Industries, Ltd. | Mercury oxidation catalyst and method for producing the same |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7491676B2 (en) | 2004-10-19 | 2009-02-17 | Millennium Inorganic Chemicals | High activity titania supported metal oxide DeNOx catalysts |
| US20220176349A1 (en) * | 2019-03-07 | 2022-06-09 | The Chugoku Electric Power Co., Inc. | Denitration catalyst, and production method therefor |
| SG11202109723RA (en) * | 2019-03-07 | 2021-10-28 | The Chugoku Electric Power Co Inc | Denitration catalyst and method for producing same |
-
1998
- 1998-05-12 JP JP12871198A patent/JP3310926B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8288309B2 (en) | 2009-10-01 | 2012-10-16 | Mitsubishi Heavy Industries, Ltd. | Mercury oxidation catalyst and method for producing the same |
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| Publication number | Publication date |
|---|---|
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