JPH0420663B2 - - Google Patents
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- Publication number
- JPH0420663B2 JPH0420663B2 JP57093997A JP9399782A JPH0420663B2 JP H0420663 B2 JPH0420663 B2 JP H0420663B2 JP 57093997 A JP57093997 A JP 57093997A JP 9399782 A JP9399782 A JP 9399782A JP H0420663 B2 JPH0420663 B2 JP H0420663B2
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- powder
- denitrification
- oxides
- present
- 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
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- 239000003054 catalyst Substances 0.000 claims description 49
- 239000000843 powder Substances 0.000 claims description 29
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 20
- 239000002245 particle Substances 0.000 claims description 14
- 150000001875 compounds Chemical class 0.000 claims description 12
- 239000002253 acid Substances 0.000 claims description 10
- 229910021529 ammonia Inorganic materials 0.000 claims description 10
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 9
- 238000010531 catalytic reduction reaction Methods 0.000 claims description 9
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 8
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 7
- 239000011733 molybdenum Substances 0.000 claims description 7
- 238000000465 moulding Methods 0.000 claims description 7
- LLZRNZOLAXHGLL-UHFFFAOYSA-J titanic acid Chemical compound O[Ti](O)(O)O LLZRNZOLAXHGLL-UHFFFAOYSA-J 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 6
- 238000004898 kneading Methods 0.000 claims description 6
- 238000010304 firing Methods 0.000 claims description 5
- 229910052720 vanadium Inorganic materials 0.000 claims description 5
- 229910000476 molybdenum oxide Inorganic materials 0.000 claims description 4
- 229910001930 tungsten oxide Inorganic materials 0.000 claims description 4
- 229910001935 vanadium oxide Inorganic materials 0.000 claims description 4
- 238000007580 dry-mixing Methods 0.000 claims description 3
- 229910052750 molybdenum Inorganic materials 0.000 claims description 3
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 3
- 229910052721 tungsten Inorganic materials 0.000 claims description 3
- 239000010937 tungsten Substances 0.000 claims description 3
- 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 description 2
- VVRQVWSVLMGPRN-UHFFFAOYSA-N oxotungsten Chemical class [W]=O VVRQVWSVLMGPRN-UHFFFAOYSA-N 0.000 claims description 2
- 239000000126 substance Substances 0.000 claims description 2
- GPPXJZIENCGNKB-UHFFFAOYSA-N vanadium Chemical compound [V]#[V] GPPXJZIENCGNKB-UHFFFAOYSA-N 0.000 claims 3
- 239000007788 liquid Substances 0.000 claims 1
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 29
- 238000000034 method Methods 0.000 description 16
- 230000010718 Oxidation Activity Effects 0.000 description 14
- 230000000694 effects Effects 0.000 description 14
- 239000004480 active ingredient Substances 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 12
- 238000006243 chemical reaction Methods 0.000 description 9
- 238000002156 mixing Methods 0.000 description 7
- 238000007254 oxidation reaction Methods 0.000 description 7
- 239000000203 mixture Substances 0.000 description 6
- 230000003647 oxidation Effects 0.000 description 6
- 238000001179 sorption measurement Methods 0.000 description 6
- ZNOKGRXACCSDPY-UHFFFAOYSA-N tungsten trioxide Chemical compound O=[W](=O)=O ZNOKGRXACCSDPY-UHFFFAOYSA-N 0.000 description 6
- 229910010413 TiO 2 Inorganic materials 0.000 description 5
- 229910010415 TiO(OH) Inorganic materials 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 5
- 230000004913 activation Effects 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 3
- UNTBPXHCXVWYOI-UHFFFAOYSA-O azanium;oxido(dioxo)vanadium Chemical compound [NH4+].[O-][V](=O)=O UNTBPXHCXVWYOI-UHFFFAOYSA-O 0.000 description 3
- 238000005470 impregnation Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 239000010936 titanium Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 2
- GNTDGMZSJNCJKK-UHFFFAOYSA-N divanadium pentaoxide Chemical compound O=[V](=O)O[V](=O)=O GNTDGMZSJNCJKK-UHFFFAOYSA-N 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- JKQOBWVOAYFWKG-UHFFFAOYSA-N molybdenum trioxide Chemical compound O=[Mo](=O)=O JKQOBWVOAYFWKG-UHFFFAOYSA-N 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000012495 reaction gas Substances 0.000 description 2
- AKEJUJNQAAGONA-UHFFFAOYSA-N sulfur trioxide Chemical compound O=S(=O)=O AKEJUJNQAAGONA-UHFFFAOYSA-N 0.000 description 2
- NRKQBMOGOKEWPX-UHFFFAOYSA-N vanadyl nitrate Chemical compound [O-][N+](=O)O[V](=O)(O[N+]([O-])=O)O[N+]([O-])=O NRKQBMOGOKEWPX-UHFFFAOYSA-N 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 229910021541 Vanadium(III) oxide Inorganic materials 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
- 230000003213 activating effect Effects 0.000 description 1
- 239000012190 activator Substances 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
- 230000008901 benefit Effects 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
- YBMRDBCBODYGJE-UHFFFAOYSA-N germanium oxide Inorganic materials O=[Ge]=O YBMRDBCBODYGJE-UHFFFAOYSA-N 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- OGUCKKLSDGRKSH-UHFFFAOYSA-N oxalic acid oxovanadium Chemical compound [V].[O].C(C(=O)O)(=O)O OGUCKKLSDGRKSH-UHFFFAOYSA-N 0.000 description 1
- PVADDRMAFCOOPC-UHFFFAOYSA-N oxogermanium Chemical compound [Ge]=O PVADDRMAFCOOPC-UHFFFAOYSA-N 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000006069 physical mixture Substances 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 150000003682 vanadium compounds Chemical class 0.000 description 1
- -1 vanadyl chloride Chemical compound 0.000 description 1
- UUUGYDOQQLOJQA-UHFFFAOYSA-L vanadyl sulfate Chemical compound [V+2]=O.[O-]S([O-])(=O)=O UUUGYDOQQLOJQA-UHFFFAOYSA-L 0.000 description 1
- 229940041260 vanadyl sulfate Drugs 0.000 description 1
- 229910000352 vanadyl sulfate Inorganic materials 0.000 description 1
Description
本発明は、アンモニア接触還元用脱硝触媒に関
し、特に二酸化イオウ（SO2）の酸化活性を低減
せしめる高脱硝活性の触媒に関する。
従来排ガス中の窒素酸化物を除去する目的で、
触媒を用いてアンモニア（NH3）により該窒素
酸化物を還元して無害な窒素とする、アンモニア
接触還元脱硝法が知られている。このアンモニア
接触還元脱硝法は選択性が高く、装置構造も簡単
であることから、バナジウム、タングステン、モ
リブデン、鉄などを活性成分とする高活性触媒も
開発され、火力発電用ボイラ排ガスなどの処理に
広く用いられる。
しかしながらこの方法を重油燃焼排ガスなどの
SO2を含有する排ガスに適用する場合に、これら
の脱硝触媒のあわせ持つSO2酸化活性により、
SO2から三酸化イオウ（SO3）を生成し、この
SO3と、還元剤として注入するNH3のうち未反応
部分とが反応して硫安を形成し、これが脱硝装置
のガス下流側にある空気予熱器などに堆積すると
いう問題がある。
このような脱硝触媒のSO2酸化活性を低減する
ために、触媒の活性成分であるパナジウム化合物
の使用量を低減させたり、SO2酸化活性抑制剤
（三酸化タングステン、酸化ゲルマニウムなど）
を添加するなど種々の方法がとられているが、充
分なものとはいえない。これは脱硝活性とSO2酸
化活性とが、活性成分が持つ同じ化学性質に起因
するため、脱硝活性を変えることなく、SO2酸化
活性のみを抑制することがきわめて難しいことに
よる。そこで複雑な触媒製造工程をとつたり、高
価な活性成分である三酸化タングステンを多量に
使用することなどにより、実用に供されているの
が現状である。
本発明の目的は、上記従来技術の欠点に鑑み、
安価な活性成分を用い、簡単な工程で製造され、
SO2酸化活性が低く、しかも高脱硝活性を有する
アンモニア接触還元用触媒を提供することにあ
る。
本発明者らは、上記目的を達成するため、種々
研究の結果、脱硝触媒の併せ持つ脱硝反応活性と
SO2酸化活性とについて次の知見を得た。
(1) SO2酸化反応は活性成分（例えばパナジウム
酸化物）の表面上で進行し、よつて活性成分の
表面積が大きいほどSO2酸化活性が高くなる。
(2) 脱硝反応においては、活性成分は単に一酸化
窒素（NO）の活性化にのみ寄与し、またその
活性化速度はきわめて大きいため、活性成分の
面積はNOとNH3の反応の律速要因にはならな
い。よつて脱硝反応速度は活性成分の面積には
比例せず、活性成分の面積は微小でもよい。
(3) NOとNH3との反応速度を決定するのは触媒
上に吸着したNH3の量である。よつて触媒上
に吸着するNH3の量を増加させることにより、
脱硝活性を増加させることができる。
本発明者らは、これらの知見から触媒作用の本
質的機能であるNOの活性化と、NH3の吸着とを
別々の成分に担わせることにより、脱硝反応活性
を損なうことなく、SO2酸化活性の低減が計られ
ることを見出した。すなわち、前記のようにNO
の活性化に必要な活性成分（例えば酸化バナジウ
ム）は微小な面積で充分であるため、平均粒径
200〜350メツシユの比較的大きな粒子として用
い、それをNH3吸着性能に優れ、かつSO2酸化活
性の低い別の化合物（例えば酸化チタン）を添加
し、そして前者の粒径が維持されるように、しか
も両者が相互に密着するような製造工程を採用す
ることにより、前記の目的が達成されることを見
出した。
本発明は、平均粒径200〜350メツシユのバナジ
ウム、モリブデンもしくはタングステンの酸化物
または熱処理によりこれらの酸化物を生成する化
合物の粉末と、平均粒径200〜350メツシユの酸化
チタン、オルトチタン酸又はメタチタン酸の粉末
とを乾式混合したのち、成形し、さらに焼成して
なるアンモニア接触還元用脱硝触媒である。
本発明においてバナジウム、モリブデン又はタ
ングステンの酸化物としては、たとえば五二酸化
バナジウム（V2O5）、四二酸化バナジウム、三二
酸化バナジウム、三酸化モリブデン（M0O3）、
三酸化タングステン（WO3）などが用いられる。
また熱処理によりこれらの酸化物を生成する化合
物としては、例えば硫酸バナジル、シユウ酸バナ
ジル、塩化バナジル、メタバナジン酸アンモニウ
ム等があげられる。
これらの化合物の粉末は、前記のNOを活性化
する成分として用いられ、２種以上併用すること
ができる。
またこれらの化合物は、あらかじめ酸化チタ
ン、オルトチタン酸、メタチタン酸、Al2O3、
SiO2などの担体に、含浸または湿式混練により
担持させた粉末として使用してもよい。
一方、本発明の触媒では、酸化チタン
（TiO2）、またはこの前駆体で焼成によりTiO2を
生成するオルトチタン酸（TiO（OH）4）、メタチ
タン酸（TiO（OH）2）等のチタン化合物の粉末が
用いられるが、これらは前記のNH3吸着性能を
担う成分として用いられる。
本発明の触媒は、これらの両成分の粉末を機械
的に、かつ乾式で混合したのち、成形し、さらに
焼成するという簡単な工程により製造することが
できる。
本発明は、前記のように両成分粉末にそれぞれ
別の機能を担わせて所期の目的を達成するもので
あるが、この触媒の製造に際しては、各成分粉末
の粒径を適切に調整すること、およびその製造工
程においてその粒径を維持しうる適切な混合方法
を行なうことが肝要である。
各成分粉末の粒径に関しては、SO2れ酸化率の
抑制から考えれば大粒径であることが好ましく、
一方、NOの活性化された分子の移動から考えれ
ば小粒径が好ましい。この両者を満足するものと
して、両成分の粒径は通常200〜350メツシユに調
整される。
また両成分の混合方法に関しては、水分を加え
て混合する方法（通常の含浸法や湿式混練法な
ど）や、過度な機械力を用いる混合法を用いる
と、各成分の粒径の維持することができず、好ま
しくない。従つて本発明の触媒の製造に際して
は、両成分が物理的混合物として存在し、かつ両
成分の粒子接点が多くなるように、例えば乾式で
200メツシユ程度のフルイ上で振動させて充分に
混合することが好ましい。
上記混合物の成形は、例えば打錠成形、ローラ
プレスなど、通常の成形手段により行なわれる。
また焼成は、例えば300〜600℃で行えばよい。
本発明において、酸化チタン、オルトチタン酸
またはメタチタン酸と、バナジウム、モリブデン
もしくはタングステンの酸化物または熱処理によ
りこれらの酸化物を生成する化合物との配合割合
は、原子比で通常、99.9／0.1ないし90／10が好
ましい。
このようにして製造された本発明の触媒は、
SO2酸化活性を示すV2O5などの表面積が極少に
抑えられるので、SO2酸化活性が著しく低く、一
方、NOは、V2O5の面積が微小でも速やかに活性
され、TiO2上に吸着している多量のNH3を反応
するため、脱硝活性が充分高く保持される。
本発明の触媒は、V2O5のような活性化剤と、
TiO2のようなNH3の吸着促進剤とを混合し、両
者の粒子接点を通じて、活性化されたNOとNH3
との反応を進行させようとするものである。この
点で本発明の触媒は、活性成分を担体上に高度に
分散させて活性の向上を計つているだけの、含浸
法や湿式混練法により製造される通常の触媒とは
本質的に異なるものである。また単なる混合によ
る相互作用や担体効果を期する通常のアンモニア
接触還元用脱硝触媒とも別異のものである。
本発明によれば、SO2酸化率が低く、しかも脱
硝活性に優れた触媒が得られる。また本発明の触
媒は、工程がきわめて簡単であり、脱硝触媒のよ
うな大量消費型触媒の製造に適している。さらに
本発明の触媒の原料化合物が安価なバナジウム化
合物等でよいことも、経済的に大きな利点であ
る。
以下、本発明を実施例および比較例によりさら
に詳細に説明する。
実施例 １〜５
150℃で乾燥したメタチタン酸（TiO（OH）2）
を200メツシユ以下に粉砕した。次いでこの粉末
50ｇに、200メツシユ以下に粉砕したV2O5粉末
を、両者の割合がTi／Ｖ原子比でそれぞれ99.9／
0.1、99／１、97／３、95／５及び90／10となる
ように加えた。さらに200メツシユのフルイを用
いて、これを５回通過させることにより混合し
た。得られた粉末を３トン／cm2の圧力で径10mm、
高さ５mmの円柱状に成形したのち、空気中450℃
で２時間焼成して本発明の触媒を得た。これらの
触媒をそれぞれＡ，Ｂ，Ｃ，ＤおよびＥと称す
る。
実施例 ６〜７
V2O5粉末の代わりにそれぞれメタバナジン酸
アンモニウムおよび硝酸バナジル粉末を用い、そ
れぞれ前記原子比が95／５になるように加え、そ
の他は実施例４と同様に処理して本発明の触媒Ｆ
およびＧを得た。
実施例 ８
TiO（OH）2とメタバナジン酸アンモニウムとを
湿式混練してペーストを得、次いでこれを120℃
で24時間乾燥したのち、450℃で２時間焼成した。
このようにして得られた粉末をV2O5粉末の代わ
りに用い、その他は実施例４と同様に処理して本
発明の触媒Ｈを得た。
実施例 ９〜10
V2O5粉末の代わりにそれぞれM0O3粉末および
WO3粉末を用い、その他は実施例４と同様に処
理してそれぞれ本発明の触媒ＩおよびＪを得た。
実施例 11〜12
メタチタン酸粉末の代わりにそれぞれTiO2粉
末およびTi（OH）4粉末を用い、その他は実施例
４と同様に処理して本発明の触媒ＫおよびＬを得
た。
比較例 １〜12
実施例１〜12と同じ原料を用い、この両成分の
混合物に水40mlを加え、らいかい機で１時間混練
したのち、得られたペーストを120℃で24時間乾
燥し、次いで200メツシユのパスに粉砕した。次
いで実施例１〜４と同一の条件で成形したのち、
450℃で焼成し、比較例の触媒を得た。これらの
触媒をA′，B′，C′，D′，E′，F′，G′，H′，I′
，
J′，K′，L′と呼ぶ。
比較例 13
メタチタン酸粉末の代わりにAl2O3を用い、
Al／Ｖ原子比を95／５とし、その他は実施例４
と同様に処理して比較例の触媒を得た。
試験例
実施例および比較例により得られた触媒を破砕
して10〜20メツシユに整粒し、下記条件下で脱硝
活性及びSO2酸化活性を測定した。
脱硝活性
反応ガスの空間速度：100，000h-1
反応温度 ：350℃
ガス組成 ：NO 200ppm
NH3 240ppm
SO2 500ppm
CO2 12％
O2 ３％
H2Ｏ 12％
N2 残
SO2酸化活性
反応ガスの空間速度：20，000h-1
反応温度 ：380℃
ガス組成 ：SO2 500ppm
O2 ３％
N2 残
上記実施例１〜５（触媒Ａ〜Ｅ）および比較例
１〜５（触媒A′〜E′）を用いた試験例の結果を第
１図に示す。図中の実線は本発明の実施例および
破線は比較例の場合を示す。また実施例４，６〜
12（触媒Ｆ〜Ｌ）および比較例６〜12（触媒F′〜
L′）を用いた試験例の結果を第１表に示す。
The present invention relates to a denitrification catalyst for catalytic reduction of ammonia, and particularly to a catalyst with high denitrification activity that reduces the oxidation activity of sulfur dioxide (SO 2 ). Conventionally, for the purpose of removing nitrogen oxides from exhaust gas,
An ammonia catalytic reduction denitrification method is known in which nitrogen oxides are reduced to harmless nitrogen using ammonia (NH 3 ) using a catalyst. This ammonia catalytic reduction denitrification method has high selectivity and a simple device structure, so highly active catalysts containing vanadium, tungsten, molybdenum, iron, etc. as active ingredients have been developed, and are used to treat boiler exhaust gas for thermal power generation. Widely used. However, this method cannot be applied to heavy oil combustion exhaust gas, etc.
When applied to exhaust gas containing SO 2 , due to the SO 2 oxidation activity of these denitration catalysts,
Sulfur trioxide (SO 3 ) is produced from SO 2 , and this
There is a problem in that SO 3 and the unreacted portion of NH 3 injected as a reducing agent react to form ammonium sulfate, which is deposited in the air preheater etc. on the gas downstream side of the denitration equipment. In order to reduce the SO 2 oxidation activity of such denitrification catalysts, the amount of panadium compound used as an active component of the catalyst can be reduced, and SO 2 oxidation activity inhibitors (tungsten trioxide, germanium oxide, etc.) can be used.
Various methods have been used, such as adding , but these methods are not sufficient. This is because the denitrification activity and the SO 2 oxidation activity are caused by the same chemical properties of the active ingredients, so it is extremely difficult to suppress only the SO 2 oxidation activity without changing the denitrification activity. Therefore, it is currently put into practical use by requiring complicated catalyst manufacturing processes and using large amounts of tungsten trioxide, which is an expensive active ingredient. In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to
Manufactured using inexpensive active ingredients and simple processes,
An object of the present invention is to provide an ammonia catalytic reduction catalyst having low SO 2 oxidation activity and high denitrification activity. In order to achieve the above objective, the present inventors have conducted various studies and found that the denitrification reaction activity of the denitrification catalyst
The following findings regarding SO 2 oxidation activity were obtained. (1) The SO 2 oxidation reaction proceeds on the surface of the active ingredient (for example, panadium oxide), so the larger the surface area of the active ingredient, the higher the SO 2 oxidation activity. (2) In the denitrification reaction, the active ingredient only contributes to the activation of nitric oxide (NO), and the activation rate is extremely high, so the area of the active ingredient is the rate-limiting factor for the reaction between NO and NH 3 It won't be. Therefore, the denitrification reaction rate is not proportional to the area of the active ingredient, and the area of the active ingredient may be minute. (3) The rate of reaction between NO and NH 3 is determined by the amount of NH 3 adsorbed on the catalyst. Therefore, by increasing the amount of NH 3 adsorbed on the catalyst,
Denitrification activity can be increased. Based on these findings, the present inventors have determined that by assigning separate components to NO activation and NH 3 adsorption, which are the essential functions of catalysis, SO 2 oxidation can be achieved without impairing the denitrification reaction activity. It was found that the activity can be reduced. That is, as mentioned above, NO
Since the active ingredient (e.g. vanadium oxide) required for activation is sufficient in a small area, the average particle size
Using relatively large particles of 200 to 350 mesh, we add another compound (e.g., titanium oxide) with excellent NH 3 adsorption performance and low SO 2 oxidation activity so that the particle size of the former is maintained. Furthermore, the inventors have found that the above object can be achieved by adopting a manufacturing process in which the two are brought into close contact with each other. The present invention consists of powders of oxides of vanadium, molybdenum, or tungsten having an average particle size of 200 to 350 mesh, or powders of compounds that produce these oxides through heat treatment, and titanium oxide, orthotitanic acid, or This denitrification catalyst for ammonia catalytic reduction is obtained by dry mixing metatitanic acid powder, molding, and firing. In the present invention, vanadium, molybdenum or tungsten oxides include, for example, vanadium pentoxide (V 2 O 5 ), vanadium tetroxide, vanadium sesquioxide, molybdenum trioxide (M 0 O 3 ),
Tungsten trioxide (WO 3 ) or the like is used.
Examples of compounds that produce these oxides upon heat treatment include vanadyl sulfate, vanadyl oxalate, vanadyl chloride, and ammonium metavanadate. Powders of these compounds are used as the component for activating NO, and two or more kinds can be used in combination. In addition, these compounds are prepared in advance by titanium oxide, orthotitanic acid, metatitanic acid, Al 2 O 3 ,
It may also be used as a powder supported on a carrier such as SiO 2 by impregnation or wet kneading. On the other hand, the catalyst of the present invention uses titanium oxide (TiO 2 ), or titanium oxide such as orthotitanic acid (TiO(OH) 4 ) or metatitanic acid (TiO(OH) 2 ), which produces TiO 2 by firing with its precursor. Powders of compounds are used, and these are used as components responsible for the above-mentioned NH 3 adsorption performance. The catalyst of the present invention can be produced by a simple process of mechanically and dry mixing the powders of these two components, molding, and then calcining. As mentioned above, the present invention achieves the intended purpose by assigning different functions to both component powders, but when producing this catalyst, the particle size of each component powder is adjusted appropriately. It is important to use an appropriate mixing method that maintains the particle size during the manufacturing process. Regarding the particle size of each component powder, it is preferable to have a large particle size from the viewpoint of suppressing the SO 2 oxidation rate.
On the other hand, considering the movement of NO activated molecules, a small particle size is preferable. In order to satisfy both of these requirements, the particle sizes of both components are usually adjusted to 200 to 350 mesh. Regarding the mixing method of both components, if you use a method of mixing by adding water (such as a normal impregnation method or a wet kneading method) or a method of mixing using excessive mechanical force, it is difficult to maintain the particle size of each component. is not possible and is not desirable. Therefore, when producing the catalyst of the present invention, it is necessary to prepare, for example, a dry process, so that both components are present as a physical mixture and there are many contact points between the particles of both components.
It is preferable to mix thoroughly by vibrating on a sieve of about 200 mesh. The above-mentioned mixture is molded by conventional molding means such as tablet molding and roller press.
Further, the firing may be performed at, for example, 300 to 600°C. In the present invention, the blending ratio of titanium oxide, orthotitanic acid, or metatitanic acid and vanadium, molybdenum, or tungsten oxide or a compound that produces these oxides by heat treatment is usually 99.9/0.1 to 90 in atomic ratio. /10 is preferred. The catalyst of the present invention produced in this way is
Since the surface area of V 2 O 5 that exhibits SO 2 oxidation activity is suppressed to a minimum, SO 2 oxidation activity is extremely low. On the other hand, NO is quickly activated even if the area of V 2 O 5 is minute, and NO is oxidized on TiO 2 . Because the large amount of NH 3 adsorbed on the reactor reacts, the denitrification activity is maintained at a sufficiently high level. The catalyst of the present invention comprises an activator such as V 2 O 5 ;
By mixing with an adsorption promoter of NH 3 such as TiO 2 , activated NO and NH 3 are released through the contact between the two particles.
The aim is to promote the reaction with In this respect, the catalyst of the present invention is essentially different from ordinary catalysts produced by impregnation methods or wet kneading methods, which merely aim to improve activity by highly dispersing active ingredients on a carrier. It is. It is also different from ordinary denitrification catalysts for ammonia catalytic reduction, which expect interactions and carrier effects through simple mixing. According to the present invention, a catalyst with a low SO 2 oxidation rate and excellent denitrification activity can be obtained. Further, the catalyst of the present invention has an extremely simple process and is suitable for producing mass-consuming catalysts such as denitrification catalysts. Furthermore, it is a great economic advantage that the raw material compound for the catalyst of the present invention may be an inexpensive vanadium compound or the like. Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Examples 1-5 Metatitanic acid (TiO(OH) 2 ) dried at 150°C
was crushed to less than 200 mesh. Then this powder
50g of V 2 O 5 powder pulverized to 200 mesh or less, the Ti/V atomic ratio of the two is 99.9/
The ratios were added to be 0.1, 99/1, 97/3, 95/5 and 90/10. The mixture was further mixed by passing through a 200 mesh sieve 5 times. The obtained powder was powdered at a pressure of 3 tons/cm 2 with a diameter of 10 mm.
After molding into a cylindrical shape with a height of 5 mm, it is heated to 450℃ in air.
The catalyst of the present invention was obtained by firing for 2 hours. These catalysts are designated A, B, C, D and E, respectively. Examples 6 to 7 Ammonium metavanadate and vanadyl nitrate powder were used instead of V 2 O 5 powder, and added so that the atomic ratio was 95/5, and the other procedures were the same as in Example 4. Catalyst of invention F
and G were obtained. Example 8 TiO(OH) 2 and ammonium metavanadate were wet-kneaded to obtain a paste, which was then heated at 120°C.
After drying for 24 hours, it was fired at 450°C for 2 hours.
The thus obtained powder was used in place of the V 2 O 5 powder, and the process was otherwise carried out in the same manner as in Example 4 to obtain Catalyst H of the present invention. Examples 9-10 M 0 O 3 powder and M 0 O 3 powder instead of V 2 O 5 powder and
Catalysts I and J of the present invention were obtained by using WO 3 powder and otherwise treating in the same manner as in Example 4. Examples 11-12 Catalysts K and L of the present invention were obtained in the same manner as in Example 4 except that TiO 2 powder and Ti(OH) 4 powder were used instead of metatitanic acid powder, respectively. Comparative Examples 1 to 12 Using the same raw materials as in Examples 1 to 12, 40 ml of water was added to the mixture of both components, kneaded for 1 hour in a sieve machine, and the resulting paste was dried at 120°C for 24 hours. Then smashed into 200 mesh passes. Next, after molding under the same conditions as Examples 1 to 4,
The catalyst was calcined at 450°C to obtain a comparative catalyst. These catalysts are A′, B′, C′, D′, E′, F′, G′, H′, I′
，
Call them J′, K′, and L′. Comparative Example 13 Using Al 2 O 3 instead of metatitanic acid powder,
The Al/V atomic ratio was 95/5, and the rest was Example 4.
A catalyst of a comparative example was obtained in the same manner as above. Test Example The catalysts obtained in Examples and Comparative Examples were crushed and sized into 10 to 20 meshes, and the denitrification activity and SO 2 oxidation activity were measured under the following conditions. Denitrification activity Space velocity of reaction gas: 100,000h -1 Reaction temperature: 350℃ Gas composition: NO 200ppm NH 3 240ppm SO 2 500ppm CO 2 12% O 2 3% H 2 O 12% N 2 Remaining SO 2 Oxidation activity Reaction Gas space velocity: 20,000 h -1 Reaction temperature: 380°C Gas composition: SO 2 500 ppm O 2 3% N 2 remainder Examples 1 to 5 (catalysts A to E) and comparative examples 1 to 5 (catalyst A') The results of the test example using ~E') are shown in FIG. The solid line in the figure shows the example of the present invention, and the broken line shows the comparative example. In addition, Examples 4 and 6
12 (catalysts F to L) and comparative examples 6 to 12 (catalysts F' to
Table 1 shows the results of test examples using L').
【表】
第１図および第１表の結果から、本発明の触媒
は、いずれの活性成分組成の場合にも、高脱硝率
を維持しながら、低SO2酸化率を達成しているこ
とが分る。これに対し比較例６〜12のように湿式
混練法で得られた触媒には、高脱硝率と低SO2酸
化率との両方を同時に達成しているものは見られ
ない。またNH3吸着成分としてAl2O3を用いる場
合（比較例13）と本発明の触媒（実施例４）とを
比較しても、NH3吸着成分としてはTiO2または
その前駆体であるTi（OH）4もしくはTiO（OH）2
が優れていることが分る。[Table] From the results shown in Figure 1 and Table 1, it is clear that the catalyst of the present invention achieves a low SO 2 oxidation rate while maintaining a high denitrification rate, regardless of the active component composition. I understand. On the other hand, none of the catalysts obtained by the wet kneading method as in Comparative Examples 6 to 12 simultaneously achieved both a high denitrification rate and a low SO 2 oxidation rate. Furthermore, even when comparing the case where Al 2 O 3 is used as the NH 3 adsorption component (Comparative Example 13) and the catalyst of the present invention (Example 4), TiO 2 or its precursor Ti is used as the NH 3 adsorption component. (OH) 4 or TiO(OH) 2
is found to be superior.
第１図は本発明の実施例１〜５および比較例１
〜５の触媒の脱硝率とSO2酸化率の比較を示すも
のである。
Figure 1 shows Examples 1 to 5 of the present invention and Comparative Example 1.
This figure shows a comparison of the denitrification rate and the SO 2 oxidation rate of catalysts No. 5 to 5.
Claims (1)
モリブデンもしくはタングステンの酸化物、また
は熱処理によりこれらの酸化物を生成する化合物
の粉末と、酸化チタン、オルトチタン酸またはメ
タチタン酸の粉末とを乾式混合し、成形し、さら
に焼成してなることを特徴とする、アンモニア接
触還元用脱硝触媒。 ２ 特許請求の範囲第１項において、前記バナジ
ウム、モリブデンもしくはタングステンの酸化
物、または熱処理によりこれらの酸化物を生成す
る化合物の粉末が、あらかじめ酸化チタン、オル
トチタン酸またはメタチタン酸を含む液に含浸さ
せるか、または湿式混練によりこれらを担持され
た粉末であることを特徴とするアンモニア接触還
元用脱硝触媒。 ３ 特許請求の範囲第１項または第２項におい
て、前記酸化チタン、オルトチタン酸またはメタ
チタン酸と、前記バナジウム、モリブデンもしく
はタングステンの酸化物、または熱処理によりこ
れらの酸化物を生成する化合物との配合割合が、
原子比で99.9／0.1ないし90／10であるアンモニ
ア接触還元用脱硝触媒。[Claims] 1. Vanadium having an average particle size of 200 to 350 meshes,
It is characterized by dry mixing powders of molybdenum or tungsten oxides, or compounds that produce these oxides through heat treatment, and powders of titanium oxide, orthotitanic acid, or metatitanic acid, followed by molding and firing. A denitration catalyst for ammonia catalytic reduction. 2. In claim 1, the vanadium, molybdenum, or tungsten oxide, or a powder of a compound that produces these oxides through heat treatment, is impregnated in advance in a liquid containing titanium oxide, orthotitanic acid, or metatitanic acid. A denitrification catalyst for ammonia catalytic reduction, characterized in that it is a powder in which these substances are supported by dry kneading or wet kneading. 3. In claim 1 or 2, a combination of the titanium oxide, orthotitanic acid, or metatitanic acid with the oxide of vanadium, molybdenum, or tungsten, or a compound that produces these oxides through heat treatment. The percentage is
A denitrification catalyst for ammonia catalytic reduction with an atomic ratio of 99.9/0.1 to 90/10.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57093997A JPS58210849A (en) | 1982-06-03 | 1982-06-03 | Denitration catalyst for catalytic reduction with ammonia |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57093997A JPS58210849A (en) | 1982-06-03 | 1982-06-03 | Denitration catalyst for catalytic reduction with ammonia |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58210849A JPS58210849A (en) | 1983-12-08 |
| JPH0420663B2 true JPH0420663B2 (en) | 1992-04-06 |
Family
ID=14098037
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57093997A Granted JPS58210849A (en) | 1982-06-03 | 1982-06-03 | Denitration catalyst for catalytic reduction with ammonia |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58210849A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012200667A (en) * | 2011-03-25 | 2012-10-22 | Hitachi Zosen Corp | Preparation method for denitration catalyst |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6331540A (en) * | 1986-07-25 | 1988-02-10 | Mitsubishi Petrochem Co Ltd | Catalyst for reducing nitrogen oxide in exhaust gas by ammonia |
| JP3765942B2 (en) * | 1999-04-27 | 2006-04-12 | バブコック日立株式会社 | Exhaust gas purification catalyst compound, catalyst containing the compound, and process for producing the same |
| KR100314758B1 (en) | 1999-10-19 | 2001-11-15 | 이종훈 | Divanadium Pentaoxide-based catalysts and their preparation method for NOx removal from flue gases |
| KR100714031B1 (en) * | 2000-10-26 | 2007-05-04 | 바브콕-히다찌 가부시끼가이샤 | Exhaust gas purifying catalyst compound, catalyst comprising said compound and method for preparing the compound |
| JP5638982B2 (en) * | 2011-03-04 | 2014-12-10 | バブコック日立株式会社 | Denitration equipment |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5089291A (en) * | 1973-12-12 | 1975-07-17 | ||
| JPS5089264A (en) * | 1973-12-12 | 1975-07-17 | ||
| JPS5281090A (en) * | 1975-12-29 | 1977-07-07 | Nippon Steel Corp | Preparation of catalyst for treating discharged flue gases |
| JPS52147589A (en) * | 1976-06-03 | 1977-12-08 | Mitsubishi Chem Ind Ltd | Production of vanadium oxide catalyst |
-
1982
- 1982-06-03 JP JP57093997A patent/JPS58210849A/en active Granted
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5089291A (en) * | 1973-12-12 | 1975-07-17 | ||
| JPS5089264A (en) * | 1973-12-12 | 1975-07-17 | ||
| JPS5281090A (en) * | 1975-12-29 | 1977-07-07 | Nippon Steel Corp | Preparation of catalyst for treating discharged flue gases |
| JPS52147589A (en) * | 1976-06-03 | 1977-12-08 | Mitsubishi Chem Ind Ltd | Production of vanadium oxide catalyst |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012200667A (en) * | 2011-03-25 | 2012-10-22 | Hitachi Zosen Corp | Preparation method for denitration catalyst |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58210849A (en) | 1983-12-08 |
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