JPH06327974A - Material for purifying waste gas and purifying method of waste gas - Google Patents
Material for purifying waste gas and purifying method of waste gasInfo
- Publication number
- JPH06327974A JPH06327974A JP5142689A JP14268993A JPH06327974A JP H06327974 A JPH06327974 A JP H06327974A JP 5142689 A JP5142689 A JP 5142689A JP 14268993 A JP14268993 A JP 14268993A JP H06327974 A JPH06327974 A JP H06327974A
- Authority
- JP
- Japan
- Prior art keywords
- silver
- exhaust gas
- oxide
- nitrogen oxides
- waste gas
- 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.)
- Pending
Links
- 239000000463 material Substances 0.000 title claims abstract description 44
- 238000000034 method Methods 0.000 title claims abstract description 30
- 239000002912 waste gas Substances 0.000 title abstract 6
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims abstract description 191
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims abstract description 44
- 229910052709 silver Inorganic materials 0.000 claims abstract description 43
- 239000004332 silver Substances 0.000 claims abstract description 43
- NDVLTYZPCACLMA-UHFFFAOYSA-N silver oxide Chemical compound [O-2].[Ag+].[Ag+] NDVLTYZPCACLMA-UHFFFAOYSA-N 0.000 claims abstract description 43
- 229910052809 inorganic oxide Inorganic materials 0.000 claims abstract description 24
- 229910001923 silver oxide Inorganic materials 0.000 claims abstract description 22
- 239000002245 particle Substances 0.000 claims abstract description 19
- 150000001298 alcohols Chemical class 0.000 claims abstract description 18
- 239000003054 catalyst Substances 0.000 claims abstract description 7
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 6
- 239000007789 gas Substances 0.000 claims description 62
- 238000000746 purification Methods 0.000 claims description 20
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical group [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 14
- 239000002131 composite material Substances 0.000 claims description 4
- 238000011144 upstream manufacturing Methods 0.000 claims description 4
- 239000008188 pellet Substances 0.000 claims description 3
- 239000000919 ceramic Substances 0.000 claims description 2
- 239000008187 granular material Substances 0.000 claims description 2
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 15
- 229910052760 oxygen Inorganic materials 0.000 abstract description 15
- 239000001301 oxygen Substances 0.000 abstract description 15
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 abstract description 5
- 229910002091 carbon monoxide Inorganic materials 0.000 abstract description 5
- 229930195733 hydrocarbon Natural products 0.000 abstract description 5
- 150000002430 hydrocarbons Chemical class 0.000 abstract description 5
- 229910052739 hydrogen Inorganic materials 0.000 abstract description 3
- 239000001257 hydrogen Substances 0.000 abstract description 3
- 239000004215 Carbon black (E152) Substances 0.000 abstract description 2
- 239000000567 combustion gas Substances 0.000 abstract 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 abstract 1
- 239000002699 waste material Substances 0.000 abstract 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 14
- 238000006243 chemical reaction Methods 0.000 description 13
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 11
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 10
- 238000002485 combustion reaction Methods 0.000 description 10
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 10
- 238000012937 correction Methods 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 229910052757 nitrogen Inorganic materials 0.000 description 6
- 229910021529 ammonia Inorganic materials 0.000 description 5
- 238000010304 firing Methods 0.000 description 5
- 229910001961 silver nitrate Inorganic materials 0.000 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 description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 4
- 239000007864 aqueous solution Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 229910052878 cordierite Inorganic materials 0.000 description 3
- 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 3
- 238000001035 drying Methods 0.000 description 3
- 238000011068 loading method Methods 0.000 description 3
- 239000012629 purifying agent Substances 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 238000001354 calcination Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- 238000005470 impregnation Methods 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 238000004898 kneading Methods 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 2
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 2
- VZSRBBMJRBPUNF-UHFFFAOYSA-N 2-(2,3-dihydro-1H-inden-2-ylamino)-N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]pyrimidine-5-carboxamide Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C(=O)NCCC(N1CC2=C(CC1)NN=N2)=O VZSRBBMJRBPUNF-UHFFFAOYSA-N 0.000 description 1
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- 238000003916 acid precipitation Methods 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 238000010531 catalytic reduction reaction Methods 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000011538 cleaning material Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- 239000010457 zeolite Substances 0.000 description 1
Landscapes
- Catalysts (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は窒素酸化物と過剰の酸素
を含む燃焼排ガスから、窒素酸化物を効果的に除去する
ことのできる浄化材及びそれを用いた排ガス浄化方法に
関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a purification material capable of effectively removing nitrogen oxides from a combustion exhaust gas containing nitrogen oxides and excess oxygen, and an exhaust gas purification method using the same.
【０００２】[0002]
【従来の技術及び発明が解決しようとする課題】自動車
用エンジン等の内燃機関や、工場等に設置された燃焼機
器、家庭用ファンヒーターなどから排出される各種の燃
焼排ガス中には、過剰の酸素とともに一酸化窒素、二酸
化窒素等の窒素酸化物が含まれている。ここで、「過剰
の酸素を含む」とは、その排ガス中に含まれる一酸化炭
素、水素、炭化水素等の未燃焼成分を燃焼するのに必要
な理論酸素量より多い酸素を含むことを意味する。ま
た、以下における窒素酸化物とは一酸化窒素及び／又は
二酸化窒素を指す。2. Description of the Related Art Excessive amounts of combustion exhaust gas emitted from internal combustion engines such as automobile engines, combustion equipment installed in factories, household fan heaters, etc. Nitrogen oxides such as nitric oxide and nitrogen dioxide are contained together with oxygen. Here, "containing excess oxygen" means containing more oxygen than the theoretical oxygen amount necessary to burn unburned components such as carbon monoxide, hydrogen, and hydrocarbons contained in the exhaust gas. To do. Moreover, the nitrogen oxide in the following refers to nitric oxide and / or nitrogen dioxide.
【０００３】この窒素酸化物は酸性雨の原因の一つとさ
れ、環境上の大きな問題となっている。そのため、各種
燃焼機器が排出する排ガス中の窒素酸化物を除去するさ
まざまな方法が検討されている。This nitrogen oxide is considered to be one of the causes of acid rain and is a serious environmental problem. Therefore, various methods for removing nitrogen oxides in exhaust gas discharged from various combustion devices have been studied.
【０００４】過剰の酸素を含む燃焼排ガスから窒素酸化
物を除去する方法として、特に大規模な固定燃焼装置
（工場等の大型燃焼機等）に対しては、アンモニアを用
いる選択的接触還元法が実用化されている。As a method for removing nitrogen oxides from combustion exhaust gas containing excess oxygen, a selective catalytic reduction method using ammonia is used, particularly for large-scale fixed combustion devices (large combustors such as factories). It has been put to practical use.
【０００５】しかしながら、この方法においては、窒素
酸化物の還元剤として用いるアンモニアが高価であるこ
と、またアンモニアは毒性を有すること、そのために未
反応のアンモニアが排出しないように排ガス中の窒素酸
化物濃度を計測しながらアンモニア注入量を制御しなけ
ればならないこと、一般に装置が大型となること等の問
題点がある。However, in this method, ammonia used as a reducing agent for nitrogen oxides is expensive, and ammonia is toxic, so that unreacted ammonia is discharged so that nitrogen oxides in exhaust gas are not discharged. There are problems that the amount of ammonia injection must be controlled while measuring the concentration and that the apparatus is generally large.
【０００６】そこで、ゼオライト又はそれに遷移金属を
担持した触媒を用いて、排ガス中の酸素との理論反応量
以下の還元剤を添加して窒素酸化物を除去する方法が提
案された（たとえば、特開昭63-100919 号、同63-28372
7 号、特開平1-130735号、及び日本化学会第59春季年会
(1990年)2A526、同第60秋季年会 (1990年)3L420、3L42
2 、3L423 、「触媒」vol.33 No.2 、59ページ、1991年
等) 。又、銀を担持する触媒を用いる方法が提案された
（特開平4-281844）。Therefore, there has been proposed a method for removing nitrogen oxides by adding a reducing agent in an amount equal to or less than a theoretical reaction amount with oxygen in exhaust gas by using zeolite or a catalyst supporting a transition metal thereon (for example, a special method). Kaisho 63-100919, 63-28372
No. 7, JP-A-1-130735, and 59th Annual Meeting of the Chemical Society of Japan
(1990) 2A526, 60th Autumn Meeting (1990) 3L420, 3L42
2, 3L423, "Catalyst" vol.33 No.2, page 59, 1991 etc.). In addition, a method using a catalyst supporting silver has been proposed (JP-A-4-218844).
【０００７】しかしながら、これらの方法では、効果的
な窒素酸化物の除去は狭い温度範囲でしか得られず、ま
た、水分を含むような排ガスでは高い効率で窒素酸化物
を除去することができない。よって、水分を１０％程度
含有し、運転条件によって排ガス温度が変化する実際の
排ガスでは、窒素酸化物の効果的な除去が困難である。However, these methods can effectively remove nitrogen oxides only in a narrow temperature range, and cannot remove nitrogen oxides with high efficiency in exhaust gas containing water. Therefore, it is difficult to effectively remove nitrogen oxides in an actual exhaust gas that contains about 10% of water and the exhaust gas temperature changes depending on operating conditions.
【０００８】したがって、本発明の目的は、固定燃焼装
置および酸素過剰条件で燃焼するガソリンエンジン、デ
ィーゼルエンジン等からの燃焼排ガスのように、窒素酸
化物や、一酸化炭素、水素、炭化水素等の未燃焼分に対
する理論反応量以上の酸素を含有する燃焼排ガスから、
効果的に窒素酸化物を除去することができる排ガス浄化
材、及び浄化方法を提供することである。Therefore, an object of the present invention is to remove nitrogen oxides, carbon monoxide, hydrogen, hydrocarbons, etc., such as combustion exhaust gas from a fixed combustion apparatus and a gasoline engine, a diesel engine, etc. that burn under an excess oxygen condition. From the combustion exhaust gas that contains more than the theoretical reaction amount of oxygen for unburned components,
An exhaust gas purifying material and a purifying method capable of effectively removing nitrogen oxides.
【０００９】[0009]
【課題を解決するための手段】上記課題に鑑み鋭意研究
の結果、本発明者は、多孔質の無機酸化物に特定量の銀
または銀酸化物を、特定の形状で担持してなる浄化材を
用い、この浄化材に特定の温度及び接触時間でアルコー
ル類を添加した排ガスを接触させると、水分を１０％程
度含有する排ガスの場合でも、添加されたアルコール類
により、窒素酸化物を効果的に除去することができるこ
とを発見し、本発明を完成した。As a result of earnest research in view of the above problems, the present inventor has found that the present invention is a purification material in which a specific amount of silver or silver oxide is supported in a specific shape on a porous inorganic oxide. When the exhaust gas added with alcohols is brought into contact with this purification material at a specific temperature and contact time, nitrogen oxides are effectively removed by the added alcohols even in the case of exhaust gas containing about 10% of water. The present invention has been completed by discovering that it can be removed.
【００１０】すなわち、窒素酸化物を除去する本発明の
排ガス浄化材は、多孔質の無機酸化物１００重量％に銀
または銀酸化物を銀元素に換算して０．２〜１５重量％
担持してなる触媒を有し、前記多孔質無機酸化物上の銀
または銀酸化物が平均直径１０〜１０００ｎｍの粒子で
あり、外部から前記排ガス中に添加されたアルコール類
を還元剤として、２００〜６００℃で、前記排ガス中の
窒素酸化物を還元することを特徴とする。That is, the exhaust gas purifying material of the present invention for removing nitrogen oxides has a porous inorganic oxide content of 100% by weight and silver or silver oxide in terms of silver element of 0.2 to 15% by weight.
It has a supported catalyst, and the silver or silver oxide on the porous inorganic oxide is a particle having an average diameter of 10 to 1000 nm, and alcohols externally added to the exhaust gas as a reducing agent are 200 The nitrogen oxide in the exhaust gas is reduced at ˜600 ° C.
【００１１】また、窒素酸化物を除去する本発明の排ガ
ス浄化方法は、上記排ガス浄化材を排ガス導管の途中に
設置し、前記浄化材の上流側で前記排ガス中にアルコー
ル類を添加し、２００〜６００℃で前記排ガスを前記浄
化材に接触させ、前記アルコール類と前記窒素酸化物と
を反応させて前記窒素酸化物を除去することを特徴とす
る。Further, in the exhaust gas purifying method of the present invention for removing nitrogen oxides, the exhaust gas purifying material is installed in the middle of the exhaust gas conduit, and alcohols are added to the exhaust gas on the upstream side of the purifying material. It is characterized in that the exhaust gas is brought into contact with the purification material at ˜600 ° C., and the alcohols are reacted with the nitrogen oxides to remove the nitrogen oxides.
【００１２】以下、本発明を詳細に説明する。本発明で
は、以下に示す浄化材を用い、この浄化材に排ガスを接
触させることにより、排ガス中の残留炭化水素及び／又
は浄化材の設置部位より上流側で排ガスに添加されたア
ルコール類を還元剤として排ガス中の窒素酸化物を還元
除去する。The present invention will be described in detail below. In the present invention, the purifying agent shown below is used, and the exhaust gas is brought into contact with this purifying agent to reduce residual hydrocarbons in the exhaust gas and / or alcohols added to the exhaust gas on the upstream side from the installation site of the purifying agent. As an agent, nitrogen oxides in exhaust gas are reduced and removed.
【００１３】まず、本発明の浄化材は多孔質の無機酸化
物に銀または銀酸化物を担持してなる。多孔質の無機酸
化物としては、多孔質のアルミナ、チタニア、ジルコニ
ア、及びそれらの複合酸化物等を使用することができる
が、好ましくはγ−アルミナ又はアルミナ系複合酸化物
を用いる。γ−アルミナ又はアルミナ系複合酸化物を用
いることにより、添加したアルコール類と排ガス中の窒
素酸化物との反応が効率良く起こる。First, the purification material of the present invention comprises silver or silver oxide supported on a porous inorganic oxide. As the porous inorganic oxide, porous alumina, titania, zirconia, and their composite oxides can be used, but γ-alumina or alumina-based composite oxide is preferably used. By using γ-alumina or an alumina-based composite oxide, the reaction between the added alcohol and the nitrogen oxide in the exhaust gas occurs efficiently.
【００１４】多孔質の無機酸化物の比表面積は１０ｍ2
／ｇ以上であるのが好ましい。比表面積が１０ｍ2 ／ｇ
未満であると、無機酸化物への銀成分（銀活性種）の分
散が悪くなり、良好な窒素酸化物の除去が行えない。好
ましい多孔質無機酸化物の比表面積は３０ｍ2 ／ｇ以上
とする。The specific surface area of the porous inorganic oxide is 10 m 2
/ G or more is preferable. Specific surface area of 10 m 2 / g
If it is less than the above range, the dispersion of the silver component (silver active species) in the inorganic oxide becomes poor, and the nitrogen oxide cannot be removed well. The specific surface area of the porous inorganic oxide is preferably 30 m 2 / g or more.
【００１５】本発明の浄化材はペレット状、顆粒状、粉
末状、ハニカム状、フォーム状、板状等の形態で用いる
ことができる。本発明の浄化材の好ましい形態は多孔質
無機酸化物に銀または銀酸化物を担持した触媒を、セラ
ミック製又は金属製でハニカム状、フォーム状等の三次
元構造体の表面にコートするか、上記三次元構造体に無
機酸化物をコートしたあと、銀または銀酸化物を担持し
て調製する。セラミック材として耐熱性の優れたコージ
ェライト、ムライトなどが挙げられる。三次元構造体へ
の無機酸化物のコートは公知のウォッシュコート法など
により行なう。本発明の浄化材のもう一つの好ましい形
態はペレット状の多孔質無機酸化物に銀または銀酸化物
を担持して用いる。The purifying material of the present invention can be used in the form of pellets, granules, powder, honeycomb, foam, plate or the like. A preferred form of the purifying material of the present invention is a catalyst in which silver or silver oxide is supported on a porous inorganic oxide, a honeycomb-like or foam-like three-dimensional structure made of ceramic or metal, or coated on the surface thereof. After the inorganic oxide is coated on the three-dimensional structure, silver or silver oxide is supported to prepare the three-dimensional structure. Examples of the ceramic material include cordierite and mullite, which have excellent heat resistance. The inorganic oxide is coated on the three-dimensional structure by a known wash coating method or the like. Another preferred form of the purifying material of the present invention is used by supporting silver or silver oxide on a pellet-shaped porous inorganic oxide.
【００１６】上記したγ−アルミナ等の無機酸化物に銀
または銀酸化物を担持する場合の担持量は、無機酸化物
を１００重量％として、その０．２〜１５重量％（銀元
素換算値）とする。銀または銀酸化物が０．２重量％
（銀元素換算値）未満では低温側での窒素酸化物の除去
率が低下する。また、１５重量％（銀元素換算値）を超
す量の銀成分を担持するとアルコール自身の燃焼が起き
やすく、窒素酸化物の除去率はかえって低下する。好ま
しくは、銀成分の担持量を無機酸化物１００重量％に対
して、５重量％を越えて１５重量％以下（銀元素換算
値）とする。When silver or silver oxide is loaded on the above-mentioned inorganic oxide such as γ-alumina, the loading amount is 0.2 to 15% by weight (converted to silver element), with 100% by weight of the inorganic oxide. ). 0.2% by weight of silver or silver oxide
If it is less than the (converted value of silver element), the removal rate of nitrogen oxides on the low temperature side decreases. Further, when a silver component in an amount exceeding 15% by weight (converted to silver element) is carried, the alcohol itself is easily burned, and the nitrogen oxide removal rate is rather lowered. Preferably, the supported amount of the silver component is more than 5% by weight and 15% by weight or less (converted into silver element) with respect to 100% by weight of the inorganic oxide.
【００１７】多孔質無機酸化物に担持された銀又は銀酸
化物は粒状を呈しているが、本発明の浄化材では、銀ま
たは銀酸化物の粒子の平均直径が１０〜１０００ｎｍと
する。一般的には、銀成分の粒子径が小さいほど、反応
特性が高いが、平均粒径が１０ｎｍ未満であると、還元
剤である炭化水素や、含酸素有機化合物の酸化反応のみ
が進み、窒素酸化物の除去率が低下する。一方、平均粒
径が１０００ｎｍを越えると、銀成分の反応特性が低減
し、窒素酸化物の除去率が下がる。好ましい平均粒径は
２０〜２００ｎｍとする。なお、ここで言う平均とは算
術平均のことを意味する。また、粒子状銀成分は金属銀
または銀酸化物の形で存在するが、粒子表面では銀酸化
物の形で存在する。The silver or silver oxide supported on the porous inorganic oxide is granular, but in the purifying material of the present invention, the average diameter of the silver or silver oxide particles is 10 to 1000 nm. Generally, the smaller the particle size of the silver component, the higher the reaction characteristics. However, when the average particle size is less than 10 nm, only the oxidation reaction of the reducing agent hydrocarbon or the oxygen-containing organic compound proceeds, and the nitrogen The oxide removal rate decreases. On the other hand, if the average particle size exceeds 1000 nm, the reaction characteristics of the silver component are reduced and the nitrogen oxide removal rate is reduced. A preferable average particle size is 20 to 200 nm. In addition, the average here means an arithmetic mean. Further, the particulate silver component exists in the form of metallic silver or silver oxide, but exists in the form of silver oxide on the surface of the particles.
【００１８】γ−アルミナ等の無機酸化物に銀成分を担
持する方法としては、公知の含浸法や、混練法等を用い
ることができる。担持後の浄化材の調整は、５０〜１５
０℃程度で乾燥後、１００〜６００℃で段階的に昇温し
て焼成するのが好ましい。焼成は、空気中又は窒素流通
下、あるいは水素ガス流通下、もしくは真空排気しなが
ら行うのが好ましい。酸化雰囲気下、６００℃で一時間
以上焼成することにより、担持された銀成分の粒子径を
所望の大きさにすることができる。この時、窒素酸化物
が存在すれば、より効果的に焼成できる。なお、窒素ガ
スまたは水素ガス流通下で焼成した浄化材は、最後に酸
化処理を行うことが好ましい。As a method for supporting the silver component on the inorganic oxide such as γ-alumina, known impregnation method, kneading method and the like can be used. Adjustment of the purifying material after loading is 50 to 15
After drying at about 0 ° C., it is preferable to raise the temperature stepwise at 100 to 600 ° C. and bake. The firing is preferably performed in air or under nitrogen flow, or under hydrogen gas flow, or while evacuating. By calcining at 600 ° C. for one hour or more in an oxidizing atmosphere, the particle size of the supported silver component can be set to a desired size. At this time, if nitrogen oxide is present, the firing can be performed more effectively. In addition, it is preferable that the purification material fired under the flow of nitrogen gas or hydrogen gas is finally oxidized.
【００１９】次に、本発明の方法について説明する。ま
ず、上述した浄化材を排ガス導管の途中に設置する。Next, the method of the present invention will be described. First, the above-mentioned purification material is installed in the middle of the exhaust gas conduit.
【００２０】本発明では、外部からアルコール類を排ガ
ス中に導入する。アルコール類の導入位置は、浄化材を
設置した位置より上流側である。In the present invention, alcohols are introduced into the exhaust gas from the outside. The introduction position of the alcohols is upstream of the position where the purification material is installed.
【００２１】外部から導入するアルコール類としては、
エタノール、ブタノールなどの炭素数２以上のアルコー
ル類が好ましい。これらの添加物は、噴霧等の方法で排
ガス中に導入することができる。As alcohols introduced from the outside,
Alcohols having 2 or more carbon atoms such as ethanol and butanol are preferable. These additives can be introduced into the exhaust gas by a method such as spraying.
【００２２】外部から導入するアルコール類の量は、排
ガス中の窒素酸化物の重量の５倍以下とするのが好まし
い。添加量が５倍を超えると、燃費の悪化を招く。より
好ましくは０．２〜４倍とする。The amount of alcohols introduced from the outside is preferably not more than 5 times the weight of nitrogen oxides in the exhaust gas. If the addition amount exceeds 5 times, the fuel efficiency is deteriorated. It is more preferably 0.2 to 4 times.
【００２３】本発明では、アルコール類を含む排ガスが
上記した浄化材と接触する時間を調節し、添加物と窒素
酸化物との反応を効率良く進行させる。実用的な立場で
考えて、アルコール類を含む排ガスと浄化材との接触時
間は０．００６ｇ・秒／ml以上とする。好ましい接触時
間は０．００７ｇ・秒／ml以上とする。In the present invention, the time during which the exhaust gas containing alcohol contacts the above-mentioned purifying material is adjusted so that the reaction between the additive and the nitrogen oxides proceeds efficiently. From a practical standpoint, the contact time between the exhaust gas containing alcohols and the purification material should be 0.006 g · sec / ml or more. The preferable contact time is 0.007 g · sec / ml or more.
【００２４】また、本発明では、アルコール類と窒素酸
化物とが反応する部位である浄化材設置部位における排
ガスの温度を２００〜６００℃に保つ。排ガスの温度が
２００℃未満であると窒素酸化物の還元反応が進行せ
ず、良好な窒素酸化物の除去を行うことができない。一
方、６００℃を超す温度とするとアルコール類自身の燃
焼が始まり、窒素酸化物の還元除去が行えない。好まし
い排ガス温度は３００〜５５０℃である。Further, in the present invention, the temperature of the exhaust gas at the purification material installation site, which is the site where alcohols and nitrogen oxides react, is maintained at 200 to 600 ° C. If the temperature of the exhaust gas is less than 200 ° C., the reduction reaction of nitrogen oxides does not proceed, and good removal of nitrogen oxides cannot be performed. On the other hand, if the temperature exceeds 600 ° C., the alcohols themselves start to burn and the nitrogen oxides cannot be reduced and removed. A preferable exhaust gas temperature is 300 to 550 ° C.
【００２５】[0025]
【実施例】本発明を以下の具体的実施例によりさらに詳
細に説明する。実施例１ 市販のペレット状γ−アルミナ（直径1.5mm 、長さ約６
mm、比表面積２００ｍ2 ／ｇ）５ｇに硝酸銀水溶液を用
いて、銀成分を５重量％担持した。次に、８０℃で２時
間乾燥後、空気中段階的に６００℃まで昇温したあと、
５時間焼成し、銀又は銀酸化物の平均粒径が４５ｎｍで
ある浄化材を調製した。なお、粒子径は電子顕微鏡を用
いて計測した。The present invention will be described in more detail by the following specific examples. Example 1 Commercially available pelletized γ-alumina (diameter 1.5 mm, length about 6
mm, specific surface area 200 m 2 / g) 5 g of an aqueous silver nitrate solution was used to carry 5% by weight of a silver component. Next, after drying at 80 ° C. for 2 hours, the temperature was gradually raised to 600 ° C. in air,
Firing was performed for 5 hours to prepare a purifying material having an average particle diameter of silver or silver oxide of 45 nm. The particle size was measured using an electron microscope.
【００２６】この浄化材３．７ｇを反応管内に設置し、
表１に示す組成のガス（一酸化窒素、二酸化炭素、酸
素、プロピレン、及び窒素からなる乾燥成分の合計１０
０容量％に、さらに水分１０容量％を添加したもの）を
毎分４．４リットル（標準状態）の流量で流して（接触
時間０．０５ｇ・秒／ml、空間速度３００００ｈ
ｒ-1）、反応管内の排ガス温度を２００〜６００℃の範
囲の保ち、プロピレンと窒素酸化物とを反応させた。3.7 g of this purification material was placed in a reaction tube,
A gas having the composition shown in Table 1 (a total of 10 dry components consisting of nitric oxide, carbon dioxide, oxygen, propylene, and nitrogen).
0 volume% to which 10 volume% of water was added) at a flow rate of 4.4 liters per minute (standard condition) (contact time 0.05 g · sec / ml, space velocity 30000 h)
r −1 ), the exhaust gas temperature in the reaction tube was maintained in the range of 200 to 600 ° C., and propylene and nitrogen oxide were reacted.
【００２７】反応管通過後のガスの窒素酸化物（一酸化
窒素、二酸化窒素の合計量）の濃度を化学発光式窒素酸
化物分析計により測定し、窒素酸化物の除去率を求め
た。結果を図１に示す。The concentration of nitrogen oxides (total amount of nitric oxide and nitrogen dioxide) of the gas after passing through the reaction tube was measured by a chemiluminescence type nitrogen oxide analyzer to determine the removal rate of nitrogen oxides. The results are shown in Fig. 1.
【００２８】 表１ 成分 濃度 一酸化窒素 800 ppm 一酸化炭素 100 ppm 酸素 10 容量％ エタノール 一酸化窒素の質量の３倍 窒素 残部 水分 上記した成分からなるガス量に対して10容量％[0028] Table 1 Component Concentration nitric 800 ppm carbon monoxide 100 ppm oxygen 10 volume% ethanol of 3 times the nitrogen balance water above ingredients in the nitric oxide mass 10% by volume based on the amount of gas
【００２９】実施例２ 硝酸銀水溶液を用いて銀成分を５重量％担持した粉末状
γ−アルミナ（比表面積２００ｍ2 ／ｇ）１．０ｇを、
市販のコージェライト製ハニカム状成形体（直径３０m
m、長さ約１２．６mm、４００セル／平方インチ）にコ
ートーし、８０℃で２時間乾燥後、空気中段階的に６０
０℃まで昇温したあと、５時間焼成し、銀又は銀酸化物
の平均粒径が５０ｎｍである浄化材を調製した。 Example 2 1.0 g of powdery γ-alumina (specific surface area 200 m 2 / g) supporting 5% by weight of a silver component using an aqueous solution of silver nitrate,
Commercially available cordierite honeycomb shaped body (diameter 30 m
m, length about 12.6 mm, 400 cells / in 2) and dried at 80 ° C for 2 hours, then in air at 60
After the temperature was raised to 0 ° C., it was baked for 5 hours to prepare a purifying material having an average particle diameter of silver or silver oxide of 50 nm.
【００３０】この浄化材を反応管内に設置し、表１に示
す組成のガスを用い、実施例１と同様な条件で窒素酸化
物の除去実験を行った。A nitrogen oxide removal experiment was conducted under the same conditions as in Example 1 except that the cleaning material was placed in a reaction tube and the gas having the composition shown in Table 1 was used.
【００３１】反応管通過後のガスの窒素酸化物（一酸化
窒素、二酸化窒素の合計量）の濃度を化学発光式窒素酸
化物分析計により測定し、窒素酸化物の除去率を求め
た。結果を図１に示す。The concentration of nitrogen oxides (total amount of nitric oxide and nitrogen dioxide) of the gas after passing through the reaction tube was measured by a chemiluminescence type nitrogen oxide analyzer to determine the removal rate of nitrogen oxides. The results are shown in Fig. 1.
【００３２】比較例１ 実施例１で用いたγ−アルミナペレットと同一のもの１
０ｇに硝酸銀水溶液を用いて硝酸銀を５重量％（銀元素
換算）担持して、実施例１と同様の方法で８００℃まで
焼成し、銀または銀酸化物の平均粒径が２０００ｎｍの
浄化材を調製した。その浄化材３．６ｇを用いて、実施
例１と同様な条件で窒素酸化物の除去試験を行った。結
果を図１に示す。 Comparative Example 1 Same as γ-alumina pellets used in Example 1 1
0 g of silver nitrate aqueous solution was used to support 5 wt% of silver nitrate (calculated as silver element), and the mixture was baked up to 800 ° C. in the same manner as in Example 1 to obtain a purification material having an average particle diameter of silver or silver oxide of 2000 nm. Prepared. Using 3.6 g of the purification material, a nitrogen oxide removal test was performed under the same conditions as in Example 1. The results are shown in Fig. 1.
【００３３】図１からわかるように、銀成分の平均粒径
が５０ｎｍ前後の実施例１、２では、広い温度範囲にわ
たって窒素酸化物の良好な除去がみられた。一方、平均
粒径が１０００ｎｍ以上の比較例１では、全温度範囲に
わたって窒素酸化物除去率の低下がみられた。As can be seen from FIG. 1, in Examples 1 and 2 in which the average particle diameter of the silver component was around 50 nm, good removal of nitrogen oxide was observed over a wide temperature range. On the other hand, in Comparative Example 1 having an average particle size of 1000 nm or more, the nitrogen oxide removal rate was reduced over the entire temperature range.
【００３４】[0034]
【発明の効果】以上詳述したように、本発明によれば、
過剰の酸素を含む排ガス中の窒素酸化物を効率良く除去
することができる。また、本発明の方法では、排ガス中
に水分が１０％程度含まれている場合でも窒素酸化物の
除去を効率良く行うことができる。As described in detail above, according to the present invention,
The nitrogen oxides in the exhaust gas containing excess oxygen can be efficiently removed. Further, according to the method of the present invention, nitrogen oxides can be efficiently removed even when the exhaust gas contains about 10% of water.
【００３５】本発明の排ガス浄化材及び浄化方法は、各
種燃焼機、自動車等の排ガスに含まれる窒素酸化物の除
去に広く利用することができる。The exhaust gas purifying material and the purifying method of the present invention can be widely used for removing nitrogen oxides contained in the exhaust gas of various combustors, automobiles and the like.
【図１】実施例１、２及び比較例１における窒素酸化物
の除去率と排ガス温度との関係を示すグラフである。FIG. 1 is a graph showing a relationship between a nitrogen oxide removal rate and an exhaust gas temperature in Examples 1 and 2 and Comparative Example 1.
─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成５年１２月２１日[Submission date] December 21, 1993
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００２６[Correction target item name] 0026
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００２６】この浄化材３．７ｇを反応管内に設置し、
表１に示す組成のガス（一酸化窒素、一酸化炭素、酸
素、エタノール、及び窒素からなる乾燥成分の合計１０
０容量％に、さらに水分１０容量％を添加したもの）を
毎分４．４リットル（標準状態）の流量で流して（接触
時間０．０５ｇ・秒／ｍｌ、空間速度３００００ｈｒ
−１）、反応管内の排ガス温度を２００〜６００℃の範
囲の保ち、エタノールと窒素酸化物とを反応させた。 ─────────────────────────────────────────────────────
3.7 g of this purification material was placed in a reaction tube,
A gas having the composition shown in Table 1 (a total of 10 dry components consisting of nitric oxide, carbon monoxide , oxygen, ethanol , and nitrogen).
0 volume% to which 10 volume% of water was added) was made to flow at a flow rate of 4.4 liters per minute (standard state) (contact time 0.05 g · sec / ml, space velocity 30000 hr).
-1 ), the exhaust gas temperature in the reaction tube was kept in the range of 200 to 600 ° C, and ethanol was reacted with nitrogen oxide. ─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成６年４月１５日[Submission date] April 15, 1994
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１８[Correction target item name] 0018
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１８】γ−アルミナ等の無機酸化物に銀成分を担
持する方法としては、公知の含浸法や、混練法等を用い
ることかできる。担持後の浄化材の調製は、５０〜１５
０℃程度で乾燥後、１００〜６００℃で段階的に昇温し
て焼成するのが好ましい。焼成は、空気中又は窒素流通
下、あるいは水素ガス流通下、もしくは真空排気しなが
ら行うのが好ましい。酸化雰囲気下、６００℃で一時間
以上焼成することにより、担持された銀成分の粒子径を
所望の大きさにすることができる。この時、窒素酸化物
が存在すれば、より効果的に焼成できる。なお、窒素ガ
スまたは水素ガス流通下で焼成した浄化材は、最後に酸
化処理を行うことが好ましい。As a method for supporting the silver component on the inorganic oxide such as γ-alumina, a known impregnation method, a kneading method or the like can be used. Preparation of the purifying material after loading is 50 to 15
After drying at about 0 ° C., it is preferable to raise the temperature stepwise at 100 to 600 ° C. and bake. The firing is preferably performed in air or under nitrogen flow, or under hydrogen gas flow, or while evacuating. By calcining at 600 ° C. for one hour or more in an oxidizing atmosphere, the particle size of the supported silver component can be set to a desired size. At this time, if nitrogen oxide is present, the firing can be performed more effectively. In addition, it is preferable that the purification material fired under the flow of nitrogen gas or hydrogen gas is finally oxidized.
【手続補正２】[Procedure Amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００２９[Name of item to be corrected] 0029
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００２９】実施例２ 硝酸銀水溶液を用いて銀成分を５重量％担持した粉末状
γ−アルミナ（比表面積２００ｍ２／ｇ）１．０ｇを、
市販のコージェライト製ハニカム状成形体（直径３０ｍ
ｍ、長さ約１２．６ｍｍ、４００セル／平方インチ）に
コートし、８０℃で２時間乾燥後、空気中段階的に６０
０℃まで昇温したあと、５時間焼成し、銀又は銀酸化物
の平均粒径が５０ｎｍである浄化材を調製した。 Example 2 1.0 g of powdery γ-alumina (specific surface area 200 m 2 / g) supporting 5% by weight of a silver component using an aqueous solution of silver nitrate,
Commercially available cordierite honeycomb shaped body (diameter 30m
m, length about 12.6 mm, 400 cells / square inch)
Coat and dry at 80 ° C for 2 hours, then stepwise in air at 60
After the temperature was raised to 0 ° C., it was baked for 5 hours to prepare a purifying material having an average particle diameter of silver or silver oxide of 50 nm.
フロントページの続き (72)発明者 阿部 晃 埼玉県熊谷市末広四丁目14番１号 株式会 社リケン熊谷事業所内 (72)発明者 吉田 清英 埼玉県熊谷市末広四丁目14番１号 株式会 社リケン熊谷事業所内 (72)発明者 宮寺 達雄 茨城県つくば市小野川16番３ 工業技術院 資源環境技術総合研究所内Front page continuation (72) Inventor Akira Abe 4-14-1, Suehiro, Kumagaya, Saitama Prefecture Riken Kumagaya Plant Stock Company (72) Inventor Kiyohide Yoshida 4-1-1, Suehiro, Kumagaya, Saitama Company Riken Kumagaya Plant (72) Inventor Tatsuo Miyadera 16-3 Onogawa, Tsukuba City, Ibaraki Prefecture Institute of Industrial Science and Technology
Claims (5)
は銀酸化物を銀元素に換算して０．２〜１５重量％担持
してなる触媒を有し、窒素酸化物を除去する浄化材にお
いて、前記多孔質無機酸化物上の銀または銀酸化物が平
均直径１０〜１０００ｎｍの粒子であり、外部から前記
排ガス中に添加されたアルコール類を還元剤として、２
００〜６００℃で、前記排ガス中の窒素酸化物を還元す
ることを特徴とする排ガス浄化材。1. Purification for removing nitrogen oxides, comprising a catalyst comprising 0.2 to 15% by weight of silver or silver oxide in terms of silver element supported on 100% by weight of a porous inorganic oxide. In the material, silver or silver oxide on the porous inorganic oxide is particles having an average diameter of 10 to 1000 nm, and alcohols externally added to the exhaust gas are used as a reducing agent.
An exhaust gas purification material, which reduces nitrogen oxides in the exhaust gas at 00 to 600 ° C.
て、前記浄化材はペレット状または顆粒状であることを
特徴とする排ガス浄化材。2. The exhaust gas purifying material according to claim 1, wherein the purifying material is in the form of pellets or granules.
て、前記浄化材はさらにセラミック製又は金属製三次元
構造体を有し、前記多孔質無機酸化物が前記三次元構造
体にコートされていることを特徴とする排ガス浄化材。3. The exhaust gas purifying material according to claim 1, wherein the purifying material further has a ceramic or metal three-dimensional structure, and the porous inorganic oxide is coated on the three-dimensional structure. Exhaust gas purification material characterized by being
浄化材において、前記多孔質の無機酸化物がγ−アルミ
ナ又はアルミナ系複合酸化物であることを特徴とする排
ガス浄化材。4. The exhaust gas purifying material according to claim 1, wherein the porous inorganic oxide is γ-alumina or an alumina-based composite oxide.
求項１〜４のいずれかに記載の排ガス浄化材を排ガス導
管の途中に設置し、前記浄化材の上流側で前記排ガス中
にアルコール類を添加し、２００〜６００℃で前記排ガ
スを前記浄化材に接触させ、前記アルコール類と前記窒
素酸化物とを反応させて前記窒素酸化物を除去すること
を特徴とする排ガス浄化方法。5. A method for removing nitrogen oxides, wherein the exhaust gas purifying material according to any one of claims 1 to 4 is installed in the middle of an exhaust gas conduit, and alcohols are contained in the exhaust gas upstream of the purifying material. Is added, the exhaust gas is brought into contact with the purification material at 200 to 600 ° C., and the alcohols are reacted with the nitrogen oxides to remove the nitrogen oxides.
Priority Applications (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5142689A JPH06327974A (en) | 1993-05-21 | 1993-05-21 | Material for purifying waste gas and purifying method of waste gas |
| DE1993609245 DE69309245T2 (en) | 1992-12-28 | 1993-12-24 | Exhaust gas cleaner |
| EP19930310560 EP0605237B1 (en) | 1992-12-28 | 1993-12-24 | Exhaust gas cleaner |
| US08/434,918 US5714432A (en) | 1992-12-28 | 1995-05-04 | Exhaust gas cleaner comprising supported silver or silver oxide particles |
| US08/601,495 US5656249A (en) | 1992-12-28 | 1996-02-14 | Exhaust gas cleaner and method for removing nitrogen oxides |
| US08/805,234 US5772973A (en) | 1992-12-28 | 1997-02-24 | Exhaust gas cleaner and method for removing nitrogen oxides |
| US08/917,144 US5801117A (en) | 1992-12-28 | 1997-08-25 | Comprising supported silver sulfate or silver chloride or silver with sulfuric acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5142689A JPH06327974A (en) | 1993-05-21 | 1993-05-21 | Material for purifying waste gas and purifying method of waste gas |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06327974A true JPH06327974A (en) | 1994-11-29 |
Family
ID=15321243
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5142689A Pending JPH06327974A (en) | 1992-12-28 | 1993-05-21 | Material for purifying waste gas and purifying method of waste gas |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06327974A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5894728A (en) * | 1995-06-27 | 1999-04-20 | Komatsu Ltd. | Exhaust emission control device for diesel engines |
-
1993
- 1993-05-21 JP JP5142689A patent/JPH06327974A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5894728A (en) * | 1995-06-27 | 1999-04-20 | Komatsu Ltd. | Exhaust emission control device for diesel engines |
| DE19681452C2 (en) * | 1995-06-27 | 1999-11-18 | Komatsu Mfg Co Ltd | Exhaust emission control device for diesel engines |
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