JP5119695B2 - Manufacturing method of exhaust gas purification filter - Google Patents
Manufacturing method of exhaust gas purification filter Download PDFInfo
- Publication number
- JP5119695B2 JP5119695B2 JP2007072305A JP2007072305A JP5119695B2 JP 5119695 B2 JP5119695 B2 JP 5119695B2 JP 2007072305 A JP2007072305 A JP 2007072305A JP 2007072305 A JP2007072305 A JP 2007072305A JP 5119695 B2 JP5119695 B2 JP 5119695B2
- Authority
- JP
- Japan
- Prior art keywords
- exhaust gas
- gas purification
- purification filter
- pores
- dpf
- 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 - Fee Related
Links
- 238000000746 purification Methods 0.000 title claims description 80
- 238000004519 manufacturing process Methods 0.000 title claims description 22
- 239000007789 gas Substances 0.000 claims description 130
- 239000011148 porous material Substances 0.000 claims description 120
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 68
- 238000005192 partition Methods 0.000 claims description 60
- 239000003054 catalyst Substances 0.000 claims description 43
- 230000003647 oxidation Effects 0.000 claims description 38
- 238000007254 oxidation reaction Methods 0.000 claims description 38
- 229910052751 metal Inorganic materials 0.000 claims description 17
- 239000002184 metal Substances 0.000 claims description 17
- 239000007864 aqueous solution Substances 0.000 claims description 13
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 12
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 8
- 239000007788 liquid Substances 0.000 claims description 8
- 229910052878 cordierite Inorganic materials 0.000 claims description 6
- 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 claims description 6
- 229910052757 nitrogen Inorganic materials 0.000 claims description 6
- 150000003839 salts Chemical class 0.000 claims description 5
- 239000004745 nonwoven fabric Substances 0.000 claims description 4
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 3
- 229910010271 silicon carbide Inorganic materials 0.000 claims description 3
- 238000000034 method Methods 0.000 claims description 2
- 229910001220 stainless steel Inorganic materials 0.000 claims description 2
- 239000010935 stainless steel Substances 0.000 claims description 2
- 238000010304 firing Methods 0.000 claims 1
- 230000001590 oxidative effect Effects 0.000 claims 1
- 230000000052 comparative effect Effects 0.000 description 14
- 238000011156 evaluation Methods 0.000 description 8
- 239000002245 particle Substances 0.000 description 7
- 238000009826 distribution Methods 0.000 description 5
- 238000002485 combustion reaction Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 238000011068 loading method Methods 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- 230000003197 catalytic effect Effects 0.000 description 3
- 230000006837 decompression Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000010419 fine particle Substances 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- 238000011144 upstream manufacturing Methods 0.000 description 3
- FLJPGEWQYJVDPF-UHFFFAOYSA-L caesium sulfate Chemical compound [Cs+].[Cs+].[O-]S([O-])(=O)=O FLJPGEWQYJVDPF-UHFFFAOYSA-L 0.000 description 2
- 229910010272 inorganic material Inorganic materials 0.000 description 2
- 239000011147 inorganic material Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000013618 particulate matter Substances 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000000779 smoke Substances 0.000 description 2
- 238000009777 vacuum freeze-drying Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000003183 carcinogenic agent Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- JZCCFEFSEZPSOG-UHFFFAOYSA-L copper(II) sulfate pentahydrate Chemical compound O.O.O.O.O.[Cu+2].[O-]S([O-])(=O)=O JZCCFEFSEZPSOG-UHFFFAOYSA-L 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 229940082328 manganese acetate tetrahydrate Drugs 0.000 description 1
- CESXSDZNZGSWSP-UHFFFAOYSA-L manganese(2+);diacetate;tetrahydrate Chemical compound O.O.O.O.[Mn+2].CC([O-])=O.CC([O-])=O CESXSDZNZGSWSP-UHFFFAOYSA-L 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 239000006262 metallic foam Substances 0.000 description 1
- RBFRVUKIVGOWND-UHFFFAOYSA-L oxygen(2-);vanadium(4+);sulfate Chemical compound [O-2].[V+4].[O-]S([O-])(=O)=O RBFRVUKIVGOWND-UHFFFAOYSA-L 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 238000002459 porosimetry Methods 0.000 description 1
- 239000011164 primary particle Substances 0.000 description 1
- 230000029058 respiratory gaseous exchange Effects 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
Description
本発明は、ディーゼルエンジンから排出される排ガス中に含まれるパティキュレート（固体状炭素微粒子、液体あるいは固体状の高分子量炭化水素微粒子）を捕集・燃焼して排ガスを浄化する排ガス浄化装置に関するものである。 TECHNICAL FIELD The present invention relates to an exhaust gas purifying apparatus for purifying exhaust gas by collecting and burning particulates (solid carbon fine particles, liquid or solid high molecular weight hydrocarbon fine particles) contained in exhaust gas discharged from a diesel engine. It is.
ディーゼルエンジンから排出される排ガスに含まれるパティキュレートは、その粒子径がほぼ１μｍ以下で大気中に浮遊しやすく、呼吸時に人体に取り込まれやすい。 Particulates contained in the exhaust gas discharged from the diesel engine have a particle diameter of approximately 1 μm or less and are likely to float in the atmosphere, and are easily taken into the human body during breathing.
また、このパティキュレートは発ガン性物質も含んでいることから、ディーゼルエンジンから排出されるパティキュレートに対する規制が強化されつつある。 In addition, since this particulate matter also contains a carcinogenic substance, regulations on particulates discharged from diesel engines are being strengthened.
排ガスからのパティキュレートを除去する排ガス浄化フィルタとして、排ガス流にディーゼルパティキュレートフィルタ（以下、ＤＰＦ）がある。ＤＰＦとは、セラミックスなどの多孔質材料からなる隔壁によって区画された排ガス流路となる複数のセルを有する三次元構造体であり、セル両端のうち一方を交互にプラグで栓詰めされているハニカムフィルタである。ディーゼルエンジンから排出される排ガスがＤＰＦの多数のセル内に流入し、多孔質材料の隔壁を排ガスが通過する際に隔壁表面及び隔壁に存在する細孔内の壁面に排ガス中に含まれるパティキュレートが捕集される仕組みになっている。 As an exhaust gas purification filter for removing particulates from exhaust gas, there is a diesel particulate filter (hereinafter referred to as DPF) in the exhaust gas flow. A DPF is a three-dimensional structure having a plurality of cells serving as exhaust gas passages partitioned by partition walls made of a porous material such as ceramics, and a honeycomb in which one of both ends of the cells is alternately plugged with a plug It is a filter. When exhaust gas discharged from a diesel engine flows into many cells of the DPF and exhaust gas passes through the partition walls of the porous material, the particulates included in the exhaust gas on the partition wall surface and the wall surfaces in the pores existing in the partition walls Is a mechanism to collect.
しかしながら、ディーゼルエンジンから排出される排ガスに含まれるパティキュレートは１００ｎｍ以下の非常に微細な粒子を含むため、ＤＰＦの多孔質材料の隔壁を通過してしまうという課題があった。また、ＤＰＦはパティキュレートが連続的に捕集され続けると、ＤＰＦ前後の差圧が上昇してエンジン出力の低下に繋がるという課題があった。 However, since the particulates contained in the exhaust gas discharged from the diesel engine contain very fine particles of 100 nm or less, there is a problem that the particulates pass through the partition walls of the DPF porous material. In addition, if particulates continue to be collected in the DPF, there is a problem that the differential pressure before and after the DPF increases and the engine output decreases.
このような課題を克服するべく、特許文献１には、ＤＰＦの多孔質材料の隔壁厚みを２５０μｍ以下とし、気孔率を４０％以上とし、平均細孔径を３〜７μｍとし、細孔径が１０μｍ以上の細孔の容積を全細孔容積の２０％以下とする排ガス浄化フィルタが開示されており、圧力損失を上昇させることなく、０．０８μｍ以下の細かい固体微粒子の捕集特性を向上させている。 In order to overcome such problems, Patent Document 1 discloses that the partition wall thickness of the DPF porous material is 250 μm or less, the porosity is 40% or more, the average pore diameter is 3 to 7 μm, and the pore diameter is 10 μm or more. An exhaust gas purification filter is disclosed in which the volume of the pores is 20% or less of the total pore volume, and the collection characteristics of fine solid particles of 0.08 μm or less are improved without increasing the pressure loss. .
このような従来の排ガス浄化フィルタには、以下の課題があった。 Such a conventional exhaust gas purification filter has the following problems.
ＤＰＦの多孔質材料の隔壁厚み、気孔率、平均細孔径、細孔容積を制御することによっ
て、パティキュレートが捕集されていない状態における排ガス浄化フィルタの圧力損失を低く抑えることは可能になるが、実際のディーゼルエンジンから排出される排ガス流にＤＰＦを配置した場合、ＤＰＦの多孔質材料の隔壁表面及び隔壁に存在する細孔内の壁面にパティキュレートが捕集され、堆積層が形成されるに従ってＤＰＦの圧損が上昇するという課題があった。
By controlling the partition wall thickness, porosity, average pore diameter, and pore volume of the porous material of the DPF, it is possible to keep the pressure loss of the exhaust gas purification filter low when particulates are not collected. When the DPF is disposed in the exhaust gas flow discharged from an actual diesel engine, the particulates are collected on the partition wall surface of the porous material of the DPF and the wall surfaces in the pores existing in the partition wall, and a deposited layer is formed. Accordingly, there is a problem that the pressure loss of the DPF increases.
さらに、ＤＰＦの隔壁表面及び隔壁に存在する細孔内の壁面に捕集することによってパティキュレートの堆積層が形成され、それによって細かい固体微粒子の捕集特性を向上させることは可能であるが、ディーゼルエンジンから排出される排ガス温度程度では燃焼除去させることができず、ＤＰＦの圧損の上昇に繋がるため、電気ヒータで排ガス温度を上昇させたり、排ガス中に燃料を噴射して排ガス温度を上昇させたりして堆積したパティキュレートを燃焼除去した際に、パティキュレートの堆積層が燃焼除去されるとパティキュレートの捕集効率が低下してしまうという課題があった。 Furthermore, a particulate deposit layer is formed by collecting on the partition wall surface of the DPF and the wall surface in the pores present in the partition wall, thereby improving the collection characteristics of fine solid particles, Since it cannot be burned and removed at about the exhaust gas temperature discharged from the diesel engine, it leads to an increase in the pressure loss of the DPF. Therefore, the exhaust gas temperature is increased by an electric heater, or fuel is injected into the exhaust gas to increase the exhaust gas temperature. When the accumulated particulates are removed by combustion, there is a problem that the particulate collection efficiency decreases if the particulate deposition layer is removed by combustion.
本発明は上記従来の課題を解決するものであり、ディーゼルエンジンの排ガス温度程度で堆積したパティキュレートを燃焼除去することで堆積層が形成されるに従ってＤＰＦの圧損が上昇することを防止できると共に、堆積したパティキュレートが燃焼除去されても高い捕集効率を維持することができる排ガス浄化フィルタを提供することを目的とする。 The present invention solves the above-described conventional problems, and can prevent the pressure loss of the DPF from increasing as the deposited layer is formed by burning and removing particulates deposited at about the exhaust gas temperature of the diesel engine. An object of the present invention is to provide an exhaust gas purification filter capable of maintaining a high collection efficiency even when accumulated particulates are burned and removed.
上記目的を達成するために、本発明においては、多孔質材料からなる隔壁によって区画された排ガス流路となる複数のセルを有する三次元構造体と、前記隔壁の表面及び／または隔壁に存在する細孔内の壁面に担持された酸化触媒とを備えた排ガス浄化フィルタにおいて、多孔質材料のディーゼルパティキュレートフィルタ（ＤＰＦ）をチタニアゾルに浸漬し、この状態で減圧し、前記チタニアゾルから引き上げた後、不織布と接触させて余剰のチタニアゾルを除去し、液体窒素に浸漬した後、減圧乾燥し、さらに、酸化焼成することによって、排ガス浄化フィルタが有する細孔の内、平均細孔径が１５μｍ以下で、かつ、５μｍ以上から２５μｍ以下の細孔容積の合計が、全細孔容積の８０％以上とし、さらに、前記三次元構造体の隔壁の表面および／または隔壁に存在する細孔内の壁面には、金属塩と、１族の金属の硫酸塩および／または２族の金属の硫酸塩とを、溶解させた水溶液を用いて添着させることにより、ディーゼルエンジンの排ガス温度程度で堆積したパティキュレートを燃焼除去し、堆積したパティキュレートが燃焼除去されても高い捕集効率を維持することができるようにしたことを特徴としている。そして、三次元構造体の隔壁の表面や隔壁に存在する細孔内の壁面に均一に酸化触媒を担持することができるようにしたものである。 In order to achieve the above object, in the present invention, a three-dimensional structure having a plurality of cells serving as an exhaust gas flow passage partitioned by a partition made of a porous material, and the surface of the partition and / or the partition are present. In an exhaust gas purification filter provided with an oxidation catalyst supported on the wall surface in the pores, a diesel particulate filter (DPF) of porous material is immersed in titania sol, decompressed in this state, and pulled up from the titania sol, Excess titania sol is removed by contact with the nonwoven fabric, immersed in liquid nitrogen, dried under reduced pressure, and further oxidized and fired , whereby the average pore diameter of the pores of the exhaust gas purification filter is 15 μm or less, and , the total volume of pores 25μm from above 5μm is not less than 80% of the total pore volume, further tables of the partition walls of the three-dimensional structure And / or by attaching a metal salt and a group 1 metal sulfate and / or a group 2 metal sulfate to the wall surface in the pores present in the partition walls using a dissolved aqueous solution. Further, it is characterized in that the particulates accumulated at about the exhaust gas temperature of the diesel engine are burned and removed, and high collection efficiency can be maintained even if the accumulated particulates are removed by combustion. Then, the oxidation catalyst can be uniformly supported on the surface of the partition walls of the three-dimensional structure and the wall surfaces in the pores existing in the partition walls.
本発明によれば、隔壁の表面及び／または隔壁に存在する細孔内の壁面に担持された酸化触媒によってディーゼルエンジン排ガス温度程度でも堆積したパティキュレートを燃焼除去することができるためＤＰＦの圧損上昇を低く抑え、また、細孔径を制御することによって隔壁表面にパティキュレートが衝突する確率が上昇し、堆積したパティキュレートが燃焼除去されてもパティキュレートの捕集効率を高く維持できる排ガス浄化フィルタが得られる。そして、三次元構造体の隔壁の表面や隔壁に存在する細孔内の壁面に均一に酸化触媒を担持することができるようにしたので、排ガス温度程度でもパティキュレートを燃焼除去することができる排ガスフィルタを製造することができるようになる。 According to the present invention, the accumulated particulate matter can be burned and removed by the oxidation catalyst supported on the surface of the partition wall and / or the wall surface in the pores existing in the partition wall, so that the pressure loss of the DPF increases. By controlling the pore size, the probability that the particulates will collide with the partition wall surface increases, and an exhaust gas purification filter that can maintain high particulate collection efficiency even if accumulated particulates are removed by combustion. can get. Since the oxidation catalyst can be uniformly supported on the surface of the partition walls of the three-dimensional structure and the wall surfaces in the pores existing in the partition walls, the exhaust gas can burn and remove particulates even at about the exhaust gas temperature. The filter can be manufactured.
本発明の請求項１に記載の発明は、多孔質材料からなる隔壁によって区画された排ガス流路となる複数のセルを有する三次元構造体と、隔壁の表面および／または隔壁に存在する細孔内の壁面に担持された酸化触媒とを備えた排ガス浄化フィルタにおいて、孔質材料のディーゼルパティキュレートフィルタ（ＤＰＦ）をチタニアゾルに浸漬し、この状態で減圧し、前記チタニアゾルから引き上げた後、不織布と接触させて余剰のチタニアゾルを除去し、液体窒素に浸漬した後、減圧乾燥し、さらに、酸化焼成することによって、排ガス浄化フィルタが有する細孔の平均細孔径が１５μｍ以下で、かつ、５μｍ以上から２５μｍ以下の細孔における細孔容積の合計が、全細孔容積の８５％以上とし、さらに、前記三次元構造体の隔壁の表面および／または隔壁に存在する細孔内の壁面には、金属塩と、１族の金属の硫酸塩および／または２族の金属の硫酸塩とを、溶解させた水溶液を用いて添着させることを特徴とする排ガス浄化フィルタの製造方法である。 According to the first aspect of the present invention, there is provided a three-dimensional structure having a plurality of cells serving as exhaust gas passages partitioned by a partition made of a porous material, and pores present on the surface of the partition and / or the partition. In an exhaust gas purification filter provided with an oxidation catalyst supported on the inner wall surface, a porous particulate diesel particulate filter (DPF) is immersed in titania sol, decompressed in this state, pulled up from the titania sol, The excess titania sol is removed by contact, immersed in liquid nitrogen, dried under reduced pressure, and further oxidized and fired, whereby the average pore diameter of the pores of the exhaust gas purification filter is 15 μm or less, and from 5 μm or more. the total pore volume in the following pore 25μm is not less than 85% of the total pore volume, further surfaces of the partition walls of the three-dimensional structure and Alternatively, a metal salt and a group 1 metal sulfate and / or a group 2 metal sulfate are attached to the wall surface in the pores present in the partition walls using a dissolved aqueous solution. It is a manufacturing method of the exhaust gas purifying filter.
このような排ガス浄化フィルタを製造することによって、隔壁の表面及び／または隔壁に存在する細孔内の壁面に担持された酸化触媒によってディーゼルエンジン排ガス温度程度でも堆積したパティキュレートを燃焼除去することができるため排ガス浄化フィルタの圧力損失の上昇を低く抑え、また、排ガス浄化フィルタが有する細孔の細孔径を制御することによって隔壁表面にパティキュレートが衝突する確率が上昇し、堆積したパティキュレートが燃焼除去されてもパティキュレートの捕集効率を高く維持できる排ガス浄化フィルタが得られる。 By manufacturing such an exhaust gas purification filter, it is possible to burn and remove particulates deposited even at about the exhaust gas temperature of a diesel engine by the oxidation catalyst supported on the surface of the partition wall and / or the wall surface in the pores existing in the partition wall. As a result, the increase in pressure loss of the exhaust gas purification filter is suppressed to a low level, and by controlling the pore size of the pores of the exhaust gas purification filter, the probability that the particulates collide with the partition wall surface increases, and the accumulated particulates burn. Even if it is removed, an exhaust gas purification filter capable of maintaining high particulate collection efficiency can be obtained.
また、この構成によって、三次元構造体の隔壁の表面や隔壁に存在する細孔内の壁面に均一に酸化触媒を担持することができるようになり、堆積したパティキュレートと酸化触媒との接触性が向上し、排ガス温度程度でもパティキュレートを燃焼除去することができる排ガスフィルタを製造することができるようになる。種々の金属を酸化触媒として利用する際に、種々の金属を含む粒子を水に分散させたスラリーを用いて三次元構造体に添着することもできるが、粒子をナノオーダーレベルの非常に細かい粒子径にまで微粉砕しなければならないし、また、微粉化できたとしてもスラリー中で種々の金属を含む粒子を１次粒子として分散させなければ均一に担持させることは実現できない。これに対して、種々の金属の塩を水溶液として溶解することができれば粒子の分散スラリーと比べて非常に均一な水溶液となり、三次元構造体の隔壁の表面や隔壁に存在する細孔内の壁面に均一に添着することが可能になる。 In addition, this configuration makes it possible to uniformly support the oxidation catalyst on the surfaces of the partition walls of the three-dimensional structure and the wall surfaces in the pores existing in the partition walls, and the contact property between the deposited particulates and the oxidation catalyst. As a result, an exhaust gas filter capable of burning and removing particulates even at about the exhaust gas temperature can be manufactured. When using various metals as an oxidation catalyst, it is possible to attach to a three-dimensional structure using a slurry in which particles containing various metals are dispersed in water. Even if finely pulverized, the particles containing various metals in the slurry cannot be uniformly supported unless they are dispersed as primary particles. On the other hand, if various metal salts can be dissolved as an aqueous solution, the aqueous solution will be very uniform compared to the particle-dispersed slurry, and the surface of the partition walls of the three-dimensional structure and the wall surfaces in the pores existing in the partition walls It becomes possible to attach uniformly to the surface.
また、金属塩と、１族の金属の硫酸塩および／または２族の金属の硫酸塩とを、溶解させた水溶液を用いて三次元構造体の隔壁の表面および／または隔壁に存在する細孔内の壁面に添着させる方法として、三次元構造体を水溶液中に浸漬することで添着させても良いし、三次元構造体は固定したまま水溶液を上昇および／または下降や、平行移送させることで添着させても良いし、三次元構造体は固定したまま水溶液を吹き付けや滴下によって添着させても良い。 In addition, pores present on the surfaces of the partition walls and / or the partition walls of the three-dimensional structure using an aqueous solution in which a metal salt and a Group 1 metal sulfate and / or a Group 2 metal sulfate are dissolved. As a method of attaching to the inner wall surface, the three-dimensional structure may be attached by immersing it in an aqueous solution, or the aqueous solution may be raised and / or lowered or moved in parallel while the three-dimensional structure is fixed. The three-dimensional structure may be fixed, or the aqueous solution may be attached by spraying or dropping.
また、多孔質材料からなる隔壁によって区画された排ガス流路となる複数のセルを有する三次元構造体と、隔壁の表面および／または隔壁に存在する細孔内の壁面に担持された酸化触媒とを備えた排ガス浄化フィルタにおいて、チタニアの担持量を前記ＤＰＦに対して２１．３重量％とすることによって、排ガス浄化フィルタが有する細孔の平均細孔径が８〜１０μｍで、かつ、５μｍ以上から１５μｍ以下の細孔における細孔容積の合計が、全細孔容積の８０％以上としたことを特徴とする排ガス浄化フィルタの製造方法である。 Also, a three-dimensional structure having a plurality of cells serving as exhaust gas passages partitioned by partition walls made of a porous material, and an oxidation catalyst supported on the surfaces of the partition walls and / or the wall surfaces in the pores existing in the partition walls, In the exhaust gas purification filter provided with the above, by setting the amount of titania supported to 21.3% by weight with respect to the DPF, the average pore diameter of the pores of the exhaust gas purification filter is 8 to 10 μm and from 5 μm or more An exhaust gas purification filter manufacturing method characterized in that the total pore volume of pores of 15 μm or less is 80% or more of the total pore volume.
このような排ガス浄化フィルタを製造することによって、ディーゼルエンジンを高負荷
運転した際に発生する比較的高温の排ガスによって、排ガス浄化フィルタに担持された酸化触媒が活性化し、排ガス浄化フィルタに堆積したパティキュレートが燃焼除去してしまった場合にも、高い捕集効率を維持することが可能になる。
By manufacturing such an exhaust gas purification filter, the oxidation catalyst carried on the exhaust gas purification filter is activated by the relatively high temperature exhaust gas generated when the diesel engine is operated at a high load, and the particulates deposited on the exhaust gas purification filter are activated. Even when the curate is burned and removed, high collection efficiency can be maintained.
また、排ガス浄化フィルタの圧力損失を低く保つことが可能になる。 In addition , the pressure loss of the exhaust gas purification filter can be kept low.
また、排ガス浄化フィルタの気孔率が４０％以上であることを特徴とする排ガス浄化フィルタの製造方法である。 In addition, the exhaust gas purification filter has a porosity of 40% or more.
このような排ガス浄化フィルタを製造することによって、排ガス浄化フィルタの高い捕集効率を維持したまま、排ガス浄化フィルタの圧力損失を低く保つことが可能になる。 By manufacturing such an exhaust gas purification filter, the pressure loss of the exhaust gas purification filter can be kept low while maintaining the high collection efficiency of the exhaust gas purification filter.
また、排ガス浄化フィルタの隔壁厚みが４５０μｍ以下であることを特徴とする排ガス浄化フィルタの製造方法である。 Moreover, it is a manufacturing method of the exhaust gas purification filter characterized by the partition wall thickness of the exhaust gas purification filter being 450 μm or less.
このような排ガス浄化フィルタを製造することによって、排ガス浄化フィルタの高い捕集効率を維持したまま、排ガス浄化フィルタの圧力損失を低く保つことができるようになる。 By manufacturing such an exhaust gas purification filter, the pressure loss of the exhaust gas purification filter can be kept low while maintaining the high collection efficiency of the exhaust gas purification filter.
また、排ガス浄化フィルタのセル数が１平方インチ当たり１００セル以上であることを特徴とする排ガス浄化フィルタの製造方法である。 The exhaust gas purification filter manufacturing method is characterized in that the number of cells of the exhaust gas purification filter is 100 cells or more per square inch.
このような排ガス浄化フィルタを製造することによって、排ガス浄化フィルタの高い捕集効率を維持したまま、排ガス浄化フィルタの圧力損失を低く保つことが可能になる。 By manufacturing such an exhaust gas purification filter, the pressure loss of the exhaust gas purification filter can be kept low while maintaining the high collection efficiency of the exhaust gas purification filter.
また、多孔質材料がコージェライト、炭化珪素、ステンレスの内のいずれか一つ以上の材料であることを特徴とする排ガス浄化フィルタの製造方法である。 The porous material is one or more materials selected from the group consisting of cordierite, silicon carbide, and stainless steel.
このような排ガス浄化フィルタを製造することによって、長期に渡って排ガスに暴露されることになる排ガス浄化フィルタの排ガス温度に対する熱耐久性が確保できると共に、機械的振動に対する耐振動性が確保でき、排ガス中に含まれる腐食性ガスに対する耐腐食性を確保することができるようになる。また、酸化触媒と多孔質材料との密着性が向上するため排ガス浄化フィルタから酸化触媒が剥離することを防止することができる。また、比較的安価に入手することができるため製品コストを低減することできるし、機械的強度が高いことによって排ガス浄化フィルタの製造プロセスにおけるハンドリング性が向上する。 By manufacturing such an exhaust gas purification filter, it is possible to ensure the thermal durability against the exhaust gas temperature of the exhaust gas purification filter that will be exposed to the exhaust gas over a long period of time, and to ensure the vibration resistance against mechanical vibration, Corrosion resistance against the corrosive gas contained in the exhaust gas can be ensured. In addition, since the adhesion between the oxidation catalyst and the porous material is improved, the oxidation catalyst can be prevented from peeling off from the exhaust gas purification filter. Moreover, since it can be obtained at a relatively low cost, the product cost can be reduced, and the high mechanical strength improves the handling in the manufacturing process of the exhaust gas purification filter.
以下、本発明の実施例を説明する。 Examples of the present invention will be described below.
（実施例１）
直径が７．５インチ、高さが７インチ、セル数が１平方インチ当り１００セル、壁厚みが４３０μｍのコージェライト製ＤＰＦをチタニアゾルに浸漬し、浸漬した状態で減圧装置内に設置した。減圧装置内を約１０ｋＰａまで減圧し、その状態を５分間維持した。次に、ＤＰＦをチタニアゾルから引き上げた後、ＤＰＦを不織布と接触させ、余剰のチタニアゾルを除去した。次に、チタニアゾルを添着したＤＰＦを液体窒素に浸漬して、添着したチタニアゾルを凍結させた後、真空凍結乾燥装置を用いて乾燥させた。次に、電気炉を用いて、チタニアゾルを添着したＤＰＦを６００℃で５時間酸化焼成して、チタニアを均一にＤＰＦの隔壁表面及び隔壁に存在する細孔内の壁面に担持した。次に、純水３Ｌに、硫酸セシウムを１１４０ｇと、硫酸銅五水和物を６００ｇと、酸化硫酸バナジウムを７９
０ｇと、酢酸マンガン四水和物を３ｇとを溶解させ、触媒成分を含む水溶液を調製した。
Example 1
A cordierite DPF having a diameter of 7.5 inches, a height of 7 inches, a cell number of 100 cells per square inch, and a wall thickness of 430 μm was immersed in titania sol, and placed in a vacuum apparatus in the immersed state. The inside of the decompression device was decompressed to about 10 kPa, and this state was maintained for 5 minutes. Next, after pulling up the DPF from the titania sol, the DPF was brought into contact with the nonwoven fabric to remove excess titania sol. Next, the DPF to which the titania sol was attached was immersed in liquid nitrogen to freeze the attached titania sol, and then dried using a vacuum freeze-drying apparatus. Next, using an electric furnace, the DPF impregnated with titania sol was oxidized and fired at 600 ° C. for 5 hours to uniformly carry titania on the partition wall surface of the DPF and the wall surfaces in the pores existing in the partition wall. Next, 1140 g of cesium sulfate, 600 g of copper sulfate pentahydrate, 79 mg of vanadium oxide sulfate were added to 3 L of pure water.
0 g and 3 g of manganese acetate tetrahydrate were dissolved to prepare an aqueous solution containing a catalyst component.
次に、調製した水溶液にチタニアを均一に担持したＤＰＦを浸漬した状態で減圧装置内に設置した。減圧装置内を約１０ｋＰａまで減圧し、その状態を５分間維持した。その後、ＤＰＦを不織布と接触させ、余剰の触媒成分を含む水溶液を除去した。次に、ＤＰＦを液体窒素に浸漬して、添着した触媒成分を含む水溶液を凍結させた後、真空凍結乾燥装置を用いて乾燥させた。次に、電気炉を用いて、ＤＰＦを７００℃で５時間焼成して、酸化触媒が均一に担持された実施例１の排ガス浄化フィルタを製造した。実施例１の排ガス浄化フィルタは、チタニア担持量がＤＰＦ重量に対して１１．４％で、酸化触媒担持量がＤＰＦ重量に対して１５．１％であった。 Next, the DPF which uniformly supported titania was immersed in the prepared aqueous solution was placed in a decompression device. The inside of the decompression device was decompressed to about 10 kPa, and this state was maintained for 5 minutes. Then, DPF was made to contact with a nonwoven fabric and the aqueous solution containing an excess catalyst component was removed. Next, the DPF was immersed in liquid nitrogen to freeze the aqueous solution containing the attached catalyst component, and then dried using a vacuum lyophilizer. Next, using an electric furnace, the DPF was calcined at 700 ° C. for 5 hours to produce an exhaust gas purification filter of Example 1 in which the oxidation catalyst was uniformly supported. In the exhaust gas purification filter of Example 1, the titania loading amount was 11.4% with respect to the DPF weight, and the oxidation catalyst loading amount was 15.1% with respect to the DPF weight.
なお、実施例１、実施例２および実施例３ではチタニアゾルを用いてＤＰＦの隔壁が有する細孔を制御したが、その他の無機材料を用いて細孔を制御しても良いし、ＤＰＦ製造の原料である骨材や造孔材の種類、粒子径、配合割合を調整することによって細孔制御したものでも良く、重要なことは三次元構造体の隔壁及び／または隔壁に存在する細孔内の壁面に酸化触媒を担持した際に形成される排ガス浄化フィルタが有する細孔が制御されているかどうかである。 In Example 1, Example 2 and Example 3, the pores of the DPF partition walls were controlled using titania sol. However, the pores may be controlled using other inorganic materials. The pores may be controlled by adjusting the type of aggregate and pore former, the particle size, and the mixing ratio of the raw material. The important thing is that the pores in the three-dimensional structure and / or the pores existing in the partition walls are important. It is whether or not the pores of the exhaust gas purification filter formed when the oxidation catalyst is supported on the wall surface are controlled.
また、実施例１では多孔質材料からなるＤＰＦとしてコージェライト製ＤＰＦを用いたが、炭化珪素製ＤＰＦでも良いし、連通した気孔構造を有する発泡金属製ＤＰＦや金属繊維製ＤＰＦなどでも良い。 In Example 1, a cordierite DPF is used as the DPF made of a porous material. However, a silicon carbide DPF, a metal foam DPF having a continuous pore structure, a metal fiber DPF, or the like may be used.
また、実施例１ではＤＰＦを凍結させる際、液体窒素に浸漬したが、その他の冷温液体を用いても良いし、真空凍結乾燥装置などを用いて減圧して溶媒を気化させ、その気化熱により凍結させてもよい。 In Example 1, when the DPF was frozen, it was immersed in liquid nitrogen. However, other cold / warm liquids may be used, and the solvent is vaporized by reducing the pressure using a vacuum freeze-drying device, etc. It may be frozen.
（実施例２）
実施例１と同様のＤＰＦにチタニア濃度を変更してＤＰＦに担持し、チタニアの担持量はＤＰＦ重量に対して２１．３％で、酸化触媒の担持量はＤＰＦ重量に対して１４．１％とし、これを実施例２とした。
(Example 2)
The titania concentration was changed to the same DPF as in Example 1 and supported on the DPF. The supported amount of titania was 21.3% with respect to the DPF weight, and the supported amount of the oxidation catalyst was 14.1% with respect to the DPF weight. This was taken as Example 2.
（実施例３）
実施例１と同様のＤＰＦにチタニア濃度を変更してＤＰＦに担持し、チタニアの担持量はＤＰＦ重量に対して３０．７％で、酸化触媒の担持量はＤＰＦ重量に対して１２．４％とし、これを実施例３とした。
(Example 3)
The titania concentration was changed to the same DPF as in Example 1 and supported on the DPF. The titania loading was 30.7% with respect to the DPF weight and the oxidation catalyst loading was 12.4% with respect to the DPF weight. This was taken as Example 3.
（比較例１）
実施例１と同様のＤＰＦに、チタニアを担持せずに、酸化触媒のみを担持し、酸化触媒の担持量はＤＰＦ重量に対して１６．０％とし、これを比較例１とした。
(Comparative Example 1)
In the same DPF as in Example 1, titania was not supported, but only the oxidation catalyst was supported. The amount of the oxidation catalyst supported was 16.0% with respect to the weight of the DPF.
（評価例１）
実施例１、実施例２、実施例３及び比較例１で得た排ガス浄化フィルタを用いて、以下のような排ガス試験を行った。行った排ガス試験を、図１を参照しながら説明する。
(Evaluation example 1)
Using the exhaust gas purification filters obtained in Example 1, Example 2, Example 3, and Comparative Example 1, the following exhaust gas test was conducted. The exhaust gas test conducted will be described with reference to FIG.
排気量４．３Ｌのディーゼルエンジン１を使用し、ディーゼルエンジン１からの排気ラインには切替え弁２を設けてバイパスライン３と本ライン４の二ラインを設置し、本ライン４側には酸化触媒ハニカム５を前段に、排ガス浄化フィルタ６を後段に設置した。本排ガス試験で使用した酸化触媒ハニカム５は、直径が７．５インチ、高さが３インチ、セル数が１平方インチ当り３００セル、壁厚みが２００μｍのコージェライト製ハニカムで、ハニカムの表面には酸化触媒である白金をハニカム容積１Ｌ当り約５ｇの割合で担持した
ものである。バイパスライン３側に排気しながらディーゼルエンジン１を１，５００ｒｐｍ、トルク２１ｋｇｍの条件で１時間作動させて排気を安定させた後、切替え弁２によって排ガス浄化フィルタ６を設置した本ライン４側に排ガスを導入した。
A 4.3L diesel engine 1 is used, a switching valve 2 is provided on the exhaust line from the diesel engine 1, two bypass lines 3 and a main line 4 are installed, and an oxidation catalyst is provided on the main line 4 side. The honeycomb 5 was installed at the front stage, and the exhaust gas purification filter 6 was installed at the rear stage. The oxidation catalyst honeycomb 5 used in this exhaust gas test is a cordierite honeycomb having a diameter of 7.5 inches, a height of 3 inches, a cell number of 300 cells per square inch, and a wall thickness of 200 μm. Is one in which platinum as an oxidation catalyst is supported at a rate of about 5 g per liter of honeycomb volume. After exhausting to the bypass line 3 side, the diesel engine 1 was operated for 1 hour under conditions of 1,500 rpm and a torque of 21 kgm to stabilize the exhaust, and then the exhaust gas was discharged to the main line 4 side where the exhaust gas purification filter 6 was installed by the switching valve 2. Was introduced.
エンジン回転数は１，５００ｒｐｍ一定の状態で、排ガス温度は、酸化触媒ハニカム５に流入する直前の排ガス温度を熱電対で測定し、２５０℃から４６０℃の範囲で８段階の設定温度を設け、ディーゼルエンジン１への負荷をダイナモで変えていくことで各設定温度を３０℃刻みで昇温して排ガス試験を行った。各設定温度の保持時間は、４０分間とした。ここで、設定温度の２５０℃から４６０℃は、ディーゼルエンジン１を通常作動させる際に発生する排ガス温度レベルである。排ガス試験中は、圧力センサー７を用いて酸化触媒ハニカム５上流と排ガス浄化フィルタ６下流の位置における静圧を測定し、酸化触媒ハニカム５と排ガス浄化フィルタ６とを合せた前後の差圧を算出すると共に、酸化触媒ハニカム５上流と排ガス浄化フィルタ６下流の位置におけるパティキュレート濃度をスモークメータ８を用いて測定した。 With the engine speed at a constant 1,500 rpm, the exhaust gas temperature was measured with a thermocouple at the exhaust gas temperature immediately before flowing into the oxidation catalyst honeycomb 5, and eight set temperatures were set in the range of 250 ° C to 460 ° C. By changing the load on the diesel engine 1 with a dynamo, each set temperature was raised in steps of 30 ° C., and an exhaust gas test was conducted. The holding time of each set temperature was 40 minutes. Here, the set temperature of 250 ° C. to 460 ° C. is an exhaust gas temperature level generated when the diesel engine 1 is normally operated. During the exhaust gas test, the pressure sensor 7 is used to measure the static pressure at the position upstream of the oxidation catalyst honeycomb 5 and the downstream of the exhaust gas purification filter 6 to calculate the differential pressure before and after the oxidation catalyst honeycomb 5 and the exhaust gas purification filter 6 are combined. At the same time, the particulate concentration at the positions upstream of the oxidation catalyst honeycomb 5 and downstream of the exhaust gas purification filter 6 was measured using the smoke meter 8.
排ガスに含まれるパティキュレートが排ガス浄化フィルタ６に捕集されるにつれて、酸化触媒ハニカム５と排ガス浄化フィルタ６とを合せた前後の差圧が上昇していくが、排ガス温度が上昇するに従って触媒活性が上がるため、捕集されたパティキュレートが燃焼除去されることで差圧が下がる。このような差圧のプロファイルから各温度における単位時間当りの差圧変化率を算出し差圧変化率がゼロとなった時の温度をＢＰＴ（Ｂａｌａｎｃｅ Ｐｏｉｎｔ ｏｆ Ｔｅｍｐｅｒａｔｕｒｅ）と定義し、このＢＰＴが低いほど触媒浄化フィルタ６の触媒活性が高いものとして評価した。また、酸化触媒ハニカム５上流と排ガス浄化フィルタ６下流の位置で測定したパティキュレート濃度から２５０℃から４６０℃全域における平均捕集効率を算出した。また、排ガス温度が高温になるほどパティキュレートを燃焼する触媒の活性が向上し、排ガス浄化フィルタ６におけるパティキュレートの堆積層が減少して捕集効率が低下する虞があるので４６０℃における平均捕集効率も算出した。結果を表１に示す。 As the particulates contained in the exhaust gas are collected by the exhaust gas purification filter 6, the differential pressure before and after the oxidation catalyst honeycomb 5 and the exhaust gas purification filter 6 are combined increases. However, as the exhaust gas temperature increases, the catalytic activity increases. Therefore, the collected particulates are burned and removed, and the differential pressure is reduced. By calculating the differential pressure change rate per unit time at each temperature from such a differential pressure profile, the temperature when the differential pressure change rate becomes zero is defined as BPT (Balance Point of Temperature), and this BPT is low. The catalyst purification filter 6 was evaluated as having high catalytic activity. Further, the average collection efficiency in the entire region from 250 ° C. to 460 ° C. was calculated from the particulate concentration measured at the positions upstream of the oxidation catalyst honeycomb 5 and downstream of the exhaust gas purification filter 6. Further, the higher the exhaust gas temperature is, the more the activity of the catalyst that burns the particulates is improved, and there is a possibility that the particulate accumulation layer in the exhaust gas purification filter 6 is reduced, thereby reducing the collection efficiency. Efficiency was also calculated. The results are shown in Table 1.
今回排ガス浄化フィルタ６の前段に配置している酸化触媒ハニカム５は全ての例において同じものであるため、単純に今回のＢＰＴの結果を排ガス浄化フィルタ６の触媒活性の指標として見た時、実施例１が３０７℃、実施例２が３０５℃、実施例が２９０℃、比較例１が３１０℃となり、全ての例においてディーゼルエンジン１の排ガス温度程度でパティキュレートを燃焼除去できることが分かった。ＢＰＴの結果を詳細に比較すると、チタニアの担持量が増えるほどＢＰＴは低くなっていることから、チタニアを担持することによってパティキュレートと接触できる面積が増大し、パティキュレートをより低温から燃焼除去できるようになったと考えられる。 Since the oxidation catalyst honeycomb 5 arranged in the previous stage of the exhaust gas purification filter 6 is the same in all the examples, when the result of this BPT is simply used as an indicator of the catalytic activity of the exhaust gas purification filter 6, it is implemented. Example 1 was 307 ° C., Example 2 was 305 ° C., Example was 290 ° C., and Comparative Example 1 was 310 ° C. It was found that in all examples, particulates could be burned and removed at about the exhaust gas temperature of diesel engine 1. When the results of BPT are compared in detail, since the BPT decreases as the amount of titania supported increases, the area that can contact the particulates increases by supporting the titania, and the particulates can be removed by burning from a lower temperature. It is thought that it came to be.
また、２５０℃から４６０℃全域におけるパティキュレートの平均捕集効率の結果は、実施例１が９０％、実施例２が９６％、実施例３が９９％、比較例１が８７％となり、チ
タニアを担持して排ガス浄化フィルタ６として有する細孔の細孔径を制御することによって平均捕集効率が向上することが分かった。さらに、排ガス浄化フィルタの隔壁が有する細孔を制御することによって平均捕集効率が向上する効果は、４６０℃の時に明確に現れ、実施例１が８４％、実施例２が９７％、実施例３が１００％、比較例１が７１％となり細孔制御した場合と細孔制御していない場合とで平均捕集効率に顕著な差が生じた。
Further, the results of the average collection efficiency of the particulates in the entire range from 250 ° C. to 460 ° C. are 90% in Example 1, 96% in Example 2, 99% in Example 3, and 87% in Comparative Example 1, and titania. It has been found that the average collection efficiency is improved by controlling the pore diameter of the pores carried as the exhaust gas purification filter 6. Further, the effect of improving the average collection efficiency by controlling the pores of the partition walls of the exhaust gas purification filter clearly appears at 460 ° C., 84% for Example 1, 97% for Example 2, and Example 3 was 100%, and Comparative Example 1 was 71%. A significant difference was observed in the average collection efficiency between the case where the pores were controlled and the case where the pores were not controlled.
なお、本発明を開示するに当たってはチタニアゾルを用いてＤＰＦの隔壁が有する細孔を制御したが、その他無機材料を用いても良いし、ＤＰＦ製造の原料である骨材や造孔材の種類、粒子径、配合割合を調整することによって細孔制御したものでも良く、重要なことは三次元構造体の隔壁及び／または隔壁に存在する細孔内の壁面に酸化触媒を担持した際に形成される排ガス浄化フィルタが有する細孔が制御されているかどうかである。 In disclosing the present invention, the pores of the DPF partition walls were controlled using titania sol, but other inorganic materials may be used, and the types of aggregates and pore formers that are raw materials for DPF production, The pores may be controlled by adjusting the particle diameter and the mixing ratio, and the important thing is that it is formed when the oxidation catalyst is supported on the partition walls of the three-dimensional structure and / or the walls in the pores existing in the partition walls. Whether or not the pores of the exhaust gas purification filter are controlled.
本発明の効果は評価例１の排ガス試験結果によって示すことができた。さらに評価例２では、実施例１、実施例２、実施例３および比較例１における排ガス浄化フィルタ６がどのような特徴を有する構造体になっているかを明確にするために評価例２に示す試験を行った。 The effect of the present invention could be shown by the exhaust gas test result of Evaluation Example 1. Furthermore, in the evaluation example 2, in order to clarify what characteristic the exhaust gas purification filter 6 in the example 1, the example 2, the example 3 and the comparative example 1 has a structure, it is shown in the evaluation example 2. A test was conducted.
（評価例２）
実施例１、実施例２、実施例３および比較例１で用いたコージェライト製ＤＰＦから、プラグで栓詰めされた部分を除いた箇所で、３０ｍｍ×３０ｍｍ×５０ｍｍ程度のテストピースを切出し、実施例１、実施例２、実施例３、比較例１と同じ製法によってチタニア及び酸化触媒を担持した排ガス浄化フィルタのテストピースを用意した。これらのテストピースが有する細孔特性（平均細孔径、気孔率、細孔容積）に関して水銀圧入法により評価した。
(Evaluation example 2)
A test piece of about 30 mm × 30 mm × 50 mm was cut out from the cordierite DPF used in Example 1, Example 2, Example 3 and Comparative Example 1, except for the part plugged with a plug. A test piece for an exhaust gas purification filter carrying titania and an oxidation catalyst was prepared by the same manufacturing method as in Example 1, Example 2, Example 3, and Comparative Example 1. The pore characteristics (average pore diameter, porosity, pore volume) of these test pieces were evaluated by mercury porosimetry.
図２には実施例１、実施例２、実施例３および比較例１と同じ製法によってチタニア及び酸化触媒を担持した排ガス浄化フィルタのテストピースの隔壁が有する細孔の細孔径に対する相対細孔容積を示したグラフである。ここで相対細孔容積とは、各例におけるテストピースが有する細孔の細孔容積を比較例１の全細孔容積で除した値である。実施例１、実施例２、実施例３の細孔分布は比較例１の細孔分布と比較して、チタニアを担持しているため細孔径は小さく、かつ、細孔分布は狭く制御できていることが分かる。 FIG. 2 shows the relative pore volume with respect to the pore diameter of the pores of the test piece partition wall of the exhaust gas purification filter carrying the titania and the oxidation catalyst by the same production method as in Example 1, Example 2, Example 3 and Comparative Example 1. It is the graph which showed. Here, the relative pore volume is a value obtained by dividing the pore volume of the pores of the test piece in each example by the total pore volume of Comparative Example 1. The pore distributions of Example 1, Example 2 and Example 3 are smaller than those of Comparative Example 1 because they support titania, so that the pore diameter is small and the pore distribution can be controlled narrowly. I understand that.
表２には実施例１、実施例２、実施例３、比較例１と同じ製法によってチタニア及び酸化触媒を担持した排ガス浄化フィルタのテストピースの平均細孔径、気孔率、及び各例のテストピースが有する細孔の細孔容積の全細孔容積に対する割合を表している。 Table 2 shows the average pore diameter, the porosity, and the test pieces of each example of the exhaust gas purification filter supporting the titania and the oxidation catalyst by the same manufacturing method as in Example 1, Example 2, Example 3, and Comparative Example 1. Represents the ratio of the pore volume of the pores to the total pore volume.
比較例１は、１５μｍ未満の細孔径が存在しないのに対して、実施例１は７２％、実施例２は９２％、実施例３は９６％存在し、パティキュレートの捕集効率を向上させるためには平均細孔径が１５μｍ以下であることが重要であることが分かる。さらに例え平均細孔径が１５μｍ以下でも幅広い細孔分布であればパティキュレートの捕集効率は向上させることはできないため、実施例１の結果からも分かるように５μｍ以上から２５μｍ以下
の細孔における細孔容積の合計が、全細孔容積の８５％以上となるような細孔分布であることも重要である。
Comparative Example 1 has no pore diameter of less than 15 μm, whereas Example 1 has 72%, Example 2 has 92%, and Example 3 has 96%, improving the particulate collection efficiency. Therefore, it is understood that it is important that the average pore diameter is 15 μm or less. Furthermore, even if the average pore diameter is 15 μm or less, the particulate collection efficiency cannot be improved if the pore distribution is wide. Therefore, as can be seen from the results of Example 1, the fine pores of 5 μm or more and 25 μm or less are fine. It is also important that the pore distribution is such that the total pore volume is 85% or more of the total pore volume.
また、実施例２の結果から分かるように、平均細孔径が１０μｍ以下で、かつ、５μｍ以上から１５μｍ以下の細孔における細孔容積の合計が、全細孔容積の８０％以上であると捕集効率をさらに向上させることができることが分かる。ここで、実施例３の結果は、平均細孔径が７μｍ、気孔率が３４％と非常に小さいものであるが、パティキュレートの捕集効率は実施例２のそれと比べてさほど大きな向上が見られないことから、細孔径や気孔率が小さくなるほど排ガス浄化フィルタ自体の圧力損失が増大してくることから、実施例３までの平均細孔径や気孔率にはする必要が無い。 Further, as can be seen from the results of Example 2, the total pore volume of pores having an average pore diameter of 10 μm or less and 5 μm or more to 15 μm or less is 80% or more of the total pore volume. It can be seen that the collection efficiency can be further improved. Here, the results of Example 3 are very small with an average pore diameter of 7 μm and a porosity of 34%. However, the particulate collection efficiency is significantly improved as compared with that of Example 2. Since the pressure loss of the exhaust gas purification filter itself increases as the pore diameter and porosity decrease, there is no need to obtain the average pore diameter and porosity up to Example 3.
また、データとしては示さないが、排ガス浄化フィルタの隔壁の厚みが小さくなるほど、排ガス浄化フィルタ自体の圧力損失は下げられるため本発明で用いた４５０μｍの壁厚みより小さくなるほど良い。また、データには示さないが、排ガス浄化フィルタの単位断面積当りのセル数が大きいほど排ガスの通気抵抗は大きくなるが、パティキュレートの濾過面積が増大するためパティキュレートと酸化触媒との接触確率が向上し、燃焼除去性能が高まるため、本発明で用いた１平方インチ当り１００セルよりセル数は大きいほど良い。 Further, although not shown as data, the smaller the partition wall thickness of the exhaust gas purification filter, the lower the pressure loss of the exhaust gas purification filter itself. Therefore, the smaller the wall thickness of 450 μm used in the present invention, the better. Although not shown in the data, the larger the number of cells per unit cross-sectional area of the exhaust gas purification filter, the greater the exhaust gas ventilation resistance, but the larger the filtration area of the particulate, the greater the probability of contact between the particulate and the oxidation catalyst. The number of cells is preferably larger than 100 cells per square inch used in the present invention.
本発明の排ガス浄化フィルタは、隔壁の表面及び／または隔壁に存在する細孔内の壁面に担持された酸化触媒によってディーゼルエンジン排ガス温度程度でも堆積したパティキュレートを燃焼除去することができるためＤＰＦの圧力損失の上昇を低く抑え、また、細孔径を制御することによって隔壁表面にパティキュレートが衝突する確率が上昇し、高い捕集効率が維持できるなど、非常に有用であり、自動車だけでなく、建設機械、発電機、フォークリフト、耕運機、船舶などの排ガス浄化などにも適用できる。 The exhaust gas purifying filter of the present invention can burn and remove particulates accumulated even at about the exhaust gas temperature of a diesel engine by the oxidation catalyst supported on the surface of the partition wall and / or the wall surface in the pores existing in the partition wall. The rise in pressure loss is kept low, and by controlling the pore diameter, the probability that the particulates collide with the partition wall surface increases, and it is very useful such as maintaining high collection efficiency. It can also be applied to exhaust gas purification for construction machines, generators, forklifts, cultivators, ships, etc.
１ ディーゼルエンジン
２ 切替え弁
３ バイパスライン
４ 本ライン
５ 酸化触媒ハニカム
６ 排ガス浄化フィルタ
７ 圧力センサー
８ スモークメータ
DESCRIPTION OF SYMBOLS 1 Diesel engine 2 Switching valve 3 Bypass line 4 This line 5 Oxidation catalyst honeycomb 6 Exhaust gas purification filter 7 Pressure sensor 8 Smoke meter
Claims (6)
多孔質材料のディーゼルパティキュレートフィルタ（以下ＤＰＦ）をチタニアゾルに浸漬し、この状態で減圧し、
前記チタニアゾルから引き上げた後、不織布と接触させて余剰のチタニアゾルを除去し、液体窒素に浸漬した後、減圧乾燥し、
さらに、酸化焼成することによって、
排ガス浄化フィルタが有する細孔の平均細孔径が１５μｍ以下で、かつ、５μｍ以上から２５μｍ以下の細孔における細孔容積の合計が、全細孔容積の８５％以上とし、
さらに、前記三次元構造体の隔壁の表面および／または隔壁に存在する細孔内の壁面には、金属塩と、１族の金属の硫酸塩および／または２族の金属の硫酸塩とを、溶解させた水溶液を用いて添着させることを特徴とする排ガス浄化フィルタの製造方法。 A three-dimensional structure having a plurality of cells serving as exhaust gas flow passages partitioned by partition walls made of a porous material, and an oxidation catalyst supported on the surfaces of the partition walls and / or the wall surfaces of the pores existing in the partition walls Exhaust gas purification filter
A diesel particulate filter (DPF) of porous material is immersed in titania sol, and the pressure is reduced in this state.
After pulling up from the titania sol, the excess titania sol is removed by contact with the nonwoven fabric, immersed in liquid nitrogen, and then dried under reduced pressure.
Furthermore, by oxidizing and firing,
The average pore diameter of the pores of the exhaust gas purification filter is 15 μm or less, and the total pore volume in pores of 5 μm to 25 μm is 85% or more of the total pore volume,
Further, a metal salt and a group 1 metal sulfate and / or a group 2 metal sulfate are provided on the surface of the partition wall of the three-dimensional structure and / or the wall surface in the pores existing in the partition wall. A method for producing an exhaust gas purifying filter, comprising attaching using a dissolved aqueous solution.
ることを特徴とする、請求項１乃至５のいずれかに記載の排ガス浄化フィルタの製造方法。
The method for producing an exhaust gas purification filter according to any one of claims 1 to 5, wherein the porous material is one or more of cordierite, silicon carbide, and stainless steel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007072305A JP5119695B2 (en) | 2007-03-20 | 2007-03-20 | Manufacturing method of exhaust gas purification filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007072305A JP5119695B2 (en) | 2007-03-20 | 2007-03-20 | Manufacturing method of exhaust gas purification filter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2008229490A JP2008229490A (en) | 2008-10-02 |
| JP5119695B2 true JP5119695B2 (en) | 2013-01-16 |
Family
ID=39902924
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2007072305A Expired - Fee Related JP5119695B2 (en) | 2007-03-20 | 2007-03-20 | Manufacturing method of exhaust gas purification filter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5119695B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009262125A (en) * | 2008-03-31 | 2009-11-12 | Denso Corp | Porous honeycomb structure and method for manufacturing the same |
| JP5609084B2 (en) * | 2008-12-09 | 2014-10-22 | パナソニック株式会社 | Exhaust gas purification catalyst, exhaust gas purification filter, and exhaust gas purification device |
| AT513842B1 (en) * | 2013-06-17 | 2014-08-15 | Avl List Gmbh | Method for checking the effectiveness of an exhaust aftertreatment device |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61129043A (en) * | 1984-11-27 | 1986-06-17 | Nippon Shokubai Kagaku Kogyo Co Ltd | Method for supporting gatalytic component by ceramic substrate |
| JP3867439B2 (en) * | 1998-06-03 | 2007-01-10 | 株式会社デンソー | Honeycomb structure and manufacturing method thereof |
| JP3736242B2 (en) * | 1999-12-02 | 2006-01-18 | 松下電器産業株式会社 | Exhaust gas purification material and method for producing the same |
| JP5106716B2 (en) * | 2000-01-05 | 2012-12-26 | パナソニック株式会社 | Exhaust gas purification material and exhaust gas purification device |
| US7138358B2 (en) * | 2001-11-13 | 2006-11-21 | Sud-Chemie Inc. | Catalyzed diesel particulate matter filter with improved thermal stability |
| JP4776869B2 (en) * | 2003-01-16 | 2011-09-21 | パナソニック株式会社 | Exhaust gas purification catalyst, exhaust gas purification material using the same, and method for producing the same |
| US7179316B2 (en) * | 2003-06-25 | 2007-02-20 | Corning Incorporated | Cordierite filters with reduced pressure drop |
| US7923093B2 (en) * | 2006-06-30 | 2011-04-12 | Corning Incorporated | High porosity filters for 4-way exhaust gas treatment |
-
2007
- 2007-03-20 JP JP2007072305A patent/JP5119695B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2008229490A (en) | 2008-10-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4971166B2 (en) | Honeycomb catalyst body, precoat carrier for manufacturing honeycomb catalyst body, and method for manufacturing honeycomb catalyst body | |
| US8388721B2 (en) | Ceramic honeycomb filter and its production method | |
| JP4907860B2 (en) | Filter catalyst | |
| JP5575354B2 (en) | Exhaust gas purification filter | |
| JP4916989B2 (en) | Exhaust gas purification device and method of manufacturing the exhaust gas purification device | |
| KR100747088B1 (en) | Dpf with improving heat durability | |
| JP2007289926A (en) | Honeycomb structure and honeycomb catalytic body | |
| JPH07106290B2 (en) | Diesel Exhaust Particle Filter | |
| JP2011104524A (en) | Catalyst-carrying filter and exhaust gas cleaning system | |
| JP2010269205A (en) | Catalyst for cleaning exhaust gas | |
| JP5218056B2 (en) | Ceramic honeycomb filter | |
| JP4006645B2 (en) | Exhaust gas purification device | |
| JP2012036821A (en) | Exhaust emission control system of internal combustion engine | |
| JP5649503B2 (en) | Exhaust gas purification apparatus and exhaust gas purification method using the same | |
| JP5119695B2 (en) | Manufacturing method of exhaust gas purification filter | |
| JP2009255051A (en) | Exhaust gas purification device | |
| Stobbe et al. | SiC as a substrate for diesel particulate filters | |
| JP2005264866A (en) | Diesel exhaust emission control device | |
| JP4887550B2 (en) | Exhaust gas purification material | |
| JP2009228618A (en) | Exhaust emission control device | |
| JP5502885B2 (en) | Oxidation catalyst suitable for burning light oil components | |
| JP4910814B2 (en) | Exhaust gas purification device | |
| JP2009247995A (en) | Exhaust gas cleaning catalyst and production method thereof | |
| JP4857831B2 (en) | Manufacturing method of diesel particulate filter | |
| JP2006102577A (en) | Production method of exhaust gas purification material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20100315 |
|
| RD01 | Notification of change of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7421 Effective date: 20100413 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20110921 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20110927 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20111125 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20120117 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20120315 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20120508 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20120806 |
|
| A911 | Transfer to examiner for re-examination before appeal (zenchi) |
Free format text: JAPANESE INTERMEDIATE CODE: A911 Effective date: 20120813 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20120904 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20120907 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20120925 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20121008 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20151102 Year of fee payment: 3 |
|
| R151 | Written notification of patent or utility model registration |
Ref document number: 5119695 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R151 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20151102 Year of fee payment: 3 |
|
| LAPS | Cancellation because of no payment of annual fees |