JP2863568B2 - Exhaust gas purifying material and exhaust gas purifying method - Google Patents
Exhaust gas purifying material and exhaust gas purifying methodInfo
- Publication number
- JP2863568B2 JP2863568B2 JP25856889A JP25856889A JP2863568B2 JP 2863568 B2 JP2863568 B2 JP 2863568B2 JP 25856889 A JP25856889 A JP 25856889A JP 25856889 A JP25856889 A JP 25856889A JP 2863568 B2 JP2863568 B2 JP 2863568B2
- Authority
- JP
- Japan
- Prior art keywords
- exhaust gas
- thin layer
- density
- filter
- gas purifying
- 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
- 239000000463 material Substances 0.000 title claims description 29
- 238000000034 method Methods 0.000 title claims description 26
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical group [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 30
- 239000006260 foam Substances 0.000 claims description 8
- 229910052783 alkali metal Inorganic materials 0.000 claims description 4
- 229910052737 gold Inorganic materials 0.000 claims description 4
- 239000010931 gold Substances 0.000 claims description 4
- 150000001340 alkali metals Chemical class 0.000 claims description 3
- 229930195733 hydrocarbon Natural products 0.000 claims description 3
- 150000002430 hydrocarbons Chemical class 0.000 claims description 3
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 2
- 229910052709 silver Inorganic materials 0.000 claims description 2
- 239000004332 silver Substances 0.000 claims description 2
- 230000007704 transition Effects 0.000 claims description 2
- 229910052718 tin Inorganic materials 0.000 claims 1
- 239000007789 gas Substances 0.000 description 42
- 239000003054 catalyst Substances 0.000 description 40
- 239000010410 layer Substances 0.000 description 33
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N titanium dioxide Inorganic materials O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 16
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 12
- 238000000746 purification Methods 0.000 description 11
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 9
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 8
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 6
- 229910010413 TiO 2 Inorganic materials 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 239000000243 solution Substances 0.000 description 5
- 229910052878 cordierite Inorganic materials 0.000 description 4
- 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 4
- 229910000027 potassium carbonate Inorganic materials 0.000 description 4
- 239000011734 sodium Substances 0.000 description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 239000010953 base metal Substances 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 230000001590 oxidative effect Effects 0.000 description 3
- 229910052763 palladium Inorganic materials 0.000 description 3
- 229910052697 platinum Inorganic materials 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- 239000000377 silicon dioxide Substances 0.000 description 3
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000011069 regeneration method Methods 0.000 description 2
- 229910052703 rhodium Inorganic materials 0.000 description 2
- 239000010948 rhodium Substances 0.000 description 2
- 229910052720 vanadium Inorganic materials 0.000 description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 229910021591 Copper(I) chloride Inorganic materials 0.000 description 1
- 229910017767 Cu—Al Inorganic materials 0.000 description 1
- 229910018657 Mn—Al Inorganic materials 0.000 description 1
- 239000011865 Pt-based catalyst Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- OXBLHERUFWYNTN-UHFFFAOYSA-M copper(I) chloride Chemical compound [Cu]Cl OXBLHERUFWYNTN-UHFFFAOYSA-M 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000006866 deterioration Effects 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
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 235000011187 glycerol Nutrition 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 230000029058 respiratory gaseous exchange Effects 0.000 description 1
- 229910052702 rhenium Inorganic materials 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- 229910052713 technetium Inorganic materials 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
- Processes For Solid Components From Exhaust (AREA)
- Filtering Materials (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は排ガス浄化材及びこの排ガス浄化材を使用し
て排ガスを浄化する方法に係り、更に詳しくは触媒を担
持したフォーム型フィルタからなる排ガス浄化材と、こ
の浄化材を使用して排ガスを浄化する方法に関する。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying material and a method for purifying exhaust gas using the exhaust gas purifying material, and more particularly to an exhaust gas comprising a foam type filter carrying a catalyst. The present invention relates to a purifying material and a method for purifying exhaust gas using the purifying material.
近年、主としてディーゼルエンジンの排出ガス中の窒
素酸化物や、微粒子状炭素物質(パティキュレート)が
環境上問題化している。特にパティキュレートは大気中
に浮遊し易く、呼吸により人体内に取り込まれ易いの
で、その低減化は早急に望まれており、早くから耐熱フ
ィルタを用いてパティキュレートを捕捉し燃焼する方法
や、触媒付耐熱フィルタを用いてより低温でパティキュ
レートを燃焼してフィルタ再生を行なう方法などが提案
されてきた。特に後者の方法はより低温でフィルタの再
生が可能で、フィルタの再生時間が短くなり、またフィ
ルタの耐熱性を考慮すればより優れた方法と考えられ
る。In recent years, nitrogen oxides and particulate carbon substances (particulates) in exhaust gas of diesel engines have become environmentally problematic. In particular, particulates easily float in the air and are easily taken into the human body by breathing.Therefore, reduction of particulates is urgently needed.A method of capturing and burning particulates using a heat-resistant filter from an early stage, or a method using a catalyst A method of burning particulates at a lower temperature using a heat-resistant filter to regenerate the filter has been proposed. In particular, the latter method is considered to be a better method because the filter can be regenerated at a lower temperature, the regeneration time of the filter is shortened, and the heat resistance of the filter is considered.
しかしながら、ディーゼルエンジンの排気ガス温度は
ガソリンエンジンの場合と比較して低く、排ガス中の酸
素濃度も大きく、しかも燃料として軽油を用いるために
排ガス中にSO2量も多い。このような排ガス条件下で蓄
積した微粒子を良好に着火燃焼し、しかも二次公害を起
こさない再生方法はまだ確立されていない。However, the exhaust gas temperature of a diesel engine is lower than that of a gasoline engine, the oxygen concentration in the exhaust gas is high, and the amount of SO 2 in the exhaust gas is high because light oil is used as fuel. A regeneration method that satisfactorily ignites and burns the fine particles accumulated under such exhaust gas conditions and does not cause secondary pollution has yet been established.
たとえば、貴金属系触媒をフィルタに担持させると、
パティキュレートの着火温度の低下や、未燃焼炭化水
素、またはCOの浄化に効果があるが、排ガス中のSO2を
酸化しSO3を生成することや、アッシュによる触媒の特
性低下等の問題がおきる。一方卑金属系の触媒を用いる
とパティキュレートの着火温度の低下に効果があり、し
かもSO3の生成が少ないが、COの浄化能は低い。For example, when a noble metal catalyst is supported on a filter,
Lowering of the ignition temperature of the particulate, it is effective for purification of unburned hydrocarbons or CO,, and to produce an SO 3 to oxidize the SO 2 in the exhaust gas, it is such as characteristic deterioration of the catalyst due to ash problem Wake up. On the other hand, the use of a base metal-based catalyst is effective in lowering the ignition temperature of particulates, and the generation of SO 3 is small, but the purification ability of CO is low.
したがって本発明の目的は、ディーゼルエンジン等で
みられる比較的酸素濃度の大きい排ガス中に含まれるパ
ティキュレートを効果的に燃焼浄化する機能と、SO3生
成を抑制して未燃焼炭化水素(以下HCと呼ぶ)及びCOを
残存酸素と反応させ効果的に浄化する機能を有する排ガ
ス浄化材及びこの浄化材を用いた排ガス浄化方法を提供
することである。Therefore, an object of the present invention is to provide a function of effectively burning and purifying particulates contained in exhaust gas having a relatively high oxygen concentration found in diesel engines and the like, and an unburned hydrocarbon (hereinafter referred to as HC) by suppressing SO 3 generation. And a method of purifying exhaust gas having a function of reacting CO with residual oxygen and purifying the exhaust gas effectively, and an exhaust gas purifying method using the purifying material.
上記課題に鑑み鋭意研究の結果、本発明者は、密度の
異なる二つの層を有するフォーム型耐熱多孔性フィルタ
に、パティキュレート燃焼特性を向上させる卑金属系触
媒と、同じくパティキュレート燃焼特性を高め、HC及び
COの浄化能を有する白金族系触媒とを担持することによ
り、良好なパティキュレートの除去能力と、HC及びCOの
浄化能力を有する排ガス浄化材及びその方法を得ること
を発見し、本発明を完成した。In view of the above problems, as a result of intensive research, the present inventors have found that a foam-type heat-resistant porous filter having two layers with different densities, a base metal-based catalyst that improves particulate combustion characteristics, and a similar increase in particulate combustion characteristics, HC and
By supporting a platinum group-based catalyst having a CO purifying ability, it has been found that an exhaust gas purifying material having a good particulate removing ability and an HC and CO purifying ability and a method thereof can be obtained. completed.
すなわち、本発明の排ガス浄化材は、耐熱多孔性フォ
ーム型フィルタを担体とする排ガス浄化材において、前
記フィルタは、排ガス流の入口側に位置する高密度の薄
層部と、出口側に位置する比較的低密度の部分との二つ
の部分からなり、前記高密度の薄層部には白金族元素が
担持されており、前記比較的低密度の部分には、(a)
アルカリ金属元素と、(b)周期表のIB族、IIB族、VA
族、VIA族、VIIA族、及び白金族元素を除いたVIII族の
遷移元素、及びSnからなる群から選ばれた1種または2
種以上の元素とが担持されていることを特徴とする。That is, the exhaust gas purifying material of the present invention is an exhaust gas purifying material using a heat-resistant porous foam type filter as a carrier, wherein the filter is located at a high-density thin layer portion located at an inlet side of an exhaust gas flow and at an outlet side. The high-density thin layer portion carries a platinum group element, and the relatively low-density portion includes (a)
Alkali metal elements and (b) groups IB, IIB, VA of the periodic table
One or two members selected from the group consisting of Group VIII transition elements except for Group VIA, Group VIA, Group VIIA, and Platinum group elements, and Sn
It is characterized in that more than one kind of element is supported.
また本発明の排ガス浄化方法は、上記の耐熱多孔性フ
ォーム型フィルタからなる排ガス浄化材を用いて排ガス
を浄化する方法であって、前記高密度薄層部を排ガスの
入口側とし、前記比較的低密度のフィルタ部分を排ガス
の出口側とし、前記高密度の薄層部で、前記排ガス中の
パティキュレートの大部分を低温で燃焼又は着火させる
とともにHCとCOを酸化除去し、前記低密度の部分で前記
高密度薄層部を通過したパティキュレートを燃焼するこ
とを特徴とする。The exhaust gas purifying method of the present invention is a method of purifying exhaust gas using an exhaust gas purifying material comprising the heat-resistant porous foam type filter, wherein the high-density thin layer portion is an exhaust gas inlet side, The low-density filter portion is the outlet side of the exhaust gas, and the high-density thin-layer portion burns or ignites most of the particulates in the exhaust gas at a low temperature and oxidizes and removes HC and CO, thereby removing the low-density filter. Particulates burn the particulates that have passed through the high-density thin layer portion.
以下本発明を詳細に説明する。 Hereinafter, the present invention will be described in detail.
パティキュレートやHC、COの酸化用触媒としては、酸
化能の高い白金族元素を含む触媒を用いる。これはPt系
触媒、またPd系触媒であっても良いし、Pt系とPd系の混
合触媒、さらにはPt系、Pd系及びRh系の混合触媒として
も良い。また、この白金族元素系触媒にさらに金又は銀
を担持したものとしても良い。As a catalyst for oxidizing particulates, HC and CO, a catalyst containing a platinum group element having high oxidizing ability is used. This may be a Pt-based catalyst or a Pd-based catalyst, or a Pt-based and Pd-based mixed catalyst, or a Pt-based, Pd- and Rh-based mixed catalyst. Further, the platinum group element-based catalyst may be further loaded with gold or silver.
一方、低密度のフィルタ部分に担持するパティキュレ
ート酸化用触媒は、(a)アルカリ金属と、(b)周期
表のIB、IIB族元素、VA族(V,Nb,Ta)、VIA族(Cr,Mo,
W)、VIIA族(Mn,Tc,Re)と白金族元素を含まないVIII
族元素(Fe、Co、Ni)及びSnからなる群から選ばれた少
なくとも1つの元素とからなる。これらの触媒はパティ
キュレートの燃焼速度を上げることや、着火温度を低下
させることに有効に働く。さらにアルカリ金属と上記し
た他の元素とを組み合わせて使用すると、その触媒効果
はさらに向上することが期待できる。On the other hand, the particulate oxidation catalyst supported on the low-density filter portion includes (a) an alkali metal, and (b) elements IB, IIB, VA (V, Nb, Ta) and VIA (Cr , Mo,
W), VIIA (Mn, Tc, Re) and VIII not containing platinum group elements
And at least one element selected from the group consisting of group elements (Fe, Co, Ni) and Sn. These catalysts work effectively to increase the burning rate of particulates and to lower the ignition temperature. When an alkali metal and another element described above are used in combination, the catalytic effect can be expected to be further improved.
本発明では上記の二つの系統の触媒は、フィルタの二
つの部分に分かれて担持される。パティキュレートとH
C、COの酸化用の白金族触媒はフィルタの高密度薄層部
に担持され、この部分を排ガスの入口側とする。またパ
ティキュレート酸化用の触媒はフィルタの比較的低密度
部分に担持され、この部分を排ガスの出口側に設定す
る。In the present invention, the above two types of catalysts are separately supported on two parts of the filter. Particulates and H
The platinum group catalyst for oxidizing C and CO is supported on the high-density thin layer portion of the filter, and this portion serves as the exhaust gas inlet side. The catalyst for particulate oxidation is supported on a relatively low-density portion of the filter, and this portion is set on the exhaust gas outlet side.
このようにフィルタ及び触媒を設置すると、排ガスの
浄化作用は一段と向上することになる。その理由とし
て、下記(1)〜(5)が挙げられる。By providing the filter and the catalyst in this way, the action of purifying the exhaust gas is further improved. The reasons include the following (1) to (5).
(1)排ガスの入口側が高密度となるために、パティキ
ュレートがフィルタ入口の薄層部分で効果的に捕捉され
る。(1) Since the exhaust gas inlet side has a high density, the particulates are effectively trapped in the thin layer portion at the filter inlet.
(2)排ガスはフィルタの入口側に担持された触媒と接
触する機会が多くなるので、排ガスの入口側に担持され
た触媒の表面上でHCとCOが酸化されるとともに、パティ
キュレートが効果的に燃焼あるいは着火される。(2) Since the exhaust gas comes into contact with the catalyst supported on the inlet side of the filter more frequently, HC and CO are oxidized on the surface of the catalyst supported on the inlet side of the filter, and the particulates are effective. Burned or ignited.
(3)背圧が高くなっても、パティキュレートが外へ吹
き飛ばされないで捕捉される。そして、入口側の高密度
層を通過したパティキュレートは出口側のフィルタ内部
の細孔に入り、そこの触媒表面上で効果的に燃焼させら
れる。(3) Even if the back pressure increases, the particulates are captured without being blown out. Then, the particulates that have passed through the high-density layer on the inlet side enter pores inside the filter on the outlet side, and are effectively burned on the catalyst surface there.
(4)上記(2)により効率よく排ガスが浄化されるた
めに、急激な圧力損失が起こらない。(4) Since the exhaust gas is efficiently purified by the above (2), no abrupt pressure loss occurs.
(5)排ガスの入口側の高密度薄層部の白金族系の触媒
はパティキュレート、HCとCOの酸化を優先して行い、SO
3生成は抑制される。(5) The platinum group catalyst in the high-density thin layer on the inlet side of the exhaust gas gives priority to particulates, oxidation of HC and CO, and SO
3 Generation is suppressed.
フォーム型耐熱フィルタは必要なパティキュレート補
集性能を保有しつつ、許容範囲内の圧力損失を与えるも
のであることが必要で、通常担体として用いられるアル
ミナ、シリカ、ジルコニア、シリカ−アルミナ、アルミ
ナ−ジルコニア、アルミナ−チタニア、シリカ−チタニ
ア、シリカ−ジルコニア、チタニア−ジルコニア、ムラ
イト、コージェライト等からなるセラミックフォームを
挙げることができる。The foam-type heat-resistant filter is required to have a required particulate collection performance while providing a pressure loss within an allowable range, and alumina, silica, zirconia, silica-alumina, and alumina-usually used as a carrier are required. Examples of the ceramic foam include zirconia, alumina-titania, silica-titania, silica-zirconia, titania-zirconia, mullite, cordierite, and the like.
なお、耐熱多孔性フォーム型フィルタの一方の面に高
密度の薄層部を形成する方法はいくつか考えられるが、 (a)所望の形状の型の底面にグリセリン、水、界面活
性剤からなる離型剤を塗布し、この型にコージェライト
等のスラリーを流し込み、型を分離し、乾燥後、焼成す
る方法や、 (b)均一なフィルタをまず形成し、有機バインダーと
コージェライト等の粉末を混合し、それをフィルタの一
表面に塗布して乾燥し、焼成する方法がよい。There are several methods for forming a high-density thin layer on one surface of the heat-resistant porous foam type filter. (A) Glycerin, water, and a surfactant are formed on the bottom of a mold having a desired shape. A method of applying a release agent, pouring a slurry of cordierite or the like into the mold, separating the mold, drying and firing, or (b) first forming a uniform filter, and powdering an organic binder and cordierite or the like. Is mixed, applied to one surface of the filter, dried, and fired.
このようにして、形成される高密度薄層部でのポロシ
ティは40〜85%で、ポアサイズは3〜800(平均300μ
m)程度であるのが好ましい。アッシュの堆積を避ける
には、ポアサイズ30μm以上が好ましい。また高密度薄
層部自身の厚さは0.2〜2mmであるのがよい。In this way, the porosity of the formed high-density thin layer portion is 40 to 85%, and the pore size is 3 to 800 (300 μm on average).
m). In order to avoid ash deposition, the pore size is preferably 30 μm or more. The thickness of the high-density thin layer itself is preferably 0.2 to 2 mm.
フォーム型耐熱性フィルタにパティキュート除去触媒
を含浸させる方法としては、それらの炭酸塩、硝酸塩、
酢酸塩、水酸化物などの溶液に耐熱性フィルタを浸漬す
る方法等公知の方法を採用できる。又フェロシアン化ア
ルカリなどのように複数の卑金属系金属を含む化合物の
溶液にフィルタを浸漬して触媒を含浸させる方法も可能
である。As a method of impregnating the foam-type heat-resistant filter with the catalyst for removing the paticute, carbonates, nitrates,
A known method such as a method of immersing the heat-resistant filter in a solution such as acetate or hydroxide can be employed. A method is also possible in which the filter is immersed in a solution of a compound containing a plurality of base metal-based metals such as alkali ferrocyanide to impregnate the catalyst.
同様に、白金族系触媒をフィルタの高密度薄層部に含
浸させる方法として、白金族の塩化物等の溶液に、フィ
ルタの排ガス入口側の高密度薄層部のみを浸漬するよう
な方法を採用することができる。Similarly, as a method of impregnating the high density thin layer portion of the filter with the platinum group catalyst, a method of immersing only the high density thin layer portion on the exhaust gas inlet side of the filter in a solution of platinum group chloride or the like is used. Can be adopted.
また触媒の担持面積を大きくするためには、上記した
アルミナ、シリカ、チタニア等のように多孔性で表面積
の大きい担体粉末を介して耐熱フィルタに間接的に担持
して用いるのが実用的である。特に高密度薄層部は厚み
がほとんどないので、高濃度に触媒を担持することが望
ましく、チタニア、チタニア−アルミナ、チタニア−シ
リカ等のチタニア系の多孔質で表面積の大きい担体粉末
をコートし、Pt、Pd、Rh、Au等の塩化物水溶液等に浸漬
するのがよい。また高濃度に触媒を担持させるために、
さらに、高密度薄層部の表面のみに高濃度の触媒を含有
する溶液を塗布し、触媒の担持を増加させることもでき
る。Further, in order to increase the area for carrying the catalyst, it is practical to use it by indirectly supporting it on a heat resistant filter via a carrier powder having a large surface area, such as alumina, silica, and titania, as described above. . In particular, since the high-density thin layer portion has almost no thickness, it is desirable to support the catalyst at a high concentration, and titania, titania-alumina, titania-coated with a carrier powder having a large surface area such as titania-based porous silica, It is preferable to immerse in a chloride aqueous solution such as Pt, Pd, Rh, and Au. Also, in order to carry the catalyst at a high concentration,
Furthermore, a solution containing a high concentration of catalyst can be applied only to the surface of the high-density thin layer portion to increase the amount of supported catalyst.
さらに、Pt、Pd、Rh、Au等の塩化物水溶液等に浸漬し
たフィルタに光照射を行うと非常に効果的に触媒を担持
できる。また最初にチタニア系担体に光照射で白金族元
素系触媒を担持し、そのチタニア系担体をフィルタ薄膜
上にコートする方法も可能である。この光照射法を用い
るとチタニア系担体に高分散にしかもよく固定され、フ
ィルタのコーティング層も薄くすることができ、密度の
大きい薄層上への触媒担持では圧力損失を小さくするこ
とができ大変有効である。Further, when a filter immersed in a chloride aqueous solution of Pt, Pd, Rh, Au or the like is irradiated with light, the catalyst can be supported very effectively. Alternatively, a method in which a platinum group element-based catalyst is first supported on a titania-based carrier by light irradiation, and the titania-based carrier is coated on a filter thin film is also possible. When this light irradiation method is used, it is highly dispersed and well fixed to the titania carrier, the coating layer of the filter can be made thin, and the pressure loss can be reduced when the catalyst is carried on a thin layer having a high density. It is valid.
本発明を以下の実施例によりさらに詳細に説明する。 The present invention is described in more detail by the following examples.
実施例1 コージェライト製セラミックフォームフィルタ(見か
けの体積2l、密度0.65g/ml)の一方の側に上記した方法
で高密度(2.2g/ml)の薄層部を形成した。Example 1 A high density (2.2 g / ml) thin layer portion was formed on one side of a cordierite ceramic foam filter (apparent volume 2 l, density 0.65 g / ml) by the above-described method.
この薄層部を除いた部分にγ−アルミナを、コートす
るフォームフィルタに対して10%(重量%、以下同じ)
コートし、これに炭酸カリウムを用いγ−アルミナに対
しカリウムを2.5%、次いでCrCl3を用いてCrを2.5%含
浸した。薄層部分には薄層の重量に対して1%のγ−ア
ルミナをコートし、その後H2PtCl6水溶液からPtをγ−
アルミナに対して0.2%含浸した。(Al2O3/K/Cr−Al2O3
/Pt:実施例1) この浄化材について、排気量510cc単気筒ディーゼル
エンジンを用いてパティキュレートの着火温度(圧力損
失が低下する温度)と排気ガス浄化特性の評価を行っ
た。このときエンジン回転数は1500rpm、負荷90%で運
転した。この条件ではCOは約460ppm、酸素濃度は5%で
あった。第1表に浄化材の着火温度を、第2表にパティ
キュレート捕集効率を、第3表にCOの濃度変化を、それ
ぞれ示す。Γ-alumina is applied to the portion except the thin layer portion with respect to the foam filter to be coated at 10% (% by weight, the same applies hereinafter)
This was impregnated with potassium carbonate using potassium carbonate and 2.5% of γ-alumina, and then with CrCl 3 using 2.5% of Cr. The thin layer portion was coated with 1% of γ-alumina based on the weight of the thin layer, and then Pt was converted to γ-alumina from an aqueous H 2 PtCl 6 solution.
The alumina was impregnated with 0.2%. (Al 2 O 3 / K / Cr-Al 2 O 3
/ Pt: Example 1) For this purifying material, the ignition temperature of particulates (temperature at which pressure loss decreases) and the exhaust gas purification characteristics were evaluated using a 510 cc single cylinder diesel engine. At this time, the engine was operated at 1500 rpm and a load of 90%. Under these conditions, CO was about 460 ppm and oxygen concentration was 5%. Table 1 shows the ignition temperature of the purifying material, Table 2 shows the particulate collection efficiency, and Table 3 shows the change in CO concentration.
実施例2〜8 実施例1と同様にして、薄層部以外に炭酸ナトリウム
を用いてNaを2.5%、CuCl2を用いてCuを2.5%それぞれ
含浸し(実施例2)、又は炭酸カリウムを用いてKを2.
5%、MnCl2を用いてMnを2.5%それぞれ含浸し(実施例
3)、又は炭酸カリウムを用いてKを2.5%、NH4VO3を
用いてVを2.5%それぞれ含浸した(実施例4)。また
それぞれの薄層部分にPtを0.2%含浸し、以下の排ガス
浄化材を製造した。Examples 2 to 8 In the same manner as in Example 1, except that the thin layer portion was impregnated with 2.5% of Na using sodium carbonate and 2.5% of Cu using CuCl 2 (Example 2), or potassium carbonate was used. Using K to 2.
Mn was impregnated with 5% and MnCl 2 , respectively, at 2.5% (Example 3), or potassium carbonate was impregnated with 2.5%, and V was impregnated with NH 4 VO 3 , respectively (Example 4). ). Further, each thin layer portion was impregnated with 0.2% of Pt to produce the following exhaust gas purifying material.
(Al3O3/Na/Cu−Al2O3/Pt:実施例2) (Al2O3/K/Mn−Al2O3/Pt:実施例3) (Al2O3/K/V−Al2O3/Pt:実施例4) 同様にして、薄層部以外に上記の実施例と同様の含浸
を行い、薄層部には、Al2O3のかわりにTiO2をフィルタ
の重量に対して1%コートした後、H2PtCl6及び/又はP
dCl2の水溶液に薄層部分を浸漬し、500WのHgランプを用
い光照射をしながら、各々0.2%のPt、Pdを含浸し、以
下の排ガス浄化材を試作した。(Al 3 O 3 / Na / Cu-Al 2 O 3 / Pt: Example 2) (Al 2 O 3 / K / Mn-Al 2 O 3 / Pt: Example 3) (Al 2 O 3 / K / V-Al 2 O 3 / Pt: Example 4) Similarly, the same impregnation was performed as in the above example except for the thin layer portion, and the thin layer portion was filtered with TiO 2 instead of Al 2 O 3. After coating 1% by weight of H 2 PtCl 6 and / or P
The thin layer portion was immersed in an aqueous solution of dCl 2 and irradiated with light using a 500 W Hg lamp, impregnated with 0.2% of Pt and Pd, respectively, to produce the following exhaust gas purifying materials.
(Al2O3/K/Cr−TiO2/Pt:実施例5) (Al2O3/Na/Cu−TiO2/Pd:実施例6) (Al2O3/K/Mn−TiO2/Pt/Pd:実施例7) (Al2O3/K/V−TiO2/Pt:実施例8) この実施例2〜8の排ガス浄化材についても、実施例
1と同様の方法で、パティキュレートの着火温度と排気
ガス浄化特性の評価を行った。第1表に各浄化材での着
火温度(実施例1〜4)を、第2表に300℃でのパティ
キュレート捕集効率(実施例1、2、5)を、第3表に
400℃でのCOの濃度変化(実施例1〜8)を、それぞれ
示す。(Al 2 O 3 / K / Cr-TiO 2 / Pt: Example 5) (Al 2 O 3 / Na / Cu-TiO 2 / Pd: Example 6) (Al 2 O 3 / K / Mn-TiO 2 / Pt / Pd: Example 7) (Al 2 O 3 / K / V-TiO 2 / Pt: Example 8) The exhaust gas purifying materials of Examples 2 to 8 were also produced in the same manner as in Example 1. The ignition temperature of particulates and the exhaust gas purification characteristics were evaluated. Table 1 shows the ignition temperature (Examples 1 to 4) of each purifying material, Table 2 shows the particulate collection efficiency at 300 ° C (Examples 1, 2, and 5), and Table 3 shows the results.
Changes in the concentration of CO at 400 ° C. (Examples 1 to 8) are shown respectively.
比較例1〜4 比較のために、以下の4つの浄化材を試作し、実施例
と同様に着火温度、パティキュレート捕集効率及びCOの
濃度変化を測定した。それぞれの結果を同様に第1〜3
表に示す。Comparative Examples 1 to 4 For comparison, the following four purifying materials were experimentally manufactured, and the ignition temperature, the particulate collection efficiency, and the CO concentration change were measured in the same manner as in the examples. The respective results are similarly calculated for the first to third
It is shown in the table.
比較例1:触媒担持無しのフィルタ。Comparative Example 1: Filter with no catalyst supported.
比較例2:実施例1と同様の触媒を有するが、高密度薄層
部のないフィルタ。Comparative Example 2: A filter having the same catalyst as in Example 1, but without a high-density thin layer portion.
比較例3:高密度薄層部に白金族触媒を担持しないフィル
タで、パティキュレート浄化用にAl2O3/K/Crの触媒を有
するフィルタ。Comparative Example 3: A filter that does not carry a platinum group catalyst in the high-density thin layer portion, and has a catalyst of Al 2 O 3 / K / Cr for particulate purification.
比較例4:高密度薄層部に白金族触媒を担持しないフィル
タで、パティキュレート浄化用にAl2O3/Na/Cuの触媒を
有するフィルタ。Comparative Example 4: A filter in which a platinum group catalyst is not supported on a high-density thin layer portion, and has a catalyst of Al 2 O 3 / Na / Cu for particulate purification.
実施例1〜4の各浄化材とも400℃以下の着火温度を
示しパティキュレート浄化特性が高かった。又300℃で
測定されたパティキュレート捕集効率では、薄層付フィ
ルタが80%以上示すのに、薄層無しのフィルタではせい
ぜい50%しかなかった。COの浄化特性については、薄層
に白金族元素の担持の無い浄化材では、ほとんどCO浄化
能が無く、むしろCOが少々高くなる傾向があるが、白金
族元素を担持した浄化材では、40%以上の浄化特性を示
し、特に光照射で担持された浄化材では、45%以上の浄
化特性が得られた。また、これらの浄化材を用いた場
合、SO3の生成はほとんどみられなかった。 Each of the purifying materials of Examples 1 to 4 showed an ignition temperature of 400 ° C. or less, and the particulate purifying characteristics were high. In the particulate collection efficiency measured at 300 ° C., the filter with a thin layer showed 80% or more, while the filter without a thin layer showed only 50% at most. Regarding the purification characteristics of CO, a purification material having no platinum group element carried in a thin layer has little CO purification ability and tends to have a slightly higher CO. %, And the purification material carried by light irradiation showed a purification characteristic of 45% or more. In addition, when these purifying materials were used, SO 3 was hardly generated.
本発明の排ガス浄化材を使用すると、排ガス中のパテ
ィキュレートの捕集効率が向上し、さらにCOとHCの浄化
にもすぐれた作用を示す。このような排ガス浄化材は、
ディーゼルエンジン等のパティキュレートが多く比較的
酸素濃度の大きな排ガスの浄化に、特に有効となること
が期待できる。When the exhaust gas purifying material of the present invention is used, the collection efficiency of particulates in exhaust gas is improved, and an excellent action for purifying CO and HC is also exhibited. Such exhaust gas purifying materials are
It can be expected to be particularly effective for purifying exhaust gas containing a large amount of particulates such as diesel engines and having a relatively high oxygen concentration.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 FI B01J 23/42 B01J 23/44 A 23/44 23/78 A 23/78 35/02 P 35/02 F01N 3/02 321A F01N 3/02 321 B01D 53/36 104Z (58)調査した分野(Int.Cl.6,DB名) B01D 39/14 B01J 23/00 - 23/96,35/02──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. 6 Identification code FI B01J 23/42 B01J 23/44 A 23/44 23/78 A 23/78 35/02 P 35/02 F01N 3/02 321A F01N 3/02 321 B01D 53/36 104Z (58) Fields investigated (Int. Cl. 6 , DB name) B01D 39/14 B01J 23/00-23/96, 35/02
Claims (3)
る排ガス浄化材において、前記フィルタは、排ガス流の
入口側に位置する高密度の薄層部と、出口側に位置する
比較的低密度の部分との二つの部分からなり、前記高密
度の薄層部には白金族元素が担持されており、前記比較
的低密度の部分には、(a)アルカリ金属元素と、
(b)周期表のIB族、IIB族、VA族、VIA族、VIIA族、及
び白金族元素を除いたVIII族の遷移元素、及びSnからな
る群から選ばれた1種または2種以上の元素とが担持さ
れていることを特徴とする排ガス浄化材。An exhaust gas purifying material comprising a heat-resistant porous foam type filter as a carrier, wherein the filter comprises a high-density thin layer located on the inlet side of the exhaust gas flow, and a relatively low-density layer located on the outlet side. A platinum group element is supported on the high-density thin layer portion, and the relatively low-density portion includes (a) an alkali metal element;
(B) at least one member selected from the group consisting of Sn, IB, IIB, VA, VIA, VIIA, and VIII transition elements excluding platinum group elements; An exhaust gas purifying material characterized by carrying an element.
前記高密度の薄層部にはさらに金又は銀が担持されてい
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
An exhaust gas purifying material, wherein the high-density thin layer portion further supports gold or silver.
いて排気ガスを浄化する方法において、前記高密度の薄
層部を排ガスの入口側とし、前記比較的低密度の部分を
排ガスの出口側とし、前記高密度の薄層部で、前記排ガ
ス中のパティキュレートを低温で燃焼又は着火させると
ともに、未燃焼炭化水素とCOを酸化除去し、前記低密度
の部分で前記高密度薄層部を通過したパティキュレート
を燃焼することを特徴とする排ガス浄化方法。3. The method for purifying exhaust gas using the exhaust gas purifying material according to claim 1 or 2, wherein the high-density thin layer portion is an exhaust gas inlet side, and the relatively low-density portion is an exhaust gas purifying material. At the exit side, the particulates in the exhaust gas are burned or ignited at a low temperature in the high-density thin layer portion, and unburned hydrocarbons and CO are oxidized and removed. A method for purifying exhaust gas, comprising burning particulates that have passed through a layer portion.
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP25856889A JP2863568B2 (en) | 1989-10-03 | 1989-10-03 | Exhaust gas purifying material and exhaust gas purifying method |
US07/493,974 US5075274A (en) | 1989-03-15 | 1990-03-15 | Exhaust gas cleaner |
DE4008371A DE4008371A1 (en) | 1989-03-15 | 1990-03-15 | EXHAUST GASOLINE AND METHOD FOR CLEANING EXHAUST GASES |
US08/579,804 US5665322A (en) | 1989-03-15 | 1995-12-28 | Method of cleaning exhaust gas |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP25856889A JP2863568B2 (en) | 1989-10-03 | 1989-10-03 | Exhaust gas purifying material and exhaust gas purifying method |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH03118812A JPH03118812A (en) | 1991-05-21 |
JP2863568B2 true JP2863568B2 (en) | 1999-03-03 |
Family
ID=17322049
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP25856889A Expired - Fee Related JP2863568B2 (en) | 1989-03-15 | 1989-10-03 | Exhaust gas purifying material and exhaust gas purifying method |
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Country | Link |
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JP (1) | JP2863568B2 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020128151A1 (en) * | 1998-05-01 | 2002-09-12 | Michael P. Galligan | Catalyst members having electric arc sprayed substrates and methods of making the same |
-
1989
- 1989-10-03 JP JP25856889A patent/JP2863568B2/en not_active Expired - Fee Related
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JPH03118812A (en) | 1991-05-21 |
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