JP5697122B2 - Method for decomposing NOx with titanium low-order oxide - Google Patents
Method for decomposing NOx with titanium low-order oxide Download PDFInfo
- Publication number
- JP5697122B2 JP5697122B2 JP2009034342A JP2009034342A JP5697122B2 JP 5697122 B2 JP5697122 B2 JP 5697122B2 JP 2009034342 A JP2009034342 A JP 2009034342A JP 2009034342 A JP2009034342 A JP 2009034342A JP 5697122 B2 JP5697122 B2 JP 5697122B2
- Authority
- JP
- Japan
- Prior art keywords
- titanium
- low
- order
- support
- tio
- 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
- 239000010936 titanium Substances 0.000 title claims description 63
- 229910052719 titanium Inorganic materials 0.000 title claims description 51
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 title claims description 50
- 238000000034 method Methods 0.000 title claims description 23
- 238000000354 decomposition reaction Methods 0.000 claims description 38
- 239000000725 suspension Substances 0.000 claims description 10
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 9
- 229910052751 metal Inorganic materials 0.000 claims description 9
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 9
- 239000000919 ceramic Substances 0.000 claims description 8
- 239000002184 metal Substances 0.000 claims description 8
- 229910052878 cordierite Inorganic materials 0.000 claims description 7
- 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 7
- 238000001035 drying Methods 0.000 claims description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 3
- 239000000020 Nitrocellulose Substances 0.000 claims description 3
- 229910052799 carbon Inorganic materials 0.000 claims description 3
- 229920001220 nitrocellulos Polymers 0.000 claims description 3
- 238000007598 dipping method Methods 0.000 claims description 2
- 239000007921 spray Substances 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 claims 1
- 238000001694 spray drying Methods 0.000 claims 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 32
- KELHQGOVULCJSG-UHFFFAOYSA-N n,n-dimethyl-1-(5-methylfuran-2-yl)ethane-1,2-diamine Chemical compound CN(C)C(CN)C1=CC=C(C)O1 KELHQGOVULCJSG-UHFFFAOYSA-N 0.000 description 27
- 229910021529 ammonia Inorganic materials 0.000 description 16
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 14
- 239000007789 gas Substances 0.000 description 11
- 230000001603 reducing effect Effects 0.000 description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 8
- 239000001301 oxygen Substances 0.000 description 8
- 229910052760 oxygen Inorganic materials 0.000 description 8
- 229910052786 argon Inorganic materials 0.000 description 7
- 239000000843 powder Substances 0.000 description 6
- 239000012855 volatile organic compound Substances 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- 238000011282 treatment Methods 0.000 description 5
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 4
- 229910010413 TiO 2 Inorganic materials 0.000 description 4
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 4
- 239000004202 carbamide Substances 0.000 description 4
- 239000003054 catalyst Substances 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 239000002283 diesel fuel Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000011941 photocatalyst Substances 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 230000002829 reductive effect Effects 0.000 description 2
- RZVAJINKPMORJF-UHFFFAOYSA-N Acetaminophen Chemical compound CC(=O)NC1=CC=C(O)C=C1 RZVAJINKPMORJF-UHFFFAOYSA-N 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 238000001237 Raman spectrum Methods 0.000 description 1
- 229910001069 Ti alloy Inorganic materials 0.000 description 1
- 235000010724 Wisteria floribunda Nutrition 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- -1 but for example Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 238000000634 powder X-ray diffraction Methods 0.000 description 1
- 239000005297 pyrex Substances 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 150000003608 titanium Chemical class 0.000 description 1
Images
Landscapes
- Exhaust Gas After Treatment (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
Description
本発明は、ＮＯｘの分解に関するものであり、具体的には、ディーゼル自動車から排出されるＮＯｘを、チタン低次酸化物の還元力を利用した分解方法に係るものである。 The present invention relates to the decomposition of NO x , and specifically relates to a decomposition method using NO x discharged from a diesel vehicle using the reducing power of a titanium low-order oxide.
ＮＯｘを代表例とする揮発性有機化合物(ＶＯＣ：Volatile Organic Compounds )の分解については、これまでに幾つかの提案がなされてきたが、いずれも社会の要請に充分にマッチするものではない。具体的には、光触媒、オゾン、プラズマ、微生物等による分解方法が提案されているが、いずれも分解能力の小さいことが欠点であり、限定された風量、濃度の排気ガスにしか適応できないシステムであって、しかも、ＶＯＣをゼロベースまで完全分解することが難しいとされている。 Several proposals have been made for the decomposition of volatile organic compounds (VOCs) using NO x as a representative example, but none of them is well suited to the demands of society. Specifically, decomposition methods using photocatalysts, ozone, plasma, microorganisms, etc. have been proposed, but all of them have a disadvantage that their decomposition ability is small, and they are systems that can be applied only to exhaust gases of limited air volume and concentration. Moreover, it is difficult to completely decompose the VOC to zero base.
本発明者らは、既に、酸化物半導体を熱励起(熱触媒)することによって大量に発生する正孔を利用し、有機化合物を水と炭酸ガスにまで完全に燃焼分解する技術を提供している(特許文献１)。そして、かかる熱励起によってもたらされる酸化物半導体の分解能力を利用し、ＮＯｘなどのＶＯＣの分解除去にターゲットを絞って開発を進めてきた。 The present inventors have already provided a technology for completely burning and decomposing an organic compound into water and carbon dioxide gas by utilizing holes generated in large quantities by thermally exciting (thermal catalyst) an oxide semiconductor. (Patent Document 1). Then, such caused by thermal excitation using the degradation ability of the oxide semiconductor, have been developing more targeted to decompose and remove the VOC, such as NO x.
酸化物半導体を基材の表面に担持させる一例として、金属やセラミックなどからなる基材の表面に、チタンまたはチタン合金からなる粉体粒子を噴射し、当該基材の表面にチタニア被膜を形成する技術がある(特許文献２、３)。これは、熱触媒の対象の一つとしても考えられる。 As an example of supporting an oxide semiconductor on the surface of a base material, powder particles made of titanium or a titanium alloy are sprayed on the surface of the base material made of metal, ceramic, or the like to form a titania film on the surface of the base material. There are technologies (Patent Documents 2 and 3). This is also considered as one of the targets of the thermal catalyst.
さて、これら特許文献２〜３の代表例は、例えば、球状の酸化アルミ(Ａｌ２Ｏ３)の表面に酸化チタン(ＴｉＯ２)を被覆するいわゆるチタンボール（（株）不二機販製：ＰＩＰボール）と呼ばれるものである。しかるに、実際のチタンボールの被覆構造は、酸化チタンが一様に被覆されているものではなく、酸素濃度が傾斜的に変化する構造（ＴｉＯ２／ＴｉＯ／Ｔｉ／Ａｌ２Ｏ３）であるとされ、非特許文献１のＦｉｇ．１(ａ)にその模式図が記載されている。そして、この傾斜構造を持つために広い波長に対して応答する光触媒（酸化作用）として有効であるとされている。 Well-known examples of these patent documents 2 to 3 are so-called titanium balls (manufactured by Fuji Machine Sales Co., Ltd.) in which, for example, the surface of spherical aluminum oxide (Al 2 O 3 ) is coated with titanium oxide (TiO 2 ). PIP balls). However, the actual titanium ball coating structure is not uniformly coated with titanium oxide, but has a structure in which the oxygen concentration changes in a gradient (TiO 2 / TiO / Ti / Al 2 O 3 ). Non-Patent Document 1, FIG. The schematic diagram is described in 1 (a). And since it has this inclined structure, it is said that it is effective as a photocatalyst (oxidation action) which responds to a wide wavelength.
しかるに、かかるチタンボールの表面の色(ほぼ金属チタンの色)、及び、表面の電気抵抗が１０１〜１０１２オームのオーダーと広い範囲にばらついていることから、非特許文献１のＦｉｇ．１(ｂ)のような構造であると推定した。つまり、ＴｉＯ２層は５０〜１００Ａ程度の薄い膜であること、Ｔｉ金属が露出している箇所や、下地のＡｌ２Ｏ３が見えているところもある構造であると推定した。 However, since the surface color of the titanium ball (substantially the color of titanium metal) and the electrical resistance of the surface are in a wide range of the order of 10 1 to 10 12 ohms, FIG. The structure was estimated as 1 (b). That is, it was estimated that the TiO 2 layer is a thin film of about 50 to 100 A, and has a structure where the Ti metal is exposed and where the underlying Al 2 O 3 is visible.
従って、このチタンボールを熱触媒として利用するには、低次酸化部位を酸化することによりＴｉＯ２／Ａｌ２Ｏ３の構造とする必要があると推定し、空気中で８００℃程度で加熱し、これを熱触媒としてＶＯＣの分解に供した。結果は推定通りとなり、ＶＯＣの熱分解が可能となったもので、その知見から特許文献４を提案している。 Therefore, in order to use this titanium ball as a thermal catalyst, it is presumed that it is necessary to form a TiO 2 / Al 2 O 3 structure by oxidizing the low-order oxidation site, and it is heated at about 800 ° C. in the air. This was subjected to decomposition of VOC as a thermal catalyst. The result was as estimated, and thermal decomposition of VOC became possible, and Patent Document 4 is proposed from the knowledge.
本発明は、チタン低次酸化物を熱励起することによってＮＯｘを分解する技術の開発にあって、チタンの低次酸化物が極めて強い還元力を持つことを見出し、かかる知見に基づいてＮＯｘの完全分解を試み、本発明に到達したものである。 The present invention is based on the development of a technique for decomposing NO x by thermally exciting a titanium low-order oxide, and found that the titanium low-order oxide has extremely strong reducing power. Attempts were made to completely decompose x and the present invention was achieved.
本発明の要旨は、チタン低次酸化物（ＴｉＯｘ（０＜ｘ＜２））の還元力を用いるＮＯｘの分解方法であって、チタン低次酸化物を水分の存在下で加熱してＴｉ３+又はＴｉ４＋を発生させ、その際に放出される電子を２００〜５００℃でＮＯｘに接触させて還元分解することを特徴とする。 The gist of the present invention is a method for decomposing NO x using the reducing power of a titanium low-order oxide (TiO x (0 <x <2)), wherein the titanium low-order oxide is heated in the presence of moisture. Ti 3+ or Ti 4+ is generated, and the electrons released at that time are brought into contact with NO x at 200 to 500 ° C. for reductive decomposition.
通常は、チタン低次酸化物を、金属、セラミック、炭素から選ばれた支持体上に担持して用いるものである。かかる支持体の好適例としてはセラミック多孔体であり、特に、コージライトハニカムが好ましい。 Usually, a titanium low-order oxide is supported on a support selected from metals, ceramics, and carbon. A preferred example of such a support is a ceramic porous body, and cordierite honeycomb is particularly preferable.
本発明は、水分の存在下において、ＴｉＯｘに強力な還元力があることを見出し、これを利用してＮＯｘの分解に利用したものであり、酸素が共存するとＮＯｘが完全に窒素ガスと水とに分解されるものであり、その分解能力はきわめて高い。そして、チタンの低次酸化物は粉体状態で容易に入手でき、コージライトハニカム等に簡単に担持することができるため、コンパクトな分解素子を構築することが可能となったものである。 The present invention finds that TiO x has a strong reducing power in the presence of moisture, and utilizes this to decompose NO x , and when oxygen coexists, NO x is completely nitrogen gas. It is decomposed into water and water, and its decomposition ability is extremely high. Since the low-order oxide of titanium can be easily obtained in a powder state and can be easily supported on a cordierite honeycomb or the like, a compact decomposition element can be constructed.
本発明にあって、チタンの低次酸化物(ＴｉＯｘ(０＜ｘ＜２))に強い還元作用があることを見出したのがその端緒である。即ち、チタンの低次酸化物(ＴｉＯｘ(０＜ｘ＜２))において水分の存在下でＴｉＯｘが溶出して３価又は４価のＴｉイオン（Ｔｉ３+又はＴｉ４＋）になる。かかる溶解反応の際に放出される電子に基づく還元力を利用してＮＯｘの分解に発展させたものである。 In the present invention, the low-order oxide of titanium (TiO x (0 <x <2)) was found to have a strong reducing action. That is, in the low-order oxide of titanium (TiO x (0 <x <2)), TiO x is eluted in the presence of moisture to become trivalent or tetravalent Ti ions (Ti 3+ or Ti 4+ ). It has been developed to decompose NO x by utilizing the reducing power based on electrons released during the dissolution reaction.
さて、前述のチタンボールは非特許文献１のＦｉｇ．１(ｂ)のような構造であると推定したが、これを精査するに、金属のチタン(Ｔｉ)及び二酸化チタン(ＴｉＯ２)は全く水に溶けないが、この中間にある部分的に露出したチタンの低次酸化物(ＴｉＯｘ(０＜ｘ＜２))起因するもので、これが水に溶け、Ｔｉ３＋又はＴｉ４＋となることが分かった。つまり、チタンボールにはＴｉＯｘに起因する強力な還元性質があることを突き止め、これをＮＯｘ分解に応用したのが本発明である。 Now, the titanium ball described above is shown in FIG. Although it was estimated that the structure was 1 (b), the metal titanium (Ti) and titanium dioxide (TiO 2 ) were not soluble in water at all, but were partially exposed in the middle. It was found that this was due to the low-order oxide of titanium (TiO x (0 <x <2)), which was dissolved in water to become Ti 3+ or Ti 4+ . That is, it is the present invention that the titanium ball has been found to have a strong reducing property due to TiO x and applied to the decomposition of NO x .
そして、還元力の源泉となるチタンの低次酸化物は、取り扱い上支持体に担持されることが望ましく、用いられる支持体としては、金属、セラミック、炭素等が例示され、４０〜１００メッシュのＳＵＳメッシュや、多孔構造体が好適である。多孔構造体としては、セラミックス製の多孔体が好ましく、ハニカム多孔体や三次元網状構造体が挙げられる。中でも、コージライト製のものが好適である。 And it is desirable for the low-order oxide of titanium used as a source of reducing power to be supported on the support for handling, and examples of the support used include metals, ceramics, carbon, etc. A SUS mesh or a porous structure is suitable. The porous structure is preferably a ceramic porous body, such as a honeycomb porous body or a three-dimensional network structure. Of these, cordierite is preferred.
チタン低次酸化物の支持体上への担持の方法は、非水溶液系ＴｉＯｘ懸濁液をスプレーガンにて支持体に吹付・乾燥する方法、支持体が金属の場合には、支持体を一つの極にして、非水溶液系ＴｉＯｘ懸濁液よりＴｉＯｘを電気泳動電着させる方法、支持体を非水溶液系ＴｉＯｘ懸濁液中に浸漬・乾燥させる方法などがある。尚、非水溶液系ＴｉＯｘ懸濁液中にニトロセルロースを含有させることにより、ＴｉＯｘ粉体(粒子)の分散性が極めてよくなることも知見の一つである。 The titanium low-order oxide is supported on the support by spraying and drying a non-aqueous TiO x suspension on the support with a spray gun. When the support is a metal, the support is in the one pole, a method of a non-aqueous TiO x suspension is electrophoresed electrodeposited TiO x, and a method of dipping and drying the support in a non-aqueous TiO x suspension. One of the findings is that the dispersibility of the TiO x powder (particles) is extremely improved by incorporating nitrocellulose in the non-aqueous TiO x suspension.
チタンの低次酸化物の強い還元性の発現には水の存在が必要であるが、例えば、ディーゼル油の燃焼の際に放出される水分で十分である。即ち、ディーゼル油の燃焼にあって、ＮＯｘの処理は数多く提案されているが、自動車用に採用されている例の一つは、尿素と水を給油時に積み込み、エンジンの出口で尿素の分解から放出されるアンモニアを用いてＮＯを還元し、Ｎ２とＨ２Ｏに変換する（非特許文献２）方式があるが、本発明における水はここで生じる程度のもので充分であり、従って、エンジン出口に本発明のチタンの低次酸化物を担持した支持体を装備すればＮＯｘの処理に充分である。 The presence of water is necessary for the strong reducibility of the low-order oxide of titanium, but for example, water released during combustion of diesel oil is sufficient. That is, in the combustion of diesel oil, many NO x treatments have been proposed, but one example adopted for automobiles is to load urea and water at the time of refueling and decompose urea at the engine outlet. There is a system that uses ammonia released from NO to reduce NO and convert it to N 2 and H 2 O (Non-patent Document 2). If the engine outlet is equipped with a support carrying the low-order oxide of titanium of the present invention, it is sufficient for the treatment of NO x .
市販されているチタンの低次酸化物である三菱マテリアル（株）のＴｉ−Ｂｌａｃｋおよび日亜化学工業（株）の一酸化チタンはともに組成がＴｉＯｘ（０＜ｘ＜２）で結晶状態はＴｉＯ２のルチル型とアナターゼ型の混合物であり、使用後も結晶状態が変化していないことをラマンスペクトルならびに粉末Ｘ線回折により確認した。このことは使用済のＴｉＯｘ の再生処理は単にアンモニア等で酸素を抜く作業だけ簡単に済むことを裏付けるものである。 Both Ti-Black of Mitsubishi Materials Co., Ltd., which are commercially available low-order oxides of titanium, and Titanium Monoxide of Nichia Chemical Co., Ltd. have a composition of TiO x (0 <x <2) and the crystalline state is It was a mixture of TiO 2 rutile and anatase types, and it was confirmed by Raman spectrum and powder X-ray diffraction that the crystal state did not change after use. This confirms that the used TiO x regeneration process can be performed simply by removing oxygen with ammonia or the like.
実験例１：（チタンボールによるＮＯの分解）
還元力の源泉となるチタンの低次酸化物として、前述のチタンボール（（株）不二機販製：ＰＩＰボール）を使用した。３００ｍｌのオートクレーブにチタンボールを２５０ｍｌ充填し、これに湿潤ＮＯ／Ａｒガスを１００ｍｌ／ｍｉｎの流量で導入した。分解ガスのＮＯはＡｒで希釈し、約１０００ｐｐｍとした。分解ガスの測定には（株）ＵＬＶＡＣ製の四重極質量分析計ＲＧ−１０２を使用した。
図１に示す通り、１２０℃付近からＮＯの分解がはじまり、２５０℃では９０％以上分解している。それと同時にアルゴン量の約０．２５％アンモニアの生成が認められた。しかし、質量分析計でＮ２は検出されなかった。
Experimental Example 1: (Decomposition of NO with titanium ball)
The above-mentioned titanium ball (made by Fujiki Sales Co., Ltd .: PIP ball) was used as a low-order oxide of titanium that becomes a source of reducing power. A 300 ml autoclave was filled with 250 ml of titanium balls, and wet NO / Ar gas was introduced into the autoclave at a flow rate of 100 ml / min. The cracked gas NO was diluted with Ar to about 1000 ppm. For measurement of the cracked gas, a quadrupole mass spectrometer RG-102 manufactured by ULVAC, Inc. was used.
As shown in FIG. 1, the decomposition of NO starts from around 120 ° C., and at 250 ° C., it is decomposed by 90% or more. At the same time, formation of ammonia of about 0.25% of the amount of argon was observed. However, N 2 was not detected by the mass spectrometer.
実験例２：（チタンブラックによるＮＯの分解）
実験例１と同様の実験をチタンボールの代わりにチタンブラック粉末を用いて行った。ＴｉＯを主成分とするチタンブラックを三菱マテリアル（株）から購入した（商品名：Ｔｉ−Ｂｌａｃｋ−１３Ｍ；比表面積：１０−２０ｍ２／ｇ）。１００ｍｌのチタンブラック粉末をオートクレーブにチャージし、１５０ｒｐｍで攪拌した。
図２に示す通り、５０℃あたりからＮＯの分解が始まり、２００℃から急激な分解がおこり、４００℃では９０％の分解が観測された。これと同時にアンモニアの発生が観測された。アンモニア量はアルゴン量の０．７％程度であった。しかし、質量分析計でＮ２は検出されなかった。
Experimental example 2: (NO decomposition with titanium black)
An experiment similar to Experimental Example 1 was performed using titanium black powder instead of titanium balls. Titanium black mainly composed of TiO was purchased from Mitsubishi Materials Corporation (trade name: Ti-Black-13M; specific surface area: 10-20 m 2 / g). 100 ml of titanium black powder was charged into the autoclave and stirred at 150 rpm.
As shown in FIG. 2, decomposition of NO started at around 50 ° C., rapid decomposition occurred from 200 ° C., and 90% decomposition was observed at 400 ° C. At the same time, generation of ammonia was observed. The amount of ammonia was about 0.7% of the amount of argon. However, N 2 was not detected by the mass spectrometer.
尚、前述の非特許文献２において、“尿素と水”によるＮＯ処理を見ると、尿素分解により生じるアンモニアとＮＯの反応で、Ｎ２とＨ２Ｏが生成
してＮＯの浄化が達成されると記載されている。従って、アンモニアが発生することは歓迎されるべきことであって、ＮＯ処理の障害にはならない。
In the above-mentioned Non-Patent Document 2, when NO treatment with “urea and water” is seen, N 2 and H 2 O are generated by the reaction of ammonia and NO generated by urea decomposition, and NO purification is achieved. It is described. Therefore, the generation of ammonia should be welcomed and does not become an obstacle to NO treatment.
実験例３：（チタンブラックによるＮＯの分解：水・酸素の存在下）
ＮＯ分解は空気中で行うことが想定されるので酸素のＮＯ分解への影響を検討した。実験例２の実験で、キャリヤーをＡｒと空気の混合ガス（体積比で１：１）とし、流量は４０ｍｌ／ｍｉｎとした。
図３に示す通り、ＮＯの急激な分解は２５０℃あたりから始まり、これと同時にＮ２の急激な増加が認められた。また、アンモニアの発生はほぼゼロであった。５００℃ではＮＯの８０％が分解された。この実験例では実験例１と２で観測されたアンモニアがＮ２とＨ２Ｏに分解されることを示唆している。
Experimental Example 3: (NO decomposition with titanium black: in the presence of water and oxygen)
Since NO decomposition is assumed to be performed in the air, the influence of oxygen on NO decomposition was examined. In the experiment of Experimental Example 2, the carrier was a mixed gas of Ar and air (1: 1 by volume), and the flow rate was 40 ml / min.
As shown in FIG. 3, the rapid decomposition of NO started at around 250 ° C., and at the same time, a rapid increase in N 2 was observed. Further, the generation of ammonia was almost zero. At 500 ° C., 80% of NO was decomposed. This experimental example suggests that ammonia observed in Experimental Examples 1 and 2 is decomposed into N 2 and H 2 O.
実験例４：（一酸化チタンによるＮＯの分解）
実験例１で使用したオートクレーブを使い、チタンボールの代わりに顆粒状の一酸化チタン（ＴｉＯ：日亜化学工業（株））を１００ｍｌチャージした。３００ｍｌのオートクレーブに顆粒状のＴｉＯを充填し、湿潤ＮＯガスはアルゴンで希釈し、約１０００ｐｐｍとした。流量５０ｍｌ／ｍｉｎで実験を行った。
分解は１００℃近傍から始まり、２５０℃では約９５％分解した。また、ＮＯの分解に伴い、Ｎ２Ｏならびにアンモニアが生成し、その量はアルゴン量に対してそれぞれ、０．０３，０．０５％程度であった。
Experimental Example 4: (Decomposition of NO with titanium monoxide)
Using the autoclave used in Experimental Example 1, 100 ml of granular titanium monoxide (TiO: Nichia Corporation) was charged instead of titanium balls. A 300 ml autoclave was filled with granular TiO, and the wet NO gas was diluted with argon to about 1000 ppm. The experiment was conducted at a flow rate of 50 ml / min.
Decomposition started from around 100 ° C and decomposed at about 95% at 250 ° C. Further, N 2 O and ammonia were generated along with the decomposition of NO, and the amounts were about 0.03 and 0.05% with respect to the amount of argon, respectively.
実験例５：（一酸化チタンによるＮＯの分解）
日亜化学工業（株）から購入した顆粒状の一酸化チタン(ＴｉＯ）を一軸粉砕し、１００μｍ程度の粒子径とした。次に、ニトロセルロースを含むＴｉＯ懸濁液を調製し、これに直径２６ｍｍ、長さ５ｍｍのコージライトハニカム（２００ｃｐｉ：京セラ（株））を３秒間浸漬した。その後、空気中室温で乾燥させた。
湿潤ＮＯガスはアルゴンで希釈し、約１０００ｐｐｍとした。前記のように空気中で乾燥させたコージライトハニカムをパイレックス（登録商標）反応管に挿入し、外部ヒーターで加熱した。アルゴン希釈のＮＯガスを水中にバブリングし、流量１0ｍｌ／ｍｉｎで管内に導入した。分解ガスの測定には四重極質量分析計を用いた。
分解開始温度は２００℃近傍で、４００℃では約９０％分解していた。実施例４の流動床の場合と同様にＮＯの分解に伴い、Ｎ２Ｏならびにアンモニアの生成が認められた。アンモニアはアルゴン量の約０．０５％であった。また、２５０℃から急激に上昇している。また、ＮＯの分解開始温度も流動床に比べると約１００℃高い。
Experimental Example 5: (Decomposition of NO with titanium monoxide)
Granular titanium monoxide (TiO) purchased from Nichia Corporation was uniaxially pulverized to a particle size of about 100 μm. Next, a TiO suspension containing nitrocellulose was prepared, and cordierite honeycomb (200 cpi: Kyocera Corporation) having a diameter of 26 mm and a length of 5 mm was immersed in the suspension for 3 seconds. Then, it was dried at room temperature in the air.
Wet NO gas was diluted with argon to about 1000 ppm. Cordierite Ha Nica arm drying in air as described above was inserted into pyrex reaction tube was heated by an external heater. Argon diluted NO gas was bubbled into water and introduced into the tube at a flow rate of 10 ml / min. A quadrupole mass spectrometer was used to measure the cracked gas.
The decomposition start temperature was around 200 ° C., and the decomposition was about 90% at 400 ° C. As in the case of the fluidized bed in Example 4, N 2 O and ammonia were observed to be generated along with the decomposition of NO. Ammonia was about 0.05% of the amount of argon. Moreover, it rises rapidly from 250 ° C. Moreover, the decomposition start temperature of NO is about 100 ° C. higher than that of the fluidized bed.
実験例６：（一酸化チタンによるＮＯの分解：水・酸素の存在下）
実験例５において、実験例３と同様にキャリヤーをＡｒと空気の混合ガス（体積比で１：１）として実験を行った。
この実験例６では実験例３と同様、実験例５で観測されたアンモニアが完全分解され、Ｎ２とＨ２Ｏに分解された。
Experimental Example 6: (NO decomposition by titanium monoxide: in the presence of water and oxygen)
In Experimental Example 5, the experiment was performed using a mixed gas of Ar and air (volume ratio of 1: 1) as in Experimental Example 3.
In Experimental Example 6, similarly to Experimental Example 3, ammonia observed in Experimental Example 5 was completely decomposed and decomposed into N 2 and H 2 O.
本発明は、以上の通り、チタンの低次酸化物の還元的性質を使って、ＮＯ分解を試み、水又は酸素の非存在下でＮＯ分解と共にアンモニアの発生が認められた。一方、水・酸素存在下ではアンモニアの発生は抑えられ、窒素のみが生成していることがわかった。しかも、チタン容易に担持の低次酸化物は粉体状態で容易に入手でき、かつ、コージライトハニカム等に容易に担持することができるため、コンパクトな浄化装置を構築することが可能であるとともに、長期間の使用により活性が低下した分解素子はアンモニアなどを用いる通常の還元処理により再活性化できるので、その利用分野は極めて広い。
As described above, in the present invention, NO decomposition was attempted using the reductive nature of the low-order oxide of titanium, and generation of ammonia was observed together with NO decomposition in the absence of water or oxygen. On the other hand, in the presence of water and oxygen, the generation of ammonia was suppressed, and it was found that only nitrogen was generated. Moreover, since the low-order oxide easily supported by titanium can be easily obtained in a powder state and can be easily supported on a cordierite honeycomb or the like, it is possible to construct a compact purification device. Since the decomposition element whose activity has been lowered by long-term use can be reactivated by a normal reduction treatment using ammonia or the like, its application field is very wide.
Claims (11)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009034342A JP5697122B2 (en) | 2009-02-17 | 2009-02-17 | Method for decomposing NOx with titanium low-order oxide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009034342A JP5697122B2 (en) | 2009-02-17 | 2009-02-17 | Method for decomposing NOx with titanium low-order oxide |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2010188266A JP2010188266A (en) | 2010-09-02 |
| JP5697122B2 true JP5697122B2 (en) | 2015-04-08 |
Family
ID=42814908
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2009034342A Expired - Fee Related JP5697122B2 (en) | 2009-02-17 | 2009-02-17 | Method for decomposing NOx with titanium low-order oxide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5697122B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BR112013031855A2 (en) * | 2011-06-15 | 2016-12-13 | Henkel Ag & Co Kgaa | method and apparatus for reducing emissions and / or reducing friction in an internal combustion engine |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02144147A (en) * | 1988-11-25 | 1990-06-01 | Sakai Chem Ind Co Ltd | Catalyst for removal of nitrogen oxide |
| JP2005103471A (en) * | 2003-09-30 | 2005-04-21 | Mitsuboshi Belting Ltd | Method of manufacturing thin film of titanium oxide |
-
2009
- 2009-02-17 JP JP2009034342A patent/JP5697122B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2010188266A (en) | 2010-09-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wood et al. | An overview of photocatalyst immobilization methods for air pollution remediation | |
| Toma et al. | Comparative study on the photocatalytic decomposition of nitrogen oxides using TiO2 coatings prepared by conventional plasma spraying and suspension plasma spraying | |
| JP2011031139A (en) | Photocatalyst material and method for manufacturing the same | |
| JP5697122B2 (en) | Method for decomposing NOx with titanium low-order oxide | |
| JP3902670B2 (en) | Method for removing nitrogen oxides in exhaust gas | |
| JP5723646B2 (en) | Method for preparing denitration catalyst | |
| JP4000378B2 (en) | Visible light responsive complex oxide photocatalyst and method for decomposing and removing harmful chemicals using the same | |
| JP2009090239A (en) | NOx REDUCTION CATALYST, METHOD OF MANUFACTURING THE SAME, AND METHOD FOR USE THEREOF | |
| JP2015120117A (en) | Purification catalyst | |
| JP4720592B2 (en) | Electrochemical catalyst for exhaust gas purification | |
| JP2001276615A (en) | Titanium oxide powder for photocatalyst | |
| JP2007032400A (en) | Method for processing particulate in diesel engine exhaust gas | |
| JP2011230087A (en) | Decomposition catalyst and decomposition method of organic compound | |
| JP4923027B2 (en) | Method for preparing vanadia-titania catalyst for chlorinated organic compound decomposition using solvothermal synthesis process | |
| JP5533782B2 (en) | Exhaust gas purification catalyst and method for producing the same | |
| JP3837548B2 (en) | Bismuth complex oxide visible light responsive photocatalyst and method for decomposing and removing harmful chemicals using the same | |
| JP6190209B2 (en) | Photocatalyst fiber structure and method for producing photocatalyst fiber structure | |
| Malkhaz | IMPACT OF COMPLEX PROCESSING ON THE PHOTOCATALYTICPROPERTIES OF TITANIUM DIOXIDE | |
| Liu et al. | Catalysts for decomposing ozone tail gas | |
| JP2009233590A (en) | Toxic substance treatment method and device for treatment | |
| JP2010269238A (en) | Material for removing environmentally burdensome substance | |
| JP5541843B2 (en) | Composite oxide for exhaust gas purification catalyst and exhaust gas purification filter using the same | |
| JP2009082887A (en) | Catalyst for purification of exhaust gas | |
| JP2004267919A (en) | Combustion exhaust gas treatment apparatus and treatment method | |
| JP2023064826A (en) | Composite thermal spray material, production method thereof, and electrode using the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20120213 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20130423 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20130425 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20130621 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20140325 |
|
| 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: 20150106 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20150205 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5697122 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| LAPS | Cancellation because of no payment of annual fees |