JPH0688781B2 - Method for producing surface-treated alumina having high specific surface area at high temperature - Google Patents
Method for producing surface-treated alumina having high specific surface area at high temperatureInfo
- Publication number
- JPH0688781B2 JPH0688781B2 JP5077659A JP7765993A JPH0688781B2 JP H0688781 B2 JPH0688781 B2 JP H0688781B2 JP 5077659 A JP5077659 A JP 5077659A JP 7765993 A JP7765993 A JP 7765993A JP H0688781 B2 JPH0688781 B2 JP H0688781B2
- Authority
- JP
- Japan
- Prior art keywords
- surface area
- alumina
- specific surface
- high temperature
- treated alumina
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 title claims description 25
- 238000004519 manufacturing process Methods 0.000 title claims description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 claims description 5
- VCNTUJWBXWAWEJ-UHFFFAOYSA-J aluminum;sodium;dicarbonate Chemical compound [Na+].[Al+3].[O-]C([O-])=O.[O-]C([O-])=O VCNTUJWBXWAWEJ-UHFFFAOYSA-J 0.000 claims description 5
- 229910001647 dawsonite Inorganic materials 0.000 claims description 5
- 239000003960 organic solvent Substances 0.000 claims description 3
- 238000001354 calcination Methods 0.000 claims 1
- 238000001035 drying Methods 0.000 claims 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 10
- 239000003054 catalyst Substances 0.000 description 8
- 238000002485 combustion reaction Methods 0.000 description 7
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 6
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 5
- 238000007084 catalytic combustion reaction Methods 0.000 description 5
- 239000000446 fuel Substances 0.000 description 5
- 239000000377 silicon dioxide Substances 0.000 description 5
- 238000010304 firing Methods 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 239000000725 suspension Substances 0.000 description 3
- 238000005979 thermal decomposition reaction Methods 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000003345 natural gas Substances 0.000 description 2
- 238000004438 BET method Methods 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000003034 coal gas Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 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
- 238000003912 environmental pollution Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 239000011164 primary particle Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Landscapes
- Catalysts (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、特に高温触媒燃焼用触
媒担体に好適に用いられる、高温での高比表面積を有す
る表面処理アルミナの製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing surface-treated alumina having a high specific surface area at high temperature, which is preferably used as a catalyst carrier for high temperature catalytic combustion.
【０００２】[0002]
【従来の技術】ボイラーやガスタービンなどの運転は、
石油、石炭、天然ガスなどの燃料を直接空気で燃焼させ
る火炎燃焼によって行われているが、火炎燃焼では燃焼
を安定に継続させるために燃料濃度を高くする必要があ
り、その結果燃焼温度が２０００℃前後に達し、空気中
の窒素が酸化されて大量の環境汚染源の窒素酸化物を発
生するという欠点がある。2. Description of the Related Art The operation of a boiler or gas turbine is
Although it is performed by flame combustion in which fuel such as oil, coal, and natural gas is directly burned with air, in flame combustion, it is necessary to increase the fuel concentration in order to continue combustion stably, and as a result, the combustion temperature is 2000. There is a drawback that the temperature reaches around ℃ and the nitrogen in the air is oxidized to generate a large amount of nitrogen oxide which is a source of environmental pollution.
【０００３】これに対し、触媒燃焼では、大過剰の空気
で希釈された天然ガスなどの燃料を触媒層で着火・燃焼
させるので、火炎燃焼の場合ほど高温にはならず、窒素
酸化物の生成をきわめて少なくしうるし、また触媒不在
下では燃焼不可能な希薄濃度の燃料でも安定燃焼を続行
しうるので、省資源の観点からもきわめて好都合な燃焼
システムといえる。On the other hand, in catalytic combustion, fuel such as natural gas diluted with a large excess of air is ignited and burned in the catalyst layer. Therefore, the temperature is not as high as that in flame combustion, and nitrogen oxides are produced. The fuel consumption can be extremely reduced, and stable combustion can be continued even with a lean concentration of fuel that cannot be combusted in the absence of a catalyst. Therefore, it can be said that it is a very convenient combustion system from the viewpoint of resource saving.
【０００４】ところで、アルミナは触媒や触媒担体とし
て最も広く利用されているセラミックスであり、触媒燃
焼の触媒担体としても検討されている。By the way, alumina is the ceramic most widely used as a catalyst and a catalyst carrier, and is also being investigated as a catalyst carrier for catalytic combustion.
【０００５】しかしながら、ボイラーやガスタービンの
運転に要求される高温条件の触媒燃焼システムに上記ア
ルミナを触媒担体として用いた場合、アルミナは１１０
０℃以上に加熱され、容易に相転移して結晶構造的に安
定なα‐アルミナとなり、微細な一次粒子がα相への転
移に伴って急激に焼結し表面積が著しく減少するため、
担体としての要求特性が大きく損なわれるのを免れな
い。However, when the above alumina is used as a catalyst carrier in a catalytic combustion system under high temperature conditions required for the operation of boilers and gas turbines, the amount of alumina is 110
When heated to 0 ° C or higher, it easily undergoes a phase transition to become α-alumina with a stable crystal structure, and fine primary particles are rapidly sintered with the transition to the α phase and the surface area is significantly reduced.
It is unavoidable that the required properties as a carrier are greatly impaired.
【０００６】[0006]
【発明が解決しようとする課題】本発明は、このような
従来のアルミナのもつ欠点を克服し、高温での高比表面
積を有する表面処理アルミナを簡単に効率よく製造する
方法を提供することを目的としてなされたものである。SUMMARY OF THE INVENTION It is an object of the present invention to overcome the drawbacks of conventional alumina and to provide a method for easily and efficiently producing surface-treated alumina having a high specific surface area at high temperature. It was done for the purpose.
【０００７】[0007]
【課題を解決するための手段】本発明者らは、前記の好
ましい特徴を有する表面処理アルミナの製造法を開発す
るために鋭意研究を重ねた結果、原料にアンモニウムド
ーソナイトの熱分解により得たアルミナを選択し、これ
に焼成によるシリカコーティングを施すことにより、そ
の目的を達成しうることを見出し、この知見に基づいて
本発明をなすに至った。The inventors of the present invention have conducted extensive studies to develop a method for producing a surface-treated alumina having the above-mentioned preferable characteristics, and as a result, obtained by thermal decomposition of ammonium dawsonite as a raw material. It was found that the object can be achieved by selecting alumina and applying a silica coating by firing to this, and the present invention has been completed based on this finding.
【０００８】すなわち、本発明は、アンモニウムドーソ
ナイトを熱分解してアルミナを形成させ、次いでこれを
有機溶媒に懸濁させ、テトラアルコキシシランを加え、
乾燥したのち、１１００℃以上で焼成することを特徴と
する、高温での高比表面積を有する表面処理アルミナの
製造方法を提供するものである。That is, according to the present invention, ammonium dawsonite is pyrolyzed to form alumina, which is then suspended in an organic solvent, and tetraalkoxysilane is added.
The present invention provides a method for producing a surface-treated alumina having a high specific surface area at high temperature, which is characterized by being dried and then calcined at 1100 ° C or higher.
【０００９】本発明においてアンモニウムドーソナイト
の熱分解温度は１０００〜１１００℃の範囲で選ぶのが
好ましい。この熱分解で形成されるアルミナとしては、
比表面積２６０ｍ2／ｇ未満のθ型が好ましい。この比
表面積が２６０ｍ2／ｇを超えると表面処理アルミナの
高温での比表面積が低下する傾向がみられる。In the present invention, the thermal decomposition temperature of ammonium dawsonite is preferably selected in the range of 1000 to 1100 ° C. As alumina formed by this thermal decomposition,
Theta type having a specific surface area of less than 260 m 2 / g is preferable. If the specific surface area exceeds 260 m 2 / g, the surface area of the surface-treated alumina tends to decrease at high temperature.
【００１０】本発明において、このようにして形成され
たアルミナは、好ましくは粉末状で、アルコールなどの
有機溶媒中に懸濁させ、これにテトラエトキシシランな
どのテトラアルコキシシランをシリカ添加量が１．０〜
１５重量％、好ましくは１．５〜１３．５重量％、より
好ましくは２．０〜５．０重量％となるように加える。
シリカ添加量が５．０重量％を超えると高温でα相に転
移した場合にムライトも生成し比表面積が相対的に低下
するする傾向がみられ、特に１５重量％を超える多量と
しても使用量に見合う効果は得られず、むしろ経済的に
不利となる。In the present invention, the alumina thus formed is preferably in the form of powder and suspended in an organic solvent such as alcohol, and tetraalkoxysilane such as tetraethoxysilane is added thereto in an amount of 1 silica. .0 to
15% by weight, preferably 1.5 to 13.5% by weight, more preferably 2.0 to 5.0% by weight.
When the amount of silica added exceeds 5.0% by weight, mullite tends to be formed when the α phase is transformed at a high temperature, and the specific surface area tends to be relatively reduced. It is not economically disadvantageous, but rather economically disadvantageous.
【００１１】次いで、このようにして得られた懸濁液よ
り溶媒を蒸発させて乾燥粉末とし、これを焼成処理す
る。焼成処理は通常１１００℃以上、好ましくは１２０
０℃以上、より好ましくは１３００℃以上で行われる。Then, the solvent is evaporated from the suspension thus obtained to obtain a dry powder, which is then calcined. The firing treatment is usually 1100 ° C. or higher, preferably 120
It is performed at 0 ° C. or higher, more preferably at 1300 ° C. or higher.
【００１２】[0012]
【発明の効果】本発明方法によれば、高温での高比表面
積を有し、特にα相への転移に伴う比表面積の低下が抑
制された表面処理アルミナを簡単に効率よく製造しうる
という顕著な効果が得られる。この表面処理アルミナは
高温触媒燃焼用触媒担体に好適に用いられる。EFFECTS OF THE INVENTION According to the method of the present invention, it is possible to easily and efficiently produce a surface-treated alumina which has a high specific surface area at high temperature and in which a decrease in the specific surface area due to the transition to the α phase is suppressed. A remarkable effect is obtained. This surface-treated alumina is suitably used as a catalyst carrier for high temperature catalytic combustion.
【００１３】[0013]
【実施例】次に実施例によって本発明をさらに詳細に説
明する。The present invention will be described in more detail with reference to Examples.
【００１４】実施例１ ＴＭ１００（商品名、大明化学工業社製、アンモニウム
ドーソナイトを１０５０℃で熱分解して得た比表面積１
２０ｍ2／ｇのθ型アルミナ）を特級エタノール中に懸
濁させ、この懸濁液をかきまぜながらテトラエトキシシ
ランを添加した。添加量は、アルミナ全量当りそれぞれ
２．７％（アルミナ表面積１ｍ2当り約０．２５ｍ
ｇ）、５．４％、１３．５％のシリカ添加量となるよう
に調節した。このようにして得られた懸濁液を８０℃に
保った恒温槽中に静置し、エタノールを蒸発させて各種
乾燥粉末を得た。これらの粉末をそれぞれ１１００℃、
１２００℃、１３００℃、１４００℃でそれぞれ５時間
焼成した。Example 1 TM100 (trade name, manufactured by Daimei Chemical Industry Co., Ltd., specific surface area 1 obtained by pyrolyzing ammonium dawsonite at 1050 ° C.)
20 m 2 / g of θ-type alumina) was suspended in special grade ethanol, and tetraethoxysilane was added while stirring the suspension. The addition amount is 2.7% per total amount of alumina (about 0.25 m per 1 m 2 of alumina surface area).
g) The amount of silica added was adjusted to be 5.4% and 13.5%. The suspension thus obtained was allowed to stand in a constant temperature bath kept at 80 ° C., and ethanol was evaporated to obtain various dry powders. Each of these powders is 1100 ° C,
Baking was performed at 1200 ° C., 1300 ° C., and 1400 ° C. for 5 hours, respectively.
【００１５】このようにして得られた各種表面処理アル
ミナ及び比較のためのＴＭ１００の焼成物である比較試
料について、各比表面積をＢＥＴ法で測定した。その結
果を図１にグラフで示す。これより、比表面積は、シリ
カ添加量２．７％のものの場合、１３００℃焼成で２３
ｍ2／ｇであり、特に１４００℃焼成で１７ｍ2／ｇと比
較的高い値を示すことが分る。また、これらの焼成試料
はいずれもＸ線回折により結晶相がα相であることが確
認された。The specific surface areas of the various surface-treated alumina thus obtained and a comparative sample which was a burned material of TM100 for comparison were measured by the BET method. The results are shown graphically in FIG. From this, the specific surface area is 23 at 1300 ° C. when the amount of silica added is 2.7%.
It is found that the value is m 2 / g, and in particular, it shows a relatively high value of 17 m 2 / g at 1400 ° C. firing. Also, it was confirmed by X-ray diffraction that the crystal phase of each of these fired samples was the α phase.
【００１６】また、本発明の表面処理アルミナは比較試
料に比べ、１１００℃以上、特に１２００℃以上の高温
での比表面積がはるかに大きいことが分る。Further, it can be seen that the surface-treated alumina of the present invention has a much larger specific surface area at a high temperature of 1100 ° C. or higher, particularly 1200 ° C. or higher, as compared with the comparative sample.
【図１】 本発明の１例のアルミナ及び比較試料につい
ての比表面積と焼成温度との関係を示すグラフ。FIG. 1 is a graph showing the relationship between specific surface area and firing temperature for one example of the alumina of the present invention and a comparative sample.
Claims (1)
アルミナを形成させ、次いでこれを有機溶媒に懸濁さ
せ、テトラアルコキシシランを加え、乾燥したのち、１
１００℃以上で焼成することを特徴とする、高温での高
比表面積を有する表面処理アルミナの製造方法。1. Ammonium dawsonite is pyrolyzed to form alumina, which is then suspended in an organic solvent, tetraalkoxysilane is added, and after drying, 1
A method for producing a surface-treated alumina having a high specific surface area at a high temperature, which comprises calcination at 100 ° C. or higher.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5077659A JPH0688781B2 (en) | 1993-03-11 | 1993-03-11 | Method for producing surface-treated alumina having high specific surface area at high temperature |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5077659A JPH0688781B2 (en) | 1993-03-11 | 1993-03-11 | Method for producing surface-treated alumina having high specific surface area at high temperature |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06263435A JPH06263435A (en) | 1994-09-20 |
| JPH0688781B2 true JPH0688781B2 (en) | 1994-11-09 |
Family
ID=13640009
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5077659A Expired - Lifetime JPH0688781B2 (en) | 1993-03-11 | 1993-03-11 | Method for producing surface-treated alumina having high specific surface area at high temperature |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0688781B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4447283B2 (en) | 2003-11-05 | 2010-04-07 | 東京応化工業株式会社 | Coating liquid for silica-based film formation |
| JP4982953B2 (en) * | 2005-02-14 | 2012-07-25 | 日産自動車株式会社 | Resin composition, method for producing resin composition, automotive member, building member, and optical component |
-
1993
- 1993-03-11 JP JP5077659A patent/JPH0688781B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06263435A (en) | 1994-09-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |