JP4588856B2

JP4588856B2 - Organic substance decomposition method and decomposition apparatus using photocatalyst structure

Info

Publication number: JP4588856B2
Application number: JP2000295763A
Authority: JP
Inventors: 竜司増田; 弘幸末次; 茂男千葉
Original assignee: Nippon Muki Co Ltd
Current assignee: Nippon Muki Co Ltd
Priority date: 2000-09-28
Filing date: 2000-09-28
Publication date: 2010-12-01
Anticipated expiration: 2020-09-28
Also published as: JP2002102656A

Description

【０００１】
【産業上の利用分野】
本発明は、無機質繊維スリーブを基材とした光触媒構造体を用いた気相や液相での有機物分解方法並びに分解装置に関する。さらに詳しくは、比較的長寿命で大処理量が可能な光触媒式有機物分解方法と分解装置を提供することを目的とする。
【０００２】
【従来の技術】
従来、無機質繊維スリーブを基材とした光触媒構造体は、形状保持性が高く、高い反応活性を有し、比較的軽量な材料として、気相や液相中の有機物分解に用いられている。この光触媒構造体を有機物分解に使用する方法として、特開平１０−２８８６７号公報に記載されているように、筒状に賦形した光触媒構造体を処理流体の経路である反応管の中に設置し、さらに筒状の光触媒構造体の中に光源を配置する方法、いわゆる内部照射方式が一般にとられてきた。この方法は、反応サイトである光触媒構造体と処理流体が効率良く接触することや、光源と光触媒構造体が比較的近接しているため光エネルギを効率良く利用できることなどの利点があった。
【０００３】
【発明が解決しようとする課題】
しかしながら、前記内部照射式では光源が気体や液体などの処理流体に直接暴露されるため、光源の構成材であるガラス管の表面などが徐々に汚れ、時間とともに効率が低下するといった問題があった。特に処理流体が液相である場合、液相中のＣａなどの無機成分によって表面汚れが大きく、長期間の連続使用は困難であった。
また、流体経路内に光源があるため構造抵抗が大きく、大きな流量をとることができないといった欠点があった。
本発明は、これら従来技術の欠点を解消し、光源の汚れによる効率低下を抑制し、かつ大流量を処理できる有機物分解方法を提案する。
【０００４】
【課題を解決するための手段】
本発明者らは、前記欠点を解決するため鋭意検討の結果、光源を反応管の外部に配置し、反応管の中に光触媒構造体を充填させることにより、光源の汚れによる効率低下を抑制し、かつ大流量を処理できることを見出し、本発明を完成させた。即ち、本発明の有機物分解方法は請求項１に記載の通り、内径２〜５０ｍｍの無機質繊維スリーブに光触媒を担持させ賦形させた筒状あるいはラシヒリング状の光触媒構造体を、光透過性のある反応管内に複数個を当接するようにして充填し、前記無機質繊維スリーブが酸化珪素を主成分とする無機質繊維で構成され、前記光触媒は、主成分が酸化チタンとし、前記光触媒構造体は、組成式ＡＯｘで表される酸化物を主成分とする無機質繊維スリーブを基材とし、該基材にＢＯｙで表される光触媒をＡ−Ｏ−Ｂなる結合層を介して被覆して構成され、前記光透過性のある反応管の材質が、ガラス、石英ガラス、フッ素樹脂の何れかから構成し、該反応管内に被処理流体を通過させつつ外部から光を照射することを特徴とする。
本発明の有機物分解装置は請求項２に記載の通り、光透過性のある反応管内に、内径２〜５０ｍｍの無機質繊維スリーブに光触媒を担持させ賦形させた筒状あるいはラシヒリング状の光触媒構造体を複数個を当接するようにして充填し、該反応管の外部に光源を備えるようにし、前記無機質繊維スリーブが酸化珪素を主成分とする無機質繊維で構成され、前記光触媒は、主成分が酸化チタンとし、前記光触媒構造体は、組成式ＡＯｘで表される酸化物を主成分とする無機質繊維スリーブを基材とし、該基材にＢＯｙで表される光触媒をＡ−Ｏ−Ｂなる結合層を介して被覆して構成され、前記光透過性のある反応管の材質が、ガラス、石英ガラス、フッ素樹脂の何れかから構成したことを特徴とする。
【０００５】
【発明の実施の形態】
前記無機質繊維スリーブは、筒状の形状を達成するためには予め管状に編んだ繊維加工品を用いる必要があり、この無機質繊維スリーブの内径（ｍｍ）及び単重（ｇ／ｍ）は、特に限定されるものではないが、取り扱い性や酸化物の担持量の関係から、２〜５０ｍｍ、２〜１３０ｇ／ｍとする。
【０００６】
また、無機質繊維スリーブの材質は、ガラスやセラミック等、主成分としてＡ＝Ｓｉ、Ａｌ、Ｔｉ、Ｚｒ等の酸化物を有するものであればよい。なかでも、酸化物薄膜と強固な結合を形成できる酸化珪素を主成分とした無機質繊維体が好ましい。ここでいう、酸化珪素を含む無機質繊維とは、例えば、石英ガラス、高石英ガラス、Ｅガラス、Ｃガラス、Ｓガラス、Ａガラス等からなる繊維が挙げられるが、経済性からＥガラス繊維が好ましい。無機質繊維の平均繊維径は、特に限定されるものではないが、製造可能でしかも繊維体に加工するのが容易であることから、０．１〜２０ミクロンが好ましい。
【０００７】
前記光触媒としては、Ｂ＝Ｔｉ，Ｚｎなどの酸化物等、数多くのものが提案されているが、分解効率や安全性、安定性の点から酸化チタンとする。また、該酸化チタンに、白金、パラジウム、ロジウム、金、銀、銅等の貴金属あるいはそれらの貴金属塩類を担持させても良い。
【０００８】
反応管は、外部に設置した光源の光エネルギを内部の光触媒構造体に到達させることが必要であるため、光透過性の材質を用いる。主にガラス、石英ガラス、光透過型フッ素樹脂などの材質が有効である。特に液相系で用いる場合には、汚れを防止するために光透過型フッ素樹脂の使用が効果的である。
【０００９】
光源は、低圧水銀灯や殺菌灯あるいはブラックライト蛍光灯等を用いるとよいが、反応速度を考慮しなければ一般蛍光灯でもかまわない。
【００１０】
【実施例】
次に、より具体的な実施例を比較例と共に説明する。
（参考例１）
内径５ｍｍφのＥガラス繊維スリーブに酸化チタンを担持させた光触媒構造体を、１ｍの長さに切断し円筒状光触媒構造体１１を作製した。この構造体を内径４５ｍｍφの光透過型フッ素樹脂製反応管２の中に充填した。光源３は三共電気（株）製殺菌ランプＧＬ−４０を用い反応管２の外部に配置した。
【００１１】
この反応管２にトリクロロエチレンを含む排水をポンプで送り、このときの通過流量とトリクロロエチレン分解率を測定した。結果、表１に示すようにトリクロロエチレン分解率はほとんど低下することなく、処理流量を１５ｌ／ｍｉｎと大きくすることが可能となった。また、３０００時間経過後の分解率もほとんど低下することなく、長寿命であることが明らかになった。
ここで、図１は、参考例の円筒状光触媒構造体の外観図である。また、図２は、前記円筒状光触媒構造体を組み込んだ有機物分解方法の一例である。
【００１２】
（実施例２）
内径５ｍｍφのＥガラス繊維スリーブに酸化チタンを担持させた光触媒構造体を、２０ｍｍの長さに切断しラシヒリング状光触媒構造体１２を作製した。この構造体を内径４５ｍｍφの光透過型フッ素樹脂製反応管２の中に充填した。光源３は三共電気（株）製殺菌ランプＧＬ−４０を用い反応管２の外部に配置した。
【００１３】
この反応管２にトリクロロエチレンを含む排水をポンプで送り、このときの通過流量とトリクロロエチレン分解率を測定した。結果、表１に示すようにトリクロロエチレン分解率はほとんど低下することなく、処理流量を１０ｌ／ｍｉｎと大きくすることが可能となった。また、３０００時間経過後の分解率もほとんど低下することなく、長寿命であることが明らかになった。
ここで、図３は本実施例のラシヒリング状光触媒構造体の外観図である。また、図４は、前記ラシヒリング状光触媒構造体を組み込んだ有機物分解方法の一例である。
【００１４】
（比較例）
比較例として、従来の内部照射方式について説明する。
内径４０ｍｍφのＥガラス繊維スリーブに酸化チタンを担持させた光触媒構造体を、１ｍの長さに切断し大円筒状光触媒構造体１３を作製した。この構造体を内径４５ｍｍφの光透過型フッ素樹脂製反応管２の中に充填した。光源３は三共電気（株）製殺菌ランプＧＬ−４０を用い大円筒状光触媒構造体１３の内部に配置した。
【００１５】
この反応管２にトリクロロエチレンを含む排水をポンプで送り、このときの通過流量とトリクロロエチレン分解率を測定した。結果、表１に示すようにトリクロロエチレン分解率はほとんど変わらないが、処理流量が３ｌ／ｍｉｎと非常に小さく大流量処理には不向きであることが明らかになった。また、３０００時間経過後の分解率は、初期の１／２と小さくなり、光源の汚れによる性能低下が起こっていることが明らかになった。
ここで、図５は本比較例の大円筒状光触媒構造体の外観図である。また、図６は、前記大円筒状光触媒構造体を組み込んだ内部照射方式の比較例である。
【００１６】
【表１】

【００１７】
【発明の効果】
このように、本発明によれば、長寿命かつ大処理量が達成可能な光触媒式有機物分解方法と分解装置を提供することができる。
【図面の簡単な説明】
【図１】参考例に用いる円筒状光触媒構造体の一例を示したものである。
【図２】参考例の有機物分解方法の一例を示したもので、円筒状光触媒構造体を充填した反応管の外部に光源を配置したものである。
【図３】本発明に用いるラシヒリング状光触媒構造体の一例を示したものである。
【図４】本発明の有機物分解方法の一例を示したもので、ラシヒリング状光触媒構造体を充填した反応管の外部に光源を配置したものである。
【図５】比較例に用いた大円筒状光触媒構造体の一例を示したものである。
【図６】比較例の有機物分解方法の一例を示したもので、大円筒状光触媒構造体の内部に光源を配置したものである。
【符号の説明】
２反応管
３光源
１１円筒状光触媒構造体
１２ラシヒリング状光触媒構造体
１３大円筒状光触媒構造体[0001]
[Industrial application fields]
The present invention relates to a method for decomposing an organic substance in a gas phase or a liquid phase and a decomposing apparatus using a photocatalyst structure based on an inorganic fiber sleeve. More specifically, an object of the present invention is to provide a photocatalytic organic matter decomposition method and a decomposition apparatus capable of a relatively long life and a large throughput.
[0002]
[Prior art]
Conventionally, a photocatalyst structure based on an inorganic fiber sleeve has a high shape retention, a high reaction activity, and a relatively lightweight material, which has been used for organic matter decomposition in a gas phase or a liquid phase. As a method of using this photocatalyst structure for organic substance decomposition, as described in JP-A-10-28867, a photocatalyst structure shaped like a cylinder is installed in a reaction tube that is a path of a processing fluid. Furthermore, a method of arranging a light source in a cylindrical photocatalyst structure, that is, a so-called internal irradiation method has been generally employed. This method has advantages such as efficient contact between the photocatalyst structure, which is a reaction site, and the processing fluid, and efficient utilization of light energy because the light source and the photocatalyst structure are relatively close to each other.
[0003]
[Problems to be solved by the invention]
However, in the internal irradiation type, since the light source is directly exposed to a processing fluid such as gas or liquid, there is a problem that the surface of the glass tube, which is a constituent material of the light source, is gradually soiled and the efficiency decreases with time. . In particular, when the processing fluid is in a liquid phase, surface contamination is large due to inorganic components such as Ca in the liquid phase, and long-term continuous use is difficult.
In addition, since there is a light source in the fluid path, there is a disadvantage that the structure resistance is large and a large flow rate cannot be obtained.
The present invention proposes a method for decomposing organic substances that eliminates the drawbacks of these prior arts, suppresses a decrease in efficiency due to contamination of the light source, and can process a large flow rate.
[0004]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned drawbacks, the present inventors have arranged a light source outside the reaction tube and filled the photocatalyst structure in the reaction tube, thereby suppressing a decrease in efficiency due to contamination of the light source. In addition, the present inventors have found that a large flow rate can be processed and completed the present invention. That is, the organic matter decomposing method of the present invention, as described in claim 1, is a light-transmitting cylindrical or Raschig ring-shaped photocatalyst structure formed by supporting a photocatalyst on an inorganic fiber sleeve having an inner diameter of 2 to 50 mm. A plurality of the reaction tubes are filled in contact with each other, the inorganic fiber sleeve is composed of inorganic fibers mainly composed of silicon oxide, the photocatalyst is composed mainly of titanium oxide, and the photocatalyst structure is composed of An inorganic fiber sleeve mainly composed of an oxide represented by the formula AOx is used as a base material, and the base material is coated with a photocatalyst represented by BOy via a bonding layer of A-O-B, The material of the light-transmitting reaction tube is made of any one of glass, quartz glass, and fluororesin, and light is irradiated from the outside while allowing the fluid to be processed to pass through the reaction tube .
As the organic matter decomposition apparatus of the present invention according to claim 2, the optical transparency is the reaction tube, the tube was shaped by supporting photocatalyst inorganic fiber sleeve having an inner diameter of 2~50mm like or Raschig shaped photocatalyst structure A plurality of abutments, a light source is provided outside the reaction tube , the inorganic fiber sleeve is composed of inorganic fibers containing silicon oxide as a main component, and the photocatalyst is mainly oxidized. Titanium is used, and the photocatalyst structure has an inorganic fiber sleeve whose main component is an oxide represented by the composition formula AOx as a base material, and the photocatalyst represented by BOy is a bonding layer of AOB on the base material. The light-transmitting reaction tube is made of any one of glass, quartz glass, and fluororesin .
[0005]
DETAILED DESCRIPTION OF THE INVENTION
In order to achieve a cylindrical shape, the inorganic fiber sleeve needs to use a fiber processed product knitted in advance in a tubular shape. The inner diameter (mm) and the single weight (g / m) of the inorganic fiber sleeve are particularly Although not limited, it is set to 2 to 50 mm and 2 to 130 g / m in view of handling properties and oxide loading .
[0006]
The material of the inorganic fiber sleeve may be any material such as glass or ceramic that has an oxide such as A = Si, Al, Ti, or Zr as a main component. Among these, an inorganic fiber body mainly composed of silicon oxide capable of forming a strong bond with the oxide thin film is preferable. Examples of the inorganic fiber containing silicon oxide include fibers made of quartz glass, high quartz glass, E glass, C glass, S glass, A glass, etc., but E glass fiber is preferable from the viewpoint of economy. . The average fiber diameter of the inorganic fibers is not particularly limited, but is preferably 0.1 to 20 microns because it can be manufactured and can be easily processed into a fiber body.
[0007]
Many photocatalysts such as oxides such as B = Ti and Zn have been proposed, but titanium oxide is used from the viewpoint of decomposition efficiency, safety, and stability. Moreover, you may carry | support noble metals, such as platinum, palladium, rhodium, gold | metal | money, silver, copper, or those noble metal salts on this titanium oxide.
[0008]
The reaction tube is made of a light-transmitting material because it is necessary for the light energy of the light source installed outside to reach the internal photocatalyst structure. Mainly materials such as glass, quartz glass, and light transmission type fluororesin are effective. In particular, when used in a liquid phase system, it is effective to use a light transmission type fluororesin in order to prevent contamination.
[0009]
The light source may be a low-pressure mercury lamp, a germicidal lamp, a black light fluorescent lamp, or the like, but a general fluorescent lamp may be used if the reaction rate is not taken into consideration.
[0010]
【Example】
Next, more specific examples will be described together with comparative examples.
(Reference Example 1)
A photocatalyst structure in which titanium oxide was supported on an E glass fiber sleeve having an inner diameter of 5 mmφ was cut into a length of 1 m to produce a cylindrical photocatalyst structure 11. This structure was filled into a light transmission type fluororesin reaction tube 2 having an inner diameter of 45 mmφ. The light source 3 was disposed outside the reaction tube 2 using a sterilization lamp GL-40 manufactured by Sankyo Electric Co., Ltd.
[0011]
Waste water containing trichlorethylene was pumped into the reaction tube 2 and the passing flow rate and trichloroethylene decomposition rate at this time were measured. As a result, as shown in Table 1, it was possible to increase the treatment flow rate to 15 l / min with almost no decrease in the decomposition rate of trichlorethylene. Moreover, it became clear that it has a long lifetime, with the decomposition rate after 3000 hours hardly decreasing.
Here, FIG. 1 is an external view of a cylindrical photocatalyst structure of a reference example . Moreover, FIG. 2 is an example of the organic substance decomposition | disassembly method incorporating the said cylindrical photocatalyst structure.
[0012]
(Example 2)
A photocatalyst structure in which titanium oxide was supported on an E glass fiber sleeve having an inner diameter of 5 mmφ was cut into a length of 20 mm to produce a Raschig ring-shaped photocatalyst structure 12. This structure was filled into a light transmission type fluororesin reaction tube 2 having an inner diameter of 45 mmφ. The light source 3 was disposed outside the reaction tube 2 using a sterilization lamp GL-40 manufactured by Sankyo Electric Co., Ltd.
[0013]
Waste water containing trichlorethylene was pumped into the reaction tube 2 and the passing flow rate and trichloroethylene decomposition rate at this time were measured. As a result, as shown in Table 1, it was possible to increase the treatment flow rate to 10 l / min with almost no decrease in the decomposition rate of trichlorethylene. Moreover, it became clear that it has a long lifetime, with the decomposition rate after 3000 hours hardly decreasing.
Here, FIG. 3 is an external view of the Raschig ring-like photocatalyst structure of the present embodiment. FIG. 4 is an example of an organic matter decomposition method incorporating the Raschig ring-like photocatalyst structure.
[0014]
(Comparative example)
As a comparative example, a conventional internal irradiation method will be described.
A photocatalyst structure in which titanium oxide was supported on an E glass fiber sleeve having an inner diameter of 40 mmφ was cut to a length of 1 m to produce a large cylindrical photocatalyst structure 13. This structure was filled into a light transmission type fluororesin reaction tube 2 having an inner diameter of 45 mmφ. The light source 3 was disposed inside the large cylindrical photocatalyst structure 13 using a sterilization lamp GL-40 manufactured by Sankyo Electric Co., Ltd.
[0015]
Waste water containing trichlorethylene was pumped into the reaction tube 2 and the passing flow rate and trichloroethylene decomposition rate at this time were measured. As a result, as shown in Table 1, the trichlorethylene decomposition rate hardly changed, but the treatment flow rate was as small as 3 l / min, and it became clear that it was not suitable for high flow treatment. In addition, the decomposition rate after lapse of 3000 hours was reduced to 1/2 of the initial value, and it was revealed that the performance was deteriorated due to contamination of the light source.
Here, FIG. 5 is an external view of the large cylindrical photocatalyst structure of this comparative example. FIG. 6 is a comparative example of the internal irradiation method incorporating the large cylindrical photocatalyst structure.
[0016]
[Table 1]

[0017]
【The invention's effect】
Thus, according to the present invention, it is possible to provide a photocatalytic organic matter decomposition method and a decomposition apparatus that can achieve a long life and a large throughput.
[Brief description of the drawings]
FIG. 1 shows an example of a cylindrical photocatalyst structure used in a reference example .
FIG. 2 shows an example of a method for decomposing organic substances of a reference example , in which a light source is arranged outside a reaction tube filled with a cylindrical photocatalyst structure.
FIG. 3 shows an example of a Raschig ring-shaped photocatalyst structure used in the present invention.
FIG. 4 shows an example of the organic substance decomposition method of the present invention, in which a light source is arranged outside a reaction tube filled with a Raschig ring-like photocatalyst structure.
FIG. 5 shows an example of a large cylindrical photocatalyst structure used in a comparative example.
FIG. 6 shows an example of a method for decomposing an organic substance according to a comparative example, in which a light source is disposed inside a large cylindrical photocatalyst structure.
[Explanation of symbols]
2 Reaction tube 3 Light source 11 Cylindrical photocatalyst structure 12 Raschig ring-like photocatalyst structure 13 Large cylindrical photocatalyst structure

Claims

A cylindrical or Raschig ring-shaped photocatalyst structure in which a photocatalyst is supported and shaped on an inorganic fiber sleeve having an inner diameter of 2 to 50 mm is filled so as to contact a plurality in a light-transmitting reaction tube,
The inorganic fiber sleeve is composed of inorganic fibers mainly composed of silicon oxide, the photocatalyst is composed mainly of titanium oxide, and the photocatalyst structure is composed mainly of an oxide represented by a composition formula AOx. A fiber sleeve is used as a base material, and the base material is coated with a photocatalyst represented by BOy through a bonding layer of A-O-B.
The material of the light-transmitting reaction tube is composed of any one of glass, quartz glass, and fluororesin,
A method for decomposing an organic substance, comprising irradiating light from outside while allowing a fluid to be treated to pass through the reaction tube.

A reaction tube having light permeability is filled with a cylindrical or Raschig ring-shaped photocatalyst structure formed by supporting and shaping a photocatalyst on an inorganic fiber sleeve having an inner diameter of 2 to 50 mm, and the reaction tube as comprising a light source to the outside,
The inorganic fiber sleeve is composed of inorganic fibers mainly composed of silicon oxide, the photocatalyst is composed mainly of titanium oxide, and the photocatalyst structure is composed mainly of an oxide represented by a composition formula AOx. A fiber sleeve is used as a base material, and the base material is coated with a photocatalyst represented by BOy through a bonding layer of A-O-B.
An organic matter decomposing apparatus, wherein the light-transmitting reaction tube is made of glass, quartz glass, or fluororesin .