JP4081546B2 - Air purification method and apparatus using sunlight - Google Patents
Air purification method and apparatus using sunlight Download PDFInfo
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- JP4081546B2 JP4081546B2 JP2003148951A JP2003148951A JP4081546B2 JP 4081546 B2 JP4081546 B2 JP 4081546B2 JP 2003148951 A JP2003148951 A JP 2003148951A JP 2003148951 A JP2003148951 A JP 2003148951A JP 4081546 B2 JP4081546 B2 JP 4081546B2
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- Separation Of Gases By Adsorption (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
- Disinfection, Sterilisation Or Deodorisation Of Air (AREA)
Description
【０００１】
【発明の属する技術分野】
大気中の有害化学物質を効率的に分解除去する大気浄化方法及びその方法に用いられる装置に関するものである。
【０００２】
【従来の技術】
光触媒は、光を吸収して活性酸素種を生成し化学反応を引き起こすものであり、この化学反応を利用して、室内環境中や大気環境中の有害化学物質を酸化・分解させる技術が研究開発されており、既に一部では実用化されている。光触媒が作用するには光照射を必要とし、その光源には、キセノン灯、水銀灯、ブラックライトなどの人工光源または太陽光という自然光源が用いられる。ところが、人工光源を用いる場合には電力を必要とするため、エネルギー消費及びランニングコストを低く抑えることは困難である。また、太陽光を用いる場合、太陽光が十分に得られない時間帯には、反応効率が低下したり、反応が停止するという問題があった。
【０００３】
そこで、発熱体に吸着材と光触媒を担持させ、その吸着材に反応対象物質を吸着させた後、通電加熱により対象物質を吸着材より脱離させると同時に光照射を行い、反応対象物質の分解を行う方法が検討されている（例えば、特許文献１参照）が、この方法は、人工光源を用いた時と同じく、エネルギー消費が大きく、ランニングコストが高いという問題がある。
また、太陽光集光器を用いて得られる高温を利用した触媒反応・反応システム（例えば、特許文献２参照）が提案され、その実用化研究が進められているが、日射条件に恵まれた砂漠地帯などにおける使用に限られており、四季があり一年を通して日射条件の変化の大きい我が国においては、実用化は殆ど進んでいないのが現状である。
【０００４】
【特許文献１】
特開２００１−１７８８０３号公報
【特許文献２】
特開２０００−１０２５９７号公報
【０００５】
【発明が解決しようとする課題】
ところで、太陽光を用いて光触媒反応を行う場合、日照条件の悪い日や夜間には光が不足することから反応を進行させることができない。最近、光触媒反応を利用した空気浄化が検討されているが、実際の空気汚染は連続的に起きているため、２４時間かつ通年利用できる空気浄化システムの出現が要望されている。光が不足した時に人工光源を点灯したり、他のシステムを用いて空気浄化を行う方法も考えられるが、コスト、エネルギー及び簡便性などに問題がある。これらの問題を解決する方法として、太陽光のみを利用する汚染空気の連続的処理を可能とする新たなシステムの構築が求められる。
【０００６】
本発明は、従来の技術における上記した実状に鑑みてなされたものである。すなわち、本発明の目的は、太陽光を主なエネルギー源に用いて大気中の有害な化学物質を吸着及び触媒反応により連続的に分解除去し、環境汚染ガスを安価で簡便に処理できる大気浄化方法及びその方法に用いられる大気浄化装置を提供することにある。
【０００７】
【課題を解決するための手段】
本発明者らは、太陽光を用いる環境汚染物質の除去法について鋭意検討を重ねた結果、太陽光集光器と吸着材を複合的に利用することにより、太陽熱を有効に活用して大気中の有害化学物質を吸着し、その脱着を制御した後に光触媒で分解処理して有害化学物質を効率的に除去できることを見出し、本発明を完成させるに至った。
【０００８】
すなわち、本発明は、大気中の有害化学物質を吸着材に吸着させた後、該有害化学物質を光触媒により分解除去させる大気浄化方法において、太陽光集光器で集光される太陽光を受光して吸着材及び光触媒の加熱温度を調整し、有害化学物質の吸着及び脱着を制御した後、脱着した有害化学物質を光触媒と接触させて分解させることを特徴とする太陽光を利用した大気浄化方法を提供するものである。
また、本発明は、太陽光集光器と、その集光器で集光される太陽光を受光する部位に大気中の有害化学物質を吸着する吸着材とその吸着された有害化学物質を分解させる光触媒とを備えてなり、該集光器で集光される太陽光により吸着材及び光触媒の加熱温度が調整され、吸着材による有害化学物質の吸着及び脱着を制御し、脱着した有害化学物質を光触媒により分解させることを特徴とする太陽光を利用した大気浄化装置を提供するものである。
【０００９】
【発明の実施の形態】
本発明は、太陽光集光器、吸着材及び光触媒を組み合わせ、太陽光を利用して大気中に含まれる有害化学物質を自動的かつ連続的に反応させて除去する大気浄化方法及びそれに用いる装置である。この場合、太陽光集光器の焦点部位に、その集光を利用する吸着材を充填した管状体（吸脱着カラム）を配置することが重要であり、これによって太陽光の集光熱を用いる吸着材の温度変化により吸・脱着を制御するものである。
【００１０】
本発明方法によると、日射条件の悪い時間帯には、吸脱着カラムの温度は低く、有害化学物質は吸着材により空気から取り除かれる。一方、日射条件の良好な時間帯には、吸脱着カラムの温度は上昇し、吸着材から有害化学物質は脱着されて、反応器内の光触媒により反応させる。このことから、有害化学物質を含む大気を吸脱着カラムに連続的に供給して有害化学物質を吸着材に吸着させ、太陽光が十分に照射されているときに限り触媒反応器に送り込んで反応させることができる。この方法及び装置を用いると、工場及び家庭などから連続して空気中に排出される有機溶剤、臭気物質及び排気ガス等の有害化学物質を常時除去し、分解させることが可能となる。
【００１１】
以下、本発明を、代表的な装置を参照して詳細に説明する。
１）本発明に用いられる集光器としては、図１に見られるように、太陽光を集光し熱エネルギー及び光エネルギーとして利用できる構造及び形状を有するものであればよく、例えば、雨どい（トラフ）型、タワー型、複合パラボラ集光型（ＣＰＣ）等のミラー、フレネル型等のレンズなどが挙げられ、また、それにより得られる加熱温度によって吸着材による有害化学物質の吸・脱着をコントロールできるものであれば、いずれも使用可能である。その集光器のミラーとしては、ガラスなどの透明な無機材料やアクリル樹脂などのプラスチック製の基材に、アルミニウムなどの光反射に有効な金属類を蒸着し、シリカなどの無機材料で保護したものが望ましいが、太陽光を集光できるものであれば、その他の材質も使用可能である。その形状としては、曲面状に成形した基材にミラーを付けたものでも、平板ミラーを曲面状に湾曲させたものでもよい。
【００１２】
２）集光器は、一年を通じて太陽光を十分に受光できる駆動手段が設けられていることが好ましい。その駆動方式は、太陽光の照射角度の変化に対応できるものであって、通常、図１（ａ）の２軸方式と（ｂ）の１軸方式が考えられる。２軸方式は定常的に比較的高温が得られるのに対し、１軸方式はコストが低く、大規模化しやすい利点を有する。集光時間が短くても良い場合には、駆動軸が無くても良い（図６参照）。
【００１３】
３）吸着材としては、吸着力の大きい高表面積のものであって、かつ数百度の高温に耐え得る耐熱性のものが好ましく、例えば、ゼオライト、炭素材料、シリカ、アルミナ、多孔質ガラスなどが挙げられるが、吸着対象とする物質や環境に応じて選択する必要がある。また、吸着材自体に金属微粒子を担持して、触媒作用を持たせたものでも良い。
【００１４】
４）光触媒反応器は、酸化チタン、酸化亜鉛、酸化タングステンなどの光触媒、またはこれらを酸化チタン、シリカ、アルミナ、ゼオライトなどの担体に担持した光触媒、またはこれらに白金、ロジウム、銀などの金属を担持した光触媒（触媒）と、主にガラスなどの光透過性材料で構成されている。形態としては、固定床式、流動層式などのいずれの方式も使用可能である。
【００１５】
５）太陽光集光器には、有害化学物質（対象物質）を含むガス気流の流れに対し、順に上記の吸着材及び触媒反応器を配置する。図２(a)は、その１例を示すものであり、吸着材カラムと触媒反応器が同心円上に配置されている。図２(b)のように、ミラー自身に光触媒を担持する方法も採用できる。
【００１６】
本発明方法では、有害化学物質（対象物質）を含むガス気流は、まず吸着材充填層を通り、対象物質が吸着材に吸着される。その際、曇り、雨天のような日射条件の悪い時間帯では温度が低く抑えられるために、優先的に吸着が起こる。日射条件の良い時間帯では、これら吸着した対象物質が温度上昇により吸着材から脱着して触媒反応器に移送され、光・熱による触媒反応が行われる。
【００１７】
本発明においては、大気中に放出され大気汚染の原因となる工場排ガス、都市排ガス、家庭内の汚染された空気のように、ベンゼン、トルエン、キシレンなどの炭化水素類、アセトアルデヒドなどのアルデヒド類、臭化物、アンモニア、酢酸などの臭い成分、一酸化炭素、窒素酸化物などの有害化学物質を含む空気を、吸着材を充填したカラムなどの一定の流路内を通すことにより、太陽光量に応じて自動的に吸着または脱着が選択されることから、単純な処理システムの形成が可能である。また、必要なエネルギーは太陽光と集光器を駆動させる僅かな電力で十分なため、省エネルギーで低コストである。また、用いる吸着材は、太陽光量が十分な時間帯に自動的に再活性化されるため、吸着材を交換する必要がなくなり、メンテナンスも容易である。このことから、室内環境中や大気環境中の有害化学物質の酸化・分解による環境汚染物質の除去に有用である。
【００１８】
【実施例】
以下、本発明を実施例によりさらに具体的に説明するが、本発明はこれらの実施例によって何ら限定されるものではない。
実施例１
大気浄化装置として、下記する太陽光集光ミラーと透明なガラス製同心円２重管を備えた装置を用いた。
まず、２次元パラボラ型に成形したガラス基板の裏面に、アルミニウム薄膜の反射層とシリカの保護層を順に蒸着し、太陽光入射面積が１．００ｍ２のパラボラトラフミラーからなる集光器を作成した。この集光器は、２方向のステップモーターにより常に太陽光の方向にミラーの垂直方向を合わせることができる。
次に、そのパラボラトラフミラーに太陽光を照射した際に形成される直線状の焦点部位に円筒形の同心円２重ガラス管（２重パイレックス（登録商標）管、ほう珪酸ガラス製）を設置した（図１（ａ））。この２重パイレックス（登録商標）管は、吸着材による吸脱着カラム、受光器及び光触媒反応器の３種の役割を果すものであり、その断面図を図２に示す。
その２重パイレックス（登録商標）管の内側管内には、活性炭ペレットを充填し、その活性炭ペレットは、集光された太陽光を吸収して熱に変換する受光器及び吸着材として作用させた。また、その内側パイレックス（登録商標）管の外周面には酸化チタンを含む光触媒を塗布し、その外側は他のパイレックス（登録商標）管でカバーして、その間を光触媒反応器とした。
【００１９】
汚染空気は、吸脱着カラムを通った後、反応器へと導かれて浄化され、その後に排出された。観測された紫外線強度と吸脱着カラム（受光器）の温度を、図３に示す。午前１０時から午後２時までの間、３〜４ｍｗ／ｃｍ２の紫外線強度があり、吸脱着カラムの中心は２００〜２５０℃を保ち続けた。ここでは受光器を直径３ｃｍの円筒のものを用いたが、使用する円筒の直径を適宜調節することにより、最高温度を４００℃までの間で制御することができる。
図４には、１０ｐｐｍのトルエンを所定の温度にした吸着材（粒状活性炭）に流通させた時の流出濃度を示した。吸着材の温度が２００℃以下の場合には、９９．９％以上のトルエンが除去されており、２００℃を超えるとトルエンの放出が始まることが分かる。図４に見られるように、日照条件の良好な１０時頃までは吸脱着カラムの温度は２００℃以下であり、トルエンは吸脱着カラムに吸着される。午前１０時から午後２時までの４時間の間、吸脱着カラム（受光器）の温度は２００〜２５０℃になり、トルエンの脱着が起こった。その脱着したトルエンは光触媒反応器に導かれ、この際には３〜４ｍＷ／ｃｍ２の十分な紫外線強度があり、トルエンは迅速に炭酸ガスと水に分解された。
また、特願２００２−２５８０４５号に示す白金担持光触媒等を用いた場合には、集光した熱を併用してさらに高い分解能力を発揮した（図５）。図５は、トルエン濃度１５ｐｐｍの空気（湿度８０％）を０．２重量％の白金担持酸化チタン触媒反応器に流速２００ｍｌ／分で通した時の光触媒温度とトルエン分解速度との関係を示す。
一般に、日照条件が悪くなる午後３時以降には、吸脱着カラムの温度が２００℃以下に低下するため、トルエンは吸着材に吸着されており光触媒反応器には到達しない。そのため、光量が不十分であるために不完全な反応が生起して中間体を放出したり失活が起こる可能性を大きく低減できる。ここで吸着されたトルエンは、次回の日照条件の良い時に脱着されて光触媒反応器中で接触分解される。
【００２０】
【発明の効果】
本発明によれば、太陽光を有効利用して、空気浄化を日照条件に因らずに連続的かつ省エネルギー的に容易に行うことができるから、本発明の方法及び装置は工業的実施に有用である。また、これらは、空気浄化以外の太陽光を利用する化学反応にも応用可能である。
【図面の簡単な説明】
【図１】 本発明に用いる太陽光集光器の一例を示す模式構成図である。
【図２】 本発明の装置において（ａ）は吸脱着カラム（受光器）と反応器とを同心円上に配置した構成の一断面図を示し、（ｂ）は集光器やカバーにも触媒を担持させた構成の一断面図を示す。
【図３】 太陽光集光の紫外線強度と吸脱着カラムの温度（実測値）の関係を示すグラフである。
【図４】 トルエンを含む空気を通したときの吸脱着カラムの温度と流出するトルエン濃度の関係を示すグラフである。
【図５】 トルエンを含む空気を通したときの光触媒温度とトルエン分解速度の 関係を示すグラフである。
【図６】 本発明における一例の大気洗浄装置の写真である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air purification method for efficiently decomposing and removing harmful chemical substances in the atmosphere and an apparatus used in the method.
[0002]
[Prior art]
A photocatalyst absorbs light and generates reactive oxygen species to cause a chemical reaction. Using this chemical reaction, technology to oxidize and decompose harmful chemical substances in indoor and atmospheric environments is researched and developed. Has already been put into practical use in some areas. The photocatalyst requires light irradiation, and an artificial light source such as a xenon lamp, a mercury lamp, or a black light or a natural light source such as sunlight is used as the light source. However, when an artificial light source is used, power is required, so it is difficult to keep energy consumption and running cost low. Moreover, when using sunlight, there existed a problem that reaction efficiency fell or reaction stopped in the time slot | zone when sunlight is not fully obtained.
[0003]
Therefore, after supporting the adsorbent and photocatalyst on the heating element and adsorbing the target substance to the adsorbent, the target substance is desorbed from the adsorbent by energization heating, and at the same time, light irradiation is performed to decompose the target substance. However, this method has the problem of high energy consumption and high running cost, as in the case of using an artificial light source.
In addition, a catalytic reaction / reaction system using a high temperature obtained using a solar concentrator has been proposed (for example, see Patent Document 2), and its practical application research is in progress. In Japan, where there are four seasons and the change in solar radiation conditions is large throughout the year, practical use has hardly progressed.
[0004]
[Patent Document 1]
JP 2001-178803 [Patent Document 2]
Japanese Patent Laid-Open No. 2000-102597 [0005]
[Problems to be solved by the invention]
By the way, when performing a photocatalytic reaction using sunlight, reaction cannot be advanced on day and night with bad sunshine conditions, since light runs short. Recently, air purification using a photocatalytic reaction has been studied. However, since actual air pollution occurs continuously, the appearance of an air purification system that can be used 24 hours a year is desired. Although a method of turning on an artificial light source when light is insufficient or performing air purification using another system is conceivable, there are problems in cost, energy, simplicity, and the like. As a method for solving these problems, it is required to construct a new system that enables continuous treatment of contaminated air using only sunlight.
[0006]
This invention is made | formed in view of the above-mentioned actual condition in a prior art. That is, an object of the present invention is to purify the atmosphere by using sunlight as a main energy source, continuously decomposing and removing harmful chemical substances in the atmosphere by adsorption and catalytic reaction, and processing environmental pollutant gases at a low cost. It is providing the method and the air purification apparatus used for the method.
[0007]
[Means for Solving the Problems]
As a result of intensive studies on a method for removing environmental pollutants using sunlight, the present inventors have effectively utilized solar heat in the atmosphere by using a solar concentrator and an adsorbent in combination. It was found that the harmful chemical substances can be adsorbed and the desorption is controlled and then decomposed with a photocatalyst to remove the harmful chemical substances efficiently, and the present invention has been completed.
[0008]
That is, the present invention receives sunlight collected by a solar concentrator in an air purification method in which harmful chemical substances in the atmosphere are adsorbed on an adsorbent and then decomposed and removed by a photocatalyst. After adjusting the heating temperature of the adsorbent and the photocatalyst to control the adsorption and desorption of harmful chemical substances, the desorbed harmful chemical substances are brought into contact with the photocatalyst and decomposed, and the atmosphere is purified using sunlight. A method is provided.
The present invention also provides a solar concentrator, an adsorbent that adsorbs harmful chemical substances in the atmosphere to a portion that receives sunlight collected by the concentrator, and decomposes the adsorbed harmful chemical substances. The adsorbent and the photocatalyst are heated by adjusting the heating temperature of the adsorbent and the photocatalyst by the sunlight collected by the concentrator, and control the adsorption and desorption of the hazardous chemical by the adsorbent. It is intended to provide an air purification device using sunlight, which is characterized in that it is decomposed by a photocatalyst.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a method for purifying air and a device used therefor, which combine a solar concentrator, an adsorbent and a photocatalyst to automatically and continuously react and remove harmful chemical substances contained in the air using sunlight. It is. In this case, it is important to arrange a tubular body (adsorption / desorption column) filled with an adsorbent that uses the light condensing at the focal point of the solar concentrator. Adsorption / desorption is controlled by changing the temperature of the material.
[0010]
According to the method of the present invention, the adsorption / desorption column temperature is low and the harmful chemical substances are removed from the air by the adsorbent during a period of bad solar radiation conditions. On the other hand, in the time zone with good solar radiation conditions, the temperature of the adsorption / desorption column rises, and harmful chemical substances are desorbed from the adsorbent and reacted with the photocatalyst in the reactor. For this reason, the atmosphere containing harmful chemical substances is continuously supplied to the adsorption / desorption column to adsorb the harmful chemical substances to the adsorbent, and sent to the catalytic reactor only when the sunlight is sufficiently irradiated. Can be made. By using this method and apparatus, it is possible to always remove and decompose harmful chemical substances such as organic solvents, odorous substances, and exhaust gas continuously discharged into the air from factories and homes.
[0011]
Hereinafter, the present invention will be described in detail with reference to typical apparatuses.
1) As shown in FIG. 1, the concentrator used in the present invention may have any structure and shape that can collect sunlight and use it as heat energy and light energy. (Trough) type, tower type, compound parabolic concentrator (CPC) and other mirrors, Fresnel type lenses etc. Any device that can be controlled can be used. As a mirror for the concentrator, metals effective for light reflection such as aluminum were vapor-deposited on a transparent base material such as glass or a plastic base material such as acrylic resin, and protected with an inorganic material such as silica. However, other materials can be used as long as they can collect sunlight. As the shape thereof, a base material formed into a curved surface may be attached with a mirror, or a flat mirror may be curved into a curved surface.
[0012]
2) It is preferable that the concentrator is provided with driving means that can sufficiently receive sunlight throughout the year. The driving method can cope with the change in the irradiation angle of sunlight, and the two-axis method shown in FIG. 1A and the one-axis method shown in FIG. While the biaxial system can constantly obtain a relatively high temperature, the monoaxial system has the advantages of low cost and a large scale. If the light collection time may be short, the drive shaft may be omitted (see FIG. 6).
[0013]
3) The adsorbent is preferably one having a high surface area with a large adsorbing power and heat resistance capable of withstanding a high temperature of several hundred degrees, such as zeolite, carbon material, silica, alumina, porous glass, etc. Although it is mentioned, it is necessary to select according to the substance to be adsorbed and the environment. Further, the adsorbent itself may be supported with metal fine particles to have a catalytic action.
[0014]
4) The photocatalytic reactor is a photocatalyst such as titanium oxide, zinc oxide or tungsten oxide, or a photocatalyst in which these are supported on a carrier such as titanium oxide, silica, alumina or zeolite, or a metal such as platinum, rhodium or silver. It consists of a supported photocatalyst (catalyst) and a light-transmitting material such as glass. As a form, any system such as a fixed bed system and a fluidized bed system can be used.
[0015]
5) In the solar concentrator, the adsorbent and the catalytic reactor are arranged in order with respect to the flow of the gas stream containing the hazardous chemical substance (target substance). FIG. 2 (a) shows an example, in which the adsorbent column and the catalyst reactor are arranged concentrically. A method of supporting a photocatalyst on the mirror itself as shown in FIG.
[0016]
In the method of the present invention, a gas stream containing a harmful chemical substance (target substance) first passes through the adsorbent packed bed, and the target substance is adsorbed by the adsorbent. At that time, the adsorption is preferentially performed because the temperature is kept low in a time zone where the solar radiation condition is bad such as cloudy or rainy weather. In the time zone with good solar radiation conditions, these adsorbed target substances are desorbed from the adsorbent due to the temperature rise and transferred to the catalytic reactor, where catalytic reaction by light and heat is performed.
[0017]
In the present invention, factory exhaust gas, city exhaust gas, and polluted air in the home, which are released into the atmosphere and cause air pollution, hydrocarbons such as benzene, toluene, xylene, aldehydes such as acetaldehyde, Depending on the amount of sunlight by passing air containing odorous components such as bromide, ammonia and acetic acid, and harmful chemicals such as carbon monoxide and nitrogen oxides through certain channels such as columns filled with adsorbents Since adsorption or desorption is automatically selected, a simple processing system can be formed. Moreover, since the necessary energy is sufficient for the sunlight and the slight electric power for driving the collector, it is energy saving and low cost. In addition, since the adsorbent used is automatically reactivated in a time zone in which the amount of sunlight is sufficient, it is not necessary to replace the adsorbent, and maintenance is easy. Therefore, it is useful for removing environmental pollutants by oxidation and decomposition of harmful chemical substances in the indoor environment and the air environment.
[0018]
【Example】
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
Example 1
As the air purification device, a device provided with a sunlight collecting mirror and a transparent glass concentric double tube described below was used.
First, a reflective layer of an aluminum thin film and a protective layer of silica are sequentially deposited on the back surface of a glass substrate molded into a two-dimensional parabolic shape, thereby creating a concentrator comprising a parabolic trough mirror with a sunlight incident area of 1.00 m 2. did. This concentrator can always adjust the vertical direction of the mirror to the direction of sunlight by a step motor in two directions.
Next, a cylindrical concentric double glass tube (double Pyrex (registered trademark) tube, made of borosilicate glass) was installed at the linear focal point formed when the parabolic trough mirror was irradiated with sunlight. (FIG. 1 (a)). This double Pyrex (registered trademark) tube plays three roles: an adsorption / desorption column with an adsorbent, a light receiver, and a photocatalytic reactor, and a cross-sectional view thereof is shown in FIG.
The inner tube of the double Pyrex (registered trademark) tube was filled with activated carbon pellets, and the activated carbon pellets acted as a light receiver and an adsorbent for absorbing the condensed sunlight and converting it into heat. Further, a photocatalyst containing titanium oxide was applied to the outer peripheral surface of the inner Pyrex (registered trademark) tube, and the outer side was covered with another Pyrex (registered trademark) tube, and a photocatalytic reactor was formed between them.
[0019]
After passing through the adsorption / desorption column, the contaminated air was led to the reactor to be purified, and then discharged. The observed ultraviolet intensity and the temperature of the adsorption / desorption column (light receiver) are shown in FIG. Between 10 am and 2 pm, there was an ultraviolet intensity of 3-4 mw / cm 2 and the center of the adsorption / desorption column kept 200-250 ° C. Here, the light receiver is a cylinder having a diameter of 3 cm. However, the maximum temperature can be controlled up to 400 ° C. by appropriately adjusting the diameter of the cylinder to be used.
FIG. 4 shows the outflow concentration when 10 ppm of toluene was passed through an adsorbent (granular activated carbon) having a predetermined temperature. It can be seen that when the temperature of the adsorbent is 200 ° C. or lower, 99.9% or more of toluene is removed, and when the temperature exceeds 200 ° C., the release of toluene starts. As shown in FIG. 4, the temperature of the adsorption / desorption column is 200 ° C. or less until about 10:00 when the sunshine condition is good, and toluene is adsorbed on the adsorption / desorption column. During the 4 hours from 10 am to 2 pm, the temperature of the adsorption / desorption column (photoreceiver) became 200 to 250 ° C., and desorption of toluene occurred. The desorbed toluene was introduced into the photocatalytic reactor, and at this time, it had a sufficient ultraviolet intensity of 3 to 4 mW / cm 2 , and the toluene was rapidly decomposed into carbon dioxide gas and water.
In addition, when the platinum-supported photocatalyst shown in Japanese Patent Application No. 2002-258045 was used, a higher decomposition ability was exhibited by using the collected heat together (FIG. 5). FIG. 5 shows the relationship between the photocatalytic temperature and the toluene decomposition rate when air having a toluene concentration of 15 ppm (humidity 80%) is passed through a 0.2 wt% platinum-supported titanium oxide catalyst reactor at a flow rate of 200 ml / min.
Generally, after 3:00 pm when the sunshine conditions are worse, the temperature of the adsorption / desorption column is lowered to 200 ° C. or lower, so that toluene is adsorbed on the adsorbent and does not reach the photocatalytic reactor. For this reason, since the amount of light is insufficient, it is possible to greatly reduce the possibility that an incomplete reaction occurs to release an intermediate or deactivate. The toluene adsorbed here is desorbed and subjected to catalytic cracking in the photocatalytic reactor when the next sunshine condition is good.
[0020]
【The invention's effect】
According to the present invention, the method and apparatus of the present invention are useful for industrial implementation because sunlight can be effectively used and air purification can be easily performed continuously and energy-saving regardless of sunshine conditions. It is. Moreover, these are applicable also to the chemical reaction using sunlight other than air purification.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an example of a solar collector used in the present invention.
2A is a cross-sectional view showing a configuration in which an adsorption / desorption column (photodetector) and a reactor are arranged concentrically in the apparatus of the present invention, and FIG. FIG.
FIG. 3 is a graph showing the relationship between the ultraviolet intensity of sunlight collection and the temperature (actually measured value) of the adsorption / desorption column.
FIG. 4 is a graph showing the relationship between the temperature of the adsorption / desorption column when passing air containing toluene and the concentration of outflowing toluene.
FIG. 5 is a graph showing the relationship between photocatalyst temperature and toluene decomposition rate when air containing toluene is passed.
FIG. 6 is a photograph of an example of an air cleaning device according to the present invention.
Claims (4)
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| JP5145140B2 (en) * | 2008-07-03 | 2013-02-13 | 三菱重工業株式会社 | Air cleaning apparatus and air cleaning method |
| JPWO2011114861A1 (en) * | 2010-03-18 | 2013-06-27 | コニカミノルタ株式会社 | Sunlight collecting mirror, trough solar power generator and trough solar power generator using the same |
| JP2013029537A (en) * | 2011-07-26 | 2013-02-07 | Sumitomo Heavy Ind Ltd | Concentrator and concentration apparatus including the same |
| JP6517053B2 (en) * | 2014-05-21 | 2019-05-22 | 株式会社フジコー | Air purification device |
| JP5968400B2 (en) * | 2014-11-04 | 2016-08-10 | 國家中山科學研究院 | Photocatalytic exhaust VOC treatment equipment |
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