JPS61187930A - photoreactor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a photoreactor that performs chemical reactions using light.

[Prior art and its problems] Conventionally, chemical reactions are carried out by activating molecules under high temperature and high pressure conditions and increasing the frequency of collisions between molecules. However, in recent years, so-called photochemical reactions have been put into practical use in which light irradiation excites substances and induces chemical reactions at room temperature and pressure, or even at low temperatures and low pressures close to normal temperature and normal pressure. FIG. 2 is a cross-sectional view of a conventional photoreactor. a
is the reactor main body that stores the raw material liquid that causes the photoreaction, b is the light source such as a mercury lamp immersed in the raw material liquid, C and C are the stirring devices, d is the forced circulation device, e is the raw material inlet, and f is the This is the reaction product outlet.

In such a photoreactor, in the case of a photochemical reaction that occurs easily and quickly when exposed to light, the reaction tends to be uniform and there is no problem, but if the reaction takes a long time, the raw material liquid in the part near the light source may Because the light hits strongly, the reaction progresses quickly, and the reaction progresses slowly at parts of the raw material liquid far from the light source because the light is weak. Therefore, in order to proceed with the reaction uniformly within the reactor body, a stirring device or forced circulation device is required.In the case of IMA temperature reaction, a heating means is required not only for the reactor body but also for the forced circulation device. Met. Therefore, there was a problem in that the operating cost was also high.

On the other hand, in most cases there is a difference in specific gravity between the raw material liquid (reactant) and the reaction product.

For example, in the case of chlorination reaction: CH2-Ct(2+ CI2z → CH2=CHCj!+HC,i' specific gravity 0.6246 Q, 9692, the reaction product is heavier than the raw material liquid to be reacted, and conversely, decomposition reaction: H20t → H2o+ Ox When the specific gravity is 1.46 1.0, the reaction product is lighter than the raw material liquid to be reacted.

This difference in specific gravity may cause natural convection, but
It was only possible to do so partially within the reactor body, and it was not possible to omit the stirring device and forced circulation.

[Object of the Invention] The present invention has been devised in view of the problems of the prior art, and is capable of generating a natural circulation flow throughout the reactor body to cause a chemical reaction to occur uniformly throughout. Moreover, it is an object of the present invention to provide a photoreactor that does not require a stirring device or a forced circulation device or can be downsized, and can reduce equipment costs and operating costs.

[Means for solving the problem] In order to achieve the above-mentioned purpose, there is provided a reactor body that stores a raw material liquid that causes a photochemical reaction, and a reactor body that protrudes into the interior from the reactor body.
It consists of a light source installed to be immersed in the raw material liquid, and a cylindrical body with open top and bottom ends surrounding the light source.
The cylindrical body is characterized in that its upper end is below the surface of the raw material liquid, and its lower end has a gap between it and the reactor body.

[Function] The photoreactor of the present invention uses a cylindrical body with open upper and lower ends that surrounds the light source and is immersed in the raw material liquid to cause the liquid inside the reactor main body to react with the part that causes a photoreaction. A natural circulation flow is generated due to the difference in specific gravity between the part of the liquid that causes a photoreaction and the part that does not, and this allows the raw material liquid in the outside of the cylindrical body to react and the part that does not. Light is directed inside the body to cause a uniform chemical reaction to occur in all the raw material liquid within the reactor body.

Note that the cylindrical body may be cylindrical or rectangular.

[Example] A preferred example of the photoreactor of the present invention will be described with reference to FIG.

Reference numeral 1 is a reactor main body that stores a raw material liquid 4 for causing a photochemical reaction, and 2 is a light source that protrudes from the reactor main body and is provided so as to be immersed in the raw material liquid 4. Reference numeral 3 denotes a cylindrical body with open upper and lower ends that surrounds the light source, and the upper end 3a of the cylindrical body is below the liquid level 4a of the raw material liquid by a required height h, and the lower end 3b is Gap h between reactor body 1
It has 2.

Reference numeral 5 denotes a gas introduction pipe that is attached to the reactor main body 1 and introduces the gas involved in the reaction; surface.

This vibrator 5 is used not only when a gas is required to participate in a chemical reaction, but also as an inlet for a gas that does not participate in the reaction, such as air, to promote circulation of the raw material liquid inside and outside the cylindrical body 3. Ru.

11 is an inlet for the raw material liquid 4, and 12 is an outlet for the reaction product.

Next, the effect will be explained.

Inside the reactor body 1, a raw material liquid 4 that causes a photochemical reaction is at a liquid level 4.
It is filled up to a.

Light from a light source 2 such as a mercury lamp is irradiated onto the raw material liquid 4 inside the cylindrical body 2, and the raw material liquid 4 causes a photochemical reaction. Cylindrical body 3
A reaction product is generated by a photochemical reaction inside the cylindrical body, and the interior of the cylindrical body becomes a mixed state of the reaction product and unreacted raw material liquid. Now, if there is a difference in specific gravity between the unreacted raw material liquid and the reaction product, and the reaction product is lighter than the raw material liquid, the mixture of the unreacted raw material liquid and the reaction product is lighter than the raw material liquid itself, so the upper Instead, the unreacted raw material liquid outside the cylindrical body 3 enters the cylindrical body 3 from below, causing an upward flow inside the cylindrical body 3 and a downward flow outside the cylindrical body 3, as shown by the arrows. A natural cycle occurs.

Further, when the reaction product has a higher specific gravity than the unreacted raw material, a natural circulation occurs in which a downward flow occurs inside the cylindrical body 3 and an upward flow occurs outside the cylindrical body 3. Similar to a stirring device or a forced circulation device, this natural circulation creates a stirring effect between the parts that cause a photoreaction and the parts that do not cause a photoreaction in the reactor main body 1, so as a result, there is no need for a stirring device or the like. In both cases, the entire contents inside the reactor body 1 are uniformly irradiated with light, allowing the reaction to proceed.

Gas may also be involved in photochemical reactions.

For example, CeHs+60Rz → CG H8Cnoe +6HC In this case, the gas is ejected from the gas jet port 5a of the gas introducing vibrator 5, turns into bubbles and rises in the raw material liquid, but at this time, the raw material liquid is dragged by the bubbles and rises. A flow occurs. If all the air bubbles generated there are introduced into the inside of the cylindrical body, a natural circulating flow will be generated around the cylindrical body 3, as described above. Note that if the natural circulation flow is not sufficiently generated due to the specific gravity difference between the reaction product and the unreacted raw material liquid, gas may be introduced from the gas introduction pipe even if the gas is not involved in the reaction.

[Modifications] The present invention is not limited to the above-mentioned embodiments, and the following modifications can be made within the scope of the claims.

+11 The inner peripheral surface of the cylindrical body may be a mirror that reflects light from a light source. Since the light from the light source is reflected by the mirror, the illuminance of the light irradiated onto the raw material liquid inside the cylindrical body increases and the reaction is promoted.

If only the light from the light source is to be reflected, the inner wall of the reactor body may be mirror-plated or the inner wall may be lined with mirrors, but doing so would be troublesome to repair or replace when damaged or deteriorated. On the other hand, in this modification, maintenance is easy because in such a case, it is only necessary to replace the entire part.

[Effects of the Invention] As explained above, the photoreactor of the present invention has the following effects.

(1) By dividing the liquid inside the reactor main body into a part inside the cylinder that causes a photochemical reaction and a part outside the cylinder that does not cause a photochemical reaction, the liquid inside the cylinder is Natural circulation occurs due to the difference in specific gravity between the inside and outside, so even without the need for a stirrer or forced circulation device, all the raw material liquids within the reactor body are sequentially and uniformly irradiated with light, promoting the reaction.

■ Equipment costs and operating costs can be reduced because there is no need to install a stirring device or forced circulation device.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a photoreactor of the present invention, and FIG. 2 is a sectional view of a conventional photoreactor. 1... Reactor body 2... Light source 3... Cylindrical body 3a... Cylindrical body upper end 3b... Cylindrical body lower end 5... Gas introduction pipe

Claims (3)

[Claims] (1) A reactor body that stores a raw material liquid that causes a photochemical reaction, a light source that protrudes from the reactor body and is immersed in the raw material liquid, and upper and lower ends that surround the light source. 1. A photoreactor comprising an open cylindrical body, wherein the cylindrical body has an upper end below the liquid level of the raw material liquid and a lower end having a gap between it and the reactor main body. (2) The photoreactor according to claim 1, wherein the cylindrical body has a mirrored inner surface. (3) The photoreactor according to claim 1 or 2, wherein the reactor main body is provided with a gas introduction pipe so that bubbles generated from the pipe are introduced into the inside of the cylindrical mirror. .