CN205379786U - Gaseous phase photodissociation - liquid phase light catalytic oxidation purifies volatile organic compounds's device - Google Patents

Abstract

The utility model discloses a gas-phase photolysis-liquid-phase photocatalytic oxidation purification device for volatile organic matter. The gas-phase photolysis-liquid-phase photocatalysis device includes a gas-phase photolysis chamber, a liquid-phase photocatalytic spray tower and a liquid recovery regeneration box, and is characterized in that the liquid-phase photocatalytic spray tower is sequentially Equipped with an exhaust gas intake device, a filter ball layer, an absorption liquid spray device and a gas discharge port, the lower part of the liquid phase photocatalytic spray tower is connected to the upper part of the liquid recovery and regeneration box, and the liquid recovery and regeneration box passes through the liquid The pipeline and circulating pump are connected to the absorption liquid spraying device; an ultraviolet lamp and a gas phase photolysis chamber are also arranged in the liquid-phase photocatalytic spraying tower, and the ultraviolet lamp in the liquid-phase photocatalytic spraying tower is arranged on the filter ball layer and the Between the gas discharge ports, the end of the absorbing liquid spraying device is provided with several atomizing nozzles, and the gas phase photolysis chamber includes a quartz glass casing and an ultraviolet lamp arranged therein, and the quartz glass casing respectively It is connected with the air inlet and the exhaust air intake device. The device has the advantages of simple structure, complete pollutant degradation, no secondary waste water pollution, high purification efficiency, stable operation, etc., and can be carried out at normal temperature, the reaction process is mild and simple, and has high economic benefits.

Description

A device for purifying volatile organic compounds by gas-phase photolysis-liquid-phase photocatalytic oxidation

technical field

The utility model belongs to the field of gas pollutant treatment, in particular to a device for purifying volatile organic compounds by gas-phase photolysis-liquid-phase photocatalytic oxidation.

Background technique

With the rapid advancement of urbanization and industrialization in my country, the emission of organic waste gas is increasing, air pollution is becoming more and more serious, and volatile organic compounds (VOCs) in ambient air have increased significantly. Volatile organic compounds (VOCs) are important precursors for the formation of key atmospheric pollutants PM2.5 and _O3 in China, and are easily coupled with other atmospheric pollutants. The new pollutants formed are difficult to decompose naturally, and the damage is more persistent. In addition, it can also participate in photochemical reactions, leading to photochemical smog pollution. Organic waste gas often has a foul smell, which not only stimulates the human body and various sense organs, but also has certain toxicity, causing great harm to human health. The elimination and treatment of organic waste gas is an urgent and important task, which has become a difficult and hot spot in current research.

At present, the widely used processes such as activated carbon adsorption and catalytic combustion still have certain limitations in the actual use process, and it is difficult to meet the increasingly stringent emission regulations and the urgent requirements of the people for improving air quality. If the adsorption method cannot fundamentally eliminate pollutants, the desorption equipment, control system and desorption operation costs are high, and the adsorbent needs to be regenerated or replaced after saturation. Catalytic combustion usually uses noble metals as catalysts, which is costly; there are safety hazards in high-temperature environments and the catalyst is easily deactivated; the concentration of organic waste gas is low and external heat is required to maintain combustion.

Photocatalytic technology has received extensive attention in recent years. It can decompose organic matter under light at room temperature. It has the advantages of strong oxidation ability and mild reaction conditions. It is a relatively promising technology. However, intermediate products such as aldehydes, ketones, acids, and esters are produced during the commonly used gas/solid photocatalytic oxidation of volatile organic compounds, which not only cause secondary pollution, but also cover the catalytic active sites with intermediate products, which will lead to a decrease in catalyst efficiency or even complete inactivation. , and by-products such as ozone remain in the purified gas. These problems become the bottleneck restricting the further development and application of this technology. In order to improve the efficiency of photocatalytic degradation, effectively solve catalyst deactivation and eliminate ozone by-products, it is necessary to reform the gas/solid photocatalytic oxidation system of organic waste gas.

Utility model content

The utility model aims at the deficiencies of the organic waste gas treatment technology in the prior art, and proposes on the basis of gas/solid photocatalysis

A device for purifying volatile organic compounds by gas-phase photolysis-liquid-phase photocatalytic oxidation.

The above-mentioned purpose of the utility model is achieved through the following technical solutions.

A device for purifying volatile organic compounds by gas-phase photolysis-liquid-phase photocatalytic oxidation, including a gas-phase photolysis chamber, a liquid-phase photocatalytic spray tower and a liquid recovery regeneration box. The upper part is provided with an exhaust gas inlet device, a filter ball layer, an absorption liquid spray device and a gas discharge port in sequence. The lower part of the liquid-phase photocatalytic spray tower is connected with the upper part of the liquid recovery and regeneration box, and the liquid recovery and regeneration box passes through The liquid delivery pipeline and circulating pump are connected with the absorption liquid spraying device; the liquid phase photocatalytic spray tower is also equipped with an ultraviolet lamp and a gas phase photolysis chamber, and the ultraviolet lamp in the liquid phase photocatalytic spray tower is arranged on a filter ball Between the layer and the gas discharge port, the end of the absorbing liquid spraying device is provided with several atomizing nozzles, and the gas phase photolysis chamber includes a quartz glass casing and an ultraviolet lamp arranged in it, and the quartz glass casing The pipes are respectively connected with the air inlet and the exhaust air intake device.

When in use, the catalyst slurry is installed in the liquid recovery and regeneration box, and the catalyst slurry is sprayed from the top of the liquid-phase photocatalytic spray tower through a circulation pump, a liquid delivery pipeline and an absorption liquid spray device. After the exhaust gas is photolyzed through the gas-phase photolysis chamber from the air inlet, it is then passed into the liquid-phase photocatalytic spray tower through the exhaust gas inlet device, and the exhaust gas passing through the filter ball layer is in reverse contact with the spray to perform the liquid-phase photocatalytic oxidation step. Most of the exhaust gas is converted into harmless small molecular compounds, a small part of the intermediate product is transferred to the catalyst for wild species, and the liquid phase photocatalysis is further completely oxidized and degraded, and the catalyst slurry after in-situ synchronous treatment in the liquid recovery regeneration box continues to circulate use. Both the liquid-phase photocatalytic spray tower and the gas-phase photolysis chamber are equipped with ultraviolet lamps, and the ultraviolet lamps in the gas-phase photolysis chamber can not only be used for gas-phase photolysis, but because the gas-phase photolysis chamber is a quartz glass casing, the inner ultraviolet lamp can also It can play a role in the liquid-phase photocatalytic process in the liquid-phase photocatalytic spray tower, thereby reducing the number of ultraviolet lamps and saving energy and high efficiency.

The utility model effectively combines the gas-phase photolysis and the liquid-phase photocatalytic oxidation, and the two steps influence each other, act synergistically, and cannot be separated. The method fundamentally solves the problems of catalyst deactivation caused by the deposition of intermediate products on the surface of gas-solid photocatalysis and the low efficiency of VOCs liquid-phase absorption. function, reduce the production and accumulation of intermediate products, and realize the efficient and stable degradation of organic waste gas. In addition, this method makes full use of ultraviolet energy to provide energy for gas-phase photolysis and liquid-phase photocatalytic oxidation at the same time, and the ozone generated during the gas-phase photolysis process can also enhance the oxidation of VOCs under the action of liquid-phase catalysts.

The catalyst slurry uses water as the medium, and is mixed with titanium dioxide or titanium dioxide modified by transition metals. It has stronger photocatalytic activity than ordinary titanium dioxide, and the catalyst and water can produce more powerful photocatalysts under the excitation of ultraviolet lamps. Oxidative free radicals can improve the oxidation capacity of the system, and can non-selectively decompose refractory pollutants into carbon dioxide and water. It has strong organic waste gas adsorption performance, high ozone utilization efficiency and high photocatalytic activity. The method of the utility model has many advantages such as high purification efficiency, mild reaction, simple process, stable performance and economy, and can provide a new efficient and economical solution for the treatment of volatile organic compounds.

Preferably, the liquid-phase photocatalytic spray tower and the ultraviolet lamp in the gas-phase photolysis chamber are equipped with several vacuum ultraviolet lamps of 185 nm.

Preferably, the ultraviolet lamps in the liquid-phase photocatalytic spray tower are distributed in a ring shape. More preferably, the ultraviolet lamps in the liquid-phase photocatalytic spray tower form a one-stage or multi-stage annular array, that is, one or more layers of rings can be formed in the spray tower, and the outermost ultraviolet lamps are arranged along the inner wall of the spray tower. Evenly distributed.

Preferably, the gas-phase photolysis chamber is provided with several parallel quartz glass sleeves, and the quartz glass sleeves are connected through pipelines, and ultraviolet lamps are respectively arranged in them.

Preferably, the gas-phase photolysis chamber is arranged in an exhaust gas intake device.

Preferably, the absorption liquid spraying device includes several solution branch pipes, and the solution branch pipes are all in communication with the liquid delivery pipeline. More preferably, the solution branch pipe is provided with a branch pipe control valve for controlling the flow rate and atomization effect of the absorption liquid spraying device.

Preferably, the atomizing nozzle adopts a stainless steel fine atomizing nozzle, the atomized particles reach 50-100 μm, and it can also prevent the absorbed liquid from being corroded. According to the type, water solubility, flow rate and concentration of the exhaust gas, preferably, the diameter of the atomizing nozzle is 1-3mm, so as to ensure that the catalyst particles pass through smoothly without clogging. Preferably, the atomizing nozzle is provided with a radial spray pipe, and the spray is sprayed radially, which is more conducive to full contact with the exhaust gas.

Preferably, several gas outlet channels are provided on the exhaust gas inlet device, and the gas outlet channels correspond to the positions of the atomizing nozzles. The air outlet channel faces upwards to the atomizing nozzle, or faces downwards in the same direction as the atomizing nozzle. As an implementation manner, the air outlet channel is an air outlet hole, and the number of the air outlet holes is equal to that of the atomizing nozzle, and the positions correspond to each other. As another embodiment, the exhaust gas inlet device is provided with a trumpet-shaped air guide plate, the opening of which is downward and several layers of air outlet channels are arranged inside.

Preferably, the length of the ultraviolet lamp in the liquid-phase photocatalytic spray tower is 1200mm-1800mm, which is adjusted according to the height of the spray tower to ensure that the interior of the spray tower is irradiated by ultraviolet light in all directions.

Preferably, the filter ball layer is filled with polypropylene filter balls, and the height is 10cm-30cm.

Preferably, a mist eliminator is provided above the absorption liquid spraying device, and the mist eliminator adopts a swirl plate type mist eliminator or a flat plate type mist eliminator.

Preferably, a liquid delivery control valve is provided on the liquid delivery pipeline.

Preferably, an inspection window is provided on the liquid-phase photocatalytic spray tower.

Compared with the prior art, the beneficial effect of the utility model lies in that the utility model combines gas-phase photolysis and liquid-phase photocatalysis, wherein the gas-phase photolysis not only degrades a part of organic waste gas, but also generates ozone for ozone oxidation and degradation of organic waste gas. Exhaust gas, improve the degradation rate of organic waste gas, in addition, the intermediate products produced by photolysis are soluble, which is conducive to its further degradation. Liquid-phase photocatalysis overcomes the problem of catalyst deactivation in traditional gas/solid photocatalytic reactions. Due to the washing effect in the liquid phase, the intermediate product is washed away from the surface of the catalyst, making photocatalysis efficient and stable. In addition, strong adsorption in the liquid phase The use of catalysts with high toxicity, high ozone utilization rate and high photocatalytic activity can realize the efficient and stable degradation of volatile organic compounds and organic waste gases, and finally realize the harmlessness of volatile organic compounds. Moreover, the method can be carried out at normal temperature, the reaction process is mild and simple, and has high economic benefits.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the device in Example 1.

Fig. 2 is the air guide plate of the exhaust gas intake device described in embodiment 1.

Figure 3 is the bottom view of the outlet of the air guide plate.

Figure 4 is a schematic diagram of the overall structure of the device in Example 2.

Legend: 1-liquid phase photocatalytic spray tower; 2-circulation pump; 3-gas phase photolysis chamber; 4-photolysis chamber ultraviolet lamp; 5-liquid delivery pipeline; 6-liquid delivery control valve; 7-inspection window ;8-spray tower UV lamp;9-absorbing liquid spray device;10-atomizing nozzle;11-filter ball layer;12-demister;13-exhaust gas inlet device;14-gas discharge port; Liquid recovery regeneration box; 16-air guide plate.

detailed description

The utility model will be described in further detail below in conjunction with the accompanying drawings and specific embodiments, but the embodiments do not limit the utility model in any form. Wherein, the accompanying drawings are for illustrative purposes only, and represent only schematic diagrams, rather than actual drawings, and should not be construed as limitations on this patent; in order to better illustrate the embodiments of the present utility model, some parts of the accompanying drawings will be omitted , enlargement or reduction, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some known structures and their descriptions in the drawings may be omitted.

Example 1

This embodiment provides a gas phase photolysis-liquid phase photocatalysis device based on the above method, as shown in Figures 1 to 3, comprising a gas phase photolysis chamber 3, a liquid phase photocatalytic spray tower 1 and a liquid recovery regeneration box 15, The liquid-phase photocatalytic spray tower 1 is sequentially provided with an exhaust gas inlet device 13, a filter ball layer 11, an absorption liquid spray device 9, a demister 12 and a gas discharge port 14 from bottom to top. The lower part of the photocatalytic spray tower 1 is connected with the upper part of the liquid recovery and regeneration box 15, and the liquid recovery and regeneration box 15 is connected with the absorption liquid spraying device 9 through the liquid delivery pipeline 5 and the circulation pump 2. The absorption liquid spraying device 9 includes several solution branch pipes, and the solution branch pipes are all communicated with the liquid delivery pipeline 5, and the solution branch pipes are provided with branch control valves for controlling the flow rate of the absorption liquid spraying device. and fog effects. The end of the absorbing liquid spraying device 9 is provided with several stainless steel fine atomizing nozzles 10, the atomized particles reach 50-100 μm, which can also prevent the absorbed liquid from corroding. The exhaust gas inlet device 13 is provided with a trumpet-shaped air guide plate 16, the opening of which is downward and several layers of air outlet channels are arranged inside. The air outlet channel is directed downwards in the same direction as the atomizing nozzle 10 . The filter ball layer 11 is filled with polypropylene filter balls and has a height of 10cm-30cm. The liquid delivery pipeline 5 is provided with a liquid delivery control valve 6 . The liquid-phase photocatalytic spray tower 1 is provided with an inspection window 7 .

More specifically, the exhaust gas intake device 13 includes an intake port, a quartz glass sleeve and an air guiding disc 16 that communicate with each other. The gas-phase photolysis chamber 3 is arranged between the filter ball layer 11 and the liquid recovery regeneration box 15, and is composed of a quartz glass sleeve and several horizontal 185nm photolysis chamber ultraviolet lamps 4 arranged therein. Several 185nm spray tower ultraviolet lamps 8 are vertically arranged in the liquid-phase photocatalytic spray tower 1 , and the spray tower ultraviolet lamps 8 are arranged between the filter ball layer 11 and the gas discharge port 14 . The length of the spray tower ultraviolet lamp 8 in the liquid-phase photocatalytic spray tower 1 is 1200mm-1800mm, which is adjusted according to the height of the spray tower to ensure that all directions in the spray tower are irradiated by ultraviolet light.

During use, the exhaust gas enters the gas phase photolysis chamber 3 through the air inlet of the exhaust gas inlet device 13, and after passing through the gas phase photolysis of the ultraviolet lamp 4 in the photolysis chamber, enters the liquid phase photocatalytic spray tower 1 through the gas guide plate 16 Inside, the liquid-phase photocatalytic oxidation step is carried out in reverse contact with the catalyst slurry spray. Ultraviolet lamps are all provided in the liquid-phase photocatalytic spray tower 1 and the gas-phase photolysis chamber 3, and the photolysis chamber ultraviolet lamp 4 in the gas-phase photolysis chamber 3 can not only be used for gas-phase photolysis, because the gas-phase photolysis chamber 3 is The ultraviolet lamp inside the quartz glass casing can also play a role in the liquid-phase photocatalytic process in the liquid-phase photocatalytic spray tower 1, thereby reducing the number of ultraviolet lamps and saving energy and high efficiency.

Example 2

The gas-phase photolysis-liquid-phase photocatalysis device provided in this embodiment is substantially the same as in Example 3, as shown in Figure 4, the difference is that the quartz glass casing and the photolysis chamber ultraviolet lamp 4 are all vertically arranged, The gas-phase photolysis chamber 3 is provided with two parallel quartz glass casing pipes, which are connected by pipelines. The two quartz glass casing pipes are respectively equipped with photolysis chamber ultraviolet lamps 4, and the quartz glass casing pipes are connected by pipelines. , which are respectively equipped with photolysis chamber ultraviolet lamp 4.

Apparently, the above-mentioned embodiments of the present utility model are only examples for clearly illustrating the present utility model, rather than limiting the implementation manner of the present utility model. For those of ordinary skill in the art, on the basis of the above description, other changes or changes in different forms can also be made, and it is not necessary and impossible to exhaustively enumerate all the implementation manners here. All modifications, equivalent replacements and improvements made within the spirit and principle scope of the present utility model shall be included in the protection scope of the claims of the present utility model.

Claims (8)

1. A device for gas-phase photolysis-liquid-phase photocatalytic oxidation purification of volatile organic compounds, comprising a gas-phase photolysis chamber, a liquid-phase photocatalytic spray tower and a liquid recovery regeneration box, characterized in that the liquid-phase photocatalytic spray The waste gas inlet device, filter ball layer, absorption liquid spray device and gas discharge port are arranged in sequence from bottom to top in the shower tower. The lower part of the liquid-phase photocatalytic spray tower is connected with the upper part of the liquid recovery regeneration box. The liquid recovery and regeneration box is connected to the absorption liquid spraying device through a liquid delivery pipeline and a circulation pump; an ultraviolet lamp and a gas-phase photolysis chamber are also arranged in the liquid-phase photocatalytic spray tower, and the liquid-phase photocatalytic spray tower The ultraviolet lamp is arranged between the filter ball layer and the gas discharge port, and the end of the absorbing liquid spraying device is provided with several atomizing nozzles, and the gas phase photolysis chamber includes a quartz glass casing and an ultraviolet lamp arranged in it , the quartz glass casing is respectively connected with the air inlet and the exhaust gas inlet device. 2. The device according to claim 1, characterized in that, the liquid-phase photocatalytic spray tower and the ultraviolet lamp in the gas-phase photolysis chamber are all provided with several vacuum ultraviolet lamps of 185nm. 3. The device according to claim 2, characterized in that, the ultraviolet lamps in the liquid-phase photocatalytic spray tower are distributed in a ring shape. 4. The device according to claim 2, characterized in that, the gas-phase photolysis chamber is provided with several parallel quartz glass bushings, the quartz glass bushings are connected by pipelines, and ultraviolet lamps are respectively arranged in it. . 5. The device according to claim 1, characterized in that the atomizing nozzle is a stainless steel fine atomizing nozzle. 6. The device according to claim 1, characterized in that, the exhaust gas inlet device is provided with several outlet channels, and the outlet channels correspond to the positions of the atomizing nozzles. 7 . The device according to claim 1 , wherein a demister is arranged above the absorption liquid spraying device, and the demister is a swirling plate demister or a flat plate demister. 8. The device according to claim 1, characterized in that a liquid sending control valve is provided on the liquid sending pipeline.