CN108211686A - A kind of tail gas photooxidation cracking purification method - Google Patents

Abstract

The invention discloses a kind of tail gas photooxidation cracking purification method, 1) factory's organic exhaust gas enters front end spray column, and the dust particle in organic exhaust gas is fixed in spray liquid；2) organic exhaust gas after rough dusting enters photooxidation cracking cabinet progress off-gas oxidizing processing by air hose；3) the 2) in step processing procedure, and signal detection exhaust gas concentration and will be fed back to the regular combination open and close of fluorescent tube in single-chip computer control system, control high energy ultraviolet lamp group module, ozone supply module by the exhaust gas concentration detection sensor mounted on photooxidation cracking cabinet inlet in real time；4) gas after processing enters the fixation that dry method flue gas integrated treatment tank realizes sulphur, nitrogen oxides under the action of air-introduced machine, and the gas that system discharge standard is not achieved enters front end cycle.The service life that can be realized the energy-efficient operation of whole system, extend lamp group module of the present invention, improves VOCs treatment effect, and secondary pollution problem caused by avoiding conventional wet technique realizes ultra-clean discharge.

Description

A method for purifying tail gas by photooxygen cracking

technical field

The invention relates to the technical field of waste gas treatment, in particular to a method for photo-oxygen cracking and purification of tail gas.

Background technique

Air pollution is one of the most prominent environmental problems in my country at present. Among them, industrial waste gas is an important source of air pollutants. The most difficult to deal with in industrial waste gas is organic waste gas, which mainly comes from the waste gas emitted during the production process of petrochemical rubber industry. Organic waste gas not only causes direct air pollution, but also participates in complex reactions in the atmosphere to generate secondary pollutants. Become one of the main sources of PM2.5. Therefore, the treatment and purification of organic waste gas need to be solved urgently.

Traditional organic waste gas purification treatment methods mainly include: direct high-temperature combustion method, catalytic oxidation method, ozone deodorization method, activated carbon adsorption method, acid-base liquid spray method, biological deodorization method, etc. These methods have problems such as high equipment investment, high operating cost, small processing gas volume, unstable work, large space occupation, low deodorization and purification efficiency, and secondary pollution to varying degrees. At present, the new ultraviolet exhaust gas treatment system has been used more and more. The molecular chain of the macromolecular organic waste gas after ultraviolet treatment is interrupted and turned into small molecular pollutants, and then the exhaust gas can be discharged after subsequent equipment treatment. down to a very low level.

In the Chinese patent literature, CN103505990A relates to a UV-VOC exhaust gas treatment device, including a box body, in which a photolytic oxidative fission chamber is arranged, and the photolytic oxidative fission chamber is connected to the exhaust gas inlet through a pipeline. connection; an excitation high-voltage device is provided in the photolysis oxidation fission chamber to fission and decompose organic waste gas; a control system is also provided on the box, and the control system includes a main controller, a negative pressure sensor, a photoelectric sensor , to realize the overall operation and safety control of the equipment. The invention effectively realizes the purification treatment of waste gas through the photolysis oxidation fission chamber, fully oxidizes and fissions the organic waste gas and discharges it without pollution; realizes the filtration and separation of waste gas through the pretreatment section, and provides the follow-up photolysis oxidation fission treatment system for the waste gas. The treatment creates conditions; the application of the water circulation system doubles the service life of the treatment system of the photolytic oxidation fission device. CN104667674B relates to the technical field of air purification treatment, especially to the coating waste gas treatment process and its device, including paint mist treatment, which uses water spraying to treat dust particles in the waste gas; The molecular chain is degraded and transformed into low-molecular compounds, which are then modified into hydrophilic gases; and the gas-liquid mixing treatment removes the peculiar smell in the exhaust gas, and the exhaust gas treatment is more thorough. The device has a paint mist treatment tower, a photocatalytic processor and a gas-liquid mixing processor. The three are coaxially connected in sequence to form a sealed channel. The coating exhaust gas is treated according to the above process. The structure is simple, easy to manufacture, and the purification effect is excellent. Good, suitable for industrial waste gas treatment. CN105964120A discloses a waste gas treatment system, including an alkali spray tower, a plant liquid spray tower, a photocatalytic oxidation device, a fan and a chimney, the alkali spray tower, a plant liquid spray tower, a photocatalytic oxidation device, a fan and a The chimneys are connected in turn. Compared with the traditional technology, the present invention has scientific design and obvious waste gas treatment effect. It combines acid-base treatment, biochemical treatment and photocatalytic oxidation treatment in one system, which can fully treat mixed waste gas and make it discharge after reaching the standard. The utility model patent titled "Combined Plastic Granulation Waste Gas Purification System" and publication number CN205550040U discloses a technical solution, including a spray scrubber, a cyclone water-gas separation device, and waste gas treatment equipment. The waste gas treatment equipment includes activated carbon adsorption Chamber, UV photo-oxygen catalytic chamber and low-temperature plasma equipment. The above technology can effectively remove smoke and organic waste in the exhaust gas. However, the intelligent control level of the above-mentioned technical scheme is very low, and the processing power of the ultraviolet equipment cannot be controlled in real time according to the concentration of pollutants, resulting in the waste of energy or the problem that the treatment of pollutants is not up to standard. In addition, the exhaust gas treated by ultraviolet equipment will also cause secondary pollution caused by the discharge of pollutants with the flow of water mist in the gas due to the limitations of traditional wet post-treatment equipment (generally using scrubbers).

Contents of the invention

In order to solve the above technical problems, the present invention provides a tail gas photo-oxygen pyrolysis purification method, the purpose of which is to realize the intelligent control of tail gas detection and photo-oxygen cracking of tail gas, which can be used for cracking waste gas such as waste rubber and waste plastics in chemical plants, rubber product processing and Exhaust gas treatment during reclaimed rubber processing and catering industry; effectively save energy, improve work efficiency, and achieve ultra-clean emission of exhaust gas.

To achieve the above object, the technical scheme of the present invention is as follows:

A method for purifying tail gas by photooxygen cracking, comprising:

1) The organic waste gas from the factory enters the front-end spray tower, and the front-end spray tower fixes the dust particles in the organic waste gas in the spray liquid by spraying;

2) After preliminary dust removal, the organic waste gas enters the photo-oxygen pyrolysis cabinet through the air duct, and the organic waste gas passes through the dust-proof filter at the entrance of the photo-oxygen pyrolysis cabinet to further remove dust and filter moisture, and the high-energy ultraviolet lamp group module breaks the chain of organic waste gas macromolecules , the ozone supply module further oxidizes the small molecule waste gas after the broken chain, the TiO ₂ catalytic network participates in the catalysis, and the organic waste gas is decomposed into CO ₂ , H ₂ O, sulfur oxides, and nitrogen oxides;

3) In the process of step 2), the exhaust gas concentration detection sensor installed at the entrance of the photo-oxygen cracking cabinet will detect the exhaust gas concentration in real time and feed back the signal to the single-chip microcomputer control system. The single-chip microcomputer control system judges the corresponding concentration range according to the input signal and activates it. The self-optimized control program is used to control the regular combination of high-energy ultraviolet lamp module and ozone supply module to turn on and off, so as to realize energy-saving and efficient treatment of organic waste gas;

4) The treated gas enters the dry flue gas comprehensive treatment tank under the action of the negative pressure induced draft fan to fix sulfur and nitrogen oxides.

5) If the gas concentration after treatment does not reach the minimum exhaust gas concentration discharge standard set by the system, the intelligent control cabinet controls the three-way electromagnetic switch valve to discharge the gas into the atmosphere. The air pipe connected to the three-way electromagnetic switch valve connected to the side of the mouth pipe is opened, so that the untreated gas that reaches the standard is transported through the pipe to the front-end processing equipment for further processing, until the detection value of the rear exhaust gas concentration detection sensor meets the system setting. Concentration standard value, and finally realize the ultra-clean discharge of organic waste gas after treatment.

Compared with the existing technology, this scheme is based on the concept of intelligent control. The single-chip microcomputer control system controls the regular combination of on and off of the light group modules through the feedback signal of the sensor that detects the concentration of pollutants at the entrance of the photo-oxygen cracking cabinet. Energy-saving and efficient treatment of organic waste gas. In addition, the treated gas enters the dry flue gas comprehensive treatment tank under the action of the induced draft fan to fix the sulfur oxides, avoid the leakage of sulfur oxides caused by the traditional spraying method, and clean the treated gas into the atmosphere. The front-end spray tower is used to fix the dust particles in the factory's organic waste gas in the spray liquid by spraying for preliminary dust removal. This solution is beneficial to prolong the service life of the lamp group module and improve the treatment effect of organic waste gas. Through experimental research, it is found that the service life of the lamp module can be extended by 30%, and the treatment effect of organic waste gas can be improved by 23%.

Based on the above scheme, the present invention also makes the following improvements:

The lamp tube layout of the high-energy ultraviolet lamp group module and the ozone supply module lamp tube opening follows the principle of spatial distribution uniformity. In this improvement plan, the feedback signal of the sensor that detects the exhaust gas concentration at the entrance of the photo-oxygen cracking cabinet is used. The photo-oxygen cracking cabinet is also equipped with an intelligent control cabinet for installing a single-chip control system, and the control program independently optimized and designed by the single-chip microcomputer is used to control the ultraviolet lamp. , The regular combination of high-energy ion tubes is turned on and off. The opening of the lamp follows the principle of spatial distribution uniformity to ensure the uniformity of the reaction.

The high-energy ultraviolet lamp group module includes 4 groups, the ozone supply module includes 3 groups, each group of lamp groups contains 4 lamp tubes, and the method for controlling the opening of the lamp tubes is as follows:

When the exhaust gas concentration is 0-150mg/ ^m3 ; in the high-energy ultraviolet lamp group module, only one lamp tube is turned on in each group, and the positions of the lamp tubes turned on in all groups are different, and the overall shape is "W" or "M" type arrangement; in the ozone supply module, only one lamp tube in the middle of the first group and the third group is turned on, and the positions of the turned on lamp tubes are arranged in a staggered manner;

When the exhaust gas concentration is 150-200mg/m ³ , in the high-energy ultraviolet lamp group module, each group turns on 2 lamp tubes, and the whole is arranged in a staggered pattern of ">" and "<"; in the ozone supply module, the first group and the second group are turned on. 2 lamps in the second group, the position of the turned on lamp is ">" or "<"type;

When the exhaust gas concentration is 200-250mg/m ³ , in the high-energy ultraviolet lamp group module, the first and third groups of lamps are all turned on, and the second and fourth groups both turn on two lamps and the lamps are arranged in a staggered manner; In the ozone supply module, each group turns on 2 lamp tubes, and the whole is arranged in a staggered manner of ">" and "<";

When the exhaust gas concentration is ^above 250mg/m3, all the lamps of the high-energy ultraviolet lamp group module are turned on; in the ozone supply module, the first group of lamps are all turned on, and the second and third groups of lamps are both turned on. The second and third groups of lamp tubes are arranged in the shape of ">" or "<".

The entrance of the photo-oxygen cracking cabinet is provided with a replaceable dust-proof and moisture-filtering net. In this improvement plan, a replaceable dust-proof filter and wet filter is used to further remove dust and filter moisture from the exhaust gas, protect the photo-oxygen cracking cabinet, avoid excessive moisture from causing accidental discharge of the lamp group module, and ensure a suitable working environment for the photo-oxygen cracking cabinet .

TiO ₂ catalytic nets are evenly distributed between the lamp group modules, and the TiO ₂ catalytic nets participate in the catalysis, and the organic waste gas is decomposed into CO ₂ , H ₂ O, sulfur oxides, and nitrogen oxides. In this improvement scheme, the macromolecules of the organic waste gas are more efficiently destroyed and oxidized under the catalytic action of the TiO ₂ catalytic network, and the efficiency is improved.

The induced draft fan is a negative pressure induced draft fan. The gas flow power of the whole device in this improvement plan is provided by a negative pressure induced draft fan. Due to the existence of negative pressure, it is guaranteed that the untreated organic waste gas in the photo-oxygen cracking cabinet and even the whole device will not leak out, causing environmental pollution.

The single-chip microcomputer control system in the intelligent control cabinet can record the function of the exhaust gas components that are still not up to the standard after the exhaust gas is purified. Turn on the lamp tube at a level higher than this exhaust gas concentration for processing.

Description of drawings

Fig. 1 three-dimensional structure diagram of equipment included in the present invention

Fig. 2 internal three-dimensional structural diagram of photo-oxygen cracking cabinet of the present invention

Fig. 3 three-dimensional structural diagram of the high-energy ultraviolet lamp group module of the present invention

Fig. 4 structure diagram of high-energy ultraviolet lamp group module and ozone supply module lamp group of the present invention

In the figure, 1. Front-end spray tower, 2. Exhaust gas concentration detection sensor, 3. Photooxygen cracking cabinet, 4. Dust-proof and wet filter, 5. High-energy ultraviolet lamp group module, 6. Ozone supply module, 7. TiO ₂ Catalytic network, 8. Intelligent control cabinet, 9. Negative pressure induced draft fan, 10. Dry flue gas comprehensive treatment tank, 11. Rear exhaust gas concentration detection sensor, 12. Three-way electromagnetic switch valve.

Detailed ways

The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

A method for purifying tail gas by photooxygen cracking, comprising:

1) The factory organic waste gas enters the front-end spray tower 1, and the front-end spray tower 1 fixes the dust particles in the organic waste gas in the spray liquid by spraying;

2) The organic waste gas after preliminary dust removal enters the photo-oxygen pyrolysis cabinet 3 through the air duct, and the organic waste gas passes through the dust-proof filter and humidity filter 4 at the entrance of the photo-oxygen pyrolysis cabinet 3 to further remove dust and filter moisture, and the high-energy ultraviolet lamp group module 5 converts the organic waste gas The macromolecular chain is broken, and the ozone supply module 6 further oxidizes the small molecule waste gas after the chain breaking;

3) In the process of step 2), the exhaust gas concentration detection sensor 2 installed at the entrance of the photo-oxygen cracking cabinet will detect the exhaust gas concentration in real time and feed back the signal to the single-chip microcomputer control system. The single-chip microcomputer control system judges the corresponding concentration range according to the input signal and Use the self-optimized control program to control the regular combination of high-energy ultraviolet lamp module 5 and ozone supply module 6 to turn on and off, so as to realize energy-saving and efficient treatment of organic waste gas;

4) The treated gas enters the dry flue gas comprehensive treatment tank 10 under the action of the induced draft fan 9 to realize the fixation of sulfur and nitrogen oxides;

5) If the gas concentration after treatment does not reach the minimum exhaust gas concentration discharge standard set by the system, the intelligent control cabinet controls the three-way electromagnetic switch valve to discharge the gas into the atmosphere. The air pipe connected to the three-way electromagnetic switch valve connected to the side of the mouth pipe is opened, so that the untreated gas that reaches the standard is transported through the pipe to the front-end processing equipment for further processing, until the detection value of the rear exhaust gas concentration detection sensor meets the system setting. Concentration standard value, and finally realize the ultra-clean discharge of organic waste gas after treatment.

As shown in Figures 2 and 3, wherein, the high-energy ultraviolet lamp group module in the 3rd) step includes 4 groups, the ozone supply module includes 3 groups, and each group of lamp groups includes 4 lamp tubes, and the method for controlling the lamp tube opening is:

When the exhaust gas concentration is 0-150mg/ ^m3 ; in the high-energy ultraviolet lamp group module, only one lamp tube is turned on in each group, and the positions of the lamp tubes turned on in all groups are different, and the overall shape is "W" or "M" type arrangement; in the ozone supply module, only one lamp tube in the middle of the first group and the third group is turned on, and the positions of the turned on lamp tubes are arranged in a staggered manner;

When the exhaust gas concentration is 150-200mg/m ³ , in the high-energy ultraviolet lamp group module, each group turns on 2 lamp tubes, and the whole is arranged in a staggered pattern of ">" and "<"; in the ozone supply module, the first group and the second group are turned on. 2 lamps in the second group, the position of the turned on lamp is ">" or "<"type;

When the exhaust gas concentration is 200-250mg/m ³ , in the high-energy ultraviolet lamp group module, the first and third groups of lamps are all turned on, and the second and fourth groups both turn on two lamps and the lamps are arranged in a staggered manner; In the ozone supply module, each group turns on 2 lamp tubes, and the whole is arranged in a staggered manner of ">" and "<";

When the exhaust gas concentration is ^above 250mg/m3, all the lamps of the high-energy ultraviolet lamp group module are turned on; in the ozone supply module, all the first group of lamps are turned on, and the second and third groups of lamps are both turned on. The second and third groups of lamp tubes are arranged in the shape of ">" or "<". As shown in Figure 1, a TiO ₂ catalytic net is provided between the high-energy ultraviolet lamp module 5 and the ozone supply module 6. The TiO ₂ catalytic net 7 participates in the catalysis, and the organic waste gas is decomposed into CO ₂ , H ₂ O, Sulfur oxides, nitrogen oxides. Humidity affects the catalytic efficiency of the TiO ₂ catalytic network. The surface of TiO ₂ is hydrophilic and strongly adsorbs water. When the water content increases, water molecules compete with the adsorption of toluene molecules on the surface of TiO ₂ , hindering the adsorption of toluene molecules on the active sites of the catalyst surface. , so that the surface reaction rate decreases. Therefore, in this embodiment, the exhaust gas is filtered through the setting of the dehumidification filter. The entrance of the photo-oxygen cracking cabinet is provided with a replaceable dust-proof and moisture-filtering net. The induced draft fan is a negative pressure induced draft fan.

As shown in Figure 1, the present invention relates to an intelligent tail gas photo-oxygen cracking and purification device, which includes a front-end spray tower 1 connected to the factory organic waste gas pipeline, and a lamp group connected to the front-end spray tower 1 through an air duct. The photo-oxygen pyrolysis cabinet 3 of the module, the negative pressure induced draft fan 9 installed at the air outlet of the photo-oxygen pyrolysis cabinet, the dry-process flue gas comprehensive treatment tank 10 connected to the air outlet of the negative pressure induced draft fan 9; the entrance of the photo-oxygen pyrolysis cabinet 3 A waste gas concentration detection sensor 2 is provided, a replaceable dust-proof wet filter 4 is provided in the slot at the entrance of the photo-oxygen cracking cabinet 3, and a rear exhaust gas is installed on the exhaust pipe of the dry flue gas comprehensive treatment tank. Concentration detection sensor 11, the exhaust pipe is a T-shaped pipe, one branch is directly connected to the outside, and the other branch is connected to the air inlet pipeline of the front spray tower 1; the branch of the exhaust pipe is bifurcated There is a three-way electromagnetic switch valve 12 controlled by a single-chip microcomputer control system. If the gas concentration after treatment does not reach the minimum waste gas concentration discharge standard set by the system, the single-chip microcomputer control system in the intelligent control cabinet 8 records the gas components simultaneously, and the intelligent control cabinet 9 controls the three-way electromagnetic switch valve 14 to The pipe switch on the side where the gas is discharged into the atmosphere is closed, and the gas pipe connected to the three-way electromagnetic switch valve connected to the side of the air inlet pipe of the front spray tower 1 is opened. The next time the tail gas treatment of the same composition is performed, the intelligent control cabinet is 8 miles away. The single-chip microcomputer control system controls the high-energy ultraviolet lamp group module and the ozone supply module to turn on the lamp tube for treatment according to the level higher than the exhaust gas concentration.

Claims (7)

1. a kind of tail gas photooxidation cracking purification method, it is characterised in that：Including,

1) factory's organic exhaust gas enters the front end spray column, and front end spray column is by spraying the dust particles in organic exhaust gas Object is fixed in spray liquid；

2) organic exhaust gas after rough dusting enters photooxidation cracking cabinet by air hose, and organic exhaust gas enters by photooxidation cracking cabinet Mouthful dust-proof filter wet web further dedusting filter it is wet, high energy ultraviolet lamp group module is by organic exhaust gas macromolecular chain rupture, ozone supply Module further aoxidizes the small molecule exhaust gas after chain rupture；

3) in the 2) step processing procedure, the exhaust gas concentration detection sensor mounted on photooxidation cracking cabinet inlet will detect in real time Signal is simultaneously fed back to single-chip computer control system by exhaust gas concentration, and single-chip computer control system is according to input-signal judging respective concentration model It encloses and enables the control program of autonomous optimization design fluorescent tube in high energy ultraviolet lamp group module, ozone supply module to be controlled to have rule The energy-efficient processing to organic exhaust gas is realized in the combination open and close of rule；

4) gas after processing enters dry method flue gas integrated treatment tank realization sulphur, nitrogen oxygen under the action of the air-introduced machine The fixation of compound；

5) such as treated, and the minimum exhaust gas concentration discharge standard of default, Intelligent control cabinet control three is not achieved in gas concentration The pipe switch that gas is discharged into air side by logical electromagnetic switch valve is closed, and is connected with the air inlet duct side of front end spray column The connection of three-way electromagnetic switch valve tracheae it is open-minded, be given to leading portion so as to which untreated gas up to standard be made to pass through pipeline and convey again Processing equipment is handled again, until the detection numerical value of postposition exhaust gas concentration detection sensor meets the concentration standard of default Value, the final ultra-clean discharge realized after VOCs treatment.

2. a kind of tail gas photooxidation cracking purification method according to claim 1, it is characterised in that：Described 3) described in step The fluorescent tube layout that high energy ultraviolet lamp group module and ozone supply module fluorescent tube are opened follows uniform spatial distribution principle.

3. a kind of tail gas photooxidation cracking purification method according to claim 2, it is characterised in that：The high energy ultraviolet lamp Group module includes 3 groups including 4 groups, ozone supply module, and every group of lamp group includes 4 fluorescent tubes, and control fluorescent tube open method is：

When exhaust gas concentration is 0-150mg/m³；In high energy ultraviolet lamp group module, every group is only opened 1 fluorescent tube, and all groups of unlatchings Fluorescent tube open lamp strip position differ, integral into " W " or " M " type arrange；In ozone supply module, first group is only opened With 1 fluorescent tube among third group, the lamp strip position of unlatching is staggered；

When exhaust gas concentration is 150-200mg/m³, in high energy ultraviolet lamp group module, 2 fluorescent tubes of every group of unlatching, integral into ">" and “<" staggered；In ozone supply module, open first group and second group in 2 fluorescent tubes, unlatching lamp strip position ">" or “<" type；

When exhaust gas concentration is 200-250mg/m³, in high energy ultraviolet lamp group module, first group and third group fluorescent tube are all turned on, Second group and the 4th group is opened 2 fluorescent tubes and fluorescent tube is staggered；In ozone supply module, every group is opened 2 fluorescent tubes, whole Body into ">" and "<" staggered；

When exhaust gas concentration is 250mg/m³More than, all fluorescent tubes of high energy ultraviolet lamp group module are opened；In ozone supply module, First group of fluorescent tube is all turned on, and second group and third group fluorescent tube open 2 fluorescent tubes, second and third group of fluorescent tube arrangement in ">" or “<" type.

4. a kind of tail gas photooxidation cracking purification method according to claim 1 or 2, it is characterised in that：The photooxidation cracking Cabinet inlet is equipped with the dust-proof filter wet web of changeable type.

5. a kind of tail gas photooxidation cracking purification method according to claim 1 or 2, it is characterised in that：The lamp group module Between be evenly distributed with TiO₂Catalysis net, TiO₂Catalysis net participates in catalysis, and organic exhaust gas is broken down into CO₂、H₂O, the oxidation of sulphur Object, nitrogen oxide.

6. a kind of tail gas photooxidation cracking purification method according to claim 1 or 2, it is characterised in that：The air-introduced machine is Suction type air-introduced machine.

7. tail gas photodestruciton purification method according to claim 2, it is characterised in that：In the Intelligent control cabinet Single-chip computer control system is able to record the function of exhaust gas component still not up to standard after tail gas clean-up, carry out next time equally into During the vent gas treatment divided, single-chip computer control system control high energy ultraviolet lamp group module and ozone supply module are according to useless higher than this Rank is opened fluorescent tube and is handled where gas concentration.