Catalytic oxidation treatment system for sulfur-containing VOCs waste gas

Abstract

The utility model relates to a catalytic oxidation treatment system for sulfur-containing VOCs (Volatile Organic Compounds) waste gas, which aims to solve the technical problem that a catalyst is permanently inactivated due to high operation cost of the existing VOCs waste gas treatment, and adopts the technical scheme that the catalytic oxidation treatment system comprises a water-sealed tank, a carbonyl sulfide removal tower, a hydrogen sulfide removal tower, a fan, a catalytic oxidation system and a chimney, the gas outlet is communicated with the carbonyl sulfide removal tower, the carbonyl sulfide removal tower is communicated with the hydrogen sulfide removal tower, the hydrogen sulfide removal tower is communicated with the catalytic oxidation system through a catalytic oxidation gas inlet pipeline, the catalytic oxidation system is connected to the chimney, and the fan is communicated with the catalytic oxidation gas inlet pipeline; sulfur-containing VOCs waste gas enters a gas inlet pipeline, a discharge pipeline is branched from the gas inlet pipeline and connected to a chimney, and block valves are arranged on the two pipelines respectively. The pre-desulfurization of original gas can be realized, the service life and the activity of the VOCs catalyst can be guaranteed, and the cost and the operation energy consumption of sulfur-containing VOCs waste gas treatment are reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of catalytic oxidation treatment of sulfur-containing VOCs waste gas, and specifically relates to a catalytic oxidation treatment system for sulfur-containing VOCs waste gas. Background Art

[0002] VOCs (Volatile Organic Compounds) are defined by the World Health Organization (WHO) as volatile organic compounds with a melting point below room temperature and a boiling point between 50 and 260°C under standard pressure (101.325 kPa). Chemical and coal chemical industries are key VOCs emission industries. With the in-depth promotion of VOCs emission reduction in my country, the comprehensive treatment of VOCs waste gas in chemical and coal chemical industries continues to receive widespread attention.

[0003] According to the emission sources and emission characteristics of VOCs waste gas from chemical and coal chemical industries, recycling technologies are usually given priority for VOCs waste gas with recycling value, such as adsorption technology, absorption technology, condensation technology, membrane separation technology, etc.; for waste gas with low or no recycling value, destruction technologies are usually used, such as oxidation technology, photocatalytic degradation technology, biodegradation technology, plasma technology, etc. Among them, oxidation technology is a treatment method with extremely high treatment efficiency and is widely used in the chemical and coal chemical industries. Oxidation technology specifically includes catalytic oxidation technology and thermal oxidation technology. The thermal oxidation temperature required for thermal oxidation technology is generally above 750°C, while catalytic oxidation technology makes full use of catalysts such as precious metals, transition metals, and metal oxide carriers to achieve the removal of VOCs at a lower temperature (300-450°C). However, VOCs waste gas emitted by chemical and coal chemical industries often contains components such as organic sulfur and inorganic sulfur that are easy to poison the catalyst. If catalytic oxidation technology is directly used for treatment, the catalyst will be permanently deactivated and cannot be restored to activity. Utility Model Content

[0004] The utility model aims to solve the above problems and provide a catalytic oxidation treatment system for sulfur-containing VOCs waste gas.

[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0006] A catalytic oxidation treatment system for sulfur-containing VOCs waste gas, comprising a water seal tank, a decarbonylation sulfide tower, a dehydrogen sulfide tower, a fan, a catalytic oxidation system and a chimney, wherein the air inlet of the water seal tank is externally connected to an air inlet pipeline, the air outlet of the water seal tank is connected to the bottom of the decarbonylation sulfide tower, the top of the decarbonylation sulfide tower is connected to the bottom of the dehydrogen sulfide tower, the top of the dehydrogen sulfide tower is connected to the air inlet of the catalytic oxidation system through a catalytic oxidation air inlet pipeline, the air outlet of the catalytic oxidation system is connected to the chimney through a flue gas pipeline, and the air outlet of the fan is connected to the catalytic oxidation air inlet pipeline; sulfur-containing VOCs waste gas from upstream enters the air inlet pipeline, a discharge pipeline is branched out on the air inlet pipeline, the other end of the discharge pipeline is connected to the chimney, a first shut-off valve is provided on the air inlet pipeline on one side of the water seal tank, and a second shut-off valve is provided on the discharge pipeline.

[0007] Furthermore, a first electric heater is provided at the lower part of the decarbonylation sulfide tower, and a decarbonylation sulfide catalyst bed is provided at the upper part.

[0008] Furthermore, the decarbonylation sulfide catalyst bed is any one of Al2O3-based, TiO2-based or a mixture of the solid catalysts, and the active component is any one of alkali metals, alkaline earth metals or transition metals.

[0009] Furthermore, a second electric heater is provided in the lower part of the dehydrogen sulfide tower, and a dehydrogen sulfide catalyst bed is provided in the upper part.

[0010] Furthermore, the dehydrogen sulfide catalyst bed is an iron oxide-based catalyst.

[0011] Furthermore, a combustible gas analyzer is provided on the catalytic oxidation air intake pipeline, and the combustible gas analyzer is interlocked with the motor of the fan.

[0012] Furthermore, an online detection port is provided on the upper side wall of the chimney.

[0013] Furthermore, the catalytic oxidation system is provided with any one of an electric heater and a VOCs catalyst.

[0014] Furthermore, the catalytic oxidation system adopts any one of a heat storage catalytic oxidation system and a heat recovery catalytic oxidation system.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] The utility model can not only realize the pre-desulfurization of the original gas volume, avoiding the installation of a large-volume flue gas desulfurization system at the rear end of the conventional VOCs waste gas treatment device, but also ensure the service life and activity of the VOCs catalyst, realize the treatment of VOCs waste gas at a relatively low temperature, reduce the investment cost and operating energy consumption of the sulfur-containing VOCs waste gas treatment device, and has good promotion and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the utility model;

[0018] In the figure: 1. air intake pipeline; 2. discharge pipeline; 3. water seal tank; 4. decarbonylation sulfide tower; 5. first electric heater; 6. decarbonylation sulfide catalyst bed; 7. dehydrogen sulfide tower; 8. second electric heater; 9. dehydrogen sulfide catalyst bed; 10. fan; 11. catalytic oxidation air intake pipeline; 12. catalytic oxidation system; 13. flue gas pipeline; 14. chimney; 15. first shut-off valve; 16. second shut-off valve; 17. combustible gas analyzer; 18. motor; 19. online detection port. DETAILED DESCRIPTION

[0019] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0020] Example 1

[0021] like Figure 1 As shown, a catalytic oxidation treatment system for sulfur-containing VOCs waste gas comprises a water seal tank 3, a decarbonylation sulfur tower 4, a dehydrogen sulfide tower 7, a fan 10, a catalytic oxidation system 12 and a chimney 14, wherein the air inlet of the water seal tank 3 is externally connected to an air inlet pipeline 1, and the air outlet of the water seal tank 3 is communicated with the bottom of the decarbonylation sulfur tower 4, a first electric heater 5 is provided at the lower part of the decarbonylation sulfur tower 4, and a decarbonylation sulfur catalyst bed 6 composed of an Al2O3-based solid catalyst and a potassium active component is provided at the upper part, the top of the decarbonylation sulfur tower 4 is communicated with the bottom of the dehydrogen sulfide tower 7, a second electric heater 8 is provided at the lower part of the dehydrogen sulfide tower 7, and a second electric heater 8 is provided at the upper part of the decarbonylation sulfur tower 4. A dehydrogen sulfide catalyst bed 9 formed of an iron oxide-based catalyst is provided, the top of the dehydrogen sulfide tower 7 is connected to the air inlet of the catalytic oxidation system 12 through a catalytic oxidation air inlet pipeline 11, the catalytic oxidation system 12 adopts a regenerative catalytic oxidation system, an electric heater and any VOCs catalyst are provided inside, a combustible gas analyzer 17 is provided on the catalytic oxidation air inlet pipeline 11, the air outlet of the catalytic oxidation system 12 is connected to the chimney 14 through a flue gas pipeline 13, the air outlet of the fan 10 is connected to the catalytic oxidation air inlet pipeline 11, and the combustible gas analyzer 17 is interlocked with the motor 18 of the fan 10;

[0022] Sulfur-containing VOCs waste gas from upstream enters the air intake pipeline 1, and a discharge pipeline 2 is branched out from the air intake pipeline 1. The other end of the discharge pipeline 2 is connected to the chimney 14. A first shut-off valve 15 is provided on the air intake pipeline 1 on one side of the water seal tank 3, and a second shut-off valve 16 is provided on the discharge pipeline 2. An online detection port 19 is provided on the upper side wall of the chimney 14.

[0023] The decarbonylation sulfide catalyst bed 6 may also be any one of TiO2-based, Al2O3-based, and TiO2-based mixed solid catalysts, and the active component may also be any one of other alkali metals, alkaline earth metals, or transition metals.

[0024] The catalytic oxidation system 12 may also be a heat recovery catalytic oxidation system, and any other VOCs catalyst may be used inside.

[0025] The working process of this utility model:

[0026] VOCs waste gas emitted from upstream chemical, coal chemical and other fields often contains organic sulfur and inorganic sulfur components such as carbonyl sulfide and hydrogen sulfide, which can easily cause catalyst poisoning and deactivation.

[0027] The second shut-off valve 16 is closed, and the first shut-off valve 15 is opened. The VOCs waste gas emitted from the upstream chemical industry, coal chemical industry and other fields enters the water seal tank 3 through the air intake pipe 1 and is then sent to the downstream pretreatment system. By configuring the water seal tank 3, on the one hand, when the rear-end catalytic oxidation system 12 fails, it can play a role in preventing backfire and effectively protect the front-end chemical industry and coal chemical industry equipment; on the other hand, it can make the sulfur-containing VOCs waste gas carry a certain amount of water vapor before entering the downstream pretreatment system;

[0028] The sulfur-containing VOCs waste gas from the water seal tank 3 enters the decarbonylation sulfide tower 4, is first heated to 50-150°C by the first electric heater 5, and then passes through the decarbonylation sulfide catalyst 6 bed layer, where carbonyl sulfide and carbon disulfide in the sulfur-containing VOCs waste gas react with the trace amount of water vapor carried to generate hydrogen sulfide and carbon dioxide, thereby effectively removing organic sulfur components such as carbonyl sulfide and carbon disulfide;

[0029] Then, the VOCs waste gas from which organic sulfur components such as carbonyl sulfide and carbon disulfide have been removed comes out of the decarbonylation sulfide tower 4 and enters the dehydrogen sulfide tower 7, where it is first heated to 400°C by an electric heater 8 and then passes through a dehydrogen sulfide catalyst bed 9, where the hydrogen sulfide in the VOCs waste gas is catalytically oxidized into elemental sulfur, thereby achieving effective removal of inorganic sulfur components such as hydrogen sulfide.

[0030] The total sulfur in the VOCs waste gas after pretreatment in the decarbonylation sulfide tower 4 and the dehydrogen sulfide tower 7 meets the sulfur resistance technical index requirements of the catalyst in the downstream catalytic oxidation system 12. At the same time, fresh air is sent to the catalytic oxidation air intake pipeline 11 through the fan 10, mixed with the treated VOCs waste gas and then sent to the catalytic oxidation system 12; a combustible gas analyzer 17 is provided on the catalytic oxidation air intake pipeline 11, and the combustible gas analyzer 17 is interlocked with the motor 18 of the fan 10 to control the concentration of the combustible gas at the entrance of the catalytic oxidation system 12 to be below 25% of the lower explosion limit;

[0031] After the mixed gas enters the catalytic oxidation system 12, it is heated by an electric heater to stabilize the gas temperature at 400°C. Under the action of the catalyst, it is converted into harmless water vapor and carbon dioxide, and then discharged to the chimney 14 through the flue gas pipeline 13 to achieve standard emission.

[0032] When the decarbonyl sulfide tower 4, the dehydrogen sulfide tower 7 or the catalytic oxidation system 12 needs to be overhauled or the catalyst needs to be replaced, the second shut-off valve 16 is opened, the first shut-off valve 15 is closed, and the sulfur-containing VOCs waste gas enters the emergency discharge pipeline 2 and is directly sent to the chimney 14 for discharge;

[0033] The online detection port 19 provided on the chimney 14 can detect the exhaust gas in real time and grasp the treatment effect of the gas.

Claims

1. A catalytic oxidation treatment system for sulfur-containing VOCs waste gas, characterized in that: The invention comprises a water seal tank (3), a decarbonyl sulfide tower (4), a dehydrogen sulfide tower (7), a fan (10), a catalytic oxidation system (12) and a chimney (14), wherein the air inlet of the water seal tank (3) is externally connected to an air inlet pipeline (1), the air outlet of the water seal tank (3) is connected to the bottom of the decarbonyl sulfide tower (4), the top of the decarbonyl sulfide tower (4) is connected to the bottom of the dehydrogen sulfide tower (7), the top of the dehydrogen sulfide tower (7) is connected to the air inlet of the catalytic oxidation system (12) through a catalytic oxidation air inlet pipeline (11), the air outlet of the catalytic oxidation system (12) is connected to the chimney (14) through a flue gas pipeline (13), and the air outlet of the fan (10) is connected to the catalytic oxidation air inlet pipeline (11); Sulfur-containing VOCs waste gas from upstream enters an air intake pipeline (1), and a discharge pipeline (2) is branched from the air intake pipeline (1). The other end of the discharge pipeline (2) is connected to a chimney (14). A first shutoff valve (15) is provided on the air intake pipeline (1) on one side of the water seal tank (3), and a second shutoff valve (16) is provided on the discharge pipeline (2).

2. A catalytic oxidation treatment system for sulfur-containing VOCs waste gas according to claim 1, characterized in that: The decarbonylation sulfide tower (4) has a first electric heater (5) at the lower part and a decarbonylation sulfide catalyst bed (6) at the upper part.

3. A catalytic oxidation treatment system for sulfur-containing VOCs waste gas according to claim 1, characterized in that: A second electric heater (8) is provided at the lower part of the dehydrogen sulfide tower (7), and a dehydrogen sulfide catalyst bed (9) is provided at the upper part.

4. A catalytic oxidation treatment system for sulfur-containing VOCs waste gas according to claim 3, characterized in that: The dehydrogen sulfide catalyst bed (9) is an iron oxide-based catalyst.

5. A catalytic oxidation treatment system for sulfur-containing VOCs waste gas according to claim 1, characterized in that: A combustible gas analyzer (17) is provided on the catalytic oxidation air intake pipeline (11), and the combustible gas analyzer (17) is interlocked with the motor (18) of the fan (10).

6. A catalytic oxidation treatment system for sulfur-containing VOCs waste gas according to claim 1, characterized in that: An online detection port (19) is provided on the upper side wall of the chimney (14).

7. A catalytic oxidation treatment system for sulfur-containing VOCs waste gas according to claim 1, characterized in that: The catalytic oxidation system (12) is provided with either an electric heater or a VOCs catalyst.

8. A catalytic oxidation treatment system for sulfur-containing VOCs waste gas according to claim 1, characterized in that: The catalytic oxidation system (12) adopts any one of a heat storage type catalytic oxidation system and a heat recovery type catalytic oxidation system.

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