Organic waste gas treatment device and treatment method

Abstract

The invention discloses an organic waste gas treatment device and treatment method, and belongs to the technical field of waste gas treatment. Aiming at the problems of low treatment efficiency, high operation cost, secondary pollution and the like in the existing organic waste gas treatment technology, the device disclosed by the invention is formed by sequentially connecting a pretreatment unit, an adsorption concentration unit, a catalytic oxidation unit and a tail gas treatment unit, the adsorption concentration unit adsorbs organic matters by using activated carbon, after saturation, high-concentration waste gas is formed through hot air desorption, the catalytic oxidation unit converts the organic matters into carbon dioxide and water under the action of heating and a noble metal catalyst, and the tail gas treatment unit ensures that tail gas reaches the standard to be discharged through alkali liquor spraying and demisting. The processing method is matched with the device, and specific processing parameters are set in each step. Cooperative treatment of all the units is achieved, the organic matter removal rate is high, catalytic oxidation energy consumption is low, secondary pollution is reduced, the environmental protection performance is excellent, and good application prospects are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of waste gas treatment, and more particularly to a device and method for treating organic waste gas. Background Art

[0002] With the acceleration of the global industrialization process, the emission of organic waste gas has shown an exponential growth trend. The total amount of volatile organic compounds (VOCs) emitted into the atmosphere by petrochemical, printing, coating and other industries has exceeded 15 million tons each year. These organic waste gases are not only important precursors to the formation of PM2.5 and ozone pollution, but also contain various carcinogens such as benzene and formaldehyde. Long-term exposure to an environment containing such pollutants can cause respiratory diseases, nervous system damage and even induce malignant tumors.

[0003] The current mainstream organic waste gas treatment technologies each have their limitations. Although the adsorption method has the advantage of simple operation, the adsorption capacity of adsorbents such as activated carbon and molecular sieves is limited. They usually need to be replaced after a few months of operation. The resulting hazardous waste treatment costs increase the company's operating costs. Although the direct incineration technology in the combustion method has a high treatment efficiency, it requires heating the waste gas to above 800°C, resulting in high energy consumption costs. At the same time, secondary pollutants such as nitrogen oxides are easily generated during the high-temperature combustion process. Although the catalytic oxidation method can reduce the reaction temperature, the catalyst activity is easily affected by dust and sulfides in the waste gas, resulting in a shortened service life. Frequent catalyst replacement further increases the treatment cost. Developing a new organic waste gas treatment technology that combines high removal rate, low energy consumption, and zero secondary pollution is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a treatment device and method for organic waste gas. Through innovative composite treatment process and modular structural design, the problems of low treatment efficiency, high operating cost, secondary pollution and so on existing organic waste gas treatment technology are overcome, and the multiple goals of efficient purification of organic waste gas, resource recycling and low-carbon energy saving are achieved.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] First, the present invention provides a device for treating organic waste gas, comprising:

[0007] The pretreatment unit includes a pretreatment box, wherein an air inlet and an air outlet are respectively provided at both ends of the pretreatment box, and a filter screen, a porous partition plate and a condenser are sequentially arranged in the direction of exhaust gas flow in the pretreatment box;

[0008] The adsorption concentration unit includes an adsorption tower, wherein a honeycomb activated carbon adsorption layer is provided in the adsorption tower, the bottom end of the adsorption tower is connected to the condenser through a first pipeline, the top end of the adsorption tower is provided with a first outlet and a second outlet, and the bottom end of the adsorption tower is connected to a hot air generator;

[0009] A catalytic oxidation unit includes a catalytic reactor, wherein an inlet 1 and an inlet 2 are provided at an air inlet end of the catalytic reactor, wherein the inlet 1 is connected to the outlet 1 via a pipe 2, and the inlet 2 is connected to the outlet 2 via a pipe 3. A heating network and a catalyst bed are provided in the catalytic reactor in the order of exhaust gas flow, and valves are provided on both the pipe 2 and the pipe 3.

[0010] The tail gas treatment unit includes a spray tower and an alkali solution storage tank. The gas outlet of the catalytic reactor is connected to the bottom end of the spray tower through a pipeline 4. A spray layer is arranged in the middle of the spray tower. The spray layer is connected to the alkali solution storage tank through a liquid supply pipe. A demister is arranged at the top of the spray layer in the spray tower, and an exhaust port is arranged at the top of the spray tower.

[0011] Preferably, the filter is made of stainless steel and has a pore size of 0.1-0.5 mm.

[0012] Preferably, the pretreatment tank is provided with a liquid collecting hopper at the bottom end of the condenser, and the liquid collecting hopper is connected to the collection tank.

[0013] Preferably, the cooling temperature of the condenser is 5-15°C.

[0014] Preferably, the specific surface area of ​​the honeycomb activated carbon adsorption layer is greater than 1000m 2 / g, pore volume 0.6-0.8cm 3 / g, and multiple layers are provided.

[0015] Preferably, the hot air generator produces hot air at a temperature of 120-150°C and a flow rate of 50-100m 3 / h.

[0016] Preferably, the catalyst bed is made of a honeycomb ceramic carrier loaded with a precious metal platinum catalyst, the catalytically active component content is 1-3%, and the catalyst bed is provided with , and is arranged in parallel and staggered manner.

[0017] Preferably, the heating temperature of the heating network is 250-350°C.

[0018] Preferably, the spray layer is provided with multiple layers, and the alkali solution is a sodium hydroxide aqueous solution with a mass concentration of 5%-10%.

[0019] The present invention also provides a method for treating organic waste gas, which uses the device described in the above technical solution and includes the following steps:

[0020] Step 1: Preprocessing

[0021] The organic waste gas enters the pretreatment unit through the air inlet pipe, is filtered by the filter to remove particulate matter and impurities in the waste gas, and then enters the condenser through the porous partition to cool and remove high-boiling-point organic matter;

[0022] Step 2: Adsorption and concentration

[0023] Close the valve on pipeline three, and the pretreated organic waste gas enters the adsorption tower, where it fully contacts the honeycomb activated carbon adsorbent. The organic matter is adsorbed by the adsorbent and then discharged from pipeline two through outlet one.

[0024] When the activated carbon adsorbent reaches saturation, close the valve on pipeline 2, open the valve on pipeline 3, start the hot air generator, and use hot air to desorb and regenerate the activated carbon. The high-concentration organic waste gas generated by desorption is discharged from pipeline 3 through outlet 2.

[0025] Step 3: Catalytic oxidation

[0026] The organic waste gas after adsorption or the high-concentration organic waste gas after desorption enters the catalytic reactor, and after being heated by the heating net, a catalytic oxidation reaction occurs under the action of the catalyst bed, converting the organic matter into carbon dioxide and water;

[0027] Step 4: Exhaust gas treatment

[0028] The tail gas after catalytic oxidation enters the spray tower, where it comes into contact with the alkaline solution under the action of the spray layer to remove the acid gas and residual organic matter in the tail gas. Finally, it is discharged after the water mist is removed by the demister.

[0029] It can be seen from the above technical solutions that, compared with the prior art, the present invention provides a device and method for treating organic waste gas, which has the following beneficial effects:

[0030] The organic waste gas treatment device of the present invention integrates multiple units such as pretreatment, adsorption concentration, catalytic oxidation and tail gas treatment. Through the synergistic effect of each unit, it can efficiently treat organic waste gas, with high treatment efficiency and high organic matter removal rate; it adopts adsorption concentration technology to concentrate low-concentration organic waste gas into high-concentration waste gas for catalytic oxidation treatment, which reduces the energy consumption of catalytic oxidation and saves operating costs; the catalytic oxidation unit adopts a high-efficiency catalyst to achieve complete oxidation of organic matter at a lower temperature, reducing energy consumption and the generation of secondary pollutants such as nitrogen oxides; the tail gas treatment unit further removes pollutants in the tail gas through alkali solution spraying and demisting treatment, ensuring that the discharged tail gas meets the relevant national emission standards and has good environmental performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0032] Figure 1 This is an overall structural diagram of an organic waste gas treatment device of the present invention;

[0033] In the figure, 1-pretreatment box, 2-air inlet, 3-air outlet, 4-filter, 5-porous partition, 6-condenser, 7-adsorption tower, 8-activated carbon adsorption layer, 9-pipeline one, 10-outlet one, 11-outlet two, 12-catalytic reactor, 13-inlet one, 14-inlet two, 15-pipeline two, 16-pipeline three, 17-valve, 18-heating network, 19-catalyst bed, 20-spray tower, 21-alkali solution storage tank, 22-pipeline four, 23-spray layer, 24-liquid supply pipe, 25-demister, 26-exhaust port, 27-hot air generator, 28-liquid collecting hopper, 29-collection box. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0035] As attached Figure 1 The organic waste gas treatment device includes:

[0036] The pretreatment unit includes a pretreatment box 1, with an air inlet 2 and an air outlet 3 provided at both ends of the pretreatment box 1. The pretreatment box 1 includes a filter 4, a porous partition 5 and a condenser 6 arranged in sequence in the direction of exhaust gas flow;

[0037] The adsorption concentration unit includes an adsorption tower 7, wherein a honeycomb activated carbon adsorption layer 8 is provided in the adsorption tower 7. The bottom end of the adsorption tower 7 is connected to the condenser 6 via a pipe 9. The top of the adsorption tower 7 is provided with an outlet 10 and an outlet 2 11. The bottom end of the adsorption tower 7 is connected to a hot air generator 27.

[0038] The catalytic oxidation unit includes a catalytic reactor 12. The catalytic reactor 12 is provided with an inlet 13 and an inlet 2 14 at the air inlet end. The inlet 13 is connected to the outlet 10 via a pipe 2 15. The inlet 2 14 is connected to the outlet 2 11 via a pipe 3 16. A heating network 18 and a catalyst bed are sequentially provided in the catalytic reactor 12 in the direction of exhaust gas flow. Valves 17 are provided on both the pipe 2 15 and the pipe 3 16.

[0039] The tail gas treatment unit includes a spray tower 20 and an alkali liquid storage tank 21. The gas outlet of the catalytic reactor 12 is connected to the bottom end of the spray tower 20 via a pipeline 22. A spray layer 23 is provided in the middle of the spray tower 20. The spray layer 23 is connected to the alkali liquid storage tank 21 via a liquid supply pipe 24. A demister 25 is provided at the top of the spray layer 23 in the spray tower 20. An exhaust port 26 is provided at the top of the spray tower 20.

[0040] The filter 4 is made of stainless steel with a pore size of 0.1-0.5 mm, and is used to filter particulate matter and impurities in the exhaust gas to prevent them from entering the subsequent treatment unit and affecting the treatment effect.

[0041] The pretreatment box 1 is provided with a liquid collecting hopper 28 at the bottom end of the condenser 6. The liquid collecting hopper 28 is connected to the collection box 29. The cooling temperature of the condenser 6 is 5-15°C. The condenser 6 cools the organic waste gas, so that some of the high-boiling point organic matter in the waste gas is condensed into liquid and enters the collection box 29 for subsequent separation.

[0042] The specific surface area of ​​the honeycomb activated carbon adsorption layer 8 is greater than 1000m 2 / g, pore volume 0.6-0.8cm 3 / g, and is equipped with multiple layers, which has good adsorption performance for organic waste gas.

[0043] The hot air generator 27 produces hot air at a temperature of 120-150°C and a flow rate of 50-100m 3 / h;

[0044] The catalyst bed 19 is made of a honeycomb ceramic carrier loaded with precious metal platinum catalyst, and the catalytic active component content is 1-3%. The catalyst bed 19 is provided with a plurality of catalyst beds 19 and arranged in parallel and staggered manner. The exhaust gas flows back and forth to extend the treatment path and improve the treatment effect.

[0045] The heating temperature of the heating network 18 is 250-350°C, which fully heats the exhaust gas and improves the catalytic oxidation treatment effect.

[0046] The spray layer 23 is provided with multiple layers, and the alkali solution is a sodium hydroxide aqueous solution with a mass concentration of 5%-10%. The multi-layer spraying ensures that the exhaust gas is fully in contact with the alkali solution.

[0047] The specific processing process is as follows:

[0048] Step 1: Preprocessing

[0049] The organic waste gas enters the pretreatment unit through the air inlet pipe, is filtered by the filter 4 to remove particulate matter and impurities in the waste gas, and then passes through the porous partition 5 to enter the condenser 6 for cooling to remove high-boiling-point organic matter;

[0050] Step 2: Adsorption and concentration

[0051] Close valve 17 on pipeline three 16, and the pretreated organic waste gas enters adsorption tower 7, where it fully contacts the adsorbent in honeycomb activated carbon layer 8. After being adsorbed by the adsorbent, the organic matter is discharged from pipeline two 15 through outlet one 10.

[0052] When the activated carbon adsorbent layer 8 reaches saturation, the valve 17 on the second pipe 15 is closed, the valve 17 on the third pipe 16 is opened, and the hot air generator 27 is started to desorb and regenerate the activated carbon using hot air. The high-concentration organic waste gas generated by desorption is discharged from the third pipe 16 through the second outlet 11;

[0053] Step 3: Catalytic oxidation

[0054] The organic waste gas after adsorption or the high-concentration organic waste gas after desorption enters the catalytic reactor 12, and after being heated by the heating network 18, a catalytic oxidation reaction occurs under the action of the catalyst bed 19, converting the organic matter into carbon dioxide and water;

[0055] Step 4: Exhaust gas treatment

[0056] The tail gas after catalytic oxidation enters the spray tower 20 and is contacted with the alkaline solution under the action of the spray layer 23 to remove the acid gas and residual organic matter in the tail gas. Finally, it passes through the demister 25 to remove the water mist and is discharged through the exhaust port 26.

[0057] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0058] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A device for treating organic waste gas, characterized in that: include: The pretreatment unit includes a pretreatment box, wherein an air inlet and an air outlet are respectively provided at both ends of the pretreatment box, and a filter screen, a porous partition plate and a condenser are sequentially arranged in the direction of exhaust gas flow in the pretreatment box; The adsorption concentration unit includes an adsorption tower, wherein a honeycomb activated carbon adsorption layer is provided in the adsorption tower, the bottom end of the adsorption tower is connected to the condenser through a first pipeline, the top end of the adsorption tower is provided with an outlet first and an outlet second, and the bottom end of the adsorption tower is connected to a hot air generator; A catalytic oxidation unit includes a catalytic reactor, wherein an inlet 1 and an inlet 2 are provided at an air inlet end of the catalytic reactor, the inlet 1 is connected to the outlet 1 via a pipe 2, and the inlet 2 is connected to the outlet 2 via a pipe 3. A heating network and a catalyst bed are provided in the catalytic reactor in the order of exhaust gas flow, and valves are provided on both pipes 2 and 3. The tail gas treatment unit includes a spray tower and an alkali solution storage tank. The gas outlet of the catalytic reactor is connected to the bottom end of the spray tower through a pipeline 4. A spray layer is arranged in the middle of the spray tower. The spray layer is connected to the alkali solution storage tank through a liquid supply pipe. A demister is arranged at the top of the spray layer in the spray tower, and an exhaust port is arranged at the top of the spray tower.

2. The organic waste gas treatment device according to claim 1, characterized in that: The filter is made of stainless steel and has a pore size of 0.1-0.5 mm.

3. The organic waste gas treatment device according to claim 1, characterized in that: The pretreatment box is provided with a liquid collecting hopper at the bottom end of the condenser, and the liquid collecting hopper is connected to the collection box.

4. The organic waste gas treatment device according to claim 1, characterized in that: The cooling temperature of the condenser is 5-15°C.

5. The organic waste gas treatment device according to claim 1, characterized in that: The specific surface area of ​​the honeycomb activated carbon adsorption layer is greater than 1000m 2 / g, pore volume 0.6-0.8cm 3 / g, and multiple layers are provided.

6. The organic waste gas treatment device according to claim 1, characterized in that: The hot air generator produces hot air at a temperature of 120-150°C and a flow rate of 50-100m 3 / h.

7. The organic waste gas treatment device according to claim 1, characterized in that: The catalyst bed is made of a honeycomb ceramic carrier loaded with a precious metal platinum catalyst, and the content of the catalytically active component is 1-3%. The catalyst bed is provided with , and is arranged in parallel and staggered manner.

8. The organic waste gas treatment device according to claim 1, characterized in that: The heating temperature of the heating network is 250-350°C.

9. The organic waste gas treatment device according to claim 1, characterized in that: The spray layer is provided with multiple layers, and the alkali solution is a sodium hydroxide aqueous solution with a mass concentration of 5%-10%.

10. A method for treating organic waste gas, characterized in that: The device according to any one of claims 1 to 9 comprises the following steps: Step 1: Preprocessing The organic waste gas enters the pretreatment unit through the air inlet pipe, is filtered by the filter to remove particulate matter and impurities in the waste gas, and then enters the condenser through the porous partition to cool and remove high-boiling-point organic matter; Step 2: Adsorption and concentration Close the valve on pipeline three, and the pretreated organic waste gas enters the adsorption tower, where it fully contacts the honeycomb activated carbon adsorbent. The organic matter is adsorbed by the adsorbent and then discharged from pipeline two through outlet one. When the activated carbon adsorbent reaches saturation, close the valve on pipeline 2, open the valve on pipeline 3, start the hot air generator, and use hot air to desorb and regenerate the activated carbon. The high-concentration organic waste gas generated by desorption is discharged from pipeline 3 through outlet 2. Step 3: Catalytic oxidation The organic waste gas after adsorption or the high-concentration organic waste gas after desorption enters the catalytic reactor, and after being heated by the heating net, a catalytic oxidation reaction occurs under the action of the catalyst bed, converting the organic matter into carbon dioxide and water; Step 4: Exhaust gas treatment The tail gas after catalytic oxidation enters the spray tower, where it comes into contact with the alkaline solution under the action of the spray layer to remove the acid gas and residual organic matter in the tail gas. Finally, it is discharged after the water mist is removed by the demister.

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