Organic tail gas resourceful treatment equipment and method thereof

Abstract

The invention relates to machine tail gas resourceful treatment equipment and a method thereof.The machine tail gas resourceful treatment equipment comprises a first-stage absorption tower used for recycling tail gas; the secondary absorption tower is used for carrying out secondary treatment on the tail gas and meeting up-to-standard emission; the reaction device is suitable for treating the secondarily treated absorption liquid; the absorption liquid circulating cooler is suitable for providing the absorption liquid treated by the reaction device to the secondary absorption tower to serve as an absorbent; the absorbent cooler is suitable for cooling an absorbent and supplying the absorbent to the primary absorption tower and the secondary absorption tower; step S1, discharging the absorption liquid out of the first-stage absorption tower, and carrying out resource recovery on effective components of the absorption liquid; s2, the tail gas and an absorbent are mixed in a second-stage absorption tower, so that pollutants in the tail gas are fully absorbed in a countercurrent mode, and harmful substances in absorption liquid in the reactor are decomposed. According to the machine tail gas resourceful treatment equipment and method, the treated tail gas can be discharged into the atmosphere.

Description

Technical Field

[0001] The present invention relates to the field of tail gas treatment, and in particular to equipment and method for resource-based treatment of organic tail gas. Background Art

[0002] Organic tail gas containing toxic and harmful compounds is generated during the production or storage and transportation of chemical, pharmaceutical, resin and other related industries. The direct emission of organic tail gas not only causes environmental pollution and harms human health, but also easily causes safety risks such as fire and explosion. Therefore, the tail gas must be treated and recycled.

[0003] The application number is: CN201520013012.8, the publication (announcement) number is: CN204619569U, and a waste gas treatment system generated in the production of epichlorohydrin is disclosed, including an epichlorohydrin waste gas treatment device, a dust-containing waste gas treatment device and a chimney. The epichlorohydrin waste gas treatment device includes a primary condenser and a secondary condenser, the primary condenser and the secondary condenser are connected, the secondary condenser is connected to a liquid nitrogen condenser, the liquid nitrogen condenser is connected to a UV photolysis catalyst, the UV photolysis catalyst is connected to an alkali liquid spray tower, and the alkali liquid spray tower is connected to the chimney through a centrifugal fan; the publication (announcement) number is: CN112657315A, and the patent application number is: CN20191097 5996.0, discloses a method for treating epichlorohydrin waste gas, comprising the following steps: (1) the ECH waste gas is sent from the bottom to an acid washing tower, and the top of the acid washing tower is sprayed with hydrochloric acid to wash and absorb the ECH waste gas, and the washed ECH waste gas comes out from the top of the acid washing tower and enters the next process; (2) the washed ECH waste gas from step (1) is sent to an incinerator for incineration at a temperature of 850-1000°C, and ECH is incinerated and decomposed in the incinerator to obtain incineration waste gas; (3) the incineration waste gas from step (2) is rapidly cooled to 80-100°C and then sent from the bottom to an alkali washing tower, and the top of the alkali washing tower is sprayed with alkali solution to wash and absorb HCl, and the remaining CO2 and H2O come out from the top of the alkali washing tower and are discharged through a chimney. After treatment, the present invention not only reduces the ECH content in the waste gas to 5 mg / m3, meeting the ECH waste gas emission standard, but also converts more than 95% of the ECH into recyclable dichloropropanol; Publication (Announcement) No.: CN204619569U, application No. 201520013012.8, discloses a waste gas treatment system generated in the production of epichlorohydrin, which adopts a primary condenser and a secondary condenser for graded condensation, and then passes through a UV photolysis catalyst after condensation, and finally sprays alkali washing before discharge; Publication (Announcement) No.: CN111233622A, application No.: Patent application number 2018114426686 discloses a method for treating waste gas generated in the process of producing epichlorohydrin by epoxidation of allyl chloride. In this method, nitrogen is first added to dilute the tail gas. After dilution, the tail gas passes through a three-stage condenser to recover condensed allyl chloride and condensed water, and then enters a membrane filter to filter the gas containing allyl chloride. The gas containing allyl chloride is compressed to recover the allyl chloride; the inorganic gas filtered out by the membrane filter is condensed through a four-stage condenser to recover trace allyl chloride therein to meet the emission standards; the above technical solution can solve the problem of ordinary tail gas; it cannot solve the problem of epichlorohydrin in the tail gas.

[0004] Since the organic tail gas contains epichlorohydrin, which has very strong bactericidal properties, it is poorly biodegradable; epichlorohydrin is easily hydrolyzed by heat and produces highly corrosive media such as hydrogen chloride and high-boiling point propylene glycol, which makes desorption difficult, so the adsorption method is difficult to apply; there is currently a lack of technical problems in the treatment of tail gas containing epichlorohydrin, and it is urgent to design an efficient method for resource recovery and treatment of epichlorohydrin tail gas.

[0005] It should be noted that the above information disclosed in this background technology section is only for understanding the background technology of the present application concept, and therefore, it may contain information that does not constitute the prior art. Summary of the invention

[0006] The purpose of the present invention is to provide an organic tail gas resource treatment device and method to solve the above problems.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] Organic tail gas resource treatment equipment and method, including:

[0009] A primary absorption tower, which is used for preliminary treatment of tail gas;

[0010] A secondary absorption tower is used for secondary treatment of tail gas so that the tail gas can be graded;

[0011] A reaction device adapted to process the secondary treated absorption liquid;

[0012] An absorption liquid circulation cooler, which is suitable for providing the absorption liquid treated by the reaction device to the secondary absorption tower to serve as an absorbent;

[0013] The absorbent cooler is suitable for cooling the absorbent and providing it to the primary absorption tower and the secondary absorption tower.

[0014] In an optional embodiment, the reaction device includes a heater for heating the absorption liquid and a reactor serving as a reaction vessel;

[0015] One end of the heater is connected to the secondary absorption tower, and the other end of the heater is connected to the reactor;

[0016] The reactor is connected to the secondary absorption tower through an absorption liquid circulation cooler, so that the unreacted absorption liquid acts as an absorbent and is supplied to the secondary absorption tower after being cooled.

[0017] In a second aspect, the present disclosure also provides a method for resource processing of organic tail gas, comprising the following steps:

[0018] Step S1, the tail gas enters the primary absorption tower from the bottom after cooling, and the absorbent enters the primary absorption tower from the top after cooling, and the tail gas and the absorbent are mixed in the primary absorption tower so that the pollutants in the tail gas are initially countercurrently absorbed, and the absorbent becomes an absorption liquid after absorbing the tail gas pollutants, and the absorption liquid is discharged from the primary absorption tower to recycle its effective components;

[0019] Step S2, the tail gas discharged from the primary absorption tower enters the secondary absorption tower from the bottom, the absorbent enters the secondary absorption tower from the top after cooling, the tail gas and the absorbent are mixed in the secondary absorption tower so that the pollutants in the tail gas are fully countercurrently absorbed, the secondary absorption tower directly discharges the treated tail gas, the absorption liquid discharged from the secondary absorption tower passes through the heater and then enters the reactor, and the harmful substances in the absorption liquid are decomposed in the reactor; after the absorption liquid discharged from the reactor passes through the absorption liquid circulating cooler and reaches the secondary absorption tower, the absorption liquid continues to be used as an absorbent.

[0020] In an optional embodiment, in the step S1, the tail gas is transported to a gas cooler for cooling, the cooling medium used is chilled water, and the cooled tail gas enters a primary absorption tower; after the absorbent is transported to an absorbent cooler using chilled brine as a cooling medium for cooling, the absorbent enters the primary absorption tower and is fully distributed by a liquid distributor and then countercurrently contacts with the tail gas, and organic matter in the tail gas is diffused and dissolved into the absorption liquid; the absorption liquid is extracted from the bottom of the primary absorption tower via a primary absorption liquid extraction pump, a part of which is extracted to an organic matter recovery system, and a part of which is cooled by an absorption liquid circulation cooler and then enters a secondary absorption tower to serve as an absorbent and continue to be recycled;

[0021] In the step S2, the tail gas enters the secondary absorption tower from the bottom, the absorbent is cooled by the absorbent cooler and the absorption liquid circulation cooler, enters the secondary absorption tower, and is fully distributed by the liquid distributor and countercurrently contacts with the tail gas, and the organic matter in the tail gas is diffused and dissolved into the absorption liquid, and the tail gas after the secondary absorption is discharged through the chimney;

[0022] The absorption liquid after secondary absorption is taken out from the bottom of the secondary absorption tower through the secondary absorption liquid extraction pump, enters the heater for preheating, and then enters the reactor for reaction to remove organic matter. The absorption liquid treated in the reactor is sent to the absorption liquid circulation cooler for cooling, and then returns to the secondary absorption tower for recycling as absorbent.

[0023] In an optional embodiment, the primary absorption tower and the secondary absorption tower are both sieve plate towers, floating valve towers or packed towers;

[0024] The number of the primary absorption tower and the secondary absorption tower is the same.

[0025] In an optional embodiment, the tail gas is one or more combinations of epichlorohydrin, ethylene oxide and propylene oxide;

[0026] The organic matter concentration in the tail gas is 2000-100000 mg / Nm 3 .

[0027] In an optional embodiment, the absorbent is water; water has a good absorption effect on epichlorohydrin, ethylene oxide, and propylene oxide. Moreover, using water as an absorbent will not introduce new organic matter, and the subsequent recovery unit will not introduce new impurities.

[0028] In an optional embodiment, the reactor is a tubular reactor, a tank reactor or a tower reactor;

[0029] The reactor is loaded with a basic catalyst.

[0030] In an optional embodiment, the base catalyst in the reactor is a solid catalyst;

[0031] The alkaline catalyst is one or a combination of an inorganic porous material-supported alkaline catalyst and a resin-supported alkaline catalyst.

[0032] In an optional embodiment, the heater heats the absorption liquid discharged from the secondary absorption tower to a temperature in the range of 50 to 90°C.

[0033] In an optional embodiment, the heater heats the absorption liquid discharged from the secondary absorption tower to a temperature preferably in the range of 60 to 80°C.

[0034] The beneficial effects of the present invention are: providing equipment and method for resource-based treatment of organic tail gas, by using a primary absorption tower, a secondary absorption tower, a reaction device and an absorption liquid circulating cooler in coordination with each other, manufacturing equipment and method for resource-based treatment of organic tail gas, treating organic tail gas, achieving the effect of resource-based treatment of tail gas containing epoxychlorobenzene, the treated tail gas can be discharged into the atmosphere, and the intermediate product can be utilized as a resource. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1A flow chart of the tail gas absorption method of the organic tail gas resource treatment equipment and method provided in the embodiments of the present disclosure.

[0037] In the figure: 1. Primary absorption tower;

[0038] 2. Secondary absorption tower;

[0039] 3. Heater;

[0040] 4. Reactor;

[0041] 5. Absorption liquid circulation cooler;

[0042] 6. Absorbent cooler. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] In this article, when it is mentioned that the first component is located on the second component, this may mean that the first component may be directly formed on the second component, or the third component may be interposed between the first component and the second component. In addition, in the drawings, in order to effectively describe the technical content, the thickness of the components may be exaggerated or reduced.

[0045] Herein, example embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as "at least one of..." modify the entire list of elements when following a list of elements, rather than modifying individual elements in the list. For example, the expression "at least one of a, b, and c" should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0046] The terms used herein are only used to describe specific exemplary configurations and are not intended to be limiting. As used herein, the singular articles "a", "an", and "the" may also be intended to include plural forms, unless the above text clearly indicates otherwise. The terms "comprise", "include", and "have" are inclusive, thus specifying the presence of features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof.

[0047] As used herein, the phrases "in one embodiment," "according to one embodiment," "in some embodiments," and the like generally refer to the fact that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure. Therefore, a particular feature, structure, or characteristic may be included in more than one embodiment of the present disclosure, so that these phrases do not necessarily refer to the same embodiment. As used herein, the terms "example," "exemplary," and the like are used to "serve as an example, instance, or illustration." Any implementation, aspect, or design described herein as "example" or "exemplary" is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. On the contrary, the use of the terms "example," "exemplary," and the like is intended to present concepts in a concrete manner.

[0048] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0049] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0050] Example 1

[0051] refer to Figure 1 At least one embodiment provides an organic tail gas resource treatment device, including a primary absorption tower 1, a secondary absorption tower 2, a heater 3, a reactor 4, an absorption liquid circulating cooler 5 and an absorbent cooler 6; the primary absorption tower 1, the secondary absorption tower 2, the heater 3, the reactor 4, the absorption liquid circulating cooler 5 and the absorbent cooler 6 are all provided with an inlet and an outlet; the first outlet of the primary absorption tower 1 is connected to the first inlet pipeline of the secondary absorption tower 2; the first outlet of the secondary absorption tower 2 is connected to the first inlet pipeline of the heater 3; the first outlet of the heater 3 is connected to the second inlet pipeline of the reactor 4; the outlet of the reactor 4 is connected to the inlet pipeline of the absorption liquid circulating cooler 5; the first outlet of the absorbent cooler 6 is connected to the first inlet pipeline of the primary absorption tower 1; the second outlet of the absorbent cooler 6 is connected to the second inlet pipeline of the secondary absorption tower 2.

[0052] In some embodiments, a method for treating organic tail gas for resource utilization is provided, comprising the following steps:

[0053] In step S1, the tail gas enters the primary absorption tower 1 from the bottom after being cooled, and the absorbent enters the absorption tower from the top after being cooled by the absorbent coolant 6, and is countercurrently absorbed in the absorption tower, and the absorption liquid returns to the method system to recycle the effective components; the first absorption tower 1 and the second absorption tower 2 are sieve plate towers, floating valve towers or packed towers.

[0054] The tail gas after primary absorption enters the secondary absorption tower 2 from the bottom, and the absorbent enters the secondary absorption tower 2 from the top after cooling, and is absorbed in the absorption tower in countercurrent. The tail gas after secondary absorption is directly discharged through the chimney, and the absorption liquid is preheated by the heater 3 and enters the reactor 4. Substances such as epichlorohydrin in the absorption liquid undergo hydrolysis reaction under the action of alkaline catalyst to generate water-soluble substances such as polyols. The absorption liquid after reaction treatment is cooled as absorbent and provided to the secondary absorption tower 2 for continued use. The absorbent is supplemented according to the volatilization amount during the absorption process. The tail gas contains one or more combinations of water-soluble organic matter; the water-soluble organic compound is epichlorohydrin, ethylene oxide or propylene oxide.

[0055] The absorption liquid circulating cooler 5 is a tubular reactor, a kettle reactor or a tower reactor.

[0056] Example 2

[0057] refer to Figure 1 At least one embodiment provides an organic tail gas resource processing equipment, comprising the following steps: in step S1, the organic tail gas to be treated is transported to a gas cooler for cooling, the refrigerant used for cooling the gas cooler is chilled water, and the cooled organic tail gas enters the primary absorption tower 1 from the bottom; the absorbent is transported to the primary absorbent cooler by a primary absorbent delivery pump, and the primary absorbent cooler uses chilled brine as a refrigerant for cooling, and the absorbent in the primary absorbent cooler enters the primary absorption tower 1 from the top, and after being fully distributed by a liquid distributor, it contacts with the tail gas in the absorption tower 1 in countercurrent, and the organic matter in the organic tail gas is diffused and dissolved into the absorbent; the absorption liquid is extracted from the bottom of the tower through a primary absorption liquid extraction pump, and a part of it enters the middle or top of the absorption tower after cooling and is recycled as an absorbent, and a part of it is extracted to the organic matter recovery system for treatment. The organic matter recovery system can borrow the distillation tower system of the epichlorohydrin production process to recover the organic matter such as epichlorohydrin to be recovered through distillation.

[0058] In step S2, the tail gas after primary absorption enters the secondary absorption tower 2 from the bottom, and the absorbent enters the secondary absorption tower 2 from the top after cooling. After being fully distributed by the liquid distributor, it contacts with the gas phase in the secondary absorption tower 2 in countercurrent. The organic matter in the tail gas enters the liquid phase after diffusion and dissolution. The tail gas after secondary absorption is discharged through the chimney. The absorption liquid is extracted from the bottom of the tower through the secondary absorption liquid extraction pump and enters the secondary absorption liquid heater 3. Then the secondary absorption liquid enters the reactor 4 to react and remove the organic matter therein. Substances such as epichlorohydrin in the absorption liquid undergo hydrolysis reaction under the action of an alkaline catalyst to generate water-soluble substances such as polyols. The absorption liquid after the reaction treatment is cooled as an absorbent and provided to the secondary absorption tower 2 for continued use. The reaction liquid absorbent is sent to the primary absorption liquid preheater through a circulation pump for cooling, and then circulated as an absorbent.

[0059] Example 3

[0060] The exhaust gas contains 30000mg / Nm 3 Epichlorohydrin, gas flow rate 2000m 3 / h, the tail gas is cooled to 0℃ and then enters the primary absorption tower 1. After absorption in the primary absorption tower 1, the tail gas concentration is 3300mg / m 3 The concentration of the first-stage absorption liquid is 3.4Wt.%, which is returned to the production section for resource recovery. The tail gas after the first-stage absorption enters the second-stage absorption tower 2. After absorption treatment, the tail gas concentration is 4mg / m 3 , meeting emission standards.

[0061] The secondary absorption liquid is preheated to 60°C by the heater 3 and enters the reactor 4 for reaction treatment. Under the action of the molecular sieve-loaded alkali catalyst with a concentration of 5%, epichlorohydrin is hydrolyzed into substances such as propylene glycol and glycerol. These substances will not affect the absorption effect of epichlorohydrin, but will improve the absorption effect. The absorption liquid after the reaction treatment is used as an absorbent and then cooled and recycled. The alcohol substances in the reactor 4 will be enriched over time, and can be regularly extracted in small quantities and sent to the wastewater treatment system for biochemical treatment. Compared with epichlorohydrin, alcohol substances are easily degraded by fungi and can meet the requirements for emission standards.

[0062] Example 4

[0063] The exhaust gas contains 8000mg / Nm 3 Ethylene oxide and epichlorohydrin, gas flow rate 3000m 3 / h, the tail gas is cooled to 0℃ and then enters the primary absorption tower 1. After being absorbed by the primary absorption tower 1, the tail gas concentration is 2400mg / m 3 The concentration of the first-stage absorption liquid is 3.0Wt.%, which is returned to the production section for resource recovery. The tail gas after the first-stage absorption enters the second-stage absorption tower 2. After absorption treatment, the tail gas concentration is 3mg / m3 , meeting emission standards.

[0064] The secondary absorption liquid is preheated to 80°C by a heater and enters reactor 4 for treatment. Under the action of a resin-supported alkaline catalyst with a concentration of 5%, the secondary absorption liquid is hydrolyzed into substances such as ethylene glycol, which will not affect the absorption effect of ethylene oxide and epichlorohydrin, but will improve the absorption effect. The absorption liquid after the reaction treatment is used as an absorbent and then cooled for recycling. The alcohol substances in reactor 4 will be enriched over time and can be regularly extracted in small quantities to the wastewater system for biochemical treatment.

[0065] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0066] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0067] Although this patent document contains many details, they should not be construed as limitations on the scope of any invention or the claims, but rather as descriptions of features of particular embodiments of particular inventions. Certain features described in this patent document in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various functions described in the context of a single embodiment may also be implemented separately in multiple embodiments, or in any suitable subcombination. In addition, although the above-mentioned features may be described as working in certain combinations, or even initially claimed to be so, in some cases, one or more features in the claim combination may be removed from the combination, and the claim combination may be directed to subcombinations or variations of subcombinations.

[0068] Likewise, although operations are described in a particular order in the drawings, this should not be understood as requiring that such operations be performed in the particular order or order shown, or that all illustrated operations be performed, in order to achieve the desired results. In addition, the separation of various system components in the embodiments of this patent document should not be understood as requiring such separation in all embodiments.

[0069] Only a few implementations and examples are described, and other implementations, enhancements, and variations can be made based on what is described and illustrated in this patent document.

[0070] Although several embodiments are provided in the present disclosure, it should be understood that the disclosed systems and methods may be embodied in many other specific forms without departing from the spirit or scope of the present disclosure. The present examples are considered to be illustrative rather than restrictive and are not limited to the details given. For example, various elements or components may be combined or integrated in another system, or certain features may be omitted or not implemented.

Claims

1. An organic tail gas resource treatment equipment, characterized in that: include: A primary absorption tower (1), which is used to recover and process tail gas; A secondary absorption tower (2) is used for secondary treatment of the tail gas so that the tail gas is graded; A reaction device adapted to process the secondary treated absorption liquid; An absorption liquid circulation cooler (5), which is suitable for providing the absorption liquid treated by the reaction device to the secondary absorption tower (2) to serve as an absorbent; An absorbent cooler (6) is adapted to cool the absorbent and supply it to the primary absorption tower (1) and the secondary absorption tower (2).

2. The organic tail gas resource treatment equipment according to claim 1, characterized in that: The reaction device comprises a heater (3) for heating the absorption liquid and a reactor (4) serving as a reaction container; One end of the heater (3) is connected to the secondary absorption tower (2), and the other end of the heater (3) is connected to the reactor (4); The reactor (4) is connected to the secondary absorption tower (2) via an absorption liquid circulation cooler (5) so that the unreacted absorption liquid can be supplied to the secondary absorption tower (2) as an absorbent after being cooled.

3. A method for recycling organic tail gas, characterized in that: The steps include: Step S1, the exhaust gas is cooled and enters the primary absorption tower (1) from the bottom, the absorbent is cooled and enters the primary absorption tower (1) from the top, the exhaust gas and the absorbent are mixed in the primary absorption tower (1) so that the pollutants in the exhaust gas are initially absorbed by countercurrent, the absorbent absorbs the exhaust gas pollutants and becomes an absorption liquid, and the absorption liquid is discharged from the primary absorption tower (1) to recover its effective components; Step S2, the tail gas discharged from the primary absorption tower (1) enters the secondary absorption tower (2) from the bottom, the absorbent enters the secondary absorption tower (2) from the top after cooling, the tail gas and the absorbent are mixed in the secondary absorption tower (2) so that the pollutants in the tail gas are fully countercurrently absorbed, the secondary absorption tower (2) directly discharges the treated tail gas, the absorption liquid discharged from the secondary absorption tower (2) passes through the heater (3) and then enters the reactor (4), and the harmful substances in the absorption liquid are decomposed in the reactor (4); after the absorption liquid discharged from the reactor (4) passes through the absorption liquid circulation cooler (5) and reaches the secondary absorption tower (2), the absorption liquid continues to be used as an absorbent.

4. The method for recycling organic tail gas according to claim 3, characterized in that: In the step S1, the tail gas is transported to a gas cooler for cooling, and the cooling medium used is chilled water. The cooled tail gas enters a primary absorption tower (1); the absorbent is transported to an absorbent cooler (6) using chilled brine as a cooling medium for cooling, and then the absorbent enters the primary absorption tower (1) and is fully distributed by a liquid distributor and then countercurrently contacts with the tail gas, and organic matter in the tail gas is diffused and dissolved into the absorption liquid; the absorption liquid is extracted from the bottom of the primary absorption tower (1) via a primary absorption liquid extraction pump, a portion of which is extracted to an organic matter recovery system, and a portion of which is cooled by an absorption liquid circulation cooler (5) and then enters a secondary absorption tower (2) to serve as an absorbent and continue to be circulated; In the step S2, the tail gas enters the secondary absorption tower (2) from the bottom, the absorbent is cooled by the absorbent cooler (6) and the absorption liquid circulation cooler (5) and then enters the secondary absorption tower (2), and is fully distributed by the liquid distributor and then countercurrently contacts with the tail gas, and the organic matter in the tail gas is diffused and dissolved into the absorption liquid, and the tail gas after the secondary absorption is discharged through the chimney; The absorption liquid after the secondary absorption is taken out from the bottom of the secondary absorption tower (2) via the secondary absorption liquid taking-out pump, enters the heater (3) for preheating, and then enters the reactor (4) for reaction to remove organic matter therein. The absorption liquid treated in the reactor (4) is sent to the absorption liquid circulation cooler (5) for cooling, and then returns to the secondary absorption tower (2) for recycling as an absorbent.

5. The method for recycling organic tail gas according to claim 3, characterized in that: The primary absorption tower (1) and the secondary absorption tower (2) are both sieve plate towers, floating valve towers or packed towers; The number of the primary absorption tower (1) and the number of the secondary absorption tower (2) are the same.

6. The method for recycling organic tail gas according to claim 3, characterized in that: The tail gas is one or more combinations of epichlorohydrin, ethylene oxide and propylene oxide; The organic matter concentration in the tail gas is 2000-100000 mg / Nm 3 .

7. The method for recycling organic tail gas according to claim 3, characterized in that: The reactor (4) is a tubular reactor, a tank reactor or a tower reactor; The reactor (4) is loaded with a basic catalyst.

8. The method for recycling organic tail gas according to claim 8, characterized in that: The alkaline catalyst in the reactor (4) is a solid catalyst; The alkaline catalyst is one or a combination of an inorganic porous material-supported alkaline catalyst and a resin-supported alkaline catalyst.

9. The method for recycling organic tail gas according to claim 3, characterized in that: The heater (3) heats the absorption liquid discharged from the secondary absorption tower (2) to a temperature in the range of 50 to 90°C.

10. The method for recycling organic tail gas according to claim 9, characterized in that: The heater (3) heats the absorption liquid discharged from the secondary absorption tower (2) preferably in the temperature range of 60 to 80°C.

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