Toluene absorbent and application thereof

Abstract

The invention relates to the technical field of tail gas treatment, in particular to the technical field of high-concentration methylbenzene tail gas treatment in epoxy resin production, and more particularly relates to an absorbent for stably and efficiently removing methylbenzene in tail gas in epoxy resin production, in particular to an absorbent for absorbing and recovering methylbenzene from tail gas in epoxy resin production and application thereof. The toluene absorbent comprises a benzene solvent and dioctyl phthalate, and the benzene solvent is a mixture of durene, unsym-trimethylbenzene and m-methyl-ethylbenzene. When high-concentration toluene tail gas is treated in the device, the range of the toluene absorbent / tail gas (mass flow ratio) is 2.10-2.60, and the use temperature range of the toluene absorbent is 25-50 DEG C. The absorbent provided by the invention has the characteristics of high selectivity to toluene, strong structural stability, low loss rate and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of tail gas treatment, in particular to the technical field of high-concentration toluene tail gas treatment in epoxy resin production, and more particularly to an absorbent for stably and efficiently removing toluene from epoxy resin production tail gas, specifically to an absorbent for absorbing and recovering toluene from epoxy resin production tail gas and application thereof. Background Art

[0002] Toluene is widely used as an organic solvent in the production of organic chemicals, medicine, explosives, synthetic fibers, and epoxy resins. Toluene-based organic waste gas can cause serious damage to the human body, and its release into the atmosphere can also affect the environment. Reducing the concentration of toluene in tail gas has become a problem that toluene users must consider.

[0003] The existing treatment process ideas for toluene tail gas can be roughly divided into elimination method and recovery method. The elimination method is to eliminate toluene and other VOCs (Volatile Organic Compounds, i.e. organic compounds that are volatile at room temperature) in the tail gas through combustion, photocatalytic oxidation, biodegradation and other measures, and convert them into other harmless forms to be discharged into the environment; the recovery method is based on the concept of reducing costs and increasing efficiency, and recovers useful components in the tail gas as much as possible, including condensation method, absorption method, adsorption method, membrane separation method, etc. For epoxy resin manufacturers, adhering to the concept of reducing costs and increasing efficiency, recovering toluene while treating toluene tail gas is obviously a better choice. Among the recovery methods, the condensation method has a stable recovery effect, but it is difficult to obtain a very high VOCs removal rate due to the limitation of gas-liquid phase equilibrium; although the adsorption method has a high purification rate, the adsorption effect will decrease with the increase of the use time of the adsorbent, and it is difficult to achieve continuous treatment of toluene tail gas, and the adsorbent is also difficult to regenerate and needs to be replaced frequently, which increases production costs; the membrane separation method has a simple process and high VOCs tail gas treatment efficiency, but the investment cost is high, the treatment volume is low, and the subsequent maintenance costs are high; the absorption method is mainly divided into two methods: physical absorption and chemical absorption. VOCs tail gas treatment mainly adopts physical absorption, which has a simple process, easy operation, and the absorbent can be recycled. It is easy to achieve continuous operation and is an ideal method for resource-based treatment of medium and high concentrations of toluene tail gas.

[0004] CN 101229471A discloses a toluene-benzene tail gas recovery process, which uses a mixture of hydrocarbons and lipids as an absorbent, and involves an absorption tower and a desorption tower. Although it has a certain toluene tail gas treatment effect, the boiling point of the absorbent is relatively low (about 200°C), and the absorption tower needs to be operated at a pressure of 0.5-1MPa, resulting in high equipment investment costs and the risk of absorbent evaporation loss.

[0005] CN 109364695A discloses an absorbent for recovering toluene from industrial waste gas, using a mixture of NDH, NMP and lipids as the absorbent, involving an absorption tower and a regeneration tower. However, lipids will hydrolyze to generate acidic substances in a water-containing environment, and there is a risk of corroding equipment and pipelines.

[0006] In summary, finding an absorbent with good absorption effect and stable properties has become an urgent problem to be solved in order to achieve safety, environmental protection, cost reduction and efficiency improvement in epoxy resin production. Summary of the invention

[0007] The purpose of the present invention is to provide an absorbent for stably and efficiently removing benzene series from tail gas produced by epoxy resin production, which can effectively remove benzene series, such as toluene, from the tail gas mixture.

[0008] The main technical solutions of the present invention are: One aspect of the present invention provides a toluene absorbent, which comprises a benzene solvent and dioctyl phthalate, wherein the benzene solvent is a mixture of durene, trimethylolbenzene and m-ethylmethylbenzene.

[0009] In a preferred embodiment of the present application, the toluene absorbent comprises duren, trimethylolbenzene, m-ethylmethylbenzene and dioctyl phthalate. The mass percentage concentration of duren is 60-75wt%, the mass percentage concentration of trimethylolbenzene is 15-25wt%, the mass percentage concentration of m-ethylmethylbenzene is 5-15wt%, and the mass percentage concentration of dioctyl phthalate is 5-10wt%. In the case of duren < 60wt%, trimethylolbenzene < 15wt%, m-ethylmethylbenzene < 5wt%, and dioctyl phthalate < 5wt%, there are problems of poor stability and poor treatment effect of the toluene absorbent. In the case of duren> 75wt%, trimethylolbenzene> 25wt%, m-ethylmethylbenzene> 15wt%, and dioctyl phthalate> 10wt%, there are problems such as poor fluidity of the toluene absorbent, low boiling point, easy evaporation, and hydrolysis reaction. The present application can ensure that the absorbent has a series of advantages such as strong fluidity, good absorption effect and high stability by limiting the mass percentage concentration of durene, trimethylolene, m-ethylbenzene and dioctyl phthalate within the above range.

[0010] In a preferred embodiment of the present application, in the toluene absorbent, the mass percentage concentration of duren is 65-70wt%. By limiting the mass percentage concentration of duren to the above range, the boiling point of the absorbent can be increased, which has the advantage of enhancing the stability of the absorbent.

[0011] In a preferred embodiment of the present application, in the toluene absorbent, the mass percentage concentration of the trimethylolbenzene is 16-20wt%. By limiting the mass percentage concentration of the trimethylolbenzene to the above range, the solubility of the absorbent in toluene can be enhanced, which has the advantage of improving the absorption effect of the absorbent.

[0012] In a preferred embodiment of the present application, in the toluene absorbent, the mass percentage concentration of the m-ethylmethylbenzene is 6-11wt%. By limiting the mass percentage concentration of the m-ethylmethylbenzene to the above range, the viscosity of the absorbent can be reduced, which has the advantage of enhancing the fluidity of the absorbent.

[0013] In a preferred embodiment of the present application, in the toluene absorbent, the mass percentage concentration of dioctyl phthalate is 6-8wt%. By limiting the mass percentage concentration of dioctyl phthalate to the above range, it is possible to ensure that the boiling point of the absorbent is high and is not prone to evaporation loss, and also avoid the phenomenon of hydrolysis of the absorbent.

[0014] Another aspect of the present application provides the use of the toluene absorbent in removing benzene series from tail gas produced by epoxy resin production.

[0015] Another aspect of the present invention provides a method for removing benzene series from tail gas produced during epoxy resin production, which uses the toluene absorbent described in the present application.

[0016] In a preferred embodiment of the present application, during the use of tail gas treatment, the mass flow ratio of the toluene absorbent to the tail gas (absorbent / tail gas) is in the range of 2.10 to 2.60, and more preferably 2.20 to 2.50. By adjusting the mass flow ratio of absorbent / tail gas within the above range, it can be ensured that the toluene in the tail gas is fully absorbed, and the load and energy consumption of the device can be kept at a reasonable level. If the mass flow ratio is higher than 2.60, there will be a problem of excessive absorbent circulation causing high energy consumption of the device; if the mass flow ratio is lower than 2.10, there will be a problem of weakened absorption effect and failure to meet the treatment requirements.

[0017] In a preferred embodiment of the present application, during the use of tail gas treatment, the use temperature of the toluene absorbent is 25-50°C, preferably 25-35°C. Within this temperature range, the toluene absorbent can fully absorb the toluene in the tail gas; since the solubility of the gas decreases with increasing temperature, if the temperature is higher than 50°C, the absorption effect will be significantly weakened; if the temperature is lower than 25°C, the fluidity of the absorbent will decrease, which is not conducive to mass transfer in the device.

[0018] The present invention has the following remarkable characteristics: when treating high-concentration toluene tail gas in the device, the absorbent has the characteristics of high selectivity for toluene, strong structural stability, low loss rate, etc. Durene, unsymmetrical trimesulphur, m-ethyl methyl benzene, dioctyl phthalate and toluene are homologous. According to the principle of like dissolves like, toluene has good solubility, so it has excellent selectivity for toluene gas in the mixed gas. The benzene ring structure in the structure of durene, unsymmetrical trimesulphur, m-ethyl methyl benzene and dioctyl phthalate is stable, and hydrogen bonds can be formed between each other to further improve the structural stability of the absorbent solution. In addition, dioctyl phthalate has a high boiling point, reaching 416°C under normal pressure, and is not easy to evaporate under high temperature operation, which further reduces the loss rate of the absorbent. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the process absorption flow of an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The following combination Figure 1 The process shown further illustrates the present invention through implementation examples, the purpose of which is to provide a better understanding of the content of the present invention, but it does not limit the protection scope of the present invention.

[0021] Figure 1 This is the process absorption-desorption process adopted in the embodiment of the present invention. High-concentration toluene tail gas enters from the bottom of the absorption tower, flows from bottom to top and countercurrently contacts with the absorbent sprayed from the top of the tower. In this process, the toluene in the tail gas is absorbed and removed by the absorbent, and the purified tail gas is discharged from the top of the absorption tower; and the absorbent rich liquid that absorbs the toluene gas is discharged from the bottom of the absorption tower, and is sent to the middle of the desorption tower after heat exchange. The bottom of the desorption tower evaporates toluene from the absorbent rich liquid by heating, and the toluene gas is discharged from the top of the desorption tower and condensed and recovered. The absorbent after the toluene is evaporated is discharged from the bottom of the desorption tower, and is sent to the top of the absorption tower after heat exchange, and is recycled in the system.

[0022] Table 1. Summary of main data of examples and comparative examples

[0023] Example 1 The absorbent of this embodiment adopts formula 1.

[0024] High-concentration toluene tail gas (containing 30831ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.50, the temperature is 25℃; the toluene concentration in the tail gas at the top outlet of the absorption tower is 986ppm, and the VOCs concentration drops by 29845ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 99.55wt%. After 30 days of recycling, the absorbent loss rate is 0.9wt%.

[0025] Example 2 The absorbent of this embodiment adopts formula 2.

[0026] High-concentration toluene tail gas (containing 30357ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.49, the temperature is 25℃; the toluene concentration in the tail gas at the top outlet of the absorption tower is 827ppm, and the VOCs concentration drops by 29530ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 99.51wt%. After 30 days of recycling, the absorbent loss rate is 1.0wt%.

[0027] Example 3 The absorbent of this embodiment adopts formula 3.

[0028] High-concentration toluene tail gas (containing 30034ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.41, the temperature is 25℃; the toluene concentration in the tail gas at the top outlet of the absorption tower is 979ppm, and the VOCs concentration drops by 29055ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 99.62wt%. After 30 days of recycling, the absorbent loss rate is 0.9wt%.

[0029] Example 4 The absorbent of this embodiment adopts formula 4.

[0030] High-concentration toluene tail gas (containing 30265ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.20, the temperature is 25°C; the toluene concentration in the tail gas at the top outlet of the absorption tower is 835ppm, and the VOCs concentration drops by 29430ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 99.68wt%. After 30 days of recycling, the absorbent loss rate is 0.5wt%.

[0031] Example 5 The absorbent of this embodiment adopts formula 5.

[0032] High-concentration toluene tail gas (containing 30587ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.36, the temperature is 25℃; the toluene concentration in the tail gas at the top outlet of the absorption tower is 503ppm, and the VOCs concentration drops by 30084ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 99.59wt%. After 30 days of recycling, the absorbent loss rate is 0.5wt%.

[0033] Example 6 The absorbent of this embodiment adopts formula 6.

[0034] High-concentration toluene tail gas (containing 30943ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.42, the temperature is 25℃; the toluene concentration in the tail gas at the top outlet of the absorption tower is 476ppm, and the VOCs concentration drops by 30467ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 99.71wt%. After 30 days of recycling, the absorbent loss rate is 0.4wt%.

[0035] Example 7 The absorbent of this embodiment adopts formula 7.

[0036] High-concentration toluene tail gas (containing 30176ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.37, the temperature is 25℃; the toluene concentration in the tail gas at the top outlet of the absorption tower is 1074ppm, and the VOCs concentration decreases by 29102ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 99.53wt%. After 30 days of recycling, the absorbent loss rate is 1.1wt%.

[0037] Example 8 The absorbent of this embodiment adopts formula 8.

[0038] High-concentration toluene tail gas (containing 30148ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.31, the temperature is 30℃; the toluene concentration in the tail gas at the top outlet of the absorption tower is 2141ppm, and the VOCs concentration drops by 28007ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 99.59wt%. After 30 days of recycling, the absorbent loss rate is 1.3wt%.

[0039] Example 9 The absorbent of this embodiment adopts formula 6.

[0040] High-concentration toluene tail gas (containing 30087ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.10, the temperature is 20℃; the toluene concentration in the tail gas at the top outlet of the absorption tower is 2877ppm, and the VOCs concentration drops by 27210ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 99.01wt%. After 30 days of recycling, the absorbent loss rate is 0.4wt%.

[0041] Example 10 The absorbent of this embodiment adopts formula 6.

[0042] High-concentration toluene tail gas (containing 30225ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.60, the temperature is 50℃; the toluene concentration in the tail gas at the top outlet of the absorption tower is 7073ppm, and the VOCs concentration decreases by 23152ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 98.11wt%. After 30 days of recycling, the absorbent loss rate is 0.4wt%.

[0043] Comparative Example 1 The absorbent of this comparative example adopts Formula 9, and the absorbent / tail gas (mass flow ratio) and temperature are consistent with those of Example 6.

[0044] High-concentration toluene tail gas (containing 31055ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.42, the temperature is 25°C; the toluene concentration in the tail gas at the top outlet of the absorption tower is 5062ppm, and the VOCs concentration decreases by 25993ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 98.12wt%. After 30 days of recycling, the absorbent loss rate is 1.2wt%.

[0045] Comparative Example 2 The absorbent of this comparative example adopts formula 10, and the absorbent / tail gas (mass flow ratio) and temperature are consistent with those of Example 6.

[0046] High-concentration toluene tail gas (containing 31526ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.42, the temperature is 25℃; the toluene concentration in the tail gas at the top outlet of the absorption tower is 5955ppm, and the VOCs concentration drops by 25571ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 98.05wt%. After 30 days of recycling, the absorbent loss rate is 2.2wt%.

[0047] Comparative Example 3 The absorbent of this comparative example adopts formula 11, and the absorbent / tail gas (mass flow ratio) and temperature are consistent with those of Example 2.

[0048] High-concentration toluene tail gas (containing 31054ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.49, the temperature is 25℃; the toluene concentration in the tail gas at the top outlet of the absorption tower is 2747ppm, and the VOCs concentration drops by 28307ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 98.11wt%. After 30 days of recycling, the absorbent loss rate is 0.9wt%.

[0049] Comparative Example 4 The absorbent of this comparative example adopts formula 12, and the absorbent / tail gas (mass flow ratio) and temperature are consistent with those of Example 6.

[0050] High-concentration toluene tail gas (containing 31336ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.42, the temperature is 25℃; the toluene concentration in the tail gas at the top outlet of the absorption tower is 3027ppm, and the VOCs concentration drops by 28309ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 98.08wt%. After 30 days of recycling, the absorbent loss rate is 1.1wt%.

[0051] Comparative Example 5 The absorbent of this comparative example adopts formula 13, and the absorbent / tail gas (mass flow ratio) and temperature are consistent with those of Example 6.

[0052] High-concentration toluene tail gas (containing 30877ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.42, the temperature is 25°C; the toluene concentration in the tail gas at the top outlet of the absorption tower is 3049ppm, and the VOCs concentration decreases by 27828ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 98.02wt%. After 30 days of recycling, the absorbent loss rate is 1.5wt%.

[0053] Comparative Example 6 The absorbent formulation of this comparative example is the same as that of Example 6.

[0054] High-concentration toluene tail gas (containing 30530ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 2.42, the temperature is 55°C; the toluene concentration in the tail gas at the top outlet of the absorption tower is 10473ppm, and the VOCs concentration drops by 20057ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 98.26wt%. After 30 days of recycling, the absorbent loss rate is 0.4wt%.

[0055] Comparative Example 7 The absorbent formulation of this comparative example is the same as that of Example 6.

[0056] High-concentration toluene tail gas (containing 30997ppm toluene) enters the absorption tower from the bottom, and the absorbent enters from the top of the tower. The absorbent / tail gas (mass flow ratio) = 1.80, the temperature is 25℃; the toluene concentration in the tail gas at the top outlet of the absorption tower is 6441ppm, and the VOCs concentration decreases by 24556ppm. The toluene liquid after condensation in the detoluene unit is collected and recovered, and the toluene purity is 98.11wt%. After 30 days of recycling, the absorbent loss rate is 0.4wt%.

[0057] Through the analysis of the results of Examples 1-9 and Comparative Examples 1-7, it can be seen that the toluene tail gas absorbent in the epoxy resin production involved in the present invention, when the mass percentage concentration of durene in the absorbent is 60-75wt%, the mass percentage concentration of trimethylbenzene is 15-25wt%, the mass percentage concentration of m-ethylbenzene is 5-15wt%, and the mass percentage concentration of dioctyl phthalate is 5-10wt%, under the conditions of absorption temperature 20-50°C and absorbent / tail gas (mass flow ratio) = 2.10-2.60, the VOCs concentration of high-concentration tail gas with toluene content>30000ppm can be reduced by more than 20000ppm. The purity of the recovered toluene liquid can reach more than 98wt%, and after 30 days of recycling, the absorbent loss rate is less than 2.5wt%.

[0058] It can be concluded through Example 6 and Comparative Example 1 that if the content of durene>75wt%, the content of unsymmetrical trimethylbenzene<15wt%, and the content of dioctyl phthalate<5wt% in the liquid absorbent, not only the absorbent loss rate is high, affecting the tail gas treatment effect, but also the purity of the recovered toluene liquid is affected. It can be concluded through Example 6 and Comparative Example 2 that if the content of durene>75wt%, the content of meta-ethylmethylbenzene<5wt%, and the content of dioctyl phthalate<5wt% in the liquid absorbent, not only the absorbent loss rate is high, affecting the tail gas treatment effect, but also the purity of the recovered toluene liquid is affected. It can be concluded through Example 6 and Comparative Example 3 that if the content of durene<60wt% in the liquid absorbent, not only the absorbent loss rate is high, but also the purity of the recovered toluene liquid is affected.

[0059] Through Example 6 and Comparative Example 4, it is concluded that if the content of dioctyl phthalate in the liquid absorbent is less than 5wt%, the boiling point of the absorbent is low, and it is easy to be evaporated together with toluene during desorption, which not only increases the absorbent loss rate but also affects the purity of the recovered toluene liquid; through Example 6 and Comparative Example 5, it is concluded that if the content of dioctyl phthalate in the absorbent is higher than 8%, partial hydrolysis of dioctyl phthalate will occur in the absorbent, affecting the exhaust gas treatment effect and also causing a high absorbent loss rate.

[0060] In addition, by comparing Example 6 with Comparative Examples 6 and 7, it can be concluded that too low absorbent / tail gas (mass flow ratio) and too high absorbent temperature will affect the treatment effect of the absorbent tail gas.

[0061] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A toluene absorbent, characterized in that: include: A benzene solvent and dioctyl phthalate, wherein the benzene solvent is a mixture of durene, trimethylolbenzene and m-ethylmethylbenzene.

2. The toluene absorbent according to claim 1, characterized in that In the toluene absorbent, the mass percentage concentration of durene is 60-75wt%, the mass percentage concentration of trimethylolbenzene is 15-25wt%, the mass percentage concentration of m-ethylmethylbenzene is 5-15wt%, and the mass percentage concentration of dioctyl phthalate is 5-10wt%.

3. The toluene absorbent according to claim 2, characterized in that: The mass percentage concentration of the durene is 65-70wt%.

4. The toluene absorbent according to claim 2, characterized in that: The mass percentage concentration of the trimethylolbenzene is 16-20wt%.

5. The toluene absorbent according to claim 2, characterized in that: The mass percentage concentration of the m-ethylmethylbenzene is 6-11wt%.

6. The toluene absorbent according to claim 2, characterized in that: The mass percentage concentration of the dioctyl phthalate is 6-8wt%.

7. Use of the toluene absorbent according to any one of claims 1 to 6 in removing benzene series from tail gas in epoxy resin production.

8. A method for removing benzene series from tail gas produced by epoxy resin production, characterized in that: The toluene absorbent according to any one of claims 1 to 6 is used.

9. The method according to claim 8, characterized in that The mass flow ratio of the toluene absorbent to the tail gas is in the range of 2.10 to 2.60, preferably 2.20 to 2.

50.

10. The method according to claim 8 or 9, characterized in that: The use temperature of the toluene absorbent is 25-50°C, preferably 25-35°C.

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