Continuous treatment method for waste gas containing halogenated hydrocarbon

Abstract

The invention belongs to the technical field of waste gas treatment, and particularly relates to a continuous treatment method for waste gas containing halogenated hydrocarbon. The invention provides a continuous treatment method of halogenated hydrocarbon-containing waste gas, which comprises the following steps: introducing halogenated hydrocarbon-containing waste gas into an adsorption system for treatment to obtain treated gas; the adsorption system comprises three adsorption columns; in the treatment process, any two adsorption columns are connected in series for adsorption, and the other adsorption column is standby; the adsorption columns for series adsorption are sequentially divided into a first-stage adsorption column and a second-stage adsorption column according to the gas inlet direction; when the first-stage adsorption column reaches adsorption saturation, the first-stage adsorption column is stopped, the second-stage adsorption column is connected with the standby adsorption column in series according to the gas inlet direction for re-adsorption, and meanwhile, the stopped adsorption column is subjected to desorption regeneration; and repeating the process of stopping, re-adsorption and desorption regeneration. The treatment method provided by the invention is simple, convenient and higher in treatment efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of waste gas treatment, and in particular relates to a continuous treatment method for waste gas containing halogenated hydrocarbons. Background Art

[0002] Halogenated hydrocarbon waste gas mainly comes from industrial production processes. For example, it is used as solvents, detergents, etc. in the manufacturing process, and as raw materials for pesticide manufacturing and various chemicals. Since halogenated hydrocarbons are carcinogens, the halogenated hydrocarbon waste gas needs to be treated to reduce the content of halogenated hydrocarbons in it in order to meet emission standards.

[0003] The traditional method for treating halogenated hydrocarbon waste gas is activated carbon adsorption, but the efficiency of activated carbon adsorption is low; at the same time, the traditional activated carbon adsorption treatment process is an intermittent treatment process, and the service life of the activated carbon is short and the regeneration effect is poor. Summary of the invention

[0004] The object of the present invention is to provide a method for continuously treating waste gas containing halogenated hydrocarbons.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a method for continuously treating waste gas containing halogenated hydrocarbons, comprising the following steps:

[0007] Passing the halogenated hydrocarbon waste gas into an adsorption system for treatment to obtain treated gas;

[0008] The adsorption system includes three adsorption columns;

[0009] During the treatment, any two adsorption columns are connected in series, and the other one is kept as a standby; the adsorption columns connected in series are divided into first-stage adsorption columns and second-stage adsorption columns in sequence according to the air intake direction;

[0010] When the first-stage adsorption column reaches adsorption saturation, the first-stage adsorption column is deactivated, and the second-stage adsorption column is connected in series with the spare adsorption column according to the air intake direction for re-adsorption, and the deactivated adsorption column is simultaneously subjected to analytical regeneration; the above deactivation-re-adsorption-analysis regeneration process is repeated.

[0011] Preferably, the air volume of the halogenated hydrocarbon waste gas entering the adsorption system is 7000-9000m 3 / h.

[0012] Preferably, the halogenated hydrocarbons in the halogenated hydrocarbon-containing waste gas include one or more of 1,2-dichloropropane, dichloroethane, 1,3-dichloropropane and dichloromethane.

[0013] Preferably, the adsorption resin filled in the adsorption column is a macroporous adsorption resin, and the pore size of the macroporous adsorption resin is 50 to 100 meshes.

[0014] Preferably, the macroporous adsorption resin comprises One or more of LXQ-10 resin, Amberlite XAD-2 resin, ZXDA-1B resin and SP207 resin.

[0015] Preferably, the loading amount of adsorption resin in each adsorption column is 5 to 7 m 3 .

[0016] Preferably, the regeneration process comprises: passing water vapor into the deactivated adsorption column for analysis, and then condensing and separating the water vapor obtained after the analysis into oil and water to obtain a water phase and an oil phase, wherein the oil phase is a halogenated hydrocarbon;

[0017] The water phase is returned to the adsorption system for circulation treatment.

[0018] Preferably, the mass ratio of the adsorption resin to water vapor is 5 to 7:1 based on the mass of water.

[0019] Preferably, the water vapor is introduced for 0.5 to 2 hours.

[0020] Preferably, the content of halogenated hydrocarbons in the treated gas is less than 50 mg / m 3 .

[0021] The present invention provides a continuous treatment method for halogenated hydrocarbon waste gas, comprising the following steps: introducing the halogenated hydrocarbon waste gas into an adsorption system for treatment to obtain treated gas; the adsorption system comprises three adsorption columns; during the treatment process, any two of the adsorption columns are connected in series, and the other is kept as a standby; the adsorption columns connected in series are divided into a first-stage adsorption column and a second-stage adsorption column in sequence according to the air intake direction; when the first-stage adsorption column reaches adsorption saturation, the first-stage adsorption column is deactivated, and the second-stage adsorption column is connected in series with the standby adsorption column according to the air intake direction for re-adsorption, and the deactivated adsorption column is analytically regenerated at the same time; and the above-mentioned deactivation-re-adsorption-analysis regeneration process is repeated.

[0022] The treatment method provided by the present invention can achieve efficient removal of halogenated hydrocarbons in waste gas, and can also achieve continuous adsorption, and the resin can be reused after regeneration. The amount of hazardous waste generated is only 10-20% of activated carbon, which reduces costs and simplifies the production process. At the same time, the existing technology uses liquid alkali for desorption and regeneration, which produces alkaline wastewater and causes secondary pollution. The present invention uses water vapor desorption to reduce secondary pollution and improve treatment efficiency. The desorption process requires less steam and can be combined with a condensation system to achieve energy cascade utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a schematic diagram of the process of the treatment method provided by the present invention. DETAILED DESCRIPTION

[0024] The present invention provides a method for continuously treating waste gas containing halogenated hydrocarbons, comprising the following steps:

[0025] Passing the halogenated hydrocarbon waste gas into an adsorption system for treatment to obtain treated gas;

[0026] The adsorption system includes three adsorption columns;

[0027] During the treatment, any two adsorption columns are connected in series, and the other one is kept as a standby; the adsorption columns connected in series are divided into first-stage adsorption columns and second-stage adsorption columns in sequence according to the air intake direction;

[0028] When the first-stage adsorption column reaches adsorption saturation, the first-stage adsorption column is deactivated, and the second-stage adsorption column is connected in series with the spare adsorption column according to the air intake direction for re-adsorption, and the deactivated adsorption column is simultaneously subjected to analytical regeneration; the above deactivation-re-adsorption-analysis regeneration process is repeated.

[0029] The process flow diagram of the processing method provided by the present invention is as follows Figure 1 shown.

[0030] In the present invention, the air volume of the halogenated hydrocarbon waste gas entering the adsorption system is 7000-9000m 3 / h, more preferably 8000m 3 In the present invention, the content of halogenated hydrocarbons in the halogenated hydrocarbon-containing waste gas is not particularly limited, but is preferably not less than 2000 mg / m 3 In the present invention, the halogenated hydrocarbons in the halogenated hydrocarbon waste gas preferably include one or more of 1,2-dichloropropane, dichloroethane, 1,3-dichloropropane and dichloromethane. The present invention has no particular limitation on the temperature of the halogenated hydrocarbon waste gas, and is preferably 25 to 28°C.

[0031] In the present invention, the adsorption resin filled in the adsorption column is preferably a macroporous adsorption resin, and the pore size of the macroporous adsorption resin is preferably 50 to 100 meshes. In the present invention, the macroporous adsorption resin preferably includes One or more of LXQ-10 resin, Amberlite XAD-2 resin, ZXDA-1B resin and SP207 resin.

[0032] In the present invention, the loading amount of the adsorption resin in each adsorption column is preferably 5 to 7 m 3 In a specific embodiment of the present invention, when adsorption saturation is reached, the introduction time of the halogenated hydrocarbon-containing waste gas is preferably 11 to 12.5 hours.

[0033] In the present invention, the regeneration process preferably includes: passing water vapor into a deactivated adsorption column for analysis, and then condensing and separating the water vapor obtained after analysis into oil and water to obtain a water phase and an oil phase, wherein the oil phase is a mixture of halogenated hydrocarbons; and returning the water phase to the adsorption system for circulation treatment.

[0034] In the present invention, the mass ratio of the adsorption resin to water vapor is preferably 5 to 7: 1, based on the mass of water. In the present invention, the introduction time of the water vapor is preferably 0.5 to 2 hours.

[0035] In the present invention, the content of halogenated hydrocarbons in the treated gas is preferably less than 50 mg / m 3 .

[0036] Unless otherwise specified, the materials and equipment used in the present invention are all commercially available products in the art.

[0037] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. 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.

[0038] Example 1

[0039] Prepare three adsorption columns, each of which is filled with 6.3m 3 macroporous resin (specifically Amberlite XAD-2 resin, pore size 50 mesh, mass 6400kg); two of them are connected in series, and the remaining one is for standby;

[0040] The halogenated hydrocarbon waste gas (wherein the halogenated hydrocarbon is 1,2-dichloropropane, with a content of 2600 mg / m 3 ) are sequentially introduced into two adsorption columns connected in series for adsorption, wherein the temperature of the halogenated hydrocarbon waste gas is 25°C and the air volume is 8000m 3 / h; when the air is introduced for 12.5h, the first-stage adsorption column in series is deactivated, and the second-stage adsorption column is connected in series with the spare adsorption column according to the air inlet direction for re-adsorption;

[0041] Water vapor is introduced into the deactivated adsorption column for analytical regeneration, wherein the amount of water vapor introduced is 1026 kg and the introduction time is 1 hour, and the water vapor obtained after the analysis is condensed and separated into oil and water in turn to obtain a water phase and an oil phase, wherein the oil phase is 1,2-dichloropropane; the water phase is returned to the adsorption system for cyclic treatment;

[0042] Repeat the above deactivation-re-adsorption-analysis regeneration process, and the content of 1,2-dichloropropane in the treated gas is 40 mg / m 3 .

[0043] Example 2

[0044] Prepare three adsorption columns, each of which is filled with 6.3m 3 macroporous resin (specifically ZXDA-1B resin, pore size 50 mesh, mass 6120kg); two of them are connected in series, and the remaining one is for standby;

[0045] The halogenated hydrocarbon waste gas (wherein the halogenated hydrocarbon is ethylene dichloride, with a content of 3200 mg / m 3 ) are sequentially introduced into two adsorption columns connected in series for adsorption, wherein the temperature of the halogenated hydrocarbon waste gas is 28°C and the air volume is 7300m 3 / h; when the air is introduced for 11h, the first-stage adsorption column in series is deactivated, and the second-stage adsorption column is connected in series with the spare adsorption column according to the air inlet direction for re-adsorption;

[0046] Water vapor is introduced into the deactivated adsorption column for analytical regeneration, wherein the amount of water vapor introduced is 1100 kg and the introduction time is 1 hour, and the water vapor obtained after the analysis is condensed and separated into oil and water in turn to obtain a water phase and an oil phase, wherein the oil phase is ethylene dichloride; the water phase is returned to the adsorption system for cyclic treatment;

[0047] Repeat the above process of deactivation-re-adsorption-analysis regeneration, and the content of dichloroethane in the treated gas is 42 mg / m 3 .

[0048] Example 3

[0049] Prepare three adsorption columns, each of which is filled with 6.3m 3 The macroporous resin (specifically LXQ-10 resin, pore size 60 mesh, mass 6200kg); two of them are connected in series, and the remaining one is for standby;

[0050] The halogenated hydrocarbon waste gas (wherein the halogenated hydrocarbon is dichloromethane, with a content of 3500 mg / m 3 ) are sequentially introduced into two adsorption columns connected in series for adsorption, wherein the temperature of the halogenated hydrocarbon waste gas is 28°C and the air volume is 8400m 3 / h; when the air is introduced for 12.5h, the first-stage adsorption column in series is deactivated, and the second-stage adsorption column is connected in series with the spare adsorption column according to the air inlet direction for re-adsorption;

[0051] Water vapor is introduced into the deactivated adsorption column for analytical regeneration, wherein the amount of water vapor introduced is 1100 kg and the introduction time is 1 hour. The water vapor obtained after the analysis is condensed and separated into oil and water in turn to obtain a water phase and an oil phase, wherein the oil phase is dichloromethane; the water phase is returned to the adsorption system for cyclic treatment;

[0052] Repeat the above process of deactivation-re-adsorption-analysis regeneration, and the content of dichloromethane in the treated gas is 46 mg / m 3 .

[0053] Example 4

[0054] Prepare three adsorption columns, each of which is filled with 6.3m 3 The macroporous resin (specifically, the mass ratio is 1:1 LXQ-10 resin and Amberlite XAD-2 resin, pore size 60 mesh, mass 6200kg); two of them are connected in series, and the remaining one is for standby;

[0055] The halogenated hydrocarbon waste gas (wherein the halogenated hydrocarbon is 1,3-dichloropropane, with a content of 2600 mg / m 3 ) are sequentially introduced into two adsorption columns connected in series for adsorption, wherein the temperature of the halogenated hydrocarbon waste gas is 28°C and the air volume is 8400m 3 / h; when the air is introduced for 12.5h, the first-stage adsorption column in series is deactivated, and the second-stage adsorption column is connected in series with the spare adsorption column according to the air inlet direction for re-adsorption;

[0056] Water vapor is introduced into the deactivated adsorption column for analytical regeneration, wherein the amount of water vapor introduced is 1100 kg and the introduction time is 1 hour, and the water vapor obtained after the analysis is condensed and separated into oil and water in turn to obtain a water phase and an oil phase, wherein the oil phase is 1,3-dichloropropane; the water phase is returned to the adsorption system for cyclic treatment;

[0057] Repeat the above deactivation-re-adsorption-analysis regeneration process, and the content of 1,3-dichloropropane in the treated gas is 31 mg / m 3 .

[0058] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for continuously treating waste gas containing halogenated hydrocarbons, characterized in that: The following steps are involved: Passing the halogenated hydrocarbon waste gas into an adsorption system for treatment to obtain treated gas; The adsorption system includes three adsorption columns; During the treatment, any two adsorption columns are connected in series, and the other one is kept as a standby; the adsorption columns connected in series are divided into first-stage adsorption columns and second-stage adsorption columns in sequence according to the air intake direction; When the first-stage adsorption column reaches adsorption saturation, the first-stage adsorption column is deactivated, and the second-stage adsorption column is connected in series with the spare adsorption column according to the air intake direction for re-adsorption, and the deactivated adsorption column is simultaneously subjected to analytical regeneration; the above deactivation-re-adsorption-analysis regeneration process is repeated.

2. The continuous processing method according to claim 1, characterized in that: The air volume of the halogenated hydrocarbon waste gas entering the adsorption system is 7000-9000m 3 / h.

3. The continuous processing method according to claim 1, characterized in that: The halogenated hydrocarbons in the halogenated hydrocarbon-containing waste gas include one or more of 1,2-dichloropropane, dichloroethane, 1,3-dichloropropane and dichloromethane.

4. The continuous processing method according to claim 1, characterized in that: The adsorption resin filled in the adsorption column is a macroporous adsorption resin, and the pore size of the macroporous adsorption resin is 50-100 meshes.

5. The continuous processing method according to claim 4, characterized in that: The macroporous adsorption resin comprises One or more of LXQ-10 resin, Amberlite XAD-2 resin, ZXDA-1B resin and SP207 resin.

6. The continuous processing method according to claim 1, 4 or 5, characterized in that: The loading amount of adsorption resin in each adsorption column is 5-7m 3 .

7. The continuous processing method according to claim 1, characterized in that: The regeneration process comprises: passing water vapor into the deactivated adsorption column for analysis, and then condensing and separating the water vapor obtained after analysis into oil and water to obtain a water phase and an oil phase, wherein the oil phase is a halogenated hydrocarbon; The water phase is returned to the adsorption system for circulation treatment.

8. The continuous processing method according to claim 1, characterized in that: Calculated based on the mass of water, the mass ratio of the adsorption resin to water vapor is 5 to 7:

1.

9. The continuous processing method according to claim 8, characterized in that: The water vapor is introduced for 0.5 to 2 hours.

10. The continuous processing method according to claim 1, characterized in that: The content of halogenated hydrocarbons in the treated gas is less than 50 mg / m 3 .

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