A device and method for treating volatile organic compounds (VOCs)

Abstract

The present invention belongs to the technical field of volatile organic compounds (VOCs) treatment, and specifically relates to a device and method for treating volatile organic compounds (VOCs). The treatment device of the present invention includes a collecting mechanism, an absorbing mechanism, a membrane separation assembly, a liquid ring vacuum pump, a buffer mechanism and a catalytic cracking regenerator; one end of the collecting mechanism is connected to a VOCs release source, and the other end of the collecting mechanism is connected to the absorbing mechanism; the membrane separation assembly is provided with an interception zone and a permeation zone, the interception zone is connected to the absorbing mechanism, the upper part of the interception zone is connected to the input end of the buffer mechanism, and the bottom of the permeation zone is connected to the collecting mechanism through a liquid ring vacuum pump; the output end of the buffer mechanism is connected to the catalytic cracking regenerator. The present invention fully recovers the heavy components in the volatiles after oxidizing VOCs by applying absorption or condensation + membrane + catalytic regenerator, effectively reduces the VOCs emission limit, and the device can operate smoothly. The transformation process of the present invention is simple, the cost is low, and the cycle is short.

Description

Technical Field

[0001] The present invention belongs to the technical field of volatile organic compounds (VOCs) treatment, and specifically relates to a device and method for treating volatile organic compounds (VOCs). Background Art

[0002] VOCs (volatile organic compounds) refer to organic compounds with a saturated vapor pressure greater than 70.91 Pa at room temperature, a boiling point below 50-260°C at a standard atmospheric pressure of 101.3 kPa, and an initial distillation point equal to 250 degrees Celsius, or any organic solid or liquid that can evaporate at room temperature and pressure.

[0003] At present, there are many methods for VOCs treatment, which can be divided into three categories: oxidation technology, recovery technology and biotechnology. Recovery methods include absorption, adsorption, membrane separation, condensation, etc., which generally concentrate and separate volatile organic compounds through physical methods. Oxidation methods include direct combustion, thermal combustion, catalytic oxidation, thermal storage combustion, etc., which mainly convert volatile organic compounds into harmless CO2 and H2O and other non-toxic inorganic compounds through chemical reactions. Biological methods include bio-scrubbing, bio-filtration and bio-trickling, which use microorganisms to use VOCs as metabolic substrates to degrade them into harmless substances.

[0004] At present, when the recycling treatment method is adopted, it is greatly affected by the VOCs components. When the components contain light components, it is basically impossible to achieve 120mg / m 3 , it is necessary to introduce oxidation treatment methods, and biotechnology has high requirements for VOCs components. It is mainly used to treat VOCs in sewage equipment. Due to the complexity of components, unstable quantity, oxygen content and other limitations, VOCs cannot be stably discharged to meet the standards, and there are hidden dangers in operational safety. Summary of the invention

[0005] In order to solve the problem that multi-component or special-component volatile organic compounds (VOCs) cannot be treated to meet the standards, the present invention provides a device and method for treating volatile organic compounds (VOCs).

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A device for treating volatile organic compounds (VOCs), comprising a collecting mechanism, an absorbing mechanism, a membrane separation assembly, a liquid ring vacuum pump, a buffer mechanism and a catalytic cracking regenerator; one end of the collecting mechanism is connected to a VOCs release source, and the other end of the collecting mechanism is connected to the absorbing mechanism; the membrane separation assembly is provided with an interception zone and a permeation zone, the interception zone is connected to the absorbing mechanism, the upper part of the interception zone is connected to the input end of the buffer mechanism, and the bottom of the permeation zone is connected to the collecting mechanism through the liquid ring vacuum pump; the output end of the buffer mechanism is connected to the catalytic cracking regenerator.

[0008] The collecting mechanism comprises a collecting pipeline and a raw material buffer tank; one end of the collecting pipeline is connected to a VOCs release source, and the other end of the collecting pipeline is connected to the raw material buffer tank; a first nitrogen control valve is connected to the bottom of the raw material buffer tank, and the top of the raw material buffer tank is connected to the absorption mechanism.

[0009] The absorption mechanism includes a first liquid ring compressor and an absorption tower; the input end of the first liquid ring compressor is connected to the collection mechanism through a pipeline, and the output end of the first liquid ring compressor is connected to the absorption tower; the top of the absorption tower is connected to the membrane separation component, the bottom of the absorption tower is provided with an output port, and the upper side wall of the absorption tower is provided with an absorbent input port.

[0010] The pipeline connecting the first liquid ring compressor and the collecting mechanism is connected with an emergency drain valve, a first concentration detector and a first self-protection control system.

[0011] The buffer mechanism comprises a buffer tank and a second liquid ring compressor; the buffer tank is connected to the membrane separation assembly, the top of the buffer tank is connected to the catalytic cracking regenerator through the second liquid ring compressor, and the bottom of the buffer tank is connected to a second nitrogen control valve.

[0012] The second liquid ring compressor is provided with a pressure self-maintaining control valve and a check valve on the pipeline connected to the catalytic cracking regenerator; a second concentration detector and a second self-maintaining control system are provided on the pipeline between the second liquid ring compressor and the pressure self-maintaining control valve; and a pressure detection system is provided on the pressure self-maintaining control valve.

[0013] It also includes a protection check valve; the protection check valve is arranged on the pipeline connecting the buffer mechanism and the catalytic cracking regenerator, and is close to the connection port of the catalytic cracking regenerator.

[0014] It also includes a controller; the controller is respectively connected with the collection mechanism, the absorption mechanism, the membrane separation component, the liquid ring vacuum pump, the protection check valve and the buffer mechanism by electrical signals.

[0015] A method for treating volatile organic compounds (VOCs) comprising the following steps:

[0016] Step 1: The controller closes the emergency exhaust valve, the first nitrogen control valve, and the second nitrogen valve in the volatile organic compound (VOCs) treatment device;

[0017] Step 2: The controller controls the first liquid ring compressor and the second liquid ring compressor to start, and the collecting mechanism collects VOCs from the VOCs release source; the controller obtains the test value of the first concentration detector and the first self-protection control system. When the value measured by the first concentration detector and the first self-protection control system exceeds the preset value, the controller controls the first nitrogen control valve to open and inject nitrogen into the raw material buffer tank. If the first concentration detector and the first self-protection control system show that the concentration exceeds the preset value, the controller controls the emergency drain valve to open and interlocks and stops the first liquid ring compressor and the second liquefied compressor;

[0018] Step 3: The volatile organic compounds (VOCs) collected by the collection mechanism enter the absorption tower in the absorption mechanism, and the absorbent is sprayed from the upper part of the absorption tower. The absorbent absorbs the hydrocarbons that can be absorbed in the volatile organic compounds (VOCs). After absorption, the hydrocarbons are collected and temporarily stored in the liquid phase layer at the bottom of the absorption tower, and are discharged after the preset amount is collected; a part of the hydrocarbons and the inert gas that cannot be absorbed enter the membrane separation component through the upper part of the absorption tower;

[0019] Step 4: The volatile organic compounds (VOCs) entering the membrane separation component are treated with a membrane; the hydrocarbons therein pass through the permeation membrane, are enriched in the permeation zone, are returned to the raw material buffer tank by the suction action of the liquid ring vacuum pump, and re-enter the absorption tower for absorption through the first liquid ring compressor; and the hydrocarbon-poor gas stream retained in the interception zone enters the buffer tank;

[0020] Step 5: The gas entering the buffer tank enters the catalytic cracking regenerator through the second liquid ring compressor after being buffered in the buffer tank; when the concentration value of the second concentration detector and the second self-protection control system obtained by the controller exceeds the preset value, the controller controls the opening of the second nitrogen control valve to inject nitrogen into the buffer tank; when the concentration value of the second concentration detector and the second self-protection control system obtained by the controller exceeds the preset value, the first liquid ring compressor and the second liquid ring compressor are interlocked and stopped, and the emergency vent valve is opened at the same time; when the pressure value of the pressure detection system is lower than the preset value, the pressure self-protection control valve is closed;

[0021] Step 6: The gas treated in step 5 enters the catalytic cracking regenerator through a distributor, and the gas treated in the catalytic cracking regenerator is discharged.

[0022] Beneficial effects:

[0023] (1) The present invention fully recovers the heavy components in the volatiles after oxidizing the volatile organic compounds (VOCs) by applying absorption or condensation + membrane + catalytic regenerator, effectively reducing the emission limit of volatile organic compounds (VOCs), and the device can operate smoothly.

[0024] (2) The transformation process of the present invention is simple, low-cost and short-term.

[0025] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail below. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a schematic diagram of the device composition of the present invention.

[0028] In the figure: 1-VOCs release source; 2-raw material buffer tank; 3-emergency drain valve; 4-first nitrogen control valve; 5-first liquid ring compressor; 6-absorption tower; 7-membrane separation component; 8-buffer tank; 9-second liquid ring compressor; 10-second nitrogen control valve; 11-pressure self-protection control valve; 12-catalytic cracking regenerator; 13-liquid ring vacuum pump; 14-first concentration detector and first self-protection control system; 15-second concentration detector and second self-protection control system; 16-pressure detection system; 17-check valve; 18-protection one-way valve.

[0029] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only 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.

[0031] Embodiment 1:

[0032] Reference Figure 1A volatile organic compound (VOCs) treatment device shown in the figure includes a collecting mechanism, an absorption mechanism, a membrane separation assembly 7, a liquid ring vacuum pump 13, a buffer mechanism and a catalytic cracking regenerator 12; one end of the collecting mechanism is connected to the VOCs release source 1, and the other end of the collecting mechanism is connected to the absorption mechanism; the membrane separation assembly 7 is provided with an interception zone and a permeation zone, the interception zone is connected to the absorption mechanism, the upper part of the interception zone is connected to the input end of the buffer mechanism, and the bottom of the permeation zone is connected to the collecting mechanism through the liquid ring vacuum pump 13; the output end of the buffer mechanism is connected to the catalytic cracking regenerator 12.

[0033] In specific applications, the collection mechanism collects the volatile organic compounds (VOCs) from the VOCs release source 1; then the volatile organic compounds (VOCs) collected by the collection mechanism enter the absorption mechanism, and the absorption mechanism sprays the absorbent, and the absorbent absorbs the hydrocarbons that can be absorbed in the volatile organic compounds (VOCs). After absorption, the hydrocarbons are temporarily stored in the liquid phase layer at the bottom of the absorption tower 6 in the absorption mechanism, and are discharged after the preset amount is collected; a part of the hydrocarbons and the inert gas that cannot be absorbed enter the membrane separation component 7 through the upper part of the absorption tower 6; The volatile organic compounds (VOCs) entering the membrane separation component 7 are subjected to membrane treatment; the hydrocarbons therein pass through the permeable membrane in the membrane separation component 7, are enriched in the permeation zone, are returned to the raw material buffer tank 2 by the suction action of the liquid ring vacuum pump 13, and then re-enter the absorption tower 6 for absorption; and the hydrocarbon-poor gas flow trapped in the interception zone enters the buffer tank 8 in the buffer mechanism; the gas entering the buffer tank 8 enters the catalytic cracking regenerator 12 after being buffered; the gas treated by the catalytic cracking regenerator 12 is discharged.

[0034] The present invention fully recovers the heavy components in the volatiles after oxidizing the volatile organic compounds (VOCs) through absorption or condensation + membrane + catalytic regenerator, effectively reduces the emission limit of volatile organic compounds (VOCs), and the device can run smoothly, ultimately achieving mg-level emission standards. The present invention has a simple transformation process, low cost and short cycle.

[0035] The membrane separation component in this embodiment adopts the existing technology, and its interior is a columnar arrangement structure. The number of columnar membranes is set according to the concentration of VOCs, and its interior is a dense multi-base separation membrane, and hydrocarbons and non-hydrocarbon substances are separated according to the different rates of passing through the membrane; each columnar membrane can be divided into two parts: a retention area and a permeation area; a through hole connected to the absorption mechanism is set on the side wall of the retention area, and a through hole connected to the buffer mechanism is set on the top of the retention area; a through hole connected to the liquid ring vacuum pump is set at the bottom of the permeation area. In actual use, after the volatile organic matter VOCs that have been treated at the primary level enter the membrane separation component 7, under the suction action of the liquid ring vacuum pump 13, there is a pressure difference on both sides of the permeation membrane. The larger molecular weight hydrocarbons preferentially permeate through the permeable membrane, are enriched in the permeation zone, and return to the compressor 5 through the suction action of the liquid ring vacuum pump 13 to re-enter the absorption tower 6 for absorption; while in the interception zone is the intercepted hydrocarbon-poor gas flow, the main substances of which are air and a small amount of hydrocarbons. Through this separation process, the hydrocarbons in the intercepted gas are reduced by most and then enter the buffer tank 8 for buffering, and then enter the liquid ring compressor 9 after buffering in the buffer tank 8, and enter the catalytic cracking regenerator unit after compression and pressure increase. The adoption of the technical solution of the present invention greatly reduces the concentration of volatile organic compounds (VOCs), and the concentration is stably controlled. There is no impact on the catalytic operation when it enters the catalytic regenerator for oxidation. The oxidized volatile organic compounds (VOCs) can fully meet the emission limit requirements, effectively solving the problem of substandard volatile organic compound emissions.

[0036] Embodiment 2:

[0037] Reference Figure 1 A volatile organic compound (VOCs) treatment device shown in the figure is based on the first embodiment, and the collecting mechanism includes a collecting pipeline and a raw material buffer tank 2; one end of the collecting pipeline is connected to the VOCs release source 1, and the other end of the collecting pipeline is connected to the raw material buffer tank 2; the bottom of the raw material buffer tank 2 is connected to a first nitrogen control valve 4, and the top of the raw material buffer tank 2 is connected to the absorption mechanism.

[0038] In actual use, the volatile organic compounds (VOCs) released by the VOCs release source 1 are gathered in the raw material buffer tank 2 through the collection pipeline. When the concentration of the volatile organic compounds (VOCs) in the raw material buffer tank 2 is greater than a preset value, the first nitrogen control valve 4 is opened to add nitrogen to the raw material buffer tank 2 to reduce the concentration of the volatile organic compounds (VOCs) and ensure that the volatile organic compounds (VOCs) treatment process is carried out safely.

[0039] Embodiment three:

[0040] Reference Figure 1A volatile organic compound (VOCs) treatment device is shown. Based on the first embodiment, the absorption mechanism includes a first liquid ring compressor 5 and an absorption tower 6; the input end of the first liquid ring compressor 5 is connected to the collection mechanism through a pipeline, and the output end of the first liquid ring compressor 5 is connected to the absorption tower 6; the top of the absorption tower 6 is connected to the membrane separation component 7, the bottom of the absorption tower 6 is provided with an output port, and the upper side wall of the absorption tower 6 is provided with an absorbent input port.

[0041] Furthermore, the pipeline connecting the first liquid ring compressor 5 and the collecting mechanism is connected with an emergency drain valve 3, a first concentration detector and a first self-protection control system 14.

[0042] In actual use, the volatile organic compounds (VOCs) collected by the collection mechanism enter the absorption tower 6, and the upper part of the absorption tower 6 sprays the absorbent on the volatile organic compounds (VOCs) inside the absorption tower 6. The absorbent fully contacts the volatile organic compounds (VOCs) and absorbs the hydrocarbons therein. After absorption, the hydrocarbons are collected and temporarily stored in the liquid phase layer at the bottom of the absorption tower 6, and are discharged after a preset amount is collected; a part of the hydrocarbons and the inert gases that cannot be absorbed enter the membrane separation component 7 through the upper part of the absorption tower 6, thereby completing the primary treatment of the volatile organic compounds (VOCs).

[0043] The absorbent can also be replaced by gasoline or diesel or other absorbents.

[0044] The absorption tower 6 in this embodiment can be replaced by condensation.

[0045] Embodiment 4:

[0046] Reference Figure 1 A volatile organic compound (VOCs) treatment device shown is based on Example 1: the buffer mechanism includes a buffer tank 8 and a second liquid ring compressor 9; the buffer tank 8 is connected to the membrane separation component 7, the top of the buffer tank 8 is connected to the catalytic cracking regenerator 12 through the second liquid ring compressor 9, and the bottom of the buffer tank 8 is connected to a second nitrogen control valve 10.

[0047] Furthermore, the second liquid ring compressor 9 is provided with a pressure self-maintaining control valve 11 and a check valve 17 on the pipeline connected to the catalytic cracking regenerator 12; a second concentration detector and a second self-maintaining control system 15 are provided on the pipeline between the second liquid ring compressor 9 and the pressure self-maintaining control valve 11; and a pressure detection system 16 is provided on the pressure self-maintaining control valve 11.

[0048] In actual use, the adoption of this technical solution enables the volatile organic compound (VOCs) treatment device to operate safely.

[0049] Embodiment five:

[0050] Reference Figure 1 The volatile organic compound (VOCs) treatment device shown in the figure, based on the first embodiment, also includes a protection check valve 18; the protection check valve 18 is arranged on the pipeline connecting the buffer mechanism and the catalytic cracking regenerator 12, and is close to the connection port of the catalytic cracking regenerator 12.

[0051] In actual use, the protection check valve 18 is provided for back-blowing to prevent the catalyst in the chemical cracking regenerator 12 from pouring out and clogging the check valve 17, thereby causing a safety hazard.

[0052] Embodiment six:

[0053] Reference Figure 1 The volatile organic compound (VOCs) treatment device shown in the figure, based on the first embodiment, also includes a controller; the controller is electrically connected to the collection mechanism, the absorption mechanism, the membrane separation component 7, the liquid ring vacuum pump 13, the protection check valve 18 and the buffer mechanism.

[0054] In actual use, the adoption of this technical solution automates the management process, greatly saves manpower, and ensures the safety and stability of operation.

[0055] Embodiment seven:

[0056] Reference Figure 1The volatile organic compound (VOC) treatment device shown in the figure is based on the first embodiment: it also includes a protection check valve 18 and a controller; the collecting mechanism includes a collecting pipeline and a raw material buffer tank 2; one end of the collecting pipeline is connected to the VOCs release source 1, and the other end of the collecting pipeline is connected to the raw material buffer tank 2; the bottom of the raw material buffer tank 2 is connected to a first nitrogen control valve 4, and the top of the raw material buffer tank 2 is connected to the absorption mechanism; the absorption mechanism includes a first liquid ring compressor 5 and an absorption tower 6; the input end of the first liquid ring compressor 5 is connected to the collecting mechanism through a pipeline, and the first liquid ring compressor 5 The output end is connected to the absorption tower 6; the top of the absorption tower 6 is connected to the membrane separation assembly 7, the bottom of the absorption tower 6 is provided with an output port, and the upper side wall of the absorption tower 6 is provided with an absorbent input port; the pipeline connecting the first liquid ring compressor 5 and the collecting mechanism is connected with an emergency drain valve 3, a first concentration detector and a first self-protection control system 14; the buffer mechanism includes a buffer tank 8 and a second liquid ring compressor 9; the buffer tank 8 is connected to the membrane separation assembly 7, the top of the buffer tank 8 is connected to the catalytic cracking regenerator 12 through the second liquid ring compressor 9, and the bottom of the buffer tank 8 is connected with a second nitrogen control valve 10; the second liquid ring compressor The machine 9 is provided with a pressure self-protection control valve 11 and a check valve 17 on the pipeline connected to the catalytic cracking regenerator 12; a second concentration detector and a second self-protection control system 15 are provided on the pipeline between the second liquid ring compressor 9 and the pressure self-protection control valve 11; a pressure detection system 16 is provided on the pressure self-protection control valve 11; the protection check valve 18 is provided on the pipeline connecting the buffer mechanism and the catalytic cracking regenerator 12, and is close to the connection port of the catalytic cracking regenerator 12; the controller is respectively connected with the collecting mechanism, the absorbing mechanism, the membrane separation component 7, the liquid ring vacuum pump 13, the protection check valve 18 and the buffer mechanism by electrical signals.

[0057] In actual use, the controller closes the emergency drain valve 3 and the first nitrogen control valve 4 in the volatile organic compound (VOCs) treatment device, and closes the second nitrogen valve 10; then the controller controls the first liquid ring compressor 5 and the second liquid ring compressor 9 to start, and the collecting mechanism collects the volatile organic compound (VOCs) from the VOCs release source 1; the controller obtains the test value of the first concentration detector and the first self-protection control system 14. When the values ​​measured by the first concentration detector and the first self-protection control system 14 exceed the preset values, the controller controls the first nitrogen control valve 4 to open, and injects nitrogen into the raw material buffer tank 2. If the first concentration detector and the first self-protection control system 14 show that the concentration exceeds the preset value, the controller controls the emergency drain valve 3 to open, and stops the first liquid ring compressor 5 and the second liquid ring compressor 9 at the same time; The volatile organic compounds VOCs collected by the collecting mechanism enter the absorption tower 6 in the absorption mechanism, and the absorbent is sprayed from the upper part of the absorption tower 6. The absorbent absorbs the hydrocarbons that can be absorbed in the volatile organic compounds VOCs, and after absorption, they are collected in the liquid phase layer at the bottom of the absorption tower 6 for temporary storage, and are discharged after the preset amount is collected; a part of the hydrocarbons and the inert gas that cannot be absorbed enter the membrane separation component 7 through the upper part of the absorption tower 6; the volatile organic compounds VOCs entering the membrane separation component 7 are subjected to membrane treatment; the larger molecular weight hydrocarbons therein pass through the permeation membrane, are enriched in the permeation zone, and are returned to the raw material buffer tank 2 through the suction action of the liquid ring vacuum pump 13, and re-enter the absorption tower 6 through the first liquid ring compressor 5 for absorption; and the hydrocarbon-poor gas flow trapped in the interception zone enters the buffer tank 8. The gas entering the buffer tank 8 enters the catalytic cracking regenerator 12 through the second liquid ring compressor 9 after being buffered in the buffer tank 8; when the concentration value of the second concentration detector and the second self-protection control system 15 obtained by the controller exceeds the preset value, the controller controls the opening of the second nitrogen control valve 10 to inject nitrogen into the buffer tank 8 to reduce the concentration of volatile organic compounds (VOCs) in the buffer tank 8; when the concentration value of the second concentration detector and the second self-protection control system 15 obtained by the controller exceeds the preset value, the first liquid ring compressor 5 and the second liquid ring compressor 9 are interlocked and stopped, and the emergency vent valve 3 is opened at the same time; when the pressure value of the pressure detection system 16 is lower than the preset value, the pressure self-protection control valve 11 is closed.

[0058] The gas treated by the catalytic cracking regenerator 12 is directly discharged.

[0059] In actual use, the dispersed volatile organic compounds (VOCs) are collected, absorbed, and treated with membranes before entering the catalytic cracking regenerator 12 for oxidation, which greatly reduces the emission concentration of volatile organic compounds (VOCs). The concentration of volatile organic compounds (VOCs) can be reduced to 30 mg / m 3After absorption pretreatment, the heavy components of volatile organic compounds (VOCs) can be recovered in large quantities, and after membrane treatment, the emission concentration of volatile organic compounds (VOCs) after the membrane can be stabilized, which is not affected by the fluctuation of the source quantity and has no impact on the catalytic cracking regenerator 12, and finally achieves mg-level emission standards.

[0060] Embodiment nine:

[0061] A method for treating volatile organic compounds (VOCs) comprising the following steps:

[0062] Step 1: The controller closes the emergency exhaust valve 3, the first nitrogen control valve 4 and the second nitrogen valve 10 in the volatile organic compound (VOCs) treatment device;

[0063] Step 2: The controller controls the first liquid ring compressor 5 and the second liquid ring compressor 9 to start, and the collecting mechanism collects the volatile organic compounds VOCs from the VOCs release source 1; the controller obtains the test values ​​of the first concentration detector and the first self-protection control system 14. When the values ​​measured by the first concentration detector and the first self-protection control system 14 exceed the preset values, the controller controls the first nitrogen control valve 4 to open, and injects nitrogen into the raw material buffer tank 2. If the first concentration detector and the first self-protection control system 14 show that the concentration exceeds the preset value, the controller controls the emergency drain valve 3 to open, and interlocks and stops the first liquid ring compressor 5 and the second liquefied compressor 9;

[0064] Step 3: The volatile organic compounds VOCs collected by the collection mechanism enter the absorption tower 6 in the absorption mechanism, and the absorbent is sprayed from the upper part of the absorption tower 6. The absorbent absorbs the hydrocarbons that can be absorbed in the volatile organic compounds VOCs, and after absorption, they are collected and temporarily stored in the liquid phase layer at the bottom of the absorption tower 6, and discharged after the preset amount is collected; a part of the hydrocarbons and the inert gas that cannot be absorbed enter the membrane separation component 7 through the upper part of the absorption tower 6;

[0065] Step 4: The volatile organic compounds (VOCs) entering the membrane separation component 7 are subjected to membrane treatment; the hydrocarbons with larger molecular weight pass through the permeation membrane, are enriched in the permeation zone, and are returned to the raw material buffer tank 2 by the suction action of the liquid ring vacuum pump 13, and re-enter the absorption tower 6 through the first liquid ring compressor 5 for absorption; and the hydrocarbon-poor gas stream trapped in the interception zone enters the buffer tank 8;

[0066] Step 5: The gas entering the buffer tank 8 enters the catalytic cracking regenerator 12 through the second liquid ring compressor 9 after being buffered by the buffer tank 8; when the concentration value of the second concentration detector and the second self-protection control system 15 obtained by the controller exceeds the preset value, the controller controls the opening of the second nitrogen control valve 10 to inject nitrogen into the buffer tank 8; when the concentration value of the second concentration detector and the second self-protection control system 15 obtained by the controller exceeds the preset value, the first liquid ring compressor 5 and the second liquid ring compressor 9 are interlocked and stopped, and the emergency vent valve 3 is opened at the same time; when the pressure value of the pressure detection system 16 is lower than the preset value, the pressure self-protection control valve 11 is closed;

[0067] Step 6: The gas treated in step 5 enters the catalytic cracking regenerator 12 through a distributor, and the gas treated in the catalytic cracking regenerator 12 is discharged.

[0068] In actual use, the dispersed volatile organic compounds (VOCs) are collected, absorbed, and treated with membranes before entering the catalytic cracking regenerator 12 for oxidation, which greatly reduces the emission concentration of volatile organic compounds (VOCs). The concentration of volatile organic compounds (VOCs) can be reduced to 30 mg / m 3 The following does not add a VOCs discharge port. After absorption pretreatment, the heavy components of volatile organic matter VOCs can be recovered in large quantities, and after membrane treatment, the emission concentration of volatile organic matter VOCs after the membrane can be stabilized, which is not affected by the fluctuation of the source amount and has no impact on the catalytic cracking regenerator 12.

[0069] In specific operation, the amount of absorbent is generally the absorption design amount, which can be adjusted around the absorption design amount. The specific design absorbent dosage needs to be calculated based on the VOCs components entering the absorption tower and the theoretical VOCs components leaving the tower through material balance, heat balance, number of plates, tower height, etc. The use of absorption technology as a pretreatment technology is mature, with relatively low one-time investment and strong operational reliability. The injected nitrogen can meet the operating requirements as industrial nitrogen.

[0070] The distributor in this embodiment adopts the existing technology.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

[0072] In the absence of conflicts, technicians in this field can combine the relevant technical features in the above examples according to actual conditions to achieve corresponding technical effects. The specific combinations are not described here one by one.

[0073] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0074] The above are only preferred embodiments of the present invention. The present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features disclosed herein. Any simple modification, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A device for treating volatile organic compounds (VOCs), characterized by: It comprises a collecting mechanism, an absorbing mechanism, a membrane separation assembly (7), a liquid ring vacuum pump (13), a buffer mechanism and a catalytic cracking regenerator (12); one end of the collecting mechanism is connected to a VOCs release source (1), and the other end of the collecting mechanism is connected to the absorbing mechanism; the membrane separation assembly (7) is provided with an interception zone and a permeation zone, the interception zone is connected to the absorbing mechanism, the upper part of the interception zone is connected to the input end of the buffer mechanism, and the bottom of the permeation zone is connected to the collecting mechanism via the liquid ring vacuum pump (13); the output end of the buffer mechanism is connected to the catalytic cracking regenerator (12); The collecting mechanism comprises a collecting pipeline and a raw material buffer tank (2); one end of the collecting pipeline is connected to the VOCs release source (1), and the other end of the collecting pipeline is connected to the raw material buffer tank (2); the bottom of the raw material buffer tank (2) is connected to a first nitrogen control valve (4), and the top of the raw material buffer tank (2) is connected to the absorption mechanism; The absorption mechanism comprises a first liquid ring compressor (5) and an absorption tower (6); the input end of the first liquid ring compressor (5) is connected to the collection mechanism through a pipeline, and the output end of the first liquid ring compressor (5) is connected to the absorption tower (6); the top of the absorption tower (6) is connected to the membrane separation component (7), the bottom of the absorption tower (6) is provided with an output port, and the upper side wall of the absorption tower (6) is provided with an absorbent input port.

2. A device for treating volatile organic compounds (VOCs) as claimed in claim 1, characterized in that: The pipeline connecting the first liquid ring compressor (5) and the collecting mechanism is connected to an emergency drain valve (3), a first concentration detector and a first self-protection control system (14).

3. The device for treating volatile organic compounds (VOCs) as claimed in claim 1, characterized in that: The buffer mechanism comprises a buffer tank (8) and a second liquid ring compressor (9); the buffer tank (8) is connected to the membrane separation assembly (7), the top of the buffer tank (8) is connected to the catalytic cracking regenerator (12) through the second liquid ring compressor (9), and the bottom of the buffer tank (8) is connected to a second nitrogen control valve (10).

4. A device for treating volatile organic compounds (VOCs) as claimed in claim 3, characterized in that: The second liquid ring compressor (9) is provided with a pressure self-maintaining control valve (11) and a check valve (17) on a pipeline connected to the catalytic cracking regenerator (12); a second concentration detector and a second self-maintaining control system (15) are provided on the pipeline between the second liquid ring compressor (9) and the pressure self-maintaining control valve (11); and a pressure detection system (16) is provided on the pressure self-maintaining control valve (11).

5. The device for treating volatile organic compounds (VOCs) as claimed in claim 1, characterized in that: It also includes a protection check valve (18); the protection check valve (18) is arranged on a pipeline connecting the buffer mechanism and the catalytic cracking regenerator (12), and is close to a connection port of the catalytic cracking regenerator (12).

6. The device for treating volatile organic compounds (VOCs) as claimed in claim 1, characterized in that: It also includes a controller; the controller is respectively connected to the collection mechanism, the absorption mechanism, the membrane separation component (7), the liquid ring vacuum pump (13), the protection check valve (18) and the buffer mechanism through electrical signal connections.

7. A method for treating volatile organic compounds (VOCs) by using a treatment device, characterized in that: The following steps are included: Step 1: The controller closes the emergency exhaust valve (3), the first nitrogen control valve (4), and the second nitrogen control valve (10) in the volatile organic compound (VOCs) treatment device; Step 2: The controller controls the first liquid ring compressor (5) and the second liquid ring compressor (9) to start, and the collecting mechanism collects volatile organic compounds (VOCs) from the VOCs release source (1); the controller obtains the test value of the first concentration detector and the first self-protection control system (14); when the value measured by the first concentration detector and the first self-protection control system (14) exceeds the preset value, the controller controls the first nitrogen control valve (4) to open, and nitrogen is injected into the raw material buffer tank (2); if the first concentration detector and the first self-protection control system (14) show that the concentration exceeds the preset value, the controller controls the emergency drain valve (3) to open, and interlocks and stops the first liquid ring compressor (5) and the second liquid ring compressor (9); Step 3: The volatile organic compounds (VOCs) collected by the collecting mechanism enter the absorption tower (6) in the absorption mechanism, and an absorbent is sprayed from the upper part of the absorption tower (6). The absorbent absorbs the hydrocarbons that can be absorbed in the volatile organic compounds (VOCs). After absorption, the hydrocarbons are collected and temporarily stored in the liquid phase layer at the bottom of the absorption tower (6). After a preset amount is collected, the hydrocarbons are discharged; A portion of hydrocarbons and inert gases that cannot be absorbed enter the membrane separation component (7) through the upper portion of the absorption tower (6); Step 4: The volatile organic compounds (VOCs) entering the membrane separation component (7) are subjected to membrane treatment; the hydrocarbons with larger molecular weight therein pass through the permeation membrane, are enriched in the permeation zone, are returned to the raw material buffer tank (2) by the suction action of the liquid ring vacuum pump (13), and re-enter the absorption tower (6) for absorption through the first liquid ring compressor (5); and the hydrocarbon-poor gas stream retained in the interception zone enters the buffer tank (8); Step 5: The gas entering the buffer tank (8) enters the catalytic cracking regenerator (12) through the second liquid ring compressor (9) after being buffered by the buffer tank (8); when the concentration value obtained by the controller from the second concentration detector and the second self-protection control system (15) exceeds a preset value, the controller controls the opening of the second nitrogen control valve (10) to inject nitrogen into the buffer tank (8); when the concentration value obtained by the controller from the second concentration detector and the second self-protection control system (15) exceeds a preset value, the first liquid ring compressor (5) and the second liquid ring compressor (9) are interlocked and stopped, and the emergency drain valve (3) is opened at the same time; when the pressure value of the pressure detection system (16) is lower than the preset value, the pressure self-protection control valve (11) is closed; Step 6: The gas treated in step 5 enters the catalytic cracking regenerator (12) through a distributor, and the gas treated in the catalytic cracking regenerator (12) is discharged.

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