VOC tail gas treatment device for polypropylene stock bin

Abstract

The utility model relates to a polypropylene stock bin VOC tail gas treatment device which comprises a conveyor compressor, a cooler and a fine removal reactor which are sequentially communicated through pipelines, the conveyor compressor is communicated with one end of a tail gas supply pipeline, and the other end of the tail gas supply pipeline is used for being communicated with a polypropylene stock bin; the top of the fine removal reactor is respectively communicated with one end of a nitrogen recovery pipeline and one end of a regeneration gas pipeline, the other end of the nitrogen recovery pipeline is communicated with the flash kettle, and the other end of the regeneration gas pipeline is used for being communicated with a low-pressure torch system; the bottom of the fine removal reactor is communicated with one end of a nitrogen supply pipeline, and the other end of the nitrogen supply pipeline is communicated with a nitrogen tank; and the cooler is communicated with the lower part of the fine removal reactor through a pipeline. The VOC tail gas treatment device has the advantages of being simple in structure, reasonable in design, capable of achieving rapid treatment of VOC tail gas of the polypropylene stock bin, capable of guaranteeing standard emission of the tail gas of the polypropylene stock bin, energy-saving, environment-friendly and low in cost.

Description

Technical Field

[0001] The utility model relates to the technical field of polypropylene tail gas treatment, in particular to a polypropylene silo VOC tail gas treatment device. Background Art

[0002] Polypropylene is a polymer formed by the addition polymerization of propylene. It is widely used in the fields of automobiles, electronics, packaging, home appliances, building materials, etc. In the normal production process of polypropylene, in order to ensure stable production and achieve the purpose of safety control, it is necessary to discharge part of the tail gas to the flare for a long time and stably. The tail gas from the reactor, degassing bin, and propylene refining system contains a large amount of recyclable hydrocarbons, but because it contains some harmful substances, it is not conducive to the recycling and utilization of downstream devices. In the existing process technology, most of them are directly discharged into the flare for combustion, which not only causes the increase of material consumption of the device and the loss of economic benefits, but also brings environmental problems. At present, the world's major polypropylene production processes, especially the gas phase polypropylene process, basically choose the gas phase emission method for tail gas, which is discharged to the flare network or the fuel gas network. This method is easy to operate and has rapid emission, but with the increasing requirements for energy saving and consumption reduction, green environmental protection, etc., gas phase emission has highlighted many disadvantages.

[0003] As the national and local governments' environmental protection requirements are increasing, the requirements for pollutant emissions from oil refineries are also getting higher and higher. Faced with such a severe environmental situation, chemical companies are improving their environmental protection facilities and systems. For example, the polypropylene units of Sinopec and other companies have also taken a number of measures to actively carry out VOC prevention and control work in the polypropylene production process.

[0004] At present, there is a problem of VOCs unorganized emission in the silo of polypropylene equipment. For example, the peak value of non-methane total hydrocarbons at the exhaust port on the top of the silo of a certain enterprise is 6000mg / m 3 About, particulate matter> 88mg / m 3 , does not meet the requirements of the resin industry "Synthetic Resin Industry Pollutant Emission Standard GB 31572-2015" for total non-methane hydrocarbons <60mg / m 3 、Particulate matter<20mg / m 3 In order to prevent low-concentration VOCs in the silo from escaping into the atmosphere, it is necessary to treat the silo tail gas as soon as possible and strive to achieve standard emissions as soon as possible. Utility Model Content

[0005] The utility model provides a polypropylene silo VOC tail gas treatment device, aiming to solve the problems in the prior art.

[0006] The technical solution of the utility model to solve the above technical problems is as follows:

[0007] A polypropylene silo VOC tail gas treatment device comprises a conveyor compressor, a cooler and a fine stripping reactor which are sequentially connected through pipelines, wherein the conveyor compressor is connected to one end of a tail gas supply pipeline, and the other end of the tail gas supply pipeline is used to connect to the polypropylene silo; the top of the fine stripping reactor is respectively connected to one end of a nitrogen recovery pipeline and one end of a regeneration gas pipeline, the other end of the nitrogen recovery pipeline is connected to a flash kettle, and the other end of the regeneration gas pipeline is used to connect to a low-pressure flare system; the bottom of the fine stripping reactor is connected to one end of a nitrogen supply pipeline, and the other end of the nitrogen supply pipeline is used to connect to a nitrogen tank; the cooler is connected to the lower part of the fine stripping reactor through a pipeline.

[0008] The beneficial effects of the utility model are as follows: during the treatment process, the tail gas to be treated is compressed and increased by the conveyor compressor and then enters the cooler for cooling treatment, the cooled tail gas enters the fine degassing reactor for adsorption treatment, the discharged nitrogen is recovered, and the regenerated gas is sent to the low-pressure flare system, which is convenient for treatment and energy-saving and environmentally friendly.

[0009] The utility model has a simple structure and a reasonable design, can realize the rapid treatment of VOC tail gas of the polypropylene silo, ensures that the tail gas of the polypropylene silo is discharged up to the standard, is energy-saving and environmentally friendly, and has low cost.

[0010] On the basis of the above technical solution, the present invention can also be improved as follows.

[0011] Furthermore, it also includes a spare fine degassing reactor, the top of which is connected to the nitrogen recovery pipeline and the regeneration gas pipeline through two spare pipelines, the bottom of the spare fine degassing reactor is connected to one end of the spare nitrogen pipeline, and the other end of the spare nitrogen pipeline is used to connect to the nitrogen tank.

[0012] The beneficial effect of adopting the above further scheme is that during the treatment process, the tail gas to be treated is compressed and increased by the conveyor compressor and then enters the cooler for cooling treatment, the cooled tail gas enters the fine stripping reactor for adsorption treatment, the discharged nitrogen is recovered, and the regenerated gas is sent to the low-pressure flare system; in this process, the standby fine stripping reactor is not started;

[0013] When the fine desorption reactor is saturated with adsorption, the standby fine desorption reactor is started and the standby fine desorption reactor performs adsorption operation; during this process, the fine desorption reactor performs desorption treatment;

[0014] This process is repeated to complete the treatment of a large amount of exhaust gas.

[0015] Furthermore, a nitrogen supply valve is fixedly installed on the nitrogen supply pipeline and / or the standby nitrogen pipeline.

[0016] The beneficial effects of adopting the above further solution are simple structure, reasonable design of the nitrogen supply valve, and controlling the on-off of the nitrogen supply through the nitrogen supply valve.

[0017] Furthermore, spare valves are fixedly installed on the two spare pipelines respectively.

[0018] The beneficial effects of adopting the above further scheme are simple structure and reasonable design. The two standby valves are opened when the standby fine degassing reactor is started to carry out standby treatment operations, which is convenient for operation.

[0019] Furthermore, a recovery valve is fixedly installed at a portion between one end of the nitrogen recovery pipeline and the connection point between one of the spare pipelines and the nitrogen recovery pipeline and / or a portion between one end of the regeneration gas pipeline and the connection point between the other end of the spare pipeline and the regeneration gas pipeline.

[0020] The beneficial effects of adopting the above further scheme are simple structure, reasonable design, and rapid switching of the fine stripping reactor and the standby fine stripping reactor controlled by the recovery valve to facilitate treatment operations.

[0021] Furthermore, a filter is fixedly installed on the exhaust gas supply pipeline.

[0022] The beneficial effects of adopting the above further scheme are simple structure, reasonable design, and removal of large particles in the exhaust gas through the filter, thereby preventing large particles from entering the system and affecting the working performance of various components, thereby ensuring the normal operation of the system.

[0023] Furthermore, the filter is a microporous filter.

[0024] The beneficial effect of adopting the above further scheme is that the microporous filter is reasonably selected, most of the large particles are filtered out, and the filtering effect is better.

[0025] Furthermore, a fan is fixedly installed at the other end of the regeneration gas pipeline.

[0026] The beneficial effects of adopting the above further scheme are simple structure, reasonable design, and high efficiency by using a fan to quickly deliver the regenerated gas to the low-pressure flare system.

[0027] Furthermore, the blower is a Roots blower.

[0028] The beneficial effect of adopting the above further scheme is that the Roots blower is reasonably selected, has a simple structure and high efficiency.

[0029] Furthermore, the cooler is an air cooler or a water cooler.

[0030] The beneficial effect of adopting the above further solution is that the air cooler or water cooler has a better cooling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0032] Figure 2 It is a schematic diagram of the structure of the fine desorption reactor in the utility model during adsorption;

[0033] Figure 3 It is a schematic diagram of the structure of the fine desorption reactor in the utility model during desorption;

[0034] Figure 4 This is a control flow chart of the utility model.

[0035] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0036] 1. Conveyor compressor; 2. Cooler; 3. Fine stripping reactor; 4. Tail gas supply pipeline; 5. Nitrogen recovery pipeline; 6. Regeneration gas pipeline; 7. Nitrogen supply pipeline; 8. Spare fine stripping reactor; 9. Spare nitrogen pipeline; 10. Nitrogen supply valve; 11. Spare valve; 12. Recovery valve; 13. Filter; 14. Fan. DETAILED DESCRIPTION

[0037] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0038] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0040] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0041] Example 1

[0042] like Figures 1 to 4 As shown, this embodiment provides a VOC tail gas treatment device for a polypropylene silo, comprising a conveyor compressor 1, a cooler 2 and a fine degassing reactor 3 which are sequentially connected through pipelines, the conveyor compressor 1 is connected to one end of a tail gas supply pipeline 4, and the other end of the tail gas supply pipeline 4 is used to connect to the polypropylene silo; the top of the fine degassing reactor 3 is respectively connected to one end of a nitrogen recovery pipeline 5 and one end of a regeneration gas pipeline 6, the other end of the nitrogen recovery pipeline 5 is connected to a flash kettle, and the other end of the regeneration gas pipeline 6 is used to connect to a low-pressure flare system; the bottom of the fine degassing reactor 3 is connected to one end of a nitrogen supply pipeline 7, and the other end of the nitrogen supply pipeline 7 is used to connect to a nitrogen tank; the cooler 2 is connected to the lower part of the fine degassing reactor 3 through a pipeline.

[0043] During the treatment process, the tail gas to be treated is compressed and increased by the conveyor compressor 1 and then enters the cooler 2 for cooling treatment. The cooled tail gas enters the fine degassing reactor 3 for adsorption treatment, the discharged nitrogen is recovered, and the regenerated gas is sent to the low-pressure flare system. The treatment is convenient, energy-saving and environmentally friendly.

[0044] It should be noted that the above-mentioned conveyor compressor 1 and cooler 2 both adopt existing technologies, and their specific structures and principles are not described in detail here.

[0045] This embodiment has a simple structure and a reasonable design, and can achieve rapid treatment of VOC tail gas from a polypropylene silo, ensuring that the tail gas from the polypropylene silo meets emission standards, and is energy-saving, environmentally friendly, and low-cost.

[0046] Example 2

[0047] On the basis of Example 1, this embodiment also includes a spare fine degassing reactor 8, the top of which is connected to the nitrogen recovery pipeline 5 and the regeneration gas pipeline 6 through two spare pipelines, and the bottom of the spare fine degassing reactor 8 is connected to one end of a spare nitrogen pipeline 9, and the other end of the spare nitrogen pipeline 9 is used to connect to a nitrogen tank.

[0048] During the treatment process, the tail gas to be treated is compressed and increased by the conveyor compressor 1 and then enters the cooler 2 for cooling treatment. The cooled tail gas enters the fine stripping reactor 3 for adsorption treatment, the discharged nitrogen is recovered, and the regenerated gas is sent to the low-pressure flare system; during this process, the standby fine stripping reactor 8 is not started;

[0049] When the fine desorption reactor 3 is saturated with adsorption, the standby fine desorption reactor 8 is started, and the standby fine desorption reactor 8 performs adsorption operation; during this process, the fine desorption reactor 3 performs desorption treatment, and after the desorption is completed, the adsorption operation is performed again, and the fine desorption reactor 3 and the standby fine desorption reactor 8 perform adsorption and desorption alternately;

[0050] This process is repeated to complete the treatment of a large amount of exhaust gas.

[0051] Based on the above scheme, the SIS control system (safety instrument) is used to monitor in real time whether the adsorption and desorption in the fine desorption reactor 3 and the standby fine desorption reactor 8 are completed, and automatic switching is performed with high accuracy and efficiency.

[0052] Preferably, in this embodiment, the other end of the nitrogen supply pipeline 7 and the other end of the backup nitrogen pipeline 9 are preferably connected to a nitrogen tank.

[0053] Example 3

[0054] On the basis of Example 2, in this embodiment, a nitrogen supply valve 10 is fixedly installed on the nitrogen supply pipeline 7 and / or the backup nitrogen pipeline 9 respectively.

[0055] The solution has a simple structure, and the nitrogen supply valve 10 is reasonably designed, and the nitrogen supply is controlled by the nitrogen supply valve 10 .

[0056] Preferably, in this embodiment, the nitrogen supply valve 10 is preferably a solenoid valve, but a manual valve may also be used.

[0057] Example 4

[0058] On the basis of any one of Embodiments 2 to 3, in this embodiment, a backup valve 11 is fixedly installed on each of the two backup pipelines.

[0059] This solution has a simple structure and a reasonable design. The two standby valves 11 are opened when the standby fine degassing reactor 8 is started to perform standby treatment operations, which is convenient for operation.

[0060] Preferably, in this embodiment, the backup valve 11 is preferably a solenoid valve, but a manual valve may also be used.

[0061] Example 5

[0062] On the basis of any one of Examples 2 to 4, in this embodiment, a recovery valve 12 is fixedly installed at a portion between one end of the nitrogen recovery pipeline 5 and the connection point between one of the spare pipelines and the nitrogen recovery pipeline 5 and / or a portion between one end of the regeneration gas pipeline 6 and the connection point between the other end of the spare pipeline and the regeneration gas pipeline 6.

[0063] This solution has a simple structure and a reasonable design. The recovery valve 12 is used to control the rapid switching of the fine degassing reactor 3 and the standby fine degassing reactor 8 so as to carry out the treatment operation, and the operation is convenient.

[0064] Preferably, in this embodiment, the recovery valve 12 is preferably a solenoid valve, but a manual valve may also be used.

[0065] Example 6

[0066] On the basis of the above embodiments, in this embodiment, a filter 13 is fixedly installed on the exhaust gas supply pipeline 4 .

[0067] This solution has a simple structure and a reasonable design. Large particles in the exhaust gas are removed by the filter 13 to prevent the large particles from entering the system and affecting the working performance of various components, thereby ensuring the normal operation of the system.

[0068] Example 7

[0069] On the basis of Example 6, in this embodiment, the filter 13 is a microporous filter.

[0070] The microporous filter is selected reasonably to remove most of the large particles and achieve better filtering effect.

[0071] It should be noted that the above-mentioned microporous filter adopts the existing technology, and its specific structure and principle are not described in detail here.

[0072] Example 8

[0073] On the basis of the above embodiments, in this embodiment, a fan 14 is fixedly installed at the other end of the regeneration gas pipeline 6 .

[0074] This solution has a simple structure and a reasonable design. The fan 14 is used to quickly deliver the regenerated gas to the low-pressure flare system, and the efficiency is high.

[0075] Example 9

[0076] On the basis of Example 8, in this embodiment, the blower 14 is a Roots blower.

[0077] The Roots blower is reasonably selected, simple in structure and high in efficiency.

[0078] It should be noted that the above-mentioned Roots blower adopts the existing technology, and its specific structure and principle are not described in detail here.

[0079] Example 10

[0080] On the basis of the above embodiments, in this embodiment, the cooler 2 is an air cooler or a water cooler.

[0081] Air cooler or water cooler has better cooling effect.

[0082] The working principle of the utility model is as follows:

[0083] During the treatment process, the tail gas to be treated is first filtered by the filter 13, the filtered tail gas is compressed and increased by the conveyor compressor 1 and then enters the cooler 2 for cooling treatment, the cooled tail gas enters the fine degassing reactor 3 for adsorption treatment, the discharged nitrogen is recovered, and the regenerated gas is sent to the low-pressure flare system; during this process, the standby fine degassing reactor 8 is not started;

[0084] When the fine desorption reactor 3 is saturated with adsorption, the standby fine desorption reactor 8 is started, and the standby fine desorption reactor 8 performs adsorption operation; during this process, the fine desorption reactor 3 performs desorption treatment, and after the desorption is completed, the adsorption operation is performed again, and the fine desorption reactor 3 and the standby fine desorption reactor 8 perform adsorption and desorption alternately;

[0085] This process is repeated to complete the treatment of a large amount of exhaust gas.

[0086] The purpose of the utility model is to build a polypropylene silo VOC tail gas treatment device, which uses nitrogen as a carrier to effectively remove the polypropylene monomer in the polypropylene powder, and obtains high-purity recyclable nitrogen by adsorption at room temperature; in addition, it can solve the pollution problem caused by VOC exhaust into the atmosphere, optimize resources, and reduce production costs.

[0087] The tail gas from the silo of the polypropylene unit first passes through a filter to remove a large amount of particulate matter. After adsorption in the fine desorption reactor, the propylene and propane in the tail gas are adsorbed. The product gas is nitrogen with a purity of more than 99.9%, and the desorbed gas is about 50-70% propylene, which is transported to the original low-pressure flare system through a fan.

[0088] Compared with the prior art, the utility model has the following advantages:

[0089] (1) The process flow is simple, the adsorption process operating temperature is moderate, the operating pressure is low, and the energy consumption of the entire device is low; during the operation, the process parameters should be adjusted according to the trend of the analysis data, and online monitoring facilities should be set up to ensure that the exhaust gas from the polypropylene silo meets the emission standards.

[0090] (2) The device occupies a small area, has low operating energy consumption, and is easy to maintain;

[0091] (3) The equipment investment is low, the operating cost is low, and the economic benefits are good.

[0092] (4) High degree of automation, easy to start and stop.

[0093] (5) No secondary pollution, truly achieving green environmental protection.

[0094] The device is effective in recovering and treating polypropylene gas with certain value. The device has a good effect on gas separation. The main advantages of this technology are: low energy consumption, relatively low cost, automated process operation, relatively high purity of the mixture after separation and purification, and low environmental pollution. The market development prospect is broad and will become the development direction of organic waste gas treatment technology in the future.

[0095] It should be noted that all electronic components involved in the present invention adopt the existing technology, and the above-mentioned components are electrically connected to the controller, and the control circuit between the controller and each component is the existing technology.

[0096] In addition, the arrows in the drawings merely indicate the direction of gas flow and have no other substantial meaning.

[0097] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

[0098] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0099] 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 principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A polypropylene silo VOC tail gas treatment device, characterized by: The invention comprises a conveyor compressor (1), a cooler (2) and a fine degassing reactor (3) which are connected in sequence through pipelines, wherein the conveyor compressor (1) is connected to one end of an exhaust gas supply pipeline (4), and the other end of the exhaust gas supply pipeline (4) is used to connect to a polypropylene silo; the top of the fine degassing reactor (3) is respectively connected to one end of a nitrogen recovery pipeline (5) and one end of a regeneration gas pipeline (6), the other end of the nitrogen recovery pipeline (5) is connected to a flash kettle, and the other end of the regeneration gas pipeline (6) is used to connect to a low-pressure flare system; the bottom of the fine degassing reactor (3) is connected to one end of a nitrogen supply pipeline (7), and the other end of the nitrogen supply pipeline (7) is used to connect to a nitrogen tank; the cooler (2) is connected to the lower part of the fine degassing reactor (3) through a pipeline.

2. The polypropylene silo VOC tail gas treatment device according to claim 1 is characterized by: The invention also comprises a spare fine degassing reactor (8), the top of which is connected to the nitrogen recovery pipeline (5) and the regeneration gas pipeline (6) via two spare pipelines, the bottom of which is connected to one end of a spare nitrogen pipeline (9), and the other end of which is used to connect to a nitrogen tank.

3. The polypropylene silo VOC tail gas treatment device according to claim 2 is characterized by: A nitrogen supply valve (10) is fixedly installed on the nitrogen supply pipeline (7) and / or the standby nitrogen pipeline (9), respectively.

4. The polypropylene silo VOC tail gas treatment device according to claim 2 is characterized by: A spare valve (11) is fixedly installed on each of the two spare pipelines.

5. The polypropylene silo VOC tail gas treatment device according to claim 2 is characterized by: A recovery valve (12) is fixedly installed at a portion between one end of the nitrogen recovery pipeline (5) and a connection point between one of the spare pipelines and the nitrogen recovery pipeline (5) and / or a portion between one end of the regeneration gas pipeline (6) and a connection point between the other end of the spare pipeline and the regeneration gas pipeline (6).

6. The polypropylene silo VOC tail gas treatment device according to any one of claims 1 to 5, characterized in that: A filter (13) is fixedly mounted on the exhaust gas supply pipeline (4).

7. The polypropylene silo VOC tail gas treatment device according to claim 6 is characterized by: The filter (13) is a microporous filter.

8. The polypropylene silo VOC tail gas treatment device according to any one of claims 1 to 5, characterized in that: A fan (14) is fixedly mounted on the other end of the regeneration gas pipeline (6).

9. The polypropylene silo VOC tail gas treatment device according to claim 8, characterized in that: The blower (14) is a Roots blower.

10. The polypropylene silo VOC tail gas treatment device according to any one of claims 1 to 5, characterized in that: The cooler (2) is an air cooler or a water cooler.

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