WO2021128723A1

WO2021128723A1 - System and method for treating acrylic acid and ester waste water thereof

Info

Publication number: WO2021128723A1
Application number: PCT/CN2020/092659
Authority: WO
Inventors: 张志炳; 周政; 张锋; 李磊; 孟为民; 王宝荣; 杨高东; 罗华勋; 杨国强; 田洪舟; 曹宇
Original assignee: 南京延长反应技术研究院有限公司
Priority date: 2019-12-23
Filing date: 2020-05-27
Publication date: 2021-07-01
Also published as: CN113087254A; CN113087254B

Abstract

The present invention provides a system and a method for treating acrylic acid and ester waste water thereof. The treatment system comprises: a raw water tank, a waste water heat exchanger, a waste water heater, and an oxidation reaction device, the waste water heat exchanger is provided with a material inlet, a material outlet, a heat source inlet, and a heat source outlet; the oxidized water from the oxidation reaction device enters the waste water heat exchanger from the heat source inlet, the heat source outlet is connected with a finished product tank, the material inlet is connected with the raw water tank, the material outlet is connected with the waste water heater; the oxidation reaction device comprises a first-stage oxidation reactor and a second-stage oxidation reactor connected in sequence; the lower part of the first-stage oxidation reactor is provided with a first-stage micro-interface generation system for dispersing the crushed gas into bubbles, the second-stage oxidation reactor is provided with a second-stage micro-interface generation system for dispersing the crushed gas into bubbles. The treatment system of the present invention improves the contact of the reaction phase interface by arranging the micro-interface generation system, and obtains a good waste water treatment effect without using a catalyst.

Description

System and method for treating acrylic acid and its ester wastewater

Technical field

The present invention relates to the field of acrylic acid and its ester wastewater treatment, in particular to a system and method for acrylic acid and its ester wastewater treatment.

Background technique

In recent years, with the rapid development of acrylic acid and its esters industry, the treatment of acrylic acid and its esters wastewater has become an increasingly serious problem. The COD in acrylic acid and its ester wastewater is 10000-100000mg/L, and the concentration is relatively high. The formaldehyde content is 1wt%-4wt%, which is very toxic. In addition, it contains acrylic acid, acetic acid, formaldehyde, acrolein, methyl acrylate, Many organic substances such as ethyl acrylate have complex components, which makes the treatment of acrylic acid and its ester wastewater very difficult. At present, the main method for treating acrylic acid and its ester wastewater is incineration, but due to the high cost of incineration and secondary pollution, there are also biological methods and catalytic wet oxidation methods. Biological methods are divided into aerobic methods, anaerobic methods, and aerobic-anaerobic combined methods. Biological methods need to be further resolved due to problems such as large area, high investment cost, poor economic feasibility, cumbersome process, and substandard effluent. . Catalytic wet oxidation technology has the characteristics of low reaction temperature and reaction pressure, high reaction decomposition ability, low corrosion to equipment, low operating cost, etc. It is suitable for the treatment of some high-concentration, high-toxic, and difficult-to-degrade organic wastewater, and does not need to consider acrylic acid and The toxicity of its ester wastewater, and the COD concentration in acrylic acid and its ester wastewater is within its suitable treatment concentration range. Therefore, in contrast, the catalytic wet oxidation method has more application prospects.

Traditional wet air oxidation requires high temperature and high pressure, which not only requires high energy consumption but also requires high equipment materials. Therefore, the industry generally adds catalysts to reduce the activation energy of the reaction when the traditional wet catalytic oxidation method is used to treat organic wastewater. The reaction can be completed under milder conditions and in a shorter time. At present, the most researched oxidants are H ₂ O ₂ , Fenton reagent and ozone. The catalysts used in wet catalytic oxidation can be divided into two types: homogeneous and heterogeneous according to their different forms.

However, in the wet oxidation process, after using a catalyst, although the reaction time is shortened to a certain extent, and the operating temperature and pressure are lowered, the reaction conditions are more mild, but the cost of the catalyst is relatively high. After the subsequent reaction is completed, The follow-up recovery and treatment of the catalyst should also be considered. The operation is very inconvenient, and a lot of follow-up work has been added invisibly.

In view of this, the present invention is proposed.

Summary of the invention

The first object of the present invention is to provide a treatment system for acrylic acid and its ester wastewater. The treatment system improves the mass transfer effect between the two phases by deploying a micro-interface generation system. The micro-interface generation system can blow bubbles. It is broken into micron-level bubbles, thereby increasing the area of the phase boundary between the gas phase and the liquid phase, so that oxygen can better fuse with acrylic acid and its ester wastewater to form a gas-liquid emulsion, which improves the efficiency of the oxidation reaction. After the oxygen in the wastewater is broken into small bubbles, the volume of the gas becomes smaller, thereby slowing the buoyancy of the bubbles, making the oxygen stay in the acrylic acid and its ester wastewater longer, further improving the reaction efficiency, and increasing the reaction phase interface The mass transfer effect.

At the same time, through the use of the micro-interface generation system, the entire processing system can be operated without using a catalyst. The absence of a catalyst not only saves costs, but also eliminates the need for subsequent recovery and treatment of the catalyst, which causes secondary pollution. Appears, the entire processing method is easier and faster to operate, and the operation process is correspondingly simplified.

The second object of the present invention is to provide a method for treating acrylic acid and its ester wastewater by adopting the above treatment system. The treatment method is easy to operate, has milder operating conditions, and has low energy consumption. The treated acrylic acid and its ester wastewater are harmful The material removal rate can reach about 99%, which is worthy of widespread promotion and application.

In order to achieve the above objectives of the present invention, the following technical solutions are specially adopted:

The present invention provides a wastewater treatment system for treating acrylic acid and its ester wastewater, comprising: a raw water tank, a wastewater heat exchanger, a wastewater heater, and an oxidation reaction device connected in sequence, and the wastewater heat exchanger is provided with materials Import, material export, heat source import and heat source export;

The oxidized water from the oxidation reaction device enters the waste water heat exchanger from the heat source inlet, the material inlet of the heat source is connected to the raw water tank, and the material outlet is connected to the waste water heater;

The oxidation reaction device includes a primary oxidation reactor and a secondary oxidation reactor connected in sequence, and the oxidized water after the oxidation treatment of the primary oxidation reactor continues to enter the secondary oxidation reactor for oxidation treatment;

The lower part of the primary oxidation reactor is provided with a primary micro-interface generating system for dispersing crushed gas into bubbles, and the secondary oxidation reactor is provided with a secondary micro-interface generating system for dispersing crushed gas into bubbles, so The secondary micro-interface generation system includes a first micro-interface generator and a second micro-interface generator arranged one above the other. The first micro-interface generator passes through the waste water circulating back from the oxidation reactor, and the first micro-interface generator The interface generator is connected with an air duct, and the top of the air duct protrudes from the liquid surface of the oxidation reactor for recovering air or oxygen.

The wastewater of acrylic acid and its esters to be treated by the present invention mainly contains acrylic acid, acetic acid, formaldehyde, acrolein, methyl acrylate, ethyl acrylate and other organic substances. The composition is complex, which makes the treatment of acrylic acid and its ester wastewater very difficult. The prior art mainly adopts the catalytic wet oxidation method, but in the catalytic wet oxidation process, after the catalyst is used, although the operating temperature and pressure are not high, the cost is relatively high after the catalyst is used. After the subsequent reaction is completed, The follow-up recovery and treatment of the catalyst should also be considered. The operation is very inconvenient, and a lot of follow-up work has been added invisibly.

In order to solve the above technical problems, the present invention provides a treatment system specifically for the treatment of acrylic acid and its ester wastewater. The treatment system is equipped with a micro-interface generation system at the bottom of the oxidation reactor to improve the mass transfer effect of the phase interface, and it is specially designed Two-stage oxidation reactors are set up, and the micro-interface generation system in each oxidation reactor has different setting methods. In this way, the two-stage oxidation reactors work together to strengthen the mass transfer effect. Of course, this setting method has also undergone a lot of After optimizing the experiment, it was determined that the setting of the micro-interface generator was found to be the most conducive to the contact mass transfer between the two phases.

In this way, the air or oxygen entering the oxidation reactor is broken and dispersed into bubbles, so that the bubbles and the wastewater form a gas-liquid emulsion, thereby increasing the area of the phase boundary between the gas and the wastewater, further improving the reaction efficiency and increasing After the mass transfer effect of the reaction phase interface, the oxygen can be incorporated into the wastewater as much as possible, so that a good treatment effect can be ensured under relatively low pressure and temperature conditions, without the use of catalysts, or in order to ensure better treatment As a result, some catalysts can be added less, which can fully reduce the amount of catalysts used in the traditional process, and you can freely choose to add or not add catalysts according to the actual operating conditions.

Preferably, a first air inlet is provided at the bottom of the first-stage oxidation reactor, and the first air inlet is in communication with the first-stage micro-interface generation system.

Preferably, the side wall of the secondary oxidation reactor is provided with a second air inlet, and the end of the second air inlet extends into the second micro-interface generator.

Preferably, the processing system further includes an air pressure device, the air pressure device is in communication with the first air inlet and the second air inlet, and the air or compressed oxygen compressed by the air pressure device enters through the air inlet The micro-interface generator disperses and breaks. The compressed air or oxygen from the air compressor is preferably heated in a gas heating device before entering the micro-interface generator. The gas heating device is preferably a heat exchanger.

For the micro-interface generation system in the secondary oxidation reactor of the present invention, in order to enable the waste liquid to circulate and provide power for the first micro-interface generator, the side wall of the secondary oxidation reactor is provided with a circulating waste liquid outlet. A circulating waste liquid inlet is arranged on the top of the micro-interface generator, and the circulating waste liquid inlet and the circulating waste liquid outlet are connected by a circulating pipe, and a circulating pump that provides power is arranged on the circulating pipe. In this way, during the wet oxidation reaction process, a part of the oxygen will run to the space above the liquid level of the wastewater in the reactor. In order to fully recycle this part of the oxygen, the circulating waste liquid is used as the power cycle to achieve the air duct. Oxygen is entrained to form turbulence to increase the contact area of the two phase interfaces.

Therefore, the first micro-interface generator is preferably a hydraulic micro-interface generator. In actual operation, the circulating waste liquid enters the middle of the top of the first micro-interface generator, and oxygen is removed from the channels on both sides of the first micro-interface generator. Entrained in, the gas and liquid phases are fully contacted inside the micro-interface generator, and the mass transfer effect is increased.

The second micro-interface generator is preferably a pneumatic micro-interface generator. After the compressed air or oxygen is passed into the micro-interface generator, it is broken into the form of micro-bubbles after contact with wastewater, thereby improving the mass transfer effect.

In order to further improve the full contact of the reaction material and liquid, the outlet of the first micro-interface generator and the outlet of the second micro-interface generator are preferably arranged oppositely.

Since the two micro-interface generators are both below the liquid level, in order to avoid instability caused by the impact of the flow of the liquid, it is better to provide a fixed connection between the first micro-interface generator and the second micro-interface generator The specific material, shape, and number of the rods and connecting rods are not limited, as long as they can achieve a fixing effect, and are preferably in the shape of a long rod.

Those skilled in the art can understand that the micro-interface generator used in the present invention can realize that before the multi-phase reaction medium enters the reactor, the gas and/or liquid phase in the multi-phase reaction medium can be placed in the micro-interface generator. Through mechanical microstructures and/or turbulent flow microstructures, they are broken into micro-bubbles and/or micro-droplets with a diameter of micrometers in a predetermined action mode to increase the gas and/or liquid phase and liquid phase and/or liquid phase and/or liquid phases during the reaction process. The mass transfer area of the phase boundary between the solid phases improves the mass transfer efficiency between the reaction phases, and strengthens the multiphase reaction within the preset temperature and/or preset pressure range.

The micro-interface generator can be used for the reaction of gas-liquid, liquid-liquid, liquid-solid, gas-liquid-liquid, gas-liquid-solid and liquid-liquid-solid and other multiphase reaction media. Its specific structure can be based on The different flowing media can be freely selected. The specific structure and specific functions of the previous patents and documents also have corresponding records, and no additional details are given here. At the same time, according to actual engineering needs, the number and position of the air inlets can be adjusted according to the height, length, diameter, waste water flow rate and other factors of the oxidation reactor in this system, so as to achieve better air supply effect and improve oxidation degradation. rate.

In addition, in the scheme of the present invention, in order to recover the resources in the wastewater of acrylic acid and its esters, reduce the difficulty of wet oxidation of the wastewater of acrylic acid and its esters, and improve the COD removal rate of the wastewater, it is best to treat the acrylic acid and its esters before the wet oxidation. The wastewater is pretreated. The pretreatment includes pretreatment methods such as flocculation, sedimentation and separation. Of course, other pretreatment methods can also be used according to actual working conditions.

Therefore, in the acrylic acid and its ester wastewater treatment system of the present invention, a flocculation tank and a separation tank are also included, and the raw water tank is sequentially connected to the flocculation tank and the separation tank.

Preferably, the upper side of the secondary oxidation reactor is provided with an oxidizing water outlet, and the oxidizing water outlet is connected to the heat source inlet through a pipe.

In the processing system of the present invention, a pump body can be arranged on the corresponding connecting pipeline according to actual needs.

The treatment system of the acrylic acid and its ester wastewater of the present invention has a high treatment capacity. After treatment by the treatment system, it can ensure a relatively high treatment effect under relatively low energy consumption conditions, and the removal rate of harmful substances can reach 99%.

In addition, the present invention also provides a method for treating acrylic acid and its ester wastewater, which includes the following steps:

Acrylic acid and its ester wastewater are heated and enter the oxidation reaction device. At the same time, compressed air or compressed oxygen is passed into the oxidation reaction device to cause an oxidation reaction;

The compressed air or compressed oxygen entering the oxidation reaction device is first dispersed and broken through the micro-interface generation system.

The reaction temperature of the above-mentioned catalytic wet oxidation reaction is between 180-200℃, the reaction pressure is between 0.3-6MPa, and the reaction time is between 0.5-3h. After adopting the micro-interface generation system, no catalyst is required, which avoids the existing The use of lanthanum, cerium and other precious metal catalysts in the technology can easily block pipelines, increase the burden of post-processing, and greatly reduce costs.

The method for treating acrylic acid and its ester wastewater of the present invention has simple operation, milder operating conditions and low energy consumption. In the treated acrylic acid and its ester wastewater, the removal rate of harmful substances and COD can reach 99%, which reduces the discharge of industrial waste. , More environmentally friendly, worthy of widespread promotion and application.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The treatment system of acrylic acid and its ester wastewater of the present invention improves the mass transfer effect between the two phases after the micro-interface generator is arranged. The micro-interface generator can break the bubbles into micron-level bubbles, thereby Increase the area of the phase boundary between the gas phase and the liquid phase, so that oxygen can better fuse with acrylic acid and its ester wastewater to form a gas-liquid emulsion, and improve the efficiency of the oxidation reaction;

(2) In the wastewater treatment system of the present invention, a two-stage oxidation reactor is adopted to enhance the wastewater treatment effect;

(3) The waste water treatment system of the present invention has a simple structure, less three wastes, realizes full recovery and utilization of oxygen, and occupies a small area;

(4) The wastewater treatment system of the present invention improves the mass transfer effect between the two phases by arranging the micro-interface generation system, reduces energy consumption and production costs, and significantly improves the efficiency of the oxidation reaction;

(5) The treatment system of the present invention does not need to use a catalyst, and can realize the wet oxidation reaction under relatively low temperature and pressure conditions. The absence of a catalyst not only saves costs, but also eliminates the need for subsequent recovery and treatment of the catalyst, resulting in two With the emergence of secondary pollution, the entire treatment method is simpler and faster, and the operation process is correspondingly simplified.

Description of the drawings

By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only used for the purpose of illustrating the preferred embodiments, and are not considered as a limitation to the present invention. Also, throughout the drawings, the same reference symbols are used to denote the same components. In the attached picture:

Figure 1 is a schematic structural diagram of a treatment system for acrylic acid and its ester wastewater provided by an embodiment of the present invention.

Description of the drawings:

10-Original water tank; 20-Flocculation tank;

30-Separation tank; 40-One-stage oxidation reactor;

41-First air inlet; 42-First-level micro-interface generation system;

50-Waste water heat exchanger; 51-Material import;

52-material export; 53-heat source import;

54-heat source exit; 60-waste water heater;

70-Secondary oxidation reactor; 71-Oxidation water outlet;

72-First micro-interface generator; 73-Second micro-interface generator;

74-Air compressor; 75-Vent;

76-Second air inlet; 77-Air duct;

78-Connecting rod; 79-Gas heating device;

80-Transport pump; 90-Finished product tank.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific implementations. However, those skilled in the art will understand that the embodiments described below are part of the embodiments of the present invention, rather than all of them. It is only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention. If no specific conditions are indicated in the examples, it shall be carried out in accordance with the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used without the manufacturer's indication are all conventional products that can be purchased on the market.

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

In the description of the present invention, it should be noted that the terms "installed", "connected", and "connected" should be understood in a broad sense unless otherwise clearly specified and limited. For example, they can be fixed or detachable. Connected or integrally connected; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above-mentioned terms in the present invention can be understood in specific situations.

In order to explain the technical solutions of the present invention more clearly, the following description will be given in the form of specific embodiments.

Example

Referring to Figure 1, it is an acrylic acid and its ester wastewater treatment system according to an embodiment of the present invention, which includes a raw water tank 10, a wastewater heat exchanger 50, a wastewater heater 60, a primary oxidation reactor 40, and two connected in sequence. Stage oxidation reactor 70 and air compressor 74.

Among them, the waste water heat exchanger 50 has a material inlet 51, a material outlet 52, a heat source inlet 53, and a heat source outlet 54. The oxidized water from the primary oxidation reactor 40 continues to enter the secondary oxidation reactor to continue oxidation. The oxidized water enters the waste water heat exchanger 50 from the heat source inlet 53. The heat source outlet 54 is connected to a finished product tank 90, the material inlet 51 is connected to the raw water tank 10, and the material outlet 52 is connected to a waste water heater 60. In the heat exchanger 50, the oxidized water after the reaction of the oxidation reaction device is exchanged with the acrylic acid and its ester wastewater to be treated, so as to achieve the effect of making full use of energy.

The lower part of the first-stage oxidation reactor 40 is provided with a first-stage micro-interface generating system 42 for dispersing the crushed gas into bubbles. The first-stage micro-interface generating system 42 includes 3 micro-interface generators, which are arranged side by side in the oxidation reaction device. In the lower part, a branch pipe is connected to the bottom of each micro-interface generator, and all branch pipes are connected to the main pipe after being collected. The main pipe is connected to the first air inlet 41, and the first air inlet 41 is connected to the air pressure device 74.

The secondary oxidation reactor 70 is provided with a secondary micro-interface generating system. The secondary micro-interface generating system is used to disperse and crush the gas into bubbles. The secondary micro-interface generating system includes a first micro-interface generator 72 and a second micro-interface generator arranged up and down. The micro-interface generator 73, the first micro-interface generator 72 passes the waste water circulating back from the oxidation reactor, the first micro-interface generator 72 is connected with a gas pipe 77, and the top of the gas pipe 77 extends out of the oxidation reactor The liquid level of 70 is used to recover air or oxygen. The side wall of the secondary oxidation reactor 70 is provided with a second air inlet 76, and the end of the second air inlet 76 extends into the second micro-interface generator 73. The second air inlet 76 and the second micro-interface generator 73 are connected by a pipe, the air pressure device 74 is in communication with the second air inlet 76, and the air or oxygen compressed by the air pressure device 74 enters through the second air inlet 76 In the second micro-interface generator 73, the gas is crushed and dispersed to enhance the mass transfer effect between the two phases. The air compressor 74 is preferably an air compressor. The air or oxygen compressed by the air compressor is preheated by the gas heating device 79 and then enters the corresponding micro-interface generator to improve the efficiency of the reaction. The type of air compressor can be selected as a centrifugal air compressor, which is low in cost and convenient to use.

The first micro-interface generator 72 is a hydraulic micro-interface generator, the second micro-interface generator 73 is a pneumatic micro-interface generator, and the first micro-interface generator 72 and the second micro-interface generator 73 are provided for mutual The fixed connecting rod 78 fixes the micro-interface generator to prevent the impact of the waste liquid. And the outlet of the first micro-interface generator 72 is opposite to the outlet of the second micro-interface generator 73 to increase the hedging effect between the two and accelerate the turbulent flow.

The first micro-interface generator 72 can be fixed inside the oxidation reactor by a grid plate, and the second micro-interface generator 73 can be reinforced by a pipe.

The side wall of the secondary oxidation reactor 70 is provided with a circulating waste liquid outlet, and the top of the first micro-interface generator 72 is provided with a circulating waste liquid inlet. The circulating waste liquid inlet and the circulating waste liquid outlet are connected by a circulating pipe. A circulating pump is provided on the pipeline.

The upper side of the secondary oxidation reactor 70 is provided with an oxidizing water outlet 71, the oxidizing water from the oxidizing water outlet 71 is connected to the heat source inlet 53 through a pipe, and the oxidizing water from the oxidation reactor 70 goes directly to the waste water heat exchanger 50 for heat exchange After the heat exchange, it is cooled down and transported to the finished product tank 90 for storage. The water coming out of the finished product tank 90 can continue to be subjected to subsequent desalination treatment, and the conventional means of the prior art may be used for desalination.

The treatment system also includes a pretreatment system of the flocculation tank 20 and the separation tank 30, and the waste water after being removed from impurities through the pretreatment system enters the waste water heat exchanger 50 through the transfer pump 80.

In the above embodiment, the number of micro-interface generators in the micro-interface generation system is not limited. In order to increase the dispersion and mass transfer effect, additional micro-interface generators can also be added, especially the installation position of the micro-interface generators. It is not limited, and it can be installed externally or internally. When it is built-in, it can also be installed on the side wall of the kettle to realize the hedging of micro-bubbles from the outlet of the micro-interface generator.

In the above two embodiments, there is no specific requirement for the number of pump bodies, and they can be set in corresponding positions as needed.

The following briefly describes the working process and principle of the acrylic acid and its ester wastewater treatment system of the present invention:

First, after nitrogen purges the raw water tank 10, the waste water heat exchanger 50, the waste water heater 60, the pipelines of the primary oxidation reactor 40, the secondary oxidation reactor 70, and the inside of the reactor, the acrylic acid and its interior in the raw water tank 10 The ester wastewater is sent to the flocculation tank 20 to add flocculants and stirred. After precipitation, the sedimentation is separated in the separation tank 30, and after the separation and sedimentation, it is sent to the waste water heat exchanger 50 through the transfer pump 90 for heat exchange.

Then, the waste water after heat exchange in the waste water heat exchanger 50 is further heated by the waste water heater 60, and the heated acrylic acid and its ester waste water enters the primary oxidation reactor 40 for oxidation treatment. The oxidized water enters the secondary oxidation reactor 70 for further processing. Compressed air or compressed oxygen is introduced from the bottom of the primary oxidation reactor 40 and the side bottom of the secondary oxidation reactor 70, and then passes through the primary micro-interface The generation system 42, the first micro-interface generator 72, and the second micro-interface generator 73 are dispersed and broken into micro-bubbles to achieve the effect of strengthening the oxidation reaction and improve the mass transfer efficiency of the phase interface. The top of the stage oxidation reactor 70 is provided with a vent 75.

Finally, the oxidized water after the oxidation reaction in the secondary oxidation reactor 70 returns from the top of the secondary oxidation reactor 70 to the waste water heat exchanger 50 for heat exchange and cooling treatment, and then is transported to the finished product tank 90 for storage.

The above process steps are repeated to make the entire processing system run smoothly.

The processing system of the present invention ensures that the wet oxidation is performed under relatively mild pressure and temperature conditions by laying a micro-interface generation system, and does not require the use of a catalyst. Compared with the prior art acrylic acid and its ester wastewater treatment system, the treatment system of the present invention has fewer equipment components, small floor space, low energy consumption, low cost, high safety, and controllable response, and is worthy of being widely promoted and applied.

In short, the acrylic acid and its ester wastewater treatment system of the present invention has a high processing capacity. After the treatment system is processed, it can ensure that it has a relatively high treatment effect under relatively low energy consumption conditions, and the removal rate of harmful substances and COD can reach 99%.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions recorded in the foregoing embodiments can still be modified, or some or all of the technical features can be equivalently replaced; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention. range.

Claims

A treatment system for acrylic acid and its ester wastewater, which is characterized by comprising: a raw water tank, a waste water heat exchanger, a waste water heater, and an oxidation reaction device connected in sequence, and the waste water heat exchanger is provided with a material inlet and a material outlet , Heat source inlet and heat source outlet;

The oxidized water from the oxidation reaction device enters the waste water heat exchanger from the heat source inlet, the material inlet of the heat source is connected to the raw water tank, and the material outlet is connected to the waste water heater;

The oxidation reaction device includes a primary oxidation reactor and a secondary oxidation reactor connected in sequence, and the oxidized water after the oxidation treatment of the primary oxidation reactor continues to enter the secondary oxidation reactor for oxidation treatment;

The lower part of the primary oxidation reactor is provided with a primary micro-interface generating system for dispersing crushed gas into bubbles, and the secondary oxidation reactor is provided with a secondary micro-interface generating system for dispersing crushed gas into bubbles, so The secondary micro-interface generation system includes a first micro-interface generator and a second micro-interface generator arranged one above the other. The first micro-interface generator passes through the waste water circulating back from the oxidation reactor, and the first micro-interface generator The interface generator is connected with an air duct, and the top of the air duct protrudes from the liquid surface of the oxidation reactor for recovering air or oxygen.
The processing system according to claim 1, wherein a first air inlet is provided at the bottom of the first-stage oxidation reactor, and the first air inlet is in communication with the first-stage micro-interface generation system.
The processing system according to claim 1, wherein the side wall of the secondary oxidation reactor is provided with a second air inlet, and the end of the second air inlet extends to the second micro-interface器内。 In the device.
The treatment system according to claim 1, wherein the treatment system further comprises a flocculation tank and a separation tank, and the raw water tank is sequentially connected to the flocculation tank and the separation tank.
The processing system according to claim 1, wherein the side wall of the secondary oxidation reactor is provided with a circulating waste liquid outlet, the top of the first micro-interface generator is provided with a circulating waste liquid inlet, and the The circulating waste liquid inlet and the circulating waste liquid outlet are connected by a circulating pipeline;

Preferably, a circulation pump is provided on the circulation pipeline.
The processing system according to claim 1, wherein a connecting rod for mutual fixing is provided between the first micro-interface generator and the second micro-interface generator.
The processing system according to any one of claims 1 to 6, wherein the first micro-interface generator is a hydraulic micro-interface generator, and the second micro-interface generator is a pneumatic micro-interface generator.
8. The processing system according to claim 7, wherein the outlet of the first micro-interface generator is opposite to the outlet of the second micro-interface generator.
The processing system according to any one of claims 1-6, wherein the upper side of the secondary oxidation reactor is provided with an oxidizing water outlet, and the oxidizing water outlet is connected to the heat source inlet through a pipe.
The method for treating acrylic acid and its ester wastewater using the treatment system of any one of claims 1-9, characterized in that it comprises the following steps:

Acrylic acid and its ester wastewater are heated and enter the oxidation reaction device. At the same time, compressed air or compressed oxygen is passed into the oxidation reaction device to cause an oxidation reaction;

The compressed air or compressed oxygen entering the oxidation reaction device is first dispersed and broken through the micro-interface generation system.