CN116617816A - A system and method for safe release and recovery of maleic anhydride plant - Google Patents

Abstract

The invention provides a maleic anhydride device safety release recovery system and method, comprising the following steps: the tower bottom of the recovery tower is connected with a safety discharge main pipe of the maleic anhydride device, and a solvent absorption section and a water washing section are sequentially arranged in the recovery tower from bottom to top; the liquid inlet of the solvent absorption section is connected with the solvent input structure, and the liquid outlet is connected with the solvent recovery unit; the liquid inlet of the washing section is connected with a desalted water input structure, and the liquid outlet is connected with a wastewater treatment unit; and the tail gas control device can analyze and detect the maleic anhydride component content of the tail gas on line, discharge qualified tail gas to the atmosphere according to a detection result, and return unqualified tail gas to the tower kettle and/or discharge unqualified tail gas to the incinerator. The technical scheme of the invention has the beneficial effects that the qualified tail gas is discharged to the atmosphere to meet the environmental protection standard, the unqualified tail gas is continuously treated to reach the discharge standard, and the maleic anhydride and the solvent can be recovered, so that the economic benefit is improved, and the problems of treatment and recovery of the discharged materials of the maleic anhydride device are solved.

Description

A system and method for safe release and recovery of maleic anhydride plant

technical field

The invention belongs to the technical field of maleic anhydride plant production, and more specifically relates to a system and method for safe release and recovery of maleic anhydride plant.

Background technique

The traditional safety release measure of maleic anhydride plant is to discharge the high point of the system material to the atmosphere through the safety valve. The waste gas of volatile organic compounds should be connected to the organic waste gas recovery or treatment device, and the emission limit of maleic anhydride in the waste gas should be 10mg/m3.

The freezing point of maleic anhydride is 52.8°C, which is easy to solidify and precipitate. According to the requirements of SH3009-2013 "Code for Design of Combustible Gas Discharge System in Petrochemical Industry", flammable gases that have an adverse effect on the passage capacity of the discharge system pipeline should not be discharged into the whole plant Combustible gas discharge system. Therefore, the materials containing maleic anhydride cannot be directly discharged to the atmosphere, and at the same time cannot be discharged to the flare system, and there are technical difficulties in material treatment and recovery after the safety valve is released.

In view of this, it is expected a maleic anhydride device safety release recovery system and method, which can not only meet the safety release requirements, but also process and recover the release materials, and solve the technical problems of material treatment and recovery after the release of the safety valve.

Contents of the invention

The object of the present invention is to solve the problems existing in the prior art, to provide a maleic anhydride device safety release recovery system and method, to realize the discharge of tail gas to the atmosphere to meet environmental protection standards, and to recover maleic anhydride and solvents at the same time, improve economic benefits, and solve the problem of Disposal and recovery of materials discharged from maleic anhydride plant.

In order to achieve the above object, the technical scheme of the present invention is as follows:

A maleic anhydride device safety release recovery system, comprising:

A recovery tower, the tower kettle of the recovery tower is connected to the safety discharge main pipe of the maleic anhydride device, and a solvent absorption section and a water washing section are sequentially arranged in the recovery tower from bottom to top;

The liquid inlet of the solvent absorption section is connected to a solvent input structure and is provided with a solvent regulating valve, and the liquid outlet of the solvent absorption section is connected to a solvent recovery unit;

The liquid inlet of the water washing section is connected to the desalinated water input structure and is provided with a desalinated water regulating valve, and the liquid outlet of the water washing section is connected to the wastewater treatment unit;

Tail gas control device, the tail gas control device can monitor in real time the temperature of the release material containing maleic anhydride released from the safety release main pipe, and can analyze and detect the maleic anhydride component content of the tail gas on-line;

The tail gas control device discharges the qualified tail gas to the atmosphere according to the detection result, and returns the unqualified tail gas to the bottom of the tower and/or discharges it to the incinerator.

Preferably, the exhaust gas control device includes:

A remote thermometer, the remote thermometer monitors in real time the temperature of the discharge material containing maleic anhydride discharged from the safety relief main pipe;

Tail gas analyzer, described tail gas analyzer online analysis detects the maleic anhydride component content of described tail gas;

Pressure gauge, said pressure gauge monitors the tower top pressure of said recovery tower in real time;

A first control unit, the first control unit controls the opening of the solvent regulating valve and the desalinated water regulating valve according to the temperature monitoring result of the remote thermometer and/or the detection result of the exhaust gas analyzer;

A second control unit, the second control unit controls the opening and closing of the first valve to discharge the qualified tail gas to the atmosphere according to the detection result, and controls the opening and closing of the second valve to return the unqualified tail gas to the The tail gas is discharged to the incinerator according to the tower bottom pressure and/or according to the tower top pressure.

Preferably, the solvent absorption section includes an absorption filler, a solvent distributor and a wire mesh demister arranged sequentially from bottom to top;

A solvent circulation pump, the inlet side of the solvent circulation pump is connected to the bottom of the recovery tower, the outlet side of the solvent circulation pump is respectively connected to the solvent recovery unit and the solvent distributor, and the solvent circulation pump can The solvent is circulated back to the solvent absorption section.

Preferably, a solvent circulation cooler is provided between the solvent circulation pump and the solvent absorption section.

Preferably, the water-washing section includes a riser tray, a water-washing packing, and a water distributor arranged sequentially from bottom to top;

A water circulation pump, the inlet side of the water circulation pump is connected to the lift tray, the outlet of the water circulation pump is respectively connected to the waste water treatment unit and the water distributor, and the water circulation pump can circulate desalinated water back to the Washing section.

Preferably, a water circulation cooler is provided between the water circulation pump and the water washing section.

Preferably, the liquid level control side of the gas lift tray is provided with a liquid collection tank and a water washing liquid level control device.

Preferably, the liquid level control side of the tower bottom is provided with a tower bottom liquid level control device.

The present invention also provides a maleic anhydride device safety release recovery method, using the above-mentioned maleic anhydride device safety release recovery system, the method includes:

Real-time monitoring of the release of maleic anhydride-containing material from the safety relief main pipe, and control the opening of the solvent regulating valve and the desalinated water regulating valve to the initial opening;

On-line analysis detects the maleic anhydride component content of the tail gas, and if the test result is qualified, the qualified tail gas is discharged to the atmosphere, and at the same time, the flow of desalted water and solvent is reduced by adjusting the solvent regulating valve and the desalinated water regulating valve;

If the detection result is unqualified, increase the flow rate of desalted water and solvent until the detection result of the tail gas is qualified, and return the unqualified tail gas to the tower tank and/or discharge it to the incinerator.

Preferably, the method also includes:

Detect whether the top pressure of the recovery tower exceeds the interlock set pressure;

If the tower top pressure of the recovery tower does not exceed the interlocking set pressure, the unqualified tail gas is returned to the tower still to carry out secondary maleic anhydride recovery;

If the top pressure of the recovery tower exceeds the interlock set pressure, the tail gas will be discharged to the incinerator until the top pressure drops back to the interlock set pressure.

The beneficial effects of the technical solution of the present invention are:

The recovery tower of this system includes a solvent absorption section and a water washing section. The solvent in the solvent absorption section can absorb maleic anhydride in the discharge material, and the desalted water in the water washing section can remove acidic impurities. The exhaust gas is analyzed and detected online by the tail gas control device. Whether the content of the maleic anhydride component is qualified, discharge the qualified tail gas to the atmosphere, and continue to treat the unqualified tail gas until it reaches the discharge standard. At the same time, the maleic anhydride and solvent can be recovered, the economic benefit is improved, and the material released from the maleic anhydride device is solved. disposal and recycling problems.

The system can recycle desalted water and solvent through the solvent circulation pump and water circulation pump, saving desalted water and solvent consumption, reducing energy consumption and material consumption.

The system ensures that the liquid-phase desalted water in the recovery tower will not enter the solvent absorption section through the liquid collection tank and the washing liquid level control device, so as to ensure the solvent absorption effect.

The system can detect the top pressure of the recovery tower through the tail gas control device, and realize the discharge of tail gas to the incinerator according to whether the top pressure of the tower exceeds the interlock set pressure, so as to minimize material discharge, reduce material loss, and improve economic benefits.

Other features and advantages of the present invention will be described in detail in the detailed description that follows.

Description of drawings

The above and other objects, features and advantages of the present invention will become more apparent by describing the exemplary embodiments of the present invention in more detail with reference to the accompanying drawings, wherein, in the exemplary embodiments of the present invention, the same reference numerals generally represent same parts.

Fig. 1 shows the structural representation of a kind of maleic anhydride plant safe discharge recovery system that an embodiment of the present invention provides;

Fig. 2 shows the structural representation of a kind of maleic anhydride device safe discharge recovery system that another embodiment of the present invention provides;

Fig. 3 shows a schematic flow chart of a safe release recovery method of a maleic anhydride plant according to the present invention.

Explanation of reference signs:

1. Recovery tower; 1-1. Water distributor; 1-2. Washing packing; 1-3. Lifting tray; 1-4. Wire mesh demister; 1-5. Solvent distributor; 1-6. Absorption filler; 1-7, tower kettle; 1-8, liquid collection tank; 2, tail gas control device; 2-1, remote thermometer; 2-2, tail gas analyzer; 2-3, pressure gauge; 2-4 , the first valve; 2-5, the second valve; 3-1, solvent circulation pump; 3-2, solvent circulation cooler; 4-1, water circulation pump; 4-2, water circulation cooler; 5-1, water washing Liquid level control device; 5-2. Tower kettle liquid level control device; 6. Atmosphere; 7. Safety discharge main pipe; 8. Solvent input structure; 8-1. Solvent regulating valve; 9. Desalted water input structure; 9- 1. Desalinated water regulating valve; 10. Solvent recovery unit; 11. Waste water treatment unit; 12. Incinerator.

Detailed ways

Preferred embodiments of the present invention will be described in more detail below. Although preferred embodiments of the present invention are described below, it should be understood that the present invention can be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Referring to Fig. 1 and Fig. 2, in order to solve the problems existing in the safe release of maleic anhydride devices in the treatment and recovery of materials, and to reduce the material consumption and energy consumption under the premise of ensuring the treatment effect, the present invention provides a safe maleic anhydride device Release recovery system, including:

A recovery tower 1, the tower kettle 1-7 of the recovery tower 1 is connected to the safety discharge main pipe 7 of the maleic anhydride device, and the recovery tower 1 is sequentially provided with a solvent absorption section and a water washing section from bottom to top;

The liquid inlet of the solvent absorption section is connected to the solvent input structure 8 and is provided with a solvent regulating valve 8-1, and the liquid outlet of the solvent absorption section is connected to the solvent recovery unit 10;

The liquid inlet of the washing section is connected to the desalinated water input structure 9 and is provided with a desalinated water regulating valve 9-1, and the liquid outlet of the washing section is connected to the waste water treatment unit 11;

The tail gas control device 2, the tail gas control device 2 can monitor in real time the temperature of the release material containing maleic anhydride released from the safety release main pipe 7, and can analyze and detect the maleic anhydride component content of the tail gas online;

The tail gas control device 2 discharges the qualified tail gas to the atmosphere 6 according to the detection results, and returns the unqualified tail gas to the tower bottom 1-7 and/or discharges to the incinerator 12 .

Specifically, a solvent absorption section and a water washing section are sequentially arranged above the tower kettle 1-7 in the recovery tower 1, and the safety relief main pipe 7 is connected to the discharge port of the maleic anhydride device, and the entrance of the safety relief main pipe 7 is The tower kettle 1-7 connected to the recovery tower 1 is arranged at the lower part of the solvent absorption section. The liquid outlet of the solvent absorption section is set at the bottom of the tower kettle 1-7, and the liquid outlet of the water washing section is set at the edge side of the upgas tray 1-3 above the solvent absorption section to prevent desalinated water from entering the solvent absorption section. The discharge material is discharged into the safety discharge main pipe 7, and the remote thermometer 2-1 installed in the safety discharge main pipe 7 monitors the temperature of the discharge material in the safety discharge main pipe 7. After the temperature rise is detected, the exhaust gas The signal from the control device 2 controls the solvent regulating valve 8-1 and the desalinated water regulating valve 9-1 to open to the initial opening, the solvent input structure 8 sends the solvent into the solvent absorption section of the recovery tower 1 through the solvent regulating valve 8-1, and the desalinated water The input structure 9 sends the desalted water to the water washing section of the recovery tower 1 through the desalinated water regulating valve 9-1, the solvent in the solvent absorption section absorbs the maleic anhydride in the gas phase discharge material, and the desalinated water in the water washing section discharges the gas phase to the material The entrained solvent is washed out for recycling and removal of water-soluble impurities, the amount of both solvent and desalinated water is directly proportional.

The vented materials are processed by the recovery process to form tail gas that gathers at the top of the recovery tower 1, and the tail gas analyzer 2-2 in the tail gas control device 2 is set at the top of the recovery tower 1, and the maleic anhydride component content in the tail gas is passed through the tail gas analyzer. 2-2 Conduct online analysis and detection and generate detection results. If the test result is qualified, the tail gas control device 2 signals to control the first valve 2-4 to open, and the qualified tail gas is discharged to the atmosphere 6; The opening of 9-1 increases the amount of desalted water and the amount of solvent respectively, until the tail gas is discharged after the on-line analysis and detection pass.

The pressure gauge 2-3 in the tail gas control device 2 is set on the top of the recovery tower 1 to monitor the pressure at the top of the recovery tower 1 in real time. The tail gas control device 2 is preset with an interlocking set pressure. If the preset interlocking set pressure is not exceeded, the tail gas control device 2 signals to control the first outlet of the second valve 2-5 to open, and the unqualified tail gas is returned to the tower kettle 1-7 to continue the recovery process to If the emission standard is met, the tail gas control device 2 signals to control the second outlet of the second valve 2-5 to open, and the unqualified tail gas is discharged to the incinerator 12 for incineration to reduce the pressure in the tower.

The wastewater generated in the washing section is discharged to the wastewater treatment unit 11 through the wastewater discharge pipeline for further treatment to meet the wastewater discharge standard, and the maleic anhydride-containing rich solvent generated in the solvent absorption section is discharged to the solvent recovery unit 10 through the solvent discharge pipeline for further recovery of maleic anhydride and solvent . Realize that the tail gas discharged to the atmosphere meets the emission standard, which is the emission limit of maleic anhydride in the waste gas specified in GB31571-2015 "Petrochemical Industry Pollutant Discharge Standard" 10mg/m3, which meets environmental protection requirements and can be recycled at the same time Maleic anhydride and solvents improve economic benefits and solve the problem of disposal and recovery of materials discharged from maleic anhydride devices.

Preferably, the interlock set pressure design value is 20-50kPaG, preferably 30kPaG.

Preferably, the initial openings of the solvent regulating valve 8-1 and the desalted water regulating valve 9-1 are designed to be 30-70%, preferably 50%.

Preferably, the solvent is dibutyl phthalate.

Optionally, the exhaust control device 2 includes:

The remote thermometer 2-1, the remote thermometer 2-1 monitors in real time the temperature of the release material containing maleic anhydride released from the safety release main pipe;

Exhaust gas analyzer 2-2, exhaust gas analyzer 2-2 online analysis and detection of maleic anhydride component content of exhaust gas;

Pressure gauge 2-3, pressure gauge 2-3 monitors the tower top pressure of recovery tower 1 in real time;

The first control unit, the first control unit controls the opening of the solvent regulating valve 8-1 and the desalted water regulating valve 9-1 according to the temperature monitoring result of the remote thermometer 2-1 and/or the detection result of the exhaust gas analyzer 2-2 ;

The second control unit, the second control unit controls the opening and closing of the first valve 2-4 to discharge the qualified tail gas to the atmosphere 6 according to the detection result, and controls the opening and closing of the second valve 2-5 to return the unqualified tail gas to the tower kettle 1 -7 and/or discharge the tail gas to the incinerator 12 according to the pressure at the top of the tower.

Specifically, the first control unit controls the initial opening of the solvent regulating valve 8-1 and the desalinated water regulating valve 9-1 according to the temperature monitoring result signal of the remote thermometer 2-1, and then passes the detection result of the exhaust gas analyzer 2-2 , when the tail gas detection result is unqualified, the first control unit signals to control the opening of the solvent regulating valve 8-1 and the desalinated water regulating valve 9-1 to increase the flow of solvent and desalinated water until the tail gas is discharged after the on-line analysis and detection is qualified. When the tail gas detection result is qualified and reaches the discharge standard, the signal controls the opening of the solvent regulating valve 8-1 and the desalinated water regulating valve 9-1 to reduce the flow of solvent and desalinated water, so that the maleic anhydride component content determined in the tail gas is lower than Emission standards, reduce energy consumption, material consumption, save desalted water and solvent consumption.

Further, the second control unit monitors the tower top pressure of the recovery tower 1 in real time through the pressure gauge, and when the tower top pressure exceeds the interlock set pressure, the unqualified tail gas is discharged to the incinerator 12 to ensure the normal operation of the recovery tower 1 Pressure, minimize the discharge of vented materials to the incinerator, reduce the loss of vented materials, and improve economic benefits.

Further, when the tail gas test results meet the discharge standard, the flow rate of solvent and desalted water can be reduced to save material consumption, and the maleic anhydride component content determined in the tail gas can be lower than the discharge standard within 10%, preferably 6%.

Optionally, the solvent absorption section includes absorption fillers 1-6, solvent distributors 1-5 and wire mesh demisters 1-4 arranged sequentially from bottom to top;

The solvent circulation pump 3-1, the inlet side of the solvent circulation pump 3-1 is connected to the bottom of the recovery tower 1, the outlet side of the solvent circulation pump 3-1 is respectively connected to the solvent recovery unit 10 and the solvent distributor 1-5, the solvent circulation pump 3-1 It is possible to circulate the solvent back to the solvent absorption section.

Specifically, the solvent absorption section will absorb the maleic anhydride in the gas phase release material through the absorption packing 1-6, the solvent distributor 1-5 and the wire mesh demister 1-4 arranged in sequence from bottom to top, so that the gas phase can flow from the The air outlet of the screen demister 1-4 flows out, and at the same time, the solvent containing maleic anhydride is separated. The solvent circulation pump 3-1 can pump a part of the solvent containing maleic anhydride into the solvent recovery unit 10, and the other part is pumped back to the solvent absorption section of the recovery tower 1 and mixed with the solvent of the unabsorbed maleic anhydride in the liquid inlet of the solvent absorption section After that, it enters the solvent absorption section to reuse the solvent, which can achieve the circulation operation of part of the solvent in the system, improve the use efficiency of the solvent, and save the consumption of the solvent.

Optionally, a solvent circulation cooler 3-2 is provided between the solvent circulation pump 3-1 and the solvent absorption section.

Specifically, setting the solvent circulation cooler 3-2 in the solvent circulation pipeline can be used to adjust the temperature of the solvent circulation pipeline in the system, improve process safety and reduce solvent loss.

Optionally, the water washing section includes a riser tray 1-3, a water washing packing 1-2 and a water distributor 1-1 arranged sequentially from bottom to top;

Water circulation pump 4-1, the inlet side of water circulation pump 4-1 is connected with lifting tray 1-3, the outlet of water circulation pump 4-1 is respectively connected with wastewater treatment unit 11 and water distributor 1-1, and water circulation pump 4-1 can The desalinated water is circulated back to the water washing section.

Specifically, the water washing section washes out the solvent entrained in the gas phase venting material through the gas lift tray 1-3, water washing packing 1-2 and water distributor 1-1 arranged in sequence from bottom to top for recycling and reuse. Remove water-soluble impurities in the discharge material.

Further, the tail gas control device 2 can also control the working power of the solvent circulation pump 3-1 and the water circulation pump 4-1 according to the temperature monitoring result signal of the remote thermometer 2-1, and according to the discharge material flow rate in the safety discharge main pipe 7, Adjust the working power of the pump to speed up or slow down the circulation speed of the solvent and desalinated water in the pipeline, which can be used in the scene where the discharge material flow rate is quite different.

Optionally, a water circulation cooler 4-2 is provided between the water circulation pump 4-1 and the water washing section.

Specifically, setting the water circulation cooler 4-2 in the water circulation pipeline can be used to adjust the temperature of the water circulation pipeline in the system, improve the process safety, and reduce the loss of desalinated water.

Optionally, a liquid collecting tank 1-8 and a washing liquid level control device 5-1 are arranged on the liquid level control side of the gas lift tray 1-3.

Specifically, only the gaseous phase is allowed to pass through the air hole of the gas lift tray 1-3, and the edge side of the gas lift tray 1-3 is provided with a liquid collection tank 1-8 and a water washing liquid level control device 5-1, and the desalted water is The edge side of the gas lift tray 1-3 is extracted and flows into the liquid collection tank 1-8, and the water washing liquid level control device 5-1 is realized by the liquid level gauge and the pump output flow in the liquid collection tank 1-8 Control the liquid level of the desalinated water in the liquid collection tanks 1-8 to prevent the liquid-phase desalinated water from entering the solvent absorption section through the air hole, so as to ensure the absorption effect of the solvent.

Optionally, a tank liquid level control device 5-2 is provided on the liquid level control side of the tower tank 1-7.

Specifically, the control principle of the tower still liquid level control device 5-2 is the same as that of the washing liquid level control device 5-1, and the control of the tower still 1- The liquid level control of the solvent in 7 enables the rich solvent containing maleic anhydride in the tower kettle 1-7 to be pumped in time to the solvent recovery unit 10 for effective recovery.

Shown in Fig. 3 with reference to, the present invention also provides a kind of maleic anhydride plant safe discharge recovery method, utilizes above-mentioned maleic anhydride plant safe discharge recovery system, this method comprises:

Real-time monitoring of the release of the release material containing maleic anhydride in the safety discharge main pipe 7, and control the opening of the solvent regulating valve 8-1 and the desalinated water regulating valve 9-1 to the initial opening;

On-line analysis detects the maleic anhydride component content of the tail gas, and if the test result is qualified, the qualified tail gas is discharged to the atmosphere, and at the same time, the flow of desalted water and solvent is reduced by adjusting the solvent regulating valve 8-1 and the desalinated water regulating valve 9-1;

If the test result is unqualified, increase the flow rate of desalted water and solvent until the test result of the tail gas is qualified, and return the unqualified tail gas to the tower kettle 1-7 and/or discharge it to the incinerator 12 .

Preferably, the method also includes:

Detect whether the top pressure of the recovery tower 1 exceeds the interlock set pressure;

If the top pressure of the recovery tower 1 does not exceed the interlock set pressure, the unqualified tail gas is returned to the tower kettle 1-7 for secondary maleic anhydride recovery;

If the top pressure of the recovery tower 1 exceeds the interlock set pressure, the tail gas is discharged to the incinerator 12 until the top pressure falls back to the interlock set pressure.

Specifically, the discharge material is discharged into the safety discharge main pipe 7, and the remote thermometer 2-1 arranged in the safety discharge main pipe 7 monitors the temperature of the discharge material in the safety discharge main pipe 7, and the temperature rise is detected. Finally, the tail gas control device 2 signals control the solvent regulating valve 8-1 and the desalted water regulating valve 9-1 to open to the initial opening, and the solvent input structure 8 sends the solvent into the solvent absorption section of the recovery tower 1 through the solvent regulating valve 8-1 , the desalted water input structure 9 sends the desalted water to the water washing section of the recovery tower 1 through the desalinated water regulating valve 9-1, the solvent absorption section absorbs the maleic anhydride in the gas phase discharge material through the solvent, and the water washing section discharges the gas phase through the desalted water The solvent entrained in the discharge material is washed out for recycling and removal of water-soluble impurities, and the amount of solvent and desalinated water sent in is directly proportional.

The vented materials are processed by the recovery process to form tail gas that gathers at the top of the recovery tower 1, and the tail gas analyzer 2-2 in the tail gas control device 2 is set at the top of the recovery tower 1, and the maleic anhydride component content in the tail gas is passed through the tail gas analyzer. 2-2 Conduct online analysis and detection and generate detection results. If the test result is qualified, the tail gas control device 2 signals to control the first valve 2-4 to open, and the qualified tail gas is discharged to the atmosphere 6; The opening of 9-1 increases the amount of desalted water and the amount of solvent respectively, until the tail gas is discharged after the on-line analysis and detection pass. Realize that the tail gas discharged into the atmosphere reaches the emission standard, which is the emission limit of maleic anhydride in the waste gas specified in GB31571-2015 "Petrochemical Industry Pollutant Discharge Standard" 10mg/m3, which meets environmental protection requirements and solves the problem of maleic anhydride Disposal and recycling of materials released from the device.

The pressure gauge 2-3 in the tail gas control device 2 is set on the top of the recovery tower 1 to monitor the pressure at the top of the recovery tower 1 in real time. The tail gas control device 2 is preset with an interlocking set pressure. If the preset interlocking set pressure is not exceeded, the tail gas control device 2 signals to control the first outlet of the second valve 2-5 to open, and the unqualified tail gas is returned to the tower kettle 1-7 to continue the recovery process to If the emission standard is met, the tail gas control device 2 signals to control the second outlet of the second valve 2-5 to open, and the unqualified tail gas is discharged to the incinerator 12 for incineration to reduce the pressure in the tower. Ensure the normal working pressure of recovery tower 1, minimize the discharge of vented materials to the incinerator, reduce the loss of vented materials, and improve economic benefits.

Further, the wastewater produced in the washing section is discharged to the wastewater treatment unit 11 through the wastewater discharge pipeline for further processing to meet the wastewater discharge standard, and the maleic anhydride-containing rich solvent produced in the solvent absorption section is discharged to the solvent recovery unit 10 through the solvent discharge pipeline for further recovery of maleic anhydride. Anhydrides and solvents, reducing energy consumption, material consumption, and improving economic benefits.

Further, when the tail gas test results are up to the discharge standard, the flow of solvent and desalted water is reduced to save material consumption, and the maleic anhydride component content determined in the tail gas can be lower than the discharge standard within 10%, preferably 6%.

Preferably, the interlock set pressure design value is 20-50kPaG, preferably 30kPaG.

Preferably, the initial openings of the solvent regulating valve 8-1 and the desalted water regulating valve 9-1 are designed to be 30-70%, preferably 50%.

Preferably, the solvent is dibutyl phthalate.

Embodiment one

With reference to shown in Fig. 1, present embodiment provides a kind of maleic anhydride device safe discharge recovery system, comprises:

A recovery tower 1, the tower kettle 1-7 of the recovery tower 1 is connected to the safety discharge main pipe 7 of the maleic anhydride device, and the recovery tower 1 is sequentially provided with a solvent absorption section and a water washing section from bottom to top;

The liquid inlet of the solvent absorption section is connected to the solvent input structure 8 and is provided with a solvent regulating valve 8-1, and the liquid outlet of the solvent absorption section is connected to the solvent recovery unit 10;

The liquid inlet of the washing section is connected to the desalinated water input structure 9 and is provided with a desalinated water regulating valve 9-1, and the liquid outlet of the washing section is connected to the waste water treatment unit 11;

The tail gas control device 2, the tail gas control device 2 can monitor in real time the temperature of the release material containing maleic anhydride released from the safety release main pipe 7, and can analyze and detect the maleic anhydride component content of the tail gas online;

The tail gas control device 2 discharges the qualified tail gas to the atmosphere 6 according to the detection results, and returns the unqualified tail gas to the tower bottom 1-7 and/or discharges to the incinerator 12 .

In this embodiment, the exhaust gas control device 2 includes:

The remote thermometer 2-1, the remote thermometer 2-1 monitors in real time the temperature of the release material containing maleic anhydride released from the safety release main pipe;

Exhaust gas analyzer 2-2, exhaust gas analyzer 2-2 online analysis and detection of maleic anhydride component content of exhaust gas;

Pressure gauge 2-3, pressure gauge 2-3 monitors the tower top pressure of recovery tower 1 in real time;

The first control unit, the first control unit controls the opening of the solvent regulating valve 8-1 and the desalted water regulating valve 9-1 according to the temperature monitoring result of the remote thermometer 2-1 and/or the detection result of the exhaust gas analyzer 2-2 ;

The second control unit, the second control unit controls the opening and closing of the first valve 2-4 to discharge the qualified tail gas to the atmosphere 6 according to the detection result, and controls the opening and closing of the second valve 2-5 to return the unqualified tail gas to the tower kettle 1 -7 and/or discharge the tail gas to the incinerator 12 according to the pressure at the top of the tower.

In this embodiment, the solvent absorption section includes absorption fillers 1-6, solvent distributors 1-5 and wire mesh demisters 1-4 arranged in sequence from bottom to top;

The solvent circulation pump 3-1, the inlet side of the solvent circulation pump 3-1 is connected to the bottom of the recovery tower 1, the outlet side of the solvent circulation pump 3-1 is respectively connected to the solvent recovery unit 10 and the solvent distributor 1-5, the solvent circulation pump 3-1 It is possible to circulate the solvent back to the solvent absorption section.

In this embodiment, the water washing section includes a riser tray 1-3, a water washing packing 1-2, and a water distributor 1-1 arranged sequentially from bottom to top;

Water circulation pump 4-1, the inlet side of water circulation pump 4-1 is connected with lifting tray 1-3, the outlet of water circulation pump 4-1 is respectively connected with wastewater treatment unit 11 and water distributor 1-1, and water circulation pump 4-1 can The desalinated water is circulated back to the water washing section.

In this embodiment, the liquid level control side of the gas lift tray 1-3 is provided with a liquid collection tank 1-8 and a water washing liquid level control device 5-1.

In this embodiment, a tower kettle liquid level control device 5-2 is provided on the liquid level control side of the tower kettle 1-7.

Embodiment two

Referring to Fig. 2, the present embodiment provides a maleic anhydride device safety discharge recovery system, different from the first embodiment, in the present embodiment, a solvent circulation is provided between the solvent circulation pump 3-1 and the solvent absorption section Cooler 3-2, a water circulation cooler 4-2 is provided between the water circulation pump 4-1 and the water washing section, and a circulation cooler is provided in the safety discharge main pipe 7.

Embodiment three

With reference to shown in Figure 3, the present embodiment provides a method for safe release and recovery of a maleic anhydride plant, and the specific steps are as follows:

After the remote thermometer 2-1 monitors the temperature rise, control the solvent regulating valve 8-1 and the desalted water regulating valve 9-1 to open to the initial opening;

Solvent circulation pump 3-1 and water circulation pump 4-1 and corresponding solvent circulation cooler 3-2 and water circulation cooler 4-2 delay start;

Exhaust gas analyzer 2-2 online analysis and detection of maleic anhydride component content in exhaust gas;

If the test result is qualified, the qualified tail gas is discharged to the atmosphere, and at the same time, the flow of desalted water and solvent is reduced by adjusting the solvent regulating valve 8-1 and the desalinated water regulating valve 9-1;

The waste water produced is discharged to the waste water treatment unit 11, and the rich solvent containing maleic anhydride produced is discharged to the solvent recovery unit 10;

If the test result is unqualified, increase the flow rate of desalted water and solvent until the test result of tail gas is qualified, and check whether the top pressure of recovery tower 1 exceeds the interlocking set pressure;

If the top pressure of the recovery tower 1 does not exceed the interlock set pressure, the unqualified tail gas is returned to the tower kettle 1-7 for secondary maleic anhydride recovery;

If the top pressure of the recovery tower 1 exceeds the interlock set pressure, the tail gas will be discharged to the incinerator 12 until the top pressure falls back to the interlock set pressure.

Among them, the solvent regulating valve 8-1 and the desalted water regulating valve 9-1 are opened to an initial opening of 50%; the solvent circulation pump 3-1 and the water circulation pump 4-1 and the corresponding solvent circulation cooler 3-2 and water circulation cooling Device 4-2 starts with a delay of 30s; the interlocking setting pressure at the top of recovery tower 1 is 30kPaG.

In summary, the recovery tower of the present invention includes a solvent absorption section and a water washing section. The solvent in the solvent absorption section can absorb the maleic anhydride in the discharge material, and the desalted water in the water washing section can remove acidic impurities. Analyze and detect whether the maleic anhydride component content in the tail gas is qualified, discharge the qualified tail gas to the atmosphere, and continue to treat the unqualified tail gas until it reaches the emission standard, and can recover maleic anhydride and solvents at the same time, improve economic benefits, and solve the problem of maleic anhydride Difficulties in the treatment and recovery of materials released from anhydride plants. A solvent circulation pump and a water circulation pump are also provided to recycle desalted water and solvents, saving desalted water and solvent consumption, reducing energy consumption and material consumption.

Having described various embodiments of the present invention, the foregoing description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and alterations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims (10)

1. A maleic anhydride plant safety discharge recovery system, characterized in that it comprises: A recovery tower, the tower kettle of the recovery tower is connected to the safety discharge main pipe of the maleic anhydride device, and a solvent absorption section and a water washing section are sequentially arranged in the recovery tower from bottom to top; The liquid inlet of the solvent absorption section is connected to a solvent input structure and is provided with a solvent regulating valve, and the liquid outlet of the solvent absorption section is connected to a solvent recovery unit; The liquid inlet of the water washing section is connected to the desalinated water input structure and is provided with a desalinated water regulating valve, and the liquid outlet of the water washing section is connected to the wastewater treatment unit; Tail gas control device, the tail gas control device can monitor in real time the temperature of the release material containing maleic anhydride released from the safety release main pipe, and can analyze and detect the maleic anhydride component content of the tail gas on-line; The tail gas control device discharges the qualified tail gas to the atmosphere according to the detection result, and returns the unqualified tail gas to the bottom of the tower and/or discharges it to the incinerator. 2. according to the described maleic anhydride device safe discharge recovery system of claim 1, it is characterized in that, described tail gas control device comprises: A remote thermometer, the remote thermometer monitors in real time the temperature of the discharge material containing maleic anhydride discharged from the safety relief main pipe; Tail gas analyzer, described tail gas analyzer online analysis detects the maleic anhydride component content of described tail gas; Pressure gauge, said pressure gauge monitors the tower top pressure of said recovery tower in real time; A first control unit, the first control unit controls the opening of the solvent regulating valve and the desalinated water regulating valve according to the temperature monitoring result of the remote thermometer and/or the detection result of the exhaust gas analyzer; A second control unit, the second control unit controls the opening and closing of the first valve to discharge the qualified tail gas to the atmosphere according to the detection result, and controls the opening and closing of the second valve to return the unqualified tail gas to the The tail gas is discharged to the incinerator according to the tower bottom pressure and/or according to the tower top pressure. 3. according to claim 1 described maleic anhydride device safe discharge recovery system, it is characterized in that, described solvent absorbing section comprises the absorbing filler that arranges successively from bottom to top, solvent distributor and wire mesh demister; A solvent circulation pump, the inlet side of the solvent circulation pump is connected to the bottom of the recovery tower, the outlet side of the solvent circulation pump is respectively connected to the solvent recovery unit and the solvent distributor, and the solvent circulation pump can The solvent is circulated back to the solvent absorption section. 4. According to claim 3, the maleic anhydride device safety discharge recovery system is characterized in that, a solvent circulation cooler is arranged between the solvent circulation pump and the solvent absorption section. 5. According to claim 1, the maleic anhydride device safety discharge recovery system is characterized in that, the water washing section comprises a gas lift tray, a water washing packing and a water distributor arranged sequentially from bottom to top; A water circulation pump, the inlet side of the water circulation pump is connected to the lift tray, the outlet of the water circulation pump is respectively connected to the waste water treatment unit and the water distributor, and the water circulation pump can circulate desalinated water back to the Washing section. 6. According to claim 5, the maleic anhydride device safety discharge recovery system is characterized in that, a water circulation cooler is provided between the water circulation pump and the water washing section. 7. According to claim 5, the maleic anhydride device safety discharge recovery system is characterized in that, the liquid level control side of the gas lift tray is provided with a liquid collection tank and a water washing liquid level control device. 8. The maleic anhydride device safety release recovery system according to claim 1, characterized in that, the liquid level control side of the tower still is provided with a tower still liquid level control device. 9. A maleic anhydride plant safety discharge recovery method, utilizing the maleic anhydride plant safe discharge recovery system according to any one of claims 1-8, is characterized in that the method comprises: Real-time monitoring of the release of maleic anhydride-containing material from the safety relief main pipe, and control the opening of the solvent regulating valve and the desalinated water regulating valve to the initial opening; On-line analysis detects the maleic anhydride component content of the tail gas, and if the test result is qualified, the qualified tail gas is discharged to the atmosphere, and at the same time, the flow of desalted water and solvent is reduced by adjusting the solvent regulating valve and the desalinated water regulating valve; If the detection result is unqualified, increase the flow rate of desalted water and solvent until the detection result of the tail gas is qualified, and return the unqualified tail gas to the tower tank and/or discharge it to the incinerator. 10. according to the described recovery method of maleic anhydride device safe release of claim 9, it is characterized in that, described method also comprises: Detect whether the top pressure of the recovery tower exceeds the interlock set pressure; If the tower top pressure of the recovery tower does not exceed the interlocking set pressure, the unqualified tail gas is returned to the tower still to carry out secondary maleic anhydride recovery; If the top pressure of the recovery tower exceeds the interlock set pressure, the tail gas will be discharged to the incinerator until the top pressure drops back to the interlock set pressure.