Phosgene production device, phosgene production system and phosgene production method

Abstract

The invention discloses a phosgene production device and system and a phosgene production method, the phosgene production device comprises a reactor and a protective shell arranged outside the reactor, and a gap exists between the reactor and the protective shell. The phosgene production device disclosed by the invention adopts a double-layer structure, so that the production of phosgene is safer, and a gas-phase product is prevented from being in contact with the environment in an undesirable manner. According to the reactor of the phosgene production device, the auxiliary reactor is additionally arranged on the basis of the main reactor, the phosgene reaction efficiency is further improved, and it is guaranteed that the chlorine content at an outlet of the reactor is qualified. The reactor of the phosgene production device is provided with a refrigerating and heating integrated system, the reactor is preheated to 50-75 DEG C at the beginning of starting, and normal production can be achieved within 10 min after the reactor is started. In addition, the reactor of the phosgene production device also adopts an automatic DCS (Distributed Control System), so that stable production of the material system, the heat exchange system and the like is ensured.

Description

Technical Field

[0001] The present invention belongs to the field of phosgene reaction safety production equipment, and in particular relates to a phosgene production device, system and method for producing phosgene. Background Art

[0002] Phosgene (COCl2), also known as carbonyl chloride, is a colorless, highly toxic gas with a special odor. Since the phosgene molecule contains two acyl chloride functional groups, its chemical properties are very active. For example, phosgene can react with primary amine compounds and bisphenol A to form isocyanates and polycarbonates. Therefore, phosgene can be widely used as a raw material in organic synthesis, and the industrialized phosgenation products developed from it can reach tens of thousands. At the same time, phosgene is also widely used in the synthesis of intermediates such as pesticides, medicines and dyes.

[0003] The high toxicity of phosgene itself and the potential danger of phosgenation production make phosgenation products strictly controlled. Therefore, how to use phosgene resources safely and with higher quality is the focus of the development of the phosgene and phosgenation product industry, and it is also a problem that phosgenation production companies need to face. At present, according to the requirements of current technical specifications and from the perspective of safety, phosgene production mainly adopts a spray absorption protection system and seals the reactor in a closed device to solve safety problems. However, this design causes operators to have a greater safety hazard of poisoning when entering the closed device for inspection and operation. At the same time, according to the requirements of the design specifications, the number of air replacements in the above-mentioned closed device is designed to be 6 to 12 times, and the tail gas needs to be absorbed by alkali solution. Therefore, the current phosgenation production also needs to be equipped with larger fans and alkali solution absorption towers.

[0004] In addition, the phosgenation reaction is the reaction of carbon monoxide and chlorine (catalyst activated carbon), which is an exothermic reaction process. Therefore, in order to ensure the safe progress of the reaction, the current reactor adopts a shell and tube reactor, with an activated carbon catalyst installed in the reactor tubes, and the outer shell uses a refrigerant for heat recovery. However, if the phosgenation reaction product contains free chlorine, it will cause great trouble to downstream production, and will cause the unit consumption of organic amines in the reaction raw materials (that is, the amount of material consumed per unit product) to increase. Therefore, in order to control the content of free chlorine in the phosgenation reaction product, a process control scheme with a slight excess of carbon monoxide is generally adopted. In addition, in the process of just starting up the reactor, due to the low temperature of the reactor, the reaction temperature required for the phosgenation reaction of 70 to 90°C is not reached, which will cause the free chlorine in the reaction product to exceed the standard, and the materials in the initial stage of the reaction cannot be used downstream, so they can only be discharged to the alkali solution absorption unit, resulting in an increase in unit consumption. Summary of the invention

[0005] In order to improve the above technical problems, the present invention provides a phosgene production device, comprising a reactor and a protective shell arranged outside the reactor, wherein a gap exists between the reactor and the protective shell.

[0006] According to an embodiment of the present invention, the protective shell is made of metal material, such as carbon steel.

[0007] According to an embodiment of the present invention, the reactor is concentrically located in the protective shell. Preferably, the reactor is coaxially located in the protective shell.

[0008] According to an embodiment of the present invention, the outer diameter of the reactor is smaller than the inner diameter of the protective shell. Preferably, the ratio of the outer diameter of the reactor to the inner diameter of the protective shell is 1:(1-3), exemplified by 1:1, 1:1.5, 1:1.75, 1:1.2, 1:25, 1:3.

[0009] According to an embodiment of the present invention, the protective shell includes a shell and a closing element. Preferably, the closing element can be arranged at the upper part and / or the lower part of the shell. For example, the closing element can be selected from covers and / or heads known in the art. For example, when present, each closing element can be independently connected to the shell by a flange welded to the shell, or directly welded to the shell. As an example, the protective shell includes a shell in the middle, a cover arranged at the upper part of the shell, and a head arranged at the lower part of the shell, wherein the cover is connected to the shell by a flange welded to the shell, so that the reactor can be hoisted out as a whole during maintenance.

[0010] According to an embodiment of the present invention, the phosgene production device is further provided with bolt holes so as to be fixed by bolts (such as anchor bolts).

[0011] According to an embodiment of the present invention, a supporting device is connected between the outer wall of the reactor and the inner wall of the protective shell outside the reactor. For example, a supporting lug is provided on the outer wall of the reactor, and a supporting bolt is provided on the inner wall of the protective shell outside the reactor, so as to fix the reactor.

[0012] According to an embodiment of the present invention, the phosgene production device also includes elements required for phosgene production. The elements include, but are not limited to, one or more selected from an air inlet unit, an air outlet unit, a feed unit, a discharge unit, an instrument unit, and an overhaul unit. It should be understood by those skilled in the art that when the phosgene production device is provided with the above-mentioned elements, the elements should not affect the air tightness of the reactor and / or the protective shell. For this purpose, the elements can be connected to the protective shell and the reactor by welding, flanges and / or piping. It should be understood that the structure and function of the elements are known in the art. For example, the air inlet unit and the air outlet unit can be used to pass in and out nitrogen to achieve the cleaning of the reaction atmosphere. The feed unit can be used to pass in the reaction raw materials for preparing phosgene, and the discharge unit can be used to discharge the reaction products or undesirable residues. The instrument unit can be used to display or monitor the process parameters of the phosgene production device or the reactor. The overhaul unit can be used to overhaul the phosgene production device. For convenience, the unit is preferably connected to the phosgene production device by a flange.

[0013] According to an embodiment of the present invention, the gas outlet unit of the phosgene production device includes an exhaust port, an exhaust pipeline, and a gas detection element arranged on the exhaust pipeline, such as a phosgene detection element and / or a chlorine detection element. The phosgene detection element can be known in the prior art, such as a phosgene alarm (exemplarily, the phosgene alarm RBK-6000 is composed of a gas alarm controller and a point-type phosgene gas detector to form a system.). Preferably, when the above-mentioned gas detection element detects that the gas exceeds the standard, an alarm message can be issued.

[0014] According to an embodiment of the present invention, the phosgene production device may further include a gas mixer to mix carbon monoxide and chlorine before entering the reactor. For example, the gas mixer may be arranged outside the protective shell of the phosgene production device. It should be understood that when the gas mixer is arranged outside the protective shell of the phosgene production device, the feed unit of carbon monoxide and chlorine is connected to the gas mixer (for example, via flange connection or direct welding), so that the reaction raw materials enter the reactor after the gas mixer, so there is no need to connect the feed unit of carbon monoxide and chlorine to the phosgene production device by flange connection or direct welding.

[0015] According to an embodiment of the present invention, the phosgene production device may further include one or more elements selected from a manhole, a sight glass, a sight hole lamp, etc., to facilitate the maintenance or monitoring of the device.

[0016] According to an embodiment of the present invention, the reactor may optionally include a two-stage reactor. For example, the reactor includes a primary reactor and a secondary reactor. Preferably, the primary reactor is a main reactor and the secondary reactor is a secondary reactor.

[0017] According to an embodiment of the present invention, the primary reactor is connected in series with the secondary reactor, for example, the discharge unit of the primary reactor is connected with the feed unit of the secondary reactor through a pipeline, so that the reaction of carbon monoxide and chlorine is first carried out in the primary reactor and then in the secondary reactor.

[0018] According to an embodiment of the present invention, the inner diameter of the secondary reactor is smaller than the inner diameter of the primary reactor. Preferably, the ratio of the inner diameter of the secondary reactor to the inner diameter of the primary reactor is (0.5-0.9):1, exemplified by 0.5:1, 0.6:1, 0.75:1, 0.8:1, 0.9:1.

[0019] According to an embodiment of the present invention, the reactors (eg, the primary reactor and / or the secondary reactor) are each independently a tubular reactor.

[0020] According to an embodiment of the present invention, each of the reactors (eg, the primary reactor and / or the secondary reactor) is independently provided with tubes therein, for example, tubes selected from DN32 to DN50.

[0021] According to an embodiment of the present invention, the tube array is further provided with a catalyst fixing unit. For example, a wire mesh support may be installed at the bottom of the tube array, and a wire mesh gland may be installed at the top to fix the catalyst particles.

[0022] According to an embodiment of the present invention, the catalyst is a catalyst known in the art for catalyzing phosgene production reaction, preferably an activated carbon catalyst, exemplified by activated carbon prepared from rice husks.

[0023] According to an embodiment of the present invention, one or more temperature detectors, such as one or more temperature detection tubes, are independently arranged inside the reactor (e.g., the primary reactor and / or the secondary reactor). As an example, each temperature detector is equipped with more than 3 temperature detection points, such as 3 to 7 temperature detection points, so as to observe and accurately monitor the reaction temperature at different positions.

[0024] According to an embodiment of the present invention, the heat carrier outlet of the secondary reactor is connected to the heat carrier inlet of the primary reactor through a pipeline, and the heat exchange medium is connected in series. The heat carrier exchanges heat with the material in the reactor in countercurrent through the gap between the shell-side tubes, removes the reaction heat in time, and ensures the safety of the reaction.

[0025] According to an embodiment of the present invention, the phosgene production device may further include a condensation unit to condense the gas phase product discharged from the reactor (preferably the secondary reactor) into a gas phase and a liquid phase.

[0026] According to an embodiment of the present invention, in addition to connecting the above-mentioned and other units or elements required for phosgene production, the protective shell arranged outside the reactor is closed to prevent the gas and liquid produced by the reaction from directly contacting the environment in an undesirable manner.

[0027] The present invention also provides a phosgene production system, which contains the phosgene production device.

[0028] According to an embodiment of the present invention, the phosgene production system further includes a DCS (Distributed Control System) control system.

[0029] When there is a leak in the internal reactor, the leaked gas is sealed by the protective shell and collected in the alkali liquid washing tower for phosgene destruction without leaking into the environment. At the same time, a phosgene detection element is added to the exhaust pipeline. Once a signal is detected, the DCS control system will be triggered to synchronously alarm the operator, so as to achieve early detection and early treatment to avoid safety accidents.

[0030] According to an exemplary embodiment of the present invention, the DCS control system includes detection instruments, cards (used to collect signals from the detection instruments and output analog or digital signals to actuators), an instrument transmission network and a control station.

[0031] In one embodiment of the present invention, the detection instruments include a thermometer, a pressure gauge and a flow meter.

[0032] In one embodiment of the present invention, the control station includes an engineer station and an operator station.

[0033] The carbon monoxide and chlorine flow rates of the phosgene reactor are transmitted remotely to the DCS control system, and a carbon monoxide flow control loop is set up to achieve stable control of the carbon monoxide flow rate. A chlorine flow control loop is set up to achieve chlorine flow control. A carbon monoxide and chlorine flow ratio adjustment control loop is set up, and the volume flow ratio of carbon monoxide and chlorine V(CO):V(Cl2) is controlled to be 1.01~1.1:1 through formula calculation (including temperature compensation and LIMIS analytical purity), so as to achieve precise control and ensure the chlorine content in the reactor discharge.

[0034] According to an embodiment of the present invention, the phosgene production system further comprises a refrigeration unit.

[0035] According to an embodiment of the present invention, the phosgene production system further comprises a heating unit.

[0036] According to the embodiment of the present invention, the refrigeration unit and the heating unit are an integrated refrigeration and heating system. The reaction heat can be removed in time to ensure the safety of the reaction; at the same time, the system has a heating function, which can increase the temperature of the reaction system during initial start-up, shortening the time for the device to reach normal level to within 10 minutes. At the same time, an external emergency cooling water system is used as a backup to further improve production safety.

[0037] According to an embodiment of the present invention, the phosgene production system further comprises a phosgene separation tank connected to the condensation unit.

[0038] According to an embodiment of the present invention, the phosgene production system further comprises an alkali solution washing tower.

[0039] The mixed gas coming out of the phosgene secondary reactor (secondary reactor) is condensed by a condensation unit (such as a condenser) and the gas and liquid phases enter the phosgene separation tank. The gas phase is mostly carbon monoxide, which is absorbed by the alkali-removing liquid washing tower and then enters the incinerator as fuel gas. The liquid phase is phosgene and is pressurized by a pressure pump and sent to the subsequent device.

[0040] The present invention also provides a method for producing phosgene, comprising preparing phosgene in the above-mentioned phosgene production device or phosgene production system.

[0041] According to an embodiment of the present invention, the phosgene production method comprises reacting carbon monoxide and chlorine in the phosgene production system in the presence of a catalyst to obtain a product gas mixture containing phosgene.

[0042] According to an embodiment of the present invention, the method further comprises: introducing chlorine and carbon monoxide into a gas mixer after flow adjustment, mixing them, and then introducing them into a primary reactor for reaction; the reacted materials enter a secondary reactor for further reaction to consume all the chlorine.

[0043] According to an embodiment of the present invention, the flow rate ratio of carbon monoxide to chlorine is 1.01 to 1.1:1, exemplified by 1.01:1, 1.02:1, 1.03:1, 1.04:1, 1.05:1, 1.06:1, 1.07:1, 1.08:1, 1.09:1, and 1.1:1.

[0044] According to an embodiment of the present invention, the reaction temperature in the primary reactor is 70-90°C, exemplified by 70°C, 80°C, and 90°C.

[0045] According to an embodiment of the present invention, the reaction temperature in the secondary reactor is 70.5-90.5° C., exemplified by 70.5° C., 80° C., and 90.5° C. According to an embodiment of the present invention, the method further comprises removing the heat released by the reaction in the primary reactor and the secondary reactor by circulating water of a refrigeration unit.

[0046] According to an exemplary embodiment of the present invention, in the method for producing phosgene, the control method of the DCS control system is as follows:

[0047] 1) Set the volume flow rate Q1 of chlorine gas, and the flow meter controls the opening of the regulating valve FV to keep the volume flow rate of chlorine gas stable;

[0048] 2) Control the volume flow rate ratio of carbon monoxide and chlorine by K inputting the set value. The carbon monoxide flow set value is KQ1. The carbon monoxide flow set value controls the opening of the flow regulating valve to ensure stable flow.

[0049] 3) Reaction temperature control: At the beginning of the start-up, the temperature is set to T1. The cooling and heating integrated system compares the measured value with the set value. If the measured value is less than the set value, the heating mode is turned on to heat the reaction system. After the temperature reaches T1, the system is shut down to keep warm. After the feed reaction begins, the set value is adjusted to T2. As the reaction proceeds, the measured value is greater than the set value T2, and the cooling mode is automatically turned on to control the temperature of the reaction system.

[0050] 4) Set the reaction pressure P1, adjust the opening of the reactor outlet regulating valve, and control the reaction pressure to maintain at the set value P1.

[0051] 5) Interlocking: After the phosgene detection element detects that the phosgene concentration in the protective shell outside the reactor exceeds the standard and alarms, the interlocking feed chlorine and carbon monoxide feed valves are closed and the system is shut down.

[0052] 6) When the outlet chlorine detector detects that the chlorine content at the reactor outlet exceeds the standard, it will sound an alarm and reduce the chlorine feed flow rate (for example, reduce the chlorine feed flow rate to 0.9 times the original). If the alarm is not relieved after 10 minutes, the interlocked chlorine and carbon monoxide feed valves will be closed and the system will be shut down.

[0053] Beneficial effects of the present invention:

[0054] The phosgene production device of the present invention adopts a double-layer structure, which makes the production of phosgene safer and prevents the gas phase product from contacting the environment in an undesirable manner. The reactor of the phosgene production device of the present invention is equipped with a secondary reactor on the basis of the main reactor, which further improves the phosgene reaction efficiency and ensures that the chlorine content at the reactor outlet is qualified. The phosgene production device of the present invention is equipped with an integrated refrigeration and heating system. The reactor is preheated to 50-75°C at the beginning of operation, and the reactor can be put into normal production within 10 minutes of operation. In addition, the phosgene production device of the present invention also adopts an automatic DCS control system to ensure stable production of materials, heat exchange and other systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a structural schematic diagram of the phosgene production device of the present invention;

[0056] The meanings of the reference numerals in the figure are as follows: 1. protective shell; 11. cover; 12. flange; 13. support bolt; 14. shell; 15. head; 16. gas outlet unit; 2. reactor; 21. primary reactor; 22. secondary reactor; 23. gas inlet unit; 24. support ear; 25. pipeline; 26. discharge unit.

[0057] Figure 2 It is a structural schematic diagram of the phosgene production system of the present invention. DETAILED DESCRIPTION

[0058] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0059] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0060] Example 1

[0061] Reference Figure 1 A phosgene production device includes a reactor 2 and a protective shell 1 arranged outside the reactor 2, wherein there is a gap between the reactor 2 and the protective shell 1, and the reactor 2 is coaxially located in the protective shell 1.

[0062]

Protective case

[0063] The protective shell 1 is made of metal material, such as carbon steel.

[0064] The protective shell 1 includes a central shell 14, a cover 11 arranged on the upper part of the shell 14 and a head 15 arranged on the lower part of the shell 14. The cover 11 is connected to the shell 14 through a flange 12 welded on the shell, so that the reactor 2 can be hoisted out as a whole during maintenance.

[0065]

Reactor

[0066] The ratio of the outer diameter of the reactor 2 to the inner diameter of the protective shell 1 is 1:1.75.

[0067] A support ear 24 is provided on the outer wall of the reactor 2 , and a support bolt 13 is provided on the inner wall of the protective shell 1 outside the reactor 2 , so as to fix the reactor 2 .

[0068] The reactor 2 includes a primary reactor 21 and a secondary reactor 22, wherein the primary reactor 21 is a main reactor and the secondary reactor 22 is a secondary reactor. The discharge unit 26 of the primary reactor 21 is connected to the feed unit of the secondary reactor 22 via a pipeline 25, so that the reaction of carbon monoxide and chlorine is first carried out in the primary reactor 21 and then in the secondary reactor 22.

[0069] The ratio of the inner diameter of the secondary reactor 22 to the inner diameter of the primary reactor 21 is 0.75:1.

[0070] The primary reactor 21 and the secondary reactor 22 are each independently a tubular reactor, and each of the primary reactor 21 and the secondary reactor 22 is independently provided with a tube array of DN32 to DN50.

[0071] The tube array is also provided with a catalyst fixing unit, a wire mesh support is installed at the lower part of the tube array, and a wire mesh pressure cover is installed at the upper part to fix the activated carbon catalyst particles.

[0072] One or more temperature detection tubes are independently arranged inside the primary reactor 21 and the secondary reactor 22. Each temperature detector is equipped with 3 to 7 temperature detection points to observe and precisely monitor the reaction temperature at different positions.

[0073] The heat carrier outlet of the secondary reactor 22 is connected to the heat carrier inlet of the primary reactor 21 through a pipeline, and the heat exchange medium is connected in series. The heat carrier exchanges heat with the material in the reactor 2 in countercurrent through the gap between the shell-side tubes, removes the reaction heat in time, and ensures the safety of the reaction.

[0074]

Inlet unit, outlet unit

[0075] The phosgene production device also includes an air inlet unit 23, an air outlet unit 16, a feed unit, a discharge unit 26, an instrument unit and a maintenance unit required for phosgene production. The components are connected to the protective shell 1 and the reactor 2 by welding, flanges and / or pipelines.

[0076] The air inlet unit 23 and the air outlet unit 16 can be used to pass in and out nitrogen to achieve the cleaning of the reaction atmosphere. The feed unit can be used to pass in carbon monoxide and chlorine, nitrogen, heat carrier, etc. for preparing the reaction raw materials of phosgene, and the discharge unit can be used to discharge the reaction product or undesirable residue. The instrument unit can be used to display or monitor the process parameters of the phosgene production device or reactor. The maintenance unit can be used to overhaul the phosgene production device. For convenience, the unit is preferably connected to the phosgene production device by a flange.

[0077] The gas outlet unit 16 of the phosgene production device includes an exhaust port, an exhaust pipeline, and a gas detection element arranged on the exhaust pipeline; the gas detection element includes a phosgene detection element and / or a chlorine detection element.

[0078] The phosgene detection element is the phosgene alarm RBK-6000, which is composed of a gas alarm controller and a contact-type phosgene gas detector. When the gas detection element detects that the gas exceeds the standard, an alarm message can be issued.

[0079] The phosgene production device also includes a gas mixer to mix carbon monoxide and chlorine before entering the reactor. The gas mixer is arranged outside the protective shell of the phosgene production device. The feed units of carbon monoxide and chlorine are connected to the gas mixer (for example, by flange connection or direct welding), so that the reaction raw materials enter the reactor after passing through the gas mixer, so there is no need to connect the feed units of carbon monoxide and chlorine to the phosgene production device by flange connection or direct welding.

[0080] The phosgene production device also includes one or more elements selected from manholes, sight glasses, sight hole lights, etc., to facilitate the maintenance or monitoring of the device.

[0081] In addition to connecting the above-mentioned and other units or elements required for phosgene production, the protective shell arranged outside the reactor is closed to prevent the gas and liquid produced by the reaction from directly contacting the environment in an undesirable manner.

[0082] The operation method of the phosgene production device of the present invention is as follows:

[0083] 1) The device installation and leak test are completed; the single machine debugging is completed, and the instruments and electrical appliances are ready for operation.

[0084] 2) The tail gas absorption device (alkaline solution washing tower) has been debugged and the circulation pump is turned on for normal operation.

[0085] 3) The condensation unit (e.g., condenser) at the outlet of reactor 2 is put into use, and the cooling medium supply is normal.

[0086] 4) The temperature of the reactor 2 is set to T1 (50° C.), and the cooling and heating system is in heating operation.

[0087] 5) When the temperature T1 reaches the set value, open the CO feed valve and the chlorine feed valve. Adjust the volume flow ratio of carbon monoxide: chlorine to maintain the K value. Slowly increase the operating load;

[0088] 6) Modify the temperature of reactor 2 to the set value T2; the integrated cooling and heating system changes from heating to cooling and automatically controls the temperature according to the rising reaction temperature.

[0089] 7) Set the reaction pressure P1. After reaching the set pressure, adjust the opening of the reactor outlet regulating valve to control the reaction pressure to maintain at the set value P1.

[0090] 8) Wait for the system to stabilize and change the above automatic valve to automatic.

[0091] 9) Safety interlock commissioning: After the phosgene detection element detects that the phosgene concentration in the protective shell outside the reactor exceeds the standard and alarms, the interlocked feeding chlorine and carbon monoxide feed valves are closed and the system is shut down.

[0092] 10) Take samples for analysis. If the relevant indicators of liquid phosgene meet the quality requirements, start the phosgene delivery pump to feed the next process.

[0093] Example 2

[0094] Reference Figure 2 , a method for producing phosgene, including in the phosgene production device of Example 1 (wherein the protective shell 1 includes a Q235B steel shell 14 in the middle, a butterfly head arranged on the upper part of the shell 14 and a butterfly head arranged on the lower part of the shell 14, the lower butterfly head is welded to the shell 14, the upper butterfly head is connected to the shell 14 by flange, and the weld is 100% non-destructively tested. An annular support is arranged on the inner wall of the protective shell 1, a vertical plate reinforcement rib is installed between the two flat plates, the upper plane is guaranteed to be horizontal, and a U-shaped bolt hole is arranged for fixing the internal reactor 2. The primary reactor 21 and the secondary reactor 22 are each independently a tubular reactor, and the primary reactor 21 and the secondary reactor 22 are each independently provided with a DN32 tube. The primary reactor 21 and the secondary reactor 22 are each independently provided with one or more temperature detection tubes. Each temperature detector is equipped with 7 temperature detection points. ), the raw materials chlorine and carbon monoxide enter the gas mixer for mixing after flow adjustment, and the gas fully mixed in the mixer enters the main reactor (primary reactor 21) of the phosgene reaction, and reacts in the main reactor, with a reaction temperature of 75°C and a pressure of 0.8MPa. The reaction is an exothermic reaction, and the heat released by the reaction is removed by the circulating water of the refrigeration unit. The mixed gas coming out of the main reactor enters the phosgene secondary reactor (secondary reactor 22) to ensure that the chlorine conversion rate is qualified, and the reaction heat is removed by the circulating water of the refrigeration unit. The mixed gas coming out of the phosgene auxiliary reactor is condensed by the cooler of the refrigeration unit and the gas-liquid phase enters the phosgene separation tank. The gas phase is mostly carbon monoxide, which is absorbed by the alkali-removing liquid washing tower and then enters the incinerator as fuel gas. The liquid phase is phosgene and is pressurized by a pressure pump and sent to the subsequent device.

[0095] The above is an explanation of the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A phosgene production device, characterized in that: The invention comprises a reactor and a protective shell arranged outside the reactor, wherein the reactor is concentrically located inside the protective shell, and a gap exists between the reactor and the protective shell.

2. The phosgene production device according to claim 1, characterized in that The protective shell comprises a shell in the middle, a cover arranged on the upper part of the shell and a head arranged on the lower part of the shell, wherein the cover is connected to the shell through a flange welded on the shell.

3. The phosgene production device according to claim 1, characterized in that A supporting device is connected between the outer wall of the reactor and the inner wall of the protective shell outside the reactor. A supporting lug is arranged on the outer wall of the reactor, and a supporting bolt is arranged on the inner wall of the protective shell outside the reactor.

4. The phosgene production device according to any one of claims 1 to 3, characterized in that: The phosgene production device also includes one or more components of an air intake unit, an air outlet unit, a feed unit, a discharge unit, an instrument unit, and a maintenance unit required for phosgene production; The gas outlet unit of the phosgene production device comprises an exhaust port, an exhaust pipeline, and a phosgene detection element and / or a chlorine detection element arranged on the exhaust pipeline.

5. The phosgene production device according to any one of claims 1 to 3, characterized in that: The phosgene production device further comprises a gas mixer disposed outside the protective shell of the phosgene production device, and a feeding unit of carbon monoxide and chlorine is connected to the gas mixer; The phosgene production device further comprises one or more elements selected from a manhole, a sight glass, and a sight hole lamp.

6. The phosgene production device according to any one of claims 1 to 3, characterized in that: The reactor comprises a primary reactor and a secondary reactor, wherein the primary reactor is connected in series with the secondary reactor; The primary reactor and the secondary reactor are each independently a tubular reactor, and each of the primary reactor and the secondary reactor is independently provided with a tube array inside, and the tube array is also provided with a catalyst fixing unit; The first-stage reactor and the second-stage reactor are each independently provided with one or more temperature detectors, and each temperature detector is equipped with 3 to 7 temperature detection points; The phosgene production device also includes a condensation unit.

7. A phosgene production system, characterized in that: It contains the phosgene production device according to any one of claims 1 to 6.

8. The phosgene production system according to claim 7, characterized in that The phosgene production system further includes a DCS control system, a refrigeration unit, and a heating unit; the refrigeration unit and the heating unit are an integrated refrigeration and heating system; The phosgene production system also includes a phosgene separation tank connected to the condensation unit; The phosgene production system also includes an alkali solution washing tower.

9. A method for producing phosgene, characterized in that The method comprises preparing phosgene in the phosgene production device according to any one of claims 1 to 6 or the phosgene production system according to any one of claims 7 to 8.

10. The method for producing phosgene according to claim 9, characterized in that The method comprises reacting carbon monoxide and chlorine in the phosgene production system according to any one of claims 7 to 8 in the presence of a catalyst to obtain a product gas mixture containing phosgene; The flow rate ratio of carbon monoxide to chlorine is 1.01 to 1.1:1; The reaction temperature in the primary reactor is 70-90°C; The reaction temperature in the secondary reactor is 70.5-90.5°C.

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