Device for continuously producing ethephon intermediate

Abstract

The utility model provides a device for continuously producing an ethephon intermediate. The device comprises a feeding unit which comprises a phosphorus trichloride storage tank and a plurality of ethylene oxide storage tanks; the esterification reaction unit comprises a plurality of esterification reactors which are connected in series; the rearrangement reaction unit comprises a rearrangement reactor; wherein the plurality of ethylene oxide storage tanks are connected with the plurality of esterification reactors through the plurality of mixers in a one-to-one correspondence manner, and the rearrangement reactor is connected with the final esterification reactor. By utilizing the device, the esterification reaction and the rearrangement reaction are directly and continuously carried out, and meanwhile, the efficient mixer is attached in the reaction unit, so that the mass transfer effect of the reaction is obviously improved, the dosage of ethylene oxide is saved, the step of recovering excessive ethylene oxide is omitted, and the influence of ethylene oxide on the rearrangement reaction is reduced. The purity of the ethephon intermediate product is improved.

Description

[0001] This application is based on the Chinese application with CN application number 202311230432.7 and application date September 22, 2023, and claims its priority. The disclosed content of the CN application is again introduced as a whole into this application. Technical Field

[0002] The utility model relates to the technical field of preparation of ethephon intermediates, in particular to a device for continuous production of ethephon intermediates. Background Art

[0003] Tris-(2-chloroethyl) phosphite and di-(2-chloroethyl) phosphite are intermediates of the plant growth regulator ethephon. At present, the production process of the main ethephon intermediates uses phosphorus trichloride and ethylene oxide as raw materials, and sequentially performs esterification reaction and rearrangement reaction. The esterification reaction is carried out in an enameled reactor at 30-40°C under the traditional batch process. The specific reaction related equation is:

[0004]

[0005] The current batch production process of tris-(2-chloroethyl) phosphite generally has the following shortcomings: 1. Poor heat control effect. The reaction is a strong exothermic reaction with an extremely fast reaction rate. The heat exchange area of ​​the traditional enamel kettle is limited, and the heat generated cannot be removed in time and will accumulate in the reactor; 2. Low production efficiency. The reaction time under the traditional production method takes dozens of hours; 3. If the raw materials and products are not well controlled, they are very likely to deteriorate, affecting the reaction effect; 4. There are many side reactions and the yield is low. In addition, there are also problems with the continuous flow synthesis process of tris-(2-chloroethyl) phosphite:

[0006] CN104119374A discloses a method for preparing tris-(2-chloroethyl) phosphite by microchannel, the method is: using phosphorus trichloride and ethylene oxide as raw materials, firstly, phosphorus trichloride and ethylene oxide are continuously pumped into a pipeline premixer for premixing, then introduced into a microchannel reaction device, after the reaction is complete, the effluent of the microchannel reaction device is collected, and the effluent is tris-(2-chloroethyl) phosphite. Although the reaction time can be reduced to more than ten minutes, the temperature control effect of the process still has certain problems, the reactor outlet temperature is high, which is easy to cause many side reactions and reduced product purity.

[0007] The rearrangement reaction is a process of using tris(2-chloroethyl)phosphite to generate di-(2-chloroethyl)phosphite, and is a key step in the production of ethephon. Di-(2-chloroethyl)phosphite is an intermediate of the plant growth regulator ethephon, and the content of di-(2-chloroethyl)phosphite plays a decisive role in the acidolysis reaction. At present, the rearrangement reaction of tris(2-chloroethyl)phosphite is mainly based on the batch production process of the kettle reactor, that is, the reaction is stirred in an enamel reactor at 150-160°C for 8-12 hours, and the content of the rearrangement product di-(2-chloroethyl)phosphite is 70-80%.

[0008] CN201410090994 discloses a production process of di-(2-chloroethyl) phosphate diester by combining a rearrangement reactor and a vertical rearrangement reactor, wherein tris(2-chloroethyl) phosphite is first stirred and reacted in a rearrangement reactor, and then enters a vertical rearrangement reactor for heat preservation, and the average content of di-(2-chloroethyl) phosphate diester is about 95%. However, both the batch production process and the vertical rearrangement reactor are prone to over-temperature material rushing, the product stability is poor, and the operation safety is low.

[0009] In addition, the process of rearranging tris-(2-chloroethyl) phosphite to form di-(2-chloroethyl) phosphate diester generally has the following disadvantages: 1. Low production efficiency, and the batch production process requires 8-12 hours for the raw materials to be completely converted; 2. It is difficult to quickly remove the reaction heat in the batch production process, the temperature rises too quickly, there are many side reactions, and the product purity is low.

[0010] Under the traditional batch process, the esterification reaction is transferred to the rearrangement reactor after the reaction is completed. The two-step reaction is carried out intermittently, which seriously affects the production efficiency. At the same time, it is easy to expose tris-(2-chloroethyl) phosphite to the air, causing hydrolysis side reactions and producing more impurities. In addition, the esterification reaction and rearrangement reaction production processes each have high defects, which affect the production process of ethephon intermediates. At present, there are continuous production processes for esterification or rearrangement reactions in the production process of ethephon intermediates, but there is no process for continuous production of the two-step reaction. Utility Model Content

[0011] The main purpose of the utility model is to provide a device for continuous production of ethephon intermediates, so as to solve the problem of low purity of intermediates obtained in the continuous production process of ethephon intermediates in the prior art.

[0012] In order to achieve the above-mentioned purpose, according to the first aspect of the utility model, a device for continuous production of ethephon intermediate is provided, which comprises: a feeding unit, which comprises a phosphorus trichloride storage tank and a plurality of ethylene oxide storage tanks; an esterification reaction unit, which comprises a plurality of esterification reactors connected in series; a rearrangement reaction unit, which comprises a rearrangement reactor; wherein the plurality of ethylene oxide storage tanks are connected to the plurality of esterification reactors in a one-to-one correspondence through a plurality of mixers, and the rearrangement reactor is connected to the last esterification reactor; the mixer is a static mixer, and the plurality of static mixers are independently selected from any one of the following: an SK type mixer, an SX type mixer, an SH type mixer and a JHF type mixer.

[0013] Furthermore, the multiple ethylene oxide storage tanks include a first ethylene oxide storage tank and a second ethylene oxide storage tank; the multiple esterification reactors include a first esterification reactor and a second esterification reactor; the multiple mixers include a first mixer and a second mixer; the esterification reaction unit includes a first mixer, a first esterification reactor, a second mixer and a second esterification reactor connected in series in sequence; the phosphorus trichloride storage tank and the first ethylene oxide storage tank are respectively connected to the first esterification reactor through the first mixer; the second ethylene oxide storage tank and the first esterification reactor are respectively connected to the second esterification reactor through the second mixer.

[0014] Furthermore, the phosphorus trichloride storage tank and the first mixer further include: a phosphorus trichloride feed pump, a first flow meter and a first precooling device which are connected in series in sequence.

[0015] Furthermore, the first ethylene oxide storage tank and the first mixer also include: a first ethylene oxide feed pump 302, a second flow meter and a second precooling device connected in series in sequence; the second ethylene oxide storage tank and the second mixer also include: a second ethylene oxide feed pump, a third flow meter and a third precooling device connected in series in sequence.

[0016] Furthermore, the first mixer, the second mixer, the first precooling device, the second precooling device and the third precooling device are each independently provided with a jacket device outside thereof, and the jacket device contains a cooling medium.

[0017] Furthermore, a first valve is provided between the second flow meter and the second precooling device.

[0018] Furthermore, a second valve is provided between the third flow meter and the third precooling device.

[0019] Furthermore, the rearrangement reactor and the last esterification reactor further include: a third valve, a tris-(2-chloroethyl) phosphite storage tank, a tris-(2-chloroethyl) phosphite feed pump, a fourth flow meter and a fourth precooling device which are connected in series in sequence.

[0020] Furthermore, the rearrangement reaction unit also includes a fourth valve and a di-(2-chloroethyl) phosphate diester storage tank which are sequentially connected in series with the outlet of the rearrangement reactor.

[0021] Furthermore, a jacket device is arranged outside the rearrangement reactor, and a heating medium is contained in the jacket device.

[0022] By applying the technical solution of the utility model, a plurality of ethylene oxide storage tanks and a plurality of esterification reactors connected in series included in a device for continuous production of ethephon intermediates can enable phosphorus trichloride and ethylene oxide to complete continuous multi-batch esterification reactions at the same temperature. By using the device, the esterification reaction and the rearrangement reaction are continuously carried out, so that the mass transfer effect of the reaction is significantly improved, the amount of ethylene oxide is saved, the step of recovering excess ethylene oxide is omitted, the influence of ethylene oxide on the rearrangement reaction is reduced, and the purity of the ethephon intermediate product is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0024] Figure 1 A schematic diagram of a device for performing esterification reaction of ethylene oxide twice according to the utility model is shown;

[0025] The above drawings include the following reference numerals:

[0026] 101, first esterification reactor; 102, second esterification reactor; 103, rearrangement reactor; 201, phosphorus trichloride storage tank; 202, first ethylene oxide storage tank; 203, second ethylene oxide storage tank; 204, tris-(2-chloroethyl) phosphite storage tank; 205, di-(2-chloroethyl) phosphate diester storage tank; 301, phosphorus trichloride feed pump; 302, first ethylene oxide feed pump; 303, second ethylene oxide feed pump; 304, phosphite Tris-(2-chloroethyl) phosphate feed pump; 401, first flow meter; 402, second flow meter; 403, third flow meter; 404, fourth flow meter; 501, first precooling device; 502, second precooling device; 503, third precooling device; 504, fourth precooling device; 601, first mixer; 602, second mixer; 701, first valve; 702, second valve; 703, third valve; 704, fourth valve. DETAILED DESCRIPTION

[0027] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present utility model will be described in detail below in conjunction with the embodiments.

[0028] As mentioned in the background technology, in the process of ethephon production, the purity of ethephon intermediates such as tris-(2-chloroethyl) phosphite and di-(2-chloroethyl) phosphate diester has a certain influence on the quality of the final product ethephon. In the prior art, the production process of ethephon intermediates often has defects, resulting in low purity of ethephon intermediates, which affects ethephon production.

[0029] The ethephon production process includes an esterification reaction using phosphorus trichloride and ethylene oxide as raw materials to generate tris-(2-chloroethyl) phosphite and a rearrangement reaction using tris-(2-chloroethyl) phosphite to generate di-(2-chloroethyl) phosphate. Existing esterification reaction and rearrangement reactors often have problems such as poor heat exchange effect, low reaction efficiency, and many side reaction products, resulting in high ethylene oxide consumption and low purity of the final tris-(2-chloroethyl) phosphite. If post-treatment is not performed, it is difficult to achieve high purity for subsequent rearrangement reaction; and the prior art esterification reaction time is long, ethylene oxide is fed in gaseous form, it is difficult to accurately control the metering ratio of phosphorus trichloride and ethylene oxide, the reactants of the esterification reaction, and the feed is unstable. There is no device and method for continuously performing the two-step reaction in the prior art.

[0030] In addition, the esterification reaction and rearrangement reaction are carried out intermittently, which easily exposes tris-(2-chloroethyl) phosphite to the air, causing hydrolysis side reactions and producing more impurities. Therefore, the present application intends to protect a device that can carry out the esterification reaction and rearrangement reaction in a continuous reaction form and obtain a higher purity ethephon intermediate.

[0031] In a first typical embodiment of the present application, a device for continuous production of ethephon intermediates is provided, the device comprising: a feeding unit, the feeding unit comprising a phosphorus trichloride storage tank 201 and a plurality of ethylene oxide storage tanks; an esterification reaction unit, the esterification reaction unit comprising a plurality of esterification reactors connected in series; a rearrangement reaction unit, the rearrangement reaction unit comprising a rearrangement reactor 103; wherein the plurality of ethylene oxide storage tanks are connected to the plurality of esterification reactors in a one-to-one correspondence through a plurality of mixers, and the rearrangement reactor 103 is connected to the last esterification reactor; the mixer is a static mixer, and the plurality of static mixers are each independently selected from any one of the following: an SK type mixer, an SX type mixer, an SH type mixer, and a JHF type mixer.

[0032] The ethephon intermediate esterification reaction device of the present application is provided with multiple ethylene oxide storage tanks, multiple esterification reactors and multiple mixers to achieve the process conditions of continuous feeding and continuous production, accurately control the mixing amount of phosphorus trichloride and ethylene oxide, and then control the reaction process of phosphorus trichloride esterification reaction, thereby achieving the purpose of accurately controlling the overall esterification reaction conditions. The tris-(2-chloroethyl) phosphite product obtained by the present application after being treated by the aforementioned multiple esterification reaction devices has a high purity, so it can be achieved without any intermediate treatment of tris-(2-chloroethyl) phosphite, directly entering the above-mentioned rearrangement reactor for rearrangement reaction, avoiding the phenomenon that tris-(2-chloroethyl) phosphite is easy to generate impurities during the esterification reaction and intermediate treatment process, and then can obtain a di-(2-chloroethyl) phosphoric acid diester ethephon intermediate with a high purity.

[0033] At the same time, the esterification reaction and the rearrangement reaction are directly carried out continuously, and an efficient mixer is set in the reaction unit, so that the mass transfer effect of the reaction is significantly improved, the amount of ethylene oxide is saved, the recovery step of excess ethylene oxide is omitted, and the influence of ethylene oxide on the rearrangement reaction is reduced. In order to make the reaction materials mixed more fully. Among them, the SK type mixer is a single-helix mixer, with a spiral blade twisted 180° or 270° as a unit component, and adjacent units are left-handed or right-handed during assembly; the SX type mixer is a horizontal bar mixer, and the horizontal bar is set at 45° to the axis of the mixer; the SH type mixer is a double-helix mixer, each unit component has two spiral blades, and a mixing chamber is set between each unit component; the JHF type mixer is a low-pressure drop horizontal bar mixer, and the horizontal bar is set at 45° to the axis of the mixer.

[0034] In a preferred embodiment, the multiple ethylene oxide storage tanks include a first ethylene oxide storage tank 202 and a second ethylene oxide storage tank 203; the multiple esterification reactors include a first esterification reactor 101 and a second esterification reactor 102; the multiple mixers include a first mixer 601 and a second mixer 602; the esterification reaction unit includes a first mixer 601, a first esterification reactor 101, a second mixer 602 and a second esterification reactor 102 connected in series in sequence; the phosphorus trichloride storage tank 201 and the first ethylene oxide storage tank 202 are respectively connected to the first esterification reactor 101 through the first mixer 601; the second ethylene oxide storage tank 203 and the first esterification reactor 101 are respectively connected to the second esterification reactor 102 through the second mixer 602.

[0035] Compared with the prior art in which two raw materials are contacted at one time, strong heat release makes the reaction conditions difficult to control, and multiple side reaction products appear, resulting in low purity of the target intermediate, in the present application, the reactant ethylene oxide in the esterification reaction is divided into multiple parts, preferably two or three parts. The esterification reaction unit with multiple ethylene oxide storage tanks, esterification reactors and mixers can realize "small amounts and multiple times" esterification reaction, reduce the heat release of raw material contact, make the reaction conditions relatively stable and easy to control, thereby reducing or even avoiding the phenomenon of impurity generation caused by unstable conditions, and improving the purity of the target intermediate product.

[0036] In order to further accurately control the efficiency of the esterification reaction and improve the purity of the product, the addition of the reactants can be more accurately controlled. In a preferred embodiment, the phosphorus trichloride storage tank 201 and the first mixer 601 further include: a phosphorus trichloride feed pump 301, a first flow meter 401 and a first precooling device 501 connected in series in sequence. In a preferred embodiment, the first ethylene oxide storage tank 202 and the first mixer 601 further include: a first ethylene oxide feed pump 302, a second flow meter 402 and a second precooling device 502 connected in series in sequence. In a preferred embodiment, the second ethylene oxide storage tank 203 and the second mixer 602 further include: a second ethylene oxide feed pump 303, a third flow meter 403 and a third precooling device 503 connected in series in sequence.

[0037] The above preferred embodiment controls the feed rate of the reactants through the feed pump and the flow meter, so that the reactants can be accurately fed according to the metering ratio to maintain the esterification reaction in the esterification reactor in a state of efficient reaction. In addition, the use of a precooling device to cool the reactants before the reaction can facilitate the control of the temperature in the esterification reaction, so as to avoid the formation of side reaction products due to the failure to exchange heat in time during the esterification reaction.

[0038] In order to further dissipate the heat generated in the esterification reaction in a timely manner and improve the purity of the reaction product, in a preferred embodiment, the first mixer 601, the second mixer 602, the first precooling device 501, the second precooling device 502 and the third precooling device 503 are each independently provided with a jacket device outside, and the jacket device contains a cooling medium. The mixer and the precooling device containing the reactants are kept at low temperature by the interlayer with the cooling medium, so as to further control the temperature of the reaction materials inside them.

[0039] In order to increase the heat exchange area of ​​the esterification reactor and enable the esterification reactor to promptly remove the heat generated by the reaction during the esterification reaction, thereby achieving the purpose of accurately controlling the reaction temperature, in a preferred embodiment, the esterification reactor independently includes one or more of the following structures: fin structure, nail head structure, thread structure, corrugated structure, spiral ring structure or spiral groove structure.

[0040] Since ethylene oxide has a low boiling point and is a gaseous substance at room temperature, in order to avoid cavitation caused by the gasification of ethylene oxide during feeding, affecting the feeding stability of the feed pump and avoiding accelerated wear of the feed pump, in a preferred embodiment, a first valve 701 connected in series is further provided between the second air pressure flow meter 402 and the second precooling device 502, preferably a back pressure valve; in a preferred embodiment, a second valve 702 connected in series is further provided between the third flow meter 403 and the third precooling device 503, preferably a back pressure valve. In order to avoid cavitation, it is necessary to ensure that the feed pressure is greater than the reaction pressure, thereby ensuring that the ethylene oxide feed is negative pressure feed and ensuring the liquid state of ethylene oxide.

[0041] In order to more accurately control the reaction pressure in the rearrangement reaction, collect the products of the esterification reaction and more easily detect the purity of the products, further accurately control the efficiency of the rearrangement reaction, and improve the purity of the product, it is necessary to more accurately control the addition of the reactants. In a preferred embodiment, the rearrangement reactor 103 and the last esterification reactor also include the following connected in series: a third valve 703, a tris-(2-chloroethyl) phosphite storage tank 204, a tris-(2-chloroethyl) phosphite feed pump 304, a fourth flowmeter 404 and a fourth precooling device 504.

[0042] In order to more accurately control the reaction pressure in the rearrangement reaction and collect the products of the rearrangement reaction, in a preferred embodiment, the rearrangement reaction unit also includes a fourth valve 704 and a di-(2-chloroethyl) phosphate diester storage tank 205 which are connected in series with the outlet of the rearrangement reactor 103.

[0043] In order to further enable the rearrangement reaction in the rearrangement reactor to proceed efficiently, in a preferred embodiment, the rearrangement reactor 103 is selected from one or more of the following reactors: a fully mixed flow reactor, a continuous horizontal reactor, a continuous vertical tubular reactor or a continuous coil reactor.

[0044] In order to further control the reaction temperature of the rearrangement reaction well and improve the purity of the reaction product, in a preferred embodiment, a jacket device is provided outside the rearrangement reactor 103, and a heating medium is contained in the jacket device. The rearrangement reactor undergoing the rearrangement reaction is kept warm by the interlayer with the heating medium, and the temperature of the reactants inside is further controlled.

[0045] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0046] Examples 1-2 of the present application all utilize Figure 1 The apparatus shown carries out the continuous production of the ethephon intermediate.

[0047] Example 1

[0048] The ethylene oxide was fed in two drops.

[0049] 1. The phosphorus trichloride in the phosphorus trichloride storage tank 201 is pumped in by the phosphorus trichloride feed pump 301, flows through the first flowmeter 401 to control the feed rate of the phosphorus trichloride to be 3g / min, enters the first precooling device 501, precools the phosphorus trichloride, and then passes into the first mixer 601; at the same time, the ethylene oxide in the first ethylene oxide storage tank 202 is pumped in by the first ethylene oxide feed pump 302, flows through the second flowmeter 402 to control the feed rate of the ethylene oxide to be 1.5g / min, and the feed pressure of the ethylene oxide is controlled by the first valve 701 to be 1.0MPa, enters the second precooling device 502, precools the ethylene oxide, and then passes into the first mixer 601. Among them, the first precooling device 501, the second precooling device 502 and the jacket device of the first mixer 601 are filled with an ethylene glycol aqueous solution at a temperature of -10°C, and the temperature in the system is -10°C.

[0050] 2. The phosphorus trichloride in the phosphorus trichloride storage tank 201 and the ethylene oxide in the first ethylene oxide storage tank 202 are mixed in the first mixer 601 for 30 seconds and enter the first esterification reactor 101 for the first stage esterification reaction. The jacket device of the first esterification reactor is filled with an ethylene glycol aqueous solution at a temperature of -15°C, wherein the stoichiometric ratio of phosphorus trichloride to ethylene oxide in the first esterification reaction is 1:1, the reaction temperature is -15°C, the reaction time is 10 minutes, and the reaction pressure is controlled by the third valve 703 and is 0.8 MPa.

[0051] 3. The ethylene oxide in the second ethylene oxide storage tank 203 is pumped in by the second ethylene oxide feed pump 303, flows through the third flowmeter 403 to control the ethylene oxide feed rate to be 1.5 g / min, and the second valve 702 controls the ethylene oxide feed pressure to be 1.0 MPa, enters the third precooling device 503, and after precooling the ethylene oxide, it is passed into the second mixer 602. The third precooling device 503 and the jacket device of the second mixer 602 are filled with an ethylene glycol aqueous solution at a temperature of -10°C, and the temperature in the system is -10°C.

[0052] 4. The ethylene oxide in the second ethylene oxide storage tank 203 and the incompletely reacted phosphorus trichloride discharged from the first esterification reactor 101 are mixed in the second mixer 602 and enter the second esterification reactor 102 for the second stage esterification reaction. The jacket device of the second esterification reactor is filled with an ethylene glycol aqueous solution at a temperature of -15°C, wherein the stoichiometric ratio of phosphorus trichloride to ethylene oxide in the second esterification reaction is 1:1, the reaction temperature is -15°C, the reaction time is 10 minutes, and the reaction pressure is controlled by the third valve 703 and is 0.8 MPa.

[0053] 5. The purity of the tris-(2-chloroethyl) phosphite product collected in the tris-(2-chloroethyl) phosphite storage tank 204 is 98.39%. Tris-(2-chloroethyl) phosphite is not post-processed, and is pumped in by the tris-(2-chloroethyl) phosphite feed pump 304, flows through the fourth flowmeter 404 to control the feed rate of tris-(2-chloroethyl) phosphite to be 6g / min, and enters the rearrangement reactor 103 through the fourth precooling device 504 to carry out rearrangement reaction. Silicone oil with a temperature of 200°C is filled into the jacket device of the rearrangement reactor 103. The reaction temperature of the rearrangement reaction is 200°C, the reaction time is 10min, and the reaction pressure is controlled by the fourth valve 704 and is 2.0MPa. The content of the product di-(2-chloroethyl) phosphite diester collected in the detection di-(2-chloroethyl) phosphite storage tank 205 is 84.01%.

[0054] Example 2

[0055] The ethylene oxide was added dropwise in three portions.

[0056] 1. The phosphorus trichloride in the phosphorus trichloride storage tank 201 is pumped in by the phosphorus trichloride feed pump 301, flows through the first flowmeter 401 to control the feed rate of the phosphorus trichloride to be 12 g / min, enters the first precooling device 501, precools the phosphorus trichloride, and then passes into the first mixer 601; at the same time, the ethylene oxide in the first ethylene oxide storage tank 202 is pumped in by the first ethylene oxide feed pump 302, flows through the second flowmeter 402 to control the feed rate of the ethylene oxide to be 4.62 g / min, and the feed pressure of the ethylene oxide is controlled by the first valve 701 to be 1.5 MPa, enters the second precooling device 502, precools the ethylene oxide, and then passes into the first mixer 601. Among them, the first precooling device 501, the second precooling device 502 and the jacket device of the first mixer 601 are filled with an ethylene glycol aqueous solution at a temperature of -30°C, and the system temperature is -30°C.

[0057] 2. The phosphorus trichloride in the phosphorus trichloride storage tank 201 and the ethylene oxide in the first ethylene oxide storage tank 202 are mixed in the first mixer 601 for 5 seconds and enter the first esterification reactor 101 for the first esterification reaction. The jacket device of the first esterification reactor is filled with an ethylene glycol aqueous solution at a temperature of -25°C, wherein the stoichiometric ratio of phosphorus trichloride to ethylene oxide in the first esterification reaction is 1:1.2, the reaction temperature is -25°C, the reaction time is 5 minutes, and the reaction pressure is controlled by the third valve 703 and is 1.0 MPa.

[0058] 3. The ethylene oxide in the second ethylene oxide storage tank 203 is pumped in by the second ethylene oxide feed pump 303, flows through the third flowmeter 403 to control the ethylene oxide feed rate to be 4.62 g / min, and the second valve 702 controls the ethylene oxide feed pressure to be 1.5 MPa, enters the third precooling device 503, and after precooling the ethylene oxide, it is passed into the second mixer 602. The third precooling device 503 and the jacket device of the second mixer 602 are filled with an ethylene glycol aqueous solution at a temperature of -30°C.

[0059] The ethylene oxide in the second ethylene oxide storage tank 203 and the incompletely reacted system discharged from the first esterification reactor 101 are mixed in the second mixer 602 and enter the second esterification reactor 102 for the second esterification reaction. The jacket device of the second esterification reactor is filled with an ethylene glycol aqueous solution at a temperature of -25°C, wherein the stoichiometric ratio of phosphorus trichloride to ethylene oxide in the second esterification reaction is 1:1.2, the reaction temperature is -25°C, the reaction time is 8 minutes, and the reaction pressure is controlled by the third valve 703 and is 1.0 MPa.

[0060] 4. The ethylene oxide in the third ethylene oxide storage tank (not shown in the figure) is pumped in by the third ethylene oxide feed pump (not shown in the figure), flows through the fifth flow meter (not shown in the figure) to control the ethylene oxide feed rate to be 3.08 g / min, and the fifth valve (not shown in the figure) controls the ethylene oxide feed pressure to be 1.5 MPa, enters the fifth precooling device (not shown in the figure), and after precooling the ethylene oxide, it is passed into the third mixer (not shown in the figure). Among them, the fifth precooling device (not shown in the figure) and the jacket device of the third mixer (not shown in the figure) are filled with ethylene glycol aqueous solution at a temperature of -30°C, and the system temperature is -30°C.

[0061] The ethylene oxide in the third ethylene oxide storage tank (not marked in the figure) is mixed with the unreacted phosphorus trichloride discharged from the second esterification reactor 102 in the third mixer (not marked in the figure), and enters the third esterification reactor (not marked in the figure) for the third esterification reaction. The jacket device of the third esterification reactor is filled with an ethylene glycol aqueous solution at a temperature of -25°C, wherein the stoichiometric ratio of phosphorus trichloride to ethylene oxide in the third esterification reaction is 1:0.8, the reaction temperature is -25°C, the reaction time is 30 minutes, and the reaction pressure is controlled by the third valve 703 and is 1.0 MPa.

[0062] 5. The purity of the tris-(2-chloroethyl) phosphite product collected in the tris-(2-chloroethyl) phosphite storage tank 204 is 97.83%. Tris-(2-chloroethyl) phosphite is not post-processed, and is pumped in by the tris-(2-chloroethyl) phosphite feed pump 304, flows through the fourth flowmeter 404 to control the feed rate of tris-(2-chloroethyl) phosphite to be 24.32g / min, and enters the rearrangement reactor 103 through the fourth precooling device 504 to carry out rearrangement reaction. Silicone oil with a temperature of 160°C is filled into the jacket device of the rearrangement reactor 103. The reaction temperature of the rearrangement reaction is 160°C, the reaction time is 180min, and the reaction pressure is controlled by the fourth valve 704 and is 1.2MPa. The content of the product di-(2-chloroethyl) phosphite diester collected in the detection di-(2-chloroethyl) phosphite storage tank 205 is 92.01%.

[0063] From the above description, it can be seen that the above-mentioned embodiments of the utility model achieve the following technical effects: by using the device and method of the utility model, ethylene oxide is divided into multiple portions, a multi-point feeding method is adopted, and a continuous reaction device is used instead of a traditional reactor batch reaction, thereby improving the reaction efficiency, shortening the esterification reaction time to tens of minutes, shortening the rearrangement reaction time to 10min-180min, and effectively improving the heat exchange effect of the equipment, avoiding heat accumulation, controlling the reaction temperature within a better range, effectively reducing the occurrence of side reactions during the reaction process, and improving the yield and purity of the product. In addition, the continuous production of the ethylene intermediate of the present application realizes continuous automation, reduces manual participation, and improves the safety of the reaction; at the same time, the raw materials and products are isolated from contact with water and air to avoid deterioration.

[0064] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. 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 device for continuous production of ethephon intermediates, characterized in that: The device comprises: A feeding unit, the feeding unit comprising a phosphorus trichloride storage tank (201) and a plurality of ethylene oxide storage tanks; An esterification reaction unit, wherein the esterification reaction unit comprises a plurality of esterification reactors connected in series; a rearrangement reaction unit, the rearrangement reaction unit comprising a rearrangement reactor (103); wherein the plurality of ethylene oxide storage tanks are connected to the plurality of esterification reactors in a one-to-one correspondence via a plurality of mixers, and the rearrangement reactor (103) is connected to the last esterification reactor; The mixer is a static mixer, and the plurality of static mixers are each independently selected from any one of the following: an SK mixer, an SX mixer, an SH mixer or a JHF mixer.

2. The device according to claim 1, characterized in that The plurality of ethylene oxide storage tanks include a first ethylene oxide storage tank (202) and a second ethylene oxide storage tank (203); The plurality of esterification reactors include a first esterification reactor (101) and a second esterification reactor (102); The plurality of mixers include a first mixer (601) and a second mixer (602); The esterification reaction unit comprises the first mixer (601), the first esterification reactor (101), the second mixer (602) and the second esterification reactor (102) which are sequentially connected in series; The phosphorus trichloride storage tank (201) and the first ethylene oxide storage tank (202) are respectively connected to the first esterification reactor (101) through the first mixer (601); The second ethylene oxide storage tank (203) and the first esterification reactor (101) are connected to the second esterification reactor (102) via the second mixer (602), respectively.

3. The device according to claim 2, characterized in that The phosphorus trichloride storage tank (201) and the first mixer (601) further include: a phosphorus trichloride feed pump (301), a first flow meter (401) and a first precooling device (501) which are sequentially connected in series.

4. The device according to claim 3, characterized in that The first ethylene oxide storage tank (202) and the first mixer (601) further include: a first ethylene oxide feed pump (302), a second flow meter (402) and a second precooling device (502) connected in series in sequence; Also included between the second ethylene oxide storage tank (203) and the second mixer (602) are: a second ethylene oxide feed pump (303), a third flow meter (403) and a third precooling device (503) which are sequentially connected in series.

5. The device according to claim 4, characterized in that The first mixer (601), the second mixer (602), the first precooling device (501), the second precooling device (502) and the third precooling device (503) are each independently provided with a jacket device on the outside, and the jacket device contains a cooling medium.

6. The device according to claim 4, characterized in that A first valve (701) is also provided between the second flow meter (402) and the second precooling device (502).

7. The device according to claim 4, characterized in that A second valve (702) is also provided between the third flow meter (403) and the third precooling device (503).

8. The device according to claim 1, characterized in that The rearrangement reactor (103) and the last esterification reactor further include: a third valve (703), a tris-(2-chloroethyl) phosphite storage tank (204), a tris-(2-chloroethyl) phosphite feed pump (304), a fourth flow meter (404) and a fourth precooling device (504) which are connected in series in sequence.

9. The device according to claim 1, characterized in that The rearrangement reaction unit further comprises a fourth valve (704) and a di-(2-chloroethyl) phosphate diester storage tank (205) which are sequentially connected in series with the outlet of the rearrangement reactor (103).

10. The device according to claim 1, characterized in that The rearrangement reactor (103) is provided with a jacket device outside, and the jacket device contains a heating medium.

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