Method and device for preparing polychloropropene through continuous dehydrochlorination of polychloropropane

Abstract

The invention provides a method and device for preparing polychloropropene through continuous dehydrochlorination of polychloropropane, and the method comprises the following steps: introducing liquid caustic soda and polychloropropane into a filler, forming liquid drops on the surface of the filler under a supergravity condition, and synchronously carrying out a dehydrochlorination reaction to obtain a reaction material containing polychloropropene. The device comprises a supergravity reactor; the supergravity reactor comprises a rotating system, the rotating system comprises a rotatable cavity and a driving part connected with the rotatable cavity, and the driving part is used for driving the rotatable cavity to rotate; and a filler area for placing filler is arranged in the rotatable cavity. According to the present invention, the efficient mixing of the caustic soda liquid and the polychloropropane can be achieved, the efficient dehydrochlorination reaction can be achieved under the mild condition, and the efficient separation of the chloropropene-containing product can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of polychlorinated propene preparation, and in particular to a method and a device for continuously dehydrochlorinating polychlorinated propane to prepare polychlorinated propene. Background Art

[0002] 1,1,2,3-Tetrachloropropene is an important precursor of refrigerants HFO-1234yf (2,3,3,3-tetrafluoropropene) and HFO-1234ze(E) (trans-1,3,3,3-tetrafluoropropene). As the fourth generation of new environmentally friendly refrigerants, HFO-1234yf and HFO-1234ze(E) have the characteristics of low ODP (Ozone Depletion Potential) and low GWP (Global Warming Potential) and are considered to be the most promising alternatives to the new generation of refrigerants. In addition, 1,1,2,3-tetrachloropropene can also be used to prepare chemical herbicides such as wild barley chlorpyrifos and pesticides such as chlormequat, and has a very broad application prospect.

[0003] At present, the production of 1,1,2,3-tetrachloropropene mainly uses ethylene + carbon tetrachloride and trichloropropane as raw materials, and the tetrachloropropene product is obtained through multi-step chlorination, HCl removal, distillation, and water removal. The process route is long, a large amount of waste salt is produced as a by-product, and there is also great environmental pressure. Using chloropropylene / dichloropropylene as raw materials through multi-step chlorination and HCl removal reactions can effectively reduce the production cost of 1,1,2,3-tetrachloropropene, but the process often involves one or more steps of polychloropropane dehydrochlorination to produce polychloropropene.

[0004] CN101754941B discloses a method for preparing 1,1,2,3-tetrachloropropene, which uses a halogenated transition metal oxide as a catalyst and uses a gas phase method to dechlorinate polychloropropane to prepare polychloropropene. However, the reaction temperature of this method is as high as 500°C, which is prone to produce a large amount of tar, and the recovery and regeneration of the catalyst are difficult, which is not conducive to industrial production.

[0005] CN115160104B discloses a method for producing pesticide-grade 1,1,2,3-tetrachloropropene, which uses Fe-ZSM-5 / Al-MCM-41 as a catalyst and can produce tetrachloropropene by dehydrochlorination of pentachloropropane under relatively mild conditions (100-160°C). However, the catalyst preparation process of this method is relatively complicated and the process cost is relatively high.

[0006] CN116194430A discloses a method for preparing pentachloropropane and tetrachloropropene from dichloropropene, wherein liquid alkali and a phase transfer catalyst are used together to achieve a dehydrochlorination reaction of tetrachloropropane / pentachloropropane. However, due to the presence of a phase transfer catalyst, an emulsion layer is easily formed in the final reaction liquid due to the mixing of oil and water, which greatly affects the separation yield and product quality of the target product. In addition, the high-salinity wastewater produced by the method is very difficult to treat due to the presence of a large amount of chlorinated organic matter, which is very challenging.

[0007] Therefore, how to achieve efficient dehydrochlorination of polychloropropane to produce polychlorinated propenes has become one of the important means to reduce the production cost of 1,1,2,3-tetrachloropropene and improve its economic benefits. Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides a method and device for continuously dehydrochlorinating polychloropropane to prepare polychloropropylene. By adopting a supergravity reactor for reaction, efficient dehydrochlorination reaction can be achieved under mild conditions without using a catalyst, and efficient separation of chlorinated propene products can be achieved at the same time, which has broad application prospects.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a method for continuously dehydrochlorinating polychloropropane to prepare polychloropropenes, the method comprising the following steps:

[0011] Liquid alkali and polychloropropane are introduced into the filler, and droplets are formed on the surface of the filler under supergravity conditions and dehydrochlorination reaction is carried out simultaneously to obtain a reaction material containing polychloropropene.

[0012] It is worth noting that in the process of preparing 1,1,2,3-tetrachloropropene from chloropropene / dichloropropene, there are multiple steps of dehydrochlorination of chloropropane to produce chloropropene. This step will have the problem of difficult product separation and low yield regardless of whether it is a high-temperature gas phase dechlorination process or a liquid alkali liquid phase dechlorination process. Therefore, the purpose of the present invention is to provide a method for preparing polychloropropene by efficient and continuous dehydrochlorination of polychloropropane, which can achieve efficient dehydrochlorination reaction under relatively mild conditions and simultaneously achieve efficient separation of chloropropene products.

[0013] Specifically, liquid alkali and polychloropropane are introduced into the filler, and the filler will rotate under supergravity conditions. Under the condition of high-speed rotation, micron-sized droplets will form on the surface of the filler, thereby greatly improving the liquid-liquid mass and heat transfer effects. The conversion of polychloropropane to polychlorinated propene can be achieved under mild and non-catalytic conditions, and the application prospect is broad.

[0014] The present invention adopts high gravity reaction conditions to prepare polychloropropanes to polychloropropylenes, which has the following advantages:

[0015] A. The high gravity condition adopts the mode of horizontal rotation, which not only rotates the material, but also rotates the filler therein, so that the material is dispersed into micron-sized droplets, which greatly improves the mixing effect of polychloropropane and liquid alkali, improves the reaction effect, and significantly improves the reaction yield and product quality;

[0016] B. Due to the good reaction effect, there is no need to use the phase transfer catalyst commonly used in liquid phase dehydrochlorination, nor is there any need to use other transition metal catalysts to promote the reaction, thus reducing the reaction cost;

[0017] C. In the present invention, no emulsion is formed during the reaction process, and the oil-water separation can be achieved by directly leaving the material to stand after the reaction.

[0018] Preferably, the liquid alkali comprises an aqueous NaOH solution.

[0019] Preferably, the mass fraction of alkali in the liquid alkali is 10-32wt.%, for example, it can be 10wt.%, 13wt.%, 15wt.%, 18wt.%, 20wt.%, 23wt.%, 25wt.%, 28wt.%, 30wt.% or 32wt.%, etc., preferably 20wt.%.

[0020] Preferably, the polychloropropane comprises any one of 1,2,3-trichloropropane, 1,1,2,3-tetrachloropropane, 1,2,2,3-tetrachloropropane, 1,1,1,2,3-pentachloropropane or 1,1,2,2,3-pentachloropropane, or a combination of at least two thereof, wherein typical but non-limiting combinations are a combination of 1,2,3-trichloropropane and 1,1,2,3-tetrachloropropane, a combination of 1,2,2,3-tetrachloropropane and 1,1,2,3-tetrachloropropane, a combination of 1,2,3-trichloropropane and 1,2,2,3-tetrachloropropane, a combination of 1,2,3-trichloropropane and 1,1,2,2,3-pentachloropropane, and a combination of 1,1,1,2,3-pentachloropropane and 1,1,2,2,3-pentachloropropane.

[0021] Preferably, the porosity of the filler is 40-90%, for example, it may be 40%, 46%, 52%, 57%, 63%, 68%, 74%, 79%, 85% or 90%.

[0022] The porosity of the filler of the present invention is preferably within the above range to form a droplet size within an ideal range and have a better reaction effect.

[0023] Preferably, the filler is made of foam ceramic.

[0024] Preferably, the thickness of the droplet is 50 to 500 microns, for example, 50 microns, 100 microns, 150 microns, 200 microns, 250 microns, 300 microns, 350 microns, 400 microns, 450 microns or 500 microns.

[0025] The present invention preferably controls the size of the droplets within the above range. When the size of the droplets is greater than 500 microns, the two-phase mixing effect will be weakened, affecting the reaction rate and incomplete conversion of polychloropropanes. When the size of the droplets is less than 50 microns, the two-phase mixing effect is too strong, which will lead to problems such as overreaction and increased side reactions. At the same time, too strong a mixing effect will affect the water-oil stratification efficiency of the subsequent reaction liquid.

[0026] Preferably, the feed molar ratio of liquid caustic soda to polychloropropane in the dehydrochlorination reaction is 0.5 to 2.0:1, for example, it can be 0.5:1, 0.7:1, 0.9:1, 1:1, 1.2:1, 1.4:1, 1.5:1, 1.7:1, 1.9:1 or 2.0:1, and is preferably 1.0 to 1.2:1.

[0027] Preferably, the rotation speed of the supergravity reaction device in the dehydrochlorination reaction is 200-3000 r / min, for example, it can be 200 r / min, 510 r / min, 820 r / min, 1130 r / min, 1445 r / min, 1750 r / min, 2060 r / min, 2370 r / min, 2680 r / min or 3000 r / min, etc., preferably 800-1200 r / min.

[0028] The present invention preferably controls the rotation speed of the supergravity reaction device within the above range, which has a better reaction effect.

[0029] Preferably, the temperature of the dehydrochlorination reaction is 0-80°C, for example, 0°C, 9°C, 18°C, 27°C, 36°C, 45°C, 54°C, 63°C, 72°C or 80°C, etc., preferably 40-60°C.

[0030] Preferably, during the dehydrochlorination reaction, the average residence time of the material in the supergravity reactor device is 30 min to 300 min, for example, it can be 30 min, 60 min, 90 min, 120 min, 150 min, 180 min, 210 min, 240 min, 270 min or 300 min, etc., preferably 60 to 120 min.

[0031] The present invention preferably controls the average residence time of the material in the supergravity reactor device within the above range, which has a better reaction effect.

[0032] Preferably, after the dehydrochlorination reaction, the method further comprises: allowing the reaction material to stand for oil-water separation, and obtaining a polychlorinated propene product in the oil layer.

[0033] In a second aspect, the present invention provides an apparatus for continuously dehydrochlorinating polychloropropane to prepare polychlorinated propenes, wherein the apparatus is capable of operating the method for continuously dehydrochlorinating polychloropropane to prepare polychlorinated propenes as described in the first aspect.

[0034] Preferably, the device includes a supergravity reactor; the supergravity reactor includes a rotation system, the rotation system includes a rotatable cavity, and a driving component connected to the rotatable cavity, used to drive the rotatable cavity to rotate; a filling area for placing fillers is provided in the rotatable cavity.

[0035] The device provided in the second aspect of the present invention can realize the efficient conversion of polychloropropanes into polychlorinated propenes, has excellent performance and broad application prospects.

[0036] Preferably, the driving component comprises a rotating shaft and a motor connected to the rotating shaft. The rotating shaft is fixedly connected to the rotatable cavity;

[0037] Preferably, the supergravity reactor further comprises a liquid-phase feeding component arranged on one side of the rotatable cavity.

[0038] Preferably, the liquid phase feeding component comprises a first pipe member extending into the rotatable cavity, and a second pipe member disposed at one end of the first pipe member and perpendicular to the first pipe member. A liquid phase distributor is disposed at one end of the first pipe member extending into the rotatable cavity.

[0039] The preferred liquid phase feeding component of the present invention comprises a first pipe and a second pipe, wherein liquid-liquid two-phase feeding is performed, and two groups of liquid phase feeding pipes can respectively feed liquid alkali and polychloropropane simultaneously, and a liquid phase distributor is provided to improve the dispersion effect of the liquid phase.

[0040] Preferably, the supergravity reactor further comprises a liquid phase outlet arranged at the bottom of the rotatable cavity.

[0041] Preferably, the supergravity reactor comprises a supplementary inlet arranged at the top of the rotatable cavity, and a supplementary outlet arranged at one side of the rotatable cavity.

[0042] The supplementary inlet and the supplementary outlet of the present invention can be used as a gas phase inlet and a gas phase outlet for other situations where there is a need.

[0043] Preferably, the supergravity reactor further comprises a heat exchange interlayer outside the packing area for introducing a heat exchange medium.

[0044] The design of the heat exchange interlayer in the present invention can keep the reaction process warm and has a better reaction effect.

[0045] Preferably, a heat exchange medium inlet and a heat exchange medium outlet are provided on the heat exchange interlayer.

[0046] Preferably, the supergravity reactor further comprises a heat-insulating interlayer on the outside of the heat-exchange interlayer. The design of the heat-insulating interlayer can further improve the heat-insulating effect.

[0047] Compared with the prior art, the present invention has at least the following beneficial effects:

[0048] The method for preparing polychloropropene by continuous dehydrochlorination of polychloropropane provided by the present invention and the method thereof utilize the characteristics of a supergravity reactor, promote the mixing of oil-water two phases, avoid the phase transfer catalyst commonly used in liquid phase dehydrochlorination, and do not need to use other transition metal catalysts to promote the reaction, thereby reducing the reaction cost. At the same time, due to the excellent mass transfer and heat transfer efficiency of the reactor, the reaction conditions are milder, the reaction liquid can be directly separated after entering the oil-water separator, no emulsified layer and tar exist, the yield of the target product and the product quality are significantly improved, wherein under the preferred conditions, the yield of polychloropropene reaches more than 96.83%, and the conversion rate of polychloropropane is more than 99%, and the application prospect is broad. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic diagram of the device for continuously dehydrochlorinating polychloropropane to prepare polychloropropenes provided in Example 1 of the present invention.

[0050] In the figure: 1. first pipe fitting; 2. second pipe fitting; 3. liquid phase distributor; 4. packing area; 5. liquid phase outlet; 6. supplementary inlet; 7. supplementary outlet; 8. rotating shaft; 9. motor; 10. thermal insulation interlayer; 11. heat exchange medium inlet; 12. heat exchange medium outlet. DETAILED DESCRIPTION

[0051] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0052] It should be understood that, in the description of the present invention, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0053] It should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0054] Those skilled in the art should understand that the present invention necessarily includes necessary pipelines, conventional valves and general pump equipment for realizing a complete process, but the above content does not belong to the main inventive point of the present invention. Those skilled in the art can add layouts on their own based on the process flow and equipment structure selection, and the present invention does not make special requirements and specific limitations on this.

[0055] As a specific embodiment of the present invention, a device for continuously dehydrochlorinating polychloropropane to prepare polychloropropene is provided. Figure 1 The device includes a supergravity reactor; the supergravity reactor includes a rotation system, the rotation system includes a rotatable cavity, and a driving component connected to the rotatable cavity, used to drive the rotatable cavity to rotate; a filling area for placing fillers is provided in the rotatable cavity.

[0056] The driving component includes a rotating shaft and a motor connected to the rotating shaft; the rotating shaft is fixedly connected to the rotatable cavity; the supergravity reactor also includes a liquid-phase feeding component arranged on one side of the rotatable cavity; the liquid-phase feeding component includes a first pipe fitting extending into the interior of the rotatable cavity, and a second pipe fitting arranged at one end of the first pipe fitting and perpendicular to the first pipe fitting; a liquid-phase distributor is arranged at one end of the first pipe fitting extending into the interior of the rotatable cavity.

[0057] The high-gravity reactor also includes a liquid phase outlet arranged at the bottom of the rotatable cavity; the high-gravity reactor includes a supplementary inlet arranged at the top of the rotatable cavity, and a supplementary outlet arranged on one side of the rotatable cavity; on the outside of the packing area, the high-gravity reactor also includes a heat exchange interlayer for passing heat exchange medium; the heat exchange interlayer is provided with a heat exchange medium inlet and a heat exchange medium outlet; on the outside of the heat exchange interlayer, the high-gravity reactor also includes a thermal insulation interlayer.

[0058] Example 1

[0059] This embodiment provides a method for continuously dehydrochlorinating polychloropropane to prepare polychloropropenes. The method is carried out using the device provided in the above specific embodiment. Specifically, the method comprises the following steps:

[0060] According to the feed molar ratio of liquid caustic soda to trichloropropane being 1.1:1, a sodium hydroxide solution with a concentration of 20wt.% is passed into a filler (the filler is made of foam ceramic with a porosity of 45%) from a first pipe fitting, and 1,2,3-trichloropropane is passed into the filler from a second pipe fitting. The sodium hydroxide solution in the aqueous phase and the 1,2,3-trichloropropane in the oil phase rotate under supergravity conditions at a speed of 1000r / min, and droplets with a size of about 200 microns are formed after passing through the filler. A dehydrochlorination reaction is simultaneously carried out at 40°C, and the average residence time of the material in the supergravity reactor device is 90min, so as to obtain a reaction material containing dichloropropylene; the reaction material is simply allowed to stand for oil-water separation, and a dichloropropylene product is obtained in the oil layer.

[0061] Example 2

[0062] This embodiment provides a method for continuously dehydrochlorinating polychloropropane to prepare polychloropropenes. The method is carried out using the device provided in the above specific embodiment. Specifically, the method comprises the following steps:

[0063] According to the feed molar ratio of liquid caustic soda to trichloropropane being 1.1:1, a sodium hydroxide solution with a concentration of 25wt.% is passed into a filler (the filler is made of foam ceramic with a porosity of 55%) from a first pipe fitting, and 1,2,3-trichloropropane is passed into the filler from a second pipe fitting. The sodium hydroxide solution in the aqueous phase and the 1,2,3-trichloropropane in the oil phase rotate under supergravity conditions at a speed of 1200r / min, and droplets with a size of 150 microns are formed after passing through the filler. A dehydrochlorination reaction is simultaneously carried out at 60°C, and the average residence time of the material in the supergravity reactor device is 90min, so as to obtain a reaction material containing dichloropropene; the reaction material is simply allowed to stand for oil-water separation, and a dichloropropene product is obtained in the oil layer.

[0064] Example 3

[0065] This embodiment provides a method for continuously dehydrochlorinating polychloropropane to prepare polychloropropenes. The method is carried out using the device provided in the above specific embodiment. Specifically, the method comprises the following steps:

[0066] According to the feed molar ratio of liquid caustic soda to trichloropropane being 1.2:1, a sodium hydroxide solution with a concentration of 32wt.% is passed into a filler (the filler is made of foam ceramic with a porosity of 90%) from a first pipe fitting, and 1,2,3-trichloropropane is passed into the filler from a second pipe fitting. The sodium hydroxide solution in the aqueous phase and the 1,2,3-trichloropropane in the oil phase rotate under supergravity conditions at a speed of 2000r / min, and droplets with a size of about 50 microns are formed after passing through the filler. A dehydrochlorination reaction is simultaneously carried out at 80°C, and the average residence time of the material in the supergravity reactor device is 120min, so as to obtain a reaction material containing dichloropropene; the reaction material is simply allowed to stand for oil-water separation, and a dichloropropene product is obtained in the oil layer.

[0067] Example 4

[0068] This embodiment provides a method for continuously dehydrochlorinating polychloropropane to prepare polychloropropenes. The method is carried out using the device provided in the above specific embodiment. Specifically, the method comprises the following steps:

[0069] According to the feed molar ratio of liquid caustic soda to tetrachloropropane being 1.1:1, a sodium hydroxide solution with a concentration of 10 wt.% is passed through a filler (the filler is made of foam ceramics with a porosity of 40%) from a first pipe fitting, and 1,1,2,3-tetrachloropropane is passed through a second pipe fitting into the filler. The sodium hydroxide solution in the aqueous phase and the 1,1,2,3-tetrachloropropane in the oil phase rotate under supergravity conditions at a speed of 1000 r / min, and droplets with a size of about 200 microns are formed after passing through the filler. A dehydrochlorination reaction is simultaneously carried out at 40° C. The average residence time of the material in the supergravity reactor device is 90 minutes, and a post-reaction material containing trichloropropene is obtained. The post-reaction material is simply allowed to stand for oil-water separation, and a trichloropropene product is obtained in the oil layer.

[0070] Example 5

[0071] This embodiment provides a method for continuously dehydrochlorinating polychloropropane to prepare polychloropropenes. The method is carried out using the device provided in the above specific embodiment. Specifically, the method comprises the following steps:

[0072] According to the feed molar ratio of liquid caustic soda to tetrachloropropane being 1.1:1, a sodium hydroxide solution with a concentration of 15wt.% is passed through a filler (the filler is made of foam ceramic with a porosity of 58%) from a first pipe fitting, and 1,1,2,3-tetrachloropropane is passed through a second pipe fitting into the filler. The sodium hydroxide solution in the aqueous phase and the 1,1,2,3-tetrachloropropane in the oil phase rotate under supergravity conditions at a speed of 1200r / min, and droplets with a size of about 150 microns are formed after passing through the filler. A dehydrochlorination reaction is simultaneously carried out at 60°C, and the average residence time of the material in the supergravity reactor device is 90min, so as to obtain a post-reaction material containing trichloropropene; the post-reaction material is simply allowed to stand for oil-water separation, and a trichloropropene product is obtained in the oil layer.

[0073] Example 6

[0074] This embodiment provides a method for continuously dehydrochlorinating polychloropropane to prepare polychloropropenes. The method is carried out using the device provided in the above specific embodiment. Specifically, the method comprises the following steps:

[0075] According to the feed molar ratio of liquid caustic soda to tetrachloropropane being 1.2:1, a sodium hydroxide solution with a concentration of 30wt.% is passed through a filler (the filler is made of foam ceramic with a porosity of 88%) from a first pipe fitting, and 1,1,2,3-tetrachloropropane is passed through a second pipe fitting into the filler. The aqueous sodium hydroxide solution and the oily 1,1,2,3-tetrachloropropane rotate under supergravity conditions at a speed of 2000r / min, and droplets with a size of about 50 microns are formed after passing through the filler. A dehydrochlorination reaction is simultaneously carried out at 80°C, and the average residence time of the material in the supergravity reactor device is 120min, so as to obtain a post-reaction material containing trichloropropene. The post-reaction material is simply allowed to stand for oil-water separation, and a trichloropropene product is obtained in the oil layer.

[0076] Example 7

[0077] This embodiment provides a method for continuously dehydrochlorinating polychloropropane to prepare polychloropropenes. The method is carried out using the device provided in the above specific embodiment. Specifically, the method comprises the following steps:

[0078] According to the feed molar ratio of liquid caustic soda to pentachloropropane being 1.15:1, a sodium hydroxide solution with a concentration of 12 wt.% is passed into a filler (the filler is made of foam ceramic with a porosity of 42%) from a first pipe fitting, and pentachloropropane is passed into the filler from a second pipe fitting. The sodium hydroxide solution in the aqueous phase and the pentachloropropane in the oil phase rotate under supergravity conditions at a speed of 1000 r / min, and droplets with a size of about 200 microns are formed after passing through the filler. A dehydrochlorination reaction is simultaneously carried out at 40° C., and the average residence time of the material in the supergravity reactor device is 90 minutes, so as to obtain a post-reaction material containing tetrachloropropene; the post-reaction material is simply allowed to stand for oil-water separation, and a tetrachloropropene product is obtained in the oil layer.

[0079] Example 8

[0080] This embodiment provides a method for continuously dehydrochlorinating polychloropropane to prepare polychloropropenes. The method is carried out using the device provided in the above specific embodiment. Specifically, the method comprises the following steps:

[0081] According to the feed molar ratio of liquid caustic soda to pentachloropropane being 1.1:1, a sodium hydroxide solution with a concentration of 15wt.% is passed into a filler (the filler is made of foam ceramic with a porosity of 56%) from a first pipe fitting, and pentachloropropane is passed into the filler from a second pipe fitting. The sodium hydroxide solution in the aqueous phase and the pentachloropropane in the oil phase rotate under supergravity conditions at a speed of 1200r / min, and droplets with a size of about 150 microns are formed after passing through the filler. A dehydrochlorination reaction is simultaneously carried out at 60°C, and the average residence time of the material in the supergravity reactor device is 90min, thereby obtaining a post-reaction material containing tetrachloropropene; the post-reaction material is simply allowed to stand for oil-water separation, and a tetrachloropropene product is obtained in the oil layer.

[0082] Example 9

[0083] This embodiment provides a method for continuously dehydrochlorinating polychloropropane to prepare polychloropropenes. The method is carried out using the device provided in the above specific embodiment. Specifically, the method comprises the following steps:

[0084] According to the feed molar ratio of liquid caustic soda to pentachloropropane being 1.21:1, a sodium hydroxide solution with a concentration of 28 wt.% is passed through a filler (the filler is made of foam ceramic with a porosity of 89%) from a first pipe fitting, and pentachloropropane is passed through a second pipe fitting into the filler. The sodium hydroxide solution in the aqueous phase and the pentachloropropane in the oil phase rotate under supergravity conditions at a speed of 2000 r / min, and droplets with a size of about 50 microns are formed after passing through the filler, and a dehydrochlorination reaction is simultaneously carried out at 80° C. The average residence time of the material in the supergravity reactor device is 120 min, and a reaction material containing tetrachloropropene is obtained; the reaction material is simply allowed to stand for oil-water separation, and a tetrachloropropene product is obtained in the oil layer.

[0085] The reaction liquid of the oil layer is weighed and tested at the same time to calculate the yield, conversion rate and selectivity of the product.

[0086] The results of Examples 1 to 9 are shown in Table 1.

[0087] Table 1

[0088]

[0089]

[0090] Example 10

[0091] This embodiment provides a method for continuously dehydrochlorinating polychloropropane to prepare polychloropropene. The method is the same as that of Embodiment 1 except that the rotation speed of the supergravity reaction device is 3500 r / min, and will not be described in detail here.

[0092] Embodiment 11

[0093] This embodiment provides a method for continuously dehydrochlorinating polychloropropane to prepare polychloropropene. The method is the same as that of Embodiment 1 except that the rotation speed of the supergravity reaction device is 150 r / min, and the details are not described again.

[0094] Example 12

[0095] This embodiment provides a method for continuously dehydrochlorinating polychloropropane to prepare polychloropropene. The method is the same as that of Example 1 except that the average residence time of the material in the supergravity reactor device is 400 minutes, and will not be described in detail here.

[0096] Example 13

[0097] This embodiment provides a method for continuously dehydrochlorinating polychloropropane to prepare polychloropropene. The method is the same as that of Embodiment 1 except that the porosity of the filler is relatively low, only 25%, and will not be described in detail here.

[0098] Embodiment 14

[0099] This embodiment provides a method for continuously dehydrochlorinating polychloropropane to prepare polychloropropene. The method is the same as that of embodiment 1 except that the porosity of the filler is relatively high, up to 95%, and will not be described in detail here.

[0100] Comparative Example 1

[0101] This comparative example provides a method for preparing polychlorinated propenes by continuous dehydrochlorination of polychlorinated propanes. The method is the same as Example 1 except that no filler is added, and will not be described in detail here.

[0102] Comparative Example 2

[0103] This comparative example provides a method for preparing polychlorinated propenes by dehydrochlorinating polychlorinated propane. The method is the same as Example 1 except that a simple stirred reactor is used, and details thereof will not be repeated here.

[0104] Specifically, according to the feed molar ratio of liquid alkali to trichloropropane being 1.1:1, a sodium hydroxide solution with a concentration of 20wt.% and 1,2,3-trichloropropane are introduced into a reactor from the top, and a stirring paddle is turned on for stirring at a speed of 300r / min, and a dehydrochlorination reaction is simultaneously carried out at 40°C, and the average residence time of the material in the reactor is 90min to obtain a post-reaction material; the post-reaction material is simply allowed to stand for oil-water separation, and a dichloropropylene product is obtained in the oil layer.

[0105] The substances used in the above examples and comparative examples are as follows: 1,2,3-trichloropropane: GC normalized content 96.5%; 1,1,2,3-tetrachloropropane: GC normalized content 99.5%; pentachloropropane: GC normalized content 1,1,1,2,3-pentachloropropane 65.0%, 1,1,2,2,3-pentachloropropane 34.5%. The liquid alkali used is purchased NaOH aqueous solution.

[0106] The test results of the above embodiments and comparative examples are shown in Table 2.

[0107] Table 2

[0108]

[0109] From Table 1, we can see the following points:

[0110] (1) It can be seen from Examples 1 to 9 that the method for continuous dehydrochlorination of polychloropropane to prepare polychloropropene provided by the present invention has the effect of achieving high efficiency and high selectivity of polychloropropene conversion without a catalyst, the conversion rate of polychloropropane is above 99.21%, the selectivity of the corresponding polychloropropene is above 96.84%, and the yield of polychloropropene is above 96.83%;

[0111] (2) Combining Example 1 and Examples 10 to 11, it can be seen that the high-gravity speed of 1000 r / min used in Example 1 is compared with 3500 r / min and 150 r / min used in Examples 10 to 11, respectively. In Example 1, the conversion rate of dichloropropane is 99.21%, the selectivity of dichloropropylene is 99.25%, and the yield is 98.47%, while the yields of dichloropropane in Examples 10 to 11 are only 94.76% and 68.37%, respectively. In Example 10, the speed is fast and the droplet size is small, but the side reactions increase and the yield decreases. In Example 11, the speed is slow, the droplet size is small, and the conversion rate is low, which ultimately leads to a decrease in the yield. This shows that the present invention can further improve the yield of polychloropropylene by preferably using a suitable high-gravity speed;

[0112] (3) It can be seen from Example 1 and Example 12 that, when the residence time of 90 min is used in Example 1, compared with 400 min used in Example 12, the conversion rate of dichloropropane in Example 1 is 99.21%, the selectivity of dichloropropylene is 99.25%, and the yield is 98.47%, while the yield of dichloropropane in Example 12 is only 86.43%. This is because the extension of the residence time leads to an increase in side reactions, which reduces the reaction yield. This shows that the present invention can further improve the yield of polychloropropylene by preferably adopting a suitable residence time;

[0113] (4) It can be seen from the combination of Example 1 and Examples 13-14 that the filler with a porosity of 55% used in Example 1 is compared with the fillers with a porosity of 25% and 95% used in Examples 13-14, respectively. In Example 1, the conversion rate of dichloropropane is 99.21%, the selectivity of dichloropropylene is 99.25%, and the yield is 98.47%, while the yields of dichloropropane in Examples 13-14 are only 95.77% and 97.40%, respectively. In Example 14, the size of the droplets is small, but the side reactions increase and the yield decreases. In Example 13, the porosity is large, the size of the droplets increases, and the conversion rate decreases. This shows that the present invention can further improve the yield of polychloropropylene by preferably using a suitable filler porosity;

[0114] (3) It can be seen from Example 1 and Comparative Examples 1-2 that in Comparative Example 1, no filler is added, the conversion rate of the reaction is extremely low, and the final yield of dichloropropylene is only 36.59%. In Comparative Example 2, a traditional reactor is used, and the overall conversion rate is even lower, only 27.44%, and the final yield of dichloropropylene is only 27.25%, which is much lower than that in Example 1. This shows that the present invention preferably uses an ultra-gravity reactor to carry out the reaction and selects suitable fillers to carry out the reaction, which significantly improves the conversion rate of the reaction and the yield of polychloropropylene, and has broad application prospects.

[0115] The present invention illustrates the detailed features of the present invention through the above embodiments, but the present invention is not limited to the above detailed features, that is, it does not mean that the present invention must rely on the above detailed features to be implemented. Those skilled in the art should understand that any improvement to the present invention, equivalent replacement of the technical features selected by the present invention, addition of auxiliary technical features, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing polychlorinated propenes by continuous dehydrochlorination of polychlorinated propanes, characterized in that: The method comprises the following steps: Liquid alkali and polychloropropane are introduced into the filler, and droplets are formed on the surface of the filler under supergravity conditions and dehydrochlorination reaction is carried out simultaneously to obtain a reaction material containing polychloropropene.

2. The method according to claim 1, characterized in that The liquid alkali comprises a NaOH aqueous solution; Preferably, the mass fraction of alkali in the liquid alkali is 10 to 32 wt.%.

3. The method according to claim 1 or 2, characterized in that: The polychloropropane includes any one of 1,2,3-trichloropropane, 1,1,2,3-tetrachloropropane, 1,2,2,3-tetrachloropropane, 1,1,1,2,3-pentachloropropane or 1,1,2,2,3-pentachloropropane, or a combination of at least two thereof; Preferably, the porosity of the filler is 40-90%; Preferably, the size of the droplets is 50 to 500 microns.

4. The method according to any one of claims 1 to 3, characterized in that: The feed molar ratio of liquid caustic soda to polychloropropane in the dehydrochlorination reaction is 0.5 to 2.0:1, preferably 1.0 to 1.2:

1.

5. The method according to any one of claims 1 to 4, characterized in that: The rotation speed of the supergravity reaction device in the dehydrochlorination reaction is 200 to 3000 r / min, preferably 800 to 1200 r / min; Preferably, the temperature of the dehydrochlorination reaction is 0 to 80°C, preferably 40 to 60°C; Preferably, during the dehydrochlorination reaction, the average residence time of the material in the supergravity reactor device is 30 min to 300 min, preferably 60 to 120 min.

6. The method according to any one of claims 1 to 5, characterized in that: After the dehydrochlorination reaction, the method further comprises: allowing the reaction material to stand for oil-water separation, and obtaining polychlorinated propene products in the oil layer.

7. A device for continuously dehydrochlorinating polychloropropane to prepare polychloropropylene, characterized in that: The device is capable of operating the method for continuously dehydrochlorinating polychloropropane to prepare polychloropropenes as described in any one of claims 1 to 6.

8. The device according to claim 7, characterized in that The device includes a high gravity reactor; The supergravity reactor comprises a rotation system, wherein the rotation system comprises a rotatable cavity and a driving component connected to the rotatable cavity, and is used to drive the rotatable cavity to rotate; A filling area for placing fillers is arranged in the rotatable cavity.

9. The device according to claim 8, characterized in that The driving component includes a rotating shaft and a motor connected to the rotating shaft; the rotating shaft is fixedly connected to the rotatable cavity; Preferably, the supergravity reactor further comprises a liquid-phase feeding component arranged on one side of the rotatable cavity; Preferably, the liquid-phase feeding component includes a first pipe extending into the rotatable cavity, and a second pipe arranged at one end of the first pipe and perpendicular to the first pipe; a liquid-phase distributor is arranged at one end of the first pipe extending into the rotatable cavity.

10. The device according to claim 8 or 9, characterized in that The supergravity reactor also includes a liquid phase outlet disposed at the bottom of the rotatable cavity; Preferably, the supergravity reactor further comprises a heat exchange interlayer outside the packing area for introducing a heat exchange medium; Preferably, the heat exchange interlayer is provided with a heat exchange medium inlet and a heat exchange medium outlet; Preferably, the supergravity reactor further includes a thermal insulation interlayer on the outside of the heat exchange interlayer.

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