A method for preparing 1,1,2,3-tetrachloropropene using microchannel reaction

Abstract

This invention provides a method for preparing 1,1,2,3-tetrachloropropene using a microchannel reaction. The method includes the following steps: (1) dichloropropene feedstock undergoes a first chlorination reaction in a microchannel reactor to obtain a first material containing tetrachloropropane; (2) the first material undergoes a first purification to obtain tetrachloropropane, and the tetrachloropropane undergoes a first dehydrochlorination reaction to obtain a second material containing trichloropropene; (3) the second material undergoes a second chlorination reaction in a microchannel reactor to obtain a third material containing pentachloropropane; (4) the third material undergoes a second dehydrochlorination reaction to obtain a fourth material containing tetrachloropropene; (5) the fourth material undergoes a photocatalytic isomerization reaction in a microchannel reactor to obtain 1,1,2,3-tetrachloropropene. The method provided by this invention can shorten the reaction time, significantly improve the reaction yield, and has good economic benefits and industrial application potential.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fine chemical technology, and particularly relates to a method for preparing 1,1,2,3-tetrachloropropene by using a micro-channel reaction. BACKGROUND

[0002] HFO-1234yf (2,3,3,3-tetrafluoropropene) and HFO-1234ze (E) (trans-1,3,3,3-tetrafluoropropene) are mainly used for the fourth generation refrigerant of vehicle air conditioner, and have low ODP (Ozone Depletion Potential) and low GWP (Global Warming Potential) characteristics. They can be prepared by using hexafluoropropylene and 1,1,2,3-tetrachloropropene as raw materials.

[0003] At present, the mature hexafluoropropylene process of HFO-1234yf is prepared by cracking dichloromonofluoromethane (freon) to prepare tetrafluoroethylene, and then performing electric cyclization to generate octafluorocyclobutane. The octafluorocyclobutane is mixed with tetrafluoroethylene and then sent into a cracking furnace to perform thermal cracking to generate hexafluoropropylene. Hydrogen is allowed to react with the hexafluoropropylene (HFP) to generate hexafluoropropane, and then a removal reaction is performed to generate pentafluoropropylene (HFO-1225ye). The generated pentafluoropropylene (HFO-1225ye) is also allowed to react with hydrogen to generate pentafluoropropane (HFO236ea), and then a removal reaction is performed to finally generate the product tetrafluoropropylene (HFO-1234yf). The production process is complex. The tetrachloropropene process is gas-phase synthesis of trifluoromonochloropropene (HCFO-1233xf) by using 1,1,2,3-tetrachloropropene (TCP). The trifluoromonochloropropene (HCFO-1233xf) is added with HF to generate tetrafluoromonochloropropane (HCFO-244bb), and the tetrafluoromonochloropropane is removed of HF to generate tetrafluoropropylene (HFO-1234yf). Compared with the hexafluoropropylene process, the production process and flow of the tetrachloropropene process are simple and more easy to realize industrialized production.

[0004] At present, 1,1,2,3-tetrachloropropene is mainly produced by using ethylene, carbon tetrachloride and trichloropropane as raw materials, and then performing multi-step chlorination, dehydrochlorination, rectification and water removal to generate the tetrachloropropene product. The process route is long, a large amount of waste salt is generated, and there is a great environmental protection pressure.

[0005] The prior art reports that 1,1,2,3-tetrachloropropene is synthesized from 1,1,1,3-tetrachloropropane as raw material. The raw material is subjected to dehydrochlorination reaction with 10% potassium hydroxide ethanol solution to obtain a mixture of 3,3,3-trichloropropene and 1,1,3-trichloropropene; 3,3,3-trichloropropene is chlorinated to obtain 1,1,1,2,3-pentachloropropane; 1,1,1,2,3-pentachloropropane is subjected to dehydrochlorination with potassium hydroxide ethanol to obtain a mixture of 2,3,3,3-tetrachloropropene and 1,1,2,3-tetrachloropropene; 2,3,3,3-tetrachloropropene and 1,1,2,3-tetrachloropropene are separated by distillation; 2,3,3,3-tetrachloropropene is isomerized in the presence of aluminum trichloride to obtain 1,1,2,3-tetrachloropropene with a yield of 51%. This method was one of the main methods for synthesizing 1,1,2,3-tetrachloropropene, but the synthesis process was complex, and the yield of the product was low (see "Part II. Synthesis and reactions of some 3:3:3-trihalogenopropenes", Fluoro-olefins. et al., Journal of the Chemical Society, pages 1953:3371-3378).

[0006] CN108033872A discloses a clean and environmentally friendly method for producing 1,1,2,3-tetrachloropropene. Under the premise of nitrogen pressure protection, carbon tetrachloride and chloroethylene are added to a first high-pressure reaction kettle, and a mixture is obtained by catalytic reaction with a catalyst and a catalyst promoter. The mixture is then poured into a second high-pressure reaction kettle, and the molar ratio of nitrogen to 1,1,1,3,3-pentachloropropane and nitrogen is controlled to obtain a tetrachloropropene mixture by catalytic reaction. Fe-FeCl3 is used as a catalyst in a third high-pressure reaction kettle, and the reaction temperature is controlled to obtain the product 1,1,2,3-tetrachloropropene. Using multiple high-pressure reaction kettles, 1,1,2,3,3-pentachloropropane and nitrogen are used as starting materials for continuous production. The process is complex, requires high equipment, and takes a long time.

[0007] US4650914A discloses a method for producing 1,1,1,2,3-pentachloropropane from ethylene and carbon tetrachloride as raw materials through multiple steps, then 1,1,1,2,3-pentachloropropane is subjected to dehydrochlorination with liquid alkali to obtain a mixture of 2,3,3,3-tetrachloropropene and 1,1,2,3-tetrachloropropene, then anhydrous ferric chloride is added as a catalyst to isomerize 2,3,3,3-tetrachloropropene into 1,1,2,3-tetrachloropropene product, or directly using anhydrous FeCl3 as a catalyst at a high temperature of 164°C to directly dehydrochlorinate and pyrolyze 1,1,1,2,3-pentachloropropane to obtain 1,1,2,3-tetrachloropropene product.

[0008] At present, different routes for synthesizing 1,1,2,3-tetrachloropropene all have the shortcomings of complex reaction process, low reaction rate, and many by-products; these methods have the problems of high requirement for equipment, high energy consumption, complex process route and post-treatment, etc.

[0009] Therefore, it is urgent to develop a new production method of 1,1,2,3-tetrachloropropene.

[0010] In order to improve the yield of 1,1,2,3-tetrachloropropene and reduce the reaction time, a new method for simply preparing 1,1,2,3-tetrachloropropene by using a multi-stage micro-channel reactor and taking cis-1,3-dichloropropene as a raw material is developed. The method utilizes the advantage of high mass transfer rate of the micro-channel, reduces the contact time of the raw material, efficiently controls the dechlorination rate, reduces the generation of by-products caused by excessive chlorination or excessive dechlorination, obviously reduces the reaction time, reduces the production energy consumption, simplifies the experimental steps, and therefore has good economic benefits and industrial application potential. SUMMARY

[0011] In view of the problems in the prior art, in order to improve the yield of 1,1,2,3-tetrachloropropene and reduce the reaction time, the application provides a method for preparing 1,1,2,3-tetrachloropropene by using a micro-channel reaction, which simply prepares 1,1,2,3-tetrachloropropene by using a micro-channel reactor and taking cis-1,3-dichloropropene as a raw material. The method can reduce the contact time of the raw material, efficiently control the dechlorination rate, reduce the generation of by-products caused by excessive chlorination or excessive dechlorination, obviously reduce the reaction time, reduce the production energy consumption, simplify the operation steps, and therefore has good economic benefits and industrial application potential.

[0012] To achieve this purpose, the application adopts the following technical solutions:

[0013] In a first aspect, the application provides a method for preparing 1,1,2,3-tetrachloropropene by using a micro-channel reaction, which comprises the following steps:

[0014] (1) dichloropropene raw material is subjected to a first chlorination reaction in a micro-channel reactor to obtain a first material containing tetrachloropropane;

[0015] (2) the first material is subjected to a first purification to obtain tetrachloropropane, and the tetrachloropropane is subjected to a first dehydrochlorination reaction to obtain a second material containing trichloropropene;

[0016] (3) the second material is subjected to a second chlorination reaction in a micro-channel reactor to obtain a third material containing pentachloropropane;

[0017] (4) the third material is subjected to a second dehydrochlorination reaction to obtain a fourth material containing tetrachloropropene;

[0018] (5) the fourth material is subjected to a photo-catalytic isomerization reaction in a micro-channel reactor to obtain 1,1,2,3-tetrachloropropene.

[0019] The method for preparing 1,1,2,3-tetrachloropropene by using a micro-channel reaction provided by the present application adopts dichloropropene as the most original reactant, and obtains tetrachloropropene through two chlorination reactions and two dehydrochlorination reactions, and then obtains 1,1,2,3-tetrachloropropene through a photo-catalytic isomerization reaction. The reaction process has the advantages of short process and convenient operation, and the first chlorination reaction, the second chlorination reaction and the photo-catalytic isomerization reaction are carried out by using a micro-channel reactor, which can significantly reduce the reaction time and obtain an ultra-high reaction yield, thereby providing a good basis for the purification of tetrachloropropene, and finally significantly improving the yield and purity of 1,1,2,3-tetrachloropropene.

[0020] The first material containing tetrachloropropane prepared in step (1) in the present application also contains by-products such as trichloropropane, trichloropropene or pentachloropropane, and the purity of tetrachloropropane can be improved after the first purification, thereby avoiding the generation of by-products that are difficult to separate in the subsequent second dehydrochlorination reaction, and causing the subsequent 1,1,2,3-tetrachloropropene purification to be difficult.

[0021] Preferably, the first chlorination reaction in step (1) includes a first stage and a second stage.

[0022] Preferably, the first chlorination reaction is carried out in two stages, and the temperature of the first stage is lower than that of the second stage. At the front end of the micro-channel reactor, the concentration of the reactant is high, and the reaction has a high heat effect. A lower reaction temperature can better avoid the generation of by-products such as trichloropropane, trichloropropene or pentachloropropane, and facilitate the subsequent first purification of the first material containing tetrachloropropane. Slightly increasing the reaction temperature in the second stage can improve the conversion rate of the reactant with a lower concentration in the later stage of the reaction. The combination of the temperatures of the two stages finally improves the yield of tetrachloropropane.

[0023] Preferably, the temperature of the first stage in the first chlorination reaction is 40-50°C, for example, it can be 40°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C or 50°C, but is not limited to the listed values, and other values not listed in this range are also applicable.

[0024] Preferably, the temperature of the second stage in the first chlorination reaction is 55-65°C, for example, it can be 55°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C or 65°C, but is not limited to the listed values, and other values not listed in this range are also applicable.

[0025] Preferably, the total residence time of the first chlorination reaction in the microchannel reactor is 55-75 s, for example, it can be 55 s, 58 s, 60 s, 62 s, 64 s, 67 s, 69 s, 71 s, 73 s, 75 s, or the like, but not limited to the listed values, and other values not listed in this range are also applicable.

[0026] Preferably, the ratio of the residence time of the first stage to the second stage in the first chlorination reaction is 2-4:1, for example, it can be 2:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.8:1, 3.0:1, 3.5:1, or 4.0:1, or the like, but not limited to the listed values, and other values not listed in this range are also applicable.

[0027] It is worth noting that the ratio of the residence time of the two stages in the present application is matched with the temperature of the two stages, and the two process parameters cooperate to better improve the yield of tetra-chloropropane.

[0028] Preferably, the molar ratio of chlorine gas to dichloropropene raw material in the first chlorination reaction in step (1) is 1.01-1.04:1, for example, it can be 1.01:1, 1.02:1, 1.03:1, or 1.04:1, or the like, but not limited to the listed values, and other values not listed in this range are also applicable.

[0029] Using a microchannel reactor for the reaction, chlorine gas does not need to be excessive, and only a molar ratio of 1.01-1.04:1 is needed to achieve a high conversion rate of dichloropropene raw material.

[0030] Preferably, the dichloropropene raw material includes cis-dichloropropene.

[0031] Preferably, the purity of cis-dichloropropene in the dichloropropene raw material is ≥98%, for example, it can be 98%, 98.2%, 98.3%, 98.4%, 98.5%, 98.8%, or 99%, or the like, but not limited to the listed values, and other values not listed in this range are also applicable.

[0032] Preferably, the dichloropropene raw material also includes trans-dichloropropene and 3,3-dichloropropene.

[0033] Preferably, the first purification method includes first distillation.

[0034] Preferably, the pressure of the first distillation is 50-100 mmHg, for example, it can be 50 mmHg, 55 mmHg, 60 mmHg, 65 mmHg, 70 mmHg, 75 mmHg, 80 mmHg, 85 mmHg, 95 mmHg, or 100 mmHg, or the like, but not limited to the listed values, and other values not listed in this range are also applicable.

[0035] Preferably, the reflux ratio of the first distillation is 3-5:1, for example, it can be 3:1, 3.3:1, 3.5:1, 3.7:1, 3.9:1, 4.2:1, 4.4:1, 4.6:1, 4.8:1 or 5:1, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0036] Preferably, the temperature of the first distillation is 60-120℃, for example, it can be 60℃, 65℃, 70℃, 80℃, 90℃, 100℃, 110℃ or 120℃, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0037] Preferably, the purity of the tetra-chloropropane is ≥99.9wt%, for example, it can be 99.91wt%, 99.92wt%, 99.93wt%, 99.94wt%, 99.95wt%, 99.96wt% or 99.97wt%, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0038] Preferably, the first dehydrochlorination reaction in step (2) comprises: mixing a first phase transfer catalyst and the tetra-chloropropane, adding alkali liquor dropwise at a first reaction temperature, and performing the first dehydrochlorination reaction.

[0039] Preferably, the first phase transfer catalyst comprises any one or a combination of at least two of polyethylene glycol, benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride or hexamethylene-1-n-hexyldimethyl-6-octadecyldimethylammonium bromide, wherein a typical but non-limiting combination is a combination of polyethylene glycol and benzyltriethylammonium chloride, a combination of tetrabutylammonium bromide and benzyltriethylammonium chloride, a combination of polyethylene glycol and tetrabutylammonium bromide, a combination of tetrabutylammonium hydrogen sulfate and hexamethylene-1-n-hexyldimethyl-6-octadecyldimethylammonium bromide, preferably hexamethylene-1-n-hexyldimethyl-6-octadecyldimethylammonium bromide.

[0040] The present application has better selectivity and yield by using hexamethylene-1-n-hexyldimethyl-6-octadecyldimethylammonium bromide as the phase transfer catalyst.

[0041] Preferably, the mass ratio of the first phase transfer catalyst to tetra-chloropropane is 2-4:1000, for example, it can be 2:1000, 2.3:1000, 2.5:1000, 2.7:1000, 2.9:1000, 3.2:1000, 3.4:1000, 3.6:1000, 3.8:1000 or 4:1000, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0042] Preferably, the first reaction temperature is 55-65℃, for example, it can be 55℃, 57℃, 58℃, 59℃, 60℃, 61℃, 62℃, 63℃, 64℃ or 65℃, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0043] Preferably, the alkali solution in the first dehydrochlorination reaction includes sodium hydroxide solution.

[0044] Preferably, the concentration of the alkali solution in the first dehydrochlorination reaction is 15-30wt%, for example, it can be 15wt%, 17wt%, 19wt%, 20wt%, 22wt%, 24wt%, 25wt%, 27wt%, 29wt% or 30wt%, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0045] Preferably, the molar ratio of the amount of alkali solution to tetra-chloropropane in the first dehydrochlorination reaction is 1.005-1.030:1, for example, it can be 1.005:1, 1.006:1, 1.008:1, 1.009:1, 1.010:1, 1.011:1, 1.015:1, 1.020:1, 1.025:1, 1.028:1 or 1.030:1, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0046] Preferably, the tail gas generated in the first chlorination reaction is absorbed by alkali.

[0047] Preferably, the dropping time of the alkali solution in the first dehydrochlorination reaction is 1-2h, for example, it can be 1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.8h, 1.9h or 2.0h, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0048] Preferably, after the first dehydrochlorination reaction in step (2), the obtained reaction solution is sequentially adjusted to neutral pH and left to separate into layers to obtain a second material containing trichloropropylene.

[0049] Preferably, the adjusting agent for adjusting the pH to neutral is an acid.

[0050] Preferably, the acid comprises hydrochloric acid.

[0051] Preferably, the concentration of the hydrochloric acid is 10-25wt%, for example, it can be 10wt%, 12wt%, 14wt%, 15wt%, 17wt%, 19wt%, 20wt%, 22wt%, 24wt% or 25wt%, etc., but is not limited to the listed values, and other values not listed in this range are also applicable.

[0052] Preferably, the second chlorination reaction in step (3) comprises a first stage and a second stage.

[0053] Preferably, the second chlorination reaction is carried out in two stages, wherein the temperature of the first stage is lower than that of the second stage, and the concentration of the reactant is high at the front end of the micro-channel reactor, and a higher heat effect of the reaction can be better avoided by using a lower reaction temperature to avoid the production of by-products; slightly increasing the reaction temperature in the second stage can improve the conversion rate of the reactant with lower concentration in the later stage of the reaction, and the cooperation of the temperatures of the two stages ultimately improves the yield of pentachloropropane.

[0054] Preferably, the temperature of the first stage in the second chlorination reaction is 40-50℃, for example, it can be 40℃, 42℃, 43℃, 44℃, 45℃, 46℃, 47℃, 48℃, 49℃ or 50℃, etc., but is not limited to the listed values, and other values not listed in this range are also applicable.

[0055] Preferably, the temperature of the second stage in the second chlorination reaction is 55-65℃, for example, it can be 55℃, 57℃, 58℃, 59℃, 60℃, 61℃, 62℃, 63℃, 64℃ or 65℃, etc., but is not limited to the listed values, and other values not listed in this range are also applicable.

[0056] Preferably, the total residence time of the second chlorination reaction in the micro-channel reactor is 55-75s, for example, it can be 55s, 58s, 60s, 62s, 64s, 67s, 69s, 71s, 73s or 75s, etc., but is not limited to the listed values, and other values not listed in this range are also applicable.

[0057] Preferably, the ratio of the residence time of the first stage to the second stage in the second chlorination reaction is 2-4:1, for example, it can be 2:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.8:1, 3.0:1, 3.5:1 or 4.0:1, etc., but is not limited to the listed values, and other values not listed in this range are also applicable.

[0058] Preferably, the molar ratio of chlorine gas to the second material in the second chlorination reaction is 1.01-1.04:1, for example, it can be 1.01:1, 1.02:1, 1.03:1, or 1.04:1, etc., but is not limited to the listed values, and other values not listed in this range are also applicable.

[0059] Preferably, the tail gas generated in the second chlorination reaction is absorbed by a base.

[0060] Preferably, the second dehydrochlorination reaction in step (4) comprises mixing a second phase transfer catalyst and the tetrachloropropane, adding a lye dropwise at a second reaction temperature, and performing the second dehydrochlorination reaction.

[0061] Preferably, the second phase transfer catalyst comprises any one or a combination of at least two of polyethylene glycol, benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride, or hexamethylene-1-n-hexyldimethyl-6-octadecyldimethylammonium bromide, preferably hexamethylene-1-n-hexyldimethyl-6-octadecyldimethylammonium bromide.

[0062] Preferably, the mass ratio of the second phase transfer catalyst to the third material is 2-4:1000, for example, it can be 2:1000, 2.3:1000, 2.5:1000, 2.7:1000, 2.9:1000, 3.2:1000, 3.4:1000, 3.6:1000, 3.8:1000, or 4:1000, etc., but is not limited to the listed values, and other values not listed in this range are also applicable.

[0063] Preferably, the second reaction temperature is 55-65°C, for example, it can be 55°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C, or 65°C, etc., but is not limited to the listed values, and other values not listed in this range are also applicable.

[0064] Preferably, the lye of the second dehydrochlorination reaction comprises a sodium hydroxide solution.

[0065] Preferably, the concentration of the lye of the second dehydrochlorination reaction is 15-30wt%, for example, it can be 15wt%, 17wt%, 19wt%, 20wt%, 22wt%, 24wt%, 25wt%, 27wt%, 29wt%, or 30wt%, etc., but is not limited to the listed values, and other values not listed in this range are also applicable.

[0066] Preferably, the molar ratio of the amount of the lye used in the second dehydrochlorination reaction to the third material is 1.005-1.030:1, for example, it can be 1.005:1, 1.006:1, 1.008:1, 1.009:1, 1.010:1, 1.011:1, 1.015:1, 1.020:1, 1.025:1, 1.028:1 or 1.030:1, etc., but is not limited to the listed values, and other values not listed in the range are also applicable.

[0067] Preferably, after the second dehydrochlorination reaction, the obtained reaction solution is sequentially adjusted to neutral pH and allowed to stand and separate into layers to obtain a fourth material containing tetrachloropropylene.

[0068] Preferably, the adjusting agent for adjusting the pH to neutral is an acid.

[0069] Preferably, the acid includes hydrochloric acid.

[0070] Preferably, the concentration of the hydrochloric acid is 10-25 wt%, for example, it can be 10 wt%, 12 wt%, 14 wt%, 15 wt%, 17 wt%, 19 wt%, 20 wt%, 22 wt%, 24 wt% or 25 wt%, etc., but is not limited to the listed values, and other values not listed in the range are also applicable.

[0071] Preferably, the photocatalytic isomerization reaction in step (5) includes a first stage and a second stage.

[0072] The photocatalytic isomerization reaction of the present application is preferably carried out in two stages, and by selecting different photocatalytic conditions in the two stages, the selectivity of isomerization is significantly improved.

[0073] Preferably, the temperature of the first stage of the photocatalytic isomerization reaction is 70-80℃, for example, it can be 70℃, 72℃, 73℃, 74℃, 75℃, 76℃, 77℃, 78℃, 79℃ or 80℃, etc., but is not limited to the listed values, and other values not listed in the range are also applicable.

[0074] Preferably, the light source of the first stage of the photocatalytic isomerization reaction is an LED light source with a power of 25-40 W and a wavelength of 350-450 nm, wherein the power can be, for example, 25 W, 27 W, 29 W, 30 W, 32 W, 34 W, 35 W, 37 W, 39 W or 40 W, etc., but is not limited to the listed values, and other values not listed in the range are also applicable; the wavelength can be, for example, 350 nm, 362 nm, 373 nm, 384 nm, 395 nm, 406 nm, 417 nm, 428 nm, 439 nm or 450 nm, etc., but is not limited to the listed values, and other values not listed in the range are also applicable.

[0075] Preferably, the temperature of the second stage of the photo-catalytic isomerization reaction is 85-95℃, for example, it can be 85℃, 87℃, 88℃, 89℃, 90℃, 91℃, 92℃, 93℃, 94℃ or 95℃, etc., but not limited to the listed values, other values not listed in this range are also applicable.

[0076] Preferably, the light source of the second stage of the photo-catalytic isomerization reaction is an LED light source with a power of 45-55W and a wavelength of 250-340nm, wherein the power can be, for example, 45W, 47W, 48W, 49W, 50W, 51W, 52W, 53W, 54W or 55W, etc., but not limited to the listed values, other values not listed in this range are also applicable; the wavelength can be, for example, 250nm, 260nm, 270nm, 280nm, 290nm, 300nm, 310nm, 320nm, 330nm or 340nm, etc., but not limited to the listed values, other values not listed in this range are also applicable.

[0077] Preferably, the total residence time of the photo-catalytic isomerization reaction is 90-110s, for example, it can be 90s, 93s, 95s, 97s, 99s, 102s, 104s, 106s, 108s or 110s, etc., but not limited to the listed values, other values not listed in this range are also applicable.

[0078] Preferably, the ratio of the residence time of the first stage to the second stage of the photo-catalytic isomerization reaction is 2-3:1, for example, it can be 2:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.8:1 or 3.0:1, etc., but not limited to the listed values, other values not listed in this range are also applicable.

[0079] The residence time of the first stage and the second stage of the photo-catalytic isomerization reaction in the present application, in combination with the parameters of the light source of the photo-catalytic isomerization reaction, can improve the selectivity and yield of the reaction.

[0080] Preferably, the catalyst of the photo-catalytic isomerization reaction is any one or a combination of at least two of nano-titanium dioxide, nano-zinc oxide, chlorine, bromine or iodine, wherein a typical but non-limiting combination is a combination of nano-titanium dioxide and nano-zinc oxide, a combination of chlorine and nano-zinc oxide, a combination of nano-titanium dioxide and chlorine, a combination of bromine and nano-zinc oxide, a combination of bromine and iodine.

[0081] Preferably, the 1,1,2,3-tetrachloropropene obtained in step (5) is further purified to obtain refined 1,1,2,3-tetrachloropropene.

[0082] Preferably, the method of the second purification comprises distillation and decoking and rectification in sequence.

[0083] Preferably, the temperature of the column bottom in the second rectification process of the purification is 104-106℃, for example, it can be 104℃, 104.3℃, 104.5℃, 104.7℃, 104.9℃, 105.2℃, 105.4℃, 105.6℃, 105.8℃ or 106℃, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0084] Preferably, the temperature of the column top in the second rectification process of the purification is 91-97℃, for example, it can be 91℃, 92℃, 93℃, 93℃, 94℃, 95℃, 95℃, 96℃, 97℃ or 97℃, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0085] Preferably, the pressure in the second rectification process of the purification is 80-100mmHg, for example, it can be 80mmHg, 83mmHg, 85mmHg, 87mmHg, 89mmHg, 92mmHg, 94mmHg, 96mmHg, 98mmHg or 100mmHg, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0086] Preferably, the reflux ratio in the second rectification process of the purification is 4-6:1, for example, it can be 4:1, 4.3:1, 4.5:1, 4.7:1, 4.9:1, 5.2:1, 5.4:1, 5.6:1, 5.8:1 or 6:1, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0087] Preferably, the temperature in the second rectification process of the purification is 96-106℃, for example, it can be 96℃, 98℃, 99℃, 100℃, 101℃, 102℃, 103℃, 104℃, 105℃ or 106℃, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0088] Preferably, the pressure in the second rectification process of the purification is -0.09--0.10MPa, for example, it can be -0.09MPa, -0.091MPa, -0.092MPa, -0.093MPa, -0.094MPa, -0.095MPa, -0.096MPa, -0.097MPa, -0.098MPa, -0.10MPa, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0089] As a preferred technical solution of the present application, the method comprises the following steps:

[0090] (1) dichloropropene raw material and chlorine gas are sequentially introduced into the first module and the second module of the micro-channel reactor to respectively undergo the first stage and the second stage of the first chlorination reaction, the temperature of the first stage is 40-50℃, the temperature of the second stage is 55-65℃, the molar ratio of chlorine gas:dichloropropene is 1.01-1.04:1, the tail gas is absorbed by alkali to obtain a first material containing tetrachloropropane;

[0091] (2) the first material is subjected to the first rectification at 50-100mmHg and a reflux ratio of 3-5:1 to obtain tetrachloropropane; a first phase transfer catalyst and the tetrachloropropane are mixed at a mass ratio of 2-4:1000, a lye with a concentration of 15-30wt% is added dropwise at 55-65℃, the molar ratio of the amount of lye to tetrachloropropane is 1.005-1.030:1, a first dehydrochlorination reaction is carried out, and the reaction liquid obtained is sequentially subjected to neutralization by hydrochloric acid and static layer separation to obtain a second material containing trichloropropylene in the oil phase;

[0092] (3) the second material and chlorine gas are sequentially introduced into the first module and the second module of the micro-channel reactor to respectively undergo the first stage and the second stage of the second chlorination reaction, the temperature of the first stage is 40-50℃, the residence time is 40-50s, the temperature of the second stage is 55-65℃, the residence time is 15-30s, the molar ratio of chlorine gas:the second material is 1.01-1.04:1, the tail gas is absorbed by alkali to obtain a third material containing pentachloropropane;

[0093] (4) a second phase transfer catalyst and the third material are mixed at a mass ratio of 2-4:1000, a lye with a concentration of 15-30wt% is added dropwise at 55-65℃, the molar ratio of the amount of lye to the third material is 1.005-1.030:1, a second dehydrochlorination reaction is carried out, and the reaction liquid obtained is sequentially subjected to neutralization by hydrochloric acid and static layer separation to obtain a fourth material containing tetrachloropropylene in the oil phase;

[0094] (5) a photocatalytic isomerization catalyst and the fourth material are sequentially introduced into the first module and the second module of the micro-channel reactor to respectively undergo the first stage and the second stage of the photocatalytic isomerization reaction, the temperature of the first stage is 70-80℃, the light source is an LED light source with a wavelength of 350-450nm and a power of 25-40W, and the residence time is 60-75s; the temperature of the second stage is 85-95℃, the light source is an LED light source with a wavelength of 250-340nm and a power of 45-55W, and the residence time is 25-40s, to obtain 1,1,2,3-tetrachloropropylene crude product;

[0095] (6) the crude 1,1,2,3-tetrachloropropene is first subjected to liquid phase component extraction under the conditions of pressure of-0.09 to-0.10 MPa, kettle temperature of 96 to 106 ℃, and gas temperature of 84 to 90 ℃; and the liquid phase component is subjected to second rectification under the conditions of kettle temperature of 104 to 106 ℃, overhead temperature of 91 to 97 ℃, pressure of 80 to 100 mmHg, and reflux ratio of 4 to 6:1, to obtain refined 1,1,2,3-tetrachloropropene.

[0096] Compared with the prior art, the present application has at least the following beneficial effects:

[0097] (1) The method for preparing 1,1,2,3-tetrachloropropene by micro-channel reaction provided by the present application has a short process flow, is easy to operate, and has low catalyst consumption;

[0098] (2) The method for preparing 1,1,2,3-tetrachloropropene by micro-channel reaction provided by the present application uses a micro-channel reactor to complete strong exothermic unit reactions such as chlorination and rearrangement, uses cis-dichloropropene, chlorine gas, and liquid alkali as raw materials, strengthens the reaction through the reaction process, avoids excessive chlorination of by-products caused by back mixing, greatly improves the chlorination selectivity and reaction rate coupling, the micro-channel light reactor directly isomerizes the generated 2,3,3,3-tetrachloropropene under the conditions of a catalyst and a light source to form the target product 1,1,2,3-tetrachloropropene, the isomerization conversion rate of 1,1,2,3-tetrachloropropene reaches about 100%, the selectivity is 100%, the overall preparation process has a yield of 1,1,2,3-tetrachloropropene of 91% or more, and the purity of 1,1,2,3-tetrachloropropene is 99.8% or more;

[0099] (3) The method for preparing 1,1,2,3-tetrachloropropene by micro-channel reaction provided by the present application uses a micro-channel reactor to realize continuous production of 1,1,2,3-tetrachloropropene, can be quickly industrialized, has small land occupation, and is suitable for large-scale production. BRIEF DESCRIPTION OF DRAWINGS

[0100] Figure 1 is the mass spectrum of 1,1,2,3-tetrachloropropene prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0101] The technical solutions of the present application are further illustrated below by specific embodiments in combination with the accompanying drawings.

[0102] The present application is further described below. However, the following examples are only simple examples of the present application, and do not represent or limit the protection scope of the present application, and the protection scope of the present application is subject to the claims.

[0103] It should be understood that, in the description of the present application, 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 the technical features indicated. Therefore, the features defined with "first", "second", etc. can be explicitly or implicitly included one or more of the features.

[0104] Example 1

[0105] The present embodiment provides a method for preparing 1,1,2,3-tetrachloropropene by micro-channel reaction, which comprises the following steps:

[0106] (1) Dichloropropene raw material (cis-DCP 98wt%, trans-DCP 1wt%, 3,3-DCP 1wt%) and chlorine gas are sequentially introduced into the first module and the second module of the micro-channel reactor to undergo the first stage and the second stage of the first chlorination reaction, respectively, the temperature of the first stage is 45℃, the residence time is 30s, the temperature of the second stage is 60℃, the residence time is 30s, the molar ratio of chlorine gas to dichloropropene is 1.03:1, the tail gas is absorbed by sodium hydroxide solution, and a first material containing tetrachloropropane is obtained;

[0107] (2) The first material is subjected to first rectification under 50-100mmHg (pressure difference between the tower kettle and the top), with a reflux ratio of 3.5:1, to obtain tetrachloropropane; a first phase transfer catalyst (hexamethylene-1-n-hexyl dimethyl-6-octadecyl dimethyl ammonium bromide) and the tetrachloropropane are mixed at a mass ratio of 3:1000 in a kettle reactor, heated to 60℃, and then a 20wt% sodium hydroxide solution is added dropwise, the molar ratio of sodium hydroxide to tetrachloropropane is 1.01:1, and the first dehydrochlorination reaction is carried out, and the reaction liquid obtained is sequentially subjected to hydrochloric acid (concentration 18wt%) to adjust the pH to neutral (pH 7.0) and static layering, to obtain a second material containing trichloropropene in the oil phase;

[0108] (3) The second material and chlorine gas are sequentially introduced into the first module and the second module of the micro-channel reactor to undergo the first stage and the second stage of the second chlorination reaction, respectively, the temperature of the first stage is 48℃, the residence time is 30s, the temperature of the second stage is 60℃, the residence time is 30s, the molar ratio of chlorine gas to the second material is 1.03:1, the tail gas is absorbed by sodium hydroxide solution, and a third material containing pentachloropropane is obtained;

[0109] (4) mixing the second phase transfer catalyst (hexamethylene-1-n-hexyldimethyl-6-octadecyldimethylammonium bromide) and the third material in a mass ratio of 3:1000 in a tank reactor, heating to 60°C, then adding a 20wt% sodium hydroxide solution dropwise, the molar ratio of sodium hydroxide to the third material being 1.01:1, to perform a second dehydrochlorination reaction, and then sequentially adjusting the pH to neutral (7.1) with hydrochloric acid and allowing the reaction mixture to separate into layers to obtain an oil phase containing tetra-chloropropylene in the fourth material;

[0110] (5) passing liquid bromine and the fourth material into the first module and the second module of a micro-channel reactor in sequence to perform a first stage and a second stage of photocatalytic isomerization reaction, the temperature of the first stage being 75°C, the light source being a 30W LED light source with a wavelength of 400nm, and the residence time being 30s; the temperature of the second stage being 85°C, the light source being a 50W LED light source with a wavelength of 300nm, and the residence time being 30s, to obtain 1,1,2,3-tetrachloropropylene crude product;

[0111] (6) the 1,1,2,3-tetrachloropropylene crude product is first subjected to a liquid phase component at a pressure of -0.094MPa, a tank temperature of 100°C, and a gas temperature of 85°C; and the liquid phase component is then subjected to a second rectification (using 1.8m glass spring packing) at a column still temperature of 105°C, a column top temperature of 957°C, a pressure of 95mmHg, and a reflux ratio of 5:1 to obtain refined 1,1,2,3-tetrachloropropylene, the mass spectrum of which is shown in Figure 1

[0112] The main components of the first material obtained in step (1) of the embodiment include: 1,2-dichloropropane 0.252%, cis-dichloropropene 0.403%, trans-dichloropropene 0.063%, and tetrachloropropane 92.64%.

[0113] The main components of the second material include: 2,3,3-trichloropropene 19.5%, 1,1,3-trichloropropene 65.5%, and 1,2,3-trichloropropene 13%.

[0114] The main components of the third material include: 1,1,1,2,3-pentachloropropane / 1,1,2,2,3-pentachloropropane in a molar ratio of 62:30.

[0115] The main components of the fourth material include: 1,1,2,3-tetrachloropropylene 54.57% and 2,3,3,3-tetrachloropropylene 35.4%.

[0116] Example 2

[0117] The embodiment provides a method for preparing 1,1,2,3-tetrachloropropylene by using a micro-channel reaction, the method comprising the following steps:​

[0118] (1) dichloropropene raw material (cis-DCP 98wt%, trans-DCP 1wt%, 3,3-DCP 1wt%) and chlorine gas are sequentially introduced into the first module and the second module of the micro-channel reactor to respectively undergo the first stage and the second stage of the first chlorination reaction, the temperature of the first stage is 40°C, the residence time is 45s, the temperature of the second stage is 65°C, the residence time is 20s, the molar ratio of chlorine gas to dichloropropene is 1.01:1, the tail gas is absorbed by sodium hydroxide solution, and a first material containing tetrachloropropane is obtained;

[0119] (2) the first material is subjected to first rectification under 60-100mmHg (there is a pressure difference between the tower kettle and the top) and a reflux ratio of 5:1 to obtain tetrachloropropane; a first phase transfer catalyst (hexamethylene-1-n-hexyl dimethyl-6-octadecyl dimethyl ammonium bromide) and the tetrachloropropane are mixed at a mass ratio of 2:1000 in a kettle reactor, heated to 65°C, and then a 15wt% sodium hydroxide solution is added dropwise, the molar ratio of the amount of sodium hydroxide to tetrachloropropane is 1.03:1, a first dehydrochlorination reaction is carried out, and the reaction liquid obtained is sequentially subjected to hydrochloric acid (concentration 20wt%) to adjust the pH to neutral (pH 7.1) and static layering to obtain a second material containing trichloropropylene in the oil phase;

[0120] (3) the second material and chlorine gas are sequentially introduced into the first module and the second module of the micro-channel reactor to respectively undergo the first stage and the second stage of the second chlorination reaction, the temperature of the first stage is 40°C, the residence time is 55s, the temperature of the second stage is 65°C, the residence time is 20s, the molar ratio of chlorine gas to the second material is 1.04:1, the tail gas is absorbed by sodium hydroxide solution, and a third material containing pentachloropropane is obtained;

[0121] (4) a second phase transfer catalyst (hexamethylene-1-n-hexyl dimethyl-6-octadecyl dimethyl ammonium bromide) and the third material are mixed at a mass ratio of 4:1000 in a kettle reactor, heated to 55°C, and then a 15wt% sodium hydroxide solution is added dropwise, the molar ratio of the amount of sodium hydroxide to the third material is 1.03:1, a second dehydrochlorination reaction is carried out, and the reaction liquid obtained is sequentially subjected to hydrochloric acid to adjust the pH to neutral (7.1) and static layering to obtain a fourth material containing tetrachloropropylene in the oil phase;

[0122] (5) The nano-titanium oxide (average particle size 200 nm) and the fourth material are sequentially introduced into the first module and the second module of the micro-channel reactor at a mass ratio of 1.3:1000 to undergo the first stage and the second stage of the photo-catalytic isomerization reaction, the temperature of the first stage is 80°C, the light source is a 25W LED light source with a wavelength of 450 nm, and the residence time is 75s; the temperature of the second stage is 95°C, the light source is a 55W LED light source with a wavelength of 340 nm, and the residence time is 35s, to obtain the 1,1,2,3-tetrachloropropene crude product;

[0123] (6) The 1,1,2,3-tetrachloropropene crude product is first subjected to a liquid phase component extraction under a pressure of -0.1 MPa, a kettle temperature of 106°C, and an air temperature of 84°C; and the liquid phase component is then subjected to a second rectification (using 1.8m glass spring packing) under a column kettle temperature of 104°C, a column top temperature of 95°C, a pressure of 80mmHg, and a reflux ratio of 6:1, to obtain the refined 1,1,2,3-tetrachloropropene.

[0124] Example 3

[0125] The present embodiment provides a method for preparing 1,1,2,3-tetrachloropropene by using a micro-channel reaction, which comprises the following steps:

[0126] (1) The dichloropropene raw material (cis-DCP 98wt%, trans-DCP 1wt%, 3,3-DCP 1wt%) and chlorine gas are sequentially introduced into the first module and the second module of the micro-channel reactor to undergo the first stage and the second stage of the first chlorination reaction, the temperature of the first stage is 50°C, the residence time is 40s, the temperature of the second stage is 55°C, the residence time is 25s, the molar ratio of chlorine gas to dichloropropene is 1.04:1, and the tail gas is absorbed by a sodium hydroxide solution to obtain the first material containing tetrachloropropane;

[0127] (2) The first material is subjected to a first rectification under a pressure difference of 60-90mmHg (the column kettle and the column top have a pressure difference) and a reflux ratio of 3:1 to obtain tetrachloropropane; a first phase transfer catalyst (hexamethylene-1-n-hexyldimethyl-6-octadecyldimethylammonium bromide) and the tetrachloropropane are mixed at a mass ratio of 4:1000 in a kettle reactor, heated to 55°C, and then a 30wt% sodium hydroxide solution is added dropwise, the molar ratio of the amount of sodium hydroxide to tetrachloropropane is 1.005:1, to perform the first dehydrochlorination reaction, and the obtained reaction liquid is sequentially subjected to adjustment of pH to neutral (pH is 7.3) by a hydrochloric acid (concentration is 22wt%) and static layering to obtain the second material containing trichloropropene in the oil phase;

[0128] (3) the second material and chlorine gas are sequentially introduced into the first module and the second module of the micro-channel reactor to respectively undergo the first stage and the second stage of the second chlorination reaction, the temperature of the first stage is 50℃, the residence time is 53s, the temperature of the second stage is 55℃, the residence time is 21s, the molar ratio of chlorine gas to the second material is 1.014:1, the tail gas is absorbed by a sodium hydroxide solution, and a third material containing pentachloropropane is obtained;

[0129] (4) the second phase transfer catalyst (hexamethylene-1-n-hexyl dimethyl-6-octadecyl dimethyl ammonium bromide) and the third material are mixed at a mass ratio of 2:1000 in a tank reactor, heated to 65℃, and then a 30wt% sodium hydroxide solution is added dropwise, the molar ratio of the amount of sodium hydroxide to the third material is 1.005:1, a second dehydrochlorination reaction is carried out, and the obtained reaction liquid is sequentially adjusted to neutral (7.2) by hydrochloric acid and is allowed to stand and separate into layers, and an oil phase containing tetrachloropropylene in the fourth material is obtained;

[0130] (5) liquid bromine and the fourth material are sequentially introduced into the first module and the second module of the micro-channel reactor to respectively undergo the first stage and the second stage of the photocatalytic isomerization reaction, the temperature of the first stage is 70℃, the light source is a 40W LED light source with a wavelength of 350nm, and the residence time is 65s; the temperature of the second stage is 85℃, the light source is a 45W LED light source with a wavelength of 250nm, and the residence time is 26s, and a 1,1,2,3-tetrachloropropylene crude product is obtained;

[0131] (6) the 1,1,2,3-tetrachloropropylene crude product is first subjected to a liquid phase component at a pressure of -0.09MPa, a tank temperature of 96℃, and an air temperature of 90℃; and the liquid phase component is then subjected to a second rectification (using 1.8m glass spring packing) at a column still temperature of 106℃, a column top temperature of 91℃, a pressure of 100mmHg, and a reflux ratio of 4:1, and refined 1,1,2,3-tetrachloropropylene is obtained.

[0132] Example 4

[0133] This example adjusts the conditions of the first chlorination reaction based on Example 1, and the specific conditions are shown in Table 1.

[0134] Table 1

[0135]

[0136]

[0137] As can be seen from Table 1, the present application sets the first chlorination reaction to be carried out in two stages, and strictly limits the temperature and residence time of the first stage and the second stage, which is more conducive to improving the yield of tetrachloropropane and the conversion rate of dichloropropylene.

[0138] Example 5

[0139] This example adjusts the conditions of the first dehydrochlorination reaction on the basis of Example 1, and the details are shown in Table 2 below.

[0140] Table 2

[0141]

[0142] As can be seen from Table 2, the first dehydrochlorination reaction provided by the present application uses a preferred catalyst and controls the amount of catalyst, which is more conducive to improving the yield of trichloropropene and the conversion rate of tetrachloropropane.

[0143] Example 6

[0144] This example adjusts the conditions of the second chlorination reaction on the basis of Example 1, and the details are shown in Table 3 below.

[0145] Table 3

[0146]

[0147] As can be seen from Table 3, the present application sets the second chlorination reaction to be carried out in two stages, and strictly limits the temperature and residence time of the first stage and the second stage, which is more conducive to improving the yield of pentachloropropane and the conversion rate of trichloropropene.

[0148] Example 7

[0149] This example adjusts the conditions of the isomerization reaction on the basis of Example 1, and the details are shown in Table 4 below.

[0150] Table 4

[0151]

[0152]

[0153] As can be seen from Table 4, Example 1 carries out the isomerization reaction in two stages, and sets the temperature of the first stage to be lower than that of the second stage, and the content of 1,1,2,3-tetrachloropropene in the product is basically 100%, while in Examples 7A-7E, the isomerization conditions are not within the preferred temperature, time and power range, and the content of 1,1,2,3-tetrachloropropene in the product is ≤96%, which shows that by combining the isomerization reaction to be carried out in stages, the reaction temperature, time and power, the selectivity of 1,1,2,3-tetrachloropropene is significantly improved.

[0154] Comparative Example 1

[0155] The comparative example 1 provides a method for preparing 1,1,2,3-tetrachloropropene, which is the same as example 1 except that step (1) uses a tank reactor.

[0156] Specifically, (1) dichloropropene raw material (cis-DCP 98wt%, trans-DCP 1wt%, 3,3-DCP 1wt%) and chlorine are sequentially introduced into the tank reactor and reacted at 45°C for 3h, the molar ratio of chlorine to dichloropropene is 1.03:1, the tail gas is absorbed by sodium hydroxide solution, and a first material containing tetrachloropropane is obtained.

[0157] Comparative example 2

[0158] The comparative example 1 provides a method for preparing 1,1,2,3-tetrachloropropene, which is the same as example 1 except that step (1) uses a tank reactor.

[0159] Specifically, (3) the second material and chlorine are introduced into the tank reactor and reacted at 48°C for 3h, the molar ratio of chlorine to the second material is 1.03:1, the tail gas is absorbed by sodium hydroxide solution, and a third material containing pentachloropropane is obtained.

[0160] Comparative example 3

[0161] The comparative example 1 provides a method for preparing 1,1,2,3-tetrachloropropene, which is the same as example 1 except that step (1) uses a tank reactor.

[0162] Specifically, (5) liquid bromine and the fourth material are introduced into the tank reactor at a mass ratio of 1.3:1000, and the reaction is carried out at a temperature of 75°C, a light source of 30W and a wavelength of 400nm LED light source, to obtain a crude product of 1,1,2,3-tetrachloropropene.

[0163] Test method: gas chromatography-mass spectrometry is used to detect the components in the above materials. The detection results are shown in Tables 1-5. The detailed detection results of examples 1-3 and comparative examples 1-3 are shown in Table 5.

[0164] Table 5

[0165]

[0166]

[0167] From Table 5, the following two points can be seen:

[0168] (1) From the comprehensive examples 1-3, it can be seen that the method for preparing 1,1,2,3-tetrachloropropene by using the micro-channel reaction provided by the application can improve the total yield of 1,1,2,3-tetrachloropropene to ≥91.7%, and the purity of the refined 1,1,2,3-tetrachloropropene is >99.5%;

[0169] (2) From the comprehensive examples 1 and the comparative examples 1-3, it can be seen that, in the example 1, the micro-channel reactor is used, compared with the comparative examples 1-3 in which the kettle type reactor is used in a certain step, the total yield of 1,1,2,3-tetrachloropropene in the final example 1 is 91.7%, while in the comparative examples 1-3, it is only 87.0%, 82.9% and 82.5% respectively, which shows that by using the micro-channel reactor in the two-step chlorination reaction and the photo-catalytic isomerization reaction, the selectivity of the reaction is significantly improved. The applicant declares that the above description is only a specific embodiment of the application, but the protection scope of the application is not limited to this. It should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the application can be easily thought out by those skilled in the art, and all of them fall within the protection scope and disclosure scope of the application.

Claims

1. A process for the production of 1,1,2,3-tetrachloropropene by microchannel reaction, characterized in that, The method comprises the following steps: (1) the dichloropropene raw material is subjected to a first chlorination reaction in a micro-channel reactor to obtain a first material containing tetrachloropropane; the first chlorination reaction comprises a first stage and a second stage; the reaction temperature of the first stage is lower than that of the second stage; (2) the first material is subjected to a first purification to obtain tetrachloropropane, and the tetrachloropropane is subjected to a first dehydrochlorination reaction to obtain a second material containing trichloropropene; (3) the second material is subjected to a second chlorination reaction in a micro-channel reactor to obtain a third material containing pentachloropropane; the second chlorination reaction comprises a first stage and a second stage; the reaction temperature of the first stage is lower than that of the second stage; (4) the third material is subjected to a second dehydrochlorination reaction to obtain a fourth material containing tetrachloropropene; (5) the fourth material is subjected to a photocatalytic isomerization reaction in a micro-channel reactor to obtain 1,1,2,3-tetrachloropropene; The temperature of the first stage of the first chlorination reaction is 40-50℃. The temperature of the second stage of the first chlorination reaction is 55-65℃. The catalyst of the photocatalytic isomerization reaction is nano-titanium dioxide or bromine.

2. The method of claim 1, wherein, The total residence time of the first chlorination reaction in the micro-channel reactor is 55-75s.

3. The method of claim 1, wherein, The ratio of the residence time of the first stage to that of the second stage in the first chlorination reaction is 1-3:

1.

4. The method of claim 1, wherein, The molar ratio of chlorine gas to dichloropropene raw material in the first chlorination reaction in step (1) is 1.01-1.04:

1.

5. The method of claim 1, wherein, The dichloropropene raw material comprises cis-dichloropropene.

6. The method of claim 1, wherein, The first purification is performed by first rectification.

7. The method of claim 1, wherein, In step (2), the first dehydrochlorination reaction comprises: mixing a first phase transfer catalyst with the tetrachloropropane, adding an alkali solution dropwise at a first reaction temperature, and performing the first dehydrochlorination reaction.

8. The method of claim 7, wherein, The first phase transfer catalyst comprises any one or a combination of at least two of polyethylene glycol, benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, or trioctylmethylammonium chloride.

9. The method of claim 7, wherein, The mass ratio of the first phase transfer catalyst to tetrachloropropane is 2-4:1000.

10. The method of claim 7, wherein, The first reaction temperature is 55-65℃.

11. The method of claim 7, wherein, The alkali solution in the first dehydrochlorination reaction comprises a sodium hydroxide solution.

12. The method of claim 7, wherein, The concentration of the alkali solution in the first dehydrochlorination reaction is 15-30wt%.

13. The method of claim 7, wherein, The molar ratio of the amount of alkali solution to tetrachloropropane in the first dehydrochlorination reaction is 1.005-1.030:

1.

14. The method of claim 7, wherein, After the first dehydrochlorination reaction in step (2), the obtained reaction liquid is sequentially adjusted to neutral pH and allowed to stand and separate into layers to obtain the second material containing trichloropropene.

15. The method of claim 14, wherein, The adjusting agent for adjusting the pH to neutral is an acid.

16. The method of claim 1, wherein, The temperature of the first stage of the second chlorination reaction is 40-50℃.

17. The method of claim 1, wherein, The temperature of the second stage of the second chlorination reaction is 55-65℃.

18. The method of claim 1, wherein, The total residence time of the second chlorination reaction in the micro-channel reactor is 55-75s.

19. The method of claim 1, wherein, The ratio of the residence time of the first stage to that of the second stage in the second chlorination reaction is 2-4:

1.

20. The method of claim 1, wherein, The molar ratio of chlorine gas to the second material in the second chlorination reaction is 1.01-1.04:

1.

21. The method of claim 1, wherein, Tail gas generated in the second chlorination reaction is absorbed by alkali.

22. The method of claim 1, wherein, The second dehydrochlorination reaction in step (4) comprises mixing a second phase transfer catalyst and the tetrachloropropane, and adding a lye dropwise at a second reaction temperature to perform the second dehydrochlorination reaction.

23. The method of claim 22, wherein, The second phase transfer catalyst comprises any one or a combination of at least two of polyethylene glycol, benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, or trioctylmethylammonium chloride.

24. The method of claim 22, wherein, The mass ratio of the second phase transfer catalyst to the third material is 2-4:1000.

25. The method of claim 22, wherein, The second reaction temperature is 55-65℃.

26. The method of claim 22, wherein, The lye for the second dehydrochlorination reaction comprises a sodium hydroxide solution.

27. The method of claim 22, wherein, The concentration of the lye for the second dehydrochlorination reaction is 15-30wt%.

28. The method of claim 22, wherein, The molar ratio of the amount of the lye to the third material in the second dehydrochlorination reaction is 1.005-1.030:

1.

29. The method of claim 22, wherein, After the second dehydrochlorination reaction, the obtained reaction liquid is sequentially adjusted to neutral pH and left to separate into layers to obtain a fourth material containing tetrachloropropene.

30. The method of claim 29, wherein, The adjusting agent for adjusting the pH to neutral is an acid.

31. The method of claim 1, wherein, The photocatalytic isomerization reaction in step (5) comprises a first stage and a second stage.

32. The method of claim 31, wherein, The temperature in the first stage of the photocatalytic isomerization reaction is 70-80℃.

33. The method of claim 31, wherein, The light source in the first stage of the photocatalytic isomerization reaction is an LED light source with a power of 25-40W and a wavelength of 350-450nm.

34. The method of claim 31, wherein, The temperature in the second stage of the photocatalytic isomerization reaction is 85-95℃.

35. The method of claim 31, wherein, The light source in the second stage of the photocatalytic isomerization reaction is an LED light source with a power of 45-55W and a wavelength of 250-340nm.

36. The method of claim 31, wherein, The total residence time of the photocatalytic isomerization reaction is 90-110s.

37. The method of claim 31, wherein, The ratio of the residence time of the first stage to that of the second stage in the photocatalytic isomerization reaction is 2-3:

1.

38. The method of claim 1, wherein, The 1,1,2,3-tetrachloropropene obtained in step (5) is further purified to obtain refined 1,1,2,3-tetrachloropropene.

39. The method of claim 38, wherein, The method of the second purification comprises sequentially performing distillation to remove coke and rectification.

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