A method for treating deteriorated trans-dichloropropylene products

Abstract

The present invention provides a method for treating a trans-dichloropropylene deteriorated product, the method comprising the following steps: (1) mixing the trans-dichloropropylene deteriorated product with a solid inorganic base to react, and obtaining a filtrate after solid-liquid separation; (2) mixing the filtrate with a Tulsimer ARR‑1 anion exchange resin to perform an aldehyde removal reaction to obtain a mixed dichloropropylene crude product; (3) the mixed dichloropropylene crude product is subjected to a molecular sieve to remove water and then subjected to a rectification treatment to obtain high-purity trans-1,3‑dichloropropylene; and a catalyst Fe / ZSM‑5 is added during the rectification treatment. The treatment method of the present invention is simple to operate, does not need to react under conditions such as high temperature or high pressure, realizes the resource treatment of the trans-dichloropropylene deteriorated product, greatly reduces the treatment cost of organic waste liquid, and has good economic and environmental benefits.

Description

Technical Field

[0001] The invention relates to the technical field of chemistry and chemical engineering, and in particular to a method for treating a deteriorated trans-dichloropropylene product. Background Art

[0002] 1,3-Dichloropropene is widely used in the fields of medicine and agronomy. Trans-1,3-dichloropropene is mainly used to synthesize chloroallyloxyamine (intermediate of cyclohexenone herbicides) and the antifungal drug terbinafine hydrochloride. However, the concentration of trans-1,3-dichloropropene on the market is mainly 95%, which can only be used in the production of pesticide intermediates. The medical field requires trans-1,3-dichloropropene with a purity of more than 99%.

[0003] CN108409527A discloses a refining process of trans-1,3-dichloropropylene, in which the low-concentration trans-1,3-dichloropropylene produced by the chloropropylene device is transported to the distillation tower, and the extractant in the feed tank is pumped to the top of the distillation tower through the feed pump. After the low-concentration trans-1,3-dichloropropylene enters the distillation tower, it is mixed with the extractant, separated by distillation, and the gas phase at the top of the tower enters the condenser. After condensation with circulating water, the liquid phase enters the reflux tank, and the uncondensed gas phase enters the cryogenic freezer. After secondary cooling with cold water, the liquid phase enters the impurity recovery tank, and the uncondensed gas phase of the cryogenic freezer enters the vacuum pump to ensure the stability of the negative pressure in the tower. After the liquid phase in the reflux tank is pressurized by the reflux pump, part of it is sent to the top of the distillation tower as reflux liquid, and the other part is used as a high-concentration trans-1,3-dichloropropylene finished product. The process achieves a trans-1,3-dichloropropylene concentration of more than 99.5% through a continuous vacuum extraction process, which is upgraded to a pharmaceutical grade application.

[0004] CN104387226A discloses a method for purifying dichloropropylene, which is specifically implemented according to the following steps: crude dichloropropylene enters a DD mixture raw material storage tank, solid caustic soda and sodium hydroxide are added for mixing, and dichloropropylene and a low-boiling mixture are obtained; the dichloropropylene and the low-boiling mixture are sent to a low-boiling tower through a feed pump, and the bottom liquid of the tower is forced to circulate through a low-boiling tower reboiler by a circulating pump and extracted; the extracted material is sent to a dichloropropane tower and extracted; the material extracted from the dichloropropane circulation section is sent to a dichloropropylene tower, and the bottom liquid of the tower is forced to circulate through a tower reboiler by a tower bottom circulating pump, extracted, and after cooling, it enters a dichloropropylene storage tank for storage, and the top steam of the tower is condensed by a dichloropropylene condenser to obtain a dichloropropylene product. The crude dichloropropylene purification method contains 48.54% of cis-1,3-dichloropropylene and 51.32% of trans-1,3-dichloropropylene, and the purification rate can reach more than 99.9%.

[0005] CN107879891A discloses a method for purifying dichloropropane and dichloropropylene using a DD mixture, comprising the following steps: (1) conveying the DD mixture to a 1# tower, separating most of the water and a small amount of dichloropropane from the top of the 1# tower, and conveying the bottom liquid to a 2# tower; (2) separating the light component product from the top of the 2# tower and conveying it to a 3# tower, and conveying the bottom liquid to a 6# tower; (3) separating 1,2-dichloropropane from the top of the 3# tower as a product and conveying it to a 7# tower; The bottom liquid is sent to the 4# tower; (4) cis-1,3-dichloropropene is separated from the top of the 4# tower as the product and sent to the 5# tower; (5) trans-1,3-dichloropropene is separated from the top of the 5# tower as the product and sent to the 6# tower; (6) The residual light component product (mainly trans-1,3-dichloropropene) is separated from the top of the 6# tower and sent to the 3# tower, and the bottom liquid is sent to the heavy component and sent to the 3# tower.

[0006] However, the storage requirements of high-purity trans-1,3-dichloropropylene are high and the storage environment is harsh. During the storage and transportation of trans-dichloropropylene products, dichloropropylene is easy to change from colorless and transparent to yellow and produce insoluble brown impurities. After deterioration, the impurity composition of the product is complex and it cannot be further used as a raw material. It is usually treated as hazardous waste incineration. Dichloropropylene is a chlorine-containing organic matter, and high-temperature incineration can produce dioxins and other pollutants to pollute the atmospheric environment.

[0007] Therefore, it is of great significance to develop a method for treating the deteriorated trans-dichloropropylene product, to recycle the deteriorated trans-dichloropropylene waste liquid into resources, and to obtain a high-purity trans-dichloropropylene product. Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides a method for treating a deteriorated trans-dichloropropylene product. By adopting a suitable method to sequentially separate impurities in the deteriorated trans-dichloropropylene product, the resource utilization of the dichloropropylene product is realized, the economic losses caused by product deterioration can be greatly reduced, and the environmental pressure is reduced.

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

[0010] The present invention provides a method for treating a deteriorated trans-dichloropropylene product, the method comprising the following steps:

[0011] (1) mixing the deteriorated trans-dichloropropylene product with a solid inorganic base to react, and obtaining a filtrate after solid-liquid separation;

[0012] (2) mixing the filtrate with Tulsimer ARR-1 anion exchange resin to perform an aldehyde removal reaction to obtain a crude mixed dichloropropylene product;

[0013] (3) The mixed dichloropropylene crude product is subjected to a molecular sieve to remove water and then subjected to a distillation treatment to obtain high-purity trans-1,3-dichloropropylene; a catalyst Fe / ZSM-5 is added during the distillation treatment.

[0014] The method for treating a trans-dichloropropylene deteriorated product of the present invention comprises the following steps: firstly, a solid inorganic base is used to remove acetic acid and hydrochloric acid as impurities in the trans-dichloropropylene deteriorated product; and then a Tulsimer ARR-1 anion exchange resin is used to remove aldehyde impurities 1-chloro-acetaldehyde, 1,2-dichloroacetaldehyde, 1,2,3-trichloroacetaldehyde and 2-chloro-acrolein in the trans-dichloropropylene deteriorated product. The Tulsimer ARR-1 anion exchange resin is a commercial resin containing bisulfite, which can react with the carbonyl group of the aldehyde impurities by nucleophilic addition reaction, thereby removing the aldehyde impurities in the filtrate and obtaining a mixed dichloropropylene crude product. The mixed dichloropropylene crude product is first subjected to molecular sieve dehydration and then subjected to rectification treatment. Under the action of a catalyst Fe / ZSM-5, cis-1,3-dichloropropylene is re-isomerized into trans-1,3-dichloropropylene, and finally high-purity trans-1,3-dichloropropylene is obtained. The treatment method of the present invention is simple to operate, greatly reduces the treatment cost of trans-dichloropropylene deterioration products, and realizes the resource utilization of trans-dichloropropylene deterioration waste.

[0015] In the present invention, when the solid inorganic alkali removes the impurities acetic acid and hydrochloric acid in the deteriorated trans-dichloropropylene product, water will be produced. The presence of water will affect the purity of trans-1,3-dichloropropylene obtained by subsequent distillation treatment, so molecular sieving is first performed to remove water.

[0016] In the present invention, the 1-chloro-2-propanol in the deteriorated product of trans-dichloropropylene is converted into a fore fraction or a still residue during the distillation process and is separated and removed.

[0017] The catalyst Fe / ZSM-5 in the present invention is synthesized by a conventional hydrothermal method, which specifically comprises the following steps:

[0018] Take 80g of tetraethyl orthosilicate (0.76mol), 57.3g of 25% tetrapropylammonium hydroxide, 270g of water, and 7.2g of tetrapropylammonium bromide template, hydrolyze at 45℃ for 3h, remove alcohol and add water to the same volume, add Fe(NO3)3﹒9H2O and NaAlO2, add a small amount of NH4F as a crystallization regulator, and then transfer to a 500mL hydrothermal kettle for crystallization at 175℃ for 48h. The molar ratio of the feed is SiO2: 0.072TPABr: 0.072TPAOH: 1.5NH4F: xFe: 0.05Al: 80H2O, x = 0.005 or 0.01. After the catalyst is crystallized, it is filtered, washed, and added with aluminum sol to form strips.

[0019] Preferably, the contents of various substances in the trans-dichloropropylene deteriorated product in step (1) are: trans-1,3-dichloropropylene 59-63wt%, for example, 59wt%, 60wt%, 61wt%, 62wt% or 63wt%, etc., but are not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0020] cis-1,3-dichloropropylene 33.2-37.2wt%, for example, 33.2wt%, 34wt%, 35wt%, 36wt% or 37.2wt%, etc., but not limited to the listed values, other values ​​not listed in the numerical range are also applicable; 3,3-dichloropropylene 0.03wt%, acetic acid 1wt%, hydrochloric acid 0.5wt%;

[0021] 1-Chloro-acetaldehyde 0.3-1.6wt%, for example, 0.3wt%, 0.5wt%, 0.9wt%, 1.2wt% or 1.6wt%, etc., but not limited to the listed values, other values ​​not listed within the numerical range are also applicable;

[0022] 1,2-dichloroacetaldehyde 0.4-0.9wt%, for example, 0.4wt%, 0.5wt%, 0.6wt%, 0.8wt% or 0.9wt%, etc., but not limited to the listed values, other values ​​not listed within the numerical range are also applicable;

[0023] 1,2,3-trichloroacetaldehyde 0.2-0.7wt%, for example, 0.2wt%, 0.3wt%, 0.5wt%, 0.6wt% or 0.7wt%, etc., but not limited to the listed values, other values ​​not listed within the numerical range are also applicable;

[0024] 2-chloro-acrolein 0.1-0.9wt%, for example, 0.1wt%, 0.3wt%, 0.5wt%, 0.7wt% or 0.9wt%, etc., but not limited to the listed values, other values ​​not listed within the numerical range are also applicable;

[0025] 1-Chloro-2-propanol 0.03-0.05wt%, for example, 0.03wt%, 0.035wt%, 0.04wt%, 0.045wt% or 0.05wt%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable; insoluble impurities 0.3wt%.

[0026] Preferably, the solid inorganic base comprises any one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate or potassium bicarbonate, or a combination of at least two thereof, wherein typical but non-limiting combinations include a combination of sodium hydroxide and potassium hydroxide, a combination of sodium carbonate and potassium carbonate, a combination of sodium bicarbonate and sodium hydroxide, a combination of potassium hydroxide and potassium carbonate, or a combination of sodium bicarbonate, potassium hydroxide and sodium carbonate.

[0027] In the preferred step (1) of the present invention, solid inorganic base is used to remove the acid in the deteriorated product of trans-dichloropropylene, which can reduce the generation of moisture, thereby reducing the amount of molecular sieve added in the subsequent steps and reducing the processing cost.

[0028] Preferably, the amount of the ion exchange resin added is 50-200 g, for example, 50 g, 80 g, 100 g, 150 g, 180 g or 200 g, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] Preferably, the molecular sieve in step (3) comprises any one of 3A molecular sieve, 4A molecular sieve or 5A molecular sieve, or a combination of at least two of them, wherein typical but non-limiting combinations include a combination of 3A molecular sieve and 4A molecular sieve, a combination of 5A molecular sieve and 3A molecular sieve, or a combination of 4A molecular sieve, 5A molecular sieve and 3A molecular sieve.

[0030] Preferably, the molecular sieve is activated at 500-600°C, for example, 500°C, 520°C, 550°C, 580°C, 590°C or 600°C, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0031] Preferably, the amount of the molecular sieve added is 50-150 g, for example, 50 g, 60 g, 80 g, 100 g, 120 g or 150 g, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] Preferably, the amount of the catalyst added is 60-80 g, for example, 60 g, 65 g, 70 g, 75 g or 80 g, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] Preferably, the temperature of the distillation treatment in step (3) is 58-127°C, for example, it can be 58°C, 60°C, 70°C, 90°C, 100°C or 127°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] The temperature of the distillation treatment in the present invention is 58-127° C. In the actual distillation process, the temperature ranges of the bottom, the middle and the top of the tower can be further refined according to the pressure of the distillation treatment.

[0035] Preferably, the pressure of the distillation treatment is 160-350 mmHg, for example, it can be 160 mmHg, 180 mmHg, 200 mmHg, 250 mmHg, 300 mmHg or 350 mmHg, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] Preferably, during the distillation treatment in step (3), the front fraction is taken out when the gas phase temperature at the top of the tower is 45-50°C, and when the gas phase temperature at the top of the tower is 65-68°C, total reflux is maintained for 2 hours, and after the total reflux is completed, the temperature is raised to the gas phase temperature at the top of the tower at 70-75°C to obtain high-purity trans-1,3-dichloropropylene.

[0037] The gas phase temperature at the top of the tower is 45-50°C, for example, it can be 45°C, 46°C, 47°C, 48°C, 49°C or 50°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0038] The gas phase temperature at the top of the tower is 65-68°C, for example, 65°C, 65.5°C, 66°C, 67°C or 68°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] After the total reflux is completed, the temperature is raised to a gas phase temperature at the top of the tower of 70-75°C, for example, 70°C, 71°C, 73°C, 74°C or 75°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] As a preferred technical solution of the present invention, the processing method comprises the following steps:

[0041] (1) mixing the deteriorated trans-dichloropropylene product with a solid inorganic base to react, and obtaining a filtrate after solid-liquid separation;

[0042] The contents of various substances in the deteriorated trans-dichloropropylene product are: 59-63wt% of trans-1,3-dichloropropylene, 33.2-37.2wt% of cis-1,3-dichloropropylene, 0.03wt% of 3,3-dichloropropylene, 1wt% of acetic acid, 0.5wt% of hydrochloric acid, 0.3-1.6wt% of 1-chloro-acetaldehyde, 0.4-0.9wt% of 1,2-dichloroacetaldehyde, 0.2-0.7wt% of 1,2,3-trichloroacetaldehyde, 0.1-0.9wt% of 2-chloro-acrolein, 0.03-0.05wt% of 1-chloro-2-propanol and 0.3wt% of insoluble impurities; the solid inorganic base includes any one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate or potassium bicarbonate, or a combination of at least two thereof;

[0043] (2) mixing the filtrate with Tulsimer ARR-1 anion exchange resin to carry out an aldehyde removal reaction to obtain a crude mixed dichloropropylene product; the amount of the ion exchange resin added is 50 to 200 g;

[0044] (3) After the mixed dichloropropylene crude product is dehydrated by 50-150g molecular sieve, it is subjected to rectification treatment at a temperature of 58-127°C and a pressure of 160-350mmHg. During the rectification treatment, the front fraction is taken out when the gas phase temperature at the top of the tower is 45-50°C, and when the gas phase temperature at the top of the tower is 65-68°C, it is maintained at full reflux for 2h. After the full reflux is completed, the temperature is raised to a gas phase temperature at the top of the tower of 70-75°C to obtain high-purity trans-1,3-dichloropropylene;

[0045] The molecular sieve comprises any one of 3A molecular sieve, 4A molecular sieve or 5A molecular sieve or a combination of at least two thereof; the molecular sieve is activated at 500-600° C.; a catalyst Fe / ZSM-5 is added during the distillation treatment; and the amount of the catalyst added is 60-80 g.

[0046] Compared with the prior art, the present invention has at least the following beneficial effects:

[0047] The method for treating the deteriorated trans-dichloropropylene provided by the invention is simple to operate, does not need to react under conditions such as high temperature or high pressure, realizes the resource treatment of the deteriorated trans-dichloropropylene products, recovers high-purity trans-1,3-dichloropropylene, greatly reduces the treatment cost of organic waste liquid, and has good economic and environmental benefits. DETAILED DESCRIPTION

[0048] 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.

[0049] The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0050] Example 1

[0051] This embodiment provides a method for treating a deteriorated trans-dichloropropylene product, the method comprising the following steps:

[0052] (1) mixing 2 kg of the deteriorated trans-dichloropropylene product with 4 g of sodium hydroxide and stirring at room temperature for 30 minutes, filtering out insoluble solids by conventional suction filtration to obtain a filtrate, the composition of which is 60.0 wt% of trans-dichloropropylene, 37.2 wt% of cis-dichloropropylene, 0.03 wt% of 3,3-dichloropropylene, 0.4 wt% of 1-chloro-acetaldehyde, 0.5 wt% of 1,2-dichloroacetaldehyde, 0.2 wt% of 1,2,3-trichloroacetaldehyde, 0.03 wt% of 1-chloro-2-propanol, and 0.1 wt% of 2-chloro-acrolein;

[0053] (2) mixing the filtrate with 50 g of Tulsimer ARR-1 anion exchange resin, stirring at room temperature for 30 min to carry out aldehyde removal reaction, to obtain 1972 g of a crude mixed dichloropropylene product, wherein the composition is 62.7 wt % of trans-dichloropropylene, 37 wt % of cis-dichloropropylene, 0.12 wt % of 3,3-dichloropropylene, and 0.13 wt % of 1-chloro-2-propanol;

[0054] (3) The crude mixed dichloropropylene was mixed with 50 g of 4A molecular sieve activated and dehydrated at 500° C. and dehydrated at room temperature to obtain 1968 g of product for distillation separation. The distillation column had a diameter of 30 mm, a glass filler height of 1.8 m, 160 mmHg, a bottom temperature of 120-127° C., a middle temperature of 100-110° C., and a top temperature of 78-80° C. The tower was filled with 80 g of Fe / ZSM-5 catalyst. When the top temperature was 45-50° C., a small amount of fore fraction was extracted. When the top gas phase temperature was 65-68° C., total reflux was maintained for 2 h. After the total reflux was completed, the temperature was raised to a gas phase temperature of 70-75° C. to obtain 1660 g of high-purity trans-1,3-dichloropropylene, which was composed of 99.7 wt % of trans-dichloropropylene, 0.2 wt % of cis-dichloropropylene, and 0.03 wt % of 3,3-dichloropropylene.

[0055] Example 2

[0056] This embodiment provides a method for treating a deteriorated trans-dichloropropylene product, the method comprising the following steps:

[0057] (1) mixing 2 kg of the deteriorated trans-dichloropropylene product with 4 g of sodium carbonate and stirring at room temperature for 30 min, filtering out insoluble solids by conventional suction filtration to obtain a filtrate, wherein the filtrate comprises 60.0 wt % of trans-dichloropropylene, 37.2 wt % of cis-dichloropropylene, 0.03 wt % of 3,3-dichloropropylene, 0.3 wt % of 1-chloro-acetaldehyde, 0.4 wt % of 1,2-dichloroacetaldehyde, 0.3 wt % of 1,2,3-trichloroacetaldehyde, 0.04 wt % of 1-chloro-2-propanol, and 0.1 wt % of 2-chloro-acrolein;

[0058] (2) mixing the filtrate with 100 g of Tulsimer ARR-1 anion exchange resin, stirring at room temperature for 30 min to carry out aldehyde removal reaction, to obtain 1955 g of a crude mixed dichloropropylene product, wherein the composition is 60.7 wt % of trans-dichloropropylene, 39 wt % of cis-dichloropropylene, 0.09 wt % of 3,3-dichloropropylene, and 0.13 wt % of 1-chloro-2-propanol;

[0059] (3) The crude mixed dichloropropylene was mixed with 50 g of 3A molecular sieve activated and dehydrated at 500° C. and dehydrated at room temperature to obtain 1955 g of product for distillation separation. The distillation column had a diameter of 30 mm, a glass filler height of 1.8 m, 160 mmHg, a bottom temperature of 120-127° C., a middle temperature of 100-110° C., and a top temperature of 78-80° C. The tower was filled with 80 g of Fe / ZSM-5 catalyst. When the top temperature was 45-50° C., a small amount of fore fraction was extracted. When the top gas phase temperature was 65-68° C., total reflux was maintained for 2 h. After the total reflux was completed, the temperature was raised to a gas phase temperature of 70-75° C. to obtain 1627 g of high-purity trans-1,3-dichloropropylene, which was composed of 99.7 wt % of trans-dichloropropylene, 0.2 wt % of cis-dichloropropylene, and 0.03 wt % of 3,3-dichloropropylene.

[0060] Example 3

[0061] This embodiment provides a method for treating a deteriorated trans-dichloropropylene product, the method comprising the following steps:

[0062] (1) mixing 2 kg of the deteriorated trans-dichloropropylene product with 4 g of sodium bicarbonate and stirring at room temperature for 30 min, filtering out insoluble solids by conventional suction filtration to obtain a filtrate having a composition of 63.0 wt % of trans-dichloropropylene, 34.2 wt % of cis-dichloropropylene, 0.03 wt % of 3,3-dichloropropylene, 0.4 wt % of 1-chloro-acetaldehyde, 0.5 wt % of 1,2-dichloroacetaldehyde, 0.2 wt % of 1,2,3-trichloroacetaldehyde, 0.03 wt % of 1-chloro-2-propanol, and 0.1 wt % of 2-chloro-acrolein;

[0063] (2) mixing the filtrate with 100 g of Tulsimer ARR-1 anion exchange resin, stirring at room temperature for 30 min to carry out aldehyde removal reaction, to obtain 1975 g of a crude mixed dichloropropylene product, wherein the composition is 64.3 wt % of trans-dichloropropylene, 35.3 wt % of cis-dichloropropylene, 0.12 wt % of 3,3-dichloropropylene, and 0.13 wt % of 1-chloro-2-propanol;

[0064] (3) The crude mixed dichloropropylene was mixed with 150 g of 5A molecular sieve activated and dehydrated at 500° C. and dehydrated at room temperature to obtain 1975 g of product for distillation separation. The distillation column had a diameter of 30 mm, a glass filler height of 1.8 m, 200 mmHg, a bottom temperature of 105-110° C., a middle temperature of 95-100° C., and a top temperature of 75-78° C. The tower was filled with 80 g of Fe / ZSM-5 catalyst. When the top temperature was 45-50° C., a small amount of fore fraction was extracted. When the top gas phase temperature was 65-68° C., total reflux was maintained for 2 h. After the total reflux was completed, the temperature was raised to a gas phase temperature of 70-75° C. to obtain 1598 g of high-purity trans-1,3-dichloropropylene, which was composed of 99.94 wt% trans-dichloropropylene, 0.02 wt% cis-dichloropropylene, and 0.03 wt% 3,3-dichloropropylene.

[0065] Example 4

[0066] This embodiment provides a method for treating a deteriorated trans-dichloropropylene product, the method comprising the following steps:

[0067] (1) mixing 2 kg of the deteriorated trans-dichloropropylene product with 4 g of potassium hydroxide and stirring at room temperature for 30 min, filtering out insoluble solids by conventional suction filtration to obtain a filtrate having a composition of 59.0 wt % of trans-dichloropropylene, 36.2 wt % of cis-dichloropropylene, 0.03 wt % of 3,3-dichloropropylene, 1.0 wt % of 1-chloro-acetaldehyde, 0.8 wt % of 1,2-dichloroacetaldehyde, 0.5 wt % of 1,2,3-trichloroacetaldehyde, 0.03 wt % of 1-chloro-2-propanol, and 0.9 wt % of 2-chloro-acrolein;

[0068] (2) mixing the filtrate with 150 g of Tulsimer ARR-1 anion exchange resin, stirring at room temperature for 30 min to carry out aldehyde removal reaction, to obtain 1985 g of a crude mixed dichloropropylene product, wherein the composition is 61.6 wt % of trans-dichloropropylene, 37.8 wt % of cis-dichloropropylene, 0.18 wt % of 3,3-dichloropropylene, and 0.20 wt % of 1-chloro-2-propanol;

[0069] (3) The crude mixed dichloropropylene was mixed with 100 g of 5A molecular sieve activated and dehydrated at 500° C. and dehydrated at room temperature to obtain 1985 g of product for distillation separation. The distillation column had a diameter of 30 mm, a glass filler height of 1.8 m, 350 mmHg, a bottom temperature of 85-90° C., a middle temperature of 75-80° C., and a top temperature of 58-60° C. The tower was filled with 60 g of Fe / ZSM-5 catalyst. When the top temperature was 45-50° C., a small amount of fore fraction was extracted. When the top gas phase temperature was 65-68° C., total reflux was maintained for 2 h. After the total reflux was completed, the temperature was raised to a gas phase temperature of 70-75° C. to obtain 1598 g of high-purity trans-1,3-dichloropropylene, which was composed of 99.95 wt % of trans-dichloropropylene, 0.02 wt % of cis-dichloropropylene, and 0.01 wt % of 3,3-dichloropropylene.

[0070] Example 5

[0071] This embodiment provides a method for treating a deteriorated trans-dichloropropylene product, the method comprising the following steps:

[0072] (1) mixing 2 kg of the deteriorated trans-dichloropropylene product with 4 g of sodium hydroxide and stirring at room temperature for 30 min, filtering out insoluble solids by conventional suction filtration to obtain a filtrate, the composition of which is 61.0 wt % of trans-dichloropropylene, 33.2 wt % of cis-dichloropropylene, 0.03 wt % of 3,3-dichloropropylene, 1.6 wt % of 1-chloro-acetaldehyde, 0.9 wt % of 1,2-dichloroacetaldehyde, 0.7 wt % of 1,2,3-trichloroacetaldehyde, 0.05 wt % of 1-chloro-2-propanol, and 0.4 wt % of 2-chloro-acrolein;

[0073] (2) mixing the filtrate with 200 g of Tulsimer ARR-1 anion exchange resin, stirring at room temperature for 30 min to carry out aldehyde removal reaction, to obtain 1981 g of a crude mixed dichloropropylene product, wherein the composition is 63.7 wt % of trans-dichloropropylene, 35.8 wt % of cis-dichloropropylene, 0.17 wt % of 3,3-dichloropropylene, and 0.28 wt % of 1-chloro-2-propanol;

[0074] (3) The crude mixed dichloropropylene was mixed with 150 g of 5A molecular sieve activated and dehydrated at 500° C. and dehydrated at room temperature to obtain 1981 g of product for distillation separation. The distillation column had a diameter of 30 mm, a glass filler height of 1.8 m, 350 mmHg, a bottom temperature of 85-90° C., a middle temperature of 75-80° C., and a top temperature of 58-60° C. The tower was filled with 100 g of Fe / ZSM-5 catalyst. When the top temperature was 45-50° C., a small amount of fore fraction was extracted. When the top gas phase temperature was 65-68° C., total reflux was maintained for 2 h. After the total reflux was completed, the temperature was raised to a gas phase temperature of 70-75° C. to obtain 1655 g of high-purity trans-1,3-dichloropropylene, which was composed of 99.8 wt % of trans-dichloropropylene, 0.02 wt % of cis-dichloropropylene, and 0.01 wt % of 3,3-dichloropropylene.

[0075] Comparative Example 1

[0076] This comparative example provides a method for treating a deteriorated trans-dichloropropylene product. The method is the same as Example 1 except that step (2) the filtrate is mixed with a Fenton reagent to perform an aldehyde removal reaction until the aldehyde impurities in the filtrate are completely removed.

[0077] Since the comparative example adopts Fenton's reagent to remove aldehyde, new impurities are introduced, and additional processing steps are required later, which increases the processing cost.

[0078] Comparative Example 2

[0079] This comparative example provides a method for treating a deteriorated trans-dichloropropylene product. The method is the same as Example 1 except that the catalyst added in the distillation treatment in step (3) is ZSM-5.

[0080] In this comparative example, since the catalyst used in the distillation treatment is ZSM-5, the catalytic effect is poor, and the content of cis-1,3-dichloropropylene in the finally obtained trans-1,3-dichloropropylene is relatively high.

[0081] In summary, the method for treating the deteriorated trans-dichloropropylene provided by the present invention adopts a specific resin to remove aldehyde impurities in the deteriorated trans-dichloropropylene product, and adopts a specific catalyst to perform distillation treatment to re-isomerize cis-1,3-dichloropropylene into trans-1,3-dichloropropylene, and finally obtain high-purity trans-1,3-dichloropropylene; the treatment method is simple to operate, and the reaction conditions are mild, and the resource treatment of the deteriorated trans-dichloropropylene product is realized.

[0082] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for treating a deteriorated product of trans-dichloropropylene, characterized in that: The processing method comprises the following steps: (1) mixing the deteriorated trans-dichloropropylene product with a solid inorganic base to react, and obtaining a filtrate after solid-liquid separation; (2) mixing the filtrate with Tulsimer ARR-1 anion exchange resin to perform an aldehyde removal reaction to obtain a crude mixed dichloropropylene product; (3) After the mixed dichloropropylene crude product is dehydrated by molecular sieve, it is subjected to distillation treatment to obtain high-purity trans-1,3-dichloropropylene; a catalyst Fe / ZSM-5 is added during the distillation treatment, and the distillation treatment temperature is 58 to 127° C.; The contents of various substances in the deteriorated product of trans-dichloropropylene in step (1) are: trans-1,3-dichloropropylene 59-63wt%, cis-1,3-dichloropropylene 33.2-37.2wt%, 3,3-dichloropropylene 0.03wt%, acetic acid 1wt%, hydrochloric acid 0.5wt%, 1-chloro-acetaldehyde 0.3-1.6wt%, 1,2-dichloroacetaldehyde 0.4-0.9wt%, 1,2,3-trichloroacetaldehyde 0.2-0.7wt%, 2-chloro-acrolein 0.1-0.9wt%, 1-chloro-2-propanol 0.03-0.05wt% and insoluble impurities 0.3wt%.

2. The processing method according to claim 1, characterized in that: The solid inorganic base includes any one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate or potassium bicarbonate, or a combination of at least two thereof.

3. The processing method according to claim 1, characterized in that: The amount of ion exchange resin added in step (2) is 50 to 200 g.

4. The processing method according to claim 1, characterized in that: The molecular sieve in step (3) includes any one of 3A molecular sieve, 4A molecular sieve or 5A molecular sieve, or a combination of at least two of them.

5. The processing method according to claim 1, characterized in that: The molecular sieve in step (3) is activated at 500-600°C.

6. The processing method according to claim 1, characterized in that: The added amount of the molecular sieve is 50 to 150 g.

7. The processing method according to claim 1, characterized in that: The amount of the catalyst added in step (3) is 60 to 80 g.

8. The processing method according to claim 1, characterized in that: The pressure of the distillation treatment in step (3) is 160-350 mmHg.

9. The processing method according to claim 1, characterized in that: During the distillation treatment in step (3), the front fraction is extracted when the gas phase temperature at the top of the tower is 45-50°C, and when the gas phase temperature at the top of the tower is 65-68°C, total reflux is maintained for 2 hours. After the total reflux is completed, the temperature is raised to a gas phase temperature at the top of the tower of 70-75°C to obtain high-purity trans-1,3-dichloropropylene.

10. The processing method according to claim 1, characterized in that: The processing method comprises the following steps: (1) mixing the deteriorated trans-dichloropropylene product with a solid inorganic base to react, and obtaining a filtrate after solid-liquid separation; The contents of various substances in the deteriorated trans-dichloropropylene product are: 59-63wt% of trans-1,3-dichloropropylene, 33.2-37.2wt% of cis-1,3-dichloropropylene, 0.03wt% of 3,3-dichloropropylene, 1wt% of acetic acid, 0.5wt% of hydrochloric acid, 0.3-1.6wt% of 1-chloro-acetaldehyde, 0.4-0.9wt% of 1,2-dichloroacetaldehyde, 0.2-0.7wt% of 1,2,3-trichloroacetaldehyde, 0.1-0.9wt% of 2-chloro-acrolein, 0.03-0.05wt% of 1-chloro-2-propanol and 0.3wt% of insoluble impurities; the solid inorganic base includes any one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate or potassium bicarbonate, or a combination of at least two thereof; (2) mixing the filtrate with Tulsimer ARR-1 anion exchange resin to carry out an aldehyde removal reaction to obtain a crude mixed dichloropropylene product; the amount of the ion exchange resin added is 50 to 200 g; (3) After the mixed dichloropropylene crude product is dehydrated by 50-150g molecular sieve, it is subjected to rectification treatment at a temperature of 58-127°C and a pressure of 160-350mmHg. During the rectification treatment, the front fraction is taken out when the gas phase temperature at the top of the tower is 45-50°C, and when the gas phase temperature at the top of the tower is 65-68°C, it is maintained at full reflux for 2h. After the full reflux is completed, the temperature is raised to a gas phase temperature at the top of the tower of 70-75°C to obtain high-purity trans-1,3-dichloropropylene; The molecular sieve comprises any one of 3A molecular sieve, 4A molecular sieve or 5A molecular sieve or a combination of at least two thereof; the molecular sieve is activated at 500-600° C.; a catalyst Fe / ZSM-5 is added during the distillation treatment; and the amount of the catalyst added is 60-80 g.