Method for treating high boiling residual liquid of trichloroacetone

Abstract

The invention relates to the field of waste liquid treatment, and discloses a method for treating a high-boiling residual liquid of trichloroacetone, comprising reacting the high-boiling residual liquid of trichloroacetone with a metal element under the condition of the presence of water and a phase transfer catalyst. The method has a safe reaction process, does not destroy the original acetone structure, has a simple process, has a high reduction efficiency of high-chloroacetone in the residual liquid, does not generate waste water after the reaction is completed, does not discharge organic chlorinated substances, and the reaction product can be continuously used to prepare 1,1,3-trichloroacetone, thereby having good economic benefits.

Description

Technical Field

[0001] The invention relates to the field of waste liquid treatment, and in particular to a method for treating trichloroacetone high-boiling residual liquid. Background Art

[0002] The main components of the high-boiling residual liquid of trichloroacetone are 1,1,1-trichloroacetone or 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone, hexachloroacetone and other high-chlorinated acetones. However, high-chlorinated acetone has a large density, a pungent odor and tear-inducing properties. It slowly hydrolyzes into hydrogen chloride in water. Microorganisms cannot survive in the residual liquid, so it cannot be directly degraded by microorganisms. If it is directly incinerated, it will not be flammable due to the high chlorine content. The addition of combustion-supporting materials will increase the processing cost. In addition, the incineration product contains hydrogen chloride, which is easy to damage the equipment. Improper waste gas treatment will generate dioxins, causing environmental damage.

[0003] CN106984635A discloses the use of an organic solvent and a strong base to convert perchloroacetone into an inorganic salt through a substitution reaction, and recover the solvent. Although this method renders perchloroacetone harmless, it destroys its original structure, the reaction product cannot continue to generate trichloroacetone, and a large amount of concentrated alkali is required. The generated inorganic salt also needs to be processed by a company with processing qualifications.

[0004] CN108218079A discloses the use of carbide slag (main component calcium hydroxide) to treat high-chlorinated acetone, and finally obtains calcium chloride as a by-product. The added calcium hydroxide destroys the structure of high-chlorinated acetone, so that high-chlorinated acetone is converted into hydroxy ketone, aldehyde ketone, hydroxy aldehyde ketone, aldehyde, and hydroxy aldehyde. This method can only make high-chlorinated acetone reach the condition of microbial degradation, and the subsequent filtrate needs to be degraded by microorganisms to meet the emission standards, and it cannot be recycled and reused.

[0005] CN106957222A discloses a method of directly reducing high-chlorinated acetone to 1,1,3-trichloroacetone and 1,3-dichloroacetone by hydrodechlorination. Although the resource treatment of high-chlorinated acetone is achieved, the hydrodechlorination reaction requires the use of expensive palladium catalysts, which increases the cost of use; at the same time, the byproduct hydrogen chloride generated is corrosive to the equipment. To solve this problem, the cost of equipment investment needs to be increased; during the reaction, alkali needs to be added to adjust the pH of the system to ensure that the reaction proceeds in the forward direction. After the hydrodechlorination reaction of high-chlorinated acetone is completed, a certain amount of tetrachloroacetone is still not completely dechlorinated.

[0006] The trichloroacetone residual liquid has complex components, and the high-chlorinated acetone contained in it is at risk of leakage during transportation, causing pollution to the environment. Therefore, it is necessary to dispose the trichloroacetone residual liquid harmlessly on site. Therefore, it is particularly important to find a method for harmlessly treating the high-boiling trichloroacetone residual liquid, which has a safe reaction process, high high-chlorinated acetone reduction efficiency, does not destroy the original acetone structure, has a simple process, and is easy to handle by-products. Summary of the invention

[0007] The purpose of the present invention is to overcome the problems in the prior art of low dechlorination efficiency of highly chlorinated acetone during harmless treatment of highly chlorinated acetone residual liquid, easy destruction of the original acetone structure, difficulty in treating reaction by-products, and easy generation of waste liquid, and provide a method for treating trichloroacetone high-boiling residual liquid.

[0008] In order to achieve the above object, the first aspect of the present invention provides a method for treating a high-boiling residue of trichloroacetone, wherein the method comprises contacting the high-boiling residue of trichloroacetone with a metal element to react in the presence of water and a phase transfer catalyst.

[0009] The second aspect of the present invention provides an application of the method of the present invention in the reaction of preparing 1,1,3-trichloroacetone.

[0010] The third aspect of the present invention provides a method for preparing 1,1,3-trichloroacetone, wherein the reaction process of the method comprises the following steps:

[0011] (a) subjecting acetone and chlorine to a chlorination reaction to obtain 1,1,3-trichloroacetone and a trichloroacetone high-boiling residue;

[0012] (b) treating the trichloroacetone high boiling residue according to the aforementioned method to obtain a fraction and a residual liquid;

[0013] (c) using the fraction for the chlorination reaction to further generate 1,1,3-trichloroacetone, and recovering the remaining liquid for classification and treatment.

[0014] The method for treating the high-boiling residue of trichloroacetone provided by the present invention achieves the following beneficial technical effects:

[0015] 1. The treatment method of the present invention can reduce the high-boiling residue of trichloroacetone under normal pressure without destroying the original acetone structure, and the reaction product can continue to prepare 1,1,3-trichloroacetone, thereby improving the utilization rate of the high-boiling residue of trichloroacetone;

[0016] 2. The phase transfer catalyst added in the present invention helps to improve the efficiency of the reduction reaction. After the reaction is completed, it remains in the filtrate and can be recycled without separating the phase transfer catalyst separately;

[0017] 3. The technical solution of the present invention can reduce high-chloroacetones such as 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone and hexachloroacetone together. After the reaction is completed, the sum of the gas phase normalized contents of acetone and low-chloroacetone in the reaction product is greater than 95%, effectively reducing high-chloroacetone.

[0018] Through the above technical scheme, the trichloroacetone high-boiling residual liquid of the present invention has high treatment efficiency, the original structure of the compound contained in the residual liquid is not destroyed, the reaction product can be recycled to continue to prepare 1,1,3-trichloroacetone, no corrosive by-products are generated during the reaction process, no waste water is generated after the reaction is completed, and no organic chlorinated substances are discharged. According to the method provided by the present invention, the trichloroacetone high-boiling residual liquid reacts under the action of a metal element and a phase transfer catalyst, the reaction is more thorough, and the amount of the fraction containing acetone and low-chloroacetone is higher. DETAILED DESCRIPTION

[0019] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0020] The first aspect of the present invention provides a method for treating a high-boiling residue of trichloroacetone, wherein the method comprises contacting the high-boiling residue of trichloroacetone with a metal element to react in the presence of water and a phase transfer catalyst.

[0021] In the present invention, the trichloroacetone high boiling residue includes at least one of 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone and hexachloroacetone.

[0022] In the present invention, the weight of each component in the method refers to the weight based on the weight of the high-boiling residual liquid of trichloroacetone.

[0023] In the present invention, the composition and content of the trichloroacetone high-boiling residue are determined by a method combining a gas chromatograph and a mass spectrometer.

[0024] The inventors of the present invention have found that by using a metal element and water to act together on the reduction reaction of a high-boiling residue of trichloroacetone, high-chlorinated acetones such as 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone, and hexachloroacetone can be reduced to acetone and low-chlorinated acetones such as monochloroacetone, 1,3-dichloroacetone, and 1,1-dichloroacetone under normal pressure conditions without destroying the original acetone structure.

[0025] In the present invention, the phase transfer catalyst can accelerate the reduction reaction of perchloroacetone, and adding a small amount of the phase transfer catalyst can make the reaction proceed more efficiently and more thoroughly.

[0026] According to the present invention, the phase transfer catalyst can be a phase transfer catalyst that promotes the reduction reaction of perchloroacetone. In some embodiments, the phase transfer catalyst is at least one of tetrabutylammonium chloride, tetrabutylammonium bromide, benzyltriethylammonium chloride, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, polyethylene glycol and polyethylene glycol dialkyl ether.

[0027] The phase transfer catalyst of the present invention has a wide selection range, and when the phase transfer catalyst is a polymer, there is no special limitation on the molecular weight.

[0028] According to the present invention, the weight ratio of the phase transfer catalyst to the trichloroacetone high boiling residue is 0.001-0.05:1, preferably 0.005-0.03:1.

[0029] According to the present invention, the weight ratio of water to trichloroacetone high boiling residue is 0.1-3:1, preferably 0.4-2:1.

[0030] According to the present invention, the metal element is at least one of iron, aluminum, magnesium and zinc.

[0031] In the present invention, the shape and source of the metal element are not particularly limited, and preferably, the metal element can be in any shape such as block, flake, strip, or powder.

[0032] According to the present invention, the weight ratio of the metal element to the high-boiling residue of trichloroacetone is 0.05-1:1, preferably 0.1-0.6:1.

[0033] In the present invention, the weight ratio of the metal element to the high-boiling residue of trichloroacetone should be controlled within an appropriate range. When the weight of the metal element is too low, the high-boiling residue of trichloroacetone will not react completely, and there will be high-chlorinated acetone that has not been reduced; and when the weight of the metal element is too high, low-chlorinated acetone will be excessively reduced, wasting the metal element.

[0034] According to the present invention, the reduction temperature of the trichloroacetone high boiling residue in contact with the metal element is 50-95°C.

[0035] Preferably, the reduction temperature of the trichloroacetone high boiling residue in contact with the metallic elemental iron is 70-95°C, preferably 85-90°C.

[0036] Preferably, the reduction temperature of the trichloroacetone high boiling residual liquid in contact with the metallic aluminum is 70-95°C, preferably 75-85°C.

[0037] Preferably, the reduction temperature of the trichloroacetone high boiling residue in contact with the metallic zinc is 55-80°C, preferably 65-75°C.

[0038] Preferably, the reduction temperature of the trichloroacetone high boiling residue in contact with the metal elemental magnesium is 50-75°C, preferably 60-70°C.

[0039] According to the present invention, the metal element is added in batches for 1-10 hours, preferably 3-8 hours.

[0040] In the present invention, adding the metal element in batches can make the reaction proceed smoothly and evenly and prevent material rushing.

[0041] In the present invention, controlling the time of adding the metal element in batches is beneficial to the smooth and uniform reaction and preventing the material from rushing.

[0042] According to the present invention, after the metal element is added in batches, the product is continuously subjected to heat preservation reaction, which helps to reduce the content of high chlorine components to below the required standard content.

[0043] In the present invention, the insulation reaction time is 1-5 hours. According to the type and form of the metal element and the reaction rate, the insulation time can be appropriately extended or shortened, preferably 2-4 hours.

[0044] According to the present invention, the sum of the residual gas phase normalized contents of high-chloroacetone such as 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone, hexachloroacetone and 1,1,3-trichloroacetone in the product of the insulation reaction is less than 0.5% as an evaluation criterion for stopping the reaction.

[0045] In the present invention, the composition and content of the insulation reaction product are determined by gas chromatography-mass spectrometry.

[0046] According to the present invention, the pH value of the product obtained by adjusting the pH is 3-7, preferably 3.5-5.5.

[0047] In the present invention, the pH value of the insulation reaction product is adjusted to 3-7, so that the metal hydroxide is dissolved into hydrochloride, which is convenient for subsequent by-product treatment.

[0048] According to the present invention, the process of adjusting pH is to add hydrochloric acid to the reaction product.

[0049] In the present invention, hydrochloric acid is used to adjust the pH of the obtained product to avoid the formation of mixed salts in the product. If other acids are used to adjust the pH, the generated product is a mixed salt, which cannot be recycled and is a hazardous waste.

[0050] In some embodiments, the hydrochloric acid is added in the form of a solution, and the concentration of the hydrochloric acid solution is 20wt%-40wt%, preferably 25wt%-35wt%.

[0051] In the present invention, the amount of the hydrochloric acid solution used is sufficient to achieve a pH value of 3-7 for the heat preservation reaction product.

[0052] In the present invention, the product obtained by adjusting the pH value is subjected to vacuum distillation after filtering out the unreacted metal to obtain a fraction and a residual liquid.

[0053] In the present invention, after the reaction is completed, the reaction product can be recycled, the obtained fraction contains acetone and low-chlorinated acetone for preparing 1,1,3-trichloroacetone, and the remaining liquid is a metal chloride solution that can be recycled, and has no impact on equipment and the environment.

[0054] In the present invention, the residual liquid after distillation is decolorized by an adsorbent, concentrated and then filtered, and the filter cake is further processed to recover the corresponding chloride salt for resource treatment, wherein hydrated ferrous chloride and hydrated aluminum chloride are used as flocculants for water treatment, hydrated magnesium chloride is used as a snow-melting agent, and hydrated zinc chloride is handed over to dry cell manufacturers for electrolyte recovery.

[0055] In the present invention, the adsorbent may be any substance with adsorption capacity, and the adsorbent may be at least one selected from activated carbon, diatomaceous earth, molecular sieve, alumina and silicon dioxide.

[0056] In some preferred embodiments of the present invention, the weight ratio of the adsorbent to the high-boiling residue of trichloroacetone is 0.001-0.05:1.

[0057] In the present invention, under preferred conditions, the remaining liquid after distillation is filtered, and the obtained filtrate is added again to new trichloroacetone high-boiling residual liquid for reaction, without the need to separate the phase transfer catalyst separately, and the amount of the phase transfer catalyst can be reduced.

[0058] The second aspect of the present invention provides an application of the method of the present invention in the reaction of preparing 1,1,3-trichloroacetone.

[0059] The third aspect of the present invention provides a method for preparing 1,1,3-trichloroacetone, characterized in that the reaction process of the method comprises the following steps:

[0060] (a) subjecting acetone and chlorine to a chlorination reaction to obtain 1,1,3-trichloroacetone and a trichloroacetone high-boiling residue;

[0061] (b) treating the trichloroacetone high boiling residue according to the aforementioned method to obtain a fraction and a residual liquid;

[0062] (c) using the fraction for the chlorination reaction to further generate 1,1,3-trichloroacetone, and recovering the remaining liquid for classification and treatment.

[0063] In the present invention, the conditions of the chlorination reaction are not particularly limited, and the chlorination reaction can be achieved by any existing method.

[0064] In the present invention, the fraction is used to react with chlorine to generate 1,1,3-trichloroacetone, the obtained 1,1,3-trichloroacetone is used to continue to produce folic acid, and the high-chlorinated acetone impurities generated by excessive chlorination are repeatedly subjected to the trichloroacetone high-boiling residue treatment reaction.

[0065] According to a particularly preferred embodiment of the present invention, (1) water and a phase transfer catalyst are added to a high boiling residue of trichloroacetone, wherein the weight ratio of the water to the high boiling residue of trichloroacetone is 0.8-1.5:1, and the weight ratio of the phase transfer catalyst to the high boiling residue of trichloroacetone is 0.01-0.025:1, to obtain a mixed solution;

[0066] (2) heating the mixed solution to a temperature of 60-90° C. under stirring, and then adding metal elements to the mixed solution in batches to carry out the reaction, wherein the weight ratio of the metal elements to the high-boiling residue of trichloroacetone is 0.12-0.5:1, and the addition time of the metal elements is 4-8 hours;

[0067] (3) After the addition of the metal element is completed, the product obtained in step (2) is subjected to a heat preservation reaction for 2-4 hours. When the sum of the gas phase normalized content of high-chloroacetone in the product of the heat preservation reaction is less than 0.5%, the heat preservation reaction is stopped.

[0068] The present invention will be described in detail below through examples and comparative examples. In the following examples and comparative examples, the reagents or instruments used without indicating the manufacturer are all conventional products that can be obtained through commercial channels.

[0069] If no specific conditions are specified in the following examples and comparative examples, the experiments were carried out according to conventional conditions or conditions recommended by the manufacturer.

[0070] The composition and content of the high-boiling residue of trichloroacetone and the reaction product after the reaction were determined by gas chromatography-mass spectrometry.

[0071] Example 1

[0072] (1) Weigh 500 g of trichloroacetone high boiling residue, and determine the composition and content of the residue by gas phase detection: 41.5% of 1,1,1-trichloroacetone, 11.2% of 1,1,3,3-tetrachloroacetone, 23.5% of 1,1,1,3-tetrachloroacetone, 6.7% of pentachloroacetone, 3.1% of hexachloroacetone, and 7.6% of 1,1,3-trichloroacetone, to which 600 g of water and 6 g of tetrabutylammonium chloride as a phase transfer catalyst are added;

[0073] (2) Stirring and heating the mixed solution, adding 70 g of iron powder, raising the temperature to 85°C to start the reaction, adding iron powder details: adding 50 g after 1 hour of reaction, 40 g after 2.5 hours, 30 g after 4.5 hours, 10 g after 6 hours, and the feeding is completed after 8 hours, with a total of 200 g of iron powder added;

[0074] (3) After the addition of the metal element is completed, the product obtained in step (2) is subjected to a heat preservation reaction, and the heat preservation reaction is stopped when the sum of the residual gas phase normalized contents of 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone, hexachloroacetone and 1,1,3-trichloroacetone detected in the gas phase of the product of the heat preservation reaction is less than 0.5%;

[0075] (4) The pH value of the reaction product obtained in step (3) was adjusted to 3.6 using 30 wt % hydrochloric acid, and then filtered to remove 3.4 g of unreacted iron powder. The obtained filtrate was subjected to vacuum distillation to obtain 290.6 g of fraction and 1050 g of residual liquid (containing 446 g of ferrous chloride and 6 g of tetrabutylammonium chloride). 3 g of activated carbon was added for decolorization and then the waste carbon was incinerated. The decolorized liquid was concentrated and filtered again. After further treatment of the filter cake, 650 g of hydrated ferrous chloride was recovered as a flocculant for water treatment. The filtrate containing water and a phase transfer catalyst was used for the next reaction.

[0076] Example 2

[0077] (1) Weigh 500 g of trichloroacetone high boiling residue, determine the composition and content of the residue by gas phase detection: 41.5% of 1,1,1-trichloroacetone, 11.2% of 1,1,3,3-tetrachloroacetone, 23.5% of 1,1,1,3-tetrachloroacetone, 6.7% of pentachloroacetone, 3.1% of hexachloroacetone, and 7.6% of 1,1,3-trichloroacetone, add 750 g of water and 8 g of tetrabutylammonium bromide as a phase transfer catalyst;

[0078] (2) Stir and heat the mixed solution, add 20 g of aluminum flakes, raise the temperature to 75°C to start the reaction, add aluminum flakes details: add 15 g for 1 hour, 15 g for 2 hours, 10 g for 4 hours, 5 g for 5 hours, and the feeding is completed after 6 hours, with a total of 65 g of aluminum flakes added;

[0079] (3) After the addition of the metal element is completed, the product obtained in step (2) is subjected to a heat preservation reaction, and the heat preservation reaction is stopped when the sum of the residual gas phase normalized contents of 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone, hexachloroacetone and 1,1,3-trichloroacetone detected in the gas phase of the product of the heat preservation reaction is less than 0.5%;

[0080] (4) The pH value of the reaction product obtained in step (3) was adjusted to 3.8 using 30 wt % hydrochloric acid, and then filtered to remove 2.1 g of unreacted aluminum flakes. The obtained filtrate was subjected to vacuum distillation to obtain 297.2 g of a fraction and 1060 g of a residual liquid (containing 311 g of aluminum chloride and 8 g of tetrabutylammonium bromide). After decolorization with 4 g of adsorbent aluminum oxide, the aluminum oxide was incinerated and recovered for use. The filtrate was concentrated and filtered again. After further treatment of the filter cake, 582 g of hydrated aluminum chloride was recovered as a flocculant for water treatment. The filtrate contained water and a phase transfer catalyst for the next reaction.

[0081] Example 3

[0082] (1) Weigh 500 g of trichloroacetone high boiling residue, determine the composition and content of the residue by gas phase detection: 41.5% of 1,1,1-trichloroacetone, 11.2% of 1,1,3,3-tetrachloroacetone, 23.5% of 1,1,1,3-tetrachloroacetone, 6.7% of pentachloroacetone, 3.1% of hexachloroacetone, and 7.6% of 1,1,3-trichloroacetone, add 400 g of water and 10 g of benzyltriethylammonium chloride as a phase transfer catalyst;

[0083] (2) Stir and heat the mixed solution, add 90 g of zinc particles, raise the temperature to 65°C to start the reaction, and add zinc particles in detail: add 60 g after 1.5 hours of reaction, 50 g after 3 hours, 30 g after 4.5 hours, 10 g after 6 hours, and the feeding is completed after 7 hours, with a total of 240 g of zinc particles added;

[0084] (3) After the addition of the metal element is completed, the product obtained in step (2) is subjected to a heat preservation reaction, and the heat preservation reaction is stopped when the sum of the residual gas phase normalized contents of 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone, hexachloroacetone and 1,1,3-trichloroacetone detected in the gas phase of the product of the heat preservation reaction is less than 0.5%;

[0085] (4) The pH value of the reaction product obtained in step (3) was adjusted to 4.2 using 30 wt % hydrochloric acid, and then filtered to remove 6.7 g of unreacted zinc particles. The obtained filtrate was subjected to vacuum distillation to obtain 287.4 g of a fraction and 880 g of a residual liquid (containing 485 g of zinc chloride and 10 g of benzyltriethylammonium chloride). After being decolorized by 4 g of diatomaceous earth as an adsorbent, the diatomaceous earth was incinerated and continued to be used. The filtrate was concentrated and filtered again. After the filter cake was further treated, 780 g of hydrated zinc chloride was recovered and handed over to a dry cell manufacturer for electrolyte recovery. The filtrate contained water and a phase transfer catalyst for the next reaction.

[0086] Example 4

[0087] (1) Weigh 500 g of trichloroacetone high boiling residue, and determine the composition and content of the residue by gas phase detection: 41.5% of 1,1,1-trichloroacetone, 11.2% of 1,1,3,3-tetrachloroacetone, 23.5% of 1,1,1,3-tetrachloroacetone, 6.7% of 1,1,1,3,3-pentachloroacetone, 3.1% of hexachloroacetone, and 7.6% of 1,1,3-trichloroacetone, to which 700 g of water and 6 g of tetrabutylammonium hydrogen sulfate as a phase transfer catalyst are added;

[0088] (2) Stir and heat the mixed solution, add 30 g of magnesium ribbon, raise the temperature to 50°C to start the reaction, add 25 g of magnesium ribbon after 1 hour, 20 g after 2 hours, 10 g after 3 hours, 5 g after 4 hours, and the feeding is completed after 5 hours, with a total of 90 g of magnesium ribbon added;

[0089] (3) After the addition of the metal element is completed, the product obtained in step (2) is subjected to a heat preservation reaction, and the heat preservation reaction is stopped when the sum of the normalized residual gas phase contents of 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone, hexachloroacetone and 1,1,3-trichloroacetone detected in the gas phase of the product of the heat preservation reaction is less than 0.5%;

[0090] (4) The pH value of the reaction product obtained in step (3) was adjusted to 5 using 30 wt % hydrochloric acid, and then filtered to remove 2.9 g of unreacted magnesium ribbon. The obtained filtrate was subjected to vacuum distillation to obtain 291.6 g of fraction and 1030 g of residual liquid (containing 341 g of magnesium chloride and 6 g of tetrabutylammonium hydrogen sulfate). The residual liquid was decolorized by 5 g of adsorbent silica, and the silica was incinerated and then used continuously. The filtrate was concentrated and filtered again. The filter cake was further treated to recover 601 g of hydrated magnesium chloride for use as a snow melting agent. The filtrate contained water and a phase transfer catalyst for the next reaction.

[0091] Example 5

[0092] (1) Weigh 500 g of trichloroacetone high boiling residue, determine the composition and content of the residue by gas phase detection: 41.5% of 1,1,1-trichloroacetone, 11.2% of 1,1,3,3-tetrachloroacetone, 23.5% of 1,1,1,3-tetrachloroacetone, 6.7% of pentachloroacetone, 3.1% of hexachloroacetone, and 7.6% of 1,1,3-trichloroacetone, add 400 g of water and 10 g of tetradecyltrimethylammonium chloride as a phase transfer catalyst;

[0093] (2) Stir and heat the mixed solution, add 90 g of zinc particles, raise the temperature to 65°C to start the reaction, and add zinc particles in detail: add 60 g after 1.5 hours of reaction, 50 g after 3 hours, 30 g after 4.5 hours, 20 g after 6 hours, and the feeding is completed after 7 hours. A total of 250 g of zinc particles are added;

[0094] (3) After the addition of the metal element is completed, the product obtained in step (2) is subjected to a heat preservation reaction, and the heat preservation reaction is stopped when the sum of the residual contents of 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone, hexachloroacetone and 1,1,3-trichloroacetone detected in the gas phase of the product of the heat preservation reaction is less than 0.5%;

[0095] (4) The pH value of the reaction product obtained in step (3) was adjusted to 3.5 using 30 wt % hydrochloric acid, and then filtered to remove 6.7 g of unreacted zinc particles. The obtained filtrate was subjected to vacuum distillation to obtain 285.2 g of a fraction and 960 g of a residual liquid (containing 507 g of zinc chloride and 10 g of tetradecyltrimethylammonium chloride). After decolorization with 10 g of diatomaceous earth as an adsorbent, the residue was concentrated and filtered again. After further treatment of the filter cake, 734 g of hydrated zinc chloride was recovered and handed over to a dry cell manufacturer for electrolyte recovery. The filtrate contained water and a phase transfer catalyst for the next reaction.

[0096] Example 6

[0097] (1) Weigh 500 g of trichloroacetone high boiling residue, determine the composition and content of the residue by gas phase detection: 41.5% of 1,1,1-trichloroacetone, 11.2% of 1,1,3,3-tetrachloroacetone, 23.5% of 1,1,1,3-tetrachloroacetone, 6.7% of pentachloroacetone, 3.1% of hexachloroacetone, and 7.6% of 1,1,3-trichloroacetone, add 800 g of water and 12 g of polyethylene glycol (PEG400) as a phase transfer catalyst;

[0098] (2) Stir and heat the mixed solution, add 30 g of magnesium ribbon, raise the temperature to 50°C to start the reaction, add 25 g of magnesium ribbon after 1 hour, 20 g after 2 hours, 10 g after 3 hours, 10 g after 4 hours, and the feeding is completed after 5 hours, with a total of 95 g of magnesium ribbon added;

[0099] (3) After the addition of the metal element is completed, the product obtained in step (2) is subjected to a heat preservation reaction, and the heat preservation reaction is stopped when the sum of the residual contents of 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone, hexachloroacetone and 1,1,3-trichloroacetone detected in the gas phase of the product of the heat preservation reaction is less than 0.5%;

[0100] (4) The pH value of the reaction product obtained in step (3) was adjusted to 3.6 using 30 wt % hydrochloric acid, and then filtered to remove 5.2 g of unreacted magnesium ribbon. The obtained filtrate was subjected to vacuum distillation to obtain 291.6 g of fraction and 1135 g of residual liquid (containing 352 g of magnesium chloride and 12 g of polyethylene glycol). After decolorization with 3 g of adsorbent silica, it was concentrated and filtered again. After further treatment of the filter cake, 700 g of hydrated magnesium chloride was recovered for use as a snow-melting agent. The filtrate contained water and a phase transfer catalyst for the next reaction.

[0101] Example 7

[0102] (1) Weigh 500 g of trichloroacetone high-boiling residue, and determine the composition and content of the residue by gas phase detection: 41.5% of 1,1,1-trichloroacetone, 11.2% of 1,1,3,3-tetrachloroacetone, 23.5% of 1,1,1,3-tetrachloroacetone, 6.7% of pentachloroacetone, 3.1% of hexachloroacetone, and 7.6% of 1,1,3-trichloroacetone. Add 100 g of the remaining filtrate after filtering ferrous chloride in Example 1 (containing 50 g of ferrous chloride, 45 g of water, and 5 g of tetrabutylammonium chloride), 550 g of water, and 1 g of tetrabutylammonium chloride as a phase transfer catalyst;

[0103] (2) Stir and heat the mixed solution, add 70 g of iron powder, raise the temperature to 85°C to start the reaction, add magnesium strip details: add 50 g after 1 hour of reaction, 40 g after 2.5 hours, 30 g after 4.5 hours, 10 g after 6 hours, and the feeding is completed after 8 hours, with a total of 200 g of iron powder added;

[0104] (3) After the addition of the metal element is completed, the product obtained in step (2) is subjected to a heat preservation reaction, and the heat preservation reaction is stopped when the sum of the residual gas phase normalized contents of 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone, hexachloroacetone and 1,1,3-trichloroacetone detected in the gas phase of the product of the heat preservation reaction is less than 0.5%;

[0105] (4) The pH value of the reaction product obtained in step (3) was adjusted to 3.6 using 30 wt % hydrochloric acid, and then filtered to remove 4.2 g of unreacted iron powder. The obtained filtrate was subjected to vacuum distillation to obtain 293.1 g of a fraction and 1100 g of a residual liquid (containing 488 g of an aqueous solution of ferrous chloride and 6 g of tetrabutylammonium chloride). The residual liquid was decolorized with 3 g of activated carbon as an adsorbent and then concentrated and filtered. The waste activated carbon was incinerated, and the decolorized liquid was concentrated and filtered. The filter cake was further treated to recover 706 g of hydrated ferrous chloride for use as a snow-melting agent. The filtrate contained water and a phase transfer catalyst for the next reaction.

[0106] Example 8

[0107] (1) Weigh 500 g of trichloroacetone high boiling residue, and determine the composition and content of the residue by gas phase detection: 41.5% of 1,1,1-trichloroacetone, 11.2% of 1,1,3,3-tetrachloroacetone, 23.5% of 1,1,1,3-tetrachloroacetone, 6.7% of pentachloroacetone, 3.1% of hexachloroacetone, and 7.6% of 1,1,3-trichloroacetone, to which 700 g of water and 7 g of trioctylmethylammonium chloride as a phase transfer catalyst are added;

[0108] (2) Stirring and heating the mixed solution, adding 70 g of iron powder, raising the temperature to 85°C to start the reaction, adding iron powder details: adding 70 g for 1 hour, 70 g for 2.5 hours, 70 g for 4.5 hours, 70 g for 6 hours, and the feeding is completed after 8 hours, with a total of 350 g of iron powder added;

[0109] (3) After the addition of the metal element is completed, the product obtained in step (2) is subjected to a heat preservation reaction, and the heat preservation reaction is stopped when the sum of the residual gas phase normalized contents of 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone, hexachloroacetone and 1,1,3-trichloroacetone detected in the gas phase of the product of the heat preservation reaction is less than 0.5%;

[0110] (4) The pH value of the reaction product obtained in step (3) was adjusted to 3.6 using 30 wt % hydrochloric acid, and then filtered to remove 29.1 g of unreacted iron powder. The obtained filtrate was subjected to vacuum distillation to obtain 137 g of fraction and 1530 g of residual liquid (containing 727 g of ferrous chloride and 7 g of trioctylmethylammonium chloride). After decolorization with 5 g of adsorbent molecular sieve, it was concentrated and filtered to obtain 1150 g of hydrated ferrous chloride. The flocculant used for water treatment was further recovered, and the filtrate containing water and phase transfer catalyst was used for the next reaction.

[0111] Example 9

[0112] (1) Weigh 500 g of trichloroacetone high boiling residue, determine the composition and content of the residue by gas phase detection: 41.5% of 1,1,1-trichloroacetone, 11.2% of 1,1,3,3-tetrachloroacetone, 23.5% of 1,1,1,3-tetrachloroacetone, 6.7% of pentachloroacetone, 3.1% of hexachloroacetone, and 7.6% of 1,1,3-trichloroacetone, add 800 g of water and 9 g of dodecyltrimethylammonium chloride as a phase transfer catalyst;

[0113] (2) Stir and heat the mixed solution, add 20 g of aluminum flakes, raise the temperature to 75°C to start the reaction, add aluminum flakes details: add 5 g after 1 hour, 5 g after 2 hours, 5 g after 4 hours, 5 g after 5 hours, and end the feeding after 6 hours. A total of 40 g of aluminum flakes are added;

[0114] (3) After the addition of the metal element is completed, the product obtained in step (2) is subjected to a heat preservation reaction, wherein the sum of the normalized residual gas phase contents of 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone, hexachloroacetone and 1,1,3-trichloroacetone detected in the gas phase in the product of the heat preservation reaction is 13% and does not change any more;

[0115] (4) The pH value of the reaction product obtained in step (3) was adjusted to 3.6 using 30 wt % hydrochloric acid, and then filtered to remove 0.1 g of unreacted aluminum flakes. The obtained filtrate was subjected to vacuum distillation to obtain 168 g of a fraction (4% high-boiling raw material content) and 1210 g of a residual liquid (containing 145 g of aluminum chloride and 9 g of dodecyltrimethylammonium chloride, and 163 g of a high-boiling residual liquid). The high-boiling residual liquid was separated and decolorized with 5 g of an adsorbent aluminum oxide. The aluminum oxide was incinerated and then used again. The decolorized liquid was concentrated and filtered again. The filter cake was further treated to recover 316 g of hydrated aluminum chloride as a flocculant for water treatment. The filtrate contained water and a phase transfer catalyst for the next reaction.

[0116] Example 10

[0117] (1) Weigh 500 g of trichloroacetone high boiling residue, and determine the composition and content of the residue by gas phase detection: 41.5% of 1,1,1-trichloroacetone, 11.2% of 1,1,3,3-tetrachloroacetone, 23.5% of 1,1,1,3-tetrachloroacetone, 6.7% of pentachloroacetone, 3.1% of hexachloroacetone, and 7.6% of 1,1,3-trichloroacetone, to which 600 g of water and 1 g of tetrabutylammonium chloride as a phase transfer catalyst are added;

[0118] (2) Stirring and heating the mixed solution, adding 70 g of iron powder, raising the temperature to 85°C to start the reaction, adding iron powder details: adding 50 g after 1 hour of reaction, 40 g after 2.5 hours, 30 g after 4.5 hours, 10 g after 6 hours, and the feeding is completed after 8 hours, with a total of 200 g of iron powder added;

[0119] (3) After the addition of the metal element is completed, the product obtained in step (2) is subjected to a heat preservation reaction. When the sum of the normalized residual gas phase contents of 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone, hexachloroacetone and 1,1,3-trichloroacetone detected in the gas phase of the product of the heat preservation reaction is 5%, and heating is continued, and the decrease is less than 0.5% per hour, the heat preservation reaction is stopped;

[0120] (4) The pH value of the reaction product obtained in step (3) was adjusted to 4.5 using 30 wt % hydrochloric acid, and then filtered to remove 26.2 g of unreacted iron powder. The obtained filtrate was subjected to vacuum distillation to obtain 223 g of a fraction (1.5% high-boiling raw material content) and 1100 g of a residual liquid (containing 394 g of ferrous chloride and 1 g of tetrabutylammonium chloride, and 46 g of high-boiling substances). The high-boiling substances were removed by separation, and 3 g of activated carbon was added for decolorization. The activated carbon was incinerated, and the decolorized liquid was concentrated and filtered. After further treatment of the filter cake, 610 g of hydrated ferrous chloride was recovered as a flocculant for water treatment. The filtrate contained water and a phase transfer catalyst for the next reaction.

[0121] Embodiment 11

[0122] (1) Weigh 500 g of trichloroacetone high boiling residue, and determine the composition and content of the residue by gas phase detection: 41.5% of 1,1,1-trichloroacetone, 11.2% of 1,1,3,3-tetrachloroacetone, 23.5% of 1,1,1,3-tetrachloroacetone, 6.7% of pentachloroacetone, 3.1% of hexachloroacetone, and 7.6% of 1,1,3-trichloroacetone, to which 600 g of water and 6 g of tetrabutylammonium chloride as a phase transfer catalyst are added;

[0123] (2) Stir and heat the mixed solution, add 200 g of iron powder, and raise the temperature to 85°C to start the reaction. The reaction is uncontrolled and violent boiling occurs.

[0124] Example 12

[0125] (1) Weigh 500 g of trichloroacetone high boiling residue, and determine the composition and content of the residue by gas phase detection: 41.5% of 1,1,1-trichloroacetone, 11.2% of 1,1,3,3-tetrachloroacetone, 23.5% of 1,1,1,3-tetrachloroacetone, 6.7% of pentachloroacetone, 3.1% of hexachloroacetone, and 7.6% of 1,1,3-trichloroacetone, to which 1000 g of water and 12 g of a phase transfer catalyst, polyethylene glycol dialkyl ether, are added;

[0126] (2) Stir and heat the mixed solution, add 70 g of iron powder, raise the temperature to 55°C to start the reaction, add iron powder details: add 50 g for 2 hours, 40 g for 5 hours, 30 g for 8 hours, 10 g for 10 hours, and end the feeding after 12 hours, with a total of 200 g of iron powder added;

[0127] (3) After the addition of the metal element is completed, the product obtained in step (2) is subjected to a heat preservation reaction. When the sum of the residual contents of 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone, hexachloroacetone and 1,1,3-trichloroacetone detected in the gas phase in the product of the heat preservation reaction reaches 11%, and after the heating time is extended, the raw material content slowly decreases, and the heat preservation reaction is stopped;

[0128] (4) The pH value of the reaction product obtained in step (3) was adjusted to 3.6 using 30 wt % hydrochloric acid, and then filtered to remove 23.1 g of unreacted iron powder. The obtained filtrate was subjected to vacuum distillation to obtain 181.1 g of a fraction (containing 4.5% of a high-boiling raw material) and 1550 g of a residual liquid (containing 400 g of ferrous chloride and 12 g of polyethylene glycol dialkyl ether, and 104 g of a high-boiling substance). The high-boiling substance was separated, and the aqueous phase was decolorized by 4 g of adsorbent activated carbon. The waste carbon was incinerated, and the decolorized liquid was concentrated and filtered to obtain 568 g of a filter cake for water treatment as a flocculant. The filtrate contained water and a phase transfer catalyst for the next reaction.

[0129] Comparative Example 1

[0130] (1) Weigh 500 g of trichloroacetone high boiling residue, determine the composition and content of the residue by gas phase detection: 41.5% of 1,1,1-trichloroacetone, 11.2% of 1,1,3,3-tetrachloroacetone, 23.5% of 1,1,1,3-tetrachloroacetone, 6.7% of pentachloroacetone, 3.1% of hexachloroacetone, and 7.6% of 1,1,3-trichloroacetone, and add 600 g of water;

[0131] (2) Stirring and heating the mixed solution, adding 70 g of iron powder, raising the temperature to 85° C. to start the reaction, adding details of iron powder: adding 50 g after 2.5 hours of reaction, adding 40 g after 5 hours, adding 30 g after 7 hours, the iron powder no longer dissolves, adding 20 g after 10 hours, and detecting that 22.4% of high-chlorinated acetone remains after 15 hours, adding a total of 210 g of iron powder;

[0132] (3) During the reaction, when the sum of the residual contents of 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone, hexachloroacetone and 1,1,3-trichloroacetone detected in the gas phase was 22.4%, the reaction was no longer carried out;

[0133] (4) The pH value of the reaction product obtained in step (3) was adjusted to 3.6 using 30 wt % hydrochloric acid, and then filtered to remove 55.9 g of unreacted iron powder. The obtained filtrate was subjected to vacuum distillation to obtain 131.1 g of a fraction (containing 7% of a high boiling raw material). Gas phase detection showed that the sum of the contents of acetone, monochloroacetone, 1,1-dichloroacetone and 1,3-dichloroacetone was 78.3%, and trichloroacetone and higher chlorine were evaporated. The reduction reaction was not complete without adding a phase transfer catalyst.

[0134] The technical solution of the present invention is used to treat the high-boiling residue of trichloroacetone, and the high-boiling residue of trichloroacetone can be reduced under mild conditions without destroying the original acetone structure. The reaction product is low-chloroacetone, which can be used to continue to prepare 1,1,3-trichloroacetone. The phase transfer catalyst contained in the residual liquid can be added again with the filtrate to a new reaction for reducing the high-boiling residue of trichloroacetone.

[0135] Phase transfer catalyst was not added during the processing of Comparative Example 1, and the reaction was not carried out thoroughly, indicating that the phase transfer catalyst helps to improve the efficiency of the reduction reaction. Excessive iron powder was added during the processing of Example 8, and the reaction over-reduced low-chloroacetone, resulting in a waste of iron powder, and the fraction content in the product was small. The amount of aluminum flakes added in Example 9 was insufficient, and the reaction was not carried out thoroughly, and high-chloroacetone was still present and not reduced. In Example 10, the amount of phase transfer catalyst added was insufficient, and a certain amount of high-chloroacetone and iron powder were still contained when the reaction was stopped and not completely reacted, and the reaction was not carried out thoroughly.

[0136] In Example 11, the metal element was not added in batches, and the iron powder was added all at once, resulting in an uncontrolled reaction and violent boiling. In Example 12, the iron powder was not heated to the reduction reaction temperature for reaction, and a large amount of high-chloroacetone remained in the product, and the reaction was not thorough.

[0137] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for treating a high-boiling residue of trichloroacetone, characterized in that: The method comprises the steps of reacting trichloroacetone high boiling residual liquid with a metal element in the presence of water and a phase transfer catalyst; The phase transfer catalyst is selected from at least one of tetrabutylammonium chloride, tetrabutylammonium bromide, benzyltriethylammonium chloride, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, polyethylene glycol and polyethylene glycol dialkyl ether; The trichloroacetone high boiling residue comprises at least one of 1,1,1-trichloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1,3-tetrachloroacetone, pentachloroacetone and hexachloroacetone; The metal element is selected from at least one of iron, aluminum, magnesium and zinc; The weight ratio of the metal element to the trichloroacetone high boiling residue is 0.05-1:1; The reduction temperature of the trichloroacetone high boiling residual liquid in contact with the metallic elemental iron is 70-95°C; The metal element is added in batches, and the time for adding the metal element in batches is 1-10 hours.

2. The method according to claim 1, wherein: The weight ratio of the phase transfer catalyst to the trichloroacetone high boiling residual liquid is 0.001-0.05:

1.

3. The method according to claim 2, wherein: The weight ratio of the phase transfer catalyst to the trichloroacetone high boiling residual liquid is 0.005-0.03:

1.

4. The method according to claim 1, wherein: The weight ratio of water to trichloroacetone high boiling residual liquid is 0.1-3:

1.

5. The method according to claim 4, wherein: The weight ratio of the water to the trichloroacetone high boiling residual liquid is 0.4-2:

1.

6. The method according to claim 1, wherein: The weight ratio of the metal element to the trichloroacetone high-boiling residual liquid is 0.1-0.6:

1.

7. The method according to any one of claims 1 to 6, wherein: The process of the reaction comprises the following steps: (1) mixing trichloroacetone high boiling residue, water and a phase transfer catalyst to obtain a mixed solution; (2) heating the mixed solution to a temperature of 50-95° C. under stirring, and then adding at least one of metal elements selected from aluminum, magnesium and zinc to the mixed solution in batches to carry out the reaction, wherein the metal element is added for 1-10 hours; (3) After the addition of the metal element is completed, the product obtained in step (2) is subjected to a heat preservation reaction. When the sum of the gas phase normalized content of high-chlorinated acetone in the product of the heat preservation reaction is less than 0.5%, the heat preservation reaction is stopped.

8. The method according to claim 7, wherein: The process of the reaction comprises the following steps: The adding time of the metal element is 3-8 hours.

9. The method according to claim 7, wherein: The reaction process also includes: adjusting the pH of the reaction product obtained by the reaction, filtering to remove the unreacted metal element, and performing vacuum distillation on the obtained filtrate to obtain a fraction and a residual liquid.

10. The method according to claim 9, wherein: The process of adjusting the pH is to add hydrochloric acid to the reaction product; The pH value of the product obtained by adjusting the pH is 3-7.

11. The method according to claim 10, wherein: The pH value of the product obtained by adjusting the pH is 3.5-5.5.