CN108117487B - Acetyl chloride decoloring method and application of acidic strong oxidant in acetyl chloride decoloring - Google Patents
Acetyl chloride decoloring method and application of acidic strong oxidant in acetyl chloride decoloring Download PDFInfo
- Publication number
- CN108117487B CN108117487B CN201711450586.1A CN201711450586A CN108117487B CN 108117487 B CN108117487 B CN 108117487B CN 201711450586 A CN201711450586 A CN 201711450586A CN 108117487 B CN108117487 B CN 108117487B
- Authority
- CN
- China
- Prior art keywords
- acetyl chloride
- acidic
- strong oxidant
- oxidant
- strong
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/58—Preparation of carboxylic acid halides
- C07C51/64—Separation; Purification; Stabilisation; Use of additives
Abstract
The invention discloses an acetyl chloride decoloring method, which comprises the following steps: s1: adding an acidic strong oxidant into the discolored acetyl chloride while stirring at the temperature of not higher than 45 ℃; the mass ratio of the acidic strong oxidant to the acetyl chloride is 1: 250-1: 1000; s2: heating until fractions appear, and carrying out total reflux reaction; s3: after the total reflux reaction is finished, rectifying the mixture at the temperature of not higher than 85 ℃ until the flow is cut off. The invention also discloses the application of the acidic strong oxidant in the decoloring of acetyl chloride. The method disclosed by the invention can remove organic matters which contain unsaturated bonds and have more active properties from acetyl chloride, effectively prevent the acetyl chloride from discoloring in transportation and storage, and improve the use value of the acetyl chloride.
Description
Technical Field
The invention relates to the field of organic matter decolorization, and particularly relates to an acetyl chloride decolorization method and application of a strong acidic oxidant in acetyl chloride decolorization.
Background
In the industrial synthesis process of methyl triacetoxysilane by using acetic anhydride and methyl trichlorosilane, acetyl chloride is generated as a byproduct. Acetyl chloride is used as an organic synthesis raw material for producing pesticides, medicines, novel electroplating complexing agents, catalysts for chlorination reaction of carboxylic acid, acetylation reagents and other various fine organic synthesis intermediates.
As other side reactions exist in the production process, the acetyl chloride with active organic matters has unstable properties of trace impurities in the storage and transportation processes, so that the color of the acetyl chloride is darkened.
The time period for the current acetyl chloride to change from colorless to a color range distinguishable to the naked eye is about 7 days, and if the storage and transportation temperature is too high, the time period for the color change is shorter.
The acetyl chloride which has changed color contains trace impurities, and the acetyl chloride which has changed color is re-purified and rectified, and still changes color in the later storage and transportation process, so that the appearance is influenced, the impurities can influence the reaction participated in by the acetyl chloride, the normal use of the acetyl chloride as a reaction raw material in various downstream fields is not facilitated, and at present, the acetyl chloride is more active, so that the activated carbon is generally adopted to decolor the acetyl chloride, and the effect is poor.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide an acetyl chloride decoloring method, which can remove organic matters containing unsaturated bonds and having more active properties in acetyl chloride, effectively prevent the acetyl chloride from discoloring in transportation and storage and improve the use value of the acetyl chloride.
In order to achieve the above purposes, the technical scheme adopted by the invention is as follows: an acetyl chloride decoloring method comprises the following steps:
s1: adding an acidic strong oxidant into the discolored acetyl chloride while stirring at the temperature of not higher than 45 ℃; the mass ratio of the acidic strong oxidant to the acetyl chloride is 1: 250-1: 1000;
s2: heating until fractions appear, and carrying out total reflux reaction;
s3: after the total reflux reaction is finished, rectifying the mixture at the temperature of not higher than 85 ℃ until the flow is cut off.
Further, the mass ratio of the acidic strong oxidant to the acetyl chloride is 1: 500.
Further, the acidic strong oxidant comprises one of concentrated nitric acid, potassium permanganate and concentrated sulfuric acid with the mass fraction not less than 70%.
Further, the mass fraction of the concentrated sulfuric acid is 98%.
Further, when the acidic strong oxidant is in a liquid state, the acidic strong oxidant is added into the acetyl chloride in a dropwise manner;
when the acidic strong oxidant is in a solid state, the acidic strong oxidant is added into the acetyl chloride in a fractional manner.
Further, in the step S1, the acidic strong oxidant is added within 30min to 60 min.
Further, in the step S2, the total reflux reaction time is 60min to 120 min.
Further, the step of S1 includes the steps of: the strong acidic oxidizing agent is added into the acetyl chloride at one time while stirring, and the temperature is increased to 62 ℃ within 10min after the addition.
The invention also provides the application of the acidic strong oxidant in the decoloring of acetyl chloride.
Further, the acidic strong oxidant comprises one of concentrated nitric acid, potassium permanganate and concentrated sulfuric acid with the mass fraction not less than 70%.
Compared with the prior art, the invention has the advantages that:
(1) according to the method for decoloring acetyl chloride, impurities in acetyl chloride are deeply analyzed, the main substance causing the acetyl chloride to discolor is determined to be ketene, the substance causing the discoloration in the acetyl chloride is converted into a new substance with more stable property by using a strong acidic oxidant, and the acetyl chloride is purified in the subsequent rectification process, so that the quality abnormity of the acetyl chloride caused by discoloration in storage is avoided, and the use value of the acetyl chloride is improved.
(2) The implementation method of the invention has simple operation, safety and reliability, easy obtainment of the decolorizing agent and little addition amount. The industrial implementation is simple, safe and easy.
Detailed Description
The present invention will be described in further detail with reference to examples.
The embodiment of the invention provides an acetyl chloride decoloring method, which comprises the following steps:
s1: adding an acidic strong oxidant into the discolored acetyl chloride while stirring at the temperature of not higher than 45 ℃; the mass ratio of the acidic strong oxidant to the acetyl chloride is 1: 250-1: 1000;
s2: heating until fractions appear, and carrying out total reflux reaction;
s3: after the total reflux reaction is finished, rectifying the mixture at the temperature of not higher than 85 ℃ until the flow is cut off.
When the mass ratio of the acidic strong oxidant to the acetyl chloride is 1:500, the economic benefit is the best.
The acidic strong oxidant comprises one of concentrated nitric acid, potassium permanganate and concentrated sulfuric acid with the mass fraction not less than 70%. The mass fraction of the concentrated sulfuric acid is preferably 98%, and the potassium permanganate is preferably powdery potassium permanganate.
When the acidic strong oxidant is in a liquid state, the acidic strong oxidant is added into acetyl chloride in a dropwise manner;
when the acidic strong oxidant is in a solid state, the acidic strong oxidant is added into acetyl chloride in a fractional manner.
In the step S1, the acidic strong oxidant is added within 30-60 min.
In the step S2, the total reflux reaction time is 60-120 min.
The step of S1 includes the following steps: adding the strong acidic oxidant into acetyl chloride at one time while stirring, and raising the temperature to 62 ℃ within 10min after the addition.
When the method provided by the invention is used for decoloring acetyl chloride, the discolored acetyl chloride is added into a device with rectification and reflux measures, then the acidic strong oxidant is added into the device in a manner of fractional or dropwise addition within 0.5-1 hour, the temperature is controlled to be less than 45 ℃ in the process, and the stirring is started in the whole process. Then the temperature is raised until the distillate in the device is distilled out, and the total reflux reaction is carried out for 1 to 2 hours. After the reaction treatment stage is finished, carrying out rectification collection process operation, properly controlling reflux ratio according to working conditions to collect qualified acetyl chloride until collection and cutoff, wherein the temperature of a rectification kettle in the rectification process is not more than 85 ℃. The reaction mechanism is roughly as follows:
strong acidic oxidant + unstable target → organic matter that is stable and colorless in nature.
At present, the specific colored product generated by storing acetyl chloride cannot be considered, and the invention analyzes the side reactions related to all reactants and reaction products, and deduces that the reaction raw material acetic anhydride is decomposed in the high-temperature production process, and the generated ketene is a main component which is easy to cause color change and is difficult to remove.
However, the purity of acetyl chloride produced industrially is usually more than 98%, other impurities are contained in the acetyl chloride, the content of ketene is too low, and it is difficult to determine whether the substance causing color change is ketene by conventional inspection means (such as gas chromatography, liquid chromatography, mass spectrometry, etc.), so the industry has not been able to solve the problem of color change of acetyl chloride.
When the acetyl chloride is produced, the boiling point of acetic acid is 117.9 ℃, the boiling point of methyltrichlorosilane is 66.5 ℃, the boiling point of methyltriacetoxysilane is 110-112 ℃/17mmHg which are higher than the boiling point of acetyl chloride by 51 ℃, so that low-temperature fraction acetyl chloride can be obtained by distillation, and the acetyl chloride can be purified by rectification because the boiling point of the acetyl chloride is low; however, since ketene has a boiling point of-56 ℃ and is a gas at normal temperature, when acetyl chloride is obtained or purified by distillation, ketene inevitably enters acetyl chloride, and ketene can be dissolved in acetyl chloride, that is, a trace amount of ketene remains in acetyl chloride, and is difficult to remove by multiple distillation.
The method comprises the steps of adding 0.1-0.5 mass percent of ketene which is obtained by an inventor according to a plurality of test results and cannot be matched with a control group in other ranges into acetyl chloride with the purity of 99% as an experimental group, taking the existing byproduct acetyl chloride as the control group, taking acetyl chloride with the purity of 99% as a blank group, and storing (or transporting) the acetyl chloride under the same conditions to obtain the acetyl chloride with the purity of 99% and the acetyl chloride with the purity of 99%, wherein the discoloration time and the discoloration color of the experimental group and the color of the control group are basically consistent, and the blank group has no discoloration.
Since the acidic strong oxidant can generate oxidation-reduction reaction with ketene to generate a new substance with more stable product physical and chemical properties, the ketene in acetyl chloride is removed according to the reaction mechanism, although the reaction mechanism is simpler, the cause of the discoloration is determined after long-term research and exploration, and the result of the invention can not be obtained by simply looking up the literature.
For those skilled in the art, the standard of acetyl chloride discoloration is that the solution has a chroma of more than 30 Hazen, and the existing acetyl chloride storage and transportation process usually has a chroma of 50-60 Hazen after one week of storage.
The following is a detailed description of the 12 specific examples.
Example 1
200g of acetyl chloride to be treated was put into a 500ml four-necked flask equipped with a thermometer, mechanical stirring, reflux condenser, and dropping funnel having a constant pressure at a time. After the feeding is finished, the three-neck flask is immersed in cooling water and stirring is started. Adding 0.2g of concentrated sulfuric acid with the mass fraction not less than 98% into a constant-pressure dropping funnel, and dropwise adding into acetyl chloride at a constant speed, wherein the temperature is not more than 45 ℃ in the dropwise adding process, and the dropwise adding time is 0.5-1 h. After the concentrated sulfuric acid is dripped, cooling water is removed and replaced by an electric heating sleeve, and a constant-pressure dropping funnel is removed and replaced by a sealing plug. Slowly raising the temperature of acetyl chloride until the acetyl chloride is completely refluxed, wherein the reflux reaction time is 1 hour. After the reflux reaction is finished, the reflux device is changed into a rectifying device, and acetyl chloride is rectified and purified to finally obtain a colorless and transparent acetyl chloride product with the content of more than 98 percent. The temperature in the rectification and purification process is not more than 85 ℃.
Example 2
The operation steps of this example are substantially the same as those of example 1, except that: the mass fraction of the dropwise added concentrated sulfuric acid is not less than 0.8g of 98 percent.
Example 3
The operation steps of this example are substantially the same as those of example 1, except that: the mass fraction of the dropwise added concentrated sulfuric acid is not less than 0.1g of 98 percent.
Example 4
The operation steps of this example are substantially the same as those of example 1, except that: 0.4g of concentrated sulfuric acid with the mass fraction not less than 98 percent is added at one time, and the temperature is increased to 62 ℃ from 24 ℃ within 10min after the addition.
Example 5
The operation steps of this example are substantially the same as those of example 1, except that: the reflux reaction time was 0.5 h.
Example 6
The operation steps of this example are substantially the same as those of example 1, except that: the reflux reaction time was 2 h.
Example 7
The operation steps of this example are substantially the same as those of example 1, except that: the temperature in the rectification and purification process is 90 ℃. The final product was 96.2% acetyl chloride in the form of a pale yellow transparent liquid.
Example 8
The operation steps of this example are substantially the same as those of example 1, except that: the dropwise added acidic strong oxidant is nitric acid, and the total amount of dropwise addition is 0.4 g.
Example 9
The operation steps of this example are substantially the same as those of example 1, except that: the added acidic strong oxidant is potassium permanganate, the adding mode is divided adding, and the adding amount is 0.4 g.
Example 10
The operation steps of this example are substantially the same as those of example 1, except that: the dropwise added strong acidic oxidant is concentrated sulfuric acid with the mass fraction of 70%, and the dropwise added total amount is 0.55 g.
Example 11
The operation steps of this example are substantially the same as those of example 1, except that: the dropwise added strong acidic oxidant is concentrated sulfuric acid with the mass fraction of 80%, and the total dropwise added amount is 0.5 g.
Example 12
The operation steps of this example are substantially the same as those of example 1, except that: no acidic strong oxidant was added.
Except for example 7, the acetyl chloride obtained after the treatment of other 11 groups of examples is purified to be colorless transparent liquid, and the acetyl chloride content is more than 98 percent. The 12 acetyl chloride purified samples are placed in an experimental group, a control group and a blank group, and the samples in example 10 are all changed into 40-Mezengzhou color by visual discoloration after being placed for 3 days under the same conditions; example 10 was 55 Megazen in color; example 3 was 50 Mesoh in color. After 30 days of standing, the color of examples 3, 5, 10 and 11 appeared to change to the naked eye, wherein the color of example 3 was 45 Mesozenes, and the color of example 5 was 40 Mesozenes; the sample of example 7 was still a light yellow transparent liquid with no darkening in color. The other example samples still did not change significantly in apparent color after 3 months of storage. Therefore, the decoloring effect is better when the mass ratio of the acidic strong oxidizing agent to the discolored acetyl chloride is 1: 250-1: 1000, and the optimal ratio of the acidic strong oxidizing agent to the discolored acetyl chloride is 1: 500.
the invention also provides the application of the acidic strong oxidant in the decoloring of acetyl chloride.
The acidic strong oxidant is one of concentrated nitric acid, potassium permanganate and concentrated sulfuric acid with the mass fraction not less than 70%. The mass fraction of concentrated sulfuric acid is preferably 98%.
The present invention is not limited to the above-described embodiments, and it will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and such modifications and improvements are also considered to be within the scope of the present invention. Those not described in detail in this specification are within the skill of the art.
Claims (8)
1. An acetyl chloride decoloring method is characterized by comprising the following steps:
s1: adding an acidic strong oxidant into the discolored acetyl chloride while stirring at the temperature of not higher than 45 ℃; the mass ratio of the strong acidic oxidizing agent to the acetyl chloride is 1: 250-1: 1000, and the strong acidic oxidizing agent comprises one of concentrated nitric acid, potassium permanganate and concentrated sulfuric acid with the mass fraction not lower than 70%;
s2: heating until fractions appear, and carrying out total reflux reaction;
s3: after the total reflux reaction is finished, rectifying the mixture at the temperature of not higher than 85 ℃ until the flow is cut off.
2. The method of decolorizing acetyl chloride according to claim 1, characterized in that: the mass ratio of the acidic strong oxidant to the acetyl chloride is 1: 500.
3. The method of decolorizing acetyl chloride according to claim 1, characterized in that: the mass fraction of the concentrated sulfuric acid is 98%.
4. A method of decolorizing the acetyl chloride of any of the claims 1 to 3, characterized in that:
when the acidic strong oxidant is in a liquid state, the acidic strong oxidant is added into the acetyl chloride in a dropwise manner;
when the acidic strong oxidant is in a solid state, the acidic strong oxidant is added into the acetyl chloride in a fractional manner.
5. The method of decolorizing acetyl chloride according to claim 1, characterized in that: in the step S1, the addition of the acidic strong oxidant is completed within 30-60 min.
6. The method of decolorizing acetyl chloride according to claim 1, characterized in that: in the step S2, the total reflux reaction time is 60-120 min.
7. The method of decolorizing acetyl chloride according to claim 1, characterized in that: the step of S1 includes the steps of: the strong acidic oxidizing agent is added into the acetyl chloride at one time while stirring, and the temperature is increased to 62 ℃ within 10min after the addition.
8. The application of the strong acidic oxidant in the decoloring of acetyl chloride is characterized in that: the strong acidic oxidant comprises one of concentrated nitric acid, potassium permanganate and concentrated sulfuric acid with the mass fraction not less than 70%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711450586.1A CN108117487B (en) | 2017-12-27 | 2017-12-27 | Acetyl chloride decoloring method and application of acidic strong oxidant in acetyl chloride decoloring |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711450586.1A CN108117487B (en) | 2017-12-27 | 2017-12-27 | Acetyl chloride decoloring method and application of acidic strong oxidant in acetyl chloride decoloring |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108117487A CN108117487A (en) | 2018-06-05 |
| CN108117487B true CN108117487B (en) | 2021-01-05 |
Family
ID=62231889
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711450586.1A Active CN108117487B (en) | 2017-12-27 | 2017-12-27 | Acetyl chloride decoloring method and application of acidic strong oxidant in acetyl chloride decoloring |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108117487B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105646192A (en) * | 2016-03-22 | 2016-06-08 | 湖北新蓝天新材料股份有限公司 | Acetylchloride decoloring method |
-
2017
- 2017-12-27 CN CN201711450586.1A patent/CN108117487B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105646192A (en) * | 2016-03-22 | 2016-06-08 | 湖北新蓝天新材料股份有限公司 | Acetylchloride decoloring method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108117487A (en) | 2018-06-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5666429B2 (en) | Production of ethylenically unsaturated acids or their esters | |
| CN108117487B (en) | Acetyl chloride decoloring method and application of acidic strong oxidant in acetyl chloride decoloring | |
| DE1593861B2 (en) | PROCESS FOR THE PREPARATION OF PHENYLESTERS FROM BENZENE | |
| US2321823A (en) | Oxidation of perchloroethylene | |
| EP3205643A1 (en) | Method for the preparation of 3-methylthiopropionaldehyde | |
| WO2015159893A1 (en) | Method for manufacturing fatty acid chloride and fatty acid chloride | |
| EP0106445B2 (en) | Process for modifying and stabilising the colour of carboxylic acids or their mixtures | |
| US3205041A (en) | Process for producing pure yellow phosphorus sulfides | |
| CN105646192B (en) | A kind of chloroacetic chloride discoloration method | |
| FI66195B (en) | FOERFARANDE FOER NEDSAETTNING AV KCENTRATION AV EN FOERORENING | |
| JP6562379B2 (en) | Method for producing fatty acid chloride | |
| KR19980042700A (en) | Method for preparing ruthenium (III) acetate solution | |
| EP3152187B1 (en) | Method for separating high-boiling carboxylic acid vinyl ester/carboxylic acid mixtures | |
| US2803588A (en) | Distillation process for making pure acetic acid | |
| EP3684747B1 (en) | Method of preparing glycol esters with low color and peroxide content | |
| KR101699148B1 (en) | Method for purification of an epoxidized soybean oil | |
| Lyon et al. | Rate of reaction of hexahalocyclopentadienes with long-chain olefins | |
| JP6873856B2 (en) | Method for producing acetic anhydride | |
| EP3214064B1 (en) | Method for preparing 1,4-cyclohexanedicarboxylic acid dichloride | |
| US2450389A (en) | Manufacture of crotonic acid | |
| DE1593861C3 (en) | Process for the preparation of phenyl esters from benzene | |
| JPS63112562A (en) | Production of 5,6,7,8-tetrahydroquinolines | |
| CN116606203A (en) | Method for improving purity of acetic acid | |
| WO2023054644A1 (en) | Method for producing fluorenone | |
| CN112778085A (en) | 1, 2-hexanediol and purification method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |