CN101967099B - Purification method of dimethyl dicarbonate - Google Patents
Purification method of dimethyl dicarbonate Download PDFInfo
- Publication number
- CN101967099B CN101967099B CN 201010532392 CN201010532392A CN101967099B CN 101967099 B CN101967099 B CN 101967099B CN 201010532392 CN201010532392 CN 201010532392 CN 201010532392 A CN201010532392 A CN 201010532392A CN 101967099 B CN101967099 B CN 101967099B
- Authority
- CN
- China
- Prior art keywords
- dimethyl
- dimethyl dicarbonate
- carbonic ethers
- carbonic
- temperature
- 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
Abstract
The invention provides a purification method of dimethyl dicarbonate. The invention relates to a food additive refining process. Because the dimethyl dicarbonate is unstable at room temperature, the dimethyl dicarbonate is decomposed due to higher distillation temperature even under the condition of high vacuum degree when a common distillation method is used, thus a product can not be obtained. In order to solve the problem, the invention adopts a method of bubbling by dry compressed air and compressed nitrogen at the temperature lower than the freezing point of the dimethyl dicarbonate to remove low-boiling point impurities in the coarse dimethyl dicarbonate, thereby obtaining a purified dimethyl dicarbonate product.
Description
Technical field
The present invention relates to the refining technological process of a kind of foodstuff additive
Background technology
Dimethyl two carbonic ethers are a kind of foodstuff additive of a kind of high effect nontoxic, are generally used for nectar, soda pop, the sterilization and anticorrosion in tea drink and the Production of Wine process.The principal feature of this product is, add drink after, dimethyl two carbonic ethers rapidly complete hydrolysis become micro-carbonic acid gas and methyl alcohol, this additive is not remaining in drink.Because the concentration very low (dimethyl two carbonic ethers of 150ppm just are enough to kill typical drink spoilage organism) of using is so the methanol concentration that hydrolysis generates is extremely low, fully in the scope that food allows.In fact, owing to the Technology reason, in the drinks drink of fermentation brew, usually contain the methyl alcohol of trace.So this food preservatives is safety non-toxic.Just because of this, dimethyl two carbonic ethers have become western developed country, the requisite green food sterilant of grape wine and fruit juice series products.
In dimethyl two carbonic ethers are produced, because arts demand usually will add organic solvent.Along with the attention of the public to food safety, strict regulation all to the content of detrimental impurity in the foodstuff additive, has been done such as chloroparaffin, toluene solvant etc. in countries in the world.Cl content requires to be not more than 3ppm in European Union's regulation dimethyl two carbonic ethers.So in dimethyl two carbonic ethers were produced, product purification played very important effect.In traditional chemical technique, refining Technology means such as distillation, rectifying that adopt of organic products more.In US Patent No. patent 3326958, a kind of process for purifying distillation of dimethyl two carbonic ethers has been proposed: the dimethyl two carbonic ether crude products that reaction generates, first under 50 ℃ of normal pressures, steam the enpara solvent, then the flask temperature is increased to 90 degree under vacuum tightness 11 mmhg, steams dimethyl two carbonic ether products.But find in actual applications these process meanses, not exclusively be applicable to the refining pure work of dimethyl two carbonic ethers.Since there is the dibasic acid esters key in the dimethyl two carbonic ether molecules, very unstable, at room temperature can decompose, decomposition rate is accelerated under the high temperature.With the distillation rectification process of routine, in the situation that does not have protection, can't obtain highly purified dimethyl two carbonic ether products at all.Opposite dimethyl two carbonic ethers can under distillation temperature, resolve into byproduct.So be necessary to seek a kind of processing method, protection dimethyl two carbonic ethers decompose in purification process avoiding.On the other hand, it is found that dimethyl two carbonic ethers have reasonable stability being lower than under the temperature of its freezing point.In US Patent No. patent 3979524, disclosed a kind of method that stores at low temperatures dimethyl two carbonic ethers.This patent report is under normal temperature 25 degree, and the purity of dimethyl two carbonic ethers can drop to 87.3% from 99.1% in 36 hours.But under 10 ℃ temperature, the concentration of dimethyl two carbonic ethers does not but change within the same time.
Boiling point and the saturated vapor pressure difference of contained impurity are very large in dimethyl two carbonic ether crude products: the boiling point of dimethyl two carbonic ethers is 172 ℃, and the saturated vapor pressure under 25 ℃ is 0.187kpa; The boiling point of methylcarbonate is 90 ℃, and 20 ℃ of lower saturated vapor pressures are 6.27kPa; The boiling point of methyl-chloroformate is 70-72 ℃, the saturated vapor pressure 33.1kpa under 20 ℃; And the boiling point of methylene dichloride is 39.8 ℃, and the saturated vapor pressure under 10 ℃ is 30.55kpa.That is to say that if dimethyl two carbonic ethers are enough stable at rectifying, the difficulty that dimethyl two carbonic ethers and other impurity are separated is not very large.
In general, existing rectifying, distillation technique are not having under the prerequisite of sfgd., are not suitable for the refining separation of dimethyl two carbonic ethers.Simultaneously, boiling point, the saturated vapor pressure of impurity and target product in the dimethyl two carbonic ether crude products, difference is very large, just can well separate under relatively low temperature.On the other hand, dimethyl two carbonic ethers have preferably stability under the temperature below the zero pour.So necessary, design a kind of refining Technology of separating of dimethyl two carbonic ethers that is applicable to according to the characteristics of product.
Summary of the invention
In order to overcome the above problems, according to the physicochemical property of product and impurity, the present invention's usefulness is way cleverly, has proposed a kind of process for refining of dimethyl two carbonic ethers, has reached the purpose that reaches promising result with less investment.
For realizing above purpose, the present invention realizes by following process means.The freezing point of dimethyl two carbonic ethers is 17 degree.Under the condition near freezing point, dimethyl two carbonic ethers have reasonable stability.Simultaneously in dimethyl two carbonic ether preparation feedbacks, used reactant, solvent, the byproduct that produces, such as methyl-chloroformate, ethylene dichloride, methylcarbonate etc., saturated vapor pressure and dimethyl two carbonic ether difference are very large, can in the situation of pressurized air or nitrogen bubble, be removed fully, generate purer dimethyl two carbonic ether products.
The objective of the invention is, a kind of method of purification of dimethyl two carbonic ethers is provided, processing step is as follows:
A, crude product dimethyl two carbonic ethers add refining kettle, and the temperature in the still remains between 10-15 ℃, passes into nitrogen or pressurized air under whipped state, contained impurity in the bubbling removal system.
B, when dimethyl two carbonic ether purity increase gradually, the crystallization meeting of dimethyl two carbonic ethers is separated out from solution in a large number.When bubbling becomes relatively more difficult, stop purification operations.
Above-mentioned dimethyl two carbonic ether process for purification, the temperature of the described reaction system of steps A will remain on the 10-15 degree.If near the freezing point zero degree of methylcarbonate, can cause methylcarbonate separation difficulty from system.If temperature is higher conversely, even in the situation of 20-25 degree, also can cause the methylcarbonate decomposed.
Above-mentioned dimethyl two carbonic ether process for purification on the nitrogen that passes into or pneumatic line, be installed strainer, and moisture eliminator is to remove wherein dust, the foreign material such as greasy dirt and moisture.Wherein moisture content will strictly be controlled, and after discolour silica gel becomes redness in the moisture eliminator, change the blue silica gel of oven dry into, to guarantee the drying regime of gas.
Above-mentioned dimethyl two carbonic ether process for purification, the nitrogen of required usefulness or the pressure of air, reduce product and carry secretly to guarantee even blebbing at 0.03-0.05Mpa.
The invention will be further described below by embodiment.It should be understood that the invention process example is described is only used for illustrating the present invention, rather than limitation of the present invention, and the simple modifications to preparation method of the present invention under design prerequisite of the present invention all belongs to the scope of protection of present invention.
Embodiment
Embodiment 1
After the reaction, the crude product dimethyl two carbonic ether concentration of acquisition are 43.1%.Crude product dimethyl two carbonic ethers are put into refining kettle, pass into chilled brine by chuck, the temperature in the refining kettle is remained between 10-15 ℃.The compressed nitrogen tracheae is inserted under the liquid level, adjust nitrogen pressure and make it to be controlled at 0.03-0.05Mpa, carry out nitrogen bubble.On the nitrogen pipeline that passes into, strainer is installed, moisture eliminator is to remove wherein dust, the foreign material such as greasy dirt and moisture.Wherein moisture content will strictly be controlled, and after discolour silica gel becomes redness in the moisture eliminator, change the blue silica gel of oven dry into, with the drying regime that guarantees to give vent to anger.Refining kettle is provided with agitator, and stirring velocity is controlled at 50rpm.Along with lower boiling material in the solution is removed gradually, the concentration of dimethyl two carbonic ethers increases gradually.Dimethyl two carbonic ethers of high density when temperature is lower than its freezing point (17 ℃), have crystallization, make the nitrogen bubble difficult.At this moment, stop nitrogen bubble and stirring.Dimethyl two carbonic ethers record concentration with volumetry and can reach 99.2% in the still.
Embodiment 2
After the reaction, the crude product dimethyl two carbonic ether concentration of acquisition are 43.1%.Crude product dimethyl two carbonic ethers are put into refining kettle, and the temperature in the refining kettle remains between room temperature 20-25 ℃.The compressed nitrogen tracheae is inserted under the liquid level, adjust nitrogen pressure and make it to be controlled at 0.03-0.05Mpa, carry out nitrogen bubble.On the nitrogen pipeline that passes into, strainer is installed, moisture eliminator is to remove wherein dust, the foreign material such as greasy dirt and moisture.Wherein moisture content will strictly be controlled, and after discolour silica gel becomes redness in the moisture eliminator, change the blue silica gel of oven dry into, to guarantee the drying regime of gas.Refining kettle is provided with agitator, and stirring velocity is controlled at 50rpm.Along with lower boiling material in the solution is removed gradually, the concentration of dimethyl two carbonic ethers increases gradually.But, do not have crystallization in the solution.With the concentration of dimethyl two carbonic ethers in the titration measuring solution, find in the stage dimethyl two carbonic ether concentration increases of beginning very soon, when concentration reaches more than 85%, concentration increases slowly, and along with the increase of time, concentration begins slow decreasing.After 24 hours, stop bubbling with nitrogen bubble.Concentration with dimethyl two carbonic ethers in the titration measuring still is 83.6%.
Embodiment 3
Replace nitrogen with dried pressurized air, other repeat embodiment 1.Adjusting compressed-air actuated pressure makes it to remain in the 0.03-0.05Mpa scope.With pressurized air thick dimethyl two carbonate solutions are carried out bubbling.Along with lower boiling material in the solution is removed gradually, the concentration of dimethyl two carbonic ethers increases gradually.Dimethyl two carbonic ethers of high density when temperature is lower than its freezing point (17 ℃), have crystallization, make pressurized air bubbling difficult.At this moment, stop air bubbling and agitator.Dimethyl two carbonic ethers record concentration with volumetry and can reach 99.3% in the still.
Embodiment 4
Other operational conditions just do not have moisture eliminator in the pneumatic line with embodiment 3, contain moisture in the pressurized air air.Adjusting compressed-air actuated pressure makes it to remain in the 0.03-0.05Mpa scope.With pressurized air thick dimethyl two carbonate solutions are carried out bubbling.With volumetry the concentration of two carbonic ethers of dimethyl in the still is analyzed, found that beginning concentration increases than very fast.Along with the increase of bubbling time, concentration begins slow decreasing.Behind the bubbling 24 hours, stop the air bubbling, find that the concentration of dimethyl two carbonic ethers in the still only has 75.3%.
According to embodiment 1 and embodiment 3, finally can obtain the dimethyl two carbonic ether products of purity more than 99%.
Claims (1)
1. the method for purification of dimethyl two carbonic ethers is characterized in that purifying technique finishes by following two steps:
A, pass into dried compressed air or the nitrogen that pressure is 0.03～0.05MPa to being in 10～15 ℃ of crude product dimethyl two carbonic ethers under the whipped state;
B, separate out in a large number from solution when crystal, stop purification operations when making ventilation bubbling difficult.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010532392 CN101967099B (en) | 2010-11-05 | 2010-11-05 | Purification method of dimethyl dicarbonate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010532392 CN101967099B (en) | 2010-11-05 | 2010-11-05 | Purification method of dimethyl dicarbonate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101967099A CN101967099A (en) | 2011-02-09 |
| CN101967099B true CN101967099B (en) | 2013-04-17 |
Family
ID=43546339
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201010532392 Active CN101967099B (en) | 2010-11-05 | 2010-11-05 | Purification method of dimethyl dicarbonate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101967099B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116655471B (en) * | 2023-05-23 | 2023-11-17 | 杭州元素添加剂科技有限公司 | Method for purifying dicarbonate diester compound |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1046518A (en) * | 1989-03-31 | 1990-10-31 | 三井东压化学株式会社 | The purification of methyl methacrylate and preparation method |
-
2010
- 2010-11-05 CN CN 201010532392 patent/CN101967099B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1046518A (en) * | 1989-03-31 | 1990-10-31 | 三井东压化学株式会社 | The purification of methyl methacrylate and preparation method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101967099A (en) | 2011-02-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10941100B2 (en) | Method for the purification of natural vanillin | |
| JP6549582B2 (en) | Improved process for producing polylactic acid | |
| RU2012102626A (en) | EXTRACTION OF HIGHER ALCOHOLS FROM DILUTED AQUEOUS SOLUTIONS | |
| JPH0699341B2 (en) | Purification method of crude ethanol aqueous solution | |
| KR20140128338A (en) | Process for preparing cyclohexanol and cyclohexanone by cyclohexane oxidation, and device for same | |
| US8563292B2 (en) | Preparation of vanillin from microbial transformation media by extraction by means supercritical fluids or gases | |
| CN101967099B (en) | Purification method of dimethyl dicarbonate | |
| US20120220003A1 (en) | Method for continuously separating organic materials of interest from fermentation | |
| CN111072453A (en) | Purification method of byproduct methanol in industrial production of diphenyl carbonate | |
| CN110563676A (en) | Preparation method of 2, 5-dimethyl-4-hydroxy-3 (2H) -furanone | |
| JPS6261006B2 (en) | ||
| CN111138240B (en) | Water removal device and water removal method for hexafluorobutadiene | |
| CN111018672B (en) | Method for preparing linalool | |
| KR20190062878A (en) | Isolation and purification method of lactic acid | |
| JP6407797B2 (en) | Process for producing dialkyl carbonate | |
| EP4273115A1 (en) | Process for producing pure methanol from a carbon dioxide-rich synthesis gas with single column purification | |
| CN213416720U (en) | Furanol molecule rectification purification device | |
| CN116655471B (en) | Method for purifying dicarbonate diester compound | |
| CN219209021U (en) | Tertiary butanol purifying system | |
| CN116217635B (en) | Deacidifying and purifying method for sucrose-6-acetate | |
| KR20140134699A (en) | Process for making amides | |
| CN115181011B (en) | Preparation process of high-purity phenoxyethanol | |
| KR101802343B1 (en) | Refining method of organic amine | |
| CN1173955C (en) | Process for preparing ketone condensate of L-(+)-2-amino-1-p-nitrophenyl-1,3-propanediol | |
| CN114685402A (en) | Method for preparing high-quality diketene by eutectic crystallization method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |