CN117736098A - Synthetic method and production system of DMDC - Google Patents

Synthetic method and production system of DMDC Download PDF

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Publication number
CN117736098A
CN117736098A CN202311742001.9A CN202311742001A CN117736098A CN 117736098 A CN117736098 A CN 117736098A CN 202311742001 A CN202311742001 A CN 202311742001A CN 117736098 A CN117736098 A CN 117736098A
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methyl chloroformate
catalyst
diluent
dmdc
alkali liquor
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唐聪
方舟
李怡
柳亚玲
兰剑平
张骏
秦浩
蒋绍琴
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Chongqing Chemical Research Institute Co ltd
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Chongqing Chemical Research Institute Co ltd
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Abstract

The invention discloses a synthesis method and a production system of DMDC, which are obtained by taking methyl chloroformate as a starting material, taking an alkaline anion exchange resin as a catalyst, and carrying out condensation reaction with alkali liquor, wherein the catalyst is strong alkaline anion exchange resin or weak alkaline anion exchange resin. The catalyst can be recycled after being filtered, and when the catalytic activity is reduced, the catalyst can be regenerated by using a high-concentration NaOH solution, so that the catalyst loss is small, and the catalyst regeneration step is simple. And the catalyst can be applied to synthesis reaction after being diluted by alkali after regeneration, and the waste salt is less. The invention adopts high boiling point solvent, is convenient to adapt to the reaction concentration of methyl chloroformate in a wider range, has high yield and is simple to operate. The production system is simple, the operation is simple, the catalyst is filled in the extraction reaction tower in a filler mode, the filtering and recycling treatment is not needed, and the catalyst is directly taken out for regeneration when the catalytic activity is poor, so that the method is suitable for industrial production.

Description

Synthetic method and production system of DMDC
Technical Field
The invention relates to the field of synthesis, in particular to a synthesis method and a production system of DMDC.
Background
DMDC, dimethyl dicarbonate, is a kind of "self-decomposing cold bactericide", and has passed the authentication of European Union's scientific food society, american food and drug administration, the joint expert committee of food additives of world health organization, etc., and is widely used in the antisepsis and sterilization of wine, soda water, tea beverage.
The known synthetic process route of DMDC mainly comprises the steps of condensation reaction, phase separation, catalyst removal, dehydration, rectification and the like, and similar processes are disclosed in patent CN 107188805A, CN 102219690B. The condensation reaction is a contact reaction of methyl chloroformate solvent mixture with alkali liquor, wherein alkali is acid-binding agent, and currently adopted phase transfer catalysts comprise triisooctylamine, quaternary ammonium salt, dodecyl dimethyl benzyl ammonium chloride, tri- (dodecyl) methyl ammonium chloride, tri- (tetradecyl) methyl ammonium chloride, tetra- (octaalkyl) ammonium chloride and the like. In the reaction, it mainly catalyzes the hydrolysis reaction of methyl chloroformate, decomposing into dimethyl carbonate and methanol. Organic solvents such as benzene and toluene are used as diluents. And (3) separating phases, namely standing and layering the reacted mixed liquid, wherein the water phase is waste liquid. The organic phase is usually washed with concentrated sulfuric acid and concentrated phosphoric acid to remove catalyst and water. DMDC has active properties, and self-decomposition phenomenon can occur in the synthesis process, and high temperature, water, alcohol, acid, amine, phase transfer catalyst and the like can accelerate the decomposition, so that the rapid realization of influencing the separation of components in the process is a key for improving the yield of the DMDC.
Patent CN 108191659B discloses a method for rapid dehydration, and the patent indicates that the oil phase component obtained by separation is sent to a low vacuum evaporator for distillation, and then the crude product is sent to a high vacuum evaporator for rectification to obtain a DMDC product with purity of 99.9% or more. In addition, in the process, solvents with lower boiling points such as toluene and the like are used, and during rectification, the solvents are distilled out firstly and then products are recovered through rectification, so that the distillation residence time of the DMDC is too long, and the decomposition amount of the DMDC is increased; meanwhile, the rectification process cannot realize continuous operation because the solvent must be distilled off first. Therefore, to increase the efficiency and yield of DMDC synthesis, improvements in the DMDC synthesis process are necessary.
Secondly, the catalysts are not ideal catalysts for synthesizing dimethyl dicarbonate at present, and the catalyst is inconvenient to recycle.
Disclosure of Invention
In order to solve the above technical problems, a first object of the present invention is to provide a method for synthesizing DMDC, and a second object is to provide a production system of DMDC, so as to meet the requirement of continuous and efficient production.
In order to achieve the first object, the present invention provides the following technical solutions: a synthesis method of DMDC is characterized in that: methyl chloroformate is used as an initial raw material, alkaline anion exchange resin is used as a catalyst, and the catalyst is obtained through condensation reaction with alkali liquor.
In the scheme, the method comprises the following steps: the catalyst is a strong basic anion exchange resin or a weak basic anion exchange resin.
In the scheme, the method comprises the following steps: the catalyst is a catalyst having-NR 1 R 2 Anion exchange resins of tertiary amine structure.
In the scheme, the method comprises the following steps: the catalyst is one or a mixture of D301 weak basic anion exchange resin, D354 weak basic anion exchange resin and styrene-olefin-tertiary amine cation exchange resin.
In the scheme, the method comprises the following steps: basic anion exchange resin: methyl chloroformate mass ratio=0.1-2.0:1, wherein the alkali liquor is sodium hydroxide or potassium hydroxide, methyl chloroformate: molar ratio of sodium hydroxide or potassium hydroxide
The reaction temperature is 0-15 ℃ and the reaction time is 30-90 min, which are 1-1.2:1.
In the scheme, the method comprises the following steps: the solvent is selected to be a solvent with low polarity and boiling point higher than 190 ℃.
In the scheme, the method comprises the following steps: the method comprises the following steps of:
(1) Mixing materials, namely mixing methyl chloroformate with a solvent to prepare a solution with the mass content of 10-60% of the methyl chloroformate; mixing alkali such as sodium hydroxide, potassium hydroxide and the like with deionized water to prepare an alkali solution with the mass content of 10-32%; the solvent is No. 260 solvent oil and aromatic hydrocarbon solvent oil;
(2) Adding methyl chloroformate solution after condensation reaction and mixing into a reaction vessel, adding a catalyst, stirring, dropwise adding an alkali solution under ice bath, controlling the temperature of the reaction solution to be lower than 15 ℃ when dropwise adding, continuously stirring until the reaction is complete, quickly filtering and recovering the catalyst, then quickly splitting phases, adding concentrated sulfuric acid into an organic layer for vibration dehydration, splitting phases again, decompressing and rectifying the organic layer, and collecting fractions to obtain DMDC.
In the scheme, the method comprises the following steps: when the catalytic activity is obviously reduced, the catalyst is soaked in 40-50% sodium hydroxide solution for 30-120 min for regeneration, the treatment temperature is 20-40 ℃, and the treated high-concentration sodium hydroxide solution is diluted and then used for synthesis reaction.
The second object of the present invention is achieved by: a DMDC production system, characterized by: the method comprises an extraction reaction tower, wherein the middle part in the extraction reaction tower is filled with catalyst alkaline anion exchange resin, the upper part of the side surface of the extraction reaction tower is provided with an alkali liquor inlet, the alkali liquor inlet is positioned above the catalyst alkaline anion exchange resin, the alkali liquor inlet is connected with an alkali liquor feeding system, the lower part of the side wall of the extraction reaction tower is provided with a methyl chloroformate diluent inlet, the methyl chloroformate diluent inlet is positioned below the catalyst, the methyl chloroformate diluent inlet is connected with a methyl chloroformate diluent feeding system, and the solvent for preparing methyl chloroformate diluent is one of No. 260 solvent oil and aromatic hydrocarbon solvent oil; the bottom of the extraction reaction tower is provided with a drainage pipeline connected with a brine storage tank, the top of the extraction reaction tower is provided with an organic phase outlet pipeline connected with a phase separator, the emulsion at the bottom of the phase separator is connected with a second heat exchanger through an emulsion circulating pump, and after being cooled by the second heat exchanger, the emulsion enters the extraction reaction tower from a reflux liquid inlet at the middle part of the extraction reaction tower to cool the catalyst, and meanwhile, the reaction is continued; the upper organic phase outlet pipeline of the phase separator is connected with the membrane separator, the organic phase is dehydrated in the membrane separator, the outlet pipeline of the membrane separator is connected with the crude distillation column, the bottom solvent methyl chloroformate diluent feeding system of the crude sulfur column is used for preparing methyl chloroformate diluent, the top pipeline of the crude distillation column is connected with the first condenser, the collecting pipeline of the first condenser is respectively connected with the light component tank, the heavy component tank and the crude product tank, the liquid of the light component tank and the heavy component tank enters the methyl chloroformate diluent feeding system and is used for preparing methyl chloroformate diluent, the fraction of the crude product tank enters the rectifying column, the top outlet pipeline of the rectifying column is connected with the second condenser, the bottom kettle liquid enters the methyl chloroformate diluent feeding system and is used for preparing methyl chloroformate diluent, and the outlet pipeline of the second condenser is respectively connected with the product tank and the rear fraction tank.
In the scheme, the method comprises the following steps: the alkali liquor feeding system comprises an alkali liquor storage tank, wherein the alkali liquor storage tank is connected with a first heat exchanger through an alkali liquor feeding pump, the mass content of alkali liquor is 10-32%, and the alkali liquor is cooled to 0-5 ℃ through the first heat exchanger and then enters an extraction reaction tower; the methyl chloroformate diluent feeding system comprises a mixing kettle, wherein the bottom solvent of the crude sulfur tower, the liquid of the light component tank and the heavy component tank and the bottom kettle liquid of the rectifying tower all enter the mixing kettle, the mixing kettle is further connected with a methyl chloroformate storage tank, a bottom liquid outlet pipeline of the mixing kettle is connected with the diluent storage tank, an outlet of the diluent storage tank is connected to a third heat exchanger through a diluent feed pump, the third heat exchanger is connected with a methyl chloroformate diluent inlet, the mass content of methyl chloroformate solution is 10-60%, and the methyl chloroformate solution enters the extraction reaction tower after being cooled to 0-5 ℃ through the third heat exchanger.
Compared with the known phase transfer catalyst with long hydrocarbon chain (the long hydrocarbon chain is used for making the phase transfer catalyst insoluble in water under neutral or alkaline condition so as to recover the catalyst), the synthesis method of the invention can directly and rapidly realize separation of the catalyst and the product by filtration and other methods, thereby improving the convenience of catalyst separation. The known method requires washing and extracting with concentrated sulfuric acid or concentrated phosphoric acid, adding alkali into the extracted acid to neutralize to neutral or alkaline, and then carrying out phase separation to obtain a catalyst for recycling, wherein the catalyst recovery step is complicated; the catalyst provided by the invention can be recycled after being filtered, and when the catalytic activity is reduced, the catalyst can be regenerated by using a high-concentration NaOH solution, so that the catalyst loss is small, and the catalyst regeneration step is simple. When the catalyst is recovered by the known method, high-concentration acid is needed, and then alkali is used for neutralization, so that a large amount of waste salt is generated; the catalyst regenerated by the method can be applied to synthesis reaction after alkali dilution, and waste salt is less.
The solvent used in the synthesis method of the present invention has a boiling point higher than 190 ℃, and a known method is to use a low boiling point solvent such as dimethyl carbonate, toluene, xylene, etc. In the refining process of distillation/rectification and the like, the known method needs to distill and remove the solvent firstly to obtain the product; the method can directly distill out the product, is more convenient for separating the product from the solvent, and does not consume a large amount of energy to separate the solvent. Because of the characteristic, the concentration of methyl chloroformate in the reaction can be controlled to be in a wide range of 10-60%, and the DMDC yield can be improved due to the low concentration of methyl chloroformate according to the DMDC phase transfer catalysis characteristic. In addition, because the solvent is a high-boiling point solvent, the continuous rectification operation can be realized by using conventional tower kettle type equipment during distillation and refining, and the cost is low.
The production system of the invention. The resin catalyst is filled in the middle of the extraction reaction tower, so that the double functions of a fixed bed and the extraction tower can be realized, the oil-water two-phase separation can be realized rapidly, the contact between DMDC and water is reduced, and the DMDC yield is improved; the middle part of the filling material of the extraction reaction tower is skillfully provided with a feed inlet, the organic phase with incomplete phase separation is cooled and then fed, and the continuous phase separation in the extraction tower also plays a role in cooling the resin. The organic phase after the phase separation of the system is dehydrated by using a membrane separation, so that the use of drying agents such as anhydrous calcium chloride, anhydrous magnesium sulfate and the like is avoided, the process flow is shortened, and the environmental pollution is reduced.
Drawings
FIG. 1 is a process flow diagram of a production system of the present invention.
Detailed Description
The invention is further described below with reference to the drawings and examples.
The synthesis method of the self-made styrene-olefin-tertiary amine weak-base anion exchange resin comprises the following steps:
01, styrene and divinylbenzene are used as reaction monomers, gelatin is used as an initiator, an intermediate product white ball is prepared by suspension polymerization reaction in water, a small amount of sodium hydroxide is added to adjust the pH value to 8-9, polymerization is carried out for 4-6 hours at 80-90 ℃, white particles are obtained by filtration after the reaction is finished, washing is carried out for 2 times, and drying is carried out, thus obtaining the intermediate product white ball; the molar ratio of the styrene to the divinylbenzene is 1:1, the addition amount of gelatin is 0.5% of the weight of the resin.
02, adding intermediate products of white balls, chloromethyl ether and ferric trichloride into a reaction kettle for functional group modification, wherein the reaction temperature is 60-70 ℃, the treatment time is 3 hours, and the ratio (mass ratio) of the using amount of the chloromethyl ether and the ferric trichloride resin to the resin white balls is 1:5:2. filtering and separating the product, and washing with water to obtain an intermediate product chlorine ball; wherein chloromethyl ether can be recycled.
03 mixing chlorine ball and excessive poly isopropyl methyl amine (CH 3 NH(OCH 2 CHCH 3 ) 6 Adding the OH) solution into a reaction kettle, reacting for 6 hours at normal pressure and room temperature, filtering and separating a product, and washing with water to obtain the styrene-olefin-tertiary amine weak-base anion exchange resin.
Example 1:
100g methyl chloroformate (1.058 mol) and 300g No. 260 solvent oil are mixed to prepare 400g 25% methyl chloroformate diluent, the diluent is transferred to a 1L three-neck flask, 50g self-made styrene-olefin-tertiary amine weak-base anion exchange resin is added, stirring and ice-water bath are carried out, 300g14% sodium hydroxide (1.05 mol) aqueous solution is dropwise added within 30min, stirring is carried out for 10min at the temperature of 0-15 ℃, the catalyst is quickly filtered and recovered, then quick phase separation is carried out, 10g 85% sulfuric acid is added into an organic layer for oscillation for 5min, and the phase separation is carried out on the organic layer again under reduced pressure for rectification. Collecting 200Pa fraction at 25-30 ℃ to obtain 46g of colorless liquid product dimethyl dicarbonate with GC purity of 99.8%; collecting the fraction at 30-35 ℃ to obtain 18.4g of fraction, wherein the GC purity is 89.9%; the yield thereof was found to be about 88.08%.
Example 2:
100g methyl chloroformate (1.058 mol) and 900g No. 260 solvent oil are mixed to prepare 1000g 10% methyl chloroformate diluent, the diluent is transferred to a 1L three-neck flask, 50g self-made styrene-olefin-tertiary amine weak-base anion exchange resin is added, stirring and ice-water bath are carried out, 300g14% sodium hydroxide (1.05 mol) aqueous solution is dropwise added within 30min, stirring is carried out for 10min at the temperature of 0-15 ℃, the catalyst is quickly filtered and recovered, then quick phase separation is carried out, 10g 85% sulfuric acid is added into an organic layer for oscillation for 5min, and the phase separation organic layer is decompressed and rectified again. Collecting fractions of 200Pa and 25-30 ℃ to obtain 48.2g of dimethyl dicarbonate which is a colorless liquid product, wherein the GC purity is 99.8%; collecting the fraction at 30-35 ℃ to obtain fraction 19.3g and GC purity 89.82%; the yield thereof was found to be about 92.3%.
Example 3
100g methyl chloroformate (1.058 mol) and 66g No. 260 solvent oil are mixed to prepare 166g 60% methyl chloroformate diluent, the diluent is transferred to a 1L three-neck flask, 50g self-made styrene-olefin-tertiary amine weak-base anion exchange resin is added, stirring and ice-water bath are carried out, 300g14% sodium hydroxide (1.05 mol) aqueous solution is dropwise added within 30min, stirring is carried out for 10min at the temperature of 0-15 ℃, the catalyst is quickly filtered and recovered, then quick phase separation is carried out, 10g 85% sulfuric acid is added into an organic layer for oscillation for 5min, and the phase separation organic layer is carried out again under reduced pressure for rectification. Collecting fractions of 200Pa and 25-30 ℃ to obtain 43.3g of colorless liquid product dimethyl dicarbonate with GC purity of 99.8%; collecting the fraction at 30-35 ℃ to obtain 17.3g of fraction with GC purity of 89.5%; the yield thereof was found to be about 82.9%.
Example 4
50g of methyl chloroformate and 450g of 260 solvent oil are mixed to prepare 500g of 10% methyl chloroformate diluent, the diluent is transferred to a 1L three-neck flask, 25g of D301 weak-base anion exchange resin is added, the mixture is stirred, an ice-water bath is carried out, 200g of 10.6% sodium hydroxide aqueous solution is dropwise added in 30min, the temperature is kept at 15 ℃ and is stirred for 10min, the catalyst is quickly filtered and recovered, then the phase is quickly separated, 10g of 75% sulfuric acid is added in an organic layer to oscillate for 5min, and then the phase is decompressed and rectified. Collecting fractions of 200Pa and 25-30 ℃ to obtain 21g of colorless liquid product dimethyl dicarbonate with GC purity of 99.8%; the fraction at 30-35 ℃ is collected to obtain 11.5g of fraction, the GC purity is 82.5%, and the yield is about 84.2%.
Example 5:
88.8g methyl chloroformate and 59.2g No. 260 solvent oil are mixed to prepare 148g 60% methyl chloroformate diluent, the diluent is transferred to a 500ml three-neck flask, 44.4g 001X7 strong base anion exchange resin is added, the mixture is stirred, ice-water bath is carried out, 124g 32% sodium hydroxide aqueous solution is dropwise added in 30min, the temperature is kept at 13 ℃ and is stirred for 10min, rapid phase separation is carried out, 16g 75% sulfuric acid is added in an organic layer for shaking for 5min, and the phase separation organic layer is subjected to reduced pressure rectification. Collecting fractions of 200Pa and 25-30 ℃ to obtain a colorless liquid product of 32g of dimethyl dicarbonate with GC purity of 99.8%; the fraction at 30-35 ℃ is collected to obtain 15g of fraction, the GC purity is 86.5%, and the yield is about 72%.
Example 6:
88.8g methyl chloroformate and 799.2g No. 260 solvent oil are mixed to prepare 10% methyl chloroformate diluent, the 10% methyl chloroformate diluent is transferred to a 500ml three-neck flask, 44.4g 001X7 strong-base anion exchange resin is added, stirring and ice-water bath are carried out, 124g 32% sodium hydroxide aqueous solution is dropwise added in 30min, stirring is carried out for 10min at the temperature of 13 ℃, rapid phase separation is carried out, 16g 75% sulfuric acid is added in an organic layer for shaking for 5min, and the phase separation organic layer is subjected to reduced pressure rectification. Collecting fractions of 200Pa and 25-30 ℃ to obtain 38.3g of dimethyl dicarbonate as a colorless liquid product, wherein the GC purity is 99.8%; the fraction at 30-35 ℃ is collected to obtain 17.9g of fraction, the GC purity is 85.9%, and the yield is about 86.2%.
Example 7
100g methyl chloroformate (1.058 mol) and 900g No. 260 solvent oil are mixed to prepare 1000g 10% methyl chloroformate diluent, the diluent is transferred to a 1L three-neck flask, 200g self-made styrene-olefin-tertiary amine weak-base anion exchange resin is added, stirring and ice-water bath are carried out, 300g14% sodium hydroxide (1.05 mol) aqueous solution is dropwise added within 30min, stirring is carried out for 10min at the temperature of 0-15 ℃, the catalyst is quickly filtered and recovered, then quick phase separation is carried out, 10g 85% sulfuric acid is added into an organic layer for oscillation for 5min, and the phase separation organic layer is decompressed and rectified again. Collecting fractions of 200Pa and 25-30 ℃ to obtain 48.3g of dimethyl dicarbonate as a colorless liquid product, wherein the GC purity is 99.8%; collecting the fraction at 30-35 ℃ to obtain fraction 19.34g and GC purity 89.3%; the yield thereof was found to be about 92.5%.
Example 8
100g methyl chloroformate (1.058 mol) and 900g No. 260 solvent oil are mixed to prepare 1000g 10% methyl chloroformate diluent, the diluent is transferred to a 1L three-neck flask, 200g self-made styrene-olefin-tertiary amine weak-base anion exchange resin is added, stirring and ice-water bath are carried out, 420g 14% potassium hydroxide (1.05 mol) aqueous solution is dropwise added within 30min, stirring is carried out for 10min at the temperature of 0-15 ℃, the catalyst is quickly filtered and recovered, then quick phase separation is carried out, 10g 85% sulfuric acid is added into an organic layer for oscillation for 5min, and the phase separation organic layer is decompressed and rectified again. Collecting fractions of 200Pa and 25-30 ℃ to obtain 47.2g of dimethyl dicarbonate as a colorless liquid product, wherein the GC purity is 99.81%; collecting the fraction at 30-35 ℃ to obtain 18.9g of fraction with GC purity of 90.2%; the yield thereof was found to be about 90.5%.
Example 9:
100g methyl chloroformate (1.058 mol) and 300g SWASOL1800 aromatic hydrocarbon solvent oil are mixed to prepare 400g 25% methyl chloroformate diluent, the diluent is transferred to a 1L three-neck flask, 50g self-made styrene-olefin-tertiary amine alkalescent anion exchange resin is added, stirring and ice-water bath are carried out, 300g14% sodium hydroxide (1.05 mol) aqueous solution is dropwise added within 30min, stirring is carried out for 10min at the temperature of 0-15 ℃, the catalyst is quickly filtered and recovered, then quick phase separation is carried out, 10g 85% sulfuric acid is added into an organic layer for oscillation for 5min, and the phase separation organic layer is decompressed and rectified again. Collecting 200Pa fraction at 25-30 ℃ to obtain 45g of colorless liquid product dimethyl dicarbonate with GC purity of 99.85%; collecting the fraction at 30-35 ℃ to obtain 18g of fraction, wherein the GC purity is 89.8%; the yield thereof was found to be about 86.08%.
Example 10:
100g methyl chloroformate (1.058 mol) and 300g SOLVESSO150 aromatic hydrocarbon solvent oil are mixed to prepare 400g of 25% methyl chloroformate diluent, the diluent is transferred into a 1L three-neck flask, 50g of self-made styrene-olefin-tertiary amine weak-base anion exchange resin is added, stirring and ice-water bath are carried out, 300g of 14% sodium hydroxide (1.05 mol) aqueous solution is dropwise added within 30min, stirring is carried out for 10min at the temperature of 0-15 ℃, the catalyst is recovered by rapid filtration, then rapid phase separation is carried out, 10g of 85% sulfuric acid is added into an organic layer for oscillation for 5min, and the phase separation organic layer is decompressed and rectified again. Collecting fractions of 200Pa and 25-30 ℃ to obtain 45.2g of colorless liquid product dimethyl dicarbonate with GC purity of 99.82%; collecting the fraction at 30-35 ℃ to obtain 18.1g of fraction with GC purity of 90.2%; the yield thereof was found to be about 86.4%.
Example 11:
the DMDC production system comprises an extraction reaction tower 1, wherein the middle part in the extraction reaction tower 1 of an alkali liquor feed pump is filled with a catalyst alkali anion exchange resin 2, the upper part of the side surface of the extraction reaction tower 1 of the alkali liquor feed pump is provided with an alkali liquor inlet, the alkali liquor inlet of the alkali liquor feed pump is positioned above the catalyst alkali anion exchange resin 2, and the alkali liquor inlet of the alkali liquor feed pump is connected with an alkali liquor feeding system. The alkali liquor feeding system of the alkali liquor feeding pump comprises an alkali liquor storage tank 3, wherein the alkali liquor storage tank 3 of the alkali liquor feeding pump is connected with a first heat exchanger 5 through an alkali liquor feeding pump 4, the mass content of alkali liquor is 10-32%, and the alkali liquor is cooled to 0-5 ℃ through the first heat exchanger and then enters the extraction reaction tower.
The lower part of the side wall of the extraction reaction tower 1 is provided with a methyl chloroformate diluent inlet, the methyl chloroformate diluent inlet is positioned below the catalyst, the methyl chloroformate diluent inlet of the alkali liquor feed pump is connected with a methyl chloroformate diluent feeding system, and the solvent for preparing the methyl chloroformate diluent is one of No. 260 solvent oil and aromatic hydrocarbon solvent oil.
The bottom of the alkali liquor feed pump extraction reaction tower 1 is provided with a drainage pipeline connected with a brine storage tank 6, the top of the alkali liquor feed pump extraction reaction tower is provided with an organic phase outlet pipeline connected with a phase separator 7, the emulsion at the bottom of the alkali liquor feed pump phase separator 7 is connected with a second heat exchanger 9 through an emulsion circulating pump 8, and after being cooled by the second heat exchanger 9, the emulsion enters the extraction reaction tower from a reflux inlet at the middle part of the extraction reaction tower to cool the catalyst, and meanwhile, the reaction is continued. The upper organic phase outlet pipeline of the alkali liquor feeding pump phase separator 7 is connected with the membrane separator 14, the organic phase is dehydrated in the membrane separator 14, the outlet pipeline of the alkali liquor feeding pump membrane separator 14 is connected with the crude distillation column 15, the bottom solvent methyl chloroformate diluent feeding system of the alkali liquor feeding pump crude distillation column 15 is used for preparing methyl chloroformate diluent, the top pipeline of the alkali liquor feeding pump crude distillation column 15 is connected with the first condenser 16, the collecting pipeline of the alkali liquor feeding pump first condenser 16 is respectively connected with the light component tank 17, the heavy component tank 18 and the crude product tank 19, the liquid of the alkali liquor feeding pump light component tank 17 and the heavy component tank 18 enters the methyl chloroformate diluent feeding system for preparing methyl chloroformate diluent, the fraction of the alkali liquor feeding pump crude product tank 19 enters the rectification column 20, the outlet pipeline of the alkali liquor feeding pump rectification column 20 is connected with the second condenser 21, the bottom kettle liquid enters the methyl chloroformate diluent feeding system for preparing methyl chloroformate diluent, and the outlet pipeline of the alkali liquor feeding pump second condenser 21 is respectively connected with the product tank 22 and the post-distillation tank 23. The latter fraction is returned to the crude sulfur column.
The methyl chloroformate diluent feeding system comprises a mixing kettle 10, wherein the bottom solvent of the crude sulfur tower, the liquid of the light component tank and the heavy component tank and the bottom kettle liquid of the rectifying tower all enter the mixing kettle 10, the mixing kettle 10 is also connected with a methyl chloroformate storage tank, a bottom liquid outlet pipeline of the mixing kettle 10 is connected with a diluent storage tank 11, an outlet of the diluent storage tank 11 is connected to a third heat exchanger 13 through a diluent feed pump 12, the third heat exchanger 13 is connected with a methyl chloroformate diluent inlet, the mass content of the methyl chloroformate solution is 10-60%, and the methyl chloroformate solution enters the extraction reaction tower after being cooled to 0-5 ℃ through the third heat exchanger.
Example 12
According to the production system of example 11,
1. mixing methyl chloroformate and 260 solvent oil into 30% methyl chloroformate diluent in a diluent mixing kettle, and temporarily storing the diluent and the diluent in a storage tank; an 18% NaOH solution was prepared in a NaOH tank.
2. The extraction reaction column was charged with 30kg of a homemade styrene-olefin-tertiary amine weakly basic anion exchange resin.
3. The diluent is cooled to 0-5 ℃ by a diluent feeding pump with the feeding amount of 100 kg/h; naOH solution enters a reactor extraction reaction tower for reaction at 75kg/h through a NaOH feeding pump, and is cooled to 0-5 ℃; pumping the phase splitter emulsion into the middle part of the extraction reaction tower through an emulsion circulating pump, controlling the feeding temperature to be 0-5 ℃ at the flow rate of 15 kg/h; maintaining the temperature in the tower at 10-20 ℃;
4. the organic phase enters a phase separator for continuous phase separation, and the supernatant enters a membrane separator for separation, wherein the operating temperature of the membrane separator is 30 ℃ and the absolute pressure is 200Pa; the organic phase is withdrawn after membrane separation at a flow rate of 90.2 kg/h.
5. The organic phase after membrane separation is collected to 860kg and then is coarsely distilled in a coarse distillation tower kettle, and fractions with 200Pa and 30-35 ℃ are collected by a coarse product collecting tank, so that 160kg of colorless liquid product dimethyl dicarbonate is obtained, and the GC concentration is 98.7%.
6. And (3) feeding 98.7% of dimethyl dicarbonate product into a continuous rectifying tower kettle system for rectification to obtain 99.9% of dimethyl dicarbonate product. The cumulative yield reaches 93.5%.
The effective exchange volume in the middle of the extraction reaction tower in the embodiment is 10L, and the volumes of the split-phase areas at the two ends are 10L respectively; a separator 50L; crude distillation column bottoms 1200L; and the rectification kettle 300L adopts continuous rectification.
Example 13
The catalyst is trimethyl octadecyl ammonium chloride.
1.2g of catalyst 50g of toluene and 65g of methyl chloroformate are uniformly mixed, 176g of 12% sodium hydroxide solution is added dropwise into the mixture for 20min, strong stirring is kept in the dropping process, and phase separation is carried out after the dropping is completed. The organic phase was washed 1 time with 1g of 85% concentrated sulfuric acid and 2g of 75% phosphoric acid, respectively, and the phases were separated to obtain a mixed solution containing 10.8g of dimethyl dicarbonate, 8.5g of methyl chloroformate, 34.5g of toluene and 12g of methanol. The theoretical yield was 23.4%.
Example 14
The catalyst used was trilaurylamine.
Uniformly mixing 1.2g of catalyst 40g of toluene and 60g of methyl chloroformate, dropwise adding 155g of 12% sodium hydroxide solution into the mixture for 20min, keeping strong stirring in the dropwise adding process, and carrying out phase separation after the dropwise adding is finished. The organic phase was washed 1 time with 1g of 85% concentrated sulfuric acid and 2g of 75% phosphoric acid, respectively, and the phases were separated to obtain a mixed solution containing 21.5g of dimethyl dicarbonate, 5.5g of methyl chloroformate, 34.5g of toluene and 10g of methanol. The theoretical yield was 46.6%.
Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (10)

1. A synthesis method of DMDC is characterized in that: methyl chloroformate is used as an initial raw material, alkaline anion exchange resin is used as a catalyst, and the catalyst is obtained through condensation reaction with alkali liquor.
2. The method for synthesizing DMDC according to claim 1, wherein: the catalyst is a strong basic anion exchange resin or a weak basic anion exchange resin.
3. The method for synthesizing DMDC according to claim 2, wherein: the catalyst is a catalyst having-NR 1 R 2 Anion exchange resins of tertiary amine structure.
4. A method of synthesizing DMDC according to claim 3, wherein: the catalyst is one or a mixture of D301 weak basic anion exchange resin, D354 weak basic anion exchange resin and styrene-olefin-tertiary amine anion exchange resin.
5. The method for synthesizing DMDC according to claim 4, wherein: basic anion exchange resin: methyl chloroformate mass ratio=0.1-2.0:1, wherein the alkali liquor is sodium hydroxide or potassium hydroxide, methyl chloroformate: sodium hydroxide or potassium hydroxide molar ratio=1-1.2:1, reaction temperature 0-15 ℃, reaction time 30-90 min.
6. The method for synthesizing DMDC according to claim 5, wherein: the solvent is selected to be a solvent with low polarity and boiling point higher than 190 ℃.
7. A method of synthesizing DMDC according to any one of claims 1 to 6, wherein the synthesis is performed according to the steps of:
(1) Mixing materials, namely mixing methyl chloroformate with a solvent to prepare a solution with the mass content of 10-60% of the methyl chloroformate; mixing alkali such as sodium hydroxide, potassium hydroxide and the like with deionized water to prepare an alkali solution with the mass content of 10-32%; the solvent is No. 260 solvent oil and aromatic hydrocarbon solvent oil;
(2) Adding methyl chloroformate solution after condensation reaction and mixing into a reaction vessel, adding a catalyst, stirring, dropwise adding an alkali solution under ice bath, controlling the temperature of the reaction solution to be lower than 15 ℃ when dropwise adding, continuously stirring until the reaction is complete, quickly filtering and recovering the catalyst, then quickly splitting phases, adding concentrated sulfuric acid into an organic layer for vibration dehydration, splitting phases again, decompressing and rectifying the organic layer, and collecting fractions to obtain DMDC.
8. The method for synthesizing DMDC according to claim 7, wherein: when the catalytic activity is obviously reduced, the catalyst is soaked in 40-50% sodium hydroxide solution for 30-120 min for regeneration, the treatment temperature is 20-40 ℃, and the treated high-concentration sodium hydroxide solution is diluted and then used for synthesis reaction.
9. A DMDC production system, characterized by: the method comprises an extraction reaction tower, wherein the middle part in the extraction reaction tower is filled with catalyst alkaline anion exchange resin, the upper part of the side surface of the extraction reaction tower is provided with an alkali liquor inlet, the alkali liquor inlet is positioned above the catalyst alkaline anion exchange resin, the alkali liquor inlet is connected with an alkali liquor feeding system, the lower part of the side wall of the extraction reaction tower is provided with a methyl chloroformate diluent inlet, the methyl chloroformate diluent inlet is positioned below the catalyst, the methyl chloroformate diluent inlet is connected with a methyl chloroformate diluent feeding system, and the solvent for preparing methyl chloroformate diluent is one of No. 260 solvent oil and aromatic hydrocarbon solvent oil; the bottom of the extraction reaction tower is provided with a drainage pipeline connected with a brine storage tank, the top of the extraction reaction tower is provided with an organic phase outlet pipeline connected with a phase separator, the emulsion at the bottom of the phase separator is connected with a second heat exchanger through an emulsion circulating pump, and after being cooled by the second heat exchanger, the emulsion enters the extraction reaction tower from a reflux liquid inlet at the middle part of the extraction reaction tower to cool the catalyst, and meanwhile, the reaction is continued; the upper organic phase outlet pipeline of the phase separator is connected with the membrane separator, the organic phase is dehydrated in the membrane separator, the outlet pipeline of the membrane separator is connected with the crude distillation column, the bottom solvent methyl chloroformate diluent feeding system of the crude sulfur column is used for preparing methyl chloroformate diluent, the top pipeline of the crude distillation column is connected with the first condenser, the collecting pipeline of the first condenser is respectively connected with the light component tank, the heavy component tank and the crude product tank, the liquid of the light component tank and the heavy component tank enters the methyl chloroformate diluent feeding system and is used for preparing methyl chloroformate diluent, the fraction of the crude product tank enters the rectifying column, the top outlet pipeline of the rectifying column is connected with the second condenser, the bottom kettle liquid enters the methyl chloroformate diluent feeding system and is used for preparing methyl chloroformate diluent, and the outlet pipeline of the second condenser is respectively connected with the product tank and the rear fraction tank.
10. The DMDC production system of claim 9, wherein: the alkali liquor feeding system comprises an alkali liquor storage tank, wherein the alkali liquor storage tank is connected with a first heat exchanger through an alkali liquor feeding pump, the mass content of alkali liquor is 10-32%, and the alkali liquor is cooled to 0-5 ℃ through the first heat exchanger and then enters an extraction reaction tower; the methyl chloroformate diluent feeding system comprises a mixing kettle, wherein the bottom solvent of the crude sulfur tower, the liquid of the light component tank and the heavy component tank and the bottom kettle liquid of the rectifying tower all enter the mixing kettle, the mixing kettle is further connected with a methyl chloroformate storage tank, a bottom liquid outlet pipeline of the mixing kettle is connected with the diluent storage tank, an outlet of the diluent storage tank is connected to a third heat exchanger through a diluent feed pump, the third heat exchanger is connected with a methyl chloroformate diluent inlet, the mass content of methyl chloroformate solution is 10-60%, and the methyl chloroformate solution enters the extraction reaction tower after being cooled to 0-5 ℃ through the third heat exchanger.
CN202311742001.9A 2023-12-18 2023-12-18 Synthetic method and production system of DMDC Pending CN117736098A (en)

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Citations (5)

* Cited by examiner, † Cited by third party
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CN1953957A (en) * 2004-05-13 2007-04-25 兰爱克谢斯德国有限责任公司 Method for producing dialkyl dicarbonates
CN102219690A (en) * 2011-04-29 2011-10-19 浙江手心医药化学品有限公司 Preparation method for dimethyl dicarbonate
CN103980124A (en) * 2014-05-09 2014-08-13 天津大学 Synthetic method of diphenyl carbonate from propylene carbonate by catalysis of ionic liquid
CN107188805A (en) * 2016-03-14 2017-09-22 重庆长风生物科技有限公司 A kind of continuous preparation technology of the carbonate of dimethyl two
CN108191659A (en) * 2018-01-22 2018-06-22 宁波斯特莱生物技术有限公司 A kind of production method and its production system of two carbonic ester of dimethyl

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1953957A (en) * 2004-05-13 2007-04-25 兰爱克谢斯德国有限责任公司 Method for producing dialkyl dicarbonates
CN102219690A (en) * 2011-04-29 2011-10-19 浙江手心医药化学品有限公司 Preparation method for dimethyl dicarbonate
CN103980124A (en) * 2014-05-09 2014-08-13 天津大学 Synthetic method of diphenyl carbonate from propylene carbonate by catalysis of ionic liquid
CN107188805A (en) * 2016-03-14 2017-09-22 重庆长风生物科技有限公司 A kind of continuous preparation technology of the carbonate of dimethyl two
CN108191659A (en) * 2018-01-22 2018-06-22 宁波斯特莱生物技术有限公司 A kind of production method and its production system of two carbonic ester of dimethyl

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