CN114436839B - Process and system for preparing methyl ethyl carbonate by using double-reaction-section reaction rectifying tower - Google Patents
Process and system for preparing methyl ethyl carbonate by using double-reaction-section reaction rectifying tower Download PDFInfo
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- CN114436839B CN114436839B CN202210365222.8A CN202210365222A CN114436839B CN 114436839 B CN114436839 B CN 114436839B CN 202210365222 A CN202210365222 A CN 202210365222A CN 114436839 B CN114436839 B CN 114436839B
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C68/00—Preparation of esters of carbonic or haloformic acids
- C07C68/06—Preparation of esters of carbonic or haloformic acids from organic carbonates
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/009—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping in combination with chemical reactions
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/14—Fractional distillation or use of a fractionation or rectification column
- B01D3/143—Fractional distillation or use of a fractionation or rectification column by two or more of a fractionation, separation or rectification step
- B01D3/146—Multiple effect distillation
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C68/00—Preparation of esters of carbonic or haloformic acids
- C07C68/08—Purification; Separation; Stabilisation
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Abstract
The invention provides a process and a system for preparing methyl ethyl carbonate by using a double-reaction-section reaction rectifying tower, wherein DMC, ethanol and DEC are used as raw materials, and EMC is prepared by using the double-reaction-section reaction rectifying tower and two different solid base catalysts; the preparation process can realize the industrial production of the methyl ethyl carbonate product with high efficiency through the double-reaction-section reaction rectifying tower for continuous production, has simple operation mode and high production efficiency, shortens the flow, avoids the generation of DMC and methanol azeotrope, directly obtains high-purity methanol at the tower top, replaces three tower bodies of the traditional process with one tower body, and greatly saves the equipment cost and the process energy consumption.
Description
Technical Field
The invention relates to the technical field of preparing methyl ethyl carbonate, in particular to a process and a system for preparing methyl ethyl carbonate by a double-reaction-section reaction rectifying tower.
Background
Ethyl Methyl Carbonate (EMC) is a green asymmetric carbonate that is not harmful to the environment, has the characteristics of diethyl carbonate and dimethyl carbonate, can react with alcohols, esters, phenols, amines and the like, and is suitable for various organic reactions. And the methyl ethyl carbonate is used as a novel electrolyte of the lithium ion battery, has low viscosity, high dielectric constant and better solubility to lithium salt, so that the electrolyte has the advantages of improving the discharge capacity and energy density of the battery, improving the safety performance of the lithium ion battery and prolonging the service life. In addition, the good low-temperature service performance is also the advantage of the electrolyte.
The EMC synthesis process is various, mainly comprises three methods, namely a phosgene method, an oxidative carbonylation method and an ester exchange method, wherein the ester exchange method is generally adopted to synthesize methyl ethyl carbonate at present, and the synthesis of the methyl ethyl carbonate by the ester exchange method is divided into the following two methods: diethyl carbonate (DEC) was transesterified with methanol, dimethyl carbonate (DMC) with ethanol, dimethyl carbonate with diethyl carbonate.
At present, the ethyl methyl carbonate is prepared by a transesterification method by adopting a reactive distillation technology in industry, but the equipment cost and the energy consumption are quite high, and the method mainly has the problems that a product at the top of a reactive distillation tower is an azeotrope of DMC and methanol, the composition of the azeotrope is DMC30 percent, the methanol is 70 percent, the method for separating the azeotrope is mainly pressure swing distillation, the azeotropic is broken by adopting two tower processes of a pressurized tower and an atmospheric tower, DMC and methanol products are respectively obtained from the bottom of the pressurized tower and the bottom of the atmospheric tower, and the DMC returns to the reactive tower for continuous reaction. The pressurizing tower has high pressure, high cost and energy consumption, complicated flow path and great DMC and normal pressure azeotrope circulating amount, and this results in complicated technological process and high power consumption.
At present, related reports exist and industrial processes for preparing methyl ethyl carbonate are realized, DMC and ethanol in a certain molar ratio are mixed and fed from the middle part of a reaction rectifying tower, and a catalyst sodium methoxide methanol solution is fed from the top of the reaction rectifying tower. After the raw materials are fully reacted in the reaction rectifying tower, methanol generated by the reaction and a small amount of unreacted DMC are extracted from the top of the reaction rectifying tower, and a ternary mixture of DMC, EMC and DEC enters a light component removal tower from the tower kettle of the reaction rectifying tower; extracting DMC from the top of the light component removal tower, recovering and reusing the DMC, and allowing a binary mixture of EMC and DEC to enter a product refining tower from a tower kettle of the light component removal tower; and (3) obtaining a high-purity methyl ethyl carbonate product at the top of the product refining tower, and extracting a byproduct DEC from the bottom of the tower. The disadvantages of this process are: the selectivity of the reaction and the yield of EMC are very low, and the proportion of the finally obtained EMC to the DEC product is only 1:1 at most; the process comprises 3 complete columns, so the equipment cost and the process energy consumption are very high.
The author is Schoenling and the article name is "control and analysis of double reaction section reaction rectifying tower: the article "transesterification of dimethyl carbonate with ethanol" proposes the use of a reactive rectification column technique having two reaction stages in the transesterification of dimethyl carbonate with ethanol, the upper and lower reaction stages being intended to complete the reaction for the preparation of DEC together. The two reaction sections are set up in the technology only for relieving the strong interaction between two continuous reversible reactions, the catalyst fillers of the upper reaction section and the lower reaction section are the same, and the two reactions have good forward conversion rate through the reasonable arrangement of intermediate products. The two stages of catalyst packing did not show specificity and selectivity in the reaction.
Disclosure of Invention
In view of the above, the invention provides a preparation process and a system of ethyl methyl carbonate, which have the advantages of high conversion rate, no azeotrope generation, simple separation process and low energy consumption.
In order to achieve the purpose, the invention provides a process for preparing methyl ethyl carbonate by using a double-reaction-section reaction rectifying tower, which comprises the following specific steps:
DMC, ethanol and recycled DEC are used as raw materials, the double-reaction-section reaction rectifying tower consists of an upper rectifying section, an upper reaction section, a middle rectifying section, a lower reaction section and a stripping section, and EMC is prepared through ester exchange reaction and normalization reaction in the double-reaction-section reaction rectifying tower.
The catalyst for the ester exchange reaction and the normalization reaction can be a molecular sieve supported alkali metal catalyst or an anion exchange resin catalyst, but when the same kind of catalyst is selected for the ester exchange reaction and the normalization reaction, the selected catalyst has different functional groups and is two different high-selectivity catalysts.
Further, the mass ratio of the normalized reaction catalyst to the transesterification catalyst is 1: 1-1: 3.
further, the ester exchange reaction process comprises the following steps: ethanol and DMC feed are mixed and subjected to transesterification reaction in the lower reaction section, so that methanol and a small amount of unreacted DMC enter the middle rectification section; the generated EMC and DEC enter a stripping section.
Further, the normalization reaction process comprises the following steps: the middle rectifying section enriches and purifies azeotrope of DMC and methanol to the upper reaction section, feeding DEC and the azeotrope are in countercurrent contact and are subjected to normalized reaction with DMC to generate EMC, gas-phase methanol enters the upper rectifying section, methanol is extracted from the top of the tower, EMC, DEC and DMC are produced from the tower kettle, EMC with higher yield can be obtained by subsequent separation through the existing mature process, and the byproduct DEC is used for reaction feeding, so that the yield of EMC is improved, and the pressure of excess capacity of DEC in the market is relieved.
Furthermore, the number of the upper reaction section theoretical plates of the reactive distillation column is 10-15, the number of the lower reaction section theoretical plates is 20-30, the number of the stripping section plates is 20-30, the number of the middle distillation section plates is 10-20, and the number of the upper distillation section plates is 20-30.
Further, the DMC and ethanol mixed feed position is tray 45-55, and the DEC feed position is tray 21-31.
Further, the molar ratio of DMC to ethanol in the mixed feed is 1: 1-3: 1, controlling the feeding amount of the DEC and the DMC in a molar ratio of 2: 1-3: 1.
further, the operating pressure of the reactive distillation column is 90-110KPa, the operating pressure determines the operating temperature, the reaction temperature is 65-80 ℃, the pressure drop of the whole column is controlled at 10-30KPa in order to ensure that the temperature does not exceed the standard, and the reflux ratio of the reactive distillation column is 2-7.
The working principle of the double-reaction-section reaction rectification is as follows: in the double-reaction-section reactive distillation tower, the lower reaction section mainly comprises the following reaction formulas (1) and (2), ethanol and DMC generate transesterification reaction under the catalysis of a catalyst in the lower reaction section, and in the upper reaction section, the transesterification reaction of DEC and methanol is avoided by adopting a high-selectivity catalyst to catalyze a normalization reaction (reaction formula (3)), wherein the high-selectivity catalyst is used for avoiding the transesterification reaction of DEC and methanol, the conversion rate of methanol is controlled within 5%, and the side reaction is avoided by regulating and controlling an active group of the catalyst, so that DMC is selectively removed, the azeotropic composition is broken, the problem of separating azeotrope by subsequent pressure swing distillation is avoided, the flow is simplified, and the energy consumption is reduced.
The invention also provides a system for preparing ethyl methyl carbonate by using the double-reaction-section reaction rectifying tower, which comprises the double-reaction-section reaction rectifying tower, a condenser and a reboiler, wherein the condenser is arranged at the upper part of the reaction rectifying tower, and the reboiler is arranged at the lower part of the reaction rectifying tower; an upper rectifying section, an upper reaction section, an intermediate rectifying section, a lower reaction section and a stripping section are arranged in the double-reaction-section reaction rectifying tower;
a DMC and ethanol mixed feed inlet is formed between the lower reaction section and the stripping section, a DEC feed inlet is formed between the upper reaction section and the upper rectifying section, a methanol discharge outlet is formed in the top of the tower, and an EMC discharge outlet is formed in the bottom of the tower.
Optionally, a pre-reactor is further arranged on the DMC and ethanol mixing feed inlet.
In conclusion, the production process and the system of the methyl ethyl carbonate can realize the industrial production of the methyl ethyl carbonate product with high efficiency through the novel process of the double-reaction-section reaction rectifying tower for continuous production, and have simple operation mode and high production efficiency.
Has the advantages that:
(1) according to the invention, different catalysts are designed in the double-reaction-section reaction rectifying tower for catalytic normalization reaction and esterification reaction, so that the generation of DMC and methanol azeotrope is avoided, the EMC yield is improved and can reach 98-99.5%, methanol with purity of 98-99.9% is directly obtained at the tower top, the process is simplified, and the purpose of controlling various reactions in the system is achieved.
(2) Compared with the three tower bodies, the three condensers and the three reboilers in the prior art, the double-reaction-section reactive distillation process can save about 50% of energy consumption and 60% of equipment cost.
Drawings
FIG. 1 is a schematic diagram of a double-reaction-section reaction rectifying tower for preparing methyl ethyl carbonate
1. A DEC feed port; 2. DMC and ethanol mixing feed; 3. a pre-reactor; 4. a methanol discharge hole; 5. DMC \ EMC \ DEC discharge port; 6. a condenser; 7. a reboiler;
8. an upper rectifying section, 9, an upper reaction section, 10, an intermediate rectifying section, 11, a lower reaction section, 12 and a stripping section.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.
Example 1
As shown in fig. 1, this embodiment describes a process for preparing ethyl methyl carbonate by using a dual-reaction-section reactive distillation column, which specifically includes the following steps:
ethanol and DMC feed are mixed and subjected to transesterification reaction in the lower reaction section, so that methanol and a small amount of unreacted DMC enter the middle rectification section; the generated EMC and DEC enter a stripping section.
The middle rectifying section enriches and purifies azeotrope of DMC and methanol to the upper reaction section, feeding DEC and the azeotrope are in countercurrent contact and are subjected to normalized reaction with DMC to generate EMC, gas-phase methanol enters the upper rectifying section, methanol is extracted from the top of the tower, and EMC, DEC and DMC are produced from the bottom of the tower.
The normalized catalyst is A550 type anion exchange resin, and the ester exchange catalyst is a molecular sieve loaded Cs metal catalyst.
Further, the mass ratio of the catalyst for the normalization reaction and the transesterification reaction is 1: 1.
further, the molar ratio of the raw material DMC to the ethanol is 1:1, and the feeding amount of the DEC to the DMC is controlled to be 2: 1.
Further, the operating pressure of the reactive distillation column is 110KPa, the pressure drop of the whole column is 30KPa, and the reaction temperature is 65 ℃.
Furthermore, the number of upper reaction section theoretical plates of the reactive distillation column is 10, the number of lower reaction section theoretical plates is 20, the number of stripping section plates is 20, the number of middle distillation section plates is 10, the number of upper distillation section plates is 20, the position of DMC and ethanol mixed feeding is the 45 th tower plate, and the position of DEC feeding is the 21 st tower plate.
Further, the reflux ratio of the reactive distillation column is 7.
The purity of the methanol produced at the top of the column was 99.9%, and the EMC yield at the bottom of the column was 99.5%.
Example 2
Similar to example 1, the process parameters of this example are:
the normalized catalyst is D201 type anion exchange resin, and the ester exchange catalyst is a molecular sieve loaded K metal catalyst.
The mass ratio of the catalyst for the normalization reaction and the transesterification reaction is 1: 3.
The molar ratio of the raw material DMC to the ethanol is 3:1, and the feeding amount of the DEC to the DMC is controlled to be 3: 1.
The operation pressure of the reaction rectifying tower is 90KPa, the pressure drop of the whole tower is 10KPa, and the reaction temperature is 80 ℃.
The reaction rectifying tower has 10 upper reaction section theoretical plates, 30 lower reaction section theoretical plates, 30 stripping section plates, 10 middle rectifying section plates and 30 upper rectifying section plates, and the DMC and ethanol mixture feeding position is the 55 th tower plate and the DEC feeding position is the 31 th tower plate.
The reflux ratio of the reactive distillation column is 2.
The purity of the methanol produced at the top of the tower is 99.3%, and the yield of EMC at the bottom of the tower is 99.2%.
Example 3
The normalized catalyst is a molecular sieve supported Na metal catalyst, and the ester exchange catalyst is a 717 type anion exchange resin catalyst.
The mass ratio of the catalyst for the normalization reaction to the transesterification reaction is 1: 2.
The molar ratio of the raw material DMC to the ethanol is 2:1, and the feeding amount of the DEC to the DMC is controlled to be 2: 1.
The operation pressure of the reaction rectifying tower is 100KPa, the pressure drop of the whole tower is 20KPa, and the reaction temperature is 72 ℃.
The reaction rectifying tower has the upper reaction section with theoretical plate number of 10, the lower reaction section with theoretical plate number of 25, the stripping section with plate number of 25, the middle rectifying section with plate number of 10, the upper rectifying section with plate number of 25, the DMC and ethanol mixture feeding position as the 50 th tower plate and the DEC feeding position as the 26 th tower plate.
The reflux ratio of the reactive distillation column is 4.
The purity of the methanol produced at the top of the tower is 99.6%, and the yield of EMC at the bottom of the tower is 99.4%.
Example 4
The process parameters of the embodiment are as follows:
the catalyst for the normalization reaction and the ester exchange reaction is a molecular sieve supported Na metal catalyst with different activated groups.
The mass ratio of the catalyst for the normalization reaction and the transesterification reaction is 1: 2.
The molar ratio of the raw material DMC to the ethanol is 2:1, and the feeding amount of the DEC to the DMC is controlled to be 2: 1.
The operation pressure of the reaction rectifying tower is 100KPa, the pressure drop of the whole tower is 20KPa, and the reaction temperature is 72 ℃.
The reaction rectifying tower has the upper reaction section with theoretical plate number of 10, the lower reaction section with theoretical plate number of 25, the stripping section with plate number of 25, the middle rectifying section with plate number of 10, the upper rectifying section with plate number of 25, the DMC and ethanol mixture feeding position as the 50 th tower plate and the DEC feeding position as the 26 th tower plate.
The reflux ratio of the reactive distillation column is 4.
The purity of the methanol produced at the top of the column is 99.5%, and the EMC yield at the bottom of the column is 99.2%.
Example 5
The process parameters of the embodiment are as follows:
the catalysts for the normalization reaction and the transesterification reaction are 717 type anion exchange resin catalysts with different activating groups.
The mass ratio of the catalyst for the normalization reaction and the transesterification reaction is 1: 3.
The molar ratio of the raw material DMC to the ethanol is 3:1, and the feeding amount of the DEC to the DMC is controlled to be 3: 1.
The operation pressure of the reaction rectifying tower is 90KPa, the pressure drop of the whole tower is 10KPa, and the reaction temperature is 80 ℃.
The reaction rectifying tower has the upper reaction section with theoretical plate number of 10, the lower reaction section with theoretical plate number of 30, the stripping section with plate number of 30, the middle rectifying section with plate number of 10, the upper rectifying section with plate number of 30, the DMC and ethanol mixture feeding position of the 55 th tower plate and the DEC feeding position of the 31 th tower plate.
The reflux ratio of the reactive distillation column is 2.
The purity of the methanol produced at the top of the column was 99.7%, and the EMC yield at the bottom of the column was 99.4%.
Example 6
This example describes a system of a double reaction section reaction rectifying tower according to the present invention, which comprises a double reaction section reaction rectifying tower, a condenser 6, and a reboiler 7, according to fig. 1; the upper part of the reaction rectifying tower is provided with a condenser 6, and the lower part of the reaction rectifying tower is provided with a reboiler 7;
the double-reaction-section reaction rectifying tower consists of an upper rectifying section 8, an upper reaction section 9, an intermediate rectifying section 10, a lower reaction section 11 and a stripping section 12;
a DMC and ethanol mixed feed inlet 2 is arranged between the lower reaction section 11 and the stripping section 12, a DEC feed inlet 1 is arranged between the upper rectifying section 8 and the upper reaction section 9, a methanol discharge outlet 4 is arranged at the top of the tower, and a DMC/EMC/DEC discharge outlet 5 is arranged at the bottom of the tower.
Further, a pre-reactor 3 is arranged on the DMC and ethanol mixing feed inlet 2.
Furthermore, the number of the upper reaction section theoretical plates of the reactive distillation column is 10-15, the number of the lower reaction section theoretical plates is 20-30, the number of the stripping section plates is 20-30, the number of the middle distillation section plates is 10-20, and the number of the upper distillation section plates is 20-30.
Further, the DMC and ethanol mixed feed position is tray 45-55, and the DEC feed position is tray 21-31.
Comparative example 1
This comparative example is compared to example 1 by varying the normalized catalyst to transesterification catalyst mass ratio.
The normalized catalyst is A550 type anion exchange resin, and the ester exchange catalyst is a molecular sieve loaded Cs metal catalyst.
The mass ratio of the catalyst for the normalization reaction to the transesterification reaction is 4: 1.
the molar ratio of the raw material DMC to the ethanol is 1:1, and the feeding amount of the DEC to the DMC is controlled to be 2: 1.
The operating pressure of the reactive distillation column is 110KPa, the pressure drop of the whole column is 30KPa, and the reaction temperature is 65 ℃.
The reaction rectifying tower has 10 upper reaction section theoretical plates, 20 lower reaction section theoretical plates, 20 stripping section plates, 10 middle rectifying section plates and 20 upper rectifying section plates, and the DMC and ethanol mixture feeding position is the 45 th tower plate and the DEC feeding position is the 21 st tower plate.
The reflux ratio of the reactive distillation column is 7.
The purity of the methanol produced at the top of the column is 78%, and the EMC yield at the bottom of the column is 80%.
Comparative example 2
This comparative example is compared to example 3 by varying the ratio of the raw material feeds.
The normalized catalyst is a molecular sieve supported Na metal catalyst, and the ester exchange catalyst is a 717 type anion exchange resin catalyst.
The mass ratio of the catalyst for the normalization reaction and the transesterification reaction is 1: 2.
The molar ratio of the raw material DMC to the ethanol is 5:1, and the feeding amount of the DEC to the DMC is controlled to be 4: 1.
The operation pressure of the reaction rectifying tower is 100KPa, the pressure drop of the whole tower is 20KPa, and the reaction temperature is 72 ℃.
The reaction rectifying tower has 10 upper reaction section theoretical plates, 25 lower reaction section theoretical plates, 25 stripping section plates, 10 middle rectifying section plates and 25 upper rectifying section plates, and the DMC and ethanol mixture feeding position is the 50 th tower plate and the DEC feeding position is the 26 th tower plate.
The reflux ratio of the reactive distillation column is 4.
The purity of the methanol produced at the top of the tower is 86%, and the yield of EMC at the bottom of the tower is 82%.
Comparative example 3
This comparative example was compared with example 2 by changing the operating pressure and reaction temperature of the double reaction-stage rectification column.
The normalized catalyst is D201 type anion exchange resin, and the ester exchange catalyst is a molecular sieve loaded K metal catalyst.
The catalyst mass ratio of the normalization reaction to the ester exchange reaction is 1: 3.
The molar ratio of the raw material DMC to the ethanol is 3:1, and the feeding amount of the DEC to the DMC is controlled to be 3: 1.
The operation pressure of the reaction rectifying tower is 80KPa, the pressure drop of the whole tower is 10KPa, and the reaction temperature is 50 ℃.
The reaction rectifying tower has 10 upper reaction section theoretical plates, 30 lower reaction section theoretical plates, 30 stripping section plates, 10 middle rectifying section plates and 30 upper rectifying section plates, and the DMC and ethanol mixture feeding position is the 55 th tower plate and the DEC feeding position is the 31 th tower plate.
The reflux ratio of the reactive distillation column is 2.
The purity of the methanol produced at the top of the column was 92% and the EMC yield at the bottom of the column was 91.5%.
Comparative example 4
| Name(s) | Ton product energy consumption (ton steam/ton product) | Power consumption (kW. h/ton product) |
| CN110845334A | 5.2 | 100 |
| Example 1 | 1.2 | 50 |
| Example 2 | 2.3 | 63 |
Patent CN110845334A discloses a device and method for producing battery-grade ethyl methyl carbonate by using dimethyl carbonate and ethanol, the device mainly comprises a reaction tower, a diethyl carbonate removing tower and an ethyl methyl carbonate refining tower, and dimethyl carbonate and methanol are not separated, and diethyl carbonate is not refined.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and should not be taken as limiting the invention, so that any modifications, equivalents and the like included in the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (7)
1. A process for preparing methyl ethyl carbonate by using a double-reaction-section reaction rectifying tower is characterized in that DMC, ethanol and DEC are used as raw materials, the double-reaction-section reaction rectifying tower consists of an upper rectifying section, an upper reaction section, an intermediate rectifying section, a lower reaction section and a stripping section, and EMC is prepared in the double-reaction-section reaction rectifying tower through ester exchange reaction and normalization reaction;
the ester exchange reaction process comprises the following steps: ethanol and DMC feed are mixed and subjected to transesterification reaction in the lower reaction section, so that methanol and a small amount of unreacted DMC enter the middle rectification section; the generated EMC and the generated DEC enter a stripping section;
the normalized reaction process comprises the following steps: enriching and purifying an azeotrope of DMC and methanol generated by transesterification to an upper reaction section by a middle rectification section, feeding DEC to be in countercurrent contact with the azeotrope and to perform normalization reaction with DMC to generate EMC, feeding vapor phase methanol to the upper rectification section, extracting methanol from the top of the tower, and producing EMC, DEC and DMC in the bottom of the tower;
the normalized catalyst is A550 type anion exchange resin, and the ester exchange catalyst is a molecular sieve loaded Cs metal catalyst; or the normalized catalyst is D201 type anion exchange resin, and the ester exchange catalyst is a molecular sieve loaded K metal catalyst; or the normalized catalyst is a molecular sieve loaded Na metal catalyst, and the ester exchange catalyst is a 717 type anion exchange resin catalyst.
2. The process for preparing methyl ethyl carbonate by using the double-reaction-section reaction rectifying tower according to claim 1, wherein the mass ratio of the catalyst for the normalized reaction to the catalyst for the ester exchange reaction is 1: 1-1: 3.
3. the process for preparing ethyl methyl carbonate by using the double-reaction-section reaction rectifying tower as claimed in claim 1, wherein the number of theoretical plates of the upper reaction section of the reaction rectifying tower is 10-15, the number of theoretical plates of the lower reaction section is 20-30, the number of theoretical plates of the stripping section is 20-30, the number of theoretical plates of the middle rectifying section is 10-20, and the number of theoretical plates of the upper rectifying section is 20-30.
4. The process for preparing methyl ethyl carbonate by the double-reaction-section reaction rectifying tower as claimed in claim 1, wherein the DMC and ethanol mixed feeding position is the 45 th to 55 th trays, and the DEC feeding position is the 21 st to 31 th trays.
5. The process for preparing methyl ethyl carbonate by using the double-reaction-section reaction rectifying tower as claimed in claim 1, wherein the molar ratio of DMC to ethanol in the mixed feed is 1: 1-3: the feed amount of the DEC and the DMC is controlled in a molar ratio of 2: 1-3: 1.
6. the process for preparing ethyl methyl carbonate by using the double-reaction-section reaction rectifying tower as claimed in claim 1, wherein the operating pressure of the reaction rectifying tower is 90-110KPa, the pressure drop of the whole tower is 10-30KPa, the reaction temperature of the ester exchange reaction and the normalized reaction is 65-80 ℃, and the reflux ratio of the reaction rectifying tower is 2-7.
7. A system for preparing ethyl methyl carbonate by using a double-reaction-section reaction rectifying tower is characterized by comprising the double-reaction-section reaction rectifying tower, a condenser and a reboiler, wherein the condenser is arranged at the upper part of the reaction rectifying tower, and the reboiler is arranged at the lower part of the reaction rectifying tower; an upper rectifying section, an upper reaction section, an intermediate rectifying section, a lower reaction section and a stripping section are arranged in the double-reaction-section reaction rectifying tower; a DMC and ethanol mixed feed port is formed between the lower reaction section and the stripping section, a pre-reactor is further arranged on the DMC and ethanol mixed feed port, a DEC feed port is formed between the upper reaction section and the upper rectifying section, a methanol discharge port is formed in the top of the tower, and an EMC discharge port is formed in the bottom of the tower.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103483200A (en) * | 2013-09-16 | 2014-01-01 | 河北工业大学 | Method for synthesizing ethyl methyl carbonate through ester exchange |
| CN109776322A (en) * | 2019-03-14 | 2019-05-21 | 福州大学 | A kind of method that partition wall type reactive distillation column prepares high-purity methyl ethyl carbonate |
| CN111773755A (en) * | 2020-07-16 | 2020-10-16 | 河北工业大学 | Method and device for preparing methyl ethyl carbonate by using bulkhead reaction rectifying tower |
| CN113354540A (en) * | 2021-07-26 | 2021-09-07 | 华东理工大学 | Method for efficiently and continuously preparing methyl ethyl carbonate |
| CN113636935A (en) * | 2021-09-18 | 2021-11-12 | 凯瑞环保科技股份有限公司 | Preparation method of methyl ethyl carbonate |
| CN114057579A (en) * | 2021-12-08 | 2022-02-18 | 河北工业大学 | Method for preparing asymmetric carbonate by rectifying catalytic reaction of symmetric carbonate |
-
2022
- 2022-04-08 CN CN202210365222.8A patent/CN114436839B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103483200A (en) * | 2013-09-16 | 2014-01-01 | 河北工业大学 | Method for synthesizing ethyl methyl carbonate through ester exchange |
| CN109776322A (en) * | 2019-03-14 | 2019-05-21 | 福州大学 | A kind of method that partition wall type reactive distillation column prepares high-purity methyl ethyl carbonate |
| CN111773755A (en) * | 2020-07-16 | 2020-10-16 | 河北工业大学 | Method and device for preparing methyl ethyl carbonate by using bulkhead reaction rectifying tower |
| CN113354540A (en) * | 2021-07-26 | 2021-09-07 | 华东理工大学 | Method for efficiently and continuously preparing methyl ethyl carbonate |
| CN113636935A (en) * | 2021-09-18 | 2021-11-12 | 凯瑞环保科技股份有限公司 | Preparation method of methyl ethyl carbonate |
| CN114057579A (en) * | 2021-12-08 | 2022-02-18 | 河北工业大学 | Method for preparing asymmetric carbonate by rectifying catalytic reaction of symmetric carbonate |
Non-Patent Citations (3)
| Title |
|---|
| Di-methyl carbonate transesterification with EtOH over MOFs: Basicity and synergic effect of basic and acid active sites;Luca Desidery,等;《Catalysis Communications》;20171028;第104卷;全文 * |
| Zeolite and other heterogeneous catalysts for the transesterification reaction of dimethyl carbonate with ethanol;I. Zielinska-Nadolska，等;《Catalysis Today》;20060210;第114卷;全文 * |
| 隔壁反应精馏合成碳酸甲乙酯节能新工艺;王红星，等;《化工进展》;20201231;第39卷(第S2期);全文 * |
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Application publication date: 20220506 Assignee: Qingke New Materials Technology (Hebei) Co.,Ltd. Assignor: TIANJIN University OF SCIENCE AND TECHNOLOGY Contract record no.: X2023120000018 Denomination of invention: A Process and System for the Preparation of Methyl Ethyl Carbonate by a Dual Reaction Stage Reaction Distillation Column Granted publication date: 20220722 License type: Common License Record date: 20230418 |