CN113880712B - Preparation method of ethyl acetate - Google Patents
Preparation method of ethyl acetate Download PDFInfo
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- CN113880712B CN113880712B CN202111084991.2A CN202111084991A CN113880712B CN 113880712 B CN113880712 B CN 113880712B CN 202111084991 A CN202111084991 A CN 202111084991A CN 113880712 B CN113880712 B CN 113880712B
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/08—Preparation of carboxylic acid esters by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/02—Sulfur, selenium or tellurium; Compounds thereof
- B01J27/053—Sulfates
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
- B01J31/02—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides
- B01J31/06—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides containing polymers
- B01J31/08—Ion-exchange resins
- B01J31/10—Ion-exchange resins sulfonated
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
- B01J31/26—Catalysts comprising hydrides, coordination complexes or organic compounds containing in addition, inorganic metal compounds not provided for in groups B01J31/02 - B01J31/24
- B01J31/38—Catalysts comprising hydrides, coordination complexes or organic compounds containing in addition, inorganic metal compounds not provided for in groups B01J31/02 - B01J31/24 of titanium, zirconium or hafnium
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/48—Separation; Purification; Stabilisation; Use of additives
- C07C67/52—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
- C07C67/54—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation by distillation
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2231/00—Catalytic reactions performed with catalysts classified in B01J31/00
- B01J2231/40—Substitution reactions at carbon centres, e.g. C-C or C-X, i.e. carbon-hetero atom, cross-coupling, C-H activation or ring-opening reactions
- B01J2231/49—Esterification or transesterification
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/584—Recycling of catalysts
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- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
The invention provides a preparation method of ethyl acetate, raw materials of acetic acid, absolute ethyl alcohol and recovered ester (including head ester and supplemental ester) are metered and placed into an esterification kettle, under the action of a catalyst, the raw materials are heated by steam to generate ethyl acetate and water, an azeotrope is formed in an esterification tower, the mixture is distilled out from the top of the tower, condensed and cooled, and then enters a phase separator for separation, and a water phase enters the recovery tower; part of the ester phase flows back to the esterification tower, the rest enters the crude ester buffer tank for preheating, then enters the concentration tower, the finished product with qualified ester content, acidity and moisture is obtained at the bottom of the tower through rectification, after cooling, part of the product returns to the esterification kettle for supplementing ester, and the rest of the product enters the metering tank; the water phase is waste water containing ester and alcohol, and after entering a recovery tower, the waste water is distilled and separated, the head ester with a certain content is recovered from the top of the recovery tower, the head ester returns to the esterification tower, and the recovered waste water is discharged from the bottom of the recovery tower.
Description
Technical Field
The invention relates to a preparation method of ethyl acetate.
Background
Ethyl acetate is an important organic chemical raw material, can be used for manufacturing acetamide, acetoacetate and the like, and can be used as an industrial solvent in products such as paint coatings, adhesives, ethylcellulose, artificial leather, linoleum coloring agents, artificial fibers and the like; as adhesive for printing ink and artificial pearl production; as extractant for the production of medicine, organic acid and other products; and can be widely applied to industries such as essence and spice, medicine, high-grade printing ink, collodion cotton, nitrocellulose, dye and the like. In the traditional industrial production method of ethyl acetate, concentrated sulfuric acid is used as a catalyst, raw materials of ethanol and acetic acid react in an esterification kettle, acetic acid is excessive in the esterification kettle, reaction products are distilled out from the top of the esterification kettle in a ternary azeotropic mode of ethyl acetate, ethanol and water, and materials with higher boiling points such as acetic acid carried out in the esterification kettle together flow back to the esterification kettle from the bottom of the esterification kettle for continuous reaction. The method mainly has the following defects: 1. concentrated sulfuric acid is used as a catalyst, and the method has the defects of serious equipment corrosion and multiple side reactions although the reaction activity is high; the water content in the reflux organic phase is higher, and the ethyl acetate which is a common finished product is used for carrying water, so that the yield of the finished product is wasted.
Disclosure of Invention
The invention provides a preparation method of ethyl acetate, raw materials of acetic acid, absolute ethyl alcohol and recovered ester (including head ester and supplemental ester) are metered and put into an esterification kettle, under the action of a catalyst, the raw materials are heated by steam to generate ethyl acetate and water, an azeotrope is formed in an esterification tower, the mixture is distilled out from the top of the tower, and after condensation and cooling, the mixture enters a phase separator for separation, and water phase enters the recovery tower to recover dissolved ester and alcohol; part of the ester phase flows back to the esterification tower, the rest enters the crude ester buffer tank for preheating, then enters the concentration tower, the components at the top of the concentration tower are rectified, condensed by the cooling condenser and split-phase by the phase splitter in sequence, the water phase enters the recovery tower, and the ester phase returns to the concentration tower; the components in the concentration tower are cooled by a cooler and then separated by a phase separator, the water phase is removed from the recovery tower, and the ester phase is returned to the concentration tower again; the bottom of the tower is provided with a finished product with qualified ester content, acidity and moisture, part of the finished product is returned to the esterification kettle to be used as ester supplement after being cooled, and the rest of the finished product is completely fed into the metering tank; the water phase is waste water containing ester and alcohol, and after entering a recovery tower, the waste water is distilled and separated, the head ester with a certain content is recovered from the top of the recovery tower, the head ester returns to the esterification tower, and the recovered waste water is discharged from the bottom of the recovery tower. The specific scheme is as follows:
a preparation method of ethyl acetate comprises the following steps:
1) Metering acetic acid, absolute ethyl alcohol and recovered ester (including head ester and supplemental ester) into an esterification kettle;
2) Under the action of a catalyst, ethyl acetate and water are generated by steam heating, an azeotrope is formed in the esterification tower, and the mixture is distilled out from the top of the tower;
3) After condensing and cooling, separating the mixture in a phase separator, and allowing the water phase to enter a recovery tower to recover the dissolved ester and alcohol; part of the ester phase flows back to the esterification tower, and the rest enters the crude ester buffer tank for preheating and then enters the concentration tower;
4) Rectifying in a concentrating tower, sequentially condensing the components at the top of the concentrating tower through a cooling condenser and separating phases through a phase separator, enabling a water phase to enter a recovery tower, and returning an ester phase to the concentrating tower; the components in the concentration tower are cooled by a cooler and then separated by a phase separator, the water phase enters a recovery tower, and the ester phase returns to the concentration tower again; the bottom of the tower is provided with a finished product with qualified ester content, acidity and moisture, part of the finished product is returned to the esterification kettle to be used as ester supplement after being cooled, and the rest of the finished product is completely fed into the metering tank;
5) The water phase is waste water containing ester and alcohol, and after entering a recovery tower, the waste water is distilled and separated, the head ester with a certain content is recovered from the top of the recovery tower, the head ester returns to the esterification tower, and the recovered waste water is discharged from the bottom of the recovery tower.
Further, the catalyst is a mixture of strong acid macroporous cation exchange resin Amberlyst-15 and Zr (SO 4) 2/TiO2 solid acid, wherein the mass ratio of Amberlyst-15 to Zr (SO 4) 2/TiO2 is 1.62-1.65.
Further, the temperature T (°c) in the esterification tower is 75-80 ℃, the pressure P (MPa) is 0.2-0.5MPa, and the following relation is satisfied, 0.58 x (Amberlyst-15 and Zr (SO 4) 2/TiO2 mass ratio) = (k+8.5xp)/T, where k=70-72.
The invention has the following beneficial effects:
1) The method has the advantages of high yield and selectivity of ethyl acetate, full utilization of products in each process step for recycling, simple operation and low cost;
2) The further inventors found that the use of a composite catalyst instead of the concentrated sulfuric acid catalyst can avoid corrosion of the concentrated sulfuric acid to equipment, and that the conversion (%) of acetic acid and the selectivity (%) of ethyl acetate are higher than those of concentrated sulfuric acid as the catalyst;
3) The inventors have further found that when the pressure and temperature in the esterification column are controlled to satisfy a specific relationship for a specific catalyst, the catalyst is controlled to be a catalyst having a specific value of 0.58 x (Amberlyst-15 and Zr (SO 4 ) 2 /TiO 2 Mass ratio) = (k+8.5×p)/T, the conversion (%) of acetic acid and the selectivity (%) of ethyl acetate are very high.
Drawings
FIG. 1 is a flow chart of a production process of ethyl acetate
Detailed Description
The present invention will be described in more detail by way of specific examples, but the scope of the present invention is not limited to these examples.
Examples
1) Metering acetic acid, absolute ethyl alcohol and recovered ester (including head ester and supplemental ester) into an esterification kettle;
2) Under the action of a catalyst, ethyl acetate and water are generated by steam heating, an azeotrope is formed in the esterification tower, and the mixture is distilled out from the top of the tower;
3) After condensing and cooling, separating the mixture in a phase separator, and allowing the water phase to enter a recovery tower to recover the dissolved ester and alcohol; part of the ester phase flows back to the esterification tower, and the rest enters the crude ester buffer tank for preheating and then enters the concentration tower;
4) Rectifying in a concentrating tower, sequentially condensing the components at the top of the concentrating tower through a cooling condenser and separating phases through a phase separator, enabling a water phase to enter a recovery tower, and returning an ester phase to the concentrating tower; the components in the concentration tower are cooled by a cooler and then separated by a phase separator, the water phase enters a recovery tower, and the ester phase returns to the concentration tower again; the bottom of the tower is provided with a finished product with qualified ester content, acidity and moisture, part of the finished product is returned to the esterification kettle to be used as ester supplement after being cooled, and the rest of the finished product is completely fed into the metering tank;
5) The water phase is waste water containing ester and alcohol, and after entering a recovery tower, the waste water is distilled and separated, the head ester with a certain content is recovered from the top of the recovery tower, the head ester returns to the esterification tower, and the recovered waste water is discharged from the bottom of the recovery tower.
The catalyst is strong acid macroporous cation exchange resin Amberlyst-15 and Zr (SO) 4 ) 2 /TiO 2 Mixtures of solid acids, wherein Amberlyst-15 and Zr (SO 4 ) 2 /TiO 2 The mass ratio of (2) is 1.62-1.65, and the catalyst is 1wt% of the alcohol.
The temperature T (DEG C) in the esterification tower is 75-80 ℃, the pressure P (MPa) is 0.2-0.5MPa, and the following relational expression is satisfied, 0.58 (Amberlyst-15 and Zr (SO) 4 ) 2 /TiO 2 Mass ratio) = (k+8.5×p)/T, where k=70-72.
Conversion (%) of acetic acid= (amount of acetic acid-amount of acetic acid in reaction product)/(amount of acetic acid×100%)
Selectivity (%) of ethyl acetate=actual yield of ethyl acetate ≡theoretical yield of ethyl acetate × 100%
The experimental data of the examples and comparative examples are shown in Table 1
TABLE 1
While the present invention has been described in detail through the foregoing description of the preferred embodiment, it should be understood that the foregoing description is not to be considered as limiting the invention.
Claims (1)
1. A preparation method of ethyl acetate comprises the following steps:
1) Metering acetic acid, absolute ethyl alcohol and recovered ester into an esterification kettle, wherein the recovered ester comprises head ester and supplemental ester;
2) Under the action of a catalyst, ethyl acetate and water are generated by steam heating, an azeotrope is formed in the esterification tower, and the mixture is distilled out from the top of the tower; the catalyst is strong acid macroporous cation exchange resin Amberlyst-15 and Zr (SO) 4 ) 2 /TiO 2 Mixtures of solid acids, wherein Amberlyst-15 and Zr (SO 4 ) 2 /TiO 2 The mass ratio of (1.62-1.65), and is characterized in that: the temperature T (DEG C) in the esterification tower is 75-80 ℃, the pressure P (MPa) is 0.2-0.5MPa, and the following relational expression is satisfied, 0.58× (Amberlyst-15 and Zr (SO) 4 ) 2 /TiO 2 Mass ratio) = (k+8.5×p)/T, where k=70-72;
3) After condensing and cooling, separating the mixture in a phase separator, and allowing the water phase to enter a recovery tower to recover the dissolved ester and alcohol; part of the ester phase flows back to the esterification tower, and the rest enters the crude ester buffer tank for preheating and then enters the concentration tower;
4) Rectifying in a concentrating tower, sequentially condensing the components at the top of the concentrating tower through a cooling condenser and separating phases through a phase separator, enabling a water phase to enter a recovery tower, and returning an ester phase to the concentrating tower; the components in the concentration tower are cooled by a cooler and then separated by a phase separator, the water phase enters a recovery tower, and the ester phase returns to the concentration tower again; the bottom of the tower is provided with a finished product with qualified ester content, acidity and moisture, part of the finished product is returned to the esterification kettle to be used as ester supplement after being cooled, and the rest of the finished product is completely fed into the metering tank;
5) The water phase is waste water containing ester and alcohol, and after entering a recovery tower, the waste water is distilled and separated, the head ester with a certain content is recovered from the top of the recovery tower, the head ester returns to the esterification tower, and the recovered waste water is discharged from the bottom of the recovery tower.
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| CN202111084991.2A CN113880712B (en) | 2021-09-16 | 2021-09-16 | Preparation method of ethyl acetate |
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| CN202111084991.2A CN113880712B (en) | 2021-09-16 | 2021-09-16 | Preparation method of ethyl acetate |
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| CN114751822B (en) * | 2022-03-16 | 2024-04-09 | 浙江建业化工股份有限公司 | Device for producing n-propyl acetate by thermal coupling and production method thereof |
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