CN111167378B - Method for producing n-propyl acetate by continuous two-stage esterification reaction - Google Patents
Method for producing n-propyl acetate by continuous two-stage esterification reaction Download PDFInfo
- Publication number
- CN111167378B CN111167378B CN202010077430.9A CN202010077430A CN111167378B CN 111167378 B CN111167378 B CN 111167378B CN 202010077430 A CN202010077430 A CN 202010077430A CN 111167378 B CN111167378 B CN 111167378B
- Authority
- CN
- China
- Prior art keywords
- esterification kettle
- catalytic
- kettle
- acetic acid
- esterification
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- 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
- B01J4/00—Feed or outlet devices; Feed or outlet control devices
- B01J4/001—Feed or outlet devices as such, e.g. feeding tubes
- B01J4/002—Nozzle-type elements
-
- 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
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0053—Details of the reactor
-
- 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
-
- 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
-
- 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
- Y02P20/141—Feedstock
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
The invention discloses a method for producing n-propyl acetate by continuous two-stage esterification reaction, acetic acid and n-propanol are continuously added into a pre-esterification kettle and subjected to non-catalytic esterification reaction under the action of high temperature; the reaction liquid after pre-esterification is decompressed and vaporized and is sent into a catalytic esterification kettle through a liquid distributor; the top of the pre-esterification kettle is connected with the top of the catalytic esterification kettle through a gas pipeline, the bottom of the pre-esterification kettle is connected with a liquid pipeline, and a pressure control valve is arranged on the pre-esterification kettle; vaporizing the reaction liquid after catalytic esterification, separating acetic acid in a deacidification tower, and returning the unreacted acetic acid to the catalytic esterification kettle; the distillate at the top of the deacidification tower is condensed and layered, one part of the lower water phase reflows, the other part is extracted, and the upper oil phase is sent to be refined. The method has the advantages of high conversion rate, simple process and low operation energy consumption, and is suitable for industrial production.
Description
Technical Field
The invention relates to a process method of n-propyl acetate, in particular to a method for producing n-propyl acetate by two-stage reaction of continuous non-catalytic esterification and catalytic esterification.
Background
N-propyl acetate is a commonly used fine chemical raw material, has good solubility for various synthetic resins, and is an excellent solvent for various synthetic resins such as ethyl cellulose, nitrocellulose, polymethacrylate and the like. N-propyl acetate is widely used in the fields of printing ink, coating and the like.
At present, the industrial production process of n-propyl acetate is a continuous sulfuric acid catalytic esterification method, namely, acetic acid and n-propanol are mixed according to a molar ratio of 1:1, continuously feeding the mixture into an esterification kettle filled with a mixed solution of sulfuric acid and acetic acid, and obtaining a final product through esterification and distillation separation, wherein the yields of the two steps are 94.8 percent and 98.7 percent respectively (chemical engineering, 2015, 4: 259). Compared with the traditional batch production process, the production efficiency and the utilization rate of sulfuric acid are obviously improved, and simultaneously, the raw material consumption and the energy consumption are greatly reduced (2016, 8: 79-80).
With the increasing competition of the industry in recent years, in order to reduce the production cost, n-propyl acetate production enterprises pay more attention to the reduction of process energy consumption, the improvement of product purity and the improvement of utilization efficiency of a sulfuric acid catalyst. In order to improve the utilization efficiency of the catalyst, the chinese patent CN 104610055 a adopts a strong acid cation exchange resin as the catalyst, and although the purity of the refined product is greater than 99%, the reaction raw materials thereof reflux in the esterification kettle for 30min, and continuous production cannot be realized. The Chinese patent CN 101863760A fills strong acid ion exchange resin into the fixed bed, the total conversion rate of raw materials can reach 98.5%, and simultaneously, the utilization efficiency of the catalyst is improved. However, the molar ratio of acetic acid to n-propanol in the feed was 1: 1.1-1.3, namely, the n-propanol is excessive, and the refining and separation are difficult. Both of these approaches inevitably result in a significant increase in energy consumption compared to the existing continuous sulfuric acid catalyzed esterification process.
Therefore, in order to overcome the defects of the existing n-propyl acetate production process, a process method which has the advantages of improving the conversion efficiency, reducing the energy consumption and being suitable for industrial production needs to be developed.
Disclosure of Invention
The invention aims to solve the technical problem of providing a method for producing n-propyl acetate by continuous two-stage esterification reaction, which can not only reduce the energy consumption of the prior art, but also improve the purity of the product and is convenient for industrial production.
In order to solve the technical problem, the invention provides a method for producing n-propyl acetate by continuous two-stage esterification reaction, wherein the production device comprises a pre-esterification kettle, a catalytic esterification kettle with a liquid distributor arranged at the bottom of an inner cavity, a deacidification tower, a condenser, an oil-water separator and a circulating pump; a pre-esterification kettle emptying valve on the pre-esterification kettle is connected with a catalytic esterification kettle valve on the catalytic esterification kettle through a pipeline; the liquid distributor is of a calandria structure and is provided with a liquid outlet;
opening a pre-esterification kettle vent valve and a catalytic esterification kettle valve, and according to concentrated sulfuric acid: acetic acid and concentrated sulfuric acid are added into a catalytic esterification kettle in advance according to the mass ratio of 0.1-0.5%; adding a mixed raw material consisting of acetic acid and n-propanol into a pre-esterification kettle in advance; after the feeding is finished, closing an emptying valve of the pre-esterification kettle and a valve of the catalytic esterification kettle; heating the pre-esterification kettle to 120-150 ℃ and heating the catalytic esterification kettle to 100-120 ℃, preserving heat (keeping the temperature stable), and continuously adding the mixed raw materials into the pre-esterification kettle to realize continuous feeding; the reaction liquid after pre-esterification discharged from the pre-esterification kettle is vaporized under reduced pressure and then is sent into a catalytic esterification kettle through a liquid distributor for catalytic esterification reaction; the reaction product after catalytic esterification enters a deacidification tower for deacidification treatment (separation of acetic acid); the unreacted acetic acid returns to the catalytic esterification kettle; cooling the distillate at the tower top of the deacidification tower by a condenser, and layering in an oil-water separator; refluxing one part of the water phase (lower water phase) obtained by layering to the top of the deacidification tower by a circulating pump, and extracting the other part of the water phase; the oil phase (upper oil phase) obtained by layering is crude n-propyl acetate.
Description of the invention: in the crude product of the n-propyl acetate, the purity of the n-propyl acetate is more than or equal to 96.40, and the n-propyl acetate can be refined according to a conventional mode.
The improvement of the method for producing the n-propyl acetate by the continuous two-stage esterification reaction of the invention is as follows: the mixed raw materials are mixed according to the mass ratio of 1:1 with n-propanol.
As a further improvement of the method for producing the n-propyl acetate by the continuous two-stage esterification reaction of the invention: the acetic acid added into the catalytic esterification kettle in advance accounts for 1/4-1/3 of the volume of the catalytic esterification kettle.
As a further improvement of the method for producing the n-propyl acetate by the continuous two-stage esterification reaction of the invention: the mixed raw materials added into the pre-esterification kettle in advance account for 1/2-2/3 of the volume of the pre-esterification kettle.
As a further improvement of the method for producing the n-propyl acetate by the continuous two-stage esterification reaction of the invention: after continuous feeding, the retention time of the mixed raw materials in the pre-esterification kettle is 0.2-1.0 h.
As a further improvement of the method for producing the n-propyl acetate by the continuous two-stage esterification reaction of the invention: refluxing aqueous phase: the extracted aqueous phase is 1: 0.5-2 volume ratio.
As a further improvement of the method for producing the n-propyl acetate by the continuous two-stage esterification reaction of the invention: the tower top temperature of the deacidification tower is 80-85 ℃; and cooling the tower top distillate of the deacidification tower to 50-60 ℃ by a condenser.
As a further improvement of the method for producing the n-propyl acetate by the continuous two-stage esterification reaction of the invention: the liquid outlets on the liquid distributor face the bottom of the catalytic esterification kettle, namely all the liquid outlets are vertically downward.
Compared with the prior art, the invention has the following technical advantages:
1) according to the invention, the pre-esterification kettle is arranged before acetic acid and n-propanol enter the catalytic esterification kettle, and high-temperature non-catalytic esterification reaction is carried out, so that micro-primary mixing of two raw materials is realized, the high-temperature esterification reaction is carried out, the two raw materials are converted by 20-50%, the time and the use amount of a sulfuric acid catalyst required by subsequent catalytic esterification are greatly reduced, and the probability that the n-propanol preferentially participates in the esterification reaction but is not separated out of the catalytic esterification kettle is increased. The method not only reduces the circulation amount of n-propyl alcohol in the whole n-propyl acetate, thereby reducing the energy consumption, but also improves the separation and purification efficiency of the n-propyl acetate;
2) according to the invention, the gas pipeline and the valve are arranged on the tops of the pre-esterification kettle and the catalytic esterification kettle for connection, so that the emission of organic waste gas generated by volatilization of organic matters in the feeding and discharging operation processes is reduced. The liquid pipeline and the pressure control valve are arranged at the bottom of the pre-esterification kettle and the catalytic esterification kettle to be connected, and the higher reaction temperature is maintained by controlling the heating and the pressure of the pre-esterification kettle (the higher the saturated vapor pressure in the pre-esterification kettle is, the higher the temperature in the kettle is), so that the conversion efficiency of the raw materials without catalytic esterification is favorably improved, and meanwhile, when the raw materials are sent into the catalytic esterification kettle, the partial vaporization is caused by the reduction of the pressure, and the mass transfer and heat transfer efficiency of the raw materials in the catalytic esterification kettle are accelerated; namely, opening pressure control valves on liquid pipelines at the bottoms of the pre-esterification kettle and the catalytic esterification kettle, decompressing and vaporizing reaction liquid after pre-esterification, and sending the reaction liquid into the catalytic esterification kettle through a liquid distributor;
3) in the invention, a calandria liquid distributor is arranged in the catalytic esterification kettle, and the liquid outlet of the calandria liquid distributor faces downwards. The liquid passing through the pressure control valve is changed into a gas-liquid mixture flowing at a high speed, and the gas-liquid mixture is quickly dispersed into the catalytic esterification kettle through the liquid distributor and is uniformly mixed with the liquid in the kettle, so that the reaction rate of catalytic esterification is greatly increased, the probability that the n-propanol is separated out without participating in the esterification reaction is greatly reduced, and the reduction of energy consumption and the improvement of the subsequent n-propyl acetate separation efficiency are also facilitated.
In conclusion, in the production method of the n-propyl acetate, acetic acid and n-propanol are continuously added into the pre-esterification kettle and subjected to non-catalytic esterification reaction under the action of high temperature; the reaction liquid after pre-esterification is decompressed and vaporized and is sent into a catalytic esterification kettle through a liquid distributor; the top of the pre-esterification kettle is connected with the top of the catalytic esterification kettle through a gas pipeline, the bottom of the pre-esterification kettle is connected with a liquid pipeline, and a pressure control valve is arranged on the pre-esterification kettle; vaporizing the reaction liquid after catalytic esterification, separating acetic acid in a deacidification tower, and returning the unreacted acetic acid to the catalytic esterification kettle; the distillate at the top of the deacidification tower is condensed and layered, one part of the lower water phase reflows, the other part is extracted, and the upper oil phase is sent to be refined. The method has the advantages of high conversion rate, simple process and low operation energy consumption, and is suitable for industrial production.
Drawings
The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.
FIG. 1 is a process flow diagram of the present invention;
fig. 2 is an enlarged schematic view (a schematic bottom view) of the liquid distributor 8 in fig. 1.
Detailed Description
The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto:
in the invention, concentrated sulfuric acid refers to sulfuric acid with the mass fraction omega being more than or equal to 98%.
Device example 1, a production device for producing n-propyl acetate by continuous two-stage esterification reaction, comprising a pre-esterification kettle 1, a catalytic esterification kettle 2, a deacidification tower 3, a condenser 4, an oil-water separator 5 and a circulating pump 6.
An acetic acid feed valve Ia, an n-propanol feed valve b and a pre-esterification kettle emptying valve c which are communicated with the inner cavity of the pre-esterification kettle 1 are respectively arranged at the top of the pre-esterification kettle 1, and an acetic acid feed valve IIe, a sulfuric acid feed valve f and a catalytic esterification kettle valve g which are communicated with the inner cavity of the catalytic esterification kettle 2 are respectively arranged at the top of the catalytic esterification kettle 2; the emptying valve c of the pre-esterification kettle is communicated with the valve g of the catalytic esterification kettle through a pipeline.
A liquid distributor 8 is arranged at the bottom of the inner cavity of the catalytic esterification kettle 2, and the bottom outlet of the pre-esterification kettle 1 is communicated with the liquid distributor 8 through a pressure control valve d; a connecting pipe 21 (the diameter is about 80 percent of the tower diameter of the deacidification tower 3) is arranged between the top of the catalytic esterification kettle 2 and the bottom of the deacidification tower 3; the top outlet 31 of the deacidification tower 3 is connected with an oil-water separator 5 after passing through a condenser 4; the oil-water separator 5 is provided with an oil phase outlet 51 near the top and a water phase outlet 52 at the bottom, the water phase outlet 52 is divided into two paths after passing through the circulating pump 6, one path is a water phase extraction outlet, and the other path is connected with the feed back port 32 of the deacidification tower 3 through a reflux valve h.
The liquid distributor 8 is a calandria structure, and as shown in fig. 2, is composed of a main pipe 81 and a plurality of branch pipes 82 symmetrically arranged at two sides of the main pipe 81. The main pipe 81 and the branch pipes 82 are provided with liquid discharge ports 83, respectively, and all of the liquid discharge ports 83 face the bottom of the catalytic esterification reactor 2.
The aperture of the liquid discharge ports 83 is about 1.0mm, the distance between adjacent liquid discharge ports 83 is about 20mm, and the inner diameter of the main pipe 81 is about 100 mm; the internal diameter of the branch 82 is about 25 mm.
The process comprises the following steps:
opening a pre-esterification kettle vent valve c and a catalytic esterification kettle valve g, so that organic waste gas generated by volatilization of organic matters in the feeding process can be balanced in the heating pre-esterification kettle 1 and the catalytic esterification kettle 2;
through acetic acid feed valve IIe to catalytic esterification 2 in advance add the acetic acid that accounts for 2 volumetric 1/4 ~ 1/3 of catalytic esterification cauldron, through sulphuric acid feed valve f to catalytic esterification 2 in advance add concentrated sulfuric acid to make the concentrated sulfuric acid in the catalytic esterification cauldron 2: 0.1-0.5% of acetic acid by mass; and closing the acetic acid feeding valve II e and the sulfuric acid feeding valve f after the feeding is finished.
Acetic acid is added into the pre-esterification kettle 1 through an acetic acid feed valve Ia in advance, and n-propanol is added into the pre-esterification kettle 1 through an n-propanol feed valve b in advance, so that the mass ratio of the acetic acid to the n-propanol in the pre-esterification kettle 1 is 1:1, the pre-added mixed raw materials account for 1/2-2/3 of the volume of the pre-esterification kettle 1. And after the feeding is finished, closing the pre-esterification kettle emptying valve c and the catalytic esterification kettle valve g.
Setting the reaction temperature in the pre-esterification kettle 1 to be 120-150 ℃; the reaction temperature in the catalytic esterification kettle 2 is 100-120 ℃.
When the pre-esterification kettle 1 and the catalytic esterification kettle 2 are heated to reach the reaction temperature and the temperature is kept stable, continuous feeding of acetic acid and normal propyl alcohol is realized by using an acetic acid feeding valve Ia and a normal propyl alcohol feeding valve b, the acetic acid and the normal propyl alcohol are always kept in a mass ratio of 1:1 as mixed raw materials, and the retention time of the mixed raw materials in the pre-esterification kettle 1 is 0.2-1.0 h after the continuous feeding; the residence time is controlled by the feed flow and the liquid level (liquid volume) in the pre-esterification reactor 1.
The mixed raw materials are subjected to pre-esterification reaction in a pre-esterification kettle 1 to obtain pre-esterified reaction liquid, the pre-esterified reaction liquid mainly comprises n-propyl acetate, acetic acid and n-propanol, the pre-esterified reaction liquid is discharged from the bottom of the pre-esterification kettle 1, is subjected to reduced pressure vaporization through a pressure control valve d, enters a liquid distributor 8, is sprayed out from a liquid outlet 83, enters an inner cavity of a catalytic esterification kettle 2, and is subjected to catalytic esterification reaction with a mixture of concentrated sulfuric acid and acetic acid in the inner cavity of the catalytic esterification kettle 2; the resultant (composed of acetic acid, n-propyl acetate, water, n-propanol, etc.) enters the deacidification tower 3 through the connecting pipe 21 for deacidification treatment; setting the tower top temperature of the deacidification tower 3 to be 80-85 ℃; unreacted acetic acid in the deacidification tower 3 returns to the catalytic esterification kettle 2 through a connecting pipe 21; the overhead distillate discharged from the top outlet 31 of the deacidification tower 3 comprises n-propyl acetate, water, n-propanol and the like, and is cooled by a condenser 4 (cooled to 50-60 ℃) and then enters an oil-water separator 5 for layering; the upper oil phase is a crude product of n-propyl acetate, and can be refined in a conventional manner; one part of the lower-layer water phase flows back to the top of the deacidification tower 3 through the circulating pump 6 and the feed back port 32, and the other part is extracted; the refluxed aqueous phase: extracted water phase 1: 0.5-2 volume ratio.
The residence time of the pre-esterified reaction liquid in the catalytic esterification kettle 2 is about 0.1-2 seconds;
pre-esterification kettle 1: catalytic esterification kettle 2 ═ 1: 0.5 to 2 by volume;
the pressure of the pre-esterification kettle 1 is 0.2-0.5 Mpa (determined according to the temperature of liquid in the pre-esterification kettle); the pressure in the catalytic esterification reactor 2 is normal pressure.
All of the following examples were carried out using the apparatus and following the procedures described above.
Example 1:
adding acetic acid into the catalytic esterification kettle 2 until the volume of the acetic acid is 30 percent of the volume of the catalytic esterification kettle 2, and adding concentrated sulfuric acid which accounts for 0.5 percent of the mass of the acetic acid in the catalytic esterification kettle 2 into the catalytic esterification kettle 2. Adding a mixture of 1:1, taking acetic acid and n-propanol as mixed raw materials until the mixed raw materials account for 50 percent of the volume of the pre-esterification kettle 1. Heating the pre-esterification kettle 1-125-135 ℃, heating the catalytic esterification kettle 2-105-115 ℃, and keeping the temperature stable.
After the temperature of the pre-esterification kettle 1 and the catalytic esterification kettle 2 is stable, continuously adding a mixture of 1: acetic acid and n-propanol in the reaction kettle 1 are used as mixed raw materials, and the retention time of the mixed raw materials in the pre-esterification kettle 1 is 0.5 h.
The retention time of the gasified pre-esterified reaction liquid in the catalytic esterification kettle 2 is about 0.2 s;
the pressure of the pre-esterification kettle 1 is 0.2-0.3 MPa; the refluxed aqueous phase: the extracted aqueous phase is 1:1 in a volume ratio;
the results of the continuous reaction time and the purity of the crude n-propyl acetate obtained are shown in Table 1 below.
TABLE 1 results of esterification reaction
As can be seen from Table 1, the present invention can be continuously produced for at least 48 hours. The total conversion rate of raw materials in the esterification and deacidification steps is up to 99.0%, and the content of the n-propanol in the crude product is low, so that the energy consumption of subsequent refining is reduced.
Example 2, the mass ratio of the concentrated sulfuric acid in the acetic acid in the example 1 is changed from 0.5 percent to 0.3 percent; the retention time of the mixed raw materials in the pre-esterification kettle 1 is 0.5h, and the retention time of the gasified pre-esterified reaction liquid in the catalytic esterification kettle 2 is about 0.2 s; the pressure of the pre-esterification kettle 1 is 0.2-0.3 MPa; the refluxed aqueous phase: the extracted aqueous phase is 1:1 in a volume ratio;
the rest is equivalent to example 1.
The results obtained are shown in Table 2 below:
TABLE 2 results of esterification reaction
As can be seen from Table 2, the present invention was continuously produced stably for 48 hours. The total conversion rate of the raw materials in the esterification and deacidification steps is still more than 99.0 percent, and the content of the n-propanol in the crude product is low, thereby being beneficial to reducing the energy consumption of subsequent refining. Compared with the example 1, the purity of the crude product of the example 2 is slightly reduced, the content of the n-propanol in the crude product is also increased, but the content of the concentrated sulfuric acid serving as a catalyst is reduced, so that the occurrence of side esterification reaction can be reduced, and the service life of the sulfuric acid catalyst can be prolonged.
Example 3: the concentrated sulfuric acid from example 1: the mass fraction of acetic acid is changed from 0.5% to 0.3%; the residence time of the mixed raw materials in the pre-esterification kettle 1 is 1h, and the residence time of the gasified pre-esterified reaction liquid in the catalytic esterification kettle 2 is about 0.2 s; the pressure of the pre-esterification kettle 1 is 0.2-0.3 MPa; the refluxed aqueous phase: the extracted aqueous phase is 1:1 in a volume ratio;
the rest is equivalent to embodiment 1.
The results obtained are shown in Table 3 below:
TABLE 3 results of esterification reaction
As can be seen from Table 3, the present invention was continuously and stably produced for 48 hours. Compared with the example 2, the purity of the crude product can be improved and the content of the normal propyl alcohol in the crude product can be reduced by increasing the residence time of the raw materials in the pre-esterification kettle 1. The disadvantages are that the increase of the retention time not only increases part of energy consumption, but also reduces the feeding flow of raw materials, which is not beneficial to increasing the yield.
Finally, it is also noted that the above-mentioned list is only a few specific embodiments of the present invention. It is obvious that the invention is not limited to the above embodiments, but that many variations are possible. All modifications which can be derived or suggested by a person skilled in the art from the disclosure of the present invention are to be considered within the scope of the invention.
Claims (2)
1. The method for producing n-propyl acetate by continuous two-stage esterification reaction is characterized by comprising the following steps: the production device comprises a pre-esterification kettle (1), a catalytic esterification kettle (2) with a liquid distributor (8) arranged at the bottom of an inner cavity, a deacidification tower (3), a condenser (4), an oil-water separator (5) and a circulating pump (6);
an acetic acid feed valve I (a), an n-propanol feed valve (b) and a pre-esterification kettle emptying valve (c) which are communicated with the inner cavity of the pre-esterification kettle (1) are respectively arranged at the top of the pre-esterification kettle (1), and an acetic acid feed valve II (e), a sulfuric acid feed valve (f) and a catalytic esterification kettle valve (g) which are communicated with the inner cavity of the catalytic esterification kettle (2) are respectively arranged at the top of the catalytic esterification kettle (2); the pre-esterification kettle vent valve (c) is communicated with the catalytic esterification kettle valve (g) through a pipeline;
a liquid outlet (83) is arranged on the liquid distributor (8);
opening a pre-esterification kettle vent valve (c) and a catalytic esterification kettle valve (g), so that organic waste gas generated by volatilization of organic matters in the feeding process can be balanced in the heating pre-esterification kettle (1) and the catalytic esterification kettle (2);
acetic acid which occupies 1/4-1/3 of the volume of the catalytic esterification kettle (2) is added into the catalytic esterification kettle (2) through an acetic acid feed valve II (e) in advance, and concentrated sulfuric acid is added into the catalytic esterification kettle (2) through a sulfuric acid feed valve (f) in advance, so that the concentrated sulfuric acid in the catalytic esterification kettle (2): 0.3-0.5% of acetic acid by mass; closing the acetic acid feed valve II (e) and the sulfuric acid feed valve (f) after the feeding is finished;
acetic acid is added into the pre-esterification kettle (1) in advance through an acetic acid feeding valve I (a), and n-propanol is added into the pre-esterification kettle (1) in advance through an n-propanol feeding valve (b), so that the mass ratio of acetic acid to n-propanol in the pre-esterification kettle (1) is 1:1, taking the pre-added mixed raw material as a pre-added mixed raw material, wherein the volume of the pre-added mixed raw material accounts for 1/2-2/3 of the volume of the pre-esterification kettle (1); after the feeding is finished, closing the emptying valve (c) of the pre-esterification kettle and the valve (g) of the catalytic esterification kettle;
setting the reaction temperature in the pre-esterification kettle (1) to be 120-150 ℃; the reaction temperature in the catalytic esterification kettle (2) is 100-120 ℃;
after the pre-esterification kettle (1) and the catalytic esterification kettle (2) are heated to reach the reaction temperature and keep the temperature stable, continuously feeding acetic acid and normal propyl alcohol by using an acetic acid feeding valve I (a) and a normal propyl alcohol feeding valve (b), wherein the acetic acid and the normal propyl alcohol are always kept in a mass ratio of 1:1 as mixed raw materials, and the retention time of the mixed raw materials in the pre-esterification kettle (1) is 0.5h after the continuous feeding;
the mixed raw materials are subjected to pre-esterification reaction in a pre-esterification kettle (1) to obtain pre-esterified reaction liquid, the pre-esterified reaction liquid is discharged from the bottom of the pre-esterification kettle (1), is subjected to reduced pressure vaporization through a pressure control valve (d), enters a liquid distributor (8), is sprayed out from a liquid outlet (83), enters an inner cavity of a catalytic esterification kettle (2), and is subjected to catalytic esterification reaction with a mixture of concentrated sulfuric acid and acetic acid in the inner cavity of the catalytic esterification kettle (2); the resultant of the reaction enters a deacidification tower (3) through a connecting pipe (21) for deacidification treatment; setting the tower top temperature of the deacidification tower (3) to be 80-85 ℃; unreacted acetic acid in the deacidification tower 3 returns to the catalytic esterification kettle (2) through a connecting pipe (21); the distillate discharged from the top outlet (31) of the deacidification tower (3) at the top of the tower is cooled to 50-60 ℃ by a condenser (4) and then enters an oil-water separator (5) for layering; the upper oil phase is a crude product of n-propyl acetate, one part of the lower water phase flows back to the top of the deacidification tower (3) through a circulating pump (6) and a feed back port (32), and the other part is extracted; the refluxed aqueous phase: the extracted aqueous phase is 1: 0.5-2 volume ratio;
the retention time of the pre-esterified reaction liquid in the catalytic esterification kettle (2) is 0.1-2 seconds;
pre-esterification kettle (1): catalytic esterification kettle (2) ═ 1: 0.5 to 2 by volume;
the pressure of the pre-esterification kettle (1) is 0.2-0.5 Mpa; the pressure in the catalytic esterification kettle (2) is normal pressure.
2. The method for producing n-propyl acetate by continuous two-stage esterification according to claim 1, wherein: liquid outlets (83) on the liquid distributor (8) face the bottom of the catalytic esterification kettle (2).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010077430.9A CN111167378B (en) | 2020-01-29 | 2020-01-29 | Method for producing n-propyl acetate by continuous two-stage esterification reaction |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010077430.9A CN111167378B (en) | 2020-01-29 | 2020-01-29 | Method for producing n-propyl acetate by continuous two-stage esterification reaction |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111167378A CN111167378A (en) | 2020-05-19 |
| CN111167378B true CN111167378B (en) | 2022-09-02 |
Family
ID=70620769
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010077430.9A Active CN111167378B (en) | 2020-01-29 | 2020-01-29 | Method for producing n-propyl acetate by continuous two-stage esterification reaction |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111167378B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0712386B1 (en) * | 1993-08-03 | 1998-01-21 | Orgral International Technologies Corporation | Process for the alkylation of olefins and apparatus for carrying out this process |
| CN102311342A (en) * | 2010-07-07 | 2012-01-11 | 中国石油化工股份有限公司 | Method for producing 1,6-dimethyl adipate |
| CN102557932A (en) * | 2011-12-16 | 2012-07-11 | 浙江建业化工股份有限公司 | Method for producing isobutyl acetate |
| CN104513158A (en) * | 2014-11-28 | 2015-04-15 | 江门天诚溶剂制品有限公司 | Acetic ether energy saving production increase new method |
| CN104557529A (en) * | 2014-12-26 | 2015-04-29 | 江苏九天高科技股份有限公司 | Refining method and device for n-propyl acetate esterification synthesis |
-
2020
- 2020-01-29 CN CN202010077430.9A patent/CN111167378B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0712386B1 (en) * | 1993-08-03 | 1998-01-21 | Orgral International Technologies Corporation | Process for the alkylation of olefins and apparatus for carrying out this process |
| CN102311342A (en) * | 2010-07-07 | 2012-01-11 | 中国石油化工股份有限公司 | Method for producing 1,6-dimethyl adipate |
| CN102557932A (en) * | 2011-12-16 | 2012-07-11 | 浙江建业化工股份有限公司 | Method for producing isobutyl acetate |
| CN104513158A (en) * | 2014-11-28 | 2015-04-15 | 江门天诚溶剂制品有限公司 | Acetic ether energy saving production increase new method |
| CN104557529A (en) * | 2014-12-26 | 2015-04-29 | 江苏九天高科技股份有限公司 | Refining method and device for n-propyl acetate esterification synthesis |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111167378A (en) | 2020-05-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101130530B (en) | System and method for producing furol by using agricultural and forestry castoff | |
| CN100378051C (en) | Rectifying tech. and equipment of high purity methanol | |
| WO2020078476A1 (en) | Production device and production method for synthesizing acetic acid by low-pressure carbonylation of methanol | |
| CN110467595A (en) | A kind of no sulfuric acid process metaformaldehyde synthesizer and its synthesis route | |
| CN109748791B (en) | Energy-saving method for producing dimethyl adipate | |
| CN104649862B (en) | With ethyl acetate be raw material production alcohol product method and equipment | |
| CN111167378B (en) | Method for producing n-propyl acetate by continuous two-stage esterification reaction | |
| CN108530264A (en) | New heat energy utilization system and heat energy utilization method in a kind of cyclohexanol production | |
| CN114247386B (en) | Evaporation type isothermal hydrogenation reaction method and evaporation type isothermal reaction system | |
| CN113667700B (en) | Method and system for producing ethanol by fermenting mixed raw materials | |
| CN210796289U (en) | High-efficient low energy consumption sodium methoxide purification equipment | |
| CN213294754U (en) | Normal-pressure energy-saving continuous fractionating device | |
| CN107778132B (en) | Method for preparing cyclohexanol and cyclohexanone based on multilayer guide cylinder bubble reactor | |
| CN102453008B (en) | Novel process for preparing furfural by two towers and dedicated comprehensive tower | |
| CN109748827B (en) | Process for continuous synthesis of dimethyl sulfate | |
| CN104829452B (en) | Energy-saving production system of ethyl acetate and corresponding energy-saving production technology | |
| CN209685643U (en) | New heat energy utilization system in a kind of cyclohexanol production | |
| CN201372255Y (en) | Formaldehyde preparation device | |
| CN111807959A (en) | Energy-saving process and process equipment for n-propyl acetate | |
| CN111732496A (en) | System for producing 3,3, 5-trimethylcyclohexanol by hydrogenation of isophorone and use method thereof | |
| CN101143807A (en) | Method for producing dimethyl ether by separating heat tube type reactor | |
| CN114751822B (en) | Device for producing n-propyl acetate by thermal coupling and production method thereof | |
| CN220090530U (en) | Cyclohexanol knockout tower and cyclohexanol rectifying column economizer system | |
| CN205252611U (en) | Gas and liquid separator | |
| CN110280033B (en) | Device and method for preparing propyl propionate through self-heating recovery reaction rectification |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |