阅读说明：本技术 一种利用乙醇和醋酸工业废料合成乙酸乙酯的系统及方法 (System and method for synthesizing ethyl acetate by using ethanol and acetic acid industrial waste ) 是由 冯烈 陈云斌 孙琪 吴方丽 蒋红华 宋同辉 蒋开炎 于 2020-11-10 设计创作，主要内容包括：本发明涉及有机合成技术领域,尤其涉及一种利用乙醇和醋酸工业废料合成乙酸乙酯的系统及方法,所述系统包括酯化单元,萃取单元和膜处理单元,所述酯化单元包括废醋酸高位槽,废乙醇中间槽,酯化釜,脱酸塔和粗酯槽；所述粗酯槽与脱酸塔相连接；所述萃取单元包括萃取塔；所述膜处理单元包括膜处理中间槽,膜壳和乙酸乙酯成品槽,所述膜壳外侧设有膜加热器,顶部设有膜顶冷凝器,所述膜壳与乙酸乙酯成品槽相连接。本发明的合成系统设计巧妙,资源化利用制备乙酸乙酯,变废液为工业产品,产生经济效益和环保效益；合成方法简单,工艺条件温和,易于控制,易于产业化。(The invention relates to the technical field of organic synthesis, in particular to a system and a method for synthesizing ethyl acetate by using ethanol and acetic acid industrial waste, wherein the system comprises an esterification unit, an extraction unit and a membrane treatment unit, wherein the esterification unit comprises a waste acetic acid head tank, a waste ethanol intermediate tank, an esterification kettle, a deacidification tower and a crude ester tank; the crude ester tank is connected with an acid removal tower; the extraction unit comprises an extraction column; the membrane processing unit comprises a membrane processing intermediate tank, a membrane shell and an ethyl acetate finished product tank, wherein a membrane heater is arranged on the outer side of the membrane shell, a membrane top condenser is arranged at the top of the membrane shell, and the membrane shell is connected with the ethyl acetate finished product tank. The synthesis system disclosed by the invention is ingenious in design, the ethyl acetate is prepared by resource utilization, the waste liquid is changed into an industrial product, and economic benefits and environmental protection benefits are generated; the synthesis method is simple, the process conditions are mild, the control is easy, and the industrialization is easy.)

1. A system for synthesizing ethyl acetate by using ethanol and acetic acid industrial waste is characterized by comprising an esterification unit, an extraction unit and a membrane treatment unit, wherein the esterification unit comprises a waste acetic acid elevated tank, a waste ethanol intermediate tank, an esterification kettle, an acid removal tower and a crude ester tank; the top of the esterification kettle is provided with a gas-phase discharge hole, the bottom of the deacidification tower is provided with a first feed inlet, the top of the tower is provided with a reflux feed inlet and a first discharge hole, the gas-phase discharge hole is connected with the first feed inlet of the deacidification tower through a pipeline, and the crude ester tank is connected with the first discharge hole of the deacidification tower; the extraction unit comprises an extraction tower, and the extraction tower is connected with the crude ester tank; the membrane treatment unit comprises a membrane treatment intermediate tank, a membrane shell and an ethyl acetate finished product tank, wherein the top of the membrane shell is provided with a crude ester feeding hole, the bottom of the membrane shell is provided with a finished product discharging hole, the inlet of the membrane treatment intermediate tank is connected with the extraction tower, and the outlet of the membrane treatment intermediate tank is connected with the crude ester feeding hole of the membrane shell; the membrane shell is characterized in that a membrane heater is arranged on the outer side of the membrane shell, a membrane top condenser is arranged at the top of the membrane shell, and a finished product discharge port of the membrane shell is connected with an ethyl acetate finished product tank through a pipeline.

2. The system for synthesizing ethyl acetate from ethanol and acetic acid industrial waste according to claim 1, wherein the esterification unit further comprises an esterification phase separator, the esterification phase separator is provided with a second feeding hole, a reflux outlet and a second discharging hole, the second feeding hole is connected with the first discharging hole of the deacidification tower through a pipeline, the reflux outlet is connected with the reflux feeding hole of the deacidification tower through a pipeline, and the second discharging hole is connected with the crude ester tank.

3. The system for synthesizing the ethyl acetate by utilizing the ethanol and the acetic acid industrial waste material as the claim 2, wherein a pipeline between the deacidification tower and the esterification phase separator is provided with a heat exchanger and a cooler, and the heat exchanger is communicated with a pipeline between the waste ethanol intermediate tank and the esterification kettle.

4. The system for synthesizing the ethyl acetate by using the ethanol and the acetic acid industrial waste material as claimed in claim 1, wherein a third feeding port is arranged in the middle of the extraction tower, a third discharging port is arranged at the top of the extraction tower, and the third feeding port is connected with the crude ester tank; and the third discharge hole is connected with the film intermediate treatment tank.

5. The system for synthesizing ethyl acetate by using ethanol and acetic acid industrial waste according to claim 1, wherein a pipeline between the membrane shell and the ethyl acetate finished product tank is provided with a membrane post-heat exchanger and a membrane post-cooler, and the membrane post-heat exchanger is communicated with a pipeline between the membrane treatment intermediate tank and the crude ester feed inlet of the membrane shell.

6. The system for synthesizing ethyl acetate by using ethanol and acetic acid industrial waste material according to claim 1, wherein the extraction unit further comprises a waste water pump, the bottom of the extraction tower is provided with a waste water discharge port, the top of the extraction tower is provided with a waste water inlet port, and the waste water discharge port is connected with the waste water inlet port through a pipeline and the waste water pump.

7. A method for synthesizing ethyl acetate from ethanol and acetic acid industrial waste by using the system as claimed in any one of claims 1 to 6, comprising the steps of:

(1) inputting waste acetic acid in a waste acetic acid elevated tank into an esterification kettle through an acetic acid feeding hole, inputting waste ethanol in a waste ethanol intermediate tank into the esterification kettle through an ethanol feeding hole, adding sulfuric acid into the esterification kettle from a sulfuric acid feeding hole, performing esterification reaction to generate crude ester, wherein the crude ester flows out from a gas phase discharging hole of the esterification kettle, enters a deacidification tower from a first feeding hole, is subjected to deacidification treatment, and then flows into a crude ester tank;

(2) feeding the crude ester subjected to deacidification treatment in the crude ester tank into an extraction tower from the lower part of the extraction tower, and extracting by taking water as an extracting agent;

(3) inputting the extracted crude ester in the membrane treatment intermediate tank into a membrane shell, circulating the crude ester between the membrane shell and a membrane heater, and leading water vapor permeated by the membrane shell to come out from the top of the membrane shell and to a wastewater pool after being condensed by a membrane top condenser; and the ethyl acetate finished product after the membrane treatment flows out of the product discharge hole and then enters an ethyl acetate finished product tank.

8. The method of claim 7, wherein in the step (3), the extracted crude ester is discharged from the top of the extraction tower to enter a membrane treatment intermediate tank, and a part of wastewater discharged from the bottom of the extraction tower is recycled to the top of the extraction tower through a wastewater pump, and the other part of wastewater flows to a wastewater tank.

9. The method according to claim 7, wherein in the step (1), the crude ester after the deacidification treatment and the waste ethanol flowing out from the waste ethanol intermediate tank are subjected to heat exchange treatment through a heat exchanger, and then are input into an esterification phase separator, a part of an organic phase flows back to the deacidification tower, a part of the organic phase flows out to the crude ester tank, and the lower layer water of the esterification phase separator flows into a waste water tank.

10. The method according to any one of claims 7 to 9,

in the step (1), the mass ratio of the waste acetic acid to the waste ethanol is 2: 1; the adding amount of the sulfuric acid is 3 percent based on the total mass of the waste acetic acid and the waste ethanol;

the esterification reaction temperature is 100-105 ℃, and the pressure is 0-30 kPa;

the deacidification treatment temperature is 70-80 ℃, the reflux ratio is 2.5, the deacidification process is continuous, and the content of acetic acid in the crude ester after the deacidification treatment is less than 0.01 wt%;

in the step (2), the extraction temperature is 20-30 ℃, and the ratio of materials to water is 3: 1;

in the step (3), the membrane treatment temperature is 45-65 ℃, and the pressure is-90 to-80 kPa.

Technical Field

The invention relates to the technical field of organic synthesis, in particular to a system and a method for synthesizing ethyl acetate by using ethanol and acetic acid industrial waste.

Background

The industrial ethyl acetate is a very important organic chemical raw material and can be used as an industrial solvent for products such as coating, adhesive, artificial fiber and the like; the adhesive is applied to the production of printing ink and artificial pearls; the extract is used as an extractant for the production of medicines, organic acids and other products; the perfume raw material can be applied to white spirit and artificial essence; as an extractant many compounds can be extracted from the solution.

The raw materials for preparing ethyl acetate by the traditional process are industrial ethanol (95%) and acetic acid (99.8%), the ethyl acetate is prepared, a rectifying device is adopted to remove ethanol and water in the crude ester, and the cost for producing the finished ethyl acetate product is high.

Chinese patent literature discloses a method for producing ethyl acetate, the application publication number of which is CN 102260718A, the method adopts natural raw materials to generate ethanol and acetic acid under the action of microorganisms, the ethanol and the acetic acid are all biological fermentation processes, and no other chemical substances are brought in. However, the process cost of the invention is high, the fermentation condition is not easy to control, and the economic benefit of enterprises is low.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention provides a system for synthesizing ethyl acetate by using ethanol and acetic acid industrial waste, the system recovers 73 percent of waste ethanol and 75 percent of waste acetic acid, performs resource utilization to prepare ethyl acetate, changes waste liquid into industrial products, and generates economic benefit and environmental protection benefit.

The invention also provides a method for synthesizing ethyl acetate by using ethanol and acetic acid industrial waste, which has mild process conditions, is easy to control and is easy to industrialize.

In order to achieve the purpose, the invention adopts the following technical scheme:

a system for synthesizing ethyl acetate by using ethanol and acetic acid industrial waste comprises an esterification unit, an extraction unit and a membrane treatment unit, wherein the esterification unit comprises a waste acetic acid elevated tank, a waste ethanol intermediate tank, an esterification kettle, an acid removal tower and a crude ester tank; the top of the esterification kettle is provided with a gas-phase discharge hole, the bottom of the deacidification tower is provided with a first feed inlet, the top of the tower is provided with a reflux feed inlet and a first discharge hole, the gas-phase discharge hole is connected with the first feed inlet of the deacidification tower through a pipeline, and the crude ester tank is connected with the first discharge hole of the deacidification tower; the extraction unit comprises an extraction tower, and the extraction tower is connected with the crude ester tank; the membrane treatment unit comprises a membrane treatment intermediate tank, a membrane shell and an ethyl acetate finished product tank, wherein the top of the membrane shell is provided with a crude ester feeding hole, the bottom of the membrane shell is provided with a finished product discharging hole, the inlet of the membrane treatment intermediate tank is connected with the extraction tower, and the outlet of the membrane treatment intermediate tank is connected with the crude ester feeding hole of the membrane shell; the membrane shell is characterized in that a membrane heater is arranged on the outer side of the membrane shell, a membrane top condenser is arranged at the top of the membrane shell, and a finished product discharge port of the membrane shell is connected with an ethyl acetate finished product tank through a pipeline.

The system for synthesizing the ethyl acetate by utilizing the ethanol and the acetic acid industrial waste materials uses the waste acetic acid and the waste ethanol as raw materials, firstly performs esterification reaction in the esterification unit to obtain the ethyl acetate crude ester, then removes the ethanol and impurities in the ethyl acetate crude ester through the extraction unit, and finally removes the water in the crude ester by adopting the membrane treatment unit to obtain the high-purity ethyl acetate finished product for sale, thereby generating economic benefit and environmental protection benefit. Wherein, the deacidification tower is used for deacidifying to remove excessive acetic acid in the crude ester.

Preferably, the top of the esterification kettle is also provided with an acetic acid feed port, a sulfuric acid feed port and an ethanol feed port, the acetic acid feed port is connected with the waste acetic acid elevated tank through a pipeline, and the ethanol feed port is connected with the waste ethanol intermediate tank through a pipeline.

Preferably, the esterification unit further comprises an esterification phase separator, the esterification phase separator is provided with a second feeding hole, a reflux outlet and a second discharging hole, the second feeding hole is connected with the first discharging hole of the deacidification tower through a pipeline, the reflux outlet is connected with the reflux feeding hole of the deacidification tower through a pipeline, and the second discharging hole is connected with the crude ester tank. The principle of the esterification phase separator is to separate ethyl acetate and water by increasing the residence time.

Preferably, a heat exchanger and a cooler are arranged on a pipeline between the deacidification tower and the esterification phase separator, and the heat exchanger is communicated with a pipeline between the waste ethanol intermediate tank and the esterification kettle.

The system for synthesizing the ethyl acetate by using the ethanol and the acetic acid industrial waste material is ingenious in design, the heat generated by the esterification reaction can be transferred to the raw material waste ethanol by the design of the heat exchanger, the reaction rate is improved, and the raw material waste ethanol does not need to be additionally heated, so that the energy consumption is reduced.

Preferably, a third feed inlet is arranged in the middle of the extraction tower, a third discharge outlet is arranged at the top of the extraction tower, and the third feed inlet is connected with the crude ester tank; and the third discharge hole is connected with the film intermediate treatment tank.

Preferably, a pipeline between the membrane shell and the ethyl acetate finished product tank is provided with a membrane post-heat exchanger and a membrane post-cooler, and the membrane post-heat exchanger is communicated with a pipeline between the membrane treatment intermediate tank and the crude ester feed inlet of the membrane shell.

In the synthetic process, the heat exchanger behind the membrane can shift the finished heat of the ethyl acetate that goes out from membrane processing intermediate tank to treating the ethyl acetate of dewatering from membrane processing intermediate tank in the membrane shell, make it effectively heat before getting into the membrane shell, need not the independent heating, reduce the energy consumption, reduce the manufacturing cost of enterprise, simultaneously, the finished heat of the ethyl acetate that goes out through membrane processing is also effectively released, cool off more high-efficiently when next through the cooler behind the membrane, improve production efficiency.

Preferably, the extraction unit further comprises a wastewater pump, a wastewater discharge port is arranged at the bottom of the extraction tower, a wastewater inlet is arranged at the top of the extraction tower, and the wastewater discharge port is connected with the wastewater inlet through a pipeline and the wastewater pump.

The invention firstly detects the waste water, and the waste water reaching the standard can flow back and be introduced into the extraction tower again, on one hand, the waste water can be used as an extracting agent to be in countercurrent contact with the crude ester in the extraction tower to extract water-soluble impurities in the crude ester, on the other hand, the resource is saved, and the production cost of enterprises is reduced. Directly discharging the wastewater which does not reach the standard into a wastewater tank.

A method for synthesizing ethyl acetate by using ethanol and acetic acid industrial waste by adopting the system comprises the following steps:

(1) inputting waste acetic acid in a waste acetic acid head tank into an esterification kettle through an acetic acid feed inlet, inputting waste ethanol in a waste ethanol intermediate tank into the esterification kettle through an ethanol feed inlet, adding sulfuric acid into the esterification kettle from a sulfuric acid feed inlet to perform esterification reaction, wherein the esterification reaction temperature is 100-105 ℃, the pressure is 0-30 kPa to generate crude ester, and the crude ester flows out from a gas phase discharge port of the esterification kettle, enters an acid removal tower from a first feed inlet to perform deacidification treatment and then flows into a crude ester tank; the concentration of the sulfuric acid in the step is 98%, and the sulfuric acid is used as a catalyst for esterification reaction of ethanol and acetic acid. Concentrated sulfuric acid is selected as a catalyst, the boiling point of the concentrated sulfuric acid is as high as 338 ℃, the boiling point is far higher than the esterification temperature, and the concentrated sulfuric acid does not enter the deacidification tower after the esterification reaction is finished;

(2) feeding the crude ester subjected to deacidification treatment in the crude ester tank into an extraction tower from the lower part of the extraction tower for extraction; in the step, water is used as an extracting agent, ethanol and water-soluble impurities in the ethyl acetate crude ester can be extracted by the water, and the purity of the ethyl acetate is improved; the extraction temperature is room temperature, and the mixture ratio of materials to water is 3: 1;

(3) inputting the extracted crude ester in the membrane treatment intermediate tank into a membrane shell, circulating the crude ester between the membrane shell and a membrane heater, and leading water vapor permeated by the membrane shell to come out from the top of the membrane shell and to a wastewater pool after being condensed by a membrane top condenser; and the ethyl acetate finished product after the membrane treatment flows out of the product discharge hole and then enters an ethyl acetate finished product tank.

Preferably, in the step (3), the extracted crude ester comes out from the top of the extraction tower and enters a membrane treatment intermediate tank, one part of wastewater flowing out from the bottom of the extraction tower is circulated to the top of the extraction tower through a wastewater pump, and the other part exceeding the standard flows to a wastewater tank; the crude ester and the waste water are in countercurrent contact in an extraction tower, and water-soluble impurities are extracted by water.

Preferably, in the step (1), the crude ester after the deacidification treatment and the waste ethanol flowing out from the waste ethanol intermediate tank are subjected to heat exchange treatment through a heat exchanger, then the crude ester and the waste ethanol are input into an esterification phase separator, one part of an organic phase reflows to the deacidification tower, one part of the organic phase is discharged into the crude ester tank, and the lower layer water of the esterification phase separator is discharged into a waste water tank.

In the step (1), the mass ratio of the waste acetic acid to the waste ethanol is 2: 1; the adding amount of the sulfuric acid is 3 percent based on the total mass of the waste acetic acid and the waste ethanol; the esterification reaction temperature is 100-105 ℃, and the pressure is 0-30 kPa; the deacidification treatment temperature is 70-80 ℃, the reflux ratio is 2.5, the deacidification process is continuous, and the content of acetic acid in the crude ester after the deacidification treatment is less than 0.01 wt%; the content of acetic acid in the crude ester can be controlled to be less than 0.01 percent by controlling the temperature of the deacidification tower to be lower than 80 ℃.

In an esterification reaction system, waste acetic acid is excessive relative to waste ethanol, excessive acetic acid is mixed into crude ester after esterification reaction, the deacidification treatment mechanism is that the boiling point of sulfuric acid is 330 ℃, the acetic acid is remained in an esterification kettle, the boiling point of acetic acid is 118 ℃, when the content of acetic acid in the esterification kettle is higher than 75%, the acetic acid enters a deacidification tower together with ethyl acetate and water in an azeotropic manner, the reflux ratio and the temperature of the deacidification tower need to be controlled to be lower than 80 ℃, the acetic acid in the crude ester can be effectively removed through the deacidification treatment, and the purity of the product is improved.

In the step (2), the extraction temperature is 20-30 ℃, and the ratio of materials to water is 3: 1.

in the step (3), the membrane treatment temperature is 45-65 ℃, and the pressure is-90 to-80 kPa.

Therefore, the invention has the following beneficial effects:

(1) the synthesis system disclosed by the invention is ingenious in design, effectively utilizes the heat generated in the synthesis process, reduces the energy consumption, realizes the efficient recovery of waste ethanol (73%) and waste acetic acid (75%), prepares ethyl acetate by resource utilization, changes waste liquid into industrial products, and generates economic benefits and environmental protection benefits;

(2) the synthesis method is simple, mild in process conditions, easy to control and easy to industrialize.

Drawings

FIG. 1 is a schematic diagram showing the construction of a system for synthesizing ethyl acetate from ethanol and acetic acid industrial waste according to example 1.

In the figure: the device comprises a waste acetic acid elevated tank 1, an esterification kettle 2, a deacidification tower 3, a heat exchanger 4, a cooler 5, an esterification phase separator 6, a waste ethanol intermediate tank 7, a crude ester tank 8, an extraction tower 9, a membrane treatment intermediate tank 10, a membrane shell 11, a membrane heater 12, a membrane post-heat exchanger 13, a membrane post-cooler 14, an ethyl acetate finished product tank 15, a membrane top condenser 16, a waste acetic acid delivery pump 17, a waste ethanol feed pump 18, a waste ethanol delivery pump 19, a membrane treatment feed pump 20, a crude ester pump 21, a waste water pump 22, a first feed inlet 23, a first discharge outlet 24, a second feed inlet 25, a second discharge outlet 26, a gas phase discharge outlet 27, a reflux outlet 28, a third feed inlet 29, a third discharge outlet 30, a waste water discharge outlet 31, a waste water through inlet 32, a crude ester feed inlet 33, a finished product discharge outlet 34, an acetic acid feed inlet 35, a sulfuric acid feed inlet 36, an ethanol feed inlet 37.

Detailed Description

The technical solution of the present invention is further specifically described below by using specific embodiments and with reference to the accompanying drawings.

In the present invention, all the equipment and materials are commercially available or commonly used in the art, and the methods in the following examples are conventional in the art unless otherwise specified.

Example 1

As shown in fig. 1, a system for synthesizing ethyl acetate by using ethanol and acetic acid industrial waste comprises an esterification unit, an extraction unit and a membrane treatment unit, wherein the esterification unit comprises a waste acetic acid elevated tank 1 connected with a waste acetic acid delivery pump 17, a waste ethanol intermediate tank 7 with an inlet connected with a waste ethanol delivery pump 18 and an outlet connected with a waste ethanol feed pump 19, an esterification kettle 2, a deacidification tower 3, an esterification phase separator 6 and a crude ester tank 8 with an outlet connected with a crude ester pump 21, the kettle top of the esterification kettle is provided with an acetic acid feed port 35, a sulfuric acid feed port 36, an ethanol feed port 37 and a gas phase discharge port 27, the acetic acid feed port is connected with the waste acetic acid elevated tank through a pipeline, and the outlet of the waste ethanol intermediate tank is connected with the ethanol feed port of the esterification kettle through the waste ethanol feed pump 18 through a pipeline; the crude ester tank is connected with a gas-phase discharge port of the esterification kettle; the bottom of the deacidification tower is provided with a first feed inlet 23, and the top of the tower is provided with a reflux feed inlet 38 and a first discharge outlet 24; the gas phase discharge port of the esterification kettle is connected with the first feed port through a pipeline, the esterification phase separator is provided with a second feed port 25, a reflux outlet 28 and a second discharge port 26, the second feed port is connected with the first discharge port of the deacidification tower through a pipeline, the reflux outlet is connected with the reflux feed port of the deacidification tower through a pipeline, and the second discharge port is connected with the crude ester tank; a heat exchanger 4 and a cooler 5 are arranged on a pipeline between the deacidification tower and the esterification phase separator, and the heat exchanger is communicated with a pipeline between the waste ethanol intermediate tank and the esterification kettle.

The extraction unit comprises an extraction tower 9 and a waste water pump 22, and the crude ester tank is connected with the extraction tower through a pipeline via a crude ester pump 21; the middle part of the extraction tower is provided with a third feed port 29, the top part of the extraction tower is provided with a third discharge port 30, and the third feed port is connected with the crude ester tank; the third discharge hole is connected with the film intermediate treatment tank; the bottom of the extraction tower is provided with a waste water outlet 31, the top of the extraction tower is provided with a waste water inlet 32, and the waste water outlet is connected with a waste water inlet through a waste water pump by a pipeline.

The membrane treatment unit comprises a membrane treatment intermediate tank 10, a membrane treatment feed pump 20, a membrane shell 11 and an ethyl acetate finished product tank 15, wherein the top of the membrane shell is provided with a crude ester feed inlet 33, the bottom of the membrane shell is provided with a finished product discharge outlet 34, the inlet of the membrane treatment intermediate tank is connected with the extraction tower, and the outlet of the membrane treatment intermediate tank is connected with the crude ester feed inlet 33 through the membrane treatment feed pump 20 by a pipeline; a membrane heater 12 is arranged on the outer side of the membrane shell, a membrane top condenser 16 is arranged at the top of the membrane shell, and a finished product discharge port of the membrane shell is connected with an ethyl acetate finished product tank through a pipeline; and a pipeline between the membrane shell and the ethyl acetate finished product tank is provided with a membrane post-heat exchanger 13 and a membrane post-cooler 14, and the membrane post-heat exchanger is communicated with a pipeline between the membrane treatment intermediate tank and the crude ester feed inlet of the membrane shell.

Referring to fig. 1, a method for synthesizing ethyl acetate by using ethanol and acetic acid industrial waste by using the above system comprises the following steps:

(1) waste acetic acid is pumped into the waste acetic acid elevated tank 1 through a waste acetic acid delivery pump 17, and the waste acetic acid is input into the esterification kettle 2 through an acetic acid feed port 35; waste ethanol is pumped into a waste ethanol intermediate tank 7 through a waste ethanol delivery pump 19, waste ethanol is input into an esterification kettle 2 through an ethanol feed port 37 through a waste ethanol feed pump 18, sulfuric acid (the concentration is 98 percent, and the addition amount is 3 percent of the liquid holdup of the kettle liquid) is added into the esterification kettle from a sulfuric acid feed port 36 to perform esterification reaction, crude ester is generated, the crude ester flows out from a gas phase discharge port 27 of the esterification kettle and enters a deacidification tower 3 to perform deacidification treatment to remove redundant acetic acid, a product enters an esterification phase separator to be separated, one part of an organic phase flows back to the deacidification tower 3 through a backflow feed port 38, one part of the organic phase is discharged into a crude ester tank 8 from a second discharge port of the delayer, and lower layer water of the esterification phase separator flows into a waste water tank. In the step, the mass ratio of the waste acetic acid to the waste ethanol is 2: 1; the adding amount of the sulfuric acid is 3 percent based on the total mass of the waste acetic acid and the waste ethanol; the esterification reaction temperature is 105 ℃, and the pressure is 25 kPa; the temperature of deacidification treatment is 74 ℃, and the time is continuous production;

(2) feeding the crude ester in the crude ester tank into an extraction tower 9 from the lower part of the tower, and extracting by taking water as an extracting agent; the wastewater generated by extraction is detected, and the wastewater reaching the standard can be pumped into the extraction tower 9 through the wastewater inlet 32 by the wastewater pump 22, so that the wastewater can be used as an extracting agent to be in countercurrent contact with the crude ester in the extraction tower to extract water-soluble impurities in the crude ester, resources are saved, and the production cost of enterprises is reduced; directly discharging the wastewater which does not reach the standard into a wastewater tank; the extraction temperature is 25 ℃, and the mixture ratio of materials to water is 3: 1;

(3) pumping the extracted crude ester in the membrane treatment intermediate tank into a membrane shell 11 through a membrane treatment feed pump 20 through a crude ester feed port 33, circulating the crude ester between the membrane shell and a membrane heater 12, discharging water vapor permeated by the membrane shell from the top of the membrane shell, and condensing the water vapor by a membrane top condenser 16 and then sending the water vapor to a wastewater pool; the membrane treatment temperature is 48 ℃, and the pressure is-90 kPa; the finished ethyl acetate product after the membrane treatment flows out of the product discharge port 34 and enters the finished ethyl acetate product tank 15. The heat exchanger can shift the finished heat of the ethyl acetate that goes out from membrane processing intermediate tank to the ethyl acetate of treating the dewatering from membrane processing intermediate tank in the membrane shell after the membrane, make it effectively heat before getting into the membrane shell, need not the independent heating, reduce the energy consumption, reduce the manufacturing cost of enterprise, simultaneously, the finished heat of the ethyl acetate that goes out through membrane processing is also effectively released, cools off more high-efficiently when next through the cooler behind the membrane, improves production efficiency.

The ethyl acetate product obtained in this example had a purity of 98% and a yield of 90%.

Example 2

Referring to fig. 1, a method for synthesizing ethyl acetate using ethanol and acetic acid industrial waste using the system described in example 1, comprises the steps of:

(1) waste acetic acid is pumped into the waste acetic acid elevated tank 1 through a waste acetic acid delivery pump 17, and the waste acetic acid is input into the esterification kettle 2 through an acetic acid feed port 35; waste ethanol is pumped into a waste ethanol intermediate tank 7 through a waste ethanol delivery pump 19, waste ethanol is input into an esterification kettle 2 through an ethanol feed port 37 through a waste ethanol feed pump 18, sulfuric acid (the concentration is 98 percent, and the addition amount is 3 percent of the liquid holdup of the kettle liquid) is added into the esterification kettle from a sulfuric acid feed port 36 to perform esterification reaction, crude ester is generated, the crude ester flows out from a gas phase discharge port 27 of the esterification kettle and enters a deacidification tower 3 to perform deacidification treatment to remove redundant acetic acid, a product enters an esterification phase separator to be separated, one part of an organic phase flows back to the deacidification tower 3 through a backflow feed port 38, one part of the organic phase is discharged into a crude ester tank 8 from a second discharge port of the delayer, and lower layer water of the esterification phase separator flows into a waste water tank. In the step, the mass ratio of the waste acetic acid to the waste ethanol is 2: 1; the adding amount of the sulfuric acid is 3 percent based on the total mass of the waste acetic acid and the waste ethanol; the esterification reaction temperature is 100 ℃, and the pressure is 30 kPa; the temperature of deacidification treatment is 76 ℃, and the time is continuous production;

(2) feeding the crude ester in the crude ester tank into an extraction tower 9 from the lower part of the tower, and extracting by taking water as an extracting agent; the wastewater generated by extraction is detected, and the wastewater reaching the standard can be pumped into the extraction tower 9 through the wastewater inlet 32 by the wastewater pump 22, so that the wastewater can be used as an extracting agent to be in countercurrent contact with the crude ester in the extraction tower to extract water-soluble impurities in the crude ester, resources are saved, and the production cost of enterprises is reduced; directly discharging the wastewater which does not reach the standard into a wastewater tank; the extraction temperature is 20 ℃, and the mixture ratio of materials to water is 3: 1;

(3) pumping the extracted crude ester in the membrane treatment intermediate tank into a membrane shell 11 through a membrane treatment feed pump 20 through a crude ester feed port 33, circulating the crude ester between the membrane shell and a membrane heater 12, discharging water vapor permeated by the membrane shell from the top of the membrane shell, and condensing the water vapor by a membrane top condenser 16 and then sending the water vapor to a wastewater pool; the membrane treatment temperature is 56 ℃, and the pressure is-85 kPa; the finished ethyl acetate product after the membrane treatment flows out of the product discharge port 34 and enters the finished ethyl acetate product tank 15. The heat exchanger can shift the finished heat of the ethyl acetate that goes out from membrane processing intermediate tank to the ethyl acetate of treating the dewatering from membrane processing intermediate tank in the membrane shell after the membrane, make it effectively heat before getting into the membrane shell, need not the independent heating, reduce the energy consumption, reduce the manufacturing cost of enterprise, simultaneously, the finished heat of the ethyl acetate that goes out through membrane processing is also effectively released, cools off more high-efficiently when next through the cooler behind the membrane, improves production efficiency.

The ethyl acetate product obtained in this example had a purity of 96% and a yield of 88%.

Example 3

Referring to fig. 1, a method for synthesizing ethyl acetate using ethanol and acetic acid industrial waste using the system described in example 1, comprises the steps of:

(1) waste acetic acid is pumped into the waste acetic acid elevated tank 1 through a waste acetic acid delivery pump 17, and the waste acetic acid is input into the esterification kettle 2 through an acetic acid feed port 35; waste ethanol is pumped into a waste ethanol intermediate tank 7 through a waste ethanol delivery pump 19, waste ethanol is input into an esterification kettle 2 through an ethanol feed port 37 through a waste ethanol feed pump 18, sulfuric acid (the concentration is 98 percent, and the addition amount is 3 percent of the liquid holdup of the kettle liquid) is added into the esterification kettle from a sulfuric acid feed port 36 to perform esterification reaction, crude ester is generated, the crude ester flows out from a gas phase discharge port 27 of the esterification kettle and enters a deacidification tower 3 to perform deacidification treatment to remove redundant acetic acid, a product enters an esterification phase separator to be separated, one part of an organic phase flows back to the deacidification tower 3 through a backflow feed port 38, one part of the organic phase is discharged into a crude ester tank 8 from a second discharge port of the delayer, and lower layer water of the esterification phase separator flows into a waste water tank. The mass ratio of the waste acetic acid to the waste ethanol is 2: 1; the adding amount of the sulfuric acid is 3 percent based on the total mass of the waste acetic acid and the waste ethanol; the esterification reaction temperature is 103 ℃, and the pressure is 0 kPa; the temperature of deacidification treatment is 71 ℃, and the time is continuous production;

(2) feeding the crude ester in the crude ester tank into an extraction tower 9 from the lower part of the tower, and extracting by taking water as an extracting agent; the wastewater generated by extraction is detected, and the wastewater reaching the standard can be pumped into the extraction tower 9 through the wastewater inlet 32 by the wastewater pump 22, so that the wastewater can be used as an extracting agent to be in countercurrent contact with the crude ester in the extraction tower to extract water-soluble impurities in the crude ester, resources are saved, and the production cost of enterprises is reduced; directly discharging the wastewater which does not reach the standard into a wastewater tank; the extraction temperature is 30 ℃, and the mixture ratio of materials to water is 3: 1;

(3) pumping the extracted crude ester in the membrane treatment intermediate tank into a membrane shell 11 through a membrane treatment feed pump 20 through a crude ester feed port 33, circulating the crude ester between the membrane shell and a membrane heater 12, discharging water vapor permeated by the membrane shell from the top of the membrane shell, and condensing the water vapor by a membrane top condenser 16 and then sending the water vapor to a wastewater pool; the membrane treatment temperature is 62 ℃, and the pressure is-80 kPa; the finished ethyl acetate product after the membrane treatment flows out of the product discharge port 34 and enters the finished ethyl acetate product tank 15. The heat exchanger can shift the finished heat of the ethyl acetate that goes out from membrane processing intermediate tank to the ethyl acetate of treating the dewatering from membrane processing intermediate tank in the membrane shell after the membrane, make it effectively heat before getting into the membrane shell, need not the independent heating, reduce the energy consumption, reduce the manufacturing cost of enterprise, simultaneously, the finished heat of the ethyl acetate that goes out through membrane processing is also effectively released, cools off more high-efficiently when next through the cooler behind the membrane, improves production efficiency.

The ethyl acetate product obtained in this example was 97% pure and 89% yield.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and other variations and modifications may be made without departing from the spirit of the invention as set forth in the claims.