Production system for improving utilization rate of raw materials for esterification reaction of butyl acetate

Abstract

The utility model relates to a production system for improving the utilization rate of butyl acetate esterification reaction raw materials. The raw material preheater is communicated with the esterification reboiler, the esterification reboiler is communicated with the esterification kettle, a discharge port of the esterification kettle is communicated with a feed port of the sulfuric acid trap, and a discharge port of the sulfuric acid trap is communicated with a feed port of the esterification tower; a discharge port of the esterification tower is communicated with a feed port of the tower top condenser, a discharge port of the tower top condenser is communicated with a feed port of the oil-water layering tank, and oil phase and water phase discharge ports of the oil-water layering tank are communicated with a reflux inlet in the top of the esterification tower; a water phase discharge port of the oil-water layering tank is communicated with a feed port of the stripping tower, and a gas phase port of the stripping tower is communicated with the esterification tower. The device disclosed by the utility model has the advantages that the catalyst entrained in the gas phase of the esterification kettle is separated and recycled through the sulfuric acid trap, so that the catalyst is prevented from being lost, the esterification reaction is promoted to move towards the positive direction, and the utilization conversion rate of raw materials is improved; materials dissolved in a water phase are recycled through the stripping tower, so that the loss of the materials is avoided, and the utilization conversion rate of the raw materials is increased to the maximum extent.

Description

TECHNICAL FIELD

[0001] The utility model relates to butyl acetate production technical field, specifically relates to the production system of promoting butyl acetate esterification reaction raw material utilization rate. BACKGROUND

[0002] Butyl acetate is an important basic organic chemical raw material, often as organic solvent, extracting agent, dehydrating agent, is applied to fire cotton, nitrocellulose, varnish, artificial leather, medicine, plastic and spice industry. With the requirement of energy saving higher and higher, butyl acetate production enterprise also pays more and more attention to the raw material utilization rate problem of production process.

[0003] Traditional butyl acetate esterification production, raw material butyl alcohol and acetic acid are used as catalyst with concentrated sulfuric acid, reaction generates butyl acetate, butyl alcohol excess (butyl alcohol and acetic acid volume ratio is 4:1), reaction temperature is 116 DEG C, using such esterification production method, raw material conversion utilization rate is only about 65%, conversion utilization rate is lower, the crude ester content in the upper layer of oil-water separation tank is about 75%, and a small amount of catalyst concentrated sulfuric acid is entrained into esterification tower with esterification kettle gas phase, makes the catalyst in esterification kettle lack, influences reaction rate, and causes corrosion to equipment, and about 2% butyl alcohol and crude butyl acetate are dissolved in the water phase in the lower layer of oil-water separation tank as waste water discharge system, causes material loss.

[0004] In view to the lower raw material utilization conversion rate of existing butyl acetate esterification reaction, it is necessary to develop a kind of production system that can effectively improve the raw material utilization conversion rate of butyl acetate esterification reaction. UTILITY MODEL CONTENT

[0005] The technical problem to be solved by the utility model is to provide the production system of promoting butyl acetate esterification reaction raw material utilization rate, can solve the problems, such as the lower raw material utilization conversion rate of butyl acetate esterification reaction in prior art, a small amount of catalyst concentrated sulfuric acid is entrained into esterification tower with esterification kettle gas phase, makes the catalyst in esterification kettle lack, influences reaction rate and causes corrosion to equipment, butyl alcohol and crude butyl acetate are dissolved in the water phase in the lower layer of oil-water separation tank as waste water discharge system, causes material loss.

[0006] To solve the above technical problem, the technical scheme of the utility model is as follows: including raw material preheater, esterification reboiler, esterification kettle, sulfuric acid trap, esterification tower, tower top condenser, oil-water separation tank and stripping column;

[0007] The raw material preheater is equipped with raw material feed inlet, and the outlet of the raw material preheater is communicated with the inlet at the bottom of the esterification reboiler, the top outlet of the esterification reboiler is communicated with the top inlet of the esterification kettle through the first pipeline, the top outlet of the esterification kettle is communicated with the lower inlet of the sulfuric acid trap through the second pipeline, and the upper outlet of the sulfuric acid trap is communicated with the lower inlet of the esterification tower through the third pipeline.

[0008] The esterification tower top part discharge port is communicated with the tower top condenser feed port through a sixth pipeline, the tower top condenser discharge port is communicated with the oil-water separation tank feed port through a seventh pipeline, and the oil-water separation tank upper oil phase and lower water phase discharge ports are communicated with the esterification tower top part reflux port through an eighth pipeline.

[0009] The oil-water separation tank bottom water phase discharge port is communicated with the stripping tower top part feed port through a ninth pipeline, and the stripping tower top part gas phase port is communicated with the esterification tower bottom part through a tenth pipeline.

[0010] Further, the sulfuric acid catcher bottom reflux port is communicated with the esterification kettle top part sulfuric acid reflux port through a fourth pipeline.

[0011] Further, the esterification tower bottom reflux port is communicated with the esterification reboiler bottom part through a fifth pipeline.

[0012] Further, the upper part of the esterification reboiler is provided with a steam inlet, and the lower part of the esterification reboiler is provided with a condensate water outlet.

[0013] Further, the stripping tower lower part is provided with a steam inlet, and the stripping tower bottom part is provided with a waste water discharge outlet.

[0014] After the above structure is adopted, the production system for improving butyl acetate esterification reaction raw material utilization rate has the advantages that the catalyst carried by the gas phase of the esterification kettle is separated and reused through the added sulfuric acid catcher, catalyst loss is avoided, the esterification reaction is promoted to move in a positive direction, the raw material utilization conversion rate can be improved, the material dissolved in the water phase is recycled and reused through the added stripping tower, material loss is avoided, and the raw material utilization conversion rate is maximized. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The figure is a structural schematic diagram of the utility model. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the utility model more clear and obvious, the utility model is further described in detail below by combining with the drawings and specific embodiments. The following embodiments can make the technical personnel of the profession more fully understand the utility model, but the utility model is not limited in the scope of the embodiments.

[0017] As shown in the drawings, Figure 1 The specific embodiment adopts the following technical scheme: a production system for improving butyl acetate esterification reaction raw material utilization rate, which comprises a raw material preheater 1, an esterification reboiler 2, an esterification kettle 3, a sulfuric acid catcher 4, an esterification tower 5, a tower top condenser 6, an oil-water separation tank 7 and a stripping tower 8.

[0018] The raw material preheater 1 is provided with a raw material inlet, butanol and acetic acid are added into the raw material preheater 1 from the raw material inlet at a volume ratio of 1.2:1, the outlet of the raw material preheater 1 is communicated with the inlet of the bottom of the esterification reboiler 2, the upper part of the esterification reboiler 2 is provided with a steam inlet, the lower part of the esterification reboiler 2 is provided with a condensate water outlet, the raw material is preheated in the raw material preheater 1 and then enters the esterification reboiler 2 to be heated and vaporized.

[0019] The top outlet of the esterification reboiler 2 is communicated with the top inlet of the esterification kettle 3 through the first pipeline 9, the esterification reboiler 2 is heated and vaporized and then enters the esterification kettle 3 to carry out esterification reaction, the top outlet of the esterification kettle 3 is communicated with the lower inlet of the sulfuric acid trap 4 through the second pipeline 10, the bottom reflux port of the sulfuric acid trap 4 is communicated with the top sulfuric acid reflux port of the esterification kettle 3 through the fourth pipeline 12, the butyl acetate gas phase after reaction passes through the sulfuric acid trap 4 to separate a small amount of concentrated sulfuric acid entrained in the gas phase.

[0020] The upper outlet of the sulfuric acid trap 4 is communicated with the lower inlet of the esterification column 5 through the third pipeline 11, the bottom reflux port of the esterification column 5 is communicated with the bottom of the esterification reboiler 2 through the fifth pipeline 13.

[0021] The top outlet of the esterification column 5 is communicated with the inlet of the overhead condenser 6 through the sixth pipeline 14, the outlet of the overhead condenser 6 is communicated with the inlet of the oil-water separation tank 7 through the seventh pipeline 15, the material separated and purified through the esterification column 5 is taken from the top of the esterification column 5, condensed through the overhead condenser 6 and then enters the oil-water separation tank 7.

[0022] The upper oil phase and the lower water phase of the oil-water separation tank 7 are communicated with the top reflux port of the esterification column 5 through the eighth pipeline 16, part of the oil phase of the oil-water separation tank 7 returns to the top of the esterification column 5 as reflux, and the rest enters the subsequent rectification process for further purification to obtain qualified butyl ester product.

[0023] The water phase of the bottom of the oil-water separation tank 7 is communicated with the top inlet of the stripping column 8 through the ninth pipeline 17, part of the water phase of the bottom of the oil-water separation tank 7 returns to the top of the esterification column 5 as reflux, and the rest enters the stripping column 8 to recover the material in the water phase, the recovered material is evaporated from the top of the stripping column 8 and then enters the esterification to continue the reaction.

[0024] The top gas phase port of the stripping column 8 is communicated with the bottom of the esterification column 5 through the tenth pipeline 18, the lower part of the stripping column 8 is provided with a steam inlet, and the bottom of the stripping column 8 is provided with a waste water outlet.

[0025] The raw material preheater 1, the esterification reboiler 2, the esterification kettle 3, the sulfuric acid trap 4, the esterification column 5, the overhead condenser 6, the oil-water separation tank 7 and the stripping column 8 described above are all general standard parts or parts known by those skilled in the art, the structure and principle of which can be known by those skilled in the art through technical manuals or through conventional experimental methods, and will not be described.

[0026] Working principle: raw material butanol and acetic acid are mixed, the volume ratio of butanol and acetic acid is 1.2:1, after preheating by raw material preheater 1, they are heated and vaporized in esterification reboiler 2, then enter esterification kettle 3, and esterification reaction is carried out at 120℃. After reaction, butyl acetate gas phase is separated from a small amount of concentrated sulfuric acid entrained in the gas phase by sulfuric acid trap 4, and then enters esterification tower 5 for separation and purification. The product is collected from the top of the esterification tower 5, condensed by tower top condenser 6, and then enters oil-water separation tank 7. Part of the oil phase in the upper layer of the oil-water separation tank 7 is returned to the top of the esterification tower 5 as reflux, and the rest enters the subsequent rectification process for further purification to obtain qualified butyl acetate product. Part of the water phase in the lower layer of the oil-water separation tank 7 is returned to the top of the esterification tower 5 as reflux, and the rest enters the stripping tower 8 to recover the materials in the water phase. The recovered materials are vaporized from the top of the stripping tower 8 and enter the esterification kettle for further reaction.

[0027] After one week of continuous production using the above production system, the conversion rate of raw materials is about 75-80%, the crude ester content at the top of the esterification tower is 88-92%, and the materials in the water phase can be recovered and reused after stripping tower 8, avoiding material loss. A small amount of concentrated sulfuric acid entrained in the gas phase of the esterification kettle 3 is separated by the sulfuric acid trap 4, and the concentrated sulfuric acid is returned to the esterification kettle 3 for further use as catalyst, avoiding the loss of catalyst, ensuring the reaction rate, and reducing the corrosion degree of equipment.

[0028] However, using the traditional butyl acetate esterification production system, the raw materials butanol and acetic acid are mixed in a volume ratio of 4:1, and esterification reaction is carried out at a temperature of 116℃. After esterification, butyl acetate gas phase enters the esterification tower for separation and purification, and then enters the oil-water separation tank after being condensed by the tower top condenser. Part of the water phase in the lower layer of the oil-water separation tank is returned to the top of the esterification tower as reflux, and the rest is discharged as waste water to the sewage treatment. After one week of continuous production using this production system, the conversion rate of raw materials is about 65%, the crude ester content at the top of the esterification tower is 75-80%, and about 30 kg of material dissolved in the water phase is discharged with the waste water to the sewage treatment for every ton of butyl acetate product, resulting in high material loss. A small amount of catalyst concentrated sulfuric acid is entrained in the gas phase of the esterification kettle and enters the esterification tower, causing the loss of catalyst in the esterification kettle, affecting the reaction rate, and causing corrosion to the equipment.

[0029] From the above comparison, it can be concluded that adjusting the raw material feed ratio, appropriately increasing the reaction temperature, and recycling and reusing the materials in the water phase, and separating and recycling the concentrated sulfuric acid entrained in the gas phase of the esterification kettle, can improve the conversion and utilization rate of raw materials and the crude ester content at the top of the esterification tower.

[0030] The basic principle and main features of the present application and the advantages of the present application are shown and described above. Those skilled in the art should understand that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A production system for improving the utilization rate of raw materials in the esterification reaction of butyl acetate, characterized in that: It includes a raw material preheater, esterification reboiler, esterification kettle, sulfuric acid trap, esterification tower, tower top condenser, oil-water separation tank, and stripping tower; The raw material preheater is provided with a raw material inlet. The outlet of the raw material preheater is connected to the inlet at the bottom of the esterification reboiler. The outlet at the top of the esterification reboiler is connected to the inlet at the top of the esterification kettle through a first pipe. The outlet at the top of the esterification kettle is connected to the inlet at the bottom of the sulfuric acid trap through a second pipe. The outlet at the top of the sulfuric acid trap is connected to the inlet at the bottom of the esterification tower through a third pipe. The top outlet of the esterification tower is connected to the inlet of the top condenser through the sixth pipe, the top condenser outlet is connected to the inlet of the oil-water separation tank through the seventh pipe, and the outlets of the upper oil phase and lower water phase of the oil-water separation tank are connected to the top reflux port of the esterification tower through the eighth pipe. The water phase discharge port at the bottom of the oil-water separation tank is connected to the top feed port of the stripping tower via the ninth pipe, and the gas phase port at the top of the stripping tower is connected to the bottom of the esterification tower via the tenth pipe.

2. The production system for improving the utilization rate of raw materials in the esterification reaction of butyl acetate according to claim 1, characterized in that: The bottom reflux port of the sulfuric acid trap is connected to the top sulfuric acid reflux port of the esterification reactor via a fourth pipe.

3. The production system for improving the utilization rate of raw materials in the esterification reaction of butyl acetate according to claim 1, characterized in that: The bottom reflux port of the esterification tower is connected to the bottom of the esterification reboiler via a fifth pipe.

4. The production system for improving the utilization rate of raw materials in the esterification reaction of butyl acetate according to claim 1, characterized in that: The esterification reboiler is provided with a steam inlet at the top and a condensate outlet at the bottom.

5. The production system for improving the utilization rate of raw materials in the esterification reaction of butyl acetate according to claim 1, characterized in that: The stripping tower is equipped with a steam inlet at the bottom and a wastewater outlet at the bottom of the stripping tower.

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