CN115245791A - Device and method for producing high-end fine chemicals alpha-alkyl ester - Google Patents

Abstract

The device comprises an ester raw material tank and an aldehyde raw material tank, wherein the top of the ester raw material tank is provided with a variable frequency stirrer, the bottom of the ester raw material tank is connected with an ester raw material circulating pump, the inlet of the ester raw material feeding pump is connected with the outlet pipeline of the ester raw material circulating pump, the outlet of the aldehyde raw material tank is connected with the inlet of the aldehyde raw material feeding pump, the inlet end of a pre-reactor is connected with the outlet pipeline of the aldehyde raw material feeding pump, the outlet of the pre-reactor is connected with the inlet end of a reactor, the inlet end of a gas-liquid cooling separator is connected with the outlet of the reactor, the top of a gas-liquid separator is connected with a gas discharge device, the bottom of the gas-liquid separator is connected with a liquid level control valve, liquid passes through the liquid level control valve and is conveyed to a rectifying tower, the bottom of the rectifying tower is connected with a catalyst separation inlet end, the outlet of the catalyst separator is connected with the inlet of a circulating pump of the rectifying tower, and the outlet of the rectifying tower is connected with a heating kettle to form a cycle. The method has the characteristics of mild reaction conditions, short process flow and high product purity.

Description

A device and method for producing high-end fine chemicals α-alkyl ester

technical field

The invention relates to the technical field of high-end fine chemical α-alkyl ester production, in particular to a device and method for producing high-end fine chemical α-alkyl ester.

Background technique

In the field of production technology of high-end fine chemicals α-alkyl esters, batch-operated reactors are used, with esters and aldehydes as raw materials and micron-sized palladium carbon as catalysts. -8 hours and in a hydrogen atmosphere, the reaction produces a high-end fine chemical product α-alkyl ester with high added value, which has long reaction time, poor mass transfer and heat transfer efficiency, high manual operation cost, low degree of automation, and difficulty in continuous production Production is not conducive to post-scale enlargement and industrial mass production.

SUMMARY OF THE INVENTION

In order to overcome the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide a device and method for producing high-end fine chemicals α-alkyl ester, which has the characteristics of mild reaction conditions, short process flow and high product purity.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A device for producing high-end fine chemical α-alkyl esters, comprising an ester raw material tank 1 and an aldehyde raw material tank 2, the top of the ester raw material tank 1 is equipped with a frequency conversion agitator, and the bottom is connected with an ester raw material circulation pump 3 to form a large amount of circulation Raw material, the frequency conversion agitator that aldehyde raw material tank 2 bottoms are provided with, the inlet of ester raw material feed pump 4 is connected with ester raw material circulation pump 3 outlet pipelines, and the outlet of described ester raw material feed pump 4 is ester raw material feed flow meter 6, by adjusting The stroke and frequency conversion of the ester raw material feed pump 4 regulate the feed amount of the ester. The outlet of the aldehyde raw material tank 2 is connected to the inlet of the aldehyde raw material feed pump 5. The outlet of the aldehyde raw material feed pump 5 is the aldehyde raw material feed flowmeter 7. The stroke and frequency conversion of the raw material pump 5 are used to adjust the feed amount of aldehyde. The inlet of the prereactor 8 is connected to the outlet pipeline of the ester raw material feed pump 4 and the aldehyde raw material feed pump 5, and the outlet of the prereactor 8 is connected to the inlet of the reactor 9. The inlet end of the gas-liquid cooling separator 10 is connected to the outlet of the reactor 9, the top of the gas-liquid separator 10 is connected to the gas discharge 11, the bottom of the gas-liquid separator 10 is connected to the liquid level control valve 12, and the liquid passes through the liquid level control valve 12 To the rectification tower 13, the bottom of the rectification tower 13 is connected to the inlet end of the catalyst separator 14, the outlet of the catalyst separator 14 is connected to the inlet of the rectification tower circulation pump 15, and the outlet of the rectification tower circulation pump 15 is connected to the heating tank of the rectification tower to form a cycle.

The bottom of the reactor 9 is provided with a stirrer, which is used to prevent a large amount of sedimentation and deposition of the catalyst, further strengthen the mixing of the solvent and the raw material, and keep the catalyst into a homogeneous phase. The micro-reaction is enhanced, and the catalyst is pushed to the top of the reactor 9.

The reactor 9 is a tubular reactor with a temperature measuring device inside, which can be a multi-section temperature measurement of the central tube, or a side tube insertion type temperature measurement; the top and bottom of the reactor are flanged and sealed, and the bottom The flange is equipped with agitator, feed inlet and air inlet, the flange on the top of the reactor has air inlet and material outlet, and the outside of the reactor is equipped with a heating device and a heat preservation device.

The separator 10 has a settling tube, and the reacted product is transported to the lower part of the separator 10, and the gas is separated from the top and discharged to the gas recovery system through the pressure regulating valve 11, and the liquid-solid material at the bottom of the separator Through the liquid level control valve 12 to the rectification tower, fractional distillation is carried out; the separator 10 is equipped with a heat preservation and heating system to maintain the reaction conditions. A small amount of hydrogen entering the bottom can prevent the deposition of the catalyst, and can also promote the further reaction of unreacted substances in the product Completely, there is a radar level gauge on the top of the separator, which forms an automatic control system with the separator liquid level control valve.

The liquid-solid products separated by the rectification tower 13 and the separator 10 pass through the separator liquid level control valve 12 to the bottom of the rectification tower 13, and are heated to a certain temperature by the heater at the bottom of the rectification tower 13, and are separated in different towers respectively. The layers were separated to give alkyl esters, aldehydes, ethanol. Part of the product at the bottom of the rectification tower flows out from the bottom to the catalyst separation system 14 together with the catalyst, and the liquid after separation is circulated at the bottom of the rectification tower 13 by the tower bottom circulation pump 15 .

A method for using a device for producing high-end fine chemicals α-alkyl esters, comprising the following steps;

(1) Process gas purging: the ester raw material tank 1 and the aldehyde raw material tank 2, the top is filled with nitrogen, the raw material tank and the pump pipeline are purged, and a temporary pipeline is added. Device 10 is purged respectively, adopts 0.3Mpa nitrogen purging to rectifying system;

(3) System cleaning: Add 50% ethanol to the ester raw material tank 1 and aldehyde raw material tank 2, start the agitator, start the ester raw material circulation pump 3, ester raw material feed pump 4, aldehyde raw material feed pump 5, feed ratio 1:1, so that ethanol is filled with reactor 8, reactor 9, and the liquid level of the separator is 50% to start draining, adding ethanol to the rectification tower to establish a 50% liquid level, heating to 110 ° C, washing the tower, and the whole system Ethanol cycle cleaning, detection impurity content ≤ 0.5% is the system cleaning;

(3) Device initialization: Catalyst in ester raw material tank 1, additives are mixed in proportion and added to raw materials to 60%, ester raw material circulation pump 3 starts circulation; Aldehyde raw material tank 2 adds raw materials to 60%, starts raw material tank agitator; The sealing has been completed, the hydrogen system is started, the hydrogen purity is 99.9%, the CO content is ≤10ppm, the hydrogen gas volume of each channel has been debugged, the system pressure condition of 2Mpa and the venting system have become a stable state, the pre-reactor 8 and the reactor 9 have been heated to 65 ℃-90℃, the agitator of pre-reactor 8 and reactor 9 starts; the liquid level of the separator is set to 30%; cycle;

(4) Device startup: start the ester raw material feed pump 4, the aldehyde raw material feed pump 5, the ratio of the aldehyde raw material to the ester raw material is 4:6, the system feeds, the liquid level of the separator reaches 35%, and the rear rectifying tower maintains The liquid level is 45%-50%, gradually heated to 230°C-260°C, and ethanol 16, ester 17, and α-alkyl ester 18 are separated from the rectifying tower 13;

(5) Device shutdown: cool down the system to normal temperature, depressurize the system to normal pressure, stop the ester raw material feed pump 4, the aldehyde raw material feed pump 5, and the ester raw material circulation pump 3 to start the cycle, and drain the ester raw material tank 1 from the drain port , the remaining raw materials in the aldehyde raw material tank 2 are discharged from the pre-reactor 8 and the product of the reactor 9, and the materials of the separator 10 and the separation tower 13 are discharged, the system is purged and replaced, and the shutdown is completed.

Beneficial effects of the present invention:

1. The present invention adopts a continuous production process to replace the traditional batch-operated reactor mode, which overcomes the problems of long reaction time, poor mass and heat transfer efficiency, high manual operation cost, low degree of automation, and difficulty in realizing continuous production, which is not conducive to subsequent scale-up Disadvantages of scale-up and industrial mass production.

2. The continuous production method of the present invention has the advantages of mild reaction conditions, short process flow, reliable operation, high safety, high economic benefits, and large profit margins, and can produce products with a purity higher than 98%.

3. The ester raw material tank of the present invention adopts two mixing methods of circulation and stirring to mix materials, which ensures that the catalyst is homogeneous and not easy to settle, and solves the problem that the catalyst is easy to settle in low-viscosity liquid materials.

4. The present invention adopts the pre-reactor, the material reacts in advance, reduces the load of the reactor, shortens the reaction time of the material in the reactor, increases the total reaction time of the material, and improves the reaction efficiency and reaction effect.

5. The present invention pre-reactor, reactor, and the bottom of the gas-liquid separator all have hydrogen entering, and there is a heat preservation device, which is equivalent to prolonging the reaction time, promoting the complete reaction of materials, and improving the conversion rate of materials.

6. Both the top of the pre-reactor and the bottom of the reactor are stirred and hydrogen enters from the bottom, which ensures that the catalyst is uniformly mixed in the material and promotes the reaction.

7. Carry out under 65 ℃ of reaction temperature of the present invention, reaction pressure 2MPa condition, reaction condition is gentle, raw material ester and aldehyde will all be converted into target product under this reaction condition, used solvent ethanol enters in the reaction product, reclaims by solvent recovery method, can Continue to use as a solvent.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the present invention.

Reference number:

Ester raw material tank 1, aldehyde raw material tank 2, ester raw material circulation pump 3, ester raw material feed pump 4, aldehyde raw material feed pump 5, ester raw material feed flow meter 6, aldehyde raw material feed flow meter 7, pre-reactor 8 , reactor 9, gas-liquid cooling separator 10, gas discharge 11, decompression discharge valve 12, rectification tower 13, catalyst separation 14, rectification tower circulation pump 15, ethanol 16, aldehyde 17, α-alkyl ester 18 .

Detailed ways

The present invention is described in further detail below in conjunction with embodiment.

As shown in Figure 1, a frequency conversion agitator is installed on the top of the ester raw material tank 1, and the bottom of the ester raw material tank 1 is connected with the ester raw material circulation pump 3 to form a large amount of circulating raw materials, so that the ratio of ester to solvent ethanol in the ester raw material tank 1 is 1:1.3, 0.1 % (raw material aldehyde) catalyst mixes evenly, prevents catalyst from settling or gathering at the bottom of ester raw material tank 1. In the aldehyde raw material tank 2, the mixing ratio of aldehyde and solvent ethanol is 1:1, which is a mixture of two liquid miscible substances. Only the frequency conversion agitator installed at the bottom of the aldehyde raw material tank is required to stir evenly in advance. The ester raw material tank 1 and the top of the aldehyde raw material tank 2 There are 0.3Mpa nitrogen on the one hand as nitrogen sealed storage, on the other hand to provide pressure for the pump inlet.

The 4 outlets of the ester raw material feed pump are the ester raw material feed flowmeter 6, and the feed amount of the ester is adjusted by adjusting the stroke and frequency conversion of the ester raw material feed pump, and the 5 outlets of the aldehyde raw material feed pump are the aldehyde raw material feed flowmeters 7. Adjust the feed amount of aldehyde by adjusting the stroke and frequency conversion of the aldehyde raw material pump 5, so that the mass flow ratio of the aldehyde raw material and the ester raw material is 4:6.

In the pre-reactor 8, the aldehyde raw material and the ester raw material enter the pre-reactor 8 at a ratio of 4:6 for pre-heating and pre-reaction, and mix with hydrogen at the bottom of the reactor. The amount of hydrogen and feed is 100NL/kg. Stirring and heating is carried out under the condition of hydrogen in the reactor. The aldehyde and ester react under the condition of solvent ethanol as the carrier to form intermediate products. The hydrogen enters from the bottom of the reactor, which can effectively prevent the catalyst from settling and speed up the reaction rate. The reaction time with the reactor is 1h.

The hydrogen system 15, the hydrogen is divided into three parts, through the hydrogen flow meters 19 and 16, one part passes through the hydrogen flow meter 16 to the bottom of the pre-reactor, one part passes through the hydrogen flow meter 16 to the bottom of the reactor, and the third part of hydrogen flows to the reactor The pressure difference 21 formed by the hydrogen gas in the hydrogen flow meter 16 at the top of the reactor and at the bottom of the reactor can be used as a detection means for serious subsidence inside the reactor 9. The gravity pressure value of the material in the reactor can be calculated according to the density of the material and the height of the reactor as a reference. If the pressure difference 21 is greater than the gravity pressure value, it means that the reactor is blocked. If the pressure difference 21 is too high, the hydrogen raw material cannot be fed. Indicates that the reactor is clogged.

There is an agitator at the bottom of the reactor 9, which prevents a large amount of sedimentation and deposition of the catalyst, further strengthens the mixing of the solvent and the raw material, and keeps the catalyst in a homogeneous phase. Drive the catalyst to the top of the reactor 9, the total feed of hydrogen and raw materials in the reactor is 280NL/kg, and the reaction time in the reactor is 5h.

The separator 10 has a settling tube, and the reacted product is transported to the lower part of the separator 10, and the gas is separated from the top and discharged to the gas recovery system through the pressure regulating valve 11, and the liquid-solid material at the bottom of the separator Through the liquid level control valve 12 to the rectification tower, the separation is carried out; the separator is equipped with a heat preservation and heating system to maintain the reaction conditions. A small amount of hydrogen entering the bottom can prevent the deposition of the catalyst, and can also promote the further complete reaction of the unreacted substances in the product , There is a radar level gauge on the top of the separator, which forms an automatic control system with the separator liquid level control valve. The liquid level control is an automatic system. After the liquid level is set, it will automatically open the valve and discharge the liquid.

The liquid-solid products separated by the rectification tower 13 and the separator 10 pass through the separator liquid level control valve 12 to the bottom of the rectification tower, are heated to a certain temperature by the heater at the bottom of the rectification tower, and are separated in different tower layers Alkyl esters, aldehydes, ethanol. Part of the product at the bottom of the rectification tower flows out from the bottom to the catalyst separation system 14 together with the catalyst, and the liquid after separation is circulated at the bottom of the rectification tower 13 by the tower bottom circulation pump 15 .

A method for using a device for producing high-end fine chemicals α-alkyl esters, comprising the following steps;

A method for using a device for producing high-end fine chemicals α-alkyl esters, comprising the following steps;

(1) Process gas purge: ester raw material tank 1, aldehyde raw material tank 2, fill the top with nitrogen, purge the raw material tank and pump pipeline, add temporary pipeline, 1Mpa respectively for pre-reactor 8, reactor 9, separation Device 10 is purged respectively, adopts 0.3Mpa nitrogen purging to rectifying system;

(3) System cleaning: ester raw material tank 1, aldehyde raw material tank 2 add ethanol 50% liquid level, start the agitator, start ester raw material circulation pump 3, ester raw material feed pump 4, aldehyde raw material feed pump 5, feed ratio The ratio is 1:1, so that ethanol is filled with pre-reactor 8 and reactor 9, and the liquid level of the separator is 50% to start draining, adding ethanol to the rectification tower to establish a 50% liquid level, heating to 110°C, and washing the tower. The entire system is cleaned by ethanol circulation, and the detected impurity content is less than 0.5% for the system to be cleaned.

(3) Device initialization: Catalyst in ester raw material tank 1, additives are mixed in proportion and added to raw materials to 60%, ester raw material circulation pump 3 starts circulation; aldehyde raw material tank 2 adds raw materials to 60%, starts raw material tank agitator; The sealing has been completed, the hydrogen system is started, the hydrogen purity reaches 99.9%, the CO content is ≤10ppm, and the hydrogen gas volume of each channel has been debugged. ℃-90℃, the agitator of pre-reactor 8 and reactor 9 starts; the liquid level of the separator is set to 30%; the liquid level of the rectification tower is established at 45%-50%, the temperature is 60℃-80℃, and the bottom circulation is established .

(4) Device startup: start the ester raw material feed pump 4, the aldehyde raw material feed pump 5, the ratio of the aldehyde raw material to the ester raw material is 4:6, the system feeds, the liquid level of the separator reaches 35%, and the rear rectifying tower maintains The liquid level is 45%-50%, gradually heated to 230°C-260°C, ethanol 16, ester 17, and α-alkyl ester 18 are separated from the rectification tower.

(5) Device shutdown: cool down the system to normal temperature, depressurize the system to normal pressure, stop the ester raw material feed pump 4, the aldehyde raw material feed pump 5, and the ester raw material circulation pump 3 to start the cycle, and drain the ester raw material tank 1 from the drain port , the remaining raw materials in the aldehyde raw material tank 2 are discharged from the pre-reactor 8 and the product of the reactor 9, and the materials of the separator 10 and the separation tower 13 are discharged, the system is purged and replaced, and the shutdown is completed.

Claims (6)

1. A device for producing high-end fine chemicals α-alkyl esters, characterized in that it comprises an ester raw material tank (1) and an aldehyde raw material tank (2), and the top of the ester raw material tank (1) is provided with a frequency conversion agitator, The bottom is connected to the ester raw material circulation pump (3) to form a large amount of circulating raw materials. The frequency conversion agitator is arranged at the bottom of the aldehyde raw material tank (2), and the inlet of the ester raw material feed pump (4) is connected to the outlet pipeline of the ester raw material circulation pump (3). The outlet of the ester raw material feed pump (4) is an ester raw material feed flow meter (6), and the feed rate of the ester is regulated by adjusting the stroke and frequency conversion of the ester raw material feed pump (4), and the outlet of the aldehyde raw material tank (2) is Connect the inlet of the aldehyde raw material feed pump (5), and the outlet of the aldehyde raw material feed pump (5) is the aldehyde raw material feed flowmeter (7), and adjust the aldehyde feed amount by adjusting the stroke and frequency conversion of the aldehyde raw material pump (5) , the inlet of the prereactor (8) is connected to the outlet pipeline of the ester raw material feed pump (4) and the aldehyde raw material feed pump (5), and the outlet of the prereactor (8) is connected to the inlet of the reactor (9). The inlet of the liquid cooling separator (10) is connected to the outlet of the reactor (9), the top of the gas-liquid separator (10) is connected to the gas discharge (11), and the bottom of the gas-liquid separator (10) is connected to the liquid level control valve (12) , the liquid passes through the liquid level control valve (12) to the rectification tower (13), the bottom of the rectification tower (13) is connected to the inlet port of the catalyst separator (14), and the outlet of the catalyst separator (14) is connected to the rectification tower circulation pump (15 ) inlets are connected, and the outlet of the rectifying tower circulation pump (15) is connected with the rectifying tower heating kettle to form a circulation. 2. a kind of device of producing high-end fine chemical product α-alkyl ester according to claim 1, is characterized in that, the bottom of described reactor (9) is provided with stirrer, is used to prevent the massive settlement of catalyst, Deposition further strengthens the mixing of solvent and raw materials to keep the catalyst in a homogeneous phase. The hydrogen gas at the bottom of the reactor (9) enters in the form of micro-hole injection to enhance the micro-reaction and drive the catalyst to the top of the reactor (9). 3. A device for producing high-end fine chemicals α-alkyl ester according to claim 1, characterized in that, the reactor (9) is a tubular reactor with a temperature measuring device inside, which can be The center tube can be used for multi-segment point temperature measurement, and the side tube can also be inserted into the temperature measurement; the top and bottom of the reactor are connected and sealed by flanges, and the bottom flange is equipped with agitator, feed inlet, air inlet, and the top flange of the reactor There is an air inlet and a material outlet, and a heating device and a heat preservation device are installed outside the reactor. 4. A device for producing high-end fine chemicals α-alkyl ester according to claim 1, characterized in that, the separator (10) has a settling tube, and the product after the reaction is mixed with a gas-liquid-solid mixture Transported to the lower part of the separator (10), the gas is separated and discharged from the top to the gas recovery system through the pressure regulating valve (11), and the liquid-solid material at the bottom of the separator passes through the liquid level control valve (12) to the rectification tower (13), Carry out fractional distillation; Separator (10) has insulation and heating system, keeps the small amount of hydrogen that enters at the bottom of reaction condition to be used for preventing the deposition of catalyst, promotes the further complete reaction of unreacted material in the product, separator (10) top has The radar liquid level gauge forms an automatic control system with the liquid level control valve of the separator (10). 5. A device for producing high-end fine chemicals α-alkyl ester according to claim 1, characterized in that, the liquid-solid product separated by the rectification tower (13) and the separator (10) is passed through The separator liquid level control valve (12) reaches the bottom of the rectification tower (13), and is heated to a certain temperature by the heater at the bottom of the rectification tower (13), and alkyl esters, aldehydes, ethanol, etc. are separated in different tower layers respectively. Part of the product at the bottom of the rectification tower (13) flows out from the bottom together with the catalyst to the catalyst separation system (14), and the liquid after separation is circulated at the bottom of the rectification tower 13 by the tower bottom circulation pump 15. 6. A method for using a device for producing high-end fine chemicals α-alkyl esters according to any one of claims 1-5, characterized in that it comprises the following steps; (1) Process gas purge: ester raw material tank (1) and aldehyde raw material tank (2), fill the top with nitrogen, purge the raw material tank and pump pipeline, add temporary pipeline, 1Mpa respectively for the pre-reactor (8) , reactor (9), separator (10) is purged respectively, adopts 0.3Mpa nitrogen purging to rectifying system; (3) System cleaning: Add the 50% liquid level of ethanol to the ester raw material tank (1) and the aldehyde raw material tank (2), start the agitator, start the ester raw material circulation pump (3), the ester raw material feed pump (4), and the aldehyde raw material Feed pump (5), feed ratio is 1:1, makes ethanol be full of pre-reactor (8), reactor (9), separator liquid level is 50% and starts draining, and rectifying tower (13) adds ethanol Establish a 50% liquid level, heat to 110°C, and wash the tower. The entire system is cleaned with ethanol in a circular manner. If the impurity content is detected to be ≤0.5%, the system is cleaned; (3) Device initialization: Catalyst in ester raw material tank (1), additives are mixed in proportion to add raw materials to 60%, ester raw material circulation pump (3) starts circulation; Aldehyde raw material tank (2) adds raw materials to 60%, start ester Raw material tank (1) agitator; the airtightness of the system has been completed, start the hydrogen system, the hydrogen purity reaches 99.9%, the CO content is ≤10ppm, the hydrogen gas volume of each channel has been debugged, the system 2Mpa pressure condition and the venting system have become a stable state, pre-reaction Device (8), reactor (9) has been heated to 65 ℃-90 ℃, and prereactor (8), the agitator of reactor (9) starts; Separator liquid level is set to 30%; Rectifying column (13 ) The liquid level is established at 45%-50%, the temperature is 60°C-80°C, and the bottom circulation is established; (4) Device startup: start the ester raw material feed pump (4), the aldehyde raw material feed pump (5), the ratio of the aldehyde raw material to the ester raw material is 4:6, the system feeds, the separator liquid level reaches 35%, and then The rectification tower (13) keeps the liquid level at 45%-50%, gradually heats up to 230°C-260°C, and separates ethanol (16), ester (17), and α-alkyl ester (18) from the rectification tower; (5) Device shutdown: the system is cooled to normal temperature, the system is depressurized to normal pressure, the ester raw material feed pump (4), the aldehyde raw material feed pump (5), and the ester raw material circulation pump (3) are started to circulate. Outlet row ester raw material tank (1), the remaining raw material of aldehyde raw material tank (2), row prereactor (8), the product of reactor (9), row separator (10), the material of separation tower (13), The system is purged and replaced, and the shutdown is over.

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