CN106810455B - A kind of production method of high-quality essence hexamethylene diamine - Google Patents

Abstract

The invention discloses a production method of high-quality refined hexamethylenediamine, which comprises the preparation of semi-finished hexamethylenediamine and the purification of high-quality refined hexamethylenediamine, specifically mixing adiponitrile, ethanol and sodium hydroxide according to a certain mass ratio Uniformity, then add nickel-based catalyst, carry out hydrogenation reaction, obtain semi-finished hexamethylene diamine; then carry out multiple distillation and purification of semi-finished hexamethylene diamine, and obtain high-quality refined hexamethylene diamine. The present invention adopts ethanol as diluent, is conducive to recovery and reuse, and adopts nickel-based catalyst as cocatalyst to ensure the conversion rate of hexamethylenediamine; adopts vacuum rectification technology, according to the different boiling points of impurities in semi-finished hexamethylenediamine, After dehydration, removal of light components, and removal of heavy components under vacuum conditions, a high-quality product with a purity ≥ 99.9% (mass percentage), polarographic value ≤ 100 mmolIB/T-HMD, and total volatile bases ≤ 4 mL/100g was finally obtained. Refined hexamethylenediamine products.

Description

A kind of production method of high-quality refined hexamethylenediamine

technical field

The invention belongs to the technical field of chemical industry, and in particular relates to a production method of high-quality refined hexamethylenediamine.

Background technique

Hexamethylenediamine is an important raw material for chemical synthesis. It is mainly used in the production of nylon 66 and 610 resins. It can be used to make adhesives, additives for rubber products, stabilizers, bleaching agents, and coatings in the textile and paper industry. Hexamethylenediamine can react with electrophilic compounds such as H+, haloalkane, hydroxyl and other compounds to make various fiber fabrics and plastic products, and can also be used to synthesize polyimide carboxylate foam and hexylene diisocyanate foam , Coatings and ZSN type zeolites.

Hexamethylenediamine can be produced by the hexanediol method and the caprolactam method. The hexanediol method is to synthesize 1,6-hexanediol by hydrogenation of caprolactone, and then use a skeleton nickel catalyst to carry out ammoniation and dehydration reaction. The reaction is as follows:

HOCH ₂ (CH ₂ ) ₄ CH ₂ OH + 2NH ₃ ─→ H ₂ N(CH ₂ ) ₆ NH ₂ + 2H ₂ O;

In order to prevent the dehydrogenation of hexamethylenediamine, a small amount of hydrogen needs to be added during the reaction. The reaction temperature is 200°C, the pressure is 2.3 MPa, and the yield is about 90%.

The caprolactam method is a gas-phase reaction of caprolactam and ammonia in the presence of a phosphate (such as manganese, aluminum, calcium, barium or zinc phosphate) catalyst to generate aminocapronitrile. The reaction temperature is about 350°C and the yield is almost 100%. The aminocapronitrile of generation carries out hydrogenation reaction again and generates hexamethylenediamine, and reaction is as follows:

H ₂ N(CH ₂ ) ₅ CN+2H ₂ ─→H ₂ N(CH ₂ ) ₆ NH ₂ ;

The caprolactam method is generally used in small-scale production units dealing with foreign products such as caprolactam.

Hexamethylenediamine can also be produced by the adiponitrile method, and almost all large-scale production methods of hexamethylenediamine start from the adiponitrile method. The preparation of hexamethylenediamine from adiponitrile usually adopts the method of catalytic hydrogenation, which is industrially divided into two types: high-pressure method and low-pressure method, and the reaction is as follows:

NC(CH ₂ ) ₄ CN+4H ₂ ─→H ₂ N(CH ₂ ) ₆ NH ₂ .

Among them, the high pressure method uses cobalt-copper catalyst, the reaction temperature is 100~135°C, and the pressure is 60~65 MPa; the high pressure method can also use iron catalyst, the reaction temperature is 100~180°C, and the pressure is 30~35 MPa. The solvent can be liquid ammonia, and sometimes aromatic hydrocarbons (such as toluene) are added, and the selectivity of hexamethylenediamine is about 90% to 95%. The low-pressure method uses a nickel-based catalyst, and the reaction is carried out in an ethanol solution. The reaction temperature is about 70-100°C, the pressure is about 1.8-2.7 MPa, and the selectivity of hexamethylenediamine can reach 99%. In order to prevent catalyst poisoning during the preparation process of the low-pressure method, The purity of the adiponitrile raw material is very high. The semi-finished hexamethylenediamine produced by the reaction is subjected to azeotropic distillation with water, and then undergoes several times of negative pressure distillation to obtain high-quality refined hexamethylenediamine.

Adiponitrile uses nickel, cobalt, etc. as catalysts, sodium hydroxide as a cocatalyst, and ethanol as a solvent for hydrogenation. It can react continuously at a certain temperature and pressure to produce hexamethylenediamine. However, in the production process of hexamethylenediamine, there are still Some side reactions occur, and the main by-products are azepane, aminocapronitrile, 1,2-diaminocyclohexane, N-ethylhexamethylenediamine, aminomethylcyclopentane, etc. Among them, azepane, 1,2-diaminocyclohexane, N-ethylhexamethylenediamine, etc. are difficult to separate from hexamethylenediamine, and there are excess ethanol, sodium hydroxide, and nickel-based catalysts in the mixture. Components, the existence of the above substances will affect the final product high-quality refined hexamethylenediamine and the product quality of downstream users, such as chroma, purity and other indicators.

Therefore, how to choose the specific technological process and equipment to improve the technological production process, optimize the technological production conditions, minimize the production cost, and produce high-quality refined hexamethylenediamine technology is very critical.

Contents of the invention

In order to produce high-quality refined hexamethylene diamine, the object of the present invention is to provide a kind of production method of high-quality refined hexamethylene diamine.

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

A production method of high-quality refined hexamethylenediamine, comprising the following steps:

Mix adiponitrile, ethanol, and sodium hydroxide evenly according to the mass ratio of 50~90:40~80:1, and then add a nickel-based catalyst to obtain a reaction mixture. Under the condition of hydrogenation reaction, obtain the semi-finished hexamethylenediamine;

The semi-finished hexamethylenediamine is sent to the first evaporator for distillation, and the bottom liquid of the first evaporator is sent to the second evaporator for distillation;

The bottom liquid of the second evaporator is centrifuged to obtain clear liquid and turbid liquid. The clear liquid is sent to the sixth evaporator for distillation, and the turbid liquid is sent to the seventh evaporator for distillation; the top distillation of the second evaporator The output is sent to the third evaporator for distillation;

The bottom liquid of the third evaporator and the top distillate of the sixth evaporator are all sent to the fourth evaporator for distillation;

The bottom liquid of the sixth evaporator is sent to the seventh evaporator for distillation, and the top distillate of the seventh evaporator is recovered and sent to the first evaporator;

Send the bottom liquid of the fourth evaporator to the fifth evaporator for distillation, and the top return port of the fourth evaporator is connected to the third evaporator, so that the top distillate of the fourth evaporator can be sent to the third evaporator middle;

The bottom liquid of the fifth evaporator is sent to the sixth evaporator, and the top return port of the fifth evaporator is connected to the fourth evaporator, so that the top distillate of the fifth evaporator is partially returned to the fourth evaporator , to maintain the pressure in the system, another part of the top distillate of the fifth evaporator is sent to the refined hexamethylene diamine tank from the product outlet, to obtain high-quality refined hexamethylene diamine;

Wherein, the mass percentage of the nickel-based catalyst in the reaction mixture is 0.5~5 wt%; the pressure inside the first distiller is 40~130 mmHg, the top temperature is 10~80°C, and the bottom temperature is 90~160°C; the second evaporation The pressure inside the evaporator is 40~130 mmHg, the top temperature is 90~150°C, and the bottom temperature is 90~150°C; the pressure inside the third evaporator is 5~60 mmHg, the top temperature is 60~130°C, and the bottom temperature is 90~150°C. 80~150°C; the pressure inside the fourth evaporator is 5~60 mmHg, the top temperature is 60~130°C, and the bottom temperature is 100~170°C; the pressure inside the fifth evaporator is 5~60 mmHg, and the top temperature is 60~130℃, temperature at the bottom of the device is 100~170℃; pressure inside the sixth evaporator is 5~60 mmHg, temperature at the top of the device is 60~130℃, temperature at the bottom of the device is 100~170℃; pressure inside the seventh evaporator is 5 ~60 mmHg, the temperature at the top of the device is 60~130°C, and the temperature at the bottom of the device is 100~170°C.

Preferably, the hydrogenation reaction is that the reaction mixture is placed in a three-phase boiling reactor, and hydrogen gas is introduced into the reaction. After the reaction product liquid in the three-phase boiling reactor is separated from ethanol and sodium hydroxide, the semi-finished hexadiene diacetate is obtained. amine.

Preferably, the gas from the gas phase outlet of the three-phase ebullating reactor is washed with water and then re-introduced into the three-phase ebullating reactor.

The pressure in the above-mentioned evaporator all refers to the absolute pressure, and the nickel-based catalyst adopts common commercially available products.

The invention includes the preparation of semi-finished hexamethylenediamine and the purification of high-quality refined hexamethylenediamine. In order to ensure the preparation efficiency of semi-finished hexamethylenediamine, organic solvent ethanol is used as diluent, which is beneficial to recovery and reuse, and a nickel-based catalyst is used as an auxiliary Catalyst, to ensure the conversion rate of hexamethylenediamine; in order to ensure the purity of high-quality refined hexamethylenediamine, vacuum distillation technology is used, and according to the different boiling points of impurities in semi-finished hexamethylenediamine, dehydration and light removal are carried out under vacuum conditions. Components, removal of heavy components, and finally a high-quality refined hexamethylenediamine product with a purity ≥ 99.9% (mass percentage), a polarographic value ≤ 100 mmolIB/T-HMD, and a total volatile base ≤ 4 mL/100g.

Description of drawings

Fig. 1 is a production process flow chart of the present invention.

Detailed ways

In order to make the technical purpose, technical solution and beneficial effect of the present invention clearer, the technical solution of the present invention will be further described below in conjunction with specific embodiments.

Example 1

A kind of production method of high-quality refined hexamethylenediamine, as shown in Figure 1, comprises the following steps:

Mix adiponitrile, ethanol, and sodium hydroxide uniformly according to the mass ratio of 50:40:1, and then add a nickel-based catalyst to obtain a reaction mixture. The reaction mixture is placed in a three-phase boiling reactor, and hydrogen is passed through. The reaction is carried out under the conditions of ℃ and pressure of 1.8 MPa. The gas from the gas phase outlet of the three-phase boiling reactor is washed with water and then re-introduced into the three-phase boiling reactor. The reaction product of the three-phase boiling reactor is separated from ethanol and sodium hydroxide. , to obtain semi-finished hexamethylenediamine;

The semi-finished hexamethylenediamine is sent to the first evaporator for distillation, the bottom liquid of the first evaporator is sent to the second evaporator for distillation, and the top return port of the first evaporator is connected to the waste pit, containing azepane The production wastewater is discharged from the top of the first evaporator into the waste pit;

The bottom liquid of the second evaporator contains high boiling matter and sodium hydroxide mixed slag, the bottom liquid of the second evaporator is centrifuged to obtain clear liquid and turbid liquid, and the clear liquid is sent to the sixth evaporator for distillation , the turbid liquid is sent to the seventh evaporator for distillation; the top distillate of the second evaporator is sent to the third evaporator for distillation;

The bottom liquid of the third evaporator and the top distillate of the sixth evaporator are all sent to the fourth evaporator for distillation, and the top return port of the third evaporator is connected to the transfer tank, and is distilled by the third evaporator. Distilled diaminocyclohexane, aminomethylaminocyclopentane and other low boilers are discharged into the transfer tank;

The bottom liquid of the sixth evaporator is sent to the seventh evaporator for distillation, the top distillate of the seventh evaporator is recovered and sent to the first evaporator, and the bottom liquid of the seventh evaporator is intermittently discharged into the transfer Can;

The bottom liquid of the fourth evaporator is sent to the fifth evaporator for distillation, and the top return port of the fourth evaporator is connected to the third evaporator;

The bottom liquid of the fifth evaporator is sent to the sixth evaporator, the top return port of the fifth evaporator is connected to the fourth evaporator, and the top distillate of the fifth evaporator is sent to the refined hexamethylenediamine tank, that is, Obtain high-quality refined hexamethylene diamine;

Wherein, the mass percentage of the nickel-based catalyst in the reaction mixture is 0.5 wt%; the pressure inside the first distiller is 40mmHg, the top temperature is 10°C, and the bottom temperature is 90°C; the pressure inside the second evaporator is 40 mmHg, and the top The temperature is 90°C, the bottom temperature is 90°C; the pressure inside the third evaporator is 5 mmHg, the top temperature is 60°C, and the bottom temperature is 80°C; the pressure inside the fourth evaporator is 5 mmHg, and the top temperature is 60°C , the bottom temperature is 100°C; the pressure inside the fifth evaporator is 5 mmHg, the top temperature is 60°C, and the bottom temperature is 100°C; the pressure inside the sixth evaporator is 5 mmHg, the top temperature is 60°C, and the bottom temperature is 60°C 100°C; the pressure inside the seventh evaporator is 5 mmHg, the top temperature is 60°C, and the bottom temperature is 100°C.

Example 2

A production method of high-quality refined hexamethylenediamine, comprising the following steps:

Mix adiponitrile, ethanol, and sodium hydroxide uniformly according to the mass ratio of 60:50:1, and then add a nickel-based catalyst to obtain a reaction mixture. The reaction mixture is placed in a three-phase boiling reactor, and hydrogen is passed through. The reaction is carried out under the conditions of ℃ and pressure of 2.0 MPa. The gas from the gas phase outlet of the three-phase boiling reactor is washed with water and then re-introduced into the three-phase boiling reactor. The reaction product of the three-phase boiling reactor is separated from ethanol and sodium hydroxide. , to obtain semi-finished hexamethylenediamine;

The semi-finished hexamethylenediamine is sent to the first evaporator for distillation, the bottom liquid of the first evaporator is sent to the second evaporator for distillation, and the top return port of the first evaporator is connected to the waste pit, containing azepane The production wastewater is discharged from the top of the first evaporator into the waste pit;

The bottom liquid of the second evaporator contains high boiling matter and sodium hydroxide mixed slag, the bottom liquid of the second evaporator is centrifuged to obtain clear liquid and turbid liquid, and the clear liquid is sent to the sixth evaporator for distillation , the turbid liquid is sent to the seventh evaporator for distillation; the top distillate of the second evaporator is sent to the third evaporator for distillation;

The bottom liquid of the third evaporator and the top distillate of the sixth evaporator are all sent to the fourth evaporator for distillation, and the top return port of the third evaporator is connected to the transfer tank, and is distilled by the third evaporator. Distilled diaminocyclohexane, aminomethylaminocyclopentane and other low boilers are discharged into the transfer tank;

The bottom liquid of the sixth evaporator is sent to the seventh evaporator for distillation, the top distillate of the seventh evaporator is recovered and sent to the first evaporator, and the bottom liquid of the seventh evaporator is intermittently discharged into the transfer Can;

The bottom liquid of the fourth evaporator is sent to the fifth evaporator for distillation, and the top return port of the fourth evaporator is connected to the third evaporator;

The bottom liquid of the fifth evaporator is sent to the sixth evaporator, the top return port of the fifth evaporator is connected to the fourth evaporator, and the top distillate of the fifth evaporator is sent to the refined hexamethylenediamine tank, that is, Obtain high-quality refined hexamethylene diamine;

Wherein, the mass percent of nickel-based catalyst in the reaction mixture is 1.0 wt%; the pressure in the first distiller is 60mmHg, the top temperature is 30°C, and the bottom temperature is 110°C; the pressure in the second evaporator is 60 mmHg, and the top The temperature is 110°C, the bottom temperature is 110°C; the pressure inside the third evaporator is 15 mmHg, the top temperature is 80°C, and the bottom temperature is 120°C; the pressure inside the fourth evaporator is 15 mmHg, and the top temperature is 80°C , the temperature at the bottom of the device is 120°C; the pressure inside the fifth evaporator is 15 mmHg, the temperature at the top of the device is 80°C, and the temperature at the bottom of the device is 120°C; the pressure inside the sixth evaporator is 15 mmHg, the temperature at the top of the device is 80°C, the temperature at the bottom of the device is 120°C; the pressure inside the seventh evaporator is 15 mmHg, the top temperature is 80°C, and the bottom temperature is 120°C.

Example 3

A production method of high-quality refined hexamethylenediamine, comprising the following steps:

Mix adiponitrile, ethanol, and sodium hydroxide uniformly according to the mass ratio of 70:60:1, and then add a nickel-based catalyst to obtain a reaction mixture. The reaction mixture is placed in a three-phase boiling reactor, and hydrogen is passed through. The reaction is carried out under the conditions of ℃ and pressure of 2.2 MPa. The gas from the gas phase outlet of the three-phase boiling reactor is washed with water and then re-introduced into the three-phase boiling reactor. The reaction product of the three-phase boiling reactor is separated from ethanol and sodium hydroxide. , to obtain semi-finished hexamethylenediamine;

The semi-finished hexamethylenediamine is sent to the first evaporator for distillation, the bottom liquid of the first evaporator is sent to the second evaporator for distillation, and the top return port of the first evaporator is connected to the waste pit, containing azepane The production wastewater is discharged from the top of the first evaporator into the waste pit;

The bottom liquid of the second evaporator contains high boiling matter and sodium hydroxide mixed slag, the bottom liquid of the second evaporator is centrifuged to obtain clear liquid and turbid liquid, and the clear liquid is sent to the sixth evaporator for distillation , the turbid liquid is sent to the seventh evaporator for distillation; the top distillate of the second evaporator is sent to the third evaporator for distillation;

The bottom liquid of the third evaporator and the top distillate of the sixth evaporator are all sent to the fourth evaporator for distillation, and the top return port of the third evaporator is connected to the transfer tank, and is distilled by the third evaporator. Distilled diaminocyclohexane, aminomethylaminocyclopentane and other low boilers are discharged into the transfer tank;

The bottom liquid of the sixth evaporator is sent to the seventh evaporator for distillation, the top distillate of the seventh evaporator is recovered and sent to the first evaporator, and the bottom liquid of the seventh evaporator is intermittently discharged into the transfer Can;

The bottom liquid of the fourth evaporator is sent to the fifth evaporator for distillation, and the top return port of the fourth evaporator is connected to the third evaporator;

The bottom liquid of the fifth evaporator is sent to the sixth evaporator, the top return port of the fifth evaporator is connected to the fourth evaporator, and the top distillate of the fifth evaporator is sent to the refined hexamethylenediamine tank, that is, Obtain high-quality refined hexamethylene diamine;

Wherein, the mass percentage of the nickel-based catalyst in the reaction mixture is 2.0 wt%; the pressure inside the first distiller is 80mmHg, the top temperature is 50°C, and the bottom temperature is 130°C; the pressure inside the second evaporator is 80 mmHg, and the top The temperature is 130°C, the bottom temperature is 130°C; the pressure inside the third evaporator is 30 mmHg, the top temperature is 100°C, and the bottom temperature is 140°C; the pressure inside the fourth evaporator is 30 mmHg, and the top temperature is 100°C , the bottom temperature is 140°C; the pressure inside the fifth evaporator is 30 mmHg, the top temperature is 100°C, and the bottom temperature is 140°C; the pressure inside the sixth evaporator is 30 mmHg, the top temperature is 100°C, and the bottom temperature is 140°C; the pressure inside the seventh evaporator is 30 mmHg, the top temperature is 100°C, and the bottom temperature is 140°C.

Example 4

A production method of high-quality refined hexamethylenediamine, comprising the following steps:

Mix adiponitrile, ethanol, and sodium hydroxide uniformly according to the mass ratio of 80:70:1, and then add a nickel-based catalyst to obtain a reaction mixture. The reaction mixture is placed in a three-phase boiling reactor, and hydrogen is passed through. The reaction is carried out under the conditions of ℃ and pressure of 2.5 MPa. The gas from the gas phase outlet of the three-phase boiling reactor is washed with water and then re-introduced into the three-phase boiling reactor. The reaction product of the three-phase boiling reactor is separated from ethanol and sodium hydroxide. , to obtain semi-finished hexamethylenediamine;

The semi-finished hexamethylenediamine is sent to the first evaporator for distillation, the bottom liquid of the first evaporator is sent to the second evaporator for distillation, and the top return port of the first evaporator is connected to the waste pit, containing azepane The production wastewater is discharged from the top of the first evaporator into the waste pit;

The bottom liquid of the second evaporator contains high boiling matter and sodium hydroxide mixed slag, the bottom liquid of the second evaporator is centrifuged to obtain clear liquid and turbid liquid, and the clear liquid is sent to the sixth evaporator for distillation , the turbid liquid is sent to the seventh evaporator for distillation; the top distillate of the second evaporator is sent to the third evaporator for distillation;

The bottom liquid of the third evaporator and the top distillate of the sixth evaporator are all sent to the fourth evaporator for distillation, and the top return port of the third evaporator is connected to the transfer tank, and is distilled by the third evaporator. Distilled diaminocyclohexane, aminomethylaminocyclopentane and other low boilers are discharged into the transfer tank;

The bottom liquid of the sixth evaporator is sent to the seventh evaporator for distillation, the top distillate of the seventh evaporator is recovered and sent to the first evaporator, and the bottom liquid of the seventh evaporator is intermittently discharged into the transfer Can;

The bottom liquid of the fourth evaporator is sent to the fifth evaporator for distillation, and the top return port of the fourth evaporator is connected to the third evaporator;

The bottom liquid of the fifth evaporator is sent to the sixth evaporator, the top return port of the fifth evaporator is connected to the fourth evaporator, and the top distillate of the fifth evaporator is sent to the refined hexamethylenediamine tank, that is, Obtain high-quality refined hexamethylene diamine;

Among them, the mass percentage of nickel-based catalyst in the reaction mixture is 3.0 wt%; the pressure in the first distiller is 100 mmHg, the top temperature is 70 °C, and the bottom temperature is 150 °C; the pressure in the second evaporator is 100 mmHg, and the The top temperature is 150°C and the bottom temperature is 150°C; the internal pressure of the third evaporator is 50 mmHg, the top temperature is 120°C, and the bottom temperature is 150°C; the internal pressure of the fourth evaporator is 50 mmHg, and the top temperature is 120 ℃, the temperature at the bottom of the device is 160°C; the pressure inside the fifth evaporator is 50mmHg, the temperature at the top of the device is 120°C, the temperature at the bottom of the device is 160°C; the pressure inside the sixth evaporator is 50 mmHg, the temperature at the top of the device is 120°C, the temperature 160°C; the pressure inside the seventh evaporator is 50 mmHg, the top temperature is 120°C, and the bottom temperature is 160°C.

Example 5

A production method of high-quality refined hexamethylenediamine, comprising the following steps:

Mix adiponitrile, ethanol, and sodium hydroxide uniformly according to the mass ratio of 90:80:1, and then add a nickel-based catalyst to obtain a reaction mixture. The reaction mixture is placed in a three-phase boiling reactor, and hydrogen is passed through. The reaction is carried out under the conditions of ℃ and pressure of 2.7 MPa. The gas from the gas phase outlet of the three-phase boiling reactor is washed with water and then re-introduced into the three-phase boiling reactor. The reaction product of the three-phase boiling reactor is separated from ethanol and sodium hydroxide. , to obtain semi-finished hexamethylenediamine;

The semi-finished hexamethylenediamine is sent to the first evaporator for distillation, the bottom liquid of the first evaporator is sent to the second evaporator for distillation, and the top return port of the first evaporator is connected to the waste pit, containing azepane The production wastewater is discharged from the top of the first evaporator into the waste pit;

The bottom liquid of the second evaporator contains high boiling matter and sodium hydroxide mixed slag, the bottom liquid of the second evaporator is centrifuged to obtain clear liquid and turbid liquid, and the clear liquid is sent to the sixth evaporator for distillation , the turbid liquid is sent to the seventh evaporator for distillation; the top distillate of the second evaporator is sent to the third evaporator for distillation;

The bottom liquid of the third evaporator and the top distillate of the sixth evaporator are all sent to the fourth evaporator for distillation, and the top return port of the third evaporator is connected to the transfer tank, and is distilled by the third evaporator. Distilled diaminocyclohexane, aminomethylaminocyclopentane and other low boilers are discharged into the transfer tank;

The bottom liquid of the sixth evaporator is sent to the seventh evaporator for distillation, the top distillate of the seventh evaporator is recovered and sent to the first evaporator, and the bottom liquid of the seventh evaporator is intermittently discharged into the transfer Can;

The bottom liquid of the fourth evaporator is sent to the fifth evaporator for distillation, and the top return port of the fourth evaporator is connected to the third evaporator;

The bottom liquid of the fifth evaporator is sent to the sixth evaporator, the top return port of the fifth evaporator is connected to the fourth evaporator, and the top distillate of the fifth evaporator is sent to the refined hexamethylenediamine tank, that is, Obtain high-quality refined hexamethylene diamine;

Among them, the mass percentage of nickel-based catalyst in the reaction mixture is 5.0 wt%; the pressure in the first distiller is 130 mmHg, the top temperature is 80 °C, and the bottom temperature is 160 °C; the pressure in the second evaporator is 130 mmHg, and the The top temperature is 150°C and the bottom temperature is 150°C; the internal pressure of the third evaporator is 60 mmHg, the top temperature is 130°C, and the bottom temperature is 150°C; the internal pressure of the fourth evaporator is 60 mmHg, and the top temperature is 130 ℃, the temperature at the bottom of the device is 170°C; the pressure inside the fifth evaporator is 60mmHg, the temperature at the top of the device is 130°C, and the temperature at the bottom of the device is 170°C; the pressure inside the sixth evaporator is 60 mmHg, the temperature at the top of the device is 130°C, 170°C; the pressure inside the seventh evaporator is 60 mmHg, the top temperature is 130°C, and the bottom temperature is 170°C.

The product quality index of the high-quality refined hexamethylenediamine that adopts embodiment 1～5 to obtain is as follows:

Polarographic value ≤100 mmolIB/T-HMD, total volatile base ≤4 mL/100g, purity ≥99.9% (mass percentage).

Claims (3)

1. a kind of production method of high-quality essence hexamethylene diamine, it is characterised in that comprise the following steps：

By adiponitrile, ethanol, sodium hydroxide according to mass ratio 50 ~ 90：40~80：1 is uniformly mixed, and adds nickel-base catalyst, obtains To reaction mixture, by reaction mixture under conditions of 70 ~ 100 DEG C, 1.8 ~ 2.7 MPa of pressure hydrogenation reaction, obtain half into Product hexamethylene diamine；

Semi-finished product hexamethylene diamine is sent into the first evaporator and is distilled, the device bottom liquid of the first evaporator, which is sent into the second evaporator, to be steamed Evaporate；

The device bottom liquid of second evaporator is centrifuged, and obtains clear liquid and turbid, and clear liquid is sent into the 6th evaporator and is distilled, turbid Liquid, which is sent into the 7th evaporator, to be distilled；The device top distillate of second evaporator, which is sent into the 3rd evaporator, to be distilled；

The device top distillate of the device bottom liquid of 3rd evaporator and the 6th evaporator is sent into the 4th evaporator and is distilled；

The device bottom liquid of 6th evaporator is sent into the 7th evaporator and is distilled, the device top distillate of the 7th evaporator is recycled and sent Enter the first evaporator；

The device bottom liquid of 4th evaporator is sent into the 5th evaporator and is distilled, the device top refluxing opening connection the 3rd of the 4th evaporator is steamed Send out device；

The device bottom liquid of 5th evaporator is sent into the 6th evaporator, the device top refluxing opening of the 5th evaporator connects the 4th evaporator, The device top distillate of 5th evaporator is sent into smart hexamethylene diamine tank, up to high-quality essence hexamethylene diamine；

Wherein, the mass percent of nickel-base catalyst is 0.5 ~ 5 wt% in reaction mixture；In first distiller pressure for 40 ~ 130 mmHg, device top temperature are 10 ~ 80 DEG C, 90 ~ 160 DEG C of device bottom temperature；Second evaporimeter internal pressure is 40 ~ 130 mmHg, device It is 90 ~ 150 DEG C to push up temperature, 90 ~ 150 DEG C of device bottom temperature；3rd evaporimeter internal pressure is 5 ~ 60 mmHg, device top temperature for 60 ~ 130 DEG C, 80 ~ 150 DEG C of device bottom temperature；4th evaporimeter internal pressure is 5 ~ 60 mmHg, and device top temperature is 60 ~ 130 DEG C, device bottom temperature 100 ~ 170 DEG C of degree；5th evaporimeter internal pressure is 5 ~ 60 mmHg, and device top temperature is 60 ~ 130 DEG C, 100 ~ 170 DEG C of device bottom temperature； 6th evaporimeter internal pressure is 5 ~ 60 mmHg, and device top temperature is 60 ~ 130 DEG C, 100 ~ 170 DEG C of device bottom temperature；In 7th evaporator Pressure is 5 ~ 60 mmHg, and device top temperature is 60 ~ 130 DEG C, 100 ~ 170 DEG C of device bottom temperature.

2. the production method of high-quality essence hexamethylene diamine according to claim 1, it is characterised in that：The hydrogenation reaction be by Reaction mixture is placed in three-phase boiling reactor, and is passed through hydrogen and is reacted, the reaction generation liquid of three-phase boiling reactor After isolating ethanol, sodium hydroxide, semi-finished product hexamethylene diamine is obtained.

3. the production method of high-quality essence hexamethylene diamine according to claim 2, it is characterised in that：The three-phase boiling reaction The gas that device gaseous phase outlet comes out is passed through three-phase boiling reactor again after washing.