Aniline and cyclohexylamine co-production device

Abstract

The invention discloses an aniline and cyclohexylamine co-production device which comprises an aniline tail gas treatment unit, a hydrogenation reaction unit and a product refining unit, the aniline tail gas treatment unit is used for removing liquid organic matters and catalyst particles in aniline tail gas and separating hydrogen and aniline, and the hydrogenation reaction unit is used for carrying out hydrogenation reaction on aniline and defective aniline in the aniline tail gas to obtain a cyclohexylamine and dicyclohexylamine mixture; and evaporating the mixture through a product refining unit to remove low-boiling-point substances such as cyclohexane, cyclohexanol, water and the like, so as to obtain the products cyclohexylamine and dicyclohexylamine. According to the method, aniline tail gas resources and defective aniline are fully utilized, the three-waste treatment cost is reduced, product benefits can be improved, pollution to the environment can be reduced, and economic benefits and social benefits are remarkable.

Description

Technical Field

[0001] The invention relates to the technical field of cyclohexylamine preparation, and in particular to a device for co-producing aniline and cyclohexylamine. Background Art

[0002] The industrial production of aniline began in 1857. The nitrobenzene iron powder reduction method was initially used. However, due to the shortcomings of large equipment, severe corrosion, large iron powder consumption, and serious pollution of "three wastes", it was gradually replaced by the advanced nitrobenzene catalytic hydrogenation method after the 1950s. In 1962, the phenol amination method was successfully developed and industrialized production was achieved in 1970. At present, the production of aniline in the world is mainly based on the nitrobenzene catalytic hydrogenation method, and its production capacity accounts for about 85% of the total aniline production capacity. The tail gas of the nitrobenzene catalytic hydrogenation production unit contains a large amount of hydrogen and a small amount of aniline vapor and other organic matter. Commonly used methods for treating organic waste gas include activated carbon adsorption, condensation, combustion, etc. The activated carbon adsorption method has high operating costs; the condensation method is suitable for high-concentration organic waste gas, and the treatment efficiency of low-concentration organic waste gas is low; the combustion method treats nitrogen-containing organic waste gas, produces nitrogen oxides, and causes secondary pollution. In addition, the aniline with excessive light components in the aniline production unit and the aniline in the top discharge of the light component removal tower have low aniline content and contain cyclohexanol, cyclohexane, phenol, cyclohexylamine and other components, which need to be further separated and purified or sold at a low price, with low economic benefits.

[0003] Cyclohexylamine and dicyclohexylamine are important organic chemical raw materials and intermediates for fine chemical products. They are widely used in rubber additives, food additives, anti-corrosion, papermaking, plastic processing and textile industries. At present, the industrial preparation methods of cyclohexylamine are catalytic hydrogenation of aniline and catalytic ammonolysis of cyclohexanol. Since the catalytic hydrogenation of aniline has low raw material cost and simple process route, it can realize the co-production of cyclohexylamine and dicyclohexylamine, and the output ratio of the two products can be freely switched by adjusting the catalyst formula and synthesis process conditions. It has attracted extensive attention from domestic and foreign research institutions and manufacturers.

[0004] Cyclohexylamine is a downstream product of aniline. Manufacturers usually produce aniline and cyclohexylamine as two independent product units. If the aniline and cyclohexylamine units can be co-produced, the aniline tail gas resources and defective aniline can be fully utilized to turn waste into treasure, which can not only improve product efficiency but also reduce environmental pollution, with significant economic and social benefits. Summary of the invention

[0005] In order to achieve the above object, the present invention provides a device for co-producing aniline and cyclohexylamine.

[0006] The technical solution adopted by the present invention is:

[0007] An aniline and cyclohexylamine co-production device, comprising an aniline tail gas treatment unit, a hydrogenation reaction unit and a product refining unit;

[0008] The aniline tail gas treatment unit includes a cyclone separator, a wire mesh filter, a modified special fiber filter, a ceramic membrane filter and a gas-liquid separator; the hydrogenation reaction unit includes a hydrogen buffer tank, an aniline raw material tank, a hydrogen metering pump, an aniline metering pump, a hydrogen preheater, an aniline vaporization chamber, a fixed bed reactor, a condenser, a gas-liquid separator B, a circulating hydrogen delivery pump, a crude product tank and a crude product tank delivery pump; the product refining unit includes a primary distillation tower preheater, a primary distillation tower, a heat exchanger A, a primary distillation tower kettle delivery pump, a distillation tower, a condenser B, a heat exchanger B, a cyclohexylamine receiving tank, a dicyclohexylamine receiving tank, a tar delivery pump and a tar tank;

[0009] The tail gas from aniline production flows through a cyclone separator, a metal mesh filter, a modified special fiber filter, and a ceramic membrane filter in sequence before entering a gas-liquid separator; the aniline tail hydrogen separated from the top of the gas-liquid separator enters a hydrogen buffer tank, and the aniline condensate separated from the bottom of the gas-liquid separator enters an aniline raw material tank; the aniline tail hydrogen entering the hydrogen buffer tank and the fresh hydrogen enter the fixed bed reactor in sequence through a hydrogen metering pump and a hydrogen preheater; the aniline condensate entering the aniline raw material tank and the defective aniline and the fresh aniline enter the fixed bed reactor in sequence through an aniline metering pump and an aniline vaporization chamber; the fixed The hydrogenation product of the bed reactor enters the gas-liquid separator B through the condenser; the gas phase separated from the top of the gas-liquid separator B is returned to the inlet of the hydrogen preheater through the circulating hydrogen delivery pump; the liquid phase separated from the bottom of the gas-liquid separator B enters the crude product tank, and the liquid phase in the crude product tank enters the primary distillation tower through the crude product tank delivery pump and the primary distillation tower preheater in turn; the material at the bottom of the primary distillation tower enters the distillation tower through the heat exchanger A and the primary distillation tower kettle delivery pump in turn; the material at the top of the distillation tower enters the cyclohexylamine receiving tank and the dicyclohexylamine receiving tank respectively through the condenser B, and the material at the bottom of the distillation tower enters the tar tank in turn through the heat exchanger B and the tar delivery pump.

[0010] Furthermore, the filtering accuracy of the metal wire mesh filter is 50 to 200 μm, the filtering accuracy of the modified special fiber filter is 0.1 to 50 μm, and the filtering accuracy of the ceramic membrane filter is 10 to 100 nm.

[0011] Furthermore, flow meters are provided on the hydrogen pipeline and the aniline pipeline entering the fixed bed reactor.

[0012] Furthermore, the fixed bed reactor is filled with a novel cobalt-based catalyst, which uses modified silica gel as a carrier, loads an active component Co and an auxiliary agent, and the auxiliary agent is composed of two metal elements A and B, the metal element A is La, and the metal element B is at least one of Zn, Cu, Mg and Ni. The loading amount of Co is 1 to 40wt%, the loading amount of the auxiliary agent is 0.6 to 5wt%, and the mass percentage of La in the auxiliary agent is 4 to 50%.

[0013] Furthermore, the preparation method of the novel cobalt-based catalyst carrier is as follows: tetrapropylammonium hydroxide and ammonium dihydrogen phosphate are prepared into a 1.5-5% solution at a ratio of 1: (2-4); silica gel is added to the above solution, and heat-treated at 120-160° C. and 0.11-0.14 MPa for 4-8 hours; the mass ratio of silica gel to solution is (0.5-1):1; the heat-treated solution is vacuum-dried to obtain a carrier.

[0014] Furthermore, the molar ratio of defective aniline to fresh aniline is 1:(20-5), the hydrogen-to-oil ratio is (5-22):1, the hydrogenation reaction temperature is 120-200°C, the pressure is 0-0.6 MPa, and the feed space velocity is 0.05-1h -1 Defective aniline refers to aniline with excessive light components in the aniline production unit and the top discharge from the light component removal tower.

[0015] Furthermore, the number of theoretical plates of the primary distillation tower is 8 to 15, and the reflux ratio of the primary distillation is (1 to 6): 1 (the primary distillation tower is atmospheric distillation and has no filler).

[0016] Furthermore, the top material of the primary distillation tower enters the wastewater tank through condenser A.

[0017] Furthermore, the number of theoretical plates of the distillation tower is 10 to 25, and the reflux ratio of the distillation is (2 to 12):1.

[0018] Beneficial effects of the present invention:

[0019] 1) Optimize and integrate the aniline and cyclohexylamine units to achieve the combined production of aniline and cyclohexylamine with a small footprint.

[0020] 2) Making full use of aniline tail gas resources and unqualified aniline products and reducing the cost of three wastes treatment can not only improve product benefits but also reduce environmental pollution, with significant economic and social benefits.

[0021] 3) The device is easy to operate, the process conditions are mild, and the industrial application effect is good.

[0022] 4) In the catalytic hydrogenation reaction of aniline, modified silica gel is used as a carrier, the active component Co is loaded, and elements such as Zn, Cu, Mg, Ni and La are added as catalytic aids. The carrier surface has abundant alkaline sites, which can improve the selectivity and life of the catalyst. The aniline conversion rate reaches 100% and the product selectivity is greater than 98%. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a schematic structural diagram of an aniline and cyclohexylamine co-production device.

[0024] Description of reference numerals:

[0025] 101-Aniline production tail gas; 102-Fresh hydrogen; 103-Fresh aniline; 104-Aniline with excessive light components in the aniline production unit; 105-Dehydrogenation tower top discharge; 106-Catalyst particles and aniline tar; 1-Cyclone separator; 2-Wire mesh filter; 3-Modified special fiber filter; 4-Ceramic membrane filter; 5-Gas-liquid separator A; 6-Hydrogen buffer tank; 7-Aniline raw material tank; 8-Hydrogen metering pump; 9-Aniline metering pump; 10-Hydrogen preheater; 11-Aniline Vaporization chamber; 12-fixed bed reactor; 13-condenser; 14-gas-liquid separator B; 15-circulating hydrogen delivery pump; 16-crude product tank; 17-crude product tank delivery pump; 18-primary distillation tower preheater; 19-primary distillation tower; 20-condenser A; 21-heat exchanger A; 22-waste water tank; 23-primary distillation tower kettle delivery pump; 24-rectifying tower; 25-condenser B; 26-heat exchanger B; 27-cyclohexylamine receiving tank; 28-dicyclohexylamine receiving tank; 29-tar delivery pump; 30-tar tank. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and embodiments.

[0027] Example 1

[0028] See also Figure 1 , this embodiment provides an aniline and cyclohexylamine co-production device, including an aniline tail gas treatment unit, a hydrogenation reaction unit and a product refining unit;

[0029] The aniline tail gas treatment unit comprises a cyclone separator 1, a metal mesh filter 2, a modified special fiber filter 3, a ceramic membrane filter 4 and a gas-liquid separator 5A; the tail gas pipeline generated by the fluidized bed of nitrobenzene gas-phase hydrogenation to produce aniline is connected to the inlet of the cyclone separator 1, the outlet of the cyclone separator 1 is connected to the inlet of the metal mesh filter 2 through a pipeline, the outlet of the metal mesh filter 2 is connected to the inlet of the modified special fiber filter 3 through a pipeline, the outlet of the modified special fiber filter 3 is connected to the inlet of the ceramic membrane filter 4 through a pipeline, and the outlet of the ceramic membrane filter 4 is connected to the inlet of the gas-liquid separator 5A through a pipeline.

[0030] The hydrogenation reaction unit comprises a hydrogen buffer tank 6, an aniline raw material tank 7, a hydrogen metering pump 8, an aniline metering pump 9, a hydrogen preheater 10, an aniline vaporization chamber 11, a fixed bed reactor 12, a condenser 13, a gas-liquid separator B14, a circulating hydrogen delivery pump 15, a crude product tank 16 and a crude product tank delivery pump 17; the top outlet of the gas-liquid separator 5A is connected to the hydrogen buffer tank 6 through a hydrogen buffer tank inlet pipeline, and a fresh hydrogen feed pipe for introducing fresh hydrogen 102 is arranged on the hydrogen buffer tank inlet pipeline; the bottom outlet of the gas-liquid separator 5A is connected to the aniline raw material tank 7 through an aniline raw material tank inlet pipeline, and a fresh aniline feed pipe for introducing fresh aniline 103, a light component excess aniline feed pipe for introducing aniline 104 with light components exceeding the standard in the aniline production device, and a dehydrogenation tower discharge feed pipe for introducing a dehydrogenation tower top discharge 105. The discharge port of the hydrogen buffer tank 6 is connected to the inlet of the hydrogen metering pump 8 through a pipeline, the outlet of the hydrogen metering pump 8 is connected to the inlet of the hydrogen preheater 10 through a pipeline, the outlet of the hydrogen preheater 10 is connected to the inlet pipeline of the fixed bed reactor 12 through a hydrogen pipeline, and a hydrogen flowmeter is provided on the hydrogen pipeline. The discharge port of the aniline raw material tank 7 is connected to the inlet of the aniline metering pump 9 through a pipeline, the outlet of the aniline metering pump 9 is connected to the inlet of the aniline vaporization chamber 11 through a pipeline, the outlet of the aniline vaporization chamber 11 is connected to the inlet pipeline of the fixed bed reactor 12 through an aniline pipeline, and an aniline flowmeter is provided on the aniline pipeline. The bottom discharge port of the fixed bed reactor 12 is connected to the inlet of the condenser 13 through a pipeline, the outlet of the condenser 13 is connected to the inlet of the gas-liquid separator B14 through a pipeline, the top outlet of the gas-liquid separator B14 is connected to the inlet of the circulating hydrogen delivery pump 15 through a pipeline, and the outlet of the circulating hydrogen delivery pump 15 is connected to the inlet pipeline of the hydrogen preheater 10 through a pipeline; the bottom outlet of the gas-liquid separator B14 is connected to the inlet of the crude product tank 16 through a pipeline, and the outlet of the crude product tank 16 is connected to the inlet of the crude product tank delivery pump 17 through a pipeline.

[0031] The product refining unit includes a primary distillation tower preheater 18, a primary distillation tower 19, a condenser A20, a heat exchanger A21, a wastewater tank 22, a primary distillation tower kettle delivery pump 23, a distillation tower 24, a condenser B25, a heat exchanger B26, a cyclohexylamine receiving tank 27, a dicyclohexylamine receiving tank 28, a tar delivery pump 29 and a tar tank 30. The outlet of the crude product tank delivery pump 17 is connected to the inlet of the primary distillation tower preheater 18 through a pipeline, the outlet of the primary distillation tower preheater 18 is connected to the feed port of the primary distillation tower 19 through a pipeline, the side outlet of the primary distillation tower 19 is connected to the condenser A20 and the wastewater tank 22 through pipelines, the outlet of the condenser A20 is connected to the top inlet of the primary distillation tower 19 through a pipeline; the bottom outlet of the primary distillation tower 19 is connected to the heat exchanger A21 and the primary distillation tower kettle delivery pump 23 through pipelines, the outlet of the heat exchanger A21 is connected to the lower inlet of the primary distillation tower 19 through a pipeline, and the primary distillation tower 19 is connected to the bottom outlet of the primary distillation tower 19 through a pipeline. The outlet of the bottom delivery pump 23 is connected to the feed port of the distillation tower 24 through a pipeline, the upper outlet of the distillation tower 24 is connected to the condenser B25, the cyclohexylamine receiving tank 27 and the dicyclohexylamine receiving tank 28 through pipelines, the outlet of the condenser B25 is connected to the top inlet of the distillation tower 24 through a pipeline, the lower outlet of the distillation tower 24 is connected to the heat exchanger B26 and the tar delivery pump 29 through pipelines, the outlet of the heat exchanger B26 is connected to the lower inlet of the distillation tower 24 through a pipeline, and the outlet of the tar delivery pump 29 is connected to the tar tank 30 through a pipeline.

[0032] The method of using this device is:

[0033] 1. The tail gas produced by the fluidized bed of nitrobenzene gas-phase hydrogenation to aniline enters the cyclone separator 1 to remove part of the catalyst particles and aniline tar; then it passes through the metal mesh filter 2 and the modified special fiber filter 3 in sequence to further remove the tiny particles and water mist, and then passes through the ceramic membrane filter 4 to remove the liquid organic matter and trace catalyst particles in the tail gas, and then enters the gas-liquid separator 5A. The aniline tail hydrogen separated at the top of the gas-liquid separator 5A is mixed with the fresh hydrogen and enters the hydrogen buffer tank 6; the tail gas condensate separated at the bottom of the gas-liquid separator 5A is mixed with the defective aniline produced by the aniline device and the fresh aniline in a certain proportion and enters the aniline raw material tank 7;

[0034] 2. Hydrogen is introduced into a hydrogen preheater 10 through a hydrogen metering pump 8, and aniline is pumped into an aniline vaporization chamber 11 through an aniline metering pump 9. Both feeds are equipped with flow meters to control a certain hydrogen-to-oil ratio. The raw materials are preheated and mixed before entering a fixed bed reactor 12, where they are contacted with a catalyst and subjected to a hydrogenation reaction at a certain reaction temperature and pressure. The hydrogenation product enters a gas-liquid separator 14 after passing through a condenser 13. The gas phase returns to the reaction system through a circulating hydrogen delivery pump 15, and the liquid phase is mainly a mixture of cyclohexylamine and dicyclohexylamine, which enters a crude product tank 16;

[0035] 3. The crude product at the crude product tank outlet is fed into the primary distillation tower preheater A18 through a delivery pump. The material at the primary distillation tower outlet is heated to a suitable temperature through a heat exchanger 21 and then fed into the distillation tower 24 through a primary distillation tower bottom delivery pump 23. The side line discharge from the top of the distillation tower 24 is cooled by a condenser B25 and then collected in a cyclohexylamine receiving tank 27 and a dicyclohexylamine product receiving tank 28 according to the top gas phase temperature. The material in the distillation tower bottom is cooled by a heat exchanger 26 and then enters a tar tank 30 through a tar delivery pump 29.

[0036] Example 2

[0037] This embodiment provides a method for producing cyclohexylamine and dicyclohexylamine using the aniline and cyclohexylamine co-production device described in Example 1, comprising:

[0038] (1) Preparation of catalyst carrier: Tetrapropylammonium hydroxide and ammonium dihydrogen phosphate were prepared into a 1.5% solution at a mass ratio of 1:2; silica gel was added to the above solution at a mass ratio of 0.5:1, and heat-treated at 120°C and 0.11 MPa for 8 h. The heat-treated solution was vacuum-dried at 80°C for 4 h to obtain modified silica gel.

[0039] (2) Using the modified silica gel as a carrier, loading the active component Co1wt% and the additives Zn4.5wt% and La0.2wt%, a new cobalt-based catalyst was prepared. The catalyst preparation method is a prior art and will not be described in detail here.

[0040] (3) loading the novel cobalt-based catalyst into a fixed bed reactor 12;

[0041] (4) Cyclohexylamine and dicyclohexylamine were produced according to the method described in Example 1, and the production process parameters were:

[0042] The aniline content in the defective aniline is 95.5%, and the molar ratio of the defective aniline to the fresh aniline is 1:15; the process of the fixed bed hydrogenation reaction: the reaction temperature is 120°C, the pressure is 0.1MPa, and the aniline feed space velocity is 0.05h -1 , hydrogen to oil ratio 5:1.

[0043] Primary distillation process: atmospheric distillation at 80°C; distillation process: vacuum degree is 16 mmHg, the theoretical number of plates of the distillation column is 10, and the reflux ratio is 2:1.

[0044] Collect cyclohexylamine and dicyclohexylamine fractions respectively and carry out gas chromatography analysis (GC), cyclohexylamine purity is 99.8%, and dicyclohexylamine purity is 99.6%; Calculation shows that the total selectivity of cyclohexylamine and dicyclohexylamine is 98.7%, and the total yield of cyclohexylamine and dicyclohexylamine is about 96% (in terms of aniline).

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications are also within the protection scope of the present invention.

Claims

1. A device for co-producing aniline and cyclohexylamine, characterized in that: It includes aniline tail gas treatment unit, hydrogenation reaction unit and product refining unit; The aniline tail gas treatment unit comprises a cyclone separator (1), a metal wire mesh filter (2), a modified special fiber filter (3), a ceramic membrane filter (4) and a gas-liquid separator (5); The hydrogenation reaction unit comprises a hydrogen buffer tank (6), an aniline raw material tank (7), a hydrogen metering pump (8), an aniline metering pump (9), a hydrogen preheater (10), an aniline vaporization chamber (11), a fixed bed reactor (12), a condenser (13), a gas-liquid separator B (14), a circulating hydrogen delivery pump (15), a crude product tank (16) and a crude product tank delivery pump (17); The product refining unit comprises a primary distillation tower preheater (18), a primary distillation tower (19), a heat exchanger A (21), a primary distillation tower kettle delivery pump (23), a distillation tower (24), a condenser B (25), a heat exchanger B (26), a cyclohexylamine receiving tank (27), a dicyclohexylamine receiving tank (28), a tar delivery pump (29) and a tar tank (30); Aniline production tail gas flows through a cyclone separator (1), a metal mesh filter (2), a modified special fiber filter (3), and a ceramic membrane filter (4) in sequence before entering a gas-liquid separator (5); aniline tail hydrogen separated at the top of the gas-liquid separator (5) enters a hydrogen buffer tank (6), and aniline condensate separated at the bottom of the gas-liquid separator (5) enters an aniline raw material tank (7); The aniline tail hydrogen and fresh hydrogen entering the hydrogen buffer tank (6) are sequentially passed through a hydrogen metering pump (8) and a hydrogen preheater (10) into a fixed bed reactor (12) via a hydrogen pipeline; Aniline condensate, defective aniline and fresh aniline entering the aniline raw material tank (7) are sequentially passed through the aniline metering pump (9) and the aniline vaporization chamber (11) into the fixed bed reactor (12) via the aniline pipeline; The hydrogenation product of the fixed bed reactor (12) enters the gas-liquid separator B (14) through the condenser (13); the gas phase separated from the top of the gas-liquid separator B (14) is returned to the inlet of the hydrogen preheater (10) through the circulating hydrogen delivery pump (15); the liquid phase separated from the bottom of the gas-liquid separator B (14) enters the crude product tank (16), and the liquid phase in the crude product tank (16) enters the primary distillation tower (19) in sequence through the crude product tank delivery pump (17) and the primary distillation tower preheater (18); The bottom material of the primary distillation tower (19) enters the distillation tower (24) through the heat exchanger A (21) and the primary distillation tower kettle delivery pump (23) in sequence; the top material of the distillation tower (24) enters the cyclohexylamine receiving tank (27) and the dicyclohexylamine receiving tank (28) respectively through the condenser B (25); the bottom material of the distillation tower (24) enters the tar tank (30) in sequence through the heat exchanger B (26) and the tar delivery pump (29).

2. The aniline and cyclohexylamine co-production device according to claim 1, characterized in that: The filtering accuracy of the metal wire mesh filter (2) is 50 to 200 μm, the filtering accuracy of the modified special fiber filter (3) is 0.1 to 50 μm, and the filtering accuracy of the ceramic membrane filter (4) is 10 to 100 nm.

3. The device for co-producing aniline and cyclohexylamine according to claim 1, characterized in that: Flow meters are provided on the hydrogen pipeline and the aniline pipeline entering the fixed bed reactor (12).

4. The device for co-producing aniline and cyclohexylamine according to claim 1, characterized in that: The fixed bed reactor (12) is filled with a novel cobalt-based catalyst, which uses modified silica gel as a carrier, and loads an active component Co and an auxiliary agent, wherein the auxiliary agent is composed of two metal elements A and B, wherein the metal element A is La, and the metal element B is at least one of Zn, Cu, Mg and Ni, the loading amount of Co is 1 to 40 wt%, the loading amount of the auxiliary agent is 0.6 to 5 wt%, and the mass percentage of La in the auxiliary agent is 4 to 50%.

5. The device for co-producing aniline and cyclohexylamine according to claim 4, characterized in that: The preparation method of the novel cobalt-based catalyst carrier is as follows: tetrapropylammonium hydroxide and ammonium dihydrogen phosphate are prepared into a 1.5-5% solution at a ratio of 1: (2-4); silica gel is added to the above solution, and heat-treated at 120-160° C. and 0.11-0.14 MPa for 4-8 hours; the mass ratio of silica gel to solution is (0.5-1):1; the heat-treated solution is vacuum-dried to obtain the carrier.

6. The device for co-producing aniline and cyclohexylamine according to claim 3, characterized in that: The molar ratio of defective aniline to fresh aniline is 1:(20-5), the hydrogen-to-oil ratio is (5-22):1, the hydrogenation reaction temperature is 120-200°C, the pressure is 0-0.6MPa, and the feed space velocity is 0.05-1h -1 Defective aniline refers to aniline with excessive light components in the aniline production unit and the top discharge from the light component removal tower.

7. The device for co-producing aniline and cyclohexylamine according to claim 1, characterized in that: The theoretical number of plates of the primary distillation tower is 8 to 15, and the reflux ratio of the primary distillation is (1 to 6):

1.

8. The device for co-producing aniline and cyclohexylamine according to claim 1, characterized in that: The top material of the primary distillation tower (19) enters the waste water tank (22) through the condenser A (20).

9. The device for co-producing aniline and cyclohexylamine according to claim 1, characterized in that: The theoretical number of plates of the distillation tower is 10 to 25, and the reflux ratio of the distillation is (2 to 12):1.

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