Continuous production device for 1, 2-cyclohexanediamine
By optimizing reaction conditions and recycling resources through continuous production units, the problems of high cost and numerous by-products in the production of 1,2-cyclohexanediamine have been solved, achieving efficient and low-cost production of 1,2-cyclohexanediamine.
Patent Information
- Application Number
- CN202423183591.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-23
- Publication Date
- 2025-12-30
- Estimated Expiration
- 2034-12-23
AI Technical Summary
The existing 1,2-cyclohexanediamine production process suffers from high costs, numerous byproducts, and difficulties in catalyst recovery, resulting in persistently high production costs.
The continuous production unit includes a first reactor, a second reactor, a hydrogen separation tower, a liquid ammonia separation tower, a solvent distillation tower, a hydrogen compressor, and a liquid ammonia compressor. Through multi-stage reaction and separation processes, the reaction conditions are optimized, by-products are reduced, the selectivity of the target product is improved, and hydrogen and liquid ammonia are recycled.
It improves the conversion rate and selectivity of 1,2-cyclohexanediamine, reduces production costs, reduces exhaust emissions and environmental pollution, and achieves economical and efficient production.
Smart Images
Figure CN223732718U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of chemical equipment technology, specifically to a continuous production device for 1,2-cyclohexanediamine. Background Technology
[0002] 1,2-Cyclohexanediamine belongs to the alicyclic diamine group. At room temperature, it is a clear, colorless to pale yellow transparent liquid with a slightly ammonia-like odor. It is a specialty amine product. As an important organic chemical, 1,2-cyclohexanediamine has a wide range of applications. It can be used as an intermediate raw material for dyes and feed additives such as biotin, and is applied in dyes, auxiliaries, pharmaceuticals, pesticides, and feed additives. It is also a novel amine curing agent with advantages such as low dosage and low cost. It is a curing agent for preparing high-grade epoxy resins, specifically used in epoxy waterproof adhesives for bridge deck paving, epoxy adhesives for high-speed rail concrete repair, anti-corrosion coatings for oil and gas pipeline repair, raw materials for emulsified asphalt emulsifiers, and high-strength epoxy mortar for building foundations. In the coatings industry, it is used as a curing agent for alkaline epoxy resins. Simultaneously, 1,2-cyclohexanediamine has a C2 symmetry axis and is a chiral compound with great research potential. It can be used to synthesize various chiral ligands or chiral catalysts, and has wide applications in asymmetric catalysis and molecular recognition. It is also an important raw material for the third-generation platinum-based anticancer drug oxaplatin.
[0003] There are two main processes for preparing 1,2-cyclohexanediamine: the cyclohexane oxide amination method (hereinafter referred to as the cyclohexane oxide amination method) and the adiponitrile high-pressure hydrogenation to hexanediamine by-product method. The existing process for synthesizing 1,2-cyclohexanediamine using cyclohexane oxide and liquid ammonia as raw materials involves reacting in a high-pressure reactor at a reaction temperature of 180–210°C and a certain hydrogen pressure in the presence of catalysts such as skeletal nickel and copper to obtain 1,2-cyclohexanediamine. However, this batch reactor process suffers from high production costs due to the high expansion coefficient of liquid ammonia, high reaction pressure, and difficulty in catalyst recovery. Furthermore, the reaction generates a large amount of by-products. Utility Model Content
[0004] To address the aforementioned problems, this invention provides a continuous production apparatus for 1,2-cyclohexanediamine.
[0005] The technical solution adopted in this utility model is:
[0006] A continuous production apparatus for 1,2-cyclohexanediamine includes a first reactor, a second reactor, a hydrogen separation tower, a liquid ammonia separation tower, a solvent distillation tower, a hydrogen compressor, a liquid ammonia compressor, and a crude 1,2-cyclohexanediamine collection tank.
[0007] The first reactor, the second reactor, the hydrogen separation tower, the liquid ammonia separation tower, the solvent distillation tower, and the crude 1,2-cyclohexanediamine collection tank are connected in sequence.
[0008] The first reactor is used for the ring-opening reaction of cyclohexane oxide to produce 2-aminocyclohexanol; the second reactor is used for the amination reaction of 2-aminocyclohexanol to produce crude 1,2-cyclohexanediamine; a hydrogen separation tower is used to separate hydrogen from the reaction products, and a hydrogen compressor is used to compress the hydrogen separated by the hydrogen separation tower and send it to the inlet of the second reactor for recycling; a liquid ammonia separation tower is used to separate excess liquid ammonia from the reaction products, and a liquid ammonia compressor is used to liquefy the ammonia separated by the liquid ammonia separation tower and send it to the inlet of the first reactor for recycling; a solvent distillation tower is used to remove solvent from the reaction products under certain vacuum and temperature; the removed solvent is condensed and then sent to the inlets of the first and second reactors for recycling via solvent pumps. A crude 1,2-cyclohexanediamine collection tank is used to collect the crude 1,2-cyclohexanediamine from the bottom of the solvent distillation tower.
[0009] Furthermore, the first reactor is a fixed-bed reactor with a height-to-diameter ratio of 1.5 to 20. A jacket is installed outside the reactor to allow the introduction of a heat transfer medium and maintain a constant reactor temperature.
[0010] Furthermore, the second reactor is a fixed-bed reactor with a height-to-diameter ratio of 1.5 to 20. The reactor is equipped with a jacket for introducing a heat medium to maintain a constant reactor temperature. The reactor is equipped with one or more catalyst beds inside.
[0011] Furthermore, a first heat exchanger is installed on the pipe connecting the first reactor and the second reactor.
[0012] Furthermore, a second heat exchanger is installed on the pipeline connecting the second reactor and the hydrogen separation tower.
[0013] Furthermore, a third heat exchanger is installed on the pipeline connecting the hydrogen separation tower and the hydrogen compressor.
[0014] Furthermore, a fourth heat exchanger is installed on the pipeline connecting the liquid ammonia separation tower and the liquid ammonia compressor.
[0015] Furthermore, it also includes an epoxy cyclohexane storage tank, a liquid ammonia storage tank, and a solvent storage tank. The epoxy cyclohexane storage tank is connected to the epoxy hexane inlet of the first reactor via a first metering pump. The liquid ammonia storage tank is connected to the liquid ammonia inlet of the first reactor via a second metering pump. The solvent storage tanks are connected to the solvent inlets of the first reactor and the second reactor via a third metering pump and a fourth metering pump, respectively.
[0016] Furthermore, the first reactor is equipped with a liquid ammonia flow meter at the circulating liquid ammonia inlet and a nitrogen flow meter at the nitrogen inlet.
[0017] Furthermore, the second reactor is equipped with a first hydrogen flow meter at the circulating hydrogen inlet and a second hydrogen flow meter at the hydrogen inlet.
[0018] The beneficial effects of this utility model are:
[0019] 1. This invention couples a first reactor for the ring-opening reaction of cyclohexane oxide to form 2-aminocyclohexanol and a second reactor for the amination reaction of 2-aminocyclohexanol to form 1,2-cyclohexanediamine, effectively avoiding the phenomenon of by-products easily formed during the direct amination of cyclohexane oxide.
[0020] 2. By setting solvent injection ports before the first and second reactors, the concentration of the reaction solution can be controlled according to the amount of solvent injected under different catalyst activity states, ensuring that the reaction conversion rate and selectivity are maintained at different stages of catalyst lifetime. Furthermore, solvent injection reduces the probability of reactant collisions, minimizes side reactions, and improves the selectivity of the target product, 1,2-cyclohexanediamine. Using this device, 1,2-cyclohexanediamine can be continuously prepared from cyclohexane oxide, exhibiting high conversion rates of cyclohexane oxide and 2-aminocyclohexanol, and high selectivity for 1,2-cyclohexanediamine.
[0021] 3. By sequentially installing a hydrogen separator, a liquid ammonia separator, and a solvent distillation column in the downstream section of the ammoniation reactor, hydrogen, liquid ammonia, and solvent are separated and collected from the reaction products, and recycled for reuse, thereby reducing production costs, exhaust emissions and treatment costs, and avoiding environmental pollution. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the continuous production apparatus for 1,2-cyclohexanediamine according to this application. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solution of this utility model will be clearly and completely described below in conjunction with the accompanying drawings and a preferred embodiment.
[0024] See Figure 1 This embodiment provides a continuous production apparatus for 1,2-cyclohexanediamine, including a first reactor 1, a second reactor 2, a hydrogen separation tower 3, a liquid ammonia separation tower 4, a solvent distillation tower 5, a hydrogen compressor 6, a liquid ammonia compressor 7, an epoxy cyclohexane storage tank 8, a liquid ammonia storage tank 9, a solvent storage tank 10, a first metering pump 11, a second metering pump 12, a third metering pump 13, a fourth metering pump 14, a fifth metering pump 28, a first solvent pump 26, a second solvent pump 27, a first heat exchanger 15, a second heat exchanger 16, a third heat exchanger 17, a fourth heat exchanger 18, a fifth heat exchanger 29, and a crude 1,2-cyclohexanediamine collection tank 19.
[0025] The first reactor 1 is equipped with a nitrogen inlet, an epoxide inlet, a liquid ammonia inlet, a solvent inlet, a recovered solvent inlet, and a circulating liquid ammonia inlet at the top, and a reactant outlet at the bottom; the circulating liquid ammonia inlet is equipped with a liquid ammonia flow meter 22, and the nitrogen inlet is equipped with a nitrogen flow meter 20.
[0026] The second reactor 2 has a reactant inlet at the bottom and a hydrogen inlet, a circulating hydrogen inlet, a solvent inlet, a recovered solvent inlet, and a reactant outlet at the top; the hydrogen inlet is equipped with a second hydrogen flow meter 25, and the circulating hydrogen inlet is equipped with a first hydrogen flow meter 24.
[0027] The reactant outlet at the bottom of the first reactor 1 is connected to the reactant inlet at the bottom of the second reactor 2 via a pipeline, the fifth metering pump 28, and the first heat exchanger 15. The reactant outlet at the top of the second reactor 2 is connected to the feed inlet of the hydrogen separation tower 3 via a pipeline and the second heat exchanger 16. The gas outlet at the top of the hydrogen separation tower 3 is connected to the inlet of the hydrogen compressor 6 via a pipeline and the third heat exchanger 17. The outlet of the hydrogen compressor 6 is connected to the circulating hydrogen inlet of the second reactor 2 via a pipeline and the first hydrogen flow meter 24. The discharge outlet at the bottom of the hydrogen separation tower 3 is connected to the feed inlet of the liquid ammonia separation tower 4 via a pipeline. The top outlet of the liquid ammonia separation tower 4 is connected to the inlet of the liquid ammonia compressor 7 via a pipeline and the fourth heat exchanger 18. The outlet of the liquid ammonia compressor 7 is connected to the circulating liquid ammonia inlet of the first reactor 1 via a pipeline and the liquid ammonia flow meter 22. The bottom outlet of the liquid ammonia separation tower 4 is connected to the inlet of the solvent distillation tower 5 via a pipeline. The top outlet of the solvent distillation tower 5 is connected to the recovery solvent inlets of the first reactor 1 and the second reactor 2 via the fifth heat exchanger 29, the first solvent pump 26, and the second solvent pump 27, respectively. The bottom outlet of the solvent distillation tower 5 is connected to the crude 1,2-cyclohexanediamine collection tank 19 via a pipeline.
[0028] The cyclohexane oxide storage tank 8 is connected to the cyclohexane oxide inlet of the first reactor 1 via the first metering pump 11, the liquid ammonia storage tank 9 is connected to the liquid ammonia inlet of the first reactor 1 via the second metering pump 12, and the solvent storage tank 10 is connected to the solvent inlets of the first reactor 1 and the second reactor 2 via the third metering pump 13 and the fourth metering pump 14, respectively.
[0029] The first reactor 1 is used for the ring-opening reaction of cyclohexane oxide to produce 2-aminocyclohexanol. It is a fixed-bed reactor with a height-to-diameter ratio of 1.5 to 20. The reactor is equipped with a jacket for introducing a heat medium to maintain a constant reactor temperature.
[0030] The second reactor 2 is used for the amination reaction of 2-aminocyclohexanol to produce crude 1,2-cyclohexanediamine. It is a fixed-bed reactor with a height-to-diameter ratio of 1.5 to 20. The reactor is equipped with a jacket for introducing heat medium to maintain a constant reactor temperature. The reactor is equipped with one or more layers of catalyst bed.
[0031] Hydrogen separator 3 is used to separate hydrogen from other reactants from cooled materials through pressure regulation. The separated hydrogen is output from the top of the separator and pressurized by hydrogen compressor 6 before entering the hydrogen circulation pipeline to replenish the inlet of the second reactor 2 for recycling. Other components (1,2-cyclohexanediamine, liquid ammonia, unreacted 2-aminocyclohexanol, etc.) are fed into liquid ammonia separator 4 from the bottom of the separator.
[0032] The liquid ammonia separation tower 4 is used to separate excess liquid ammonia from the mixed products by adjusting the pressure and temperature. The ammonia flows out from the top of the tower and enters the liquid ammonia compressor 7 to liquefy the ammonia gas. The liquefied ammonia gas is then transported to the inlet of the first reactor 1 to form a recycling of liquid ammonia. Other components (1,2-cyclohexanediamine, unreacted 2-aminocyclohexanol, etc.) are fed into the solvent distillation tower 5 from the bottom of the tower.
[0033] Solvent distillation column 5 is used to remove the solvent used in the reaction under a certain vacuum and temperature. The solvent distilled from the top of the distillation column is condensed and then transported to the inlet of the first reactor and the second reactor for recycling.
[0034] The working principle of this utility model is as follows:
[0035] (1) Nitrogen gas is introduced into the first reactor 1 and the second reactor 2 through the nitrogen inlet to establish a certain pressure and raise the temperature. After reaching the predetermined conditions, liquid ammonia is pumped into the first reactor 1 through the second metering pump 12 to replace the nitrogen gas. After the replacement is completed, cyclohexane oxide and solvent are pumped into the first reactor 1 through the first metering pump 11 and the third metering pump 13 respectively to carry out the reaction.
[0036] (2) After the reactants flow out of the first reactor 1, the fifth metering pump 28 pumps the reactants, which have been heated by the first heat exchanger 15, into the bottom of the second reactor 2. At the same time, hydrogen is introduced through the hydrogen inlet and metered by the second hydrogen flow meter 25, and the solvent is pumped in through the fourth metering pump 14. In the catalyst loading area, the reactants undergo an amination reaction at a certain space velocity, pressure, and temperature. Under continuous injection conditions, the reactants flow out from the top pipeline of the main reactor and enter the second heat exchanger 16 for cooling.
[0037] (3) The condensed material enters the hydrogen separation tower 3. The gaseous product, mainly composed of hydrogen, is output from the top of the hydrogen separation tower 3, and the liquid product is output from the bottom of the hydrogen separation tower 3 to the liquid ammonia separation tower 4. The material undergoes ammonia removal in the liquid ammonia separation tower 4. The gaseous product, mainly composed of liquid ammonia or ammonia, is output from the top of the liquid ammonia separation tower 4, and the liquid product is output from the bottom of the liquid ammonia separation tower 4 to the solvent distillation tower 5. After the solvent is removed in the solvent distillation tower 5, the crude 1,2-cyclohexanediamine product flows out from the bottom of the solvent distillation tower 5 and is collected in the crude 1,2-cyclohexanediamine collection tank 19, and then enters the next stage of purification.
[0038] (4) In the hydrogen separation tower 3, the gaseous product, mainly hydrogen, is dried to adsorb moisture and other small molecules, then cooled by heat exchange with the third heat exchanger 17, and then fed into the hydrogen compressor 6. After compression, it is metered by the first hydrogen flow meter 24 and returned to the second reactor 2 for recycling. In the liquid ammonia separation tower 4, the liquid product, mainly liquid ammonia, is dried to adsorb moisture and other small molecules, then cooled by heat exchange with the fourth heat exchanger 18, and then fed into the liquid ammonia compressor 7. After liquefaction, it is metered by the liquid ammonia flow meter 22 and returned to the first reactor 1 for recycling. The solvent distilled from the top of the solvent distillation tower 3 is condensed and liquefied by the fifth heat exchanger 29 and then returned to the first reactor 1 and the second reactor 2 for recycling via the first solvent pump 26 and the second solvent pump 27, respectively. When hydrogen, liquid ammonia, and solvent are recycled at a certain flow rate, the replenishment of fresh hydrogen, liquid ammonia, and solvent is reduced by an equal amount.
[0039] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications are also within the protection scope of the present utility model.
Claims
1. A device for continuous production of 1,2-cyclohexanediamine, characterized by The first reactor (1), the second reactor (2), the hydrogen separation tower (3), the liquid ammonia separation tower (4), the solvent rectification tower (5), the hydrogen compressor (6), the liquid ammonia compressor (7) and the crude 1,2-cyclohexanediamine collection tank (19) are sequentially connected. The first reactor (1), the second reactor (2), the hydrogen separation tower (3), the liquid ammonia separation tower (4), the solvent rectification tower (5) and the crude 1,2-cyclohexanediamine collection tank (19) are sequentially connected. The first reactor (1) is used for ring-opening reaction of epoxycyclohexane to generate 2-aminocyclohexanol. The second reactor (2) is used for amination reaction of 2-aminocyclohexanol to generate crude 1,2-cyclohexanediamine. The hydrogen separation tower (3) is used for separating hydrogen from the reaction product, and the hydrogen compressor (6) is used for compressing the hydrogen separated from the hydrogen separation tower (3) and delivering the hydrogen to the second reactor (2) for recycling. The liquid ammonia separation tower (4) is used for separating excess liquid ammonia from the reaction product, and the liquid ammonia compressor (7) is used for liquefying the ammonia separated from the liquid ammonia separation tower (4) and delivering the ammonia to the first reactor (1) for recycling. The solvent rectification tower (5) is used for removing solvent from the reaction product under a certain vacuum degree and temperature; the removed solvent is condensed and delivered to the inlets of the first reactor (1) and the second reactor (2) for recycling by a solvent pump. The crude 1,2-cyclohexanediamine collection tank (19) is used for collecting crude 1,2-cyclohexanediamine at the bottom of the solvent rectification tower (5).
2. The apparatus for continuous production of 1,2-cyclohexanediamine according to claim 1, wherein The first reactor (1) is a fixed bed reactor with a height-diameter ratio of 1.5-20, and a jacket is arranged outside the reactor for passing heat medium to maintain the temperature of the reactor constant.
3. The apparatus for continuous production of 1,2-cyclohexanediamine according to claim 1, wherein The second reactor (2) is a fixed bed reactor with a height-diameter ratio of 1.5-20, and a jacket is arranged outside the reactor for passing heat medium to maintain the temperature of the reactor constant; and one or more layers of catalyst bed are arranged inside the reactor.
4. The apparatus for continuous production of 1,2-cyclohexanediamine according to claim 1, wherein A first heat exchanger (15) is arranged on the pipeline connecting the first reactor (1) and the second reactor (2).
5. The apparatus for continuous production of 1,2-cyclohexanediamine according to claim 1, wherein A second heat exchanger (16) is arranged on the pipeline connecting the second reactor (2) and the hydrogen separation tower (3).
6. The apparatus for continuous production of 1,2-cyclohexanediamine according to claim 1, wherein A third heat exchanger (17) is arranged on the pipeline connecting the hydrogen separation tower (3) and the hydrogen compressor (6).
7. The apparatus for continuous production of 1,2-cyclohexanediamine according to claim 1, wherein A fourth heat exchanger (18) is arranged on the pipeline connecting the liquid ammonia separation tower (4) and the liquid ammonia compressor (7).
8. The apparatus for continuous production of 1,2-cyclohexanediamine according to claim 1, wherein An epoxycyclohexane storage tank (8), a liquid ammonia storage tank (9) and a solvent storage tank (10) are further included, the epoxycyclohexane storage tank (8) is connected with the epoxycyclohexane inlet of the first reactor (1) through a first metering pump (11), the liquid ammonia storage tank (9) is connected with the liquid ammonia inlet of the first reactor (1) through a second metering pump (12), and the solvent storage tank (10) is connected with the solvent inlets of the first reactor (1) and the second reactor (2) through a third metering pump (13) and a fourth metering pump (14) respectively.
9. The apparatus for continuous production of 1,2-cyclohexanediamine according to claim 1, wherein A liquid ammonia flowmeter (22) is arranged on the circulating liquid ammonia inlet of the first reactor (1), and a nitrogen flowmeter (20) is arranged on the nitrogen inlet.
10. The apparatus for continuous production of 1,2-cyclohexanediamine according to claim 1, wherein A first hydrogen flowmeter (24) is arranged on the circulating hydrogen inlet of the second reactor (2), and a second hydrogen flowmeter (25) is arranged on the hydrogen inlet.