An amination reaction system

Abstract

The present application relates to a kind of amination reaction systems, including raw material tank, inert gas tank, inert gas buffer tank, liquid ammonia tank, ammonia gas buffer tank, raw material microwave preheater, inert gas preheater, ammonia gas preheater, microwave heater, fluidized bed reactor, condenser, gas-liquid separator, product tank, inert gas separation tower, inert gas refining tower, pressure swing adsorption separation tower, ammonia gas refining tower, liquid tank.The system has good heat transfer performance, reactor bed internal temperature is uniform and easy to control, it is convenient to carry out the continuous regeneration and circulation of catalyst, catalyst, ammonia utilization rate is high and ammonia gas amount is less and the like characteristics.In the present application, the process system breaks through the existing process route;Unreacted ammonia is recycled, so that ammonia can be more efficiently utilized, and the amount of ammonia used is reduced;At the same time, inert gas is also separated and recycled for reuse, thereby further reducing energy consumption.

Description

Technical Field

[0001] This invention relates to the field of organic chemical technology, and in particular to an amination reaction system. Background Technology

[0002] According to patent CN201711061104.3, a method for preparing cyclohexylamine by ammonolysis of cyclohexanol is described, wherein the catalyst is formed by hydrotalcite or hydrotalcite-like composite transition metal elemental active components.

[0003] Patent CN201810001682.6 describes a catalyst for the ammonolysis reaction between aldehydes or ketones and ammonia in a hydrogen atmosphere.

[0004] Patent CN202110164835.0 describes a method for preparing adiponitrile by amination and dehydration of adipic acid.

[0005] Patent CN202010374890.8 describes a catalyst composition for esterification and dehydration reaction and a method for preparing L-menthamide.

[0006] Patent CN201910775834.2 describes a catalyst for the preparation of 6-aminohexanonitrile by caprolactam amination and dehydration reaction.

[0007] Patent CN201310355337.X describes a method for synthesizing aniline compounds by ammonolysis of aromatic chlorides, using a 13X molecular sieve treated with cuprous ion exchange as the catalyst.

[0008] Among them, the products prepared by amination-related reactions (such as adiponitrile and 6-aminohexanonitrile, which are intermediates for the synthesis of hexamethylenediamine) are important intermediates. Therefore, it is particularly important to invent an amination reaction system with good heat transfer performance, uniform and easy-to-control internal temperature of the reactor bed, convenient continuous regeneration and circulation of catalyst, high catalyst utilization rate, high ammonia utilization rate and low ammonia quantity. Summary of the Invention

[0009] The purpose of this invention is to provide an amination reaction system that solves the problems of high ammonia source utilization, low efficiency, and high energy consumption in conventional amination reaction systems.

[0010] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: This invention provides an amination reaction system, comprising a raw material tank, a raw material microwave preheater, an inert gas tank, an inert gas buffer tank, an inert gas preheater, a liquid ammonia tank, an ammonia buffer tank, an ammonia preheater, a mixed gas buffer tank, a microwave heater, a reactor, a condenser, a gas-liquid separator, a product tank, an inert gas separation tower, an inert gas purification tower, a pressure swing adsorption separation tower, an ammonia purification tower, and a liquid tank; The raw material tank, liquid ammonia tank, and inert gas tank are respectively connected to the mixed gas buffer tank through pipelines; and the raw material tank, liquid ammonia tank, and inert gas tank are preheated by a raw material microwave preheater, an ammonia preheater, and an inert gas preheater, respectively, on the conveying pipelines of the raw material tank, liquid ammonia tank, and inert gas tank. The mixed gas buffer tank is connected to the feed inlet of the reactor via a pipeline, and the product of the reactor is transported to the condenser via a pipeline. The condenser is connected to the gas-liquid separator via a pipeline. A microwave heater is installed on the pipeline between the mixed gas buffer tank and the reactor. The liquid phase outlet of the gas-liquid separator is connected to the product tank, and the gas phase outlet of the gas-liquid separator is connected to the inert gas separation tower through a pipeline; The top of the inert gas separation tower is connected to the inert gas purification tower via a pipeline, and the purified product from the inert gas purification tower is returned to the inert gas buffer tank; the bottom of the inert gas separation tower is connected to the pressure swing adsorption separation tower via a pipeline. The top of the pressure swing adsorption (PSA) separation tower is connected to the ammonia refining tower via a pipeline, wherein the refined ammonia is returned to the ammonia buffer tank; the top of the PSA separation tower is connected to the liquid tank via a pipeline.

[0011] Furthermore, the raw material reactants in the raw material tank are one or more of alcohols, aldehydes, ketones, acids, esters, amides, and halogenated hydrocarbon compounds.

[0012] Furthermore, the reactor is a fluidized bed reactor or a fixed bed reactor.

[0013] Furthermore, the reactor is a fluidized bed reactor and is equipped with a catalyst regeneration device.

[0014] Furthermore, the inert gas tank is connected to the inert gas buffer tank via a pipeline, and then connected to the mixed gas buffer tank via the inert gas buffer tank.

[0015] Furthermore, the liquid ammonia tank is connected to the ammonia buffer tank via a pipeline, and then connected to the mixed gas buffer tank via the ammonia buffer tank.

[0016] Furthermore, the following application steps are also included: S1. The preheated ammonia and inert gas are mixed with the preheated raw materials and then introduced into the reactor. S2. After the reaction, the gas-liquid mixture is condensed by the condenser and then enters the gas-liquid separator. The product and possibly unreacted raw materials and by-products flow to the liquid tank, while ammonia, inert gas and a small amount of other gaseous substances flow to the inert gas separation tower. S3. The inert gas separation tower operates under a certain pressure. The gaseous inert gas flows from the top of the tower to the inert gas purification tower for purification and reuse. The liquid ammonia and residual by-products, products and raw materials flow together to the pressure swing adsorption separation tower. S4, the pressure swing adsorption separation tower is mainly used to separate ammonia. Ammonia flows from the top of the tower to the ammonia refining tower, where it is refined and reused. After depressurization at the bottom of the tower, the remaining by-products, products, and raw materials flow from the bottom of the tower to the liquid tank.

[0017] Compared with the prior art, the beneficial technical effects of the present invention are as follows: the process system in this application breaks through the existing process route; in this application, the unreacted ammonia is recovered, thereby enabling more efficient use of ammonia and reducing the amount of ammonia used; at the same time, the inert gas is also separated, recovered and reused, thereby further reducing energy consumption. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings.

[0019] Figure 1 This is a schematic diagram of the amination reaction system of the present invention.

[0020] Explanation of reference numerals in the attached diagram: 1. Raw material tank; a. Raw material pipeline; 2. Raw material microwave preheater; 3. Inert gas tank; b. Inert gas pipeline; 4. Inert gas buffer tank; 5. Inert gas preheater; 6. Liquid ammonia tank; c. Ammonia pipeline; 7. Ammonia buffer tank; 8. Ammonia preheater; 9. Mixed gas buffer tank; d. Mixed gas pipeline; 10. Microwave heater; 11. Reactor; e. Post-reaction material pipeline; 12. Condenser; f. Post-condensation material pipeline. ; 13 is a gas-liquid separator, g is a product pipeline, 14 is a product tank; h is a gas phase pipeline, 15 is an inert gas separation tower, i is an inert gas pipeline, 16 is an inert gas purification tower, j is the purified inert gas; k is a liquefied ammonia pipeline, 17 is a pressure swing adsorption separation tower, m is a liquid pipeline of one or more of the following: residual by-products, products, raw materials, and ammonia, 18 is a liquid tank, n is the separated gaseous ammonia, 19 is an ammonia purification tower, and o is the purified ammonia. Detailed Implementation

[0021] This embodiment discloses an amination reaction system, including a raw material tank 1, a raw material microwave preheater 2, an inert gas tank 3, an inert gas buffer tank 4, an inert gas preheater 5, a liquid ammonia tank 6, an ammonia buffer tank 7, an ammonia preheater 8, a mixed gas buffer tank 9, a microwave heater 10, a reactor 11, a condenser 12, a gas-liquid separator 13, a product tank 14, an inert gas separation tower 15, an inert gas purification tower 16, a pressure swing adsorption separation tower 17, an ammonia purification tower 19, and a liquid tank 18. The raw material tank 1, liquid ammonia tank 6, and inert gas tank 3 are respectively connected to the mixed gas buffer tank 9 through pipelines; and the raw material tank 1, liquid ammonia tank 6, and inert gas tank 3 are preheated through the raw material microwave preheater 2, ammonia preheater 8, and inert gas preheater 5 respectively on the conveying pipelines. The mixed gas buffer tank 9 is connected to the feed inlet of the reactor 11 through a pipeline. The product of the reactor 11 is transported to the condenser 12 through a pipeline. The condenser 12 is connected to the gas-liquid separator 13 through a pipeline. A microwave heater 10 is installed on the pipeline between the mixed gas buffer tank 9 and the reactor 11. The liquid phase outlet of the gas-liquid separator 13 is connected to the product tank 14, and the gas phase outlet of the gas-liquid separator 13 is connected to the inert gas separation tower 15 through a pipeline. The top of the inert gas separation tower 15 is connected to the inert gas purification tower 16 via a pipeline, and the purified product of the inert gas purification tower 16 is returned to the inert gas buffer tank 4; the bottom of the inert gas separation tower 15 is connected to the pressure swing adsorption separation tower 17 via a pipeline. The top of the pressure swing adsorption (PSA) separation tower 17 is connected to the ammonia refining tower 19 via a pipeline, where the refined ammonia gas is refluxed to the ammonia buffer tank 7. The bottom of the PSA separation tower 17 is connected to the liquid tank 18 via a pipeline. The PSA separation tower 17 is a pressure swing adsorption tower, mainly used for separating ammonia. Ammonia flows from the top of the tower to the ammonia refining tower, where it is refined and reused. After depressurization at the bottom of the tower, the remaining by-products, products, and raw materials flow from the bottom to the liquid tank. The ammonia gas will carry trace amounts of reactants, such as by-products, products, water, and raw materials. After PSA, the ammonia gas (which will carry trace amounts of water) flows out of the adsorption tower from the top, while the water and other liquids flow to the liquid tank. Once the liquid in the liquid tank accumulates to a certain level, it can be transferred to the product tank. Depending on the system, the product in the product tank can be further refined to obtain a pure product.

[0022] In this embodiment, the raw material reactants in the raw material tank 1 are one or more compounds selected from alcohols, aldehydes, ketones, acids, esters, amides, and halogenated hydrocarbons.

[0023] The reactor 11 is a fluidized bed reactor or a fixed bed reactor.

[0024] The reactor 11 is a fluidized bed reactor and is equipped with a catalyst regeneration device.

[0025] The inert gas tank 3 is connected to the inert gas buffer tank 4 via a pipeline, and then connected to the mixed gas buffer tank 9 via the inert gas buffer tank 4.

[0026] The liquid ammonia tank 6 is connected to the ammonia buffer tank 7 via a pipeline, and then connected to the mixed gas buffer tank 9 via the ammonia buffer tank 7.

[0027] Example 1 like Figure 1 As shown, an amination reaction system includes: 1. a raw material tank, a is a raw material pipeline, 2 is a raw material microwave preheater; 3. an inert gas tank, b is an inert gas pipeline, 4 is an inert gas buffer tank, 5 is an inert gas preheater; 6. a liquid ammonia tank, c is an ammonia pipeline, 7 is an ammonia buffer tank, 8 is an ammonia preheater; 9. a mixed gas buffer tank, d is a mixed gas pipeline; 10. a microwave heater; 11. a reactor, e is a post-reaction material pipeline; 12. a condenser, f is a condenser for the condensed material. Material pipeline; 13 is gas-liquid separator, g is product pipeline, 14 is product tank; h is gas phase pipeline, 15 is inert gas separation tower, i is inert gas pipeline, 16 is inert gas purification tower, j is purified inert gas; k is liquefied ammonia pipeline, 17 is pressure swing adsorption separation tower, m is a liquid pipeline of one or more of the following: residual by-products, products, raw materials, and ammonia, 18 is liquid tank, n is separated gaseous ammonia, 19 is ammonia purification tower, o is purified ammonia.

[0028] The process of caprolactam amination and dehydration using the above-mentioned amination reaction system is as follows: (1) The preheated ammonia and nitrogen are mixed and then mixed with the preheated caprolactam and fed into a fixed-bed reactor. The molar ratio of ammonia to caprolactam is 6, the molar ratio of nitrogen to caprolactam is 3, the reaction temperature is 350℃, and the reaction pressure is slightly positive. (2) The gas-liquid mixture after the reaction is condensed by the condenser and then enters the gas-liquid separator. 6-aminohexanonitrile, caprolactam, water and other by-reaction products flow to the liquid tank, while ammonia, nitrogen and a small amount of other gaseous substances flow to the nitrogen separation tower. (3) After the nitrogen separation tower is pressurized to a certain level, the gaseous nitrogen flows from the top of the tower to the nitrogen purification tower. After purification, it is reused. The liquid ammonia and the residual 6-aminehexanonitrile, caprolactam, water and other by-reaction products flow together to the pressure swing adsorption separation tower. (4) The pressure swing adsorption separation tower separates gaseous ammonia. The ammonia flows from the top of the tower to the ammonia purification tower. After purification, it is reused. After the pressure is released at the bottom of the tower, 6-amine hexanonitrile, caprolactam, water and other by-reaction products flow from the bottom of the tower to the liquid tank.

[0029] The conversion rate of caprolactam was 97.1%, and the selectivity of 6-aminehexanoate was 98.2%.

[0030] Example 2 The process of caprolactam amination and dehydration using the above-mentioned amination reaction system is as follows: (1) The preheated ammonia and nitrogen are mixed and then mixed with the preheated caprolactam and fed into the fluidized bed reactor. The molar ratio of ammonia to caprolactam is 5, the molar ratio of nitrogen to caprolactam is 2, the reaction temperature is 310℃, and the reaction pressure is slightly positive. (2) The gas-liquid mixture after the reaction is condensed by the condenser and then enters the gas-liquid separator. 6-aminohexanonitrile, caprolactam, water and other by-reaction products flow to the liquid tank, while ammonia, nitrogen and a small amount of other gaseous substances flow to the nitrogen separation tower. (3) After the nitrogen separation tower is pressurized to a certain level, the gaseous nitrogen flows from the top of the tower to the nitrogen purification tower. After purification, it is reused. The liquid ammonia and the residual 6-aminehexanonitrile, caprolactam, water and other by-reaction products flow together to the pressure swing adsorption separation tower. (4) The pressure swing adsorption separation tower separates gaseous ammonia. The ammonia flows from the top of the tower to the ammonia purification tower. After purification, it is reused. After the pressure is released at the bottom of the tower, 6-amine hexanonitrile, caprolactam, water and other by-reaction products flow from the bottom of the tower to the liquid tank.

[0031] The conversion rate of caprolactam was 98.4%, and the selectivity of 6-aminohexanonitrile was 99.1%.

[0032] Example 3 The process of using the above-mentioned amination reaction system to produce acetonitrile via acetic acid amination and dehydration is as follows: (1) The preheated ammonia and nitrogen are mixed and then mixed with the preheated acetic acid and fed into the fluidized bed reactor. The molar ratio of ammonia to acetic acid is 1.2, the molar ratio of nitrogen to acetic acid is 1, the reaction temperature is 340℃, and the reaction pressure is slightly positive. (2) The gas-liquid mixture after the reaction is condensed by the condenser and then enters the gas-liquid separator. Acetonitrile, water and other by-reaction products flow to the liquid tank, while ammonia, nitrogen and a small amount of other gaseous substances flow to the nitrogen separation tower. (3) After the nitrogen separation tower is pressurized to a certain level, the gaseous nitrogen flows from the top of the tower to the nitrogen purification tower, and is reused after purification. The liquid ammonia, residual acetonitrile, water and other by-reaction products flow together to the pressure swing adsorption separation tower. (4) The pressure swing adsorption separation tower separates gaseous ammonia. The ammonia flows from the top of the tower to the ammonia purification tower, and is reused after purification. After the pressure is released at the bottom of the tower, acetonitrile, water and other by-reaction products flow from the bottom of the tower to the liquid tank.

[0033] Acetic acid conversion rate 100%, acetonitrile selectivity 99.5%.

[0034] Example 4 The process of using the above-mentioned amination reaction system to produce acetonitrile via acetic acid amination and dehydration is as follows: (1) The preheated ammonia and nitrogen are mixed and then mixed with the preheated acetic acid and fed into the fixed bed reactor. The molar ratio of ammonia to acetic acid is 1.5, the molar ratio of nitrogen to acetic acid is 1.2, the reaction temperature is 360℃, and the reaction pressure is slightly positive. (2) The gas-liquid mixture after the reaction is condensed by the condenser and then enters the gas-liquid separator. Acetonitrile, water and other by-reaction products flow to the liquid tank, while ammonia, nitrogen and a small amount of other gaseous substances flow to the nitrogen separation tower. (3) After the nitrogen separation tower is pressurized to a certain level, the gaseous nitrogen flows from the top of the tower to the nitrogen purification tower, and is reused after purification. The liquid ammonia, residual acetonitrile, water and other by-reaction products flow together to the pressure swing adsorption separation tower. (4) The pressure swing adsorption separation tower separates gaseous ammonia. The ammonia flows from the top of the tower to the ammonia purification tower, and is reused after purification. After the pressure is released at the bottom of the tower, acetonitrile, water and other by-reaction products flow from the bottom of the tower to the liquid tank.

[0035] Acetic acid conversion rate 100%, acetonitrile selectivity 99.2%.

[0036] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0037] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An amination reaction system, characterized in that: This includes raw material tanks, raw material microwave preheaters, inert gas tanks, inert gas buffer tanks, inert gas preheaters, liquid ammonia tanks, ammonia buffer tanks, ammonia preheaters, mixed gas buffer tanks, microwave heaters, reactors, condensers, gas-liquid separators, product tanks, inert gas separation towers, inert gas purification towers, pressure swing adsorption separation towers, ammonia purification towers, and liquid tanks. The raw material tank, liquid ammonia tank, and inert gas tank are respectively connected to the mixed gas buffer tank through pipelines; and the raw material tank, liquid ammonia tank, and inert gas tank are preheated by a raw material microwave preheater, an ammonia preheater, and an inert gas preheater, respectively, on the conveying pipelines of the raw material tank, liquid ammonia tank, and inert gas tank. The mixed gas buffer tank is connected to the feed inlet of the reactor via a pipeline, and the product of the reactor is transported to the condenser via a pipeline. The condenser is connected to the gas-liquid separator via a pipeline. A microwave heater is installed on the pipeline between the mixed gas buffer tank and the reactor. The liquid phase outlet of the gas-liquid separator is connected to the product tank, and the gas phase outlet of the gas-liquid separator is connected to the inert gas separation tower through a pipeline; The top of the inert gas separation tower is connected to the inert gas purification tower via a pipeline, and the purified product from the inert gas purification tower is returned to the inert gas buffer tank; the bottom of the inert gas separation tower is connected to the pressure swing adsorption separation tower via a pipeline. The top of the pressure swing adsorption (PSA) separation tower is connected to the ammonia refining tower via a pipeline, wherein the refined ammonia is returned to the ammonia buffer tank; the bottom of the PSA separation tower is connected to a liquid tank via a pipeline.

2. The amination reaction system according to claim 1, characterized in that: The raw material reactants in the raw material tank are one or more of the following: alcohols, aldehydes, ketones, acids, esters, amides, and halogenated hydrocarbons.

3. The amination reaction system according to claim 1, characterized in that: The reactor is either a fluidized bed reactor or a fixed bed reactor.

4. The amination reaction system according to claim 3, characterized in that: The reactor is a fluidized bed reactor and is equipped with a catalyst regeneration device.

5. The amination reaction system according to claim 1, characterized in that: The inert gas tank is connected to the inert gas buffer tank via a pipeline, and then connected to the mixed gas buffer tank via the inert gas buffer tank.

6. The amination reaction system according to claim 1, characterized in that: The liquid ammonia tank is connected to the ammonia buffer tank via a pipeline, and then connected to the mixed gas buffer tank via the ammonia buffer tank.

7. The amination reaction system according to claim 1, characterized in that: The application steps include the following: S1. The preheated ammonia and inert gas are mixed with the preheated raw materials and then introduced into the reactor. S2. After the reaction, the gas-liquid mixture is condensed by the condenser and then enters the gas-liquid separator. The product, unreacted raw materials, and by-products flow to the liquid tank, while ammonia, inert gas, and a small amount of other gaseous substances flow to the inert gas separation tower. S3. The inert gas separation tower operates under a certain pressure. The gaseous inert gas flows from the top of the tower to the inert gas purification tower for purification and reuse. The liquid ammonia and residual by-products, products and raw materials flow together to the pressure swing adsorption separation tower. S4, the pressure swing adsorption separation tower is mainly used to separate ammonia. Ammonia flows from the top of the tower to the ammonia refining tower, where it is refined and reused. After depressurization at the bottom of the tower, the remaining by-products, products, and raw materials flow from the bottom of the tower to the liquid tank.

Images