Tubular reactor and equipment for preparing organic amine

Abstract

The utility model discloses a tubular reactor and equipment for preparing organic amine. The tubular reactor comprises an outer barrel, a tube bundle assembly and a heat exchange assembly, wherein the tube bundle assembly and the heat exchange assembly are arranged in the outer barrel; the tube bundle assembly comprises an upper tube bundle section and a lower tube bundle section; the heat exchange assembly is arranged between the upper tube bundle section and the lower tube bundle section; and the height ratio of the upper tube bundle section to the lower tube bundle section is (0.2-0.8): 1. The tube bundle is segmented, the hot-spot temperature of a bed layer is reduced by adjusting the height ratio of the upper part and the lower part of the tube bundle, and inlet mixed gas is preheated by arranging the heat exchange assembly at the segmented part, so that the temperature distribution of the catalyst bed layer is uniform, the side reaction occurrence probability is reduced, the full utilization of high-temperature heat is realized, and the effects of energy conservation and emission reduction are achieved. By utilizing the tubular reactor and the equipment for preparing the organic amine by utilizing the tubular reactor disclosed by the utility model, the conversion per pass of raw materials and the selectivity of target products can be improved.

Description

Technical Field

[0001] The present application relates to a tubular reactor and equipment for preparing organic amines, belonging to the field of low-carbon nitrogen-containing chemical production. Background Art

[0002] Organic amines are an important class of organic chemical raw materials. Common examples include ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, and tert-butylamine. Tert-butylamine is a very valuable organic chemical raw material, widely used in synthetic rubber vulcanization accelerators, pharmaceuticals, pesticides, colorants, synthetic resins, surfactants, and organic synthesis.

[0003] There are many methods for preparing tert-butylamine. The methods that have been industrially applied mainly include the hydrolysis of tert-butyl urea, the hydrocyanic acid method of methyl tert-butyl ether, the chlorination and amination of tert-butyl alcohol, and the hydrocyanic acid method of isobutylene. These production processes involve the use and treatment of strong acids / strong bases, the large-scale emission of waste and highly toxic substances, and serious equipment corrosion and pollution problems, which do not meet the requirements of green chemical industry.

[0004] The direct amination of isobutylene uses isobutylene and ammonia to directly react to produce tert-butylamine. The process is clean and has an atomic utilization rate of 100%. It meets the requirements of green chemical industry and sustainable development and is the development direction of tert-butylamine research and development and industrial production.

[0005] The synthesis of organic amines is typically an exothermic process. The direct catalytic reaction of isobutylene with ammonia to produce tert-butylamine is also an exothermic reaction, typically utilizing a shell-and-tube reactor. However, there are few reports on the impact of the internal structure of the shell-and-tube reactor on the conversion and selectivity of the direct amination of isobutylene. Utility Model Content

[0006] To address existing problems, the present invention proposes a tubular reactor and equipment for preparing organic amines using the same. These reactors effectively control the reactor bed temperature, improve product selectivity, and reduce energy consumption. The present invention is used for the direct amination of isobutylene to produce tert-butylamine and is also applicable to the production of organic amines such as ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, and sec-butylamine.

[0007] The purpose of the utility model is to provide a tubular reactor and equipment for preparing organic amines using the same, which can improve the selectivity of products and promote the comprehensive utilization of energy by effectively controlling the reactor bed temperature.

[0008] According to one aspect of the present application, a shell-and-tube reactor is provided.

[0009] A shell-and-tube reactor, comprising an outer cylinder, and a tube bundle assembly and a heat exchange assembly disposed inside the outer cylinder;

[0010] The tube bundle assembly includes an upper tube bundle section and a lower tube bundle section;

[0011] The heat exchange component is arranged between the upper tube bundle section and the lower tube bundle section;

[0012] The height ratio of the upper tube bundle section to the lower tube bundle section is 0.2-0.8:1.

[0013] As a specific embodiment, the shell-and-tube reactor includes an outer cylinder, a tube bundle and a heat exchange component. The tube bundle can be one section or segmented near the hot spot temperature into upper and lower parts, and a heat exchange component is provided.

[0014] Optionally, the heat exchange assembly is composed of a front manifold, a rear manifold, a connecting pipe and fins;

[0015] The front collecting pipe and the rear collecting pipe are arc-shaped pipes, and the front collecting pipe and the rear collecting pipe are connected through a connecting pipe.

[0016] Optionally, the connecting pipe of the heat exchange assembly consists of at least one heat exchange pipe;

[0017] Fins are provided on the outer side of the heat exchange tube.

[0018] Optionally, the ratio of the cross-sectional area of ​​the heat exchange component to the cross-sectional area of ​​the shell-and-tube reactor is 0.04 to 0.4:1.

[0019] Optionally, the fins on the outer side of the heat exchange tube are vertically inclined and arranged alternately;

[0020] The included angle α between the fin and the horizontal direction is 5 to 45 degrees.

[0021] Another aspect of the present application provides an apparatus for preparing organic amines, the apparatus comprising a shell-and-tube reactor, a gas-liquid separator, an ammonia recovery tower, a raw material recovery tower, and a product tower connected in sequence;

[0022] Wherein, the shell and tube reactor is selected from the above-mentioned shell and tube reactors.

[0023] Optionally, the device further comprises a heat exchanger and a superheater connected in sequence;

[0024] The equipment is provided with an inlet for reaction raw materials;

[0025] The reaction raw material inlet is connected to the cold raw material inlet of the heat exchanger;

[0026] The material outlet of the superheater is connected to the inlet I of the shell and tube reactor;

[0027] The outlet I of the shell and tube reactor is connected to the hot material inlet of the heat exchanger.

[0028] Optionally, the device further comprises a condenser;

[0029] The hot material outlet of the heat exchanger is connected to the inlet II of the condenser;

[0030] The outlet II of the condenser is connected to the inlet of the gas-liquid separator;

[0031] The gas-liquid separator is provided with a gas phase outlet and a liquid phase outlet;

[0032] The gas phase outlet is connected to the tail gas treatment system;

[0033] The liquid phase outlet is connected to the ammonia recovery tower.

[0034] Optionally, the top outlet I of the ammonia recovery tower is connected to the cold raw material inlet of the heat exchanger;

[0035] The tower kettle outlet I of the ammonia recovery tower is connected to the raw material recovery tower.

[0036] Optionally, the top outlet II of the raw material recovery tower is connected to the cold raw material inlet of the heat exchanger;

[0037] The tower bottom outlet II of the raw material recovery tower is connected to the product tower;

[0038] The top of the product tower is provided with a tert-butylamine product extraction outlet;

[0039] The tower kettle of the product tower is provided with a high-boiling-substance extraction outlet.

[0040] As a specific embodiment, the apparatus for preparing organic amines using the above-mentioned shell-and-tube reactor comprises a shell-and-tube reactor, a heat exchanger, a superheater, a condenser, a gas-liquid separator, an ammonia recovery tower, a raw material recovery tower, and a product tower. The reaction raw material inlet is connected to the cold raw material inlet, the superheater material outlet is connected to the shell-and-tube reactor inlet, the shell-and-tube reactor outlet is connected to the hot raw material inlet of the heat exchanger, the hot raw material outlet of the heat exchanger is connected to the condenser inlet, and after condensation, the raw material enters a gas-liquid separator, the gas phase of the gas-liquid separator is degassing the tail gas treatment system, the liquid phase outlet of the gas-liquid separator is connected to the ammonia recovery tower, the top outlet of the ammonia recovery tower is connected to the cold raw material inlet of the heat exchanger, the bottom outlet of the ammonia recovery tower is connected to the raw material recovery tower, the top outlet of the raw material recovery tower is connected to the cold raw material inlet of the heat exchanger, the bottom outlet of the raw material recovery tower is connected to the product tower, tert-butylamine product is extracted from the top of the product tower, and high-boiling products are extracted from the bottom of the product tower. The ammonia recovery tower, the raw material recovery tower, and the product tower are all equipped with a condenser and a reboiler.

[0041] The raw material isobutylene and ammonia enter the heat exchanger together to exchange heat with the reaction product, and then enter the shell and tube reactor after being heated to the specified temperature by the superheater; the reaction product first exchanges heat with the feed, and then enters the gas-liquid separation tank after condensation by the condenser; the gas phase of the gas-liquid separation tank is discharged to the tail gas treatment system, and the liquid phase enters the downstream ammonia recovery tower; the ammonia recovery tower is equipped with a condenser and a reboiler, and the liquid ammonia produced from the top of the tower is returned to the feed inlet, and the liquid phase produced from the bottom of the tower is entered into the downstream raw material recovery tower; the raw material recovery tower is equipped with a condenser and a reboiler, and the raw material isobutylene produced from the top of the tower is returned to the feed inlet, and the liquid phase produced from the bottom of the tower is entered into the downstream product tower; the product tower is equipped with a condenser and a reboiler, and the product tert-butylamine is produced from the top of the tower, and high-boiling substances are produced from the bottom of the tower.

[0042] The tubular reactor of the utility model determines the hot spot position of the catalyst bed according to the kinetic data of different reactions and adjusts the ratio of the upper and lower parts of the tubular reactor bundle to make the temperature inside the reactor relatively uniform.

[0043] The shell-and-tube reactor of the utility model is applied to prepare tert-butylamine by direct amination of isobutylene. The ratio of the height of the upper and lower parts of the tube bundle of the shell-and-tube reactor is 0.2-0.7, the reactor inlet temperature is controlled at 200-350°C, the reaction pressure is controlled at 5-25 MPaG, the mass space velocity of isobutylene is 0.4-4h-1, and the ammonia-olefin ratio at the reactor inlet is 1-8.

[0044] The beneficial effects of this application include:

[0045] The utility model provides a simple shell-and-tube reactor, which divides the tube bundle into sections. By adjusting the height ratio of the upper and lower sections of the tube bundle, the bed hotspot temperature is reduced. Heat exchange components are provided at the sections to preheat the inlet mixed gas, achieving uniform temperature distribution in the catalyst bed, reducing the probability of side reactions, and fully utilizing the high-temperature heat, thereby achieving energy conservation and emission reduction. The shell-and-tube reactor and the equipment for preparing organic amines using the same can effectively catalyze the direct amination of isobutylene to produce tert-butylamine under the reaction conditions of a reaction temperature of 200-350°C, a reaction pressure of 5-25 MPaG, an isobutylene mass space velocity of 0.4-4 h⁻¹, and a trans-amine-olefin ratio of 1-8. The isobutylene single-pass conversion rate can reach 15-25% or even higher, and the tert-butylamine selectivity is greater than 99%. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a schematic diagram of the tubular reactor structure of this application.

[0047] Figure 2 for Figure 1 Top view of the heat exchange component.

[0048] Figure 3 The side view of the fin.

[0049] Figure 4 It is a schematic diagram of equipment connection of the present utility model.

[0050] List of parts and reference numerals:

[0051] 1-upper tube bundle section, 2-heat exchange component, 3-lower tube bundle section, 4-front manifold, 5-connecting pipe, 6-rear manifold, 7-fin;

[0052] R01-shell and tube reactor, E01-heat exchanger, E02-superheater, E03-condenser, V01-gas-liquid separator, T01-ammonia recovery tower, T02-raw material recovery tower, T03-product tower. DETAILED DESCRIPTION

[0053] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0054] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0055] The conversion rate and selectivity in the examples of this application are calculated as follows:

[0056] Isobutylene conversion = (moles of isobutylene in the reactants - moles of isobutylene in the products) / moles of isobutylene in the reactants × 100%;

[0057] Tert-butylamine selectivity = mole number of tert-butylamine in the product / (mole number of isobutylene in the reactants - mole number of isobutylene in the product) × 100%.

[0058] Figure 1 This is a schematic diagram of the structure of a shell-and-tube reactor of the present invention. The tube bundle inside the shell-and-tube reactor consists of an upper tube bundle section 1 and a lower tube bundle section 3. The catalyst is loaded in the tube bundle. A heat exchange component 2 is set between the upper and lower tube bundle sections. The heat exchange component 2 is as shown in FIG. Figure 2 As shown, it is composed of a front manifold 4, a connecting pipe 5, a rear manifold 6 and fins installed on the connecting pipe 5. The fins on the outside of the heat exchange tube are vertically inclined and arranged alternately, as shown in FIG. Figure 3 As shown, the angle α between the fin and the horizontal direction is 5 to 45 degrees.

[0059] Figure 4 This is an example of equipment connection for preparing organic amines using the tubular reactor of the present invention. Figure 4As shown, the raw material isobutylene and ammonia enter the heat exchanger E01 together to exchange heat with the reaction product, and then enter the shell and tube reactor after being heated to the specified temperature by the superheater E02; the reaction product first exchanges heat with the feed, and then enters the gas-liquid separator V01 after condensation by the condenser E03; the gas phase of the gas-liquid separator V01 is discharged to the tail gas treatment system, and the liquid phase enters the downstream ammonia recovery tower T01; the ammonia recovery tower T01 is equipped with a condenser and a reboiler, and the liquid ammonia produced from the top of the tower is returned to the feed inlet, and the liquid phase produced from the bottom of the tower enters the downstream raw material recovery tower T02; the raw material recovery tower T02 is equipped with a condenser and a reboiler, and the raw material isobutylene produced from the top of the tower is returned to the feed inlet, and the liquid phase produced from the bottom of the tower enters the downstream product tower T03; the product tower T03 is equipped with a condenser and a reboiler, and the product tert-butylamine is produced from the top of the tower and the high-boiling substances are produced from the bottom of the tower.

[0060] use Figure 4 The equipment connection mode and the equipment described in this application are as follows: the reaction temperature is 200-350 ° C, the reaction pressure is 5-25 MPaG, and the mass space velocity of isobutylene is 0.4-4h -1 Under the reaction conditions of an amino-olefin ratio of 1 to 8, it can effectively catalyze the direct amination of isobutylene to prepare tert-butylamine, the single-pass conversion rate of isobutylene can reach 15 to 25% or even higher, and the selectivity of tert-butylamine is greater than 99%.

[0061] The following are specific embodiments of the present invention:

[0062] Example 1

[0063] The shell-and-tube reactor of the present invention is used for direct amination of isobutylene to prepare tert-butylamine. The structure and type of the reactor are as follows: Figure 1 As shown, the ratio of the cross-sectional area of ​​the heat exchange assembly to the cross-sectional area of ​​the reactor is 0.2, the ratio of the height of the upper and lower parts of the tube bundle is 0.4, the fins on the outside of the heat exchange tubes are vertically inclined and arranged alternately, and the angle α between the fins and the horizontal direction is 15°. The catalyst used is the F-ZSM-11 catalyst disclosed in patent CN201610389918.9, using Figure 4 The equipment connection method shown is as follows: the reactor inlet temperature is controlled at 230℃, the reaction pressure is controlled at 10MPaG, and the mass space velocity of isobutylene is 1h -1 The ammonia-olefin ratio at the reactor inlet is 4. The temperature difference between the reactor inlet and outlet is controlled to not exceed 5°C by the internal heat pipe assembly and the flow rate of the shell-side refrigerant.

[0064] According to calculations, the single-pass conversion rate of isobutylene is 19.5% and the selectivity of tert-butylamine is 99.7%.

[0065] Comparative Example 1

[0066] A conventional shell-and-tube reactor is used for the direct amination of isobutylene to produce tert-butylamine. Figure 4The equipment connection mode shown is as follows: the reactor inlet temperature is controlled at 230 ° C, the reaction pressure is controlled at 10 MPaG, and the mass space velocity of isobutylene is 0.3 h -1 , the ammonia-olefin ratio at the reactor inlet is 1.

[0067] According to calculation, the single-pass conversion rate of isobutylene in this embodiment is 18.9%, and the selectivity of tert-butylamine is 99.5%.

[0068] By comparing Example 1 with Comparative Example 1, it can be seen that the use of the shell-and-tube reactor of the present invention improves the single-pass conversion rate of isobutylene and improves the selectivity of the product tert-butylamine.

[0069] Example 2

[0070] The shell-and-tube reactor of the present invention is used for direct amination of isobutylene to prepare tert-butylamine. The structure and type of the reactor are as follows: Figure 1 As shown, the ratio of the cross-sectional area of ​​the heat exchange assembly to the cross-sectional area of ​​the reactor is 0.25, the ratio of the height of the upper and lower parts of the tube bundle is 0.5, the fins on the outside of the heat exchange tubes are vertically inclined and arranged alternately, and the angle α between the fins and the horizontal direction is 10°. The catalyst used is the F-ZSM-11 catalyst disclosed in patent CN201610389918.9, using Figure 4 The equipment connection mode shown is as follows: the reactor inlet temperature is controlled at 250 ° C, the reaction pressure is controlled at 15 MPaG, and the mass space velocity of isobutylene is 0.5 h -1 The ammonia-olefin ratio at the reactor inlet is 0.5. The temperature difference between the reactor inlet and outlet is controlled by the internal heat pipe assembly and the flow of the shell-side refrigerant to not exceed 5°C.

[0071] According to calculations, the single-pass conversion rate of isobutylene is 22.5% and the selectivity of tert-butylamine is 99.8%.

[0072] The above descriptions are merely a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, they are not intended to limit the present application. Any technical personnel familiar with the present profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A shell and tube reactor, characterized in that: The shell-and-tube reactor comprises an outer cylinder, and a tube bundle assembly and a heat exchange assembly (2) disposed inside the outer cylinder; The tube bundle assembly comprises an upper tube bundle section (1) and a lower tube bundle section (3); The heat exchange component (2) is arranged between the upper tube bundle section (1) and the lower tube bundle section (3); The height ratio of the upper tube bundle section (1) to the lower tube bundle section (3) is 0.2-0.8:

1.

2. The shell and tube reactor according to claim 1, characterized in that The heat exchange assembly (2) is composed of a front collecting pipe (4), a rear collecting pipe (6), a connecting pipe (5) and fins (7); The front collecting pipe (4) and the rear collecting pipe (6) are arc-shaped pipes, and the front collecting pipe (4) and the rear collecting pipe (6) are connected via a connecting pipe (5).

3. The shell and tube reactor according to claim 1, characterized in that The connecting pipe (5) of the heat exchange assembly (2) is composed of at least one heat exchange pipe; Fins (7) are provided on the outer side of the heat exchange tube.

4. The shell and tube reactor according to claim 1, characterized in that The ratio of the cross-sectional area of ​​the heat exchange component (2) to the cross-sectional area of ​​the shell-and-tube reactor is 0.04-0.4:

1.

5. The shell and tube reactor according to claim 3, characterized in that The fins (7) on the outside of the heat exchange tubes are vertically inclined and arranged alternately; The angle α between the fin (7) and the horizontal direction is 5-45°.

6. An apparatus for preparing organic amines, characterized in that: The equipment includes a shell and tube reactor (R01), a gas-liquid separator (V01), an ammonia recovery tower (T01), a raw material recovery tower (T02), and a product tower (T03) connected in sequence; in, The shell-and-tube reactor (R01) is selected from the shell-and-tube reactor described in any one of claims 1 to 5.

7. The device according to claim 6, characterized in that The device also includes a heat exchanger (E01) and a superheater (E02) connected in sequence; The equipment is provided with an inlet for reaction raw materials; The reaction raw material inlet is connected to the cold raw material inlet of the heat exchanger (E01); The material outlet of the superheater (E02) is connected to the inlet I of the shell-and-tube reactor (R01); The outlet I of the shell-and-tube reactor (R01) is connected to the hot material inlet of the heat exchanger (E01).

8. The device according to claim 7, characterized in that The apparatus further comprises a condenser (E03); The hot material outlet of the heat exchanger (E01) is connected to the inlet II of the condenser (E03); The outlet II of the condenser (E03) is connected to the inlet of the gas-liquid separator (V01); The gas-liquid separator (V01) is provided with a gas phase outlet and a liquid phase outlet; The gas phase outlet is connected to the tail gas treatment system; The liquid phase outlet is connected to the ammonia recovery tower (T01).

9. The device according to claim 7, characterized in that The top outlet I of the ammonia recovery tower (T01) is connected to the cold raw material inlet of the heat exchanger (E01); The bottom outlet I of the ammonia recovery tower (T01) is connected to the raw material recovery tower (T02).

10. The device according to claim 7, characterized in that The top outlet II of the raw material recovery tower (T02) is connected to the cold raw material inlet of the heat exchanger (E01); The bottom outlet II of the raw material recovery tower (T02) is connected to the product tower (T03); The top of the product tower (T03) is provided with a tert-butylamine product extraction outlet; The bottom of the product tower (T03) is provided with a high-boiling-substance extraction outlet.

Images