Production process of tert-butylamine

Abstract

The invention provides a tert-butylamine production process, a tert-butylamine production device is adopted, the tert-butylamine production device comprises a reactor, a heater, a heat exchanger, an isobutene preheater, a liquid ammonia preheater, a liquid ammonia vaporizer, a liquid ammonia reheater and an isobutene vaporizer, the reactor is provided with a reaction pipeline and a heat conduction pipeline, and the tert-butylamine production process comprises the following steps: (1) preheating, heating and vaporizing liquid ammonia to obtain ammonia gas; (2) preheating and vaporizing liquid isobutene to obtain vaporized isobutene; (3) sequentially preheating and heating the ammonia gas and the vaporized isobutene, feeding the ammonia gas and the vaporized isobutene into a reaction pipeline, reacting the ammonia gas and the vaporized isobutene in the reaction pipeline to synthesize tert-butylamine so as to obtain a mixed gas, and exchanging heat between the heat-conducting medium in the heat-conducting pipeline and the gas in the reaction pipeline; (4) exchanging heat among the mixed gas, ammonia gas and vaporized isobutene; (5) sequentially preheating and liquefying isobutene and liquid ammonia by using the mixed gas; and (6) preparing a heat-conducting medium, wherein the heat-conducting medium sequentially vaporizes liquid isobutene and heats liquid ammonia. And the tert-butylamine production process is green, environment-friendly and good in economical efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of tert-butylamine synthesis, and in particular to a production process of tert-butylamine. Background Art

[0002] At present, the methods used for industrial production of tert-butylamine mainly include tert-butylurea hydrolysis synthesis method, hydrocyanic acid method, tert-butyl alcohol chlorination amination method and isobutylene amination method. In the tert-butylurea hydrolysis synthesis method and the hydrocyanic acid method, the tert-butyl group comes from isobutylene, tert-butyl alcohol or methyl tert-butyl ether, and the nitrogen source comes from urea or a cyano group. Condensation is carried out in the presence of strong acids such as sulfuric acid, and then a strong base is used to hydrolyze the intermediate product to obtain tert-butylamine. In the tert-butyl alcohol chlorination amination method, tert-butyl alcohol and hydrochloric acid generate chloroalkane, which then undergoes a substitution reaction with ammonia to generate tert-butylamine, and a base is used to neutralize the generated acid during the reaction. The production process of the above method involves the treatment of strong acid / base, and there are toxic and harmful substances in the three wastes, which does not conform to the current environmental protection concept of green chemical industry. The isobutylene amination method is a method in which isobutylene and ammonia directly react to produce tert-butylamine under the action of a solid acid catalyst. Compared with other methods, this method has a short reaction route, high selectivity, few by-products, and a simple product separation method. It has obvious competitive advantages under the current situation of increasingly stringent environmental protection policies.

[0003] In the current patented method for producing tert-butylamine by isobutylene amination, the raw materials isobutylene and liquid ammonia need to be vaporized and heated before entering the reactor. If the heat coupling is not sufficient when designing the process route, the operating energy consumption of the entire process will be greatly increased. At the same time, the isobutylene amination reaction is an exothermic reaction. In order to keep the reactor constant temperature, a shell-and-tube reactor is generally used in the prior art, and the reactor heat release is removed by passing a circulating heat transfer oil through the shell side. In the existing patented technology, a shell-and-tube heat exchanger, a heat transfer oil furnace and two raw material vaporizers are connected in series through a heat transfer oil circulation system, and the reaction heat release is transferred through the circulating heat transfer oil and supplied to the raw material vaporization. Due to the limited reaction heat release, it is not enough to vaporize all the raw materials. The heat transfer oil at the reactor shell side outlet first supplements heat through the heat transfer oil furnace, and then passes through the liquid ammonia vaporizer and the isobutylene vaporizer in sequence to complete the vaporization of the liquid ammonia and isobutylene raw materials.

[0004] At present, in the process of preparing tert-butylamine by isobutylene amination, the design work of the heat transfer oil circulation system of the reaction process is not sufficiently studied, and there is still room for further optimization of the heat transfer oil circulation system. In the heat transfer oil circulation system of the existing patented technology, the heat transfer oil is first used to preheat the feed raw gas after removing the heat released from the reactor, and the remaining heat is used to produce low-pressure steam, and finally returns to the reactor. At the same time, the raw materials isobutylene and liquid ammonia are vaporized by steam under high pressure. Since isobutylene and liquid ammonia have high boiling points under high pressure, this method uses steam to vaporize high-pressure raw materials, which will result in high energy consumption in the process operation. Moreover, the heat transfer oil that absorbs the heat of reaction is at a low temperature after preheating the feed raw gas, and the steam thermal energy grade of the residual heat byproduct is low, and the thermal energy utilization rate of the heat transfer oil circulation system is not high. Summary of the invention

[0005] In order to solve the above problems in the prior art, the present invention provides a production process of tert-butylamine.

[0006] The present invention provides a tert-butylamine production process, which adopts a tert-butylamine production device, which includes a reactor, a heater, a heat exchanger, an isobutylene preheater, a liquid ammonia preheater, a liquid ammonia vaporizer, a liquid ammonia reheater and an isobutylene vaporizer. The reactor is provided with a reaction pipeline and a heat conduction pipeline, and a heat conduction medium is contained in the heat conduction pipeline. The process comprises the following steps:

[0007] (1) Liquid ammonia enters a liquid ammonia preheater, a liquid ammonia reheater and a liquid ammonia vaporizer in sequence. The liquid ammonia is preheated in the liquid ammonia preheater, heated in the liquid ammonia reheater and vaporized in the liquid ammonia vaporizer to obtain ammonia gas;

[0008] (2) liquid isobutylene sequentially enters an isobutylene preheater and an isobutylene vaporizer, the liquid isobutylene is preheated by the isobutylene preheater, and is vaporized by the isobutylene vaporizer to obtain vaporized isobutylene;

[0009] (3) ammonia gas and vaporized isobutylene are mixed and preheated in a heat exchanger and heated by a heater in sequence before entering a reaction pipeline of a reactor. Ammonia gas and vaporized isobutylene react in the reaction pipeline of the reactor to synthesize tert-butylamine to obtain a mixed gas. A heat transfer medium in the heat transfer pipeline of the reactor exchanges heat with the gas in the reaction pipeline. The mixed gas and the heat transfer medium are discharged from the reactor.

[0010] (4) The mixed gas discharged from the reactor enters the heat exchanger to exchange heat with ammonia and vaporized isobutylene in the heat exchanger;

[0011] (5) The mixed gas discharged from the heat exchanger enters the isobutylene preheater and the liquid ammonia preheater in sequence, and preheats the liquefied isobutylene in the isobutylene preheater and the liquid ammonia in the liquid ammonia preheater in sequence;

[0012] (6) The heat transfer medium discharged from the reactor enters the isobutylene vaporizer and the liquid ammonia reheater in sequence, and the heat transfer medium vaporizes the liquid isobutylene in the isobutylene vaporizer and heats the liquid ammonia in the liquid ammonia reheater in sequence, and then returns to the reactor.

[0013] As a specific embodiment of the present invention, the liquid ammonia vaporizer is an electric heating vaporizer or a steam heating vaporizer.

[0014] As a specific embodiment of the present invention, in step (1), liquid ammonia is vaporized using low-pressure steam, and the pressure of the low-pressure steam is 0.2-0.5 Mpag.

[0015] In a specific embodiment of the present invention, in step (1), liquid ammonia is vaporized by electric heating, and preferably, the electric heating is green electricity heating. The green electricity in the present invention is electricity generated by solar energy, wind energy, biomass, etc.

[0016] As a specific embodiment of the present invention, in step (1), liquid ammonia is preheated to 100-120° C. in a liquid ammonia preheater, heated to 105-125° C. in a liquid ammonia reheater, and heated to 120-140° C. in a liquid ammonia vaporizer.

[0017] As a specific embodiment of the present invention, in step (2), liquid isobutylene is preheated to 150-170° C. by an isobutylene preheater and heated to 200-220° C. by an isobutylene vaporizer.

[0018] As a specific embodiment of the present invention, in step (3), the reaction conditions of ammonia and vaporized isobutylene in the reaction pipeline include: temperature: 240°C to 260°C, pressure: 5.0MPaG to 15MPaG.

[0019] As a specific embodiment of the present invention, in step (3), the temperature of the ammonia gas and the vaporized isobutylene after mixing is 160-180°C, the ammonia gas and the vaporized isobutylene are preheated to 225-245°C by a heat exchanger, and heated to 240-260°C by a heater.

[0020] As a specific embodiment of the present invention, in step (4), the temperature of the mixed gas discharged from the reactor is 240-260°C, and the temperature of the mixed gas drops to 170-190°C after heat exchange in the heat exchanger. After the mixed gas is preheated with isobutylene, the temperature drops to 120-140°C, and after the mixed gas is preheated with liquid ammonia, the temperature drops to 90-110°C.

[0021] As a specific embodiment of the present invention, in step (5), the temperature of the heat transfer medium discharged from the reactor is 240-260°C, and the temperature of the heat transfer medium returned to the reactor is 220-240°C.

[0022] Preferably, the heat transfer medium is heat transfer oil, the flow rate of the heat transfer oil is 0.5-2 m / s, the heat capacity is 0.08-0.10 kcal / kg°C, and the density is 700-900 kg / m 3 .

[0023] The tert-butylamine production process provided by the present invention is green, environmentally friendly and economical. The tert-butylamine production process provided by the present invention uses a production device that does not have a large footprint, consumes a lot of natural gas, and has complicated environmental treatment operations. Low-pressure steam or green electricity is used instead of natural gas to supplement the heat gap of vaporized raw materials, which has the advantages of low device operation energy consumption, low operation cost, small footprint, high environmental protection, etc.

[0024] In the process of tert-butylamine production, both liquid ammonia and liquid isobutylene need to be vaporized. The present invention utilizes limited reaction heat to preferentially vaporize liquid isobutylene with a higher boiling point and lower latent heat of vaporization, thereby improving the utilization of heat energy from the reaction heat. At the same time, after the liquid isobutylene is vaporized, the residual heat of the heat transfer medium heats the liquid ammonia to a temperature close to the vaporization temperature. In the tert-butylamine production process of the present invention, the vaporization process of liquid isobutylene is completed by the reaction heat absorbed by the heat transfer oil, and the vaporization of low-boiling point liquid ammonia is completed by the reaction heat absorbed by the heat transfer oil and cheap and readily available low-pressure steam or green electricity. The present invention utilizes different heat sources to specifically complete the vaporization process of the two raw materials based on the differences in boiling points and latent heats of vaporization of the two raw materials, thereby greatly reducing the energy consumption and operating costs of the device.

[0025] The present invention strictly controls the temperature of the heat-conducting medium entering and exiting the shell of the reactor through design calculation, so that the reactor is kept in a constant temperature reaction state. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A diagram of an apparatus used in a process for producing tert-butylamine in Example 1 of the present invention;

[0027] Figure 2 A diagram of an apparatus used in a tert-butylamine production process in Comparative Example 1 of the present invention;

[0028] Among them, 1-first tubular reactor, 2-first heater, 3-first heat exchanger; 4-first isobutylene preheater; 5-first liquid ammonia preheater; 6-first liquid ammonia vaporizer; 7-first liquid ammonia reheater; 8-first isobutylene vaporizer;

[0029] 21-second tubular reactor; 22-second heater; 23-second heat exchanger, 24-second isobutylene preheater, 25-second liquid ammonia preheater, 26-thermal oil furnace, 27-second liquid ammonia vaporizer, 28-second isobutylene vaporizer. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with specific embodiments, but they do not constitute any limitation to the present invention.

[0031] Example 1

[0032] The tert-butylamine production process provided by the present invention adopts Figure 1 The tert-butylamine production device shown includes a first tubular reactor 1, a first heater 2, a first heat exchanger 3, a first isobutylene preheater 4, a first liquid ammonia preheater 5, a first liquid ammonia vaporizer 6, a first liquid ammonia reheater 7 and a first isobutylene vaporizer 8. A reaction pipeline and a heat transfer pipeline are arranged in the first tubular reactor 1. Ammonia gas in the reaction pipeline reacts with vaporized isobutylene to generate tert-butylamine, and a mixed gas containing unreacted ammonia gas, unreacted vaporized isobutylene and tert-butylamine is obtained. The heat transfer pipeline is filled with heat transfer oil, and the heat transfer oil exchanges heat with the gas in the reaction pipeline. During the operation of the tert-butylamine production device, liquid ammonia enters the first liquid ammonia preheater 5, the first liquid ammonia reheater 7 and the first liquid ammonia vaporizer 6 in sequence, and liquefied isobutylene enters the first isobutylene preheater 4 and the first isobutylene vaporizer 8 in sequence. The ammonia discharged from the first liquid ammonia vaporizer 6 is mixed with the vaporized isobutylene discharged from the first isobutylene vaporizer 8 and then enters the first heat exchanger 3. The mixed gas discharged from the first tubular reactor 1 exchanges heat with the ammonia and vaporized isobutylene in the first heat exchanger 3. The ammonia and vaporized isobutylene discharged from the first heat exchanger 3 are heated by the first heater 2 and enter the first tubular reactor 1. The mixed gas discharged from the first heat exchanger 3 enters the first isobutylene preheater 4 and the first liquid ammonia preheater 5 in turn, and after preheating the liquefied isobutylene and liquid ammonia in turn, enters the downstream distillation equipment to separate tert-butylamine. The heat transfer oil discharged from the first tubular reactor 1 enters the first isobutylene vaporizer 8 and the first liquid ammonia reheater 7 in turn, vaporizes isobutylene in turn, heats the liquid ammonia, and then returns to the first tubular reactor 1 to complete a cycle. The first liquid ammonia vaporizer 6 is a steam-heated vaporizer, and the liquid ammonia is completely vaporized by low-pressure steam in the first liquid ammonia vaporizer 6.

[0033] In the tert-butylamine production process in this embodiment, the feed molar ratio of liquid ammonia to isobutylene is 2.5:1, based on an annual operating time of 8,000 hours and an annual output of 100,000 tons of tert-butylamine. In this embodiment, the tert-butylamine production process is operated according to the following parameters: liquid ammonia enters the first liquid ammonia preheater 5, and the liquid ammonia is preheated to 120°C in the first liquid ammonia preheater 5, and then heated to 124°C by the first liquid ammonia reheater 7, and enters the first liquid ammonia vaporizer 6. In the first liquid ammonia vaporizer 6, the temperature of the liquid ammonia rises to 128°C under the action of 0.3Mpag low-pressure steam, and the liquid ammonia is completely vaporized into ammonia gas. Liquid isobutylene is preheated to 160°C by the first isobutylene preheater 4, enters the first isobutylene vaporizer 8, and is heated to 210°C in the first isobutylene vaporizer 8. The liquid isobutylene is completely vaporized to obtain vaporized isobutylene. Ammonia gas and vaporized isobutylene are mixed and enter the first heat exchanger 3. The temperature of the mixed gas of ammonia and vaporized isobutylene entering the first heat exchanger 3 is 172°C, and the mixed gas discharged from the first tubular reactor 1 exchanges heat with ammonia and vaporized isobutylene in the first heat exchanger 3. The temperature of ammonia and vaporized isobutylene in the first heat exchanger 3 rises to 240°C, and ammonia and vaporized isobutylene enter the first heater 2 after being discharged from the first heat exchanger 3. After being heated to 250°C by the first heater 2, ammonia and vaporized isobutylene enter the reaction pipeline in the first tubular reactor 1.

[0034] In the reaction pipeline, the reaction conditions of ammonia and vaporized isobutylene are a temperature of 250°C and a pressure of 10MPaG. In the reaction pipeline in the first tubular reactor 1, ammonia and vaporized isobutylene react to generate tert-butylamine to obtain a mixed gas. The temperature of the mixed gas discharged from the first tubular reactor 1 is 250°C, and the temperature of the mixed gas drops to 188°C after heat exchange in the heat exchanger 3. The mixed gas discharged from the first heat exchanger 3 enters the first isobutylene preheater 4 and the first liquid ammonia preheater 5 in sequence, and preheats the liquid isobutylene and liquid ammonia in turn. The temperature of the mixed gas after preheating the liquefied isobutylene drops to 132°C, and the temperature of the mixed gas after preheating the liquid ammonia drops to 107°C. The mixed gas discharged from the first liquid ammonia preheater 5 enters the downstream distillation equipment to separate and obtain tert-butylamine. The temperature of the heat transfer oil discharged from the first tubular reactor 1 is 240°C, and the flow rate is 1.57m / s. The heat transfer oil enters the first isobutylene vaporizer 8 and the first liquid ammonia reheater 7 in turn, vaporizes the liquid isobutylene, heats the liquid ammonia, and after vaporizing the isobutylene, the heat transfer oil is cooled to 233.6°C. After heating the liquid ammonia, the heat transfer oil is cooled to 230°C and returns to the first tubular reactor 1 to complete a cycle. The heat capacity of the heat transfer oil is 0.093kcal / kg℃, and the density is 820kg / m 3 The temperature difference of the heat transfer oil entering and exiting the first tube reactor 1 is 10°C.

[0035] Example 1 The energy consumption analysis of the tert-butylamine production process is shown in Table 1, and the temperature change of the reaction system is shown in Table 2. The heat transfer oil absorbs 2522.93 kWh of heat released from the first tubular reactor 1, and the heat consumed by the vaporization of liquid isobutylene is 1609.28 kWh. The remaining 913.65 kWh can heat the liquid ammonia to 124°C, and then 5207.8 kWh is provided by 0.3 Mpag steam to vaporize all the liquid ammonia at 124°C.

[0036] Table 1 Energy consumption analysis of the reaction system of tert-butylamine production process in Example 1

[0037]

[0038] Table 2 Temperature variation of the reaction system in the tert-butylamine production process in Example 1

[0039] Process Description Heat kWh △t / ℃ illustrate Absorption reaction exothermic 2522.93 10 After the absorption reaction releases heat, the temperature out of the reactor is 240℃ Vaporized isobutylene 1609.28 6.4 After vaporizing isobutylene, the heat transfer oil is cooled to 233.6℃ Heat liquid ammonia to 124°C 913.65 3.6 After vaporizing the liquid ammonia, the heat transfer oil is cooled to 230°C and returned to the reactor.

[0040] In this embodiment, the calorific value of 0.3Mpag steam is 2725.5kJ / kg (0.757kWh), the price is 200 yuan / t, and 6.88t / h of steam is required to provide 5207.8kWh, and the annual operating cost is 11.008 million yuan / year.

[0041] Example 2

[0042] Example 2 provides a tert-butylamine production process. The difference between Example 2 and Example 1 is that the first liquid ammonia vaporizer is an electric heating vaporizer, the slurry ammonia is completely vaporized in the first liquid chlorine vaporizer, and the electricity used by the electric heating vaporizer in this embodiment is green electricity, specifically solar power generation. The rest is the same as Example 1.

[0043] Green electricity is used as the energy source for liquid ammonia vaporization, providing 5207.8 kWh of heat. The price of green electricity is 0.4 yuan / kWh, and the annual operating cost is 16.665 million yuan / year.

[0044] Comparative Example 1

[0045] A process for producing tert-butylamine, using Figure 2 The tert-butylamine production device shown includes a second tubular reactor 21, a second heater 22, a second heat exchanger 23, a second isobutylene preheater 24, a second liquid ammonia preheater 25, a thermal oil furnace 26, a second liquid ammonia vaporizer 27, and a second isobutylene vaporizer 28.

[0046] The second tubular reactor 21 is provided with a reaction pipeline and a heat transfer pipeline. Ammonia in the reaction pipeline reacts with vaporized isobutylene to generate tert-butylamine, and a mixed gas containing unreacted ammonia, unreacted vaporized isobutylene and tert-butylamine is obtained. The heat transfer pipeline is filled with heat transfer oil, and the heat transfer oil exchanges heat with the gas in the reaction pipeline. During the operation of the device, liquid ammonia enters the second liquid ammonia preheater 25 and the second liquid ammonia vaporizer 27 in sequence, and liquid isobutylene enters the first isobutylene preheater 24 and the second isobutylene vaporizer 28 in sequence. The ammonia discharged from the second liquid ammonia vaporizer 27 is mixed with the vaporized isobutylene discharged from the second isobutylene vaporizer 28 and then enters the second heat exchanger 23. The mixed gas discharged from the second tubular reactor 21 exchanges heat with ammonia and vaporized isobutylene in the second heat exchanger 23. The ammonia and vaporized isobutylene discharged from the second heat exchanger 23 are heated by the second heater 22 and then enter the second tubular reactor 21. The mixed gas discharged from the second heat exchanger 23 enters the second isobutylene preheater 24 and the second liquid ammonia preheater 25 in sequence, preheats the liquid isobutylene and liquid ammonia in sequence, and then enters the downstream distillation equipment to separate tert-butylamine. The heat transfer oil discharged from the second tubular reactor 21 enters the heat transfer oil furnace 6, the second liquid ammonia vaporizer 27 and the second isobutylene vaporizer 28 in sequence, and the heat transfer oil is heated by the heat transfer oil furnace 26 to vaporize the liquid ammonia and liquid isobutylene in sequence, and then returns to the second tubular reactor 21, completing a cycle.

[0047] The tert-butylamine production process in this comparative example is based on an annual operating time of 8,000 hours and an annual output of 100,000 tons of tert-butylamine, and the feed molar ratio of liquid ammonia to isobutylene is 2.5:1. The tert-butylamine production process in this comparative example is operated according to the following parameters: liquid ammonia enters the second liquid ammonia preheater 25, and the liquid ammonia is preheated to 120°C in the second liquid ammonia preheater 25, and then enters the second liquid ammonia vaporizer 27. In the second liquid ammonia vaporizer 27, the liquid ammonia temperature rises to 128°C, and the liquid ammonia is completely vaporized into ammonia gas. Liquid isobutylene is preheated to 160°C in the second isobutylene preheater 24, and then enters the second isobutylene vaporizer 28, and is heated to 210°C in the second isobutylene vaporizer 28, and is completely vaporized into vaporized isobutylene. After ammonia and vaporized isobutylene are mixed, they enter the second heat exchanger 23. The temperature of the mixed gas of ammonia and vaporized isobutylene entering the second heat exchanger 23 is 172°C. The mixed gas discharged from the second tube-in-tube reactor 21 exchanges heat with ammonia and vaporized isobutylene in the second heat exchanger 23. After the temperature of the ammonia and vaporized isobutylene discharged from the second heat exchanger 23 rises to 240°C, they enter the second heater 22. After being heated to 250°C by the second heater 22, they enter the reaction pipeline in the second tube-in-tube reactor 21.

[0048] In the reaction pipeline, the reaction conditions of ammonia and vaporized isobutylene are a temperature of 250°C and a pressure of 10MPaG. In the reaction pipeline in the second tubular reactor 21, ammonia and vaporized isobutylene react to generate tert-butylamine to obtain a mixed gas. The temperature of the mixed gas discharged from the second tubular reactor 21 is 250°C, and the temperature drops to 188°C after heat exchange in the second heat exchanger 23. The mixed gas discharged from the second heat exchanger 23 enters the second isobutylene preheater 24 and the second liquid ammonia preheater 25 in turn, and preheats the liquid isobutylene and liquid ammonia in turn. The temperature of the mixed gas after preheating the liquefied isobutylene drops to 132°C, and the temperature of the mixed gas after preheating the liquid ammonia drops to 107°C. The mixed gas discharged from the second liquid ammonia preheater 25 enters the downstream distillation equipment to separate and obtain tert-butylamine. The temperature of the heat transfer oil discharged from the second tubular reactor 21 is 240°C, and the flow rate is 1.57m / s. The heat transfer oil enters the heat transfer oil furnace 26, the second liquid ammonia vaporizer 27 and the second isobutylene vaporizer 28 in sequence. After being heated by the heat transfer oil furnace 26, the temperature of the heat transfer oil rises to 260.6°C, and then the heat transfer oil vaporizes liquid ammonia and liquid isobutylene in sequence. After vaporizing isobutylene, the heat transfer oil cools down to 236.4°C. After heating the liquid ammonia, the heat transfer oil cools down to 230°C and returns to the second tubular reactor 21, completing a cycle. The heat capacity of the heat transfer oil is 0.093kcal / kg℃, and the density is 820kg / m 3 The temperature difference of the heat transfer oil entering and leaving the reactor is 10°C.

[0049] In Comparative Example 1, the heat required for preheating liquid ammonia and preheating isobutylene is provided by the mixed gas discharged from the second tubular reactor 21, that is, provided by the reaction exothermic heat; the heat required for vaporizing liquid ammonia and vaporizing liquid isobutylene is provided by the reaction exothermic heat and the heat transfer oil furnace 26, and is transferred through the heat transfer oil.

[0050] The energy consumption analysis of the tert-butylamine production process in Comparative Example 1 is shown in Table 3, and the temperature change of the reaction system is shown in Table 4.

[0051] Table 3 Energy consumption analysis of the production process of tert-butylamine in Comparative Example 1

[0052]

[0053] Table 4 Temperature variation of tert-butylamine production process in comparative example 1

[0054] Process Description Heat kWh △t / ℃ illustrate Absorption reaction exothermic 2522.93 10 After the absorption reaction releases heat, the temperature out of the reactor is 240℃ Heating furnace heating 5207.80 20.6 After being heated by the heat transfer oil, the temperature of the heat transfer oil rises to 260.6℃ Vaporized liquid ammonia 6121.45 24.2 After vaporizing the liquid ammonia, the heat transfer oil is cooled to 236.4℃ Vaporized isobutylene 1609.28 6.4 After vaporizing isobutylene, the heat transfer oil is cooled to 230°C and returned to the reactor.

[0055] In Comparative Example 1, the total heat required for raw material vaporization and the heat absorbed by the heat transfer oil from the reaction pipeline are consistent with those in Example 1. The total heat required for raw material vaporization is 7730.73 kWh, and the heat absorbed by the heat transfer oil from the reactor is 2522.93 kWh. Therefore, before the circulating heat transfer oil is passed into the two raw material vaporizers, 5207.8 kWh of heat must be supplemented by the heat transfer oil furnace.

[0056] The heat of the thermal oil furnace in this comparative example is generally provided by burning natural gas, and the calorific value of natural gas is 389.31GJ / 10,000Nm 3 (10.8kWh / Nm 3 ), the natural gas price is 4 yuan / Nm 3 , 5207.8kWh requires 482.2Nm of natural gas 3 / h, and the annual operating cost is 15.431 million yuan / year.

[0057] According to the "Guidelines for Calculating and Reporting Greenhouse Gas Emissions of Petrochemical Enterprises in China", the CO2 emissions from the combustion of natural gas in the thermal oil furnace in Example 1 are It is 2276 tons of CO2 / year.

[0058] Compared with the tert-butylamine production process operating costs in Example 1 and Comparative Example 1, Example 1 saves 4.423 million yuan per year in the heat transfer oil circulation system of the raw material vaporization part and reduces CO2 emissions.

[0059] The operating costs of using a thermal oil furnace to vaporize liquid ammonia in Example 2 and Comparative Example 1 are similar, but it is generally believed that green electricity has no carbon emissions, so the CO2 emissions of Example 2 are 0. Compared with the combustion of natural gas in the thermal oil furnace in Comparative Example 1, Example 2 reduces carbon dioxide emissions by 2,276 tons per year.

[0060] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A tert-butylamine production process, using a tert-butylamine production device, the tert-butylamine production device includes a reactor, a heater, a heat exchanger, an isobutylene preheater, a liquid ammonia preheater, a liquid ammonia vaporizer, a liquid ammonia reheater and an isobutylene vaporizer, the reactor is provided with a reaction pipeline and a heat transfer pipeline, the heat transfer pipeline is filled with a heat transfer medium, characterized in that: The steps include: (1) Liquid ammonia enters the liquid ammonia preheater, liquid ammonia reheater and liquid ammonia vaporizer in sequence, and is preheated, heated and vaporized to obtain ammonia gas; (2) liquid isobutylene enters an isobutylene preheater and an isobutylene vaporizer in sequence, and is preheated and vaporized to obtain vaporized isobutylene; (3) ammonia gas and vaporized isobutylene are mixed and preheated by a heat exchanger and heated by a heater in sequence before entering a reaction pipeline, where ammonia gas and vaporized isobutylene react to synthesize tert-butylamine in the reaction pipeline to obtain a mixed gas, a heat transfer medium exchanges heat with the gas in the reaction pipeline, and the mixed gas and the heat transfer medium are discharged from the reactor; (4) The mixed gas discharged from the reactor enters the heat exchanger to exchange heat with ammonia and vaporized isobutylene in the heat exchanger; (5) The mixed gas discharged from the heat exchanger enters the isobutylene preheater and the liquid ammonia preheater in sequence to preheat the liquid isobutylene and liquid ammonia in sequence; (6) The heat transfer medium discharged from the reactor enters the isobutylene vaporizer and the liquid ammonia reheater in sequence, vaporizes the liquid isobutylene and heats the liquid ammonia in sequence, and then returns to the reactor.

2. The process for producing tert-butylamine according to claim 1, characterized in that: The liquid ammonia vaporizer is an electric heating vaporizer or a steam heating vaporizer.

3. The process for producing tert-butylamine according to claim 2, characterized in that: In step (1), liquid ammonia is vaporized using low-pressure steam, wherein the pressure of the low-pressure steam is 0.2-0.5 Mpag.

4. The process for producing tert-butylamine according to claim 2, characterized in that: In step (1), liquid ammonia is vaporized by electric heating. Preferably, the electric heating is green electricity heating.

5. The process for producing tert-butylamine according to any one of claims 1 to 4, characterized in that: In step (1), liquid ammonia is preheated to 100-120° C. in a liquid ammonia preheater, heated to 105-125° C. in a liquid ammonia reheater, and heated to 120-140° C. in a liquid ammonia vaporizer.

6. The process for producing tert-butylamine according to any one of claims 1 to 5, characterized in that: In step (2), liquid isobutylene is preheated to 150-170° C. in an isobutylene preheater and heated to 200-220° C. in an isobutylene vaporizer.

7. The process for producing tert-butylamine according to any one of claims 1 to 6, characterized in that: In step (3), the reaction conditions of ammonia and vaporized isobutylene in the reaction pipeline include: temperature: 240° C. to 260° C., pressure: 5.0 MPaG to 15 MPaG.

8. The process for producing tert-butylamine according to any one of claims 1 to 7, characterized in that: In step (3), the temperature of the ammonia gas and the vaporized isobutylene after mixing is 160-180° C. The ammonia gas and the vaporized isobutylene are preheated to 225-245° C. by a heat exchanger and heated to 240-260° C. by a heater.

9. The process for producing tert-butylamine according to any one of claims 1 to 8, characterized in that: In step (4), the temperature of the mixed gas discharged from the reactor is 240-260° C., and the temperature of the mixed gas drops to 170-190° C. after heat exchange in the heat exchanger. After the mixed gas is preheated with isobutylene, the temperature drops to 120-140° C., and after the mixed gas is preheated with liquid ammonia, the temperature drops to 90-110° C.

10. The process for producing tert-butylamine according to any one of claims 1 to 9, characterized in that: In step (5), the temperature of the heat-conducting medium discharged from the reactor is 240-260°C, and the temperature of the heat-conducting medium returned to the reactor is 220-240°C; preferably, the heat-conducting medium is heat-conducting oil, the flow rate of the heat-conducting oil is 0.5-2 m / s, the heat capacity is 0.08-0.100 cal / 0g°C, and the density is 700-9000 g / m 3 .

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