阅读说明：本技术 工业化生产四氢糠醇***中循环使用溴元素的装置及方法 (Device and method for recycling bromine element in industrial production of tetrahydrofurfuryl alcohol ether ) 是由 朱荣辉 于 2019-09-30 设计创作，主要内容包括：本发明涉及一种工业化生产四氢糠醇乙醚中循环使用溴元素的装置及方法,所述装置包括依次顺序相连的原料储蓄-计量输送系统、内置床反应釜、溴化氢吸收罐、固定床反应器、降膜蒸发器、冷凝器和产品罐,所述装置还包括乙烯储蓄-计量输送单元和硫酸钾罐,所述乙烯储蓄-计量输送单元与所述固定床反应器相连,所述硫酸钾罐与所述内置床反应釜的底部相连。通过本发明的装置和方法生产得到的溴乙烷综合收率为92～95％,且纯度达到98.5～99.5％,可满足四氢糠醇乙醚生产对原料质量的要求,大幅降低了四氢糠醇乙醚的生产成本,实现高价值溴元素的循环利用,节约资源,环境友好。(The invention relates to a device and a method for recycling bromine in industrial production of tetrahydrofurfuryl alcohol ether, wherein the device comprises a raw material storage-metering conveying system, a built-in bed reaction kettle, a hydrogen bromide absorption tank, a fixed bed reactor, a falling film evaporator, a condenser and a product tank which are sequentially connected, the device also comprises an ethylene storage-metering conveying unit and a potassium sulfate tank, the ethylene storage-metering conveying unit is connected with the fixed bed reactor, and the potassium sulfate tank is connected with the bottom of the built-in bed reaction kettle. The comprehensive yield of the bromoethane produced by the device and the method is 92-95%, the purity of the bromoethane reaches 98.5-99.5%, the requirement of tetrahydrofurfuryl alcohol ether production on the quality of raw materials can be met, the production cost of tetrahydrofurfuryl alcohol ether is greatly reduced, the cyclic utilization of high-value bromine elements is realized, resources are saved, and the method is environment-friendly.)

1. A device for recycling bromine in the process of industrially producing tetrahydrofurfuryl alcohol ether is characterized by comprising a raw material storage-metering conveying system, a built-in bed reaction kettle (7), a hydrogen bromide absorption tank (8), a fixed bed reactor (12), a falling film evaporator (19), a condenser (16) and a product tank (17) which are connected in sequence;

a stirring paddle is arranged in the built-in bed reaction kettle (7), and a fixed bed layer made of sintered ceramics is arranged above the stirring paddle;

the raw material storage-metering conveying system consists of a potassium bromide aqueous solution storage-metering conveying unit, a concentrated sulfuric acid storage-metering conveying unit and a hydrogen storage-metering conveying unit which are arranged in parallel;

the device also comprises an ethylene storage-metering conveying unit and a potassium sulfate tank (20), wherein the ethylene storage-metering conveying unit is connected with the fixed bed reactor (12), and the potassium sulfate tank (20) is connected with the bottom of the built-in bed reaction kettle (7).

2. The device according to claim 1, wherein the potassium bromide aqueous solution storage-metering conveying unit consists of a potassium bromide solution storage tank (1) and a potassium bromide solution conveying pump (2) which are connected in sequence, the concentrated sulfuric acid storage-metering conveying unit consists of a concentrated sulfuric acid storage tank (3) and a concentrated sulfuric acid conveying pump (4) which are connected in sequence, the hydrogen storage-metering conveying unit consists of a hydrogen storage tank (5) and a hydrogen meter (6) which are connected in sequence, and the ethylene storage-metering conveying unit consists of an ethylene storage tank (10) and an ethylene meter (11) which are connected in sequence; the potassium bromide solution delivery pump (2), the concentrated sulfuric acid delivery pump (4) and the hydrogen gauge (6) are respectively connected with the built-in bed reaction kettle (7), and the ethylene gauge (11) is connected with the fixed bed reactor (12).

3. The device according to claim 1 or 2, wherein the fixed bed layer of the built-in bed reaction kettle (7) is provided with two circles of through holes penetrating through the upper side and the lower side of the fixed bed layer, preferably, the bed volume of the built-in bed reaction kettle (7) is less than or equal to 20% of the volume of the reaction kettle.

4. The apparatus according to any one of claims 1 to 3, wherein the fixed bed reactor (12) has a bed volume of 70% or less of the reactor volume and the bed packing is alumina ceramic balls.

5. The device according to any one of claims 1 to 4, wherein a spray head for spraying atomized water is arranged in the hydrogen bromide absorption tank (8), and a hydrogen outlet for emptying hydrogen is arranged on the hydrogen bromide absorption tank (8).

6. The apparatus according to any one of claims 1-5, wherein a circulation line is provided between the top and the bottom of the fixed bed reactor (12).

7. The plant according to any one of claims 1 to 6, further comprising a crude bromoethane storage tank (14), the crude bromoethane storage tank (14) being provided between the fixed bed reactor (12) and the falling film evaporator (19).

8. A method for recycling bromine in the industrial production process of tetrahydrofurfuryl alcohol ethyl ether by using the device of any one of claims 1-7, which is characterized by comprising the following steps: inputting a potassium bromide aqueous solution and concentrated sulfuric acid which are byproducts generated in the industrial production process of tetrahydrofurfuryl alcohol ether into a reactor (7) with a built-in bed to react in the presence of hydrogen to obtain a gas-phase product, inputting the gas-phase product into a hydrogen bromide absorption tank (8), spraying atomized water to absorb hydrogen bromide to obtain a hydrogen bromide solution, inputting the hydrogen bromide solution and ethylene into a fixed bed reactor (12) to react, and processing the reaction product by a falling film evaporator (19) to obtain a bromoethane product.

9. The method according to claim 8, wherein the method comprises the steps of:

(1) inputting a potassium bromide aqueous solution and hydrogen which are byproducts generated in the industrial production process of tetrahydrofurfuryl alcohol ether into a built-in bed reaction kettle (7), slowly adding concentrated sulfuric acid into the built-in bed reaction kettle (7), and outputting a gas-phase product after full reaction;

(2) inputting the gas-phase product obtained in the step (1) into a hydrogen bromide absorption tank (8), spraying atomized water to absorb hydrogen bromide to obtain a hydrogen bromide solution, inputting the hydrogen bromide solution and ethylene into a fixed bed reactor (12) for cyclic reaction, and outputting a reaction product after full reaction;

(3) inputting the reaction product in the step (2) into a falling-film evaporator (19), and collecting a fraction at 35-40 ℃ to obtain bromoethane;

(4) recycling the bromoethane to a raw material system for producing tetrahydrofurfuryl alcohol ether, namely completing the recycling of bromine;

preferably, the mass fraction of the potassium bromide in the potassium bromide aqueous solution is 25-35%, based on the total input amount of concentrated sulfuric acid, and the potassium bromide in the potassium bromide aqueous solution and the H in the concentrated sulfuric acid are added into the built-in bed reaction kettle (7)₂SO₄The molar ratio is 1.55-2.15: 0.75 to 1.65; the mass fraction of hydrogen bromide in the hydrogen bromide solution is 45-55%, and the molar ratio of hydrogen bromide to ethylene in the hydrogen bromide solution input into the fixed bed reactor (12) is 0.66-1.15: 0.77-1.25.

10. The method according to claim 8 or 9, wherein the reaction temperature of the built-in bed reaction kettle (7) is 15-45 ℃, the hydrogen partial pressure is 500-750 Pa, the reaction temperature of the fixed bed reactor (12) is 45-70 ℃, and the reaction pressure is 0.2-0.3 MPa;

preferably, the reaction temperature of the built-in bed reaction kettle (7) is 22-41 ℃, the reaction temperature of the fixed bed reactor (12) is 50-65 ℃, and the pressure is 0.22-0.3 Mpa;

more preferably, the reaction temperature of the fixed bed reactor (12) is 55-65 ℃.

Technical Field

The invention belongs to the technical field of preparation of halogenated hydrocarbon compounds, and particularly relates to a device and a method for recycling bromine in an industrial production process of tetrahydrofurfuryl alcohol ether.

Background

Bromoethane, also known as ethyl bromide, has the molecular formula C₂H₅B_r. The invention patent with the publication number of CN105503784A discloses a method for producing tetrahydrofurfuryl alcohol ethyl ether by industrial ultrasonic reaction, which comprises the steps of mixing tetrahydrofurfuryl alcohol, ethyl bromide and potassium hydroxide aqueous solution, and performing ultrasonic treatmentFully reacting under the condition, removing most of water from the obtained reaction product, and then carrying out reduced pressure distillation to obtain the tetrahydrofurfuryl alcohol ether. In the method disclosed in CN105503784A, bromoethane is one of the main raw materials for the industrial production of tetrahydrofurfuryl alcohol ethyl ether, but the bromine element, which is the most valuable part, appears as a low-value-added potassium bromide byproduct after the production process, resulting in a great waste of resources.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a device and a method for recycling bromine in the industrial production process of tetrahydrofurfuryl alcohol ethyl ether, which take byproduct potassium bromide aqueous solution and ethylene easily obtained in a resource enrichment area in the industrial production process of tetrahydrofurfuryl alcohol ethyl ether as main raw materials, convert the main raw materials into production raw material of tetrahydrofurfuryl alcohol ethyl ether, namely bromoethane through a specific reaction process, and comprehensively couple the production raw material into the production optimization of tetrahydrofurfuryl alcohol ethyl ether, thereby realizing the recycling of high-value bromine, saving resources and being environment-friendly.

Specifically, the present invention provides the following technical solutions.

A device for recycling bromine in the process of industrially producing tetrahydrofurfuryl alcohol ether comprises a raw material storage-metering conveying system, a built-in bed reaction kettle 7, a hydrogen bromide absorption tank 8, a fixed bed reactor 12, a falling film evaporator 19, a condenser 16 and a product tank 17 which are connected in sequence;

a stirring paddle is arranged inside the reaction kettle 7 with the built-in bed, and a fixed bed layer made of sintered ceramics is arranged above the stirring paddle;

the raw material storage-metering conveying system consists of a potassium bromide aqueous solution storage-metering conveying unit, a concentrated sulfuric acid storage-metering conveying unit and a hydrogen storage-metering conveying unit which are arranged in parallel;

the device also comprises an ethylene storage-metering conveying unit and a potassium sulfate tank 20, wherein the ethylene storage-metering conveying unit is connected with the fixed bed reactor 12, and the potassium sulfate tank 20 is connected with the bottom of the reaction kettle 7 with the built-in bed.

Preferably, in the above device, the potassium bromide aqueous solution storage-metering conveying unit is composed of a potassium bromide solution storage tank 1 and a potassium bromide solution conveying pump 2 which are connected in sequence, the concentrated sulfuric acid storage-metering conveying unit is composed of a concentrated sulfuric acid storage tank 3 and a concentrated sulfuric acid conveying pump 4 which are connected in sequence, the hydrogen storage-metering conveying unit is composed of a hydrogen storage tank 5 and a hydrogen meter 6 which are connected in sequence, and the ethylene storage-metering conveying unit is composed of an ethylene storage tank 10 and an ethylene meter 11 which are connected in sequence; the potassium bromide solution delivery pump 2, the concentrated sulfuric acid delivery pump 4 and the hydrogen gauge 6 are respectively connected with the built-in bed reaction kettle 7, and the ethylene gauge 11 is connected with the fixed bed reactor 12.

Preferably, in the above apparatus, as shown in fig. 2, two circles of through holes penetrating through the upper and lower sides of the fixed bed layer are provided on the fixed bed layer of the internal bed reaction kettle 7, more preferably, the bed volume of the internal bed reaction kettle 7 is less than or equal to 20% of the reaction kettle volume, and most preferably, the volume of the internal bed reaction kettle 7 is less than or equal to 2000L. Because the reaction of the potassium bromide aqueous solution and the sulfuric acid to generate the hydrogen bromide is violent and is easy to generate the phenomenon of 'bumping' so as to cause the occurrence of unsafe conditions, the inventor of the patent designs a special reaction kettle with a built-in bed, the upper part of a stirring paddle is provided with a section of fixed bed made of sintered ceramics, the porous structure of the fixed bed is favorable for the overflow of the hydrogen bromide, and two circles of small-diameter through holes are arranged so as to be favorable for the liquid to pass through, thereby having the functions of providing more reaction contact areas and inhibiting 'bumping'.

Preferably, in the above device, the bed volume of the fixed bed reactor 12 is less than or equal to 70% of the reactor volume, and the bed packing is alumina ceramic balls, more preferably, the volume of the fixed bed reactor 12 is less than or equal to 2000L.

Preferably, in the above device, a spray head for spraying atomized water is arranged in the hydrogen bromide absorption tank 8, and a hydrogen outlet for emptying hydrogen is arranged on the hydrogen bromide absorption tank 8.

Preferably, in the above apparatus, a circulation line is provided between the top and the bottom of the fixed bed reactor 12.

Preferably, the device further comprises a crude bromoethane storage tank 14, wherein the crude bromoethane storage tank 14 is arranged between the fixed bed reactor 12 and the falling film evaporator 19.

Preferably, in the above device, a product reflux pump 18 is connected to the product tank 17 to reflux the product to the falling film evaporator 19.

The invention also provides a method for recycling bromine element in the process of industrially producing tetrahydrofurfuryl alcohol ether by using the device, which comprises the following steps: inputting a potassium bromide aqueous solution and concentrated sulfuric acid which are byproducts generated in the industrial production process of tetrahydrofurfuryl alcohol ether into a reactor 7 with a built-in bed to react in the presence of hydrogen to obtain a gas-phase product, inputting the gas-phase product into a hydrogen bromide absorption tank 8, spraying atomized water to absorb hydrogen bromide to obtain a hydrogen bromide solution, inputting the hydrogen bromide solution and ethylene into a fixed bed reactor 12 to react, and processing the reaction product by a falling film evaporator 19 to obtain a bromoethane product.

The main reactions occurring in the internal bed reactor 7 are:

H₂SO₄+2KBr→2HBr↑+K₂SO₄

the main reaction mechanism of the above reaction is: potassium bromide is oxidized to hydrobromic acid in a strong acid environment.

The reactions that mainly take place in the fixed bed reactor 12 are:

HBr+C₂H₄→C₂H₅Br

the main reaction mechanism of the above reaction is: hydrobromic acid undergoes an addition reaction with ethylene on a fixed bed to produce ethyl bromide.

Preferably, the above method comprises the steps of:

(1) inputting a potassium bromide aqueous solution and hydrogen which are byproducts generated in the industrial production process of tetrahydrofurfuryl alcohol ether into a built-in bed reaction kettle 7, slowly adding concentrated sulfuric acid into the built-in bed reaction kettle 7, and outputting a gas-phase product after full reaction;

(2) inputting the gas-phase product obtained in the step (1) into a hydrogen bromide absorption tank 8, spraying atomized water to absorb hydrogen bromide to obtain a hydrogen bromide solution, inputting the hydrogen bromide solution and ethylene into a fixed bed reactor 12 for cyclic reaction, and outputting a reaction product after full reaction;

(3) inputting the reaction product in the step (2) into a falling-film evaporator 19, and collecting 35-40 ℃ fraction which is bromoethane;

(4) recycling the bromoethane to a raw material system for producing tetrahydrofurfuryl alcohol ether, namely completing the recycling of bromine;

preferably, in the above method, the mass fraction of the aqueous solution of potassium bromide is 25-35%, based on the total input amount of concentrated sulfuric acid, and the potassium bromide in the aqueous solution of potassium bromide and the H in the concentrated sulfuric acid in the reactor 7 with built-in bed are in the reactor₂SO₄The molar ratio is 1.55-2.15: 0.75 to 1.65; the mass fraction of the hydrogen bromide in the hydrogen bromide solution is 45-55%, and the molar ratio of the hydrogen bromide to the ethylene in the hydrogen bromide solution input into the fixed bed reactor 12 is 0.66-1.15: 0.77-1.25.

Preferably, in the method, the reaction temperature of the reaction kettle 7 with the built-in bed is 15-45 ℃, the hydrogen partial pressure is 500-750 Pa, the reaction temperature of the fixed bed reactor 12 is 45-70 ℃, and the reaction pressure is 0.2-0.3 Mpa; more preferably, the reaction temperature of the reaction kettle 7 with the built-in bed is 22-41 ℃, the reaction temperature of the fixed bed reactor 12 is 50-65 ℃, and the pressure is 0.22-0.3 Mpa; most preferably, the reaction temperature of the fixed bed reactor 12 is 55-65 ℃.

Preferably, in the method, the stirring frequency of the internal bed reaction kettle 7 is 10-20 Hz, and the fixed bed reactor 12 has no stirring frequency.

Preferably, in the step (3), the temperature of the bottom of the falling-film evaporator 19 is controlled to be 55-80 ℃, the temperature of the top of the falling-film evaporator 19 is controlled to be 30-45 ℃, and the component is the bromine ethane recovered as the bromine element product when the temperature of the top of the falling-film evaporator 19 is stabilized to be 35-40 ℃. In order to ensure that the product quality is qualified, the pressure of the falling-film evaporator 19 is stabilized within the range of 1-1.5 Kpa.

Under the condition that the metering accuracy reaches the standard, the raw materials can be added by an electronic scale and a metering tank under pressure, and in a preferred embodiment, the metering mode of the gas-phase product of the built-in bed reaction kettle 7 into the hydrogen bromide absorption tank 8 is carried out in the form of the metering tank.

The invention also provides application of the device or the method in recycling bromine in the process of industrially producing tetrahydrofurfuryl alcohol ether.

The invention has the following beneficial effects:

the comprehensive yield of the bromoethane produced by the device and the method is 92-95%, the purity of the bromoethane reaches 98.5-99.5%, the requirement of tetrahydrofurfuryl alcohol ether production on the quality of raw materials can be met, the production cost of tetrahydrofurfuryl alcohol ether is greatly reduced, the cyclic utilization of high-value bromine elements is realized, resources are saved, and the method is environment-friendly.

Drawings

FIG. 1 is a schematic view of the apparatus described in example 1; the device comprises a potassium bromide solution storage tank, a potassium bromide solution delivery pump, a concentrated sulfuric acid storage tank, a concentrated sulfuric acid delivery pump, a hydrogen storage tank, a hydrogen meter, a built-in bed reaction kettle, a hydrogen bromide absorption tank, a hydrogen bromide solution meter, a ethylene storage tank, an ethylene meter, 11, an ethylene meter, 12, a fixed bed reactor, 13, a reaction liquid delivery pump, 14, a crude bromoethane storage tank, 15, a crude product delivery pump, 16, a condenser, 17, a product tank, 18, a product reflux pump, 19, a falling film evaporator, 20, a potassium sulfate tank, 21 and a potassium sulfate delivery pump.

FIG. 2 is a top view of the fixed bed layer of the internal bed reactor of the present invention; wherein, 7-2 parts of fixed bed layer, 7-2-1 parts of through hole.

FIG. 3 is a schematic view of the structure of a reactor with a built-in bed according to example 1; wherein, 7-1 part of stirring paddle and 7-2 parts of fixed bed layer.

FIG. 4 is a sectional view of a fixed bed layer of the reactor with a built-in bed in example 1; wherein, 7-2 parts of fixed bed layer, 7-2-1 parts of through hole.

FIG. 5 is a gas chromatogram of the final product of example 2.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the scope of the present invention is not limited thereto.