Thiophane-sodium sulfide co-production system

Abstract

The utility model provides a thiophane-sodium sulfide co-production system, relates to the technical field of compound preparation, and aims to solve the technical problem that waste liquid in thiophane generated by direct reaction of tetrahydrofuran and hydrogen sulfide cannot be treated. The tetrahydrothiophene-sodium sulfide co-production system comprises: a mixing system, which is used for gasifying tetrahydrofuran and then mixing the gasified tetrahydrofuran with hydrogen sulfide gas; tetrahydrofuran and hydrogen sulfide react in the reactor; products in the reactor are condensed and separated by the condenser; the rectification system is used for purifying the condensed and separated crude product; and the waste gas recovery system is used for separating products in the waste gas and preparing sodium sulfide. The tetrahydrothiophene-sodium sulfide co-production system provided by the utility model is safer and more environment-friendly in a tetrahydrothiophene preparation process, and meanwhile, the waste liquid is treated to increase a sodium sulfide product, so that the economic benefit of the whole process is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of compound preparation, in particular to a tetrahydrothiophene-sodium sulfide co-production system. Background Art

[0002] Tetrahydrothiophene is an important sulfur-containing saturated heterocyclic compound and a high-value-added fine organic chemical raw material. It is mainly used as an odorant or warning agent for gaseous fuels such as city gas and natural gas. It can also be used as a production raw material in the fields of medicine, pesticides and photochemicals. At present, according to international standards, tetrahydrothiophene must be used as an odorant for city gas, natural gas and other gases. In addition, tetrahydrothiophene is currently mainly imported in China, so tetrahydrothiophene has a huge market space in China.

[0003] There are three main methods for producing tetrahydrothiophene: (1) Thiophene catalytic hydrogenation method, using thiophene as raw material, and synthesizing tetrahydrothiophene through catalytic hydrogenation reduction reaction. This process has problems such as high thiophene raw material price, high catalyst price, complex process conditions, high production cost, and no obvious market advantage; (2) 1,4-dichlorobutane direct thiolation method, 1,4-dichlorobutane and sodium sulfide containing crystal water are used as raw materials, ethanol is used as solvent, and tetrahydrothiophene is generated under the action of iodine catalyst. Water is produced during this reaction, which is difficult to separate from the product; (3) Cyclopentane sulfone hydrogenation method, cyclopentane sulfone and hydrogen are catalyzed by a catalyst to generate tetrahydrothiophene. This reaction process involves hazardous hydrogen, and this reaction process cannot achieve continuous production; (4) Tetrahydrofuran direct thiolation method, under the action of a solid acid catalyst, tetrahydrofuran directly reacts with hydrogen sulfide to generate tetrahydrothiophene.

[0004] Patent Publication No. CN116586003A discloses a tetrahydrofuran sulfidation catalytic reactor and a tetrathiophene industrial synthesis system, including a tetrahydrofuran sulfidation catalytic reactor, a hydrogen sulfide storage tank, a tetrahydrofuran storage tank, an oil-water separator, a crude product tank, a distillation tower and a condenser, wherein the hydrogen sulfide storage tank and the tetrahydrofuran storage tank are connected to the inlet end of the tetrahydrofuran sulfidation catalytic reactor through a first group of heat exchangers and a second group of heat exchangers, respectively; and the outlet end of the tetrahydrofuran sulfidation catalytic reactor is connected to the oil-water separator, the crude product tank, the distillation tower and the condenser in sequence through a third heat exchanger. The system is only used to prepare high-purity tetrahydrothiophene, and the waste liquid generated in the production is not treated. Utility Model Content

[0005] In view of the above technical problems, the utility model proposes a tetrahydrothiophene-sodium sulfide co-production system, which makes the production process safer and more environmentally friendly, and at the same time, the waste liquid is treated to increase the sodium sulfide product, thereby improving the overall process economic benefits.

[0006] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0007] A tetrahydrothiophene-sodium sulfide co-production system comprises: a mixing system for gasifying tetrahydrofuran and mixing it with hydrogen sulfide gas; a reactor in which tetrahydrofuran and hydrogen sulfide react; a condenser in which the products in the reactor are condensed and separated; a distillation system for purifying the crude product separated by condensation; and a waste gas recovery system for separating the products in the waste gas and preparing sodium sulfide.

[0008] The mixing system comprises: a tetrahydrofuran storage tank, a vaporizer, a hydrogen sulfide gas storage tank and a gas premixer; the tetrahydrofuran storage tank is connected to the vaporizer, and the vaporizer vaporizes the tetrahydrofuran liquid; the gas premixer is connected to the hydrogen sulfide gas storage tank and the vaporizer respectively, and the tetrahydrofuran gas and the hydrogen sulfide gas are mixed in the gas premixer and then transported to the reactor.

[0009] The reactor is provided with a catalyst and a heater for catalyzing tetrahydrofuran and hydrogen sulfide to generate tetrahydrothiophene.

[0010] The condenser comprises an air inlet, an air outlet, a liquid outlet, a condensate inlet and a condensate outlet; the air inlet is connected to the reactor, the liquid outlet is connected to the distillation system, and the air outlet is connected to the waste gas recovery system.

[0011] The distillation system comprises a tetrahydrothiophene crude product tank, a distillation tower and a tetrahydrothiophene product tank which are connected in sequence, and the tetrahydrothiophene crude product tank is connected to the liquid outlet of the condenser.

[0012] The waste gas recovery system comprises a separation tank, a tetrahydrofuran recovery system and a waste liquid recovery system; the gas outlet of the condenser is connected to the separation tank, water is stored in the separation tank, tetrahydrofuran is condensed and separated and flows into the tetrahydrofuran recovery system, and the water in the separation tank flows into the waste liquid recovery system to prepare sodium sulfide.

[0013] The separation tank comprises a shell, wherein a tetrahydrofuran overflow port is arranged on the upper part of the shell, and a liquid discharge port is arranged on the lower part of the shell; a waste gas inlet is also arranged on the shell, and the waste gas inlet is inserted into the bottom of the shell through an air guide pipe.

[0014] The end of the air guide pipe is communicated with the coil, and air outlet holes are distributed on the coil.

[0015] The tetrahydrofuran recovery system comprises a tetrahydrofuran recovery tank, which is connected to a tetrahydrofuran overflow port and is used to store tetrahydrofuran; the tetrahydrofuran recovery tank is connected to a tetrahydrofuran storage tank and can transport the recovered tetrahydrofuran to the tetrahydrofuran storage tank.

[0016] The waste liquid recovery system comprises a neutralizer, a filter, an evaporator and a sodium sulfide product tank which are connected in sequence.

[0017] The beneficial effects of the utility model are as follows: the sulfur-containing waste gas in coal gasification / coal coking is mainly pre-treated, impurity-removed and purified, and then reacted with tetrahydrofuran to synthesize tetrahydrothiophene. The tetrahydrofuran storage tank pumps tetrahydrofuran to the gasifier, gaseous tetrahydrofuran and hydrogen sulfide are mixed in the premixer, and then the mixed gas is pumped into the reactor for reaction (hydrogen sulfide and tetrahydrofuran react to prepare tetrahydrothiophene), and the mixed gas after the reaction first passes through a condenser to separate tetrahydrothiophene and water and enter the tetrahydrothiophene crude product tank, and tetrahydrofuran and hydrogen sulfide enter the storage tank and mix with water. After the separation tank is layered, the upper layer of liquid is pumped into the neutralizer, and after treatment, a sodium sulfide product is obtained, and the lower layer of product is pumped into a tetrahydrofuran recovery device for product recovery. The crude tetrahydrothiophene product is refined by a distillation tower to obtain the main product tetrahydrothiophene, and the overall process achieves "zero" three wastes. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a structural schematic diagram of the tetrahydrothiophene-sodium sulfide co-production system of the utility model.

[0020] Figure 2 Schematic diagram of the condenser structure.

[0021] Figure 3 It is a schematic diagram of the structure of the separation tank.

[0022] In the figure, 1. tetrahydrofuran storage tank; 2. gasifier; 3. hydrogen sulfide gas storage tank; 4. gas premixer; 5. reactor; 6. condenser; 61. air inlet; 62. air outlet; 63. liquid outlet; 64. condensate inlet; 65. condensate outlet; 7. separation tank; 71. shell; 72. tetrahydrofuran overflow port; 73. drain port; 74. waste gas inlet; 75. air duct; 76. coil; 8. tetrahydrothiophene crude product tank; 9. distillation tower; 10. tetrahydrothiophene product tank; 11. tetrahydrofuran recovery tank; 12. neutralizer; 13. filter; 14. evaporator; 15. sodium sulfide product tank. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] Example 1

[0025] A tetrahydrothiophene-sodium sulfide co-production system, such as Figure 1 As shown, it includes: a mixing system for gasifying tetrahydrofuran and mixing it with hydrogen sulfide gas; a reactor 5, in which tetrahydrofuran and hydrogen sulfide react to generate tetrahydrothiophene and water; a condenser 6, in which the products in the reactor 5 are condensed and separated by the condenser 6, and the gas discharged from the reactor 5 includes unreacted tetrahydrofuran and hydrogen sulfide gas, and the generated water and tetrahydrothiophene and other impurity heavy components. By adjusting the temperature of the condenser 6, water, tetrahydrothiophene and other impurity heavy components can be condensed and liquefied to obtain a crude tetrahydrothiophene product. A distillation system is used to purify the crude product separated by condensation to separate tetrahydrothiophene. A waste gas recovery system, in which the tetrahydrofuran and hydrogen sulfide waste gas discharged from the condenser 6 are introduced into the waste gas recovery system, and the waste gas recovery system separates tetrahydrofuran and hydrogen sulfide again, and the separated tetrahydrofuran can be put into reaction again, and the separated hydrogen sulfide is neutralized with alkali to prepare sodium sulfide.

[0026] Specifically, the mixing system includes: a tetrahydrofuran storage tank 1, a vaporizer 2, a hydrogen sulfide storage tank 3 and a gas premixer 4; the tetrahydrofuran is pumped to the tetrahydrofuran storage tank 1 for storage, the tetrahydrofuran storage tank 1 is connected to the vaporizer 2, the vaporizer 2 is a device that converts liquid into gas by heating, and the vaporizer 2 vaporizes the tetrahydrofuran liquid; the hydrogen sulfide is pumped to the hydrogen sulfide storage tank 3 for storage. The gas premixer 4 is connected to the hydrogen sulfide storage tank 3 and the vaporizer 2 respectively, and the gas premixer 4 is a commonly used gas-gas mixer in industry, which can evenly mix multiple gases, and the tetrahydrofuran gas and the hydrogen sulfide gas are mixed in the gas premixer 4 and then transported to the reactor 5.

[0027] The reactor 5 is provided with a catalyst and a heater. The reactor 5 may be a tubular fixed bed reactor 5. The catalyst may be a heteropolyacid catalyst, or a catalyst disclosed in patent publication numbers CN116675669A, CN117000264A, CN117358272A, etc. After passing through the reactor 5, tetrahydrofuran and hydrogen sulfide generate tetrahydrothiophene.

[0028] The condenser 6 is a type of heat exchanger that can convert gas or steam into liquid, such as a shell-and-tube heat exchanger. Figure 2As shown, it includes an air inlet 61, an air outlet 62, a liquid outlet 63, a condensate inlet 64 and a condensate outlet 65, and the condensate is heat transfer oil or water; the air inlet 61 is connected to the reactor 5, and the water, tetrahydrothiophene and other impurity heavy components liquefied by the condenser 6 are discharged from the liquid outlet 63, and the liquid outlet 63 is connected to the distillation system; tetrahydrofuran and hydrogen sulfide gas are discharged from the air outlet 62, and the air outlet 62 is connected to the exhaust gas recovery system.

[0029] The distillation system includes a tetrahydrothiophene crude product tank 8, a distillation tower 9 and a tetrahydrothiophene product tank 10 which are connected in sequence. The tetrahydrothiophene crude product tank 8 is connected to the liquid outlet 63 of the condenser 6. The water, tetrahydrothiophene and other impurities discharged from the condenser 6 are recombined and stored in the tetrahydrothiophene crude product tank 8. Since water and water and tetrahydrothiophene are incompatible, they can be separated in the tetrahydrothiophene crude product tank 8 first, and then passed into the distillation tower 9 for further purification. The distillation tower 9 is a sieve plate distillation tower 9 and a packed distillation tower 9. Finally, pure tetrahydrothiophene is obtained and stored in the tetrahydrothiophene product tank 10.

[0030] Example 2

[0031] A tetrahydrothiophene-sodium sulfide co-production system, such as Figure 1 and 2 As shown, it includes: a mixing system for mixing tetrahydrofuran with hydrogen sulfide gas after gasification; a reactor 5, in which tetrahydrofuran and hydrogen sulfide react; a condenser 6, in which the product in the reactor 5 is condensed and separated by the condenser 6; a distillation system for purifying the crude product separated by condensation; and a waste gas recovery system for separating the product in the waste gas and preparing sodium sulfide. The mixing system includes: a tetrahydrofuran storage tank 1, a vaporizer 2, a hydrogen sulfide storage tank 3 and a gas premixer 4; the tetrahydrofuran storage tank 1 is connected to the vaporizer 2, and the vaporizer 2 vaporizes the tetrahydrofuran liquid; the gas premixer 4 is connected to the hydrogen sulfide storage tank 3 and the vaporizer 2 respectively, and the tetrahydrofuran gas and the hydrogen sulfide gas are mixed in the gas premixer 4 and then transported to the reactor 5. The reactor 5 is provided with a catalyst and a heater for catalyzing tetrahydrofuran and hydrogen sulfide to generate tetrahydrothiophene. The condenser 6 includes an air inlet 61, an air outlet 62, a liquid outlet 63, a condensate inlet 64 and a condensate outlet 65; the air inlet 61 is connected to the reactor 5, the liquid outlet 63 is connected to the distillation system, and the air outlet 62 is connected to the waste gas recovery system. The distillation system includes a tetrahydrothiophene crude product tank 8, a distillation tower 9 and a tetrahydrothiophene product tank 10 connected in sequence, and the tetrahydrothiophene crude product tank 8 is connected to the liquid outlet 63 of the condenser 6.

[0032] Specifically, the waste gas recovery system includes a separation tank 7, a tetrahydrofuran recovery system and a waste liquid recovery system; the gas outlet 62 of the condenser 6 is connected to the separation tank 7, water is stored in the separation tank 7, tetrahydrofuran and hydrogen sulfide waste gas are introduced into the water, tetrahydrofuran will be condensed into liquid and is incompatible with water, hydrogen sulfide is dissolved in water, tetrahydrofuran and hydrogen sulfide can be separated by the separation tank 7, the separated tetrahydrofuran enters the tetrahydrofuran recovery system, and the water containing hydrogen sulfide in the separation tank 7 flows into the waste liquid recovery system and is neutralized to prepare sodium sulfide.

[0033] like Figure 3 As shown, the separation tank 7 includes a shell 71, and a tetrahydrofuran overflow port 72 is provided above the shell 71. The density of tetrahydrofuran is less than that of water. The condensed tetrahydrofuran will float above the separation tank 7 and be separated through the tetrahydrofuran overflow port 72; a drain port 73 is provided below the separation tank 7 for discharging waste liquid containing hydrogen sulfide; a waste gas inlet 74 is also provided on the shell 71. The waste gas inlet 74 is provided at the top of the separation tank 7 and is connected to the air guide pipe 75. The waste gas inlet 74 is inserted into the bottom of the shell 71 through the air guide pipe 75, and the waste gas entering through the condenser 6 enters the bottom of the shell 71 through the air guide pipe 75.

[0034] A coil 76 may be provided at the bottom of the separation tank 7. The end of the air guide pipe 75 is connected to the coil 76. The coil 76 is provided with air outlet holes so that the tetrahydrofuran and hydrogen sulfide waste gases can be more fully contacted with water, thereby improving the absorption efficiency of the waste gases.

[0035] The tetrahydrofuran recovery system includes a tetrahydrofuran recovery tank 11, which is connected to a tetrahydrofuran overflow port 72 and is used to store tetrahydrofuran; the tetrahydrofuran recovery tank 11 is connected to a tetrahydrofuran storage tank 1 and can transport the recovered tetrahydrofuran to the tetrahydrofuran storage tank 1.

[0036] The waste liquid recovery system includes a neutralizer 12, a filter 13, an evaporator 14 and a sodium sulfide product tank 15 connected in sequence. The neutralizer 12 is connected to the drain port 73 at the bottom of the separation tank 7, and water containing hydrogen sulfide is pumped into the neutralizer 12, and an alkaline reagent such as sodium hydroxide is added thereto. Subsequently, the neutralized solution is filtered for impurities through the filter 13, and then the solvent is evaporated through the evaporator 14 to crystallize sodium sulfide, which is then stored in the sodium sulfide product tank 15.

[0037] The process method of the above tetrahydrothiophene-sodium sulfide co-production system is as follows:

[0038] (1) Tetrahydrofuran is pumped to a tetrahydrofuran storage tank 1 for storage; and hydrogen sulfide is pumped to a hydrogen sulfide storage tank for storage. Tetrahydrofuran is then transported to a tetrahydrofuran vaporizer 2 for gasification, wherein the gasification temperature is 66°C-150°C. At the same time, nitrogen is purged online into the gaseous tetrahydrofuran vaporizer 2 to ensure that the gaseous tetrahydrofuran output of the system is stable. Gaseous tetrahydrofuran and hydrogen sulfide are simultaneously pumped to a gas premixer 4 for raw material premixing, wherein the molar ratio of tetrahydrofuran to hydrogen sulfide is 1:1.1-2.

[0039] (2) The raw material premixed gas enters the tubular fixed bed reactor 5 for catalytic reaction (tetrahydrofuran is directly sulfided to produce tetrahydrothiophene). The reaction temperature of the tubular fixed bed reactor 5 is 240°C-290°C, the reaction pressure is 0.1Mpa-1Mpa, the space velocity is 30-900h-1, and the catalyst is a solid acid catalyst.

[0040] (3) The generated gas is sent to the condenser 6 through an air pump for separation to generate a secondary mixed gas and a liquid product. The secondary mixed gas is mainly hydrogen sulfide and tetrahydrofuran, and the liquid product is mainly a crude tetrahydrothiophene product including tetrahydrothiophene, water and heavy components. The cold source of the condenser 6 is one of heat transfer oil and water. The temperature range of the condenser 6 is 67°C-99°C. The liquid product is transported to the crude tetrahydrothiophene tank 8.

[0041] (4) The secondary mixed gas is transported to the separation tank 7 for absorption and cooling stratification, wherein hydrogen sulfide is soluble in water, and tetrahydrofuran is immiscible with water. Liquid stratification occurs in the storage tank, and the lower layer of liquid is pumped to the neutralizer 12, and after being neutralized with sodium hydroxide, a sodium sulfide solution is obtained, which is then passed through the filter 13 one by one, and the evaporator 14 finally produces a sodium sulfide product, which is stored in the sodium sulfide product tank 15, wherein the temperature of the evaporator 14 is 100°C-150°C. The upper layer of liquid is pumped to the tetrahydrofuran recovery tank 11, and can be circulated to the tetrahydrofuran storage tank 1 for standby use.

[0042] (5) The crude tetrahydrothiophene is refined by a distillation tower 9 to obtain a tetrahydrothiophene product, which is stored in a tetrahydrothiophene product tank 10, wherein the distillation tower 9 is one of a sieve plate distillation tower 9 and a packed distillation tower 9.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A tetrahydrothiophene-sodium sulfide co-production system, characterized in that: include: A mixing system for gasifying tetrahydrofuran and mixing it with hydrogen sulfide gas; Reactor (5), tetrahydrofuran and hydrogen sulfide react in the reactor (5); condenser (6), the product in the reactor (5) is condensed and separated by the condenser (6); a distillation system is used to purify the crude product separated by condensation; and a waste gas recovery system is used to separate the product in the waste gas and prepare sodium sulfide.

2. The tetrahydrothiophene-sodium sulfide co-production system according to claim 1, characterized in that: The mixing system comprises: a tetrahydrofuran storage tank (1), a vaporizer (2), a hydrogen sulfide gas storage tank (3) and a gas premixer (4); the tetrahydrofuran storage tank (1) is connected to the vaporizer (2), and the vaporizer (2) vaporizes the tetrahydrofuran liquid; the gas premixer (4) is connected to the hydrogen sulfide gas storage tank (3) and the vaporizer (2) respectively, and the tetrahydrofuran gas and the hydrogen sulfide gas are mixed in the gas premixer (4) and then transported to the reactor (5).

3. The tetrahydrothiophene-sodium sulfide co-production system according to claim 2, characterized in that: The reactor (5) is provided with a catalyst and a heater for catalyzing tetrahydrofuran and hydrogen sulfide to generate tetrahydrothiophene.

4. The tetrahydrothiophene-sodium sulfide co-production system according to claim 3, characterized in that: The condenser (6) comprises an air inlet (61), an air outlet (62), a liquid outlet (63), a condensate inlet (64) and a condensate outlet (65); the air inlet (61) is connected to the reactor (5), the liquid outlet (63) is connected to the distillation system, and the air outlet (62) is connected to the waste gas recovery system.

5. The tetrahydrothiophene-sodium sulfide co-production system according to claim 4, characterized in that: The distillation system comprises a tetrahydrothiophene crude product tank (8), a distillation tower (9) and a tetrahydrothiophene product tank (10) which are connected in sequence. The tetrahydrothiophene crude product tank (8) is connected to a liquid outlet (63) of a condenser (6).

6. The tetrahydrothiophene-sodium sulfide co-production system according to claim 5, characterized in that: The waste gas recovery system comprises a separation tank (7), a tetrahydrofuran recovery system and a waste liquid recovery system; the gas outlet (62) of the condenser (6) is connected to the separation tank (7), water is stored in the separation tank (7), the tetrahydrofuran is condensed and separated and flows into the tetrahydrofuran recovery system, and the water in the separation tank (7) flows into the waste liquid recovery system to prepare sodium sulfide.

7. The tetrahydrothiophene-sodium sulfide co-production system according to claim 6, characterized in that: The separation tank (7) comprises a shell (71), wherein a tetrahydrofuran overflow port (72) is provided on the upper side of the shell (71), and a liquid discharge port (73) is provided on the lower side of the shell (71); an exhaust gas inlet (74) is also provided on the shell (71), and the exhaust gas inlet (74) is inserted into the bottom of the shell (71) through an air guide pipe (75).

8. The tetrahydrothiophene-sodium sulfide co-production system according to claim 7, characterized in that: The end of the air guide pipe (75) is communicated with the coil (76), and the coil (76) is provided with air outlet holes.

9. The tetrahydrothiophene-sodium sulfide co-production system according to claim 8, characterized in that: The tetrahydrofuran recovery system comprises a tetrahydrofuran recovery tank (11), which is connected to a tetrahydrofuran overflow port (72) and is used to store tetrahydrofuran; the tetrahydrofuran recovery tank (11) is connected to a tetrahydrofuran storage tank (1) and can transport the recovered tetrahydrofuran to the tetrahydrofuran storage tank (1).

10. The tetrahydrothiophene-sodium sulfide co-production system according to claim 9, characterized in that: The waste liquid recovery system comprises a neutralizer (12), a filter (13), an evaporator (14) and a sodium sulfide product tank (15) which are connected in sequence.

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