Ethanethiol continuous rectification small-scale test device

Abstract

The utility model discloses an ethanethiol continuous rectification small-scale test device which is characterized in that in a hydrogen sulfide removal unit, a middle branch opening of a reaction bottle I is connected with a spherical condensation pipe by adopting an adapter, and an outlet of the spherical condensation pipe is connected with a conical flask I through a vacuum tail connecting pipe I; in the ethanethiol rectification unit, the speed of materials flowing into a second reaction bottle from a first reaction bottle is controlled through the opening degree of two cocks on a second guide pipe, a middle branch opening of the second reaction bottle is connected with the lower end of a filler-containing vertical thorn fractionating column, and the upper end of the filler-containing vertical thorn fractionating column is connected with a snake-shaped condensation pipe through a distillation head. The tail end of the snake-shaped condenser pipe is connected with a vacuum tail connecting pipe II, and the lower end of the vacuum tail connecting pipe II is connected with a middle sample receiving bottle and then connected with a sample receiving bottle. And taking the ethanethiol liquid-phase crude product condensed in the synthesis section as a raw material, degassing and rectifying to obtain an ethanethiol product. According to the technology, a small glass rectification device is adopted for continuous rectification, and the device comprises a hydrogen sulfide removal unit, an ethanethiol rectification unit and a tail gas absorption unit.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical rectification, and particularly relates to an ethyl mercaptan rectification process and a laboratory glass rectification device to produce high-quality ethyl mercaptan. Background Art

[0002] Ethyl mercaptan is an organic compound with the chemical formula C2H6S. It is a colorless and transparent liquid. In terms of chemical synthesis, it can be used as a reducing agent in organic synthesis reactions to prepare organic sulfur compounds. In terms of drug synthesis, it can be used in the synthesis of various drugs, such as anti-tumor and anti-gout drugs. In terms of pesticide production, it can be used as an important raw material for derivative synthesis to synthesize various insecticides, herbicides, etc. In the odorant industry, it can be used as an odorant in natural gas pipelines to prevent accidents such as fires or explosions caused by leakage.

[0003] Due to the numerous uses of ethyl mercaptan, the quality requirements for the product vary. For example, in the odorant and pesticide industries, the purity requirements for ethyl mercaptan are not high, but in the pharmaceutical industry, the quality requirements for ethyl mercaptan are more stringent. By building the device, ethyl mercaptan products with a purity of up to 99.9% can be produced, making it suitable for high-end fields such as medicine and meeting the quality requirements of downstream customers. Summary of the Invention

[0004] The purpose of the utility model is to develop an ethyl mercaptan rectification device aiming at the existing technical bottlenecks. The device includes a hydrogen sulfide removal unit, an ethyl mercaptan rectification unit, and a tail gas treatment unit.

[0005] A small-scale ethyl mercaptan rectification device includes a hydrogen sulfide removal unit and an ethyl mercaptan rectification unit.

[0006] In the hydrogen sulfide removal unit, an adapter is used to connect the middle branch port of the first reaction flask to a spherical condenser. The outlet of the spherical condenser is connected to a first conical flask through a first vacuum adapter.

[0007] In the ethyl mercaptan rectification unit, the material in the first reaction flask flows into the second reaction flask through the control of the opening degrees of two cocks on the second conduit. The middle branch port of the second reaction flask is connected to the lower end of a vertical spike fractionating column with packing. The upper end of the vertical spike fractionating column with packing is connected to a coiled condenser through a distillation head. The tail end of the coiled condenser is connected to a second vacuum adapter. The lower end of the second vacuum adapter is connected to an intermediate sample collecting bottle, and then to a sample collecting bottle.

[0008] One branch port of the first reaction flask is connected to a gas guide tube, and the other branch port is a sample adding port or a sampling port.

[0009] The first conical flask is connected to a first liquid alkali absorption bottle through a first polytetrafluoroethylene tube, and the first liquid alkali absorption bottle is connected to a second liquid alkali absorption bottle through a second polytetrafluoroethylene tube.

[0010] The second gas phase outlet of the vacuum tail pipe is connected to the oxidation bottle through a polytetrafluoroethylene tube three, and the oxidation bottle is connected to the liquid alkali absorption bottle three through a polytetrafluoroethylene tube four.

[0011] The lower end of the sample bottle is connected to the second conical flask, or is connected to the second reaction flask.

[0012] Thermometers, namely, thermometer 1 and thermometer 2, are provided on the reaction flask 2 and the filler vertical thorn fractionation column.

[0013] In view of the above-mentioned device, the city effectively provides an ethyl mercaptan distillation process, which simplifies the operation process, reduces labor intensity, and saves labor costs while obtaining the ethyl mercaptan product. Therefore, the utility model provides an ethyl mercaptan distillation process, comprising the following steps:

[0014] S1. Nitrogen enters the initial material reaction bottle through the air guide tube for aeration, removes hydrogen sulfide gas in the liquid phase of the solution, and sends it to the tail gas absorption unit. The other components entrained by the nitrogen are condensed by a spherical condenser and placed in a conical flask;

[0015] S2. After the initial nitrogen aeration is completed, the sample is analyzed for residual hydrogen sulfide gas and then transported to the reaction flask via the lower end conduit for heating;

[0016] S3. After heating, the distillation column is separated, the heavy component is refluxed in the distillation column, the light component is sent to the serpentine condenser and condensed into a liquid phase in the sample bottle, and the uncondensed gas phase is sent to the tail gas absorption unit;

[0017] S4. The condensed light component liquid product is sampled and analyzed through the right branch of the sample bottle. The qualified products are sent to a conical flask for collection, and the unqualified products are returned to the reaction flask;

[0018] The main component of the initial material described in S1 is ethyl mercaptan, and the impurities are hydrogen sulfide, methyl mercaptan, ethyl sulfide, isopropyl mercaptan or C3 or higher sulfides or mercaptans, etc., wherein the ethyl mercaptan content is 60-90%, the hydrogen sulfide content is 3-10%, the ethyl sulfide content is 5-15%, and the total content of other impurities is less than 5%; the nitrogen flow rate is 5-30 mL / min, and the purge time is 5-30 min;

[0019] The tail gas in S1 is sequentially introduced into the primary alkali solution and the secondary alkali solution; the concentration of the primary alkali solution is 15-40%, and the concentration of the secondary alkali solution is 5-10%;

[0020] The residual hydrogen sulfide-free gas standard described in S2 is that the hydrogen sulfide content is ≤0.5%; the liquid phase can be transported to the reaction bottle partially or completely;

[0021] The heating temperature in S3 is 30-50° C., the length of the vertical thorn fractionation column is 120 mm-300 mm, and the length of the serpentine condenser is 200 mm-400 mm;

[0022] The qualified products described in S4 are divided into industrial grade (≥95%), first-class products (≥99.5%), and superior products (≥99.9%) according to their purity;

[0023] The tail gas in S4 is sequentially introduced into a sodium hypochlorite solution and an alkaline solution; the concentration of the sodium hypochlorite solution is 3-10%, and the concentration of the alkaline solution is 15-25%;

[0024] The process performed by the device of the present invention utilizes the different boiling points of various substances in the crude product to control the temperature of the tower, the length of the fractionating column, the length of the condenser tube, and the temperature of the cooling water to produce an ethyl mercaptan product with a purity of 99.9% or higher. The device of the present invention can be used to perform industrial conversion. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a structural diagram of the ethyl mercaptan distillation device of the present utility model.

[0026] 1. Gas guide tube, 2. Reaction flask (one), 3. Adapter, 4. Spherical condenser, 5. Vacuum tail pipe (one), 6. Erlenmeyer flask (one), 7. Polytetrafluoroethylene tube (one), 8. Liquid alkali absorption flask (one), 9. Polytetrafluoroethylene tube (two), 10. Liquid alkali absorption flask (two), 11. Emptying pipe (one), 12. Conduit connector (one), 13. Conduit (two), 14. Heater, 15. Reaction flask (two), 16. Thermometer (one), 17. Filled vertical barbed fractionation column, 18. Distillation head, 19. Thermometer (two), 20. Serpentine condenser, 21. Vacuum tail pipe (two), 22. Intermediate sample flask, 23. Sample flask, 24. Erlenmeyer flask (two), 25. Polytetrafluoroethylene tube (three), 26. Polytetrafluoroethylene tube (four), 27. Emptying pipe (two), 28. Oxidation flask, 29. Liquid alkali absorption flask (three), 30. Conduit connector (two), 31. Conduit (two). DETAILED DESCRIPTION

[0027] Example 1

[0028] An ethyl mercaptan distillation pilot plant comprises a hydrogen sulfide removal unit and an ethyl mercaptan distillation unit;

[0029] In the dehydrogen sulfide unit, an adapter 3 is used to connect the middle branch of the reaction bottle 2 to the spherical condenser 4, and the outlet of the spherical condenser 4 is connected to the conical flask 6 through a vacuum tail pipe 5;

[0030] In the ethanethiol distillation unit, the material in reaction flask 12 flows into reaction flask 2 15 at a speed controlled by the opening of two stopcocks on conduit 2 13. The middle branch of reaction flask 2 15 is connected to the lower end of a vertically spiked fractionation column 17 containing fillers. The upper end of the vertically spiked fractionation column 17 containing fillers is connected to a serpentine condenser 20 through a distillation head 18. The tail end of the serpentine condenser 20 is connected to a vacuum tail pipe 21. The lower end of the vacuum tail pipe 21 is connected to a middle sample receiving bottle 22, and then to a sample receiving bottle 23.

[0031] One branch port of the reaction bottle 1 is connected to the air guide tube 1, and the other branch port is a sample addition port or a sampling port.

[0032] The conical flask 1 (6) is connected to the liquid alkali absorption bottle 1 (8) through a polytetrafluoroethylene tube 1 (7), and the liquid alkali absorption bottle 1 (8) is connected to the liquid alkali absorption bottle 2 (10) through a polytetrafluoroethylene tube 2 (9).

[0033] The gas phase outlet of the vacuum tail pipe 21 is connected to the oxidation bottle 28 through the polytetrafluoroethylene tube 3 25, and the oxidation bottle 28 is connected to the liquid alkali absorption bottle 3 29 through the polytetrafluoroethylene tube 4 26.

[0034] The lower end of the sample receiving bottle 23 is connected to the second conical flask 24, or is connected to the second reaction flask 15.

[0035] Thermometers, namely, thermometer 16 and thermometer 2 19, are provided on both the reaction flask 2 15 and the packed vertical thorn fractionation column 17.

[0036] Example 2

[0037] In the present invention, the purity of the liquid sample to be tested is detected by an Agilent GC8860 chromatograph, and a liquid phase automatic sampler is used for injection to avoid human error. The needle is not cleaned with a solvent, and only 1 uL of the sample to be tested is injected after rinsing 8 times.

[0038] Ethyl mercaptan crude product liquid phase 1, components: ethyl mercaptan 75.4%, ethyl sulfide 12.7%, hydrogen sulfide 9.1%, and the total content of other impurities 2.8%.

[0039] 450 mL of the crude product was added to the reaction flask, and nitrogen was introduced into the crude product from the left outlet through the air guide tube for aeration, maintaining a nitrogen flow rate of 20 mL / min for a total of 15 minutes. After the nitrogen aeration was completed, a sample was taken from the right outlet for analysis, and the hydrogen sulfide content in the crude product was 0.3%, which met the allowable residual hydrogen sulfide standard in the crude product. The two stopcocks on the conduit were opened, and about 300 mL of the treated crude product was sent to the reaction flask;

[0040] A 200mm-long vertical spiked fractionation column with filler and a 300mm serpentine condenser were used. The cooling water temperature was -6°C and the heater was heated in an oil bath. The temperature was controlled at 35°C to start distillation. The calculation started from the first drop of liquid from the sample bottle. In addition, the fractions collected in the first 10 minutes were not refluxed to prevent the light components from being continuously present in the product and unable to be removed.

[0041] From the 10th minute onwards, when the sample bottle stopped dripping, 1.5 mL of sample was taken for analysis, and the content of ethyl mercaptan in about 80 mL was 95.1%, which met the industrial grade quality.

[0042] Raise the temperature of the heater to 37°C and continue rectification. After the sample collection bottle stops dripping, take 1.5 mL of the sample for analysis. The content of ethyl mercaptan is 99.2%, which does not meet the quality of first-class products. It is returned to the reaction flask through the conduit. Rectify again and take a sample for analysis, obtaining approximately 60 mL of ethyl mercaptan with a content of 99.5%, meeting the requirements of first-class products.

[0043] Raise the temperature of the heater to 42°C. After the sample collection bottle stops dripping, take 1.5 mL of the sample for analysis. The content of ethyl mercaptan is 99.6%, which does not meet the quality of superior products. It is returned to the reaction flask. Rectify for the second time and take a sample for analysis, obtaining an ethyl mercaptan content of 99.8%. It is returned to the reaction flask. Rectify for the third time and take a sample for analysis, obtaining approximately 25 mL of ethyl mercaptan with a content of 99.9%, meeting the quality of superior products.

[0044] When the liquid level in the reaction flask is too low, the remaining treated crude product in the reaction flask can be sent back to the reaction flask to continue rectification.

[0045] Example 2

[0046] For the liquid phase 1 of crude ethyl mercaptan, the components are: ethyl mercaptan 85.7%, ethyl sulfide 6.1%, hydrogen sulfide 7.1%, and the total content of other impurities is 1.1%.

[0047] Add 500 mL of the above-mentioned crude product to the reaction flask. Nitrogen enters the crude product for aeration through the left branch port by the gas conduit, maintaining a nitrogen flow rate of 15 mL / min for a total of 15 min. After completing nitrogen aeration, take a sample from the right branch port to analyze the content of hydrogen sulfide in the crude product, which is 0.2%, meeting the allowable residual standard of hydrogen sulfide in the crude product. Open the two cocks on the conduit and send approximately 300 mL of the treated crude product to the reaction flask;

[0048] Use a packed vertical spike fractionating column with a length of 150 mm and a 200 mm serpentine condenser. The cooling water temperature is -8°C. The heater uses an oil bath for heating, controlling its temperature to start rectification at 34°C. Starting from the first drop of liquid dripping from the sample collection bottle, collect the first 10 min of distillate without reflux to prevent light components from continuously remaining in the product and being unable to be removed;

[0049] Starting from the 10th minute, collect until the sample collection bottle stops dripping, then take 1.5 mL of the sample for analysis, obtaining approximately 100 mL of ethyl mercaptan with a content of 97.3%, meeting the industrial-grade quality;

[0050] Raise the temperature of the heater to 37°C and continue rectification. After the sample collection bottle stops dripping, take 1.5 mL of the sample for analysis, obtaining approximately 80 mL of ethyl mercaptan with a content of 99.6%, meeting the requirements of first-class products.

[0051] Raise the heater temperature to 40°C. After the sample receiving bottle stops dripping, take 1.5 mL of the sample for analysis. The content of ethanethiol is 99.7%, which does not meet the quality of first-class products. Return it to the reaction flask, conduct secondary rectification and sampling analysis, and obtain approximately 40 mL of ethanethiol with a content of 99.9%, which meets the quality of first-class products.

[0052] When the liquid level in the reaction flask is too low, the remaining treated crude product in the reaction flask can be sent back to the reaction flask for continuous rectification.

[0053] Example 3

[0054] The liquid phase of crude ethanethiol 1, components: ethanethiol 68.8%, ethyl sulfide 14.6%, hydrogen sulfide 12.7%, total content of other impurities 3.9%.

[0055] Add 380 mL of the above-mentioned crude product to the reaction flask. Nitrogen enters the crude product for aeration through the left branch port by the gas guide tube. Keep the nitrogen flow rate at 30 mL / min for 25 min. After completing the nitrogen aeration, take a sample from the right branch port to analyze the content of hydrogen sulfide in the crude product, which is 0.4%, meeting the allowable residual standard of hydrogen sulfide in the crude product. Open the two cocks on the conduit and send approximately 300 mL of the treated crude product to the reaction flask;

[0056] Use a packed vertical spike fractionating column with a length of 300 mm and a 400 mm serpentine condenser. The cooling water temperature is -5°C. The heater uses oil bath heating and controls its temperature at 36°C to start rectification. Starting from the first drop of liquid dripping from the sample receiving bottle, collect the first 10 min of distillate without reflux to prevent light components from continuously remaining in the product and being unable to be removed;

[0057] Starting from the 10th minute, collect until the sample receiving bottle stops dripping. Take 1.5 mL of the sample for analysis. The content of ethanethiol is 92.7%, which does not meet the industrial grade quality. Return it to the reaction flask. Conduct re-rectification and sampling analysis again to obtain approximately 75 mL of ethanethiol with a content of 95.8%, which meets the industrial grade quality;

[0058] Raise the heater temperature to 40°C to continue rectification. After the sample receiving bottle stops dripping, take 1.5 mL of the sample for analysis. The content of ethanethiol is 98.4%, which does not meet the quality of first-class products. Return it to the reaction flask. Conduct re-rectification and sampling analysis again to obtain approximately 50 mL of ethanethiol with a content of 99.5%, meeting the requirements of first-class products.

[0059] Raise the heater temperature to 44°C. After the sample receiving bottle stops dripping, take 1.5 mL of the sample for analysis. The content of ethanethiol is 99.6%, which does not meet the quality of first-class products. Return it to the reaction flask. Conduct secondary rectification and sampling analysis. The content of ethanethiol is 99.8%, which does not meet the quality of first-class products. Return it to the reaction flask. Conduct tertiary rectification and sampling analysis. The content of ethanethiol is 99.9%, which meets the quality of first-class products;

[0060] When the liquid level in the reaction flask is too low, the remaining crude product after treatment in the reaction flask can be sent back to the reaction flask for continuous rectification.

Claims

1. A small-scale continuous rectification pilot plant for ethyl mercaptan, characterized in that, It includes a hydrogen sulfide removal unit and an ethyl mercaptan rectification unit; In the hydrogen sulfide removal unit, an adapter (3) is used to connect the middle branch port of the first reaction flask (2) to the spherical condenser (4), and the outlet of the spherical condenser (4) is connected to the first conical flask (6) through the first vacuum adapter (5); In the ethyl mercaptan rectification unit, the material in the first reaction flask (2) flows into the second reaction flask (15) through the control of the opening degrees of two cocks on the second conduit (13). The middle branch port of the second reaction flask (15) is connected to the lower end of the packed vertical spike fractionating column (17). The upper end of the packed vertical spike fractionating column (17) is connected to the coiled condenser (20) through the distillation head (18). The tail end of the coiled condenser (20) is connected to the second vacuum adapter (21), and the lower end of the second vacuum adapter (21) is connected to the middle sample receiving flask (22), and then connected to the sample receiving flask (23).

2. The continuous rectification pilot plant for ethanethiol according to claim 1, wherein One branch port of the first reaction flask (2) is connected to the gas guide tube (1), and the other branch port is a sample addition port or a sampling port.

3. The continuous rectification pilot test device for ethanethiol according to claim 1, wherein The first conical flask (6) is connected to the first liquid alkali absorption flask (8) through the first polytetrafluoroethylene tube (7), and the first liquid alkali absorption flask (8) is connected to the second liquid alkali absorption flask (10) through the second polytetrafluoroethylene tube (9).

4. The continuous rectification pilot plant for ethanethiol according to claim 1, characterized in that, The gas phase outlet of the second vacuum adapter (21) is connected to the oxidation flask (28) through the third polytetrafluoroethylene tube (25), and the oxidation flask (28) is connected to the third liquid alkali absorption flask (29) through the fourth polytetrafluoroethylene tube (26).

5. The continuous rectification pilot test device for ethanethiol according to claim 1, characterized in that, The lower end of the sample receiving flask (23) is connected to the second conical flask (24) or connected to the second reaction flask (15).

6. The continuous rectification pilot device for ethanethiol according to claim 1, characterized in that, Thermometers are provided on both the second reaction flask (15) and the packed vertical spike fractionating column (17), namely the first thermometer (16) and the second thermometer (19).

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