A method for post-processing hydrogen sulfide

Abstract

The present application discloses a hydrogen sulfide post-treatment method, which belongs to the field of sulfide synthesis technology. The method uses a mixed solution containing methanol and carbon disulfide as an absorption liquid for solid sulfur. The mixed solution can be circulated and absorbed multiple times in a kettle via a metering pump, resulting in a fast sulfur dissolution rate and high sulfur removal efficiency. The treated hydrogen sulfide product is free of sulfur entrainment, avoiding blockage of pipelines and equipment caused by solid sulfur. The hydrogen sulfide product has a purity of 99.95%. The mixed solution can be recycled and reused, eliminating waste and reducing environmental pollution. After the mixed solution absorbs a certain amount of sulfur, the sulfur is precipitated by cooling. The precipitated sulfur can be used as a raw material for synthesizing hydrogen sulfide. The methanol and carbon disulfide absorption liquid can be recycled and reused, eliminating waste and reducing production costs.

Description

Technical Field

[0001] The present application belongs to the technical field of sulfide synthesis, and in particular relates to a method for post-processing hydrogen sulfide. Background Art

[0002] Hydrogen sulfide is an important industrial intermediate, used, for example, in the synthesis of mercaptans, sulfides, and thiophenes, as well as in numerous sulfide reactions. Industrial production of hydrogen sulfide typically involves the reaction of sulfur with hydrogen. However, excess sulfur is produced during this reaction, and the byproduct decomposes to produce hydrogen sulfide and sulfur. This excess sulfur cannot be completely condensed and refluxed, leading to sulfur deposition in downstream pipes, valves, and equipment along the airflow. This can cause blockages, unstable equipment operation, and difficulty in cleaning, impacting production.

[0003] US2863725 provides a method for producing hydrogen sulfide over a molybdenum catalyst. Hydrogen bubbles upward through a sulfur melt, and some sulfur is incorporated into the final product. While the sulfur can be condensed in a gas cooler, the condensed sulfur powder is entrained in the gas stream, and the byproduct polysulfanes decompose into hydrogen sulfide and sulfur, causing sulfur to accumulate in subsequent pipelines.

[0004] FR2844208B1 reports a method for producing crude hydrogen sulfide by reacting hydrogen with liquid sulfur. The crude hydrogen sulfide produced must be passed through a solid filter containing porous particles selected from activated carbon, alumina, and silica to remove sulfur and other impurities. After loading the sulfur, the filter material must be burned. This has the disadvantages of high maintenance costs associated with replacing the activated carbon bed, high activated carbon consumption, and environmental pollution caused by combustion.

[0005] US5686056 discloses a method for purifying crude hydrogen sulfide gas. This method involves passing crude hydrogen sulfide through a filter medium containing a molecular sieve to decompose polysulfanes into hydrogen sulfide and sulfur, with the sulfur retained in the filter medium. To remove the accumulated sulfur from the filter medium, heated hydrogen gas must be passed through the filter medium in the opposite direction to the crude hydrogen sulfide gas, making this method cumbersome.

[0006] Based on the existing hydrogen sulfide production technology and equipment, the following problems were found: crude hydrogen sulfide will carry some sulfur, and after condensing in the condenser, some sulfur powder will enter the subsequent pipelines and equipment with the air flow, causing sulfur deposition; crude hydrogen sulfide will decompose polysulfides through filtering devices such as molecular sieves, and the sulfur produced will accumulate in the filter medium, requiring the filter medium to be regenerated, which is inefficient and increases costs. Summary of the Invention

[0007] The purpose of the present application is to provide a hydrogen sulfide post-treatment method and equipment, which removes sulfur entrained in hydrogen sulfide synthesis gas without using a filtering device, eliminates the impact of sulfur deposition on production, and obtains high-purity hydrogen sulfide gas; and solves the technical problems existing in the prior art of sulfur entrainment in hydrogen sulfide products, low product purity, and solid sulfur causing blockage of pipeline equipment.

[0008] To achieve the above objectives, the technical solution adopted in this application is to provide a hydrogen sulfide post-treatment method, which specifically includes the following steps:

[0009] Hydrogen sulfide synthesis gas is added to a mixed solution containing methanol and carbon disulfide, and stirred to absorb and dissolve sulfur. The solution, which has absorbed sulfur, can be circulated into the reactor via a metering pump, where it continues to come into countercurrent contact with the rising hydrogen sulfide synthesis gas to further absorb and dissolve sulfur. The mixed solution, which has absorbed sulfur, can be cooled to precipitate solid sulfur, which can then be used as a raw material for synthesizing hydrogen sulfide.

[0010] In one embodiment,

[0011] The mass percentage of methanol is 40-95%, and the mass percentage of carbon disulfide is 5-30%. Preferably, the mass percentage of methanol is 70-95%, and the mass percentage of carbon disulfide is 10-25%.

[0012] In one embodiment,

[0013] The temperature of the mixed solution is 10-50 o C, preferably 12-30 o C.

[0014] In one embodiment,

[0015] The hydrogen sulfide synthesis gas comprises, by mass percentage, 85-98% hydrogen sulfide and 2-15% solid sulfur. Preferably, the hydrogen sulfide is 90-98% and the solid sulfur is 2-5%.

[0016] In one embodiment,

[0017] The temperature in the reactor is 10-50 o C, preferably 10-30 o C.

[0018] In one embodiment,

[0019] The pressure in the reactor is 2-5 bar, preferably 2-4 bar.

[0020] In one embodiment,

[0021] The hydrogen sulfide synthesis gas is directly introduced into the reactor below the liquid level. The temperature of the hydrogen sulfide synthesis gas entering the reactor is 10-30 o C, preferably 10-25 o C.

[0022] In one embodiment,

[0023] After entering the reactor, the hydrogen sulfide synthesis gas directly contacts the mixed solution, and the rising hydrogen sulfide gas further contacts the circulating solution after absorbing sulfur through spraying in reverse; the spraying device is located at the absorption liquid circulation inlet pipe mouth.

[0024] The present application also provides a hydrogen sulfide post-treatment device, including a reactor, a spray assembly is provided above the reactor, and the reactor and the spray assembly are connected by a pipeline; the spray assembly includes a spray device, a spray port is provided at the bottom of the spray device, and a defoaming device is provided inside the spray device.

[0025] In one embodiment,

[0026] The reactor comprises an outer wall of the reactor, an inner wall of the reactor is provided with a stirring paddle, the stirring paddle is an anchor frame type stirring paddle, a stirring motor is provided on the top of the stirring paddle, and the outer wall of the reactor is provided with a reactor jacket, a temperature sensor sleeve, a sight glass and an inlet and outlet.

[0027] In one embodiment,

[0028] The pipeline comprises a metering pump outlet pipeline, on which a metering pump is arranged.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] Compared with the prior art using only carbon disulfide, the addition of methanol can significantly reduce the amount of carbon disulfide used, reduce the risk of explosion and combustion caused by carbon disulfide, and make the desulfurization method safer and more environmentally friendly; the mixed solution containing methanol and carbon disulfide absorbs and dissolves sulfur at a fast rate, has a high sulfur removal efficiency, and the product after absorption is free of sulfur entrainment, thus avoiding the deposition of sulfur in pipelines, equipment, valves, etc. The purity of hydrogen sulfide gas is above 99.95%, and the device can operate continuously and stably; the mixed solution containing methanol and carbon disulfide is used as an absorption liquid for solid sulfur. After absorbing a certain amount of sulfur, the sulfur is precipitated by cooling. The precipitated sulfur can be used as a raw material for synthesizing hydrogen sulfide and reacts with methane to regenerate hydrogen sulfide, thereby realizing the recycling of methanol and carbon disulfide absorption liquid, reducing production costs, and reducing environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0032] Figure 1 This is the structural diagram of the mixed solution desulfurization reactor;

[0033] Figure 2 This is a top view of the spray device in the reactor.

[0034] Explanation of symbols in the figure:

[0035] 1. Stirring motor; 2. Hydrogen sulfide synthesis gas outlet; 3. Absorption liquid circulation inlet; 4. Defoaming device; 5. Spraying device; 6. Reactor jacket; 7. First sight glass; 8. Temperature sensor sleeve; 9. Reactor outer wall; 10. Stirring paddle; 11. Circulating water inlet; 12. Circulating water drain outlet; 13. Absorption liquid outlet in reactor; 14. Second sight glass; 15. Third sight glass; 16. Hydrogen sulfide synthesis gas inlet; 17. Circulating water outlet; 18. Pressure sensor; 19. Solution drain outlet / fresh absorption liquid inlet; 20. Metering pump; 21. Metering pump outlet pipeline. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clear and understandable, this application is further described in detail. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0037] Example 1

[0038] like Figure 1-2 As shown, a hydrogen sulfide post-treatment equipment includes a reactor, a spray assembly is provided above the reactor, and the reactor and the spray assembly are connected by a pipeline; the spray assembly includes a spray device 5, a spray port is provided at the bottom of the spray device 5, and a defoaming device 4 is provided inside the spray device 5.

[0039] The reactor includes an outer wall 9 of the reactor, a stirring paddle 10 is provided inside the outer wall 9 of the reactor, the stirring paddle 10 is an anchor frame type stirring paddle, a stirring motor 1 is provided on the top of the stirring paddle 10, and the outer wall 9 of the reactor is provided with a reactor jacket 6, a temperature sensor sleeve 8, a pressure sensor 18, a sight glass and an inlet and outlet;

[0040] The sight glasses include a first sight glass 7, a second sight glass 14 and a third sight glass 15; the inlets and outlets include a hydrogen sulfide synthesis gas inlet 16 and a hydrogen sulfide synthesis gas outlet 2, a circulating water inlet 11 and a circulating water outlet 17, a circulating water drain outlet 12, an absorption liquid circulation inlet 3 and an absorption liquid outlet 13 in the kettle; the spray device 5 is connected to the absorption liquid circulation inlet 3;

[0041] The pipeline includes a metering pump outlet pipeline 21 , on which a metering pump 20 is provided; a solution drain port / fresh absorption liquid inlet 19 is provided on the metering pump outlet pipeline 21 ; and the absorption liquid outlet 13 in the kettle is connected to the metering pump outlet pipeline 21 .

[0042] Example 2

[0043] A mixed solution containing 80% methanol and 20% carbon disulfide was heated at 20 o C, pumped into the reactor, controlled the liquid level to be above the third sight glass 15 and below the first sight glass 7, turned on the metering pump 20, and started the circulation; hydrogen sulfide synthesis gas entered the reactor at 9.5 kg / h, and the composition of hydrogen sulfide synthesis gas was 96.8% hydrogen sulfide and 3.1% sulfur. The temperature when entering the reactor was 20 o C, reactor pressure is 2.5 bar;

[0044] The hydrogen sulfide synthesis gas entering the reactor directly contacts and reacts with the mixed solution. The solution after absorbing sulfur reaches the spray device 5 through the absorption liquid outlet 13 in the reactor, the metering pump 20, the metering pump outlet pipeline 21, and the absorption liquid circulation inlet 3. The rising hydrogen sulfide gas and the sulfur-absorbing solution sprayed from the spray device 5 come into countercurrent contact within the reactor. After the sulfur-absorbing solution absorbs a certain amount of sulfur again, the methanol content is 66%, the carbon disulfide content is 18%, and the sulfur content is 16%. The desulfurized hydrogen sulfide gas is collected from the hydrogen sulfide synthesis gas outlet 2 at a flow rate of 9.18 kg / h.

[0045] Example 3

[0046] This embodiment differs from embodiment 2 in that the composition of the mixed solution is: 85% methanol, 15% carbon disulfide; hydrogen sulfide synthesis gas enters the reactor at a rate of 9.2 kg / h; the composition of the hydrogen sulfide synthesis gas is: 97.3% hydrogen sulfide, 2.6% sulfur, and the remaining operations are the same; after the solution that has absorbed sulfur absorbs a certain amount of sulfur again, the methanol content is 76%, the carbon disulfide content is 10%, and the sulfur content is 14%; the desulfurized hydrogen sulfide gas is collected from the hydrogen sulfide synthesis gas outlet 2 at a flow rate of 9.0 kg / h.

[0047] Example 4

[0048] This embodiment differs from embodiment 2 in that the composition of the mixed solution is 75% methanol and 25% carbon disulfide, and the remaining operations are the same; after the solution that has absorbed sulfur absorbs a certain amount of sulfur again, the methanol content is 64%, the carbon disulfide content is 21%, and the sulfur content is 15%.

[0049] Example 5

[0050] This embodiment differs from embodiment 2 in that the composition of the mixed solution is 90% methanol and 10% carbon disulfide, and the remaining operations are the same; after the solution that has absorbed sulfur absorbs a certain amount of sulfur again, the methanol content is 78%, the carbon disulfide content is 7%, and the sulfur content is 15%.

[0051] Example 6

[0052] The difference between this embodiment and embodiment 2 is that the temperature of the mixed solution is 12 o C, the temperature in the reactor is 12 o C, the rest of the operations are the same.

[0053] Example 7

[0054] The difference between this embodiment and embodiment 2 is that the temperature of the mixed solution is 30 o C, the temperature in the reactor is 30 o C, the rest of the operations are the same.

[0055] Example 8

[0056] The difference between this embodiment and embodiment 2 is that the temperature of the mixed solution is 50 o C, the temperature in the reactor is 50 o C, the rest of the operations are the same.

[0057] Example 9

[0058] This embodiment differs from embodiment 2 in that the composition of the hydrogen sulfide synthesis gas is: 85% hydrogen sulfide and 15% sulfur, and the remaining operations are the same; after the solution after absorbing sulfur absorbs a certain amount of sulfur again, the methanol content is 59%, the carbon disulfide content is 13%, and the sulfur content is 28%.

[0059] Example 10

[0060] This embodiment differs from embodiment 2 in that the composition of the hydrogen sulfide synthesis gas is: 90% hydrogen sulfide and 10% sulfur, and the remaining operations are the same; after the solution that has absorbed sulfur absorbs a certain amount of sulfur again, the methanol content is 62%, the carbon disulfide content is 14%, and the sulfur content is 24%.

[0061] Example 11

[0062] This embodiment differs from embodiment 2 in that the composition of the hydrogen sulfide synthesis gas is: 95% hydrogen sulfide and 5% sulfur, and the remaining operations are the same; after the solution after absorbing sulfur absorbs a certain amount of sulfur again, the methanol content is 65%, the carbon disulfide content is 16%, and the sulfur content is 19%.

[0063] Example 12

[0064] The difference between this embodiment and embodiment 2 is that the pressure in the reactor is 4 bar, and the other operations are the same.

[0065] Example 13

[0066] The difference between this embodiment and embodiment 2 is that the pressure in the reactor is 5 bar, and the other operations are the same.

[0067] The present application provides a hydrogen sulfide post-treatment method, which specifically includes the following steps: adding hydrogen sulfide synthesis gas to a mixed solution containing methanol and carbon disulfide, stirring to absorb and dissolve sulfur, and circulating the solution after absorbing sulfur into a reactor through a metering pump, and then continuously contacting with the rising hydrogen sulfide synthesis gas in reverse to further absorb and dissolve sulfur. The method uses the mixed solution containing methanol and carbon disulfide as an absorption liquid for solid sulfur, and the mixed solution can be circulated and absorbed multiple times in the reactor through a metering pump, with a fast sulfur dissolution rate and high sulfur removal efficiency. The treated hydrogen sulfide product is free of sulfur entrainment, thereby avoiding blockage of pipelines, equipment, etc. caused by solid sulfur. The hydrogen sulfide product has a purity of 99.95%, and the mixed solution can be recycled and reused, without causing waste and reducing environmental pollution. After the mixed solution absorbs a certain amount of sulfur, the solid sulfur can be precipitated by cooling. The precipitated sulfur can be used as a raw material for synthesizing hydrogen sulfide, reacting with methane to regenerate hydrogen sulfide, and recycled and reused, without causing waste and reducing production costs.

[0068] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0069] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A method for post-processing hydrogen sulfide, characterized in that: The specific steps include: The hydrogen sulfide synthesis gas is added to a mixed solution containing methanol and carbon disulfide, and the solution is stirred to absorb and dissolve sulfur. The solution after absorbing sulfur is circulated into the reactor through a metering pump and then continuously contacts the rising hydrogen sulfide synthesis gas in a countercurrent manner to further absorb and dissolve sulfur. In the mixed solution, the mass percentage of methanol is 40-95%, and the mass percentage of carbon disulfide is 5-30%; The hydrogen sulfide synthesis gas comprises, by mass percentage, 85-98% hydrogen sulfide and 2-15% solid sulfur; The temperature in the reactor is 10-50 o C, pressure is 2-5 bar.

2. A hydrogen sulfide post-treatment method according to claim 1, characterized in that: The temperature of the mixed solution is 10-50 o C.

3. A hydrogen sulfide post-treatment method according to claim 1, characterized in that: The hydrogen sulfide synthesis gas is directly introduced into the reactor below the liquid level, and the temperature of the hydrogen sulfide synthesis gas entering the reactor is 10-30 o C.

4. A hydrogen sulfide post-treatment method according to claim 1, characterized in that: The hydrogen sulfide synthesis gas directly contacts the mixed solution after entering the reactor, and the rising hydrogen sulfide gas further contacts the circulating solution after absorbing sulfur through spraying in reverse direction.

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