Hydrogen sulfide post-treatment method

Abstract

The invention discloses a hydrogen sulfide post-treatment method, and belongs to the technical field of sulfide synthesis, the method uses a mixed solution containing methanol and carbon disulfide as an absorption liquid of solid sulfur, the mixed solution can be circularly absorbed for multiple times in a kettle through a metering pump, the sulfur dissolving rate is high, and the sulfur removal efficiency is high. The treated hydrogen sulfide product is free of sulfur entrainment, the situation that pipelines, equipment and the like are blocked due to solid sulfur is avoided, the purity of the hydrogen sulfide product reaches 99.95%, the mixed solution can be recycled, waste is avoided, and environmental pollution is reduced; after the mixed solution absorbs a certain amount of sulfur, the sulfur is separated out by cooling, the separated sulfur can be used as a raw material for synthesizing hydrogen sulfide, and the absorption liquid of methanol and carbon disulfide can be recycled, so that waste is avoided, and the production cost is reduced.

Description

Technical Field

[0001] This application belongs to the technical field of sulfide synthesis, and particularly relates to a method for post-treatment of hydrogen sulfide. Background Art

[0002] Hydrogen sulfide is an important intermediate in industry. For example, it can be used in the synthesis of mercaptans, thioethers, thiophenes and applied to many reactions of sulfides. Industrially, hydrogen sulfide is usually produced by reacting sulfur with hydrogen. In the reaction process, sulfur is in excess, and the by-products are decomposed to produce hydrogen sulfide and sulfur after decomposition. The excessive sulfur cannot be completely condensed and refluxed, resulting in sulfur being easily deposited in subsequent pipelines, valves and equipment along the gas flow direction, causing pipeline blockage, unstable operation of the equipment, and being difficult to clean, thus affecting production.

[0003] US2863725 provides a method for producing hydrogen sulfide under the action of a molybdenum catalyst. Hydrogen rises through the sulfur melt in the form of bubbles, and part of sulfur is mixed in the final product. Although sulfur can be condensed by a gas cooler, the condensed sulfur powder will be entrained by the gas flow, and the by-product polysulfane will also be decomposed into hydrogen sulfide and sulfur, resulting in sulfur deposition in the subsequent pipelines.

[0004] FR2844208B1 reports a method for preparing crude hydrogen sulfide by reacting hydrogen with liquid sulfur. The prepared crude hydrogen sulfide needs to pass through a solid filter containing porous particles selected from activated carbon, alumina and silica to remove impurities such as sulfur. After the filter material is sulfur-loaded, it must be treated by combustion. The disadvantages are high maintenance cost for replacing the activated carbon bed, large amount of activated carbon used, and environmental pollution caused during combustion.

[0005] US5686056 reports a method for purifying crude hydrogen sulfide gas. This method is to pass the crude hydrogen sulfide through a filter medium containing molecular sieves to decompose polysulfane into hydrogen sulfide and sulfur, and the sulfur is retained in the filter medium. To remove the aggregated sulfur from the filter medium, heated hydrogen needs to be passed through the filter medium in the opposite direction to the crude hydrogen sulfide gas, and this method is cumbersome to operate.

[0006] According to the existing hydrogen sulfide production technologies and devices, the following problems are found: Crude hydrogen sulfide will entrain some sulfur, and some sulfur powder will also enter the subsequent pipelines and equipment along with the gas flow after condensation in the condenser, resulting in sulfur deposition; The sulfur generated by decomposing polysulfides through a filter device such as molecular sieves will accumulate in the filter medium, and the filter medium needs to be regenerated, with low efficiency and increased cost. Summary of the Invention

[0007] The purpose of the implementation of this application is to provide a method and equipment for post-treatment of hydrogen sulfide, which does not use a filtering device, removes the sulfur entrained in the hydrogen sulfide synthesis gas, eliminates the influence of sulfur deposition on production, and obtains high-purity hydrogen sulfide gas; it solves the technical problems existing in the prior art, such as sulfur entrainment in hydrogen sulfide products, low product purity, and blockage of pipelines and equipment caused by solid sulfur.

[0008] To achieve the above purpose, the technical solution adopted in this application is: to provide a method for post-treatment of hydrogen sulfide, which specifically includes the following steps: Add the hydrogen sulfide synthesis gas to a mixed solution containing methanol and carbon disulfide, stir to absorb and dissolve sulfur, and the solution after absorbing sulfur can be circulated into the reaction kettle through a metering pump and then continuously contact the rising hydrogen sulfide synthesis gas reversely to further absorb and dissolve sulfur. The mixed solution after absorbing sulfur can be cooled to precipitate solid sulfur, and the precipitated sulfur can be used as a raw material for synthesizing hydrogen sulfide.

[0009] In one embodiment, The mass percentage content of methanol is 40 - 95%, and the mass percentage content of carbon disulfide is 5 - 30%. Preferably, the mass percentage content of methanol is 70 - 95%, and the mass percentage content of carbon disulfide is 10 - 25%.

[0010] In one embodiment, The temperature of the mixed solution is 10 - 50 o °C, preferably 12 - 30 o °C.

[0011] In one embodiment, The hydrogen sulfide synthesis gas, by mass percentage, includes 85 - 98% hydrogen sulfide and 2 - 15% solid sulfur. Preferably, hydrogen sulfide is 90 - 98%, and solid sulfur is 2 - 5%.

[0012] In one embodiment, The temperature in the reaction kettle is 10 - 50 o °C, preferably 10 - 30 o °C.

[0013] In one embodiment, The pressure in the reaction kettle is 2 - 5 bar, preferably 2 - 4 bar.

[0014] In one embodiment, The hydrogen sulfide synthesis gas is directly introduced below the liquid level in the reaction kettle, and the temperature of the hydrogen sulfide synthesis gas entering the reaction kettle is 10 - 30 o °C, preferably 10 - 25 o °C.

[0015] In one embodiment, After the hydrogen sulfide syngas enters the reactor, it directly contacts the mixed solution, and the rising hydrogen sulfide gas further contacts the solution after absorbing sulfur in a countercurrent manner through spraying; the spraying device is located at the position of the inlet pipe of the absorption liquid circulation.

[0016] The present application also provides a hydrogen sulfide post-treatment device, including a reactor, a spraying assembly is provided above the reactor, and the reactor and the spraying assembly are connected by a pipeline; the spraying assembly includes a spraying device, a spraying port is provided at the bottom of the spraying device, and a demisting device is provided inside the spraying device.

[0017] In one embodiment, The reactor includes a reactor outer wall, a stirring paddle is provided inside the reactor outer wall, the stirring paddle is an anchor frame type stirring paddle, a stirring motor is provided at the top of the stirring paddle, and a reactor jacket, a temperature sensor sleeve, a sight glass and an inlet and outlet are provided on the reactor outer wall.

[0018] In one embodiment, The pipeline includes a metering pump outlet pipeline, and a metering pump is provided on the metering pump outlet pipeline.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: Compared with the simple use of carbon disulfide in the prior art, the addition of methanol can significantly reduce the dosage of carbon disulfide, reduce the explosion and combustion risks brought by carbon disulfide, and make the sulfur removal method safer and more environmentally friendly; the mixed solution containing methanol and carbon disulfide has a fast absorption and dissolution rate of sulfur, high sulfur removal efficiency, and no sulfur entrainment in the product after absorption, 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 the absorption liquid for solid sulfur. After absorbing a certain amount of sulfur, sulfur is precipitated by cooling, and the precipitated sulfur can be used as a raw material for synthesizing hydrogen sulfide, reacting with methane to regenerate hydrogen sulfide, realizing the recycling of the methanol and carbon disulfide absorption liquid, reducing production costs, and reducing environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a structural diagram of a reactor for sulfur removal from a mixed solution; Figure 2 It is a top view of the spraying device inside the reactor.

[0022] Description of Symbol Marks in the Figures: 1. Stirring motor; 2. Hydrogen sulfide synthesis gas outlet; 3. Absorbent liquid circulation inlet; 4. Demisting 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 port; 13. Absorbent liquid outlet inside the 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 port / fresh absorbent liquid inlet; 20. Metering pump; 21. Metering pump outlet pipeline. Specific Embodiments

[0023] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application clearer and more understandable, this application will be 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.

[0024] Embodiment 1 As Figure 1-2 shown, a hydrogen sulfide post-treatment device includes a reactor, and a spraying assembly is provided above the reactor, and the reactor and the spraying assembly are connected by a pipeline; the spraying assembly includes a spraying device 5, a spraying port is provided at the bottom of the spraying device 5, and a demisting device 4 is provided inside the spraying device 5.

[0025] The reactor includes a reactor outer wall 9, a stirring paddle 10 is provided inside the reactor outer wall 9, the stirring paddle 10 is an anchor frame type stirring paddle, a stirring motor 1 is provided at the top of the stirring paddle 10, and a reactor jacket 6, a temperature sensor sleeve 8, a pressure sensor 18, sight glasses and inlets and outlets are provided on the reactor outer wall 9; 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 port 12, an absorbent liquid circulation inlet 3 and an absorbent liquid outlet inside the reactor 13; the spraying device 5 is communicated with the absorbent liquid circulation inlet 3; The pipeline includes a metering pump outlet pipeline 21, a metering pump 20 is provided on the metering pump outlet pipeline 21; a solution drain port / fresh absorbent liquid inlet 19 is provided on the metering pump outlet pipeline 21; the absorbent liquid outlet inside the reactor 13 is communicated with the metering pump outlet pipeline 21.

[0026] Embodiment 2 A mixed solution containing 80% methanol and 20% carbon disulfide at 20 oUnder C, it is introduced into the reaction kettle, and the liquid level is controlled above the third sight glass 15 and below the first sight glass 7. The metering pump 20 is opened, and the circulation is started; the hydrogen sulfide synthesis gas enters the reaction kettle at 9.5 kg / h. The composition of the hydrogen sulfide synthesis gas is 96.8% hydrogen sulfide and 3.1% sulfur. The temperature when it enters the reaction kettle is 20 o °C, and the pressure in the reaction kettle is 2.5 bar; The hydrogen sulfide synthesis gas entering the reaction kettle directly contacts and reacts with the mixed solution. The solution after absorbing sulfur passes through the absorption liquid outlet 13 in the kettle, the metering pump 20, the metering pump outlet pipeline 21, and the absorption liquid circulation inlet 3 to reach the spraying device 5. The rising hydrogen sulfide gas contacts the solution after absorbing sulfur sprayed by the spraying device 5 in the reaction kettle in a countercurrent manner; after the solution after absorbing sulfur 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 hydrogen sulfide gas after desulfurization is collected from the hydrogen sulfide synthesis gas outlet 2 at a flow rate of 9.18 kg / h.

[0027] Example 3 The difference between this example and Example 2 is that the composition of the mixed solution is: 85% methanol and 15% carbon disulfide; the hydrogen sulfide synthesis gas enters the reaction kettle at 9.2 kg / h; the composition of the hydrogen sulfide synthesis gas is: 97.3% hydrogen sulfide and 2.6% sulfur, and the rest of the operations are the same; after the solution after absorbing 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 hydrogen sulfide gas after desulfurization is collected from the hydrogen sulfide synthesis gas outlet 2 at a flow rate of 9.0 kg / h.

[0028] Example 4 The difference between this example and Example 2 is that the composition of the mixed solution is: 75% methanol and 25% carbon disulfide, and the rest of the operations are the same; after the solution after absorbing 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%.

[0029] Example 5 The difference between this example and Example 2 is that the composition of the mixed solution is: 90% methanol and 10% carbon disulfide, and the rest of the operations are the same; after the solution after absorbing 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%.

[0030] Example 6 The difference between this example and Example 2 is that the temperature of the mixed solution is 12 o °C, and the temperature in the reaction kettle is 12 o °C, and the rest of the operations are the same.

[0031] Example 7 This example is different from Example 2 in that the temperature of the mixed solution is 30 o °C, and the temperature in the reaction kettle is 30 o °C, and the rest of the operations are the same.

[0032] Example 8 This example is different from Example 2 in that the temperature of the mixed solution is 50 o °C, and the temperature in the reaction kettle is 50 o °C, and the rest of the operations are the same.

[0033] Example 9 This example is different from Example 2 in that the composition of the hydrogen sulfide synthesis gas is: 85% hydrogen sulfide, 15% sulfur, and the rest of the operations are the same; after the solution absorbs sulfur and then absorbs a certain amount of sulfur again, the methanol content is 59%, the carbon disulfide content is 13%, and the sulfur content is 28%.

[0034] Example 10 This example is different from Example 2 in that the composition of the hydrogen sulfide synthesis gas is: 90% hydrogen sulfide, 10% sulfur, and the rest of the operations are the same; after the solution absorbs sulfur and then absorbs a certain amount of sulfur again, the methanol content is 62%, the carbon disulfide content is 14%, and the sulfur content is 24%.

[0035] Example 11 This example is different from Example 2 in that the composition of the hydrogen sulfide synthesis gas is: 95% hydrogen sulfide, 5% sulfur, and the rest of the operations are the same; after the solution absorbs sulfur and then absorbs a certain amount of sulfur again, the methanol content is 65%, the carbon disulfide content is 16%, and the sulfur content is 19%.

[0036] Example 12 This example is different from Example 2 in that the pressure in the reaction kettle is 4 bar, and the rest of the operations are the same.

[0037] Example 13 This example is different from Example 2 in that the pressure in the reaction kettle is 5 bar, and the rest of the operations are the same.

[0038] The present application provides a method for post-treatment of hydrogen sulfide. The method 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. The solution after absorbing sulfur can enter the reaction kettle through a metering pump in a cycle and continuously contact the rising hydrogen sulfide synthesis gas reversely to further absorb and dissolve sulfur. This method uses a mixed solution containing methanol and carbon disulfide as the absorbent for solid sulfur. The mixed solution can be circulated and absorbed multiple times through the metering pump in the kettle, with a fast rate of dissolving sulfur and high sulfur removal efficiency. The treated hydrogen sulfide product has no sulfur entrainment, avoiding blockage of pipelines, equipment, etc. caused by solid sulfur. The purity of the hydrogen sulfide product reaches 99.95%. The mixed solution can be recycled and reused without waste, reducing environmental pollution. After absorbing a certain amount of sulfur, the mixed solution can precipitate solid sulfur by cooling. The precipitated sulfur can be used as a raw material for synthesizing hydrogen sulfide, reacting with methane to regenerate hydrogen sulfide, and being recycled and reused without waste, reducing production costs.

[0039] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality of" means two or more, unless otherwise specifically defined.

[0040] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for post-treatment of hydrogen sulfide, characterized in that, Specifically, the following steps are included: Add the hydrogen sulfide synthesis gas to the mixed solution containing methanol and carbon disulfide, stir to absorb and dissolve sulfur. The solution after absorbing sulfur can be circulated into the reaction kettle through a metering pump and continuously contact the rising hydrogen sulfide synthesis gas reversely to further absorb and dissolve sulfur; In the said mixed solution, the mass percentage content of methanol is 40 - 95%, and the mass percentage content of carbon disulfide is 10 - 25%.

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

3. The post-treatment method for hydrogen sulfide according to claim 1, wherein The said hydrogen sulfide synthesis gas, by mass percentage, includes 85 - 98% of hydrogen sulfide and 2 - 15% of solid sulfur.

4. A method for post-treatment of hydrogen sulfide according to claim 1, characterized in that, The temperature in the reactor is 10 - 50 o °C, and the pressure is 2 - 5 bar.

5. A method for post-treatment of hydrogen sulfide according to claim 1, characterized in that, The hydrogen sulfide synthesis gas is directly introduced below the liquid level in the reaction kettle, and the temperature of the hydrogen sulfide synthesis gas entering the reaction kettle is 10 - 30 o °C.

6. A method for post-treatment of hydrogen sulfide according to claim 1, wherein After the said hydrogen sulfide synthesis gas enters the reaction kettle, it directly contacts the said mixed solution, and the rising hydrogen sulfide gas further contacts the circulated solution after absorbing sulfur through spraying reversely.

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