A hydrogen sulfide removal and sulfur recovery system and its working method

Abstract

The present invention discloses a hydrogen sulfide removal and sulfur recovery system and its working method, which belong to the field of energy chemical industry and environmental technology. A desulfurizer is used to chemically react with hydrogen sulfide generated by coal gasification in the gasification reaction section of a supercritical water reaction unit, and hydrogen sulfide is chemically adsorbed and removed from the product. The clean fluid enters the downstream process along with the supercritical water; the sulfided desulfurizer can be recycled through recovery and regeneration. The present invention can not only achieve full contact reaction between the desulfurizer and hydrogen sulfide, with high desulfurization efficiency, but also achieve continuous purification of gas produced by supercritical water gasification; while producing sulfate by-products, it can also achieve the reuse of the desulfurizer, with low operating and maintenance costs. In addition, the present invention has wide applicability, and is not only suitable for the removal of hydrogen sulfide in the supercritical water gasification process of coal, but also suitable for the removal of hydrogen sulfide in the supercritical water gasification process of various sulfur-containing organic matter.

Description

Technical Field

[0001] The present invention belongs to the field of energy chemical industry and environmental technology, and particularly relates to a hydrogen sulfide removal and sulfur recovery system and a working method thereof. Background Art

[0002] During the coal combustion process, nitrogen and sulfur elements will generate large amounts of sulfur oxides and nitrogen oxides, causing great damage to the ecological environment and bringing emission reduction pressure and costs to coal-fired power plants.

[0003] Supercritical water gasification of coal for hydrogen production is an emerging clean coal conversion and utilization technology. Under supercritical water gasification reaction conditions, the carbon and hydrogen elements in coal are mainly converted into hydrogen and carbon dioxide, while the nitrogen and sulfur elements are converted into ammonia and hydrogen sulfide, respectively.

[0004] In coal supercritical water gasification hydrogen production technology, hydrogen sulfide is not only harmful to the environment, but also damages hydrogen pressure swing adsorption (PSA) separation equipment. Ammonia is dissolved in the liquid after gas-liquid separation, and direct discharge will cause environmental pollution. Summary of the Invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a hydrogen sulfide removal and sulfur recovery system and its working method. The system has a reasonable design, wide applicability, high sulfur removal efficiency, good continuity, and can produce sulfate by-products while also achieving the reuse of the desulfurizer, with low operating and maintenance costs.

[0006] The present invention is achieved through the following technical solutions:

[0007] The present invention discloses a hydrogen sulfide removal and sulfur recovery system, comprising a supercritical water reaction unit, a desulfurizer storage unit, a desulfurizer feeding unit, a desulfurizer recovery unit, a desulfurizer regeneration unit, a sulfate recovery unit, a water tank and a pressure reducing valve;

[0008] The supercritical water reaction unit includes a connected gasification reaction section and a desulfurization reaction section, the outlet of the desulfurization reaction section is connected to the downstream process; the outlet of the desulfurizer storage unit is connected to the desulfurizer inlet of the desulfurizer feeding unit, the water inlet of the desulfurizer feeding unit is connected to the water tank, and the outlet of the desulfurizer feeding unit is connected to the upper inlet of the desulfurization reaction section; the lower outlet of the desulfurization reaction section is connected to the desulfurizer inlet of the desulfurizer recovery unit, and the water inlet of the desulfurizer recovery unit is connected to the water tank; the outlet of the desulfurizer recovery unit is connected to the desulfurizer regeneration unit through a pressure reducing valve, the desulfurizer regeneration unit is provided with a regeneration agent inlet, the desulfurizer outlet of the desulfurizer regeneration unit is connected to the desulfurizer storage unit, and the sulfur outlet of the desulfurizer regeneration unit is connected to the sulfate recovery unit; the sulfate recovery unit is provided with an absorbent inlet.

[0009] Preferably, the desulfurizer in the desulfurizer storage unit is a single metal oxide or a composite metal oxide.

[0010] Preferably, a flow detection device is provided on the pipeline between the outlet of the desulfurizer recovery unit and the desulfurizer regeneration unit, and a regulating valve is provided on the connecting pipeline of the regeneration agent inlet; a flow detection device is provided between the sulfur outlet of the desulfurizer regeneration unit and the sulfate recovery unit, and a regulating valve is provided on the connecting pipeline of the absorbent inlet.

[0011] Preferably, the desulfurization reaction section, the desulfurization agent feeding unit and the desulfurization agent recovery unit are all provided with pressure monitoring devices.

[0012] Preferably, a first water pump is provided on the pipeline between the water inlet of the desulfurization agent recovery unit and the water tank.

[0013] Preferably, a second water pump is provided on the pipeline between the water inlet of the desulfurizing agent feeding unit and the water tank.

[0014] Preferably, a first valve is provided on the pipeline between the outlet of the desulfurizer storage unit and the desulfurizer inlet of the desulfurizer feeding unit.

[0015] Preferably, a second valve is provided on the pipeline between the outlet of the desulfurizing agent feeding unit and the upper inlet of the desulfurization reaction section.

[0016] Preferably, a third valve is provided on the pipeline between the lower outlet of the desulfurization reaction section and the desulfurizer inlet of the desulfurizer recovery unit.

[0017] The working method of the hydrogen sulfide removal and sulfur recovery system disclosed in the present invention includes:

[0018] The fresh desulfurizer slurry in the desulfurizer storage unit enters the desulfurizer feeding unit, and water is passed through the water tank to pressurize the feeding unit, and the desulfurizer is sent to the desulfurization reaction section by pressure; the desulfurizer entering the desulfurization reaction section chemically reacts with the hydrogen sulfide generated by coal gasification in the gasification reaction section, and the hydrogen sulfide is chemically adsorbed and removed from the product, and the clean fluid enters the downstream process; the sulfided desulfurizer is deposited in the lower part of the desulfurization reaction section; water is passed through the water tank to pressurize the desulfurizer recovery unit, and the sulfided desulfurizer is discharged from the desulfurization reaction section through the pressure difference and enters the desulfurizer recovery unit; the pressure reducing valve is opened, and the desulfurizer in the desulfurizer recovery unit enters the desulfurizer regeneration unit; the pressure reducing valve is closed, and a regenerating agent is passed into the desulfurizer regeneration unit for regeneration, and the released sulfur is sent to the sulfate recovery unit, and an absorbent is passed into the sulfate recovery unit to absorb the sulfur to form a sulfate by-product; the regenerated desulfurizer is again made into fresh desulfurizer slurry and sent to the desulfurizer storage unit for recycling.

[0019] Compared with the prior art, the present invention has the following beneficial technical effects:

[0020] The present invention discloses a hydrogen sulfide removal and sulfur recovery system, which utilizes a desulfurizer to chemically react with hydrogen sulfide generated from coal gasification in the gasification reaction section of a supercritical water reaction unit. The hydrogen sulfide is chemically adsorbed and removed from the product, and the clean fluid enters the downstream process along with the supercritical water. The sulfided desulfurizer can be recycled and regenerated. The present invention can not only achieve full contact reaction between the desulfurizer and hydrogen sulfide, resulting in high desulfurization efficiency, but also achieve continuous purification of gas produced by supercritical water gasification. While producing sulfate byproducts, it can also achieve the reuse of the desulfurizer. The desulfurizer is transported while flushing using water pressure, which reduces the energy consumption of the system and has low operating and maintenance costs. In addition, the present invention has wide applicability and is not only suitable for the removal of hydrogen sulfide in the supercritical water gasification process of coal, but also for the removal of hydrogen sulfide in the supercritical water gasification process of various sulfur-containing organic matter.

[0021] Furthermore, the desulfurizer used is a single metal oxide or a composite metal oxide, which can be regularly recovered and regenerated after desulfurization. The sulfur released during the regeneration process can be made into various sulfate by-products by a variety of absorbents, and the regenerated desulfurizer can be reused.

[0022] Furthermore, a flow detection device is provided on the pipeline between the outlet of the desulfurizer recovery unit and the desulfurizer regeneration unit, and a regulating valve is provided on the connecting pipeline of the regeneration agent inlet. This can adjust the feed amount of the regeneration agent according to the amount of desulfurizer to be regenerated, thereby accurately controlling the system reaction process. A flow detection device is provided between the sulfur outlet of the desulfurizer regeneration unit and the sulfate recovery unit, and a regulating valve is provided on the connecting pipeline of the absorbent inlet. This can adjust the amount of regeneration agent according to the amount of sulfur, thereby accurately controlling the system reaction process.

[0023] Furthermore, the desulfurization reaction section, desulfurizer feeding unit and desulfurizer recovery unit are all equipped with pressure monitoring devices, which can monitor the pressure of each unit in real time and accurately adjust the pressure parameters in the system.

[0024] The working method of the hydrogen sulfide removal and sulfur recovery system disclosed in the present invention has wide applicability, high sulfur removal efficiency, good continuity, and can achieve the reuse of the desulfurizer while producing sulfate byproducts, with low operating and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the overall structure of the system of the present invention.

[0026] In the figure: 1 is the gasification reaction section, 2 is the desulfurization reaction section, 3 is the desulfurizer storage unit, 4 is the desulfurizer feeding unit, 5 is the desulfurizer recovery unit, 6 is the desulfurizer regeneration unit, 7 is the sulfate recovery unit, 8 is the water tank, 9 is the first water pump, 10 is the second water pump, 11 is the first valve, 12 is the second valve, 13 is the third valve, and 14 is the pressure reducing valve. DETAILED DESCRIPTION

[0027] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments, which are intended to explain rather than limit the present invention:

[0028] like Figure 1 The hydrogen sulfide removal and sulfur recovery system of the present invention includes a supercritical water reaction unit, a desulfurizer storage unit 3, a desulfurizer feeding unit 4, a desulfurizer recovery unit 5, a desulfurizer regeneration unit 6, a sulfate recovery unit 7, a water tank 8 and a pressure reducing valve 14;

[0029] The supercritical water reaction unit includes a connected gasification reaction section 1 and a desulfurization reaction section 2, the outlet of the desulfurization reaction section 2 is connected to the downstream process; the outlet of the desulfurizer storage unit 3 is connected to the desulfurizer inlet of the desulfurizer feeding unit 4, the water inlet of the desulfurizer feeding unit 4 is connected to the water tank 8, and the outlet of the desulfurizer feeding unit 4 is connected to the upper inlet of the desulfurization reaction section 2; the lower outlet of the desulfurization reaction section 2 is connected to the desulfurizer inlet of the desulfurizer recovery unit 5, and the water inlet of the desulfurizer recovery unit 5 is connected to the water tank 8; the outlet of the desulfurizer recovery unit 5 is connected to the desulfurizer regeneration unit 6 through a pressure reducing valve 14, the desulfurizer regeneration unit 6 is provided with a regeneration agent inlet, the desulfurizer outlet of the desulfurizer regeneration unit 6 is connected to the desulfurizer storage unit 3, and the sulfur outlet of the desulfurizer regeneration unit 6 is connected to the sulfate recovery unit 7; the sulfate recovery unit 7 is provided with an absorbent inlet.

[0030] In a preferred embodiment of the present invention, the desulfurizer in the desulfurizer storage unit 3 is a single metal oxide or a composite metal oxide.

[0031] In a preferred embodiment of the present invention, a flow detection device is provided on the pipeline between the outlet of the desulfurizer recovery unit 5 and the desulfurizer regeneration unit 6, and a regulating valve is provided on the connecting pipeline of the regeneration agent inlet; a flow detection device is provided between the sulfur outlet of the desulfurizer regeneration unit 6 and the sulfate recovery unit 7, and a regulating valve is provided on the connecting pipeline of the absorbent inlet.

[0032] In a preferred embodiment of the present invention, the desulfurization reaction section 2, the desulfurization agent feeding unit 4 and the desulfurization agent recovery unit 5 are all provided with pressure monitoring devices.

[0033] In a preferred embodiment of the present invention, a first water pump 9 is provided on the pipeline between the water inlet of the desulfurizer recovery unit 5 and the water tank 8 .

[0034] In a preferred embodiment of the present invention, a second water pump 10 is provided on the pipeline between the water inlet of the desulfurizing agent feeding unit 4 and the water tank 8 .

[0035] In a preferred embodiment of the present invention, a first valve 11 is provided on the pipeline between the outlet of the desulfurizing agent storage unit 3 and the desulfurizing agent inlet of the desulfurizing agent feeding unit 4 .

[0036] In a preferred embodiment of the present invention, a second valve 12 is provided on the pipeline between the outlet of the desulfurizing agent feeding unit 4 and the upper inlet of the desulfurization reaction section 2 .

[0037] In a preferred embodiment of the present invention, a third valve 13 is provided on the pipeline between the lower outlet of the desulfurization reaction section 2 and the desulfurizer inlet of the desulfurizer recovery unit 5 .

[0038] The above-mentioned hydrogen sulfide removal and sulfur recovery system includes the following processes when in operation:

[0039] Open the first valve 11, and the fresh desulfurizer slurry stored in the desulfurizer storage unit 3 enters the desulfurizer feeding unit 4, and then close the valve 11. The second water pump 10 pressurizes the feeding unit 4. When the pressure of the feeding unit 4 is slightly higher than the pressure of the desulfurization reaction section 2, open the second valve 12 to feed the desulfurizer into the desulfurization reaction section 2. The desulfurizer entering the desulfurization reaction section 2 chemically reacts with the hydrogen sulfide generated by coal gasification in the gasification reaction section 1. The hydrogen sulfide is chemically adsorbed and removed from the product, and the clean fluid enters the downstream process; the sulfided desulfurizer is deposited in the lower part of the desulfurization reaction section 2. The first water pump 9 regularly pressurizes the desulfurizer recovery unit 5. When the pressure rises to a value close to that of the desulfurization reaction section 2, open the third valve 13, and the sulfided desulfurizer is discharged from the desulfurization reaction section 2 through the pressure difference and enters the desulfurizer recovery unit 5. After closing the third valve 13, the pressure reducing valve 14 is opened, and the desulfurizer in the desulfurizer recovery unit 5 can be flushed by the first water pump 9 and sent to the desulfurizer regeneration unit 6. The pressure reducing valve 14 is closed, and a regeneration agent is introduced into the desulfurizer regeneration unit 6 for regeneration at a certain temperature. The released sulfur is sent to the sulfate recovery unit 7, and an absorbent is introduced into the sulfate recovery unit 7 to absorb the sulfur and form sulfate as a byproduct. The regenerated desulfurizer can be made into a slurry again and sent to the desulfurizer storage unit 3 for recycling.

[0040] The above description is only part of the embodiments of the present invention. Although some terms are used in the present invention, the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of the present invention. Interpreting them as any additional limitations is contrary to the spirit of the present invention. The above description is only to further illustrate the content of the present invention with examples to facilitate easier understanding, but it does not mean that the embodiments of the present invention are limited to these. Any technical extension or re-creation made according to the present invention is protected by the present invention.

Claims

1. A hydrogen sulfide removal and sulfur recovery system, characterized in that: It comprises a supercritical water reaction unit, a desulfurizing agent storage unit (3), a desulfurizing agent feeding unit (4), a desulfurizing agent recovery unit (5), a desulfurizing agent regeneration unit (6), a sulfate recovery unit (7), a water tank (8) and a pressure reducing valve (14); The supercritical water reaction unit comprises a connected gasification reaction section (1) and a desulfurization reaction section (2), the outlet of the desulfurization reaction section (2) is connected to a downstream process; the outlet of the desulfurization agent storage unit (3) is connected to the desulfurization agent inlet of the desulfurization agent feeding unit (4), the water inlet of the desulfurization agent feeding unit (4) is connected to a water tank (8), the outlet of the desulfurization agent feeding unit (4) is connected to the upper inlet of the desulfurization reaction section (2); the lower outlet of the desulfurization reaction section (2) is connected to the outlet of the desulfurization agent recovery unit (5) The desulfurizing agent inlet is connected, and the water inlet of the desulfurizing agent recovery unit (5) is connected to the water tank (8); the outlet of the desulfurizing agent recovery unit (5) is connected to the desulfurizing agent regeneration unit (6) through a pressure reducing valve (14); the desulfurizing agent regeneration unit (6) is provided with a regeneration agent inlet, the desulfurizing agent outlet of the desulfurizing agent regeneration unit (6) is connected to the desulfurizing agent storage unit (3), and the sulfur outlet of the desulfurizing agent regeneration unit (6) is connected to the sulfate recovery unit (7); and the sulfate recovery unit (7) is provided with an absorbent inlet.

2. The hydrogen sulfide removal and sulfur recovery system according to claim 1, characterized in that: The desulfurizing agent in the desulfurizing agent storage unit (3) is a single metal oxide or a composite metal oxide.

3. The hydrogen sulfide removal and sulfur recovery system according to claim 1, characterized in that: A flow detection device is provided on the pipeline between the outlet of the desulfurizer recovery unit (5) and the desulfurizer regeneration unit (6), and a regulating valve is provided on the connecting pipeline of the regeneration agent inlet; a flow detection device is provided between the sulfur outlet of the desulfurizer regeneration unit (6) and the sulfate recovery unit (7), and a regulating valve is provided on the connecting pipeline of the absorbent inlet.

4. The hydrogen sulfide removal and sulfur recovery system according to claim 1, characterized in that: The desulfurization reaction section (2), the desulfurization agent feeding unit (4) and the desulfurization agent recovery unit (5) are all provided with pressure monitoring devices.

5. The hydrogen sulfide removal and sulfur recovery system according to claim 1, characterized in that: A first water pump (9) is provided on the pipeline between the water inlet of the desulfurizing agent recovery unit (5) and the water tank (8).

6. The hydrogen sulfide removal and sulfur recovery system according to claim 1, characterized in that: A second water pump (10) is provided on the pipeline between the water inlet of the desulfurizing agent feeding unit (4) and the water tank (8).

7. The hydrogen sulfide removal and sulfur recovery system according to claim 1, characterized in that: A first valve (11) is provided on the pipeline between the outlet of the desulfurizing agent storage unit (3) and the desulfurizing agent inlet of the desulfurizing agent feeding unit (4).

8. The hydrogen sulfide removal and sulfur recovery system according to claim 1, characterized in that: A second valve (12) is provided on the pipeline between the outlet of the desulfurizing agent feeding unit (4) and the upper inlet of the desulfurizing reaction section (2).

9. The hydrogen sulfide removal and sulfur recovery system according to claim 1, characterized in that: A third valve (13) is provided on the pipeline between the lower outlet of the desulfurization reaction section (2) and the desulfurization agent inlet of the desulfurization agent recovery unit (5).

10. The operating method of the hydrogen sulfide removal and sulfur recovery system according to any one of claims 1 to 9, characterized in that: include: Fresh desulfurizer slurry in the desulfurizer storage unit (3) enters the desulfurizer feeding unit (4), and water is passed through the water tank (8) to pressurize the feeding unit (4), and the desulfurizer is sent to the desulfurization reaction section (2) by pressure; the desulfurizer entering the desulfurization reaction section (2) reacts chemically with hydrogen sulfide generated by coal gasification in the gasification reaction section (1), and the hydrogen sulfide is chemically adsorbed and removed from the product, and the clean fluid enters the downstream process; the sulfided desulfurizer is deposited in the lower part of the desulfurization reaction section (2); water is passed through the water tank (8) to pressurize the desulfurizer recovery unit (5), and the sulfided desulfurizer is deposited in the lower part of the desulfurization reaction section (2); The desulfurized desulfurizer is discharged from the desulfurization reaction section (2) through the pressure difference and enters the desulfurizer recovery unit (5); the pressure reducing valve (14) is opened, and the desulfurizer in the desulfurizer recovery unit (5) enters the desulfurizer regeneration unit (6); the pressure reducing valve (14) is closed, and a regeneration agent is introduced into the desulfurizer regeneration unit (6) for regeneration, and the released sulfur is sent to the sulfate recovery unit (7), and an absorbent is introduced into the sulfate recovery unit (7) to absorb the sulfur and form a sulfate by-product; the regenerated desulfurizer is made into fresh desulfurizer slurry again and sent to the desulfurizer storage unit (3) for recycling.

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