Hydrogen sulfide concentration system of re-absorption tower and low-temperature methanol washing system

Abstract

The utility model discloses a hydrogen sulfide concentration system of a re-absorption tower and a low-temperature methanol washing system, and relates to the technical field of low-temperature methanol washing, the hydrogen sulfide concentration system of the re-absorption tower comprises a medium-pressure flash tower, a flash deep freezer and the re-absorption tower, a liquid outlet of the upper section of the medium-pressure flash tower is communicated with a liquid inlet of the flash deep freezer; the middle upper section of the re-absorption tower is sequentially provided with at least two connecting ports from top to bottom, and each connecting port is communicated with a liquid outlet of the flash evaporation deep freezer; the hydrogen sulfide concentration system of the reabsorption tower and the low-temperature methanol washing system disclosed by the utility model not only can effectively improve the utilization rate of the reabsorption tower, but also can effectively improve the concentration of hydrogen sulfide in a methanol solution output from the reabsorption tower.

Description

Technical Field

[0001] The utility model relates to the technical field of low-temperature methanol washing, in particular to a reabsorption tower hydrogen sulfide concentration system and a low-temperature methanol washing system. Background Art

[0002] Low-temperature methanol washing uses cold methanol as the absorption solvent and utilizes the excellent property of methanol's great solubility in acidic gases at low temperatures to remove acidic gases from the feed gas.

[0003] During low-temperature methanol washing, sulfides such as hydrogen sulfide in the feed gas come into contact with and are absorbed by methanol in the absorption tower. Hydrogen sulfide reacts with methanol to form mercaptans, which dissolve in the methanol. The hydrogen sulfide-containing methanol solution after absorption undergoes heating and gas separation to separate the mercaptans from the formazan. The separated hydrogen sulfide is oxidized into sulfur-base or converted into other useful chemicals, while the methanol can be recycled. Methanol-rich solution refers to the solution formed after the methanol solution absorbs other substances (such as carbon dioxide and hydrogen sulfide) during the absorption operation in the absorption tower but has not yet been fully regenerated. This solution, in contrast to the methanol solution that has not absorbed other substances (lean solution), differs primarily in whether it contains the absorbed components. The presence of active ingredients in the rich solution, such as gases like hydrogen sulfide and carbon dioxide, makes it play a vital role in chemical processes.

[0004] In the low-temperature methanol washing, the methanol-rich liquid needs to be first charged into the medium-pressure flash tower to desorb the hydrogen and carbon monoxide in the methanol-rich liquid for recycling. The methanol solution coming out of the upper section of the medium-pressure flash tower contains carbon dioxide and hydrogen sulfide. The methanol solution coming out of the upper section of the medium-pressure flash tower needs to be passed into a flash deep freezer for cooling, and then enter the reabsorption tower to desorb the carbon dioxide. The methanol solution after washing in the reabsorption tower mainly contains hydrogen sulfide. The methanol solution after washing in the reabsorption tower is passed into a hot regeneration tower, heated to release hydrogen sulfide, and the obtained hydrogen sulfide is passed into a sulfur recovery tower to prepare sulfur.

[0005] However, in the prior art, the methanol solution coming out of the flash cryogenic refrigerator is usually transported to the top of the reabsorption tower through a pipeline. The carbon dioxide in the methanol solution is desorbed in the middle and upper sections of the reabsorption tower and then leaves the reabsorption tower. On the one hand, the utilization rate of the reabsorption tower is low. On the other hand, in the process of carbon dioxide being desorbed, part of the hydrogen sulfide is also desorbed. During the upward process of the desorbed hydrogen sulfide along with the carbon dioxide, part of it is reabsorbed by the methanol solution, and the other part leaves the reabsorption tower along with the carbon dioxide, resulting in waste of hydrogen sulfide, reducing the hydrogen sulfide concentration in the methanol solution output from the reabsorption tower, and thus reducing sulfur production. Utility Model Content

[0006] The purpose of the utility model is to provide a reabsorption tower hydrogen sulfide concentration system and a low-temperature methanol washing system to solve the problems existing in the above-mentioned prior art, which can effectively improve the utilization rate of the reabsorption tower and effectively increase the hydrogen sulfide concentration in the methanol solution output from the reabsorption tower.

[0007] To achieve the above purpose, the present invention provides the following solutions:

[0008] The utility model provides a reabsorption tower hydrogen sulfide concentration system, which comprises a medium-pressure flash tower, a flash cryogenic refrigerator and a reabsorption tower, wherein the liquid outlet of the upper section of the medium-pressure flash tower is connected to the liquid inlet of the flash cryogenic refrigerator, and the middle upper section of the reabsorption tower is provided with at least two connecting ports in sequence from top to bottom, and each of the connecting ports is connected to the liquid outlet of the flash cryogenic refrigerator.

[0009] Preferably, it includes a connecting main pipe and at least two connecting branches, the number of the connecting branches is equal to the number of the connecting ports, one end of the connecting main pipe is fixedly connected and communicated with the liquid outlet of the flash cryogenic refrigerator, the other end of the connecting main pipe is fixedly connected and communicated with one end of each of the connecting branches, and the other end of each of the connecting branches is fixedly connected and communicated with each of the connecting ports.

[0010] Preferably, it includes at least two regulating valves, the number of the regulating valves is equal to the number of the connecting branches, each regulating valve is provided on each connecting branch, and each regulating valve can adjust the flow rate of the solution in each connecting branch.

[0011] Preferably, at least two flow meters are included, the number of the flow meters is equal to the number of the connecting branches, each of the flow meters is provided on each of the connecting branches, and each of the flow meters can detect the flow of the solution in each of the connecting branches.

[0012] Preferably, the number of the connection ports is two, and one of the connection ports is opened in the upper section of the reabsorption tower, and the other of the connection ports is opened in the middle section of the reabsorption tower.

[0013] The utility model also provides a low-temperature methanol washing system, which comprises the above-mentioned reabsorption tower hydrogen sulfide concentration system.

[0014] Compared with the prior art, the utility model has achieved the following technical effects:

[0015] The utility model provides a reabsorption tower hydrogen sulfide concentration system and a low-temperature methanol washing system. The upper and middle sections of the reabsorption tower are provided with at least two connection ports in sequence from top to bottom, and each connection port is connected to the liquid outlet of the flash cryogenic refrigerator. On the one hand, the methanol solution coming out of the flash cryogenic refrigerator can be introduced into different heights of the absorption tower, which can effectively improve the utilization rate of the reabsorption tower. On the other hand, the ascending distance of the desorbed carbon dioxide and hydrogen sulfide in the reabsorption tower can be extended, and the washing amount of the methanol solution can be increased, thereby improving the efficiency of the methanol solution in absorbing hydrogen sulfide, so that the desorbed hydrogen sulfide can be fully washed and absorbed in the ascending process, which can effectively improve the hydrogen sulfide concentration in the methanol solution output from the reabsorption tower, reduce the waste of hydrogen sulfide, and increase the sulfur yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a schematic diagram of the reabsorption tower hydrogen sulfide concentration system provided by the utility model;

[0018] In the figure: 1-medium-pressure flash tower, 2-flash cryogenic cooler, 3-reabsorption tower, 4-connecting main pipe, 5-connecting branch pipe, 6-regulating valve. DETAILED DESCRIPTION

[0019] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] The purpose of the utility model is to provide a reabsorption tower hydrogen sulfide concentration system and a low-temperature methanol washing system to solve the problems existing in the above-mentioned prior art, which can effectively improve the utilization rate of the reabsorption tower and effectively increase the hydrogen sulfide concentration in the methanol solution output from the reabsorption tower.

[0021] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0022] Example 1

[0023] like Figure 1 As shown, this embodiment provides a reabsorption tower hydrogen sulfide concentration system, including a medium-pressure flash tower 1, a flash cryogenic refrigerator 2 and a reabsorption tower 3. The liquid outlet of the upper section of the medium-pressure flash tower 1 is connected to the liquid inlet of the flash cryogenic refrigerator 2, and the middle and upper section of the reabsorption tower 3 is provided with at least two connecting ports in sequence from top to bottom, and each connecting port is connected to the liquid outlet of the flash cryogenic refrigerator 2.

[0024] The reabsorption tower hydrogen sulfide concentration system provided in this embodiment is provided with at least two connecting ports in sequence from top to bottom in the middle upper section of the reabsorption tower 3, and each connecting port is connected to the liquid outlet of the flash cryogenic refrigerator 2. On the one hand, the methanol solution coming out of the flash cryogenic refrigerator 2 can be introduced into different heights of the absorption tower, which can effectively improve the utilization rate of the reabsorption tower 3. On the other hand, the upward distance of the desorbed carbon dioxide and hydrogen sulfide in the reabsorption tower 3 can be extended, and the washing amount of the methanol solution can be increased, thereby improving the efficiency of the methanol solution in absorbing hydrogen sulfide, so that the desorbed hydrogen sulfide can be fully washed and absorbed during the upward process, which can effectively increase the hydrogen sulfide concentration in the methanol solution output from the reabsorption tower 3, reduce hydrogen sulfide waste, and increase sulfur production. In this embodiment, the methanol solution coming out of the upper section of the medium-pressure flash tower 1 is introduced into the flash cryogenic refrigerator 2 and supercooled to -36°C.

[0025] Furthermore, the reabsorption tower hydrogen sulfide concentration system provided in this embodiment includes a connecting main pipe 4 and at least two connecting branch pipes 5, the number of the connecting branch pipes 5 is equal to the number of the connecting ports, one end of the connecting main pipe 4 is fixedly connected to and communicated with the liquid outlet of the flash cryogenic refrigerator 2, the other end of the connecting main pipe 4 is fixedly connected to and communicated with one end of each connecting branch pipe 5, and the other end of each connecting branch pipe 5 is fixedly connected to and communicated with each connecting port. The structure is simple and easy to use.

[0026] Furthermore, the reabsorption tower hydrogen sulfide concentration system provided in this embodiment includes at least two regulating valves 6, the number of regulating valves 6 is equal to the number of connecting branches 5, and each regulating valve 6 is arranged on each connecting branch 5. Each regulating valve 6 can adjust the solution flow in each connecting branch 5, so as to facilitate the adjustment of the solution flow entering the reabsorption tower 3.

[0027] Furthermore, the reabsorption tower hydrogen sulfide concentration system provided in this embodiment includes at least two flow meters, the number of flow meters is equal to the number of connecting branches 5, and each flow meter is provided on each connecting branch 5. Each flow meter can detect the solution flow in each connecting branch 5, so as to facilitate timely adjustment of the solution flow entering the reabsorption tower 3.

[0028] As a more preferred implementation of this embodiment, there are two connection ports, and one connection port is opened in the upper section of the reabsorption tower 3, and the other connection port is opened in the middle section of the reabsorption tower 3, which is convenient for production, use and maintenance.

[0029] Example 2

[0030] This embodiment provides a low-temperature methanol washing system, including the reabsorption tower hydrogen sulfide concentration system in the first embodiment.

[0031] The low-temperature methanol washing system provided in this embodiment is provided with at least two connecting ports in sequence from top to bottom in the middle upper section of the reabsorption tower 3, and each connecting port is connected to the liquid outlet of the flash cryogenic refrigerator 2. On the one hand, the methanol solution discharged from the flash cryogenic refrigerator 2 can be introduced into different heights of the absorption tower, which can effectively improve the utilization rate of the reabsorption tower 3. On the other hand, the upward distance of the desorbed carbon dioxide and hydrogen sulfide in the reabsorption tower 3 can be extended, and the washing amount of the methanol solution can be increased, thereby improving the efficiency of the methanol solution in absorbing hydrogen sulfide, so that the desorbed hydrogen sulfide can be fully washed and absorbed during the upward process, which can effectively increase the hydrogen sulfide concentration in the methanol solution output from the reabsorption tower 3, reduce hydrogen sulfide waste, and increase sulfur production.

[0032] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A reabsorption tower hydrogen sulfide concentration system, characterized by: It includes a medium-pressure flash tower, a flash cryogenic refrigerator and a reabsorption tower. The liquid outlet of the upper section of the medium-pressure flash tower is connected to the liquid inlet of the flash cryogenic refrigerator. The upper and middle sections of the reabsorption tower are provided with at least two connecting ports from top to bottom, and each of the connecting ports is connected to the liquid outlet of the flash cryogenic refrigerator.

2. The reabsorption tower hydrogen sulfide concentration system according to claim 1, characterized in that: It includes a connecting main pipe and at least two connecting branches, the number of the connecting branches is equal to the number of the connecting ports, one end of the connecting main pipe is fixedly connected to and communicated with the liquid outlet of the flash cryogenic refrigerator, the other end of the connecting main pipe is fixedly connected to and communicated with one end of each of the connecting branches, and the other end of each of the connecting branches is fixedly connected to and communicated with each of the connecting ports.

3. The reabsorption tower hydrogen sulfide concentration system according to claim 2, characterized in that: It comprises at least two regulating valves, the number of the regulating valves is equal to the number of the connecting branches, each regulating valve is arranged on each connecting branch, and each regulating valve can adjust the solution flow in each connecting branch.

4. The reabsorption tower hydrogen sulfide concentration system according to claim 3, characterized in that: It comprises at least two flow meters, the number of the flow meters is equal to the number of the connecting branches, each of the flow meters is arranged on each of the connecting branches, and each of the flow meters can detect the flow of the solution in each of the connecting branches.

5. The reabsorption tower hydrogen sulfide concentration system according to claim 4, characterized in that: There are two connecting ports, one of which is opened at the upper section of the reabsorption tower, and the other is opened at the middle section of the reabsorption tower.

6. A low-temperature methanol washing system, characterized in that: The invention comprises the reabsorption tower hydrogen sulfide concentration system according to any one of claims 1 to 5.

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