Novel low-concentration acid gas treatment integrated facility

Abstract

The utility model relates to the technical field of acid gas treatment, in particular to a novel low-concentration acid gas treatment integrated facility which comprises a preheating stage, a multi-stage isothermal reaction stage and an adiabatic reaction stage, the preheating stage comprises an acid gas pipeline used for inputting acid gas and a main air pipeline used for inputting air, the multi-stage isothermal reactor comprises a plurality of isothermal reactors and a condensation cooler connected with the isothermal reactors, and the adiabatic reaction stage comprises an adiabatic reactor connected with the multi-stage isothermal reaction stage. According to the novel low-concentration acid gas treatment integrated facility, the elastic range of the concentration of the treatable acid gas is wide (5%-25%), and only the acid gas with the H2S concentration being 10% or below can be treated in the prior art; the total sulfur yield is obviously improved. Fuel gas consumption is reduced, and energy conservation and consumption reduction are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of acid gas treatment, in particular to a new integrated facility for low-concentration acid gas treatment. Background Technique

[0002] Acid gas containing H 2 S exists in industries such as natural gas treatment, coal chemical industry, and oil refining. Different processes are adopted according to different acid gas concentrations. For acid gas with H 2 S greater than 25%, the main combustion furnace conventional Claus high-temperature conversion section + two-stage conventional Claus catalytic conversion section + tail gas incineration section are usually adopted, and the total sulfur recovery rate reaches more than 99.9%, meeting the requirements of current environmental protection standards;

[0003] For acid gas with H2S less than 25%, a direct oxidation process is adopted:

[0004] 1. The CLINSULF-Do process of Linde Company in Germany, including an acid gas and air preheating section + an internally cooled tubular reaction section (adiabatic layer at the upper part and isothermal layer at the lower part of the reactor) + a condensation separation section. It can treat acid gas with H2S less than 10%, and the total recovery rate is less than 90%.

[0005] 2. The SELECTOX process of UOP Company in the United States, including an acid gas and air preheating section + a catalytic oxidation section + a condensation separation section + two-stage conventional Claus catalytic conversion section + a condensation separation section. It can treat acid gas with H2S less than 10%, and the total recovery rate is less than 90%. Content of the Utility Model

[0006] The purpose of the utility model is to provide a new integrated facility for low-concentration acid gas treatment to solve the problem of low total recovery rate in the acid gas treatment process proposed in the above background technique.

[0007] To achieve the above purpose, the utility model provides the following technical scheme:

[0008] A new integrated facility for low-concentration acid gas treatment includes a preheating stage, a multi-stage isothermal reaction stage, and an adiabatic reaction stage. The preheating stage includes an acid gas pipeline for inputting acid gas and an air main pipeline for inputting air. The multi-stage isothermal reaction stage includes a plurality of isothermal reactors and a condensation cooler connected to the isothermal reactors. The adiabatic reaction stage includes an adiabatic reactor connected to the multi-stage isothermal reaction stage.

[0009] As a further scheme of the utility model: Among them, the preheating stage further includes an acid gas preheater connected to the acid gas pipeline, an air preheater connected to the air main pipeline, and an air branch pipe connecting the acid gas pipeline and the air main pipeline.

[0010] As a further solution of the present utility model: Among them, a steam drum is connected above the isothermal reactor through a steam pipeline, the steam drum is connected to the isothermal reactor through a boiler feed water pipeline, the isothermal reactor is further connected with a condensation cooler, and the condensation cooler is connected to a reheater through a process gas pipeline and then connected to the next-stage isothermal reactor.

[0011] As a further solution of the present utility model: Among them, the adiabatic reaction stage includes an adiabatic reactor connected to the final condensation cooler, and the lower part of the adiabatic reactor is connected to the condensation cooler.

[0012] As a further solution of the present utility model: Among them, the vertical heat exchange tube bundle and the catalyst bed are arranged inside the isothermal reactor.

[0013] As a further solution of the present utility model: Among them, a catalyst bed is also arranged inside the adiabatic reactor.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0015] The novel integrated facility for treating low-concentration acid gas can handle acid gas with a relatively wide elastic range of concentration (5%-25%), while the prior art can only handle acid gas with an H 2 S concentration of less than 10%; the total sulfur recovery rate is significantly improved. The fuel gas consumption is reduced, and energy is saved and consumption is reduced. Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the integrated facility of the present utility model;

[0017] The corresponding relationship between the labels of each attached drawing in the figure and the component names is as follows:

[0018] 10. Acid gas pipeline; 11. Air main pipeline; 12. Acid gas preheater; 13. Air preheater; 14. Air branch pipe; 20. Isothermal reactor; 21. Steam pipeline; 22. Steam drum; 23. Boiler feed water pipeline; 24. Condensation cooler; 25. Process gas pipeline; 26. Reheater; 27. Heat exchange tube bundle; 28. Catalyst bed; 30. Adiabatic reactor. Detailed Embodiments

[0019] Please refer to Figure 1 : A novel integrated facility for treating low-concentration acid gas, including a preheating stage, a multi-stage isothermal reaction stage, and an adiabatic reaction section.

[0020] The preheating stage includes an acid gas pipeline 10 and an air main pipeline 11. An acid gas preheater 12 is connected to the acid gas pipeline 10, and an air preheater 13 is connected to the air main pipeline 11. The two pipelines are connected through an air branch pipe 14. In the preheating stage, by heating H2 The sour gas with an S concentration of 25% is preheated to 200°C through the sour gas preheater 12, and air is input into the air preheater 13 through the main blower connected to the air inlet end of the air main pipeline 11 to preheat the air to 200°C.

[0021] The preheating stage is connected to the multi-stage isothermal reaction stage through the air branch pipe.

[0022] The multi-stage isothermal reaction stage includes three isothermal reactors 20, namely the first-stage isothermal reactor, the second-stage isothermal reactor, and the third-stage isothermal reactor; a steam drum 22 is connected above the isothermal reactor 20 through a steam pipeline 21, the steam drum 22 is connected to the isothermal reactor 20 through a boiler feed water pipeline 23, and the isothermal reactor 20 is also connected to a condensing cooler 24. In the multi-stage isothermal reaction stage, the number of condensing coolers is three, which are respectively arranged at the tail of each stage of the isothermal reactor. The condensing cooler 24 is connected to the reheater 26 through a process gas pipeline 25 and then connected to the second-stage isothermal reactor. Similarly, the second-stage isothermal reactor and the third isothermal reactor are also connected in this way, and the tail of the third isothermal reactor is connected to the adiabatic reaction stage.

[0023] During use, a selective oxidation reaction occurs in the isothermal reactor 20, and most of it generates gaseous sulfur, and a very small part generates SO 2 . Given that under the condition of a relatively high concentration of H 2 S, the activity of the catalyst for the selective oxidation reaction is relatively low, and the catalyst bed is prone to over-temperature deactivation. Therefore, it is necessary to set up a multi-stage isothermal reactor to control the inlet H 2 S concentration of the reactor to obtain an ideal sulfur yield. The space velocity of the catalyst is controlled at 800 h- 1 H 2 The sour gas with an H 2 S concentration of 25% enters the first-stage isothermal reactor through the sour gas preheater, and is mixed with a certain amount of preheated air. Under the action of the catalyst therein, a selective oxidation reaction occurs, and most of it generates gaseous sulfur, and a very small part generates SO 2 . A vertical heat exchange tube bundle is arranged in the catalyst bed, boiler feed water is introduced, steam is generated, and the reaction heat of the catalyst bed is removed to maintain it at a constant temperature of 220 degrees. With a certain amount of preheated air, the H 2The concentration of S is about 10%, and then it enters the second-stage condensation cooler, where the process gas is cooled to 165 degrees to recover liquid sulfur. The process gas enters the third-stage isothermal reactor, and a certain amount of preheated air is supplied, so that the concentration of H at the outlet of the third-stage isothermal reactor 2 is about 1%, and then it enters the third-stage condensation cooler, where the process gas is cooled to 165 degrees to recover liquid sulfur.

[0024] The adiabatic reaction stage includes an adiabatic reactor 30 connected to the third-stage condensation cooler. The lower part of the adiabatic reactor 30 is connected to the condensation cooler 24, and the condensation cooler 24 is arranged in the adiabatic reaction stage. During use, a conventional Claus reaction occurs in the adiabatic reactor, and H 2 S and SO 2 react to form sulfur. Given that the temperature of 1% H 2 S rises by 60 degrees, in order to avoid the bed temperature of the adiabatic reactor being too high, it is necessary to control the inlet H concentration of the adiabatic reactor 2 S not exceeding 1%. The space velocity of the catalyst is controlled at 1200 h- 1 After the process gas passes through multiple isothermal reaction sections, the process gas is reheated to 220 degrees and enters the adiabatic reactor. Under the action of the catalyst therein, a conventional Claus reaction occurs, and H 2 S and SO 2 react to form sulfur, and then it enters the fourth-stage condensation cooler, where the process gas is cooled to 165 degrees to recover liquid sulfur.

[0025] Furthermore, the internal vertical heat exchange tube bundle 27 and catalyst bed 28 are provided inside the isothermal reactor 20.

[0026] Even further, a catalyst bed 28 is also provided inside the adiabatic reactor 30.

[0027] Working principle: The acid gas pipeline is preheated to 200 degrees by the acid gas preheater. The total air pipeline from the main blower is preheated to 200 degrees by the air preheater. In the first-stage isothermal reactor (the first, second, third, and fourth are named in order from top to bottom), a selective oxidation reaction occurs between the acid gas pipeline and the air branch pipe in the catalyst bed, and most of it generates gaseous sulfur, and a very small part generates SO 2。A vertical heat exchange tube bundle is arranged in the catalyst bed, and the boiler feed water pipeline is introduced. The generated steam enters the steam drum through the steam pipeline, taking away the reaction heat of the catalyst bed and maintaining it at a constant temperature of 220 degrees. Subsequently, it enters the first-stage condensation cooler, and the process gas is cooled to 165 degrees to recover liquid sulfur. The process gas pipeline is preheated to 200 degrees by the first-stage reheater and enters the second-stage isothermal reactor. The process gas pipeline and the air branch pipe undergo a selective oxidation reaction in the catalyst bed, with most of it generating gaseous sulfur and a very small part generating SO,. A vertical heat exchange tube bundle is arranged in the catalyst bed, and the boiler feed water pipeline is introduced. The generated steam enters the steam drum through the steam pipeline, taking away the reaction heat of the catalyst bed and maintaining it at a constant temperature of 220 degrees. Subsequently, it enters the second-stage condensation cooler, and the process gas is cooled to 165 degrees to recover liquid sulfur. The process gas pipeline is preheated to 200 degrees by the second-stage reheater and enters the third-stage isothermal reactor. The process gas pipeline and the air branch pipe undergo a selective oxidation reaction in the catalyst bed, with most of it generating gaseous sulfur and a very small part generating SO 2 。A vertical heat exchange tube bundle is arranged in the catalyst bed, and the boiler feed water pipeline is introduced. The generated steam enters the steam drum through the steam pipeline, taking away the reaction heat of the catalyst bed and maintaining it at a constant temperature of 220 degrees. Subsequently, it enters the third-stage condensation cooler, and the process gas is cooled to 165 degrees to recover liquid sulfur. After passing through multiple isothermal reaction sections, the process gas pipeline is reheated to 220 degrees by the third-stage reheater and enters the adiabatic reactor, where a conventional Claus reaction occurs in the catalyst bed, and H 2 S and SO 2 react to form sulfur, and then enter the fourth-stage condensation cooler, where the process gas is cooled to 165 degrees to recover liquid sulfur.

[0028] The above is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A new type of integrated low-concentration acid gas treatment facility, characterized in that: The invention comprises a preheating stage, a multi-stage isothermal reaction stage and an adiabatic reaction stage. The preheating stage comprises an acid gas pipeline (10) for inputting acid gas and an air main pipeline (11) for inputting air. The multi-stage isothermal reaction stage comprises a plurality of isothermal reactors (20) and a condenser cooler (24) connected to the isothermal reactors (20). The adiabatic reaction stage comprises an adiabatic reactor (30) connected to the multi-stage isothermal reaction stage.

2. The novel low-concentration acid gas treatment integrated facility according to claim 1 is characterized in that: The preheating stage further comprises an acid gas preheater (12) connected to the acid gas pipeline (10), an air preheater (13) connected to the main air pipeline (11), and an air branch pipe (14) connecting the acid gas pipeline (10) and the main air pipeline (11).

3. The novel low-concentration acid gas treatment integrated facility according to claim 1 is characterized in that: The isothermal reactor (20) is connected to a steam drum (22) via a steam pipeline (21), and the steam drum (22) is connected to the isothermal reactor (20) via a boiler feed water pipeline (23). The isothermal reactor (20) is also connected to a condenser cooler (24), and the condenser cooler (24) is connected to a reheater (26) via a process gas pipeline (25) and then connected to the next stage isothermal reactor (20).

4. The novel low-concentration acid gas treatment integrated facility according to claim 1 is characterized in that: The adiabatic reaction stage comprises an adiabatic reactor (30) connected to a final condenser cooler, and the lower part of the adiabatic reactor (30) is connected to a condenser cooler (24).

5. The novel low-concentration acid gas treatment integrated facility according to claim 1 is characterized in that: The isothermal reactor (20) includes a vertical heat exchange tube bundle (27) and a catalyst bed (28) inside.

6. The novel low-concentration acid gas treatment integrated facility according to claim 1 is characterized in that: A catalyst bed (28) is also arranged inside the adiabatic reactor (30).

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