Coupling device for desulfurization and methanation of sulfur-containing coal gas

Abstract

The utility model provides a coupling device for desulfurization and methanation of sulfur-containing coal gas. The coupling device comprises a raw material heat exchanger, an organic sulfur hydrogenation reactor, a fine desulfurization reactor and a methanation reactor which are connected in sequence, the raw material heat exchanger comprises at least two stages of heat exchangers, the first-stage heat exchanger is positioned on an outlet pipeline of the methanation reactor, the second-stage heat exchanger is positioned on a pipeline between the organic sulfur hydrogenation reactor and the fine desulfurization reactor, the fine desulfurization reactor comprises a first-stage fine desulfurization reactor and a second-stage fine desulfurization reactor, and the first-stage fine desulfurization reactor and the second-stage fine desulfurization reactor are filled with different types of desulfurizing agents. According to the utility model, by arranging the organic sulfur hydrogenation equipment, the inorganic sulfur removal equipment, the methanation reaction equipment and the like, organic sulfur is firstly converted into inorganic sulfur through hydrogenation, then sulfur is fully removed by adopting different desulfurizing agents, and sulfur-containing coal gas is fully purified through methanation reaction, so that the sulfur-containing coal gas meets the feeding requirements of subsequent processes; according to the utility model, the heat exchange network is optimized, the reaction heat can be fully utilized, the energy consumption is saved, the equipment is simplified, and the cost is effectively reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of gas purification and utilization, and relates to a coupling device for desulfurization and methanation of sulfur-containing coal gas. Background Art

[0002] Given the significant proportion of coal in my country's energy production and consumption, the development of coal chemical technology is a crucial measure to alleviate energy shortages and improve the energy structure. With the development of coal chemical technology, the gas products it produces can be divided into multiple types, such as pyrolysis gas, coke oven gas, and raw coal gas. In traditional coal chemical plants, these gases are often used directly as fuel gas, underutilizing the effective gas components. There is room for increased added value. For example, using these gases to produce hydrogen, liquefied natural gas, and synthetic ammonia would significantly increase added value while also reducing greenhouse gas emissions.

[0003] Due to the composition of coal, the resulting coal gas is typically sulfur-containing gas, with large volumes, complex composition, and high sulfur content, including both organic and inorganic sulfur. If subsequent processes have high sulfur content requirements, refined desulfurization is essential for chemical processes. Taking coke oven gas as an example, the process for synthesizing natural gas primarily includes purification, methanation, and pressure swing adsorption / cryogenic separation. Due to the methanation catalyst's sulfur intolerance and proneness to carbon deposition, the desulfurization and purification process is particularly crucial. The organic sulfur contained in the coke oven gas must first be converted into inorganic sulfur, followed by refined removal of the inorganic sulfur. This requires a complex process with high investment and energy consumption, necessitating the simplification of the sulfur-containing gas processing equipment and the full utilization of the heat within the system to reduce energy consumption.

[0004] CN 101649232A discloses a process for synthesizing natural gas by methanation of coke oven gas. The process comprises pre-purification, desulfurization, a first-stage methanation reaction, a second-stage methanation reaction, and natural gas separation. The pre-purification comprises compression and impurity removal to obtain coarsely purified coke oven gas. The desulfurization step comprises converting organic sulfur into inorganic sulfur using a medium-temperature hydrolysis or hydrogenation conversion process, then removing the inorganic sulfur using a wet desulfurization or a dry desulfurization process, and finally obtaining pure coke oven gas using a dry fine desulfurization process. Both methanation reactions use a nickel-based methanation catalyst. During the first-stage methanation reaction, the gas is mixed with water vapor for an adiabatic reaction. After appropriate cooling, a second-stage methanation reaction is performed to obtain crude natural gas. Finally, water-rich natural gas and hydrogen-rich gas are obtained through a pressure swing adsorption process or a membrane separation process. The water-rich natural gas is dehydrated through pressure swing adsorption or temperature swing adsorption to obtain natural gas. This process method does not emphasize the desulfurization process, nor does it clarify the selection of different types of desulfurizers. Instead, it focuses on the methanation reaction step and does not involve the full utilization of heat in the process.

[0005] CN 211814294U discloses an ultra-deep removal device for organic sulfur in coke oven gas. The device includes an oil removal tower, a first heat exchanger, a pre-hydrogenation and primary hydrogenation reactors, a condenser, a normal-temperature desulfurization tower, a second heat exchanger, a secondary hydrogenation reactor, a cobalt-molybdenum hydrogenation reactor, a fine desulfurization tower, and an ultra-fine desulfurization tower. The cobalt-molybdenum hydrogenation reactor and the ultra-fine desulfurization tower are located at both ends of the fine desulfurization tower, with the cobalt-molybdenum hydrogenation reactor positioned between the secondary hydrogenation reactor and the fine desulfurization tower. The device incorporates multiple stages of hydrogenation reactors and desulfurization towers to ensure desulfurization efficiency. However, the device is complex in structure, resulting in extremely high equipment costs. Furthermore, the multiple stages of equipment perform similar functions, placing high demands on the desulfurizers in each stage. This is not clarified in the patent, nor does it disclose the subsequent methanation reaction device.

[0006] In summary, for the desulfurization and methanation coupling device of sulfur-containing coal gas, it is necessary to select a suitable combination of equipment and unit operations based on the composition characteristics of the sulfur-containing coal gas, so that both organic sulfur and inorganic sulfur in the coal gas can be fully removed, and carbon oxides can be converted into methane to meet the feed requirements of subsequent processes and achieve efficient utilization of heat inside the device. Utility Model Content

[0007] In response to the problems existing in the prior art, the purpose of the utility model is to provide a coupling device for desulfurization and methanation of sulfur-containing coal gas. The device, through the setting of equipment such as organic sulfur removal and inorganic sulfur removal and methanation reaction, can fully remove organic sulfur and inorganic sulfur from sulfur-containing coal gas, and convert CO and CO2 into methane, thereby achieving full purification of sulfur-containing coal gas so that it meets the feed requirements of subsequent processes.

[0008] To achieve this purpose, the present invention adopts the following technical solutions:

[0009] The utility model provides a coupling device for desulfurization and methanation of sulfur-containing coal gas, which comprises a raw material heat exchanger, an organic sulfur hydrogenation reactor, a fine desulfurization reactor and a methanation reactor connected in sequence; the raw material heat exchanger comprises at least two stages of heat exchangers, the first stage heat exchanger is located on the outlet pipeline of the methanation reactor, and the second stage heat exchanger is located on the pipeline between the organic sulfur hydrogenation reactor and the fine desulfurization reactor; the fine desulfurization reactor comprises two stages, namely a first stage fine desulfurization reactor and a second stage fine desulfurization reactor, and the first stage fine desulfurization reactor and the second stage fine desulfurization reactor are filled with different types of desulfurizers.

[0010] In the present invention, for the purification treatment of sulfur-containing coal gas, an organic sulfur hydrogenation reactor, an inorganic fine desulfurization reactor and a methanation reactor are respectively set according to the composition of the sulfur-containing coal gas and the components to be removed. According to the temperature requirement of the reaction, a raw material heat exchanger is first set to heat the raw material gas by utilizing the heat released by the subsequent reaction so that the feed reaches the temperature requirement of the reaction; the organic sulfur is converted into inorganic sulfur by hydrogenation, and then different desulfurizers are used in the two-stage fine desulfurization reactor to achieve full removal of sulfur in the coal gas, and then a methanation reactor is used to react and remove CO and CO2 and convert them into methane, which is convenient for further application of the purified gas; the device optimizes the heat exchange network, can fully utilize the reaction heat, and helps to save energy consumption.

[0011] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following technical solutions, the technical objectives and beneficial effects of the present invention can be better achieved and realized.

[0012] As a preferred technical solution of the present invention, the sulfur-containing coal gas includes any one of coke oven gas, pyrolysis gas or raw coal gas.

[0013] In the utility model, the sulfur-containing coal gas has a wide source and is obtained from coal through different processes, and has a wider scope of application.

[0014] As a preferred technical solution of the present invention, the primary heat exchanger is a methanation cooler, and the sulfur-containing coal gas and the purified gas obtained after methanation exchange heat in the methanation cooler.

[0015] As a preferred technical solution of the present invention, the secondary heat exchanger is a feed heater, which is located between the primary fine desulfurization reactor and the secondary fine desulfurization reactor.

[0016] As a preferred technical solution of the present invention, the types of the primary heat exchanger and the secondary heat exchanger independently include any one of a shell and tube heat exchanger, a shell and tube heat exchanger or a double-tube heat exchanger.

[0017] In the present invention, the sulfur-containing coal gas first enters the methanation cooler, exchanges heat with the purified gas after methanation to increase the temperature, and then enters the feed heater to exchange heat with the gas after organic sulfur hydrogenation. Since the organic sulfur hydrogenation reaction is an exothermic reaction, this part of the reaction heat is fully utilized. It is specifically arranged after the first-stage fine desulfurization reactor to ensure that the temperature of the first-stage fine desulfurization reaction is high, the reaction rate is fast, the sulfur capacity of the desulfurizer is increased, and the desulfurization effect is improved.

[0018] As a preferred technical solution of the present invention, the raw material heat exchanger further includes a three-stage heat exchanger, and the three-stage heat exchanger includes an electric heater located on the connecting pipeline between the second-stage heat exchanger and the organic sulfur hydrogenation reactor.

[0019] In the present invention, if the temperature of the sulfur-containing coal gas after two-stage heat exchange does not meet the feed requirement of the organic sulfur hydrogenation reactor, an electric heater can be set to heat and increase the temperature. The electric heater can also take into account the heating function during the initial operation of the device.

[0020] As a preferred technical solution of the present invention, the catalyst loaded in the organic sulfur hydrogenation reactor includes a cobalt-molybdenum catalyst or a nickel-molybdenum catalyst.

[0021] In the present invention, the organic sulfur is hydrogenated into hydrogen sulfide by a cobalt-molybdenum or nickel-molybdenum catalyst, and the feed temperature is 330-350°C, for example, 330°C, 335°C, 340°C, 345°C or 350°C, etc. The temperature after the reaction is controlled at 350-380°C, for example, 350°C, 355°C, 360°C, 365°C, 370°C, 375°C or 380°C, etc. Depending on the type of organic sulfur, such as carbon oxysulfide COS, carbon disulfide CS2, mercaptan R-SH, sulfide R1-S-R2, thiophene C4H4S and tetrahydrothiophene C4H8S, the reactions that occur are:

[0022] COS+H2=CO+H2S

[0023] CS2+4H2=CH4+2H2S

[0024] R-SH+H2=RH+H2S

[0025] R1-S-R2+2H2=R1H+H2S+R2H

[0026] C4H4S+4H2=C4H 10 +H2S

[0027] C4H8S+2H2=C4H 10 +H2S.

[0028] As a preferred technical solution of the present invention, the desulfurizer loaded in the first-stage fine desulfurization reactor is a zinc oxide desulfurizer, and the particle size of the zinc oxide desulfurizer is 3 to 5 mm, for example, 3 mm, 3.5 mm, 4 mm, 4.5 mm or 5 mm, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] In the utility model, a reaction between sulfide and metal oxide occurs in the first-stage fine desulfurization reactor to remove sulfide. The desulfurizer is mainly composed of zinc oxide and alumina as a carrier. When the desulfurizer reaches the breakthrough sulfur capacity, it is necessary to replace the desulfurizer. The reaction occurring in the process is mainly H2S+ZnO=ZnS+H2O. The working sulfur capacity of the desulfurizer is above 30wt%, such as 30wt%, 32wt%, 34wt%, 36wt%, 38wt% or 40wt%.

[0030] If organic sulfur still exists in the sulfur-containing coal gas at this time, the organic sulfur can also react with zinc oxide to achieve full removal of the organic sulfur; after a first-level fine desulfurization reaction, the sulfur content can be reduced to below 0.1ppm.

[0031] As a preferred technical solution of the present invention, the desulfurizer loaded in the secondary fine desulfurization reactor is a copper-based desulfurizer, and the copper-based desulfurizer has copper oxide and cuprous oxide as main components, and may also include zinc oxide and / or aluminum oxide. The particle size of the copper-based desulfurizer is 4 to 6 mm, for example, 4 mm, 4.5 mm, 5 mm, 5.5 mm or 6 mm, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0032] In the present invention, the secondary fine desulfurization reactor adopts a desulfurizer made of a mixture of metal oxides and additives. The desulfurizer is a copper-based desulfurizer. The reaction in the process is mainly H2S+Cu 2+ =CuS+2H + , H2S+2Cu + =Cu2S+2H + It is a different type from the desulfurizer in the first-stage fine desulfurization reactor. It has the characteristics of good dispersion, large surface area, high strength, and a wide operating temperature range (150℃~350℃). It has extremely strong adsorption performance and desulfurization effect on sulfides. After the secondary fine desulfurization reaction, the sulfur content can be reduced to below 10ppb.

[0033] As a preferred technical solution of the present invention, the catalyst loaded in the methanation reactor comprises nickel oxide, aluminum oxide and rare earth additives.

[0034] In the present invention, after the fine desulfurization reaction, CO and CO2 in the coal gas have not been removed yet, and need to be sent to the methanation reactor to convert CO and CO2 into methane, and the reactions that occur are CO2+4H2=CH4+2H2O, CO+3H2=CH4+H2O.

[0035] The temperature of the methanation reaction is controlled at 230-330°C of the feed, for example, 230°C, 250°C, 270°C, 280°C, 300°C, 320°C or 330°C, etc., and accompanied by the generation of reaction heat and the increase in temperature, the temperature after the reaction reaches 330-450°C, for example, 330°C, 350°C, 360°C, 380°C, 400°C, 420°C, 440°C or 450°C, etc. A methanation cooler is used to exchange heat between the reacted gas and the raw gas, and the reaction heat is used to heat the raw gas, while reducing the temperature of the purified gas to meet the temperature requirement for delivery to the boundary zone.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] (1) The device of the utility model is equipped with equipment such as organic sulfur hydrogenation, inorganic sulfur removal and methanation reaction, firstly converting organic sulfur into inorganic sulfur by hydrogenation, and then using two-stage fine desulfurization reactors and different desulfurizers to achieve full removal of sulfur in coal gas, and the sulfur content can be reduced to below 10ppb, and CO and CO2 are converted into methane, and the total content of the two can be reduced to below 10ppb, thereby achieving full purification of sulfur-containing coal gas to meet the feed requirements of subsequent processes;

[0038] (2) According to the temperature requirements of the reaction, the utility model first sets a raw material heat exchanger, uses the heat released by the subsequent reaction to heat the raw material gas, so that the feed reaches the temperature requirements of the reaction, optimizes the heat exchange network, can fully utilize the reaction heat, and helps save energy consumption;

[0039] (3) The device of the present invention has a simple structure, a reasonable design, simplifies equipment, can effectively reduce costs, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a schematic structural diagram of a coupling device for desulfurization and methanation of sulfur-containing coal gas provided in Example 1 of the present utility model;

[0041] Among them, 1- methanation cooler, 2- feed heater, 3- electric heater, 4- organic sulfur hydrogenation reactor, 5- primary fine desulfurization reactor, 6- secondary fine desulfurization reactor, 7- methanation reactor. DETAILED DESCRIPTION

[0042] In order to better illustrate the present invention and facilitate understanding of the technical solution of the present invention, the present invention is further described in detail below. However, the following embodiments are merely simple examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0043] The following are typical but non-limiting embodiments of the present invention:

[0044] Example 1:

[0045] This embodiment provides a coupling device for desulfurization and methanation of sulfur-containing coal gas. The structural diagram of the coupling device is shown in FIG. Figure 1 As shown, it includes a raw material heat exchanger, an organic sulfur hydrogenation reactor 4, a fine desulfurization reactor and a methanation reactor 7 connected in sequence; the raw material heat exchanger includes a three-stage heat exchanger, the first-stage heat exchanger is located on the outlet pipeline of the methanation reactor 7, and the second-stage heat exchanger is located on the pipeline between the organic sulfur hydrogenation reactor 4 and the fine desulfurization reactor. The fine desulfurization reactor includes two stages, namely, a first-stage fine desulfurization reactor 5 and a second-stage fine desulfurization reactor 6, and different types of desulfurizers are filled in the first-stage fine desulfurization reactor 5 and the second-stage fine desulfurization reactor 6.

[0046] The sulfur-containing coal gas is coke oven gas.

[0047] The primary heat exchanger is a methanation cooler 1 , and the sulfur-containing coal gas and the purified gas obtained after methanation exchange heat in the methanation cooler 1 .

[0048] The secondary heat exchanger is a feed heater 2 , which is located between the primary fine desulfurization reactor 5 and the secondary fine desulfurization reactor 6 .

[0049] The types of the primary heat exchanger and the secondary heat exchanger are both shell and tube heat exchangers.

[0050] The third-stage heat exchanger is an electric heater 3 , which is located on the connecting pipeline between the second-stage heat exchanger and the organic sulfur hydrogenation reactor 4 .

[0051] The catalyst loaded in the organic sulfur hydrogenation reactor 4 is a cobalt-molybdenum catalyst.

[0052] The desulfurizer filled in the first-stage fine desulfurization reactor 5 is zinc oxide desulfurizer, and the average particle size of the zinc oxide desulfurizer is 4 mm.

[0053] The desulfurizer loaded in the secondary fine desulfurization reactor 6 is a copper-based desulfurizer. The composition of the copper-based desulfurizer includes copper oxide, cuprous oxide, zinc oxide and aluminum oxide. The average particle size of the copper-based desulfurizer is 5 mm.

[0054] The catalyst loaded in the methanation reactor 7 is composed of nickel oxide, aluminum oxide and rare earth additives.

[0055] Example 2:

[0056] This embodiment provides a coupling device for desulfurization and methanation of sulfur-containing coal gas, which includes a raw material heat exchanger, an organic sulfur hydrogenation reactor 4, a fine desulfurization reactor and a methanation reactor 7 connected in sequence; the raw material heat exchanger includes a three-stage heat exchanger, the first-stage heat exchanger is located on the outlet pipeline of the methanation reactor 7, and the second-stage heat exchanger is located on the pipeline between the organic sulfur hydrogenation reactor 4 and the fine desulfurization reactor. The fine desulfurization reactor includes two stages, namely, a first-stage fine desulfurization reactor 5 and a second-stage fine desulfurization reactor 6, and different types of desulfurizers are filled in the first-stage fine desulfurization reactor 5 and the second-stage fine desulfurization reactor 6.

[0057] The sulfur-containing coal gas is pyrolysis coal gas.

[0058] The primary heat exchanger is a methanation cooler 1 , and the sulfur-containing coal gas and the purified gas obtained after methanation exchange heat in the methanation cooler 1 .

[0059] The secondary heat exchanger is a feed heater 2 , which is located between the primary fine desulfurization reactor 5 and the secondary fine desulfurization reactor 6 .

[0060] The types of the primary heat exchanger and the secondary heat exchanger are both shell and tube heat exchangers.

[0061] The third-stage heat exchanger is an electric heater 3 , which is located on the connecting pipeline between the second-stage heat exchanger and the organic sulfur hydrogenation reactor 4 .

[0062] The catalyst loaded in the organic sulfur hydrogenation reactor 4 is a nickel-molybdenum catalyst.

[0063] The desulfurizer filled in the primary fine desulfurization reactor 5 is zinc oxide desulfurizer, and the average particle size of the zinc oxide desulfurizer is 3.2 mm.

[0064] The desulfurizer loaded in the secondary fine desulfurization reactor 6 is a copper-based desulfurizer. The composition of the copper-based desulfurizer includes copper oxide, cuprous oxide and aluminum oxide. The average particle size of the copper-based desulfurizer is 5.6 mm.

[0065] The catalyst loaded in the methanation reactor 7 is composed of nickel oxide, aluminum oxide and rare earth additives.

[0066] Example 3:

[0067] This embodiment provides a coupling device for desulfurization and methanation of sulfur-containing coal gas, which includes a raw material heat exchanger, an organic sulfur hydrogenation reactor 4, a fine desulfurization reactor and a methanation reactor 7 connected in sequence; the raw material heat exchanger includes a two-stage heat exchanger, the first-stage heat exchanger is located on the outlet pipeline of the methanation reactor 7, and the second-stage heat exchanger is located on the pipeline between the organic sulfur hydrogenation reactor 4 and the fine desulfurization reactor; the fine desulfurization reactor includes two stages, namely, a first-stage fine desulfurization reactor 5 and a second-stage fine desulfurization reactor 6, and different types of desulfurizers are filled in the first-stage fine desulfurization reactor 5 and the second-stage fine desulfurization reactor 6.

[0068] The sulfur-containing coal gas is raw coal gas.

[0069] The primary heat exchanger is a methanation cooler 1 , and the sulfur-containing coal gas and the purified gas obtained after methanation exchange heat in the methanation cooler 1 .

[0070] The secondary heat exchanger is a feed heater 2 , which is located between the primary fine desulfurization reactor 5 and the secondary fine desulfurization reactor 6 .

[0071] The primary heat exchanger and the secondary heat exchanger are both shell-and-tube heat exchangers.

[0072] The catalyst loaded in the organic sulfur hydrogenation reactor 4 is a cobalt-molybdenum catalyst.

[0073] The desulfurizer filled in the first-stage fine desulfurization reactor 5 is zinc oxide desulfurizer, and the average particle size of the zinc oxide desulfurizer is 4.5 mm.

[0074] The desulfurizer loaded in the secondary fine desulfurization reactor 6 is a copper-based desulfurizer. The composition of the copper-based desulfurizer includes copper oxide and cuprous oxide. The average particle size of the copper-based desulfurizer is 5.6 mm.

[0075] The catalyst loaded in the methanation reactor 7 is composed of nickel oxide, aluminum oxide and rare earth additives.

[0076] The coupling device in the above embodiment is used to perform desulfurization and methanation treatment of sulfur-containing coal gas, and the operation process includes:

[0077] The sulfur-containing coal gas enters the methanation cooler to exchange heat with the purified gas after methanation to increase its temperature, and then enters the feed heater to exchange heat with the gas after organic sulfur hydrogenation. If the temperature of the raw gas does not meet the requirements for entering the organic sulfur hydrogenation reactor at this time, it can be heated by an electric heater to increase the temperature to the temperature entering the organic sulfur hydrogenation reactor; the sulfur-containing coal gas enters the organic sulfur hydrogenation reactor for hydrodesulfurization reaction to convert organic sulfur into inorganic sulfur. The reaction gas after hydrodesulfurization enters the first-stage fine desulfurization reactor, where a desulfurizer is used to remove the sulfur content to below 0.1ppm. It then enters the second-stage fine desulfurization reactor to remove the sulfur content to below 10ppb. At this time, since CO and CO2 have not been removed, they are sent to the methanation reactor to be converted into methane, and the total content of CO and CO2 is reduced to below 10ppb. At the same time, with the generation of reaction heat, the temperature of the purified gas increases. The methanation cooler is used to exchange heat between the purified gas and the raw gas, and the reaction heat is used to heat the raw gas. At the same time, the temperature of the purified gas is reduced to meet the temperature requirements for delivery to the boundary area. Through the above-mentioned coupling device and process, the heat exchange network is optimized, the reaction heat is fully utilized, and energy consumption is saved.

[0078] From the above embodiments, it can be seen that the device of the present invention first converts organic sulfur into inorganic sulfur through the arrangement of equipment such as organic sulfur hydrogenation, inorganic sulfur removal and methanation reaction, and then uses a two-stage fine desulfurization reactor and different desulfurizers to fully remove sulfur from the coal gas, and the sulfur content can be reduced to below 10ppb, and CO and CO2 are converted into methane, and the total content of the two can be reduced to below 10ppb, thereby fully purifying the sulfur-containing coal gas to meet the feed requirements of subsequent processes; according to the temperature requirements of the reaction, a raw material heat exchanger is first set up, and the heat released by the subsequent reaction is used to heat the raw gas so that the feed reaches the temperature requirements of the reaction, thereby optimizing the heat exchange network, making full use of the reaction heat, and helping to save energy consumption; the device has a simple structure, a reasonable design, simplified equipment, can effectively reduce costs, and has a wide range of applications.

[0079] The applicant declares that while the above-described embodiments illustrate the detailed apparatus of the present invention, the present invention is not limited to the above-described detailed apparatus, nor does it imply that the present invention must rely on the above-described detailed apparatus in order to be implemented. Persons skilled in the art should understand that any improvements to the present invention, equivalent replacements for the apparatus of the present invention, additions of auxiliary devices, and selections of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. A coupling device for desulfurization and methanation of sulfur-containing coal gas, characterized in that: The coupling device includes a raw material heat exchanger, an organic sulfur hydrogenation reactor, a fine desulfurization reactor and a methanation reactor connected in sequence; the raw material heat exchanger includes at least two stages of heat exchangers, the first stage heat exchanger is located on the outlet pipeline of the methanation reactor, and the second stage heat exchanger is located on the pipeline between the organic sulfur hydrogenation reactor and the fine desulfurization reactor. The fine desulfurization reactor includes two stages, namely a first stage fine desulfurization reactor and a second stage fine desulfurization reactor, and the first stage fine desulfurization reactor and the second stage fine desulfurization reactor are filled with different types of desulfurizers.

2. The coupling device for desulfurization and methanation of sulfur-containing coal gas according to claim 1, characterized in that: The sulfur-containing coal gas includes any one of coke oven gas, pyrolysis gas or raw coal gas.

3. The coupling device for desulfurization and methanation of sulfur-containing coal gas according to claim 1, characterized in that: The primary heat exchanger is a methanation cooler, and the sulfur-containing coal gas and the purified gas obtained after methanation exchange heat in the methanation cooler.

4. The coupling device for desulfurization and methanation of sulfur-containing coal gas according to claim 1, characterized in that: The secondary heat exchanger is a feed heater, which is located between the primary fine desulfurization reactor and the secondary fine desulfurization reactor.

5. The coupling device for desulfurization and methanation of sulfur-containing coal gas according to claim 1, characterized in that: The types of the primary heat exchanger and the secondary heat exchanger independently include any one of a shell and tube heat exchanger, a shell and tube heat exchanger or a double-tube heat exchanger.

6. The coupled device for desulfurization and methanation of sulfur-containing coal gas according to claim 1, characterized in that: The raw material heat exchanger further comprises a three-stage heat exchanger, and the three-stage heat exchanger comprises an electric heater, which is located on the connecting pipeline between the second-stage heat exchanger and the organic sulfur hydrogenation reactor.

7. The coupled device for desulfurization and methanation of sulfur-containing coal gas according to claim 1, characterized in that: The catalyst loaded in the organic sulfur hydrogenation reactor includes a cobalt-molybdenum catalyst or a nickel-molybdenum catalyst.

8. The coupled device for desulfurization and methanation of sulfur-containing coal gas according to claim 1, characterized in that: The desulfurizer filled in the first-stage fine desulfurization reactor is zinc oxide desulfurizer, and the particle size of the zinc oxide desulfurizer is 3-5 mm.

9. The coupled device for desulfurization and methanation of sulfur-containing coal gas according to claim 1, characterized in that: The desulfurizer filled in the secondary fine desulfurization reactor is a copper-based desulfurizer, and the copper-based desulfurizer includes copper oxide and cuprous oxide.

10. The coupled device for desulfurization and methanation of sulfur-containing coal gas according to claim 9, characterized in that: The particle size of the copper-based desulfurizer is 4 to 6 mm.

Images