Gas supplementing device of synthetic natural gas system
By designing a gas replenishment device in the synthetic natural gas system, mixing high-sulfur exhaust with coal gas, the problem of hydrogen sulfide treatment in the benzene hydrogenation exhaust gas is solved, the fine adjustment of hydrogen sulfide content and the activity of cobalt-molybdenum catalysts are achieved, and the desulfurization cost and environmental pollution are reduced.
Patent Information
- Application Number
- CN202422362166.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-26
- Publication Date
- 2025-07-01
- Estimated Expiration
- 2034-09-26
AI Technical Summary
In the prior art, the high concentration of hydrogen sulfide in the benzene hydrogenation exhaust gas cannot be effectively treated, resulting in the deactivation of the cobalt-molybdenum catalyst in the synthetic natural gas system or the hydrogen sulfide content exceeding the standard, increasing the cost of desulfurization and environmental pollution risks.
A synthetic natural gas system gas replenishment device is designed, connected to the gas pipeline through a high-sulfur exhaust pipeline, and a flowmeter, a regulating valve and a cut-off valve are used to control the mixing of high-sulfur exhaust gas and gas, ensuring that the hydrogen sulfide content is within the range of 80-120ppm and meet the system needs.
Effectively maintain the activity of cobalt-molybdenum catalysts, reduce desulfurization costs, reduce environmental pollution, and achieve fine adjustment and safe control of hydrogen sulfide content.
Smart Images
Figure CN223049853U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of chemical engineering technology, and particularly to a gas supplementing device for a synthetic natural gas system. Background Art
[0002] The tail gas from benzene hydrogenation is a complex gas containing high-concentration hydrogen sulfide generated during the operation of a benzene hydrogenation unit. The generation of this tail gas is due to the reaction of sulfur-containing organic compounds (such as thiophene, mercaptan, etc.) contained in crude benzene with hydrogen during the hydrogenation process, generating hydrogen sulfide. In order to meet the quality standards of the final product, this hydrogen sulfide needs to be discharged as tail gas together with other components in the dehydrogenation process.
[0003] The composition of the tail gas from benzene hydrogenation is complex, mainly including methane, butane, pentane, hydrogen sulfide, ammonia, and a small amount of hydrogen, benzene, etc. Since the concentration of hydrogen sulfide in the tail gas can be as high as 30% (wt) and contains some combustible gases, it cannot be directly discharged into the atmosphere.
[0004] Currently, most units send this tail gas to wet desulfurization units in coking units, sodium hydrosulfide production units using sodium hydrosulfide absorption method, zinc oxide desulfurization units, etc. for treatment. However, during actual operation, these methods have problems such as gradually decreasing desulfurization efficiency, gradually increasing operating costs, and possible environmental problems during storage.
[0005] At the same time, the gas for the coking unit's return furnace needs to be heated in the basement, which requires the hydrogen sulfide content in the gas to be as low as possible. The sulfur-tolerant shift unit in the synthetic natural gas system requires the hydrogen sulfide content in the gas to be in the range of 80 - 120 ppm. If the hydrogen sulfide content in the gas in the sulfur-tolerant shift unit is lower than 80 ppm for a long time, cobalt sulfide and molybdenum sulfide in the cobalt-molybdenum catalyst will gradually reverse sulfurize to the oxidized state, resulting in catalyst deactivation; if the hydrogen sulfide content is greater than 120 ppm, it will increase the consumption of zinc oxide in the subsequent fine desulfurization process. Summary of the Utility Model
[0006] The purpose of the embodiments of this application is to provide a gas supplementing device for a synthetic natural gas system, which is applied to a synthetic natural gas system and includes:
[0007] A high-sulfur tail gas pipeline, whose intake end is connected to the outlet end of the stable tower of coal chemical benzene hydrogenation;
[0008] A gas supplementing pipeline, whose intake end is communicated with the first outlet end of the high-sulfur tail gas pipeline. Along the gas flow direction on the gas supplementing pipeline, there are successively arranged a flow meter for detecting gas flow, a regulating valve for adjusting gas flow, and a cut-off valve for cutting off gas transmission;
[0009] A gas pipeline, whose first intake end is connected to a gas holder, whose second intake end is connected to the outlet end of the make-up gas pipeline, and whose outlet end is connected to the synthetic natural gas system, so as to supplement high-sulfur tail gas in the high-sulfur tail gas pipeline into the gas pipeline through the make-up gas pipeline when the hydrogen sulfide content in the gas is insufficient.
[0010] As an optional embodiment, a first valve is provided between the outlet end of the coal chemical benzene hydrogenation stabilizer tower and the intake end of the high-sulfur tail gas pipeline, a second valve is provided between the first outlet end of the high-sulfur tail gas pipeline and the intake end of the make-up gas pipeline, and a third valve is provided between the outlet end of the make-up gas pipeline and the second intake end of the gas pipeline.
[0011] As an optional embodiment, the second outlet end of the high-sulfur tail gas pipeline is connected to a tail gas treatment pipeline, and a fourth valve is provided therebetween.
[0012] As an optional embodiment, the make-up gas pipeline includes:
[0013] A first connection section, whose intake end is connected to the first outlet end of the high-sulfur tail gas pipeline;
[0014] A second connection section, whose intake end is connected to the outlet end of the first connection section, the first connection section is perpendicular to the second connection section, and the second connection section is sequentially provided with the flowmeter, remote pressure gauge, first gate valve, the regulating valve, second gate valve and the cut-off valve along the gas flow direction;
[0015] A third connection section, whose intake end is connected to the outlet end of the first connection section, and whose outlet end is connected to the second intake end of the gas pipeline, the third connection section is perpendicular to the second connection section and parallel to the first connection section, and the third connection section is sequentially provided with a check valve and a remote thermometer along the gas flow direction.
[0016] As an optional embodiment, a maintenance valve is provided on the second connection section, the maintenance valve is provided between the remote pressure gauge and the first gate valve, and the synthetic natural gas system make-up device further includes:
[0017] A bypass pipeline, whose intake end is connected to the pipeline between the maintenance valve and the first gate valve, and whose outlet end is connected to the pipeline between the second gate valve and the cut-off valve, and a stop valve is provided on the bypass pipeline.
[0018] As an optional embodiment, vent valves are provided on the first connection section, the second connection section and the bypass pipeline.
[0019] As an alternative embodiment, the pipe diameter of the first connecting section is the same as that of the third connecting section, and the pipe diameters of the first connecting section and the third connecting section are both smaller than that of the second connecting section.
[0020] As an alternative embodiment, the pipe diameter of the high-sulfur tail gas pipeline is smaller than that of the coal gas pipeline.
[0021] As an alternative embodiment, the high-sulfur tail gas pipeline, the make-up gas pipeline and the coal gas pipeline are all made of stainless steel.
[0022] The beneficial effects of the embodiments of the present application are as follows:
[0023] The structure of the present application is simple and convenient to use. By mixing high-sulfur tail gas with coal gas and finely adjusting the content of hydrogen sulfide in the coal gas to ensure that it is within the appropriate range of 80-120 ppm, it can not only effectively maintain the activity of the cobalt-molybdenum catalyst in the synthetic natural gas system, but also significantly reduce the desulfurization cost of high-sulfur tail gas and reduce environmental pollution. Description of the Drawings
[0024] Figure 1 It is a schematic structural diagram of the embodiment of the present application.
[0025] Reference Signs:
[0026] 1. High-sulfur tail gas pipeline; 2. Coal chemical benzene hydrogenation stabilizer tower; 3. Tail gas treatment pipeline; 4. Make-up gas pipeline; 41. Flowmeter; 42. Regulating valve; 43. Shut-off valve; 44. Remote pressure gauge; 45. First gate valve; 46. Second gate valve; 47. Maintenance valve; 48. Check valve; 49. Remote thermometer; 5. Coal gas pipeline; 6. Gas holder; 7. Synthetic natural gas system; 81. First valve; 82. Second valve; 83. Third valve; 84. Fourth valve; 9. Bypass pipeline; 91. Globe valve; 10. Vent valve. Detailed Embodiments
[0027] Reference is made herein to the various aspects and features of the present application with reference to the accompanying drawings.
[0028] It should be understood that various modifications can be made to the embodiments claimed herein. Therefore, the above description should not be construed as limiting, but merely as exemplary of the embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the present application.
[0029] The drawings included in and forming a part of this specification illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.
[0030] These and other features of the present application will become apparent from the following description of the preferred forms of the embodiments given as non - limiting examples with reference to the accompanying drawings.
[0031] It should also be understood that although the present application has been described with reference to some specific examples, those skilled in the art can surely implement many other equivalent forms of the present application.
[0032] When combined with the accompanying drawings, the above - mentioned and other aspects, features and advantages of the present application will become more apparent in view of the following detailed description.
[0033] Specific embodiments of the present application will be described hereinafter with reference to the accompanying drawings; however, it should be understood that the embodiments claimed are merely examples of the present application and can be implemented in various ways. Well - known and / or repetitive functions and structures are not described in detail to avoid obscuring the present application with unnecessary or redundant details. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but are merely used as a basis for the claims and a representative basis for teaching those skilled in the art to use the present application in substantially any suitable detailed structure in a variety of ways.
[0034] This specification may use the phrases "in one embodiment", "in another embodiment", "in yet another embodiment" or "in other embodiments", each of which may refer to one or more of the same or different embodiments according to the present application.
[0035] An air - supplementing device for a synthetic natural gas system according to an embodiment of the present application is applied to a synthetic natural gas system 7, and the synthetic natural gas system 7 is a device for producing hydrogen and methane by subjecting purified coal gas to sulfur - tolerant shift conversion and pressure swing adsorption.
[0036] As Figure 1 shown, the air - supplementing device for the synthetic natural gas system includes a high - sulfur tail gas pipeline 1, a gas - supplementing pipeline 4 and a coal gas pipeline 5. The intake end of the high - sulfur tail gas pipeline 1 is connected to the outlet end of a coal chemical benzene hydrogenation stabilizer tower 2. Among them, the coal chemical benzene hydrogenation stabilizer tower 2 is used to remove gases in the benzene hydrogenation oil, such as light hydrocarbon substances such as methane, ethane, hydrogen, etc. and a small amount of non - condensable gases such as nitrogen, so that the benzene hydrogenation oil does not contain hydrogen sulfide.
[0037] The intake end of the gas - supplementing pipeline 4 is communicated with the first outlet end of the high - sulfur tail gas pipeline 1. Along the gas flow direction on the gas - supplementing pipeline 4, there are successively arranged a flow meter 41 for detecting gas flow rate, a regulating valve 42 for adjusting gas flow rate and a cut - off valve 43 for cutting off gas transmission.
[0038] Among them, the regulating valve 42 is used to precisely adjust the gas flow rate in the gas - supplementing pipeline 4, and the cut - off valve 43 is used to quickly cut off the gas flow in case of emergency.
[0039] The first intake end of the gas pipeline 5 is connected to the gas holder 6, its second intake end is connected to the outlet end of the make-up gas pipeline 4, and its outlet end is connected to the synthetic natural gas system 7, so that when the hydrogen sulfide content in the coal gas is insufficient, the high-sulfur tail gas in the high-sulfur tail gas pipeline 1 is supplemented into the gas pipeline 5 through the make-up gas pipeline 4. Among them, the gas holder 6 is used to supply coal gas in the short term during gas buffering or emergency operations. A flow meter is provided on the gas pipeline 5 to detect the gas flow rate in the gas pipeline 5.
[0040] In this embodiment, when the hydrogen sulfide content in the coal gas at the intake end of the synthetic natural gas system 7 is lower than 80 ppm, the high-sulfur tail gas generated by the coal chemical benzene hydrogenation stabilizer tower 2 enters the high-sulfur tail gas pipeline 1 through the intake end. The first outlet end of the high-sulfur tail gas pipeline 1 is connected to the intake end of the make-up gas pipeline 4 to transport high-sulfur tail gas to the make-up gas pipeline 4.
[0041] The first intake end of the gas pipeline 5 is connected to the gas holder 6, and the second intake end is connected to the outlet end of the make-up gas pipeline 4. When the hydrogen sulfide content in the coal gas is insufficient, the high-sulfur tail gas is supplemented into the gas pipeline 5 through the make-up gas pipeline 4. The high-sulfur tail gas is mixed with the coal gas at the outlet end of the gas holder 6 to make the hydrogen sulfide content in the coal gas between 80 and 120 ppm, thus meeting the usage requirements of the synthetic natural gas system 7.
[0042] The flow meter 41 on the make-up gas pipeline 4 detects the gas flow rate, and the regulating valve 42 adjusts the gas flow rate according to requirements. Among them, it is assumed that the hydrogen sulfide content in the coal gas in the gas pipeline 5 is about 50 mg / m 3 The hydrogen sulfide content in the high-sulfur tail gas in the high-sulfur tail gas pipeline 1 is 208848 mg / m 3 , the gas flow rate of the coal gas in the gas pipeline 5 is 40000 Nm 3 / h, and the hydrogen sulfide content in the gas pipeline 5 after mixing is 120 mg / m 3 . Therefore, according to the following formula:
[0043] q(A)×50 mg / m 3 +q(B)×208848 mg / m 3 =(qA + qB)×120 mg / m 3
[0044] It can be obtained that q(B) = 13.4 mg / m 3 , where q(A) is the gas flow rate of the coal gas in the gas pipeline 5, and q(B) is the gas flow rate of the high-sulfur tail gas in the high-sulfur tail gas pipeline 1.
[0045] In this embodiment, under abnormal conditions, the cut-off valve 43 automatically cuts off, stopping the high-sulfur tail gas from entering the gas pipeline 5 after the gas holder 6. For example, the coke oven gas compressor in the synthetic natural gas system 7 shuts down abnormally. When the synthetic natural gas system 7 does not use gas during start-up and shutdown processes, the staff can manually adjust the cut-off valve 43 to the closed state to stop the high-sulfur tail gas from entering the gas pipeline 5 after the gas holder 6.
[0046] In this application, by supplementing the high-sulfur tail gas into the gas pipeline 5, the hydrogen sulfide content in the gas is adjusted to meet the requirement of 80-120 ppm of hydrogen sulfide content in the synthetic natural gas system 7.
[0047] In one embodiment, a first valve 81 is provided between the gas outlet end of the coal chemical benzene hydrogenation stabilizer tower 2 and the gas inlet end of the high-sulfur tail gas pipeline 1, a second valve 82 is provided between the first gas outlet end of the high-sulfur tail gas pipeline 1 and the gas inlet end of the supply pipeline 4, and a third valve 83 is provided between the gas outlet end of the supply pipeline 4 and the second gas inlet end of the gas pipeline 5.
[0048] In this embodiment, the first valve 81 controls the start and stop of the gas inlet from the coal chemical benzene hydrogenation stabilizer tower 2 to the high-sulfur tail gas pipeline 1, the second valve 82 controls the start and stop of the gas inlet from the high-sulfur tail gas pipeline 1 to the supply pipeline 4, and the third valve 83 controls the start and stop of the gas inlet from the supply pipeline 4 to the gas pipeline 5.
[0049] In this application, by setting the first valve 81, the second valve 82 and the third valve 83, the control ability of gas transportation is enhanced, and the safety in use and the flexibility of adjustment are improved.
[0050] In one embodiment, the second gas outlet end of the high-sulfur tail gas pipeline 1 is communicated with the tail gas treatment pipeline 3, and a fourth valve 84 is provided therebetween. The fourth valve 84 is used to control whether the gas in the high-sulfur tail gas pipeline 1 enters the tail gas treatment pipeline 3. When the gas pipeline 5 does not need to be supplemented with gas, the gas is transported from the high-sulfur tail gas pipeline 1 into the tail gas treatment pipeline 3.
[0051] Among them, the tail gas treatment pipeline 3 is the gas pipeline after the four-series fan. The tail gas in the high-sulfur tail gas pipeline 1 goes to the gas purification equipment through the gas pipeline after the four-series fan, and is sent to the synthetic natural gas system 7 after desulfurization, deammoniation and debenzylation.
[0052] In this application, by communicating the second gas outlet end of the high-sulfur tail gas pipeline 1 with the tail gas treatment pipeline 3 and setting the fourth valve 84, the recovery treatment of the tail gas is realized, and environmental pollution is reduced.
[0053] In one embodiment, the supply pipeline 4 includes a first connection section, a second connection section and a third connection section.
[0054] The intake end of the first connection section is communicated with the first outlet end of the high-sulfur tail gas pipeline 1. The intake end of the second connection section is communicated with the outlet end of the first connection section. The first connection section is perpendicular to the second connection section. The second connection section is successively provided with the flowmeter 41, the remote pressure gauge 44, the first gate valve 45, the regulating valve 42, the second gate valve 46 and the cut-off valve 43 along the gas flow direction.
[0055] The intake end of the third connection section is communicated with the outlet end of the first connection section, and its outlet end is communicated with the second intake end of the coal gas pipeline 5. The third connection section is perpendicular to the second connection section and parallel to the first connection section. The third connection section is successively provided with the check valve 48 and the remote thermometer 49 along the gas flow direction.
[0056] In this embodiment, the remote pressure gauge 44 is used to monitor the gas pressure in the make-up gas pipeline 4, and the remote thermometer 49 is used to monitor the gas temperature in the make-up gas pipeline 4. The first gate valve 45 and the second gate valve 46 are used for conventional gas flow control. The check valve 48 is used to prevent gas backflow and ensure unidirectional gas flow.
[0057] This application optimizes the gas flow characteristics and improves the efficiency of gas transmission and the accuracy of control by designing a reasonable layout of the make-up gas pipeline 4.
[0058] In one embodiment, a maintenance valve 47 is provided on the second connection section. The maintenance valve 47 is arranged between the remote pressure gauge 44 and the first gate valve 45. The make-up gas device of the synthetic natural gas system further includes a bypass pipeline 9. The intake end of the bypass pipeline 9 is connected to the pipeline between the maintenance valve 47 and the first gate valve 45, and its outlet end is connected to the pipeline between the second gate valve 46 and the cut-off valve 43. A stop valve 91 is provided on the bypass pipeline 9.
[0059] In this embodiment, the maintenance valve 47 and the bypass pipeline 9 are used to cut off the gas flow during maintenance and repair to ensure the safety of maintenance personnel. The stop valve 91 is used to control the gas flow in the bypass pipeline 9.
[0060] This application adds the maintenance valve 47 and the bypass pipeline 9, improves the maintainability and reliability of the device, and facilitates maintenance and repair without affecting the overall operation.
[0061] In one embodiment, vent valves 10 are provided on the first connection section, the second connection section and the bypass pipeline 9. The vent valve 10 is used for system overpressure protection to discharge excess gas or pressure into the atmosphere.
[0062] The present application is provided with vent valves 10 on the first connection section, the second connection section and the bypass pipeline 9, which improves the safe discharge capacity of the device and helps to control the pressure and protect the safety of the device.
[0063] In one embodiment, the pipe diameter of the first connection section is the same as that of the third connection section, and the pipe diameters of the first connection section and the third connection section are both smaller than that of the second connection section. The pipe diameter of the high-sulfur tail gas pipeline 1 is smaller than that of the coal gas pipeline 5.
[0064] Specifically, the pipe diameter of the first connection section is 20 mm, the pipe diameter of the second connection section is 50 mm, the pipe diameter of the third connection section is 20 mm, the pipe diameter of the high-sulfur tail gas pipeline 1 is 80 mm, and the pipe diameter of the coal gas pipeline 5 is 1400 mm.
[0065] The present application optimizes the flow resistance and pressure drop of the gas by designing connection sections with different pipe diameters. Moreover, the pipe diameter of the high-sulfur tail gas pipeline 1 is smaller than that of the coal gas pipeline 5, which helps to concentrate the high-sulfur tail gas and accurately control the amount of it supplemented into the coal gas pipeline 5.
[0066] In addition, the high-sulfur tail gas pipeline 1, the make-up gas pipeline 4 and the coal gas pipeline 5 are all made of stainless steel material, such as stainless steel 304 material. The present application uses stainless steel material to make the high-sulfur tail gas pipeline 1, the make-up gas pipeline 4 and the coal gas pipeline 5, which improves the corrosion resistance and durability of the pipelines and prolongs the service life of the equipment.
[0067] The above embodiments are only exemplary embodiments of the present application and are not used to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements within the essence and protection scope of the present application, and such modifications or equivalent replacements should also be regarded as falling within the protection scope of the present application.
Claims
1. A gas replenishing device for a synthetic natural gas system, characterized in that: Applications in synthetic natural gas systems, including: The high-sulfur tail gas pipeline has its air inlet connected to the air outlet of the coal chemical benzene hydrogenation stabilization tower; An air supply pipeline, the air inlet end of which is connected to the first air outlet end of the high-sulfur tail gas pipeline, and the air supply pipeline is provided with a flow meter for detecting the gas flow, a regulating valve for adjusting the gas flow, and a cut-off valve for cutting off the gas transmission in sequence along the gas flow direction; A gas pipeline, wherein a first air inlet end is connected to a gas cabinet, a second air inlet end is connected to an air outlet end of the air supply pipeline, and an air outlet end is connected to the synthetic natural gas system, so that when the hydrogen sulfide content in the coal gas is insufficient, the high-sulfur tail gas in the high-sulfur tail gas pipeline can be supplemented into the gas pipeline through the air supply pipeline.
2. The gas supply device for a synthetic natural gas system according to claim 1, characterized in that: A first valve is provided between the gas outlet end of the coal chemical benzene hydrogenation stabilization tower and the gas inlet end of the high-sulfur tail gas pipeline, a second valve is provided between the first gas outlet end of the high-sulfur tail gas pipeline and the gas inlet end of the gas supplement pipeline, and a third valve is provided between the gas outlet end of the gas supplement pipeline and the second gas inlet end of the coal gas pipeline.
3. The gas supply device for a synthetic natural gas system according to claim 1, characterized in that: The second gas outlet end of the high-sulfur tail gas pipeline is connected to the tail gas treatment pipeline, and a fourth valve is provided between the two.
4. The gas supply device for a synthetic natural gas system according to claim 1, characterized in that: The gas supply pipeline comprises: A first connecting section, the air inlet end of which is connected to the first air outlet end of the high-sulfur tail gas pipeline; a second connecting section, whose air inlet end is connected to the air outlet end of the first connecting section, the first connecting section is perpendicular to the second connecting section, and the second connecting section is provided with the flow meter, the remote pressure gauge, the first gate valve, the regulating valve, the second gate valve and the cut-off valve in sequence along the gas flow direction; The third connecting section has an air inlet end connected to the air outlet end of the first connecting section, and an air outlet end connected to the second air inlet end of the gas pipeline. The third connecting section is perpendicular to the second connecting section and parallel to the first connecting section. The third connecting section is provided with a check valve and a remote thermometer in sequence along the gas flow direction.
5. The gas replenishing device for a synthetic natural gas system according to claim 4, characterized in that: The second connecting section is provided with a check valve, and the check valve is arranged between the remote pressure gauge and the first gate valve. The synthetic natural gas system gas supply device also includes: A bypass pipeline, whose air inlet end is connected to the pipeline between the inspection valve and the first gate valve, and whose air outlet end is connected to the pipeline between the second gate valve and the cut-off valve, is provided with a stop valve on the bypass pipeline.
6. The gas replenishing device for a synthetic natural gas system according to claim 5, characterized in that: The first connecting section, the second connecting section and the bypass pipeline are all provided with vent valves.
7. The gas supply device for a synthetic natural gas system according to claim 5, characterized in that: The pipe diameter of the first connecting section is the same as the pipe diameter of the third connecting section, and the pipe diameters of the first connecting section and the third connecting section are both smaller than the pipe diameter of the second connecting section.
8. The gas supply device for a synthetic natural gas system according to claim 1, characterized in that: The diameter of the high-sulfur tail gas pipeline is smaller than the diameter of the coal gas pipeline.
9. The gas supply device for a synthetic natural gas system according to claim 1, characterized in that: The high-sulfur tail gas pipeline, the air supply pipeline and the coal gas pipeline are all made of stainless steel.