Natural gas desulfurization system

Abstract

The utility model relates to a natural gas desulfurization system. The natural gas desulfurization system comprises a communication pipeline, a gas-liquid separator, a desulfurization tower and a filter, the gas-liquid separator is communicated with the communicating pipeline, and external water-containing natural gas enters the gas-liquid separator through the communicating pipeline for gas-liquid separation; the desulfurizing tower is used for desulfurizing natural gas; the desulfurization tower comprises an input end and an output end which are respectively arranged at the top and the bottom; natural gas enters the desulfurization tower from the input end, moves downwards and is output from the output end; the input end is communicated with the downstream position of the communicating pipeline on the gas-liquid separator, and the output end is communicated with the downstream communicating pipeline; the filter is communicated with the downstream position, located at the output end, of the communication pipeline so as to filter the desulfurized natural gas. The input end of the desulfurizing tower is located at the top of the tower, the output end of the desulfurizing tower is located at the bottom of the tower, and natural gas can slowly move downwards under the action of air pressure after entering the desulfurizing tower, so that the contact time of the natural gas and desulfurizing agent filler is prolonged, and the desulfurizing effect is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of natural gas desulfurization, and in particular to a natural gas desulfurization system. Background Art

[0002] In the industrial production process, the natural gas directly obtained from mining does not meet the quality standards stipulated by the state, and a series of treatments are required to make it qualified. Untreated natural gas contains sulfur, which will corrode equipment and pipelines during the collection, transportation, storage and transportation process, and will also cause personal safety accidents once it leaks. When natural gas is burned as fuel, the sulfide in it will be converted into sulfur oxides and discharged into the atmosphere, forming acid rain, air pollution, and ecological environment damage, so desulfurization is necessary.

[0003] At present, in practical applications, desulfurization towers with built-in fillers are usually used for desulfurization. Hydrogen sulfide is not fully adsorbed in the tower, and the desulfurization effect is poor. When replacing the desulfurizer filler in the tower, it is necessary to stop production to replace the filler or replace the entire tower, resulting in production stoppage and waste of resources; in addition, when replacing the filler, the desulfurizer filler may also spontaneously combust, posing a safety hazard. Utility Model Content

[0004] In order to solve the problems existing in the prior art, the present disclosure provides a natural gas desulfurization system.

[0005] According to a first aspect of the present disclosure, there is provided a natural gas desulfurization system, comprising:

[0006] Connecting pipelines;

[0007] A gas-liquid separator, wherein the gas-liquid separator is configured to be in communication with a connecting pipeline, and external water-containing natural gas is configured to enter the gas-liquid separator through the connecting pipeline for gas-liquid separation;

[0008] A desulfurization tower, the desulfurization tower is configured to desulfurize natural gas; the desulfurization tower comprises an input end and an output end respectively arranged at the top and the bottom of the desulfurization tower; the natural gas is configured to move downward after entering the desulfurization tower from the input end, and is configured to be output from the output end; the input end is configured to be connected to a connecting pipeline located downstream of the gas-liquid separator, and the output end is configured to be connected to a downstream connecting pipeline;

[0009] The filter is configured to be in communication with the communication pipeline at a position downstream of the output end so as to filter the desulfurized natural gas.

[0010] In one embodiment of the present disclosure, the gas-liquid separator is a horizontal separator, and a feed port and a gas outlet are provided at the top of the horizontal separator, and a liquid discharge port is provided at the bottom; the water-containing natural gas is configured to enter the horizontal separator from the feed port for gas-liquid separation, the separated liquid is configured to be discharged from the liquid discharge port, and the separated sulfur-containing natural gas is configured to be discharged from the gas outlet.

[0011] In one embodiment of the present disclosure, the horizontal separator further includes a defoaming device, which is disposed at least at the gas outlet of the horizontal separator; the defoaming device is configured to eliminate foam in the natural gas; and the separated natural gas is configured to be discharged from the gas outlet through the defoaming device.

[0012] In one embodiment of the present disclosure, a desander is further included, wherein the liquid inlet of the desander is configured to be connected to the liquid discharge port of the gas-liquid separator through a connecting pipeline; the desander is configured to perform solid-liquid separation on the sewage discharged from the gas-liquid separator.

[0013] In one embodiment of the present disclosure, a sewage discharge pipeline is further included; the sewage discharge pipeline is constructed to be connected to the liquid outlet of the desander, the first sewage discharge outlet of the desulfurization tower, and the second sewage discharge outlet of the filter respectively.

[0014] In one embodiment of the present disclosure, the desulfurization tower is provided in two pieces, and the two desulfurization towers are configured to be connected in series or in parallel through a connecting pipeline;

[0015] In the series connection state, the input end of one of the desulfurization towers is configured to be connected to a connecting pipeline located downstream of the gas-liquid separator, and the output end thereof is configured to be connected to the input end of another desulfurization tower through a connecting pipeline;

[0016] In a parallel state, the input ends of the two desulfurization towers are respectively constructed to be connected to a connecting pipeline located downstream of the gas-liquid separator, and the output ends of the two desulfurization towers are respectively constructed to be connected to a downstream connecting pipeline.

[0017] In one embodiment of the present disclosure, it also includes a control valve assembly, which is constructed to be arranged on the connecting pipelines at the upstream and downstream positions of the desulfurization towers; the two desulfurization towers are configured to switch between a series state and a parallel state through the control of the control valve assembly.

[0018] In one embodiment of the present disclosure, it also includes a water inlet pipeline; a water inlet is also provided at the upper position of the desulfurization tower; the water inlet pipeline is constructed to be connected to the water inlet, and is constructed to be used to transport water into the desulfurization tower during the process of replacing the packing of the desulfurization tower.

[0019] In one embodiment of the present disclosure, the number of filters is two, and the two filters are configured to be connected in parallel via a connecting pipeline.

[0020] In one embodiment of the present disclosure, a vent line is further included, and the vent line is configured to be connected to the vent port of the gas-liquid separator and the connecting line located upstream of the desulfurization tower input end.

[0021] One beneficial effect of the present disclosure is that the water- and sulfur-containing natural gas first enters the gas-liquid separator, thereby removing most of the water therein; then enters the desulfurization tower for desulfurization, so that its sulfur content reaches the qualified standard; and then is filtered through a filter to remove the powdered desulfurizer carried out from the desulfurization tower. The input end of the desulfurization tower of the present disclosure is located at the top of the tower, and the output end is located at the bottom of the tower. After entering the desulfurization tower, the natural gas will slowly move downward under the action of air pressure, thereby increasing the contact time between the natural gas and the desulfurizer filler, thereby improving the desulfurization effect. In addition, the present disclosure adopts an integrated skid design, which has the advantages of high integration, easy installation and use, low installation cost, and short construction period.

[0022] Other features and advantages of the present disclosure will become apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0024] Figure 1 is a schematic structural diagram of the natural gas desulfurization system disclosed in the present invention;

[0025] Figure 2 It is a structural schematic diagram of the desulfurization tower disclosed in the present invention and its surrounding connecting pipelines.

[0026] Figure 1 to Figure 2 The one-to-one correspondence between the component names and the reference numerals is as follows:

[0027] 10. Station entry skid; 11. External transmission port; 12. Water inlet source; 13. Flare; 14. Sewage tank; 2. Desulfurization tower; 201. First control valve; 202. Second control valve; 203. Third control valve; 204. Fourth control valve; 205. Fifth control valve; 206. Sixth control valve; 207. Seventh control valve; 208. Eighth control valve; 21. Input end; 22. Output end; 23. Water inlet; 24. First sewage outlet; 3. Horizontal separator; 31. Feed inlet; 32. Gas outlet; 33. Liquid discharge outlet; 34. Vent; 35. Wire mesh demister; 36. demister assembly; 4. Desander; 41. Liquid inlet; 42. Liquid outlet; 43. Sand discharge outlet; 5. Filter; 51. Second sewage outlet. DETAILED DESCRIPTION

[0028] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present disclosure unless otherwise specifically stated.

[0029] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0030] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0031] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0032] In this document, “upper”, “lower”, “front”, “back”, “left”, “right”, etc. are only used to indicate the relative position relationship between related parts, rather than to limit the absolute positions of these related parts.

[0033] In this article, "first", "second", etc. are only used to distinguish each other, and do not indicate the importance and order, or the premise of each other's existence.

[0034] In this document, “equal”, “same”, etc. are not strictly limited in mathematical and / or geometric senses, but also include errors that can be understood by those skilled in the art and allowed by manufacturing or use.

[0035] The present disclosure provides a natural gas desulfurization system, including: a connecting pipeline, a gas-liquid separator, a desulfurization tower, and a filter. The natural gas outside the system can be introduced into the connecting pipeline from the station entry skid. Since the water content and sulfur content of the incoming natural gas are usually higher than the standard and cannot be used directly, the incoming gas needs to be dehydrated and desulfurized. The present disclosure uses a gas-liquid separator to remove water from the natural gas, and uses a desulfurization tower to desulfurize the natural gas.

[0036] Specifically, the gas-liquid separator is configured to be connected to the connecting pipeline, and the external water-containing natural gas is configured to enter the gas-liquid separator through the connecting pipeline for gas-liquid separation. The water in the water-containing natural gas will be basically removed in the gas-liquid separator, and the separated gas phase is the dehydrated natural gas. The sulfur content of the dehydrated natural gas still exceeds the standard, so it needs to be further transported to the desulfurization tower for desulfurization.

[0037] The desulfurization tower is used to desulfurize natural gas. The desulfurization tower is filled with fillers for desulfurization. In a specific embodiment of the present disclosure, the filler is iron oxyhydroxide. After the sulfur-containing natural gas enters the desulfurization tower, hydrogen sulfide can fully contact with the fillers in the desulfurization tower and react chemically, thereby achieving desulfurization. The desulfurization tower includes an input end and an output end respectively arranged at the top and bottom thereof. The natural gas is configured to move downward after entering the desulfurization tower from the input end, and is configured to be output from the output end. The input end is constructed to be connected to a connecting pipeline located downstream of the gas-liquid separator, and the output end is constructed to be connected to a downstream connecting pipeline. The dehydrated sour natural gas can enter the tower from the input end at the top of the desulfurization tower, and the gas entering the tower will be concentrated at the top of the tower; as more and more gas is input, the sour natural gas will gradually move downward under the action of gas pressure, so that the gas is fully in contact with the filler, thereby improving the desulfurization effect.

[0038] The desulfurized natural gas can be output from the output end at the bottom of the desulfurization tower and continue to be transported downstream along the connecting pipeline. It should be noted that since the present disclosure adopts a dry desulfurization process, the solid filler in the desulfurization tower is likely to be in a powder state, so the output natural gas is likely to be mixed with a small amount of desulfurizer powder. The solid powder is likely to follow the natural gas airflow into the downstream pipeline, thereby causing blockage and pressure buildup of pipelines, valves and equipment, thereby causing safety hazards.

[0039] To solve the above problems, the desulfurized natural gas needs to be filtered in a filter. Specifically, the filter is configured to be connected to the downstream position of the connecting pipeline at the output end to filter the desulfurized natural gas. The filter can effectively remove solid impurities in the natural gas, thereby preventing the downstream pipeline equipment from being blocked, thereby protecting the downstream pipeline equipment.

[0040] In the natural gas desulfurization system provided by the present disclosure, the water- and sulfur-containing natural gas first enters the gas-liquid separator, thereby removing most of the water therein; then enters the desulfurization tower for desulfurization, so that its sulfur content reaches the qualified standard; and then is filtered through a filter to remove the powdered desulfurizer carried out from the desulfurization tower. The input end of the desulfurization tower of the present disclosure is located at the top of the tower, and the output end is located at the bottom of the tower. After entering the desulfurization tower, the natural gas will slowly move downward under the action of air pressure, thereby increasing the contact time between the natural gas and the desulfurizer filler, thereby improving the desulfurization effect. In addition, the present disclosure adopts an integrated skid design, which has the advantages of high integration, easy installation and use, low installation cost, and short construction period.

[0041] The specific embodiments of the present disclosure are described below in conjunction with the accompanying drawings.

[0042] refer to Figure 1 The present disclosure provides a natural gas desulfurization system, including: a connecting pipeline, a gas-liquid separator, a desulfurization tower 2, and a filter 5. Natural gas outside the system can be introduced into the connecting pipeline from the station entry skid 10. Since the water content and sulfur content of the incoming natural gas are usually higher than the standard and cannot be used directly, the incoming gas needs to be dehydrated and desulfurized.

[0043] Specifically, the gas-liquid separator is configured to be connected to the connecting pipeline, and the external water-containing natural gas is configured to enter the gas-liquid separator through the connecting pipeline for gas-liquid separation. Figure 1 As shown, the gas-liquid separator is a horizontal separator 3, which can achieve gas-liquid separation through the principle of gravity sedimentation. The horizontal separator 3 can have a large volume, so that the gas-liquid mixture has a certain force buffering speed therein, thereby achieving a better separation effect. In a specific embodiment of the present disclosure, the gas-liquid mixture stays in the horizontal separator 3 for no less than 28 minutes, which is very suitable for the case where the incoming gas contains a large amount of liquid.

[0044] like Figure 1 As shown, the top of the horizontal separator 3 is provided with a feed port 31 and a gas outlet 32, and the bottom is provided with a liquid discharge port 33. The feed port 31 can be connected to the station entry skid 10 through a connecting pipeline, and the water-containing natural gas is configured to enter the horizontal separator 3 from the feed port 31 for gas-liquid separation. The water-containing natural gas stays in the horizontal separator 3 and settles by gravity, and the gas phase with a lower density gathers at the top of the horizontal separator 3, and the liquid phase with a higher density gathers at the bottom of the horizontal separator 3, thereby achieving separation.

[0045] In one embodiment of the present disclosure, the horizontal separator 3 further includes a defoaming device, which is configured to eliminate foam in the natural gas; the defoaming device is at least arranged at the gas outlet 32 ​​of the horizontal separator 3, and the separated natural gas is configured to be discharged from the gas outlet 32 ​​through the defoaming device. Figure 1 As shown, in a specific embodiment of the present disclosure, two defoaming devices can be simultaneously arranged in the horizontal separator 3, namely: a wire mesh defoamer 35 located at the gas outlet 32, and a defoamer assembly 36 located in the middle position inside the horizontal separator 3. A large number of micropores can be arranged on the wire mesh defoamer 35 and the defoamer assembly 36 to form a microporous network structure. When the liquid phase, gas phase, or gas-liquid mixture passes through the wire mesh defoamer 35 and the defoamer assembly 36, the foam therein will be intercepted, broken, and dispersed, so that the gas in the foam overflows and the liquid sinks.

[0046] refer to Figure 1 In the viewing direction, the gas-liquid mixture entering the horizontal separator 3 from the feed port 31 will gradually move to the right during the sedimentation separation process, and pass through the demister assembly 36 during the movement, thereby removing part of the foam in the gas-liquid mixture, so that the gas and liquid are fully separated. The gas phase separated by the horizontal separator 3 can pass through the wire mesh demister 35 before being discharged from the gas outlet 32. The wire mesh demister 35 can eliminate the mixed foam in the natural gas before the natural gas is discharged, so that the gas discharged from the gas outlet 32 ​​does not contain foam, further reducing the water content in the natural gas and improving the separation effect.

[0047] The present disclosure does not impose any specific restrictions on the number, type and location of the defoaming device. For example, the defoaming device may only include a wire mesh defoamer 35 arranged at the gas outlet 32, or may include more defoaming structures arranged in the horizontal separator 3, such as a defoamer may also be arranged at the drain port 33 and / or the feed port 31.

[0048] The water in the water-containing natural gas will be basically removed in the horizontal separator 3, and the separated gas phase is the dehydrated natural gas. The separated liquid is configured to be discharged from the drain port 33 at the bottom of the horizontal separator 3, and the separated sulfur-containing natural gas is configured to be discharged from the gas outlet 32 ​​at the top of the horizontal separator 3. The sulfur content of the dehydrated natural gas still exceeds the standard, so it needs to be further transported to the desulfurization tower 2 for desulfurization.

[0049] The desulfurization tower 2 is used to desulfurize natural gas. The desulfurization tower 2 is filled with fillers for desulfurization. In a specific embodiment of the present disclosure, the filler is ferric hydroxide (FeOOH), and the desulfurization reaction equation is: FeOOH+2H2S=FeSSH+2H2O. Ferric hydroxide is neutral and can be applied to a variety of conditions; the process of desulfurization using ferric hydroxide is simple and the desulfurization cost is low; and the sulfur capacity of ferric hydroxide is high, which can reach more than 35%; in addition, ferric hydroxide also has a good adsorption effect on carbon dioxide. Specifically, in this embodiment, the content of hydrogen sulfide in the natural gas before desulfurization is about 100mg / m 3 The hydrogen sulfide content in the desulfurized natural gas is about 15 mg / m 3 , in line with the natural gas quality requirements for Class II pipeline gas.

[0050] After the sulfur-containing natural gas enters the desulfurization tower 2, hydrogen sulfide can fully contact and chemically react with the filler in the desulfurization tower 2, thereby achieving desulfurization. Figure 1 As shown, the desulfurization tower 2 includes an input end 21 and an output end 22 respectively arranged at the top and bottom thereof. The natural gas is configured to move downward after entering the desulfurization tower 2 from the input end 21, and is configured to be output from the output end 22. The input end 21 is configured to be connected to the downstream position of the gas-liquid separator with the connecting pipeline. Specifically, the input end 21 and the gas outlet 32 ​​of the horizontal separator 3 are connected through the connecting pipeline; the output end 22 is configured to be connected to the downstream connecting pipeline. The dehydrated sour natural gas can enter the desulfurization tower 2 from the input end 21 at the top, and the gas entering the tower will be concentrated at the top of the tower; as more and more gas is input, the sour natural gas will gradually move downward under the action of gas pressure, so that the gas is fully in contact with the filler, thereby improving the desulfurization effect. The desulfurized natural gas can be output from the output end 22 at the bottom of the desulfurization tower 2, and continue to be transported downstream along the connecting pipeline.

[0051] In one embodiment of the present disclosure, Figure 1 As shown, two desulfurization towers 2 are provided, and the two desulfurization towers 2 are configured to be connected in series or in parallel through a connecting pipeline. In the series state, the input end 21 of one of the desulfurization towers 2 is configured to be connected to the connecting pipeline at the downstream position of the gas-liquid separator, and its output end 22 is configured to be connected to the input end 21 of the other desulfurization tower 2 through a connecting pipeline. After the sour natural gas passes through the adsorption desulfurization of one of the desulfurization towers 2, it will enter the other desulfurization tower 2 along the connecting pipeline for secondary adsorption, thereby realizing two-stage desulfurization, making the desulfurization more thorough and improving the desulfurization effect.

[0052] In the parallel state, the input ends 21 of the two desulfurization towers 2 are respectively constructed to be connected to the connecting pipeline located at the downstream position of the gas-liquid separator, and the output ends 22 of the two desulfurization towers 2 are respectively constructed to be connected to the downstream connecting pipeline. The sour natural gas can enter the two desulfurization towers at the same time, and the two towers can desulfurize the incoming gas at the same time, thereby improving the efficiency of desulfurization. In addition, the two desulfurization towers 2 arranged in parallel can also be used as a backup, that is, only one desulfurization tower 2 can be used for desulfurization, and the other desulfurization tower 2 can be used as a backup. For example, if the desulfurizer of one of the towers needs to be replaced, the other desulfurization tower 2 can be activated, so that the filler can be replaced online without stopping production.

[0053] Furthermore, the natural gas desulfurization system disclosed in the present invention also includes a control valve assembly, which is constructed to be arranged on the connecting pipelines at the upstream and downstream positions of the desulfurization tower 2. The two desulfurization towers 2 are configured to switch between a series state and a parallel state through the control of the control valve assembly. Under different working conditions, the connection mode of the two desulfurization towers 2 may also change accordingly, for example: when the sulfur content of the incoming gas is high, the two desulfurization towers 2 can be connected in series, so that the incoming gas is desulfurized twice to improve the desulfurization effect; when the incoming gas volume is large, the two desulfurization towers 2 can be connected in parallel, so that the incoming gas is desulfurized by using two desulfurization towers 2 at the same time, which improves the speed and efficiency of desulfurization; when the incoming gas volume is small and the sulfur content is low, one of the desulfurization towers 2 can be selectively used for desulfurization, and the other tower can be used as a backup; when it is necessary to replace the desulfurizer filler in one of the desulfurization towers 2, the other tower can be used to continue desulfurization without stopping production.

[0054] Specifically, refer to Figure 2 The control valve assembly includes a first control valve 201, a second control valve 202, a third control valve 203, and a fourth control valve 204 disposed on the upstream connecting pipeline of the desulfurization tower 2, and also includes a fifth control valve 205, a sixth control valve 206, a seventh control valve 207, and an eighth control valve 208 disposed on the downstream connecting pipeline of the desulfurization tower 2. By controlling the opening and closing of these eight control valves, the connection relationship between the two desulfurization towers 2 can be controlled.

[0055] refer to Figure 2In the viewing direction, when two desulfurization towers 2 need to be connected in series, and the left desulfurization tower 2 is connected in series in front and the right desulfurization tower 2 is connected in series in the back, the first control valve 201, the fifth control valve 205, the fourth control valve 204 and the eighth control valve 208 are opened at the same time, and the other control valves are all closed. At this time, the incoming gas will first pass through the first control valve 201 and enter the tower from the input end 21 of the left desulfurization tower 2 for the first desulfurization; after being discharged from the output end 22 of the left desulfurization tower 2, the gas will pass through the fifth control valve 205 and the fourth control valve 204 in sequence, and enter the tower from the input end 21 of the right desulfurization tower 2 for the second desulfurization; the natural gas that has undergone the second desulfurization will be discharged from the output end 22 of the right desulfurization tower 2 and transported downstream through the eighth control valve 208.

[0056] When two desulfurization towers 2 need to be connected in series, with the right desulfurization tower 2 connected in front and the left desulfurization tower 2 connected in the back, the second control valve 202, the sixth control valve 206, the third control valve 203 and the seventh control valve 207 are opened at the same time, and all other control valves are closed. At this time, the incoming gas will first pass through the second control valve 202 and enter the tower from the input end 21 of the right desulfurization tower 2 for the first desulfurization; after being discharged from the output end 22 of the right desulfurization tower 2, the gas will pass through the sixth control valve 206 and the third control valve 203 in turn, and enter the tower from the input end 21 of the left desulfurization tower 2 for the second desulfurization; the natural gas that has undergone the second desulfurization will be discharged from the output end 22 of the left desulfurization tower 2 and transported downstream through the seventh control valve 207.

[0057] When it is necessary to connect two desulfurization towers 2 in parallel and both towers perform desulfurization work at the same time, the first control valve 201, the second control valve 202, the seventh control valve 207, and the eighth control valve 208 are opened at the same time, and all other control valves are closed. At this time, the incoming gas will first pass through the first control valve 201 and the second control valve 202, and enter the tower from the input end 21 of the two desulfurization towers 2 for desulfurization; the desulfurized natural gas will be discharged from the output end 22 of the two desulfurization towers 2 respectively, and transported to the downstream through the seventh control valve 207 and the eighth control valve 208.

[0058] When only the left desulfurization tower 2 is opened, the first control valve 201 and the seventh control valve 207 are opened at the same time, and all other control valves are closed. At this time, the incoming gas will first pass through the first control valve 201 and enter the tower from the input end 21 of the left desulfurization tower 2 for desulfurization; the desulfurized natural gas will be discharged from the output end 22 of the left desulfurization tower 2 and transported downstream through the seventh control valve 207.

[0059] When only the right desulfurization tower 2 is opened, the second control valve 202 and the eighth control valve 208 are opened at the same time, and all other control valves are closed. At this time, the incoming gas will first pass through the second control valve 202 and enter the tower from the input end 21 of the right desulfurization tower 2 for desulfurization; the desulfurized natural gas will be discharged from the output end 22 of the right desulfurization tower 2 and transported downstream through the eighth control valve 208.

[0060] The present disclosure realizes the control of the series connection, parallel connection or single opening of any one of the two desulfurization towers 2 by setting a control valve assembly, so as to flexibly control the desulfurization process according to different working conditions. When the processing volume of sour natural gas is large, two towers can be set in parallel, and when the sulfur content of sour natural gas is high, two towers can be set in series. In other working conditions, a single tower can be opened, one for standby and the other for use, thereby improving the desulfurization efficiency and reducing the desulfurization cost. When the desulfurizer is replaced, there is no need to stop production, and the filler can be replaced online.

[0061] Since the present disclosure adopts a dry desulfurization process, the solid filler in the desulfurization tower is likely to be in a powder state, so the output natural gas is likely to be mixed with a small amount of desulfurizer powder. The solid powder is likely to follow the natural gas flow into the downstream pipeline, thereby causing blockage and pressure buildup in the pipeline, valves and equipment, thereby causing safety hazards.

[0062] To solve the above problems, the desulfurized natural gas needs to be filtered in the filter 5. Figure 1 The filter 5 is configured to be connected to the connecting pipeline at a downstream position of the output end 22 to filter the desulfurized natural gas. The filter 5 can effectively remove solid impurities in the natural gas, thereby preventing the downstream pipeline equipment from being blocked, thereby protecting the downstream pipeline equipment. The connecting pipeline downstream of the filter 5 can be connected to the external output port 11, so as to output the filtered natural gas to the outside of the system.

[0063] In one embodiment of the present disclosure, two filters 5 are provided, and the two filters 5 are configured to be connected in parallel through a connecting pipeline. The two filters 5 provided in parallel can be used as a backup, that is, only one filter 5 can be used for filtering, and the other filter 5 can be used as a backup. When one of the filters 5 needs to be repaired or replaced, the other filter 5 can be activated, so that online repair and replacement can be achieved without stopping production.

[0064] In addition, the two filters 5 arranged in parallel can also be turned on at the same time. For example, when the incoming gas volume is large, the processing efficiency of a single filter 5 is low, and the gas flow will accumulate in the connecting pipeline upstream of the filter 5; at this time, the two filters 5 can be turned on at the same time, thereby doubling the processing speed, relieving the pipeline pressure, and improving the processing efficiency of the natural gas desulfurization system.

[0065] In the natural gas desulfurization system provided by the present disclosure, the water-containing and sulfur-containing natural gas first enters the horizontal separator 3, thereby removing most of the water therein; then enters the desulfurization tower 2 for desulfurization, so that its sulfur content reaches the qualified standard; then it is filtered through the filter 5 to remove the powdered desulfurizer carried out from the desulfurization tower 2. The input end 21 of the desulfurization tower 2 of the present disclosure is located at the top of the tower, and the output end 22 is located at the bottom of the tower. After entering the desulfurization tower 2, the natural gas will slowly move downward under the action of air pressure, thereby increasing the contact time between the natural gas and the desulfurizer filler, thereby improving the desulfurization effect. In addition, the present disclosure adopts an integrated skid design, which has the advantages of high integration, easy installation and use, low installation cost, and short construction period.

[0066] Untreated natural gas contains a small amount of solid impurities such as gravel, and the horizontal separator 3 can separate the liquid and solid impurities in the natural gas together and discharge them together from the drain port 33 at the bottom of the horizontal separator 3. The gravel mixed in the liquid may cause the pipelines, pumps, valves and equipment to be blocked during the subsequent sewage treatment, thus causing safety hazards.

[0067] To solve the above problems, in one embodiment of the present disclosure, reference is made to Figure 1 The natural gas desulfurization system further includes a desander 4, which is configured to perform solid-liquid separation on the wastewater discharged from the gas-liquid separator. The liquid inlet 41 of the desander 4 is configured to be connected to the liquid discharge port 33 of the gas-liquid separator through a connecting pipeline. The solid-liquid mixture discharged from the liquid discharge port 33 of the horizontal separator 3 enters the desander 4 through the connecting pipeline, and the desander 4 performs solid-liquid separation on the wastewater by centrifugation and sedimentation.

[0068] like Figure 1 As shown, the desander 4 is provided with a liquid inlet 41, a liquid outlet 42 and a sand outlet 43, wherein the liquid inlet 41 and the liquid outlet 42 can be arranged on the side wall of the desander 4, and the sand outlet 43 is arranged at the bottom of the desander 4. After the solid-liquid separation of the solid-liquid mixture entering the desander 4 from the liquid inlet 41, the separated liquid will be located in the upper layer of the desander 4, and the separated solid will accumulate at the bottom of the desander 4. The liquid can continue to be discharged downstream from the liquid outlet 42 for sewage treatment; the solid can be discharged locally from the sand outlet 43 at the bottom of the desander 4.

[0069] In one embodiment of the present disclosure, the natural gas desulfurization system further comprises a sewage discharge pipeline, Figure 1The sewage discharge line is constructed to be connected to the liquid outlet 42 of the desander 4, the first sewage discharge port 24 of the desulfurization tower 2, and the second sewage discharge port 51 of the filter 5. Among them, the liquid outlet 42 of the desander 4 can discharge the waste liquid generated after solid-liquid separation; the desulfurization tower 2 will produce a certain amount of waste liquid during the desulfurization process, and it will be discharged from the first sewage discharge port 24 at the bottom of the desulfurization tower 2. The above two waste liquids can be gathered in the sewage discharge line and transported to the sewage tank 14. The sewage tank 14 is movable, so the sewage discharge line can be connected to the sewage tank 14 through a hose. When a certain amount of sewage is collected in the sewage tank 14, it can be discharged by vehicle transportation.

[0070] The main function of the filter 5 is to separate solids from liquids. The solid residue obtained by filtration cannot be collected together with the above-mentioned waste liquid, but needs to be discharged separately. The filter 5 has a second sewage outlet 51, which is connected to a sewage discharge pipeline, and the sewage discharge pipeline can directly output the solid residue to the outside of the system for on-site sewage discharge. As can be seen from the foregoing, the main component of the solid residue is the desulfurizer filler powder, so it can be discharged directly without causing adverse effects on the environment.

[0071] It should be noted that the sewage pipeline connecting the liquid outlet 42 and the first sewage outlet 24 and the sewage pipeline connecting the second sewage outlet 51 are two independent sewage pipelines. The former is used to discharge sewage and waste liquid, and is constructed to be connected to the sewage tank 14 for sewage discharge; the latter is used to discharge solid filter residue, and is constructed to be directly transported externally and discharged on site.

[0072] In one embodiment of the present disclosure, the natural desulfurization system further comprises a water inlet pipeline, Figure 1 The upper part of the desulfurization tower 2 is also provided with a water inlet 23, and the water inlet pipeline is configured to be connected to the water inlet 23, and is configured to be used to transport water into the desulfurization tower 2 during the process of replacing the packing of the desulfurization tower 2. It should be noted that the desulfurization agent packing iron hydroxide used in the present disclosure is a flammable substance. When the packing is replaced, the iron hydroxide will come into contact with oxygen, so it may spontaneously combust. In order to avoid the combustion of the iron hydroxide, it is necessary to transport water into the desulfurization tower 2 when replacing the packing to wet the iron hydroxide to prevent spontaneous combustion.

[0073] like Figure 1 As shown, the water inlet pipeline connects the water source 12 to the water inlet 23 of the desulfurization tower 2. When the packing of the desulfurization tower 2 is replaced, the water inlet valve on the water inlet pipeline is opened, so that water is transported into the desulfurization tower 2 through the water inlet pipeline. In a specific embodiment, a distributor or a spraying device can be provided at the water inlet 23, so that the water entering the desulfurization tower 2 can be evenly sprayed onto the packing.

[0074] In one embodiment of the present disclosure, the natural gas desulfurization system further includes a venting pipeline, which can vent gas based on the pressure in the equipment or the connecting pipeline, thereby ensuring that the pressure in the system is normal. The venting pipeline is configured to be connected to the venting port 34 of the gas-liquid separator and the connecting pipeline located upstream of the input end 21 of the desulfurization tower 2, respectively, and transport the vented gas to the flare 13 for combustion.

[0075] Specifically, the gas pressure in the horizontal separator 3 needs to be maintained at a certain level to work normally. If too much gas is introduced into the horizontal separator 3 per unit time, the internal pressure of the horizontal separator 3 will be too high, and a venting operation is required at this time. The venting port 34 of the horizontal separator 3 is opened, and the internal gas is transported to the torch 13 along the venting pipeline for combustion, thereby avoiding direct emission to pollute the atmosphere.

[0076] In addition to the need to vent the horizontal separator 3, the connecting pipeline at the upstream position of the input end 21 of the desulfurization tower 2 also needs to be vented. The venting pipeline is connected to the connecting pipeline at the downstream position of the first control valve 201 and the second control valve 202 respectively. When too much gas is introduced into the desulfurization tower 2 per unit time, the processing efficiency of the desulfurization tower 2 may not be able to meet the incoming gas, which will cause too much gas to accumulate in the connecting pipeline upstream of the desulfurization tower 2, thereby causing the gas pressure in the connecting pipeline to be too high. The connecting pipeline between the first control valve 201 and the left desulfurization tower 2 and the connecting pipeline between the second control valve 202 and the right desulfurization tower 2 can be vented when the pressure is too high, and the internal gas is transported to the flare 13 along the venting pipeline for combustion. Setting up the venting pipeline can ensure that the air pressure in the system is normal, and the pressure gauge and other equipment in the natural gas desulfurization system can monitor and adjust the air pressure in real time, thereby ensuring the normal operation of the system and improving the safety of the system.

[0077] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the marketplace, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein. The scope of the present disclosure is defined by the appended claims.

Claims

1. A natural gas desulfurization system, characterized in that: include: Connecting pipelines; A gas-liquid separator, wherein the gas-liquid separator is configured to be in communication with a connecting pipeline, and external water-containing natural gas is configured to enter the gas-liquid separator through the connecting pipeline for gas-liquid separation; A desulfurization tower (2), the desulfurization tower (2) being configured to desulfurize natural gas; the desulfurization tower (2) comprising an input end (21) and an output end (22) respectively arranged at the top and the bottom of the desulfurization tower (2); the natural gas is configured to move downward after entering the desulfurization tower from the input end (21), and is configured to be output from the output end (22); the input end (21) is configured to be connected to a connecting pipeline located downstream of the gas-liquid separator, and the output end (22) is configured to be connected to a downstream connecting pipeline; A filter (5) is configured to be connected to the connecting pipeline at a position downstream of the output end (22) so as to filter the desulfurized natural gas.

2. The natural gas desulfurization system according to claim 1, characterized in that: The gas-liquid separator is a horizontal separator (3), the top of the horizontal separator (3) is provided with a feed inlet (31) and a gas outlet (32), and the bottom is provided with a liquid discharge port (33); the water-containing natural gas is configured to enter the horizontal separator (3) from the feed inlet (31) for gas-liquid separation, the separated liquid is configured to be discharged from the liquid discharge port (33), and the separated sulfur-containing natural gas is configured to be discharged from the gas outlet (32).

3. The natural gas desulfurization system according to claim 2, characterized in that: The horizontal separator (3) further comprises a defoaming device, which is arranged at least at the gas outlet (32) of the horizontal separator (3); the defoaming device is configured to eliminate foam in the natural gas; and the separated natural gas is configured to be discharged from the gas outlet (32) through the defoaming device.

4. The natural gas desulfurization system according to claim 1, characterized in that: It also comprises a desander (4), wherein the liquid inlet (41) of the desander (4) is configured to be in communication with the liquid discharge port (33) of the gas-liquid separator via a connecting pipeline; the desander (4) is configured to perform solid-liquid separation on the sewage discharged from the gas-liquid separator.

5. The natural gas desulfurization system according to claim 4, characterized in that: It also includes a sewage discharge pipeline; the sewage discharge pipeline is constructed to be connected to the liquid outlet (42) of the desander (4), the first sewage discharge outlet (24) of the desulfurization tower (2), and the second sewage discharge outlet (51) of the filter (5) respectively.

6. The natural gas desulfurization system according to claim 1, characterized in that: The desulfurization tower (2) is provided in two pieces, and the two desulfurization towers (2) are configured to be connected in series or in parallel via a connecting pipeline; In a series connection state, the input end (21) of one desulfurization tower (2) is configured to be connected to a connecting pipeline located downstream of the gas-liquid separator, and the output end (22) thereof is configured to be connected to the input end (21) of another desulfurization tower (2) through a connecting pipeline; In a parallel state, the input ends (21) of the two desulfurization towers (2) are respectively constructed to be connected to a connecting pipeline located downstream of the gas-liquid separator, and the output ends (22) of the two desulfurization towers (2) are respectively constructed to be connected to a downstream connecting pipeline.

7. The natural gas desulfurization system according to claim 6, characterized in that: It also includes a control valve assembly, which is constructed to be arranged on the connecting pipelines at the upstream and downstream positions of the desulfurization tower (2); the two desulfurization towers (2) are configured to switch between a series state and a parallel state through the control of the control valve assembly.

8. The natural gas desulfurization system according to claim 1, characterized in that: It also includes a water inlet pipeline; a water inlet (23) is also provided at the upper position of the desulfurization tower (2); the water inlet pipeline is configured to be connected to the water inlet (23), and is configured to be used for conveying water into the desulfurization tower (2) during the process of replacing the filler in the desulfurization tower (2).

9. The natural gas desulfurization system according to claim 1, characterized in that: The filter (5) is provided in two numbers, and the two filters (5) are configured to be connected in parallel via a connecting pipeline.

10. The natural gas desulfurization system according to claim 1, characterized in that: It also includes a venting pipeline, which is constructed to be connected to the venting port (34) of the gas-liquid separator and the connecting pipeline located upstream of the input end (21) of the desulfurization tower (2).

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