A module and process for ethylene glycol regeneration

Abstract

The application discloses a module for glycol circulation regeneration and a processing method, which comprises glycol rich liquid flash tank skid, glycol lean liquid storage tank skid and glycol heat exchange skid arranged in layers from top to bottom; the glycol rich liquid flash tank skid comprises a glycol rich liquid flash tank and an overhead air cooler; the glycol lean liquid storage tank skid comprises a glycol lean liquid storage tank and an overhead condensate collection tank; the glycol heat exchange skid comprises a glycol regeneration tower, a glycol reboiler, a glycol heat exchanger, a lean glycol cooler, a plurality of glycol injection pumps and a glycol circulation pump, and the glycol regeneration tower penetrates through the module; the glycol circulation regeneration function is realized through reasonable arrangement. The module is compact in arrangement and can meet the operation, maintenance and repair requirements; the module design occupies a small area, and field connection and installation are simple; since the module is prefabricated in a factory, reinstallation operation is carried out on site, field work load is greatly reduced, and the construction period is shortened.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas storage natural gas gathering and treatment technology, in particular to a module for ethylene glycol regeneration and a processing method. BACKGROUND

[0002] The gas produced by condensate gas field contains a large amount of propane, butane, pentane and above hydrocarbons. If the untreated condensate gas enters the long-distance pipeline, it will precipitate condensate oil, which seriously affects the gas transmission efficiency of the long-distance pipeline. It is clearly stipulated in GB17820 "Natural Gas" that there is no liquid water and liquid hydrocarbon in the natural gas under the pressure and temperature conditions of the natural gas delivery point. It is stipulated in GB50251 "Design Specification for Gas Pipeline Engineering" that the hydrocarbon dew point of the gas entering the gas pipeline should be lower than the minimum ambient temperature.

[0003] For raw gas that needs to meet the hydrocarbon and water dew point requirements, low-temperature method is generally used to achieve dehydration and hydrocarbon removal, that is, by reducing the temperature of the raw gas, the water and heavy hydrocarbons in the gas are condensed and aggregated to achieve the effect of gas-liquid separation. The gas field using low-temperature separation process generally uses expansion refrigeration or external cold source refrigeration. At present, most of the high-pressure gas fields in China use alcohol injection to control the hydrocarbon and water dew point.

[0004] The commonly used antifreeze agents are mainly methanol and ethylene glycol. Methanol is generally not recovered, and the loss is large, which is not conducive to environmental protection. Except for emergency situations, large-scale injection is not commonly used. Ethylene glycol can better meet the process requirements, and the device investment is low, simple and practical, and the operation is flexible. Therefore, it is generally recommended to use ethylene glycol injection as an antifreeze agent. In order to use it economically and reasonably for a long time, a regeneration system is arranged for the ethylene glycol solution after dehydration to recover it.

[0005] The traditional ethylene glycol regeneration device has a large occupied area and high investment, and once it is built, the equipment cannot be recycled. Although the traditional ethylene glycol regeneration device can also meet the process requirements of the hydrocarbon and water dew point control of the gas field produced gas, there is still a lot of optimization space from the perspective of saving engineering investment. SUMMARY

[0006] In view of the deficiencies in the prior art, the present application provides a module for ethylene glycol regeneration.

[0007] The present application discloses a module for ethylene glycol regeneration, which comprises an ethylene glycol rich liquid flash tank skid, an ethylene glycol lean liquid storage tank skid and an ethylene glycol heat exchange skid arranged in layers from top to bottom.

[0008] The glycol rich liquid flash tank skid includes a glycol rich liquid flash tank and an overhead air cooler; the glycol lean liquid storage tank skid includes a glycol lean liquid storage tank and an overhead condensate collection tank; the glycol heat exchange skid includes a glycol regenerator, a glycol reboiler, a glycol heat exchanger, a lean glycol cooler, a plurality of glycol injection pumps and a glycol circulation pump, and the glycol regenerator is vertically through the module;

[0009] The glycol rich liquid outlet separated by the hydrocarbon water dew point control unit is connected with the glycol regenerator, the glycol heat exchanger and the glycol rich liquid flash tank in sequence through pipelines; the steam outlet of the glycol rich liquid flash tank is connected with the low pressure vent system or the fuel gas system, and the glycol rich liquid outlet of the glycol rich liquid flash tank is connected with the glycol regenerator, the glycol reboiler and the glycol heat exchanger in sequence through pipelines;

[0010] The glycol lean liquid outlet of the glycol heat exchanger is connected with the lean glycol cooler and the glycol lean liquid storage tank respectively, the lean glycol cooler delivers glycol lean liquid to the glycol injection inlet through a plurality of glycol injection pumps, the glycol lean liquid storage tank outlet is connected with the glycol injection inlet through the glycol circulation pump, the overhead water vapor outlet of the glycol regenerator is connected with the overhead air cooler, and the overhead air cooler is connected with the overhead condensate collection tank for collecting condensate;

[0011] The glycol lean liquid of the lean glycol cooler and the glycol lean liquid storage tank outlet is returned to the hydrocarbon water dew point control unit through the glycol injection inlet.

[0012] As a further improvement of the present application, the glycol rich liquid flash tank skid, the glycol lean liquid storage tank skid and the glycol heat exchange skid are all 15.4m x 3.4m x 3.8m.

[0013] As a further improvement of the present application, the upper part of the steel structure of the glycol heat exchange skid and the glycol lean liquid storage tank skid is reserved with a splicing beam with a length not less than 800mm, and the lower part of the steel structure of the glycol rich liquid flash tank skid and the glycol lean liquid storage tank skid is reserved with a splicing beam with a length not less than 500mm.

[0014] The splicing beams of the steel structures of the glycol rich liquid flash tank skid, the glycol lean liquid storage tank skid and the glycol heat exchange skid are connected through bolts to form the module.

[0015] As a further improvement of the present application, the upper part of the glycol heat exchange skid is reserved with a pipeline interface which is 30mm higher than the top of the skid, and the lower part of the glycol lean liquid storage tank is reserved with a pipeline interface which is 30mm recessed into the glycol heat exchange skid.

[0016] As a further improvement of the present application, the inlet height of the plurality of glycol injection pumps is lower than the outlet height of the glycol heat exchanger.

[0017] As a further improvement of the present application, the plurality of glycol injection pumps comprises a first glycol high-pressure injection pump, a second glycol high-pressure injection pump and a glycol low-pressure injection pump connected in sequence.

[0018] The inlet of the first glycol high-pressure injection pump is connected with the outlet of the lean glycol cooler, and the outlet of the glycol low-pressure injection pump is connected with the glycol injection inlet.

[0019] As a further improvement of the present application, a plurality of electrical junction boxes and instrument junction boxes are further included, and the external interfaces of each of the electrical junction boxes and the instrument junction boxes are cable joints.

[0020] The plurality of electrical junction boxes and instrument junction boxes are respectively arranged on the glycol rich liquid flash tank sled, the glycol lean liquid storage tank sled and the glycol heat exchange sled, so as to realize separate control and power supply of the valve groups and valves on each layer of the glycol rich liquid flash tank sled, the glycol lean liquid storage tank sled and the glycol heat exchange sled.

[0021] The present application further discloses a processing method of a module for glycol circulation regeneration, including normal operation conditions and intermittent operation conditions.

[0022] The normal operation conditions include:

[0023] 1) The glycol rich liquid separated by the hydrocarbon water dew point control unit is sequentially subjected to heat exchange with the glycol lean liquid in the glycol heat exchanger and the water vapor at the top of the glycol regeneration tower, and then enters the glycol rich liquid flash tank.

[0024] 2) The gas phase flashed out of the glycol rich liquid flash tank is selected to go to a low-pressure venting system or a fuel gas system according to needs; and the glycol rich aqueous solution of the glycol rich liquid flash tank is again returned to the glycol regeneration tower.

[0025] 3) The water vapor at the top of the glycol regeneration tower is condensed after passing through the overhead air cooler, and then enters the overhead condensate collection tank, and is regularly discharged to a blowdown system; and the glycol lean liquid at the bottom of the glycol regeneration tower enters the glycol reboiler, and the glycol lean liquid treated by the glycol reboiler is again flowed into the glycol heat exchanger for further cooling.

[0026] 4) After being cooled by the ethylene glycol heat exchanger, the lean ethylene glycol solution enters the lean ethylene glycol cooler for further cooling. The lean ethylene glycol solution cooled by the lean ethylene glycol cooler can be directly transported to the lean ethylene glycol storage tank for storage by the ethylene glycol circulation pump, or it can be pressurized by multiple ethylene glycol injection pumps and input into the ethylene glycol injection port. The solution then flows back to the hydrocarbon water dew point control unit through the ethylene glycol injection port, and is atomized and recycled by the hydrocarbon water dew point control unit.

[0027] As a further improvement of the present invention, the intermittent operation condition includes:

[0028] 1) The ethylene glycol lean solution in the ethylene glycol lean solution storage tank is pressurized by multiple ethylene glycol injection pumps and then transported to the ethylene glycol injection port. The ethylene glycol rich solution separated by the light hydrocarbon separator and the low-pressure gas-low temperature separator in the low-pressure oil-gas-water unit is fed into the ethylene glycol rich solution flash tank for storage through the ethylene glycol regeneration tower bypass.

[0029] 2) When the ethylene glycol rich liquid in the ethylene glycol rich liquid flash tank is full, repeat steps three and four in the normal operating condition to process the ethylene glycol rich liquid, and input the processed qualified ethylene glycol lean liquid into the ethylene glycol lean liquid storage tank. The ethylene glycol lean liquid storage tank is pressurized by multiple ethylene glycol injection pumps and then input into the ethylene glycol injection port.

[0030] As a further improvement of the present invention, under intermittent operation conditions, the plurality of the ethylene glycol injection pumps are in a continuous operation state, while the ethylene glycol regeneration tower is in an intermittent operation state.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] This invention employs a modular design, featuring skids for a rich ethylene glycol flash tank, a lean ethylene glycol storage tank, and an ethylene glycol heat exchanger. This design offers high integration, comprehensive functionality, and factory prefabrication capabilities. It is compact, easy to install and transport, and occupies a small area, saving investment while significantly reducing construction time and on-site construction work.

[0033] This invention is easy to manage and relocate, has a high reuse rate, and can be repeatedly moved and used in multiple locations. It is suitable for both newly built gas storage facilities and the renovation of existing gas storage facilities, and has a wide range of applications. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the module and processing method for ethylene glycol recycling disclosed in this invention;

[0035] Figure 2 for Figure 1 A schematic diagram of the structure of the ethylene glycol heat exchanger skid in the diagram;

[0036] Figure 3 forFigure 1 A schematic diagram of the structure of the ethylene glycol lean liquor storage tank skid in the diagram;

[0037] Figure 4 for Figure 1 A schematic diagram of the structure of the ethylene glycol rich liquid flash tank skid.

[0038] In the picture:

[0039] 1. External pipe interface; 2. Pipe interface between skids; 3. Ethylene glycol regeneration tower; 4. Tower top condensate collection tank; 5. Electrical junction box; 6. Instrument junction box; 7. Lean ethylene glycol storage tank; 8. Ethylene glycol low-pressure injection pump; 9. Ethylene glycol high-pressure injection pump; 10. Ethylene glycol reboiler; 11. Ethylene glycol heat exchanger; 12. Ethylene glycol circulating pump; 13. Lean ethylene glycol cooler; 14. Valve assembly before the low-pressure ethylene glycol injection pump; 15. Valve assembly after the low-pressure ethylene glycol injection pump; 16. Ethylene glycol 17. High-pressure injection pump pre-valve assembly; 18. Ethylene glycol high-pressure injection pump post-valve assembly; 19. Ethylene glycol circulating pump pre-valve assembly; 20. First safety vent valve assembly; 21. Ethylene glycol rich flash tank; 22. Ethylene glycol rich vent regulating valve assembly; 23. Tower top air cooler; 24. Second safety vent valve assembly; 25. Ethylene glycol rich flash tank regulating valve assembly; 26. Third safety vent valve assembly; 27. Ethylene glycol rich flash tank skid; 28. Ethylene glycol lean storage tank skid; 29. ​​Ethylene glycol heat exchange skid. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] The present invention will now be described in further detail with reference to the accompanying drawings:

[0044] like Figure 1 As shown, this invention discloses a module for ethylene glycol recycling and regeneration. The module includes an ethylene glycol rich flash tank skid 26, an ethylene glycol lean storage tank skid 27, and an ethylene glycol heat exchange skid 28, arranged in upper and lower layers. The ethylene glycol rich flash tank skid 26 includes an ethylene glycol rich flash tank 20 and a tower top air cooler 22; the ethylene glycol lean storage tank skid 27 includes an ethylene glycol lean storage tank 7 and a tower top condensate collection tank 4; the ethylene glycol heat exchange skid 28 includes ethylene glycol... The system includes an alcohol regeneration tower 3, an ethylene glycol reboiler 10, an ethylene glycol heat exchanger 11, a lean ethylene glycol cooler 13, multiple ethylene glycol injection pumps, and an ethylene glycol circulation pump 12. The ethylene glycol regeneration tower 3 is a through-module. The ethylene glycol rich liquid outlet, separated by the hydrocarbon dew point control unit, is connected sequentially to the ethylene glycol regeneration tower 3, the ethylene glycol heat exchanger 11, and the ethylene glycol rich liquid flash tank 20 via pipelines. The steam outlet of the ethylene glycol rich liquid flash tank 20 is connected to a low-pressure venting system. The system is connected to the fuel gas system; the outlet of the ethylene glycol-rich flash tank 20 is connected via pipeline to the ethylene glycol regeneration tower 3, the ethylene glycol reboiler 10, and the ethylene glycol heat exchanger 11 in sequence; the outlet of the ethylene glycol lean liquid of the ethylene glycol heat exchanger 11 is connected to the lean ethylene glycol cooler 13 and the lean ethylene glycol storage tank 7, respectively. The lean ethylene glycol storage tank 7 is used to store lean ethylene glycol, and the lean ethylene glycol cooler 13 delivers lean ethylene glycol through multiple ethylene glycol injection pumps. The solution is delivered to the ethylene glycol injection port; the outlet of the ethylene glycol lean storage tank 7 is connected to the ethylene glycol injection port via the ethylene glycol circulation pump 12; the steam outlet at the top of the ethylene glycol regeneration tower 3 is connected to the top air cooler 22, which is connected to the top condensate collection tank 4, which is used to collect condensate; the lean ethylene glycol from the outlets of the lean ethylene glycol cooler 13 and the lean ethylene glycol storage tank 7 is returned to the hydrocarbon dew point control unit via the ethylene glycol injection port. The low-pressure venting system or fuel gas system in this invention are existing designs and will not be described in detail here.

[0045] This invention employs a modular design, featuring a skid block 26 for a rich ethylene glycol flash tank, a skid block 27 for a lean ethylene glycol storage tank, and a skid block 28 for an ethylene glycol heat exchanger. This design achieves high integration, comprehensive functionality, and factory prefabrication, resulting in a compact structure that is easy to install and transport, occupies a small area, and saves investment while significantly reducing construction time and on-site work. Furthermore, this invention offers convenient project management, is easy to relocate, and has a high reusability rate, allowing for repeated relocation and use in multiple locations. It is suitable for both newly built gas storage facilities and the renovation of existing facilities, demonstrating a wide range of applicability.

[0046] Specifically:

[0047] Furthermore, the ethylene glycol rich flash tank skid 26, the ethylene glycol lean storage tank skid 27, and the ethylene glycol heat exchange skid 28 in this invention are all 15.4m × 3.4m × 3.8m, which meets the Class B requirements for automobile transportation.

[0048] like Figures 2-4 As shown, the upper part of the steel structure of the ethylene glycol heat exchange skid 28 and the ethylene glycol lean storage tank skid 27 in this invention is reserved with a splicing beam with a length of not less than 800 mm. Preferably, the length of the splicing beam at the upper part of the steel structure of the ethylene glycol heat exchange skid 28 and the ethylene glycol lean storage tank skid 27 is 800 mm. The lower part of the steel structure of the ethylene glycol rich flash evaporator skid 26 and the ethylene glycol lean storage tank skid 27 is reserved with a splicing beam with a length of not less than 500 mm. Preferably, the length of the splicing beam at the lower part of the steel structure of the ethylene glycol rich flash evaporator skid 26 and the ethylene glycol lean storage tank skid 27 is 500 mm. The splicing beams of the steel structure of the ethylene glycol rich flash evaporator skid 26, the ethylene glycol lean storage tank skid 27, and the ethylene glycol heat exchange skid 28 are connected vertically by high-strength bolts, thus forming a module.

[0049] Furthermore, to facilitate hoisting and installation, the present invention provides lifting lugs on the upper part of the steel structure of the ethylene glycol lean liquid storage tank skid 27.

[0050] Furthermore, the inter-skid pipe interface 2 reserved on the upper part of the ethylene glycol heat exchange skid 28 and the inter-skid pipe interface 2 of the ethylene glycol lean liquid storage tank skid 27 are both 30mm higher than the skid top. The inter-skid pipe interface 2 at the lower part of the ethylene glycol lean liquid storage tank skid 27 and the inter-skid pipe interface 2 of the ethylene glycol heat exchange skid 28 are recessed by 30mm, so that the damage to the pipeline can be minimized during transportation and storage.

[0051] Furthermore, the plurality of ethylene glycol injection pumps in this invention include a plurality of high-pressure ethylene glycol injection pumps 9 and a low-pressure ethylene glycol injection pump 8 connected in sequence. The plurality of first high-pressure ethylene glycol injection pumps 9 in this invention include a first high-pressure ethylene glycol injection pump and a second high-pressure ethylene glycol injection pump. The first high-pressure ethylene glycol injection pump, the second high-pressure ethylene glycol injection pump and the low-pressure ethylene glycol injection pump 8 are all installed on the ethylene glycol heat exchange skid 28, and the first high-pressure ethylene glycol injection pump is connected to the outlet of the lean ethylene glycol cooler 13, and the outlet of the low-pressure ethylene glycol injection pump 8 is connected to the ethylene glycol injection port.

[0052] Furthermore, in this invention, the first and second high-pressure ethylene glycol injection pumps are equipped with a pre-pump valve group 16 and a post-pump valve group 17, respectively. The low-pressure ethylene glycol injection pump 8 is equipped with a pre-pump valve group 14 and a post-pump valve group 15. The pre-pump valve group 16, post-pump valve group 17, pre-pump valve group 14, and post-pump valve group 15 are all existing designs and will not be described in detail here. Considering the net positive suction head (NPSH) of the ethylene glycol injection pumps, the inlet height of the multiple ethylene glycol injection pumps in this invention is lower than the outlet height of the ethylene glycol heat exchanger 11. Therefore, the multiple ethylene glycol injection pumps are mounted on the ethylene glycol heat exchange skid 28 and positioned below the ethylene glycol heat exchanger 11.

[0053] Furthermore, the present invention provides a first safety vent valve group 19 on the ethylene glycol rich flash tank 20, a second safety vent valve group 23 on the steam outlet pipeline at the top of the ethylene glycol regeneration tower 3, and a third safety vent valve group 25 on the pipeline above the condensate collection tank 4 at the top of the tower. The first safety vent valve group 19, the second safety vent valve group 23, and the third safety vent valve group 25 are all existing designs and will not be described in detail here. The design of the first safety vent valve group 19, the second safety vent valve group 23, and the third safety vent valve group 25 enables the discharge of residual waste gas in the pipeline when the equipment is shut down.

[0054] Furthermore, the present invention also provides an ethylene glycol rich liquid flash tank regulating valve group 24 on the outlet pipe of the ethylene glycol rich liquid flash tank 20, which is used to regulate the outflow rate of the ethylene glycol rich liquid in the ethylene glycol rich liquid flash tank 20.

[0055] Furthermore, the present invention also includes multiple electrical junction boxes 5 and instrument junction boxes 6, each of which has a cable connector as its external interface. The multiple electrical junction boxes 5 and instrument junction boxes 6 are respectively installed on the ethylene glycol rich flash tank skid 26, the ethylene glycol lean storage tank skid 27, and the ethylene glycol heat exchange skid 28, so as to realize individual control and power supply for the valve groups, pumps and valves on each layer of the ethylene glycol rich flash tank skid 26, the ethylene glycol lean storage tank skid 27 and the ethylene glycol heat exchange skid 28.

[0056] Furthermore, the hydrocarbon dew point control unit in this invention uses a low-temperature method, employing ethylene glycol as a refrigerant, to dehydrate and dehydrocarbonize the raw gas. Since ethylene glycol adsorbs a large amount of water when participating in the reaction as a refrigerant, the ethylene glycol regenerated in this module comes from the hydrocarbon dew point control unit. After the ethylene glycol is purified by this module, it is transported back to the hydrocarbon dew point control unit for recycling. The hydrocarbon dew point control unit in this invention is an existing design and will not be described in detail here.

[0057] Furthermore, the modular design in this invention adopts a unified PDMS 3D design platform with an independent database structure. Equipment, piping, structure, electrical, and instrumentation disciplines can conduct collaborative design, with full inter-disciplinary linkage and full-scale 3D solid modeling. Moreover, the design modeling is performed in a WYSIWYG manner, with unified design standards, which is the fundamental guarantee for highly integrated modular design.

[0058] Furthermore, the modules in this invention are prefabricated in the factory and reassembled on-site, which greatly reduces the amount of on-site work and shortens the construction cycle.

[0059] Furthermore, when the mixture of ethylene glycol and water enters the ethylene glycol regeneration tower 3 for separation, ethylene glycol, being heavier than water, flows downwards while the vapor rises. Therefore, in this invention, the ethylene glycol heat exchange skid 28, composed of the ethylene glycol reboiler 10 and the ethylene glycol heat exchanger 11, is placed at the bottom of the module. Since the function of the top air cooler 22 is to cool the vapor exiting from the upper part of the ethylene glycol regeneration tower 3, allowing the cooled liquid to flow by gravity into the top condensate collection tank 4, and since this flow is primarily by gravity, the top air cooler 22 needs to be higher than the top condensate collection tank 4. Therefore, the top air cooler 22 is placed on the ethylene glycol rich flash tank skid 26. In this invention, the placement of the ethylene glycol rich flash tank 20 and the ethylene glycol lean storage tank 7 can be adjusted by moving the skids upwards and downwards as needed.

[0060] This invention also discloses a processing method for a module used in ethylene glycol recycling, including normal operation and intermittent operation; specifically:

[0061] Normal operating conditions include:

[0062] 1) The ethylene glycol rich liquid separated by the hydrocarbon dew point control unit is exchanged with the water vapor at the top of the ethylene glycol regeneration tower 3 and the ethylene glycol lean liquid in the ethylene glycol heat exchanger 11 through the external pipeline interface 1, and then enters the ethylene glycol rich liquid flash tank 20.

[0063] 2) The gas phase flashed out of the ethylene glycol rich flash tank 20 is sent to the low-pressure venting system or the fuel gas system as needed; the ethylene glycol rich aqueous solution of the ethylene glycol rich flash tank 20 is returned to the ethylene glycol regeneration tower 3.

[0064] 3) The water vapor at the top of the ethylene glycol regeneration tower 3 is condensed by the top air cooler 22 and enters the top condensate collection tank 4, which is periodically discharged to the sewage system. The lean ethylene glycol solution at the bottom of the ethylene glycol regeneration tower 3 enters the ethylene glycol reboiler 10. After being treated by the ethylene glycol reboiler 10, the lean ethylene glycol solution flows back into the ethylene glycol heat exchanger 11 for further cooling.

[0065] 4) The lean ethylene glycol solution cooled by the ethylene glycol heat exchanger 11 enters the lean ethylene glycol cooler 13 for further cooling. The lean ethylene glycol solution cooled by the lean ethylene glycol cooler 13 can be directly transported to the lean ethylene glycol storage tank 7 for storage by the ethylene glycol circulation pump 12, or it can be pressurized by multiple ethylene glycol injection pumps and input into the ethylene glycol injection port. It then flows back to the hydrocarbon water dew point control unit through the ethylene glycol injection port, and is atomized by the ethylene glycol injector in the hydrocarbon water dew point control unit for recycling.

[0066] Furthermore, the intermittent operation conditions of the present invention include:

[0067] 1) The ethylene glycol lean solution in the ethylene glycol lean solution storage tank 7 is pressurized by multiple ethylene glycol injection pumps and then transported to the ethylene glycol injection port. The ethylene glycol rich solution separated by the light hydrocarbon separator and the low-pressure gas-low temperature separator in the low-pressure oil-gas-water unit is input to the ethylene glycol rich solution flash tank 20 through the bypass of the ethylene glycol regeneration tower 3 via the external pipeline interface 1.

[0068] 2) When the ethylene glycol rich liquid in the ethylene glycol rich liquid flash tank 20 is full, repeat steps three and four in the normal operation condition to process the ethylene glycol rich liquid, and input the qualified ethylene glycol lean liquid after processing into the ethylene glycol lean liquid storage tank 7. The ethylene glycol lean liquid storage tank 7 is pressurized by multiple ethylene glycol injection pumps and then input into the ethylene glycol injection port.

[0069] Furthermore, in the intermittent operation mode of this invention, multiple ethylene glycol injection pumps are in a continuous operating state, while the ethylene glycol regeneration tower 3 is in an intermittent operating state. That is, steps three and four of the normal operation mode will only be repeated when the ethylene glycol rich liquid in the ethylene glycol rich liquid flash tank 20 is full. When the ethylene glycol rich liquid in the ethylene glycol rich liquid flash tank 20 is not full, steps three and four of the normal operation mode will not be performed, thereby achieving intermittent operation mode and achieving the effect of energy saving and efficiency improvement.

[0070] Furthermore, the light hydrocarbon separator and the low-pressure gas cryogenic separator in the low-pressure oil and gas device of the present invention are existing designs and will not be described in detail here.

[0071] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A module for the recycling and regeneration of ethylene glycol, characterized in that, The module includes a skid block for a rich ethylene glycol flash tank, a skid block for a lean ethylene glycol storage tank, and a skid block for an ethylene glycol heat exchanger, arranged in upper and lower layers. The ethylene glycol rich flash tank skid includes an ethylene glycol rich flash tank and a tower top air cooler; the ethylene glycol lean storage tank skid includes an ethylene glycol lean storage tank and a tower top condensate collection tank; the ethylene glycol heat exchange skid includes an ethylene glycol regeneration tower, an ethylene glycol reboiler, an ethylene glycol heat exchanger, a lean ethylene glycol cooler, multiple ethylene glycol injection pumps and an ethylene glycol circulation pump, with the ethylene glycol regeneration tower running vertically through the entire module; The ethylene glycol-rich liquid outlet, separated by the hydrocarbon dew point control unit, is connected in sequence via pipelines to the ethylene glycol regeneration tower, the ethylene glycol heat exchanger, and the ethylene glycol-rich liquid flash tank. The steam outlet of the ethylene glycol-rich liquid flash tank is connected to a low-pressure venting system or a fuel gas system. The ethylene glycol-rich aqueous solution outlet of the ethylene glycol-rich liquid flash tank is connected in sequence via pipelines to the ethylene glycol regeneration tower, the ethylene glycol reboiler, and the ethylene glycol heat exchanger. The ethylene glycol lean liquor outlet of the ethylene glycol heat exchanger is connected to the lean ethylene glycol cooler and the lean ethylene glycol storage tank, respectively. The lean ethylene glycol cooler delivers lean ethylene glycol to the ethylene glycol injection port through multiple ethylene glycol injection pumps. The outlet of the lean ethylene glycol storage tank is connected to the ethylene glycol injection port through the ethylene glycol circulation pump. The steam outlet at the top of the ethylene glycol regeneration tower is connected to the top air cooler, which is connected to the top condensate collection tank for collecting condensate. The lean ethylene glycol from the outlets of the lean ethylene glycol cooler and the lean ethylene glycol storage tank flows back to the hydrocarbon dew point control unit through the ethylene glycol injection port.

2. The module for ethylene glycol recycling and regeneration according to claim 1, characterized in that, The ethylene glycol rich liquid flash tank skid, the ethylene glycol lean liquid storage tank skid, and the ethylene glycol heat exchange skid are all 15.4m × 3.4m × 3.8m.

3. The module for ethylene glycol recycling according to claim 2, characterized in that, The upper part of the steel structure of the ethylene glycol heat exchange skid and the ethylene glycol lean liquid storage tank skid is reserved with a splicing beam with a length of not less than 800 mm, and the lower part of the steel structure of the ethylene glycol rich liquid flash tank skid and the ethylene glycol lean liquid storage tank skid is reserved with a splicing beam with a length of not less than 500 mm. The steel structure splicing beams of the ethylene glycol rich liquid flash tank skid, the ethylene glycol lean liquid storage tank skid, and the ethylene glycol heat exchange skid are connected by bolts to form the module.

4. The module for ethylene glycol recycling according to claim 1, characterized in that, The reserved pipe interface on the upper part of the ethylene glycol heat exchange skid and the pipe interface on the ethylene glycol lean liquid storage tank skid are both 30mm higher than the skid top, and the pipe interface on the lower part of the ethylene glycol lean liquid storage tank skid and the pipe interface on the ethylene glycol heat exchange skid are recessed by 30mm.

5. The module for ethylene glycol recycling according to claim 1, characterized in that, The inlet height of the plurality of the ethylene glycol injection pumps is lower than the outlet height of the ethylene glycol heat exchanger.

6. The module for ethylene glycol recycling according to claim 5, characterized in that, The plurality of ethylene glycol injection pumps include a first ethylene glycol high-pressure injection pump, a second ethylene glycol high-pressure injection pump, and an ethylene glycol low-pressure injection pump connected in sequence; The inlet of the first high-pressure ethylene glycol injection pump is connected to the outlet of the lean ethylene glycol cooler, and the outlet of the low-pressure ethylene glycol injection pump is connected to the ethylene glycol injection port.

7. The module for ethylene glycol recycling according to claim 1, characterized in that, It also includes multiple electrical junction boxes and instrument junction boxes, each of which has a cable connector as its external interface; Multiple electrical junction boxes and instrument junction boxes are respectively installed on the ethylene glycol rich flash tank skid, the ethylene glycol lean storage tank skid, and the ethylene glycol heat exchange skid, so as to realize individual control and power supply of valve groups and valves on each layer of the ethylene glycol rich flash tank skid, the ethylene glycol lean storage tank skid, and the ethylene glycol heat exchange skid.

8. A processing method based on the module for ethylene glycol recycling as described in claim 1, characterized in that, This includes normal operating conditions and intermittent operating conditions; The normal operating conditions include: 1) The ethylene glycol rich liquid separated by the hydrocarbon dew point control unit exchanges heat with the water vapor at the top of the ethylene glycol regeneration tower and the ethylene glycol lean liquid in the ethylene glycol heat exchanger in sequence before entering the ethylene glycol rich liquid flash tank. 2) The gas phase flashed out of the ethylene glycol rich flash tank is sent to the low-pressure venting system or the fuel gas system as needed; the ethylene glycol rich aqueous solution in the ethylene glycol rich flash tank is refluxed back to the ethylene glycol regeneration tower. 3) The water vapor at the top of the ethylene glycol regeneration tower is condensed by the air cooler at the top of the tower and enters the condensate collection tank at the top of the tower. It is periodically discharged to the sewage system. The lean ethylene glycol solution at the bottom of the ethylene glycol regeneration tower enters the ethylene glycol reboiler. After being treated by the ethylene glycol reboiler, the lean ethylene glycol solution flows back into the ethylene glycol heat exchanger for further cooling. 4) After being cooled by the ethylene glycol heat exchanger, the lean ethylene glycol solution enters the lean ethylene glycol cooler for further cooling. The lean ethylene glycol solution cooled by the lean ethylene glycol cooler can be directly transported to the lean ethylene glycol storage tank for storage by the ethylene glycol circulation pump, or it can be pressurized by multiple ethylene glycol injection pumps and input into the ethylene glycol injection port. The solution then flows back to the hydrocarbon water dew point control unit through the ethylene glycol injection port, and is atomized and recycled by the hydrocarbon water dew point control unit.

9. The processing method for the module used for ethylene glycol recycling according to claim 8, characterized in that, The intermittent operation conditions include: 1) The ethylene glycol lean solution in the ethylene glycol lean solution storage tank is pressurized by multiple ethylene glycol injection pumps and then transported to the ethylene glycol injection port. The ethylene glycol rich solution separated by the light hydrocarbon separator and the low-pressure gas-low temperature separator in the low-pressure oil-gas-water unit is fed into the ethylene glycol rich solution flash tank for storage through the ethylene glycol regeneration tower bypass. 2) When the ethylene glycol rich liquid in the ethylene glycol rich liquid flash tank is full, repeat steps three and four in the normal operating condition to process the ethylene glycol rich liquid, and input the processed qualified ethylene glycol lean liquid into the ethylene glycol lean liquid storage tank. The ethylene glycol lean liquid storage tank is pressurized by multiple ethylene glycol injection pumps and then input into the ethylene glycol injection port.

10. The processing method for the module used for ethylene glycol recycling according to claim 8, characterized in that, Under intermittent operation conditions, multiple ethylene glycol injection pumps are in continuous operation, while the ethylene glycol regeneration tower is in intermittent operation.

Images