Amine liquid absorption cyclic regeneration system and natural gas production system

Abstract

The embodiment of the utility model provides an amine liquid absorption cyclic regeneration system and a natural gas production system, and relates to the field of natural gas purification. The absorption towers and the regeneration towers are connected in series, and heat source gaseous amine of each regeneration tower sequentially passes through each regeneration tower after entering from the last-stage regeneration tower, so that amine liquid absorbs acid gas and is regenerated more sufficiently, the heights of the absorption towers and the regeneration towers can be remarkably reduced, and the system is simple and convenient to pry and low in cost. And the device is convenient to move and transport, and can flexibly deal with the situation that the gas source position is relatively remote.

Description

Technical Field

[0001] The utility model relates to the field of natural gas purification, and specifically, to an amine solution absorption and circulation regeneration system and a natural gas production system. Background Technique

[0002] In the process of natural gas production, it is necessary to purify and remove impurities from the raw gas, and remove acidic gases (such as CO2, H2S, etc.) in the raw gas through the purification process. The amine method is the most mature and commonly used in the purification process. The amine solution is used to purify the acidic gas in the natural gas. After purification, the content of acidic gas in the natural gas generally needs to be controlled within 100×10 -6 The following is to meet the environmental protection emission standards.

[0003] However, the height of the tower of the traditional natural gas purification device is more than 15m, and it can only be installed at the production site, making relocation and transportation very inconvenient.

[0004] In view of this, this application is proposed. Content of the Utility Model

[0005] The purpose of the utility model is to provide an amine solution absorption and circulation regeneration system and a natural gas production system, aiming to significantly reduce the height of the absorption tower and the regeneration tower, making it easier to skid the system and more convenient for relocation and transportation.

[0006] The embodiments of the utility model can be implemented as follows:

[0007] In the first aspect, the utility model provides an amine solution absorption and circulation regeneration system, including: at least two-stage absorption towers and at least two-stage regeneration towers;

[0008] Each stage of absorption tower is used for countercurrent contact between the amine solution and the raw gas, and each stage of regeneration tower is used for countercurrent contact between the amine liquid and the gaseous amine;

[0009] A raw gas delivery pipeline and a first amine liquid delivery pipeline are arranged between adjacent two-stage absorption towers; the inlet of the raw gas delivery pipeline is communicated with the top of the previous-stage absorption tower, and the outlet of the raw gas delivery pipeline is communicated with the bottom of the next-stage absorption tower, so that the raw gas is input from the bottom of the first-stage absorption tower and then passes through each stage of absorption tower in turn and is output from the top of the last-stage absorption tower; the inlet of the first amine liquid delivery pipeline is communicated with the bottom of the next-stage absorption tower, and the outlet of the first amine liquid delivery pipeline is communicated with the top of the previous-stage absorption tower, so that the amine liquid is input from the top of the last-stage absorption tower and then passes through each stage of absorption tower in turn and is output from the bottom of the first-stage absorption tower;

[0010] A gaseous amine delivery pipeline and a second amine liquid delivery pipeline are provided between adjacent two-stage regeneration towers; the inlet of the gaseous amine delivery pipeline is connected to the top of the subsequent regeneration tower, and the outlet of the gaseous amine delivery pipeline is connected to the bottom of the previous regeneration tower, so that the gaseous amine is input from the bottom of the last regeneration tower and then passes through each regeneration tower in sequence and is output from the top of the first regeneration tower; the inlet of the second amine liquid delivery pipeline is connected to the bottom of the previous regeneration tower, and the outlet of the second amine liquid delivery pipeline is connected to the top of the subsequent regeneration tower, so that the amine liquid containing acid gas output from the bottom of the first absorption tower is input from the top of the first regeneration tower, and after being regenerated by each regeneration tower, it is output from the bottom of the last regeneration tower.

[0011] In an alternative embodiment, a reboiler is further included. The bottom of the last regeneration tower is connected to the inlet of the reboiler, and the outlet of the reboiler is connected to the bottom of the last regeneration tower to provide heat sources for each regeneration tower.

[0012] In an alternative embodiment, a heat exchanger is further included. The heat exchanger has a cold source inlet, a cold source outlet, a heat source inlet, and a heat source outlet. The cold source inlet of the heat exchanger is connected to the bottom of the first absorption tower, the cold source outlet of the heat exchanger is connected to the top of the first regeneration tower, the heat source inlet of the heat exchanger is connected to the bottom of the last regeneration tower, and the heat source outlet of the heat exchanger is connected to the top of the last absorption tower.

[0013] In an alternative embodiment, an amine liquid cooler is provided on the connecting pipeline between the heat source outlet of the heat exchanger and the last absorption tower.

[0014] In an alternative embodiment, a circulation pump is provided on the connecting pipeline between the amine liquid cooler and the heat exchanger.

[0015] In an alternative embodiment, an acid gas cooler and a gas-liquid separator are further included. The top of the first regeneration tower is connected to the inlet of the acid gas cooler, and the outlet of the acid gas cooler is connected to the inlet of the gas-liquid separator.

[0016] In an alternative embodiment, the gas-liquid separator has a bottom liquid outlet and a top gas outlet, and the bottom liquid outlet of the gas-liquid separator is connected to the first regeneration tower.

[0017] In an alternative embodiment, a regeneration pump is provided on each second amine liquid delivery pipeline.

[0018] In an alternative embodiment, an absorption pump is provided on each first amine liquid delivery pipeline.

[0019] In a second aspect, the present utility model further provides a natural gas production system, including the amine liquid absorption and circulation regeneration system in any of the above embodiments.

[0020] Beneficial effects of the embodiments of the present utility model: By connecting the absorption towers of all levels in series and the regeneration towers of all levels in series, and allowing the heat source gaseous amine of each regeneration tower to enter from the last regeneration tower and pass through each regeneration tower in sequence, the absorption of acid gas by the amine solution and the regeneration of the amine solution are completed more fully. This can significantly reduce the tower height of the absorption tower and the regeneration tower, and the system is easily assembled into a skid, facilitating relocation and transportation operations, and can flexibly respond to situations where the gas source locations are relatively remote. Brief Description of the Drawings

[0021] To more clearly illustrate the technical solutions of the embodiments of the present utility model, the accompanying drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present utility model and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a structural diagram of the amine solution absorption and circulation regeneration system provided by the embodiments of the present utility model.

[0023] Reference numerals: 100 - amine solution absorption and circulation regeneration system; 110 - absorption tower; 111 - first-stage absorption tower; 112 - second-stage absorption tower; 113 - third-stage absorption tower; 120 - regeneration tower; 121 - first-stage regeneration tower; 122 - second-stage regeneration tower; 123 - third-stage regeneration tower; 130 - reboiler; 131 - first amine solution pipeline; 132 - raw gas pipeline; 133 - gaseous amine pipeline; 134 - second amine solution pipeline; 140 - heat exchanger; 150 - amine solution cooler; 161 - circulation pump; 162 - regeneration pump; 163 - absorption pump; 170 - acid gas cooler; 180 - gas-liquid separator; 181 - bottom liquid outlet; 182 - top gas outlet. Detailed Embodiments

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Usually, the components of the embodiments of the present utility model described and shown in the accompanying drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present utility model provided in the accompanying drawings is not intended to limit the scope of the claimed present utility model, but merely represents the selected embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present utility model.

[0026] It should be noted that like reference numerals and letters refer to like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0027] In the description of the present utility model, it should be noted that if terms such as "upper", "lower", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship in which the product of the present utility model is habitually placed during use, it is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0028] In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0029] It should be noted that, without conflict, the features in the embodiments of the present utility model can be combined with each other.

[0030] Please refer to Figure 1 , this embodiment provides an amine solution absorption and circulation regeneration system 100, including: at least two-stage absorption towers 110 and at least two-stage regeneration towers 120. Each stage of the absorption tower 110 is used for countercurrent contact between the amine solution and the raw material gas, and each stage of the regeneration tower 120 is used for countercurrent contact between the amine liquid and the gaseous amine. Using at least two absorption towers 110 in series and at least two regeneration towers 120 in series is beneficial to reducing the tower height of the absorption tower 110 and the regeneration tower 120.

[0031] Figure 1 The case of a three-stage absorption tower and a three-stage regeneration tower is shown. The absorption tower 110 includes a first-stage absorption tower 111, a second-stage absorption tower 112, and a third-stage absorption tower 113, and the regeneration tower 120 includes a first-stage regeneration tower 121, a second-stage regeneration tower 122, and a third-stage regeneration tower 123. However, the number of stages of the absorption tower 110 and the regeneration tower 120 is not limited to three, and can be two, or more than three, such as four, five, six, etc., and can be adjusted according to the content of acidic gases (such as CO2, H2S, etc.) in the raw material gas and the gas volume of the raw material gas. When the content of acidic gases in the raw material gas is relatively large, the number of stages can be increased, and when the content of acidic gases in the raw material gas is relatively small, the number of stages can be decreased.

[0032] The raw material gas is input from the bottom of the first-stage absorption tower 111, passes through each stage of the absorption tower in turn. The amine solution and the raw material gas flowing in reverse contact fully in the absorption tower. The acidic components such as CO2 and H2S in the raw material gas are absorbed and enter the liquid phase (amine solution absorption process). The other components that are not absorbed are led out from the top of the last-stage absorption tower, which is the purified gas. To realize the transportation of the raw material gas and the amine solution between each stage of the absorption tower, a raw material gas transportation pipeline 132 and a first amine solution transportation pipeline 131 are provided between adjacent two-stage absorption towers 110. The raw material gas transportation pipeline 132 is used to transport the raw material gas between adjacent two-stage absorption towers 110, and the first amine solution transportation pipeline 131 is used to transport the amine solution between adjacent two-stage absorption towers 110.

[0033] Further, the inlet of the raw material gas transportation pipeline 132 is connected to the top of the previous-stage absorption tower 110, and the outlet of the raw material gas transportation pipeline 132 is connected to the bottom of the next-stage absorption tower 110, so that the raw material gas is input from the bottom of the first-stage absorption tower 111, passes through each stage of the absorption tower 110 in turn, and is output from the top of the last-stage absorption tower 110 to obtain the purified gas.

[0034] Further, the amine solution is input from the top of the last-stage absorption tower 110. The inlet of the first amine solution transportation pipeline 131 is connected to the bottom of the next-stage absorption tower 110, and the outlet of the first amine solution transportation pipeline 131 is connected to the top of the previous-stage absorption tower 110, so that the amine solution is input from the top of the last-stage absorption tower 110, passes through each stage of the absorption tower 110 in turn, and is output from the bottom of the first-stage absorption tower 111. The rich amine solution is obtained. The rich amine solution contains more acidic gases and needs to be regenerated in the regeneration tower 120 and then recycled to the absorption tower 110.

[0035] In some embodiments, an absorption pump 163 is provided on each first amine solution transportation pipeline 131 for transporting the amine solution output from the bottom of the next-stage absorption tower 110 to the top of the previous-stage absorption tower 110.

[0036] The rich amine solution output from the bottom of the first-stage absorption tower 111 enters the regeneration tower 120 for regeneration. The regeneration process passes through each stage of the regeneration tower in turn. In each regeneration tower 120, it contacts and exchanges heat with the high-temperature gaseous amine, so that the acidic gas in the amine solution vaporizes and enters the gaseous amine. To transport the gaseous amine and the amine solution between adjacent two-stage regeneration towers 120, a gaseous amine transportation pipeline 133 and a second amine solution transportation pipeline 134 are provided between adjacent two-stage regeneration towers 120. The gaseous amine transportation pipeline 133 is used to transport the gaseous amine, and the second amine solution transportation pipeline 134 is used to transport the amine solution.

[0037] Further, the inlet of the gaseous amine transfer pipeline 133 is connected to the top of the subsequent regeneration tower 120, and the outlet of the gaseous amine transfer pipeline 133 is connected to the bottom of the previous regeneration tower 120, so that the gaseous amine is input from the bottom of the last regeneration tower 120 and then passes through each regeneration tower in sequence and is output from the top of the first regeneration tower 121, and the gaseous amine containing acidic gas enters the next process.

[0038] Further, the rich amine liquid enters from the first regeneration tower 121. The inlet of the second amine liquid transfer pipeline 134 is connected to the bottom of the previous regeneration tower 120, and the outlet of the second amine liquid transfer pipeline 134 is connected to the top of the subsequent regeneration tower 120. After the amine liquid containing acidic gas output from the bottom of the first absorption tower 111 is input from the top of the first regeneration tower 121, it is regenerated through each regeneration tower and then output from the bottom of the last regeneration tower, and the regenerated lean amine liquid is obtained. The lean amine liquid is used in the absorption tower 110 to absorb acidic gas in the raw material gas.

[0039] In some embodiments, a regeneration pump 162 is provided on each second amine liquid transfer pipeline 134, and the regeneration pump 162 is used to provide power to transfer the amine liquid between two adjacent regeneration towers 120.

[0040] In some embodiments, the amine liquid absorption and circulation regeneration system 100 further includes a reboiler 130. The bottom of the last regeneration tower is connected to the inlet of the reboiler 130, and the outlet of the reboiler 130 is connected to the bottom of the last regeneration tower. A part of the amine liquid output from the bottom of the first-stage regeneration tower is heated by the reboiler 130, and gaseous amine is obtained after gasification, which is used to provide heat source for each regeneration tower 120. Specifically, after the gaseous amine output from the reboiler 130 enters from the bottom of the last regeneration tower, it passes through each regeneration tower in sequence and is output from the top of the first regeneration tower 121.

[0041] In some embodiments, the amine liquid absorption and circulation regeneration system 100 further includes a heat exchanger 140, which is used for heat exchange between the rich amine liquid and the lean amine liquid. The regenerated lean amine liquid is preliminarily cooled, which is beneficial to the absorption operation; the rich amine liquid is preliminarily heated, which is beneficial to the subsequent regeneration.

[0042] Specifically, the heat exchanger 140 has a cold source inlet, a cold source outlet, a heat source inlet, and a heat source outlet. The cold source inlet of the heat exchanger 140 is connected to the bottom of the first absorption tower 111, the cold source outlet of the heat exchanger 140 is connected to the top of the first regeneration tower 121, the heat source inlet of the heat exchanger 140 is connected to the bottom of the last regeneration tower 120, and the heat source outlet of the heat exchanger 140 is connected to the top of the last absorption tower 110. The cold source refers to the rich amine liquid, and the heat source refers to the lean amine liquid. After passing through the heat exchanger 140, the rich amine liquid is heated up and the lean amine liquid is cooled down.

[0043] Further, an amine liquid cooler 150 is provided on the connecting pipeline between the heat source outlet of the heat exchanger 140 and the last-stage absorption tower 110. The lean amine liquid is further cooled by the amine liquid cooler 150 to improve the absorption rate of the acidic gas. The temperature reduction is not limited, for example, it can be about 40°C. To facilitate the transportation of the lean amine liquid, a circulation pump 161 is provided on the connecting pipeline between the amine liquid cooler 150 and the heat exchanger 140. Using the power provided by the circulation pump 161, the lean amine liquid output from the heat exchanger 140 is transported to the amine liquid cooler 150 for further cooling.

[0044] In some embodiments, the amine liquid absorption cycle regeneration system 100 further includes an acid gas cooler 170 and a gas-liquid separator 180. The top of the first-stage regeneration tower 121 is connected to the inlet of the acid gas cooler 170, and the outlet of the acid gas cooler 170 is connected to the inlet of the gas-liquid separator 180. The gaseous amine containing the acidic gas output from the first-stage regeneration tower 121 is cooled by the acid gas cooler 170 and then enters the gas-liquid separator 180 for gas-liquid separation. The amine liquid is output from the bottom liquid outlet 181 of the gas-liquid separator 180 and circulated to the first-stage regeneration tower 121 for reuse; the acidic gas output from the top gas outlet 182 of the gas-liquid separator 180 enters the next process.

[0045] The embodiment of the present utility model provides a method for amine liquid absorption cycle regeneration, which is processed by using the amine liquid absorption cycle regeneration system 100 provided by the embodiment of the present utility model, including an absorption stage and a regeneration stage.

[0046] Absorption stage: The raw material gas is input from the bottom of the first-stage absorption tower 111 and transported between the absorption towers 110 through the raw material gas transportation pipeline 132. The amine solution and the raw material gas are in countercurrent contact using each absorption tower 110 to absorb the acidic gas in the raw material gas, and the purified gas is output from the top of the last-stage absorption tower 110; the regenerated lean amine liquid is input from the top of the last-stage absorption tower 110 and transported between the absorption towers 110 through the first amine liquid transportation pipeline 131, and the rich amine liquid is output from the bottom of the first-stage absorption tower 111. The rich amine liquid rich in acidic gas enters the regeneration stage.

[0047] Regeneration stage: The rich amine liquid and the gaseous amine are in countercurrent contact using each stage of the regeneration tower 120, enabling the acid gas in the rich amine liquid to enter the gaseous amine to achieve the regeneration of the amine liquid. Specifically, the rich amine liquid containing acid gas output from the bottom of the first-stage absorption tower 111 is input from the top of the first-stage regeneration tower 121, and then transported using the second amine liquid delivery pipeline 134. After being regenerated by each stage of the regeneration tower 120, it is output from the bottom of the last-stage regeneration tower and circulated to the absorption stage; after the gaseous amine is input from the bottom of the last-stage regeneration tower, it is transported using the gaseous amine delivery pipeline 133. After passing through each stage of the regeneration tower 120, it is output from the top of the first-stage regeneration tower 121, and the gaseous amine containing acid gas enters the next process.

[0048] In some embodiments, the amine liquid output from the bottom of the last-stage regeneration tower is heated by a reboiler 130 to generate gaseous amine for heating each stage of the regenerator. That is to say, the operating temperature of the last-stage regeneration tower is the highest, and the operating temperature of the first-stage regeneration tower is the lowest.

[0049] In some embodiments, the lean amine liquid output from the bottom of the last-stage regeneration tower and the rich amine liquid output from the bottom of the first-stage absorption tower 111 are heat-exchanged in a heat exchanger 140, cooling the lean amine liquid while heating the rich amine liquid, which is beneficial for the operations of absorption and regeneration and can also improve energy utilization efficiency. The lean amine liquid cooled by the heat exchanger 140 is further cooled by an amine liquid cooler 150 and then input to the bottom of the last-stage absorption tower. The rich amine liquid is heated in the heat exchanger 140 and then enters the first-stage regeneration tower.

[0050] The embodiment of the present invention also provides a natural gas production system, which includes the amine liquid absorption cycle regeneration system in any of the above embodiments, and may also include other conveying devices and impurity removal devices.

[0051] In summary, the embodiment of the present invention provides an amine liquid absorption cycle regeneration system and a natural gas production system. The heights of the first-stage, second-stage, and third-stage absorption towers and regeneration towers used are all within 3.2 m, while the heights of traditional absorption towers and regeneration towers are basically above 15 m. Compared with the traditional type, the technical features of this technology have the advantages of simple device, simple foundation, and convenient skidding, greatly saving costs. In addition, this system also has the advantages of convenient relocation and transportation, and can flexibly handle the situation where the gas source locations are relatively remote.

[0052] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An amine solution absorption and circulation regeneration system, characterized in that, Comprising: At least two-stage absorption towers and at least two-stage regeneration towers; Each stage of the absorption tower is used for countercurrent contact between the amine solution and the feed gas, and each stage of the regeneration tower is used for countercurrent contact between the amine liquid and the gaseous amine; A feed gas pipeline and a first amine liquid pipeline are provided between adjacent two-stage absorption towers; the inlet of the feed gas pipeline is communicated with the top of the previous-stage absorption tower, and the outlet of the feed gas pipeline is communicated with the bottom of the next-stage absorption tower, so that the feed gas is input from the bottom of the first-stage absorption tower and then passes through each stage of the absorption tower in sequence and is output from the top of the last-stage absorption tower; the inlet of the first amine liquid pipeline is communicated with the bottom of the next-stage absorption tower, and the outlet of the first amine liquid pipeline is communicated with the top of the previous-stage absorption tower, so that the amine liquid is input from the top of the last-stage absorption tower and then passes through each stage of the absorption tower in sequence and is output from the bottom of the first-stage absorption tower; A gaseous amine pipeline and a second amine liquid pipeline are provided between adjacent two-stage regeneration towers; the inlet of the gaseous amine pipeline is communicated with the top of the next-stage regeneration tower, and the outlet of the gaseous amine pipeline is communicated with the bottom of the previous-stage regeneration tower, so that the gaseous amine is input from the bottom of the last-stage regeneration tower and then passes through each stage of the regeneration tower in sequence and is output from the top of the first-stage regeneration tower; the inlet of the second amine liquid pipeline is communicated with the bottom of the previous-stage regeneration tower, and the outlet of the second amine liquid pipeline is communicated with the top of the next-stage regeneration tower, so that the amine liquid containing acid gas output from the bottom of the first-stage absorption tower is input from the top of the first-stage regeneration tower, and after being regenerated by each stage of the regeneration tower, it is output from the bottom of the last-stage regeneration tower.

2. The amine solution absorption cycle regeneration system according to claim 1, wherein It further includes a reboiler, the bottom of the last-stage regeneration tower is communicated with the inlet of the reboiler, and the outlet of the reboiler is communicated with the bottom of the last-stage regeneration tower to provide heat source for each stage of the regeneration tower.

3. The amine solution absorption and regeneration system according to claim 1 or 2, characterized in that, It further includes a heat exchanger, the heat exchanger has a cold source inlet, a cold source outlet, a heat source inlet and a heat source outlet, the cold source inlet of the heat exchanger is communicated with the bottom of the first-stage absorption tower, the cold source outlet of the heat exchanger is communicated with the top of the first-stage regeneration tower, the heat source inlet of the heat exchanger is communicated with the bottom of the last-stage regeneration tower, and the heat source outlet of the heat exchanger is communicated with the top of the last-stage absorption tower.

4. The amine solution absorption and circulation regeneration system according to claim 3, characterized in that, An amine liquid cooler is provided on the connecting pipeline between the heat source outlet of the heat exchanger and the last-stage absorption tower.

5. The amine solution absorption and circulation regeneration system according to claim 4, wherein, A circulation pump is provided on the connecting pipeline between the amine liquid cooler and the heat exchanger.

6. The amine solution absorption cycle regeneration system according to claim 1, wherein It further includes an acid gas cooler and a gas-liquid separator, the top of the first-stage regeneration tower is communicated with the inlet of the acid gas cooler, and the outlet of the acid gas cooler is communicated with the inlet of the gas-liquid separator.

7. The amine solution absorption and circulation regeneration system according to claim 6, wherein, The gas-liquid separator has a bottom liquid outlet and a top gas outlet, and the bottom liquid outlet of the gas-liquid separator is communicated with the first-stage regeneration tower.

8. The amine solution absorption cycle regeneration system according to claim 1, characterized in that A regeneration pump is provided on each of the second amine liquid pipelines.

9. The amine liquid absorption cycle regeneration system according to claim 1, characterized in that, An absorption pump is provided on each of the first amine liquid pipelines.

10. A natural gas production system, characterized in that, It includes the amine solution absorption and circulation regeneration system described in any one of claims 1-9.

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