Small-sized natural gas deacidification device

Abstract

The utility model discloses a small-sized natural gas deacidification device. A first output end of a gas-gas heat exchanger is communicated with a first input end of an absorption tower; the first output end of the absorption tower is communicated with the second input end of the gas-gas heat exchanger; the second output end of the absorption tower is communicated with the first input end of the rich and lean liquid heat exchanger; the first output end of the rich and lean liquid heat exchanger is communicated with the regeneration tower; the first output end of the regeneration tower is communicated with the acid gas cooler, and the second output end of the regeneration tower is communicated with the second input end of the rich and lean liquid heat exchanger; the acid gas cooler is communicated with the input end of the acid gas separator; a second output end of the acid gas separator is communicated with the amine liquid circulating pump; the amine liquid circulating pump is communicated with the input end of the barren liquor cooler; the output end of the barren liquor cooler is communicated with the second input end of the absorption tower; the second output end of the lean and rich liquid heat exchanger is communicated with a path from the acid gas separator to the amine liquid circulating pump, so that the requirements of external heating and cooling equipment are reduced, and the miniaturization and cost reduction of the device are realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of natural gas, in particular to a small natural gas deacidification device. BACKGROUND

[0002] Natural gas must be treated to remove acid gas during transportation and use. With the gradual improvement of national environmental awareness, in order to reduce the impact of acid gas on the environment and society, the deacidification and desulfurization process is becoming more and more important.

[0003] The common deacidification method in the prior art is chemical absorption method, which principle is to use alkaline solvent to absorb acid gas (H2S and CO2) through reversible chemical reaction. After heating, the reaction is reversed to realize solvent regeneration. For example, amine solution (such as MDEA, MEA) generates amine salt through reversible reaction of weak alkaline amino and acid gas (H2S, CO2), realizing efficient removal. The absorption reaction is carried out at low temperature and high pressure, and the regeneration process releases acid gas by decomposing amine salt through heating (105-120℃). However, in the process of using amine solution (MDEA, MEA) to deacidify acid gas in natural gas, in order to realize the regeneration of amine solution, heating is needed to decompose amine salt. Therefore, additional heating device needs to be set, and the liquefied device needs to be further cooled after heating, which increases the floor area and investment cost.

[0004] Therefore, there is an urgent need for a small natural gas deacidification device to solve the above problems. CONTENT OF THE INVENTION

[0005] The embodiment of the present application provides a small natural gas deacidification device, which aims to reduce the equipment installation space of natural gas deacidification and reduce the investment cost.

[0006] In order to achieve the above purpose, the present application provides the following technical scheme:

[0007] A small natural gas deacidification device, comprising a gas-gas heat exchanger, an absorption tower, a lean-rich liquid heat exchanger, a regeneration tower, an acid gas cooler, an acid gas separator, an amine liquid circulating pump and a lean liquid cooler;

[0008] The first input end of the gas-gas heat exchanger is in communication with the output end of the external raw material supply, and the first output end of the gas-gas heat exchanger is in communication with the first input end of the absorption tower;

[0009] The first output end of the absorption tower is in communication with the second input end of the gas-gas heat exchanger, and the second output end of the gas-gas heat exchanger is in communication with the outside for discharging the purified external raw material, and the second output end of the absorption tower is in communication with the first input end of the lean-rich liquid heat exchanger;

[0010] The first output end of the lean-rich liquid heat exchanger is in communication with the input end of the regeneration tower;

[0011] The first output end of the regeneration tower is communicated with the input end of the acid gas cooler, and the second output end of the regeneration tower is communicated with the second input end of the lean-rich liquid heat exchanger;

[0012] The output end of the acid gas cooler is communicated with the input end of the acid gas separator;

[0013] The first output end of the acid gas separator is communicated with the input end of the external high point vent for discharging carbon dioxide, and the second output end of the acid gas separator is communicated with the input end of the amine liquid circulating pump;

[0014] The output end of the amine liquid circulating pump is communicated with the input end of the lean liquid cooler;

[0015] The output end of the lean liquid cooler is communicated with the second input end of the absorption tower;

[0016] The second output end of the lean-rich liquid heat exchanger is communicated on the path of the acid gas separator to the amine liquid circulating pump.

[0017] Further, a filtering unit is further included, the input end of the filtering unit is communicated with the second output end of the absorption tower, and the output end of the filtering unit is communicated with the first input end of the lean-rich liquid heat exchanger.

[0018] Further, the filtering unit includes a solution filter and a mechanical filter;

[0019] The input end of the solution filter is communicated with the second output end of the absorption tower, and the output end thereof is communicated with the input end of the mechanical filter for removing suspended impurities in the deacidification solution;

[0020] The output end of the mechanical filter is communicated with the first input end of the lean-rich liquid heat exchanger for filtering mechanical impurities of the external raw material.

[0021] Further, the mechanical filter includes a casing, a first filter plate, a second filter plate and a filter layer;

[0022] The casing is hollow inside, and a first through hole for being communicated with the output end of the solution filter and a second through hole for being communicated with the first input end of the lean-rich liquid heat exchanger are through both ends of the casing along the axial length direction thereof;

[0023] The first filter plate in the cylindrical structure is rotationally arranged inside the casing close to one side of the first through hole, the barrel mouth of the first filter plate faces the first through hole, and a plurality of third through holes are arranged on the barrel bottom of the first filter plate;

[0024] The second filter plate is fixedly arranged inside the shell near one side of the second through hole, and a plurality of fourth through holes are arranged on the plate surface of the second filter plate, and the hole cores of the plurality of fourth through holes are arranged alternately with the hole cores of the plurality of third through holes.

[0025] The filter layer is arranged inside the shell near one side of the second through hole and is arranged spaced apart from the second filter plate.

[0026] The material arrangement of the filter layer from the first through hole to the second through hole is stainless steel mesh, polyester fiber and ceramic in sequence.

[0027] Further, the inner wall of the shell is recessed with a sliding groove, the peripheral part of the cylinder bottom of the first filter plate is provided with a connecting ring, the peripheral part of the connecting ring is in sliding contact with the inner wall of the sliding groove, and the inner diameter of the connecting ring is consistent with the outer diameter of the first filter plate.

[0028] Further, the inner part of the first filter plate is annularly arranged with a plurality of baffles along the axis, one end of the plurality of baffles is fixedly connected with the cylinder bottom of the first filter plate and is adjacent to the third through hole, and the other end of the plurality of baffles extends to the cylinder port of the first filter plate.

[0029] Further, the second output end of the absorption tower and the input end of the solution filter are provided with a rich amine liquid regulating valve for controlling the flow of rich amine liquid.

[0030] Further, the acid gas separator is provided with an acid gas regulating valve for adjusting the release rate of acid gas on the path leading to the external high point vent, and the second output end of the acid gas separator is provided with a condensate regulating valve for adjusting the condensate supply flow on the path leading to the amine liquid circulating pump.

[0031] Further, the regenerator is fixedly provided with an electric heater near one side of the second output end for heating the internal environment of the regenerator.

[0032] The one or more technical solutions provided in the embodiment of the utility model have at least the following technical effects or advantages:

[0033] The gas-gas heat exchanger in the application exchanges heat between external raw materials and purified gas output by the absorption tower, preheats the raw material gas by using the waste heat of the purified gas, and reduces the heating load of the regeneration tower; the absorption tower processes the preheated raw material gas and the regenerated amine liquid supplied by the lean-liquid cooler through two-stage input, realizes acid gas absorption and amine liquid circulation; the lean-liquid-rich-liquid heat exchanger exchanges heat between the rich-amine liquid output by the absorption tower and the high-temperature lean-amine liquid output by the regeneration tower, preheats the rich-amine liquid by using the waste heat of the lean-amine liquid, and reduces the energy consumption of the regeneration tower; the regeneration tower is connected with the acid gas cooler and the lean-liquid-rich-liquid heat exchanger through two-stage output, realizes acid gas separation and lean-amine liquid waste heat recovery; the acid gas cooler and the acid gas separator cooperate to complete acid gas condensation and gas-liquid separation, and the amine liquid circulating pump and the lean-liquid cooler form a closed loop circuit, so that the regenerated amine liquid can be ensured to be cooled and then fed back to the absorption tower. Through the multi-stage heat recovery design of the gas-gas heat exchanger, the lean-liquid-rich-liquid heat exchanger and the regeneration tower, the requirement for external heating and cooling equipment is reduced, so that the device is miniaturized and the cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the description of the embodiments of the present application or the prior art. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0035] Fig. 1 The structural schematic diagram provided for the embodiments of the application;

[0036] Fig. 2 The structural schematic diagram of the mechanical filter provided for the embodiments of the application;

[0037] Fig. 3 The side view of the baffle in the first filter plate provided for the embodiments of the application.

[0038] Icon: 1-gas-gas heat exchanger; 2-absorption tower; 3-lean-liquid-rich-liquid heat exchanger; 4-regeneration tower; 5-acid gas cooler; 6-acid gas separator; 7-amine liquid circulating pump; 8-lean-liquid cooler; 9-filtering unit; 91-solution filter; 92-mechanical filter; 921-casing; 9211-first through hole; 9212-second through hole; 9213-slotted chute; 922-first filter plate; 9221-third through hole; 9222-connection ring; 923-second filter plate; 9231-fourth through hole; 924-filtering layer; 925-baffle; 10-rich-amine liquid regulating valve; 11-acid gas regulating valve; 12-liquid condensate regulating valve; 13-electric heater; A-external raw material supply; B-external high point vent. DETAILED DESCRIPTION

[0039] Clearly and completely describe the technical scheme in the embodiments of the utility model in combination with the drawings in the embodiments of the utility model, obviously, the described embodiments are a part of embodiments of the utility model, and not all embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without making creative labor belong to the range of protection of the utility model.

[0040] In the description of the embodiments of the utility model, it should be explained that the orientation or position relation indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like is the orientation or position relation shown based on the drawings, and is only for the convenience of describing the embodiments of the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model. The terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance. In addition, the terms "mounting", "connecting", "connection" should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected, can be mechanically connected, or can be electrically connected, can be directly connected, or indirectly connected through an intermediate medium, or can be the communication inside two elements. For the person skilled in the art, the specific meaning of the above terms in the embodiments of the utility model can be understood according to the specific circumstances.

[0041] In combination with Figs. 1-3As shown, a small natural gas deacidification device includes a gas-gas heat exchanger 1, an absorption tower 2, a lean-rich liquid heat exchanger 3, a regeneration tower 4, an acid gas cooler 5, an acid gas separator 6, an amine liquid circulating pump 7, and a lean liquid cooler 8; a first input end of the gas-gas heat exchanger 1 is in communication with an output end of an external raw material supply A, a first output end of the gas-gas heat exchanger 1 is in communication with a first input end of the absorption tower 2; a first output end of the absorption tower 2 is in communication with a second input end of the gas-gas heat exchanger 1, a second output end of the gas-gas heat exchanger 1 is in communication with the outside, for discharging the external raw material after purification, a second output end of the absorption tower 2 is in communication with a first input end of the lean-rich liquid heat exchanger 3; a first output end of the lean-rich liquid heat exchanger 3 is in communication with an input end of the regeneration tower 4; a first output end of the regeneration tower 4 is in communication with an input end of the acid gas cooler 5, a second output end of the regeneration tower 4 is in communication with a second input end of the lean-rich liquid heat exchanger 3; an output end of the acid gas cooler 5 is in communication with an input end of the acid gas separator 6; a first output end of the acid gas separator 6 is in communication with an input end of an external high point vent B, for discharging carbon dioxide, a second output end of the acid gas separator 6 is in communication with an input end of the amine liquid circulating pump 7; an output end of the amine liquid circulating pump 7 is in communication with an input end of the lean liquid cooler 8; an output end of the lean liquid cooler 8 is in communication with a second input end of the absorption tower 2; a second output end of the lean-rich liquid heat exchanger 3 is in communication with a path of the acid gas separator 6 leading to the amine liquid circulating pump 7.

[0042] In the above scheme, the gas-gas heat exchanger 1 exchanges heat between the external raw material and the purified gas output by the absorption tower 2, preheats the raw material gas using the waste heat of the purified gas, and reduces the heating load of the regeneration tower 4; the absorption tower 2 processes the preheated raw material gas and the regenerated amine liquid supplied by the lean liquid cooler 8 through two-stage input, realizes acid gas absorption and amine liquid circulation; the lean-rich liquid heat exchanger 3 exchanges heat between the rich amine liquid output by the absorption tower 2 and the high-temperature lean amine liquid output by the regeneration tower 4, preheats the rich amine liquid using the waste heat of the lean amine liquid, and reduces the energy consumption of the regeneration tower 4; the regeneration tower 4 is connected to the acid gas cooler 5 and the lean-rich liquid heat exchanger 3 through two-stage output, realizes acid gas separation and waste heat recovery of the lean amine liquid; the acid gas cooler 5 and the acid gas separator 6 cooperate to complete acid gas condensation and gas-liquid separation, and the amine liquid circulating pump 7 and the lean liquid cooler 8 form a closed loop circuit to ensure that the regenerated amine liquid is cooled and then fed back to the absorption tower 2. Through the multi-stage heat recovery design of the gas-gas heat exchanger 1, the lean-rich liquid heat exchanger 3, and the regeneration tower 4, the demand for external heating and cooling equipment is reduced, thereby realizing the miniaturization of the device and reducing the cost.

[0043] Further comprising a filtering unit 9, an input end of the filtering unit 9 is in communication with a second output end of the absorption tower 2, and an output end of the filtering unit 9 is in communication with a first input end of the lean-rich liquid heat exchanger 3.

[0044] In the above scheme, the input end of the filtering unit 9 is in communication with the second output end of the absorption tower 2, and can directly receive the rich amine solution containing suspended impurities; the output end of the filtering unit 9 is in communication with the first input end of the lean-rich liquid heat exchanger 3, so as to ensure that the filtered rich amine solution has completed impurity removal before entering the lean-rich liquid heat exchanger 3, thereby avoiding the deposition of suspended impurities in the rich amine solution in the lean-rich liquid heat exchanger 3, reducing the heat transfer efficiency, preventing mechanical impurities carried by external raw materials from entering subsequent equipment to cause blockage or wear, and thus improving the overall operation stability of the device and reducing the maintenance cost.

[0045] The filtering unit 9 comprises a solution filter 91 and a mechanical filter 92; the input end of the solution filter 91 is in communication with the second output end of the absorption tower 2, and the output end thereof is in communication with the input end of the mechanical filter 92, for removing suspended impurities in the deacidification solution; the output end of the mechanical filter 92 is in communication with the first input end of the lean-rich liquid heat exchanger 3, for filtering mechanical impurities of external raw materials.

[0046] In the above scheme, the solution filter 91 is directly connected to the output end of the absorption tower 2, and the suspended impurities generated in the rich amine solution due to chemical reaction are intercepted by the internal filter medium of the solution filter 91, so as to prevent the flow channel of the subsequent lean-rich liquid heat exchanger 3 from being blocked; the mechanical filter 92 is arranged downstream of the solution filter 91, and solid particles carried by external raw materials are removed by the mechanical interception of the mechanical filter 92, so as to avoid the mechanical impurities from entering the heat exchange system to cause equipment wear.

[0047] The mechanical filter 92 comprises a casing 921, a first filter plate 922, a second filter plate 923 and a filter layer 924; the hollow casing 921 is provided with a first through hole 9211 at one end thereof for communication with the output end of the solution filter 91 and a second through hole 9212 at the other end thereof for communication with the first input end of the lean-rich liquid heat exchanger 3; the first filter plate 922 in a cylindrical structure is arranged inside the casing 921 near the first through hole 9211, and the barrel opening of the first filter plate 922 faces the first through hole 9211, and a plurality of third through holes 9221 are formed in the barrel bottom of the first filter plate 922; the second filter plate 923 is fixedly arranged inside the casing 921 near the second through hole 9212, and a plurality of fourth through holes 9231 are formed in the plate surface of the second filter plate 923, and the hole cores of the plurality of fourth through holes 9231 and the hole cores of the plurality of third through holes 9221 are arranged alternately; the filter layer 924 is arranged inside the casing 921 near the second through hole 9212 and is arranged in a spaced manner with the second filter plate 923; wherein the material arrangement of the filter layer 924 from the first through hole 9211 to the second through hole 9212 is stainless steel mesh, polyester fiber and ceramic in sequence.

[0048] The first through hole 9211 and the second through hole 9212 arranged at both ends of the shell 921 form a directional flow channel to ensure one-way flow of the solution containing impurities. The first filter plate 922 adopts a rotatable cylindrical structure, and the third through hole 9221 at the bottom of the cylinder and the fourth through hole 9231 of the second filter plate 923 are arranged in an interlaced manner. The centrifugal force generated by rotation can intercept large-particle impurities at the bottom of the cylinder, and at the same time, avoid the blockage caused by the alignment of the through holes. The second filter plate 923 is fixedly arranged and cooperates with the interlaced hole cores to further intercept medium-particle impurities. The filter layer 924 adopts three gradient materials of stainless steel mesh, polyester fiber and ceramic. The stainless steel mesh first intercepts residual large particles, the polyester fiber adsorbs small suspended solids, and the ceramic layer realizes fine filtration through the microporous structure. The different materials are arranged along the flow direction to form step-by-step filtration, which not only improves the filtration efficiency, but also realizes the efficient removal of mechanical impurities in stages, reduces the risk of equipment blockage, and prolongs the service life of the filter assembly.

[0049] The inner wall of the shell 921 is recessed with a sliding groove 9213, the bottom of the first filter plate 922 is provided with a connecting ring 9222, the periphery of the connecting ring 9222 is in sliding contact with the inner wall of the sliding groove 9213, and the inner diameter of the connecting ring 9222 is consistent with the outer diameter of the first filter plate 922.

[0050] In the above scheme, the sliding groove 9213 recessed in the inner wall of the shell 921 provides an axial sliding path for the connecting ring 9222, so that the first filter plate 922 can move axially freely during rotation. At the same time, the radial limiting is formed by the contact between the inner wall of the sliding groove 9213 and the connecting ring 9222, which avoids the gap leakage caused by the deflection of the filter plate. The design that the inner diameter of the connecting ring 9222 is consistent with the outer diameter of the first filter plate 922 ensures that the connecting ring 9222 and the filter plate cylinder bottom form a gap fit, which not only guarantees the coaxiality during rotation, but also prevents impurities from entering the connecting gap. The sliding contact mode of the connecting ring 9222 and the sliding groove 9213 not only reduces the rotation resistance, but also avoids the wear gap caused by long-term operation.

[0051] The inside of the first filter plate 922 is annularly arranged with a plurality of baffles 925 along the axis, one end of the plurality of baffles 925 is fixedly connected with the bottom of the first filter plate 922 and is adjacent to the third through hole 9221, and the other end extends to the cylinder port of the first filter plate 922.

[0052] In the above scheme, the annular arrangement of the baffles 925 along the axis can guide the fluid to form a cyclone state, increase the contact area of the impurities and the inner wall of the filter plate, and strengthen the interception effect. The baffles 925 extend to the cylinder port at one end and are fixedly connected to the cylinder bottom at the other end and located outside the third through hole 9221, which produces a centrifugal separation effect, so that large-particle impurities are far away from the third through hole 9221 area under the action of centrifugal force, avoiding the blockage caused by the direct impact of impurities on the third through hole 9221.

[0053] A rich amine liquid regulating valve 10 is arranged between the second output end of the absorption tower 2 and the input end of the solution filter 91 to control the flow of the rich amine liquid.

[0054] In the above scheme, by adjusting the valve opening of the rich amine liquid regulating valve 10, the flow of the rich amine liquid from the absorption tower 2 to the solution filter 91 can be accurately adjusted, avoiding the sudden increase of the internal pressure of the solution filter 91 or the blockage of the filter layer 924 due to excessive flow, and preventing insufficient amine liquid circulation in the regeneration tower 4 due to insufficient flow, thereby ensuring the synergistic efficiency of the deacidification reaction in the absorption tower 2 and the amine liquid regeneration in the regeneration tower 4.

[0055] An acid gas regulating valve 11 for regulating the release rate of the acid gas is arranged on the path from the first output end of the acid gas separator 6 to the external high point vent B, and a condensate regulating valve 12 for regulating the condensate supply flow is arranged on the path from the second output end of the acid gas separator 6 to the amine liquid circulating pump 7.

[0056] In the above scheme, the acid gas regulating valve 11 is arranged on the path from the acid gas separator 6 to the external high point vent B, and the valve opening can be adjusted to accurately control the acid gas release rate, avoiding the fluctuation of the system pressure or the residual acid gas due to too fast release of the acid gas, and preventing the pressure accumulation in the regeneration tower 4 due to too slow release. The condensate regulating valve 12 is arranged on the path from the acid gas separator 6 to the amine liquid circulating pump 7, and by adjusting the condensate supply flow, the input of the amine liquid circulating pump 7 can be matched with its processing capacity, avoiding the overload or idling of the pump, thereby maintaining the stability of the amine liquid circulation during the regeneration process.

[0057] An electric heater 13 for heating the internal environment of the regeneration tower 4 is fixed to one side of the regeneration tower 4 close to the second output end.

[0058] In the above scheme, the electric heater 13 is fixed to the position close to the second output end of the regeneration tower 4, which can be used for directional heating according to the temperature field required in the amine liquid regeneration stage, so that the heat required for the amine salt decomposition reaction directly acts on the internal environment of the regeneration tower 4, avoiding the energy loss and the supporting pipeline arrangement caused by the traditional steam heating or external heat exchanger, not only shortening the heat conduction path to improve the heat energy utilization rate, but also reducing the space occupation and installation cost caused by the addition of independent heating equipment.

[0059] Each embodiment in the specification is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other, and each embodiment mainly describes the difference from other embodiments.

[0060] The above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can still be modified, or some or all of the technical features thereof can be replaced by equivalents; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A small-scale natural gas deacidification device, characterized in that, It includes a gas-gas heat exchanger (1), an absorption tower (2), a lean and rich liquid heat exchanger (3), a regeneration tower (4), an acid gas cooler (5), an acid gas separator (6), an amine liquid circulation pump (7), and a lean liquid cooler (8). The first input end of the gas-to-gas heat exchanger (1) is connected to the output end of the external raw material supply (A), and the first output end of the gas-to-gas heat exchanger (1) is connected to the first input end of the absorption tower (2). The first output end of the absorption tower (2) is connected to the second input end of the gas-gas heat exchanger (1), and the second output end of the gas-gas heat exchanger (1) is connected to the outside world for discharging purified external raw materials. The second output end of the absorption tower (2) is connected to the first input end of the lean and rich liquid heat exchanger (3). The first output end of the lean and rich liquid heat exchanger (3) is connected to the input end of the regeneration tower (4); The first output end of the regeneration tower (4) is connected to the input end of the acid gas cooler (5), and the second output end of the regeneration tower (4) is connected to the second input end of the lean and rich liquid heat exchanger (3). The output end of the acid gas cooler (5) is connected to the input end of the acid gas separator (6); The first output end of the acid gas separator (6) is connected to the input end of the external high-point vent (B) for discharging carbon dioxide, and the second output end of the acid gas separator (6) is connected to the input end of the amine liquid circulation pump (7). The output end of the amine circulating pump (7) is connected to the input end of the lean liquid cooler (8); The output end of the lean liquid cooler (8) is connected to the second input end of the absorption tower (2); The second output end of the lean and rich liquid heat exchanger (3) is connected to the path from the acid gas separator (6) to the amine liquid circulation pump (7).

2. The small-scale natural gas deacidification device according to claim 1, characterized in that, It also includes a filter unit (9), the input end of which is connected to the second output end of the absorption tower (2), and the output end of which is connected to the first input end of the lean and rich liquid heat exchanger (3).

3. The small-scale natural gas deacidification device according to claim 2, characterized in that, The filtration unit (9) includes a solution filter (91) and a mechanical filter (92); The input end of the solution filter (91) is connected to the second output end of the absorption tower (2), and its output end is connected to the input end of the mechanical filter (92) for removing suspended impurities in the deacidification solution; The output end of the mechanical filter (92) is connected to the first input end of the lean and rich liquid heat exchanger (3) for filtering mechanical impurities from external raw materials.

4. The small-scale natural gas deacidification device according to claim 3, characterized in that, The mechanical filter (92) includes a housing (921), a first filter plate (922), a second filter plate (923), and a filter layer (924). The hollow housing (921) has a first through hole (9211) for communicating with the output end of the solution filter (91) and a second through hole (9212) for communicating with the first input end of the lean and rich liquid heat exchanger (3) at both ends along its axial length direction. The first filter plate (922) with a cylindrical structure is rotatably disposed inside the housing (921) on the side close to the first through hole (9211). The opening of the first filter plate (922) faces the first through hole (9211), and a plurality of third through holes (9221) are opened at the bottom of the cylinder. The second filter plate (923) is fixedly disposed inside the housing (921) on the side near the second through hole (9212), and a plurality of fourth through holes (9231) are provided on the plate surface of the second filter plate (923), and the cores of the plurality of fourth through holes (9231) are alternately arranged with the cores of the plurality of third through holes (9221); The filter layer (924) is disposed inside the housing (921) on the side near the second through hole (9212) and is spaced apart from the second filter plate (923); The filter layer (924) is arranged in the following material arrangement from the first through hole (9211) to the second through hole (9212): stainless steel mesh, polyester fiber, and ceramic.

5. The small-scale natural gas deacidification device according to claim 4, characterized in that, The inner wall of the housing (921) is recessed with a sliding groove (9213), and a connecting ring (9222) is provided on the periphery of the bottom of the first filter plate (922). The periphery of the connecting ring (9222) slides in contact with the inner wall of the sliding groove (9213), and the inner diameter of the connecting ring (9222) is consistent with the outer diameter of the first filter plate (922).

6. The small-scale natural gas deacidification device according to claim 4, characterized in that, The first filter plate (922) has multiple baffles (925) arranged in a ring along its axis inside. One end of the multiple baffles (925) is fixedly connected to the bottom of the first filter plate (922) and adjacent to the third through hole (9221), and the other end extends to the opening of the first filter plate (922).

7. The small-scale natural gas deacidification device according to claim 3, characterized in that, An amine-rich liquid regulating valve (10) for controlling the flow rate of amine-rich liquid is provided between the second output end of the absorption tower (2) and the input end of the solution filter (91).

8. The small-scale natural gas deacidification device according to claim 1, characterized in that, An acid gas regulating valve (11) for adjusting the acid gas release rate is provided on the path from the first output end of the acid gas separator (6) to the external high point vent (B), and a condensate regulating valve (12) for adjusting the condensate supply flow rate is provided on the path from the second output end of the acid gas separator (6) to the amine liquid circulation pump (7).

9. The small-scale natural gas deacidification device according to claim 1, characterized in that, An electric heater (13) for heating the internal environment of the regeneration tower (4) is fixed on one side near its second output end.

Images