CN210021644U - Device for absorbing and capturing carbon dioxide by amine method - Google Patents

Abstract

The utility model relates to the technical field of carbon dioxide absorption equipment, and provides a device for absorbing and capturing carbon dioxide by an amine method, which comprises an absorption tower, a desorption tower, an exhaust passage communicated with the desorption tower, an air inlet passage and an air outlet passage respectively communicated with the absorption tower, a reboiler providing heat for the desorption tower, a barren solution passage respectively communicated with the absorption tower and the desorption tower, and a pregnant solution passage respectively communicated with the absorption tower and the desorption tower; the device for absorbing and capturing carbon dioxide by the amine method also comprises a heat recovery mechanism which is used for recovering the residual heat left when the carbon dioxide is released in the desorption tower and conducting the residual heat to the rich liquid channel. The desorption tower can remain waste heat in the released carbon dioxide, the waste heat is recovered by the heat recovery mechanism and then is conducted into the lean solution channel, so that the rich solution in the rich solution channel is heated, and the heated rich solution enters the desorption tower to reduce the energy consumption of the desorption tower.

Description

Device for absorbing and capturing carbon dioxide by amine method

Technical Field

The utility model belongs to the technical field of carbon dioxide absorption equipment, more specifically say, relate to a device of entrapment carbon dioxide is absorbed to amine method.

Background

The carbon dioxide emitted by a large amount of fossil fuels is a main cause of global warming, and the capture, utilization and sequestration of the emitted carbon dioxide are important measures for coping with climate change. At present, carbon dioxide is captured mainly by adopting a chemical absorption method carbon capture technology after fossil fuel is combusted, and an adopted absorbent is an organic amine solution (organic amine can be selected as alcohol amine).

The conventional organic amine carbon capture system (note: in this application, the bulk of the lean solution and the rich solution is the same absorbent; the carbon dioxide absorbed in the lean solution is lower than that absorbed in the rich solution) generally comprises an absorption tower, a desorption tower, a reboiler (the reboiler conducts heat in external hot steam into the desorption tower and discharges the cooled external hot steam in the form of liquid water), and the like. Flue gas (containing CO2) enters from the lower part of the absorption tower and is in reverse contact with an absorbent (barren liquor) sprayed from the top of the tower in the tower (reverse contact: the flue gas moves from bottom to top in the absorption tower, and the absorbent is sprayed from top to bottom in the absorption tower) to react, and the flue gas without CO2 is discharged from the upper part of the absorption tower. The absorbent liquid (rich liquid) absorbing the carbon dioxide is pumped out of the absorption tower by a rich liquid pump and then sent into a desorption tower for regeneration (regeneration: releasing the carbon dioxide in the rich liquid), and the released carbon dioxide airflow is condensed by a condenser and then output. And the hot barren solution at the bottom of the desorption tower is sprayed from the top of the absorption tower under the action of a barren solution pump, so that the circulation of the system is realized. Although the carbon capture system can capture carbon dioxide in flue gas, a large amount of waste heat is wasted in the regeneration process of the desorption tower, so that energy consumption is too much, and the popularization and application of the technology are not facilitated.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a device of entrapment carbon dioxide is absorbed to amine method to the desorber who solves existence among the prior art has a large amount of waste heat to be wasted to have fallen and has leaded to consuming energy too many technical problem in regeneration process.

In order to achieve the above object, the utility model adopts the following technical scheme: the device for absorbing and capturing the carbon dioxide by the amine method comprises an absorption tower, a desorption tower, an exhaust channel communicated with the desorption tower, an air inlet channel and an air outlet channel which are respectively communicated with the absorption tower, a reboiler for providing heat for the desorption tower, a barren solution channel respectively communicated with the absorption tower and the desorption tower, and a rich solution channel respectively communicated with the absorption tower and the desorption tower; the device for absorbing and capturing carbon dioxide by the amine method also comprises a heat recovery mechanism which is used for recovering residual heat left when the carbon dioxide is released in the desorption tower and conducting the residual heat to the rich liquid channel.

Further, the heat recovery mechanism includes a first heat exchanger through which the lean passage exchanges heat with the rich passage.

Further, the heat recovery mechanism further comprises a second heat exchanger and a flash tank disposed on the lean liquid channel; the flash tank has a vapor passage in communication with the desorber; the steam passage exchanges heat with the rich liquid passage through the second heat exchanger.

Further, a vapor compressor is arranged on the vapor passage upstream of the second heat exchanger.

Further, the heat exchanger also comprises a third heat exchanger, and the rich liquid channel exchanges heat with a water outlet pipe of the reboiler through the third heat exchanger.

Further, the heat exchanger also comprises a fourth heat exchanger, and the exhaust passage exchanges heat with the rich liquid passage through the fourth heat exchanger.

The liquid-enriched air conditioner further comprises a fifth heat exchanger, a gas compressor is arranged on the exhaust passage, and the exhaust passage downstream of the gas compressor exchanges heat with the rich liquid passage through the fifth heat exchanger.

And the absorption tower further comprises a tower cooler for cooling the absorption liquid, and a liquid inlet and a liquid outlet of the tower cooler are respectively communicated with the absorption tower.

Further, still including the flue gas preliminary treatment tower that is used for spraying alkali lye, the bottom of flue gas preliminary treatment tower has first flue gas inlet port, flue gas preliminary treatment tower top has first flue gas discharge port, first flue gas discharge port with inlet channel intercommunication.

Further, still include the flue gas scrubbing tower that is used for the shower water, the bottom of flue gas scrubbing tower has the second flue gas inlet port, the top of flue gas scrubbing tower has the second flue gas discharge port with exterior space intercommunication, the second flue gas inlet with exhaust passage intercommunication.

The utility model provides a device of entrapment carbon dioxide is absorbed to amine method's beneficial effect lies in: compared with the prior art, the device for absorbing and capturing carbon dioxide by the amine method provided by the utility model has the advantages that the flue gas enters the absorption tower from the gas inlet channel, and the carbon dioxide in the flue gas is absorbed by the barren solution in the absorption tower and then is discharged from the gas outlet channel; the lean solution absorbing the carbon dioxide in the absorption tower is changed into a rich solution and is conveyed to the desorption tower along the rich solution channel, the carbon dioxide in the rich solution in the desorption tower is discharged from the exhaust channel after being released, and the reboiler provides heat for the desorption tower so that the carbon dioxide in the rich solution in the desorption tower can be released; the rich solution which releases carbon dioxide in the desorption tower is changed into a lean solution and then is conveyed to the absorption tower along a lean solution channel; the desorption tower can remain waste heat in the released carbon dioxide, the waste heat is recovered by the heat recovery mechanism and then is conducted into the lean solution channel, so that the rich solution in the rich solution channel is heated, and the heated rich solution enters the desorption tower to reduce the energy consumption of the desorption tower.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments or the prior art descriptions will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive labor.

Fig. 1 is a schematic structural diagram of a device for absorbing and capturing carbon dioxide by an amine method according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a second schematic diagram of an apparatus for absorbing and capturing carbon dioxide by an amine method according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a third schematic diagram of an apparatus for absorbing and capturing carbon dioxide by an amine method according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a device for absorbing and capturing carbon dioxide by an amine method according to an embodiment of the present invention.

Wherein, in the figures, the respective reference numerals:

Detailed Description

In order to make the technical problem, technical solution and advantageous effects to be solved by the present invention more clearly understood, the following description is given in conjunction with the accompanying drawings and embodiments to illustrate the present invention in further detail. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

Further, "high temperature" and "low temperature" refer to the designations of liquid before and after heating, and it is understood that, for example: compared with the same heating device, the liquid before heating is called low-temperature liquid, and the liquid after heating is called high-temperature liquid.

Alternatively, "high temperature" means a temperature greater than or equal to 100 degrees celsius and "low temperature" means less than 100 degrees celsius.

In addition, "cold" is understood to mean ambient temperature. For example; the cold water is water at normal temperature. "Hot" is understood to mean temperatures above ambient temperature. Specifically, optionally, the normal temperature is 25 ℃.

In the present application, in the heat exchanging device, a side through which a heat source (heat source: e.g., hot water) passes is a hot side, and a side through which a heated substance passes is a cold side; the heat source enters from the inlet of the hot side and exits from the outlet of the hot side; the heated material enters from the inlet of the cold side and exits from the outlet of the cold side.

Referring to fig. 1, the apparatus for absorbing and capturing carbon dioxide by amine method according to the present invention will now be described. The device for absorbing and capturing carbon dioxide by an amine method comprises an absorption tower 10, a desorption tower 11, an exhaust channel T1 communicated with the desorption tower 11, an air inlet channel T21 and an air outlet channel T22 respectively communicated with the absorption tower 10, a reboiler 23 for providing heat for the desorption tower 11, a lean liquid channel T31 respectively communicated with the absorption tower 10 and the desorption tower 11, and a rich liquid channel T32 respectively communicated with the absorption tower 10 and the desorption tower 11; the apparatus for absorbing and capturing carbon dioxide by the amine method further includes a heat recovery mechanism (not shown) for recovering waste heat remaining in the desorption tower 11 when releasing carbon dioxide and conducting the waste heat into the rich liquid passage T32.

Thus, the flue gas enters the absorption tower 10 from the gas inlet channel T21, and the carbon dioxide in the flue gas is absorbed by the barren solution in the absorption tower 10 and then discharged from the gas outlet channel T22; the lean liquid absorbing the carbon dioxide in the absorption tower 10 becomes rich liquid and is sent to the desorption tower 11 along the rich liquid passage T32, the carbon dioxide in the rich liquid in the desorption tower 11 is discharged from the exhaust passage T1 after being released, and the reboiler 23 supplies heat to the desorption tower 11 so that the carbon dioxide in the rich liquid in the desorption tower 11 can be released; the rich liquid that has released carbon dioxide in the desorption tower 11 becomes a lean liquid and is then sent to the absorption tower 10 along a lean liquid passage T31; the desorption tower 11 may remain residual heat in the released carbon dioxide, and the residual heat is recovered by the heat recovery mechanism and then transferred into the lean liquid passage T31, so that the rich liquid in the rich liquid passage T32 is heated, and the heated rich liquid enters the desorption tower 11, which may reduce energy consumption of the desorption tower 11.

There are various forms of the waste heat, including the waste heat contained in the discharged liquid (such as lean liquid), the waste heat contained in the discharged gas (such as discharged carbon dioxide gas), and the waste heat contained in the other place of the desorption tower 11, as long as the waste heat can be recovered and conducted to the rich liquid passage T32, which is not limited herein.

Optionally, in one embodiment, the lean passage T31 is tubular. Specifically, in one embodiment, the lean passage T31 is a round tube. Specifically, in one embodiment, the lean passage T31 has a pump therein for driving movement of the liquid/gas in the lean passage T31.

Alternatively, in one embodiment, the rich liquid passage T32 is tubular. Specifically, in one embodiment, the rich liquid passage T32 is a round tube. Specifically, in one embodiment, a pump is provided in the rich liquid passage T32 for driving liquid/gas movement in the rich liquid passage T32.

Alternatively, in one embodiment, the intake passage T21 is tubular. Specifically, in one embodiment, the intake passage T21 is a round tube. Specifically, in one embodiment, a pump is provided within the intake passage T21 for driving the movement of liquid/gas within the intake passage T21.

Optionally, in one embodiment, outlet channel T22 is in the shape of a pipe. Specifically, in one embodiment, the outlet channel T22 is a circular tube. Specifically, in one embodiment, a pump is provided in outlet channel T22 for driving liquid/gas movement in outlet channel T22.

Further, referring to fig. 1, as an embodiment of the apparatus for absorbing and capturing carbon dioxide by amine method provided by the present invention, the heat recovery mechanism includes a first heat exchanger 19, and the lean solution channel T31 exchanges heat with the rich solution channel T32 through the first heat exchanger 19. In this way, the lean liquid itself may have heat remaining after being discharged from the desorption tower 11, and this part of the heat is conducted to the rich passage T32 through the first heat exchanger 19 to raise the temperature of the lean liquid in the rich passage T32.

Optionally, in one embodiment, the first heat exchanger 19 is a dividing wall heat exchanger. Specifically, in one embodiment, the first heat exchanger 19 is any one of a plate heat exchanger, a jacketed heat exchanger, a submerged coil type, a trickle heat exchanger, a double pipe heat exchanger, and a shell and tube type heat exchanger.

Further, referring to fig. 1, as one embodiment of the apparatus for absorbing and capturing carbon dioxide by amine method provided by the present invention, the heat recovery mechanism further includes a second heat exchanger 20 and a flash tank 24 disposed on the lean solution channel T31; the flash tank 24 has a vapor passage T4 communicating with the desorber 11; the steam passage T4 exchanges heat with the rich liquid passage T32 through the second heat exchanger 20. As such, after the lean liquid in the lean liquid channel T31 passes through the flash tank 24, the liquid generated by the flash tank 24 continues to flow along the lean liquid channel T31, the gas portion generated in the flash tank 24 is transported along the steam channel T4, and the heat of the steam in the steam channel T4 is transferred to the rich liquid in the rich liquid channel T32 through the second heat exchanger 20 to heat the rich liquid in the rich liquid channel T32.

Optionally, in one embodiment, the steam channel T4 is tubular. Specifically, in one embodiment, the steam channel T4 is a round tube. Specifically, in one embodiment, a pump is provided within the vapor passage T4 for driving liquid/gas movement within the vapor passage T4.

Optionally, in one embodiment, the second heat exchanger 20 is a recuperator. Specifically, in one embodiment, second heat exchanger 20 is any one of a plate heat exchanger, a jacketed heat exchanger, a submerged coil type, a trickle heat exchanger, a double-pipe heat exchanger, and a shell-and-tube heat exchanger.

Further, referring to fig. 1, as an embodiment of the apparatus for absorbing and capturing carbon dioxide by amine method provided by the present invention, a steam compressor 25 is further disposed on the steam passage T4 upstream of the second heat exchanger 20. In this manner, the vapor compressor 25 is able to increase the temperature within the vapor passage T4 such that more heat is transferred from the vapor passage T4 through the second heat exchanger 20 into the lean liquid passage T31; in addition, the vapor compressor 25 can raise the pressure in the vapor passage T4, so that the pressure of the vapor entering the desorber 11 is more balanced with the pressure of the vapor in the desorber 11, which is advantageous for protecting the desorber 11.

Further, referring to fig. 1, as a specific embodiment of the apparatus for absorbing and capturing carbon dioxide by amine method provided by the present invention, the apparatus for absorbing and capturing carbon dioxide by amine method further includes a third heat exchanger 21, and the rich liquid channel T32 exchanges heat with the water outlet pipe T5 of the reboiler 23 through the third heat exchanger 21. In this way, the heat in the hot water discharged from the water outlet pipe T5 in the reboiler 23 is transferred to the rich liquid passage T32 through the third heat exchanger 21, and the heat in the waste water in the water outlet pipe T5 is reused.

Optionally, in one embodiment, outlet pipe T5 is tubular. Specifically, in one embodiment, outlet pipe T5 is a round pipe. Specifically, in one embodiment, a pump is provided in outlet pipe T5 for driving the movement of liquid/gas in outlet pipe T5.

Optionally, in one embodiment, the third heat exchanger 21 is a dividing wall heat exchanger. Specifically, in one embodiment, the third heat exchanger 21 is any one of a plate heat exchanger, a jacketed heat exchanger, a submerged coil type, a trickle heat exchanger, a double pipe heat exchanger, and a shell-and-tube type heat exchanger.

Specifically, referring to fig. 2, in one embodiment, high-temperature steam S16 enters the reboiler 23 from the hot-side inlet of the reboiler 23, transfers heat to the reheated lean liquid S15 entering from the cold-side inlet of the reboiler 23 through phase change, and the reheated lean liquid S15 is heated and then injected into the desorber 11 again from the cold-side outlet to increase the heat required for carbon dioxide regeneration. The high-temperature steam S16 is condensed into high-temperature water S17 in the reboiler 23 and is discharged from the hot side outlet of the reboiler 23. After the hot rich liquid S9 is desorbed and regenerated, a hot lean liquid S10 is discharged from a bottom outlet of the desorption tower 11 and enters the flash tank 24 through an inlet of the flash tank 24, and the generated flash steam S12 and the medium-temperature lean liquid S11 are discharged from a top outlet and a bottom outlet of the flash tank 24 respectively. The flash steam S12 enters the vapor compressor 25 from the inlet of the vapor compressor 25, and is compressed into high-temperature and high-pressure compressed steam S13 and then discharged. The compressed steam S13 enters the second heat exchanger 20 from the hot side inlet of the second heat exchanger 20, and becomes saturated steam S14 after being cooled and cooled. Then, saturated steam S14 is supplied from the bottom gas inlet of the desorber 11 into the desorber 11 for heat supply.

Optionally, referring to fig. 3, in an embodiment, the high-temperature water S17 enters the third heat exchanger 21 from the hot-side inlet of the third heat exchanger 21, and the high-temperature water S17 becomes cold return water S31 after heat exchange and temperature reduction and is discharged from the hot-side outlet back to the heating pipe network system.

Further, referring to fig. 1, as an embodiment of the apparatus for absorbing and capturing carbon dioxide by the amine method provided by the present invention, the apparatus for absorbing and capturing carbon dioxide by the amine method further includes a fourth heat exchanger 22, and the exhaust passage T1 exchanges heat with the rich liquid passage T32 through the fourth heat exchanger 22. In this manner, the carbon dioxide gas and the water vapor discharged from the exhaust passage T1 carry heat, and the heat is transferred to the rich liquid passage T32 through the fourth heat exchanger 22.

Optionally, in one embodiment, the fourth heat exchanger 22 is a recuperator. Specifically, in one embodiment, fourth heat exchanger 22 is any one of a plate heat exchanger, a jacketed heat exchanger, a submerged coil type, a trickle heat exchanger, a double-pipe heat exchanger, and a shell-and-tube heat exchanger.

Alternatively, referring to fig. 4, in one embodiment, the initial rich liquid S4 is divided into two split first rich liquid split S8 and second rich liquid split S18, wherein the second rich liquid split S18 enters the fourth heat exchanger 22 from the cold side inlet of the fourth heat exchanger 22, the second rich liquid split S18 is discharged into the desorber 11 from the cold side outlet after recovering the latent heat of water vapor in the initial product gas S19 generated in the desorber 11, and the initial product gas S19 enters the carbon dioxide water scrubber 28 after being cooled in the fourth heat exchanger 22. The heat supply load of the reboiler 23 can be further reduced by recovering the steam heat in the initial product gas S19 in the fourth heat exchanger 22 through the second rich liquid stream S18, thereby reducing the energy consumption for system regeneration.

Alternatively, referring to fig. 4, in one embodiment, the hot side inlet and outlet of the fourth heat exchanger 22 are connected to the top gas outlet of the desorption tower 11 and the bottom inlet of the carbon dioxide water washing tower 28, respectively, and the cold side inlet and outlet of the fourth heat exchanger 22 are connected to the outlet of the rich liquid pump 18 and the top liquid inlet of the desorption tower 11, respectively.

Further, referring to fig. 1, as an embodiment of the apparatus for absorbing and capturing carbon dioxide by an amine method provided by the present invention, the apparatus for absorbing and capturing carbon dioxide by an amine method further includes a fifth heat exchanger 29, a gas compressor 32 is disposed on the exhaust passage T1, and the exhaust passage T1 downstream of the gas compressor 32 exchanges heat with the rich liquid passage T32 through the fifth heat exchanger 29. In this way, the gas compressor 32 compresses the gas (carbon dioxide) in the discharge passage T1 for storage, and generates a large amount of heat during the compression, and the heat is transferred to the rich liquid passage T32 through the fifth heat exchanger 29.

Optionally, in one embodiment, the fifth heat exchanger 29 is a dividing wall heat exchanger. Specifically, in one embodiment, fifth heat exchanger 29 is any one of a plate heat exchanger, a jacketed heat exchanger, a submerged coil type, a trickle heat exchanger, a double-pipe heat exchanger, and a shell-and-tube type heat exchanger.

Alternatively, referring to fig. 4, in one embodiment, the cold side inlet and outlet of the fifth heat exchanger 29 are connected to the cold side outlet of the fourth heat exchanger 22 and the second stage liquid inlet of the desorber 11, respectively, and the hot side inlet and outlet of the fifth heat exchanger 29 are connected to the gas cooler 33, the first carbon dioxide cooler 35, the second carbon dioxide cooler 37, and the cooling water cooler 40, respectively. The outlet of the cooling water cooler 40 is connected with the inlets of the gas cooler 33, the first carbon dioxide cooler 35 and the second carbon dioxide cooler 37; specifically, the second rich liquid partial stream S18 is discharged from the cold-side outlet after being subjected to heat exchange and temperature rise by the fourth heat exchanger 22, enters the fifth heat exchanger 29 through the cold-side inlet of the fifth heat exchanger 29, and is discharged from the cold-side outlet after being subjected to temperature rise and enters the second column-level liquid inlet of the desorber 11. The carbon dioxide cooling water S28 is fed from the gas cooler 33, the first carbon dioxide cooler 35, and the second carbon dioxide cooler 37 to the corresponding coolers and recovers the high temperature heat of the compressed carbon dioxide to become the high temperature cooling water S29. The high-temperature cooling water S29 enters the fifth heat exchanger 29 from the hot-side inlet of the fifth heat exchanger 29, is cooled and then is discharged from the hot-side outlet of the fifth heat exchanger 29, and then enters the cooling water cooler 40 to be further cooled into the carbon dioxide cooling water S28. The fifth heat exchanger 29 is arranged to use the heat generated in the process of compressing the carbon dioxide for rich liquid regeneration, so that the heat supply load of the reboiler 23 can be further reduced, and the regeneration energy consumption of the system is reduced.

Alternatively, in one embodiment, the initial product gas S19 generated by regenerating the hot rich liquid S9 in the desorber 11 is discharged from the desorber top gas outlet and enters the carbon dioxide water wash tower 28 through the bottom gas inlet. The initial product gas S19 contains a small amount of volatile absorbent components and becomes purified product gas S20 after being removed in the carbon dioxide water scrubber 28. The purified product gas S20 is cooled by the condenser 30 and then enters the gas-liquid separator 31, the resulting condensed water S21 is refluxed to the carbon dioxide water scrubber 28 as scrubbing water, and the recovered water S22 having absorbed the volatilized absorbent component flows out from the liquid outlet at the bottom of the water scrubber and passes through the liquid inlet at the top of the desorption tower 11 to the desorption tower 11.

Specifically, in one embodiment, the carbon dioxide gas S23 discharged from the top outlet of the gas-liquid separator 31 enters the gas compressor 32 to be compressed, and is then cooled by the gas cooler 33, and thus is subjected to continuous three-stage compression cooling to obtain liquid carbon dioxide S24.

Alternatively, in one embodiment, the absorbent replenishment liquid S25 required for system operation is injected into the absorption liquid storage tank 27 through the inlet of the absorption liquid storage tank 27, and the regenerated cooled lean liquid S30 is transported from the bottom outlet of the absorption liquid storage tank 27 to the absorption liquid cooler 15 through the absorption liquid pump 41 and then injected into the absorption tower 11 after being cooled.

Further, please refer to fig. 1, which is a specific embodiment of the apparatus for absorbing and capturing carbon dioxide by amine method according to the present invention, further comprising a tower cooler 14 for cooling the absorption liquid, wherein a liquid inlet and a liquid outlet of the tower cooler 14 are respectively communicated with the absorption tower 10. In this manner, the lean liquid in the absorption tower 10 (or the middle lean liquid between the lean liquid and the rich liquid concentration) is cooled by the tower-stage cooler 14 and then refluxed into the absorption tower 10 (optionally: the lean liquid refluxed into the absorption tower 10 is sprayed down from the top of the absorption tower 10), so that the temperature of the lean liquid in the absorption tower 10 is lowered, thereby increasing the absorption liquid load (absorption liquid load: the amount of carbon dioxide absorbed per unit absorption liquid).

Alternatively, in one embodiment, the absorption liquid S3 entering the absorption tower 10 reacts with the carbon dioxide in an exothermic reaction, and the generated heat will cause the temperature of the absorption liquid to increase, which will reduce the amount of carbon dioxide absorbed by the absorption liquid, so that the higher temperature semi-lean liquid S7 is pumped out at the last stage of the absorption tower 10, cooled by the stage cooler 14, and then re-injected into the absorption tower. The initial rich liquid S4 after reaction is discharged from the liquid outlet at the bottom of the absorption tower 10, is conveyed by the rich liquid pump 18 to enter the heat exchanger from the cold side inlet of the first heat exchanger 19, is discharged from the cold side outlet of the first heat exchanger 19 after being heated and warmed, then enters the heat exchanger from the cold side inlet of the second heat exchanger 20, is discharged from the cold side outlet of the second heat exchanger 20 after being heated and warmed, enters the heat exchanger from the cold side inlet of the third heat exchanger 21, is discharged from the cold side outlet of the third heat exchanger 21 after being heated and warmed, and the obtained hot rich liquid S9 enters the desorption tower 11 from the second tower level liquid inlet of the desorption tower 11 for carbon dioxide regeneration.

Alternatively, in one embodiment, the medium-temperature lean liquid S11 (medium-temperature lean liquid S11: liquid output from the flash tank 24) is sent from the hot-side inlet of the first heat exchanger 19 into the first heat exchanger 19 through the lean liquid pump 26, and is discharged from the hot-side outlet of the first heat exchanger 19 into the absorption liquid storage tank 27 after being cooled and cooled.

Alternatively, in one embodiment, the inlet of the tower cooler 14 is connected to the last liquid outlet of the absorber tower 10, and the outlet of the tower cooler 14 is connected to the last liquid inlet of the absorber tower 10.

Further, please refer to fig. 1, as a specific embodiment of the apparatus for absorbing and capturing carbon dioxide by amine method provided by the present invention, the apparatus further comprises a flue gas pretreatment tower 12 for spraying alkali liquor, the bottom of the flue gas pretreatment tower 12 has a first flue gas inlet (not shown), the top of the flue gas pretreatment tower 12 has a first flue gas outlet (not shown), and the first flue gas outlet is communicated with the air inlet channel T21. Therefore, before the flue gas enters the absorption tower 10 from the gas inlet channel T21, the flue gas passes through the flue gas pretreatment tower 12 to be sprayed with alkali liquor for removing pollutants such as sulfur oxides and nitrogen oxides.

Alternatively, referring to FIG. 3, in one embodiment, the gas outlet of the flue gas pretreatment column 12 is connected to the gas inlet of the absorption column 10, the liquid outlet of the bottom of the flue gas pretreatment column 12 is connected to the inlet of the lye pump 38, the outlet of the lye pump 38 is connected to the inlet of the lye cooler 39, and the outlet of the lye cooler 39 is connected to the inlet of the top of the flue gas pretreatment column 12.

Alternatively, referring to fig. 4, in an embodiment, the initial flue gas S1 enters the flue gas pretreatment tower 12 from the gas inlet at the bottom thereof and reacts with the pretreatment alkaline solution S26 sprayed from the top of the flue gas pretreatment tower, so as to remove pollutants such as sulfur oxides and nitrogen oxides. The pretreated flue gas S2 enters the absorption tower 10 from the gas inlet at the bottom of the tower and reacts with the absorption liquid S3 sprayed from the top of the tower.

Further, please refer to fig. 1, as a specific embodiment of the apparatus for absorbing and capturing carbon dioxide by amine method provided by the present invention, the apparatus further includes a flue gas washing tower 13 for spraying water, the bottom of the flue gas washing tower 13 has a second flue gas inlet (not shown), the top of the flue gas washing tower 13 has a second flue gas outlet (not shown) communicated with the external space, and the second flue gas inlet is communicated with the exhaust passage T1. Therefore, the flue gas is cleaner after being sprayed and cleaned by the flue gas water washing tower 13, and the cleaned gas discharged from the second flue gas outlet is discharged to the external environment in a delayed way so as to reduce pollution.

Alternatively, in one embodiment, the gas inlet at the bottom of the flue gas washing tower 13 is connected with the gas outlet at the top of the absorption tower 10, the liquid outlet at the bottom of the flue gas washing tower 13 is connected with the inlet of the washing water pump 16, the outlet of the washing water pump 16 is connected with the inlet of the washing water cooler 17, and the outlet of the washing water cooler 17 is connected with the liquid inlet at the top of the flue gas washing tower 13.

Alternatively, in one embodiment, the decarbonized flue gas S5 is discharged from the top gas outlet of the absorption tower 10, enters the tower through the bottom gas inlet of the flue gas washing tower 13, contacts the washing tower spraying water S27 sprayed from the top of the tower, the volatile absorbent component entrained in the decarbonized flue gas S5 is absorbed by the washing water, and the resulting purified flue gas S6 is discharged from the top gas outlet of the washing tower and can be discharged into the atmosphere through a chimney.

Alternatively, in one embodiment, the absorber 10 liquid outlet is connected to the rich liquid pump 18 inlet, and the rich liquid pump 18 outlet is connected to the first heat exchanger 19 cold side inlet; the cold side outlet of the first heat exchanger 19 is connected with the cold side inlet of the second heat exchanger 20, and the cold side outlet of the second heat exchanger 20 is connected with the cold side inlet of the third heat exchanger 21; the cold side outlet of the third heat exchanger 21 is connected with the second tower level liquid inlet of the desorption tower 11; a first liquid outlet at the bottom of the desorption tower 11 is connected with a cold side inlet of a reboiler 23, and a cold side outlet of the reboiler 23 is connected with a first liquid inlet at the bottom of the desorption tower 11 (the desorption tower 11 forms a thermal cycle with the reboiler 23 through the first liquid outlet and the first liquid inlet); a second liquid outlet at the bottom of the desorption tower 11 is connected with an inlet of the flash tank 24, and a gas outlet at the top of the desorption tower 11 is connected with a gas inlet of a carbon dioxide water scrubber 28; a gas outlet of the flash tank gas 24 is connected with an inlet of a vapor compressor 25, and a liquid outlet of the flash tank 24 is connected with an inlet of a barren liquid pump 26; the outlet of the vapor compressor 25 is connected with the hot side inlet of the second heat exchanger 20, and the hot side outlet of the second heat exchanger 20 is connected with the first gas inlet at the bottom of the desorption tower 11; an outlet of the lean liquid pump 26 is connected with an inlet of a hot side of the first heat exchanger 19, and an outlet of the hot side of the first heat exchanger 19 is connected with an inlet of the absorption liquid storage tank 27; the outlet of the absorption liquid storage tank 27 is connected with the inlet of an absorption liquid pump 41, the outlet of the absorption liquid pump 41 is connected with the inlet of an absorption liquid cooler 15, and the outlet of the absorption liquid cooler 15 is connected with the liquid inlet at the top of the absorption tower 10. A gas inlet and a liquid outlet at the bottom of the carbon dioxide water washing tower 28 are respectively connected with a gas outlet and a liquid inlet at the top of the desorption tower 11, and a gas outlet and a liquid inlet at the top of the carbon dioxide water washing tower 28 are respectively connected with an inlet of a condenser 30 and a liquid outlet of a gas-liquid separator 31; the inlet and the gas outlet of the gas-liquid separator 31 are respectively connected with the outlet of the condenser 31 and the inlet of the gas compressor 32; the outlet of the gas compressor 32 is connected to the inlet of a gas cooler 33.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims (10)

1. The device for absorbing and capturing carbon dioxide by an amine method comprises an absorption tower, a desorption tower, an exhaust channel communicated with the desorption tower, an air inlet channel and an air outlet channel which are respectively communicated with the absorption tower, a reboiler for providing heat for the desorption tower, a barren solution channel respectively communicated with the absorption tower and the desorption tower, and a rich solution channel respectively communicated with the absorption tower and the desorption tower; the method is characterized in that: the carbon dioxide desorption tower further comprises a heat recovery mechanism which is used for recovering residual heat left when the carbon dioxide is released in the desorption tower and conducting the residual heat to the rich liquid channel.

2. The apparatus for absorbing and capturing carbon dioxide by amine method according to claim 1, wherein: the heat recovery mechanism includes a first heat exchanger through which the lean passage exchanges heat with the rich passage.

3. The apparatus for absorbing and capturing carbon dioxide by amine method according to claim 2, wherein: the heat recovery mechanism further comprises a second heat exchanger and a flash tank arranged on the lean liquid channel; the flash tank has a vapor passage in communication with the desorber; the steam passage exchanges heat with the rich liquid passage through the second heat exchanger.

4. The apparatus for absorbing and capturing carbon dioxide by amine method according to claim 3, wherein: a vapor compressor is also arranged on the vapor passage upstream of the second heat exchanger.

5. The apparatus for absorbing and capturing carbon dioxide by amine method according to claim 1, wherein: the heat exchanger also comprises a third heat exchanger, and the rich liquid channel exchanges heat with a water outlet pipe of the reboiler through the third heat exchanger.

6. The apparatus for absorbing and capturing carbon dioxide by amine method according to claim 1, wherein: the heat exchanger also comprises a fourth heat exchanger, and the exhaust passage exchanges heat with the rich liquid passage through the fourth heat exchanger.

7. The apparatus for absorbing and capturing carbon dioxide by amine method according to claim 1, wherein: the liquid-enriched air conditioner further comprises a fifth heat exchanger, a gas compressor is arranged on the exhaust passage, and the exhaust passage at the downstream of the gas compressor exchanges heat with the rich liquid passage through the fifth heat exchanger.

8. The apparatus for absorbing and capturing carbon dioxide by amine method according to claim 1, wherein: the absorption tower is characterized by further comprising a tower-grade cooler for cooling the absorption liquid, wherein a liquid inlet and a liquid outlet of the tower-grade cooler are respectively communicated with the absorption tower.

9. The apparatus for absorbing and capturing carbon dioxide by amine method according to claim 1, wherein: still including the flue gas preliminary treatment tower that is used for spraying alkali lye, the bottom of flue gas preliminary treatment tower has first flue gas inlet port, flue gas preliminary treatment tower top has first flue gas discharge port, first flue gas discharge port with inlet channel intercommunication.

10. The apparatus for absorbing and capturing carbon dioxide by amine method according to claim 1, wherein: still including the flue gas scrubbing tower that is used for the shower water, the bottom of flue gas scrubbing tower has the second flue gas inlet port, the top of flue gas scrubbing tower has the second flue gas discharge port with exterior space intercommunication, the second flue gas inlet with exhaust passage intercommunication.

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