CN214635243U

CN214635243U - Energy-conserving piece-rate system of carbon dioxide entrapment

Info

Publication number: CN214635243U
Application number: CN202120685543.7U
Authority: CN
Inventors: 王争荣; 汪洋; 王凯亮; 吴冲; 孙路长; 白永锋
Original assignee: China Huadian Engineering Group Co Ltd; Huadian Environmental Protection Engineering and Technology Co Ltd
Current assignee: China Huadian Engineering Group Co Ltd; Huadian Environmental Protection Engineering and Technology Co Ltd
Priority date: 2021-04-02
Filing date: 2021-04-02
Publication date: 2021-11-09
Anticipated expiration: 2031-04-02

Abstract

The utility model provides an energy-conserving piece-rate system of carbon dioxide entrapment belongs to carbon dioxide entrapment technical field, include: the system comprises an absorption tower, a regeneration tower and a reboiler, wherein a crude gas exhaust port is formed in the regeneration tower, the crude gas exhaust port is communicated with a spray tower, spray liquid is suitable for being contained in the spray tower, a spray pipeline is further arranged on the spray tower, one end of the spray pipeline leads to the spray liquid at the bottom of the spray tower, the other end of the spray pipeline leads to the inner cavity at the top of the spray tower, and a spray device is arranged at an outlet of one end of the spray pipeline, which leads to the inner cavity at the top of the spray tower; the utility model discloses an energy-conserving piece-rate system of carbon dioxide entrapment has the spray column at the coarse gas vent rear end intercommunication of regenerator column, follows regenerator column exhaust coarse carbon dioxide gas and is in cool down through spraying of liquid in the spray column to exhaust to the regenerator column carries out heat recovery, thereby reduces the power consumption of carbon dioxide entrapment system on the whole, reaches energy-conserving purpose.

Description

Energy-conserving piece-rate system of carbon dioxide entrapment

Technical Field

The utility model relates to a carbon dioxide entrapment technical field, concretely relates to energy-conserving piece-rate system of carbon dioxide entrapment.

Background

CCS technology is an abbreviation for Carbon Capture and Storage, a technology that captures and sequesters Carbon dioxide (CO 2). The CCS technology is a carbon capture technology that separates carbon dioxide produced by industry and related energy industries, and then transports and stores the separated carbon dioxide to places isolated from the atmosphere, such as the sea floor or the underground, by means of carbon storage.

CCS technology consists of two parts, carbon capture and carbon sequestration. Among them, the carbon capture technology is applied to industries such as oil refining and chemical industry for the earliest time. Due to the high concentration and pressure of CO2 emitted by these industries, the capture cost is not high. The opposite is true for CO2 emitted from coal-fired power plants, and carbon dioxide capture from power plant emissions has problems of high energy consumption and high cost.

The energy consumption of the carbon dioxide capture system is mainly the regeneration steam consumption of the regeneration tower, because the temperature difference between the lean solution at the bottom of the regeneration tower and the regeneration gas at the top of the regeneration tower is not large, the heat contained in the lean solution at the bottom of the regeneration tower and the heat contained in the regeneration gas at the top of the regeneration tower are relatively close, if the heat is recovered by the rich solution at the bottom of the absorption tower, the heat recovery of one stream in the lean solution at the bottom of the tower or the regenerator at the top of the tower can only be realized, the temperature difference between the heated rich solution and the temperature of the other stream is not large, the heat recovery of the other stream can not be realized, and the other stream can only be cooled by circulating cooling water at present, so that about half of the heat is wasted. Meanwhile, because the regeneration gas is saturated gas containing inert gas, a dividing wall type heat exchanger is generally used for heat exchange, and because the influence of the inert gas on the heat exchange coefficient of the regeneration gas side is small, the regeneration gas cooler needs a large heat exchange area.

SUMMERY OF THE UTILITY MODEL

Therefore, the to-be-solved technical problem of the utility model lies in overcoming the too high defect of energy consumption of the carbon dioxide entrapment system for power plant among the prior art to provide an energy-conserving piece-rate system of carbon dioxide entrapment.

In order to solve the technical problem, the utility model provides an energy-conserving piece-rate system of carbon dioxide entrapment, include:

one end of the absorption tower is communicated with a flue gas outlet of the power plant, the absorption tower is suitable for containing absorption liquid, and the absorption liquid in the absorption tower absorbs carbon dioxide in the flue gas and then becomes rich liquid;

the regeneration tower is communicated with rich liquid in the absorption tower through a pipeline, a crude gas exhaust port is formed in the regeneration tower and is communicated with a spray tower, spray liquid is suitable for being contained in the spray tower, a spray pipeline is further arranged on the spray tower, one end of the spray pipeline leads to the spray liquid at the bottom of the spray tower, the other end of the spray pipeline leads to the inner cavity at the top of the spray tower, and a spray device is arranged at an outlet of one end of the spray pipeline, which leads to the inner cavity at the top of the spray tower, of the spray tower;

and the reboiler is communicated with the regeneration tower and is used for vaporizing the rich liquid entering the regeneration tower into a gas-liquid two-phase state, wherein the liquid phase is changed into a lean liquid, and the gas phase is discharged from a crude gas exhaust port of the regeneration tower.

Optionally, the spray pipe is provided with a spray liquid heat exchanger.

Optionally, the spray pipe is arranged at the front end of the spray liquid heat exchanger and is further communicated with a return pipe, and the return pipe leads to an inner cavity at the top end of the regeneration tower.

Optionally, the return pipe is further communicated with an outer discharge pipe.

Optionally, the top end of the spray tower is provided with a secondary exhaust port, and the secondary exhaust port is communicated with a compressor.

Optionally, a demister is arranged at the front end of the secondary exhaust port of the spray tower.

Optionally, the absorption tower is provided with a self-circulation pipeline, one end of the self-circulation pipeline is communicated with the tower bottom absorption liquid of the absorption tower, and the other end of the self-circulation pipeline is communicated with the tower top inner cavity of the absorption tower.

Optionally, a self-circulation heat exchanger is arranged on the self-circulation pipeline.

Optionally, a spraying device is arranged on an outlet of one end of the self-circulation pipeline, which leads to the tower top inner cavity of the absorption tower.

Optionally, a tail gas emptying port is arranged on the absorption tower, a tail gas heat exchanger is arranged at the front end of the tail gas emptying port, and the tail gas heat exchanger is arranged above the self-circulation pipeline.

The utility model discloses technical scheme has following advantage:

the utility model provides an energy-conserving piece-rate system of carbon dioxide entrapment has the spray column at the coarse gas vent rear end intercommunication of regenerator column, is in from regenerator column exhaust coarse carbon dioxide gas the spraying through spraying liquid is cooled down in the spray column to exhaust to the regenerator column carries out heat recovery, thereby reduces the power consumption of carbon dioxide entrapment system on the whole, reaches energy-conserving purpose.

In addition, because the crude carbon dioxide gas is saturated gas containing inert gas, the crude carbon dioxide gas is sprayed and cooled by the spraying liquid to be cooling water and gas directly contacted for heat exchange, the heat exchange efficiency is high, the influence of the inert gas on the heat exchange coefficient when a dividing wall type heat exchanger is adopted for heat exchange is avoided, and the investment of crude carbon dioxide gas cooling equipment is reduced. In addition, the carbon dioxide gas at the top of the spray tower enters a downstream compressor, and the low-temperature water separated at the bottom of the spray tower can exchange heat with the crude carbon dioxide gas firstly, so that the temperature of the crude carbon dioxide gas is reduced, and the waste heat of the crude carbon dioxide gas is recycled for one time.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic diagram of a carbon dioxide capture energy-saving separation system provided in embodiment 1 of the present invention.

Fig. 2 is a schematic diagram of a carbon dioxide capture energy-saving separation system provided in embodiment 2 of the present invention.

Fig. 3 is an enlarged view of the spray tower region of fig. 2.

Description of reference numerals:

1. an absorption tower; 2. a regeneration tower; 3. a spray tower; 4. a tail gas evacuation port; 5. a reboiler; 6. a crude gas vent; 7. a tail gas heat exchanger; 8. a self-circulating pump; 9. a rich liquid supply pipe; 10. a barren liquor return pipe; 11. a lean-rich liquid heat exchanger; 12. a barren liquor heat exchanger; 13. pre-washing the tower; 14. a flue gas inlet; 15. pre-washing the circulating pump; 16. a washing liquid heat exchanger; 17. a pH value detection element; 18. a spray liquid heat exchanger; 19. a return line; 20. an outer discharge pipe; 21. a secondary exhaust port; 22. a demister; 23. a primary heat exchanger; 24. a compressor.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Furthermore, the technical features mentioned in the different embodiments of the invention described below can be combined with each other as long as they do not conflict with each other.

The present embodiment provides an energy-saving carbon dioxide capture separation system, as shown in fig. 1, including: the absorption tower 1, the regeneration tower 2 and the spray tower 3 are arranged in sequence. One end of an inlet of the absorption tower 1 is used for being communicated with a flue gas outlet of a power plant, absorption liquid is contained in the absorption tower 1, and the absorption liquid becomes rich liquid after absorbing carbon dioxide in flue gas; and a tail gas emptying port 4 is arranged at the top of the absorption tower 1, and after the flue gas is fully contacted with the absorption liquid, the flue gas is discharged out of the system from the tail gas emptying port 4.

The regeneration tower 2 is communicated with the rich liquid in the absorption tower 1 through a pipeline, the tower bottom of the regeneration tower 2 is communicated with a reboiler 5, the reboiler 5 is used for vaporizing the rich liquid entering the regeneration tower 2 into a gas-liquid two-phase, the liquid phase is changed into a lean liquid, and the gas phase is discharged from a crude gas exhaust port 6 of the regeneration tower 2. Specifically, the reboiler 5 heats the rich solution through steam, the steam used by the reboiler 5 is extracted from a steam turbine, and after the steam turbine is extracted in the reboiler 5 for heat exchange and condensation, condensed water returns to a deaerator of the thermodynamic system.

The tower top of the regeneration tower 2 is provided with a crude gas exhaust port 6, the crude gas exhaust port 6 is communicated with a spray tower 3, spray liquid is arranged in the spray tower 3, the spray tower 3 is also provided with a spray pipeline, one end of the spray pipeline is communicated with the spray liquid at the tower bottom of the spray tower 3, the other end of the spray pipeline is communicated with the inner cavity at the tower top of the spray tower 3, and an outlet at one end of the spray pipeline, which is communicated with the inner cavity at the tower top of the spray tower 3, is provided with a spray device; after the regenerated gas separated out from the regeneration tower 2 enters the spray tower 3, the temperature of the regenerated gas is reduced by spraying the spray liquid, so that the water content of the regenerated gas is reduced.

The energy-conserving piece-rate system of carbon dioxide entrapment that this embodiment provided, the thick gas vent 6 rear end intercommunication at regenerator 2 has spray column 3, and the thick carbon dioxide gas of follow regenerator 2 exhaust is in cool down through spraying of spray liquid in the spray column 3, and the carbon dioxide gas of spray column tower top gets into the downstream compressor, and the low temperature water of separation at the bottom of the tower can be earlier with thick carbon dioxide gas heat transfer to carry out heat recovery to regenerator 2's exhaust, reduce carbon dioxide entrapment system's regenerator steam consumption, reach energy-conserving purpose.

In addition, since the crude carbon dioxide gas is a saturated gas containing an inert gas, water is further precipitated from the crude carbon dioxide gas in the process of spraying and cooling the crude carbon dioxide gas by the spraying liquid, and the moisture content of the captured carbon dioxide can be reduced.

As shown in fig. 1, in the above-described energy-saving carbon dioxide capture separation system, the absorption tower 1 is provided with an off-gas heat exchanger 7 at the front end of the off-gas vent 4, and the temperature of the flue gas discharged from the absorption tower 1 is recovered by the off-gas heat exchanger 7. Specifically, the tail gas heat exchanger 7 is a wide-channel plate heat exchanger, the escape rate of the absorbent from the top of the absorption tower 1 can be reduced through the plate heat exchanger, and the wide-channel plate heat exchanger has the advantages of small heat exchange end difference, large heat exchange coefficient and the like.

As shown in fig. 1, in the above energy-saving separation system for capturing carbon dioxide, a self-circulation pipeline is arranged below the tail gas heat exchanger 7 on the absorption tower 1, one end of the self-circulation pipeline is led into the tower bottom absorption liquid of the absorption tower 1, the other end of the self-circulation pipeline is led into the tower top inner cavity of the absorption tower 1, a spraying device is arranged at an outlet of one end of the self-circulation pipeline which is led into the tower top inner cavity of the absorption tower 1, the absorption liquid is sprayed from top to bottom in the absorption tower 1 through the spraying device, so that the absorption liquid and the flue gas are in convection, and the carbon dioxide in the flue gas is absorbed through the absorption liquid. The self-circulation heat exchanger is arranged on the self-circulation pipeline, the absorption liquid is cooled through the self-circulation heat exchanger, the self-circulation pipeline is further provided with a self-circulation pump 8, the self-circulation pump 8 is used for forcibly driving the absorption liquid to flow in the self-circulation pipeline, so that the tower temperature of the absorption tower 1 is controlled, the absorption capacity of the absorption liquid in unit mass is increased, and the absorption capacity of the absorption liquid is changed by controlling the tower temperature of the absorption tower 1 through the self-circulation system.

As shown in fig. 1, in the above-described energy-saving carbon dioxide capture separation system, a rich liquid supply pipe 9 and a lean liquid return pipe 10 are provided between the absorption tower 1 and the regeneration tower 2, the regeneration tower 2 communicates with the rich liquid in the absorption tower 1 through the rich liquid supply pipe 9, one end of the rich liquid supply pipe 9 extends from the tower bottom of the absorption tower 1 into the absorption tower 1, the other end of the rich liquid supply pipe 9 extends from the tower top of the regeneration tower 2 into the regeneration tower 2, the rich liquid enters the tower top of the regeneration tower 2 from the absorption tower 1 and is sprayed downward from the inside of the tower top of the regeneration tower 2 in a spraying manner, and carbon dioxide gas contained in the rich liquid is deposited. One end of the barren solution return pipe 10 is communicated to the inside of the bottom end of the regeneration tower 2, the other end of the barren solution return pipe 10 is communicated to the inside of the tower top of the absorption tower 1, and the barren solution is sprayed in the tower top of the absorption tower 1 in a spraying mode. In addition, the lean liquid return pipe 10 and the rich liquid supply pipe 9 are connected through a lean-rich liquid heat exchanger 11, that is, after the hot lean liquid in the lean liquid return pipe 10 transfers heat to the rich liquid in the rich liquid supply pipe 9 through the lean-rich liquid heat exchanger 11, the lean liquid in the lean liquid return pipe 10 returns to the absorption tower 1 again, so as to recover the heat of the lean liquid in the regeneration tower 2; in addition, a lean solution heat exchanger 12 is further provided on the lean solution return pipe 10, and the lean solution is further cooled by the lean solution heat exchanger 12 to recover the absorption of the absorption liquid for the carbon dioxide in the flue gas.

As shown in fig. 1, the energy-saving carbon dioxide capture separation system further includes: and an inlet at one end of the absorption tower 1 is connected with an outlet of the pre-washing tower 13 so as to be communicated with the flue gas of the thermal power plant. The pre-washing tower 13 is provided with a flue gas inlet 14, the flue gas inlet 14 is used for communicating with desulfurized flue gas, and the flue gas enters the pre-washing tower 13 through the flue gas inlet 14; the prewashing tower 13 is mainly used for removing trace acid gases in the flue gas, reducing the temperature of the flue gas through circulating spraying of alkali liquor, and reducing the moisture content and the volume of the flue gas. The top of the pre-washing tower 13 has an outlet which is communicated to the inlet of the absorption tower 1 through a booster fan. The prewashing tower 13 is provided with a circulating pipeline, two ends of the circulating pipeline are respectively communicated with the bottom end and the top end of the prewashing tower 13, the circulating pipeline is connected with a prewashing circulating pump 15, washing liquid in the prewashing tower 13 is conveyed to the tower top from the tower bottom through the prewashing circulating pump 15, and the washing liquid returns to the tower bottom again in the tower top in a spraying mode; during the process that the flue gas flows from the flue gas inlet 14 to the outlet in the pre-washing tower 13, the flue gas and the washing liquid flow in a convection manner, so that the flue gas is pre-washed by the washing liquid. In addition, as a preferred embodiment, a washing liquid heat exchanger 16 is further connected to the circulation pipeline, and the washing liquid heat exchanger 16 is used for cooling the washing liquid, so as to control the outlet flue gas temperature of the prewashing tower, namely the inlet temperature of the absorption tower 1, and adjust the water balance of the absorption liquid of the absorption and collection system. In addition, as a preferred embodiment, a PH value detecting element 17 is further connected in parallel to the circulating pipeline, and the PH value detecting element 17 is used for detecting the PH value of the washing solution in real time so as to supplement the alkaline washing solution in time.

As a preferred embodiment, as shown in fig. 2 and 3, in the above-mentioned energy-saving carbon dioxide capturing and separating system, a primary heat exchanger 23 is provided in a regeneration gas pipe between the regeneration tower 2 and the spray tower 3; the primary heat exchanger 23 is used for carrying out primary cooling on the regeneration gas discharged from the regeneration tower 2 so as to recover the waste heat of part of the regeneration gas.

The spray pipeline is provided with a spray liquid heat exchanger 18, and the spray liquid heat exchanger 18 is used for exchanging heat for the circulating spray liquid.

As shown in fig. 3, a return pipe 19 is further connected to the spray pipe for circulating the spray liquid connected to the spray tower 3, the return pipe 19 is connected to the front end of the spray liquid heat exchanger 18, the return pipe 19 leads to the top end inner cavity of the regeneration tower 2, and a part of the spray liquid is returned to the regeneration tower 2 through the return pipe 19.

As a preferred embodiment, the return line 19 may pass through a primary heat exchanger 23 on the regeneration gas line to exchange heat with the regeneration gas by means of a spray liquid; the return line 19 may not pass through the primary heat exchanger 23.

In addition, the return pipe 19 is also communicated with an external discharge pipe 20, and the external discharge pipe 20 is used for discharging the excessive moisture precipitated from the carbon dioxide gas to the outside of the system, and can be sent to a power plant desulfurization system for recycling.

As shown in fig. 3, the spray tower 3 has a secondary exhaust port 21 at the top end thereof, and the secondary exhaust port 21 communicates with a compressor 24, and the compressor 24 compresses the carbon dioxide gas. A demister 22 is provided at the front end of the secondary exhaust port 21 of the spray tower 3, and the water content of the carbon dioxide gas discharged from the spray tower 3 is reduced by the demister 22.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious changes and modifications may be made without departing from the scope of the present invention.

Claims

1. A carbon dioxide capture economized separation system, comprising:

one end of the absorption tower (1) is communicated with a flue gas outlet of a power plant, the absorption tower is suitable for containing absorption liquid, and the absorption liquid in the absorption tower (1) absorbs carbon dioxide in the flue gas and then becomes rich liquid;

the regeneration tower (2) is communicated with rich liquid in the absorption tower (1) through a pipeline, a crude gas exhaust port (6) is formed in the regeneration tower (2), the crude gas exhaust port (6) is communicated with the spray tower (3), the spray tower (3) is suitable for containing spray liquid, a spray pipeline is further arranged on the spray tower (3), one end of the spray pipeline leads to the spray liquid at the bottom of the spray tower (3), the other end of the spray pipeline leads to the inner cavity at the top of the spray tower (3), and a spray device is arranged at an outlet of one end of the spray pipeline, which leads to the inner cavity at the top of the spray tower (3);

and the reboiler (5) is communicated with the regeneration tower (2) and is used for vaporizing the rich liquid entering the regeneration tower (2) into a gas-liquid two-phase state, wherein the liquid phase is changed into a lean liquid, and the gas phase is discharged from a crude gas exhaust port (6) of the regeneration tower (2).

2. The energy-saving carbon dioxide capture separation system of claim 1, wherein the spray pipeline has a spray liquid heat exchanger (18) thereon.

3. The energy-saving carbon dioxide capture separation system according to claim 2, characterized in that the spray pipeline is connected with a return pipeline (19) at the front end of the spray liquid heat exchanger (18), and the return pipeline (19) is opened into the top end inner cavity of the regeneration tower (2).

4. The energy-saving carbon dioxide capture separation system according to claim 3, wherein the return conduit (19) is further communicated with an external discharge conduit (20).

5. The energy-saving carbon dioxide capture separation system according to claim 1, wherein the top end of the spray tower (3) has a secondary exhaust port (21), and the secondary exhaust port (21) is communicated with a compressor (24).

6. The energy-saving carbon dioxide capturing separation system according to claim 5, wherein a demister (22) is provided at the front end of the secondary exhaust port (21) of the spray tower (3).

7. The energy-saving carbon dioxide capture separation system according to any one of claims 1 to 6, wherein the absorption tower (1) is provided with a self-circulation pipeline, one end of the self-circulation pipeline is opened into the absorption liquid at the bottom of the absorption tower (1), and the other end of the self-circulation pipeline is opened into the inner cavity at the top of the absorption tower (1).

8. The energy-saving carbon dioxide capture separation system of claim 7, wherein the self-circulation pipeline is provided with a self-circulation heat exchanger.

9. The energy-saving carbon dioxide capturing and separating system as claimed in claim 7, wherein a spraying device is arranged on an outlet of one end of the self-circulation pipeline, which leads to the tower top inner cavity of the absorption tower (1).

10. The energy-saving carbon dioxide capturing and separating system according to claim 7, wherein the absorption tower (1) is provided with a tail gas evacuation port (4), the front end of the tail gas evacuation port (4) is provided with a tail gas heat exchanger (7), and the tail gas heat exchanger (7) is arranged above the self-circulation pipeline.