JP2014108389A - Carbon dioxide recovery apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently recover thermal energy required for regenerating an absorbing solution while reducing cost required for a compressor by maintaining a low temperature of the compressor.SOLUTION: A carbon dioxide recovery apparatus 100 includes: an absorption part 120; a regeneration part 140; a passing line 210 through which recovery gas X including carbon dioxide and stream discharged from the regeneration part 140 passes; a plurality of stages of compression parts 220, 222, 224 installed in the passing line and compressing the recovery gas X; a temperature measurement part 280 for measuring an outlet temperature of each of the compression parts; a rotational frequency control part 282 for controlling rotational frequency of each of the compression parts so that the temperature measured by the temperature measurement part reaches 200°C or lower; and a heat exchange part (second heat exchange part 320) for recovering heat generated along with compression of the recovery gas X by the compression parts downstream of the compression parts and supplying the heat to the regeneration part.

Description

  The present invention relates to a carbon dioxide recovery device that separates and recovers carbon dioxide from a mixed gas containing carbon dioxide such as exhaust gas accompanying combustion.

In plants such as thermal power plants, steelworks, and boilers, a large amount of fossil fuel (for example, coal, heavy oil, super heavy oil) is burned. Therefore, exhaust gas containing carbon dioxide (CO ₂ ), sulfur oxide (SOx), and nitrogen oxide (NOx) is discharged from the plant as the fossil fuel burns. Among the substances contained in exhaust gas, carbon dioxide is a cause of global warming, and its emissions into the atmosphere are regulated by the United Nations Framework Convention on Climate Change.

  Therefore, a technology (CCS) that separates and recovers carbon dioxide from exhaust gas containing carbon dioxide such as exhaust gas accompanying combustion and exhaust gas accompanying processes, and then exhausts the exhaust gas from which carbon dioxide has been removed to the atmosphere (CCS). : Carbon dioxide Capture and Storage) has been developed. A carbon dioxide recovery device using CCS makes an absorption liquid (an absorption liquid that does not absorb carbon dioxide, hereinafter referred to as a lean absorption liquid) contact with exhaust gas to absorb carbon dioxide contained in the exhaust gas lean. An absorption tower that removes carbon dioxide from exhaust gas by absorbing the liquid, and a regeneration tower that releases carbon dioxide from an absorption liquid that absorbs carbon dioxide (hereinafter referred to as a rich absorption liquid) and regenerates it into a lean absorption liquid The lean absorbent regenerated in the regeneration tower is reused in the absorption tower. The carbon dioxide released from the regeneration tower is compressed by the compressor and is not discharged into the atmosphere, but is stored in an underground aquifer or underground oil field, or dissolved in the ocean or river. To do.

  In the regeneration tower, in order to release carbon dioxide from the rich absorbent, it is necessary to heat the rich absorbent. Therefore, in order to reduce the operating cost of the carbon dioxide recovery device as a whole, reduction of energy required for the heating is desired.

  Therefore, a plurality of compressors are provided in series on the downstream side of the regeneration tower, and the heat generated when the recovered gas containing carbon dioxide and water vapor discharged from the regeneration tower is compressed by the compressor is recovered, and the recovered heat Has been disclosed (for example, Patent Document 1).

JP 2012-538 A

  However, in the technique of Patent Document 1 described above, the temperature of the compressor after compressing the recovered gas is not considered, and depending on the temperature of the recovered gas discharged from the regeneration tower and the ratio of carbon dioxide in the recovered gas The compressor temperature sometimes exceeded 200 ° C. Therefore, the members such as the impeller of the compressor need to be made of a special material having heat resistance enough to withstand even when the temperature exceeds 200 ° C., which increases the cost of the compressor.

  Therefore, in view of such problems, the present invention is configured to keep the temperature of the compressor low, thereby efficiently recovering the thermal energy required to regenerate the absorbing liquid while reducing the cost of the compressor. An object of the present invention is to provide a carbon dioxide recovery device that can perform the above-described process.

  In order to solve the above-mentioned problem, the carbon dioxide recovery device of the present invention is configured to bring a gas containing carbon dioxide into contact with an absorption liquid, absorb the carbon dioxide in the absorption liquid, and generate a carbon dioxide-containing absorption liquid. A carbon dioxide-containing absorbent, heating the carbon dioxide-containing absorbent, and releasing the carbon dioxide from the carbon dioxide-containing absorbent, thereby regenerating the carbon dioxide-containing absorbent into the absorbent, and discharging the carbon dioxide-containing absorbent. A passage line through which the recovered gas containing carbon dioxide and water vapor passes, a plurality of compression sections provided in the passage line for compressing the recovery gas, and outlet temperatures of the compression sections of the plurality of stages are measured. A temperature measuring unit, a rotation number control unit for controlling the number of rotations of the plurality of compression units such that an outlet temperature measured by the temperature measurement unit is 200 ° C. or less, and a downstream side of the compression unit There were collected the heat generated during compression of the collected gas in said compression unit, characterized in that and a heat exchange unit for supplying to the reproducing unit.

  In addition, a gas-liquid separation unit that is provided in the passage line and separates water condensed from the recovered gas by collecting heat by the heat exchange unit is provided on the upstream side of the gas-liquid separation unit. The number of the compression parts may be larger than the number of the compression parts provided on the downstream side of the gas-liquid separation part.

  Moreover, the said heat exchange part is good also as collect | recovering the heat | fever which the condensed water isolate | separated by the said gas-liquid separation part has.

  According to the present invention, it is possible to efficiently recover thermal energy while reducing the cost of the compressor by configuring the compressor to keep the temperature low.

It is a figure for demonstrating the structure of a carbon dioxide collection apparatus.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

(CO2 recovery device 100)
FIG. 1 is a diagram for explaining a configuration of a carbon dioxide recovery device 100 according to the present embodiment. As shown in FIG. 1, the carbon dioxide recovery device 100 includes a carbon dioxide separation and recovery unit 110 and a carbon dioxide compression unit 200.

  The carbon dioxide separation / recovery unit 110 separates carbon dioxide from the gas G containing carbon dioxide, and the carbon dioxide compression unit 200 compresses the carbon dioxide separated in the carbon dioxide separation / recovery unit 110. Hereinafter, specific configurations of the carbon dioxide separation and recovery unit 110 and the carbon dioxide compression unit 200 will be described.

(Carbon dioxide separation and recovery unit 110)
The absorption part (absorption tower) 120 is composed of, for example, a counter-current gas-liquid contact device, and brings a gas G containing carbon dioxide into contact with an absorption liquid (hereinafter, referred to as a lean absorption liquid L) to obtain a lean absorption liquid L absorbs carbon dioxide to produce a carbon dioxide-containing absorbent (hereinafter referred to as rich absorbent R).

  Here, the gas G is, for example, an exhaust gas accompanying combustion or an exhaust gas accompanying a process. The gas G is a temperature suitable for efficiently absorbing the carbon dioxide into the lean absorbent L in the absorption unit 120 (for example, 40 ° C). In addition, when the exhaust gas accompanying combustion and a process is high temperature, you may introduce | transduce into the absorption part 120, after cooling with a separate cooling device. The lean absorbent L is composed of an aqueous solution containing, as an absorbent, a compound having affinity for carbon dioxide such as alkanolamines, for example.

  Moreover, the absorption part 120 is provided with the filler 122 for enlarging the contact area of the lean absorption liquid L and the gas G in the inside. The filler 122 is made of an iron-based metal material such as stainless steel or carbon steel.

  In this embodiment, the gas G is introduced from the lower part of the absorption part 120, and the lean absorbent L is introduced from the upper part of the absorption part 120. Then, the gas G passes from the lower part to the upper part of the absorber 120 and the lean absorbent L passes from the upper part to the lower part of the absorber 120, that is, while the gas G and the lean absorbent L pass through the filler 122. The carbon dioxide in the gas G is absorbed by the lean absorbent L by contacting the gas and liquid. The gas C from which carbon dioxide has been removed is discharged from the top of the absorber 120. The lean absorbing liquid L generates heat by absorbing carbon dioxide, and the liquid temperature of the rich absorbing liquid R rises, so that the cooling condensing part 124 for removing water vapor or the like that can be contained in the gas C is absorbed by the absorbing part. You may provide in the upper part of 120.

  The delivery line 130 is a line (pipe) that connects the lower part of the absorption unit 120 and the upper part of the regeneration unit 140 described later.

  The preheating unit 132 collects heat (sensible heat) of the lean absorbent L flowing through a return line 160 described later, and heats the rich absorbent R flowing through the feed line 130.

  In addition, the rich absorbent R heated by the preheating unit 132 is further heated by the first heat exchange unit 310 described later in the delivery line 130. The heat treatment by the first heat exchange unit 310 will be described in detail later.

  The regeneration unit (regeneration tower) 140 is constituted by, for example, a countercurrent gas-liquid contact device, heats the rich absorbent R sent from the absorber 120 through the delivery line 130, and generates carbon dioxide from the rich absorbent R. By releasing, the rich absorbent R is regenerated to the lean absorbent L. Specifically, the reproduction unit 140 includes a main body 142 and a reboiler 150. The main body 142 is provided with a filler 144 made of an iron-based metal material such as stainless steel or carbon steel, for example, in the same manner as the absorbing portion 120.

  The reboiler 150 includes a circulation line 152 and a heating unit 154, and refluxes the rich absorbent R in the main body 142. Specifically, the circulation line 152 circulates the rich absorbent R by re-introducing the rich absorbent R from the bottom of the main body 142 and then reintroducing it into the main body 142. The heating unit 154 is composed of a steam heater, an electric heater, or the like, and heats the rich absorbent R flowing through the circulation line 152. In the circulation line 152, the rich absorbent R is also heated by a second heat exchange unit 320 described later. The heat treatment performed by the second heat exchange unit 320 will be described in detail later.

  The return line 160 is a line (pipe) that connects the bottom of the main body 142 and the top of the absorber 120.

(Flow of absorption liquid)
Subsequently, the flow of the absorbing liquid in the carbon dioxide separation and recovery unit 110 will be described. The rich absorbent R generated in the absorption unit 120 and stored at the bottom of the absorption unit 120 is sent to the top of the main body 142 of the regeneration unit 140 through the delivery line 130 by the pump 170a. The rich absorbent R is heated by the preheating unit 132 and the first heat exchange unit 310 while passing through the delivery line 130.

  The rich absorbent R introduced into the regeneration unit 140 passes through the filler 144 in the main body 142, is stored at the bottom of the main body 142, and is heated by the reboiler 150. Then, carbon dioxide is released from the rich absorbent R at the bottom of the main body 142 by heating by the reboiler 150.

  The lean absorbent L regenerated by releasing carbon dioxide in the regeneration unit 140 is returned to the upper part of the absorption unit 120 through the return line 160 by the pump 170b. Thus, the absorbing liquid circulates between the absorbing unit 120 and the regenerating unit 140. The lean absorbent L is cooled by the preheating unit 132 and the cooling unit 162 to a temperature suitable for carbon dioxide absorption in the absorption unit 120 while passing through the return line 160.

  On the other hand, the carbon dioxide released from the rich absorbent R in the regeneration unit 140 is discharged to the carbon dioxide compression unit 200 together with the water vapor.

(CO2 compression unit 200)
The passage line 210 is a line (pipe) through which the recovered gas X (carbon dioxide and water vapor) discharged from the regeneration unit 140 constituting the carbon dioxide separation and recovery unit 110 passes. Here, the temperature of the recovered gas X discharged from the regeneration unit 140 is, for example, 110 ° C., and the ratio of carbon dioxide: water vapor is 1: 1.

  The first compression unit 220 is provided in the passage line 210 and compresses the recovered gas X discharged from the regeneration unit 140 to, for example, 500 kPa (A). Note that Pa (A) indicates an absolute pressure with the absolute vacuum set to zero. The second compression unit 222 is provided in the passage line 210 and further compresses the recovered gas X compressed by the first compression unit 220 (for example, 900 kPa (A)). The third compression unit 224 is provided in the passage line 210 and compresses the recovered gas X compressed by the second compression unit 222 to, for example, 1300 kPa (A).

  The temperature measurement unit 280 measures the outlet temperature of the first compression unit 220, the outlet temperature of the second compression unit 222, and the outlet temperature of the third compression unit 224, respectively.

  The rotation speed control unit 282 is configured by a semiconductor integrated circuit including a central processing unit (CPU), a ROM storing a program, a RAM as a work area, and the like, and includes a first compression unit 220 and a second compression unit 222. The number of rotations of the third compression unit 224 is controlled.

  In the present embodiment, the rotation speed control unit 282 is configured so that the outlet temperature of the first compression unit 220 measured by the temperature measurement unit 280 is 200 ° C. or lower, that is, the recovery compressed by the first compression unit 220. The rotation speed of the first compression unit 220 is controlled so that the temperature of the gas X is 200 ° C. or less. Further, the rotational speed control unit 282 is configured so that the outlet temperature of the second compression unit 222 measured by the temperature measurement unit 280 is 200 ° C. or lower, that is, the recovered gas X compressed by the second compression unit 222. The rotation speed of the second compression unit 222 is controlled so that the temperature becomes 200 ° C. or lower. Further, the rotation speed control unit 282 is configured so that the outlet temperature of the third compression unit 224 measured by the temperature measurement unit 280 is 200 ° C. or lower, that is, the recovered gas X compressed by the third compression unit 224. The rotation speed of the third compression unit 224 is controlled so that the temperature becomes 200 ° C. or lower.

  By doing so, members such as an impeller constituting the compression parts 220, 222, and 224 can be made of an inexpensive material, and the cost of the compression part can be reduced. In addition, since compressors having a heat resistant temperature of members such as impellers of about 200 ° C. are generally widely distributed, such compressors can be easily used for the compression units 220, 222, and 224. .

  The second heat exchanging unit 320 includes the recovered gas X from the first compression unit 220 on the downstream side of the first compression unit 220, the downstream side of the second compression unit 222, and the downstream side of the third compression unit 224. Heat (sensible heat) generated with compression of the gas, heat generated with compression of the recovered gas X by the second compression unit 222 (latent heat), and compression of the recovered gas X by the third compression unit 224 The accompanying heat (sensible heat) is recovered to heat the rich absorbent R flowing through the circulation line 152 that constitutes the carbon dioxide separation and recovery unit 110 described above.

  For example, the recovered gas X (for example, 200 ° C.) on the downstream side of the first compression unit 220 is cooled to 140 ° C. by the second heat exchange unit 320. The recovered gas X (for example, 200 ° C.) on the downstream side of the second compression unit 222 is cooled to 130 ° C. by the second heat exchange unit 320. The recovered gas X (for example, 170 ° C.) on the downstream side of the third compression unit 224 is cooled to 130 ° C. by the second heat exchange unit 320. Along with this, the 120 ° C. rich absorbent R flowing through the circulation line 152 is heated to 130 ° C. by the second heat exchange unit 320.

  Here, the recovered gas X is compressed by the second compression unit 222, and when heat is recovered by the second heat exchange unit 320, the water vapor in the recovered gas X is condensed into water. Therefore, the first gas-liquid separation unit 230 is provided on the downstream side of the second compression unit 222, on the downstream side of the second heat exchange unit 320, and on the upstream side of the third compression unit 224.

  The first gas-liquid separation unit 230 is provided on the downstream side of the second compression unit 222, and heat (latent heat) is recovered by the second heat exchange unit 320, so that water condensed in the recovered gas X ( Condensed water) is separated from the recovered gas X.

  The first heat exchange unit 310 includes heat (sensible heat) of the recovered gas X cooled by the second heat exchange unit 320 on the downstream side of the third compression unit 224, and the first gas-liquid separation unit 230. The heat (sensible heat) of the condensed water separated is recovered, and the rich absorbent R flowing through the delivery line 130 described above is heated.

  For example, the recovered gas X (for example, 130 ° C.) cooled by the second heat exchange unit 320 is cooled to 120 ° C. by the first heat exchange unit 310. Accordingly, the 110 ° C. rich absorbent R flowing through the delivery line 130 is heated to 120 ° C. by the first heat exchanging section 310.

  The second gas-liquid separation unit 250 is provided on the downstream side of the third compression unit 224, and heat (sensible heat) is recovered by the first heat exchange unit 310 and further cooled by the cooling unit 252. The water condensed in the recovered gas X (condensed water) is separated from the recovered gas X.

  The first condensed water introduction line 260 is downstream of the bottom of the first gas-liquid separation unit 230 and the third compression unit 224 in the passage line 210, and performs heat recovery by the second heat exchange unit 320. This is a line (pipe) that connects a place to be performed and a place to perform heat recovery by the first heat exchange unit 310. The first condensed water introduction line 260 is provided with a pump 260a, and the condensed water separated in the first gas-liquid separation unit 230 is passed through the first condensed water introduction line 260 by the pump 260a. In the passage line 210, the heat is recovered by the second heat exchange unit 320 and the heat recovery by the first heat exchange unit 310 is introduced.

  Thereby, the 1st heat exchange part 310 can collect | recover the heat | fever (sensible heat) of the condensed water which the 1st gas-liquid separation part 230 isolate | separated. Therefore, the heat of the condensed water separated by the first gas-liquid separation unit 230 can be efficiently used.

  The 2nd condensed water introduction line 270 is a line (pipe) which connects between the bottom part of the 2nd gas-liquid separation part 250, and the pump 170b and the cooling part 162 in the return line 160 mentioned above. The second condensed water introduction line 270 is provided with a cooling unit 272 and a pressure adjustment valve 274. The condensed water separated in the second gas-liquid separation unit 250 is cooled by the cooling unit 272, and the pressure is reduced. The pressure is adjusted by the regulating valve 274 and introduced between the pump 170 b and the cooling unit 162 in the return line 160 described above through the second condensed water introduction line 270.

  As described above, when the regeneration unit 140 is heated to release carbon dioxide from the rich absorbent R, water (water vapor) is released from the rich absorbent R together with carbon dioxide. If it does so, the quantity of the water in the lean absorption liquid L reproduced | regenerated by the reproduction | regeneration part 140 will fall, and the density | concentration of an absorber will rise. Therefore, the condensed water derived from water vapor (condensed water separated by the second gas-liquid separator 250) contained in the recovered gas X discharged from the regenerator 140 is converted into the lean absorbent L regenerated by the regenerator 140. By mixing, the concentration of the absorbent of the lean absorbent L used in the absorber 120 can be optimized.

  Here, although the structure which returns condensed water to the reproduction | regeneration part 140 is considered, the temperature of condensed water is very low temperature rather than the temperature of the lean absorption liquid L (or rich absorption liquid R) in the reproduction | regeneration part 140. FIG. Therefore, when the condensed water is returned to the regeneration unit 140, the temperature of the lean absorbent L (or the rich absorbent R) is lowered in the regeneration unit 140, and heat energy is lost. That is, in the regeneration unit 140, additional heat energy is required to release carbon dioxide from the rich absorbent R.

  Therefore, by introducing the condensed water separated in the second gas-liquid separation unit 250 to the return line 160, the lean absorbent L is maintained at an optimal concentration while suppressing the loss of thermal energy in the regeneration unit 140. It becomes possible to do.

(About the layout design of the compression part)
Then, the design method of the number of the compression parts at the time of designing the carbon dioxide recovery apparatus 100 is demonstrated. First, the temperature required for separation of the absorbent and carbon dioxide in the regeneration unit 140 is determined according to the type of absorbent used in the carbon dioxide recovery device 100 (for example, 120 ° C.). Then, in consideration of heat loss (for example, 10 ° C.) in the second heat exchange unit 320, the fluid after the heat exchange in the second heat exchange unit 320 is 130 ° C. (120 ° C. + 10 ° C.). The recovered gas X is compressed in the compression section until a proper pressure is reached. Here, since the pressure when water condenses at 130 ° C. is 1300 kPa, the pressure of the recovered gas X finally compressed by the compression unit is set to 1300 kPa.

  Further, it is assumed that the temperature of the recovered gas X discharged from the regeneration unit 140 is 110 ° C. and the ratio of water vapor: carbon dioxide is 1: 1. Then, in order to compress the recovered gas X so that the final pressure of the recovered gas X is 1300 kPa and the temperature of the recovered recovered gas X is 200 ° C. or less, respectively, Will need at least three. More specifically, for example, when it is calculated that the number of compression parts for compressing the recovery gas X to a pressure at which the temperature of the recovery gas X is 200 ° C. or less is 2.67, The minimum number is calculated as 3 by rounding up the decimal point. In this way, the minimum number of compression units on the downstream side of the reproduction unit 140 is determined.

  Further, in the recovered gas X discharged from the regeneration unit 140, when the ratio of water vapor to carbon dioxide is large, even if the compression rate is low (even if the pressure of the recovered gas X after compression is small), Water vapor condenses. Accordingly, the number of compression units on the upstream side of the first gas-liquid separation unit 230 that separates the condensed water is smaller than the number of compression units on the downstream side of the first gas-liquid separation unit 230.

  On the other hand, in the recovered gas X discharged from the regeneration unit 140, when the ratio of water vapor to carbon dioxide is small, even if the compression rate is high (even if the pressure of the recovered gas X after compression is large), Water vapor does not condense. Accordingly, the number of compression units on the upstream side of the first gas-liquid separation unit 230 that separates the condensed water is larger than the number of compression units on the downstream side of the first gas-liquid separation unit 230.

  Further, by providing more compression units on the upstream side than the downstream side of the first gas-liquid separation unit 230, it becomes possible to improve the recovery efficiency of sensible heat in addition to the recovery of latent heat.

  In recent years, the development of absorbents capable of separating carbon dioxide at a lower temperature has been promoted. That is, the ratio of water vapor to carbon dioxide in the recovered gas X discharged from the regeneration unit 140 tends to be small. Therefore, it is preferable to arrange more compression units on the upstream side than the downstream side of the first gas-liquid separation unit 230.

  As described above, according to the carbon dioxide recovery device 100 according to the present embodiment, the compressors 220, 222, and 224 are applied to the compressors 220, 222, and 224 by being configured to keep the temperatures of the compressors 220, 222, and 224 low. It is possible to efficiently recover thermal energy while reducing costs.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  For example, in the above-described embodiment, the compression units 220, 222, and 224 may be configured by separate compressors, may be configured by a single-shaft multi-stage compressor, or may be of geared type. You may comprise with one compressor.

  In addition, the case where the fillers 122 and 144 are made of an iron-based metal material such as stainless steel or carbon steel has been described as an example. However, the durability and resistance to the processing temperature of the lean absorbent L and the rich absorbent R are described. A corrosive material having a shape capable of providing a desired contact area may be appropriately selected.

  In the above-described embodiment, the rotation speed control unit 282 controls the rotation speeds of the compression units 220, 222, and 224 so that the outlet temperatures of the compression units 220, 222, and 224 are 200 ° C. or less. . However, the rotational speed control by the rotational speed control unit 282 is not limited as long as the compression efficiency of the compression parts 220, 222, and 224 can be controlled so that the outlet temperatures of the compression units 220, 222, and 224 become 200 ° C. or less. For example, when the compression units 220, 222, and 224 include unloaders, the unloader may be controlled so that the outlet temperatures of the compression units 220, 222, and 224 become 200 ° C. or less.

  INDUSTRIAL APPLICABILITY The present invention can be used for a carbon dioxide recovery device that separates and recovers carbon dioxide from a mixed gas containing carbon dioxide such as exhaust gas accompanying combustion.

DESCRIPTION OF SYMBOLS 100 ... Carbon dioxide recovery device 120 ... Absorption part 130 ... Sending line 140 ... Reproduction | regeneration part 160 ... Return line 210 ... Passing line 220 ... 1st compression part (compression part)
222 ... 2nd compression part (compression part)
224 ... Third compression unit (compression unit)
230 ... 1st gas-liquid separation part 250 ... 2nd gas-liquid separation part (gas-liquid separation part)
280 ... Temperature measurement unit 282 ... Rotational speed control unit 310 ... First heat exchange unit 320 ... Second heat exchange unit (heat exchange unit)

Claims (3)

An absorption part for bringing a gas containing carbon dioxide into contact with an absorption liquid, causing the absorption liquid to absorb carbon dioxide, and generating a carbon dioxide-containing absorption liquid;
A heating unit that heats the carbon dioxide-containing absorption liquid and releases carbon dioxide from the carbon dioxide-containing absorption liquid, thereby regenerating the carbon dioxide-containing absorption liquid into the absorption liquid;
A passing line through which the recovered gas containing carbon dioxide and water vapor discharged from the regeneration section passes;
A plurality of compression sections provided in the passage line and compressing the recovered gas;
A temperature measuring unit for measuring an outlet temperature of each of the plurality of compression units;
A rotation speed control unit that controls the rotation speeds of the compression units of the plurality of stages so that the outlet temperature measured by the temperature measurement unit is 200 ° C. or less;
A heat exchanging unit that recovers heat generated by the compression of the recovered gas in the compression unit on the downstream side of the compression unit and supplies the heat to the regeneration unit;
A carbon dioxide recovery device comprising: A gas-liquid separation unit that is provided in the passage line and separates the condensed water by collecting heat by the heat exchange unit from the collected gas;
The number of the said compression parts provided in the upstream of the said gas-liquid separation part is more than the number of the said compression parts provided in the downstream of this gas-liquid separation part, The dioxide dioxide of Claim 1 characterized by the above-mentioned. Carbon recovery device.   The carbon dioxide recovery device according to claim 2, wherein the heat exchange unit recovers heat of the condensed water separated by the gas-liquid separation unit.

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