JP6953777B2 - Carbon dioxide recovery system and recovery method - Google Patents

Description

The present invention can be used for purifying exhaust gas by separating, removing or recovering carbon dioxide from a gas containing carbon dioxide such as combustion gas by utilizing the movement of substances in contact between gas and liquid. Regarding carbon dioxide recovery system and recovery method.

Conventionally, in chemical plants, thermal power plants, etc., a gas separation device that separates, removes, or recovers a specific gas from a gas to be treated such as an exhaust gas containing various types of gases has been used by using gas-liquid contact. There is. For example, in a carbon dioxide recovery system, carbon dioxide is absorbed and separated by using an absorption device that brings a gas containing carbon dioxide into contact with an absorption liquid such as a monoethanolamine aqueous solution, and the absorbed liquid after absorption is heated while air-liquid. Carbon dioxide is released into the gas phase and recovered using a contacting regeneration device. In addition, gas purification devices for removing harmful gas components from exhaust gas and gas separation devices for separating specific gas components from mixed gas also use gas-liquid contact to absorb specific gas components by the absorbing liquid. Will be done. Further, gas-liquid contact is also used in a cooling device for cooling a high-temperature liquid or gas.

In general, a device that performs gas-liquid contact has a filler for increasing the contact area between the liquid and the gas, and the liquid and the gas are brought into gas-liquid contact on the surface of the filler to bring a specific gas in the gas. Allows liquids to absorb ingredients and heat. Various forms of fillers have been proposed that are useful for increasing the gas-liquid contact area. However, irregular fillings with complicated shapes and structures require time and effort to process and load. Therefore, in the industrial field where large-capacity processing is performed, from the viewpoint of reducing manufacturing costs and simplifying work labor, Absorption devices that use regular fillers with a simple structure are being used.

When carbon dioxide is recovered from exhaust gas generated in industrial equipment, a large amount of exhaust gas is emitted. Improper operation to stop the intake of exhaust gas for maintenance and repair of the recovery system can overwhelm the equipment and cause adverse effects. Patent Document 1 below describes the intake of exhaust gas so that the equipment is not loaded when the intake of exhaust gas is stopped.

In addition, the amount of exhaust gas emitted varies depending on the operating status of the equipment. For example, in a thermal power generation facility, since power is generated based on power demand, the amount of exhaust gas emitted fluctuates according to the amount of power generated. Therefore, in order to treat the exhaust gas emitted from the power generation facility, the recovery system is required to have a function capable of coping with fluctuations in the amount of emission. In Patent Document 2 below, it is described that the circulation amount of the absorbing liquid and the heating amount for regeneration are changed according to the fluctuation of the flow rate and the temperature of the exhaust gas. On the other hand, in Patent Document 3 below, in order to maintain the carbon dioxide recovery rate even if the amount of exhaust gas fluctuates, the carbon dioxide concentration of the exhaust gas is detected and the treatment rate of the exhaust gas is determined based on the detected concentration. Is described.

Japanese Patent No. 5039651 Japanese Patent No. 5237204 Japanese Unexamined Patent Publication No. 2013-158685

In an absorber having a filler or a gas-liquid contact plate, the gas or liquid contact efficiency decreases due to the drift of gas or liquid due to the shape and structure of the filler surface, and the pressure loss due to the gas flow resistance increases sharply. A flooding phenomenon (a state in which the flow and drip of a liquid is blocked by a gas flow pressure) and the like occur. Therefore, in the design of the absorber, an appropriate flow rate range for gas treatment is set in consideration of the above points. When treating a large flow rate of exhaust gas emitted from industrial equipment, it is difficult to design a large-scale absorption device that can be dealt with independently from the viewpoint of construction and installation conditions, so there are multiple depending on the exhaust gas emission scale. A system that can handle the flow rate of exhaust gas is constructed by combining the absorption devices of.

On the other hand, when the gas flow rate is lower than the appropriate range set in the absorption device, the carbon dioxide absorption itself is good, but the processing efficiency is lowered. Therefore, in a system in which a plurality of absorption devices are combined, if the flow rate of each absorption device is uniformly adjusted, the operating efficiency of the system as a whole can be significantly reduced when the exhaust gas emission amount is reduced.

Further, when the flow rate of the exhaust gas decreases and the amount of carbon dioxide absorbed per unit of the absorbing liquid (maximum carbon dioxide concentration) decreases, the utilization efficiency of the absorption capacity in the absorbing liquid decreases. Therefore, the consumption of the absorbent due to the regeneration treatment is more likely to proceed than the amount of gas treated.

The present invention has been devised in view of the above-mentioned problems, and when carbon dioxide is recovered from gas using a plurality of absorption devices, the gas flow rate in each absorption device is always maintained within an appropriate range. As described above, it is an object of the present invention to provide a carbon dioxide recovery system and a carbon dioxide recovery method capable of adjusting the gas distribution to each absorption device in response to fluctuations in the flow rate of the introduced gas.

In order to solve the above problems, the present inventors examined the relationship between the gas flow rate and the absorption efficiency in the absorption device, and found that in the parallel processing using a plurality of absorption devices, the treatment was performed at a gas flow rate less than a predetermined value. It was found that good gas treatment can be realized without lowering the utilization efficiency by performing gas distribution that avoids it.

According to one aspect of the present invention, the carbon dioxide recovery system is a plurality of absorption devices that recover carbon dioxide by a chemical absorption method, and a supply system capable of distributing and supplying the introduced gas to the plurality of absorption devices. An adjusting mechanism capable of adjusting the flow rate of the gas supplied to each of the plurality of absorption devices, and a gas in the absorbing device to which the gas is supplied by controlling the adjusting mechanism according to the fluctuation of the flow rate of the introduced gas. It is a gist to have a control mechanism for changing the flow rate of the gas supplied to each of the plurality of absorption devices so that the flow rate of the gas is maintained at or above the minimum value of the gas flow rate that can be efficiently processed in the absorption device. And.

The adjusting mechanism is provided to the supply system so that the number of absorption devices to which gas is supplied among the plurality of absorption devices can be changed and the flow rate of gas supplied to each of the plurality of absorption devices can be changed. Includes multiple flow control valves installed.

When each of the plurality of absorbers has a processing capacity such that the gas flow rates that can be efficiently processed are substantially equal, the control mechanism has a detector for detecting the gas flow rate to be introduced. When the gas flow rate detected by the detector is equal to or greater than the product of the minimum value and the number of the plurality of absorption devices, the control mechanism supplies the gas flow rate to each of the plurality of absorption devices. The adjustment mechanism is controlled so as to be equal to or more than the minimum value of the flow, whereby gas is supplied to all of the plurality of absorption devices, and the gas flow rate detected by the detector is the minimum value and the plurality of absorptions. When it is less than the product of the number of devices, the adjustment mechanism is controlled so as to stop the supply to a part of the plurality of absorption devices and maintain the gas flow rate in the other absorption devices at the minimum value or more. Can be set as. In this embodiment, the control mechanism is substantially evenly distributed to all of the plurality of absorbers when the gas flow rate detected by the detector is greater than or equal to the product of the minimum value and the total number of absorbers. The adjusting mechanism can be controlled so that the gas is supplied. Alternatively, the control mechanism supplies gas at the maximum value of the gas flow rate that can be processed by the absorption device when the gas flow rate detected by the detector is equal to or greater than the product of the minimum value and the total number of absorption devices. The adjustment mechanism can be controlled so that the number of absorption devices to be generated is maximized. Further, in the control mechanism, when the gas flow rate detected by the detector is less than the product of the minimum value and the number of the plurality of absorption devices, the gas flow rate in the absorption device to which the gas is supplied is substantially. The adjustment mechanism can be controlled so as to be equal to.

Each of the plurality of absorption devices is a device that recovers carbon dioxide by bringing the absorbing liquid into gas-liquid contact with the gas and absorbing carbon dioxide contained in the gas, and the carbon dioxide recovery system further comprises. A plurality of regenerating devices having the same number as the plurality of absorbing devices, and the plurality of absorbing devices and the plurality of regenerating devices, which regenerate the absorbed liquid by releasing carbon dioxide from the absorbing liquid that has absorbed the carbon dioxide by heating. It is a circulation system that can circulate the absorbing liquid between them, and the plurality of absorbing devices and the plurality of regenerating devices are connected so as to form a pair, and the absorbing liquid is connected between the paired absorbing device and the regenerating device. The control mechanism includes the circulation system in which the gas is circulated and a circulation adjustment mechanism capable of adjusting the flow rate of the absorption liquid circulating in the circulation system flowing through each of the plurality of absorption devices. In each of the above, the circulation adjusting mechanism can be controlled in response to the control of the adjusting mechanism so that the absorbing liquid flows at a flow rate corresponding to the flow rate of the supplied gas.

Alternatively, the carbon dioxide recovery system further comprises one or more regeneration devices, which are fewer in number than the plurality of absorption devices, which regenerate the absorption solution by releasing carbon dioxide from the absorption solution that has absorbed carbon dioxide by heating. A circulation system capable of circulating an absorption liquid between the plurality of absorption devices and the one or more regeneration devices, and the absorption liquids that have absorbed carbon dioxide by the plurality of absorption devices are once integrated and described in the above 1. The plurality of absorption devices and the one or more regeneration devices so that the absorption liquid supplied to the one or more regeneration devices and regenerated by the one or more regeneration devices is distributed and refluxed to the plurality of absorption devices. It has the circulation system connecting the above and a circulation adjustment mechanism capable of adjusting the flow rate of the absorption liquid circulating in the circulation system flowing through each of the plurality of absorption devices, and the control mechanism has the plurality of absorptions. Each of the devices can be configured to control the circulation adjusting mechanism in response to the control of the adjusting mechanism so that the absorbing liquid flows at a flow rate corresponding to the flow rate of the supplied gas. When the number of the one or more regenerating devices is plural, the connection between the plurality of absorbing devices and the plurality of regenerating devices in the circulatory system is such that the absorbing liquid once integrated has absorbed carbon dioxide. It is preferable that the absorbing liquids that are distributed and supplied to the regenerating device and regenerated by the plurality of regenerating devices are once integrated and distributed and refluxed to the plurality of absorbing devices.

Further, according to one aspect of the present invention, the method for recovering carbon dioxide is a plurality of absorption steps for recovering carbon dioxide by a chemical absorption method, and a supply in which the introduced gas is distributed and supplied to the plurality of absorption steps. The gas in the step, the adjustment step of adjusting the flow rate of the gas supplied to each of the plurality of absorption steps, and the gas in the absorption step in which the gas is supplied by controlling the adjustment step according to the fluctuation of the flow rate of the introduced gas. It is a gist to have a control step of changing the flow rate of the gas supplied to each of the plurality of absorption steps so that the flow rate of the gas is maintained at or above the minimum value of the gas flow rate that can be efficiently processed in the absorption step. And.

By distributing the gas according to the fluctuation of the flow rate of the exhaust gas discharged from the industrial equipment such as the power generation equipment, the gas flow rate in each of the plurality of parallel absorption devices is maintained in an appropriate range, so that the operation efficiency of the absorption device is always good. Therefore, it is possible to provide a carbon capture system with good energy efficiency during operation.

The schematic block diagram which shows the 1st Embodiment of the carbon dioxide capture system. The schematic block diagram which shows the 2nd Embodiment of the carbon dioxide capture system. The schematic block diagram which shows the 3rd Embodiment of the carbon dioxide capture system. The schematic block diagram which shows the 4th Embodiment of the carbon dioxide capture system.

Embodiments of the present invention will be described below, by way of example only, with reference to the accompanying drawings. The dimensions, materials, other specific numerical values, etc. shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention. In the specification and drawings, elements having substantially the same function and configuration are designated by the same reference numerals to omit duplicate description, and elements not directly related to the present invention are not shown. do.

The carbon dioxide recovery system according to the present invention can be roughly described, for example, as shown in FIG. 1, and has a plurality of absorption devices that recover carbon dioxide by a chemical absorption method. Although FIG. 1 describes a recovery system having two absorption devices in parallel, the configuration of the present invention can be more useful in a recovery system with a large number of absorption devices and can improve efficiency in parallel processing. In the figure, the electrical connection is shown by a broken line.

The recovery system 1 has a plurality of absorption devices 2A and 2B, and a supply system capable of distributing and supplying the introduced gas G to the plurality of absorption devices 2A and 2B. The supply system is composed of a flow path 3 whose outlet side is branched into a plurality of flow paths 3a and 3b, and gas G introduced from the inlet side of the flow path 3 is supplied to each of the absorption devices 2A and 2B through the flow path 3. As described above, the absorbers 2A and 2B are connected by the flow path 3. The absorption devices 2A and 2B bring the absorbing liquid into gas-liquid contact with the gas G to absorb the carbon dioxide contained in the gas G into the absorbing liquid, whereby the carbon dioxide is recovered from the gas G. This embodiment has two absorption devices 2A and 2B, and the gas G is configured to be distributed and supplied to the two absorption devices. The recovery system 1 further has a plurality of flow rate adjusting valves 4A and 4B as an adjusting mechanism capable of adjusting the gas flow rate, and is installed in each of the branched flow paths 3a and 3b. Therefore, the flow rate of the gas G supplied to each of the absorption devices 2A and 2B can be adjusted by controlling the flow rate adjusting valves 4A and 4B. Since the flow rate adjusting valves 4A and 4B can stop the supply of the gas G, the control of the flow rate adjusting valves 4a and 4B not only changes the gas flow rate supplied to each of the plurality of absorption devices 2A and 2B, but also absorbs a plurality of absorption devices. It is also possible to change the number of absorption devices to which the gas G is supplied among the devices 2A and 2B.

The recovery system 1 further includes a detector 5 that detects the flow rate of the gas G introduced into the system, and a control device 6 that controls the flow rate adjusting valves 4A and 4B based on the detection value of the detector 5. Each of the detector 5 and the flow rate adjusting valves 4A and 4B is electrically connected to the control device 6, and the value detected by the detector 5 is transmitted to the control device 6 as an electric signal. In the control device 6, the gas G in which the gas flow rate in the absorption devices 2A and 2B is maintained at or above the minimum value (that is, within an appropriate range) of the gas flow rate that can be efficiently processed by the absorption devices 2A and 2B. The supply distribution of is determined by arithmetic processing. According to this distribution, a control signal corresponding to the flow rate of the gas supplied to each of the absorption devices 2A and 2B is transmitted to each of the flow rate adjusting valves 4A and 4B. That is, the detector 5 and the control device 6 function as a control mechanism for controlling the adjustment mechanism, and the flow rate of the gas supplied to each of the plurality of absorption devices 2A and 2B according to the flow rate fluctuation of the introduced gas G. To change. Detectors 7A and 7B are installed in the branched flow paths 3a and 3b, respectively, to detect the actual gas flow rate in the flow paths 3a and 3b. The detectors 7A and 7B are incorporated in the electrical connection system of the flow rate adjusting valves 4A and 4B, and the flow rate adjustment by the flow rate adjusting valves 4A and 4B is determined by the control device 6 with reference to these detected values. Monitored to correspond.

In general, the efficiency of gas processing in an absorber depends on the performance of the filler used. The performance of the filler is expressed by a numerical value called HETP (filling height per theoretical plate number), and the smaller this numerical value is, the better the performance is evaluated. In the performance evaluation of various fillers, the relationship between the HETP value and the F factor (the product of the gas flow rate and the square root of the gas density) has been investigated, and known literature (see: Anil Krishana JAMMULA, "NEW LIQUID HOLDUP" , LOAD POINT AND FLOODING VELOCITY MODELS IN DIFFERENT REGIONS OF OPERATIONS FOR A ATRUCTURED PACKED COLUMN "(Dec. 2014), submitted to the Faculty of the Graduate College of the Oklahoma State University) There is a range in the F factor (particularly, page 76 of the above document, FIG. 4.9). That is, if the F factor is a value outside this range, the HETP value becomes very high. This means that the performance of the filler is improved when the gas flow rate, which is an element of the F factor, is within a specific range. That is, the gas processing efficiency in the absorber has a correlation with the gas flow rate, and there is a suitable gas flow rate range in which good processing efficiency can be achieved.

In the design of the absorber, the processable gas flow rate (processing capacity) is set in the range of the superficial velocity (the speed at which the gas can flow without the filler being loaded) or less. In a general commercially available filler, the range of the F factor at which the above-mentioned HETP value becomes the minimum is generally about 0.5 to 2.5, and if it exceeds this range, flooding occurs. Therefore, the absorber is generally designed so that the gas flow rate in the operable range is included in the gas flow rate range corresponding to the F factor of 0.5 to 2.5 as much as possible, and the operating efficiency is increased. From this point of view, the maximum value (maximum processing capacity) of the gas flow rate that can be processed is set to correspond to an F factor of 0.5 to 2.5. That is, the maximum value of the suitable gas flow rate range in the absorption device is designed to be the gas flow rate during operation at 100% of the processing capacity. This means that there is a low flow rate range where the F factor is less than 0.5, i.e., there is a flow rate range outside the suitable gas flow rate range. According to this, the suitable gas flow rate range of the absorption device is, for example, about 0.25 to 1 times the ratio based on the maximum flow rate set in the device. Then, when the gas flow rate is lower than the suitable flow rate range, the processing efficiency is remarkably reduced, which is not preferable in terms of the operating balance of the absorber. Therefore, treatment below a suitable flow rate range should be avoided. In this regard, in a recovery system using a plurality of absorption devices, even if the flow rate is less than the suitable flow rate range for all the absorption devices, the flow rate in the other absorption devices is stopped by stopping the supply to some of the absorption devices. It is possible to improve the processing efficiency per device. That is, the gas supply need not be limited to a supply that is evenly distributed to all the absorbers. Therefore, when the flow rate of the gas to be introduced fluctuates and the gas flow rate in each absorption device is less than the suitable flow rate range when the gas is evenly distributed, the supply to some of the absorption devices may be stopped. As a result, the supply flow rate to each absorption device can be adjusted so that the flow rate in the remaining absorption devices reaches a suitable flow rate range. As a result, the absorber can be operated efficiently.

Therefore, the carbon dioxide recovery method implemented in the recovery system 1 is a plurality of absorption steps for recovering carbon dioxide by a chemical absorption method in a plurality of absorption devices 2A and 2B, and a gas to be introduced is distributed to a plurality of absorption steps. In response to fluctuations in the flow rate of the gas introduced by the control device 6, the supply step of adjusting the flow rate of the gas supplied to each of the plurality of absorption steps using the flow rate adjusting valves 4A and 4B, and the control device 6 It has a control process for controlling the adjustment process. In the control step, the flow rate of the gas supplied to each of the plurality of absorption steps is changed so that the flow rate of the gas in the absorption step is maintained above the minimum value of the gas flow rate that can be efficiently processed in the absorption step. .. An example of such control will be specifically described below with reference to FIG. However, although the number of absorption devices in the recovery system of FIG. 1 is 2, the following description will be generalized to a system having several n absorption devices, not limited to the case where the number of absorption devices is two. ..

The recovery system 1 of FIG. 1 is configured by using a plurality of absorption devices 2A and 2B having substantially the same processing capacity. Therefore, the range of suitable gas flow rates that can be efficiently processed in each absorption device can be regarded as substantially the same, and the maximum value V (maximum flow rate) and the minimum value v (minimum flow rate) of the suitable flow rate range can be regarded as substantially the same. It can be set uniformly for all absorption devices. When the gas can be supplied to all the absorption devices at a flow rate equal to or higher than the minimum flow rate by equal distribution of the introduced gas, the gas flow rate s to be introduced satisfies the condition 1 shown by the following formula, and the minimum value v and the number of absorption devices are satisfied. It is equal to or greater than the product of n (in the equation, n is a natural number of 2 or more), and r is the ratio of the minimum value to the maximum value (= v / V).

(Number 1)
s ≧ nv = n (rV) [Condition 1]

When the gas flow rate s to be introduced fluctuates within the above range, the flow rate of the gas supplied to each absorption device is uniformly changed and adjusted to maintain even distribution, or a part of the absorption device. It is possible to respond to fluctuations in the flow rate of the introduced gas by any adjustment of adjusting the supply flow rate so as to change only the supply flow rate.

On the other hand, when the gas flow rate s to be introduced does not satisfy the condition 1 (that is, s <nv), the supply to a part (at least one) absorption device is stopped, and the flow rate in the remaining absorption device is the minimum. It is controlled to be maintained above the value v. In this case, the number n'(n'is a natural number of n or less) of the absorption devices for which the supply is stopped is a value that satisfies the condition 2 represented by the following formula.

(Number 2)
(Nv-s) / v ≤ n'≤ n- (s / V) [Condition 2]

When there are a plurality of number n'satisfying the condition 2, it is preferable to determine the number n'so that the fluctuation of the number n'of the absorption device stopped due to the fluctuation of the flow rate of the introduced gas is small, whereby the absorption device is stopped. / It is possible to reduce the repetition of restarting. Preferably, it is preferable that the number n'to be stopped is not changed, and the supply flow rate to each absorption device can be changed.

Alternatively, the distributed supply may be performed so that the number of absorption devices to which the gas is supplied at the maximum value V of the gas flow rate that can be processed is maximized. In this case, the maximum value of the number n'that satisfies the condition 2 is obtained, and the supply to the absorption device of the number n'is stopped. Further, the maximum value of the number x (x is a natural number of n or less) satisfying the condition 3 of the following equation is obtained, and the supply flow rate in the absorption device of the number x is set to the maximum value V. The supply flow rate of the remaining number (n−n′−x) in the absorber is (s−xV) / (n−n′−x).

(Number 3)
v ≤ s-xV [Condition 3]

As a simple example, assume a recovery system having two absorbers in which the ratio r (= v / V) of the minimum value v and the maximum value V in the appropriate range of gas flow rate is 25%. When the flow rate of the gas introduced into the recovery system is less than 25% (less than 0.5V) of the maximum processing flow rate (2V), by stopping one absorption device, processing with a gas flow rate within an appropriate range can be performed. It is possible. For example, when one absorption device is stopped and all the gas is supplied to the other absorption device at 15% (0.3V) of the maximum processing flow rate, the gas flow rate in this absorption device becomes the maximum value V. It becomes 30% and exceeds the minimum value in the appropriate range. When the number of absorption devices is 2, if the gas flow rate to be introduced is 12.5% or more of the maximum processing flow rate, processing can be performed with a gas flow rate within an appropriate range. When the number of absorption devices is n, the introduced gas flow rate is 25 / n% or more of the maximum processing flow rate, and the gas flow rate in an appropriate range can be used for processing.

The supply control as described above is carried out by the detector 5, the control device 6, and the flow rate adjusting valves 4A and 4B. The control device 6 determines the above condition 1 based on the gas flow rate s detected by the detector 5, and the gas flow rate s detected by the detector 5 has a minimum value v and a plurality of absorption devices 2A and 2B. When the product is equal to or greater than the product of the number n, an electric signal for controlling the flow rate adjusting valves 4A and 4B is transmitted so that the gas flow rates supplied to each of the plurality of absorption devices 2A and 2B are equal to or greater than the minimum value v. As a result, the gas G is supplied to all of the plurality of absorbers 2A and 2B. At this time, when gas is supplied to all of the plurality of absorption devices 2A and 2B substantially evenly, the value obtained by dividing the introduced gas flow rate s by the number n of the absorption devices is supplied to each absorption device. It is determined as the flow rate, and the corresponding electric signal is transmitted to control the flow rate adjusting valves 4A and 4B.

When the gas flow rate s detected by the detector 5 is less than the product of the minimum value v and the number n of the plurality of absorption devices, the number n'of the absorption devices for stopping the supply is set to satisfy the above condition 2. 'Determine. Based on this determination, an electrical signal is transmitted to control the flow control valve so as to stop the supply to some of the plurality of absorbers and maintain the gas flow rate in the other absorbers above the minimum value v. As a result, in the absorption device to which the gas G is supplied, the supply in a suitable flow rate range is ensured. At this time, when adjusting so that the gas flow rates in the absorption device to which the gas is supplied are substantially equal, the gas flow rate s to the number (n-n') of the absorption devices is s / (n-n'). ), The flow rate adjusting valves 4A and 4B are controlled.

The recovery system 1 of FIG. 1 further has a plurality of regenerating devices 8A and 8B, and the number of regenerating devices is the same as that of the absorbing device. Further, the recovery system 1 has a circulatory system composed of supply paths 9A and 9B and return paths 10A and 10B, and the circulatory system includes a plurality of absorption devices 2A and 2B and a plurality of regeneration devices 8A and 8B, respectively. Form two paths that connect in pairs. Therefore, the absorbing liquid can be circulated independently of each other through the circulation system between the paired absorbing device 2A and the regenerating device 8A, and the absorbing device 2B and the regenerating device 8B. The regenerating devices 8A and 8B are devices that heat the absorbing liquid that has absorbed carbon dioxide and release carbon dioxide from the absorbing liquid to regenerate the absorbing liquid. The absorption liquid L'that absorbed carbon dioxide from the gas G in each of the absorption devices 2A and 2B is regenerated by heating in each of the regeneration devices 8A and 8B, and the regenerated absorption liquid L is in the absorption devices 2A and 2B. It is refluxed to each. The circulation of the absorption liquids L and L'is urged by the pump P provided in the circulation system.

As described above, the flow rate of the gas supplied to each of the absorbers 2A and 2B is changed by the fluctuation of the flow rate of the gas G introduced into the recovery system 1. Correspondingly, in order to adjust the flow rate of the absorbing liquid supplied (circulated) to each of the absorbing devices 2A and 2B to an appropriate amount, the flow rate adjusting valves 11A, 11B, 12A and 12B have the supply paths 9A, It is installed in 9B and the return passages 10A and 10B, respectively. That is, the flow rate adjusting valves 11A, 11B, 12A, and 12B function as a circulation adjusting mechanism capable of adjusting the flow rate of the absorbing liquid circulating in the circulation system flowing through each of the plurality of absorbing devices 2A and 2B. The control mechanism of the recovery system 1 controls the circulation adjustment mechanism in response to the control of the adjustment mechanism, and the absorption liquid flows in each of the plurality of absorption devices 2A and 2B at a flow rate corresponding to the flow rate of the supplied gas. It is configured as follows. Specifically, the flow rate adjusting valves 11A, 11B, 12A, and 12B are electrically connected to the control device 6, and when the gas flow rate distributed and supplied to the absorption devices 2A and 2B is determined by the control device 6, the flow rate adjusting valves 11A, 11B, 12A, and 12B are electrically connected to the control device 6. The flow rate adjusting valves 11A, 11B, 12A, 12B are controlled so that the absorbing liquid circulates through the absorbing devices 2A and 2B at the corresponding flow rates. Detectors 13A, 13B, 14A, 14B are attached to the circulation system to monitor the flow rate of the absorbing liquid, and the flow rate adjusting valves 11A, 11B, 12A, 12B appropriately adjust the flow rate based on these detected values. It is controlled via an electrical connection so that it does. The flow rate of the absorption liquid may be adjusted so as to be proportional to the flow rate of the gas supplied to the absorption device, but the flow rate is not limited to this, and the flow rate adjustment of the absorption liquid is set in consideration of the absorption characteristics of the absorption liquid to be used. can do.

Therefore, the absorbing liquid is supplied to the upper part of each of the absorbing devices 2A and 2B at an appropriate flow rate adjusted according to the flow rate of the gas G supplied to each of the absorbing devices 2A and 2B, and the filler is loaded. It absorbs carbon dioxide from the gas G while flowing down the gas-liquid contact portion F. The absorbing liquid L'flowing down to the bottom of the absorbing devices 2A and 2B and temporarily stored is supplied to the upper part of the regenerating devices 8A and 8B at the above-mentioned appropriate flow rate, and the gas-liquid contact portion F'loaded with the filler is loaded. During the flow, it is heated by the reboiler Re to release carbon dioxide, and the absorption liquid is regenerated. The absorbing liquid L temporarily stored at the bottom of the regenerating devices 8A and 8B is supplied to the regenerating devices 8A and 8B in the heat exchanger E provided in the circulation system before being returned to the upper part of the absorbing devices 2A and 2B. It is cooled by heat exchange with the absorbing liquid, and is further cooled sufficiently in the water-cooled cooler Ra.

In each of the absorption devices 2A and 2B, the gas G'from which carbon dioxide has been removed by the absorption liquid is cooled at the upper part of the device and then discharged through the exhaust passages 15a and 15b connected to the top, respectively, and the exhaust passage 15a. , 15b are discharged to the outside from the integrated exhaust passage 15. Further, in each of the regenerating devices 8A and 8B, the carbon dioxide C released from the absorbing liquid is cooled at the upper part of the device and then discharged through the recovery paths 16a and 16b connected to the tops, respectively. A water-cooled cooler Ra and a gas-liquid separator S are provided in each of the recovery paths 16a and 16b, and the carbon dioxide C is sufficiently cooled by the cooler Ra to condense water vapor. The condensed water is separated and removed from the carbon dioxide C in the gas-liquid separator S, returned to the upper part of the regenerator, and used for cooling the carbon dioxide C. The carbon dioxide C from which the condensed water has been removed is recovered from the recovery path 16 in which the recovery paths 16a and 16b are integrated. The recovered carbon dioxide C can be appropriately used for preparation of liquefied products, burial treatment in soil, and the like.

Since the flow rate of the absorbing liquid is changed according to the flow rate fluctuation of the gas G supplied to each of the absorbing devices 2A and 2B, it is necessary to regenerate the absorbing liquid in each of the regenerating devices 8A and 8B in response to this. The amount of heat energy supplied also fluctuates. Therefore, the amount of heat supplied from the reboiler Re in each of the regenerating devices 8A and 8B is configured to be adjustable according to the fluctuation of the supply flow rate of the gas G. Specifically, the amount of heat supplied to each of the regenerating devices 8A and 8B can be adjusted by changing the flow rate of steam supplied to the reboiler Re using a flow rate adjusting valve or the like (not shown). can. It is preferable to automatically control the heat supply by the electric connection with the control device 6. Since the flow rate of carbon dioxide C released from each of the regenerating devices 8A and 8B also fluctuates due to the fluctuation of the flow rate of the gas supplied to each of the absorbing devices 2A and 2B, cooling in the cooler Ra is necessary. It may be configured so that the efficiency can be adjusted. For example, by changing the flow rate of the cooling water supplied to the cooler Ra, it is possible to cope with the fluctuation of the flow rate of carbon dioxide C.

In the above description, the recovery system 1 configured by using a plurality of absorption devices 2A and 2B having substantially the same processing capacity is described. However, the present invention is not limited to those in which a plurality of absorption devices have the same processing capacity, and the processing capacity (maximum processing flow rate) in the plurality of absorption devices may be different. The recovery system 20 of FIG. 2 is an example of a system having a plurality of absorption devices having different processing capacities. The recovery system 20 has three absorption devices 2A, 2C, and 2D, and three reproduction devices 8A, 8C, and 8D provided in pairs with each of the absorption devices 2A, 2C, and 8D, and processes the absorption devices 2A and the reproduction device 8A. The capacity is maximum, and the processing capacity of the absorption device 2D and the reproduction device 8D is the minimum.

The flow rate of the gas G introduced into the recovery system 20 is detected by the detector 5, and when the flow rate of the gas G changes, the control device 6 stops the supply of the gas based on the detection value of the detector 5. Determine the presence and number of devices. According to this, the flow rate adjusting valves 4A, 4C, and 4D on the flow paths 3a, 3c, and 3d are controlled, and the flow rate of the gas distributed and supplied to each absorption device is adjusted. Based on the detected values of the gas flow rate in the detectors 7A, 7C, 7D, it is monitored whether the flow rate adjustment is accurate. Further, according to the flow rate of the gas supplied to each absorption device, the control device 6 sets the flow rate adjusting valves 11A, 11C, 11D, and the return paths 10A, 10C on the supply paths 9A, 9C, 9D through the electrical connection. , 10D Flow rate control valves 12A, 12C, 12D are controlled. By this control, the flow rate of the absorbing liquid circulating in the supply path and the return path is also properly adjusted. Along with the adjustment of the circulating flow rate of the absorbing liquid, the supply amount of the renewable energy can also be adjusted in the same manner as described above based on the flow rate of the gas whose supply distribution is determined.

In the recovery system 20, the presence / absence and number of absorption devices that stop the gas supply when the flow rate of the introduced gas G fluctuates is based on the total value obtained by adding the minimum values of the appropriate range of the gas flow rate in each absorption device. It is determined. When the flow rate of the introduced gas G falls below this total value, the gas supply to some of the absorbers is stopped so that the gas flow rate supplied to the remaining absorbers is equal to or higher than the minimum value in the appropriate range. Is adjusted to. As this adjustment, for example, when the difference between the flow rate of the introduced gas G and the total value of the minimum value is small, the absorber having a small processing capacity (or the minimum value) is stopped, and when the difference is large, the processing capacity (or the processing capacity (or the minimum value)) is stopped. Alternatively, adjustments may be made to stop the absorber having a large (minimum value). When the flow rate fluctuation of the introduced gas G is repeated within a certain range, the absorption device that supplies the gas is selected so that the width of this flow fluctuation falls within the total width of the appropriate range of the gas flow rate in the absorption device. Then, the repetition of stopping / restarting the absorber can be reduced. Therefore, in this respect, it is advantageous to allocate the supply so as to preferentially stop the supply to the absorption device having a small processing capacity.

The recovery system of FIGS. 1 and 2 is an embodiment in which the same number of regenerators as the absorbers are provided so that the absorber and the regenerator are paired, but the present invention may be further modified in this respect. It is possible. Specifically, as shown in the recovery system 21 of FIG. 3, the recovery system may be configured to have a plurality of absorption devices and a regeneration device having a smaller number than the absorption devices. That is, the number of playback devices may be one or more, and may be one or more. In order to operate the regeneration device, it is necessary to stably supply renewable energy, and especially in regeneration under pressure, it is also necessary to stabilize the pressure condition. Therefore, once the regenerator is stopped, it takes time to stabilize the heating and pressure conditions before restarting, and it is necessary to avoid the rate-determining step when adjusting the gas supply distribution and the flow rate of the absorbing liquid. Break-in may be required. Further, since the repeated stop / restart also increases the load applied to the reproduction device, it is preferable to avoid the stop / restart of the reproduction device as much as possible. If the regeneration device is not stopped when a part of the plurality of absorption devices is stopped, it is possible to respond more quickly to the fluctuation of the flow rate of the gas G introduced into the system, so that the system as a whole can respond more quickly. It is advantageous in terms of processing efficiency and maintenance. The processing capacity of the regenerator depends on the supply of renewable energy, and the range of design is wider than that of the absorber. It is possible to design.

The recovery system 21 of FIG. 3 has two absorption devices 2A and 2B as in FIG. 1, but has only one reproduction device 8E. The supply system for supplying the gas G introduced into the recovery system 21 to the absorbers 2A and 2B is configured in the same manner as in FIG. That is, the flow path 3 is branched into the flow paths 3a and 3b and connected to each of the absorption devices 2A and 2B so that the gas G can be distributed and supplied to the absorption devices 2A and 2B. Since the recovery system 21 is installed in each of the flow paths 3a and 3b branched with the plurality of flow rate adjusting valves 4A and 4B as in FIG. 1, the absorption device is controlled by the flow rate adjusting valves 4A and 4B. It is possible to adjust the flow rate of the gas G supplied to each of 2A and 2B and change the number of absorption devices to which the gas G is supplied.

On the other hand, since the number of absorption devices and regeneration devices in the recovery system 21 is different, the circulation system for circulating the absorbing liquid is not connected so as to pair the absorption devices and the regeneration devices. In the circulation system of the recovery system 21, the absorption liquids L'that have absorbed carbon dioxide in the plurality of absorption devices 2A and 2B are once integrated into one and then supplied to the regeneration device 8E and regenerated by the regeneration device 8E. The absorption liquid L is configured to be distributed and refluxed to a plurality of absorption devices 2A and 2B. That is, the supply path 9a that sends out the absorption liquid L'from the bottom of the absorption device 2A and the supply path 9b that sends out the absorption liquid L'from the bottom of the absorption device 2B are integrated into the supply path 9u, and this is integrated into the supply path 9u. Connected to the top. The reflux path 10u that sends out the absorption liquid L from the bottom of the regenerator 8E is branched into two reflux paths 10a and 10b, and these ends are connected to the upper portions of the absorption devices 2A and 2B, respectively, and thus are regenerated. The absorption liquid L is distributed and refluxed to a plurality of absorption devices. The flow rate adjusting valves 11A and 11B are installed in the supply paths 9a and 9b, respectively, and the flow rate adjusting valves 12A and 12B are installed in the return paths 10a and 10b, respectively. The flow rate of the absorbing liquid can be adjusted.

The recovery system 21 has a gas supply adjusting mechanism and an absorbing liquid circulation adjusting mechanism as in the embodiment of FIG. 1, and the control mechanism operates in the same manner as in the embodiment of FIG. 1 to control the adjusting mechanism. At the same time, the circulation adjustment mechanism is controlled correspondingly. Specifically, the control device 6 controls the flow rate adjusting valves 4A and 4B according to the flow fluctuation of the gas G introduced into the recovery system 21, and appropriately adjusts the flow rate of the gas supplied to the absorption devices 2A and 2B. The flow rate adjusting valves 11A, 11B, 12A, and 12B are controlled to properly adjust the flow rate of the absorbing liquid flowing through each of the absorbing devices 2A and 2B. As a result, the absorbing liquid flows in each of the absorbing devices 2A and 2B at a flow rate corresponding to the flow rate of the supplied gas.

In the recovery system 21, the regeneration device is not stopped even when the gas supply to any of the absorption devices 2A and 2B is stopped according to the fluctuation of the flow rate of the introduced gas G. For example, when the gas supply and the flow of the absorption liquid in the absorption device 2B are stopped, the flow rate of the absorption liquid flowing through the regeneration device 8E through the supply path 9u and the return path 10u is equal to the flow rate of the absorption liquid flowing through the absorption device 2A. .. In this way, similarly to the recovery system 1 of FIG. 1, the absorption liquid whose flow rate is adjusted in response to the flow rate fluctuation of the introduced gas G is heated and regenerated in the regeneration device 8E, and the carbon dioxide C released. Is recovered from the recovery path 16e.

In the recovery system 21 of FIG. 3, the absorbers 2A and 2B may have the same processing capacity or different processing capacities. For example, as in the recovery system 20 of FIG. 2, a plurality of absorbing devices having different processing capacities may be used. It may be used to configure a recovery system.

An embodiment such as the recovery system 21 can be configured using a regenerator that alone has a processing capacity that can correspond to the total processing capacity of the plurality of absorption devices. Therefore, within the processing capacity of such a regenerator, it can be modified to increase the number of absorbers in the embodiment of FIG. In this regard, when the total processing capacity of the plurality of absorption devices exceeds the processing capacity of the regenerating device, for example, the embodiment as shown in FIG. 4 may be configured. That is, as long as the number of regenerating devices is smaller than the number of absorbing devices, the number of regenerating devices is not limited to one, and one or more regenerating devices may be provided.

FIG. 4 describes a recovery system 22 having a plurality of (three in FIG. 4) absorbers 2E, 2F, 2G and a plurality of (two in FIG. 4) regenerators 8H, 8I, which are less than the absorbers. In the recovery system 22, the plurality of absorption devices 2E, 2F, and 2G may have the same processing capacity or different processing capacities, and the plurality of regenerating devices 8H, 8I also have the same processing capacity. May be different. The flow path 3 of the gas G branches into the flow paths 3e, 3f, and 3g and is connected to the absorption devices 2E, 2F, and 2G, respectively. Of the supply paths and recirculation paths that make up the absorption liquid circulation system, the supply paths are supply paths 9e, 9f, 9g that branch off on the delivery side from the absorption device and supply paths 9h that branch off on the input side to the regeneration device. , 9i and a supply channel 9u that integrates them in the middle. The recirculation paths constituting the circulatory system include the recirculation paths 10h and 10i branching on the sending side from the regeneration device and the recirculation paths 10e, 10f and 10g branching on the input side to the absorption device, and the recirculation that integrates these in the middle. It is composed of a road 10u. Therefore, the absorbing liquid L'that has absorbed carbon dioxide in the absorbing devices 2E, 2F, and 2G and is sent out is once merged in the supply path 9u and then distributed and supplied to the regenerating devices 8H and 8I, and is distributed and supplied to the regenerating devices 8H and 8I. The absorbed liquid L that has been regenerated and sent out is once merged in the reflux path 10u, and then distributed and refluxed to the absorption devices 2E, 2F, and 2G.

The flow rate of the gas G introduced into the recovery system 22 is detected by the detector 5, and when the flow rate of the gas G changes, the control device 6 stops the supply of the gas based on the detection value of the detector 5. Determine the presence and number of devices and set the gas flow rate in each absorption device. According to this, the flow rate adjusting valves 4E, 4F, and 4G on the flow paths 3e, 3f, and 3g are controlled, and the flow rate of the gas distributed and supplied to each absorption device is adjusted. Based on the detected values of the gas flow rate in the detectors 7E, 7F, 7G, it is monitored whether the flow rate adjustment is accurate. Further, according to the flow rate of the gas supplied to each absorption device, the control device 6 sets the flow rate adjusting valves 11E, 11F, 11G, and the return paths 10e, 10f on the supply paths 9e, 9f, 9g through the electrical connection. , 10g of flow control valves 12E, 12F, 12G are controlled. By this control, the flow rate of the absorbing liquid flowing through each of the absorbing devices 2E, 2F, and 2G is appropriately adjusted. Based on the detected values of the flow rate of the absorbent liquid in the detectors 13E, 13F, 13G and the detectors 14E, 14F, 14G, it is monitored whether the flow rate adjustment for the absorber is accurate. At the same time, the control device 6 controls the flow rate adjusting valves 23H and 23I on the supply paths 9h and 9i and the flow rate adjusting valves 24H and 24I on the return paths 10h and 10i. By this control, the flow rate of the absorbing liquid distributed and supplied to each of the regenerating devices 8H and 8I is appropriately adjusted according to the change in the flow rate of the absorbing liquid flowing through the absorbing devices 2E, 2F and 2G. Based on the detected values of the flow rate of the absorbing liquid in the detectors 25H and 25I and the detectors 26H and 26I, it is monitored whether the flow rate adjustment for the regenerator is accurate.

In the recovery system 22, as in the recovery system 21 of FIG. 3, the regeneration device is not stopped even when the gas supply to any of the absorption devices 2E, 2F, and 2G is stopped. For example, when the gas supply and the flow of the absorbing liquid in the absorbing device 2G are stopped, the total flow rate of the absorbing liquid flowing through each of the absorbing devices 2E and 2F is the flow rate of the absorbing liquid flowing through each of the regenerating devices 8H and 8I. Is adjusted to be equal to the sum of. Therefore, this total flow rate becomes the flow rate of the absorbing liquid circulating in the recovery system through the supply path 9u and the return path 10u. In this way, in the same manner as in the recovery systems 1, 20 and 21 described above, the absorbing liquid whose flow rate in the absorbing devices 2E, 2F and 2G is adjusted in response to the flow rate fluctuation of the introduced gas G is regenerated. It is heated and regenerated at 8H and 8I. The carbon dioxide C released from the absorption liquid is recovered from the recovery path 16 together after cooling on the recovery paths 16h and 16i and gas-liquid separation.

As shown in FIG. 4, in the recovery system 22 having a plurality of regeneration devices 8H and 8I, the flow control valves 23H, 23I and 24H are used when the absorbed liquid that has absorbed carbon dioxide once integrated is distributed and supplied to the regeneration devices 8H and 8I. The flow rate adjustment by 24I can be used to change the distribution supply ratio as appropriate. For example, by distributing and supplying the absorbing liquid to the regenerating devices 8H and 8I at a ratio corresponding to the processing capacity of the regenerating device, or by fixing the flow rate of the absorbing liquid in some regenerating devices and changing the flow rate in the remaining regenerating device. Embodiments such as responding to fluctuations in the flow rate of the introduced gas G are possible. When the number of regenerating devices is two, if the flow rate of the absorbing liquid to be charged to one regenerating device is adjusted, the remaining absorbing liquid is charged to the other regenerating device. Therefore, the flow rate adjusting valve 23H, It is possible to omit one of the 23Is.

As described above, in the recovery system 22, the adjustment of the gas supply distribution to each absorption device (including the supply stop) and the flow rate of the absorption liquid in each absorption device correspond to the fluctuation of the flow rate of the introduced gas G. Adjustment (including circulation stop), flow rate adjustment of the absorbing liquid in each regeneration device (excluding circulation stop), and adjustment of the supply amount of regenerated energy to each regeneration device (excluding supply stop) are performed. The supply of renewable energy may be adjusted in the same manner based on the flow rate of the absorbing liquid in the regenerating device.

As can be understood from the above, it is possible to avoid the operation stop of the reproduction device when the operation of a part of the absorption device is stopped by using the reproduction device which is smaller than the number of absorption devices as shown in FIGS. 3 and 4. A possible recovery system can be configured. This eliminates the need for adjustments for restarting the playback device. That is, since the factor that may be the rate-determining step when adjusting the flow rate of the absorbing liquid can be eliminated, the flow rate of the absorbing liquid can be quickly adjusted in response to the fluctuation of the flow rate of the introduced gas G.

In the recovery system as described above, the shapes of the gas-liquid contact portions F and F'of the absorbing device and the regenerating device can be appropriately redesigned as needed, and are not limited to square columns and columns, but are polygonal. It can be appropriately selected from various axial shapes including a columnar shape and an elliptical columnar shape. Therefore, the same applies to the loading shape of the fillers constituting them. As the filler, it can be appropriately selected from various commercially available fillers and used. Further, the filler is not limited to a commercially available product, and a filler can be arbitrarily formed by using a flat plate, a corrugated plate, or the like. Since the gas flow resistance when the gas and the liquid are brought into contact with each other affects the energy consumption during operation, especially for the absorber, the filler is selected so as to have a suitable flow space in consideration of these factors. And design.

The recovery system as described above can suitably recover carbon dioxide by introducing waste gas (exhaust gas) or reaction gas generated in equipment such as a chemical plant or a thermal power plant. As the absorbing solution, an aqueous solution of an alkaline agent such as a cyclic amine compound, an alkanol-based amine, a phenol-based amine, or an alkali metal salt is often used. In the monoethanolamine (MEA) aqueous solution often used in the recovery of carbon dioxide, the reaction with carbon dioxide produces carbamate / amine salt (carbamate), carbonate, bicarbonate and the like.

Therefore, each part constituting the recovery system is manufactured of a material having resistance to the components of the gas G and the chemical agent contained in the absorption liquid L as described above. Examples of such a material include metals such as stainless steel, aluminum, nickel, titanium, carbon steel, brass, copper, monel, silver, tin and niobium, and resins such as polyethylene, polypropylene and PTFE. At least the surface of the filler is also made of a corrosion-resistant material that does not cause a reaction (corrosion) with the gas G to be treated and the absorption liquid L to be used as described above. The material may be one in which minute irregularities are formed on the surface by surface treatment such as sanding, sandblasting, ultraviolet ozone treatment, plasma treatment, etc. to impart surface roughness, and the surface is modified by coating or the like. Depending on the quality, the material may be prepared to meet the above-mentioned conditions of use. The material can be appropriately selected so as to maintain suitable strength according to the conditions for gas-liquid contact.

In the above description, the absorption device is described as a contact form in which the gas G and the absorption liquid L face each other, but the gas G and the absorption liquid L are supplied from above the gas-liquid contact portion F to absorb the gas G and the absorption liquid L. It is also possible to change the contact form in which the liquid L is parallel.

It is possible to provide a carbon dioxide capture system that can perform parallel processing in response to fluctuations in the gas flow rate introduced while maintaining the gas flow rate in each absorption device within an appropriate range by using a plurality of parallel absorption devices. It is useful as a gas treatment system for application to various industrial equipment such as power generation equipment and large equipment where the discharge flow rate of exhaust gas fluctuates. By generalization based on the improvement of economy, it is possible to contribute to environmental protection by popularizing the treatment of exhaust gas such as combustion gas.

1,20,21,22 Recovery system 2A ~ 2G Absorber 3,3a ~ 3g Flow path 4A ~ 4G Flow control valve 5 Detector 6 Control device 7A, 7B Detector 8A ~ 8E, 8H, 8I Reproduction device 9A ~ 9D Supply passages 9a, 9b, 9e to 9i, 9u Supply passages 10A to D Circulation passages 10a, 10b, 10e to 10i, 10u Circulation passages 11A, 11B, 12A, 12B Flow control valves 13A, 13B, 14A, 14B Detector 15, 15a, 15b Exhaust passage 16, 16a, 16b Recovery passage 23H, 23I, 24H, 24I Flow control valve 25H, 25I, 26H, 26I Detector P Pump F, F'Gas-liquid contact part E Heat exchanger Ra Cooler Re reboiler C Carbon dioxide L, L'absorbent liquid G, G'gas

Claims (10)

Multiple absorption devices that recover carbon dioxide by the chemical absorption method,
A supply system capable of distributing and supplying the gas to be introduced to the plurality of absorption devices, and
An adjustment mechanism that can adjust the flow rate of gas supplied to each of the plurality of absorption devices, and
By controlling the adjustment mechanism according to the fluctuation of the flow rate of the introduced gas, the flow rate of the gas in the absorption device to which the gas is supplied is maintained at or above the minimum value of the gas flow rate that can be efficiently processed in the absorption device. as described above, it has a control mechanism for changing the flow rate of the gas supplied to each of said plurality of absorber,
The efficiently processable gas flow rates, carbon dioxide recovery system range F factor that are controlled by the control mechanism so that 0.5 to 2.5. The adjusting mechanism is provided to the supply system so that the number of absorption devices to which gas is supplied among the plurality of absorption devices can be changed and the gas flow rate supplied to each of the plurality of absorption devices can be changed. The carbon dioxide recovery system according to claim 1, further comprising a plurality of flow control valves to be installed. Each of the plurality of absorbers has a processing capacity such that the gas flow rates that can be efficiently processed are substantially equal, and the control mechanism has a detector that detects the gas flow rate to be introduced.
The control mechanism
When the gas flow rate detected by the detector is equal to or greater than the product of the minimum value of the gas flow rate and the number of the plurality of absorbers, the gas flow rate supplied to each of the plurality of absorbers is the minimum value. The adjustment mechanism is controlled so as to be as described above, whereby gas is supplied to all of the plurality of absorption devices.
When the gas flow rate detected by the detector is less than the product of the minimum value and the number of the plurality of absorbers, the supply to a part of the plurality of absorbers is stopped and the other absorbers are stopped. The carbon dioxide capture system according to claim 1 or 2, wherein the adjusting mechanism is controlled so as to maintain the gas flow rate in the above-mentioned minimum value or more. When the gas flow rate detected by the detector is equal to or greater than the product of the minimum value and the total number of absorption devices, the control mechanism supplies gas to all of the plurality of absorption devices substantially evenly. The carbon dioxide recovery system according to claim 3, wherein the adjustment mechanism is controlled so as to be used. In the control mechanism, when the gas flow rate detected by the detector is equal to or greater than the product of the minimum value and the total number of absorption devices, the gas is supplied at the maximum value of the gas flow rate that the absorption device can process. The carbon dioxide capture system according to claim 3, wherein the adjusting mechanism is controlled so that the number of absorption devices is maximized. In the control mechanism, when the gas flow rate detected by the detector is less than the product of the minimum value and the number of the plurality of absorption devices, the gas flow rates in the absorption devices to which the gas is supplied are substantially equal. The carbon dioxide recovery system according to any one of claims 3 to 5, which controls the adjusting mechanism so as to be. Each of the plurality of absorbing devices is a device that recovers carbon dioxide by bringing the absorbing liquid into gas-liquid contact with the gas and absorbing carbon dioxide contained in the gas.
In addition
A plurality of regenerating devices having the same number as the plurality of absorbing devices, which regenerate the absorbed liquid by releasing carbon dioxide from the absorbing liquid that has absorbed carbon dioxide by heating.
It is a circulatory system capable of circulating an absorbing liquid between the plurality of absorbing devices and the plurality of regenerating devices, and the plurality of absorbing devices and the plurality of regenerating devices are connected so as to form a pair. The circulatory system in which the absorbing liquid circulates between the absorbing device and the regenerating device.
The absorption liquid circulating in the circulatory system has a circulation adjustment mechanism capable of adjusting the flow rate flowing through each of the plurality of absorption devices, and the control mechanism is a gas supplied in each of the plurality of absorption devices. The carbon dioxide recovery system according to any one of claims 1 to 6, wherein the circulation adjusting mechanism is controlled in response to the control of the adjusting mechanism so that the absorbing liquid flows at a flow rate corresponding to the flow rate of the above. Each of the plurality of absorbing devices is a device that recovers carbon dioxide by bringing the absorbing liquid into gas-liquid contact with the gas and absorbing carbon dioxide contained in the gas.
In addition
One or more regenerating devices, which are fewer than the plurality of absorbing devices, and regenerate the absorbing liquid by releasing carbon dioxide from the absorbing liquid that has absorbed carbon dioxide by heating.
A circulatory system capable of circulating an absorption liquid between the plurality of absorption devices and the one or more regeneration devices, and the absorption liquids that have absorbed carbon dioxide by the plurality of absorption devices are once integrated into the above 1 The plurality of absorption devices and the one or more regeneration devices so that the absorption liquid supplied to the one or more regeneration devices and regenerated by the one or more regeneration devices is distributed and refluxed to the plurality of absorption devices. With the circulatory system that connects
The absorption liquid circulating in the circulatory system has a circulation adjustment mechanism capable of adjusting the flow rate flowing through each of the plurality of absorption devices, and the control mechanism is a gas supplied in each of the plurality of absorption devices. The carbon dioxide recovery system according to any one of claims 1 to 6, wherein the circulation adjusting mechanism is controlled in response to the control of the adjusting mechanism so that the absorbing liquid flows at a flow rate corresponding to the flow rate of the above. The number of the one or more regenerating devices is a plurality, and in the connection between the plurality of absorbing devices and the plurality of regenerating devices in the circulatory system, the absorbing liquid that has absorbed carbon dioxide once integrated is the plurality of regenerating devices. The carbon dioxide recovery system according to claim 8, wherein the absorption liquids that are distributed and supplied to the devices and regenerated by the plurality of regenerating devices are once integrated and distributed and recirculated to the plurality of absorbing devices. Multiple absorption steps to recover carbon dioxide by chemical absorption method,
A supply process in which the introduced gas is distributed and supplied to the plurality of absorption processes, and a supply process.
An adjustment step that adjusts the flow rate of gas supplied to each of the plurality of absorption steps, and
The adjustment step is controlled according to the fluctuation of the flow rate of the introduced gas, and the flow rate of the gas in the absorption step in which the gas is supplied is maintained at or above the minimum value of the gas flow rate that can be efficiently processed in the absorption step. as described above, it has a control step of changing the flow rate of gas supplied to each of the plurality of absorption step,
The efficiently processable gas flow rates, the recovery method of carbon dioxide range of F factor that are controlled by said control step so that 0.5 to 2.5.

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