JP2023146122A - Recovery device, recovery method and computer program - Google Patents

Abstract

To provide a technique for stabilizing the quality of recovery gas in a recovery device.SOLUTION: A recovery device comprises: an adsorber which stores an adsorbent that adsorbs a specific material; an acquisition unit which acquires mixed gas information being estimation information or measurement information of a property of mixed gas including the temperature of the mixed gas and supplied to the adsorber, and an adsorption condition being estimation information or measurement information of an environmental condition affecting the adsorption performance of the adsorbent including the environmental temperature of the adsorbent; an estimation unit which estimates an adsorption amount estimation value of the adsorbent and a saturation adsorption amount of the adsorbent by using the mixed gas information and the adsorption condition; and a switching unit which switches the adsorber supplying the mixed gas according to the estimated adsorption amount estimation value and saturation adsorption amount.SELECTED DRAWING: Figure 1

Description

The present invention relates to a collection device, a collection method, and a computer program.

2. Description of the Related Art Conventionally, recovery devices for recovering specific substances contained in mixed gas have been known (for example, Patent Documents 1 and 2). The recovery device collects the specific substance by, for example, adsorbing the specific substance in the mixed gas using an adsorbent in the adsorption process, and desorbing the specific substance adsorbed by the adsorbent from the adsorbent in the recovery process. .

Patent No. 6791177 specification JP2020-78860A

When using specific substances recovered by a recovery device for manufacturing industrial products, etc., in order to stably manufacture products of a certain quality, it is necessary to use specific substances in the recovered gas that contains the specific substances desorbed from the adsorbent. It is necessary that the concentration of However, the amount of specific substances that can be adsorbed by the adsorbent varies depending on the properties of the mixed gas and the environment in which the adsorbent is placed, so there is a risk that the amount of specific substances desorbed from the adsorbent may change with each recovery process. There is. In this case, the concentration of the specific substance in the recovered gas also changes, making it difficult to stabilize the quality of the recovered gas.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a technique for stabilizing the quality of recovered gas in a recovery device.

The present invention has been made to solve at least part of the above-mentioned problems, and can be realized as the following forms.

(1) According to one embodiment of the present invention, a recovery device for recovering a specific substance contained in a mixed gas is provided. This recovery device includes an adsorber containing an adsorbent that adsorbs the specific substance, and a mixed gas that is estimated or measured information of the properties of the mixed gas supplied to the adsorber, including the temperature of the mixed gas. an acquisition unit that acquires information and adsorption conditions that are estimated information or measurement information of environmental conditions that affect the adsorption performance of the adsorbent, including the environmental temperature of the adsorbent; the mixed gas information; an estimator that estimates an estimated adsorption amount of the adsorbent and a saturated adsorption amount of the adsorbent using the adsorption conditions; A switching unit that switches between adsorbers that supply mixed gas.

According to this configuration, the switching unit is configured to adjust the estimated adsorption amount of the adsorbent and the saturated adsorption amount, which are estimated using the mixed gas information including the temperature of the mixed gas and the adsorption conditions including the environmental temperature of the adsorbent. Depending on the situation, the adsorber that supplies the mixed gas is switched. The saturated adsorption amount of the adsorbent depends on the properties of the mixed gas supplied to the adsorber and the environmental conditions that affect the adsorption performance of the adsorbent, so the saturated adsorption amount estimated in this way is, for example, , the value is more suitable for the actual situation than the saturated adsorption amount, which is fixed as a set value. As a result, by switching the supply destination of the mixed gas according to the estimated value of the adsorption amount of the adsorbent and the saturated adsorption amount estimated by the estimator, the adsorption of a specific substance while suppressing the leakage of the specific substance to the outside of the system. It is possible to stabilize the proportion of adsorbent used for Therefore, when recovering the specific substance adsorbed on the adsorbent, the concentration of the specific substance in the recovered gas can be made constant, so the quality of the recovered gas can be stabilized.

(2) In the recovery device of the above embodiment, the estimating unit estimates an estimated amount of the specific substance introduced into the adsorber using the mixed gas information, and the estimated amount of the specific substance introduced into the adsorber. is used to estimate the adsorption amount estimate representing the amount of the specific substance adsorbed by the adsorbent at a specific time, and the saturated adsorption amount estimated using the mixed gas information is multiplied by a control constant. The switching unit may calculate a switching threshold value, and then compare the estimated adsorption amount value with the switching threshold value to switch the adsorber that supplies the mixed gas. According to this configuration, the switching unit estimates the estimated adsorption amount representing the amount of the specific substance adsorbed by the adsorbent at a specific time based on the estimated amount of the specific substance introduced into the adsorber, The estimated adsorption amount is compared with a switching threshold calculated by multiplying the saturated adsorption amount by a control constant. The switching unit switches the adsorber that supplies the mixed gas according to the comparison result. That is, the supply destination of the mixed gas is switched by comparing the adsorption amount estimate estimated using only the mixed gas information with the switching threshold. Thereby, the quality of the recovered gas can be easily stabilized.

(3) In the recovery device of the above embodiment, the acquisition unit includes estimated information on the properties of the exhaust gas, including the flow rate of the exhaust gas discharged from the adsorber and the concentration of the specific substance in the exhaust gas. Alternatively, the estimator obtains exhaust gas information that is measurement information, and uses the mixed gas information to estimate an estimated amount of the specific substance to be introduced into the adsorber, and uses the exhaust gas information to estimate an estimated amount of the specific substance introduced into the adsorber. Then, estimate the estimated amount of the specific substance discharged from the adsorber, and use the difference between the estimated introduction amount and the estimated amount of emission to determine whether the adsorbent is adsorbing at a specific point in time. The switching unit estimates the adsorption amount estimated value representing the amount of the specific substance, calculates a switching threshold value by multiplying the saturated adsorption amount estimated using the mixed gas information by a control constant, and The estimated value and the switching threshold may be compared to switch the adsorber that supplies the mixed gas. According to this configuration, the estimation unit estimates the estimated amount of adsorption using the difference between the estimated amount of the specific substance introduced into the adsorber and the estimated amount of the specific substance discharged from the adsorber. do. The switching unit switches the adsorber that supplies the mixed gas by comparing the estimated adsorption amount with a switching threshold. This makes it possible to improve the estimation accuracy of the estimated adsorption amount, compared to the case where the estimated adsorption amount is estimated only from the estimated amount of the specific substance introduced into the adsorber. Therefore, since the switching unit can accurately switch the supply destination of the mixed gas, the quality of the recovered gas can be further stabilized.

(4) In the recovery device of the above embodiment, the acquisition unit acquires desorption amount information that is estimated information or measurement information of the amount of the specific substance desorbed from the adsorbent that has adsorbed the specific substance. , the estimation unit may estimate an estimated desorption amount using the desorption amount information, and calculate the control constant using a ratio of the estimated desorption amount to the estimated introduction amount. good. According to this configuration, the estimation unit calculates the control constant using the ratio of the estimated amount of desorption to the estimated amount of introduction, that is, the recovery rate of the specific substance. Thereby, it is possible to stabilize the recovery rate of the specific substance, which is one of the qualities of the recovered gas, so that the quality of the recovered gas can be further stabilized.

(5) In the recovery device of the above embodiment, the estimation unit uses the mixed gas information to average the properties of the mixed gas from the start of supply of the mixed gas to the adsorber to the specific point in time. Using the adsorption conditions, calculate the average value of the environmental conditions from the start of supply of the mixed gas to the adsorber until the specific time, and calculate the average value of the properties of the mixed gas. The saturated adsorption amount of the adsorbent may be estimated using the average value of the environmental conditions and the average value of the environmental conditions. According to this configuration, the saturated adsorption amount of the adsorbent is estimated using the average value of the properties of the mixed gas and the average value of the environmental conditions from the start of supply of the mixed gas to the adsorber up to a specific point in time. . This makes it possible to estimate the saturated adsorption amount of the adsorbent even if there is a sudden change in the properties or environmental conditions of the mixed gas after the supply of the mixed gas to the adsorber has started. Quality can be stabilized.

(6) In the recovery device of the above embodiment, the acquisition unit acquires the mixed gas information including the concentration of a substance other than the specific substance contained in the mixed gas, and the estimating unit acquires the mixed gas information. The saturated adsorption amount of the adsorbent may be estimated using the concentration of a gas other than the specific substance contained in the mixed gas. According to this configuration, the acquisition unit acquires the mixed gas information including the concentration of substances other than the specific substance contained in the mixed gas. Since substances other than the specific substance are also adsorbed by the adsorbent, the saturated adsorption amount of the adsorbent decreases. By estimating the saturated adsorption amount using the concentration of a substance other than the specific substance, the accuracy of estimating the saturated adsorption amount can be improved.

(7) According to another aspect of the present invention, a recovery method is provided in which a specific substance contained in a mixed gas is recovered by a recovery device. This recovery method includes a step of adsorbing the specific substance onto an adsorbent, mixed gas information that is estimated information or measurement information of the properties of the mixed gas supplied to the adsorber, including the temperature of the mixed gas, and a step of acquiring adsorption conditions that are estimated information or measurement information of environmental conditions that affect the adsorption performance of the adsorbent, including the environmental temperature of the adsorbent; and using the mixed gas information and the adsorption conditions. a step of estimating an estimated adsorption amount of the adsorbent and a saturated adsorption amount of the adsorbent; and an adsorption step of supplying the mixed gas according to the estimated adsorption amount estimate and the saturated adsorption amount. A step of switching the container. According to this configuration, the recovery device supplies the mixed gas according to the saturated adsorption amount of the adsorbent, which is estimated using the mixed gas information including the temperature of the mixed gas and the adsorption conditions including the environmental temperature of the adsorbent. Switch the adsorber to be used. This makes it possible to stabilize the ratio of the adsorbent used for adsorbing the specific substance, thereby stabilizing the quality of the recovered gas.

(8) According to yet another aspect of the present invention, a computer program is provided that causes a computer to recover a specific substance contained in a mixed gas. This computer program is estimated information or measurement information of the properties of the mixed gas supplied to the adsorber containing the adsorbent, including the function of adsorbing the specific substance to the adsorbent and the temperature of the mixed gas. A function of acquiring mixed gas information and adsorption conditions that are estimated information or measurement information of environmental conditions that affect the adsorption performance of the adsorbent, including the environmental temperature of the adsorbent, and the mixed gas information; a function of estimating an estimated adsorption amount of the adsorbent and a saturated adsorption amount of the adsorbent using the adsorption conditions; The computer executes the function of switching the adsorber that supplies the mixed gas. According to this configuration, the computer supplies the mixed gas according to the saturated adsorption amount of the adsorbent, which is estimated using the mixed gas information including the temperature of the mixed gas and the adsorption conditions including the environmental temperature of the adsorbent. Switch adsorber. This makes it possible to stabilize the ratio of the adsorbent used for adsorbing the specific substance, thereby stabilizing the quality of the recovered gas.

Note that the present invention can be realized in various aspects, such as a system including a collection device, a control method including a collection method using these devices and systems, a server device for distributing a computer program, It can be implemented in the form of a non-transitory storage medium or the like that stores the computer program.

FIG. 1 is a schematic diagram showing a schematic configuration of a recovery device according to a first embodiment. It is a flowchart explaining the collection method by a collection system. FIG. 3 is a diagram illustrating a set utilization rate of an adsorbent. It is a figure explaining the time change of the amount of _CO2 adsorption in a recovery method. It is a figure showing the time change of the property of mixed gas. FIG. 3 is a diagram illustrating the relationship between the utilization rate of adsorbent and the quality of recovered gas. It is a figure explaining the average _CO2 concentration of an adsorption process, and a change of an adsorption process period. FIG. 2 is a first diagram illustrating the adsorbent utilization rate and CO ₂ recovery rate. FIG. 2 is a second diagram illustrating the adsorbent utilization rate and CO ₂ recovery rate. FIG. 3 is a diagram illustrating the influence of a change in environmental temperature on an adsorbent. FIG. 3 is a third diagram illustrating the adsorbent utilization rate and CO ₂ recovery rate. FIG. 4 is a fourth diagram illustrating the adsorbent utilization rate and CO ₂ recovery rate. FIG. 5 is a fifth diagram illustrating the utilization rate of the adsorbent and the CO ₂ recovery rate. FIG. 2 is a schematic diagram showing a schematic configuration of a recovery device according to a second embodiment. FIG. 3 is a diagram illustrating the influence of a change in impurity concentration of an adsorbent. It is a schematic diagram showing the schematic structure of the recovery device of a 3rd embodiment.

<First embodiment>
FIG. 1 is a schematic diagram showing a schematic configuration of a recovery device according to a first embodiment. The recovery apparatus 1 of the first embodiment is applied to a recovery system 5 including a plurality of adsorbers shown in FIG. 1. The recovery system 5 recovers carbon dioxide (CO ₂ ) from the mixed gas containing oxygen (O ₂ ), nitrogen (N ₂ ), moisture (H ₂ O), etc., which is discharged from the combustion equipment 6. , is supplied to the hydrocarbon synthesis device 7. The recovery system 5 of this embodiment includes three adsorbers 10, a mixed gas supply channel 20, an exhaust gas channel 30, a hydrogen gas supply channel 40, a recovery gas channel 50, and a heat medium channel. 60 and a control section 70.

The adsorber 10 is a device for separating and recovering CO ₂ from a mixed gas. The adsorbent 10 houses an adsorbent 11 therein. The adsorbent 11 is, for example, zeolite, activated carbon, or silica gel, and has CO ₂ storage (adsorption) performance. When a mixed gas containing CO ₂ is supplied to the adsorber 10 , the CO ₂ is stored in the adsorbent 11 , and the remaining components of the mixed gas are discharged to the outside of the adsorber 10 . A mixed gas supply channel 20 , a hydrogen gas supply channel 40 , a recovery gas channel 50 , and a heat medium channel 60 are connected to the adsorber 10 . In addition, in this embodiment, in order to distinguish each of the three adsorbers 10, for convenience, the adsorbers 10A, 10B, and 10C accommodate adsorbents 11A, 11B, and 11C, respectively (see FIG. 1). FIG. 1 also shows a mixed gas supply channel 20 connected to an adsorber 10A during an adsorption process, an adsorber 10B during a recovery process, and an adsorber 10C during a cooling process in a recovery method to be described later. Regarding the exhaust gas flow path 30, hydrogen gas supply flow path 40, and recovery gas flow path 50, the flow paths through which gas flows are shown by solid lines, and the flow paths through which gas does not flow are shown by dotted lines.

The mixed gas supply channel 20 is a gas channel for supplying the mixed gas (arrow Gex shown in FIG. 1) discharged from the combustion equipment 6 to each of the three adsorbers 10, and is composed of a plurality of gas pipes. has been done. The mixed gas supply channel 20 is provided with a plurality of mixed gas supply valves 21 and 22. The combustion equipment 6 is, for example, a combustion furnace in a factory, and the mixed gas contains O ₂ , N ₂ , H ₂ O, etc. in addition to CO ₂ as described above. The mixed gas discharged from the combustion equipment 6 passes through the mixed gas supply valve 21 and heads to the adsorber 10A or the mixed gas supply valve 22. The mixed gas heading towards the mixed gas supply valve 22 passes through the mixed gas supply valve 22 and heads towards the adsorber 10B or 10C. The opening and closing of each of the mixed gas supply valves 21 and 22 is controlled by a control unit 70.

The exhaust gas flow path 30 is a gas flow path for exhausting the remaining gas (exhaust gas, arrow Gm shown in FIG. 1) after removing CO ₂ from the mixed gas from each of the three adsorbers 10. Consists of gas piping. The exhaust gas flow path 30 is provided with a plurality of exhaust gas valves 31 and 32. Exhaust gas discharged from the adsorbers 10A and 10B is discharged from the recovery system 5 via exhaust gas valves 31 and 32. The exhaust gas discharged from the adsorber 10C is discharged from the recovery system 5 via the exhaust gas valve 32. The opening and closing of each of the exhaust gas valves 31 and 32 is controlled by a control unit 70.

The hydrogen gas supply channel 40 is a gas channel for supplying hydrogen (H ₂ , arrow Gh shown in FIG. 1) from a hydrogen supply source (not shown) to each of the three adsorbers 10, and is supplied from a plurality of gas pipes. It is configured. The hydrogen gas supply channel 40 is provided with a plurality of hydrogen supply valves 41 and 42. H ₂ supplied from the hydrogen supply source passes through the hydrogen supply valve 41 and goes to the adsorber 10C or the hydrogen supply valve 42. H ₂ heading towards the hydrogen supply valve 42 passes through the hydrogen supply valve 42 and heads towards the adsorber 10B or 10A. The opening and closing of each of the hydrogen supply valves 41 and 42 is controlled by a control unit 70.

The recovered gas flow path 50 is a gas flow path for supplying the recovered gas (arrow Gch shown in FIG. 1) containing CO ₂ taken out from each of the three adsorbers 10 to the hydrocarbon synthesis apparatus 7. It consists of gas piping. The recovered gas flow path 50 is provided with a recovered gas valve 51 . The opening and closing of the recovery gas valve 51 is controlled by the control unit 70 and supplies the recovery gas taken out from any of the three adsorbers 10 to the hydrocarbon synthesis apparatus 7 . A pump 52 is provided in the recovered gas flow path 50 to reduce the pressure inside the adsorber 10 via the recovered gas flow path 50 . This makes it easier for CO ₂ to desorb from the adsorbent 11 .

The heat medium flow path 60 is a flow path through which a fluid heat medium (thermal fluid) such as oil flows, and is used to absorb heat generated in the hydrocarbon synthesis device 7 by a reaction for producing a hydrocarbon compound such as methane (CH ₄ ). Three adsorbers 10 are fed. After heating the adsorbent 11, the heat medium supplied to the adsorber 10 returns to the hydrocarbon synthesis device 7 and is heated again. By repeating this, CO ₂ becomes easier to desorb from the adsorbent 11. In FIG. 1, in order to avoid complicating the drawing, the heat medium flow path 60 is connected to the hydrocarbon synthesis apparatus 7 and the adsorber 10B during the recovery process, but the adsorber 10A and the adsorber 10C Similarly, the heat medium flow path 60 is connected to the heat medium flow path 60 as well.

The control unit 70 includes a computer including a ROM, a RAM, and a CPU, and controls the entire recovery system 5 based on the properties of the mixed gas, the environmental conditions of the adsorber 10, and the like. The control unit 70 functions by loading a computer program stored in the ROM into the RAM and executing it by the CPU. The control unit 70 includes a mixed gas detection unit 71, an environmental condition detection unit 72, a recovered gas detection unit 73, an information acquisition unit 74, a calculation unit 75, and a command unit 76.

The mixed gas detection unit 71 detects the properties of the mixed gas flowing through the mixed gas supply channel 20 . In this embodiment, the mixed gas detection unit 71 includes a concentration detector that detects the _{CO 2} concentration and a flow rate detector that detects the flow rate Q of the mixed gas. The mixed gas information including the CO ₂ concentration X _CO2 of the mixed gas, the pressure Pg, the temperature Tg of the mixed gas, and the flow rate Q of the mixed gas detected by the mixed gas detection unit 71 is output to the information acquisition unit 74 .

The environmental condition detection unit 72 detects adsorption conditions that affect the adsorption of CO ₂ by the adsorbent 11 in the adsorber 10 . In the present embodiment, the environmental condition detection unit 72 includes a pressure detector that detects the pressure Pa within the adsorption device 10 and a thermocouple that detects the temperature Ta within the adsorption device 10. The adsorption conditions including the pressure Pa and temperature Ta inside the adsorber 10 detected by the environmental condition detection section 72 are output to the information acquisition section 74 .

The recovered gas detection unit 73 detects the properties of the recovered gas flowing through the recovered gas flow path 50. In this embodiment, the recovered gas is a mixture of CO ₂ and H ₂ , and the recovered gas detection unit 73 includes a concentration detector that detects the CO ₂ concentration Xr _CO2 in the recovered gas, and a concentration detector that detects the CO 2 concentration It includes a pressure detector that detects Prg, a thermocouple that detects the temperature Trg of the recovered gas, and a flow rate detector that detects the flow rate Qr of the recovered gas. The recovered gas information including the CO ₂ concentration Xr _CO2 in the recovered gas, the recovered gas pressure Prg, the recovered gas temperature Trg, and the recovered gas flow rate Qr detected by the recovered gas detection unit 73 is output to the information acquisition unit 74. be done.

The information acquisition section 74 is electrically connected to the mixed gas detection section 71, the environmental condition detection section 72, and the recovered gas detection section 73, respectively. The information acquisition unit 74 collects gas information, which is measurement information of gas properties output from each of the mixed gas detection unit 71, the environmental condition detection unit 72, and the recovered gas detection unit 73, and the measurement of the environmental conditions of the adsorber. Obtain information on adsorption conditions. The information acquisition unit 74 outputs this information to the calculation unit 75 and stores it in a storage unit (not shown). The information acquisition unit 74 estimates the properties of the gas and the environmental conditions of the adsorber based on the information output from the mixed gas detection unit 71, the environmental condition detection unit 72, and the recovered gas detection unit 73. Good too.

The calculation unit 75 performs various calculations and determinations using the properties of the gas and the environmental conditions of the adsorber that are input from the information acquisition unit 74. Detailed functions of the calculation unit 75 will be described later.

The command unit 76 is electrically connected to the calculation unit 75. The command section 76 outputs commands to each section of the collection system 5 according to calculations and determinations made by the calculation section 75.

Next, a collection method using the collection system 5 will be explained. In the recovery system 5 of this embodiment, by using three adsorbers 10, CO ₂ is continuously recovered from the mixed gas, and H ₂ is supplied to the adsorbers 10 in the order in which CO ₂ has been recovered. As a result, the recovered gas containing a mixture of CO ₂ and H ₂ is supplied to the hydrocarbon synthesis device 7 . In the state shown in FIG. 1, the adsorber 10A adsorbs CO ₂ on the adsorbent 11A by being supplied with a mixed gas (adsorption step), and the adsorbent 11A is adsorbing CO 2 by being supplied with H ₂ CO ₂ is desorbed from 11B (recovery step). The adsorbent 10C cools the adsorbent 11C heated by the heat medium after the desorption of CO ₂ from the adsorbent 11C is completed (cooling step).

FIG. 2 is a flowchart illustrating a collection method by the collection system. In the recovery method of this embodiment, for example, first, a mixed gas is supplied to the adsorber 10A, and recovery of CO ₂ is started. Regarding the adsorber 10A, the time when the mixed gas is supplied to the adsorber 10A and CO ₂ recovery is started is set to ta=0 (step S11). Next, the properties of the mixed gas supplied to the adsorber 10A are acquired (step S12). In step S12, the control unit 70 uses the mixed gas detection unit 71 to detect the properties of the mixed gas flowing through the mixed gas supply channel 20. The CO ₂ concentration X _CO2 of the mixed gas, the pressure Pg, the temperature Tg of the mixed gas, and the flow rate Q of the mixed gas detected by the mixed gas detection unit 71 are output to the information acquisition unit 74 . The information acquisition unit 74 stores these input values.

Next, when time t1 has passed since step S11 (step S13), the properties of the mixed gas supplied to the adsorber 10A at time t1 are acquired (step S14). In step S14, similarly to step S12, the control unit 70 uses the mixed gas detection unit 71 to detect the properties of the mixed gas flowing through the mixed gas supply channel 20.

Next, the environmental conditions of the adsorber 10A are acquired (step S15). In step S15, the control unit 70 uses the environmental condition detection unit 72 to collect information regarding the environment within the adsorber 10A, particularly information regarding the environment within the adsorber 10, which is an item that affects when the adsorbent 11A adsorbs _CO2 . Detect pressure Pa and temperature Ta. Information regarding the environmental conditions within the adsorber 10A detected by the environmental condition detection section 72 is output to the information acquisition section 74.

Next, the average CO ₂ concentration and CO ₂ adsorption amount of the mixed gas flowing into the adsorber 10A are calculated (step S16). In step S16, the calculation unit 75 uses the properties of the mixed gas detected by the mixed gas detection unit 71 to determine the average CO ₂ concentration of the gas flowing into the adsorber 10A at time t1, and from time ta=0 to time t1. Until then, the amount of CO ₂ introduced into the adsorbent 11A is calculated. In this embodiment, the amount of CO ₂ adsorption is estimated on the assumption that all of the CO ₂ introduced into the adsorber 10 is adsorbed by the adsorbent 11 . The amount of CO ₂ introduced corresponds to the "estimated amount of introduced amount" in the claims. The amount of CO ₂ adsorption corresponds to the "estimated amount of adsorption" in the claims.

・・・（１）
なお、式（１）において、Ｘ_CO2-ave（ｔ－Δｔ）は、時刻０から時刻（ｔ－Δｔ）までの間の平均ＣＯ₂濃度であり、Ｑ_t（ｔ－Δｔ）は、時刻０から時刻（ｔ－Δｔ）までの間のガスの総流量である。Ｘ_CO2（ｔ）は、時刻ｔにおけるガス中のＣＯ₂濃度であり、ｑ（ｔ）は、時刻ｔにおけるガスの流量である。 In this embodiment, the average CO ₂ concentration X _CO2-ave (t) of the gas flowing into the adsorber from time 0 to time t is calculated using the following equation (1). _The average _{CO 2} concentration .

...(1)
Note that in equation (1), X _CO2-ave (t-Δt) is the average CO 2 concentration from time 0 to time (t-Δt), and Q _t (t-Δt) is the average CO ₂ concentration from time 0 to time It is the total flow rate of gas from time to time (t-Δt). X _CO2 (t) is the CO ₂ concentration in the gas at time t, and q(t) is the gas flow rate at time t.

・・・（２）
ＣＯ₂導入量Ｇ_t-CO2（ｔ）は、式（２）に示すように、時刻０から時刻ｔまでの間に吸着器に流入するＣＯ₂量の積算値を示している。なお、式（２）において、ＣＦは、ＣＯ₂濃度とガス流量との積の値を質量に変換する変換係数である。 The amount of CO ₂ introduced from time 0 to time t G _t-CO2 (t) is calculated using the following equation (2).

...(2)
The amount of CO ₂ introduced G _t-CO2 (t) indicates the integrated value of the amount of CO ₂ flowing into the adsorber between time 0 and time t, as shown in equation (2). Note that in equation (2), CF is a conversion coefficient that converts the product of the CO ₂ concentration and the gas flow rate into mass.

The calculation unit 75 calculates the amount of CO ₂ introduced into the adsorber 10A G _t-CO2 (t1) at time t1 from the CO ₂ concentration X _CO2 of the mixed gas and the flow rate q using equation (2). In this embodiment, as described above, the calculation unit 75 estimates the amount of CO ₂ adsorbed by the adsorbent 11 using the amount of CO ₂ introduced thus calculated, and proceeds with the steps from step S16 onwards. At this time, the calculation unit 75 may further calculate the amount of CO ₂ introduced at time t1 using the pressure Pg of the mixed gas and the temperature Tg of the mixed gas.

In this embodiment, in step S16, the average temperature Tg _-ave (t1) and the average pressure Pg _- of the mixed gas flowing into the adsorber 10A from the start of the adsorption process in the adsorber 10A to time t1 are determined. _ave (t1) is calculated. The average temperature Tg _-ave (t1) and the average pressure Pg _-ave (t1) are used in step S19, which will be described later.

Next, it is determined whether or not to change the set usage rate (step S17). In step S17, it is determined whether or not the set utilization rate set for the adsorbent 11A accommodated in the adsorbent 10A is to be changed.

FIG. 3 is a diagram illustrating the set utilization rate of the adsorbent. FIG. 3 shows the CO ₂ adsorption amount (vertical axis) of the adsorbent per unit mass of the adsorbent relative to the CO ₂ concentration (horizontal axis). Among the three curves shown in FIG. 3, the two-dot chain line Ls indicates the maximum amount of CO ₂ that can be adsorbed by the adsorbent (saturated adsorption amount). The dashed line Ld indicates the amount of CO ₂ adsorbed by the adsorbent that makes desorption impossible, and the solid line La indicates the amount of CO ₂ adsorbed by the adsorbent according to a certain set utilization rate. The amount of CO ₂ adsorption is shown. In this embodiment, the ratio of the adsorption amount Ca shown by the solid line La to the adsorption amount Cs shown by the two-dot chain line Ls is defined as the utilization rate Kset. That is, it can be said that the utilization rate Kset indicates the proportion of the adsorbent used for recovering CO ₂ from the mixed gas.

In the collection method of this embodiment, an initial value of the set usage rate is set, and in step S17, it is determined whether or not the set usage rate is to be changed. In this embodiment, the initial value for the first adsorption step is preset according to the required quality of the recovered gas, but the initial value for the adsorption step is change every time. The set utilization rate may remain fixed at the initially set value. In step S17, when the calculation unit 75 determines that the preset usage rate is to be changed (step S17: Yes), in step S18, the calculation unit 75 changes the setting usage rate (step S18), and in step S19 Transition to. If the calculation unit 75 determines that the set usage rate has been changed (step S17: No), the process moves to step S19.

Returning to FIG. 2, a switching threshold value as a target CO ₂ adsorption amount is calculated using the set utilization rate (step S19). In step S19, the calculation unit 75 first calculates the saturated adsorption amount of the adsorbent 11A. Generally, the saturated adsorption amount of an adsorbent can be determined by the environmental conditions of the adsorbent and the properties of the gas supplied to the adsorbent, in addition to the basic characteristics of the adsorbent. In this embodiment, the saturated adsorption amount of the adsorbent 11A is calculated using the CO ₂ concentration X _CO2 of the mixed gas, the temperature Tg and pressure Pg, and the temperature Ta and pressure Pa in the adsorber 10A. _The calculation unit 75 calculates the CO ₂ adsorption performance of the adsorbent 11A, the CO ₂ concentration of the mixed gas It has a data table showing the relationship with each Pa. When calculating the saturated adsorption amount of the adsorbent 11A, the calculation unit 75 first calculates the average temperature Ta _-ave (t1 ) and the average pressure Pa _-ave (t1) are calculated. Next, the calculation unit 75 calculates the calculated average temperature Ta _-ave (t1) in the adsorber 10A, the average pressure Pa _-ave (t1) in the adsorber 10A, and the mixed gas calculated in step S16. _{Using the} average _{CO 2} concentration Calculate the current saturated adsorption amount of 11A. After calculating the current saturated adsorption amount of the adsorbent 11A, the calculation unit 75 calculates a switching threshold by multiplying the calculated saturated adsorption amount by the set utilization rate determined in step S17 or step S18.

Next, it is determined whether the amount of CO ₂ adsorption is larger than the switching threshold (step S20). In step S20, the calculation unit 75 determines whether the CO ₂ adsorption amount calculated in step S16 is larger than the switching threshold calculated in step S19. When the calculation unit 75 determines that the amount of CO ₂ adsorption is less than or equal to the switching threshold (step S20: No), the process moves to step S21. When the calculation unit 75 determines that the amount of CO ₂ adsorption is larger than the switching threshold (step S20: Yes), the process moves to step S22.

When the calculation unit 75 determines that the amount of CO ₂ adsorption is equal to or less than the switching threshold, the adsorption process in the adsorber 10A is continued, and after the time ta has passed the time Δt from the time t1 (step S21), the time ta is changed to the time (t1+Δt). At time t1 (step S13), the properties of the mixed gas supplied to the adsorber 10A are acquired again (step S14). Thereafter, steps S15 to S19 are repeated, and a determination is made in step S20.

When the calculation unit 75 determines that the amount of CO ₂ adsorption is greater than the switching threshold, the command unit 76 instructs to switch the process (step S22). In step S22, the command unit 76 blocks the flow of the mixed gas supply valve 21 in the direction of the adsorber 10A, switches the flow to the direction of the mixed gas supply valve 22, and also switches the flow of the mixed gas supply valve 22 in the direction of the adsorber 10C. Open the flow. Thereby, the adsorber in which the adsorption process is performed is switched from adsorber 10A to adsorber 10C.

In the recovery method of the present embodiment, when the adsorption step of the adsorber 10A is completed, the flow of the hydrogen supply valve 41 toward the hydrogen supply valve 42 is opened, and the flow of the hydrogen supply valve 42 toward the adsorption device 10A is opened. Thereby, H ₂ is supplied to the adsorber 10A via the hydrogen gas supply channel 40. In addition to the supply of H ₂ , the adsorber 10A is supplied with a heat medium through the heat medium flow path 60, so that the adsorbent 11A is heated and the CO ₂ adsorbed on the adsorbent 11A is easily desorbed. Thereby, the recovered gas in which the CO ₂ desorbed in the adsorber 10A and the supplied H ₂ are mixed is sent to the hydrocarbon synthesis device 7 via the recovered gas flow path 50.

When H ₂ is supplied to the adsorber 10A by switching the process in step S22, CO ₂ adsorbed on the adsorbent 11A is desorbed from the adsorbent 11A and flows through the recovered gas flow path 50. The CO ₂ concentration Xr _CO2 , pressure Prg, temperature Trg, and flow rate Qr of the recovered gas flowing through the recovered gas flow path 50 are detected by the recovered gas detection unit 73 . The information acquisition unit 74 acquires desorption amount information including the CO ₂ concentration Xr _CO2 , pressure Prg, temperature Trg, and flow rate Qr of the recovered gas detected by the recovered gas detection unit 73 (step S23).

The calculation unit 75 uses the properties of the mixed gas acquired by the mixed gas detection unit 71 and the properties of the recovered gas detected by the recovered gas detection unit 73 to calculate the amount of CO ₂ desorbed relative to the amount of CO ₂ introduced into the adsorber 10A. A ratio is calculated (step S24). In step S24, the calculation unit 75 uses the desorption amount information to calculate the amount of CO ₂ supplied to the hydrocarbon synthesis device 7 as the amount of CO 2 desorption, and calculates the amount of CO ₂ to be desorbed relative to the amount of CO ₂ introduced calculated in step S16. Calculate the rate of CO ₂ desorption. Here, the ratio of the amount of CO ₂ desorbed to the amount of CO ₂ introduced into the adsorber 10A is referred to as the CO ₂ recovery rate of the adsorber 10A. When the calculated CO ₂ recovery rate is smaller than the expected value, the calculation unit 75 makes the set utilization rate smaller than the previous set utilization rate in step S18 of the next adsorption step in the adsorber 10A. When the calculated CO ₂ recovery rate is larger than the expected value, the calculation unit 75 increases the set utilization rate compared to the previous set utilization rate in step S18 of the next adsorption step in the adsorber 10A. In this way, in the recovery method of this embodiment, the saturated adsorption amount and the set utilization rate are changed according to the actual condition of the adsorber 10, and the CO ₂ concentration of the recovered gas is stabilized, and the CO ₂ recovery rate is greatly increased. do. The amount of CO ₂ desorption corresponds to the "estimated amount of desorption" in the claims.

FIG. 4 is a diagram illustrating changes over time in the amount of CO ₂ adsorption in the recovery method of this embodiment. FIG. 4 shows the CO ₂ adsorption amount CA in each of the three adsorbers 10A, 10B, and 10C included in the recovery system 5, and the switching threshold ST as the target CO ₂ adsorption amount to be adsorbed in one adsorber 10. ing. Specifically, the time period from time t1 to time t2 indicates the CO ₂ adsorption amount and switching threshold of the adsorber 10A, and the time period from time t2 to time t3 indicates the CO ₂ adsorption amount of the adsorber 10C. The amount of CO ₂ adsorbed by the adsorber 10B and the switching threshold are shown in the time period from time t3 to time t4.

In the recovery method of this embodiment, as shown in FIG. 4, each of the three adsorbers 10A, 10B, and 10C is activated when the CO ₂ adsorption amount CA exceeds the switching threshold ST at times t2, t3, and t4. , the adsorption process is completed. In this embodiment, as described above, in step S19, the saturated adsorption amount is multiplied by the set utilization rate to calculate the switching threshold ST. In this embodiment, the saturated adsorption amount of the adsorber is calculated using the _{CO 2} concentration The threshold value ST changes depending on time. Therefore, as shown in FIG. 4, the value of the switching threshold ST varies depending on the properties of the mixed gas and the environmental conditions of the adsorbent.

FIG. 5 is a diagram showing temporal changes in the properties of the mixed gas. FIG. 5(a) shows the time change in the CO ₂ concentration of the mixed gas, and FIG. 5(b) shows the time change in the flow rate of the mixed gas. In this embodiment, the mixed gas is supplied from the combustion equipment 6, and the properties of the mixed gas change over time depending on the operating state of the combustion equipment 6. Specifically, as shown in FIG. 5, the CO ₂ concentration varies in the range from 5% to 10%, and the flow rate varies in the range from 30 L/min to 90 L/min. If the properties of the mixed gas supplied to the adsorber 10 change significantly as shown in FIG. 5, the saturated adsorption amount of the adsorbent 11 will also change.

FIG. 6 is a diagram illustrating the relationship between the utilization rate of adsorbent and the quality of recovered gas. In the adsorber 10 shown in FIG. 6, the mixed gas flows into the adsorber 10 from the inlet 12 of the adsorber 10. The remaining gas in the mixed gas from which CO ₂ has been removed by adsorption by the adsorbent 11 is discharged from the outlet 13. Therefore, CO ₂ contained in the mixed gas is adsorbed in order from the adsorbent 11 closest to the inlet 12. Therefore, the adsorbent 11 is located on the inlet 12 side of the adsorber 10 and adsorbs CO ₂ (area Ra1 shown in FIG. 6), and the adsorbent is located on the exit 13 side of the adsorber 10 and adsorbs CO ₂ includes an adsorbent (area Ra2 shown in FIG. 6) that does not adsorb gases other than CO ₂ contained in the mixed gas. Here, the gases other than CO ₂ contained in the mixed gas include oxygen, nitrogen, moisture, etc. in this embodiment.

In the recovery system, when CO ₂ is desorbed and recovered from the adsorbent 11 that has adsorbed CO ₂ , the CO ₂ concentration of the recovered gas remains constant for ease of use in the subsequent process (hydrocarbon generation). It is desirable that there be. Therefore, at the end of the adsorption step, it is desirable that the ratio (utilization rate) of the adsorbent 11 adsorbing CO ₂ to the entire adsorbent 11 is constant. However, as shown in FIG. 6, even if the boundary between the adsorbent 11 adsorbing CO ₂ and the adsorbent 11 adsorbing gases other than CO ₂ is set as boundary B1, the mixed gas The saturated adsorption amount of the adsorbent 11 changes depending on the properties and operating conditions of the adsorber 10. Therefore, the boundary between the adsorbent 11 adsorbing CO ₂ and the adsorbent 11 adsorbing gases other than CO ₂ may become the boundary B2. Therefore, in this embodiment, in order to keep the utilization rate of the adsorbent 11 constant, the saturated adsorption amount of the adsorbent 11 is calculated using the properties of the mixed gas and the adsorption conditions of the adsorber 10. The utilization rate of the material 11 is adjusted so as to be constant (from step S17 to step S19 shown in FIG. 2). Thereby, the quality of the recovered gas can be stabilized. Note that when the utilization rate of the adsorbent is set to 100%, the quality of the recovered gas is stabilized, but a portion of the CO ₂ contained in the mixed gas is exhausted without being adsorbed by the adsorbent. Therefore, in order to reduce the leakage of CO _{2 while increasing the CO 2 concentration} in the recovered gas, it is desirable to set the utilization rate to about 60% to 90%, for example.

FIG. 7 is a diagram illustrating changes in the average CO ₂ concentration in the adsorption process and the adsorption process time. FIG. 7 shows changes in the average CO ₂ concentration of the mixed gas (FIG. 7(a)) and the time for one adsorption step (FIG. 7(b)) in the adsorption step of the recovery method of this embodiment. . The horizontal axis in FIG. 7 indicates the number of steps. As shown in FIG. 7(a), in the recovery system 5, the average CO _{2 concentration} Gas quality may be unstable. In this embodiment, as described above, the time for one adsorption process is determined based on the saturated adsorption amount of the adsorbent 11 calculated using the properties of the gas so that the utilization rate of the adsorbent 11 is constant. Tabs is changed (see FIG. 7(b)).

FIG. 8 is a first diagram illustrating the adsorbent utilization rate and CO ₂ recovery rate. FIG. 8 shows changes over time in the utilization rate of the adsorbent (FIG. 8(a)) and the CO ₂ recovery rate (FIG. 8(b)) when the adsorption process is repeated. As shown in FIG. 8(a), immediately after the recovery method is started, there is no CO ₂ in the adsorber, so the CO ₂ remains in the adsorber without being completely desorbed. For this reason, the CO ₂ concentration is not stable and changes over time. However, in the example shown in FIG. 8, it can be seen that the utilization rate of the adsorbent becomes stable after 15 hours have passed since the start of the recovery method. Moreover, it can be seen from FIG. 8(b) that when the utilization rate of the adsorbent becomes stable, the CO ₂ recovery rate also becomes stable. Therefore, it can be seen that the quality of the recovered gas is stable. Note that in the experimental example shown in FIG. 8, the utilization rate (kset) of the adsorbent is set to 0.6, and the CO ₂ recovery rate is approximately 100%. That is, almost all of the CO ₂ contained in the mixed gas can be recovered. Note that, as shown in FIG. 8A, the actual utilization rate after 15 hours have passed since the start of the collection method is greater than the set utilization rate of 0.6. This is because the actual utilization rate of the adsorbent includes the adsorbent adsorbing CO ₂ that cannot be desorbed as a result of being adsorbed by the adsorbent.

FIG. 9 is a second diagram illustrating the adsorbent utilization rate and CO ₂ recovery rate. FIG. 9 shows changes in the adsorbent utilization rate (FIG. 9(a)) and the CO ₂ recovery rate (FIG. 9(b)) with respect to the average CO ₂ concentration of the mixed gas. In the experimental example shown in Figure 9, the average CO ₂ concentration of the mixed gas changes from a value smaller than 6% to a value larger than 8%. It can be seen from FIG. 9(b) that the CO 2 recovery rate is maintained between 0.65 and 0.68, and the CO ₂ recovery rate is also stable. Therefore, in the recovery system 5 of this embodiment, it has become clear that even if the average CO ₂ concentration of the mixed gas changes, the CO ₂ recovery rate for each recovery process is stable.

FIG. 10 is a diagram illustrating the influence of changes in environmental temperature on the adsorbent. FIG. 10(a) is a diagram illustrating changes in the amount of CO ₂ adsorption due to changes in the environmental temperature of the adsorbent. Generally, the adsorption amount of gas adsorbents such as CO ₂ decreases as the environmental temperature increases. That is, the saturated adsorption amount of the adsorbent changes depending on the change in the environmental temperature of the adsorbent. FIG. 10(b) shows a process average change in adsorbent temperature with a change in environmental temperature in each of a plurality of adsorption steps. As shown in FIG. 10(b), it can be seen that in the recovery system 5 of this embodiment, not only the average CO ₂ concentration changes, but also the average temperature of the adsorbent.

FIG. 11 is a third diagram illustrating the adsorbent utilization rate and CO ₂ recovery rate. Figure 11 shows the adsorbent utilization rate (Figure 11(a)) and CO ₂ recovery rate (Figure 11(b)) when the adsorbent environmental temperature changes for each adsorption process. It shows changes in gas CO ₂ concentration. In the experimental example shown in FIG. 11, even if there is a change in the average temperature of the adsorbent as shown in FIG. 10(b), the utilization rate of the adsorbent is 0.7 as shown in FIG. 11(a). It can be seen that the CO 2 recovery rate is almost maintained at around the same value, and as shown in FIG. 11(b), the CO ₂ recovery rate is also stable. Therefore, in the recovery system 5 of this embodiment, it has become clear that even if the environmental temperature of the adsorbent changes, the CO ₂ recovery rate for each recovery process is stable.

FIG. 12 is a fourth diagram illustrating the adsorbent utilization rate and CO ₂ recovery rate. FIG. 13 is a fifth diagram illustrating the adsorbent utilization rate and CO ₂ recovery rate. FIG. 12 shows the assumed amount of heat medium supplied by the heat medium flow path 60 for each of the adsorbent utilization rate (FIG. 12(a)) and the CO ₂ recovery rate (FIG. 12(b)). This shows the change in the CO ₂ concentration of the mixed gas when the amount is less than the amount. For example, if the flow rate of the heat medium flowing through the heat medium flow path 60 becomes 40% of the expected amount due to a malfunction in the recovery system 5, if the utilization rate Kset of the adsorbent 11 is left at 0.6, In the recovery process, CO ₂ desorption failure occurs due to insufficient heat. Therefore, CO ₂ tends to remain in the adsorber 10, and the utilization rate increases to around 0.9 as shown in FIG. 12(a). As the utilization rate increases, C
Since O ₂ cannot be completely recovered, the CO ₂ recovery rate decreases, and gas from which CO ₂ has not been completely removed flows into the exhaust gas flow path 30, as shown in FIG. 12(b).

In this embodiment, the calculation unit 75 calculates the CO ₂ recovery rate of the adsorber 10 using the properties of the recovered gas acquired by the information acquisition unit 74 and the properties of the mixed gas acquired by the mixed gas detection unit 71. (See step S24 in FIG. 2). When the CO ₂ recovery rate has decreased, the calculation unit 75 reduces the set utilization rate in the next adsorption step to restore the CO ₂ recovery rate. Specifically, in the situation shown in FIG. 12, the utilization rate Kset is changed from 0.6 to 0.4. As a result, as shown in FIG. 13, the utilization rate becomes around 0.6, and the time for the adsorption process is also shortened, making it possible to reliably recover CO ₂ contained in the mixed gas. Therefore, as shown in FIG. 13(b), the CO ₂ recovery rate can be restored.

According to the recovery device 1 of the present embodiment described above, the control unit 70 uses the mixed gas information including the temperature of the mixed gas and the adsorption conditions including the environmental temperature of the adsorbent 11 to The adsorber 10 that supplies the mixed gas is switched depending on the CO ₂ adsorption amount and the saturated adsorption amount. The saturated adsorption amount of the adsorbent 11 depends on the properties of the mixed gas supplied to the adsorber 10 and the environmental conditions that affect the adsorption performance of the adsorbent 11, so the saturated adsorption amount estimated in this way is the value that matches the actual situation. Thereby, by switching the mixed gas supply destination according to the CO ₂ adsorption amount and saturated adsorption amount of the adsorbent 11 estimated by the calculation unit 75, CO ₂ is removed while suppressing leakage of CO 2 to the outside of the system. The ratio (utilization rate) of the adsorbent 11 used for adsorption of No. ₂ can be stabilized. Therefore, when recovering the CO ₂ adsorbed by the adsorbent 11, the concentration of CO ₂ in the recovered gas can be made constant, so the quality of the recovered gas can be stabilized.

Further, according to the recovery device 1 of the present embodiment, the calculation unit 75 estimates the amount of CO ₂ introduced into the adsorber 10 from the start of the adsorption process to the specific time t1 as the amount of CO ₂ introduced. Then, the amount of CO ₂ adsorbed by the adsorbent 11 is estimated using the estimated amount of CO ₂ introduced. The calculation unit 75 compares the estimated CO ₂ adsorption amount with a switching threshold calculated by multiplying the saturated adsorption amount by the set utilization rate. The command unit 76 switches the adsorber 10 that supplies the mixed gas according to the comparison result. That is, the recovery device 1 can switch the supply destination of the mixed gas by estimating the CO ₂ adsorption amount of the adsorbent 11 using only the mixed gas information and comparing it with the switching threshold. Therefore, the quality of the recovered gas can be easily stabilized.

Further, according to the recovery device 1 of this embodiment, the calculation unit 75 calculates the set utilization rate using the ratio of the amount of CO ₂ desorption to the amount of CO ₂ introduced, that is, the recovery rate of CO ₂ . This makes it possible to stabilize the recovery rate of CO ₂ , which is one of the qualities of the recovered gas, so that the quality of the recovered gas can be further stabilized.

Further, according to the recovery device 1 of the present embodiment, the saturated adsorption amount of the adsorbent 11 is determined by the average value of the properties of the mixed gas from the start of supply of the mixed gas to the adsorber 10 to a specific time, or the environmental Estimated using the average value of the conditions. This makes it possible to estimate the saturated adsorption amount of the adsorbent 11 even if there is a sudden change in the properties or environmental conditions of the mixed gas after the supply of the mixed gas to the adsorber 10 is started. The quality of gas can be stabilized.

Further, according to the recovery method of the present embodiment, the recovery device 1 controls the adsorber 10 that supplies the mixed gas according to the saturated adsorption amount of the adsorbent 11 calculated using the mixed gas information and the adsorption conditions. Switch. Thereby, the utilization rate of the adsorbent 11 can be stabilized, so the quality of the recovered gas can be stabilized.

Further, according to the computer program of this embodiment, the control unit 70 switches the adsorber that supplies the mixed gas according to the saturated adsorption amount of the adsorbent 11 calculated using the mixed gas information and the adsorption conditions. . Thereby, the utilization rate of the adsorbent can be stabilized, so the quality of the recovered gas can be stabilized.

<Second embodiment>
FIG. 14 is a schematic diagram showing a schematic configuration of a recovery device according to the second embodiment. The recovery device of the second embodiment differs from the recovery device of the first embodiment (FIG. 1) in that it detects the concentration of impurities contained in the mixed gas.

The control unit 70 included in the recovery system 5 of this embodiment includes a mixed gas detection unit 77, an environmental condition detection unit 72, an information acquisition unit 74, a calculation unit 75, and a command unit 76. The mixed gas detection unit 77 detects the properties of the mixed gas flowing through the mixed gas supply channel 20. The mixed gas detection unit 77 includes a CO ₂ concentration detector, a pressure detector that detects the pressure Pg, a thermocouple that detects the temperature Tg, a flow rate detector that detects the flow rate Q, and _a and an impurity concentration detector that detects the concentration X _ip of the component. The mixed gas information including the CO ₂ concentration X _CO2 , impurity concentration X _ip , pressure Pg, temperature Tg, and flow rate Q detected by the mixed gas detection unit 77 is output to the information acquisition unit 74 .

FIG. 15 is a diagram illustrating the influence of changes in the environmental temperature of the adsorbent. In general, an adsorbent for a gas such as CO ₂ will also adsorb an impurity gas when a gas different from the adsorption target, a so-called impurity gas, is included in a mixed gas containing the gas to be adsorbed. Therefore, if the mixed gas contains impurity gas, the saturated adsorption amount of the adsorbent gas on the adsorbent will decrease, and if the concentration of impurity gas increases, the saturated adsorption amount of the adsorption target gas on the adsorbent will decrease. (See Figure 15).

In the recovery method of this embodiment, when calculating the switching threshold in step S19 (see FIG. 2), the control unit 70 only uses the temperature Tg and pressure Pg of the mixed gas, and the temperature Ta and pressure Pa inside the adsorber 10. Instead, the saturated adsorption amount is calculated using also the impurity concentration _Xip of the mixed gas detected by the mixed gas detection unit 77. In this embodiment, the calculation unit 75 calculates the adsorption performance of the adsorbent 11 for CO ₂ , the temperature Tg of the mixed gas, the pressure Pg of the mixed gas, the impurity concentration X _ip of the mixed gas, the temperature Ta inside the adsorber 10A, and , has a data table showing the relationship between the pressure Pa in the adsorber 10A and each other. The calculation unit 75 calculates the saturated adsorption amount of the adsorbent 11 using this data table, and multiplies it by the set utilization rate to calculate the switching threshold. As a result, in the recovery method of this embodiment, the switching threshold is changed in accordance with the change in the impurity concentration X _ip of the mixed gas.

According to the recovery device 2 of the present embodiment described above, the mixed gas detection unit 77 acquires mixed gas information including the concentration of substances other than CO ₂ contained in the mixed gas. Since the adsorbent 11 also adsorbs substances other than CO ₂ , such as H ₂ O, the saturated adsorption amount of the adsorbent 11 decreases. Therefore, by estimating the saturated adsorption amount of the adsorbent 11 using the concentration of a substance other than CO ₂ , the accuracy of estimating the saturated adsorption amount can be improved. This improves the accuracy of the timing for switching the mixed gas supply destination, so the quality of the recovered gas can be further stabilized.

<Third embodiment>
FIG. 16 is a schematic diagram showing a schematic configuration of a recovery device according to the third embodiment. The recovery device of the third embodiment differs from the recovery device of the first embodiment (FIG. 1) in that it detects the CO ₂ concentration contained in the exhaust gas.

The control unit 70 included in the recovery system 5 of this embodiment includes a mixed gas detection unit 71, an environmental condition detection unit 72, an exhaust gas detection unit 78, an information acquisition unit 74, a calculation unit 75, and a command unit 76. , is provided. The exhaust gas detection unit 78 detects the properties of exhaust gas flowing through the exhaust gas flow path 30. The exhaust gas detection unit 78 includes a concentration detector that detects the CO ₂ concentration Xe _CO2 in the exhaust gas, a pressure detector that detects the pressure Peg of the exhaust gas, a thermocouple that detects the temperature Teg of the exhaust gas, and a thermocouple that detects the temperature Teg of the exhaust gas. A flow rate detector that detects a gas flow rate Qe is provided. Exhaust gas information including CO ₂ concentration eX _{CO 2} , pressure Peg, temperature Teg, and flow rate Qe detected by exhaust gas detection unit 78 is output to information acquisition unit 74 .

In the recovery method of this embodiment, in step S16 (see FIG. 2), the calculation unit 75 calculates the amount of CO ₂ introduced using the _{CO 2} concentration , the CO ₂ emission amount is calculated using the CO ₂ concentration Xe _CO2 in the exhaust gas detected by the exhaust gas detection unit 78 and the flow rate Qe. The calculation unit 75 calculates the amount of CO ₂ adsorption using the difference between the amount of CO 2 introduced and _{the amount of CO 2 discharged} . In step S20 (see FIG. 2), the calculation unit 75 determines whether the CO ₂ adsorption amount calculated in this way is larger than the switching threshold. The amount of CO ₂ emissions corresponds to the "estimated amount of emissions" in the claims.

According to the recovery device 3 of the present embodiment described above, the calculation unit 75 uses the difference between the amount of CO ₂ introduced into the adsorber 10 and the amount of CO ₂ discharged from the adsorber 10 to calculate Estimate the amount of CO ₂ adsorption. The control unit 70 switches the adsorber 10 that supplies the mixed gas by comparing the estimated CO ₂ adsorption amount with a switching threshold. Thereby, when determining the supply destination of the mixed gas, it is possible to improve the estimation accuracy of the CO ₂ adsorption amount of the adsorbent 11, so that the command unit 76 can accurately switch the supply destination of the mixed gas. . Therefore, the quality of the recovered gas can be further stabilized.

<Modified example of this embodiment>
The present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the spirit thereof. For example, the following modifications are also possible.

[Modification 1]
In the embodiment described above, the recovery devices 1, 2, and 3 are applied to the recovery system 5 that recovers carbon dioxide from a mixed gas containing moisture and the like. However, the field to which the recovery device is applied is not limited to this. Any system that uses an adsorbent to adsorb and recover a specific substance in a mixed gas is applicable.

[Modification 2]
In the embodiment described above, the calculation unit 75 calculates the saturated adsorption amount and the CO ₂ introduction amount using the numerical values detected (measured) by the mixed gas detection unit 71, the environmental condition detection unit 72, and the like. The calculation unit 75 may estimate the saturated adsorption amount and the CO ₂ introduction amount from the numerical values detected by the mixed gas detection unit 71, the environmental condition detection unit 72, and the like.

[Modification 3]
In the embodiment described above, the mixed gas detection unit 71 detects the CO ₂ concentration of the mixed gas, the pressure Pg of the mixed gas, the temperature Tg of the mixed gas, and the flow rate Q of the mixed gas. It is assumed that the environmental condition detection unit 72 detects the pressure Pa and temperature Ta inside the adsorber 10. The numerical values detected by these detection units are not limited to these. Any value may be used as long as it is possible to calculate or estimate the saturated adsorption amount of the adsorbent 11 or the amount of CO ₂ introduced. The same applies to the mixed gas detection section 77 of the second embodiment and the exhaust gas detection section 78 of the third embodiment.

[Modification 4]
In the above-described embodiment, the calculation unit 75 calculates the temperature of the adsorbent 11 using the average temperature in the adsorber 10, the average pressure in the adsorber 10, the average temperature of the mixed gas, and the average temperature of the mixed gas. The saturated adsorption amount was calculated. However, the numerical value used to calculate the saturated adsorption amount of the adsorbent 11 does not have to be an average value.

[Modification 5]
In the embodiment described above, in order to keep the utilization rate of the adsorbent 11 constant, the saturated adsorption amount of the adsorbent 11 is calculated using the properties of the mixed gas and the adsorption conditions of the adsorber 10. 11 will be adjusted so that the utilization rate remains constant. However, the utilization rate of the adsorbent 11 may not be constant. For example, the utilization rate of the adsorbent may be changed depending on the CO ₂ concentration of the mixed gas and the characteristics of the adsorbent. For example, the utilization rate may be set higher as the CO ₂ concentration is lower depending on the characteristics of the adsorbent. Good too.

Although the present aspect has been described above based on the embodiments and modified examples, the embodiments of the above-described aspect are for facilitating understanding of the present aspect, and do not limit the present aspect. This aspect may be modified and improved without departing from the spirit and scope of the claims, and this aspect includes equivalents thereof. Furthermore, if the technical feature is not described as essential in this specification, it can be deleted as appropriate.

1, 2, 3... Recovery device 10, 10A, 10B, 10C... Adsorber 11, 11A, 11B, 11C... Adsorbent 70... Control section 71, 77... Mixed gas detection section 72... Environmental condition detection section 73... Environmental condition Detection unit 74... Information acquisition unit 75... Calculation unit 76... Command unit 78... Exhaust gas detection unit kset... Utilization rate

Claims (8)

A recovery device for recovering specific substances contained in mixed gas,
an adsorber containing an adsorbent that adsorbs the specific substance;
Mixed gas information that is estimated or measured information on the properties of the mixed gas supplied to the adsorber, including the temperature of the mixed gas, and environmental temperature of the adsorbent, which affects the adsorption performance of the adsorbent. an acquisition unit that acquires adsorption conditions that are estimated information or measured information of environmental conditions that give
an estimation unit that estimates an estimated adsorption amount of the adsorbent and a saturated adsorption amount of the adsorbent using the mixed gas information and the adsorption conditions;
A recovery device comprising: a switching unit that switches an adsorber that supplies the mixed gas according to the estimated adsorption amount and the saturated adsorption amount. The recovery device according to claim 1,
The estimation unit is
using the mixed gas information to estimate an estimated amount of the specific substance introduced into the adsorber;
using the estimated introduction amount estimate to estimate the adsorption amount estimate representing the amount of the specific substance adsorbed by the adsorbent at a specific time;
calculating a switching threshold value by multiplying the saturated adsorption amount estimated using the mixed gas information by a control constant;
The switching unit compares the estimated adsorption amount with the switching threshold and switches the adsorber that supplies the mixed gas.
Collection device. The recovery device according to claim 1,
The acquisition unit acquires exhaust gas information that is estimated information or measurement information of the properties of the exhaust gas, including a flow rate of the exhaust gas discharged from the adsorber and a concentration of the specific substance in the exhaust gas. death,
The estimation unit is
using the mixed gas information to estimate an estimated amount of the specific substance introduced into the adsorber;
using the exhaust gas information to estimate an estimated amount of the specific substance discharged from the adsorber;
estimating the adsorption amount estimate representing the amount of the specific substance adsorbed by the adsorbent at a specific time using the difference between the introduction amount estimate and the emission amount estimate;
calculating a switching threshold value by multiplying the saturated adsorption amount estimated using the mixed gas information by a control constant;
The switching unit compares the estimated adsorption amount with the switching threshold and switches the adsorber that supplies the mixed gas.
Collection device. The recovery device according to claim 2 or 3,
The acquisition unit acquires desorption amount information that is estimated information or measurement information of the amount of the specific substance desorbed from the adsorbent that has adsorbed the specific substance,
The estimation unit is
Using the desorption amount information, estimate an estimated desorption amount,
calculating the control constant using the ratio of the estimated desorption amount to the estimated introduced amount;
Collection device. The collection device according to any one of claims 1 to 4,
The estimation unit is
Using the mixed gas information, calculate the average value of the properties of the mixed gas from the start of supply of the mixed gas to the adsorber to the specific point in time,
Using the adsorption conditions, calculate the average value of the environmental conditions from the start of supply of the mixed gas to the adsorber until the specific point in time,
estimating the saturated adsorption amount of the adsorbent using the average value of the properties of the mixed gas and the average value of the environmental conditions;
Collection device. The recovery device according to any one of claims 1 to 5,
The acquisition unit acquires the mixed gas information including the concentration of a substance other than the specific substance contained in the mixed gas,
The estimation unit estimates the saturated adsorption amount of the adsorbent using the concentration of a gas other than the specific substance contained in the mixed gas, which is included in the mixed gas information.
Collection device. A recovery method for recovering specific substances contained in a mixed gas using a recovery device,
a step of adsorbing the specific substance to an adsorbent;
Mixed gas information that is estimated or measured information on the properties of the mixed gas supplied to the adsorber, including the temperature of the mixed gas, and mixed gas information that includes the environmental temperature of the adsorbent, which affects the adsorption performance of the adsorbent. a step of acquiring adsorption conditions that are estimated information or measured information of environmental conditions to be given;
estimating an estimated adsorption amount of the adsorbent and a saturated adsorption amount of the adsorbent using the mixed gas information and the adsorption conditions;
a step of switching an adsorber that supplies the mixed gas according to the estimated adsorption amount and the saturated adsorption amount;
Collection method. A computer program that causes a computer to recover a specific substance contained in a mixed gas,
a function of adsorbing the specific substance to an adsorbent;
Mixed gas information that is estimated or measured information on the properties of the mixed gas supplied to the adsorber containing the adsorbent, including the temperature of the mixed gas, and the adsorbent, including the environmental temperature of the adsorbent. a function to obtain adsorption conditions, which are estimated or measured information on environmental conditions that affect the adsorption performance of the
a function of estimating an estimated adsorption amount of the adsorbent and a saturated adsorption amount of the adsorbent using the mixed gas information and the adsorption conditions;
causing a computer to execute a function of switching an adsorber that supplies the mixed gas according to the estimated adsorption amount and the saturated adsorption amount;
computer program.

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