JP2021023903A - Adsorber - Google Patents

Abstract

To improve adsorptivity of an adsorber by reducing pressure loss of gas flowing in the adsorber, and by suppressing unevenness of the amount of adsorption by an adsorbent changing according to the position.SOLUTION: An adsorber includes a space formation part for forming an internal space, a gas inflow port formed in the space formation part, a gas outflow port formed in the space formation part, a first adsorbent capable of adsorbing one or more specific gases contained in mixed gas, and a second adsorbent capable of adsorbing specific gas, and having lower adsorption rate for the specific gas than the first adsorbent. In the internal space, the first adsorbent is filled on the gas outflow port side, and the second adsorbent is filled on the gas inflow port side.SELECTED DRAWING: Figure 1

Description

The present invention relates to an adsorber.

An adsorber having an adsorbent that adsorbs a specific gas is known (see, for example, Patent Document 1). In the adsorber described in Patent Document 1, the adsorbent arranged in the adsorber adsorbs a specific gas from a mixed gas containing a plurality of components. This adsorber is cylindrical and has an internal space. In this adsorber, gas inlets and gas outlets through which mixed gas can enter and exit are formed at both ends along the central axis of the cylinder. The adsorbent is formed in the adsorber as a plurality of layered regions separated along the horizontal direction orthogonal to the central axis.

Japanese Unexamined Patent Publication No. 2013-49016

The adsorber described in Patent Document 1 reduces the pressure loss when the size of the adsorber is increased to improve the adsorption performance. However, in this adsorber, since a plurality of regions formed of the adsorbent are arranged in the internal space, the structure of the adsorber becomes complicated. In addition, there may be a difference between the adsorbed amount of the adsorbent located near the gas inlet and the adsorbed amount of the adsorbent located near the gas outlet. Further, since there is a space in the adsorbent that is not filled with the adsorbent, the adsorption performance may be deteriorated with respect to the size of the adsorber.

The present invention has been made to solve the above-mentioned problems, and by reducing the pressure loss of the gas flowing in the adsorber and suppressing the unevenness of the adsorbed amount of the adsorbent which changes depending on the position, the adsorber The purpose is to improve the adsorption performance.

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

(1) According to one embodiment of the present invention, an adsorber is provided. In this adsorber, a space forming portion forming an internal space, a gas inlet formed in the space forming portion, a gas outlet formed in the space forming portion, and one or more specific types contained in the mixed gas are specified. The internal space is provided with a first adsorbent capable of adsorbing the specific gas and a second adsorbent capable of adsorbing the specific gas and having a slower adsorption rate of the specific gas than the first adsorbent. The first adsorbent is filled on the gas outlet side, and the second adsorbent is filled on the gas inlet side.

According to this configuration, the second adsorbent filled on the gas inlet side in the internal space before the specific gas not adsorbed by the first adsorbent and the second adsorbent leaks from the gas outlet It is in contact with the mixed gas longer than the first adsorbent. The second adsorbent has a slower adsorption rate with a specific gas than the first adsorbent, that is, the pressure loss of the second adsorbent with respect to the gas flowing in the internal space is smaller than that of the first adsorbent. According to this configuration, by arranging the second adsorbent on the gas inflow port side where a sufficient adsorption time can be obtained, the pressure loss with respect to the mixed gas can be reduced without changing the adsorption performance. Further, by arranging the first adsorbent on the gas outlet side where only a short adsorption time can be obtained, leakage of a specific gas from the gas outlet can be suppressed. In addition, unevenness in the amount of adsorption depending on the position in the first adsorbent is suppressed, and the adsorption performance of the adsorber is improved. As a result, low pressure loss and high adsorption performance in the adsorber can be realized.

(2) In the adsorber of the above aspect, the adsorption rate of the second adsorbent may be slowed down by making at least one of the material and the shape different from that of the first adsorbent.
According to this configuration, the first adsorbent and the second adsorbent depend on the size and shape of the adsorber, the usage environment in which the mixed gas is supplied to the adsorber, the combination of the mixed gas and the specific gas, and the like. The material and shape may be selected. Therefore, it becomes easy to adjust the pressure loss of the gas flowing in the adsorber and the adsorption performance of the adsorber.

(3) In the adsorber of the above aspect, the internal space extends from the gas inlet side to the gas outlet side along the central axis, and the central axis of the region filled with the first adsorbent. The length along the central axis is greater than the length along the central axis of the portion accompanied by a temperature rise of 0.2 T or more with respect to the maximum temperature change T of the central position of the first adsorbent when the mixed gas is supplied. May be long.
When the adsorbent adsorbs a specific gas, if the temperature of the adsorbent rises beyond the temperature range suitable for the reaction, the adsorption reaction does not proceed and the adsorption rate at which the adsorbent adsorbs the specific gas slows down. Since the temperature of the adsorbent rises due to the heat of adsorption, the temperature near the central axis, which does not allow heat to escape to the outside of the adsorber, tends to rise. Therefore, regarding the temperature distribution of the adsorbent, the spherical shape centered on an arbitrary point near the central axis or the cross section centered on the arbitrary point proceeds while maintaining an elliptical shape. According to this configuration, when the position of the maximum temperature change T exists in the center of the first adsorbent, the length along the central axis of the first adsorbent is accompanied by a temperature rise of 0.2 T or more from the center. It is longer than the distance between the gas inlet side and the gas outlet side. As a result, even if the position of the maximum temperature change T advances in the first adsorbent, there is a sufficient distance from the position to the end face on the gas outlet side of the first adsorbent. As a result, even if the position of the maximum temperature change moves to the first adsorbent, the specific gas does not immediately leak from the first adsorbent, so that the adsorption performance of the first adsorbent can be improved.

(4) In the adsorber of the above aspect, the internal space extends from the gas inlet side to the gas outlet side along the central axis, and the first adsorbent in the vicinity of the central axis and the central axis. The filling length of the first adsorbent may be longer than the filling length of the first adsorbent in the outer peripheral portion of the internal space.
When the mixed gas is supplied to the adsorber, the adsorption distribution of the specific gas in the adsorbent proceeds as a parabola convex with respect to the gas outlet side. Therefore, when the inside of the adsorber is filled with a uniform adsorbent, a specific gas that has not been adsorbed starts to leak from the adsorbent on the gas outlet side in the central axis and the vicinity of the central axis. According to this configuration, the filling length of the central axis and the first adsorbent near the central axis is longer than the filling length of the outer peripheral portion. Therefore, in this configuration, the first adsorbent is specified by the difference in the filling length in the central axis and the vicinity of the central axis as compared with the case where the filling length in the central axis and the vicinity of the central axis is the same as the filling length in the outer peripheral portion. The adsorption rate for adsorbing the gas can be increased. As a result, the slope of the convex can be made gentle with respect to the adsorption distribution that progresses as a convex parabola. That is, the amount of the specific gas adsorbed by the first adsorbent can be increased before the specific gas leaks from the adsorber, and the adsorbing performance of the adsorber is improved.

(5) In the adsorber of the above aspect, the vicinity of the central axis is a range of less than 50% from the central axis to the inner surface of the space forming portion in the cross section orthogonal to the central axis, and the inside thereof. The outer peripheral portion of the space may be the residual range in the cross section.
The adsorption distribution of a specific gas in the first adsorbent and the second adsorbent proceeds as a parabola convex with respect to the gas outlet side. Therefore, a specific gas that has not been adsorbed starts to leak from the vicinity of the central portion of the first adsorbent on the gas outlet side. According to this configuration, the vicinity of the central axis of the first adsorbent and the second adsorbent is in the range of less than 50% of the distance from the central axis to the inner surface of the space forming portion, so that the inclination near the apex of the parabola is set. Can be done slowly. Therefore, the amount of the specific gas adsorbed by the first adsorbent can be further increased before the specific gas leaks from the adsorber, and the adsorbing performance of the adsorber is further improved.

The present invention can be realized in various aspects, for example, an adsorber, a gas separation device, a gas adsorption device, a device and a system including these, a gas adsorption method, a gas separation method, and the like. It can be realized in the form of a computer program for executing a system or a method, a server device for distributing the computer program, a non-temporary storage medium for storing the computer program, or the like.

It is a schematic perspective view of the adsorber as the embodiment of this invention. It is explanatory drawing of the temperature distribution in an adsorber. It is explanatory drawing of the adsorption amount distribution of carbon dioxide in an adsorber. It is explanatory drawing of the adsorption amount distribution of carbon dioxide in an adsorber. It is the schematic perspective view of the adsorbent of the comparative example. It is explanatory drawing of the adsorption amount distribution of carbon dioxide in the adsorber of the comparative example. It is a graph for demonstrating the adsorbent utilization rate. It is the schematic perspective view of the adsorbent of the modification.

<Embodiment>
FIG. 1 is a schematic perspective view of an adsorber 10 as an embodiment of the present invention. The adsorber 10 of the present embodiment is a device that separates carbon dioxide from the mixed gas GS containing _{carbon dioxide (CO 2).} FIG. 1 shows a schematic perspective view showing a part of the adsorber 10 as a cross section passing through the central axis OL. As shown in FIG. 1, the adsorber 10 has a space forming portion 2 that forms a columnar internal space SP0 along the central axis OL, and a gas formed on the lower end side of the central axis OL in the space forming portion 2. An inflow port 3, a gas outlet 4 formed on the upper end side of the central axis OL in the space forming portion 2, a plurality of first adsorbents 1 and a second adsorbent 8 capable of adsorbing carbon dioxide, and a second adsorbent, respectively. A lower mesh 5 for fixing the position of the adsorbent 8, a separation mesh 7 for separating the first adsorbent 1 and the second adsorbent 8, and an upper mesh 6 for fixing the position of each first adsorbent 1. Is equipped with. In this embodiment, for convenience, one end side along the central axis OL is set as the upper side and the other end side is set as the lower side. However, the direction along the central axis OL is, for example, the left-right direction regardless of the vertical direction. May be good. Hereinafter, the first adsorbent 1 and the second adsorbent 8 are collectively referred to as “adsorbents 1 and 8”. Further, the lower mesh 5 and the upper mesh 6 are collectively referred to as "fixed meshes 5 and 6".

As shown in FIG. 1, the internal space SP0 includes an outlet side filling space SP1 filled with the first adsorbent 1 and an inlet side filling space SP4 adjacent to the outlet side filling space SP1 via the separation mesh 7. The lower space SP2 adjacent to the inlet side filling space SP4 via the lower mesh 5 and the upper space SP3 adjacent to the outlet side filling space SP1 via the upper mesh 6 are provided. The space forming portion 2 forms the inner side surface of the outlet side filling space SP1, the inlet side filling space SP4, the lower space SP2, and the upper space SP3. The outlet side filling space SP1 is filled with the first adsorbent 1, and the inlet side filling space SP4 is filled with the second adsorbent 8. Neither the adsorbent is filled in the lower space SP2 and the upper space SP3. The internal space SP0 is a substantially columnar space having a radius R1 centered on the central axis OL. The lower end side of the space forming portion 2 is opened by the gas inflow port 3, and the upper end side of the space forming portion 2 is opened by the gas outflow port 4.

Each of the adsorbents 1 and 8 of the present embodiment has a spherical shape having a different size as shown in FIG. The size of the first adsorbent 1 is larger than the size of the second adsorbent 8. Each adsorbent 1 and 8 is made of zeolite of the same material. The adsorbents 1 and 8 adsorb carbon dioxide contained in the mixed gas GS flowing in from the gas inflow port 3. The adsorbents 1 and 8 generate heat when adsorbing carbon dioxide, and when the temperature exceeds a predetermined temperature, the carbon dioxide adsorbing ability deteriorates. Therefore, in order to increase the adsorption capacity of the adsorbents 1 and 8, it is preferable that the adsorbents 1 and 8 at the time of supplying the mixed gas GS are maintained at a predetermined temperature or lower. The mixed gas GS is supplied to the adsorber 10 of the present embodiment from the gas inflow port 3, and the exhaust gas after passing through the internal space SP0 is discharged from the gas outflow port 4. The mixed gas GS contains nitrogen and the like as a gas other than carbon dioxide. The term "shape" as used herein includes the concept of size. For example, cubes of different sizes are treated herein as different shapes.

The first adsorbent 1 and the second adsorbent 8 are made of the same material. Therefore, the total surface area of the first adsorbent 1 is larger than the total surface area of the second adsorbent 8 when the first adsorbent 1 having the same volume is filled and when the second adsorbent 8 is filled. .. Therefore, if the volume is the same, the second adsorbent 8 has a slower carbon dioxide adsorption rate than the first adsorbent 1. In other words, the pressure loss of the second adsorbent 8 with respect to the flow of the mixed gas GS is smaller than the pressure loss of the first adsorbent 1. Therefore, when the mixed gas GS is supplied into the adsorber 10, the speed at which the mixed gas GS flows through the inlet side filling space SP4 is faster than the speed at which it flows through the outlet side filling space SP1.

As shown in FIG. 1, the position on the lower end side of each first adsorbent 1 is regulated by the separation mesh 7, and the position on the upper end side of each first adsorbent 1 is regulated by the upper mesh 6. In FIG. 1, the illustration of the middle layer portion in the outlet side filling space SP1 is omitted by simplified hatching. The position on the lower end side of each second adsorbent 8 is regulated by the lower mesh 5, and the position on the upper end side of each second adsorbent 8 is regulated by the separation mesh 7.

The fixed meshes 5 and 6 and the separated mesh 7 have the same material, are formed of a mesh-like material, and hold the adsorbents 1 and 8 in a state that does not obstruct the flow of gas passing through the internal space SP0. .. The fixed meshes 5 and 6 have the same shape and have a cross-sectional shape of the central axis OL. The separation mesh 7 has a side shape of a cone of apex P on the central axis OL. As shown in FIG. 1, the separation mesh 7 forms a slope approaching from the gas inlet 3 side to the gas outlet 4 side at a constant gradient as the distance from the apex P is radially outward. Simply put, the separation mesh 7 has a downwardly convex shape. The distance from the apex P to the upper mesh 6 along the central axis OL is the length L2. The distance along the central axis OL from the position where the separation mesh 7 is in contact with the inner side surface of the space forming portion 2 to the upper mesh 6 is the length L3 (<L2). The distance from the lower mesh 5 to the upper mesh 6 along the central axis OL is the length L1.

_{In the present embodiment, for each of the adsorbents 1 and 8, the filling length L IN} along the central axis OL and the central axis OL of the central portion located near the central axis OL and the central axis of the outer peripheral portion other than the central portion The filling length L _OUT along is defined. Each filling length L _IN and L _OUT is defined as the length of the average value within the target range. In the present embodiment, the central portion is set to less than 50% of the radius R1, and the residual range other than the central portion in the cross section of the central axis OL is defined as the outer peripheral portion. _{Therefore, for example, the filling length L1 IN} of the central portion of the first adsorbent 1, the filling length L1 _OUT of the outer peripheral portion, the filling length _{L2 IN} of the central portion of the second adsorbent 8, and the filling length L2 of the outer peripheral portion. _OUT is expressed as each of the following equations (1) to (4).
L1 _IN = {L2 + (L2 + L3) / 2} / 2 = (3 ・ L2 + L3) / 4 ... (1)
L1 _OUT = {(L2 + L3) / 2 + L3} / 2 = (L2 + 3 ・ L3) / 4 ... (2)
L2 _IN = L1-L1 _IN = (4, L1-3, L2-L3) / 4 ... (3)
L2 _OUT = L1-L2 _OUT = (4 ・ L1-L2-3 ・ L3) / 4 ... (4)
As shown in the above formulas (1) to (4), in the first adsorbent 1, the filling length L1 _{IN in the central portion is longer than the filling length L1 OUT} in the outer peripheral portion, and in the second adsorbent 8, the filling length L1 IN is longer. The filling length L2 _IN in the central portion is shorter than _{the filling length L2 OUT} in the outer peripheral portion.

FIG. 2 is an explanatory diagram of the temperature distribution in the adsorber 10. In FIG. 2, the temperature distribution in each part of the adsorbents 1 and 8 is shown by the shade of hatching after a predetermined time when the mixed gas GS starts to be supplied into the adsorber 10. The portion where the hatching is dark is a high temperature portion with respect to the temperature outside the adsorber 10, and the portion where the hatching is not performed is substantially the same temperature as the temperature outside the adsorber 10. The darker the hatching, the higher the temperature. The curve that separates the different hatches is the isotherm.

In the state shown in FIG. 2, it is _{the position of the maximum temperature change T at the point P T} inside the first adsorbent 1 where the difference from the temperature outside the adsorber 10 is maximum. The temperature change of the first adsorbent 1 with respect to the outside of the adsorber 10 becomes smaller as the distance from the point P _{T is centered.} As shown in FIG. 2, the isotherm is substantially elliptical with the _{central axis OL as the long axis and the point PT as the center.} In the present embodiment, the length L2 along the central axis OL of the outlet-side filling space SP1 filled with the first adsorbent 1 is the central axis of _{AR 0.2T, which is a range of a temperature rise of 20% of the maximum temperature change T.} The length along the OL is set shorter than _{L 0.2T.}

3 and 4 are explanatory views of the carbon dioxide adsorption amount distribution in the adsorber 10. In FIGS. 3 and 4, the distribution of the amount of carbon dioxide adsorbed in each part of the adsorbents 1 and 8 at two time points after the mixed gas GS started to be supplied into the adsorber 10 is determined by the shade of hatching. It is shown. The state of FIG. 4 is a state after a certain time has elapsed from the state of FIG. It should be noted that the portion where the hatching is dark indicates a state in which more carbon dioxide is adsorbed. In FIGS. 3 and 4, the curves separating the different hatches represent the positions where the adsorption amounts are equal.

As shown in FIGS. 3 and 4, the amount of the adsorbents 1 and 8 adsorbed increases as the gas inflow port 3 side is closer to the central portion and the outer peripheral portion. Further, in the second adsorbent 8 on the gas inflow port 3 side, the adsorption amount increases toward the outer peripheral side. This is because the second adsorbent 8 near the inner side surface of the space forming portion 2 can release the adsorption heat to the outside of the space forming portion 2, so that the temperature is lowered and the adsorption capacity is increased.

While the adsorption capacity of the adsorbents 1 and 8 on the outer peripheral portion is increased, the adsorbents 1 and 8 near the central axis OL are less likely to release the adsorption heat to the outside of the space forming portion 2 as compared with the outer peripheral portion. Therefore, the adsorption capacity of the adsorbents 1 and 8 near the central axis OL is lower than that of the outer peripheral portion. As a result, for example, focusing on the vicinity of the separation mesh 7, the amount of adsorbed materials 1 and 8 in the vicinity of the central axis OL is larger than that in the outer peripheral portion. This is because, in the adsorbents 1 and 8 near the central axis OL, carbon dioxide that was not adsorbed by the adsorbents 1 and 8 in the central portion on the gas inflow port 3 side is absorbed by the adsorbent 1 in the central portion on the gas outlet 4 side. This is because it is adsorbed by, 8.

In the state of FIG. 4, as shown by the darkest hatching, the adsorbed amount of the second adsorbent 8 on the gas inflow port 3 side is saturated. Here, the average value of the slopes of the curve C1 representing the most advanced equal adsorption amount on the gas outlet 4 side in the first adsorbent 1 is a straight line LN1. The details of the straight line LN1 will be described together with a comparative example described later.

FIG. 5 is a schematic perspective view of the adsorber 10z of the comparative example. In the adsorbent 10z of the comparative example, the adsorbent of the present embodiment is filled with the third adsorbent 1z instead of the first adsorbent 1 and the second adsorbent 8 in the present embodiment in the filling space SP1z. Different compared to 10. The length of the filling space SP1z along the central axis OL is the length L1, which is the same as the length along the central axis OL of the outlet-side filling space SP1 and the inlet-side filling space SP4 of the present embodiment. The third adsorbent 1z has the same material as the first adsorbent 1 and the second adsorbent 8. The shape of the third adsorbent 1z is a spherical shape having a size different from that of the adsorbents 1 and 8. The size of the third adsorbent 1z is the same as the pressure loss when the mixed gas GS is supplied to the adsorbent 10z of the comparative example and the pressure loss when the mixed gas is supplied to the adsorber 10 of the present embodiment. It is set to the size of. Therefore, the size of the third adsorbent 1z is larger than that of the first adsorbent 1 and smaller than that of the second adsorbent 8.

FIG. 6 is an explanatory diagram of the carbon dioxide adsorption amount distribution in the adsorber 10z of the comparative example. FIG. 6 shows a state in which the mixed gas GS is supplied to the adsorbent 10z for the same time until the adsorber 10 of the present embodiment changes to the state of FIG. In FIG. 6, as in FIG. 4, the carbon dioxide adsorption amount distribution is shown by the shade of hatching. Comparing FIG. 4 and FIG. 6, the adsorption amount distribution on the gas outlet 4 side in the central portion of the comparative example is more advanced in the third adsorbent 1z than the adsorption amount distribution of the present embodiment. That is, if the mixed gas GS is further supplied to the adsorbents 10 and 10z from the states of FIGS. 4 and 6, carbon dioxide leaks from the adsorbent 10z of the comparative example first.

Further, the average value of the slopes of the curve C2 representing the equal adsorption amount on the gas outlet 4 side of the third adsorbent 1z shown in FIG. 6 is a straight line LN2. In FIG. 6, a straight line LN1 which is an average value of the slopes of the curve C1 shown in FIG. 4 is shown by a broken line for comparison. Comparing the straight line LN1 and the straight line LN2, the slope represented by the straight line LN1 of the present embodiment is gentler than that of the straight line LN2 of the comparative example. Therefore, in the adsorber 10 of the present embodiment, the first adsorbent 1 located on the outer peripheral portion on the gas outlet 4 side can be used as compared with the adsorber 10z of the comparative example. That is, the amount of carbon dioxide adsorbed by the first adsorbent 1 of the present embodiment is larger than the amount of adsorbed amount of the third adsorbent 1z of the comparative example filled in the outlet side filling space SP1 of the present embodiment.

FIG. 7 is a graph for explaining the adsorbent utilization rate K. In the present embodiment, the ratio of the amount of carbon dioxide actually adsorbed by the adsorbents 1 and 8 to the total amount of carbon dioxide adsorbable by the adsorbents 1 and 8 in the adsorber 10 is the adsorbent utilization rate. Defined as K. In this case, when the adsorbent utilization rate K reaches 100%, the adsorbed amounts of the adsorbents 1 and 8 in the adsorber 10 are saturated. When the mixed gas GS is supplied to the adsorber 10 in this state, the carbon dioxide concentration D1 in the mixed gas GS and the outlet concentration of carbon dioxide discharged from the gas outlet 4 (CO ₂ outlet concentration) are the same. become.

As shown in FIG. 4, when the behavior of the CO ₂ exit concentration of adsorber 10 is represented by curve C3, the adsorbent utilization ratio K _T1 at time T1 leaking carbon dioxide from the adsorber 10, the following formula It is expressed as (5).
_KT1 = A / (A + B) ... (5)
A: Adsorbed amount of carbon dioxide adsorbed by the adsorbent 1 up to time T1 B: Adsorbed amount of carbon dioxide adsorbed by the adsorbent 1 after time T1 By improving the adsorbent utilization rate K, in the adsorber 10. It is possible to reduce the number of adsorbents 1 and 8 that are not used. Further, in order to desorb the carbon dioxide adsorbed by the adsorbents 1 and 8, for example, when the adsorber 10 is heated by using the temperature swing adsorption method, the higher the adsorbent utilization rate K is, the more excess adsorbent 1 is. , 8 need not be heated, and the energy consumption of the entire system including the adsorber 10 can be reduced.

Since the adsorber 10 of the present embodiment can use the first adsorbent 1 located on the outer peripheral portion on the gas outlet 4 side as compared with the adsorber 10z of the comparative example, it can adsorb a large amount of carbon dioxide. Further, as shown in FIG. 6, the slope represented by the straight line LN1 of the present embodiment is gentler than the slope represented by the straight line LN2 of the comparative example. Further, comparing the state of FIG. 4 in which the same time has passed since the mixed gas GS was supplied and the state of FIG. 6, the central portion of the first adsorbent 1 of the present embodiment on the gas outlet 4 side. It is possible to adsorb more carbon dioxide than the central portion on the gas outlet 4 side in the third adsorbent 1z of the comparative example. Therefore, the time until carbon dioxide leaks from the adsorber 10 of the present embodiment is slower than that of the adsorber 10z of the comparative example. That is, the adsorption time of the adsorber 10 of the present embodiment is longer than the adsorption time of the comparative example, and the usable time of the adsorber 10 of the present embodiment is improved. As a result, the adsorbent utilization ratio K _T1 in adsorber 10 of the present embodiment is higher than the adsorbent utilization ratio K _T1 adsorbers 10z of the comparative example.

In the adsorber 10 of the present embodiment, the outlet side filling space SP1 is filled with the first adsorbent 1, and the inlet side filling space SP4 is filled with the second adsorbent 8. The second adsorbent 8 has a slower carbon dioxide adsorption rate than the first adsorbent 1. Therefore, from the time when the mixed gas GS starts to be supplied to the adsorber 10 until the carbon dioxide not adsorbed by the adsorbents 1 and 8 leaks from the gas outlet 4, the gas inlet 3 side of the first adsorbent 1 The second adsorbent 8 located in is in contact with the mixed gas GS longer than the first adsorbent 1. The second adsorbent 8 has a slower carbon dioxide adsorption rate than the first adsorbent 1, that is, the pressure loss of the second adsorbent 8 with respect to the mixed gas GS flowing in the internal space SP0 is higher than that of the first adsorbent 1. Is also small. According to the adsorber 10 of the present embodiment, by arranging the second adsorbent 8 on the gas inflow port 3 side where a sufficient adsorption time can be obtained, the adsorption performance of the adsorber 10 is not changed, and the adsorbed gas GS is not changed. The pressure loss of the adsorber 10 can be reduced. Further, by arranging the first adsorbent 1 on the gas outlet 4 side where only a short adsorption time can be obtained, it is possible to suppress the leakage of carbon dioxide from the gas outlet 4. Further, since the adsorption rate of the dicarbonate of the first adsorbent 1 is high, the unevenness of the adsorption amount in the first adsorbent 1 is suppressed, and the adsorption performance of the adsorber 10 is improved. As a result, low pressure loss and high adsorption performance in the adsorber 10 can be realized.

The second adsorbent 8 of the present embodiment has the same material as the first adsorbent 1 and has a different shape. As a result, the carbon dioxide adsorption rate of the second adsorbent 8 is slower than the adsorption rate of the first adsorbent 1. Therefore, if the material and shape of the first adsorbent 1 and the second adsorbent 8 are selected according to the size and shape of the adsorber 10, the usage environment of the adsorber 10, the gas ratio of the mixed gas GS, and the like. Good. This makes it easier to adjust the pressure loss of the mixed gas GS flowing in the adsorber 10 and the adsorption performance of the adsorber 10.

When the adsorbents 1 and 8 adsorb carbon dioxide, if the temperature of the adsorbents 1 and 8 rises beyond the temperature range suitable for the adsorption reaction, the adsorption reaction does not proceed and the adsorbents 1 and 8 absorb carbon dioxide. Adsorption speed slows down. Since the temperature of the adsorbents 1 and 8 rises due to the heat of adsorption, the temperature of the central portion where the heat cannot escape to the outside of the adsorber 10 tends to rise. The temperature distribution in the adsorbents 1 and 8 shown in FIG. 2 has a spherical shape centered on an arbitrary point near the central axis OL, or an elliptical cross section centered on the central axis with the central axis as the longitudinal axis. Proceed while keeping. In the present embodiment, as shown in FIG. 2, the length L2 along the central axis OL of the outlet-side filling space SP1 filled with the first adsorbent 1 has a temperature increase of 20% of the maximum temperature change T. Range AR _0.2T is set shorter than _{the length L 0.2T} along the central axis OL. Therefore, by supplying the mixed gas GS is continued, the maximum temperature change which is the center point P _T of T progresses into the first adsorbent 1, a gas outlet in the first adsorbent 1 from point P _T There is a sufficient distance to the end face on the 4th side. As a result, even if the point _PT advances into the first adsorbent 1, carbon dioxide does not immediately leak from the first adsorbent 1, so that the adsorption performance of the first adsorbent 1 can be improved. ..

When the mixed gas GS is supplied to the adsorber 10, as shown in FIGS. 3 and 4, the carbon dioxide adsorption distribution in the adsorbents 1 and 8 is a parabola convex with respect to the gas outlet 4 side. proceed. Therefore, when the inside of the adsorber 10 is filled with the same adsorbent, carbon dioxide that has not been adsorbed starts to leak from the adsorbent on the gas outlet 4 side in the vicinity of the central axis OL and the central axis OL. _{In the present embodiment, the filling length L IN} of the first adsorbent 1 in the central portion including the central axis OL and the vicinity of the central axis OL _{is the filling length L OUT} of the outer peripheral portion of the first adsorbent 1 by the separation mesh 7. Longer than. Therefore, in the present embodiment, as compared with the case where _{the filling length L IN} in the central portion and the filling length _{L OUT} in the outer peripheral portion are the same, only the difference between the _{filling lengths L IN} and L _{OUT in the central portion is the first.} The adsorption rate at which the adsorbent 1 adsorbs carbon dioxide can be increased. As a result, with respect to the adsorption distribution that progresses as a convex parabola, the inclination of the parabola can be made gentle as shown by the straight line LN1 in FIGS. 4 and 6. That is, the amount of carbon dioxide adsorbed by the first adsorbent 1 can be increased by the time carbon dioxide leaks from the adsorber 10, and the adsorbing performance of the adsorber 10 is improved.

As shown in FIGS. 3 and 4, the adsorption distribution of carbon dioxide in the adsorbents 1 and 8 proceeds as a parabola convex with respect to the gas outlet 4 side. Therefore, carbon dioxide begins to leak from the central portion of the first adsorbent 1 on the gas outlet 4 side. In the present embodiment, the central portion of the adsorbents 1 and 8 is in a range of less than 50% of the radius R1 from the central axis OL to the inner side surface of the space forming portion 2, and the outer peripheral portion of the adsorbents 1 and 8 is cross-sectional. It is the remaining part of the surface other than the central part. Since the central portion is in the range of less than 50% of the radius R1, the length along the central axis OL at the apex portion of the parabola can be shortened. Therefore, the amount of carbon dioxide adsorbed by the first adsorbent 1 can be further increased before the unadsorbed carbon dioxide leaks from the adsorber 10, and the adsorbing performance of the adsorber 10 is further improved.

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

[Modification 1]
The configuration and shape of the adsorber 10 in the above embodiment can be variously modified. For example, in the adsorber 10, the space forming portion 2 and the outlet side filling space SP1 and the inlet side filling space SP4 formed by the fixed meshes 5 and 6 and the separation mesh 7 are substantially cylindrical with the central axis OL as the center. It does not have to be a shape. The internal space SP0 may be a spherical space centered on a specific point, and in this case, the axis of a straight line passing through the specific point may be regarded as the central axis OL. Further, the central axis OL may be a curved line instead of a straight line. The internal space SP0 may have a different cross section at each position of the central axis OL with the curved central axis OL as the center. The cross section in this case may have, for example, a square cross-sectional shape, and the area may gradually decrease from the gas inlet 3 toward the gas outlet 4.

The shapes and positions of the gas inlet 3 and the gas outlet 4 can also be variously modified. As shown in FIG. 1, the gas inlet 3 and the gas outlet 4 have a columnar shape centered on the central axis OL, but for example, even if they are formed at positions deviated from the central axis OL. Good. Further, the gas inlet 3 and the gas outlet 4 may have different shapes (for example, circular and rectangular), and are not cylindrical but merely holes penetrating the lower space SP2 and the upper space SP3. May be good.

The shapes and materials of the adsorbents 1 and 8 can also be variously deformed. The material of the adsorbents 1 and 8 that adsorb carbon dioxide may be formed of a solid absorbent material in which an amine is supported on a porous body, instead of zeolite. Further, as the adsorbents 1 and 8, the adsorbent formed of the solid absorbent and the adsorbent formed of zeolite may be mixed. The shapes of the adsorbents 1 and 8 may be other than spherical, and may be, for example, a cube, a sphere, and a shape in which a predetermined through hole is formed in the cube. Further, as the adsorbents 1 and 8, a plurality of adsorbents having different shapes and materials may be mixed. The adsorbents 1 and 8 may be selected based on a well-known technique according to the relationship between the mixed gas GS supplied to the adsorber 10 and the gas to be separated from the mixed gas GS. That is, as the adsorbents 1 and 8, a material that adsorbs other than carbon dioxide may be selected.

In the above embodiment, the adsorption speed of the first adsorbent 1 becomes faster than that of the second adsorbent 8 by changing the size of the first adsorbent 1 and the second adsorbent 8 as one element of the shape. However, the mode for setting the adsorption rate can be variously modified. For example, by producing the first adsorbent 1 and the second adsorbent 8 having the same shape and changing the material of the first adsorbent 1 and the material of the second adsorbent 8, the adsorption speed of the first adsorbent 1 May be set to be faster than that of the second adsorbent 8. Both the shape and the material may be different between the first adsorbent 1 and the second adsorbent 8. Regarding the different shapes, not only the size but also, for example, the shape of the first adsorbent 1 is formed with a hole penetrating the cube, and the shape of the second adsorbent 8 is spherical, and per unit volume. The adsorption rate of each of the adsorbents 1 and 8 may be set by making the surface areas different.

FIG. 8 is a schematic perspective view of the adsorber 10a of the modified example. The adsorbent 10a of the modified example is different in that the outlet side filling space SP1 and the inlet side filling space SP4 in the first embodiment are each filled with a plurality of types of adsorbents 1 and 8. Specifically, as shown in FIG. 8, the outlet side filling space SP1 is filled with the first adsorbent 1 and the second adsorbent 8 having a volume of 25% of that of the first adsorbent 1. .. On the other hand, the inlet side filling space SP4 is filled with the second adsorbent 8 and the first adsorbent 1 having a volume of 25% of that of the second adsorbent 8. In this case, as the adsorption rate of the adsorbent filled in the outlet side filling space SP1 with respect to carbon dioxide, as the weighted average adsorption rate according to the volume ratio of the first adsorbent 1 and the second adsorbent 8 mixed. Can be regarded. That is, in the adsorbent 10a of the modified example, the adsorption rate of the plurality of adsorbents 1 and 8 filled in the outlet side filling space SP1 is the adsorption rate of the plurality of adsorbents 1 and 8 filled in the inlet side filling space SP4. Faster than. As described above, each of the adsorbents 1 and 8 filled in the outlet side filling space SP1 and the inlet side filling space SP4 does not have to be one kind of adsorbent, and may be a plurality of mixed kinds of adsorbents. That is, the ratio of the first adsorbent 1 filled in the outlet-side filling space SP1 is relatively higher than that of the other adsorbents, and the ratio of the second adsorbent 8 filled in the inlet-side filling space SP4 is other. When it is relatively higher than the adsorbent of, it corresponds to "the first adsorbent is filled on the gas outlet side and the second adsorbent is filled on the gas inlet side". As the adsorption rate of the adsorbent, the adsorption rate of the load average per unit length along the central axis OL connecting the gas inlet 3 and the gas outlet 4 is adopted instead of the weighted average according to the volume ratio. May be good.

Further, the outlet side filling space SP1 and the inlet side filling space SP4 do not have to have a clear boundary like the separation mesh 7. For example, even if the inside of the adsorber 10 is configured so that the proportion of the first adsorbent 1 having a small size (fast adsorption speed) increases as the gas inlet 3 side approaches the gas outlet 4 side. Good. Alternatively, a space formed by another adsorbent may be sandwiched between the outlet-side filling space SP1 and the inlet-side filling space SP4. Further, the adsorbent may be filled in each filling space so that the adsorption speed of the adsorbent increases as the gas outlet 4 side is approached by the three or more filling spaces.

[Modification 2]
The shapes of the outlet-side filling space SP1 and the inlet-side filling space SP4 in which the adsorbents 1 and 8 are filled can be variously deformed. In the adsorber 10 of the above embodiment, the separation mesh 7 has the shape of the side surface of the cone, but the shape of the separation mesh 7 can be variously deformed. For example, the separation mesh 7 may be simply formed as a cross section of the central axis OL, or may be a plane having an angle of less than 90 degrees with the central axis OL. Further, the separation mesh 7 does not have to have a slope having a constant gradient, and may be, for example, a parabolic slope or a wavy slope.

Further, there are no fixed meshes 5 and 6 and a separation mesh 7, and the adsorbents 1 and 8 on the gas inlet 3 side and the gas outlet 4 side are fixed by an adhesive to fill the adsorbents 1 and 8. The outlet side filling space SP1 and the inlet side filling space SP4 may be formed. Further, there is no at least one of the fixed meshes 5 and 6 and the separated mesh 7, and for example, the outlet side filling space SP1 may include the upper space SP3, or the inlet side filling space SP4 may include the lower space SP2. Good.

In the adsorber 10 of the above embodiment, the range of the length less than 50% of the radius R1 from the central axis OL is defined as the vicinity of the central axis OL, but the vicinity of the central axis OL is 50% or more of the radius R1. It may be. For example, it may be 65% of the radius R1 or 35% of the radius R1.

The definitions of the filling lengths L _IN and L _OUT of the first adsorbent 1 can be variously modified. As the filling lengths L _IN and L _OUT , the average value within the target range may be adopted as in the above embodiment, the length L2 (FIG. 1) on the central axis OL and the length L3 (FIG. 1) of the outer peripheral end face. 1) may be adopted. Further, with the filling lengths L _IN and L _OUT , the lower surface of the first adsorbent 1 in contact with the separation mesh 7 and the first adsorbent 1 located at the upper end on the cut surface of the adsorber 10 along the central axis OL. The average value of the distances along the central axis OL from the upper surface may be adopted. Further, using the ratio of the radius R1 from the central axis OL to the space forming portion 2, for example, the filling length L _IN is the length along the central axis OL at a position 10% away from the central axis OL with the radius R1. The filling length L _OUT may be a length along the central axis OL at a position 90% away from the central axis OL with a radius R1.

In the system using the adsorber 10 of the above embodiment, known methods such as a temperature swing adsorption method (TSA), a pressure swing method (PSA), and a pressure and temperature adsorption method (PTSA) are known. The adsorption method may be used.

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

1 ... 1st adsorbent 1z ... 3rd adsorbent 2 ... Space forming part 3 ... Gas inlet 4 ... Gas outlet 5 ... Lower mesh 6 ... Upper mesh 7 ... Separation mesh 8 ... 2nd adsorbent 10, 10a, 10z ... Adsorber A, B ... Adsorbed amount AR _0.2T ... Range C1 to C3 ... Curve D1 ... Carbon dioxide concentration GS ... Mixed gas K ... Adsorbent utilization rate K _T1 ... Adsorbent utilization rate L1 to L3, L _0.2T ... Length L _IN , L _OUT ... Filling length LN1, LN2 ... Straight line OL ... Central axis P ... _{Appointment P T} ... Point R1 ... Radius SP0 ... Internal space SP1 ... Exit side filling space SP1z ... Filling space SP2 ... Lower space SP3 … Upper space SP4… Inlet side filling space T… Maximum temperature change T1… Time

Claims (5)

It ’s an adsorber,
The space forming part that forms the internal space and
The gas inflow port formed in the space forming portion and
The gas outlet formed in the space forming portion and
A first adsorbent capable of adsorbing one or more specific gases contained in the mixed gas,
A second adsorbent capable of adsorbing the specific gas and having a slower adsorption rate of the specific gas than the first adsorbent.
With
In the internal space, the first adsorbent is filled on the gas outlet side, and the second adsorbent is filled on the gas inlet side of the first adsorbent. The adsorbent according to claim 1.
The second adsorbent is an adsorber in which the adsorption rate is slowed down by making at least one of the material and the shape different from that of the first adsorbent. The adsorbent according to claim 1 or 2.
The internal space extends from the gas inlet side to the gas outlet side along the central axis.
The length of the region filled with the first adsorbent along the central axis increases by 0.2 T or more with respect to the maximum temperature change T of the first adsorbent when the mixed gas is supplied. An adsorber that is longer than the length along the central axis of the portion with. The adsorbent according to any one of claims 1 to 3.
The internal space extends from the gas inlet side to the gas outlet side along the central axis.
An adsorber in which the filling length of the first adsorbent in the central axis and the vicinity of the central axis is longer than the filling length of the first adsorbent in the outer peripheral portion of the internal space. The adsorbent according to claim 4.
The vicinity of the central axis is a range of less than 50% from the central axis to the inner surface of the space forming portion in the cross section orthogonal to the central axis.
The outer peripheral portion of the internal space is an adsorber, which is the range of the remainder in the cross section.

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