Adsorption vessel and temperature swing adsorption apparatus

Abstract

To provide an adsorption container capable of directly heating an adsorbent with a simple structure, and a temperature swing adsorption device including the same.SOLUTION: An adsorption vessel including a cylindrical vessel and a heater unit, the heater unit including a heating element having a sheet-like disk structure, the adsorption vessel including a first gas passage annularly disposed in an inner peripheral portion of the cylindrical vessel, a second gas passage disposed in a central portion of the cylindrical vessel, and an adsorption layer disposed between the first gas passage and the second gas passage, the adsorption layer including the heating element and an adsorbent alternately stacked in a vertical direction, the cylindrical container includes an inlet port and an outlet port at at least one of an upper end and a lower end in a vertical direction, the first inlet / outlet port is connected to the first gas channel, and the second inlet / outlet port is connected to the second gas channel.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to adsorption vessels and temperature swing adsorption devices. [Background technology]

[0002] Adsorption vessels filled with adsorbent are used to separate specific gases from a gas mixture. Conventional adsorption vessels have widely been configured as vertical adsorption vessels, in which gas flows from bottom to top, as shown in Figure 1.

[0003] On the other hand, radial-type adsorption vessels are also used, as shown in Figure 2. Radial-type adsorption vessels are packed with adsorbent in a ring shape inside the adsorption vessel, and adsorption is carried out by passing gas radially from the outside to the inside, or from the inside to the outside. Radial-type adsorption vessels can reduce installation space and pressure loss compared to vertical-type adsorption vessels.

[0004] Another gas separation method using an adsorbent is temperature swing adsorption, which utilizes the temperature-dependent differences in adsorption characteristics to adsorb and desorb gases, and generally requires the adsorbent to be heated.

[0005] Patent Document 1 (Japanese Patent Laid-Open Publication No. 3-131337) discloses that a heater is installed outside a radial adsorption vessel, and a heated fluid is caused to flow inside the radial adsorption vessel. Patent Document 2 (Japanese Patent Laid-Open Publication No. 6-319933) discloses that a spiral heat transfer tube is installed in the adsorbent-filled section of a radial adsorption vessel, and a heat medium is passed through the heat transfer tube to heat the adsorbent. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 3-131337 [Patent Document 2] Japanese Patent Application Publication No. 6-319933 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the device described in Patent Document 1 has a complex structure, which results in problems such as a large amount of energy being used for purposes other than regenerating the adsorbent, and a long heating time required because the adsorbent is heated by a heated fluid.The device described in Patent Document 2 has problems such as a large device size due to the heat transfer tubes being embedded inside, and a large pressure loss due to the heat transfer tubes being present in the gas flow direction.

[0008] An object of the present disclosure is to provide an adsorption vessel that can directly heat an adsorbent with a simple structure, and a temperature swing adsorption apparatus including the adsorption vessel. [Means for solving the problem]

[0009] [1] An adsorption vessel comprising a cylindrical vessel and a heater unit, the heater portion includes a heating element having a sheet-like disc structure, the adsorption vessel includes a first gas flow path annularly disposed on an inner periphery of the cylindrical vessel, a second gas flow path disposed in a center portion of the cylindrical vessel, and an adsorption layer disposed between the first gas flow path and the second gas flow path, in which the heating element and the adsorbent are alternately stacked in a vertical direction; the cylindrical container is provided with a first inlet / outlet and a second inlet / outlet at at least one of an upper end and a lower end in a vertical direction, the first inlet / outlet is connected to the first gas flow path, The second inlet / outlet is connected to the second gas flow path.

[0010] [2] The heater portion includes an electrode, The adsorption vessel according to [1], wherein the heating element is heated by applying a voltage to the electrodes.

[0011] [3] The adsorption container according to [1] or [2], wherein the adsorption layer is formed by stacking a plurality of layers.

[0012] [4] The adsorption layer stacked in plurality has a plurality of compartments in the vertical direction, The adsorption vessel according to [3], wherein the plurality of heater units included in the plurality of compartments are temperature-controlled for each of the plurality of compartments.

[0013] [5] An adsorption vessel described in any one of [1] to [4], wherein the cylindrical vessel has the first inlet / outlet at its lower end in the vertical direction and the second inlet / outlet at its upper end in the vertical direction.

[0014] [6] The adsorption vessel according to any one of [1] to [5], wherein carbon dioxide is adsorbed by the adsorbent.

[0015] [7] A temperature swing adsorption device comprising an adsorption vessel according to any one of [1] to [6].

[0016] [8] The temperature swing adsorption device according to [7], comprising a plurality of the adsorption vessels. [Effects of the Invention]

[0017] According to the present disclosure, it is possible to provide an adsorption vessel that has a simple structure and is capable of directly heating an adsorbent, and a temperature swing adsorption apparatus including the adsorption vessel. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram showing an example of a vertical adsorption vessel. [Figure 2] FIG. 2 is a schematic diagram showing an example of a radial adsorption vessel. [Figure 3] FIG. 3 is a vertical cross-sectional view showing an example of an adsorption vessel in this embodiment. [Figure 4] FIG. 4 is a vertical cross-sectional view showing another example of an adsorption vessel according to this embodiment. [Figure 5] FIG. 5 is a vertical cross-sectional view showing another example of an adsorption vessel according to this embodiment. [Figure 6]FIG. 6 is a cross-sectional view showing an example of an adsorption vessel in this embodiment. [Figure 7] FIG. 7 is a schematic diagram showing an example of a heater unit in this embodiment. [Figure 8] FIG. 8 is a schematic diagram showing another example of the heater section in this embodiment. [Figure 9] FIG. 9 is a diagram showing an example of an adsorption vessel equipped with the heater unit shown in FIG. [Figure 10] FIG. 10 is a diagram showing another example of an adsorption vessel equipped with the heater unit shown in FIG. [Figure 11] FIG. 11 is a schematic diagram showing an example of the configuration of a temperature swing adsorption device according to this embodiment.

[0019] Hereinafter, embodiments of the present disclosure will be described, but the following description does not limit the scope of the claims.

[0020] In this disclosure, unless otherwise specified, the term "adsorption vessel" simply refers to a radial adsorption vessel, and the term "radial direction" refers to the direction from the outside to the inside or the inside to the outside.

[0021] In this disclosure, the gas introduced into the adsorption vessel is referred to as the "raw material gas," the gas contained in the raw material gas and adsorbed by the adsorbent is referred to as the "target gas," and the gas from which the target gas has been removed is referred to as the "purified gas."

[0022] <Embodiment 1> 《Adsorption container》 3 to 10, the adsorption vessel 20 in this embodiment includes a cylindrical vessel 10 and a heater unit 11. The heater unit 11 includes a heating element 4 having a sheet-like disk structure. The adsorption vessel 20 includes a first gas flow path 1 arranged in an annular shape around the inner periphery of the cylindrical vessel 10, a second gas flow path 2 arranged in the center of the cylindrical vessel 10, and an adsorption layer 3 arranged between the first gas flow path 1 and the second gas flow path 2, in which heating elements 4 and adsorbents 5 are alternately stacked in the vertical direction. The cylindrical vessel 10 includes a first inlet / outlet 6 and a second inlet / outlet 7 at at least one of the upper and lower ends in the vertical direction. The first inlet / outlet 6 is connected to the first gas flow path 1. The second inlet / outlet 7 is connected to the second gas flow path 2. The adsorption vessel 20 in this embodiment will be described below.

[0023] The cylindrical container 10 is placed upright with its cylindrical axis oriented vertically. Both vertical ends of the cylindrical container 10 are closed by end plates 8a and 8b. A first inlet / outlet 6 or a second inlet / outlet 7 is provided on end plate 8a or end plate 8b. That is, as shown in FIG. 3, the first inlet / outlet 6 is provided on end plate 8a and the second inlet / outlet 7 is provided on end plate 8b; as shown in FIG. 4, the first inlet / outlet 6 and the second inlet / outlet 7 are provided on end plate 8a; or as shown in FIG. 5, the first inlet / outlet 6 and the second inlet / outlet 7 are provided on end plate 8b.

[0024] The raw material gas can be introduced into and discharged from either of the vertical ends of the cylindrical vessel 10. When the raw material gas is introduced from the first inlet / outlet 6, the first inlet / outlet 6 serves as an inlet, and the second inlet / outlet 7 serves as an outlet. On the other hand, when the raw material gas is introduced from the second inlet / outlet 7, the second inlet / outlet 7 serves as an inlet, and the first inlet / outlet 6 serves as an outlet.

[0025] In the present disclosure, whether the adsorption vessel 20 has the configuration shown in any of Figures 3 to 5 and whether the raw material gas is introduced through the first inlet / outlet 6 or the second inlet / outlet 7 may be determined appropriately depending on the type of raw material gas and target gas.

[0026] As shown in FIG. 6 , the first gas flow path 1 is arranged in an annular shape on the inner periphery of the cylindrical container 10. The second gas flow path 2 is arranged in the center of the cylindrical container 10. The adsorption layer 3 is arranged between the first gas flow path 1 and the second gas flow path 2. That is, the gap between the outer periphery of the adsorption layer 3 and the inner periphery of the cylindrical container 10 functions as the first gas flow path 1. The inner periphery of the adsorption layer 3 functions as the second gas flow path 2. The cross-sectional areas of the first gas flow path 1 and the second gas flow path 2 may or may not be constant in the axial direction of the cylindrical container 10.

[0027] A pressure member 9a may be installed at the vertical lower end of the adsorption layer 3, and a pressure member 9b may be installed at the vertical upper end of the adsorption layer 3. In this case, a first gap is formed between the pressure member 9a and the end plate 8a, and a second gap is formed between the pressure member 9b and the end plate 8b. The first inlet / outlet 6 and the first gas flow path 1 may be connected via the first gap, and the second inlet / outlet 7 and the second gas flow path 2 may be connected via the second gap.

[0028] The adsorption layer 3 is formed by alternately stacking heating elements 4 and adsorbents 5 in the vertical direction. The adsorption layer 3 is formed by stacking at least heating elements 4, adsorbents 5, and heating elements 4 in this order in the vertical direction. The adsorption layer 3 is preferably formed by stacking multiple layers. In the present disclosure, an adsorption layer formed by stacking multiple layers will also be simply referred to as an "adsorption layer."

[0029] The heater 4 has a sheet-like disk structure. Because the heater 4 has a sheet-like disk structure, for example, when multiple adsorption layers 3 are stacked vertically, the flow of gas is less likely to be obstructed even if the gas flows in the radial direction. This is expected to reduce the pressure loss in the adsorption vessel 20.

[0030] In addition, since the volume of the heater 4 is small, its heat capacity is also small, and it is expected that the thermal energy required to heat the heater 4 will be reduced. Furthermore, by reducing the volume of the heater 4, the size of the adsorption vessel 20 can be reduced. As a result, it is expected that the energy required to heat the adsorption vessel 20 will be reduced.

[0031] Furthermore, the heating element 4 is installed inside the cylindrical vessel 10 (adsorption vessel 20). By installing the heating element 4 inside the cylindrical vessel 10, the adsorbent 5 can be directly heated. This is expected to shorten the heating time compared to installing the heating element 4 outside the cylindrical vessel 10.

[0032] The heaters 4 are preferably installed at equal intervals in the vertical direction. That is, the adsorbent 5 is preferably packed to the same thickness between the heaters 4. By installing the heaters 4 at equal intervals in the vertical direction, it is expected that the adsorbent 5 will be heated uniformly.

[0033] The heater section 11 includes a heating element 4. The heater section 11 further includes, for example, an electrode 12 to cause the heating element 4 to generate heat. In this case, by applying a voltage to the electrode 12, the heating element 4 generates heat.

[0034] The heater 4 is made of a material capable of generating heat. Examples of such materials include metals such as copper, iron, titanium, nickel, and stainless steel, as well as metals that have been subjected to surface treatments such as plating and fluororesin processing. The heater 4 may also be made of metal fibers that have been subjected to papermaking processing.

[0035] The heater 4 is preferably made of fibrous metal that has been subjected to a papermaking process. Such a heater has a porous structure, allowing gas to pass through. This is expected to alleviate the pressure and flow rate imbalance, for example, when the pressure and flow rate imbalance occurs in the first gas flow path 1 or the second gas flow path 2, by allowing the gas to pass through the heater 4.

[0036] When the heater unit 11 includes electrodes 12, the electrodes 12 may be, for example, a pair of electrodes 12 as shown in FIG. 7 or a spiral-shaped electrode 12 as shown in FIG. 8. The electrodes 12 are preferably a pair of electrodes 12 as shown in FIG. 7. With such electrodes, for example, when multiple adsorption layers 3 are stacked vertically, the radial flow of gas is less likely to be impeded. This is expected to reduce the pressure loss in the adsorption vessel 20. Furthermore, since the volume of the heater unit 11 is smaller than that of spiral-shaped electrodes, the size of the adsorption vessel 20 can be reduced. As a result, it is expected that the energy required to heat the adsorption vessel 20 can be reduced.

[0037] 9 and 10 are diagrams showing an example of an adsorption vessel 20 including the heater unit 11 shown in FIG. 7. As shown in FIGS. 9 and 10, a power supply for the electrode 12 may be provided outside the adsorption vessel 20. In FIGS. 9 and 10, the electrode 12 includes the electrode, power cable, power supply, and the like.

[0038] The adsorption layer 3 may have multiple vertical compartments, and the multiple heater units 11 included in the multiple compartments may be temperature-controlled for each of the multiple compartments. Here, an example will be described in which the adsorption layer 3 has three vertical compartments (first compartment 3a, second compartment 3b, and third compartment 3c) as shown in FIG. 10 . A first electrode 12a is connected to the first compartment 3a, a second electrode 12b is connected to the second compartment 3b, and a third electrode 12c is connected to the third compartment 3c. By applying a voltage to each compartment, the inside of the adsorption vessel 20 can be heated uniformly, and temperature variations within the adsorption vessel 20 can be reduced.

[0039] The adsorption layer 3 is filled with an adsorbent 5. The adsorbent is capable of adsorbing the target gas and is a recyclable adsorbent that can recover its adsorption performance by being heated to release the adsorbed target gas. The adsorbent 5 may be changed appropriately depending on the type of target gas. There are no particular limitations on the target gas, and examples include carbon dioxide (CO2), moisture (H2O), hydrogen (H2), and nitrogen (N2).

[0040] As described above, the adsorption vessel 20 of this embodiment has a simpler structure than conventional adsorption vessels. Furthermore, by providing the heater 4 with a sheet-like disk structure inside the adsorption vessel 20, the adsorbent 5 can be directly heated.

[0041] <<Method for producing purified gas>> A method for producing a purified gas using the above-described adsorption vessel will now be described. Note that explanations that overlap with those described above in the "adsorption vessel" section will be omitted.

[0042] The method for producing a purified gas in this embodiment includes a separation step of separating at least a portion of the target gas from the raw material gas. The separation step results in a purified gas in which the target gas has been removed from the raw material gas. The separation step includes (1) an adsorption step and (2) a thermal regeneration step.

[0043] (1) Adsorption process The adsorption step is a step of separating the target gas from the raw gas by supplying the raw gas to an adsorption vessel and allowing the target gas to be adsorbed by an adsorbent.

[0044] (2)Heating regeneration process The thermal regeneration process is a process in which the target gas is desorbed from the adsorbent by directly heating the adsorbent with a heater in the adsorption vessel after the adsorption process. In other words, the thermal regeneration process is a process in which the adsorbent filled in the adsorption vessel is made reusable.

[0045] This step may be carried out, for example, under reduced pressure, for example, by using a vacuum pump.

[0046] <Embodiment 2> <<Temperature Swing Adsorption Device>> Fig. 11 is a schematic diagram showing an example of the configuration of a temperature swing adsorption apparatus according to this embodiment. A temperature swing adsorption apparatus including the adsorption vessel of the first embodiment described above will be described below. Note that explanations that overlap with those of the first embodiment will be omitted. This embodiment will be described taking as an example a case in which a raw material gas is introduced from a first inlet / outlet 6 in a temperature swing adsorption apparatus 30 including an adsorption vessel 20 shown in Fig. 3. That is, in Fig. 3, the first inlet / outlet 6 serves as an inlet, and the second inlet / outlet 7 serves as an outlet.

[0047] Using the temperature swing adsorption device 30, each step of the temperature swing adsorption method is performed to separate the target gas from the raw material gas. The temperature swing adsorption method sequentially repeats an adsorption cycle of, for example, (1) an adsorption step, (2) a thermal regeneration step, and (3) a pressure recovery step. Note that the (1) adsorption step and (2) a thermal regeneration step are the same as the (1) adsorption step and (2) a thermal regeneration step in the first embodiment described above, and therefore a description thereof will be omitted.

[0048] (3) Repressurization process In the pressure recovery step, the adsorption vessel after the adsorption step is restored to the pressure required for the adsorption step by introducing, for example, a high-pressure gas. The high-pressure gas may be, for example, a purified gas obtained by removing the target gas from the raw material gas in the adsorption step.

[0049] In the temperature swing adsorption method, it is preferable to use multiple adsorption vessels. For example, when two adsorption vessels (e.g., adsorption vessels 20a and 20b in FIG. 11) are used, while an adsorption step is being performed in one adsorption vessel, a thermal regeneration step and a pressure recovery step are being performed in the other adsorption vessel. By operating the two adsorption vessels while switching between them in this manner, it is possible to continuously and efficiently separate the target gas from the raw material gas.

[0050] 11 , temperature swing adsorption device 30 may include blower 21, cooler 22, and vacuum pump 23. Blower 21 compresses the source gas. Cooler 22 cools the compressed source gas. Vacuum pump 23 discharges the target gas desorbed from the adsorbent to the outside.

[0051] <<Method for producing purified gas>> A method for producing purified gas using the above-described temperature swing adsorption apparatus will now be described. Note that explanations that overlap with those described above in the "Temperature Swing Adsorption Apparatus" will be omitted.

[0052] The method for producing a purified gas in this embodiment includes a separation step of separating at least a portion of the target gas from the raw material gas by temperature swing adsorption. The separation step results in a purified gas in which the target gas has been removed from the raw material gas. As described above, the temperature swing adsorption method sequentially repeats an adsorption cycle consisting of (1) the adsorption step, (2) the thermal regeneration step, and (3) the pressure recovery step.

[0053] The method for producing purified gas in this embodiment may also include a compression step and a cooling step. The compression step is a step of compressing the raw material gas. The cooling step is a step of cooling the compressed raw material gas. The raw material gas is compressed to a predetermined pressure by the compressed gas. The cooling step cools the raw material gas after the compression step to a predetermined temperature. [Example]

[0054] The following examples are provided to illustrate, but not to limit, the scope of the claims.

[0055] In the following Examples 1 and 2, CO2 is partially removed from air using the adsorption vessel described above to obtain CO2-removed air. Adsorption vessels having the configurations shown in Figures 3 and 9 were prepared. The adsorption vessels contained a heating element made of paper-treated stainless steel and an adsorbent made of zeolite (Zeolum F-9 manufactured by Tosoh Corporation).

[0056] Example 1 Air containing 400 mol ppm CO2 was passed through the first inlet of the adsorption vessel as the raw gas, and air containing 100 mol ppm CO2 was obtained from the second inlet. The adsorption vessel was then depressurized using a vacuum pump, and the air remaining in the adsorption vessel was removed. Under reduced pressure, a voltage was applied to the heater, and the adsorption vessel was heated to 100°C, desorbing the CO2 adsorbed on the adsorbent and regenerating the adsorbent. The volume of CO2 in the desorbed gas was approximately 90% by volume.

[0057] Concentrated CO2 can be supplied to agricultural greenhouses, for example, to promote the growth of vegetables.

[0058] <Example 2> Air containing 1000 mol ppm of CO2 was passed through the first inlet of the adsorption vessel as the raw gas, and air containing 200 mol ppm of CO2 was obtained from the second inlet. The pressure inside the adsorption vessel was then reduced using a vacuum pump, and the air remaining in the adsorption vessel was removed. Under reduced pressure, a voltage was applied to the heater, and the adsorption vessel was heated to 100°C, desorbing the CO2 adsorbed on the adsorbent and regenerating the adsorbent. The volume of CO2 in the desorbed gas was approximately 90% by volume.

[0059] The Building Environmental Sanitation Management Standards stipulate that the CO2 concentration inside a building must be 1000 mol ppm or less. Human activity in a confined space increases the CO2 concentration. Therefore, when ventilation with outside air is not possible for some reason, the adsorption container of the present disclosure can be used to remove CO2 from the air. The removed CO2 can be supplied to an agricultural greenhouse, for example, to promote the growth of vegetables, as in Example 1.

[0060] In this way, by using the adsorption vessel described in this disclosure, purified gas can be obtained by removing CO2 from the air. Furthermore, by effectively utilizing the removed CO2, it is possible to contribute to some of the activities of the Sustainable Development Goals (SDGs).

[0061] The embodiments and examples disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0062] 1 first gas flow path, 2 second gas flow path, 3 adsorption layer, 3a first compartment, 3b second compartment, 3c third compartment, 4 heating body, 5 adsorbent, 6 first inlet / outlet, 7 second inlet / outlet, 8a, 8b end plate, 9a, 9b pressing member, 10 cylindrical container, 11 heater section, 12 electrode, 12a first electrode, 12b second electrode, 12c third electrode, 20, 20a, 20b adsorption container, 21 blower, 22 cooler, 23 vacuum pump, 30 temperature swing adsorption device.

Claims

1. An adsorption vessel comprising a cylindrical vessel and a heater unit, the heater portion includes a heating element having a sheet-like disc structure, the adsorption vessel includes a first gas flow path annularly disposed on an inner periphery of the cylindrical vessel, a second gas flow path disposed in a center portion of the cylindrical vessel, and an adsorption layer disposed between the first gas flow path and the second gas flow path, in which the heating element and the adsorbent are alternately stacked in a vertical direction; the cylindrical container is provided with a first inlet / outlet and a second inlet / outlet at at least one of an upper end and a lower end in a vertical direction, the first inlet / outlet is connected to the first gas flow path, The second inlet / outlet is connected to the second gas flow path.

2. the heater portion includes an electrode, The adsorption vessel of claim 1 , wherein the heating element is heated by applying a voltage to the electrodes.

3. The adsorption vessel according to claim 1 , wherein the adsorption layer is a laminate of a plurality of layers.

4. The adsorption layer stacked in plurality has a plurality of compartments in the vertical direction, The adsorption vessel according to claim 3 , wherein the plurality of heater units included in the plurality of compartments are temperature-controlled for each of the plurality of compartments.

5. The adsorption vessel according to claim 1 , wherein the cylindrical vessel is provided with the first inlet / outlet at a lower end in a vertical direction and the second inlet / outlet at an upper end in a vertical direction.

6. The adsorption vessel according to claim 1 , wherein carbon dioxide is adsorbed by the adsorbent.

7. A temperature swing adsorption apparatus comprising an adsorption vessel according to any one of claims 1 to 5.

8. The temperature swing adsorption apparatus of claim 7 comprising a plurality of said adsorption vessels.

Images