Gas concentration device

Abstract

To provide a gas concentration device that highly efficiently exhibits adsorption capacity of an adsorbent and can continuously supply oxygen-enriched air with high oxygen concentration.SOLUTION: An adsorption rotor having an adsorbent that preferentially adsorbs oxygen over nitrogen is divided into at least a processing zone, a regeneration zone, and a purge zone, and rotated sequentially in this order. Raw material air is introduced into the processing zone, and oxygen is adsorbed by the adsorbent. The air that has passed through the processing zone is either supplied to a supply destination or discharged into the atmosphere. Heated air that has passed through a regeneration heater is introduced into the regeneration zone, and the oxygen adsorbed by the adsorbent is desorbed. A portion of the air that has passed through the regeneration zone is extracted as oxygen-enriched air, and the remainder is circulated back to the inlet side of the regeneration heater for regeneration. The air is made to pass through the purge zone and the oxygen-enriched air remaining in the adsorption rotor is purged.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gas concentrating apparatus that is used for oxygen-enriched combustion and the like, and that uses air as a raw material to adsorb and concentrate oxygen by temperature swing adsorption. [Background technology]

[0002] Oxygen-enriched combustion is one type of combustion technology. For example, oxygen-enriched combustion in industrial furnaces is expected to increase flame temperature and reduce exhaust gas loss, resulting in energy savings.

[0003] Methods for concentrating oxygen in air (oxygen enrichment) include cryogenic separation and pressure swing adsorption (hereinafter referred to as "PSA method"). Cryogenic separation separates oxygen by compressing and cooling the air, while the PSA method concentrates oxygen by adsorbing and removing nitrogen from the air. Both cryogenic separation and PSA methods require large amounts of electricity to compress and cool the air.

[0004] Although the cryogenic separation method can produce high-purity oxygen, it requires large equipment and is difficult to install near a furnace, for example, where air with a high oxygen concentration (hereinafter referred to as "oxygen-enriched air") is required. The PSA method can produce relatively high-purity oxygen and can be made compact, but because it is used under reduced / high pressure, the equipment needs to be airtight, necessitating the use of expensive materials such as thick steel plates and highly airtight valves. The temperature swing adsorption method (hereinafter referred to as the "TSA method") operates at normal pressure, so it is possible to use general-purpose materials and keep initial costs down.

[0005] Industrial furnaces emit low-temperature waste heat below 200℃ (hereafter, all temperatures are in degrees Celsius). By combining an adsorbent with the TSA method, the low-temperature waste heat can be used as energy to concentrate oxygen.

[0006] In addition, in order to obtain the effect of increasing the flame temperature in oxygen-enriched combustion in industrial furnaces, an oxygen concentration of 30% is sufficient, and even if the oxygen concentration is increased beyond that, the effect is almost the same and the energy saving effect can be fully achieved. If the oxygen concentration is too high, the temperature inside the furnace will rise and the furnace material cannot withstand it.

[0007] Patent Documents 1 and 2 have been proposed as economical oxygen concentrators that use the TSA method to continuously extract oxygen-enriched air with a high oxygen concentration, can be installed in areas of demand according to the amount of demand, and have a low unit power source for separation. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 02-241515 [Patent Document 2] Japanese Patent Application Publication No. 62-045317 Summary of the Invention [Problem to be solved by the invention]

[0009] As a method for concentrating oxygen in the air using the TSA method, there are a method of adsorbing nitrogen to an adsorbent and a method of adsorbing oxygen to an adsorbent. Zeolite, activated carbon, etc. are used as the adsorbent. In the oxygen concentrator (adsorption / desorption treatment device) described in Patent Document 1, an adsorbent is manufactured using Ca-X type zeolite as the adsorbent, the adsorption region is divided into two, a first adsorption region and a second adsorption region, and the region that has completed regeneration passes through the first and second adsorption regions in sequence, and the outlet gas of the first adsorption region is circulated to the inlet side of the first adsorption region via a cooling device, while the gas that has passed through the second adsorption region is merged into this circulation system, and further, a part of the circulating gas is recovered from an arbitrary position in this circulation system to obtain an oxygen-enriched gas, and in an experimental example, the oxygen concentration in the oxygen-enriched gas is said to be 30%.

[0010] In oxygen concentration using the PSA method, nitrogen-adsorbing zeolites Li-LSX and Ca-A are used as adsorbents and have been put to practical use.

[0011] When the inventors attempted to generate oxygen-enriched air using these nitrogen adsorbents in the TSA process, they found two major problems. 1. The nitrogen adsorption capacity cannot be maintained unless the dew point temperature of the feed air is kept below -50°C. In particular, Li-LSX, which has a large nitrogen adsorption capacity, is significantly affected by moisture concentration. Even Ca-A, which is said to be less affected by moisture concentration, loses its nitrogen adsorption capacity with feed air having a dew point of -5°C. 2. In order to increase the oxygen concentration in the feed air (nitrogen concentration 80%, oxygen concentration 20%) by 1%, from 20% to 21%, it is necessary to decrease the nitrogen concentration from 80% to 75.2%. In other words, by decreasing the amount of nitrogen (only nitrogen is adsorbed by zeolite) and decreasing the nitrogen concentration from 80% to 75.2% without changing the amount of oxygen in the feed air (without adsorbing oxygen), the oxygen concentration of the air after nitrogen adsorption and removal will be 21%. Thus, in order to increase the oxygen concentration, it is necessary to adsorb and remove a large amount of nitrogen contained in the feed air, which requires a nitrogen adsorbent with a large nitrogen adsorption capacity. For these reasons, it is difficult to use atmospheric air as a raw material for oxygen-enriched air with these limitations on zeolites Li-LSX and Ca-A.

[0012] In addition, since the nitrogen adsorption performance of zeolite, which adsorbs nitrogen, drops dramatically at temperatures above 40°C, the TSA method, which uses high-temperature exhaust gas, requires a large amount of adsorbent when the adsorption temperature is high, which increases equipment costs and makes it uneconomical.

[0013] Carbon molecular sieve (hereafter referred to as "CMS") is a rate-separation type adsorbent that adsorbs both oxygen and nitrogen, but has the characteristic that the adsorption rate difference between oxygen and nitrogen is very large, so oxygen and nitrogen can be separated by utilizing this difference in adsorption rate. CMS is also used in the PSA process, but in the TSA process, oxygen-enriched air can be supplied by temperature swinging a honeycomb rotor carrying CMS. Although CMS has a small oxygen adsorption capacity, it is more efficient than the method of obtaining oxygen-enriched air by adsorbing and removing nitrogen, which accounts for about 80% of the feed air, and the amount of adsorbent required can be reduced. Furthermore, if the adsorption selectivity of CMS for oxygen can be increased and desorption can be performed successfully, high concentration is also possible.

[0014] Patent Document 2 discloses an oxygen concentrator (adsorption device) that preferably uses CMS as the adsorbent for the adsorption rotor, and in Fig. 1, an adsorption rotor 1 is disposed across an air path 2 and a regeneration path 3, and a common fan 5 is provided upstream of the air path 2 and the regeneration path 3 via flow control valves 4 and 13, respectively, so that air flows in parallel and is introduced into the adsorption rotor 1. In the regeneration path 3, heated air e at 100°C or higher is passed through the adsorption rotor 1 to regenerate the adsorption rotor 1.

[0015] The inventors conducted an experiment using an adsorption rotor carrying CMS, with a treatment (adsorption) zone: regeneration zone = 1:1, one-pass regeneration (without circulation), and counterflow as described in Patent Document 2. It was found that the oxygen concentration in the oxygen-enriched air at the regeneration outlet was almost the same as that of the raw air, and the oxygen concentration performance was very low (Comparative Example 1 described later). This is because the adsorbent after leaving the regeneration zone moves to the treatment zone while still in an elevated temperature state, so the adsorption capacity of the adsorbent is low and the amount of oxygen adsorbed is extremely small. If a large amount of air is supplied to the adsorption zone in order to eliminate this inconvenience, the purpose of cooling the adsorbent is achieved, but the oxygen adsorption in the adsorbent reaches breakthrough in a short time, and the oxygen concentration cannot be increased. Therefore, it is necessary to optimize the flow, rotation speed, and temperature suitable for the TSA method using an adsorption rotor carrying CMS.

[0016] In view of this situation, a main object of the present invention is to provide a gas concentrating apparatus which can utilize the adsorption capacity of the adsorbent highly efficiently and continuously supply the desired enriched gas having a high gas concentration. [Means for solving the problem]

[0017] In order to solve the above-mentioned problems, the present invention divides an adsorption rotor equipped with an adsorbent that preferentially adsorbs oxygen over nitrogen into at least a treatment zone, a regeneration zone, and a purge zone, which are rotated in that order; raw air is passed through the treatment zone to adsorb oxygen into the adsorbent, the air that has passed through the treatment zone is sent to a supply destination or released to the atmosphere, heated air is passed through the regeneration zone to desorb the oxygen adsorbed by the adsorbent, a portion of the air that has passed through the regeneration zone is extracted as oxygen-enriched air, and the remainder is returned to the inlet side of the regeneration zone for regeneration and circulation, and air is passed through the purge zone to purge the oxygen-enriched air remaining in the adsorption rotor. Effect of the Invention

[0018] By using the waste heat from industrial furnaces as the heat source for regeneration, the running costs for oxygen concentration can be significantly reduced. In the PSA method, the power consumption rate for compressing the raw air or decompressing the adsorbent to regenerate is 0.11 kWh / Nm 3 -25%O2(2.2 yen / Nm 3 On the other hand, according to the TSA method of the present invention, when exhaust heat is used as a regenerative heat source, the power consumption rate for the blower is 0.10 kWh / Nm 3 -25%O2(2.1 yen / Nm 3 Furthermore, by increasing the honeycomb cell size to reduce the size of the blower and by increasing the adsorption capacity of the CMS, the power consumption rate can be reduced to 0.04 kWh / Nm 3 -25%O2(0.8 yen / Nm 3 It has been estimated that this can reduce oxygen levels to less than half that of the PSA method (-25% O2). [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a gas concentrating device of the present invention. [Diagram 2] FIG. 2 is a flow diagram of the gas concentrating apparatus according to the first embodiment of the present invention. [Diagram 3] FIG. 3 is a flow diagram of the gas concentrating apparatus according to the second embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing the influence of the moisture concentration in the gas concentrating device according to the second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] In the present invention, a CMS suitable for TSA operation of an adsorption rotor is used as an adsorbent that preferentially adsorbs a first gas over a second gas. Hereinafter, a gas with a high concentration of the first gas is referred to as a "first gas enriched gas." In addition, the first gas is described as oxygen and the second gas as nitrogen. The CMS can sieve (separate) gases with slightly different molecular diameters by precisely controlling the pores formed in the carbon body. The CMS used in the present invention is designed to match the speed separation of oxygen and nitrogen to the rotor rotation and temperature.

[0021] Fig. 1 is a diagram showing an example of the configuration of a gas concentrating apparatus of the present invention. In the gas concentrating apparatus of the present invention, an adsorption rotor 1 equipped with an adsorbent that preferentially adsorbs oxygen over nitrogen is divided into at least a treatment zone 2, a regeneration zone 3, and a purge zone 4, which are rotated in this order, a raw gas (e.g., air) is passed through the treatment zone 2 to adsorb oxygen to the adsorbent, the gas that has passed through the treatment zone 2 is sent to a supply destination or released to the atmosphere, heated gas that has passed through a regeneration heater 5 is passed through the regeneration zone 3 to desorb the oxygen adsorbed to the adsorbent, a part of the gas that has passed through the regeneration zone 3 is taken out and recovered as an oxygen-enriched gas, and the remainder is returned to the inlet of the regeneration heater 5 (the inlet side of the regeneration zone 3) for regeneration circulation, and a gas is passed through the purge zone 4 to purge the oxygen-enriched gas remaining in the adsorption rotor 1.

[0022] The adsorption rotor 1 is made by corrugating inorganic and / or non-combustible sheets such as ceramic fiber paper or glass fiber paper, metal sheets, plastic sheets, heat-resistant fiber nonwoven fabrics, etc., and laminating them into a block shape or winding them into a cylindrical (rotor) shape. The cross section of the adsorption rotor 1 is honeycomb-shaped, and is not limited to corrugated shapes like the cross section of cardboard, but may be triangular, trapezoidal, hexagonal, or other shapes that do not cause problems in ventilating gas. The honeycomb adsorption rotor has a wide contact area, low pressure loss, and is lightweight yet strong, so it is easy to make it large. Either a method of corrugating paper containing a powdered or fibrous adsorbent or a sheet coated with a powdered adsorbent and laminating or winding it to form a honeycomb may be used, or a method of corrugating a base sheet not containing an adsorbent and laminating or winding it to form a honeycomb, followed by immersing it in a slurry of a mixture of an adsorbent powder and a binder and drying it.

[0023] Since CMS has a small oxygen adsorption capacity, it is desirable to increase the loading rate on the adsorption rotor as much as possible. The loading rate is 50 to 500 kg / m 3 It is preferable to set the loading rate at 100%. If the loading rate is low, the amount of adsorption is small and the adsorption performance is low. On the other hand, if the loading rate is too high, the pressure loss becomes excessive, gas flowability deteriorates, and the adsorption performance decreases. Therefore, in order to maximize the adsorption performance of CMS, the honeycomb cell size and loading rate are optimized.

[0024] In processing zone 2, raw gas (e.g. air) is passed through and only oxygen is adsorbed by utilizing the difference in adsorption speed between oxygen and nitrogen in the CMS. In other words, gas is passed through processing zone 2 only for the time that oxygen can be adsorbed. To achieve this, the rotor rotation speed and processing air volume are optimized. The adsorption capacity of oxygen and nitrogen also changes depending on the temperature of the CMS, and the processing air volume also serves as cooling, so the processing air volume and rotor rotation speed are adjusted to be optimal. Note that if the rotation speed is faster than the optimum, it becomes difficult to raise and lower the temperature of the adsorption rotor 1, and if the rotation speed is slower than the optimum, the adsorption / desorption efficiency is low and the gas processing volume is reduced.

[0025] In regeneration zone 3, heated gas that has passed through regeneration heater 5 is passed through adsorption rotor 1 carrying CMS to swing the temperature, thereby desorbing the adsorbed oxygen with heat and generating oxygen-enriched gas. Furthermore, the gas that has passed through regeneration zone 3 is returned to the inlet of regeneration heater 5 (the inlet side of regeneration zone 3) and circulated for regeneration, thereby increasing the oxygen concentration. By increasing the temperature in regeneration zone 3, oxygen is not re-adsorbed by CMS. Although a certain degree of airtightness is necessary on the regeneration side, outside air is introduced through the gaps on the regeneration side, resulting in a situation in which outside air is taken in and oxygen-enriched gas is taken out. Oxygen-enriched gas is obtained by taking out and recovering a portion of the gas that has passed through regeneration zone 3.

[0026] In the purge zone 4, a wall of a purge zone is created between the treatment zone 2 and the regeneration zone 3 so that gas from the treatment side does not flow into the regeneration side due to leakage between the zones or carryover due to the rotation of the adsorption rotor 1. This prevents dilution of the oxygen concentration in the regeneration circulation. In addition, a gas is passed through the purge zone to purge the oxygen-enriched gas remaining in the adsorption rotor. In addition, if necessary, the gas introduced into the purge zone is heated to desorb oxygen that was not desorbed in the regeneration zone and remains in the adsorbent. Alternatively, a gas is passed through the purge zone 4 to cool the adsorption rotor 1. In the purge zone 4, the atmosphere, a part of the gas that has passed through the treatment zone 2 or before entering the treatment zone 2, a purge circulation gas, a part of the regeneration circulation gas, etc. are introduced. EXAMPLES

[0027] Hereinafter, a first embodiment (two-stage regeneration flow) of the gas concentrating device of the present invention will be described with reference to the flow diagram of Fig. 2. In the first embodiment, the gas concentrating device has 200 cells / inch 2 With a honeycomb cell size of 250 kg / m, the loading rate is 60% (loading amount 250 kg / m 3), an adsorption rotor 1 with a diameter of φ200 mm and a height of H400 mm was manufactured. The treatment zone was divided into three, a first treatment zone 21, a second treatment zone 22, and a third treatment zone 23. The regeneration zone was divided into two, a first regeneration zone 31 and a second regeneration zone 32. For convenience, in this specification, when a treatment zone or a regeneration zone is divided into a plurality of zones, it is written as "first, second, etc." The angles of each zone were the same, and the ratio of treatment zone:regeneration zone:purge zone was 3:2:1. The adsorption rotor 1 is rotated by a geared motor (not shown) or the like in the order of the first treatment zone 21, the second treatment zone 22, the third treatment zone 23, the first regeneration zone 31, the second regeneration zone 32, and the purge zone 4.

[0028] On the treatment side, the raw gas that has passed through the blower 6 is branched and introduced into the first treatment zone 21, the second treatment zone 22, and the third treatment zone 23, respectively. The gas that has passed through each treatment zone is joined and sent to the supply destination by the blower 7, or released into the atmosphere. In the first treatment zone 21, the gas is caused to flow at a high surface wind speed, so that the adsorption rotor 1 is cooled quickly and reliably, and the adsorption time in the second treatment zone 22 and the third treatment zone 23 is secured. The surface wind speed of the gas flowing into the first treatment zone 21 is set to be higher than the maximum surface wind speed among the surface wind speeds of the other zones (the second treatment zone 22, the third treatment zone 23, the first regeneration zone 31, the second regeneration zone 32, and the purge zone 4). However, if the surface wind speed exceeds 6 m / s, the adsorption rotor is sufficiently cooled, the oxygen-enriched gas concentration in the regeneration circulation path reaches a plateau, and the power of the blower is increased, so the upper limit is set to 6 m / s. A cooler may be provided at the inlet side of the processing zone to lower the temperature of the raw material gas. Although the processing side blowers (blowers 6 and 7) are provided at the inlet and outlet sides, respectively, only one of them may be provided. The gas that has passed through the processing zone has a relatively high nitrogen concentration (nitrogen-enriched gas), so it may be supplied to a destination for use as necessary.

[0029] On the regeneration side, gas heated by a regeneration heater 51 is introduced into the first regeneration zone 31, where the oxygen adsorbed by the adsorbent is desorbed to increase the oxygen concentration. The gas that has passed through the first regeneration zone 31 is introduced into the second regeneration zone 32 via a regeneration heater 52 by a blower 8. In the second regeneration zone 32, oxygen is desorbed, and the oxygen concentration is further increased. The gas that has passed through the second regeneration zone 32 is again passed through the regeneration heater 51 by a blower and introduced into the first regeneration zone 31. In this way, the oxygen-rich gas is regenerated and circulated in two stages through the first regeneration zone 31 and the second regeneration zone 32, and oxygen is concentrated. The gas with an increased oxygen concentration that has passed through the second regeneration zone 32 is taken out as an oxygen-rich gas.

[0030] In the purge zone 4, gas heated by a heater 10 is passed to purge the oxygen-enriched gas remaining in the honeycomb voids of the adsorption rotor 1 and to desorb the oxygen remaining in the pores of the adsorbent that could not be desorbed in the regeneration zone. The gas leaving the purge zone 4 is introduced again into the purge zone 10 by a blower 11 and circulated. By circulating the gas through the purge zone 4 alone, a loop wall of the purge zone is created between the treatment zone and the regeneration zone, and dilution of the oxygen concentration of the oxygen-enriched gas in the regeneration circuit can be prevented.

[0031] As shown in Figure 2, the gases introduced into all zones, the treatment zone, regeneration zone, and purge zone, were arranged to flow in the same direction in a parallel flow manner. This parallel flow arrangement reduces the positive pressure difference between the zones, reducing the amount of leakage and enabling the oxygen concentration of the oxygen-enriched gas to be maintained at a high level.

[0032] In the flow of this Example 1, the treatment inlet temperature was 22°C, the regeneration inlet temperature was 120°C, the purge inlet temperature was 100°C, and dehumidified air with a dew point of minus 30°C or less was used as the raw gas. The surface wind speed of the first treatment zone 21 was 5m / s, and the surface wind speed of the other zones (the second treatment zone 22, the third treatment zone 23, the first regeneration zone 31, the second regeneration zone 32, and the purge zone 4) was 1.5m / s. The rotation speed was 15rph. As a result, the oxygen concentration in the oxygen-enriched gas was 24.9% (oxygen concentration in the raw gas was 20.9%), and the oxygen concentration in the purge circulation path was 22.0%. EXAMPLES

[0033] Hereinafter, the second embodiment (parallel regeneration flow) of the gas concentrator of the present invention will be described with reference to the flow diagram of FIG. 3. The description of the parts overlapping with the first embodiment will be omitted. In the second embodiment, the flow of the first embodiment is simplified, and the regeneration circulation gas is branched and introduced in parallel into the first regeneration zone 31 and the second regeneration zone 32. That is, a part of the regeneration circulation gas is heated by the regeneration heater 51 and introduced into the first regeneration zone 31, and the remaining part of the regeneration circulation gas is heated by the regeneration heater 52 and introduced into the second regeneration zone 32. The gases that have passed through each regeneration zone are merged and circulated again to the inlet side of the regeneration zone. As a result, the number of blowers on the regeneration outlet side is two (blowers 8 and 9) in the first embodiment, but only one (blower 12) is required in the second embodiment. The other configurations are the same as those in the first embodiment. Although the regeneration heaters 51 and 52 are provided at the inlet side of each of the first regeneration zone 31 and the second regeneration zone 32, a single regeneration heater may be used and the gas that has passed through the regeneration heater may be branched and introduced into each of the regeneration zones. The gas with an increased oxygen concentration that has passed through the regeneration zones and circulated is extracted and recovered as an oxygen-enriched gas.

[0034] In the flow of this Example 2, an oxygen concentration test was carried out under the same conditions as in Example 1. As a result, the oxygen concentration in the oxygen-enriched gas was 24.9% (oxygen concentration in the raw gas: 20.9%), and the oxygen concentration in the purge circulation path was 22.1%, and it was found that the flows of Example 1 and Example 2 have equivalent performance when the gas input flow rate is the same, and there is no problem even if the flow is simplified.

[0035] (Effect of moisture concentration) In Example 1 and Example 2, dehumidified air with a dew point of -30°C or less was used. Here, in order to examine the effect of the moisture concentration, the humidity of the treatment inlet gas was gradually increased from a dew point of -44°C to a dew point of -5°C in the flow of Example 2, and the effect of humidity on the oxygen concentration performance was evaluated. The results are shown in Figure 4. Figure 4(a) shows the change over time of the dew point in the oxygen-enriched gas in the regeneration circulation path, and Figure 4(b) shows the change over time of the oxygen concentration in the oxygen-enriched gas in the regeneration circulation path. It was found that even when air with a dew point of -5°C was supplied, the oxygen concentration hardly decreased, and the oxygen concentration performance could be maintained. From this, it can be said that unlike zeolite Li-LSX and Ca-A, the effect of moisture on the oxygen concentration performance of CMS is very small. In the purge circulation path, moisture condenses, so a drain or other means is required to remove the water. It is also possible to provide a drain or the like in the regeneration circulation path.

[0036] In the first and second embodiments, the number of the treatment zones was three and the number of the regeneration zones was two, but the present invention is not limited to this, and the number of the regeneration zone and the treatment zone may be one or more. The treatment side was a one-pass, but a part or all of the gas that passed through the treatment zone may be returned to the inlet side of the treatment zone and circulated. The purge path was a circulation path, but it may be a one-pass, and a heater may not be provided on the purge inlet side (in this case, the oxygen concentration in the oxygen-enriched gas was 24.4% (oxygen concentration in the raw gas was 20.9%), and the oxygen concentration in the purge circulation path was 20.8%). An air volume adjustment device such as a damper that takes in outside air may be provided in the regeneration circulation path and the purge circulation path. Furthermore, in the present embodiment, the parallel flow was used in all the zones, but the present invention is not limited to this, and since the performance can be improved by the counterflow due to the improved heat exchange rate, some of the zones may be counterflow as appropriate.

[0037] The adsorption rotor is preferably a honeycomb adsorption rotor in which the adsorbent is supported on a honeycomb, but may be an adsorption rotor composed of an adsorption tower filled with bead-shaped or pellet-shaped adsorbent. As shown in Figs. 1 and 3 of Patent Document 1, the adsorbent may be formed in a cylindrical shape and gas may be circulated in the radial direction. In the present invention, CMS is used as the adsorbent, but an adsorbent that can separate nitrogen and oxygen by the difference in adsorption speed like CMS or an adsorbent that preferentially adsorbs oxygen over nitrogen may be used. The heated gas introduced into the regeneration zone is not limited to a regeneration heater, and if heated gas that has been heat-exchanged with combustion exhaust gas is used, the running cost can be reduced.

[0038] Comparative Example 1 Using an adsorption rotor carrying CMS, tests were conducted with a treatment zone:regeneration zone ratio of 1:1, one-pass regeneration (no circulation), and counterflow. Dry gas with a dew point of -30°C or less (oxygen concentration in the dry gas: 20.9%) was introduced into the treatment zone at a surface wind speed of 2 m / s, and heated gas at 100°C was introduced into the regeneration zone at a surface wind speed of 2 m / s. The oxygen concentrations at the regeneration inlet and regeneration outlet were both 20.9%, with no change. Therefore, it was found that the oxygen concentration in the oxygen-enriched gas at the regeneration outlet was almost the same as that of the raw gas, and the oxygen concentration performance was very low.

[0039] Comparative Example 2 Next, a test was performed with regeneration circulation under the same conditions as in Comparative Example 1. The oxygen concentration at the regeneration inlet was 20.9%, while the oxygen concentration at the regeneration outlet was 21.7%. This shows that the oxygen concentration does not increase with one-pass regeneration, and that regeneration circulation is necessary for oxygen concentration. However, the increase was only 0.8 points, and flow optimization is required to further increase the oxygen concentration.

[0040] In Examples 1 and 2, 200 cells / inch 2 A honeycomb adsorption rotor with a cell count of, for example, 50 cells / inch was used. 2 The loading amount was reduced to 250 kg / m, the same as in this example. 3 By doing so, pressure loss can be reduced by up to 75% while maintaining oxygen concentration performance, allowing the size of the blower to be reduced. Since the main energy consumed in the oxygen-enriched TSA process is electricity for blowing air, operating costs can be significantly reduced. In the oxygen-enriched PSA process, the power consumption rate for compressing the raw air or reducing the pressure for regenerating the adsorbent is 0.11 kWh / Nm 3 -25%O2(2.2 yen / Nm 3 On the other hand, in the oxygen-enriched TSA method of the present invention, 200 cells / inch 2 When using a honeycomb adsorption rotor, the power consumption rate for the blower is 0.10 kWh / Nm 3 -25%O2(2.1 yen / Nm 3-25% O2) is required, and the operating cost is equivalent to that of the oxygen-enriched PSA method. Furthermore, the number of cells is increased to, for example, 50 cells / inch 2 When reduced to 0.08 kWh / Nm, the power consumption rate is reduced to 0.08 kWh / Nm while maintaining the oxygen concentration performance. 3 -25%O2(1.6 yen / Nm 3 It is expected that the adsorption capacity of CMS can be doubled, and in this case, the power consumption rate will be 0.04 kWh / Nm 3 -25%O2(0.8 yen / Nm 3 It has been estimated that this can be reduced to less than half the level required by oxygen-enriched PSA method (-25% O2).

[0041] In the present embodiment and comparative example, the first gas is oxygen and the second gas is nitrogen, but this is not limited thereto. The first gas and the second gas may be changed as appropriate depending on the type of gas, for example, the first gas may be carbon dioxide and the second gas may be methane. [Industrial Applicability]

[0042] The gas concentrating device of the present invention is expected to be applied to industrial furnaces. It is compatible with various combustion devices that do not tolerate pressure loss, and it is relatively easy to increase the size, so it is easy to introduce, and further energy saving effects can be expected. Oxygen-enriched combustion, which increases the oxygen concentration to about 25 to 30%, is excellent in energy saving, such as reducing fuel consumption by about 10 to 30%, and contributes to fuel reduction in industrial furnaces, etc. In addition, SOFCs (solid oxide fuel cells), which are expected to improve power generation efficiency by increasing the oxygen concentration at the air electrode, are also promising applications.

[0043] The present invention is directed to the speed separation of oxygen and nitrogen, but as long as the gas can be separated at different adsorption speeds using CMS, it is also possible to separate methane and carbon dioxide, hydrogen and other substances, propane gas and propylene, etc., and the flow of the present invention can be used to separate components from several types of mixed gases. [Explanation of symbols]

[0044] 1 Adsorption rotor 2 Treatment Zone 3. Play Zone 4 Purge Zone 5 Regenerative Heater 6, 7, 8, 9, 11, 12 Blower 10 Heater 21 First Treatment Zone 22 Second Treatment Zone 23 Third Treatment Zone 31 First Play Zone 32 Second Regeneration Zone 51, 52 Regenerative heater

Claims

1. a first gas enrichment gas enriched gas that enriches the first gas in the adsorption rotor; a second gas enrichment gas enriched gas that enriches the first gas in the adsorption rotor; a regeneration zone that enriches the first gas in the adsorption rotor; a first gas enrichment gas enriched in the adsorption rotor; a second gas enrichment gas enriched in the adsorption rotor;

2. 2. The gas concentrating apparatus of claim 1, wherein the first gas is oxygen and the second gas is nitrogen.

3. 2. The gas concentrating apparatus of claim 1, wherein the first gas is carbon dioxide and the second gas is methane.

4. 4. The gas concentrating apparatus according to claim 1, wherein the adsorbent is CMS.

5. 4. The gas concentrating apparatus according to claim 1, wherein the gas that has passed through the purge zone is returned to an inlet side of the purge zone and circulated.

6. 4. The gas concentrating apparatus according to claim 1, wherein the treatment zone is divided into a plurality of treatment zones, namely, a first treatment zone, a second treatment zone, etc., and the adsorption rotor is cooled by passing a gas having a high surface wind velocity through the first treatment zone.

7. 7. The gas concentrating apparatus according to claim 6, wherein the surface velocity of the gas flowing into the first treatment zone is set to be higher than the largest surface velocity among the surface velocity of the other zones, and is set to an upper limit of 6 m / s.

8. 4. The gas concentrating apparatus according to claim 1, wherein a part or all of the gas having passed through the treatment zone is returned to an inlet side of the treatment zone for circulation.

9. 4. The gas concentrating apparatus according to claim 1, wherein the regeneration zone is divided into a plurality of regeneration zones, namely a first regeneration zone, a second regeneration zone, ..., and the gases passing through the plurality of regeneration zones are mixed and returned to the inlet side of the regeneration zone for circulation.

Images