JPH05192528A - Method for separating oxygen and nitrogen from gaseous mixture - Google Patents
Method for separating oxygen and nitrogen from gaseous mixtureInfo
- Publication number
- JPH05192528A JPH05192528A JP4008950A JP895092A JPH05192528A JP H05192528 A JPH05192528 A JP H05192528A JP 4008950 A JP4008950 A JP 4008950A JP 895092 A JP895092 A JP 895092A JP H05192528 A JPH05192528 A JP H05192528A
- Authority
- JP
- Japan
- Prior art keywords
- oxygen
- nitrogen
- pressure
- adsorption
- adsorbent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B21/00—Nitrogen; Compounds thereof
- C01B21/04—Purification or separation of nitrogen
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Analytical Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Separation Of Gases By Adsorption (AREA)
- Oxygen, Ozone, And Oxides In General (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、窒素を選択的に吸着す
る吸着剤を使用して、酸素と窒素を主成分とする混合気
体から酸素と窒素を分離する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for separating oxygen and nitrogen from a mixed gas containing oxygen and nitrogen as a main component by using an adsorbent which selectively adsorbs nitrogen.
【０００２】[0002]
【従来の技術】窒素吸着剤を利用して、空気から酸素と
窒素を分離する方法は、装置が小型簡易であり、殆ど保
守を必要とせずほぼ無人運転が可能であり、酸素製造量
１０〜３０００Ｎｍ3 Ｏ2 ／Ｈｒ程度の中小型装置とし
て近年使用例が増え、深冷分離装置で作られる液体酸素
を輸送して使用するケースからの代替が進行している。2. Description of the Related Art A method of separating oxygen and nitrogen from air by using a nitrogen adsorbent has a small size and a simple apparatus, requires almost no maintenance, and can be operated almost unattended. In recent years, the number of uses has increased as small and medium-sized devices of about 3000 Nm 3 O 2 / Hr, and replacement of the case of transporting and using liquid oxygen produced by a cryogenic separation device is in progress.
【０００３】この種の代表的な装置の概要を説明する
と、装置は２塔以上の吸着塔、空気圧縮機、場合によっ
ては真空ポンプなどから構成される。１塔の吸着塔に空
気圧縮機で圧縮空気を送ると、塔内に充填された窒素吸
着剤に空気中の窒素が吸着され、高圧の酸素を流出回収
する。他塔は真空ポンプで減圧され、必要に応じて製品
酸素の一部を向流で流すことにより窒素を脱着し、吸着
剤を再生する。このような吸着工程と再生工程を交互に
繰り返して連続的に酸素と窒素を分離する。An outline of a typical device of this type will be described. The device comprises two or more adsorption towers, an air compressor, and in some cases a vacuum pump. When compressed air is sent to one adsorption tower by an air compressor, nitrogen in the air is adsorbed by the nitrogen adsorbent filled in the tower, and high-pressure oxygen is discharged and recovered. The other column is decompressed by a vacuum pump, and if necessary, a part of product oxygen is caused to flow countercurrently to desorb nitrogen and regenerate the adsorbent. The adsorption step and the regeneration step are alternately repeated to continuously separate oxygen and nitrogen.
【０００４】ここで使用される窒素吸着剤としては、ユ
ニオンカーバイント社により実用化されたＮａ−Ａ型ゼ
オライトの６０〜７０％Ｃａ交換体が代表的なものであ
り、この窒素吸着剤は空気条件下において酸素の共吸着
が窒素吸着の１０％以下と推定される。上記の装置は１
Ｎｍ3 の酸素を製造するのに消費電力０．７５〜１ＫＷ
ｈを必要とし、大容量深冷分離方法で製造するときの消
費電力０．４５ＫＷｈに比べて大きい。また、上記の装
置は装置容量の増大に対するスケールメリットが少な
く、３０００Ｎｍ3 ( 酸素）／ｈ以上の領域では深冷分
離方法に競合できないと言われている。As the nitrogen adsorbent used here, a 60 to 70% Ca exchanger of Na-A type zeolite, which has been put into practical use by Union Carbint Co., is typical, and this nitrogen adsorbent is air. Co-adsorption of oxygen is estimated to be 10% or less of nitrogen adsorption under the conditions. The above device is 1
Power consumption 0.75 to 1 kW for producing Nm 3 oxygen
h is required, and the power consumption is 0.45 KWh, which is larger than the power consumption when manufacturing by the large-capacity cryogenic separation method. Further, it is said that the above apparatus has little economies of scale with respect to the increase of the apparatus capacity, and cannot compete with the cryogenic separation method in the region of 3000 Nm 3 (oxygen) / h or more.
【０００５】[0005]
【発明が解決しようとする課題】以下、上記の装置の欠
点を検討する。まず、消費電力の低減については、送風
圧力を低くして低圧で吸着操作を行うことが考えられる
が、窒素吸着量が圧力にほぼ比例して低下するため、装
置の容量が極めて増大する。次に、吸着量の増大を図る
ために、低温条件で吸着操作を行うことが考えられる
が、吸着・脱着速度が著しく低下するため、同一塔長で
の製品酸素濃度が室温時よりもかえって低下する。ま
た、温度の低下に伴い窒素吸着時の酸素共吸着量が上昇
するため、動力原単位が漸次上昇する。そこで、本発明
は、上記の欠点を解消し、動力原単位及び吸着剤量を大
幅に低減することができる、低温、低圧吸着条件下で酸
素と窒素を分離する方法を提供しようとするものであ
る。The drawbacks of the above device will be examined below. First, in order to reduce the power consumption, it is conceivable to lower the blast pressure and perform the adsorption operation at a low pressure, but since the nitrogen adsorption amount decreases almost in proportion to the pressure, the capacity of the device increases significantly. Next, in order to increase the amount of adsorption, it is possible to carry out the adsorption operation under low temperature conditions, but since the adsorption / desorption rate decreases significantly, the product oxygen concentration at the same column length decreases rather than at room temperature. To do. In addition, since the oxygen co-adsorption amount at the time of nitrogen adsorption increases as the temperature decreases, the power consumption rate gradually increases. Therefore, the present invention intends to provide a method for separating oxygen and nitrogen under low temperature and low pressure adsorption conditions, which can solve the above-mentioned drawbacks and can significantly reduce the power consumption rate and the adsorbent amount. is there.
【０００６】[0006]
【問題点を解決するための手段】本発明は、ＳｉＯ2 ／
Ａｌ2 Ｏ3 比２．０〜２．５に調整されたＮａ−Ｘ型ゼ
オライトを充填した少なくとも２塔の吸着塔を使用し、
酸素及び窒素を主成分とする混合気体を、室温以下の低
温で、かつ大気圧以上３ａｔａ以下の圧力で一方の吸着
塔に流入させ、混合気体から窒素を選択的に吸着させ、
高純度酸素又は酸素富化ガスを回収し、他方の吸着塔を
０．０８〜０．５ａｔａに減圧して吸着剤を再生し、窒
素を排出することを特徴とする混合気体から酸素と窒素
を分離する方法である。The present invention is based on SiO 2 /
Using at least two adsorption columns packed with Na-X type zeolite adjusted to an Al 2 O 3 ratio of 2.0 to 2.5,
A mixed gas containing oxygen and nitrogen as main components is caused to flow into one of the adsorption towers at a low temperature of room temperature or lower and a pressure of atmospheric pressure or more and 3 ata or less to selectively adsorb nitrogen from the mixed gas,
High-purity oxygen or oxygen-enriched gas is recovered, the other adsorption tower is decompressed to 0.08 to 0.5 ata to regenerate the adsorbent, and nitrogen is discharged. It is a method of separating.
【０００７】[0007]
【作用】本発明者等は、低温、低圧吸着条件下で高性能
な酸素と窒素の分離方法を鋭意研究する過程で、ＳｉＯ
2 ／Ａｌ2 Ｏ3 比２．０〜２．５に調整されたＮａ−Ｘ
型ゼオライトが、大きな窒素吸着量と実用的な範囲での
吸着速度を維持し、窒素吸着の選択性の低下が小さいこ
とを見出し、上記のゼオライトを本発明で初めて酸素と
窒素の混合気体の分離に適用することにより、ガス分離
装置の動力原単位及び吸着剤量を大幅に低減することを
可能にしたものである。The inventors of the present invention have conducted an earnest study on a high-performance method for separating oxygen and nitrogen under low-temperature and low-pressure adsorption conditions.
2 / Al 2 O 3 ratio adjusted to 2.0-2.5 Na-X
Type zeolite maintains a large amount of nitrogen adsorption and an adsorption rate in a practical range, and the decrease in selectivity of nitrogen adsorption is small, and for the first time in the present invention, the above zeolite is used to separate a mixed gas of oxygen and nitrogen. It is possible to significantly reduce the power consumption rate and the adsorbent amount of the gas separation device by applying to
【０００８】以下、本発明の有効性を図１によって説明
する。入口側ライン１から導入された空気は圧縮機２で
１．０５〜４ａｔａに加圧し、流路３で脱湿脱二酸化炭
素塔４に導入され、極めて清浄な加圧空気を得る。この
加圧空気は流路３’、開状態のバルブ５、流路６、開状
態のバルブ７を介して吸着塔８に導入される。加圧空気
は吸着塔８内の吸着剤９で窒素を吸着分離し、上方に流
れるにしたがって酸素濃度を上昇する。そして、高純度
酸素は吸着塔８の上部より流出し、開状態のバルブ１
０、１１を経て酸素製品タンク１３に貯留され、開状態
のバルブ１２及び流路２１を経て回収される。The effectiveness of the present invention will be described below with reference to FIG. The air introduced from the inlet side line 1 is pressurized to 1.05 to 4 ata by the compressor 2 and is introduced into the dehumidification / decarbonation tower 4 through the flow path 3 to obtain extremely clean pressurized air. This pressurized air is introduced into the adsorption tower 8 through the flow path 3 ′, the open valve 5, the flow path 6, and the open valve 7. The pressurized air adsorbs and separates nitrogen by the adsorbent 9 in the adsorption tower 8 and increases the oxygen concentration as it flows upward. Then, the high-purity oxygen flows out from the upper part of the adsorption tower 8 to open the valve 1
It is stored in the oxygen product tank 13 through 0 and 11, and is collected through the valve 12 and the flow path 21 in the open state.
【０００９】一方、吸着工程を終了した吸着塔８’は、
開状態のバルブ１６、流路１７を介して真空ポンプ１８
に接続されて減圧される。その際、２つの吸着塔上部を
接続する流路１４の減圧弁１５を介して製品酸素の一部
が吸着塔８’に向流で流れ、吸着塔８’内の吸着剤９’
に吸着されていた窒素を容易に脱着することができ、短
時間で吸着剤９’を再生することができる。吸着塔８の
窒素吸着剤９が飽和し、吸着塔８’の窒素吸着剤９’が
再生されると、入口空気の流路６を流路６’に切り換
え、吸着塔８を再生工程に、吸着塔８’を吸着工程に移
行してガス分離操作が継続され、連続的に製品酸素を回
収することができる。On the other hand, the adsorption tower 8'after the adsorption step is
Vacuum pump 18 through open valve 16 and flow path 17
Is connected to and the pressure is reduced. At that time, a part of the product oxygen flows countercurrently to the adsorption tower 8'through the pressure reducing valve 15 of the flow path 14 connecting the upper portions of the two adsorption towers, and the adsorbent 9'in the adsorption tower 8 '
It is possible to easily desorb the nitrogen adsorbed by the adsorbent 9 and regenerate the adsorbent 9 ′ in a short time. When the nitrogen adsorbent 9 in the adsorption tower 8 is saturated and the nitrogen adsorbent 9'in the adsorption tower 8'is regenerated, the inlet air flow path 6 is switched to the flow path 6 ', and the adsorption tower 8 is used in the regeneration step. The adsorption tower 8'is transferred to the adsorption step and the gas separation operation is continued, so that product oxygen can be continuously recovered.
【００１０】なお、入口の清浄な加圧空気の流路３’
と、離脱窒素を主成分とするガスの流路１７との間に
は、熱交換器１９を配置し、かつ、上記流路３’と、製
品酸素の回収流路２１との間には、熱交換器２２を配置
することにより、上記の加圧空気を冷却することができ
る。また、上記流路３’には、圧縮式冷凍機２０を配置
することにより、極めて能率的に上記の加圧空気を冷却
することができ、吸着工程の低温条件を確保することが
できる。また、吸着塔の切り換えを、単純に流路６と
６’の間で切り換えを行わず、切り換え直後の昇圧に伴
う入口空気の吹き抜けを防止し、かつ、吸着塔の後方に
残留する酸素及び前方の加圧空気を系外に放出すること
を最小にするために、まず、バルブ１０、１５、１０’
を全開にし、吸着直後の吸着塔８後方に残存する酸素を
再生直後の吸着塔８’に一部移すことが好ましい。It should be noted that the clean compressed air flow path 3'at the inlet
And a flow path 17 for the gas containing desorbed nitrogen as a main component, a heat exchanger 19 is arranged, and between the flow path 3 ′ and the product oxygen recovery flow path 21, By disposing the heat exchanger 22, the above pressurized air can be cooled. Further, by disposing the compression refrigerator 20 in the flow path 3 ', the compressed air can be cooled very efficiently, and the low temperature condition of the adsorption step can be secured. Further, the adsorption tower is not simply switched between the flow paths 6 and 6 ′ to prevent blow-in of the inlet air due to pressurization immediately after the switching, and to prevent oxygen remaining in the rear of the adsorption tower and the front side. In order to minimize the discharge of the pressurized air of the system out of the system, first, the valves 10, 15, 10 '
It is preferable to fully open and partially transfer the oxygen remaining behind the adsorption tower 8 immediately after adsorption to the adsorption tower 8 ′ immediately after regeneration.
【００１１】このとき、吸着塔８の圧力をＰ0 （ａｔ
ａ）、吸着塔８’の圧力をＰ1 （ａｔａ）とすると、均
圧後の圧力は約（Ｐ0 ＋Ｐ1 ）／２（ａｔａ）となる。
その後、吸着塔８’は、バルブ１０’、１１’を開状態
として製品酸素タンク１３と均圧化され、さらに高圧の
酸素を満たすことができる。製品酸素タンク１３との均
圧時の圧力Ｐ2 （ａｔａ）は吸着塔８、８’の死容積
（吸着塔内の吸着剤で占められていない空間の容積）を
Ｖ1 （リットル）、製品酸素タンクの容積をＶ2 （リッ
トル）とし、均圧前の製品酸素タンク１３の圧力をＰ0
（ａｔａ）にほぼ等しいとすると、均圧化圧力Ｐ2 （ａ
ｔａ）は概略次のとおりとなる。Ｐ2 ＝〔（（Ｐ0 ＋Ｐ
1 ）Ｖ1 ／２）＋Ｐ0 Ｖ2 〕／〔Ｖ1 ＋Ｖ2 〕したがっ
て、単に塔を切り換える時のＰ1 （ａｔａ）からＰ
0 （ａｔａ）への急速な昇圧に比べ、上記の操作では、
Ｐ1 （ａｔａ）、（Ｐ0 ＋Ｐ1 ）／２（ａｔａ）、Ｐ2
（ａｔａ）、Ｐ0 （ａｔａ）と緩やかに昇圧するため、
昇圧時の空気の吹き抜けを防止することができ、脱着工
程での残存酸素及び高圧空気の系外への放出を最小にす
ることが可能となった。At this time, the pressure in the adsorption tower 8 is changed to P 0 (at
a), assuming that the pressure of the adsorption tower 8 ′ is P 1 (ata), the pressure after equalization is about (P 0 + P 1 ) / 2 (ata).
After that, the adsorption tower 8 ′ is pressure-equalized with the product oxygen tank 13 by opening the valves 10 ′ and 11 ′, and can further fill high-pressure oxygen. The pressure P 2 (ata) at the time of pressure equalization with the product oxygen tank 13 is V 1 (liter) when the dead volume of the adsorption towers 8 and 8 ′ (volume of space not occupied by adsorbent in the adsorption tower) is V 1 (liter). The volume of the oxygen tank is V 2 (liter), and the pressure of the product oxygen tank 13 before pressure equalization is P 0.
Assuming that it is approximately equal to (ata), the pressure equalizing pressure P 2 (a
ta) is roughly as follows. P 2 = [((P 0 + P
1) V 1/2) + P 0 V 2 ] / [V 1 + V 2] Therefore, simply P from P 1 (ata) when switching the tower
Compared to the rapid boost to 0 (ata), the above operation
P 1 (ata), (P 0 + P 1 ) / 2 (ata), P 2
(Ata) and P 0 (ata) to raise the voltage gently,
It is possible to prevent blow-through of air during pressurization, and to minimize the release of residual oxygen and high-pressure air from the system during the desorption process.
【００１２】[0012]
【実施例】本発明の有効性を実証するために、ＳｉＯ2
／Ａｌ2 Ｏ3 比２．０、並びに、２．５に調整されたＮ
ａ−Ｘ型ゼオライトを窒素吸着剤として、図１の空気分
離装置に充填し、空気から酸素と窒素の分離を試みた。
なお、比較のために、ＳｉＯ2 ／Ａｌ2 Ｏ3 比２．７に
調整されたＮａ−Ｘ型ゼオライトも使用した。ガス分離
操作の諸元は、次のとおりである。 吸着塔仕様 ： 直径６０ｍｍ，長さ８５０ｍｍ 吸着剤の種類 ： ＳｉＯ2 ／Ａｌ2 Ｏ3 比２．
０のＮａ−Ｘ ＳｉＯ2 ／Ａｌ2 Ｏ3 比２．５のＮａ−Ｘ ＳｉＯ2 ／Ａｌ2 Ｏ3 比２．７のＮａ−Ｘ 吸着剤充填量 ： １．５Ｋｇ／塔 塔数 ： ２塔 塔の切り換え時間 ： １．５分 吸着塔圧力 ： １〜５ａｔａ 再生塔圧力 ： ０．１〜１ａｔａ 吸着塔温度 ： ２０〜１００℃ 出口製品流量 ： ２Ｎリットル／分 吸着塔の均圧化は、上記の手順によった。EXAMPLES To demonstrate the effectiveness of the present invention, SiO 2
/ Al 2 O 3 ratio of 2.0 and N adjusted to 2.5
The a-X type zeolite was used as a nitrogen adsorbent and filled in the air separation apparatus of FIG. 1 to try to separate oxygen and nitrogen from the air.
For comparison, Na-X type zeolite is adjusted to SiO 2 / Al 2 O 3 ratio 2.7 was also used. The specifications of the gas separation operation are as follows. Adsorption tower specifications: Diameter 60 mm, length 850 mm Adsorbent type: SiO 2 / Al 2 O 3 ratio 2.
0 of Na-X SiO 2 / Al 2 O 3 ratio Na-X adsorbent filling amount of Na-X SiO 2 / Al 2 O 3 ratio of 2.7 2.5: 1.5 Kg / tower tower: 2 tower Switching time of tower: 1.5 minutes Adsorption tower pressure: 1-5 ata Regeneration tower pressure: 0.1-1 ata Adsorption tower temperature: 20-100 ° C. Outlet product flow rate: 2 N liters / minute According to the procedure.
【００１３】上記の操作条件で空気から酸素と窒素を分
離した結果について、上記３種類の窒素吸着剤を比較し
た。図２は、吸着圧力と動力原単位の関係を示したグラ
フである。横軸は吸着圧力Ｐ0 （ａｔａ）、縦軸は１Ｎ
ｍ3 ／ｈの酸素を製造するに必要な消費電力（ＫＷｈ／
Ｎｍ3 （酸素）である。そして、吸着塔温度を２０℃、
脱着圧力Ｐ1 を０．２ａｔａ、塔空間速度Ｕを０．８ｃ
ｍ／ｓｅｃ（出口基準）に設定し、吸着塔圧力を１．５
〜４．５ａｔａに変化させて消費電力を調べた。図中、
○印はＳｉＯ2 ／Ａｌ2 Ｏ3 比２．７のＮａ−Ｘ、△印
はＳｉＯ2 ／Ａｌ2 Ｏ3 比２．５のＮａ−Ｘ、□印はＳ
ｉＯ2 ／Ａｌ2 Ｏ3 比２．０のＮａ−Ｘについてのもの
である。（図３〜５においても同様である）図２から明
らかなように、本発明のＳｉＯ2 ／Ａｌ2 Ｏ3 比の範囲
にあるゼオライト（△印及び□印）が、従来のもの（○
印）に対して小さな動力原単位で空気から酸素を分離で
きたことが分かる。The above three types of nitrogen adsorbents were compared for the results of separating oxygen and nitrogen from air under the above operating conditions. FIG. 2 is a graph showing the relationship between adsorption pressure and power consumption rate. The horizontal axis represents the adsorption pressure P 0 (ata), and the vertical axis represents 1N.
Power consumption required to produce m 3 / h of oxygen (KWh /
It is Nm 3 (oxygen). And, the temperature of the adsorption tower is 20 ° C,
Desorption pressure P 1 is 0.2 ata, tower space velocity U is 0.8 c
m / sec (outlet standard) and adsorption column pressure 1.5
The power consumption was examined by changing the power consumption to 4.5 ata. In the figure,
○ marks are Na-X with a SiO 2 / Al 2 O 3 ratio of 2.7, Δ marks are Na-X with a SiO 2 / Al 2 O 3 ratio of 2.5, and □ marks are S.
This is for Na-X having an iO 2 / Al 2 O 3 ratio of 2.0. As is clear from FIG. 2 (the same applies to FIGS. 3 to 5), the zeolites (Δ mark and □ mark) in the range of the SiO 2 / Al 2 O 3 ratio of the present invention are conventional (○).
It can be seen that oxygen can be separated from the air with a small power unit for the mark ().
【００１４】図３は、脱着圧力と動力原単位の関係を示
したグラフである。横軸は脱着圧力Ｐ1 （ａｔａ）、縦
軸は１Ｎｍ3 ／ｈの酸素を製造するに必要な消費電力
（ＫＷｈ／Ｎｍ3 （酸素）である。そして、吸着圧力Ｐ
0 は図２で有効性を確認した領域にある１．５ａｔａと
し、塔空間速度Ｕを０．８ｃｍ／ｓｅｃ（出口基準）、
温度を２０℃に設定し、脱着圧力Ｐ1 を０．１〜０．５
ａｔａに変化させて消費電力を調べた。図３から明らか
なように、本発明のＳｉＯ2 ／Ａｌ2 Ｏ3 比の範囲にあ
るゼオライト（△印及び□印）が、従来のもの（○印）
に対して小さな動力原単位で空気から酸素を分離できた
ことが分かる。脱着圧力に関連して特異的な現象は見だ
されなかったが、窒素吸着剤を用いた酸素製造の動力原
単位が０．２５ＫＷｈ／Ｎｍ3 （酸素）近傍を下限と
し、また、深冷分離方法の酸素製造の動力原単位が０．
４５〜０．６ＫＷｈ／Ｎｍ3 （酸素）であることを考慮
すると、図３から実用的な脱着圧力は、０．０８〜０．
５ａｔａ、特に、０．１〜０．３ａｔａ近傍が好ましい
ことが分かる。FIG. 3 is a graph showing the relationship between desorption pressure and power consumption. The horizontal axis represents the desorption pressure P 1 (ata), and the vertical axis represents the power consumption (KWh / Nm 3 (oxygen) required to produce 1 Nm 3 / h of oxygen.
0 is 1.5 at which the effectiveness is confirmed in FIG. 2, the tower space velocity U is 0.8 cm / sec (exit standard),
Set the temperature to 20 ° C and set the desorption pressure P 1 to 0.1 to 0.5.
The power consumption was examined by changing to ata. As is clear from FIG. 3, the zeolite (Δ mark and □ mark) in the range of the SiO 2 / Al 2 O 3 ratio of the present invention is the conventional one (◯ mark).
On the other hand, it can be seen that oxygen can be separated from air with a small power unit. Although no specific phenomenon was found in relation to desorption pressure, the lower limit of the power unit of oxygen production using a nitrogen adsorbent was around 0.25 KWh / Nm 3 (oxygen), and cryogenic separation The power consumption rate of oxygen production in the method is 0.
Considering that it is 45 to 0.6 KWh / Nm 3 (oxygen), the practical desorption pressure is 0.08 to 0.
It can be seen that 5 ata, especially 0.1 to 0.3 at around is preferable.
【００１５】次いで、吸着塔を冷却条件に導き低温条件
下での吸着分離を試みた。これは、低温条件に設定する
ことにより吸着量の上昇が一般に起こるので、吸着時の
破過帯が縮少し、装置の小型化と分離効率の向上が期待
できるためである。操作条件は、吸着圧力Ｐ0 を１．５
ａｔａ、再生圧力Ｐ1 を０．２ａｔａ、塔空間速度Ｕを
０．８ｃｍ／ｓｅｃ（出口基準）に設定し、吸着塔温度
を漸次低温に下げて１Ｎｍ3 ／ｈの酸素を製造するとき
の動力原単位を調べた。図４は、吸着塔温度と動力原単
位の関係を示したグラフである。横軸は吸着塔温度
（℃）、縦軸は１Ｎｍ3 ／ｈの酸素を製造するに必要な
消費電力（ＫＷｈ／Ｎｍ3 （酸素）である。図４から明
らかなように、全温度領域で、本発明のＳｉＯ2 ／Ａｌ
2 Ｏ3 比の範囲にあるゼオライト（△印及び□印）が、
従来のもの（○印）に対して小さな動力原単位で空気か
ら酸素を分離できたことが分かる。これは、従来のゼオ
ライトで１Ｎｍ3 ／ｈの酸素を製造するに必要な動力原
単位０．２５ＫＷｈを４０％低減し得ることとなる。ま
た、本発明のゼオライトは−６０℃までの吸着塔温度領
域で動力原単位を調べたが、空気の吸着分離に関して特
に問題はなく、一成分系のデータによると、−１００℃
程度でもその有効性は失われない。なお、それより低い
温度では、窒素吸着時の酸素の共吸着を無視することが
できないので、好ましくない。冷却手段は、特にこの温
度領域では問題はなく、深冷分離装置の冷却技術を用い
ることができる。Next, the adsorption tower was introduced into a cooling condition to attempt adsorption separation under low temperature conditions. This is because the adsorption amount generally increases by setting the temperature at low temperature, so that the breakthrough zone at the time of adsorption is reduced, and miniaturization of the device and improvement of separation efficiency can be expected. The operating condition is that the adsorption pressure P 0 is 1.5.
ata, regeneration pressure P 1 is 0.2 ata, tower space velocity U is set to 0.8 cm / sec (outlet standard), power for producing 1 Nm 3 / h of oxygen by gradually lowering the adsorption tower temperature to a low temperature. I checked the basic unit. FIG. 4 is a graph showing the relationship between adsorption tower temperature and power consumption. The horizontal axis is the adsorption tower temperature (° C.), the vertical axis represents the power consumption necessary to produce the oxygen 1Nm 3 / h (KWh / Nm 3 ( oxygen). As apparent from FIG. 4, the entire temperature range , SiO 2 / Al of the present invention
Zeolite in the range of 2 O 3 ratio (marked with △ and □)
It can be seen that oxygen can be separated from air with a smaller power consumption unit than the conventional one (marked with ○). This means that it is possible to reduce the power consumption unit 0.25 KWh required for producing 1 Nm 3 / h of oxygen by the conventional zeolite by 40%. Further, the zeolite of the present invention was examined for power consumption in the adsorption tower temperature range up to -60 ° C, but there was no particular problem with respect to adsorption / separation of air, and according to the data of one component system, -100 ° C.
Even to a degree, its effectiveness is not lost. It should be noted that if the temperature is lower than that, co-adsorption of oxygen at the time of nitrogen adsorption cannot be ignored, which is not preferable. The cooling means has no problem particularly in this temperature range, and the cooling technology of the deep-chill separator can be used.
【００１６】以上、主に動力費を中心に検討したが、次
に初期設備費について検討する。操作条件は、吸着圧力
Ｐ0 を１．５ａｔａ、再生圧力Ｐ1 を０．２ａｔａ、塔
空間速度Ｕを０．８ｃｍ／ｓｅｃ（出口基準）に設定
し、１Ｎｍ3 ／ｈの酸素を製造するのに必要な吸着剤量
を調べた。図５は、吸着塔温度と上記の吸着剤量との関
係を示したグラフであり、図中、横軸は吸着塔温度、縦
軸は１Ｎｍ3 ／ｈの酸素を製造するのに必要な吸着剤量
（Ｋｇ）である。図５から明らかなように、従来のゼオ
ライト（○印）は低温にしても、吸着剤量を室温の場合
の４５％程度しか節約できないのに対し、本発明のＳｉ
Ｏ2 ／Ａｌ2 Ｏ3 比の範囲にあるゼオライト（△印及び
□印）では吸着塔温度−３０℃で６５％程度節約するこ
とができる。吸着剤は、装置費のかなりの部分を占める
ので、上記の低減は極めて大きな効果である。The above description has been mainly focused on the power cost, but next, the initial equipment cost will be considered. The operating conditions are as follows: adsorption pressure P 0 is 1.5 ata, regeneration pressure P 1 is 0.2 ata, column space velocity U is 0.8 cm / sec (outlet standard), and 1 Nm 3 / h of oxygen is produced. The amount of adsorbent required for the test was investigated. FIG. 5 is a graph showing the relationship between the adsorption tower temperature and the amount of the adsorbent, in which the horizontal axis represents the adsorption tower temperature and the vertical axis represents the adsorption required to produce 1 Nm 3 / h of oxygen. It is the dose (Kg). As is clear from FIG. 5, the conventional zeolite (circle) can save only about 45% of the adsorbent amount at room temperature even at a low temperature, while the Si of the present invention can be saved.
Zeolites in the range of O 2 / Al 2 O 3 ratio (marked with Δ and □) can save about 65% at an adsorption tower temperature of −30 ° C. Since the adsorbent occupies a considerable part of the equipment cost, the above reduction is extremely effective.
【００１７】このように、本発明は、ＳｉＯ2 ／Ａｌ2
Ｏ3 比２．０〜２．５に調整されたＮａ−Ｘ型ゼオライ
トを使用し、吸着工程の圧力を３ａｔａ以下とし、脱着
工程の圧力を０．０８〜０．５ａｔａの低圧領域で、室
温以下の温度域で混合気体、例えば空気から圧力スィン
グ式吸着分離方法で酸素と窒素を分離すれば、毎時１Ｎ
ｍ3 の酸素を製造するのに必要な動力原単位が、深冷分
離方法で０．４５〜０．６ＫＷであり、現在実施されて
いる圧力スィング式吸着分離方法で０．２５ＫＷ以上要
していたものから一挙に０．１５ＫＷ近傍まで低減する
ことができ、かつ、吸着剤使用量も現行の方法の３５％
まで低減することができた。As described above, according to the present invention, SiO 2 / Al 2
Using Na-X type zeolite adjusted to an O 3 ratio of 2.0 to 2.5, the pressure of the adsorption step is set to 3 ata or less, and the pressure of the desorption step is set to 0.08 to 0.5 at a low pressure region at room temperature. If oxygen and nitrogen are separated from a mixed gas, such as air, by the pressure swing adsorption separation method in the following temperature range,
The power unit required for producing m 3 of oxygen is 0.45 to 0.6 kW in the deep-chill separation method, and 0.25 kW or more is required in the pressure swing adsorption separation method currently in use. It is possible to reduce to 0.15KW at once, and the amount of adsorbent used is 35% of the current method.
Could be reduced to.
【００１８】[0018]
【発明の効果】本発明は、上記の構成を採用することに
より、従来の圧力スィング式吸着分離方法と比べて、動
力原単位及び吸着剤量を大幅に低減することができるよ
うになった。According to the present invention, by adopting the above-mentioned constitution, it becomes possible to greatly reduce the power consumption rate and the amount of the adsorbent as compared with the conventional pressure swing adsorption separation method.
【図１】本発明の圧力スィング式吸着分離方法を実施す
るための装置の概念図である。FIG. 1 is a conceptual diagram of an apparatus for carrying out the pressure swing adsorption separation method of the present invention.
【図２】実施例における吸着圧力と動力原単位の関係を
示したグラフである。FIG. 2 is a graph showing the relationship between adsorption pressure and power consumption rate in an example.
【図３】実施例における脱着圧力と動力原単位の関係を
示したグラフである。FIG. 3 is a graph showing a relationship between a desorption pressure and a power consumption unit in an example.
【図４】実施例における吸着温度と動力原単位の関係を
示したグラフである。FIG. 4 is a graph showing a relationship between an adsorption temperature and a power consumption unit in an example.
【図５】実施例における吸着温度と１Ｎｍ3 ／ｈの酸素
を製造するのに必要な吸着剤量との関係を示したグラフ
である。FIG. 5 is a graph showing the relationship between the adsorption temperature and the amount of adsorbent required to produce 1 Nm 3 / h of oxygen in the examples.
２ 圧縮機、 ４ 脱湿脱二酸化炭素塔、 ８ 吸着
塔、 １３ 製品酸素タンク、 １５ 減圧弁、 １８
真空ポンプ、 １９ 熱交換器、 ２０ 圧縮式冷凍
機、 ２２ 熱交換器。2 compressor, 4 dehumidification decarbonization tower, 8 adsorption tower, 13 product oxygen tank, 15 pressure reducing valve, 18
Vacuum pump, 19 heat exchanger, 20 compression refrigerator, 22 heat exchanger.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 大嶋 一晃 長崎県長崎市飽の浦町１番１号 三菱重工 業株式会社長崎造船所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuaki Oshima 1-1 1-1 Atsunoura-machi, Nagasaki-shi, Nagasaki Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard Co., Ltd.
Claims (1)
に調整されたＮａ−Ｘ型ゼオライトを充填した少なくと
も２塔の吸着塔を使用し、酸素及び窒素を主成分とする
混合気体を、室温以下の低温で、かつ大気圧以上３ａｔ
ａ以下の圧力で一方の吸着塔に流入させ、混合気体から
窒素を選択的に吸着させ、高純度酸素又は酸素富化ガス
を回収し、他方の吸着塔を０．０８〜０．５ａｔａに減
圧して吸着剤を再生し、窒素を排出することを特徴とす
る混合気体から酸素と窒素を分離する方法。1. A SiO 2 / Al 2 O 3 ratio of 2.0 to 2.5.
The mixed gas containing oxygen and nitrogen as main components is used at a low temperature not higher than room temperature and at a pressure not lower than atmospheric pressure for 3 atm by using at least two adsorption towers packed with Na-X type zeolite adjusted to
Flow into one adsorption tower at a pressure of a or less, selectively adsorb nitrogen from the mixed gas, recover high-purity oxygen or oxygen-enriched gas, and depressurize the other adsorption tower to 0.08 to 0.5 ata. Then, the adsorbent is regenerated and nitrogen is discharged, so that oxygen and nitrogen are separated from the mixed gas.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4008950A JPH05192528A (en) | 1992-01-22 | 1992-01-22 | Method for separating oxygen and nitrogen from gaseous mixture |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4008950A JPH05192528A (en) | 1992-01-22 | 1992-01-22 | Method for separating oxygen and nitrogen from gaseous mixture |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05192528A true JPH05192528A (en) | 1993-08-03 |
Family
ID=11706955
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4008950A Pending JPH05192528A (en) | 1992-01-22 | 1992-01-22 | Method for separating oxygen and nitrogen from gaseous mixture |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05192528A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5614000A (en) * | 1995-10-04 | 1997-03-25 | Air Products And Chemicals, Inc. | Purification of gases using solid adsorbents |
| JP2012190768A (en) * | 2011-02-25 | 2012-10-04 | Kurita Water Ind Ltd | Gas injection preventing material of secondary battery, gas injection preventing system, and secondary battery system using it |
| JP2014055094A (en) * | 2012-09-14 | 2014-03-27 | Japan Pionics Co Ltd | Ammonia purification apparatus, and regeneration method thereof |
-
1992
- 1992-01-22 JP JP4008950A patent/JPH05192528A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5614000A (en) * | 1995-10-04 | 1997-03-25 | Air Products And Chemicals, Inc. | Purification of gases using solid adsorbents |
| JP2012190768A (en) * | 2011-02-25 | 2012-10-04 | Kurita Water Ind Ltd | Gas injection preventing material of secondary battery, gas injection preventing system, and secondary battery system using it |
| JP2014055094A (en) * | 2012-09-14 | 2014-03-27 | Japan Pionics Co Ltd | Ammonia purification apparatus, and regeneration method thereof |
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