201109077 六、發明說明： 【發明所屬之技術領诚】 本發明是有關惰性氣體之純化方法及其裝置。具體 上，本發明是有關在半導體製造等所使用之包含氮氣、氬 氣之稀有氣體等惰性氣體中’除去其所含有之氫氣、一氧 化碳、二氧化碳、氧氣及水’而純化該惰性氣體之方法及 其裝置。 本申請案係根據2〇09年2月24日於日本提出之特願 2009-041033號而主張慶先權’並援用其内容於此。 【先前技術】 在半導體製造步驊中係使用大I之氮氣、氬氣等惰性 氣體。此等惰性氣體係使用極冷式二氣分離I置(cryogenic air separation unit)製造。以該刀離裝置製造之惰性氣體中 含有ppm至ppb等級的氫氣、一氧化碳、二氧化碳、氧氣 及水等作為雜質。 然而，近年隨著半導體的尚積體化，在半導體製造步 驟中，由於期望使用之惰性氣體中的雜質濃度在ppb以 下，故必需更進一步純化氣體。又，由於隨著近年半導體 工廠之大規模化，氣體之使用量也大幅增加，故增加大型 純化設備之導入。另一方面’因為半導體之價格競爭激烈， 而強烈期望能降低純化設備之成本。 作為將此等適於製造半導體之惰性氣體中之微量雜 質予以除去而純化該惰性氣體的方法，在曰本特許心 2741622號公報中係揭示藉由錯除氣劑(zirconium getter) 3 321736 201109077 而除去雜質的方法。 然而，在此方法中，锆除氣劑因為是高價品且無法再 生，而有所謂的不適合大量氣體純化之問題。 又，在日本特許第2602670號公報中，係揭示藉由還 原金屬而除去氧氣及一氧化碳，接著藉由沸石等吸附劑而 除去二氧化碳與水之方法。 此純化方法中，雖可使吸附後之還原金屬藉由氫氣而 再生並再利用，但沸石之ppb等級之分壓中的二氧化碳吸 附量非常少。因此，在大量之氣體純化時裝置必須大型化， 而成為成本提南的原因。 在曰本特許第3462604號公報中，係揭示藉由氧化鋅 除去二氧化碳後，經由鎳觸媒或銅觸媒而除去一氧化碳， 更進一步藉由合成沸石而除去水之方法。 就此純化方法而言，在鎳觸媒中吸附一氧化碳、氧氣 時，於該觸媒作用下會產生微量之二氧化碳。因此，為了 使產生之二氧化碳再度吸附，必須大量充填合成沸石，結 杲吸附塔必須大型化，而有成本提高之不佳現象。 在日本特開平11-518號公報及日本特開2001-104737 號公報中，係揭示藉由氧化鋁除去二氧化碳。該二文獻皆 記載藉由在氧化鋁中含有鹼金屬、鹼土族金屬而增加氧化 鋁對二氧化碳之吸附量。 然而，該等文獻係以空氣中之二氧化碳，亦即400ppm 左右之高濃度二氧化碳作為除去對象，而未揭示關於將低 濃度二氧化碳予以吸附處理之見解。再者，在400ppm左 4 321736 201109077 右之高濃度二氧化碳的吸附處理中，由於沸石比氧化鋁吸 附更多二氧化碳，所以在以往之純化裝置中主要是使用沸 石。 又，在上述先前技術文獻中記載的方法，因為吸附劑 為高價品且同時吸附塔為大，故用以純化大量氣體的成本 亦變高。為此，殷切期望可有效純化大量氣體之方法。 [先前技術文獻]' 專利文獻1 專利文獻2 專利文獻3 專利文獻4 曰本特許第2741622號公報 曰本特許第2602670號公報 曰本特許第3462604號公報 曰本特開平11-518號公報 專利文獻5:日本特開2001-104737號公報 【發明内容】 (發明欲解決之課題） 因此，本發明之課題是提供將大量惰性氣體中之氫 氣、一氧化碳、二氧化碳、氧氣及水予以除去而純化該惰 性氣體的氣體純化方法，該方法可減少高價之锆除氣劑或 鎳觸媒等觸媒之使用量，並可削減純化成本。又，另一課 題是提供用以實施該氣體純化方法之小型簡潔（compact) 的氣體純化裝置。 (解決課題之手段） 為了解決相關課題， 本發明之第1態樣是將大量惰性氣體中之氫氣、一氧ί 化碳、二氧化碳、氧氣及水予以除去的氣體純化方法，其 5 321736 201109077 中，使前述惰性氣體與水分吸附劑接觸而除去水，同時將 惰性氣體之流動予以整流； 接著，使惰性氣體與鎳觸媒接觸而除去氫氣、一氧化 碳及氧氣； 進一步，使惰性氣體與氧化Is接觸而除去二氧化碳； 並且使惰性氣體之流動成為向下流動（down-flow); 然後將該氣體流速設成在理論上充填劑發生流動化 之速度以上者。 本發明中，前述惰性氣體中之二氧化碳的分壓係以在 19 Pa以下為佳。 本發明中，前述氧化鋁中以含有鈉0.1至10重量％ 為佳。 本發明中，前述氣體流速係以空塔速度設在31至100 cm/秒為佳。 本發明之第2態樣是將大量惰性氣體中之氫氣、一氧 化碳、二氧化碳、氧氣及水予以除去的氣體純化製置，其 具備： 從前述惰性氣體之流入側往流出側依序充填有水分 吸附劑、鎳觸媒及氧化鋁的吸附塔。 本發明中，「大量惰性氣體」是指每1小時之流量在 1000至100000 Nm3/小時之範圍的惰性氣體。又，惰性 氣體可列舉如氮氣及氬氣等稀有氣體。又，「整流」是指在 與吸附塔内之氣體流動方向呈垂直的面内，所有位置之間 的流速變動值為±1 cm/秒以内之意。 6 321736 201109077 (發明效果) 依照本發明，因為將被純化氣體藉由向下流動而以高 流速流動，故即使在1000至100000 Nm3/小時之大量被 純化氣體流動時也不需要將吸附塔製成大口徑。 又’當氣體流速為高速時，在吸附塔的上部空間會發 生壓力分佈’在吸附層内會發生氣體偏流現象。在該偏流 部無法充分除去雜質，導致有不能有效地利用吸附劑之問 題發生。然而，在前段中充填水分吸附劑，藉由該水分吸 附劑進行整流，同時也除去水分，因而可有效利用鎳觸媒， 並可減少其充填量。結果能降低成本。 _藉由氧化鋁除去二氧化碳。即使在被純化氣體中之二 =化奴的分壓為i9 pa以下之條件，亦即在被純化氣體中 t有微量時，也會將被純化氣體之流動予以整流，因而可 ^由比目前為止更小型之吸附塔而有效地除去二氧化碳。 :述氧化財若含麵’财藉由更小型之吸附塔除去二 氧1化。 山在鎳觸媒上’―氧化碳與氧反應而產生微量之二氧化 ，由於水刀口及附劑會共σ及附㈣adsco叫二氧化石炭盥 氣:所以在氮氣中幾乎沒有低分壓二氧化碳之吸附能/力。 於疋、為了吸附二氧化碳，必需充填大量之沸石。 然而，藉由使氮氣中之低分壓二氧化碳之吸附能 的含鈉之活性氧化㈣附該微量之二氧化碳 減少吸附劑之量。 」穴巾田度 【實施方式】 [ 321736 7 201109077 第1圖是表示本發明之氣體純化裝置之一例者。 在第1圖中，符號1A及1B表示吸附塔。該吸附塔 1A (1B)係在其内部從上方起積層有經充填水分吸附劑的 水分吸附劑層2、經充填鎳觸媒的鎳觸媒層3、與經充填氧 化銘的氧化銘層4，且以使被純化氣體從上方通過水分吸 附劑層2與鎳觸媒層3與氧化鋁層4並往下方流動之方式 (向下流動）而構成。 又，當一邊之吸附塔1A在進行吸附步驟時，另一邊 之吸附塔1B則進行再生步驟，藉由閥V1、V2、V3· · · V8之開關，使兩吸附塔互相交替運轉。 又，設置將再生用氣體加熱之加熱器5，並以使經加 熱之再生用氣體從吸附塔1A(1B)之底部向上方流入之方 式而構成。再生用氣體係使用氫氣與惰性氣體之混合氣體 或惰性氣體，惰性氣體係利用純化後之氣體之一部分。 前述水分吸附劑係使用活性氧化鋁、矽膠、合成沸石 等。 前述鎳觸媒係使用在活性氧化鋁、矽藻土、活性炭等 載體擔載有鎳金屬10至90重量％而成之觸媒。該觸媒是 藉由氫氣進行還原處理，再在氮氣等惰性氣體之存在下進 行加熱處理而可再使用者。 前述氧化鋁係使用含有鈉1至10重量％的7-氧化 鋁。 相較於沸石，前述氧化鋁在吸附二氧化碳之方面上之 有利點有3個。 321736 201109077 '' 第1個有利點是低分壓二氧化碳之吸附能力比沸石 高。 第2圖表示將沸石與氧化鋁的低分壓二氧化碳吸附量 ' 予以比較之圖。二氧化碳吸附量的測定係藉由使用定容量 式氣體吸附量測定裝置，在溫度設定為定溫25°C，且同時 任意設定壓力而進行。由第2圖可知，在二氧化碳為19 Pa 以下時，氧化鋁的二氧化碳吸附量比沸石的二氧化碳吸附 量多。 第2個有利點是在二氧化碳的吸附中沒有氮氣之影 響。 一般由於沸石之氮氣吸附能力亦高，尤其在以沸石純 化氮氣時，已知二氧化碳的吸附量會變少。 第3個有利點是在氧化鋁含有鈉時，二氧化碳的吸附 量變多。 相較於不含鈉之氧化鋁，含鈉之氧化鋁的二氧化碳吸 附量較多。如第3圖所示，已知在氧化銘中含有納1至10 重量％時二氧化碳吸附量變多。二氧化碳吸附量之測定是 使用定容量式氣體吸附量測定裝置，設定成溫度25°C、壓 力IPa而進行。 從深冷式空氣分離裝置所導出之1〇〇〇至100000 Nm3 /小時的氮氣、氬氣等被純化氣體，係從管6通過閥VI 而導入到吸附塔1A之上部。在該被純化氣體中含有ppm 至ppb等級之氫氣、一氧化碳、二氧化竣、氧氣及水分等[ 作為雜質。被純化氣體中之二氧化碳，係以分壓在19 Pa 9 321736 201109077 以 ，且其含量為微量為佳。 被純化氣體之流迷係設成在空塔速度為31至ι〇〇 /秒。當未達31 cm/秒時，吸附塔之直徑變大，導cm 置大型化而提高成本’當超過1〇〇 cm/秒時，導 致敦 塔内之被純化氣體的壓力損失變太大，被純化痛]°及附 尔L瑕的壓士 會變低。 刀 氣體純化裝置中’吸附塔内之純化氣體的流動〜 向上流動(up-flow)，但當空塔速度為μ 秒 叙是 上時充 填劑會發生流動化而無法充分進行氣體純化，因此， 本^發 明是以使流速變快且同時向下流動來進行純化。 第4圖是表示當使用直徑1.6 mm之球狀氧化鋁並以 充填密度780 kg/m3、空隙率0.41、厚度i〇〇mm而形成 氧化鋁層4時的空塔速度與（△p/d/gb之關係的曲線 圖。氧化鋁不流動之空塔速度可使用通過多孔質媒體之流 動所常用的Ergun式來推算。Ergun式中，Δρ為壓力損失， L是充填層厚度，GB是充填密度。 在氧化鋁層4中所充填之氧化鋁不流動的條件為（Δρ /L)/GB$1，故在此例中之氧化鋁不流動之空塔速度成 為31 cm/秒以下。因此，在31 cm//秒以上則必需採用 向下流動。 該被純化氣體首先流入最上段之水分吸附劑層2中， 此處，在雜質中，於水分被吸附、除去的同時亦將被純化 氣體之偏流予以整流。 被純化氣體以31至100 cm/秒之高流速流入到吸附 321736 10 201109077 塔1A的上方時，在水分吸附劑層2之上方產生被純化氣 體之偏流，氣體變得無法均勻地流入水分吸附劑層2，在 水分吸附劑層2之表層中，局部性地產生流速快之部分與 慢之部分，其流速差有時會變成5 cm/秒左右。 在該被純化氣體流過水分吸附劑層2内之水分吸附劑 粒子間的途中，流速差會變小。亦即，水分吸附劑層2發 揮整流機能。被純化氣體從水分吸附劑層2流出時，其流 速差變成1 cm/秒以下，且成為偏流經整流之狀態，而流 入次段之錄觸媒層3中。 被純化氣體因均勻地流入鎳觸媒層3内.，故存在之鎳 觸媒會整體有助於除去氫氣、氧氣、一氧化碳。 相對於此，當被純化氣體以偏流狀態直接流入鎳觸媒 層3時，被純化氣體與鎳觸媒粒子之接觸不能均勻地進. 行。而欲充分地除去雜質時，就有必要增加鎳觸媒層3之 厚度，導致需使用多量之高價之鎳觸媒，使成本變高。 接著，被純化氣體以經整流之狀態流入鎳觸媒層3 中。在此，除去作為雜質的氫氣、氧氣、一氧化碳。同時， 一部分之一氧化碳與氧氣反應，而生成微量之二氧化碳。 進一步，從鎳觸媒層3流出之被純化氣體係被導入氧 化鋁層4中，在此，作為雜質的二氧化碳與在鎳觸媒層3 中生成的二氧化碳係被吸附、除去。 於是，從氧化鋁層4流出之被純化氣體係變成已除去 氫氣、一氧化碳、二氧化碳、氧氣及水且該等雜質之濃良 t 為ppb等級以下之純化氣體。該純化氣體經過閥V7、管7 11 321736 201109077 導出而作為製品氣體。 將被純化氣體以預定時間導入吸附塔1A中之後，操 作閥VI至V8之開關，使被純化氣體從管6通過閥V2改 導入吸附塔1B，在吸附塔1B中進行與前述相同之吸附步 驟，將來自吸附塔1B底部之純化氣體從閥V8、管7導出 而作為製品氣體。 另一方面’吸附塔1A則進行再生步驟。 在再生步驟中，將從管8供給之氫氣與因管9而分歧 的氮氣、氬氣等純化氣體予以混合，而得到氫氣濃度2至 5 vol%之混合氣體，將其送入加熱器5中，在至 °C中加熱後，經過管10、閥V5而導入吸附塔丨八之底部， 使其向上方流動。 藉由該加熱混合氣體之導入，而使氧化鋁層4所吸附 的，氧傾脫附’在_媒層3所吸_氧氣、—氧化碳 則藉由氫氣而還原並脫附，在水分吸附劑層2所吸附的水 分亦脫附。以含有所脫附之雜質的混合氣#作排氣，將盆 從吸附塔iA之上部經由閥V3、管u排出系統外。 如此而完成再生之吸附塔1A’則等待下次之吸附步 一一…1B則進行再 吸附塔1A再度進行吸啦也趣 .....201109077 VI. Description of the Invention: [Technology of the Invention] The present invention relates to a method and apparatus for purifying an inert gas. Specifically, the present invention relates to a method for purifying an inert gas by removing a hydrogen gas, carbon monoxide, carbon dioxide, oxygen, and water contained in an inert gas such as a rare gas containing nitrogen or argon used in semiconductor manufacturing or the like. Its device. This application is based on the Japanese Patent No. 2009-041033 filed on February 24, 2009 in Japan and advocates the right to use it. [Prior Art] In the semiconductor manufacturing step, an inert gas such as nitrogen or argon of a large I is used. These inert gas systems are produced using a cryogenic air separation unit. The inert gas produced by the knife-off device contains hydrogen, carbon monoxide, carbon dioxide, oxygen, water, and the like in an amount of ppm to ppb as an impurity. However, in recent years, as semiconductors have been integrated, in the semiconductor manufacturing step, since the concentration of impurities in the inert gas to be used is below ppb, it is necessary to further purify the gas. In addition, with the large-scale production of semiconductor plants in recent years, the use of gas has also increased significantly, so the introduction of large-scale purification equipment has increased. On the other hand, 'because of the fierce price competition of semiconductors, it is strongly expected to reduce the cost of purification equipment. A method for purifying the inert gas by removing a trace amount of impurities in an inert gas suitable for producing a semiconductor is disclosed in Japanese Patent No. 2741622 by a zirconium getter 3 321736 201109077 A method of removing impurities. However, in this method, since the zirconium degassing agent is expensive and cannot be regenerated, there is a problem that it is not suitable for purification of a large amount of gas. Further, Japanese Patent No. 2602670 discloses a method of removing oxygen and carbon monoxide by reducing a metal, and then removing carbon dioxide and water by an adsorbent such as zeolite. In this purification method, although the reduced metal after adsorption can be regenerated and reused by hydrogen gas, the amount of carbon dioxide adsorbed in the partial pressure of the ppb grade of the zeolite is very small. Therefore, when a large amount of gas is purified, the device must be enlarged, which is a cause of cost increase. Japanese Patent Publication No. 3462604 discloses a method of removing carbon monoxide by removing zinc oxide by a zinc catalyst or a copper catalyst, and further removing water by synthesizing zeolite. In this purification method, when carbon monoxide or oxygen is adsorbed in the nickel catalyst, a trace amount of carbon dioxide is generated by the catalyst. Therefore, in order to re-adsorb the generated carbon dioxide, a large amount of synthetic zeolite must be filled, and the adsorption tower must be enlarged, and the cost is not improved. It is disclosed in Japanese Laid-Open Patent Publication No. Hei 11-518 and JP-A No. 2001-104737 that carbon dioxide is removed by alumina. Both of these documents disclose increasing the amount of carbon dioxide adsorbed by aluminum oxide by containing an alkali metal or an alkaline earth metal in alumina. However, these documents use carbon dioxide in the air, i.e., a high concentration of carbon dioxide of about 400 ppm, as a removal target, and do not disclose the insight into the adsorption treatment of low-concentration carbon dioxide. Further, in the adsorption treatment of 400 ppm of the left 4 321736 201109077 right high concentration carbon dioxide, since the zeolite adsorbs more carbon dioxide than the alumina, the zeolite is mainly used in the conventional purification apparatus. Further, in the method described in the above prior art document, since the adsorbent is a high-priced product and the adsorption tower is large at the same time, the cost for purifying a large amount of gas is also high. For this reason, a method for efficiently purifying a large amount of gas is eagerly desired. [Prior Art Document] Patent Document 1 Patent Document 2 Patent Document 3 Patent Document 4 PCT Patent No. 2741622 曰 特许 第 260 260 260 560 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 5: JP-A-2001-104737 SUMMARY OF THE INVENTION (Problems to be Solved by the Invention) Therefore, an object of the present invention is to provide purification of hydrogen gas, carbon monoxide, carbon dioxide, oxygen, and water in a large amount of inert gas to purify the inertia. A method for purifying a gas, which can reduce the amount of use of a catalyst such as a high-priced zirconium degasser or a nickel catalyst, and can reduce the purification cost. Still another subject is to provide a compact, compact gas purification apparatus for carrying out the gas purification process. (Means for Solving the Problem) In order to solve the related problems, a first aspect of the present invention is a gas purification method for removing a large amount of hydrogen gas, carbon monoxide, carbon dioxide, oxygen, and water in an inert gas, which is 5 321736 201109077 The inert gas is contacted with the moisture adsorbent to remove water, and the flow of the inert gas is rectified; then, the inert gas is contacted with the nickel catalyst to remove hydrogen, carbon monoxide and oxygen; further, the inert gas is contacted with the oxidized Is The carbon dioxide is removed; and the flow of the inert gas is made to be down-flow; then the gas flow rate is set to be above the rate at which the filler fluidizes theoretically. In the present invention, the partial pressure of carbon dioxide in the inert gas is preferably 19 Pa or less. In the present invention, it is preferred that the alumina contains 0.1 to 10% by weight of sodium. In the present invention, the gas flow rate is preferably set at a superficial velocity of 31 to 100 cm/sec. According to a second aspect of the present invention, a gas for removing a large amount of hydrogen gas, carbon monoxide, carbon dioxide, oxygen, and water in an inert gas is purified, and the method includes: sequentially adsorbing moisture from the inflow side to the outflow side of the inert gas Adsorption tower for agent, nickel catalyst and alumina. In the present invention, "a large amount of inert gas" means an inert gas having a flow rate of from 1,000 to 100,000 Nm 3 /hr per hour. Further, examples of the inert gas include rare gases such as nitrogen and argon. Further, "rectifying" means that the flow velocity variation between all the positions is within ±1 cm/sec in a plane perpendicular to the flow direction of the gas in the adsorption tower. 6 321736 201109077 (Effect of the Invention) According to the present invention, since the purified gas flows at a high flow rate by flowing downward, it is not necessary to make the adsorption tower even when a large amount of purified gas flows at 1000 to 100000 Nm 3 /hour. Into a large diameter. Further, when the gas flow rate is high, a pressure distribution occurs in the upper space of the adsorption tower, and gas drift occurs in the adsorption layer. The impurities cannot be sufficiently removed in the bias portion, resulting in the problem that the adsorbent cannot be effectively used. However, in the preceding stage, the moisture adsorbent is filled, the water adsorbent is rectified, and moisture is also removed, so that the nickel catalyst can be effectively utilized and the amount of the filler can be reduced. The result is a reduction in costs. Remove carbon dioxide by alumina. Even if the partial pressure of the secondary chemical in the purified gas is i9 Pa or less, that is, when there is a trace amount of t in the purified gas, the flow of the purified gas is rectified, so that it can be A smaller adsorption tower effectively removes carbon dioxide. : The description of the oxidized wealth includes the removal of the dioxin by a smaller adsorption tower. The mountain reacts with carbon on the nickel catalyst to produce a small amount of oxidation. Since the water knife edge and the attached agent will be combined with the σ and the attached (4) adsco is called the carbon dioxide anthrax: there is almost no low partial pressure carbon dioxide in the nitrogen. Adsorption capacity. In order to adsorb carbon dioxide, it is necessary to fill a large amount of zeolite. However, the amount of adsorbent is reduced by oxidizing the sodium-containing activity of the adsorption energy of the low partial pressure carbon dioxide in nitrogen (4). [Kitchen Field] [Embodiment] [321736 7 201109077 Fig. 1 is a view showing an example of a gas purifying apparatus of the present invention. In Fig. 1, reference numerals 1A and 1B denote adsorption towers. The adsorption tower 1A (1B) is provided with a moisture adsorbent layer filled with a moisture adsorbent 2, a nickel catalyst layer 3 filled with a nickel catalyst, and an oxidized inscription layer 4 filled with an oxide oxide layer. Further, the purified gas is configured to flow downward from the upper side through the moisture adsorbent layer 2 and the nickel catalyst layer 3 and the aluminum oxide layer 4 (downward flow). Further, when the adsorption column 1A on one side performs the adsorption step, the adsorption column 1B on the other side performs the regeneration step, and the two adsorption columns are alternately operated by the switches of the valves V1, V2, V3, · V8. Further, a heater 5 for heating the regeneration gas is provided, and the heated regeneration gas is introduced upward from the bottom of the adsorption tower 1A (1B). The regenerative gas system uses a mixed gas of hydrogen and an inert gas or an inert gas, and the inert gas system utilizes a part of the purified gas. As the moisture adsorbent, activated alumina, tannin, synthetic zeolite or the like is used. The nickel catalyst is a catalyst obtained by supporting 10 to 90% by weight of nickel metal on a carrier such as activated alumina, diatomaceous earth or activated carbon. The catalyst is subjected to a reduction treatment by hydrogen gas and then heat-treated in the presence of an inert gas such as nitrogen to re-user. The above alumina system uses 7 to 10% by weight of sodium 7-aluminum oxide. Compared with zeolite, the foregoing alumina has three advantages in terms of adsorbing carbon dioxide. 321736 201109077 '' The first advantage is that the adsorption capacity of low partial pressure carbon dioxide is higher than that of zeolite. Fig. 2 is a graph showing the comparison of the amount of adsorption of low partial pressure carbon dioxide between zeolite and alumina. The measurement of the carbon dioxide adsorption amount is carried out by using a constant-capacity gas adsorption amount measuring device, setting the temperature to a constant temperature of 25 ° C while arbitrarily setting the pressure. As can be seen from Fig. 2, when the carbon dioxide is 19 Pa or less, the amount of carbon dioxide adsorbed by the alumina is larger than the amount of carbon dioxide adsorbed by the zeolite. The second advantage is that there is no effect of nitrogen in the adsorption of carbon dioxide. Generally, since the nitrogen adsorption capacity of the zeolite is also high, especially when the zeolite is purified by nitrogen, it is known that the adsorption amount of carbon dioxide becomes small. The third advantage is that when the alumina contains sodium, the amount of carbon dioxide adsorbed increases. Compared to sodium-free alumina, sodium-containing alumina has a higher amount of carbon dioxide adsorbed. As shown in Fig. 3, it is known that the amount of carbon dioxide adsorbed increases when the oxide contains 1 to 10% by weight. The measurement of the carbon dioxide adsorption amount was carried out by using a constant-capacity gas adsorption amount measuring device and setting the temperature to 25 ° C and the pressure IPa. The purified gas such as nitrogen gas or argon gas from 1 〇〇〇 to 100,000 Nm 3 /hr derived from the cryogenic air separation device is introduced into the upper portion of the adsorption tower 1A from the pipe 6 through the valve VI. The purified gas contains hydrogen, carbon monoxide, cerium oxide, oxygen, water, and the like in the ppm to ppb grade [as an impurity. The carbon dioxide in the purified gas is divided into 19 Pa 9 321736 201109077, and the content thereof is preferably trace. The stream of purified gas is set at a superficial velocity of 31 to ι〇〇 / sec. When it is less than 31 cm/sec, the diameter of the adsorption tower becomes larger, and the size of the guide tube is increased to increase the cost. When it exceeds 1 〇〇cm/sec, the pressure loss of the purified gas in the tunata becomes too large. The pressure of the purified pain] ° and the attached L瑕 will become lower. In the knife gas purification device, the flow of the purified gas in the adsorption tower is up-flow, but when the superficial velocity is μ seconds, the filler fluidizes and the gas cannot be sufficiently purified. The invention was carried out by purifying the flow rate while flowing downward. Figure 4 is a diagram showing the superficial velocity and (Δp/d) when a spherical alumina having a diameter of 1.6 mm is used and the alumina layer 4 is formed at a packing density of 780 kg/m3, a void ratio of 0.41, and a thickness of i〇〇mm. A graph of the relationship of /gb. The velocity of the empty tower in which alumina does not flow can be estimated using the Ergun formula commonly used for the flow of porous media. In the Ergun formula, Δρ is the pressure loss, L is the thickness of the filling layer, and GB is the filling. Density. The condition in which the alumina filled in the alumina layer 4 does not flow is (Δρ / L) / GB $ 1, so that the superficial velocity of the alumina in which the alumina does not flow in this example is 31 cm / sec or less. At 31 cm//sec or more, it is necessary to use a downward flow. The purified gas first flows into the uppermost moisture adsorbent layer 2, where the purified gas is also adsorbed and removed in the impurities. The biased flow is rectified. When the purified gas flows into the adsorption 321736 10 201109077 above the column 1A at a high flow rate of 31 to 100 cm/sec, a bias flow of the purified gas occurs above the moisture adsorbent layer 2, and the gas becomes inhomogeneous. Inflow into the moisture adsorbent layer 2, at In the surface layer of the adsorbent layer 2, a portion having a fast flow rate and a slow portion are locally generated, and the difference in flow velocity sometimes becomes about 5 cm/sec. The moisture flowing through the moisture adsorbent layer 2 in the purified gas In the middle of the sorbent particles, the flow velocity difference is small. That is, the moisture adsorbent layer 2 functions as a rectifying function. When the purified gas flows out of the moisture adsorbent layer 2, the flow velocity difference becomes 1 cm/sec or less and becomes a bias current. In the rectified state, it flows into the recording medium layer 3 of the second stage. Since the purified gas uniformly flows into the nickel catalyst layer 3, the nickel catalyst present helps to remove hydrogen, oxygen, and carbon monoxide as a whole. On the other hand, when the purified gas directly flows into the nickel catalyst layer 3 in a biased state, the contact between the purified gas and the nickel catalyst particles cannot be uniformly performed. To sufficiently remove the impurities, it is necessary to increase the nickel. The thickness of the catalyst layer 3 causes a large amount of expensive nickel catalyst to be used, which increases the cost. Then, the purified gas flows into the nickel catalyst layer 3 in a rectified state. Here, hydrogen as an impurity is removed. Oxygen, oxygen At the same time, a part of carbon monoxide reacts with oxygen to generate a small amount of carbon dioxide. Further, the purified gas system flowing out of the nickel catalyst layer 3 is introduced into the aluminum oxide layer 4, where carbon dioxide as an impurity and nickel are present. The carbon dioxide generated in the catalyst layer 3 is adsorbed and removed. Thus, the purified gas system flowing out of the alumina layer 4 becomes hydrogen gas, carbon monoxide, carbon dioxide, oxygen, and water, and the concentration of the impurities is ppb grade. The purified gas is exported as a product gas through a valve V7 and a pipe 7 11 321736 201109077. After the purified gas is introduced into the adsorption column 1A for a predetermined time, the valves VI to V8 are operated to switch the purified gas from the gas. The tube 6 is introduced into the adsorption column 1B through the valve V2, and the adsorption step is performed in the adsorption column 1B in the same manner as described above, and the purified gas from the bottom of the adsorption column 1B is led out from the valve V8 and the tube 7 as a product gas. On the other hand, the adsorption column 1A performs a regeneration step. In the regeneration step, the hydrogen gas supplied from the tube 8 is mixed with a purified gas such as nitrogen gas or argon gas which is branched by the tube 9, and a mixed gas having a hydrogen gas concentration of 2 to 5 vol% is obtained and sent to the heater 5. After heating to °C, it is introduced into the bottom of the adsorption tower through the tube 10 and the valve V5, and flows upward. By the introduction of the heated mixed gas, the oxygen adsorbed by the aluminum oxide layer 4 is desorbed, and the oxygen and carbon monoxide adsorbed in the dielectric layer 3 are reduced and desorbed by hydrogen gas in the moisture adsorption. The moisture adsorbed by the agent layer 2 is also desorbed. The mixture is evacuated with the mixed gas # containing the desorbed impurities, and the pot is discharged from the upper portion of the adsorption tower iA through the valve V3 and the tube u to the outside of the system. The adsorption tower 1A' which completes the regeneration in this way waits for the next adsorption step. One-to-one 1B is carried out. The adsorption tower 1A is again sucked again.
生步驟 10、閥 附塔1E 實施例 用氣體經過管 上方導入，再將來自吸 11排出系統外而進行。 321736 12 201109077 (實施例1) 在内徑100 mm之不銹鋼製圓筒内，自上方起形成厚 ' 度100 mm之沸石層（MS5 A)、厚度100 mm之鎳觸媒層 • (N112)、厚度100 mm之氧化IS層，並將其作為吸附塔使 用。 該吸附塔之各層係以下述條件進行再生。 首先，將含有氫氣濃度2 vol%的氮氣加熱到200°C並 以流量3Nm3/小時流動3小時，接著將氮氣加熱到2〇〇 °(：並以流量3Nm3/小時流動3小時後，予以冷卻。 然後’將含有1 ppm之氫氣、1 ppm之一氧化碳、〇.5 ppm之二氧化碳、1 ppm之氧氣、2.6ppm之水分的氮氣當 作被純化氣體，在壓力100 PaG、温度25°C、流速（空塔速 度）53 cm/秒、流量10 Nm3/小時之條件下以向下流動之 方式導入吸附塔内。 導入開始後，在經過24小時之時間點，氫氣係被檢 測為第1穿漏(breakthrough)成分。 (實施例2) 在内徑100 mm之不銹鋼製圓筒内，自上方起形成厚 度100 mm之沸石層（MS5A)、厚度1〇〇 mm之錄觸媒層 (N112)、厚度50 mm之以重量比5.8 %含鈉之氧化鋁層， 並將其作為吸附塔使用。 以與實施例1同樣之條件再生該吸附塔後，將與實施 例1同樣組成之被純化氣體以同樣之條件導入。 rStep 10: Valve Attachment Tower 1E Example The gas is introduced through the upper portion of the tube and then discharged from the suction system to the outside of the system. 321736 12 201109077 (Example 1) In a stainless steel cylinder with an inner diameter of 100 mm, a zeolite layer (MS5 A) having a thickness of 100 mm and a nickel catalyst layer having a thickness of 100 mm (N112) were formed from above. An oxidized IS layer of 100 mm thickness is used as an adsorption tower. Each layer of the adsorption tower was regenerated under the following conditions. First, nitrogen gas containing a hydrogen concentration of 2 vol% was heated to 200 ° C and flowed at a flow rate of 3 Nm 3 /hour for 3 hours, followed by heating nitrogen gas to 2 〇〇 ° (: and flowing at a flow rate of 3 Nm 3 / hour for 3 hours, and then cooled. Then 'take nitrogen containing 1 ppm of hydrogen, 1 ppm of carbon monoxide, 5.5 ppm of carbon dioxide, 1 ppm of oxygen, 2.6 ppm of water as the purified gas at a pressure of 100 PaG, a temperature of 25 ° C, a flow rate (vacant tower speed) 53 cm / sec, flow rate 10 Nm3 / hour under the conditions of downward flow into the adsorption tower. After the start of the introduction, after 24 hours, the hydrogen system is detected as the first leakage (Example 2) In a stainless steel cylinder having an inner diameter of 100 mm, a zeolite layer (MS5A) having a thickness of 100 mm and a recording medium layer (N112) having a thickness of 1 mm were formed from above. A sodium oxide-containing alumina layer having a thickness of 50 mm and a weight ratio of 5.8% was used as an adsorption tower. After the adsorption tower was regenerated under the same conditions as in Example 1, the purified gas having the same composition as in Example 1 was used. The same conditions are imported. r
L 導入開始後，在經過24小時之時間點，氫氣係被檢 13 321736 201109077 測為第1穿漏成分。 (比較例1) 在内徑100 mm之不銹鋼製圓筒内，自上方起形成厚 度100 mm之鎳觸媒層（N112)、厚度100 mm之沸石層 (MS5A)、厚度100 mm之氧化鋁層，並將其作為吸附塔使 用。 以與實施例1同樣之條件再生該吸附塔後，將與實施 例1同樣組成之被純化氣體以同樣之條件導入。 導入開始後，在經過18小時之時間點，氫氣係被檢 測為第1穿漏成分。 (比較例2) 在内徑100 mm之不銹鋼製圓筒内，自上方起形成厚 度50 mm之鎳觸媒層（Nil 2)、厚度50 mm之沸石層 (MS5A)、厚度50 mm之氧化鋁層，並將其作為吸附塔使 用。 該吸附塔之各層係以下述條件進行再生。 首先，將含有氫氣濃度2vol%的氮氣加熱到200°C並 以流量1.5 Nm3/小時流動3小時，接著將氮氣加熱到200 °(：並以流量1.5 Nm3/小時流動3小時後，予以冷卻。 然後，將含有1 ppm之氫氣、1 ppm之一氧化碳、0.5 ppm之二氧化碳、1 ppm之氧氣、2_6ppm之水分的氮氣當 作被純化氣體，在壓力100 PaG、溫度25°C、流速（空塔速 度)26.5 cm/秒、流量15 Nm3/小時之條件下以向下流動 之方式導入吸附塔内。 14 321736 201109077 * 導入開始後，在經過23小時之時間點，氫氣係被檢 測為第1穿漏成分。 ' (比較例3) • 在内徑100 mm之不銹鋼製圓筒内，自上方起形成厚 度100 mm之海石層（MS5A)、厚度100 mm之鎳觸媒層 (N112)、厚度50 mm之氧化鋁層，並將其作為吸附塔使用。 以與實施例1同樣之條件再生該吸附塔後，將與實施 例1同樣組成之被純化氣體以同樣之條件導入。 導入開始後，在經過13小時之時間點，二氧化碳係 被檢測為第1穿漏成分。 由實施例1與比較例1可知，在鎳觸媒層上形成沸石 層，則可增加鎳觸媒層之氫氣吸附量。 · 由實施例1與比較例1至2可知，當鎳觸媒層作為第 1層時，若被純化氣體之流速為低速，則氫氣之穿漏時間 長，但若變成高流速則穿漏時間變短，而可確認到高流速 所造成之影響。 由實施例2與比較例3可知，使用含鈉之氧化铭時， 未檢測到二氧化碳。 【圖式簡單說明】 第1圖表示本發明之氣體純化裝置之一例的概略構成 圖。 第2圖表示將沸石與本發明之氧化鋁的低分壓二氧化 碳吸附量予以比較的曲線圖。 r( L ·; 第3圖表示本發明之氧化鋁中所含之鈉量與二氧化碳 15 321736 201109077 吸附量的曲線圖。 第4圖表示本發明中氧化鋁層之空塔速度與Ergun式 中之（ΔΡ/ΙΟ/ΟΒ的曲線圖。 【主要元件符號說明】 ΙΑ, 1Β 吸附塔 2 水分吸附劑層 3 鎳觸媒層 4 氧化鋁層 5 加熱器 6至11 管 VI 至 V8 閥 16 321736After the introduction of L, at the point of 24 hours, the hydrogen gas was detected as 13 321736 201109077 as the first leakage component. (Comparative Example 1) A nickel catalyst layer (N112) having a thickness of 100 mm, a zeolite layer (MS5A) having a thickness of 100 mm, and an aluminum oxide layer having a thickness of 100 mm were formed from a stainless steel cylinder having an inner diameter of 100 mm. And use it as an adsorption tower. After the adsorption column was regenerated under the same conditions as in Example 1, the purified gas having the same composition as in Example 1 was introduced under the same conditions. After the start of the introduction, the hydrogen gas was detected as the first leak-through component at the time of 18 hours. (Comparative Example 2) A nickel catalyst layer (Nil 2) having a thickness of 50 mm, a zeolite layer (MS5A) having a thickness of 50 mm, and alumina having a thickness of 50 mm were formed from a stainless steel cylinder having an inner diameter of 100 mm. Layer and use it as an adsorption tower. Each layer of the adsorption tower was regenerated under the following conditions. First, nitrogen gas containing a hydrogen concentration of 2 vol% was heated to 200 ° C and flowed at a flow rate of 1.5 Nm 3 /hr for 3 hours, and then nitrogen gas was heated to 200 ° (: and flowed at a flow rate of 1.5 Nm 3 /hr for 3 hours, and then cooled. Then, nitrogen containing 1 ppm of hydrogen, 1 ppm of carbon monoxide, 0.5 ppm of carbon dioxide, 1 ppm of oxygen, and 2-6 ppm of water is used as the purified gas at a pressure of 100 PaG, a temperature of 25 ° C, and a flow rate (vacant tower speed). ) 26.5 cm / sec, flow rate of 15 Nm3 / hour into the adsorption tower in the downward flow. 14 321736 201109077 * After the introduction of the start, after 23 hours, the hydrogen system was detected as the first leak Ingredients. ' (Comparative Example 3) • In a stainless steel cylinder with an inner diameter of 100 mm, a sea-rock layer (MS5A) with a thickness of 100 mm, a nickel catalyst layer (N112) with a thickness of 100 mm, and a thickness of 50 are formed from above. The alumina layer of mm was used as an adsorption tower. After the adsorption tower was regenerated under the same conditions as in Example 1, the purified gas having the same composition as in Example 1 was introduced under the same conditions. After 13 hours Carbon dioxide was detected as the first leak-through component. It is understood from Example 1 and Comparative Example 1 that the formation of a zeolite layer on the nickel catalyst layer increases the amount of hydrogen adsorption of the nickel catalyst layer. In Comparative Examples 1 and 2, when the nickel catalyst layer is used as the first layer, if the flow rate of the purified gas is low, the hydrogen leakage time is long, but if the flow rate becomes high, the leak time becomes short, and it can be confirmed. From the results of the high flow rate, it can be seen from Example 2 and Comparative Example 3 that carbon dioxide is not detected when sodium-containing oxidation is used. [Schematic Description] Fig. 1 shows an example of the gas purification device of the present invention. Fig. 2 is a graph comparing the adsorption amount of zeolite with the low partial pressure carbon dioxide of the alumina of the present invention. r(L ·; Fig. 3 shows the amount of sodium contained in the alumina of the present invention. Carbon dioxide 15 321736 201109077 Graph of adsorption amount. Fig. 4 is a graph showing the superficial velocity of the alumina layer in the present invention and (ΔΡ/ΙΟ/ΟΒ in the Ergun formula. [Explanation of main components] ΙΑ, 1Β adsorption tower 2 moisture adsorption Agent layer 3 nickel catalyst layer 4 aluminum oxide layer 5 heater 6 to 11 tube VI to V8 valve 16 321736