JP2008273764A - Method for producing hydrogen using permselective membrane reactor - Google Patents

Method for producing hydrogen using permselective membrane reactor Download PDF

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JP2008273764A
JP2008273764A JP2007116956A JP2007116956A JP2008273764A JP 2008273764 A JP2008273764 A JP 2008273764A JP 2007116956 A JP2007116956 A JP 2007116956A JP 2007116956 A JP2007116956 A JP 2007116956A JP 2008273764 A JP2008273764 A JP 2008273764A
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hydrogen
reforming reaction
reaction
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reforming
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JP5183962B2 (en
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Nobuhiko Mori
伸彦 森
Toshiyuki Nakamura
俊之 中村
Manabu Yoshida
学 吉田
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NGK Insulators Ltd
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing hydrogen capable of efficiently producing high purity hydrogen using a permselective membrane reactor. <P>SOLUTION: The method for producing hydrogen uses a reforming reaction wherein a permselective membrane reactor having a structure in which a reforming reaction part for reforming a raw material gas and a separation part for transferring hydrogen separated from a reaction gas formed by the reforming reaction are assembled across a permselective membrane 5 is used, and includes a process of supplying the raw material gas into the reforming reaction part, a process of reforming the raw material gas at the reforming reaction part in which a reforming reaction catalyst 6 is installed and forming a reaction gas containing hydrogen and a process of separating hydrogen from the reaction gas by the permselective membrane 5 to the separation part side. The permselective membrane 5 is a membrane containing palladium with a membrane thickness of 10 μm or less and the pressure of the reforming reaction part is controlled in measuring the purity of hydrogen at the separation part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、選択透過膜型反応器を用いた水素の製造方法に関する。さらに詳しくは、水素の分離性能に優れた選択透過膜を備え、改質反応の促進性に優れた選択透過膜型反応器を用いることによって、高純度の水素を回収することが可能な水素の製造方法に関する。   The present invention relates to a method for producing hydrogen using a selectively permeable membrane reactor. More specifically, a hydrogen permeable membrane that is capable of recovering high-purity hydrogen by using a permselective membrane reactor that is equipped with a permselective membrane that has excellent hydrogen separation performance and that is excellent in promoting the reforming reaction. It relates to a manufacturing method.

水素は石油化学の基本素材ガスとして大量に使用され、特に近年、燃料電池等の分野において、クリーンなエネルギー源として水素が注目されていることとも相俟って、利用の拡大が期待されている。このような目的に使用される水素は、メタン、ブタン、灯油等の炭化水素やメタノール、エタノール、ジメチルエーテル等の酸素を含む有機化合物(含酸素有機化合物)を主たる原料として、水蒸気や二酸化炭素の改質反応、あるいは部分酸化反応、分解反応等を利用して生成され、それをパラジウム合金膜等の水素を選択的に透過させることのできる選択透過膜にて分離し回収することにより得られる。   Hydrogen is used in large quantities as a basic raw material gas for petrochemicals, and in recent years, especially in the field of fuel cells and the like, hydrogen is attracting attention as a clean energy source. . Hydrogen used for such purposes is mainly made from hydrocarbons such as methane, butane, and kerosene, and organic compounds containing oxygen (oxygen-containing organic compounds) such as methanol, ethanol, and dimethyl ether. It is produced by using a quality reaction, a partial oxidation reaction, a decomposition reaction, etc., and is obtained by separating and recovering it with a permselective membrane that can selectively permeate hydrogen, such as a palladium alloy membrane.

近年、この水素の製造には、前記のような水素の生成反応と分離とを同時に行うことのできる選択透過膜型反応器(メンブレンリアクタ)が使用される(例えば、特許文献1参照)。従来一般的に使用されている選択透過膜型反応器は、一端部がガス入口で、他端部がガス出口である反応管と、当該反応管内に挿入された、表面に水素を選択的に透過させる選択透過膜が形成された基材部分が多孔質の分離管と、炭化水素及び/又は含酸素有機化合物の改質反応を促進する改質反応触媒とを有する。   In recent years, for the production of hydrogen, a selectively permeable membrane reactor (membrane reactor) capable of simultaneously performing hydrogen generation reaction and separation as described above is used (for example, see Patent Document 1). A permselective membrane reactor that has been generally used in the past has a reaction tube having one end as a gas inlet and the other end as a gas outlet, and hydrogen selectively inserted into the reaction tube. The base material portion on which the permselective membrane to be permeated has a porous separation tube and a reforming reaction catalyst that promotes the reforming reaction of hydrocarbons and / or oxygen-containing organic compounds.

通常、改質反応触媒はペレット形状で、反応管と分離管との間の空隙(改質反応部)にパックドベッド(Packed Bed)状等の状態で充填されており、反応管のガス入口から供給された原料ガスが、この改質反応触媒に接触し、水蒸気改質反応等により水素ガス等に分解される。例えば、メタンの水蒸気改質では、下記式(1)に示す改質反応、及び下記式(2)に示すシフト反応が促進されることによって、メタンと水蒸気とから、水素、一酸化炭素、二酸化炭素等の反応生成物を含む改質ガス(生成ガス)が得られる。
CH+HO → CO+3H ・・・(1)
CO+HO → CO+H ・・・(2)
Usually, the reforming reaction catalyst is in the form of pellets, and the gap (reforming reaction section) between the reaction tube and the separation tube is packed in a packed bed shape, etc., from the gas inlet of the reaction tube. The supplied raw material gas comes into contact with the reforming reaction catalyst and is decomposed into hydrogen gas or the like by a steam reforming reaction or the like. For example, in the steam reforming of methane, the reforming reaction shown in the following formula (1) and the shift reaction shown in the following formula (2) are promoted, so that hydrogen, carbon monoxide, dioxide dioxide from methane and steam. A reformed gas (product gas) containing a reaction product such as carbon is obtained.
CH 4 + H 2 O → CO + 3H 2 (1)
CO + H 2 O → CO 2 + H 2 (2)

こうして得られた生成ガスのうち、水素は選択透過膜を透過して分離管内(分離部)に選択的に引き抜かれ、他のガス成分と分離されて回収される。また、選択透過膜を透過しない一酸化炭素、二酸化炭素、未反応の原料ガス等の他のガス成分は、反応管のガス出口より反応器の外部へ排出される。   Of the product gas thus obtained, hydrogen permeates through the permselective membrane and is selectively extracted into the separation tube (separation part), separated from other gas components and recovered. In addition, other gas components such as carbon monoxide, carbon dioxide, and unreacted raw material gas that do not pass through the permselective membrane are discharged from the gas outlet of the reaction tube to the outside of the reactor.

このような選択透過膜型反応器は、触媒を用いた化学反応と、選択透過膜を用いた水素の分離とを同時に行うことができるため、装置構成がコンパクトで設置スペースが小さくて済むことに加え、生成物である水素が選択透過膜を透過して反応系から除去され、化学反応の平衡が生成側に移動するため、より低温での反応が可能になるというメリットがある。これにより、反応時のエネルギー消費が少なくて済む他、反応器の構成材料の劣化も抑制される。具体的な反応温度は、例えばメタンの水蒸気改質反応の場合、選択透過膜を持たない従来の非膜型反応器が600〜800℃程度であるのに対し、選択透過膜型反応器では400〜600℃程度である。   Such a selectively permeable membrane reactor can simultaneously perform a chemical reaction using a catalyst and hydrogen separation using a selectively permeable membrane, so that the apparatus configuration is compact and installation space is small. In addition, since the product hydrogen is removed from the reaction system through the permselective membrane and the equilibrium of the chemical reaction moves to the production side, there is an advantage that the reaction at a lower temperature is possible. As a result, energy consumption during the reaction can be reduced, and deterioration of the constituent materials of the reactor can be suppressed. For example, in the case of a steam reforming reaction of methane, the specific reaction temperature is about 600 to 800 ° C. in a conventional non-membrane reactor without a selectively permeable membrane, whereas in a selectively permeable membrane reactor, it is 400. It is about ~ 600 ° C.

水素を選択的に透過する選択透過膜には、一般に、シリカ膜、ゼオライト膜、パラジウム(Pd)又はパラジウム合金の薄膜が用いられる。選択透過膜は、その厚さを薄くした方が、透過性能が高まり、膜型反応器として用いた場合の反応促進効果は増大する。しかしながら、現状の成膜及び基材技術では、膜厚を薄くするほど膜欠陥が増大して、膜の分離性能が低下し、水素以外の成分も透過させる傾向がある。このように水素以外の原料ガス成分がリークすると、水素引き抜きによる反応促進効果が目減りしてしまうことになる。更に、透過膜の劣化発生時には、高濃度の不純物ガスが膜透過側へリークし水素純度が低下する。   Generally, a silica membrane, a zeolite membrane, a palladium (Pd) or a palladium alloy thin film is used as the selectively permeable membrane that selectively transmits hydrogen. When the thickness of the permselective membrane is reduced, the permeation performance increases, and the reaction promoting effect when used as a membrane reactor increases. However, in the current film formation and substrate technology, as the film thickness is reduced, the film defects increase, the separation performance of the film decreases, and components other than hydrogen tend to permeate. When the raw material gas components other than hydrogen leak in this way, the reaction promoting effect due to hydrogen extraction is diminished. Furthermore, when deterioration of the permeable membrane occurs, a high-concentration impurity gas leaks to the membrane permeable side and the hydrogen purity is lowered.

前記のとおり、近年においては、選択透過膜型反応器で得られた水素を燃料電池の燃料へ適用する技術の開発が進められており、燃料の水素に不純物が含まれる場合に、これを如何に低減して供給するかが問題となる。選択透過膜型反応器で得られた水素を固体高分子型燃料電池(PEFC)に供給するシステムを考えた場合、リークして導入される高濃度の不純物ガスの一酸化炭素(CO)は、電極を被毒させてしまうという不都合があるからである。このため、燃料ガスとなる水素中の一酸化炭素の濃度は、10ppm以下に保持しなければならないとされている。   As described above, in recent years, development of technology for applying hydrogen obtained in a selectively permeable membrane reactor to fuel of a fuel cell has been promoted. The problem is whether to reduce the supply. Considering a system that supplies hydrogen obtained in a selectively permeable membrane reactor to a polymer electrolyte fuel cell (PEFC), carbon monoxide (CO) at a high concentration of impurity gas introduced by leakage is: This is because the electrode is poisoned. For this reason, it is said that the concentration of carbon monoxide in hydrogen serving as the fuel gas must be maintained at 10 ppm or less.

このように、選択透過膜型反応器を使用した水素の製造においては、反応温度を低下させられることにより低コスト化などのメリットが得られる一方で、選択透過膜の劣化等により不純物のリークが起こり、水素純度が低下する問題があった。   In this way, in the production of hydrogen using a selectively permeable membrane reactor, while reducing the reaction temperature, it is possible to obtain merits such as cost reduction, while impurity leakage due to degradation of the selectively permeable membrane or the like can be obtained. This occurred and there was a problem that the hydrogen purity was lowered.

また、選択透過膜型反応器では触媒が改質反応部に充填されており、生成した水素は充填された触媒の空隙を移動するため、選択透過膜まで円滑に移動できず、水素の分離・回収の効率が低下するという問題があった。   Further, in the selectively permeable membrane reactor, the catalyst is filled in the reforming reaction section, and the produced hydrogen moves through the space of the filled catalyst, so that it cannot move smoothly to the selectively permeable membrane, and the hydrogen separation / There was a problem that the efficiency of the recovery was reduced.

前記のような水素純度の低下は、選択透過膜の透過性能が高い場合において顕著に現れることがあった。しかしながら、水素純度や回収効率に影響を与えると考えられる改質反応部の圧力については、これまで検討されておらず、改質反応部の圧力、すなわち、原料ガスの分圧を一定に保持する程度のことしか行われていなかった。   Such a decrease in hydrogen purity may be noticeable when the permeation performance of the permselective membrane is high. However, the pressure in the reforming reaction section that is considered to affect the hydrogen purity and recovery efficiency has not been studied so far, and the pressure in the reforming reaction section, that is, the partial pressure of the raw material gas is kept constant. Only about that was done.

特開2005−58823号公報JP 2005-58823 A

本発明は、このような従来の事情に鑑みてなされたものであり、その目的とするところは、選択透過膜型反応器を用い、効率良く高純度の水素を得ることが可能な水素の製造方法を提供することにある。   The present invention has been made in view of such conventional circumstances, and the object of the present invention is to produce hydrogen capable of efficiently obtaining high-purity hydrogen using a selectively permeable membrane reactor. It is to provide a method.

上記目的を達成するため、本発明によれば、以下に示す選択透過膜型反応器を用いた水素の製造方法が提供される。   In order to achieve the above object, according to the present invention, there is provided a method for producing hydrogen using the following selectively permeable membrane reactor.

[1] 原料ガスを改質反応させる改質反応部と、前記改質反応により生成した反応ガスから分離された水素が移動する分離部とが、水素を選択的に透過する選択透過膜を隔てて形成された構造を有する選択透過膜型反応器を用いた改質反応による水素の製造方法であって、前記原料ガスを前記改質反応部に供給する工程と、前記原料ガスを改質反応触媒が設置された前記改質反応部において改質反応させ、水素を含有する反応ガスを生成する工程と、前記選択透過膜によって、前記反応ガスから水素を前記分離部側に分離する工程とを有し、前記選択透過膜がパラジウムを含む膜厚10μm以下の膜であり、前記分離部の水素純度を計測しながら前記改質反応部の圧力を制御する水素の製造方法。 [1] A reforming reaction part for reforming the raw material gas and a separation part for transferring hydrogen separated from the reaction gas generated by the reforming reaction separate a selectively permeable membrane that selectively permeates hydrogen. A method of producing hydrogen by a reforming reaction using a selectively permeable membrane reactor having a structure formed by supplying a raw material gas to the reforming reaction section, and reforming the raw material gas with a reforming reaction A step of causing a reforming reaction in the reforming reaction section provided with a catalyst to generate a reaction gas containing hydrogen; and a step of separating hydrogen from the reaction gas to the separation section side by the selective permeation membrane. A method for producing hydrogen, wherein the selectively permeable membrane is a membrane containing palladium and having a thickness of 10 μm or less, and the pressure in the reforming reaction section is controlled while measuring the hydrogen purity in the separation section.

[2] 前記分離部の水素純度が低下した場合に、前記改質反応部の圧力を低下させる[1]に記載の水素の製造方法。 [2] The method for producing hydrogen according to [1], wherein the pressure in the reforming reaction unit is decreased when the hydrogen purity of the separation unit is decreased.

[3] 前記分離部の水素純度が低下した場合に、前記改質反応部の圧力を低下させるとともに、前記改質反応部の温度を上げる[2]に記載の水素の製造方法。 [3] The method for producing hydrogen according to [2], wherein when the hydrogen purity of the separation unit is lowered, the pressure of the reforming reaction unit is lowered and the temperature of the reforming reaction unit is raised.

[4] 前記改質反応部の圧力を周期的に変動させながら原料ガスを改質反応させる[1]に記載の水素の製造方法。 [4] The method for producing hydrogen according to [1], wherein the raw material gas is subjected to a reforming reaction while periodically changing the pressure in the reforming reaction section.

本発明の選択透過膜型反応器を用いた水素の製造方法によれば、効率よく高純度の水素を得ることが可能となる。   According to the method for producing hydrogen using the selectively permeable membrane reactor of the present invention, it is possible to efficiently obtain high-purity hydrogen.

以下、本発明の代表的な実施形態を図面を参照しながら具体的に説明するが、本発明は以下の実施形態に限定されるものではなく、本発明の趣旨を逸脱しない範囲で、当業者の通常の知識に基づいて、適宜設計の変更、改良等が加えられることが理解されるべきである。   Hereinafter, typical embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and those skilled in the art can depart from the scope of the present invention. It should be understood that design changes, improvements, and the like can be made as appropriate based on general knowledge of the above.

図1は、本発明の水素の製造方法に使用する選択透過膜型反応器の構造の一例を示す概略断面図である。この選択透過膜型反応器は、一端部がガス入口9で、他端部がガス出口10である筒状の反応管1と、反応管1内に挿入された、表面に水素を選択的に透過させる選択透過膜5を有し、選択透過膜5を透過した分離ガスの出口である分離排出口11を有する有底筒状の分離管4と、反応管1と選択透過膜5との間に配置された、原料ガスの改質反応を促進する改質反応触媒6を有する。   FIG. 1 is a schematic sectional view showing an example of the structure of a selectively permeable membrane reactor used in the method for producing hydrogen of the present invention. This permselective membrane reactor has a cylindrical reaction tube 1 having one end at the gas inlet 9 and the other end at the gas outlet 10, and a hydrogen inserted on the surface of the reaction tube 1 selectively. Between the reaction tube 1 and the permselective membrane 5, the bottomed cylindrical separation tube 4 having a permselective membrane 5 to be permeated and having a separation outlet 11 that is an outlet of the separation gas permeated through the permselective membrane 5 The reforming reaction catalyst 6 for promoting the reforming reaction of the raw material gas is disposed.

なお、この選択透過膜型反応器においては、反応管1と分離管4との間の空間が、原料ガスを改質反応させる改質反応部で、分離管4の内側が前記改質反応により生成した反応ガスから分離された水素が移動する分離部となっているが、改質反応部と分離部との配置が逆、すなわち、分離管の内側が改質反応部で、反応管と分離管との間の空間が分離部となるようにしてもよい。その場合には、一端部がガス入口で他端部がガス出口ある筒状の分離管を用い、分離管の内側に改質反応触媒を配置する。   In this selectively permeable membrane reactor, the space between the reaction tube 1 and the separation tube 4 is a reforming reaction section for reforming the raw material gas, and the inside of the separation tube 4 is formed by the reforming reaction. The separation of the hydrogen separated from the generated reaction gas is a separation part, but the arrangement of the reforming reaction part and the separation part is reversed, that is, the inside of the separation tube is the reforming reaction part and separated from the reaction tube. You may make it the space between pipes become a separation part. In that case, a cylindrical separation tube having one end at the gas inlet and the other end at the gas outlet is used, and the reforming reaction catalyst is disposed inside the separation tube.

図1の実施形態において、選択透過膜型反応器の反応管1は、筒状体(例えば、円筒体)で構成されている。反応管の材質としては、ステンレススティールやインコロイ等の高耐熱性で熱伝導性の良い金属を主成分とするものが好ましい。   In the embodiment of FIG. 1, the reaction tube 1 of the selectively permeable membrane reactor is formed of a cylindrical body (for example, a cylindrical body). As a material for the reaction tube, a material mainly composed of a metal having high heat resistance and good thermal conductivity such as stainless steel and incoloy is preferable.

反応管1のガス入口9には、原料ガス供給手段が接続される。原料ガス供給手段としては、例えば、原料ガス貯蔵容器から流量制御器を通ってパイプによって原料ガスを供給するものを用いることができる。なお、原料ガス供給手段は、装置の小型化のため反応管1と一体的に構成してもよく、反応管1から離れたところに取り外し可能に別体で構成してもよい。   A raw material gas supply means is connected to the gas inlet 9 of the reaction tube 1. As the source gas supply means, for example, one that supplies source gas by a pipe from a source gas storage container through a flow rate controller can be used. The source gas supply means may be configured integrally with the reaction tube 1 to reduce the size of the apparatus, or may be configured separately from the reaction tube 1 so as to be removable.

原料ガスとしては、メタン、エタン、プロパン、ブタン、灯油、ナフサ等の炭化水素やメタノール、エタノール等のアルコール類、ジメチルエーテル等のエーテル類、あるいはケトン類などの酸素を含む有機化合物や水蒸気、酸素、二酸化炭素等を挙げることができる。原料ガスは、必要に応じて選択、混合して反応管に供給される。なお、水やエタノール等の液体系の原料は気化器でガス化して供給される。   Source gases include hydrocarbons such as methane, ethane, propane, butane, kerosene, naphtha, alcohols such as methanol and ethanol, ethers such as dimethyl ether, or organic compounds containing oxygen such as ketones, water vapor, oxygen, Carbon dioxide etc. can be mentioned. The raw material gas is selected and mixed as necessary and supplied to the reaction tube. Note that liquid raw materials such as water and ethanol are supplied after being gasified by a vaporizer.

反応管1のガス出口10には、改質反応部のガス圧力を調整するための圧力制御器が接続される。また、未反応ガスや選択透過膜を透過しなかった生成ガスを無害化する処理装置が取り付けられる。   A pressure controller for adjusting the gas pressure in the reforming reaction section is connected to the gas outlet 10 of the reaction tube 1. In addition, a processing apparatus for detoxifying the unreacted gas and the generated gas that has not permeated the permselective membrane is attached.

本発明で用いられる選択透過膜は、水素に対する選択的透過能を有するものであり、パラジウム膜やパラジウム−銀合金膜をはじめとするパラジウム合金膜が好適に使用される。この選択透過膜は、10μm以下の膜厚を有することにより、優れた透過性能及び分離性能を確保することができる。選択透過膜の膜厚が10μmより厚いと、十分な水素引き抜き効果が得られなくなり、水素の透過性能が低くなる傾向がある。   The permselective membrane used in the present invention has a selective permeability to hydrogen, and a palladium alloy membrane such as a palladium membrane or a palladium-silver alloy membrane is preferably used. The permselective membrane can ensure excellent permeation performance and separation performance by having a film thickness of 10 μm or less. When the thickness of the permselective membrane is larger than 10 μm, a sufficient hydrogen extraction effect cannot be obtained, and the hydrogen permeation performance tends to be lowered.

選択透過膜の膜厚は、10μm以下である限り特に制限はなく、膜厚が薄いほど水素が透過し易く効率的に水素を回収することができるが、薄くなり過ぎると膜の耐久性や水素選択性が低下するおそれがある。選択透過膜型反応器の使用中にピンホール等の膜欠陥部位が増大し、水素以外の成分が膜を透過すると、不純物ガスが増大し、得られる水素の純度が低下するので、膜の耐久性と水素の回収効率とのバランスを考慮した場合、選択透過膜の膜厚は、0.06〜10μmとすることが好ましく、0.1〜6μmとすることが更に好ましい。   The thickness of the permselective membrane is not particularly limited as long as it is 10 μm or less, and the thinner the thickness, the easier hydrogen can permeate and the more efficiently hydrogen can be recovered. Selectivity may be reduced. Membrane defect sites such as pinholes increase during use of the selectively permeable membrane reactor, and when components other than hydrogen permeate the membrane, the impurity gas increases and the purity of the resulting hydrogen decreases. In consideration of the balance between the property and the hydrogen recovery efficiency, the thickness of the permselective membrane is preferably 0.06 to 10 μm, and more preferably 0.1 to 6 μm.

選択透過膜の水素の透過係数は、60ml/cm・min・atm1/2以上であることが好ましく、120ml/cm・min・atm1/2以上であることが更に好ましい。水素の透過係数が60ml/cm・min・atm1/2未満であると、水素の透過速度が低くなり、水素引き抜きによる反応促進効果が小さくなる。ここで、「水素の透過係数」は、Y=KΔP1/2で算出される値(K)をいうものとする。ただし、前記式中、Yは透過流量であり、ΔP1/2は供給側と透過側(分離部側)の水素分圧の1/2乗の差である。 The hydrogen permeation coefficient of the selectively permeable membrane is preferably 60 ml / cm 2 · min · atm 1/2 or more, and more preferably 120 ml / cm 2 · min · atm 1/2 or more. When the hydrogen permeation coefficient is less than 60 ml / cm 2 · min · atm 1/2 , the hydrogen permeation rate becomes low, and the reaction promoting effect by hydrogen abstraction becomes small. Here, the “hydrogen permeability coefficient” refers to a value (K) calculated by Y = KΔP 1/2 . In the above equation, Y is the permeate flow rate, and ΔP 1/2 is the difference in the square of the hydrogen partial pressure between the supply side and the permeate side (separator).

選択透過膜は膜厚が薄く、単独では機械的強度が低いため、多孔質である分離管の基材の表面に形成され、これにより水素を選択的に透過し分離するための分離管が得られる。この分離管の基材は、チタニアやアルミナ等のセラミックス多孔体、あるいはステンレススティール等の表面処理した金属多孔体を用いることが好ましい。なお、図1の実施形態では、選択透過膜5は分離管4の外側に形成されているが、場合によっては分離管の内側に形成されていてもよいし、分離管の両側に形成されていてもよい。   A selective permeable membrane is thin and has a low mechanical strength, so it is formed on the surface of a porous separator tube base material, thereby obtaining a separator tube that selectively permeates and separates hydrogen. It is done. It is preferable to use a porous ceramic body such as titania or alumina or a surface-treated metal porous body such as stainless steel as the base material of the separation tube. In the embodiment of FIG. 1, the permselective membrane 5 is formed outside the separation tube 4, but depending on the case, it may be formed inside the separation tube or formed on both sides of the separation tube. May be.

分離管4の形状は一端部が閉じられた有底円筒状が好ましいが、筒状体の一端部をフランジ等により気密な構造にして用いることもできる。他端部は選択透過膜により分離管内側の分離部側に透過し分離された水素を排出する分離排出口11となる。一般に、分離管4の外側と内側との水素分圧差が大きい方が、選択透過膜5の水素透過性能が良くなるため、分離部側の水素分圧を下げることが行われる。具体的には、分離部側に水蒸気等のスイープガスを流す方法、または、真空ポンプにて減圧する方法などがある。得られる水素の純度の面からは、水素以外のガス成分を加えずに、分離部側を減圧する方法が好ましい。   The shape of the separation tube 4 is preferably a bottomed cylindrical shape with one end closed, but the one end of the cylindrical body may be used in an airtight structure with a flange or the like. The other end serves as a separation discharge port 11 through which the separated hydrogen is permeated to the separation portion inside the separation tube through the selective permeable membrane and discharged. Generally, the hydrogen permeation performance of the permselective membrane 5 is improved when the hydrogen partial pressure difference between the outer side and the inner side of the separation tube 4 is larger, so that the hydrogen partial pressure on the separation unit side is lowered. Specifically, there are a method of flowing a sweep gas such as water vapor to the separation part side, or a method of reducing the pressure with a vacuum pump. From the viewpoint of the purity of the obtained hydrogen, a method in which the pressure on the separation part side is reduced without adding a gas component other than hydrogen is preferable.

反応管1のガス出口10と分離管4の分離排出口11には、それらから流出するガス量を測定するための流量計とガス成分を定量するためのガスクロマトグラフが接続されている。更に、流量計の上流側には、常温において液体となる成分(水など)を捕集するために約5℃に設定された液体トラップが設けられている。   The gas outlet 10 of the reaction tube 1 and the separation outlet 11 of the separation tube 4 are connected to a flow meter for measuring the amount of gas flowing out from them and a gas chromatograph for quantifying the gas components. Further, on the upstream side of the flow meter, a liquid trap set at about 5 ° C. is provided to collect components (such as water) that become liquid at room temperature.

反応管1と分離管4との間の空間(改質反応部)には、原料ガスの改質反応を促進する改質触媒が設置される。改質触媒には、触媒活性成分として、Fe、Co、Ni、Cu、Mo、Ru、Rh、Pd、Ag、W、Re、Os、Ir、Pt及びAuの内の少なくとも1種の金属が含有されていることが好ましい。改質触媒は、前記金属を含んだ化合物を、例えばペレット形状やビーズ形状に成形したもの、あるいは前記金属をアルミナ等からなるペレット状の基体に担持したものであることが好ましい。金属と基体との好ましい組み合わせ(金属−基体)としては、例えば、ニッケル−アルミナ、ルテニウム−アルミナ、ロジウム−アルミナを挙げることができる。   In the space (reforming reaction part) between the reaction tube 1 and the separation tube 4, a reforming catalyst that promotes the reforming reaction of the raw material gas is installed. The reforming catalyst contains at least one metal of Fe, Co, Ni, Cu, Mo, Ru, Rh, Pd, Ag, W, Re, Os, Ir, Pt and Au as catalytic active components. It is preferable that The reforming catalyst is preferably one obtained by molding the metal-containing compound into, for example, a pellet shape or a bead shape, or carrying the metal on a pellet-like substrate made of alumina or the like. Examples of preferable combinations of metal and substrate (metal-substrate) include nickel-alumina, ruthenium-alumina, and rhodium-alumina.

本発明の水素の製造方法は、前記のような構成を有する選択透過膜型反応器を使用して水素の製造を行うものであり、原料ガスを改質反応部に供給する工程と、原料ガスを改質反応触媒が設置された改質反応部において改質反応させ、水素を含有する反応ガスを生成する工程と、選択透過膜によって、反応ガスから水素を分離部側に分離する工程とを有する。なお、本実施形態においては、メタンと水蒸気との反応系(例えば、CH+2HO→CO+4Hという反応式で表されるメタンの水蒸気改質反応)について主に説明するが、他の原料系においても同様に実施できる。 The method for producing hydrogen according to the present invention is a method for producing hydrogen using a selectively permeable membrane reactor having the above-described configuration, a step of supplying a raw material gas to a reforming reaction section, and a raw material gas Reforming reaction in a reforming reaction section in which a reforming reaction catalyst is installed to generate a reaction gas containing hydrogen, and a process of separating hydrogen from the reaction gas to the separation section side by a selectively permeable membrane. Have. In this embodiment, a reaction system of methane and steam (for example, a steam reforming reaction of methane represented by a reaction formula of CH 4 + 2H 2 O → CO + 4H 2 ) will be mainly described. The same can be applied to the system.

原料ガス供給手段から供給された原料ガスのメタンと水蒸気は、ガス入口9から反応管1に導入され、改質反応部に配置された改質反応触媒6に接触すると、水素を含む混合ガスである改質ガス(反応ガス)が生成される。生成された改質ガスのうち水素は、分離管4の選択透過膜5を透過して、分離管4内側の分離部へ選択的に引き抜かれ、高純度の水素ガスとして分離排出口11から排出され、回収される。選択透過膜5を透過しない、一酸化炭素や二酸化炭素、未反応の原料ガスといった他のガス成分は、反応管1のガス出口10より選択透過膜型反応器の外部へ排出される。   The methane and water vapor of the raw material gas supplied from the raw material gas supply means are introduced into the reaction tube 1 from the gas inlet 9 and come into contact with the reforming reaction catalyst 6 arranged in the reforming reaction section. A certain reformed gas (reactive gas) is generated. Of the generated reformed gas, hydrogen passes through the permselective membrane 5 of the separation tube 4 and is selectively extracted to the separation part inside the separation tube 4 and is discharged from the separation discharge port 11 as high-purity hydrogen gas. And recovered. Other gas components such as carbon monoxide, carbon dioxide, and unreacted source gas that do not pass through the selectively permeable membrane 5 are discharged from the gas outlet 10 of the reaction tube 1 to the outside of the selectively permeable membrane reactor.

選択透過膜型反応器の周囲には、当該反応器の外部加熱が可能なように、加熱用ヒーターを設置されており、メタンの水蒸気改質反応では、改質反応部が400〜600℃、好ましくは500〜550℃になるように加熱される。   A heater for heating is installed around the permselective membrane reactor so that the reactor can be externally heated. In the steam reforming reaction of methane, the reforming reaction section has a temperature of 400 to 600 ° C. Preferably, it is heated to 500 to 550 ° C.

反応管1のガス出口10と分離管4の分離排出口11の下流側のガスラインには、それぞれ圧力調整器が取り付けてあり、分離管4の外側の改質反応部と分離管の内側の分離部とがそれぞれ所定の圧力になるように調整される。改質反応部は、全圧が3〜9atm、好ましくは5〜8atmとなるように原料ガスを導入し圧力調整される。また、分離部側は、全圧0.05〜0.6atmに減圧される。   A pressure regulator is attached to each of the gas lines on the downstream side of the gas outlet 10 of the reaction tube 1 and the separation discharge port 11 of the separation tube 4, and the reforming reaction section outside the separation tube 4 and the inside of the separation tube The separation units are adjusted to have a predetermined pressure. The reforming reaction part is pressure-adjusted by introducing the raw material gas so that the total pressure becomes 3 to 9 atm, preferably 5 to 8 atm. Moreover, the separation part side is decompressed to a total pressure of 0.05 to 0.6 atm.

選択透過膜型反応器を用いて改質反応により生成され、選択透過膜を透過して分離管から回収される水素の純度を計測すると、通常状態で99%以上の純度が得られる。しかしながら、選択透過膜の欠陥などの原因で水素以外の不純物ガスのリークが多くなると水素純度が99%以下に低下する場合がある。また、改質反応が行われている間においても、選択透過膜の劣化などが原因で水素純度が低下する場合がある。   When the purity of hydrogen produced by a reforming reaction using a selectively permeable membrane reactor and permeated through the selectively permeable membrane and recovered from the separation tube is measured, a purity of 99% or more is obtained in a normal state. However, if the leakage of impurity gases other than hydrogen increases due to defects in the selectively permeable membrane, the hydrogen purity may be reduced to 99% or less. Further, even during the reforming reaction, the hydrogen purity may decrease due to deterioration of the permselective membrane or the like.

前述のとおり、選択透過膜型反応器で製造した水素を高純度に維持することは、水素を固体電解質形燃料電池に利用する場合において特に重要である。水素に含まれるわずかの不純物、例えば、一酸化炭素が問題となるからである。本発明では、水素の選択透過膜が劣化してきた初期の段階において、燃料電池の触媒の劣化を防止することが可能となる。   As described above, maintaining high purity of hydrogen produced in the selectively permeable membrane reactor is particularly important when hydrogen is used in a solid oxide fuel cell. This is because slight impurities contained in hydrogen, for example, carbon monoxide, becomes a problem. In the present invention, it is possible to prevent the catalyst of the fuel cell from being deteriorated at the initial stage where the hydrogen selective permeable membrane has deteriorated.

本発明は、改質反応部の圧力を変化させることにより、水素純度が変化することを見出し、その知見に基づいてなされたものであり、分離部の水素純度を計測しながら改質反応部の圧力を制御することを主要な特徴としている。具体的には、前述のように選択透過膜の欠陥などの原因で分離部における水素の純度が低下した場合において、反応改質部の圧力を低下させると水素純度は向上する。例えば、初期の通常状態として改質反応部の圧力を8atmに設定して水素の製造を行い、分離部側に分離された水素純度が低下した場合に、改質反応部の圧力を5atmに低下させると水素純度が回復する。   The present invention has been made based on the knowledge that the hydrogen purity is changed by changing the pressure in the reforming reaction section, and the reforming reaction section of the reforming reaction section is measured while measuring the hydrogen purity in the separation section. The main feature is to control the pressure. Specifically, as described above, when the hydrogen purity in the separation unit is reduced due to a defect of the permselective membrane or the like, the hydrogen purity is improved by reducing the pressure in the reaction reforming unit. For example, in the initial normal state, hydrogen is produced by setting the pressure in the reforming reaction section to 8 atm, and when the purity of hydrogen separated in the separation section is reduced, the pressure in the reforming reaction section is reduced to 5 atm. Hydrogen purity is restored.

このように、分離部の水素純度が低下した場合に、改質反応部の圧力を初期の通常状態から20〜60%低下させることにより水素純度を向上させ、必要とする水素純度を保つことが可能となる。なお、改質反応部の圧力を、初期の通常状態から60%を超えて低下させることは好ましくない。この場合、十分な水素の引き抜き効果が得られなくなり、水素の透過速度が低くなる傾向があるからである。   As described above, when the hydrogen purity of the separation unit is lowered, the hydrogen purity is improved by reducing the pressure of the reforming reaction unit by 20 to 60% from the initial normal state, and the required hydrogen purity can be maintained. It becomes possible. Note that it is not preferable to reduce the pressure in the reforming reaction section by more than 60% from the initial normal state. In this case, a sufficient hydrogen drawing effect cannot be obtained, and the hydrogen permeation rate tends to be low.

前記のような圧力制御によって水素の純度が向上する理由は、次のように考えられる。水素の純度に影響を与える不純物は、選択透過膜の欠陥部を通過して分離部側の水素に混入して来る。このとき、混入する不純物量は改質反応部と分離部との圧力差に比例する。ところが、選択透過膜により分離される水素は、先に述べたように改質反応部側と分離部側との水素分圧の1/2乗の差(atm1/2)に比例する。したがって、改質反応部側の圧力を下げることによる不純物の通過量の減少が、選択透過膜により分離される水素量の減少よりも大きくなり、よって不純物量が相対的に減少し水素の純度が向上する。しかしながら、改質反応部側の圧力を大きく下げることは分離される水素量が大きく減少することになる。 The reason why the purity of hydrogen is improved by the pressure control as described above is considered as follows. Impurities that affect the purity of hydrogen pass through the defective portion of the permselective membrane and enter the hydrogen on the separation portion side. At this time, the amount of impurities to be mixed is proportional to the pressure difference between the reforming reaction section and the separation section. However, as described above, the hydrogen separated by the permselective membrane is proportional to the difference (atm 1/2 ) of the half power of the hydrogen partial pressure between the reforming reaction section side and the separation section side. Therefore, the decrease in the amount of impurities passing through by reducing the pressure on the reforming reaction section is larger than the decrease in the amount of hydrogen separated by the permselective membrane, so that the amount of impurities is relatively decreased and the purity of hydrogen is reduced. improves. However, greatly reducing the pressure on the reforming reaction unit side greatly reduces the amount of hydrogen separated.

前記の圧力制御によって分離される水素量が減少したときは、改質反応部の温度を上昇させることが好ましい。選択透過膜型反応器において、改質反応部の温度は500℃前後とするのが一般的であるが、分離される水素量が減少したときは、これを40〜100℃上昇させることが好ましい。選択透過膜としてパラジウム合金膜を用いる場合は、膜の耐熱性を考慮して、温度上昇は約600℃までとすることが好ましい。また、600℃を超えるような温度とすると、選択透過膜を用いない改質反応器を用いた場合の反応温度域に重なり、選択透過膜型反応器を用いて反応温度を低下させるという利点を生かすことができなくなるので、当該利点を生かすという観点からも、温度上昇は約600℃までとすることが好ましい。   When the amount of hydrogen separated by the pressure control decreases, it is preferable to raise the temperature of the reforming reaction section. In a selectively permeable membrane reactor, the temperature of the reforming reaction section is generally about 500 ° C., but when the amount of hydrogen to be separated is reduced, it is preferable to increase the temperature by 40 to 100 ° C. . When a palladium alloy membrane is used as the selectively permeable membrane, the temperature rise is preferably up to about 600 ° C. in consideration of the heat resistance of the membrane. Moreover, when the temperature exceeds 600 ° C., it overlaps the reaction temperature range when using a reforming reactor that does not use a selectively permeable membrane, and has the advantage that the reaction temperature is lowered using a selectively permeable membrane reactor. Since it cannot be used, it is preferable that the temperature rise is about 600 ° C. from the viewpoint of taking advantage of the advantage.

本発明の他の側面では、改質反応部の圧力を周期的に変動させながら原料ガスを改質反応をさせることが好ましい。具体的には、改質反応部の圧力を、所定の圧力と、当該所定の圧力から20〜40%低下させた圧力との間で周期的に変動させる。例えば、所定の圧力を8atm、これよりも低下させた圧力を5atmとし、この2つの圧力の間を10分間程度の周期で変動させる。このような改質反応部の圧力の周期的な変動によって、水素の引き抜き効果を向上させるとともに水素の純度を維持することができる。これは、この圧力の変動によって、改質反応部で生成した水素が選択透過膜に到達することが容易になるためと考えられる。   In another aspect of the present invention, it is preferable that the raw material gas undergoes a reforming reaction while periodically changing the pressure in the reforming reaction section. Specifically, the pressure in the reforming reaction section is periodically changed between a predetermined pressure and a pressure reduced by 20 to 40% from the predetermined pressure. For example, the predetermined pressure is 8 atm, the pressure lower than this is 5 atm, and the interval between the two pressures is changed at a cycle of about 10 minutes. Such periodic fluctuations in the pressure in the reforming reaction section can improve the hydrogen extraction effect and maintain the purity of hydrogen. This is presumably because the hydrogen generated in the reforming reaction part easily reaches the permselective membrane due to the fluctuation of the pressure.

本発明においては、このように選択透過膜型反応器の分離部から回収される水素の純度を計測しながら、改質反応部の圧力を制御することにより、高純度の水素を効率良く製造することができる。   In the present invention, high purity hydrogen is efficiently produced by controlling the pressure in the reforming reaction section while measuring the purity of hydrogen recovered from the separation section of the selectively permeable membrane reactor in this way. be able to.

以下、本発明を実施例に基づいて更に詳細に説明するが、本発明はこれらの実施例に限定されるものではない。   EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to these Examples.

(実施例1)
図1に示すような構造を有する選択透過膜型反応器を使用して、次のような改質反応試験を行った。なお、分離管の基材には、一端部が閉じられた有底円筒状のアルミナ多孔体(外径10mm、長さ75mm)を用い、その表面に選択透過膜として水素を選択的に透過するパラジウム(Pd)−銀(Ag)合金膜をメッキ法により成膜した。選択透過膜の組成は、水素透過性能を考慮してパラジウム(Pd)が75質量%、銀(Ag)が25質量%となるようにし、膜厚は2.5μmとした。改質反応触媒には、市販のルテニウム−アルミナ触媒(エヌ・イーケムキャット社製)を用いた。原料ガスとして、メタンを250cc/min、水蒸気を気化器でガス化し750cc/minで供給し、S/C(水蒸気/炭素)=3とした。改質反応部の温度は550℃に調整し、改質反応部の圧力は8atm、分離部側の圧力は0.2atmとした。このような条件で、メタンと水蒸気による改質反応とそれに付随して生ずる反応を行わせ、生成した水素は選択透過膜を透過させて、反応生成物から水素を選択的に分離した。膜透過側(分離部側)及び膜非透過側(改質反応部側)のそれぞれにおけるガスの流量と組成を調べることにより、メタン転化率と選択透過膜を透過したガス成分における水素純度を算出した。
Example 1
Using the permselective membrane reactor having the structure shown in FIG. 1, the following reforming reaction test was conducted. In addition, as the base material of the separation tube, a bottomed cylindrical alumina porous body (outer diameter: 10 mm, length: 75 mm) with one end closed is used, and hydrogen selectively permeates through the surface as a permselective membrane. A palladium (Pd) -silver (Ag) alloy film was formed by a plating method. The composition of the permselective membrane was such that palladium (Pd) was 75 mass% and silver (Ag) was 25 mass% in consideration of hydrogen permeation performance, and the film thickness was 2.5 μm. As the reforming reaction catalyst, a commercially available ruthenium-alumina catalyst (manufactured by NE Chemcat) was used. As raw material gases, methane was 250 cc / min, water vapor was gasified with a vaporizer and supplied at 750 cc / min, and S / C (water vapor / carbon) = 3. The temperature of the reforming reaction section was adjusted to 550 ° C., the pressure of the reforming reaction section was 8 atm, and the pressure on the separation section side was 0.2 atm. Under such conditions, the reforming reaction with methane and steam and the accompanying reaction were carried out, and the produced hydrogen permeated through the permselective membrane to selectively separate hydrogen from the reaction product. By examining the gas flow rate and composition on the membrane permeation side (separation part side) and the membrane non-permeation side (reformation reaction part side), the methane conversion rate and the hydrogen purity in the gas components that permeate the permselective membrane are calculated. did.

ここで、メタン転化率は、改質原料のうち何%が反応したかを示す指標である。本実施例のメタン水蒸気改質反応の場合、その反応は、CH+2HO=CO+4Hの反応式で表されるから、メタン1molに対して二酸化炭素は理想的には1mol得られることになる。メタン転化率[%]は、仮に、メタンの供給量が100mol/minで、実際にガス出口で得られた未反応メタンが20mol/minであれば、メタン転化率[%]={(100−20)/100}×100=80[%]として算出される。分離部側の水素純度は、水素純度[%]={水素の量/(水素の量+不純物の量)}×100[%]で算出した。 Here, the methane conversion rate is an index indicating how much of the reforming raw material has reacted. In the case of the methane steam reforming reaction of this example, the reaction is represented by a reaction formula of CH 4 + 2H 2 O = CO 2 + 4H 2 , so that 1 mol of carbon dioxide is ideally obtained with respect to 1 mol of methane. It will be. The methane conversion rate [%] is methane conversion rate [%] = {(100− if the supply amount of methane is 100 mol / min and the unreacted methane actually obtained at the gas outlet is 20 mol / min. 20) / 100} × 100 = 80 [%]. The hydrogen purity on the separation part side was calculated by hydrogen purity [%] = {amount of hydrogen / (amount of hydrogen + amount of impurities)} × 100 [%].

また、前記改質反応試験に先立って、用いた選択透過膜の水素の透過係数の測定を行った。具体的な手順としては、選択透過膜型反応器に水素のみを供給して、分離部側の水素流量を測定し、水素透過係数=C/(D・ΔP1/2)という式から水素透過係数を算出した。式中、Cは透過側水素流量(ml/min)、Dは膜面積(cm)、ΔP1/2は供給側と分離部側の水素分圧の1/2乗の差(atm1/2)である。ここで用いた選択透過膜は、水素の透過係数が120ml/cm・min・atm1/2であった。 Prior to the reforming reaction test, the hydrogen permeation coefficient of the selectively permeable membrane used was measured. As a specific procedure, only hydrogen is supplied to the selectively permeable membrane reactor, the hydrogen flow rate on the separation unit side is measured, and the hydrogen permeation from the equation hydrogen permeation coefficient = C / (D · ΔP 1/2 ) The coefficient was calculated. In the formula, C is the permeate-side hydrogen flow rate (ml / min), D is the membrane area (cm 2 ), ΔP 1/2 is the difference between the half power of the hydrogen partial pressure on the supply side and the separation side (atm 1 / 2 ). The permselective membrane used here had a hydrogen permeability coefficient of 120 ml / cm 2 · min · atm 1/2 .

前記改質反応試験を行いメタン転化率と得られた水素の純度を算出した結果、定常状態において、メタン転化率は80%であり、得られた水素の純度は99.92%であった。ここで、改質反応部の圧力を定常状態の8atmから5atmに低下させたところ、水素純度は99.95%に向上した。一方、改質反応部の圧力を8atmとし、分離部の圧力を0.05atm、0.1atm、0.3atmと変化させたところ、水素の純度は99.92%で変化しなかった。このように、改質反応部側の圧力を減少させることにより水素の純度が向上した。   As a result of performing the reforming reaction test and calculating the methane conversion rate and the purity of the obtained hydrogen, in a steady state, the methane conversion rate was 80%, and the obtained hydrogen purity was 99.92%. Here, when the pressure in the reforming reaction section was lowered from 8 atm in the steady state to 5 atm, the hydrogen purity was improved to 99.95%. On the other hand, when the pressure in the reforming reaction part was 8 atm and the pressure in the separation part was changed to 0.05 atm, 0.1 atm, and 0.3 atm, the purity of hydrogen did not change at 99.92%. Thus, the purity of hydrogen was improved by reducing the pressure on the reforming reaction part side.

(実施例2)
選択透過膜として、膜厚が2.0μm、水素透過係数が150ml/cm・min・atm1/2のパラジウム合金膜を用いた以外は、実施例1と同様にして改質反応試験を行った。改質反応部の温度を500℃、圧力を8atmとしたとき、メタン転化率は75%で、得られた水素の純度は98.5%であった。ここで、反応改質部の圧力を8atmから5atmに低下させると、水素純度は99.4%に向上した。更に、反応改質部の圧力を5atmに低下させたまま、改質反応部の温度を500℃から600℃に上昇させたところ、得られた水素の純度は99.4%で変化しなかった。一方、水素の回収量は205ml/minから260ml/minに向上した。
(Example 2)
A reforming reaction test was conducted in the same manner as in Example 1 except that a palladium alloy membrane having a thickness of 2.0 μm and a hydrogen permeability coefficient of 150 ml / cm 2 · min · atm 1/2 was used as the selectively permeable membrane. It was. When the temperature of the reforming reaction section was 500 ° C. and the pressure was 8 atm, the methane conversion was 75% and the purity of the obtained hydrogen was 98.5%. Here, when the pressure in the reaction reforming section was lowered from 8 atm to 5 atm, the hydrogen purity was improved to 99.4%. Furthermore, when the temperature of the reforming reaction part was raised from 500 ° C. to 600 ° C. while the pressure of the reaction reforming part was reduced to 5 atm, the purity of the obtained hydrogen did not change at 99.4%. . On the other hand, the recovery amount of hydrogen was improved from 205 ml / min to 260 ml / min.

(実施例3)
実施例1で使用した選択透過膜型反応器と同じ選択透過膜型反応器を用いて、改質反応部の圧力を周期的に変動させながら改質反応試験を行った。最初は、改質反応部の圧力を8atm、分離部の圧力を0.2atmとした。その後、改質反応部側の圧力を、8atmと6atmとの間で8分間周期で変動させながら、メタンと水蒸気による改質反応とそれに付随して生ずる反応を行わせ、生成した水素は選択透過膜を透過させて、反応生成ガスから水素を選択的に分離した。分離部での水素純度は、改質反応部の圧力を周期的に変動させる前は99.92%で、周期的に変動させてからは99.93%であった。改質反応部の圧力を周期的に変動させることによる水素純度の向上効果はわずかであったが、水素純度の変動が小さく、水素の純度を維持する効果が見られた。
(Example 3)
Using the same selectively permeable membrane reactor as that used in Example 1, a reforming reaction test was conducted while periodically changing the pressure in the reforming reaction section. Initially, the pressure in the reforming reaction section was 8 atm, and the pressure in the separation section was 0.2 atm. After that, while the pressure on the reforming reaction part is fluctuated between 8 atm and 6 atm for a period of 8 minutes, the reforming reaction with methane and steam and the accompanying reaction are performed, and the generated hydrogen is selectively permeated. The membrane was permeated to selectively separate hydrogen from the reaction product gas. The hydrogen purity in the separation unit was 99.92% before the pressure in the reforming reaction unit was periodically changed, and was 99.93% after the pressure was periodically changed. Although the effect of improving the hydrogen purity by periodically changing the pressure in the reforming reaction section was slight, the change in the hydrogen purity was small, and the effect of maintaining the hydrogen purity was observed.

本発明の選択透過膜型反応器を用いた水素の製造方法は、高純度の水素を必要とする各種産業分野で好適に利用できる。例えば、メタン、プロパン等の炭化水素を改質して得られる水素を分離して燃料ガスとして使用する燃料電池の分野で好適に利用できる。   The method for producing hydrogen using the selectively permeable membrane reactor of the present invention can be suitably used in various industrial fields requiring high-purity hydrogen. For example, it can be suitably used in the field of fuel cells in which hydrogen obtained by reforming hydrocarbons such as methane and propane is separated and used as fuel gas.

本発明に使用する選択透過膜型反応器の構造の一例を示す概略断面図である。It is a schematic sectional drawing which shows an example of the structure of the selectively permeable membrane type reactor used for this invention.

符号の説明Explanation of symbols

1:反応管、4:分離管、5:選択透過膜、6:改質反応触媒、9:ガス入口、10:ガス出口、11:分離排出口。 1: reaction tube, 4: separation tube, 5: selective permeation membrane, 6: reforming reaction catalyst, 9: gas inlet, 10: gas outlet, 11: separation outlet.

Claims (4)

原料ガスを改質反応させる改質反応部と、前記改質反応により生成した反応ガスから分離された水素が移動する分離部とが、水素を選択的に透過する選択透過膜を隔てて形成された構造を有する選択透過膜型反応器を用いた改質反応による水素の製造方法であって、
前記原料ガスを前記改質反応部に供給する工程と、
前記原料ガスを改質反応触媒が設置された前記改質反応部において改質反応させ、水素を含有する反応ガスを生成する工程と、
前記選択透過膜によって、前記反応ガスから水素を前記分離部側に分離する工程とを有し、
前記選択透過膜がパラジウムを含む膜厚10μm以下の膜であり、
前記分離部の水素純度を計測しながら前記改質反応部の圧力を制御する水素の製造方法。
A reforming reaction part for reforming the raw material gas and a separation part for transferring hydrogen separated from the reaction gas generated by the reforming reaction are formed across a selectively permeable membrane that selectively permeates hydrogen. A method for producing hydrogen by a reforming reaction using a selectively permeable membrane reactor having the above structure,
Supplying the source gas to the reforming reaction section;
A step of causing a reforming reaction in the reforming reaction section in which the reforming reaction catalyst is installed to generate a reaction gas containing hydrogen;
Separating the hydrogen from the reaction gas to the separation unit side by the selectively permeable membrane,
The permselective membrane is a membrane containing palladium and having a thickness of 10 μm or less,
A method for producing hydrogen, wherein the pressure of the reforming reaction unit is controlled while measuring the hydrogen purity of the separation unit.
前記分離部の水素純度が低下した場合に、前記改質反応部の圧力を低下させる請求項1に記載の水素の製造方法。   The method for producing hydrogen according to claim 1, wherein when the hydrogen purity of the separation unit is lowered, the pressure in the reforming reaction unit is lowered. 前記分離部の水素純度が低下した場合に、前記改質反応部の圧力を低下させるとともに、前記改質反応部の温度を上げる請求項2に記載の水素の製造方法。   The method for producing hydrogen according to claim 2, wherein when the hydrogen purity of the separation unit is reduced, the pressure of the reforming reaction unit is decreased and the temperature of the reforming reaction unit is increased. 前記改質反応部の圧力を周期的に変動させながら原料ガスを改質反応させる請求項1に記載の水素の製造方法。   The method for producing hydrogen according to claim 1, wherein the raw material gas undergoes a reforming reaction while periodically changing the pressure in the reforming reaction section.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011144088A (en) * 2010-01-15 2011-07-28 Tokyo Gas Co Ltd Two-stage hydrogen separation type reformer
JP2011251865A (en) * 2010-06-01 2011-12-15 Ihi Corp Ammonia synthesizer
JP2020142160A (en) * 2019-03-04 2020-09-10 公益財団法人地球環境産業技術研究機構 Gas separator and membrane reactor

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62108703A (en) * 1985-11-08 1987-05-20 Mitsubishi Gas Chem Co Inc Preparation of gaseous mixture having optional ratio of hydrogen to carbon monoxide
JPS63295402A (en) * 1987-05-27 1988-12-01 Ise Kagaku Kogyo Kk Production of hydrogen
JPH01219001A (en) * 1988-02-25 1989-09-01 Hidekazu Kikuchi Production of hydrogen
JP2002068703A (en) * 2000-08-23 2002-03-08 Toyota Motor Corp System to generate fuel gas for fuel battery
JP2006199509A (en) * 2005-01-18 2006-08-03 Iwatani Internatl Corp Reformer

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62108703A (en) * 1985-11-08 1987-05-20 Mitsubishi Gas Chem Co Inc Preparation of gaseous mixture having optional ratio of hydrogen to carbon monoxide
JPS63295402A (en) * 1987-05-27 1988-12-01 Ise Kagaku Kogyo Kk Production of hydrogen
JPH01219001A (en) * 1988-02-25 1989-09-01 Hidekazu Kikuchi Production of hydrogen
JP2002068703A (en) * 2000-08-23 2002-03-08 Toyota Motor Corp System to generate fuel gas for fuel battery
JP2006199509A (en) * 2005-01-18 2006-08-03 Iwatani Internatl Corp Reformer

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011144088A (en) * 2010-01-15 2011-07-28 Tokyo Gas Co Ltd Two-stage hydrogen separation type reformer
JP2011251865A (en) * 2010-06-01 2011-12-15 Ihi Corp Ammonia synthesizer
JP2020142160A (en) * 2019-03-04 2020-09-10 公益財団法人地球環境産業技術研究機構 Gas separator and membrane reactor
JP7136722B2 (en) 2019-03-04 2022-09-13 公益財団法人地球環境産業技術研究機構 Gas separator and membrane reactor

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