JPH038816B2 - - Google Patents
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- Publication number
- JPH038816B2 JPH038816B2 JP26198985A JP26198985A JPH038816B2 JP H038816 B2 JPH038816 B2 JP H038816B2 JP 26198985 A JP26198985 A JP 26198985A JP 26198985 A JP26198985 A JP 26198985A JP H038816 B2 JPH038816 B2 JP H038816B2
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- porous
- gas separation
- pore diameter
- average pore
- 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.)
- Expired
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- 238000000926 separation method Methods 0.000 claims description 63
- 239000010409 thin film Substances 0.000 claims description 47
- 239000011148 porous material Substances 0.000 claims description 42
- 239000012528 membrane Substances 0.000 claims description 40
- 229910010272 inorganic material Inorganic materials 0.000 claims description 10
- 239000011147 inorganic material Substances 0.000 claims description 10
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 8
- 239000007789 gas Substances 0.000 description 59
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 38
- 238000000034 method Methods 0.000 description 14
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 10
- 238000009792 diffusion process Methods 0.000 description 8
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 6
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 6
- 239000010408 film Substances 0.000 description 6
- 230000035699 permeability Effects 0.000 description 6
- 229910001593 boehmite Inorganic materials 0.000 description 5
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 5
- 239000000377 silicon dioxide Substances 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 229910052739 hydrogen Inorganic materials 0.000 description 4
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 239000005373 porous glass Substances 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- 230000002195 synergetic effect Effects 0.000 description 3
- 229910021536 Zeolite Inorganic materials 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 230000003301 hydrolyzing effect Effects 0.000 description 2
- 238000005342 ion exchange Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229920000620 organic polymer Polymers 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 238000005240 physical vapour deposition Methods 0.000 description 2
- 239000012808 vapor phase Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 239000010457 zeolite Substances 0.000 description 2
- 229910001316 Ag alloy Inorganic materials 0.000 description 1
- 229910001252 Pd alloy Inorganic materials 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- SMZOGRDCAXLAAR-UHFFFAOYSA-N aluminium isopropoxide Chemical compound [Al+3].CC(C)[O-].CC(C)[O-].CC(C)[O-] SMZOGRDCAXLAAR-UHFFFAOYSA-N 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 229910052878 cordierite Inorganic materials 0.000 description 1
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 1
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- PIBWKRNGBLPSSY-UHFFFAOYSA-L palladium(II) chloride Chemical compound Cl[Pd]Cl PIBWKRNGBLPSSY-UHFFFAOYSA-L 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 238000001612 separation test Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
Landscapes
- Hydrogen, Water And Hydrids (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
Description
〔産業上の利用分野〕
本発明は、混合ガス中の水素を分離するための
水素ガス分離膜に関する。
〔従来技術〕
混合ガスから特定ガスをガス拡散法によつて分
離する一手段として、ガス分子の平均自由行程よ
り小さな孔径例えば数10Å〜数100Åの細孔を持
つ多孔質のガス分離膜を使用するクヌーセン拡散
による分離法が知られている。例えば、かかる分
離法は、比較的分子量比の大きい水素（H2）−窒
素（N2）、水素（H2）−一酸化炭素（CO）等の混
合ガス中のH2ガス分離に有効であり、一般には
ガス分離膜として有機高分子膜が採用されてい
る。しかしながら、かかる有機高分子膜は耐熱
性、耐薬品性耐久性に劣るという欠陥があるた
め、セラミツク多孔体等無機質材料からなる多孔
質のガス分離膜の使用が試みられており、また特
開昭59−59223号公報にはかかる無機質材料から
なる多孔質のガス分離膜が提案されかつ従来例と
して示されている。
〔発明が解決しようとする問題点〕
ところで、上記したクヌーセン拡散による分離
法において、混合ガスの透過係数の比は理論的に
は各ガスにおける分子量比の逆数の平方根に等し
いため、同分離法が有効とされるH2−N2系混合
ガスにおける理論的透過係数の比が3.7となるが、
同比は実際にはかなり小さくてH2ガスの高濃度
分離を期待し得ない。
本発明は、PdのH2に対する吸収性および透過
性に着目し、Pdのこれらの特性を多孔質の無機
質材料に有効に利用することにより、H2ガスの
高濃度分離を可能にすることを目的とする。
〔問題点を解決するための手段〕
本発明はかかる目的を達成すべく、水素ガス分
離膜（以下2ガス分離膜という）を、連続した細
孔を有し無機質材料からなる多孔質支持体の少な
くとも一方の面に、同支持体の細孔の平均細孔径
より小さな平均細孔径の連続した細孔を有し無機
質材料からなる一層または複数層の多孔質薄膜を
備えた構成とするとともに、少なくとも最外層の
薄膜における細孔の平均孔径が1000Å以下であ
り、かつ同薄膜はPdを含有していることを特徴
とするものである。
本発明において、多孔質支持体はアルミナ、シ
リカ、シリカーアルミナ、ムライト、コージイラ
イト、ジルコニア、カーボン等の無機質材料から
なるもので、セラミツク多孔体の形成条件と同様
の条件にて成形し、その後焼成しまたは熱処理し
て得られる。また、かかる多孔質支持体は多数の
連続した細孔を有するもので、同細孔の平均細孔
径はガラス拡散の妨害とならない0.5μ以上が好ま
しく、かつ後述する多孔質薄膜の形成特に同薄膜
へのクラツク、ピンホール等の発生防止、膜厚の
均一性等の観点から30μ以下が好ましい。より好
ましくは0.5μ〜5μである。なお、多孔質支持体の
厚みは任意でよいが、支持体としての強度および
加工性等から１mm程度の厚みのものが好ましい。
また、本発明において、多孔質薄膜はアルミ
ナ、シリカ、シリカーアルミナ、ジルコニア、ゼ
オライト、多孔質ガラス、カーボン等の無機質材
料からなるもので、ゾルーゲル法によるゲル膜の
付着、微粉末の高圧圧着、多孔質ガラスの付着等
の手段にて多孔質支持体の少なくとも一方の面に
形成される。かかる多孔質薄膜には含浸法、吸着
法、イオン交換法等の方法によりPdが所定量浸
漬担持されるが、Pdを多孔質薄膜にのみスキン
構造にて担持させるにはイオン交換法が最も好ま
しい。また、これとは異なり、同薄膜自体をPd
またはPd合金で形成してもよい。この場合には、
気相化学反応法（CVD）、真空蒸着法（PVD）
等の気相法を採用することが好ましい。本発明に
おいては、かかる多孔質薄膜が実質的にH2ガス
分離に寄与するものであるため、同薄膜における
多数の連続細孔の平均細孔径は重要な要因とな
る。一般に、クヌーセン拡散による分離において
は平均細孔径が数10Å〜数100Åであるが、本発
明においては同薄膜中のPdとの相乗的効果等か
ら1000Åまで十分である。なお、高温、高圧下で
H2ガス分離を行う場合には、平均細孔径は200Å
以下であることが好ましい。また、同薄膜の膜厚
については、多孔質支持体の面上での均一な膜厚
の形成、膜内でのクラツク、ビンホール等の発生
防止の観点から10Å以上であることが好ましく、
かつガス拡散抵抗の観点から100μ以下であるこ
とが好ましいが、本発明においてはPdによるガ
ス分離能等から500μまで十分である。
さらにまた、本発明において、多孔質薄膜中の
Pdは同薄膜の細孔によるH2ガス分離効果に対し
て相乗的効果を奏するもので、同薄膜中Pd原子
換算にて0.1mol％以上であることが好ましく、
より好ましくは1mol％以上である。
なお、本発明においては、多孔質薄膜は１層に
限らず２層以上の複数層であつてもよい。この場
合、少なくとも最外層の薄膜がPdを含有し、か
つその平均細孔径が1000Å以下であることが必要
である。中間層に位置している多孔質薄膜は最外
層の薄膜と同様Pdを含有しかつその平均細孔径
が1000Å以下であつてもよく、またPdを含有せ
ず平均細孔径が最外層の薄膜と多孔質支持体との
平均細孔径の範囲にあつてもよい。
〔発明の作用・効果〕
このように構成したガス分離膜においては、多
孔質支持体の少なくとも一方の面に設けた多孔質
薄膜がクヌーセン拡散によるH2ガス分離能を有
するが、本発明においては特に、分離能を発揮す
る各細孔の内壁にPdが分散されまたは同内壁が
Pd膜となつていて、このPdがH2を選択的に吸着
しかつ透過するため、各細孔によるH2ガス分離
効果に対して相乗的効果を奏する。従つて、本発
明によればH2ガスの透過量に支障をきたすこと
なくH2ガスの高濃度分離が可能である。
なお、本発明のガス分離膜においては、Pdを
含有する多孔質薄膜を多孔質支持体にて支持して
いるため、高い強度を有するとともに加工性に富
み、モジユール化が容易でかつ高価なPdの使用
量が少なくてすむという利点がある。
〔実施例および比較例〕
ガス分離膜の作製
(1) 多孔質支持体の作製
平均粒径5μのα−Al2O3粉末をバインダであ
る澱粉糊等とともに混練してパイプ状に押出し
成形または平板状にプレス成形した後1600℃で
約10時間焼成し、平均細孔径2μで厚さ１mmの
パイプ状多孔質支持体A1または平板状多孔質
支持体A2を作製した。なお、細孔径の測定に
は公知の水銀圧入法を採用した。以下、細孔径
の測定は同法による。
(2) 多孔質薄膜の形成
アルミニウムイソプロボキシドを加水分解
して得たベーマイトゲルを多孔質支持体A1
の外表面にデツピングにより被覆して担持さ
せ、乾燥後400℃で約３時間焼成した。ベー
マイトゲルの被覆担持および焼成を繰返し行
つてその膜厚の調整を行い、多孔質支持体
A1の外表面に平均細孔径200Åで厚さ1μ，
10μ，100μおよび500μの多孔質薄膜B1〜B4
を形成した。また、上記ベーマイトゲルをか
かる方法と同様の方法にて多孔質支持体A2
の一側面に担持させて焼成し、同支持体A2
の一側面に平均細孔径200Åで厚さ10μの多
孔質薄膜B5を形成した。
アルミニウムイソプロポキシドを加水分解
して得たベーマイトゲルを800℃で仮焼して
γ−Al2O3粉末を得、これに水と解膠剤であ
るHClを添加して湿式粉砕し担持用スラリー
とした。このスラリーを多孔質支持体A2の
一側面に担持させて乾燥後、500℃で約３時
間焼成した。これにより、同支持体A2の一
側面に平均細孔径1000Åで厚さ10μの多孔質
薄膜Ｂ６を形成した。
平均粒径1μのα−Al2O3粉末を湿式粉砕し
て担持用スラリーを得、これを多孔質支持体
A2の一側面に担持させて乾燥後500℃で約３
時間焼成した。これにより、同支持体A2の
一側面に平均細孔径3000Åで厚さ10μの多孔
質薄膜Ｂ７を形成した。
(3) Pdの添加
多孔質薄膜B1〜B4を外表面に備えた多孔
質支持体A1をPdのアンミン錯体〔Pd
（NH3）4〕Cl2の0.2mol／水溶液中に浸漬
し、浸漬後これを蒸留水で１回水洗して乾燥
した。この操作を繰返し行つてPdの含有量
を調整した後500℃で約３時間焼成し、次い
でH2雰囲気下400℃で還元処理した。これに
より、同支持体A1の外表面の多孔質薄膜B1
〜B4中にPdを1.0mol％含有する４種類のガ
ス分離膜C1，C2，C3，C4を作製した。同様
にして、多孔質薄膜B2中にPdを0.1mol％お
よび10.0mol％含有する２種類のガス分離膜
CC5，C6を作製した。なお、Pd含有量の測
定は蛍光Ｘ線分析法による。
多孔質薄膜B5，B6を一側面に備えた多孔
質支持体A2を上記と同様の方法にて処理し、
これら薄膜B5，B6中にPdを1.0mol％含有す
る２種類のガス分離膜C7，C8を作製した。
(4) Pd多孔質薄膜の形成
塩化パラジウム（）を気相化学反応法
（CVD法）にのつとり、H2気流中500℃で加
熱分解して気相中のPdを常温に保持した多
孔質支持体A2の一側面、または多孔質薄膜
B5を備えた多孔質支持体A2における同薄膜
B5の一側面に約１時間積層し、平均細孔径
100Åで厚さ10μのPd薄膜を備えた２種類の
ガス離膜C9，C10を作製した。
Pd−Ag系合金線（Pd：40mol％）を真空
蒸発法（PVD法）にのつとり、タングステ
ンヒータにより1550℃に加熱して10-4Torr
の真空下で多孔質支持体A2の一側面，また
は多孔質薄膜B5を備えた多孔質支持体A2に
おける同薄膜B5の一側面にPdを積層し、平
均細孔径50Åで厚さ5μのPd薄膜を備えた２
種類のガス分離膜C11，C12を作製した。
本実施例においては、ガス分離膜として以上12
種類の分離膜C1〜C12を採用するとともに、比較
例として本発明の技術的範囲から外れる下記４種
類の分離膜C13〜C16を採用した。これらのガス
分離膜をまとめると第１表の通りとなる。
C13：多孔質支持体A2のみからなるガス分離膜
C14：多孔質支持体A1の外表面に多孔質薄膜B2
を備えてなるガス分離膜
C15：多孔質支持体A2の一側面に多孔質薄膜B6
を備えたガス分離膜
C16：多孔質支持体A2の一側面に多孔質薄膜B7
を備えたガス分離膜
Ｈガス分離試験
通常の流通式ガス分離装置に各分離膜C1〜C16
を採用し、H250vol％とN250vol％の混合ガスを
試験に供した。試験条件は常温で供給側圧力５
Kg／cm2，流出側圧力１Kg／cm2である。試験結果を
下記で示される分離係数α，透過係数ηに換算し
て第２表に示す。
分離係数α＝H2out（100−H2in）／H2in（100−H2out
）
但し、H2inは装置の入口側のH2vol％，H2out
は装置の出口側のH2のvol％
透過係数η＝（ガス透過流量）×（分離膜厚）／（膜面
積）×（圧力差）×（時間）
（cm2／sec cmHg）
但し、ηの算出においては各ガス分離膜C1〜
C16ともに分離膜厚として0.10cmを用いた。
[Industrial Application Field] The present invention relates to a hydrogen gas separation membrane for separating hydrogen in a mixed gas. [Prior art] As a means of separating a specific gas from a mixed gas by the gas diffusion method, a porous gas separation membrane having pores with a pore size smaller than the mean free path of gas molecules, for example, from several tens of Å to several hundreds of angstroms, is used. A separation method using Knudsen diffusion is known. For example, this separation method is effective for separating H2 gas from mixed gases such as hydrogen ( H2 )-nitrogen ( N2 ), hydrogen ( H2 )-carbon monoxide (CO), etc., which have a relatively large molecular weight ratio. Generally, organic polymer membranes are used as gas separation membranes. However, such organic polymer membranes have the disadvantage of poor heat resistance, chemical resistance, and durability. Therefore, attempts have been made to use porous gas separation membranes made of inorganic materials such as porous ceramics. No. 59-59223 proposes a porous gas separation membrane made of such an inorganic material and shows it as a conventional example. [Problems to be solved by the invention] By the way, in the separation method using Knudsen diffusion described above, the ratio of permeability coefficients of mixed gases is theoretically equal to the square root of the reciprocal of the molecular weight ratio of each gas, so the separation method is The ratio of theoretical permeability coefficients in the H 2 -N 2 gas mixture, which is considered to be effective, is 3.7.
The same ratio is actually quite small and high concentration separation of H 2 gas cannot be expected. The present invention focuses on the absorption and permeability of Pd to H2 , and aims to enable high-concentration separation of H2 gas by effectively utilizing these properties of Pd in porous inorganic materials. purpose. [Means for Solving the Problems] In order to achieve the above object, the present invention provides a hydrogen gas separation membrane (hereinafter referred to as a two- gas separation membrane) using a porous support made of an inorganic material and having continuous pores. At least one surface is provided with one or more layers of porous thin film made of an inorganic material and having continuous pores with an average pore diameter smaller than the average pore diameter of the pores of the support, and at least The outermost thin film has an average pore diameter of 1000 Å or less, and the thin film contains Pd. In the present invention, the porous support is made of an inorganic material such as alumina, silica, silica-alumina, mullite, cordierite, zirconia, carbon, etc., and is molded under the same conditions as the ceramic porous body, and then Obtained by firing or heat treatment. In addition, such a porous support has a large number of continuous pores, and the average pore diameter of the pores is preferably 0.5μ or more so as not to interfere with glass diffusion, and the formation of a porous thin film, which will be described later, is particularly preferred. The thickness is preferably 30 μm or less from the viewpoints of preventing cracks and pinholes from occurring and uniformity of the film thickness. More preferably, it is 0.5μ to 5μ. The thickness of the porous support may be arbitrary, but a thickness of about 1 mm is preferred from the viewpoint of strength as a support and workability. In addition, in the present invention, the porous thin film is made of an inorganic material such as alumina, silica, silica alumina, zirconia, zeolite, porous glass, carbon, etc., and the porous thin film is made of an inorganic material such as alumina, silica, silica alumina, zirconia, zeolite, porous glass, carbon, etc. It is formed on at least one surface of the porous support by means such as adhesion of porous glass. A predetermined amount of Pd is immersed and supported on such a porous thin film by methods such as an impregnation method, an adsorption method, an ion exchange method, etc., but the ion exchange method is most preferable in order to support Pd only in a porous thin film in a skin structure. . Also, unlike this, the thin film itself is Pd
Alternatively, it may be formed from a Pd alloy. In this case,
Vapor phase chemical reaction method (CVD), vacuum vapor deposition method (PVD)
It is preferable to employ a gas phase method such as In the present invention, since such a porous thin film substantially contributes to H 2 gas separation, the average pore diameter of a large number of continuous pores in the thin film is an important factor. Generally, in separation by Knudsen diffusion, the average pore diameter is several tens of angstroms to several hundreds of angstroms, but in the present invention, an average pore diameter of 1000 angstroms is sufficient due to the synergistic effect with Pd in the thin film. In addition, under high temperature and high pressure
When performing H2 gas separation, the average pore diameter is 200Å
It is preferable that it is below. Further, the thickness of the thin film is preferably 10 Å or more from the viewpoint of forming a uniform film thickness on the surface of the porous support and preventing the occurrence of cracks, bottle holes, etc. within the film.
From the viewpoint of gas diffusion resistance, the thickness is preferably 100μ or less, but in the present invention, 500μ is sufficient due to the gas separation ability of Pd. Furthermore, in the present invention, in the porous thin film,
Pd has a synergistic effect on the H 2 gas separation effect by the pores of the thin film, and is preferably 0.1 mol% or more in terms of Pd atoms in the thin film.
More preferably, it is 1 mol% or more. In addition, in the present invention, the porous thin film is not limited to one layer, but may be two or more layers. In this case, at least the outermost thin film must contain Pd and have an average pore diameter of 1000 Å or less. The porous thin film located in the middle layer may contain Pd and have an average pore diameter of 1000 Å or less like the outermost thin film, or it may not contain Pd and have an average pore diameter of 1000 Å or less. The average pore diameter may be within the range of that of the porous support. [Operations and Effects of the Invention] In the gas separation membrane configured as described above, the porous thin film provided on at least one surface of the porous support has H 2 gas separation ability due to Knudsen diffusion. In particular, Pd is dispersed on the inner wall of each pore that exhibits separation power, or
It is a Pd membrane, and since this Pd selectively adsorbs and permeates H 2 , it has a synergistic effect on the H 2 gas separation effect of each pore. Therefore, according to the present invention, high-concentration separation of H 2 gas is possible without affecting the permeation amount of H 2 gas. In addition, in the gas separation membrane of the present invention, since the porous thin film containing Pd is supported by a porous support, it has high strength and is easy to process, and can easily be made into a module without using expensive Pd. It has the advantage that only a small amount of is needed. [Examples and Comparative Examples] Production of gas separation membrane (1) Production of porous support α-Al 2 O 3 powder with an average particle size of 5μ is kneaded with a binder such as starch paste, and extruded or molded into a pipe shape. After press-molding into a flat plate, it was fired at 1600°C for about 10 hours to produce a pipe-shaped porous support A1 or a flat plate-shaped porous support A2 with an average pore diameter of 2 μm and a thickness of 1 mm. Note that a known mercury intrusion method was used to measure the pore diameter. Hereinafter, the pore diameter will be measured using the same method. (2) Formation of porous thin film Boehmite gel obtained by hydrolyzing aluminum isoproboxide is used as porous support A1.
The material was coated and supported on the outer surface of the film by dipping, and after drying, it was fired at 400°C for about 3 hours. The coating thickness of the boehmite gel is adjusted by repeatedly carrying the boehmite gel coating and firing, and the porous support is
On the outer surface of A1, the average pore diameter is 200Å and the thickness is 1μ.
10μ, 100μ and 500μ porous thin film B1~B4
was formed. In addition, the above boehmite gel was applied to the porous support A2 using the same method as above.
The same support A2 is supported on one side and fired.
A porous thin film B5 with an average pore diameter of 200 Å and a thickness of 10 μm was formed on one side of the substrate. Boehmite gel obtained by hydrolyzing aluminum isopropoxide is calcined at 800℃ to obtain γ-Al 2 O 3 powder, which is then wet-pulverized with water and HCl, a peptizing agent, for support. It was made into a slurry. This slurry was supported on one side of the porous support A2, dried, and then fired at 500° C. for about 3 hours. As a result, a porous thin film B6 having an average pore diameter of 1000 Å and a thickness of 10 μm was formed on one side of the support A2. α-Al 2 O 3 powder with an average particle size of 1μ was wet-pulverized to obtain a slurry for support, which was then applied to a porous support.
Supported on one side of A2 and dried at 500℃ for about 3
Baked for an hour. As a result, a porous thin film B7 having an average pore diameter of 3000 Å and a thickness of 10 μm was formed on one side of the support A2. (3) Addition of Pd The porous support A1 having the porous thin films B1 to B4 on the outer surface is made of an ammine complex of Pd [Pd
(NH 3 ) 4 ]Cl 2 in 0.2 mol/aqueous solution, and after immersion, it was washed once with distilled water and dried. After repeating this operation to adjust the Pd content, it was fired at 500°C for about 3 hours, and then reduced at 400°C in an H 2 atmosphere. As a result, the porous thin film B1 on the outer surface of the support A1
~Four types of gas separation membranes C1, C2, C3, and C4 containing 1.0 mol% of Pd in B4 were fabricated. Similarly, two types of gas separation membranes containing 0.1 mol% and 10.0 mol% of Pd in the porous thin film B2 were prepared.
CC5 and C6 were created. Note that the Pd content was measured by fluorescent X-ray analysis. A porous support A2 having porous thin films B5 and B6 on one side is treated in the same manner as above,
Two types of gas separation membranes C7 and C8 containing 1.0 mol% of Pd in these thin films B5 and B6 were fabricated. (4) Formation of Pd porous thin film Palladium chloride () was prepared using a vapor phase chemical reaction method (CVD method), and the porous Pd in the gas phase was maintained at room temperature by thermal decomposition at 500℃ in a H 2 stream. one side of the support A2, or a porous thin film
The same thin film on porous support A2 with B5
Layered on one side of B5 for about 1 hour, average pore size
Two types of gas separation membranes C9 and C10 with 100 Å and 10 μ thick Pd thin films were fabricated. A Pd-Ag alloy wire (Pd: 40 mol%) was prepared using the vacuum evaporation method (PVD method) and heated to 1550°C using a tungsten heater to generate 10 -4 Torr.
Pd was laminated on one side of the porous support A2 under a vacuum of 2 with
Gas separation membranes C11 and C12 were fabricated. In this example, the above 12 gas separation membranes are used.
The following four types of separation membranes C13 to C16, which are outside the technical scope of the present invention, were used as comparative examples. Table 1 summarizes these gas separation membranes. C13: Gas separation membrane consisting only of porous support A2 C14: Porous thin film B2 on the outer surface of porous support A1
Gas separation membrane C15 comprising: porous thin film B6 on one side of porous support A2
Gas separation membrane C16 with: porous thin membrane B7 on one side of porous support A2
Gas separation membrane equipped with H gas separation test Each separation membrane C1 to C16 is
A mixed gas of 50 vol% H 2 and 50 vol% N 2 was used for the test. The test conditions were room temperature and supply side pressure of 5.
Kg/cm 2 , and the outlet pressure is 1 Kg/cm 2 . The test results are converted into separation coefficient α and transmission coefficient η shown below and shown in Table 2. Separation factor α = H 2 out (100 − H 2 in) / H 2 in (100 − H 2 out
) However, H 2 in is H 2 vol% on the inlet side of the device, H 2 out
is the vol% of H 2 on the outlet side of the device. Permeability coefficient η = (Gas permeation flow rate) x (Separation membrane thickness) / (Membrane area) x (Pressure difference) x (Time) (cm 2 /sec cmHg) However, η In calculating each gas separation membrane C1~
A separation membrane thickness of 0.10 cm was used for both C16 and C16.
【表】
含有量は最外層の薄膜にお
ける値である。
＊３ Pd原子換算のmol％
[Table] The content is the value in the outermost thin film.
*3 Mol% in terms of Pd atoms
【表】【table】
【表】
考 察
以上の試験結果においては、分離係数αおよび
透過係数ηが共に大きいほどH2ガス分離能が高
いが、これら係数のうち透過係数ηについては試
験に供した全てのガス分離膜とも実用上支障がな
い程度のものである。一方、分離係数αについて
はその良否の判定基準を2.0として、α＞2.0のも
のを良とした。これにより、上記試験結果から次
のごとき結論が得られる。
(1) 実施例における全てのガス分離膜C1〜C12は
良好なH2ガス分離能を備えているのに対し、
比較例における全てのガス分離膜C13〜C16は
十分なH2ガス分離能を備えていない。これら
両例間のH2ガス分離能には、薄膜中のPdの有
無および同膜の平均細孔径の大小が大きく影響
していることが明らかである。
(2) H2ガス分離能に対するPdの及ぼす影響は大
きいが、Pdの含有量に関してはガス分離膜C5，
C2，C6，C9〜C12，C14等から明らかなように
Pdの含有量が1.0mol％まではH2ガス分離能が
著しく増大し、この値を越えると微増する傾向
にある。
(3) 薄膜の膜厚に関しては、ガス分離膜C1〜C4
等から明らかなように透過係数に及ぼす影響が
大きいが、薄膜の平均細孔径が所定以上であり
かつPdの含有量が所定以上であれば、膜厚が
500μ程度までは良好なH2ガス分離能を備えて
いる。
(4) 薄膜の平均細孔径に関しては、クヌーセン拡
散による分離が生じる孔径であることが必要で
あつて、ガス分離膜C7，C8，C15，C16等から
明らかなように孔径が大きくなるほど分離係数
αが小さくなるが、所定量のPdを含有する限
り平均細孔径1000Å程度までは良好なH2ガス
分離能を備えている。[Table] Discussion In the above test results, the larger the separation coefficient α and the permeability coefficient η, the higher the H 2 gas separation ability. In both cases, there is no problem in practical use. On the other hand, regarding the separation coefficient α, the criterion for determining its acceptability was 2.0, and those of α>2.0 were considered acceptable. As a result, the following conclusions can be drawn from the above test results. (1) All the gas separation membranes C1 to C12 in the examples have good H 2 gas separation ability, whereas
All gas separation membranes C13 to C16 in the comparative example do not have sufficient H 2 gas separation ability. It is clear that the H 2 gas separation ability between these two examples is greatly influenced by the presence or absence of Pd in the thin film and the size of the average pore diameter of the film. (2) Pd has a large influence on H2 gas separation ability, but regarding the Pd content, gas separation membrane C5,
As is clear from C2, C6, C9~C12, C14, etc.
The H 2 gas separation ability increases significantly when the Pd content reaches 1.0 mol %, and tends to increase slightly when this value is exceeded. (3) Regarding the thickness of the thin film, gas separation membranes C1 to C4
As is clear from the above, it has a large effect on the permeability coefficient, but if the average pore diameter of the thin film is greater than the specified value and the Pd content is greater than the specified value, the film thickness will increase.
It has good H2 gas separation ability up to about 500μ. (4) The average pore diameter of the thin membrane must be such that separation by Knudsen diffusion occurs; as is clear from gas separation membranes C7, C8, C15, C16, etc., the larger the pore diameter, the greater the separation coefficient α. However, as long as it contains a predetermined amount of Pd, it has good H 2 gas separation ability up to an average pore diameter of about 1000 Å.
Claims (1)
質支持体の少なくとも一方の面に、同支持体の細
孔の平均細孔径より小さな平均細孔径の連続した
細孔を有し無機質材料からなる一層または複数層
の多孔質薄膜を備え、少なくとも最外層の薄膜に
おける細孔の平均細孔径が1000Å以下であり、か
つ同薄膜はPdを含有していることを特徴とする
水素ガス分離膜。 ２ 少なくとも最外層の薄膜におけるPdの含有
量がPd原子換算にて0.1mol％以上である特許請
求の範囲第１項に記載の水素ガス分離膜。 ３ 少なくとも最外層の薄膜の膜厚が500μ以下
である特許請求の範囲第１項または第２項に記載
の水素ガス分離膜。[Scope of Claims] 1. A porous support made of an inorganic material having continuous pores, on at least one side thereof, continuous pores having an average pore diameter smaller than the average pore diameter of the pores of the support. a porous thin film of one or more layers made of an inorganic material, the average pore diameter of at least the outermost thin film is 1000 Å or less, and the thin film contains Pd. Hydrogen gas separation membrane. 2. The hydrogen gas separation membrane according to claim 1, wherein the Pd content in at least the outermost thin film is 0.1 mol% or more in terms of Pd atoms. 3. The hydrogen gas separation membrane according to claim 1 or 2, wherein at least the outermost thin film has a thickness of 500 μm or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26198985A JPS62121616A (en) | 1985-11-21 | 1985-11-21 | Separating membrane of hydrogen gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26198985A JPS62121616A (en) | 1985-11-21 | 1985-11-21 | Separating membrane of hydrogen gas |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62121616A JPS62121616A (en) | 1987-06-02 |
| JPH038816B2 true JPH038816B2 (en) | 1991-02-07 |
Family
ID=17369456
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26198985A Granted JPS62121616A (en) | 1985-11-21 | 1985-11-21 | Separating membrane of hydrogen gas |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62121616A (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS644216A (en) * | 1987-06-26 | 1989-01-09 | Agency Ind Science Techn | Production of thin membrane for separating gas |
| JPH02271902A (en) * | 1989-04-12 | 1990-11-06 | Agency Of Ind Science & Technol | Production of hydrogen separating medium |
| CA2048849A1 (en) * | 1990-08-10 | 1992-02-11 | David J. Edlund | Thermally stable composite hydrogen-permeable metal membranes |
| US5181941A (en) * | 1991-12-16 | 1993-01-26 | Texaco Inc. | Membrane and separation process |
| JP2756071B2 (en) * | 1992-12-24 | 1998-05-25 | 日本碍子株式会社 | Hydrogen gas separation device |
| IL105142A (en) * | 1993-03-23 | 1997-01-10 | Aga Ab | Method of improving the selectivity of carbon membranes by chemical carbon vapor deposition |
| JPH10113544A (en) * | 1996-07-08 | 1998-05-06 | Ngk Insulators Ltd | Gas separating body |
| US6039792A (en) * | 1997-06-24 | 2000-03-21 | Regents Of The University Of California And Bp Amoco Corporation | Methods of forming and using porous structures for energy efficient separation of light gases by capillary condensation |
| US6235417B1 (en) * | 1999-04-30 | 2001-05-22 | Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of Natural Resources | Two-phase hydrogen permeation membrane |
| JP4572385B2 (en) * | 2005-03-25 | 2010-11-04 | 独立行政法人産業技術総合研究所 | Hydrogen purification separation method |
| CN101610975A (en) | 2007-02-19 | 2009-12-23 | 三菱瓦斯化学株式会社 | Hydrogen process for purification, hydrogen separation membrane and hydrogen purification unit |
| WO2019021963A1 (en) * | 2017-07-25 | 2019-01-31 | 東レ株式会社 | Fluid separation membrane |
-
1985
- 1985-11-21 JP JP26198985A patent/JPS62121616A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62121616A (en) | 1987-06-02 |
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