JP3905948B2 - High silica zeolite catalyst - Google Patents

High silica zeolite catalyst Download PDF

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JP3905948B2
JP3905948B2 JP11418597A JP11418597A JP3905948B2 JP 3905948 B2 JP3905948 B2 JP 3905948B2 JP 11418597 A JP11418597 A JP 11418597A JP 11418597 A JP11418597 A JP 11418597A JP 3905948 B2 JP3905948 B2 JP 3905948B2
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catalyst
zeolite
hours
zinc
reaction
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JPH1052646A (en
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正嗣 川瀬
晃司 野村
幸人 永守
二郎 木下
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山陽石油化学株式会社
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y02P20/52Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

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Description

【0001】
【産業上の利用分野】
本発明は、原料または生成物中に芳香族炭化水素を含む反応に使用する高シリカゼオライト系触媒に関する。更に詳しくは、原料または生成物中に芳香族炭化水素を含む反応の間に該触媒上に蓄積する炭素質の蓄積量を低減し、かつ、該炭素質による活性の一時的な低下を抑え、更に、該炭素質を酸素含有イナートガスで燃焼除去する際に起こる如き、水分の存在する高温雰囲気下での脱アルミニウムによる永久活性劣化を抑える、耐コーキング性および耐再生劣化性に優れた高シリカゼオライト系触媒に関する。
【0002】
【従来の技術】
従来より高シリカ含有量ゼオライトを合成する方法、および、その方法にて製造された高シリカゼオライトは知られている。例えば、特公昭46−10064号公報や特公昭56−49850号公報には、シリカ,アルミナ,アルカリ金属,水および有機窒素陽イオン先駆物の供給物質を含む反応混合物を水熱処理する方法が開示されている。
【0003】
また、高耐熱水性高シリカゼオライトを製造する方法、および、その方法にて製造された高シリカゼオライトも公知である。例えば、特開平7−291620号公報には、アルミナ分当たり7.5モル倍以上の中性塩水溶液中にシリカ成分とアルミナ成分を同時注加して得られるpH11乃至13のアルミノケイ酸ゲルを水熱処理して、長軸/短軸の比が2乃至15、長軸/厚みの比が4乃至50である長六角板状結晶粒子を75個数%以上を含み且つ900℃で5時間のスチーミング処理をしたときの結晶保持率が85%以上である、従来の高シリカゼオライトに比べイオン交換率が高く、耐熱水性に優れた高シリカゼオライトおよびその製造方法が開示されている。
【0004】
更に、特開平3−293031号公報は、酸化物のモル組成で表して、aK2 O,bNa2 O,Al2 3 ,cSiO2 ,dH2 Oである高耐熱性ゼオライトであって、水分10%以上を含む水蒸気下、900℃で5時間熱水処理した後の結晶化度が、熱水処理前の90%以上である高耐熱性ゼオライト及びその製造方法について開示している。
【0005】
また、特開平3−193622号公報は、シリカ源、アルミナ源、アルカリ金属源、水を含む原料混合物を水熱合成条件下に結晶化させる際に、種スラリーとして、スラリー中の固形物の乾燥後のX線回折パターンがZSM−5であり、窒素吸着BET表面積が100〜250m3 /gである結晶化途中の水熱合成スラリーを、全体の10〜40重量%結晶化前に加えることを特徴とする、ZSM−5微粒子体の製造法について開示している。
【0006】
更にまた、特公平7−35343号公報および特公平7−94396号公報には、亜鉛を含むZSM−5型ゼオライトを触媒として軽質炭化水素より芳香族炭化水素を製造する方法において、該触媒が特定のケイ素/アルミニウム原子比と亜鉛/ケイ素原子比をもち、昇温脱離法による500〜900℃における該ZSM−5型ゼオライト1gあたりのピリジンの脱離量が40〜120μmolであることを特徴とする、芳香族炭化水素の製造方法が開示されている。
【0007】
しかし、特公昭46−10064号公報や特公昭56−49850号公報に記載されている方法で合成した高シリカ含有量ゼオライトでは、結晶性が不十分で結晶自体の耐熱性が悪くなり、該反応の間に蓄積した炭素質を燃焼除去する際に起こる如き、水分の存在する高温雰囲気下での脱アルミニウムによりゼオライト触媒が永久劣化する問題があり、更に、該反応の間に蓄積する炭素質の量が多いため、これを燃焼除去する設備が大きくなるという課題があった。
【0008】
特開平7−291620号公報や特開平3−293031号公報の方法で合成されたゼオライトは、耐熱水性の高いゼオライトではあるが、原料または生成物中に芳香族炭化水素を含む反応系での使用については記載がなく、該反応の間にゼオライト触媒上に蓄積する炭素質による活性低下という問題点自体認識されていなかった。
【0009】
また、一般に、耐熱水性の高いゼオライトは、その結晶化度を高める必要があるため、結果的に粒子径が大きくなる傾向があるが、粒子径が大きすぎると表面酸点の全酸点に対する割合が少ないため、原料または生成物中に芳香族炭化水素を含む反応において、該反応の間にゼオライト触媒上に蓄積する炭素質による活性低下が速く、実用に耐えないという問題があった。
【0010】
特開平3−193622号公報で合成されるゼオライトは、その実施例にも記載されているように、シクロヘキセンからシクロヘキサノールを生成する反応に使用される微粒子ゼオライトであって、粒子径を微粒化することで炭素質の蓄積による触媒寿命を延長させることを目的としている。
【0011】
本願のゼオライトは、例えば、特開平3−193622号公報の方法で合成することも可能であるが、その方法で合成されたゼオライトの粒径が小さすぎたり、表面酸点の全酸点に対する割合が大きすぎると、オレフィンや芳香族炭化水素、特にスチレン等の、反応中に蓄積する炭素質を多くする原因となる成分を原料中もしくは生成物中に含む反応においては、該反応の間に蓄積する炭素質の量が多くなる。
【0012】
炭素質の量が多くなると、これを燃焼除去する設備が同一であれば、炭素質の量が少ない場合に比較して燃焼除去する時間が長くなり、同一燃焼時間で燃焼除去させる場合は、燃焼除去の設備が大きくなるとともに、単位時間当たりに発生する水分が多くなり、脱アルミニウムによる永久劣化が速いという課題があった。
【0013】
また、特開平3−193622号公報の実施例に記載されているZSM−5では、結晶化度が小さく、該反応の間に蓄積した炭素質を燃焼除去する際に起こる如き、水分の存在する高温雰囲気下での脱アルミニウムによりゼオライト触媒が永久劣化する問題があった。
【0014】
特公平7−35343号公報および特公平7−94396号公報では、軽質炭化水素より芳香族炭化水素を製造する方法において、該反応の間に蓄積する炭素質による経時活性低下を減少させるため、特定のケイ素/アルミニウム原子比と亜鉛/ケイ素原子比をもつ触媒であって、昇温脱離法による500〜900℃におけるZSM−5型ゼオライト1gあたりのピリジンの脱離量が40〜120μmolであるZSM−5型ゼオライトを含む触媒を使用する製造方法を開示している。ピリジンの脱離量を上記範囲とすることで、軽質炭化水素から芳香族炭化水素を製造するための必要活性は保持しながら、蓄積する炭素質による経時活性低下を少なくしている。
【0015】
しかしながら、これらの公報では、該反応の間に蓄積した炭素質を燃焼除去する際に起こる如き、水分の存在する高温雰囲気下での脱アルミニウムによりゼオライト触媒が永久劣化する問題については解決されていない。どちらの公報でもその実施例から明らかなように、該触媒をH2 O分圧0.8atm,650℃で5時間水蒸気処理をした後での、H型にしたときの昇温脱離法による500〜900℃におけるピリジンの脱離量(B)と該水蒸気処理前のH型にしたときの昇温脱離法による500〜900℃におけるピリジンの脱離量(A)とで表されるパラメータαが1.6より大きく、各反応毎の炭素質の析出による劣化は小さいが、永久劣化が速く、反応と該反応の間に蓄積した炭素質を燃焼除去する再生とを繰り返して数ヶ月あるいは数年使用するには実用に耐えない。
【0016】
以上列挙したように、ゼオライトの合成方法は前期記載の如く種々提唱されているが、原料もしくは生成物に芳香族炭化水素が含まれる反応での、該反応の間に該触媒上に蓄積する炭素質の量が少なく、かつ、該炭素質による活性の一時的な低下を抑え、更に、該炭素質を酸素含有イナートガスで燃焼除去する際に起こる、水分の存在する高温雰囲気下での脱アルミニウムによる永久活性劣化を抑えることができる、耐コーキング性にも耐再生劣化性にも同時に優れる高シリカゼオライト系触媒は見いだされていなかった。
【0017】
【発明が解決しようとする課題】
本発明の課題は、上記の従来技術の問題点を解決し、原料もしくは生成物に芳香族炭化水素が含まれる反応に用いられる高シリカゼオライト系触媒であって、該反応の間に該触媒上に蓄積する炭素質の量を低減し、かつ、該炭素質による活性の一時的な低下を抑え、更に、該炭素質を酸素含有イナートガスで燃焼除去する際に起こるような、水分の存在する高温雰囲気下での脱アルミニウムによる永久活性劣化を抑えることができる耐コーキング性及び耐再生劣化性に優れた高シリカゼオライト系触媒を提供することにある。
【0018】
【課題を解決するための手段】
本発明者は鋭意研究を重ねた結果、原料もしくは生成物に芳香族炭化水素が含まれる反応に用いられる高シリカゼオライトとして、特定のSiO2 /Al2 3 モル比を持ち、特定の粒子径と特定の酸点の割合および特定の酸点を有するゼオライトを用いれば、上記の課題を一挙に解決できることを見いだし、本発明を完成した。
【0019】
すなわち、本発明は、オレフィンおよび/またはパラフィンを含む軽質炭化水素から芳香族炭化水素を製造する反応に用いられる高シリカゼオライト系触媒であって、下記の要件(1),(2),(3),(4)を満足する高シリカゼオライト系触媒を提供するものである。
(1)該ゼオライト系触媒を構成するゼオライトのSiO/Alモル比が20から200。
(2)該ゼオライト系触媒を構成するゼオライトの一次粒子の粒子径が0.3から3μm。
(3)該ゼオライト系触媒をH型にしたときの全酸点に対する表面酸点の割合が0.03〜0.15。
(4)該ゼオライト系触媒をHO分圧0.8atm,650℃で5時間水蒸気処理した後での、H型にしたときの昇温脱離法による500〜900℃におけるピリジンの脱離量(B)と該水蒸気処理前のH型にしたときの昇温脱離法による500〜900℃におけるピリジン脱離量(A)とが以下を満足する。
【0020】
【数2】

Figure 0003905948
【0021】
本発明における、原料もしくは生成物に芳香族炭化水素が含まれる反応とは、該反応の原料中に5重量%以上の芳香族炭化水素が含まれるか、もしくは、該反応の生成物中に5重量%以上の芳香族炭化水素が含まれる反応をいう。芳香族炭化水素特にスチレンなどの炭素数が8以上の芳香族炭化水素が原料もしくは生成物中に含まれると、該反応中に蓄積する炭素質が多い。原料もしくは生成物に芳香族炭化水素が含まれる反応としては、例えば、オレフィンおよび/またはパラフィンを含む軽質炭化水素から芳香族炭化水素を製造する環化反応や、ナフサやH−NGL等の炭化水素を含む原料から低級オレフィン類および芳香族炭化水素類を効率よく、かつエチレンを主成分とする低級オレフィン類を芳香族炭化水素類より高収率に得る接触分解反応、トルエンの不均化反応、キシレンの異性化反応、エチルベンゼン合成反応等が挙げられる。
【0022】
以下、これらの反応のうち、オレフィンおよび/またはパラフィンを含む軽質炭化水素から芳香族炭化水素を製造する環化反応について、詳細に説明する。 本発明におけるオレフィンおよび/またはパラフィンを含む軽質炭化水素とは、炭素数2以上、90%留出温度190℃以下の炭化水素である。たとえば、パラフィンとしてはエタン,プロパン,ブタン,ペンタン,ヘキサン,ヘプタン,オクタン,ノナンであり、オレフィンとしてはエチレン,プロピレン,ブテン,ペンテン,ヘキセン,ヘプテン,オクテン,ノネンがあげられる。上記以外にシクロペンタン,シクロペンテン,メチルシクロペンタン,シクロヘキサン,メチルシクロペンテン,シクロヘキセン,シクロヘキサジエンなどのナフタン,ナフテンを含んでもよく、ブタジエン,ペンタジエン,シクロペンタジエンなどのジエン類を含んでいてもよい。
【0023】
上記のそれぞれの混合物を原料として用いてもよく、該混合物には希釈剤としてN2 ,CO2 ,CO等のイナートガスや、反応にともない触媒上に蓄積する炭素質(コーク)の生成を抑えるためにH2 ,CH4 を含んでいてもよい。さらに該混合物中の飽和炭化水素と不飽和炭化水素の重量比が0.43〜2.33であると特によい。ここでいう飽和炭化水素と不飽和炭化水素の重量比とは、供給される混合物中の重量比を意味する。
【0024】
混合物としては、上記のそれぞれの混合物、あるいはナフサなどの石油系炭化水素の高温熱分解生成物のC4 留分、前記C4 留分よりブタジエンまたはブタジエンとi−ブテンを除いた留分、高温熱分解生成物のC5 留分、前記C5 留分からジエン類を除いた留分、熱分解ガソリン、熱分解ガソリンより芳香族炭化水素抽出を行ったラフィネート、FCC−LPG、FCC分解ガソリン、リフォーメートより芳香族炭化水素を抽出したラフィネート、コーカーのLPG、直留ナフサがあげられるが、この内、ナフサなどの石油系炭化水素の高温熱分解生成物のC4 留分、C5 留分、該C4 ,C5 留分からブタジエン,i−ブテン,イソプレン,シクロペンタジエンの一部もしくは全部を除いた留分が特に好適に利用でき、該C4 留分、C5 留分の重量比が3/7〜7/3である原料が特に好ましい。ここでいうC4 留分とC5 留分の重量比とは供給される混合物中の重量比を意味する。本発明の方法においては、該原料中に不純物としてTBA,メタノール等の含酸素化合物が含まれていてもよい。
【0025】
本発明における高シリカゼオライト系触媒を構成するゼオライトは、そのゼオライトのSiO2 /Al2 3 モル比が20〜200であり、例えば、β−ゼオライト、Ω−ゼオライト、Y−ゼオライト、L−ゼオライト、エリオナイト、オフレタイト、モルデナイト、フェリエライト、ZSM−5、ZSM−8、ZSM−11、ZSM−12、ZSM−35、ZSM−38等があげられるが、ZSM−5、ZSM−8、ZSM−11等のZSM−5型の結晶性アルミノシリケートまたはメタロシリケートが好ましい。ZSM−5のゼオライトについては、例えば、米国特許第5,268,162号明細書を参照することができる。
【0026】
本発明に用いるゼオライトは、いずれもH型あるいは金属置換型として用いることができ、該金属置換型の金属はVIII族,Ib族,IIb族、またはIIIb族に属する金属であることが好ましい。VIII族,Ib族,IIb族,IIIb族に属する金属としては、Zn,Cu,Ag,Ni,Pt,Pd,Gaが更に好ましく、それらのうちでもZn,Ag,Ni,Gaがより好適に用いられる。この時、該金属は、ゼオライト骨格内に含まれていてもよく、イオン交換されていてもよい。
また、更に、後述するように、アルミナ等のバインダーおよび/または酸化亜鉛等の脱水素を促進する金属酸化物と併用することもできる。
【0027】
本発明において、ゼオライトの合成方法は特に限定されないが、特開平3−193622号公報に記載されている、種スラリーを用いて合成する方法が特に好ましい。また、本発明の方法においては、国際出願番号PCT/JP95/02040記載の如き、SiO2 /Al2 3 モル比が20以上で、1種または2種以上の周期律表第Ib族に属する金属を有する、実質的にプロトンを含まない中間細孔径ゼオライトを用いることもできる。いずれの場合でも、SiO2 /Al2 3 モル比、ゼオライトの一次粒子の粒径、H型にしたときの全酸点に対する表面酸点の割合、パラメータαが本発明の範囲内にあることが重要である。
【0028】
仕込み原料のSiO2 /Al2 3 モル比、攪拌速度、合成温度等の合成条件、テンプレートの使用有無、使用テンプレートの種類等を調整することによって、ゼオライトのSiO2 /Al2 3 モル比、ゼオライトの一次粒子の粒径、H型にしたときの全酸点に対する表面酸点の割合、パラメータαを本願発明の範囲内にすることができる。
【0029】
本発明の触媒を構成するゼオライトは、SiO2 /Al2 3 モル比が20から200であり、30から100が好ましく、30から80が更に好ましい。SiO2 /Al2 3 モル比が20より小さいと、原料もしくは生成物に芳香族炭化水素が含まれる反応の間に該触媒上に蓄積する炭素質を酸素含有イナートガスで燃焼除去する際に起こる如き、水分の存在する高温雰囲気下での脱アルミニウムによる永久活性劣化が速くなる。
【0030】
脱アルミニウムによる永久活性劣化は、X線回折法による結晶化度の相対値が高いほど抑制されると考えられるが、該結晶化度の相対値はSiO2 /Al2 3 モル比に影響され、該SiO2 /Al2 3 モル比が20より小さい、あるいは200より大きいと、結晶化度の相対値が小さくなり、脱アルミニウムによる永久劣化が速く、好ましくない。また、SiO2 /Al2 3 モル比が200より大きいと、充分な活性が得られず、原料もしくは生成物に芳香族炭化水素が含まれる反応に充分なだけの活性がない触媒となる場合がある。
【0031】
本発明の触媒を構成するゼオライトのSiO2 /Al2 3 モル比とは、バインダーとしてのアルミナやシリカを含んでいない、水熱合成したゼオライトであって、水蒸気処理等の脱アルミニウム処理や、軽質炭化水素から芳香族炭化水素を生成する如き反応に供していない新鮮なゼオライトを蛍光X線装置またはEPMA(X線マクロアナライザー)で測定することによって求められるモル比である。
【0032】
本発明におけるゼオライト系触媒としては、前記記載のH型あるいは金属置換型の実質的にゼオライトからなるものを用いることができるが、上記したゼオライトと、周期律表VIII族,Ib族,IIb族およびIIIb族に属する金属類から選ばれた少なくとも一種の金属およびそれらの化合物(例えば、酸化亜鉛等の脱水素を促進する金属酸化物)からなる群から選ばれる少なくとも一種との混合物を含む、あるいは化合物として担持されていてるものが好ましい。
【0033】
VIII族,Ib族,IIb族,IIIb族に属する金属としては、Zn,Cu,Ag,Ni,Pt,Pd,Gaが更に好ましく、それらのうちでもZn,Ag,Ni,Gaがより好適に用いられる。例えば、ゼオライトと、亜鉛およびその化合物から選ばれる少なくとも一種との混合物を含むことが好ましい。更に、バインダーとしてアルミナ、シリカを併用すると、より好ましい。
【0034】
本発明において、亜鉛成分は、例えば、亜鉛、酸化亜鉛、水酸化亜鉛、あるいは硝酸亜鉛、炭酸亜鉛、硫酸亜鉛、塩化亜鉛、酢酸亜鉛、シュウ酸亜鉛などの塩、あるいはアルキル亜鉛などの有機亜鉛化合物が挙げられる。
【0035】
本発明においては、ゼオライト系触媒は、ゼオライトと、亜鉛成分、およびアルミナの混合物を含むことが好ましい。また、亜鉛成分およびアルミナの混合物を水蒸気中で熱処理したものとゼオライトの混合物であることも好ましい。いずれの触媒も、水蒸気処理すると、亜鉛成分とアルミナが反応しアルミン酸亜鉛に変化するため亜鉛が安定化され、オレフィンおよび/またはパラフィンを含む軽質炭化水素から高収率で芳香族炭化水素を製造する反応等において、亜鉛の飛散損失を大幅に低減することができる。ここでいうアルミン酸亜鉛とは、島津製作所のXD−610等のX線回折装置で観察した場合にJCPDS 5−0669NBS Circ.,539,Vol.II,38(1953)に示されるパターンと同一のX線回折パターンを持つものを意味する。
【0036】
アルミナのアルミナ源としては、無水アルミナまたはアルミナの水和物があるが、そのほかにたとえば、アルミニウム塩のように加水分解または加熱分解、酸化などにより、無水アルミナまたはアルミナ水和物を生成する原料を使用する事もできる。
【0037】
本発明において、アルミナ源としてアルミナゾルを使用することも好ましい。アルミナ源としてアルミナゾルを使用すると、上記水蒸気処理を実施せずとも亜鉛成分とアルミナが反応しアルミン酸亜鉛が生成するため、亜鉛が安定化する。
【0038】
上記したゼオライト系触媒においては、亜鉛およびその化合物から選ばれる少なくとも一種の含有量が、亜鉛として5〜25重量%であることが好ましい。 本発明において、アルミナを含む場合のアルミナ含有率は、Al2 3 として全触媒に対し5〜50重量%、好ましくは15〜40重量%であり、かつ、アルミナと亜鉛を含む場合は、アルミナと亜鉛のモル比(Al2 3 /Zn)が1以上である。
【0039】
また、本発明においては、反応に供される時点において、該ゼオライト触媒に酸化亜鉛とアルミン酸亜鉛とが共存することが好ましい。アルミン酸亜鉛はスピネル構造を持つため該ゼオライト系触媒中からの亜鉛の飛散は抑制されるものの亜鉛担持の本来の目的である芳香族選択率の向上効果が小さくなってしまうため、芳香族選択率の向上効果を発揮する酸化亜鉛を共存させておくことが好ましい。酸化亜鉛とアルミン酸亜鉛の好ましい存在量は、原料もしくは生成物に芳香族炭化水素が含まれる反応に供される時点で酸化亜鉛1.2〜20重量%、アルミン酸亜鉛8.2〜50重量%であり、更に好ましくは酸化亜鉛が1.0〜5.0重量%、アルミン酸亜鉛が14〜40重量%である。
【0040】
アルミン酸亜鉛自体の芳香族選択性向上効果は小さいが、酸化亜鉛の補給源となり、酸化亜鉛の減少を抑制し、その結果として芳香族選択率向上効果を長時間持続させることが出来る。さらにアルミン酸亜鉛が存在することで、酸化亜鉛の、原料もしくは生成物に芳香族炭化水素が含まれる反応時の、還元による飛散速度を抑制する効果もある。故に触媒に酸化亜鉛とともにアルミン酸亜鉛を共存させることは芳香族選択率向上効果維持に有効である。
【0041】
本発明でいう酸化亜鉛とは下記分析方法で測定されたものをいう。すなわち、触媒1gを乳鉢で数百ミクロン程度にすり潰し、120℃で1時間乾燥後約0.5gを正確に計りとり200ccビーカーに入れる。そこに3%塩酸水溶液150ccを加え電熱ヒーター上で80℃で2時間加熱する。その後0.2μmメンブランフィルターで濾過し、濾液を原子吸光分析計(島津製作所製 島津原子吸光/フレーム分光光度計 AA−640−12型)でフレーム分析、標準添加法で酸化亜鉛の定量分析を行なう。
【0042】
本発明におけるアルミン酸亜鉛重量は、全亜鉛重量から上記方法にて定量分析した酸化亜鉛の重量を減算したものである。ここで言う全亜鉛重量とは、蛍光X線分析装置(理学RIX1000)で標準物質の検量線より求めたものをいう。
【0043】
本発明におけるゼオライトの一次粒子の粒径とは、SiO2 /Al2 3 モル比と同様に、実質的に新鮮な状態のゼオライトを走査型電子顕微鏡で見た時の一次粒子の粒径である。本願発明では、該粒径が0.3から3μm、更には0.5から2μmであると好ましい。これら一次粒子の形状は種々のものがあるが、ここで言う粒径とは、それぞれの粒子の最も幅の広いところの平均径を示している。これらの一次粒子は、単独で存在しても、二次凝集していてもかまわない。
【0044】
粒径が0.3μmより小さいと、原料もしくは生成物に芳香族炭化水素が含まれる反応の間に該触媒上に蓄積する炭素質の量が多くなるとともに、該炭素質を酸素含有イナートガスで燃焼除去する際に起こる如き、水分の存在する高温雰囲気下での脱アルミニウムによる永久活性劣化が速くなり、逆に粒径が3μmより大きいと原料もしくは生成物に芳香族炭化水素が含まれる反応の間に該触媒上に蓄積する炭素質による、活性の一時的な低下が速くなるため、実用に耐えない。
【0045】
本発明においては、該ゼオライト系触媒を該反応に供する時点において、H型にした時の全酸点に対する表面酸点の割合が0.03から0.15であり、0.05から0.1がより好適である。全酸点に対する表面酸点の割合が0.03より小さいと、原料もしくは生成物に芳香族炭化水素が含まれる反応の間に該触媒上に蓄積する炭軽質による、活性の一時的な低下が速くなり、逆に該割合が0.15より大きいと原料もしくは生成物に芳香族炭化水素が含まれる反応の間に該触媒上に蓄積する炭軽質の量が多くなるとともに、該炭素質を酸素含有イナートガスで燃焼除去する際に起こる如き、水分の存在する高温雰囲気下での脱アルミニウムによる永久活性劣化が速くなる。
【0046】
本発明における、触媒のH2 O分圧0.8atm,650℃での5時間水蒸気処理は、第2図に示す装置において、10mmφの石英反応管10中に下から石英ウール11、触媒12、ラシヒリング13の順で充填し、温度計14で測定した触媒12の温度が650℃の等温になるように温度調節用熱電対15で温度が調節できる電気炉16にて石英反応管10を加熱し、大気圧、H2 O分圧0.8atmの条件で、実質的に新鮮な触媒に水または水蒸気を、原料流入口17より5時間供給することで実施される。
【0047】
本発明においては、該触媒を上記方法によりH2 O分圧0.8atm,650℃で5時間水蒸気処理をした後での、H型にしたときの昇温脱離法による500〜900℃におけるピリジンの脱離量(B)と該水蒸気処理前のH型にしたときの昇温脱離法による500〜900℃におけるピリジン脱離量(A)とで表される以下のパラメータαが1.6以下であり、特に好ましくは1.4以下である。
【0048】
【数3】
Figure 0003905948
【0049】
パラメータαが1.6より大きいと原料もしくは生成物に芳香族炭化水素が含まれる反応の間に該触媒上に蓄積する炭素質を酸素含有イナートガスで燃焼除去する際に起こる如き、水分の存在する高温雰囲気下での脱アルミニウムによる永久活性劣化が速く、耐再生劣化性が悪い。
【0050】
該パラメータαはX線回折法により求められる結晶化度に依存する。すなわち、後述の比較例に示すとおり、比較例1の如くゼオライトの粒径が小さい場合や、比較例3の如くSiO2 /Al2 3 モル比が小さい場合、更に比較例4の如くSiO2 /Al2 3 モル比が大きい場合は、X線回折法による結晶化度の相対値が小さく、パラメータαが大きくなり、耐再生劣化性が悪くなる。
【0051】
また、SiO2 /Al2 3 モル比、粒径が本発明の範囲にあっても、比較例5の如く、パラメータαが1.6より大きくなり、耐再生劣化性が悪くなる場合もある。比較例5も、結晶化度の相対値が小さいことから、合成されたゼオライトに非晶質のアモルファスが共存していると推定される。従って、水分の存在する高温雰囲気下での脱アルミニウムによる永久活性劣化が少ない、数年の反応/再生繰り返しに耐えうる触媒とするには、本発明の(1)〜(4)全ての要件を満たしている必要がある。
ここで、結晶化度の相対値とは、該ゼオライト系触媒のゼオライトのX線回折パターンの2θ=23.1゜、24.0゜、24.4゜それぞれのピーク高さの和の相対値をいう。
【0052】
また、脱離量および全酸点に対する表面酸点の割合を測定する方法は、以下の方法による。
(酸点測定方法)
まず、酸点を測定する前に、該ゼオライト系触媒がH型でない場合は、以下の方法に従ってH型にする必要がある。ゼオライトをH型にするには、該ゼオライトに1規定の硝酸を加えて10重量%スラリーとして、60℃で4時間イオン交換を行い、そのスラリーを濾過し、更に5倍量の水で水洗した後、120℃で10時間乾燥しする。このようにして得られたH型のゼオライトの酸点を以下の方法で測定する。
【0053】
酸点の測定装置としては、島津製作所製ガスクロマトグラフィーGC−14Aおよびデータ処理装置CR−4Aを用いた。本発明に用いる酸点測定装置を第1図に示す。すなわち、内径6mm、全長220mmのSUS製短カラム3へ試料4を0.1〜1g充填する。該試料4は、ペレット状に成形されていれば1〜5mmの長さで、粉末であれば20〜30メッシュに圧縮成型して充填する。キャリアガスとして窒素を60cc/分の流量でガス流量計1を調節しながら流し、同時に炉芯管内径20mmφ、長さ150mmの管状電気炉2の温度を、使用するアミンがピリジンの場合は180℃に、4−メチルキノリンの場合は280℃に設定する。次に、アミン(ピリジン、4−メチルキノリン)の一定量(1μcc)をオートサンプラーマイクロシリンジ(AOC)を用いて、注入口5より一定期間(2〜5分)をおいて断続的に注入し続ける。
【0054】
一方、充填カラム3を通ったキャリアガスは、FID型検出器6を用いて分析し、周期的にピークが現れる経時的なアミン濃度変化のクロマトグラムを得る。注入回数の増加とともに試料に対するアミン吸着量が飽和に近づき、それに伴って注入で得られる非吸着アミン量が増加する。従って、前記クロマトグラムにおいて、アミンの注入に対応する非吸着ピーク面積Si は次第に注入したアミンの量に対応する面積So に近づく。すなわち、データ処理装置で確認される、ピーク面積Si に対応するトータルカウント数が、面積So に対応するトータルカウント数に近づく。得られた非吸着アミン量に対応するトータルカウント数Ni と、その直前の注入時に得られた非吸着アミン量に対応するトータルカウント数Ni-1 とが、以下の条件を満たした場合に、アミン吸着量が飽和になったと判断する。
【0055】
【数4】
Figure 0003905948
【0056】
上記条件で、アミンの触媒への飽和吸着が完了したと判断された後、管状電気炉2で15℃/分の速度で昇温する。ここで、アミン注入口5の周りからFID型検出器6間でのガス流路は、電気炉内の部分を除き、リボンヒータ8等で加温し、外側を保温材9で覆ってアミンがピリジンの場合は200℃に、アミンが4−メチルキノリンの場合は300℃に保温する。温度検出は試料管外部に密着設置した温度検出端の位置で行う。温度検出端7が900℃に達するまでの間に試料4から脱離するアミンをFID型検出器6で検出し、アミンの検量線を用いてその脱離量を換算する。
【0057】
本発明における全酸点とは、アミンとしてピリジンを用いて測定した場合のピリジン脱離量で表し、表面酸点とは、アミンとして4−メチルキノリンを用いて測定した場合の4−メチルキノリン脱離量で表される。また、昇温脱離法による500〜900℃におけるピリジンの脱離量とは、温度検出端7が500℃になった時点から、更に昇温して900℃に達するまでの間に得られる脱離量である。いずれの脱離量もゼオライトを含む触媒1g当たりの脱離量として表す。
【0058】
(n−ヘキサン分解1次反応速度定数測定法)
本発明における触媒のn−ヘキサン分解の1次反応速度定数とは、第2図に示す装置を用いて、10mmφの石英反応管10中に下から石英ウール11、炭素質(コーク)が実質的に存在しない触媒12、ラシヒリング13の順で充填し、温度計14で測定した触媒12の温度が500℃の等温になるように温度調節用熱電対15で温度が調節できる電気炉16にて石英反応管10を加熱し、大気圧、重量時間空間速度(WHSV)4hr-1の条件で、n−ヘキサンを原料流入口17より供給し、n−ヘキサン供給後0.75時間から1時間後の反応生成物をコンデンサー18にて冷却した後、オイルトラップ19にて更にドライアイス・エタノール冷媒で冷却し、オイルトラップ19中に分離したオイル成分および発生ガス捕集用バッグ20中に分離したガス成分をそれぞれ全量採取する。
【0059】
そして、ヒューレット・パッカード社製のFID−TCDガスクロマトグラフィー(HP−5890 シリーズII)にてガス組成を、島津製作所社製のFIDガスクロマトグラフィー(GC−17A)にてオイル組成を分析して得られる反応生成物中のn−ヘキサン転化率を、下式に代入して求めた、上記ガス・オイル採取時間0.25時間の平均のゼオライト基準のn−ヘキサン分解1次反応速度定数をいう。
【0060】
【数5】
Figure 0003905948
【0061】
上記1次反応速度定数は、該触媒の活性を代表するものであって、本発明におけるゼオライト触媒のn−ヘキサン分解の1次反応速度定数は、反応に供される時点において、0.2以上であることが好ましく、0.3以上であれば更に好ましい。該n−ヘキサン分解の1次反応速度定数が0.2を下回る触媒は、活性が低く原料もしくは生成物に芳香族炭化水素が含まれる反応で得られる目的生成物が少なくなる。
【0062】
【発明の実施の形態】
次に、実施例および比較例によって本発明をさらに詳細に説明する。
【0063】
【実施例】
実施例1
珪酸ナトリウム水溶液(SiO2 :26重量%、Na2 O:7.0重量%)8.0kgにNaOH0.05kgとH2 O4kgを加えた溶液に、Al2 (SO4 3 ・16H2 O0.61kgと1,3−ジメチル尿素0.1kgをH2 O15kgに溶かした溶液を攪拌しながら加え、5重量%の硫酸10kgを加えて均質なゲルを得た。このゲルを50リットルのオートクレーブに仕込み、攪拌動力0.5〜1KW/m2 で攪拌しながら160℃で10時間合成反応を行い、種スラリーを得た。
【0064】
次に、特3号ケイ酸ソーダ(富士化学(株)社製,SiO2 25重量%,Na2 O 8重量%)6.44kgにH2 O17.47kgとAl2 (SO4 3 ・16H2 O(和光純薬K.K.社製)0.248kgおよび硫酸(和光純薬K.K.社製、純度97%)0.353kgを加え、種スラリーとして上記で得られたスラリーを10.49kg添加して、均質なゲルを得た。このゲルを50リットルオートクレーブに入れ、150℃で45時間、回転数110rpmで攪拌させながら結晶化させた。
【0065】
得られたスラリーを濾過した後、5倍量の水で水洗し、120℃で5時間乾燥させた。その乾燥物の走査型電子顕微鏡写真を第3図に示す。図から明らかなように生成したZSM−5は、最も幅の広い部分の厚さが1.5〜2μm、平均1.2μmであることがわかる。
【0066】
続いて、得られた乾燥物のSiO2 /Al2 3 モル比を蛍光X線装置を用いて測定したところ、36であった。
さらに、この乾燥物を1規定の硝酸中10重量%スラリーで室温で、3時間イオン交換した後、濾過して5倍量の水で水洗し、更に120℃で10時間乾燥した。
【0067】
硝酸亜鉛六水和物144gを水400gに溶かし、アルミナゾル400g(日産化学工業社製アルミナゾル520)と、上記H−ZSM−5を200g加え50℃で加熱し2時間混合した。水分が減少し粘土状になった上記混合物を直径1.6mm、長さ4〜6mmの円柱状に成型後、120℃で2時間乾燥した後、電気炉で空気雰囲気中500℃で3時間焼成し、亜鉛を10重量%含むH−ZSM−5ゼオライト触媒を成形した。
【0068】
更に、得られた成形触媒を第2図に示す装置の石英反応管に充填し、前記記載の方法で650℃、H2 O分圧0.8atmの条件で5時間水蒸気処理を実施した。次いで、上記水蒸気処理をする前後でのH型にしたときの昇温脱離法による500〜900℃におけるピリジンの脱離量を前記方法にて求めた。
【0069】
続いて、後述の実施例,比較例の触媒と初期活性をそろえるために、前記記載の方法で650℃、H2 O分圧0.8atmの条件で1.2時間追加水蒸気処理を実施した。該水蒸気処理をした後の触媒のn−ヘキサンの1次反応速度定数および表面酸点と全酸点の割合を前記記載の方法でもとめた。
【0070】
次に、この触媒の耐再生劣化性を評価するために、モデル的な再生劣化試験を実施した。すなわち、上記の合計6.2時間水蒸気処理をした触媒を第2図に示す装置に充填し、530℃、H2 O分圧0.15atmの条件で100時間追加水蒸気処理を実施し、その前後の触媒のn−ヘキサンの1次反応速度定数を上記と同様の方法にてもとめた。結果を表1に示す。
【0071】
更に、耐コーキング性を評価するために、水蒸気処理をしていない成形したH−ZSM−5ゼオライト触媒を、第4図に示す反応装置を用いて、表2に示すC5 留分と表3に示すC4 留分を6:4(重量比)で供給する、環化反応試験を行った。すなわち、該成形触媒を内径27.2mmφのSUS製の反応管21に100g充填し、温度計22で測定した触媒23の平均温度が650℃の等温になるように温度調節用熱電対24で温度が調節できる電気炉25にてSUS製反応管21を加熱し、1Kg/cm2 ・G、H2 O分圧0.8atmの条件で、実質的に新鮮な触媒に水または水蒸気を、原料流入口26より6.2時間供給することで、水蒸気処理を実施した。
【0072】
その後、触媒23の平均温度が520℃の等温になるように温度調節用熱電対24を用いて調節し、原料タンク27中の表2に示す組成を持つC5 留分と原料タンク28中の表3に示すC4 留分とをポンプ29および30にて重量比6:4、圧力5Kg/cm2 ・G、温度520℃、WHSV(重量時間空間速度)2.8hr-1の条件で、SUS製反応管21内の触媒23に48時間供給した。供給開始後5時間後および40時間後の芳香族収率を求めるとともに、48時間の反応の間に触媒上に蓄積したコークの量も求めた。結果を表1に示す。
【0073】
実施例2
特3号ケイ酸ソーダ(富士化学(株)社製,SiO2 25重量%,Na2 O 8重量%)6.75kgにH2 O23.0kgとAl2 (SO4 3 ・16H2 O(和光純薬K.K.社製)0.186kgおよび硫酸(和光純薬K.K.社製、純度97%)0.198kgを加え、種結晶としてSiO2 /Al2 3 モル比が既知の市販ZSM−5(NE−ケムキャット社製,SiO2 /Al2 3 =50)を0.167kg添加して、均質なゲルを得た。
【0074】
このゲルを50リットルオートクレーブに入れ、150℃で25時間、回転数200rpmで攪拌させながら結晶化させた。得られたスラリーを濾過した後、5倍量の水で水洗し、120℃で5時間乾燥させた。このゼオライトの走査型電子顕微鏡写真を第5図に示す。図から明らかなように生成したZSM−5は、最も幅の広い部分の厚さが0.5〜1μm、平均0.7μmであることがわかる。
【0075】
次に、得られた触媒のSiO2 /Al2 3 モル比を実施例1と同じ方法にて求めた。
また、実施例1と同じ方法で亜鉛を10重量%含むH−ZSM−5ゼオライト成形触媒を得た。この成形触媒の、650℃で5時間水蒸気処理した前後の500℃〜900℃のピリジン脱離量と、650℃で11時間水蒸気処理した後のn−ヘキサンの1次反応速度定数および表面酸点と全酸点の割合を実施例1と同じ方法でもとめた。結果を表1に示す。
【0076】
更に、650℃で11時間水蒸気処理した触媒を用いて、実施例1と同じ耐再生劣化性を評価する試験と、耐コーキング性を評価する試験を実施した。結果を表1に示す。
【0077】
実施例3
珪酸ナトリウム水溶液(SiO2 :26重量%、Na2 O:7.0重量%)8.0kgにNaOH0.05kgとH2 O4kgを加えた溶液に、Al2 (SO4 3 ・16H2 O0.61kgと1,3−ジメチル尿素0.1kgをH2 O15kgに溶かした溶液を攪拌しながら加え、5重量%の硫酸10kgを加えて均質なゲルを得た。このゲルを50リットルのオートクレーブに仕込み、攪拌動力0.5〜1KW/m2 で攪拌しながら160℃で10時間合成反応を行い、種スラリーを得た。
【0078】
次に、特3号ケイ酸ソーダ(富士化学(株)社製,SiO2 25重量%,Na2 O 8重量%)5.45kgにH2 O11.0kgとAl2 (SO4 3 ・16H2 O(和光純薬K.K.社製)3.05kgおよび硫酸(和光純薬K.K.社製、純度97%)3.15kgを加え、種スラリーとして上記で得られたスラリーを11.67kg添加して、均質なゲルを得た。このゲルを50リットルオートクレーブに入れ、150℃で39.5時間、回転数110rpmで攪拌させながら結晶化させた。
【0079】
得られたスラリーを濾過した後、5倍量の水で水洗し、120℃で5時間乾燥させ、このゼオライトの粒径を走査型電子顕微鏡により測定した。
次に、得られた触媒のSiO2 /Al2 3 モル比を実施例1と同じ方法にて求めた。
【0080】
また、実施例1と同じ方法で亜鉛を10重量%含むH−ZSM−5ゼオライト成形触媒を得た。この成形触媒の、650℃で5時間水蒸気処理した前後の500℃〜900℃のピリジン脱離量と、650℃で9.5時間水蒸気処理した後のn−ヘキサンの1次反応速度定数および表面酸点と全酸点の割合を実施例1と同じ方法でもとめた。結果を表1に示す。
【0081】
更に、650℃で9.5時間水蒸気処理した触媒を用いて、実施例1と同じ耐再生劣化性を評価する試験と、耐コーキング性を評価する試験を実施した。結果を表1に示す。
【0082】
実施例4
特3号ケイ酸ソーダ(富士化学(株)社製,SiO2 25重量%,Na2 O 8重量%)92kgにH2 O95kgとAl2 (SO4 3 ・16H2 O(和光純薬K.K.社製)7.3kgおよび硫酸(和光純薬K.K.社製、純度97%)3.8kgと1,3−ジメチル尿素1.15kgをH2 O150kgに溶かした溶液を攪拌しながら加えて均質なゲルを得た。このゲルを600リットルのオートクレーブに仕込み、攪拌しながら160℃で30時間合成反応を行い、Na型ZSM−5を合成した。この合成後のスラリーを濾過、水洗を濾液PHが8以下になるまで繰り返し、120℃で20時間乾燥し、その後550℃で3時間空気中で焼成してNa型ZSM−5の粉末20kgを得た。
【0083】
特3号ケイ酸ソーダ(富士化学(株)社製,SiO2 25重量%,Na2 O 8重量%)92kgにH2 O245kgとAl2 (SO4 3 ・16H2 O(和光純薬K.K.社製)7.3kgおよび硫酸(和光純薬K.K.社製、純度97%)3.8kg、そして、先に得たNa型ZSM−5の粉末3kgを加えて均質なゲルを得た。このゲルを600リットルのオートクレーブに仕込み、攪拌しながら150℃で10時間合成反応を行い、種スラリーを得た。
【0084】
次に、特3号ケイ酸ソーダ(富士化学(株)社製,SiO2 25重量%,Na2 O 8重量%)92kgにH2 O245kgとAl2 (SO4 3 ・16H2 O(和光純薬K.K.社製)4.8kgおよび硫酸(和光純薬K.K.社製、純度97%)4.9kgを加え、種スラリーとして上記で得られたスラリーを167kg添加して、均質なゲルを得た。このゲルを600リットルオートクレーブに入れ、160℃で45時間、回転数130rpmで攪拌させながら結晶化させた。
【0085】
得られたスラリーを遠心濾過しながらPHが9以下になるまで水洗し、そのあと120℃で5時間乾燥させた。その乾燥物の走査型電子顕微鏡写真を第6図に示す。図から明らかなように生成したNa型ZSM−5は、最も幅の広い部分の長さが2〜3μm、平均2.5μmであることがわかる。
続いて、得られた乾燥物のSiO2 /Al2 3 モル比を蛍光X線装置を用いて測定したところ、39であった。
【0086】
更に、この乾燥物を1規定の硝酸中10重量%スラリーで室温で、3時間イオン交換した後、遠心濾過しながらPHが4.5以上になるまで水洗し、更に120℃で10時間乾燥し、H−ZSM−5を得た。硝酸亜鉛六水和物144gを水200gに溶かし酢酸5gを添加し、アルミナゾル200g(日産化学工業社製アルミナゾル520)と、ベーマイト20g、そして上記H−ZSM−5を200g加え2時間混合した。粘土状になった上記混合物を直径1.6mm、長さ4〜6mmの円柱状に成型後、120℃で2時間乾燥した後、電気炉で空気雰囲気中500℃で3時間焼成し、亜鉛を10重量%含むH−ZSM−5ゼオライト触媒を成形した。
【0087】
更に、実施例1と同様に、得られた成形触媒の、650℃、H2 O分圧0.8atmの条件で5時間水蒸気処理をする前後のH型にしたときの昇温脱離法による500〜900℃におけるピリジンの脱離量を前記方法にて求めた。
続いて、前記記載の方法で650℃、H2 O分圧0.8atmの条件で8時間水蒸気処理を実施した触媒のn−ヘキサンの1次反応速度定数および表面酸点と全酸点の割合をもとめ、耐再生劣化性と耐コーキング性のテストを実施例1と同様に実施した。結果を表1に示す。
【0088】
実施例5
特3号ケイ酸ソーダ(富士化学(株)社製,SiO2 25重量%,Na2 O 8重量%)2300kgにH2 O2375kgとAl2 (SO4 3 ・16H2 O(和光純薬K.K.社製)183kgおよび硫酸(和光純薬K.K.社製、純度97%)95kgと1,3−ジメチル尿素30kgをH2 O3750kgに溶かした溶液を攪拌しながら加えて均質なゲルを得た。このゲルを18m3 のオートクレーブに仕込み、攪拌しながら160℃で30時間合成反応を行い、Na型ZSM−5を合成した。この合成後のスラリーを濾過、水洗を濾液PHが8以下になるまで繰り返し、120℃で30時間乾燥し、その後550℃で3時間空気中で焼成してNa型ZSM−5の粉末520kgを得た。
【0089】
特3号ケイ酸ソーダ(富士化学(株)社製,SiO2 25重量%,Na2 O 8重量%)1930kgにH2 O5780kgと硫酸バンド(住友化学工業製液体硫酸バンド、酸化アルミニウム8.1重量%、pH=3.7)/水=137kg/650kgおよび硫酸(和光純薬K.K.社製、純度97%)/水=81kg/800kg、そして、先に得たNa型ZSM−5の粉末75kgを加えて均質なゲルを得た。このゲルを18m3 のオートクレーブに仕込み、攪拌しながら150℃で10時間合成反応を行い、種スラリーを得た。
【0090】
次に、特3号ケイ酸ソーダ(富士化学(株)社製,SiO2 25重量%,Na2 O 8重量%)1910kgにH2 O5050kgと硫酸バンド(住友化学工業製液体硫酸バンド、酸化アルミニウム8.1重量%、pH=3.7)/水=196kg/930kgおよび硫酸(和光純薬K.K.社製、純度97%)/水=70kg/800kgを加え、種スラリーとして上記で得られた種スラリーを4480kg添加して、均質なゲルを得た。このゲルを18m3 オートクレーブに入れ、160℃で20時間、回転数40rpmで攪拌させながら結晶化させた。
【0091】
得られたスラリーを遠心濾過しながらPHが9以下になるまで水洗し、更に、1規定の硝酸中10重量%スラリーで70℃で、5時間イオン交換した後、遠心濾過しながらPHが4.5以上になるまで水洗し、120℃で30時間乾燥した。その乾燥物の走査型電子顕微鏡写真を第7図に示す。図から明らかなように生成したH−ZSM−5は、最も幅の広い部分の長さが2〜3μm、平均2.5μmであることがわかる。
続いて、得られた乾燥物のSiO2 /Al2 3 モル比を蛍光X線装置を用いて測定したところ、41であった。
【0092】
硝酸亜鉛六水和物144gを水200gに溶かし酢酸5gを添加し、アルミナゾル200g(日産化学工業社製アルミナゾル520)と、ベーマイト20g、そして上記H−ZSM−5を200g加え2時間混合した。粘土状になった上記混合物を直径1.6mm、長さ4〜6mmの円柱状に成型後、120℃で2時間乾燥した後、電気炉で空気雰囲気中500℃で3時間焼成し、亜鉛を10重量%含むH−ZSM−5ゼオライト触媒を成形した。
【0093】
更に、実施例1と同様に、得られた成形触媒の、650℃、H2 O分圧0.8atmの条件で5時間水蒸気処理をする前後でのH型にしたときの昇温脱離法による500〜900℃におけるピリジンの脱離量を前記方法にて求めた。
続いて、前記記載の方法で650℃、H2 O分圧0.8atmの条件で8.5時間水蒸気処理を実施した触媒のn−ヘキサンの1次反応速度定数および表面酸点と全酸点の割合を求め、耐再生劣化性と耐コーキング性のテストを実施例1と同様に実施した。結果を表1に示す。
【0094】
比較例1
(1)種スラリー合成
珪酸ナトリウム水溶液(SiO2 :25.2重量%、Na2 O:7.35重量%)129gにNaOH0.64gとH2 O133gを加えた溶液に、Al2 (SO4 3 ・16H2 O0.9.7gと1,3−ジメチル尿素0.2gをH2 O230gに溶かした溶液を攪拌しながら加え、4.6重量%の硫酸140gを加えて均質なゲルを得た。このゲルのPHは10.8であった。このゲルを1リットルのオートクレーブに仕込み、180℃で40時間合成反応を行った。
得られたスラリーを30℃まで冷却して、一部を濾過して120℃で8時間乾燥した。このもののX線回折パターンは、ZSM−5と一致した。
【0095】
(2)本合成
(1)と同じ組成のゲル400gに(1)で得られた種スラリー250gを加えよく混合した後、1リットルのオートクレーブに入れ、160℃で15時間結晶化させた。
得られたスラリーを濾過した後、5倍量の水で水洗した後、120℃で8時間乾燥したもののX線回折パターンはZSM−5と一致した。
このゼオライトの走査型電子顕微鏡写真を第8図に示す。図から明らかなように生成したZSM−5は、微粒体が凝集したもので、凝集体はその最も幅の広い部分の厚さが0.2μm程度の表面に凹凸のある粒子であることがわかる。
次に、得られた触媒のSiO2 /Al2 3 モル比を実施例1と同じ方法にて求めた。
【0096】
また、実施例1と同じ方法で亜鉛を10重量%含むH−ZSM−5ゼオライト成形触媒を得た。この成形触媒の、650℃で5時間水蒸気処理した前後の500℃〜900℃のピリジン脱離量と、650℃で3.8時間水蒸気処理した後のn−ヘキサンの1次反応速度定数および表面酸点と全酸点の割合を実施例1と同じ方法でもとめた。結果を表1に示す。
【0097】
更に、650℃で3.8時間水蒸気処理した触媒を用いて、実施例1と同じ耐再生劣化性を評価する試験と、耐コーキング性を評価する試験を実施した。結果を表1に示す。
粒径が小さく、全酸点に対する表面酸点の割合が大きく、また、ピリジン脱離量のパラメータαも大きいため、耐再生劣化性が悪く、また、耐コーキング性試験におけるコーク蓄積量も多いことがわかる。
【0098】
比較例2
1,8−ジアミノ−4−アミノメチルオクタン100g、硫酸アルミニウム4g、水酸化ナトリウム5gを200gに溶かし、さらにシリカゾル(30%SiO2 )250gを加えて均質な溶液を得た。この溶液にかき混ぜながら20%硫酸を滴下してpH12.5に調整して均質なゲルを得た。さらに、このゲルをミキサーに入れ2000rpm、20分間高速攪拌した。このゲルをオートクレーブに仕込み、50rpmでかき混ぜながら、150℃で24時間結晶化させた。得られたスラリーを濾過した後、5倍量の水で洗浄し、120℃で8時間乾燥させ、この触媒の粒径を走査型電子顕微鏡で測定したところ、5μm以上であった。
【0099】
また、実施例1と同じ方法で亜鉛を10重量%含むH−ZSM−5ゼオライト成形触媒を得た。この成形触媒の、650℃で5時間水蒸気処理した前後の500℃〜900℃のピリジン脱離量と、650℃で16時間水蒸気処理した後のn−ヘキサンの1次反応速度定数および表面酸点と全酸点の割合を実施例1と同じ方法でもとめた。結果を表1に示す。
【0100】
更に、650℃で16時間水蒸気処理した触媒を用いて、実施例1と同じ耐再生劣化性を評価する試験と、耐コーキング性を評価する試験を実施した。結果を表1に示す。
表1から、本触媒は粒径が大きく、表面酸点と全酸点の割合が小さいため、耐再生劣化性は良いが、コーキングによる劣化が速いことがわかる。
【0101】
比較例3
特3号ケイ酸ソーダ(富士化学(株)社製,SiO2 25重量%,Na2 O 8重量%)6.75kgにH2 O23.0kgとAl2 (SO4 3 ・16H2 O(和光純薬K.K.社製)0.41kgおよび硫酸(和光純薬K.K.社製、純度97%)0.198kgを加え、種結晶としてSiO2 /Al2 3 モル比が既知の市販ZSM−5(NE−ケムキャット社製,SiO2 /Al2 3 =25)を0.167kg添加して、均質なゲルを得た。このゲルを50リットルオートクレーブに入れ、150℃で25時間、回転数200rpmで攪拌させながら結晶化させた。
得られたスラリーを濾過した後、5倍量の水で水洗し、120℃で5時間乾燥させた。このゼオライトのSiO2 /Al2 3 モル比を実施例1と同じ方法にて求めたところ18であった。
【0102】
また、実施例1と同じ方法で亜鉛を10重量%含むH−ZSM−5ゼオライト成形触媒を得た。この成形触媒の、650℃で5時間水蒸気処理した前後の500℃〜900℃のピリジン脱離量と、650℃で3時間水蒸気処理した後のn−ヘキサンの1次反応速度定数および表面酸点と全酸点の割合を実施例1と同じ方法でもとめた。結果を表1に示す。
【0103】
更に、650℃で3時間水蒸気処理した触媒を用いて、実施例1と同じ耐再生劣化性を評価する試験と、耐コーキング性を評価する試験を実施した。結果を表1に示す。
SiO2 /Al2 3 モル比が小さいため耐再生劣化性が悪い。
【0104】
比較例4
市販のH−ZSM−5ゼオライト(NE−ケムキャット社製,SiO2 /Al2 3 =250)を用いて、一次粒子径を測定した後、実施例1と同じ方法で亜鉛を10重量%含むH−ZSM−5ゼオライト成形触媒を得た。この成形触媒の、650℃で5時間水蒸気処理した前後の500℃〜900℃のピリジン脱離量と、650℃で1時間水蒸気処理した後のn−ヘキサンの1次反応速度定数および表面酸点と全酸点の割合を実施例1と同じ方法でもとめた。結果を表1に示す。
【0105】
更に、650℃で1時間水蒸気処理した触媒を用いて、実施例1と同じ耐再生劣化性を評価する試験と、耐コーキング性を評価する試験を実施した。結果を表1に示す。
SiO2 /Al2 3 モル比が大きすぎ、結晶化度が低いため、水蒸気処理前後のピリジン脱離量のパラメータαが大きくなり、耐再生劣化性が悪い。
【0106】
比較例5
ケイ酸ソーダ(水ガラス3号)290gを蒸留水230gに溶解させたA液、別に硫酸アルミニウム16水塩11.4gおよび1,3−ジメチル尿素23.4g、硫酸13gを蒸留水300gに溶解させたB液を調合した。ついでホモジナイザーを用い、A液を強攪拌下にB液を添加し、ゲル状組成物が均一になるまで約3時間攪拌した。このゲル組成物を1リットルオートクレーブに仕込み、150℃、1000rpmでの攪拌下、35時間反応結晶化させた。反応後、固形物を濾過、水洗、脱水、乾燥し、これを550℃で3時間空気中で焼成した。得られたH−ZSM−5型ゼオライトのSiO2 /Al2 3 モル比を実施例1と同じ方法にて求めたところ46であった。また、このゼオライトの粒径を走査型電子顕微鏡により測定した。
【0107】
また、実施例1と同じ方法で亜鉛を10重量%含むZSM−5ゼオライト成形触媒を得た。この成形触媒の、650℃で5時間水蒸気処理した前後の500℃〜900℃のピリジン脱離量を求めた。650℃で3時間水蒸気処理した後のn−ヘキサンの1次反応速度定数および表面酸点と全酸点の割合を実施例1と同じ方法でもとめた。結果を表1に示す。
更に、650℃で3時間水蒸気処理した触媒を用いて、実施例1と同じ耐再生劣化性を評価する試験と、耐コーキング性を評価する試験を実施した。結果を表1に示す。
水蒸気処理前後のピリジン脱離量のパラメータαが1.8と大きいため、耐再生劣化性が悪い。
【0108】
比較例6
市販のH−ZSM−5ゼオライト(SiO2 /Al2 3 =400)を用いて、一次粒子径を測定した後、実施例1と同じ方法で亜鉛を10重量%含むH−ZSM−5ゼオライト成形触媒を得た。この成形触媒の、650℃で5時間水蒸気処理した前後の500℃〜900℃のピリジン脱離量と、水蒸気処理をする前のn−ヘキサンの1次反応速度定数および表面酸点と全酸点の割合を実施例1と同じ方法でもとめた。結果を表1に示す。
更に、水蒸気処理をしない触媒を用いて、実施例1と同じ耐再生劣化性を評価する試験と、耐コーキング性を評価する試験を実施した。結果を表1に示す。 SiO2 /Al2 3 モル比が大きすぎるため、活性が低く芳香族収率も少ない。
【0109】
実施例6
実施例4と同じ方法で合成・成形したゼオライト触媒を、一段断熱型反応器に充填し、圧力5Kg/cm2 ・G、650℃で8時間水蒸気処理を行った。さらに、表2に示すC5 留分と表3に示すC4 留分を6:4の重量比で、圧力5Kg/cm2 ・G、入り口温度530℃、WHSV(重量時間空間速度)2.8hr-1の条件下で48時間供給する環化反応を実施した。48時間の間に蓄積した炭素質を圧力5Kg/cm2 ・G、480〜530℃の雰囲気で、酸素濃度1〜1.5vol%の窒素ガスを5000Nm3/hrの流量で40〜43時間循環させることで燃焼除去(再生)させた。上記環化反応と再生とを75回(300日)繰り返した。1回目と75回目の環化反応結果を表4に示す。
【0110】
比較例7
比較例1と同じ方法で合成・成形したゼオライト触媒を、一段断熱型反応器に充填し、圧力5Kg/cm2 ・G、650℃で3.8時間水蒸気処理を行った。さらに、表2に示すC5 留分と表3に示すC4 留分を6:4の重量比で、圧力5Kg/cm2 ・G、入り口温度530℃、WHSV(重量時間空間速度)2.8hr-1の条件下で48時間供給する環化反応を実施した。48時間の間に蓄積した炭素質を圧力5Kg/cm2 ・G、480〜530℃の雰囲気で、酸素濃度1〜1.5vol%の窒素ガスを5000Nm3/hrの流量で40〜43時間循環させることで燃焼除去(再生)させた。上記環化反応と再生とを75回(300日)繰り返した。1回目と75回目の環化反応結果を表4に示す。表面酸点と全酸点の割合が大きいため、耐再生劣化性が悪く、永久活性劣化が速いことがわかる。
【0111】
実施例7
実施例4で得られた、水蒸気処理を650℃で8時間施した触媒を、蛍光X線にて全亜鉛量を求め、塩酸で触媒を処理した後に原子吸光分析法にて酸化亜鉛を求めた。触媒重量に対し酸化亜鉛2.9重量%、アルミン酸亜鉛22.4重量%であった。この触媒10gを反応管に充填し、水素を20[L/Hr]流し500℃で20Hr還元する。この水素還元前後の酸化亜鉛量、アルミン酸亜鉛量の測定結果を表5に示した。また、水素還元前後の触媒をもちいて、前期記載の方法にてC4 留分とC5 留分を用いた耐コーキング性を評価する試験を実施した。結果を表5に示す。
【0112】
比較例8
実施例4で得られた、亜鉛を含まないH−ZSM−5を100g、7重量%硝酸亜鉛水溶液中に浸し、蒸発乾固後、120℃、4時間乾燥、500℃3時間焼成し、亜鉛2.0重量%を含有する触媒を調整した。ついで、この触媒を圧縮成型後、粉砕し、9〜20メッシュにそろえたもの20gを、内径12mmの石英ガラス製反応器に充填し、水蒸気を80重量%含む水蒸気−窒素混合ガス中で、大気圧下650℃で1時間熱処理した。蛍光X線と原子吸光法にて酸化亜鉛とアルミン酸亜鉛を求め、実施例8と同様の方法で水素還元した。さらに、水素還元前後でのC4 留分とC5 留分を用いた耐コーキング性を評価する試験を実施した。結果を表5に示す。
【0113】
比較例9
実施例1で得られた、亜鉛を含まないH−ZSM−5を650℃で5時間水蒸気処理をし、高純度化学研究所製アルミン酸亜鉛を、亜鉛としての全触媒に対する濃度が10重量%となるように混合した。C4 留分とC5 留分を用いた耐コーキング性を評価する試験を実施した。結果を表5に示す。
【0114】
【表1】
Figure 0003905948
【0115】
【表2】
Figure 0003905948
【0116】
【表3】
Figure 0003905948
【0117】
【表4】
Figure 0003905948
【0118】
【表5】
Figure 0003905948
【0119】
【発明の効果】
以上の如き本発明の方法に従えば、原料もしくは生成物に芳香族炭化水素が含まれる反応の間に該触媒上に蓄積する炭素質の量を低減し、かつ、該炭素質による活性の一時的な低下を抑え、更に、該炭素質を酸素含有イナートガスで燃焼除去する際に起こる如き、水分の存在する高温雰囲気下での脱アルミニウムによる永久活性劣化を抑え得る、すなわち、耐再生劣化性と耐コーキング性に優れた触媒が得られる。従って本発明の方法は、石油化学工業、石油精製に広く利用することができ、特に芳香族化合物や高オクタン価ガソリンの製造に有効に利用できる。
【図面の簡単な説明】
【図1】本発明の方法における酸点測定装置の概略図。
【図2】本発明の方法における等温型反応装置の概略図。
【図3】本発明の方法における触媒の走査型顕微鏡写真。
【図4】本発明の方法における等温型反応装置の概略図。
【図5】本発明の方法における触媒の走査型顕微鏡写真。
【図6】本発明の方法における触媒の走査型顕微鏡写真。
【図7】本発明の方法における触媒の走査型顕微鏡写真。
【図8】本発明の方法における触媒の走査型顕微鏡写真。
【符号の説明】
1 ガス流量計
2 管状電気炉
3 SUS製短管カラム
4 試料
5 注入口
6 FID型検出器
7 温度検出端
8 リボンヒーター
9 保温材
10 石英反応管
11 石英ウール
12 触媒
13 ラシヒリング
14 温度計
15 温度調整用熱電対
16 電気炉
17 原料流入口
18 コンデンサー
19 オイルトラップ
20 発生ガス補修用バック
21 SUS製反応管
22 温度計
23 触媒
24 温度調節用熱電対
25 電気炉
26 原料流入口
27 C5 留分用原料タンク
28 C4 留分用原料タンク
29 ポンプ
30 ポンプ[0001]
[Industrial application fields]
The present invention relates to a high silica zeolite-based catalyst used for a reaction in which an aromatic hydrocarbon is contained in a raw material or a product. More specifically, the amount of carbonaceous material accumulated on the catalyst during the reaction containing aromatic hydrocarbons in the raw material or product is reduced, and the temporary decrease in activity due to the carbonaceous material is suppressed, Furthermore, high silica zeolite excellent in coking resistance and regeneration deterioration resistance, which suppresses permanent activity deterioration due to dealumination in a high temperature atmosphere where moisture exists, such as occurs when the carbonaceous material is burned and removed with an oxygen-containing inert gas. The present invention relates to a system catalyst.
[0002]
[Prior art]
Conventionally, a method for synthesizing a zeolite having a high silica content and a high silica zeolite produced by the method are known. For example, Japanese Patent Publication No. Sho 46-10063 and Japanese Patent Publication No. Sho 56-49850 disclose a method of hydrothermally treating a reaction mixture containing silica, alumina, alkali metal, water and an organic nitrogen cation precursor precursor. ing.
[0003]
Further, a method for producing a highly heat-resistant and high-silica zeolite and a high-silica zeolite produced by the method are also known. For example, JP-A-7-291620 discloses an aluminosilicate gel having a pH of 11 to 13 obtained by simultaneously adding a silica component and an alumina component in a neutral salt aqueous solution of 7.5 mole times or more per alumina content. Steaming for 5 hours at 900 ° C. containing 75% by number or more of long hexagonal plate-like crystal grains having a major axis / minor axis ratio of 2 to 15 and a major axis / thickness ratio of 4 to 50 after heat treatment A high-silica zeolite having a high ion exchange rate compared to conventional high-silica zeolite, having a crystal retention rate of 85% or more when treated, and excellent in hot water resistance, and a method for producing the same are disclosed.
[0004]
Furthermore, Japanese Patent Application Laid-Open No. 3-293301 discloses an aK expressed by a molar composition of an oxide. 2 O, bNa 2 O, Al 2 O Three , CSiO 2 , DH 2 A high heat-resistant zeolite which is O and has a crystallinity of 90% or more before hydrothermal treatment after hydrothermal treatment at 900 ° C. for 5 hours under water vapor containing 10% or more of water And a manufacturing method thereof.
[0005]
JP-A-3-193622 discloses drying a solid in a slurry as a seed slurry when a raw material mixture containing a silica source, an alumina source, an alkali metal source, and water is crystallized under hydrothermal synthesis conditions. The later X-ray diffraction pattern is ZSM-5, and the nitrogen adsorption BET surface area is 100 to 250 m. Three It discloses a method for producing ZSM-5 fine particles, characterized in that a hydrothermal synthesis slurry in the middle of crystallization of / g is added before crystallization of 10 to 40% by weight of the whole.
[0006]
Furthermore, in Japanese Patent Publication No. 7-35343 and Japanese Patent Publication No. 7-94396, in a method for producing aromatic hydrocarbons from light hydrocarbons using ZSM-5 type zeolite containing zinc as a catalyst, the catalyst is specified. Characterized by having a silicon / aluminum atomic ratio and a zinc / silicon atomic ratio of 40 to 120 μmol of pyridine per 1 g of the ZSM-5 type zeolite at 500 to 900 ° C. by a temperature programmed desorption method. A method for producing aromatic hydrocarbons is disclosed.
[0007]
However, the high silica content zeolite synthesized by the method described in Japanese Patent Publication No. 46-10063 and Japanese Patent Publication No. 56-49850 has insufficient crystallinity and the heat resistance of the crystal itself deteriorates. There is a problem that the zeolite catalyst is permanently deteriorated by dealumination in a high-temperature atmosphere where moisture exists, as occurs when the carbonaceous matter accumulated during the combustion is removed by combustion, and the carbonaceous matter accumulated during the reaction is further deteriorated. Since there is much quantity, the subject that the equipment which carries out combustion removal of this became large occurred.
[0008]
Zeolite synthesized by the methods of JP-A-7-291620 and JP-A-3-29331 is a zeolite with high hot water resistance, but is used in a reaction system containing aromatic hydrocarbons in the raw material or product. There was no description about the above, and the problem of reduced activity due to carbonaceous matter accumulated on the zeolite catalyst during the reaction was not recognized.
[0009]
In general, zeolite with high hot water resistance needs to increase its crystallinity, and as a result, the particle size tends to increase. However, if the particle size is too large, the ratio of the surface acid point to the total acid point Therefore, in the reaction containing aromatic hydrocarbon in the raw material or product, there is a problem that the activity is rapidly lowered due to carbonaceous matter accumulated on the zeolite catalyst during the reaction, and it cannot be put into practical use.
[0010]
The zeolite synthesized in Japanese Patent Laid-Open No. 3-193622 is a fine particle zeolite used in a reaction for producing cyclohexanol from cyclohexene as described in the examples, and the particle diameter is atomized. The purpose is to extend the catalyst life due to the accumulation of carbonaceous matter.
[0011]
The zeolite of the present application can be synthesized, for example, by the method disclosed in JP-A-3-193622, but the particle size of the zeolite synthesized by the method is too small or the ratio of the surface acid points to the total acid points. Is too large, it accumulates during the reaction in a raw material or product containing a component that causes more carbonaceous matter to accumulate during the reaction, such as olefin and aromatic hydrocarbon, especially styrene. Increases the amount of carbon.
[0012]
When the amount of carbon is increased, if the equipment for burning and removing this is the same, the time for burning and removing is longer than when the amount of carbon is small. As removal equipment becomes larger, moisture generated per unit time increases and permanent deterioration due to dealumination is quick.
[0013]
In addition, in ZSM-5 described in the examples of JP-A-3-193622, the crystallinity is small, and moisture is present as occurs when the carbonaceous matter accumulated during the reaction is removed by combustion. There was a problem that the zeolite catalyst was permanently deteriorated by dealumination under a high temperature atmosphere.
[0014]
In Japanese Patent Publication No. 7-35343 and Japanese Patent Publication No. 7-94396, in the method for producing aromatic hydrocarbons from light hydrocarbons, in order to reduce the decrease in activity over time due to carbonaceous matter accumulated during the reaction, specific ZSM having a silicon / aluminum atomic ratio and a zinc / silicon atomic ratio of 40 to 120 μmol of pyridine per 1 g of ZSM-5 type zeolite at 500 to 900 ° C. by a temperature programmed desorption method A production method using a catalyst containing −5 type zeolite is disclosed. By setting the amount of desorption of pyridine within the above range, while maintaining the necessary activity for producing aromatic hydrocarbons from light hydrocarbons, the decrease in activity over time due to accumulated carbonaceous matter is reduced.
[0015]
However, these publications do not solve the problem that the zeolite catalyst is permanently deteriorated by dealumination in a high-temperature atmosphere in the presence of moisture, such as occurs when the carbonaceous matter accumulated during the reaction is burned and removed. . As is apparent from the examples in both publications, the catalyst is H 2 Desorption amount (B) of pyridine at 500 to 900 ° C. by the temperature-programmed desorption method in the H type after steam treatment at O partial pressure 0.8 atm and 650 ° C. for 5 hours and before the steam treatment The parameter α represented by the amount of pyridine desorbed (A) at 500 to 900 ° C. by the temperature-programmed desorption method when the H type is used is greater than 1.6, and deterioration due to carbonaceous precipitation for each reaction Although it is small, its permanent deterioration is fast, and it is not practical to use for several months or years by repeating the reaction and regeneration for burning and removing carbonaceous matter accumulated during the reaction.
[0016]
As enumerated above, various methods for synthesizing zeolite have been proposed as described above, but carbon that accumulates on the catalyst during the reaction in a reaction in which an aromatic hydrocarbon is contained in the raw material or product. The amount of quality is small, and the temporary decrease in the activity due to the carbonaceous matter is suppressed, and furthermore, due to dealumination in a high-temperature atmosphere where moisture exists when the carbonaceous matter is burned and removed with an oxygen-containing inert gas. A high silica zeolite-based catalyst that can suppress permanent activity deterioration and is excellent in coking resistance and regeneration deterioration resistance at the same time has not been found.
[0017]
[Problems to be solved by the invention]
An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a high silica zeolite catalyst used in a reaction in which an aromatic hydrocarbon is contained in a raw material or a product, and on the catalyst during the reaction. This reduces the amount of carbonaceous matter that accumulates at the same time, suppresses a temporary decrease in activity due to the carbonaceous matter, and further, when the carbonaceous matter is burned and removed with an oxygen-containing inert gas. It is an object of the present invention to provide a high silica zeolite catalyst excellent in coking resistance and regeneration deterioration resistance that can suppress permanent activity deterioration due to dealumination in an atmosphere.
[0018]
[Means for Solving the Problems]
As a result of extensive research, the present inventor has developed a specific SiO as a high silica zeolite used in a reaction in which an aromatic hydrocarbon is contained in a raw material or product. 2 / Al 2 O Three The inventors have found that the above problems can be solved at once by using a zeolite having a molar ratio, a specific particle size, a specific acid point ratio, and a specific acid point, and completed the present invention.
[0019]
That is, the present invention Production of aromatic hydrocarbons from light hydrocarbons containing olefins and / or paraffins The present invention provides a high silica zeolite catalyst that is used in the reaction and satisfies the following requirements (1), (2), (3), and (4).
(1) Zeolite SiO constituting the zeolitic catalyst 2 / Al 2 O 4 The molar ratio is 20 to 200.
(2) The particle diameter of the primary particles of the zeolite constituting the zeolite catalyst is 0.3 to 3 μm.
(3) The ratio of the surface acid point to the total acid point when the zeolite catalyst is made to be H-type is 0.03 to 0.15.
(4) The zeolite catalyst is H 2 Oxygen partial pressure of 0.8 atm, steam treatment at 650 ° C. for 5 hours, pyridine desorption amount (B) at 500 to 900 ° C. by the temperature-programmed desorption method when using H type, and before the steam treatment The amount of pyridine desorption (A) at 500 to 900 ° C. by the temperature programmed desorption method when the H type is satisfied satisfies the following.
[0020]
[Expression 2]
Figure 0003905948
[0021]
In the present invention, the reaction in which an aromatic hydrocarbon is contained in the raw material or the product means that 5% by weight or more of the aromatic hydrocarbon is contained in the raw material of the reaction, or 5 in the product of the reaction. This refers to a reaction containing aromatic hydrocarbons by weight percent or more. When an aromatic hydrocarbon, particularly an aromatic hydrocarbon having 8 or more carbon atoms such as styrene, is contained in the raw material or product, a large amount of carbon is accumulated during the reaction. Examples of reactions in which aromatic hydrocarbons are contained in the raw material or product include, for example, cyclization reactions for producing aromatic hydrocarbons from light hydrocarbons containing olefins and / or paraffins, hydrocarbons such as naphtha and H-NGL A catalytic cracking reaction to obtain lower olefins and aromatic hydrocarbons efficiently from raw materials containing ethylene and lower olefins mainly composed of ethylene in higher yield than aromatic hydrocarbons, disproportionation reaction of toluene, Examples include xylene isomerization reaction and ethylbenzene synthesis reaction.
[0022]
Hereinafter, among these reactions, a cyclization reaction for producing an aromatic hydrocarbon from a light hydrocarbon containing olefin and / or paraffin will be described in detail. The light hydrocarbon containing olefin and / or paraffin in the present invention is a hydrocarbon having 2 or more carbon atoms and 90% distillation temperature of 190 ° C. or less. For example, ethane, propane, butane, pentane, hexane, heptane, octane and nonane are listed as paraffin, and ethylene, propylene, butene, pentene, hexene, heptene, octene and nonene are listed as olefins. In addition to the above, naphthane and naphthene such as cyclopentane, cyclopentene, methylcyclopentane, cyclohexane, methylcyclopentene, cyclohexene and cyclohexadiene may be included, and dienes such as butadiene, pentadiene and cyclopentadiene may be included.
[0023]
Each of the above mixtures may be used as a raw material, and the mixture contains N as a diluent. 2 , CO 2 In order to suppress the generation of inert gases such as CO and CO, and carbonaceous matter (coke) that accumulates on the catalyst during the reaction. 2 , CH Four May be included. Further, the weight ratio of saturated hydrocarbon to unsaturated hydrocarbon in the mixture is particularly preferably 0.43 to 2.33. The weight ratio of saturated hydrocarbon and unsaturated hydrocarbon here means the weight ratio in the supplied mixture.
[0024]
As the mixture, each of the above-mentioned mixtures or C of high-temperature pyrolysis products of petroleum hydrocarbons such as naphtha is used. Four Fraction, C Four A fraction obtained by removing butadiene or butadiene and i-butene from the fraction, C of the high-temperature pyrolysis product Five Fraction, C Five Dienes from fractions, pyrolysis gasoline, raffinate from which aromatic hydrocarbons were extracted from pyrolysis gasoline, FCC-LPG, FCC cracked gasoline, raffinate from which aromatic hydrocarbons were extracted from reformate, coker Examples include LPG and straight-run naphtha. Among these, C is a high-temperature pyrolysis product of petroleum hydrocarbons such as naphtha. Four Fraction, C Five Fraction, C Four , C Five A fraction obtained by removing part or all of butadiene, i-butene, isoprene, and cyclopentadiene from the fraction can be particularly preferably used. Four Fraction, C Five The raw material whose weight ratio of a fraction is 3/7-7/3 is especially preferable. C here Four Fraction and C Five The weight ratio of the fraction means the weight ratio in the supplied mixture. In the method of the present invention, the raw material may contain oxygen-containing compounds such as TBA and methanol as impurities.
[0025]
The zeolite constituting the high silica zeolite catalyst in the present invention is the SiO of the zeolite. 2 / Al 2 O Three Molar ratio is 20-200, for example, β-zeolite, Ω-zeolite, Y-zeolite, L-zeolite, erionite, offretite, mordenite, ferrierite, ZSM-5, ZSM-8, ZSM-11, ZSM -12, ZSM-35, ZSM-38, etc., ZSM-5 type crystalline aluminosilicates or metallosilicates such as ZSM-5, ZSM-8, and ZSM-11 are preferred. Regarding the ZSM-5 zeolite, reference can be made, for example, to US Pat. No. 5,268,162.
[0026]
Any of the zeolites used in the present invention can be used as an H-type or a metal-substituted type, and the metal-substituted metal is preferably a metal belonging to Group VIII, Group Ib, Group IIb, or Group IIIb. As metals belonging to Group VIII, Group Ib, Group IIb, Group IIIb, Zn, Cu, Ag, Ni, Pt, Pd, and Ga are more preferable, and among these, Zn, Ag, Ni, and Ga are more preferably used. It is done. At this time, the metal may be contained in the zeolite skeleton or may be ion-exchanged.
Furthermore, as described later, a binder such as alumina and / or a metal oxide that promotes dehydrogenation such as zinc oxide can be used in combination.
[0027]
In the present invention, the method for synthesizing the zeolite is not particularly limited, but the method for synthesizing using the seed slurry described in JP-A-3-193622 is particularly preferable. Further, in the method of the present invention, as described in International Application No. PCT / JP95 / 02040, SiO 2 / Al 2 O Three It is also possible to use an intermediate pore diameter zeolite having a molar ratio of 20 or more and having one or more metals belonging to Group Ib of the periodic table and substantially free of protons. In either case, SiO 2 / Al 2 O Three It is important that the molar ratio, the particle size of the primary particles of the zeolite, the ratio of the surface acid points to the total acid points when in the H-type, and the parameter α are within the scope of the present invention.
[0028]
Raw material SiO 2 / Al 2 O Three By adjusting the synthesis conditions such as molar ratio, stirring speed, synthesis temperature, use / nonuse of template, type of template used, etc. 2 / Al 2 O Three The molar ratio, the particle size of the primary particles of the zeolite, the ratio of the surface acid points to the total acid points in the H-type, and the parameter α can be within the scope of the present invention.
[0029]
The zeolite constituting the catalyst of the present invention is SiO. 2 / Al 2 O Three The molar ratio is 20 to 200, preferably 30 to 100, and more preferably 30 to 80. SiO 2 / Al 2 O Three If the molar ratio is less than 20, high temperature in the presence of moisture, such as occurs when the carbonaceous material accumulated on the catalyst during the reaction in which the raw material or product contains aromatic hydrocarbons is burned off with an oxygen-containing inert gas. Deterioration of permanent activity due to dealumination under atmosphere is accelerated.
[0030]
Permanent activity degradation due to dealumination is considered to be suppressed as the relative value of crystallinity by X-ray diffraction increases, but the relative value of crystallinity is SiO 2. 2 / Al 2 O Three Affected by the molar ratio, the SiO 2 / Al 2 O Three When the molar ratio is smaller than 20 or larger than 200, the relative value of crystallinity becomes small, and permanent deterioration due to dealumination is fast, which is not preferable. In addition, SiO 2 / Al 2 O Three If the molar ratio is greater than 200, sufficient activity may not be obtained, and the catalyst may not have sufficient activity for a reaction in which an aromatic hydrocarbon is contained in the raw material or product.
[0031]
SiO of zeolite constituting the catalyst of the present invention 2 / Al 2 O Three The molar ratio is a hydrothermally synthesized zeolite that does not contain alumina or silica as a binder, and is subjected to a dealumination treatment such as steam treatment or a reaction that generates aromatic hydrocarbons from light hydrocarbons. This is the molar ratio determined by measuring fresh fresh zeolite with a fluorescent X-ray apparatus or EPMA (X-ray macroanalyzer).
[0032]
As the zeolitic catalyst in the present invention, the above-described H-type or metal-substituted type substantially consisting of zeolite can be used, and the above-mentioned zeolite, periodic table groups VIII, Ib, IIb and A mixture of at least one metal selected from metals belonging to Group IIIb and a compound thereof (for example, a metal oxide that promotes dehydrogenation such as zinc oxide) or a compound thereof. Those supported as are preferable.
[0033]
As metals belonging to Group VIII, Group Ib, Group IIb, Group IIIb, Zn, Cu, Ag, Ni, Pt, Pd, and Ga are more preferable, and among these, Zn, Ag, Ni, and Ga are more preferably used. It is done. For example, it is preferable to include a mixture of zeolite and at least one selected from zinc and a compound thereof. Furthermore, it is more preferable to use alumina and silica as a binder.
[0034]
In the present invention, the zinc component is, for example, zinc, zinc oxide, zinc hydroxide, or a salt such as zinc nitrate, zinc carbonate, zinc sulfate, zinc chloride, zinc acetate, zinc oxalate, or an organic zinc compound such as alkyl zinc. Is mentioned.
[0035]
In the present invention, the zeolitic catalyst preferably contains a mixture of zeolite, a zinc component, and alumina. Moreover, it is also preferable that the mixture of a zinc component and alumina is heat-treated in water vapor and a zeolite. When both catalysts are treated with steam, the zinc component reacts with alumina and changes to zinc aluminate, which stabilizes zinc and produces aromatic hydrocarbons in high yield from light hydrocarbons containing olefins and / or paraffins. In such a reaction, the scattering loss of zinc can be greatly reduced. Zinc aluminate as used herein refers to JCPDS 5-0669NBS Circ. When observed with an X-ray diffractometer such as XD-610 manufactured by Shimadzu Corporation. 539, Vol. II, 38 (1953) means the same X-ray diffraction pattern as that shown in FIG.
[0036]
As an alumina source of alumina, there is anhydrous alumina or hydrated alumina. In addition, for example, a raw material that produces anhydrous alumina or hydrated alumina by hydrolysis, thermal decomposition, oxidation, etc. like an aluminum salt. It can also be used.
[0037]
In the present invention, it is also preferable to use alumina sol as the alumina source. When alumina sol is used as the alumina source, the zinc component reacts with alumina to produce zinc aluminate without performing the steam treatment, so that zinc is stabilized.
[0038]
In the above zeolitic catalyst, the content of at least one selected from zinc and its compound is preferably 5 to 25% by weight as zinc. In the present invention, when alumina is included, the alumina content is Al 2 O Three 5 to 50% by weight, preferably 15 to 40% by weight with respect to the total catalyst, and when alumina and zinc are included, the molar ratio of alumina to zinc (Al 2 O Three / Zn) is 1 or more.
[0039]
In the present invention, it is preferable that zinc oxide and zinc aluminate coexist in the zeolite catalyst at the time of being subjected to the reaction. Since zinc aluminate has a spinel structure, it is possible to suppress the scattering of zinc from the zeolite-based catalyst, but the effect of improving the aromatic selectivity, which is the original purpose of zinc loading, is reduced. It is preferable to coexist zinc oxide which exhibits the improvement effect of the above. The preferred abundance of zinc oxide and zinc aluminate is 1.2 to 20% by weight of zinc oxide and 8.2 to 50% by weight of zinc aluminate when the raw material or product contains an aromatic hydrocarbon. More preferably, zinc oxide is 1.0 to 5.0% by weight and zinc aluminate is 14 to 40% by weight.
[0040]
Although the effect of improving the aromatic selectivity of zinc aluminate itself is small, it becomes a supply source of zinc oxide and suppresses the decrease of zinc oxide. As a result, the effect of improving the aromatic selectivity can be sustained for a long time. Further, the presence of zinc aluminate also has an effect of suppressing the scattering rate due to reduction during the reaction in which the raw material or product of zinc oxide contains aromatic hydrocarbons. Therefore, the presence of zinc aluminate together with zinc oxide in the catalyst is effective for maintaining the effect of improving the aromatic selectivity.
[0041]
The zinc oxide as used in the field of this invention means what was measured with the following analysis method. That is, 1 g of the catalyst is ground to about several hundreds of microns in a mortar, dried at 120 ° C. for 1 hour, and about 0.5 g is accurately measured and placed in a 200 cc beaker. Thereto, 150 cc of 3% hydrochloric acid aqueous solution is added and heated at 80 ° C. for 2 hours on an electric heater. Thereafter, the solution is filtered through a 0.2 μm membrane filter, and the filtrate is subjected to flame analysis with an atomic absorption spectrometer (Shimadzu atomic absorption / flame spectrophotometer AA-640-12 type manufactured by Shimadzu Corporation), and zinc oxide is quantitatively analyzed by a standard addition method. .
[0042]
The zinc aluminate weight in the present invention is obtained by subtracting the weight of zinc oxide quantitatively analyzed by the above method from the total zinc weight. The total weight of zinc here refers to that obtained from a calibration curve of a standard substance with a fluorescent X-ray analyzer (Science RIX1000).
[0043]
In the present invention, the primary particle size of zeolite is SiO. 2 / Al 2 O Three Similar to the molar ratio, it is the particle size of the primary particles when the substantially fresh zeolite is viewed with a scanning electron microscope. In the present invention, the particle size is preferably 0.3 to 3 μm, more preferably 0.5 to 2 μm. These primary particles have various shapes, and the particle size referred to here indicates the average diameter of the widest portion of each particle. These primary particles may be present alone or may be secondary agglomerated.
[0044]
When the particle size is smaller than 0.3 μm, the amount of carbonaceous matter accumulated on the catalyst during the reaction in which the raw material or product contains aromatic hydrocarbons increases, and the carbonaceous matter is combusted with an oxygen-containing inert gas. Permanent activity deterioration due to dealumination in a high-temperature atmosphere in the presence of moisture is accelerated as occurs during removal, and conversely, if the particle size is larger than 3 μm, during the reaction in which the raw material or product contains aromatic hydrocarbons In addition, since the temporary decrease in activity due to the carbonaceous matter accumulated on the catalyst is accelerated, it is not practical.
[0045]
In the present invention, at the time when the zeolitic catalyst is subjected to the reaction, the ratio of the surface acid points to the total acid points when the H-type catalyst is made is 0.03 to 0.15, and 0.05 to 0.1 Is more preferred. If the ratio of the surface acid point to the total acid point is less than 0.03, there is a temporary decrease in activity due to light carbon accumulated on the catalyst during the reaction in which the raw material or product contains aromatic hydrocarbons. Conversely, if the ratio is greater than 0.15, the amount of light carbon that accumulates on the catalyst during the reaction in which the raw material or product contains aromatic hydrocarbons increases, and the carbonaceous matter is oxygenated. The permanent activity deterioration due to dealumination in a high-temperature atmosphere in which moisture exists is accelerated as occurs when burning and removing with the contained inert gas.
[0046]
In the present invention, the catalyst H 2 In the apparatus shown in FIG. 2, the steam treatment at O partial pressure of 0.8 atm and 650 ° C. for 5 hours was carried out by filling quartz wool 11, catalyst 12 and Raschig ring 13 in this order into a 10 mmφ quartz reaction tube 10, The quartz reaction tube 10 is heated in an electric furnace 16 whose temperature can be adjusted by a thermocouple 15 for temperature adjustment so that the temperature of the catalyst 12 measured by the thermometer 14 becomes an isothermal temperature of 650 ° C. 2 It is carried out by supplying water or steam to the substantially fresh catalyst from the raw material inlet 17 for 5 hours under the condition of O partial pressure of 0.8 atm.
[0047]
In the present invention, the catalyst is converted to H by the above method. 2 Desorption amount (B) of pyridine at 500 to 900 ° C. by the temperature-programmed desorption method in the H type after steam treatment at O partial pressure 0.8 atm and 650 ° C. for 5 hours and before the steam treatment The following parameter α represented by the amount of pyridine desorption (A) at 500 to 900 ° C. by the temperature-programmed desorption method when the H type is used is 1.6 or less, particularly preferably 1.4 or less. is there.
[0048]
[Equation 3]
Figure 0003905948
[0049]
If the parameter α is larger than 1.6, moisture is present as occurs when the carbonaceous material accumulated on the catalyst is burned and removed with an oxygen-containing inert gas during the reaction in which the raw material or product contains aromatic hydrocarbons. Permanent activity deterioration due to dealumination under a high temperature atmosphere is fast, and regeneration resistance is poor.
[0050]
The parameter α depends on the crystallinity obtained by the X-ray diffraction method. That is, as shown in the comparative example described later, when the particle size of the zeolite is small as in comparative example 1, or as in comparative example 3, 2 / Al 2 O Three When the molar ratio is small, SiO 2 is further added as in Comparative Example 4. 2 / Al 2 O Three When the molar ratio is large, the relative value of the crystallinity by the X-ray diffraction method is small, the parameter α is large, and the reproduction deterioration resistance is deteriorated.
[0051]
In addition, SiO 2 / Al 2 O Three Even if the molar ratio and the particle diameter are within the range of the present invention, as in Comparative Example 5, the parameter α is larger than 1.6, and the regeneration deterioration resistance may be deteriorated. In Comparative Example 5 as well, since the relative value of crystallinity is small, it is presumed that amorphous amorphous coexists in the synthesized zeolite. Therefore, in order to make a catalyst that can withstand repeated reaction / regeneration for several years with little deterioration in permanent activity due to dealumination in a high temperature atmosphere in the presence of moisture, all the requirements (1) to (4) of the present invention are satisfied. Must meet.
Here, the relative value of crystallinity is the relative value of the sum of the peak heights of 2θ = 23.1 °, 24.0 °, and 24.4 ° of the X-ray diffraction pattern of the zeolite catalyst. Say.
[0052]
The method for measuring the amount of desorption and the ratio of the surface acid points to the total acid points is as follows.
(Acid point measurement method)
First, before the acid point is measured, if the zeolitic catalyst is not H-type, it must be converted to H-type according to the following method. In order to change the zeolite into the H type, 1N nitric acid was added to the zeolite to make a 10 wt% slurry, which was subjected to ion exchange at 60 ° C. for 4 hours, the slurry was filtered, and further washed with 5 times the amount of water. Then, it is dried at 120 ° C. for 10 hours. The acid point of the H-type zeolite thus obtained is measured by the following method.
[0053]
As the acid point measuring device, Shimadzu Gas Chromatography GC-14A and Data Processing Unit CR-4A were used. FIG. 1 shows an acid point measuring apparatus used in the present invention. That is, 0.1 to 1 g of the sample 4 is packed into a SUS short column 3 having an inner diameter of 6 mm and an overall length of 220 mm. The sample 4 has a length of 1 to 5 mm if it is formed into a pellet, and is compressed and filled to 20 to 30 mesh if it is a powder. Nitrogen as a carrier gas is allowed to flow while adjusting the gas flow meter 1 at a flow rate of 60 cc / min. At the same time, the temperature of the tubular electric furnace 2 having an inner diameter of 20 mmφ and a length of 150 mm is 180 ° C. when the amine used is pyridine. In the case of 4-methylquinoline, the temperature is set to 280 ° C. Next, a fixed amount (1 μcc) of amine (pyridine, 4-methylquinoline) is intermittently injected at a fixed period (2 to 5 minutes) from the injection port 5 using an autosampler microsyringe (AOC). to continue.
[0054]
On the other hand, the carrier gas that has passed through the packed column 3 is analyzed using the FID-type detector 6 to obtain a chromatogram of changes in amine concentration over time in which peaks periodically appear. As the number of injections increases, the amount of amine adsorbed on the sample approaches saturation, and the amount of non-adsorbed amine obtained by injection increases accordingly. Therefore, in the chromatogram, the non-adsorption peak area S corresponding to the injection of amine. i Is the area S corresponding to the amount of amine injected gradually. o Get closer to. That is, the peak area S confirmed by the data processing device i The total count corresponding to the area S o It approaches the total count corresponding to. Total count N corresponding to the amount of non-adsorbed amine obtained i And a total count N corresponding to the amount of non-adsorbed amine obtained at the time of injection immediately before i-1 However, when the following conditions are satisfied, it is determined that the amine adsorption amount is saturated.
[0055]
[Expression 4]
Figure 0003905948
[0056]
Under the above conditions, it is determined that the saturated adsorption of the amine to the catalyst is completed, and then the temperature is raised in the tubular electric furnace 2 at a rate of 15 ° C./min. Here, the gas flow path from around the amine inlet 5 to the FID-type detector 6 is heated by a ribbon heater 8 or the like except for a portion in the electric furnace, and the outside is covered with a heat insulating material 9 so that the amine is covered. In the case of pyridine, it is kept at 200 ° C., and when the amine is 4-methylquinoline, it is kept at 300 ° C. Temperature detection is performed at the position of the temperature detection end that is closely attached to the outside of the sample tube. The amine desorbed from the sample 4 until the temperature detection end 7 reaches 900 ° C. is detected by the FID-type detector 6, and the desorption amount is converted using the calibration curve of the amine.
[0057]
The total acid point in the present invention is represented by the amount of pyridine desorption when measured using pyridine as an amine, and the surface acid point is 4-methylquinoline desorption when measured using 4-methylquinoline as an amine. Expressed as a separation. The desorption amount of pyridine at 500 to 900 ° C. by the temperature programmed desorption method is the desorption obtained from the time when the temperature detection end 7 reaches 500 ° C. until the temperature is further raised to 900 ° C. The amount of separation. Any desorption amount is expressed as a desorption amount per 1 g of the catalyst containing zeolite.
[0058]
(Measurement method of n-hexane decomposition primary reaction rate constant)
In the present invention, the first-order reaction rate constant of n-hexane decomposition of the catalyst means that quartz wool 11 and carbonaceous matter (coke) are substantially from the bottom in a 10 mmφ quartz reaction tube 10 using the apparatus shown in FIG. The catalyst 12 and the Raschig ring 13 which are not present in the furnace are filled in this order, and the temperature of the catalyst 12 measured by the thermometer 14 is equal to 500 ° C. so that the temperature can be adjusted by a thermocouple 15 for temperature adjustment. The reaction tube 10 is heated, atmospheric pressure, weight hourly space velocity (WHSV) 4 hr -1 N-hexane was supplied from the raw material inlet 17 under the conditions of the above, and the reaction product 0.75 to 1 hour after the supply of n-hexane was cooled by the condenser 18 and then further dried ice by the oil trap 19. Cooling with ethanol refrigerant, and collecting all of the oil component separated in the oil trap 19 and the gas component separated in the generated gas collection bag 20.
[0059]
Then, the gas composition is obtained by FID-TCD gas chromatography (HP-5890 series II) manufactured by Hewlett-Packard Co., and the oil composition is analyzed by FID gas chromatography (GC-17A) manufactured by Shimadzu Corporation. The average conversion rate constant of n-hexane decomposition based on zeolite with the above gas / oil sampling time of 0.25 hours, obtained by substituting the conversion rate of n-hexane in the obtained reaction product into the following equation.
[0060]
[Equation 5]
Figure 0003905948
[0061]
The first-order reaction rate constant represents the activity of the catalyst, and the first-order reaction rate constant of n-hexane decomposition of the zeolite catalyst in the present invention is 0.2 or more at the time of being subjected to the reaction. Preferably, it is more preferably 0.3 or more. A catalyst having a primary reaction rate constant of less than 0.2 for the decomposition of n-hexane has a low activity, and the target product obtained by a reaction in which an aromatic hydrocarbon is contained in the raw material or product decreases.
[0062]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be described in more detail with reference to examples and comparative examples.
[0063]
【Example】
Example 1
Sodium silicate aqueous solution (SiO 2 : 26% by weight, Na 2 (O: 7.0% by weight) NaOH of 0.05 kg and H of 8.0 kg 2 To a solution with O4 kg added, add Al 2 (SO Four ) Three ・ 16H 2 0.61 kg of O and 0.1 kg of 1,3-dimethylurea 2 A solution dissolved in 15 kg of O was added with stirring, and 10 kg of 5 wt% sulfuric acid was added to obtain a homogeneous gel. This gel was charged into a 50 liter autoclave and the stirring power was 0.5 to 1 KW / m. 2 A synthetic reaction was carried out at 160 ° C. for 10 hours with stirring to obtain a seed slurry.
[0064]
Next, No. 3 sodium silicate (Fuji Chemical Co., Ltd., SiO 2 25% by weight, Na 2 O 8wt%) H to 6.44kg 2 17.47 kg of O and Al 2 (SO Four ) Three ・ 16H 2 0.248 kg of O (manufactured by Wako Pure Chemical Industries, Ltd.) and 0.353 kg of sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd., purity 97%) were added, and the slurry obtained above was used as a seed slurry. 49 kg was added to obtain a homogeneous gel. This gel was placed in a 50 liter autoclave and crystallized while stirring at 150 ° C. for 45 hours at 110 rpm.
[0065]
The obtained slurry was filtered, washed with 5 times the amount of water, and dried at 120 ° C. for 5 hours. A scanning electron micrograph of the dried product is shown in FIG. As is clear from the figure, it can be seen that the ZSM-5 produced has a widest portion with a thickness of 1.5 to 2 μm and an average of 1.2 μm.
[0066]
Subsequently, SiO of the obtained dried product 2 / Al 2 O Three When the molar ratio was measured using a fluorescent X-ray apparatus, it was 36.
Further, this dried product was ion-exchanged with a 10 wt% slurry in 1N nitric acid at room temperature for 3 hours, filtered, washed with 5 times the amount of water, and further dried at 120 ° C. for 10 hours.
[0067]
144 g of zinc nitrate hexahydrate was dissolved in 400 g of water, 400 g of alumina sol (alumina sol 520 manufactured by Nissan Chemical Industries, Ltd.) and 200 g of H-ZSM-5 were added and heated at 50 ° C. and mixed for 2 hours. After the moisture-reduced clay-like mixture was formed into a cylindrical shape having a diameter of 1.6 mm and a length of 4 to 6 mm, it was dried at 120 ° C. for 2 hours and then baked in an electric atmosphere at 500 ° C. for 3 hours. Then, an H-ZSM-5 zeolite catalyst containing 10% by weight of zinc was formed.
[0068]
Further, the obtained molded catalyst was filled into a quartz reaction tube of the apparatus shown in FIG. 2, and 650 ° C., H 2 Steam treatment was performed for 5 hours under the condition of O partial pressure of 0.8 atm. Next, the amount of pyridine desorbed at 500 to 900 ° C. by the temperature-programmed desorption method before and after the steam treatment was determined by the above method.
[0069]
Subsequently, in order to align the initial activity with the catalysts of Examples and Comparative Examples described later, 650 ° C., H 2 The additional steam treatment was performed for 1.2 hours under the condition of O partial pressure of 0.8 atm. The primary reaction rate constant of n-hexane and the ratio of the surface acid point to the total acid point of the catalyst after the steam treatment were determined by the method described above.
[0070]
Next, in order to evaluate the regeneration degradation resistance of this catalyst, a model regeneration degradation test was conducted. That is, the above-mentioned catalyst subjected to steam treatment for a total of 6.2 hours is filled in the apparatus shown in FIG. 2 An additional steam treatment was carried out for 100 hours under the condition of O partial pressure of 0.15 atm, and the first-order reaction rate constant of n-hexane of the catalyst before and after that was determined by the same method as described above. The results are shown in Table 1.
[0071]
Further, in order to evaluate the coking resistance, a molded H-ZSM-5 zeolite catalyst which has not been subjected to a steam treatment is subjected to the C shown in Table 2 using the reactor shown in FIG. Five Fraction and C shown in Table 3 Four A cyclization reaction test was conducted in which the fraction was fed at 6: 4 (weight ratio). That is, 100 g of the formed catalyst was filled in a SUS reaction tube 21 having an inner diameter of 27.2 mmφ, and the temperature was adjusted by the thermocouple 24 for temperature adjustment so that the average temperature of the catalyst 23 measured by the thermometer 22 was equal to 650 ° C. The reaction tube 21 made of SUS is heated in an electric furnace 25 in which the temperature can be adjusted, and 1 kg / cm 2 ・ G, H 2 Steam treatment was performed by supplying water or steam to the substantially fresh catalyst from the raw material inlet 26 for 6.2 hours under the condition of O partial pressure of 0.8 atm.
[0072]
Thereafter, the temperature of the catalyst 23 is adjusted using a temperature adjusting thermocouple 24 so that the average temperature is 520 ° C., and C in the raw material tank 27 having the composition shown in Table 2 is obtained. Five C shown in Table 3 in the fraction and raw material tank 28 Four The fraction was pumped by pumps 29 and 30 at a weight ratio of 6: 4 and a pressure of 5 kg / cm 2 G, temperature 520 ° C., WHSV (weight hourly space velocity) 2.8 hr -1 Under the conditions, the catalyst 23 in the reaction tube 21 made of SUS was supplied for 48 hours. Aromatic yields were determined 5 hours and 40 hours after the start of the feed, and the amount of coke accumulated on the catalyst during the 48 hour reaction was also determined. The results are shown in Table 1.
[0073]
Example 2
Special 3 sodium silicate (Fuji Chemical Co., Ltd., SiO 2 25% by weight, Na 2 O 8wt%) H to 6.75kg 2 O23.0kg and Al 2 (SO Four ) Three ・ 16H 2 0.186 kg of O (manufactured by Wako Pure Chemical Industries, Ltd.) and 0.198 kg of sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd., purity 97%) were added, and SiO was used as a seed crystal. 2 / Al 2 O Three Commercially available ZSM-5 with a known molar ratio (manufactured by NE-Chemcat, SiO 2 / Al 2 O Three = 50) 0.167 kg was added to obtain a homogeneous gel.
[0074]
This gel was put into a 50 liter autoclave and crystallized while being stirred at 150 ° C. for 25 hours at a rotation speed of 200 rpm. The obtained slurry was filtered, washed with 5 times the amount of water, and dried at 120 ° C. for 5 hours. A scanning electron micrograph of this zeolite is shown in FIG. As is clear from the figure, it can be seen that the ZSM-5 produced has a thickness of 0.5-1 μm at the widest portion and an average of 0.7 μm.
[0075]
Next, SiO of the obtained catalyst 2 / Al 2 O Three The molar ratio was determined by the same method as in Example 1.
Moreover, the H-ZSM-5 zeolite shaping | molding catalyst which contains zinc 10weight% by the same method as Example 1 was obtained. The amount of pyridine desorbed from 500 ° C. to 900 ° C. before and after steaming at 650 ° C. for 5 hours, and the primary reaction rate constant and surface acid point of n-hexane after steaming at 650 ° C. for 11 hours. The ratio of total acid points was also determined by the same method as in Example 1. The results are shown in Table 1.
[0076]
Furthermore, using the catalyst steam-treated at 650 ° C. for 11 hours, the same test for evaluating the deterioration resistance against regeneration as in Example 1 and the test for evaluating the coking resistance were performed. The results are shown in Table 1.
[0077]
Example 3
Sodium silicate aqueous solution (SiO 2 : 26% by weight, Na 2 (O: 7.0% by weight) NaOH of 0.05 kg and H of 8.0 kg 2 To a solution with O4 kg added, add Al 2 (SO Four ) Three ・ 16H 2 0.61 kg of O and 0.1 kg of 1,3-dimethylurea 2 A solution dissolved in 15 kg of O was added with stirring, and 10 kg of 5 wt% sulfuric acid was added to obtain a homogeneous gel. This gel was charged into a 50 liter autoclave and the stirring power was 0.5 to 1 KW / m. 2 A synthetic reaction was carried out at 160 ° C. for 10 hours with stirring to obtain a seed slurry.
[0078]
Next, No. 3 sodium silicate (Fuji Chemical Co., Ltd., SiO 2 25% by weight, Na 2 O 8wt%) H to 5.45kg 2 O11.0kg and Al 2 (SO Four ) Three ・ 16H 2 3.05 kg of O (manufactured by Wako Pure Chemical Industries, Ltd.) and 3.15 kg of sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd., purity 97%) were added, and the slurry obtained above was used as a seed slurry. 67 kg was added to obtain a homogeneous gel. The gel was placed in a 50 liter autoclave and crystallized while stirring at 150 ° C. for 39.5 hours at 110 rpm.
[0079]
The obtained slurry was filtered, washed with 5 times the amount of water, dried at 120 ° C. for 5 hours, and the particle size of the zeolite was measured with a scanning electron microscope.
Next, SiO of the obtained catalyst 2 / Al 2 O Three The molar ratio was determined by the same method as in Example 1.
[0080]
Moreover, the H-ZSM-5 zeolite shaping | molding catalyst which contains zinc 10weight% by the same method as Example 1 was obtained. The amount of pyridine desorbed between 500 ° C. and 900 ° C. before and after steaming at 650 ° C. for 5 hours, and the primary reaction rate constant and surface of n-hexane after steaming at 650 ° C. for 9.5 hours The ratio between the acid points and the total acid points was determined in the same manner as in Example 1. The results are shown in Table 1.
[0081]
Furthermore, using the catalyst steam-treated at 650 ° C. for 9.5 hours, the same test for evaluating the deterioration resistance against regeneration as in Example 1 and the test for evaluating the coking resistance were performed. The results are shown in Table 1.
[0082]
Example 4
Special 3 sodium silicate (Fuji Chemical Co., Ltd., SiO 2 25% by weight, Na 2 O 8wt%) H to 92kg 2 O95kg and Al 2 (SO Four ) Three ・ 16H 2 7.3 kg of O (manufactured by Wako Pure Chemical Industries, Ltd.) and 3.8 kg of sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd., purity 97%) and 1.15 kg of 1,3-dimethylurea in H 2 A solution dissolved in 150 kg of O was added with stirring to obtain a homogeneous gel. This gel was charged into a 600 liter autoclave and subjected to a synthesis reaction at 160 ° C. for 30 hours with stirring to synthesize Na-type ZSM-5. The synthesized slurry was filtered and washed with water until the filtrate pH was 8 or less, dried at 120 ° C. for 20 hours, and then calcined in air at 550 ° C. for 3 hours to obtain 20 kg of Na-type ZSM-5 powder. It was.
[0083]
Special 3 sodium silicate (Fuji Chemical Co., Ltd., SiO 2 25% by weight, Na 2 O 8wt%) H to 92kg 2 O245kg and Al 2 (SO Four ) Three ・ 16H 2 7.3 kg of O (manufactured by Wako Pure Chemical Industries, Ltd.) and 3.8 kg of sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd., purity 97%), and 3 kg of the Na-type ZSM-5 powder obtained earlier Was added to obtain a homogeneous gel. This gel was charged into a 600 liter autoclave, and a synthetic reaction was performed at 150 ° C. for 10 hours with stirring to obtain a seed slurry.
[0084]
Next, No. 3 sodium silicate (Fuji Chemical Co., Ltd., SiO 2 25% by weight, Na 2 O 8wt%) H to 92kg 2 O245kg and Al 2 (SO Four ) Three ・ 16H 2 4.8 kg of O (manufactured by Wako Pure Chemical Industries, Ltd.) and 4.9 kg of sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd., purity 97%) are added, and 167 kg of the slurry obtained above is added as a seed slurry. Thus, a homogeneous gel was obtained. The gel was placed in a 600 liter autoclave and crystallized while stirring at 160 ° C. for 45 hours at 130 rpm.
[0085]
The obtained slurry was washed with centrifugal filtration until the pH was 9 or less, and then dried at 120 ° C. for 5 hours. A scanning electron micrograph of the dried product is shown in FIG. As is apparent from the figure, the produced Na-type ZSM-5 has a widest portion having a length of 2 to 3 μm and an average of 2.5 μm.
Subsequently, SiO of the obtained dried product 2 / Al 2 O Three When the molar ratio was measured using a fluorescent X-ray apparatus, it was 39.
[0086]
Further, this dried product was ion-exchanged with a 10% by weight slurry in 1N nitric acid at room temperature for 3 hours, washed with water until pH became 4.5 or more while centrifugal filtration, and further dried at 120 ° C. for 10 hours. , H-ZSM-5 was obtained. 144 g of zinc nitrate hexahydrate was dissolved in 200 g of water, 5 g of acetic acid was added, 200 g of alumina sol (alumina sol 520 manufactured by Nissan Chemical Industries, Ltd.), 20 g of boehmite, and 200 g of the H-ZSM-5 were added and mixed for 2 hours. The mixture in the form of clay is molded into a cylindrical shape having a diameter of 1.6 mm and a length of 4 to 6 mm, dried at 120 ° C. for 2 hours, and then baked in an electric furnace at 500 ° C. for 3 hours in an air furnace. An H-ZSM-5 zeolite catalyst containing 10% by weight was molded.
[0087]
Further, in the same manner as in Example 1, the obtained molded catalyst was obtained at 650 ° C., H 2 The amount of pyridine desorbed at 500 to 900 ° C. determined by the temperature-programmed desorption method when the H type was formed before and after steaming for 5 hours under the condition of O partial pressure of 0.8 atm was determined by the above method.
Subsequently, 650 ° C., H 2 Test of resistance to regeneration degradation and coking resistance by determining the primary reaction rate constant of n-hexane and the ratio of surface acid points to total acid points of the catalyst that was steamed for 8 hours under the condition of O partial pressure 0.8atm. Was carried out in the same manner as in Example 1. The results are shown in Table 1.
[0088]
Example 5
Special 3 sodium silicate (Fuji Chemical Co., Ltd., SiO 2 25% by weight, Na 2 O 8wt%) H to 2300kg 2 O2375kg and Al 2 (SO Four ) Three ・ 16H 2 183 kg of O (manufactured by Wako Pure Chemical Industries, Ltd.) and 95 kg of sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd., purity 97%) and 30 kg of 1,3-dimethylurea 2 A solution dissolved in 3750 kg of O was added with stirring to obtain a homogeneous gel. 18m of this gel Three And a synthesis reaction was carried out at 160 ° C. for 30 hours with stirring to synthesize Na-type ZSM-5. This synthesized slurry is filtered and washed with water until the filtrate PH becomes 8 or less, dried at 120 ° C. for 30 hours, and then calcined in air at 550 ° C. for 3 hours to obtain 520 kg of Na-type ZSM-5 powder. It was.
[0089]
Special 3 sodium silicate (Fuji Chemical Co., Ltd., SiO 2 25% by weight, Na 2 O 8wt%) H to 1930kg 2 O5780 kg and sulfuric acid band (Sumitomo Chemical Industries liquid sulfuric acid band, aluminum oxide 8.1 wt%, pH = 3.7) / water = 137 kg / 650 kg and sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd., purity 97%) / Water = 81 kg / 800 kg, and 75 kg of the Na-type ZSM-5 powder obtained earlier was added to obtain a homogeneous gel. 18m of this gel Three And a synthesis reaction was carried out at 150 ° C. for 10 hours with stirring to obtain a seed slurry.
[0090]
Next, No. 3 sodium silicate (Fuji Chemical Co., Ltd., SiO 2 25% by weight, Na 2 O 8wt%) H to 1910kg 2 5050 kg of O and sulfuric acid band (Sumitomo Chemical Industries liquid sulfuric acid band, aluminum oxide 8.1 wt%, pH = 3.7) / water = 196 kg / 930 kg and sulfuric acid (Wako Pure Chemical Industries, Ltd., purity 97%) / Water = 70 kg / 800 kg was added, and 4480 kg of the seed slurry obtained above was added as a seed slurry to obtain a homogeneous gel. 18m of this gel Three The mixture was placed in an autoclave and crystallized while stirring at 160 ° C. for 20 hours at a rotation speed of 40 rpm.
[0091]
The resulting slurry was washed with centrifugal water until the pH was 9 or less, and further ion-exchanged at 10 ° C. with a 10 wt% slurry in 1N nitric acid at 70 ° C. for 5 hours. It washed with water until it became 5 or more, and it dried at 120 degreeC for 30 hours. FIG. 7 shows a scanning electron micrograph of the dried product. As can be seen from the figure, the generated H-ZSM-5 has a widest portion having a length of 2 to 3 μm and an average of 2.5 μm.
Subsequently, SiO of the obtained dried product 2 / Al 2 O Three The molar ratio was 41 as measured using a fluorescent X-ray apparatus.
[0092]
144 g of zinc nitrate hexahydrate was dissolved in 200 g of water, 5 g of acetic acid was added, 200 g of alumina sol (alumina sol 520 manufactured by Nissan Chemical Industries, Ltd.), 20 g of boehmite, and 200 g of the H-ZSM-5 were added and mixed for 2 hours. The mixture in the form of clay is molded into a cylindrical shape having a diameter of 1.6 mm and a length of 4 to 6 mm, dried at 120 ° C. for 2 hours, and then baked in an electric furnace at 500 ° C. for 3 hours in an air furnace. An H-ZSM-5 zeolite catalyst containing 10% by weight was molded.
[0093]
Further, in the same manner as in Example 1, the obtained molded catalyst was obtained at 650 ° C., H 2 The amount of pyridine desorbed at 500 to 900 ° C. by the temperature-programmed desorption method when the H type was formed before and after steaming for 5 hours under the condition of O partial pressure of 0.8 atm was determined by the above method.
Subsequently, 650 ° C., H 2 The primary reaction rate constant of n-hexane and the ratio of the surface acid point to the total acid point of the catalyst subjected to the steam treatment for 8.5 hours under the condition of O partial pressure of 0.8 atm were obtained, and the regeneration deterioration resistance and coking resistance were obtained. The test was conducted in the same manner as in Example 1. The results are shown in Table 1.
[0094]
Comparative Example 1
(1) Seed slurry synthesis
Sodium silicate aqueous solution (SiO 2 : 25.2% by weight, Na 2 O: 7.35 wt%) 129 g with NaOH 0.64 g and H 2 To a solution with 133 g of O added, 2 (SO Four ) Three ・ 16H 2 0.9.7 g of O and 0.2 g of 1,3-dimethylurea 2 A solution dissolved in 230 g of O was added with stirring, and 140 g of 4.6% by weight sulfuric acid was added to obtain a homogeneous gel. The pH of this gel was 10.8. This gel was charged into a 1 liter autoclave and subjected to a synthesis reaction at 180 ° C. for 40 hours.
The resulting slurry was cooled to 30 ° C., partly filtered and dried at 120 ° C. for 8 hours. The X-ray diffraction pattern of this product was consistent with ZSM-5.
[0095]
(2) This synthesis
After adding 250 g of the seed slurry obtained in (1) to 400 g of the gel having the same composition as in (1) and mixing well, the mixture was placed in a 1 liter autoclave and crystallized at 160 ° C. for 15 hours.
The obtained slurry was filtered, washed with 5 times the amount of water, and then dried at 120 ° C. for 8 hours, the X-ray diffraction pattern of which coincided with ZSM-5.
A scanning electron micrograph of this zeolite is shown in FIG. As is apparent from the figure, the produced ZSM-5 is an agglomeration of fine particles, and the agglomerates are particles having irregularities on the surface where the thickness of the widest portion is about 0.2 μm. .
Next, SiO of the obtained catalyst 2 / Al 2 O Three The molar ratio was determined by the same method as in Example 1.
[0096]
Moreover, the H-ZSM-5 zeolite shaping | molding catalyst which contains zinc 10weight% by the same method as Example 1 was obtained. The amount of pyridine desorbed from 500 ° C. to 900 ° C. before and after steaming at 650 ° C. for 5 hours, and the primary reaction rate constant and surface of n-hexane after steaming at 650 ° C. for 3.8 hours. The ratio between the acid points and the total acid points was determined in the same manner as in Example 1. The results are shown in Table 1.
[0097]
Further, using the catalyst steam-treated at 650 ° C. for 3.8 hours, the same test for evaluating the deterioration resistance against regeneration as in Example 1 and the test for evaluating the coking resistance were performed. The results are shown in Table 1.
The particle size is small, the ratio of the surface acid points to the total acid points is large, and the parameter α for the amount of pyridine elimination is large, so the regeneration resistance is poor, and the amount of coke accumulated in the coking resistance test is large. I understand.
[0098]
Comparative Example 2
100 g of 1,8-diamino-4-aminomethyloctane, 4 g of aluminum sulfate and 5 g of sodium hydroxide are dissolved in 200 g, and silica sol (30% SiO 2 ) 250 g was added to obtain a homogeneous solution. While stirring the solution, 20% sulfuric acid was added dropwise to adjust the pH to 12.5 to obtain a homogeneous gel. Furthermore, this gel was put into a mixer and stirred at 2000 rpm for 20 minutes at high speed. This gel was charged into an autoclave and crystallized at 150 ° C. for 24 hours while stirring at 50 rpm. The obtained slurry was filtered, washed with 5 times the amount of water, dried at 120 ° C. for 8 hours, and the particle size of the catalyst was measured with a scanning electron microscope and found to be 5 μm or more.
[0099]
Moreover, the H-ZSM-5 zeolite shaping | molding catalyst which contains zinc 10weight% by the same method as Example 1 was obtained. The amount of pyridine desorbed between 500 ° C. and 900 ° C. before and after steaming at 650 ° C. for 5 hours, and the primary reaction rate constant and surface acid point of n-hexane after steaming at 650 ° C. for 16 hours. The ratio of total acid points was also determined by the same method as in Example 1. The results are shown in Table 1.
[0100]
Furthermore, using the catalyst steam-treated at 650 ° C. for 16 hours, the same test for evaluating the deterioration resistance against regeneration as in Example 1 and the test for evaluating the coking resistance were performed. The results are shown in Table 1.
From Table 1, it can be seen that the present catalyst has a large particle size and a small ratio between the surface acid points and the total acid points, so that the regeneration deterioration resistance is good, but the deterioration due to coking is fast.
[0101]
Comparative Example 3
Special 3 sodium silicate (Fuji Chemical Co., Ltd., SiO 2 25% by weight, Na 2 O 8wt%) H to 6.75kg 2 O23.0kg and Al 2 (SO Four ) Three ・ 16H 2 0.41 kg of O (manufactured by Wako Pure Chemical Industries, Ltd.) and 0.198 kg of sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd., purity 97%) were added, and SiO was used as a seed crystal. 2 / Al 2 O Three Commercially available ZSM-5 with a known molar ratio (manufactured by NE-Chemcat, SiO 2 / Al 2 O Three = 25) 0.167 kg was added to obtain a homogeneous gel. This gel was put into a 50 liter autoclave and crystallized while being stirred at 150 ° C. for 25 hours at a rotation speed of 200 rpm.
The obtained slurry was filtered, washed with 5 times the amount of water, and dried at 120 ° C. for 5 hours. SiO of this zeolite 2 / Al 2 O Three The molar ratio determined by the same method as in Example 1 was 18.
[0102]
Moreover, the H-ZSM-5 zeolite shaping | molding catalyst which contains zinc 10weight% by the same method as Example 1 was obtained. The amount of pyridine desorbed between 500 ° C. and 900 ° C. before and after steaming at 650 ° C. for 5 hours, and the primary reaction rate constant and surface acid point of n-hexane after steaming at 650 ° C. for 3 hours. The ratio of total acid points was also determined by the same method as in Example 1. The results are shown in Table 1.
[0103]
Furthermore, using the catalyst steam-treated for 3 hours at 650 ° C., the same test for evaluating the deterioration resistance against regeneration as in Example 1 and the test for evaluating the resistance to coking were performed. The results are shown in Table 1.
SiO 2 / Al 2 O Three Since the molar ratio is small, the regeneration resistance is poor.
[0104]
Comparative Example 4
Commercially available H-ZSM-5 zeolite (NE-Chemcat, SiO 2 / Al 2 O Three = 250), the H-ZSM-5 zeolite shaped catalyst containing 10% by weight of zinc was obtained in the same manner as in Example 1. The amount of pyridine desorbed between 500 ° C. and 900 ° C. before and after steaming at 650 ° C. for 5 hours, and the primary reaction rate constant and surface acid point of n-hexane after steaming at 650 ° C. for 1 hour. The ratio of total acid points was also determined by the same method as in Example 1. The results are shown in Table 1.
[0105]
Furthermore, using the catalyst steam-treated at 650 ° C. for 1 hour, the same test for evaluating the regeneration resistance as in Example 1 and the test for evaluating the coking resistance were performed. The results are shown in Table 1.
SiO 2 / Al 2 O Three Since the molar ratio is too large and the degree of crystallinity is low, the parameter α of the amount of pyridine desorption before and after the steam treatment becomes large, and the regeneration deterioration resistance is poor.
[0106]
Comparative Example 5
Solution A in which 290 g of sodium silicate (water glass No. 3) was dissolved in 230 g of distilled water, 11.4 g of aluminum sulfate 16-hydrate, 23.4 g of 1,3-dimethylurea, and 13 g of sulfuric acid were dissolved in 300 g of distilled water. B liquid was prepared. Next, using a homogenizer, solution B was added to solution A with strong stirring, and stirred for about 3 hours until the gel composition became uniform. This gel composition was charged into a 1 liter autoclave and subjected to reaction crystallization for 35 hours under stirring at 150 ° C. and 1000 rpm. After the reaction, the solid was filtered, washed with water, dehydrated and dried, and calcined in air at 550 ° C. for 3 hours. SiO of obtained H-ZSM-5 type zeolite 2 / Al 2 O Three The molar ratio determined by the same method as in Example 1 was 46. Further, the particle size of the zeolite was measured with a scanning electron microscope.
[0107]
Moreover, the ZSM-5 zeolite shaping | molding catalyst which contains zinc 10weight% by the same method as Example 1 was obtained. The amount of pyridine desorbed between 500 ° C. and 900 ° C. before and after steaming at 650 ° C. for 5 hours of this shaped catalyst was determined. The first-order rate constant of n-hexane after steaming at 650 ° C. for 3 hours and the ratio of surface acid points to total acid points were determined in the same manner as in Example 1. The results are shown in Table 1.
Furthermore, using the catalyst steam-treated for 3 hours at 650 ° C., the same test for evaluating the deterioration resistance against regeneration as in Example 1 and the test for evaluating the resistance to coking were performed. The results are shown in Table 1.
Since the parameter α of the amount of pyridine desorption before and after the steam treatment is as large as 1.8, the regeneration deterioration resistance is poor.
[0108]
Comparative Example 6
Commercially available H-ZSM-5 zeolite (SiO 2 / Al 2 O Three = 400), the H-ZSM-5 zeolite shaped catalyst containing 10% by weight of zinc was obtained by the same method as in Example 1. The amount of pyridine desorbed from 500 ° C. to 900 ° C. before and after steam treatment at 650 ° C. for 5 hours, the primary reaction rate constant of n-hexane, the surface acid point, and the total acid point of this molded catalyst before steam treatment. The ratio was also determined by the same method as in Example 1. The results are shown in Table 1.
Furthermore, using the catalyst not subjected to steam treatment, the same test for evaluating the regeneration resistance as in Example 1 and the test for evaluating the coking resistance were performed. The results are shown in Table 1. SiO 2 / Al 2 O Three Since the molar ratio is too large, the activity is low and the aromatic yield is low.
[0109]
Example 6
The zeolite catalyst synthesized and molded by the same method as in Example 4 was charged into a one-stage adiabatic reactor, and the pressure was 5 kg / cm. 2 G was steamed at 650 ° C. for 8 hours. Furthermore, C shown in Table 2 Five Fraction and C shown in Table 3 Four The fraction is 6: 4 by weight and the pressure is 5 kg / cm. 2 G, inlet temperature 530 ° C., WHSV (weight hourly space velocity) 2.8 hr -1 A cyclization reaction was carried out for 48 hours under the above conditions. The carbonaceous material accumulated during 48 hours is pressure 5 kg / cm. 2 G was burned and removed (regenerated) by circulating nitrogen gas having an oxygen concentration of 1 to 1.5 vol% at a flow rate of 5000 Nm3 / hr for 40 to 43 hours in an atmosphere of 480 to 530 ° C. The cyclization reaction and regeneration were repeated 75 times (300 days). Table 4 shows the results of the first and 75th cyclization reactions.
[0110]
Comparative Example 7
A zeolite catalyst synthesized and molded in the same manner as in Comparative Example 1 was charged into a one-stage adiabatic reactor, and the pressure was 5 kg / cm. 2 G was steamed at 650 ° C. for 3.8 hours. Furthermore, C shown in Table 2 Five Fraction and C shown in Table 3 Four The fraction is 6: 4 by weight and the pressure is 5 kg / cm. 2 G, inlet temperature 530 ° C., WHSV (weight hourly space velocity) 2.8 hr -1 A cyclization reaction was carried out for 48 hours under the above conditions. The carbonaceous material accumulated during 48 hours is pressure 5 kg / cm. 2 G was burned and removed (regenerated) by circulating nitrogen gas having an oxygen concentration of 1 to 1.5 vol% at a flow rate of 5000 Nm3 / hr for 40 to 43 hours in an atmosphere of 480 to 530 ° C. The cyclization reaction and regeneration were repeated 75 times (300 days). Table 4 shows the results of the first and 75th cyclization reactions. It can be seen that since the ratio of the surface acid points to the total acid points is large, the deterioration resistance against regeneration is poor and the permanent activity deterioration is fast.
[0111]
Example 7
The total amount of zinc obtained from the catalyst obtained in Example 4 subjected to steam treatment at 650 ° C. for 8 hours was determined by fluorescent X-ray, and the catalyst was treated with hydrochloric acid, and then zinc oxide was determined by atomic absorption spectrometry. . They were 2.9% by weight of zinc oxide and 22.4% by weight of zinc aluminate based on the catalyst weight. 10 g of this catalyst is filled in a reaction tube, hydrogen is supplied at 20 [L / Hr], and reduced at 500 ° C. for 20 Hr. Table 5 shows the measurement results of the amount of zinc oxide and the amount of zinc aluminate before and after the hydrogen reduction. In addition, using the catalyst before and after hydrogen reduction, C Four Fraction and C Five The test which evaluates the coking resistance using a fraction was implemented. The results are shown in Table 5.
[0112]
Comparative Example 8
The zinc-free H-ZSM-5 obtained in Example 4 was immersed in 100 g of a 7 wt% zinc nitrate aqueous solution, evaporated to dryness, dried at 120 ° C. for 4 hours, and calcined at 500 ° C. for 3 hours. A catalyst containing 2.0% by weight was prepared. Next, 20 g of this catalyst after compression molding, pulverized, and aligned to 9 to 20 mesh was charged into a quartz glass reactor having an inner diameter of 12 mm, and a large amount of steam in a steam-nitrogen mixed gas containing 80% by weight of steam was used. Heat treatment was performed at 650 ° C. for 1 hour under atmospheric pressure. Zinc oxide and zinc aluminate were determined by X-ray fluorescence and atomic absorption, and reduced by hydrogen in the same manner as in Example 8. Furthermore, C before and after hydrogen reduction Four Fraction and C Five The test which evaluates the coking resistance using a fraction was implemented. The results are shown in Table 5.
[0113]
Comparative Example 9
Zinc-free H-ZSM-5 obtained in Example 1 was steam treated at 650 ° C. for 5 hours, and zinc aluminate manufactured by High-Purity Chemical Laboratory was 10% by weight based on the total catalyst as zinc. It mixed so that it might become. C Four Fraction and C Five The test which evaluates the coking resistance using a fraction was implemented. The results are shown in Table 5.
[0114]
[Table 1]
Figure 0003905948
[0115]
[Table 2]
Figure 0003905948
[0116]
[Table 3]
Figure 0003905948
[0117]
[Table 4]
Figure 0003905948
[0118]
[Table 5]
Figure 0003905948
[0119]
【The invention's effect】
According to the method of the present invention as described above, the amount of carbonaceous material accumulated on the catalyst during the reaction in which the raw material or product contains aromatic hydrocarbons is reduced, and the activity of carbonaceous material is temporarily reduced. Further, it is possible to suppress permanent activity deterioration due to dealumination in a high-temperature atmosphere where moisture exists, such as occurs when the carbonaceous material is burned and removed with an oxygen-containing inert gas. A catalyst having excellent coking resistance can be obtained. Therefore, the method of the present invention can be widely used in the petrochemical industry and petroleum refining, and can be effectively used particularly for the production of aromatic compounds and high octane gasoline.
[Brief description of the drawings]
FIG. 1 is a schematic view of an acid point measuring apparatus in the method of the present invention.
FIG. 2 is a schematic view of an isothermal reactor in the method of the present invention.
FIG. 3 is a scanning photomicrograph of a catalyst in the method of the present invention.
FIG. 4 is a schematic view of an isothermal reactor in the method of the present invention.
FIG. 5 is a scanning photomicrograph of a catalyst in the method of the present invention.
FIG. 6 is a scanning photomicrograph of a catalyst in the method of the present invention.
FIG. 7 is a scanning photomicrograph of a catalyst in the method of the present invention.
FIG. 8 is a scanning photomicrograph of a catalyst in the method of the present invention.
[Explanation of symbols]
1 Gas flow meter
2 Tubular electric furnace
3 SUS short tube column
4 samples
5 Inlet
6 FID type detector
7 Temperature detection end
8 Ribbon heater
9 Insulation material
10 Quartz reaction tube
11 Quartz wool
12 Catalyst
13 Raschig rings
14 Thermometer
15 Thermocouple for temperature adjustment
16 Electric furnace
17 Raw material inlet
18 condenser
19 Oil trap
20 Back for generating gas repair
21 SUS reaction tube
22 Thermometer
23 Catalyst
24 Thermocouple for temperature control
25 Electric furnace
26 Raw material inlet
27 C Five Raw material tank for fractions
28 C Four Raw material tank for fractions
29 Pump
30 pumps

Claims (9)

オレフィンおよび/またはパラフィンを含む軽質炭化水素から芳香族炭化水素を製造する反応に用いられる高シリカゼオライト系触媒であって、下記の要件(1),(2),(3),(4)を満足する高シリカゼオライト系触媒。
(1)該ゼオライト系触媒を構成するゼオライトのSiO2 /Al2 3 モル比が20から200。
(2)該ゼオライト系触媒を構成するゼオライトの一次粒子の粒径が0.3から3μm。
(3)該ゼオライト系触媒をH型にしたときの全酸点に対する表面酸点の割合が0.03〜0.15。
(4)該ゼオライト系触媒をH2 O分圧0.8atm,650℃で5時間水蒸気処理をした後での、H型にしたときの昇温脱離法による500〜900℃におけるピリジンの脱離量(B)と該水蒸気処理前のH型にしたときの昇温脱離法による500〜900℃におけるピリジン脱離量(A)とが以下を満足する。
Figure 0003905948
A high silica zeolite catalyst used in a reaction for producing an aromatic hydrocarbon from a light hydrocarbon containing olefin and / or paraffin, which satisfies the following requirements (1), (2), (3), (4) Satisfied high silica zeolite catalyst.
(1) The SiO 2 / Al 2 O 3 molar ratio of the zeolite constituting the zeolite catalyst is 20 to 200.
(2) The primary particle diameter of the zeolite constituting the zeolitic catalyst is 0.3 to 3 μm.
(3) The ratio of the surface acid point to the total acid point when the zeolite catalyst is made to be H-type is 0.03 to 0.15.
(4) Dehydration of pyridine at 500 to 900 ° C. by the temperature-programmed desorption method when the zeolite-based catalyst is steamed for 5 hours at H 2 O partial pressure of 0.8 atm and 650 ° C. The amount of separation (B) and the amount of pyridine desorption (A) at 500 to 900 ° C. by the temperature programmed desorption method when the H-type before the steam treatment is satisfied satisfy the following.
Figure 0003905948
500℃、大気圧下で測定したゼオライト系触媒のn−ヘキサン分解の一次反応速度定数が0.2以上であることを特徴とする請求項1記載の触媒。 The catalyst according to claim 1, wherein the first-order rate constant of n-hexane decomposition of the zeolite catalyst measured at 500 ° C and atmospheric pressure is 0.2 or more. 高シリカゼオライト系触媒が、ゼオライトと、周期律表VIII族,Ib族,IIb族およびIIIb族に属する金属及びその化合物から選ばれる少なくとも一種との混合物を包含してなることを特徴とする請求項1〜のいずれかに記載の触媒。The high silica zeolite-based catalyst includes a mixture of zeolite and at least one selected from metals belonging to Group VIII, Group Ib, Group IIb and Group IIIb of the periodic table and compounds thereof. The catalyst in any one of 1-2 . 高シリカゼオライト系触媒が、ゼオライトと亜鉛成分およびアルミナとの混合物であることを特徴とする請求項記載の触媒。4. The catalyst according to claim 3, wherein the high silica zeolite catalyst is a mixture of a zeolite, a zinc component and alumina. 高シリカゼオライト系触媒が、ゼオライトと亜鉛成分およびアルミナとの混合物であって、水蒸気中で熱処理されていることを特徴とする請求項記載の触媒。4. The catalyst according to claim 3, wherein the high silica zeolite catalyst is a mixture of zeolite, a zinc component and alumina, and is heat-treated in water vapor. 高シリカゼオライト系触媒が、亜鉛成分およびアルミナの混合物を水蒸気中で熱処理したものとゼオライトとを混合したものであることを特徴とする請求項記載の触媒。4. The catalyst according to claim 3, wherein the high-silica zeolite catalyst is a mixture of a zinc component and alumina heat-treated in water vapor and zeolite. 高シリカゼオライト系触媒が、アルミン酸亜鉛と酸化亜鉛を共に含むことを特徴とする請求項記載の触媒。The catalyst according to claim 3, wherein the high silica zeolite-based catalyst contains both zinc aluminate and zinc oxide. 高シリカゼオライト系触媒が、アルミン酸亜鉛8.2〜50重量%と酸化亜鉛1.2〜20重量%とを共に含むことを特徴とする請求項記載の触媒。The catalyst according to claim 7, wherein the high silica zeolite-based catalyst contains 8.2 to 50% by weight of zinc aluminate and 1.2 to 20% by weight of zinc oxide. 請求項1〜のいずれかに記載の触媒を用いて、オレフィンおよび/またはパラフィンを含む軽質炭化水素から芳香族炭化水素を製造する方法。A method for producing an aromatic hydrocarbon from a light hydrocarbon containing olefin and / or paraffin using the catalyst according to any one of claims 1 to 8 .
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