JP4022047B2 - Method for producing methacrylic acid synthesis catalyst, methacrylic acid synthesis catalyst and methacrylic acid production method - Google Patents
Method for producing methacrylic acid synthesis catalyst, methacrylic acid synthesis catalyst and methacrylic acid production method Download PDFInfo
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- Y—GENERAL 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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Description
【０００１】
【発明の属する技術分野】
本発明は、メタクロレインを分子状酸素により気相接触酸化してメタクリル酸を合成する際に使用するメタクリル酸合成用触媒の製造方法、メタクリル酸合成用触媒およびこの触媒を用いたメタクリル酸の製造方法に関する。
【０００２】
【従来の技術】
メタクロレインを分子状酸素により気相接触酸化してメタクリル酸を合成する際に使用する触媒については数多くの提案がなされている。例えば、特開昭５０−１０１３１６号公報、特開昭５３−３７６１４号公報、特開昭５４−１０３８１９号公報、特開昭５７−１２０５４７号公報、特開昭６０−２３９４３９号公報、特開平２−２４００４３号公報等にはモリブデンおよびリンを主成分とする触媒が開示されている。通常、これらの触媒は、各金属成分を含む水性スラリーを乾燥し、必要に応じて成型した後、焼成するという一連の工程で製造される。すなわち、一種類の水性スラリーを調製し、それを元に乾燥、成型、焼成の一連の工程を経て製造される。しかしながら、この方法により得られる触媒では、活性および選択性の点で工業触媒としては必ずしも十分ではない。
【０００３】
特開平５−１７７１４１号公報には、少なくともモリブデン、リンおよびセシウムを含むヘテロポリ酸系触媒を調製する際に、少なくともモリブデン、リンおよびセシウムを含むヘテロポリ酸塩を得、該ヘテロポリ酸塩の懸濁液に少なくともモリブデンおよびリンを含みセシウムを含まない触媒原料を添加し、得られた液状物を乾燥、焼成して触媒を得る方法、すなわち２段階で触媒を調製する方法が開示されている。この方法により調製される触媒は、ヘテロポリ酸のセシウム塩の小粒子上にセシウムを含まないヘテロポリ酸が結晶成長し、結晶としては安定なセシウム塩の構造をとっているが反応に使用される触媒粒子表面には反応活性が高いセシウムを含まないヘテロポリ酸が存在していると推定され、従来の１段階で調製する方法よりも高い活性、選択性を有することが報告されている。
【０００４】
しかしながら、この方法で得られる触媒においても、活性およびメタクリル酸選択性の点で工業触媒としては必ずしも十分ではなく、さらなる触媒性能の向上が望まれている。
【０００５】
【発明が解決しようとする課題】
本発明は、メタクロレインを分子状酸素により気相接触酸化してメタクリル酸を合成する際に使用するメタクリル酸合成用触媒の新規な製造方法、この製造方法により得られる高活性、高メタクリル酸選択性のメタクリル酸合成用触媒、および、この触媒を用いた高収率のメタクリル酸の製造方法を提供することを目的とする。
【０００６】
【課題を解決するための手段】
上記課題を解決するため鋭意検討を行った結果、本発明者らは、メタクロレインを分子状酸素により気相接触酸化してメタクリル酸を合成する際に使用する触媒について、高活性、高メタクリル酸選択性を有する触媒を得ることができる新規調製法を完成させるに至った。本発明の上記課題は以下の本発明により解決できる。
（１）少なくともモリブデンと、リンと、カリウム、ルビジウム、セシウムおよびタリウムからなる群より選ばれた少なくとも１種の元素であるＸとを含むメタクリル酸合成用触媒の製造方法であって、少なくともモリブデン、リンおよびＸを含む固形物Ａを調製する工程と、少なくともモリブデン、リンおよびＸを含む水性スラリーＢを調製する工程と、固形物Ａと水性スラリーＢとを混合する工程と、固形物Ａと水性スラリーＢとを混合して得られる液状物を乾燥する工程と、この乾燥物を３００〜５００℃で焼成する工程とを含み、固形物Ａに含まれるモリブデンとＸの含有比（原子比）は１２：２．５〜１２：１２とし、水性スラリーＢに含まれるモリブデンとＸの含有比（原子比）は１２：０．０５〜１２：０．４とすることを特徴とするメタクリル酸合成用触媒の製造方法。
（２）前記（１）のメタクリル酸合成用触媒の製造方法により得られるメタクリル酸合成用触媒。
（３）前記（２）のメタクリル酸合成用触媒の存在下でメタクロレインを気相接触酸化することを特徴とするメタクリル酸の製造方法。
【０００７】
メタクリル酸合成用触媒の製造方法において、固形物Ａに含まれるモリブデンとＸの含有比（原子比）は１２：２．５〜１２：１２であり、１２：３．０５〜１２：１０、特に１２：３．６〜１２：８であることが好ましい。また、水性スラリーＢに含まれるモリブデンとＸの含有比（原子比）は１２：０．０５〜１２：０．４であり、１２：０．０７〜１２：０．３５、特に１２：０．０９〜１２：０．３であることが好ましい。
【０００８】
【発明の実施の形態】
本発明の新規な製造方法により得られるメタクリル酸製造用触媒は、メタクロレインを分子状酸素により気相接触酸化してメタクリル酸を製造するための触媒であって、高活性、高メタクリル酸選択性を有している。
【０００９】
本発明のメタクリル酸合成用触媒の製造方法は、
（１）少なくともモリブデン、リンおよびＸを含む固形物Ａを調製する工程と、
（２）少なくともモリブデン、リンおよびＸを含む水性スラリーＢを調製する工程と、
（３）固形物Ａと水性スラリーＢとを混合する工程と、
（４）固形物Ａと水性スラリーＢとを混合して得られる液状物を乾燥する工程と、
（５）この乾燥物を３００〜５００℃で焼成する工程と
を含むものである。ここで、Ｘは、カリウム、ルビジウム、セシウムおよびタリウムからなる群より選ばれた少なくとも１種の元素を表す。
【００１０】
本発明において、固形物Ａの調製法としては特に限定されず、共沈法、蒸発乾固法、酸化物混合法等の種々の方法を用いることができる。特に、少なくともモリブデン、リンおよびＸを含む水性スラリーを乾燥することにより調製する方法が好ましい。この際、水性スラリーの乾燥方法としては特に限定されず、汎用の箱型乾燥機、噴霧乾燥機、ドラムドライヤー、スラリードライヤー等を用いることができる。また、その調製過程において、３００℃以上で熱処理する過程が含まれていないことが好ましい。固形物Ａの調製条件は、少なくともモリブデン、リンおよびＸを含むメタクリル酸合成用触媒の熱処理前の前駆体の製造方法に従い、適宜決めればよい。
【００１１】
固形物Ａの調製に用いる原料は特に限定されず、各元素の硝酸塩、炭酸塩、酢酸塩、アンモニウム塩、酸化物、ハロゲン化物等を使用することができる。例えば、モリブデン原料としてはパラモリブデン酸アンモニウム、三酸化モリブデン、モリブデン酸、塩化モリブデン等が使用できる。触媒成分の原料は各元素に対して１種を用いても２種以上を用いてもよい。
【００１２】
なお、固形物Ａは実質的に固形物であればよく、含水量等に関しては特に規定されない。
【００１３】
固形物Ａの形状については特に限定されないが、粉体状が好ましい。また、固形物Ａを水性スラリーＢに混合したときにできるだけ均一に混合されるように固形物Ａを粉砕して適当な粒径の粒子にしてもよい。
【００１４】
固形物Ａは必ずしもヘテロポリ酸塩の構造を有していなくてもよい。本発明においては、固形物Ａに含まれるモリブデンとＸの含有比（原子比）が重要である。固形物Ａに含まれるモリブデンとＸの含有比（原子比）は１２：２．５〜１２：１２であり、１２：３．０５〜１２：１０、特に１２：３．６〜１２：８であることが好ましい。
【００１５】
また、固形物Ａの構成元素は、モリブデン、リンおよびＸを含有していれば特に限定されないが、モリブデン、リンおよびＸ以外に、銅、バナジウム、鉄、コバルト、ニッケル、亜鉛、マグネシウム、カルシウム、ストロンチウム、バリウム、チタン、クロム、タングステン、マンガン、銀、ホウ素、ケイ素、アルミニウム、ガリウム、ゲルマニウム、スズ、鉛、ヒ素、アンチモン、ビスマス、ニオブ、タンタル、ジルコニウム、インジウム、イオウ、セレン、テルル、ランタン、セリウムなどを適宜含んでいてもよい。
【００１６】
本発明において、水性スラリーＢの調製法は特に限定されない。少なくともモリブデン、リンおよびＸを含む水性スラリーであればよい。水性スラリーの水の量も特に限定されないが、固形物Ａがすべて再溶解しないようにしなければならない。具体的には、水性スラリーＢに含まれるモリブデンと水の質量比は１：０．５〜１：１０が好ましい。
【００１７】
水性スラリーＢの調製に用いる原料は特に限定されず、固形物Ａと同様に各元素の硝酸塩、炭酸塩、酢酸塩、アンモニウム塩、酸化物、ハロゲン化物等を使用することができる。例えば、モリブデン原料としてはパラモリブデン酸アンモニウム、三酸化モリブデン、モリブデン酸、塩化モリブデン等が使用できる。触媒成分の原料は各元素に対して１種を用いても２種以上を用いてもよい。
【００１８】
水性スラリーＢに含まれるモリブデンとＸの含有比（原子比）は１２：０．０５〜１２：０．４であり、１２：０．０７〜１２：０．３５、特に１２：０．０９〜１２：０．３であることが好ましい。
【００１９】
また、水性スラリーＢの構成元素は、モリブデン、リンおよびＸを含有していれば特に限定されないが、モリブデン、リンおよびＸ以外に、銅、バナジウム、鉄、コバルト、ニッケル、亜鉛、マグネシウム、カルシウム、ストロンチウム、バリウム、チタン、クロム、タングステン、マンガン、銀、ホウ素、ケイ素、アルミニウム、ガリウム、ゲルマニウム、スズ、鉛、ヒ素、アンチモン、ビスマス、ニオブ、タンタル、ジルコニウム、インジウム、イオウ、セレン、テルル、ランタン、セリウムなどを適宜含んでいてもよい。
【００２０】
本発明において、固形物Ａと水性スラリーＢを混合する際の手順は特に限定されない。混合においては、固形物Ａを水性スラリーＢに投入することが重要である。また、固形物Ａを水性スラリーＢへ混合するタイミングについては特に限定されないが、例えば、水性スラリーＢを調合した後に固形物Ａを投入し、できるだけ均一になるように混合して得られた液状物を乾燥することが好ましい。
【００２１】
混合する際の固形物Ａに含まれるモリブデンと水性スラリーＢに含まれるモリブデンの比（原子比）は、高活性、高メタクリル酸選択性の触媒が得られるので、１：１〜１：３０とすることが好ましい。
【００２２】
液状物の乾燥方法に関しても特に限定されず、汎用の箱型乾燥機、噴霧乾燥機、ドラムドライヤー、スラリードライヤー等を用いることができる。乾燥条件は適宜決めればよい。
【００２３】
固形物Ａと水性スラリーＢの混合液状物を乾燥して得られた乾燥物はそのまま次の焼成を行なってもよいが、通常は成形してから焼成する。
【００２４】
乾燥物を成型する方法としては特に限定されず、通常の打錠成型、押出成型、造粒等の各種成型法を適用することができる。
【００２５】
また、成型に際しては、乾燥物に対して従来公知の添加剤、例えば成型物の比表面積、細孔容積および細孔分布を再現性よく制御したり、機械的強度を高めるために、硫酸バリウム、硝酸アンモニウム等の無機塩類、グラファイト等の滑剤、セルロース類、でんぷん、ポリビニルアルコール、ステアリン酸等の有機物、シリカゾル、アルミナゾル等の水酸化物ゾル、ウィスカー、ガラス繊維、炭素繊維等の無機質繊維等を適宜添加してもよい。
【００２６】
成型物の形状についても特に限定はなく、球状、円柱状、リング状、板状等の任意の形状に成型できる。
【００２７】
本発明では、得られた成型物を３００〜５００℃の範囲の温度で焼成して本発明のメタクリル酸合成用触媒が得られる。焼成時間については特に限定されないが、良好な触媒が得られるので１時間以上であることが好ましく、通常、４０時間以下が好ましい。焼成は、通常、酸素、空気または窒素流通下で行なう。
【００２８】
このようにして得られる本発明のメタクリル酸合成用触媒中においては、ヘテロポリ酸またはヘテロポリ酸塩の構造が含まれていることが好ましい。
【００２９】
本発明のメタクリル酸合成用触媒は、下記一般式（I）で表される組成を有する複合酸化物であることが好ましい。
【００３０】
ＭｏaＰbＣｕcＶdＸeＹfＯg （I）
ここで、式中、Ｍｏ、Ｐ、Ｃｕ、ＶおよびＯはそれぞれモリブデン、リン、銅、バナジウムおよび酸素を表し、Ｘはカリウム、ルビジウム、セシウムおよびタリウムからなる群より選ばれた少なくとも１種の元素を表し、Ｙは鉄、コバルト、ニッケル、亜鉛、マグネシウム、カルシウム、ストロンチウム、バリウム、チタン、クロム、タングステン、マンガン、銀、ホウ素、ケイ素、アルミニウム、ガリウム、ゲルマニウム、スズ、鉛、ヒ素、アンチモン、ビスマス、ニオブ、タンタル、ジルコニウム、インジウム、イオウ、セレン、テルル、ランタンおよびセリウムからなる群より選ばれた少なくとも１種の元素を表す。
【００３１】
ａ、ｂ、ｃ、ｄ、ｅ、ｆおよびｇは各元素の原子比を表し、ａ＝１２のとき、０．１≦ｂ≦３、０．０１≦ｃ≦３、０．０１≦ｄ≦３、０．０５≦ｅ≦３、０≦ｆ≦３であり、ｇは前記各成分の原子比を満足するのに必要な酸素の原子比である。
【００３２】
本発明により製造される触媒の各成分の存在状態、殊にＸの存在状態は複雑であり、厳密には把握されていない。ただし、固形物Ａに含まれるＸとモリブデンの含有比（原子比）Ｘ／Ｍｏは２．５／１２〜１２／１２であり、Ｘ／Ｍｏが３／１２より大きい場合は固形物Ａは単なるＸ元素をカチオンとするヘテロポリ酸塩を形成しているとは考えにくい。したがって、特開平５−１７７１４１号公報に示された方法により製造されるような触媒の構造、すなわち、モリブデン、リンおよびＸを含むヘテロポリ酸塩の結晶粒子の表面をＸを含まないヘテロポリ酸が覆った構造になっている可能性は非常に低く、それとは異なる構造をしていると考えられる。また、Ｘ／Ｍｏが３／１２以下では、固形物Ａは単なるヘテロポリ酸塩を形成している可能性もあるが、本発明者らは、Ｘ／Ｍｏが２．５／１２以上のときに触媒活性および選択性において良好な触媒が得られることを見出した。
【００３３】
次に、本発明のメタクリル酸の製造方法について説明する。本発明のメタクリル酸の製造方法は、上記のような本発明の触媒の存在下でメタクロレインを分子状酸素により気相接触酸化してメタクリル酸を製造するものである。
【００３４】
反応は、通常、固定床で行なう。また、触媒層は１層でも２層以上でもよい。
【００３５】
原料ガス中のメタクロレインの濃度は広い範囲で変えることができるが、１〜２０容量％、特に３〜１０容量％が好ましい。原料のメタクロレインは、水、低級飽和アルデヒド等の実質的に反応に影響を与えない不純物を少量含んでいてもよい。
【００３６】
接触酸化を行う際の酸素源としては、空気を用いるのが工業的に有利であるが、必要に応じて純酸素で富化した空気等も使用できる。原料ガス中のメタクロレイン対酸素のモル比（容量比）は１：０．５〜１：３が好ましい。
【００３７】
原料ガスは反応原料と分子状酸素以外に水を含んでいることが好ましく、また窒素、二酸化炭素等の不活性ガスで希釈して用いることが好ましい。原料ガス中のメタクロレイン対水の容量比は１：０．１〜１：１０が好ましい。
【００３８】
反応圧力は常圧ないし数気圧まで用いられる。反応温度は２００〜４５０℃の範囲が好ましい。接触時間は２〜７秒が好ましい。
【００３９】
【実施例】
以下、本発明の触媒の調製法、および、その触媒を用いた反応例を実施例により説明する。
【００４０】
ただし、下記実施例および比較例中の「部」は質量部を意味する。反応試験分析はガスクロマトグラフィーにより行った。触媒組成は触媒原料の仕込み量から求めた。
【００４１】
また、実施例、比較例中の反応用原料としてのメタクロレインの転化率、生成したメタクリル酸の選択率および収率は以下のように定義される。
【００４２】
メタクロレイン転化率（％）＝反応したメタクロレインのモル数／供給したメタクロレインのモル数×１００
メタクリル酸選択率（％）＝生成したメタクリル酸のモル数／反応したメタクロレインのモル数×１００
メタクリル酸収率（％）＝生成したメタクリル酸のモル数／供給したメタクロレインのモル数×１００
＜実施例１＞
パラモリブデン酸アンモニウム２２．５部、メタバナジン酸アンモニウム１．０部および硝酸カリウム５．４部を純水９０部に溶解した。これを撹拌しながら、８５％リン酸１．８部を純水２．３部に溶解した溶液を加え、さらに硝酸銅０．３部を純水２．３部に溶解した溶液を加えた。次に、硝酸ビスマス１．６部に６０％硝酸１．６部および水９部を加えて得られた硝酸ビスマスの均一溶液を前記混合液に加えた後、９５℃に昇温した。これに、６０％ヒ酸０．５部を純水２．２部に溶解した溶液を加え、続いて三酸化アンチモン０．５部、二酸化セリウム０．４部を加えた。得られた水性スラリーを加熱撹拌しながら蒸発乾固した後、１３０℃で１６時間乾燥し、粉砕することにより固形物Ａ−１を得た。得られた固形物Ａ−１に含まれるＭｏとＫの含有比（原子比）は１２：５であった。
【００４３】
別に、水性スラリーに含まれるＭｏとＫの含有比（原子比）が１２：０．１になるように水性スラリーＢ−１を調製した。
【００４４】
パラモリブデン酸アンモニウム１００部、メタバナジン酸アンモニウム４．４部および硝酸カリウム０．５部を純水４００部に溶解した。これを撹拌しながら、８５％リン酸８．２部を純水１０部に溶解した溶液を加え、さらに硝酸銅１．１部を純水１０部に溶解した溶液を加えた。次に、硝酸ビスマス６．９部に６０％硝酸７．０部および純水４０部を加えて得られた硝酸ビスマスの均一溶液を前記混合液に加えた後、９５℃に昇温した。これに、６０％ヒ酸２．２部を純水１０部に溶解した溶液を加え、続いて三酸化アンチモン２．１部、二酸化セリウム１．６部を加え、撹拌した後、この液状物を７０℃に降温して水性スラリーＢ−１を得た。
【００４５】
このようにして得られた固形物Ａ−１全量を水性スラリーＢ−１に添加し、液状物を加熱撹拌しながら蒸発乾固した後、１３０℃で１６時間乾燥し、得られた乾燥物を粉砕した。こうして得られた紛体１００部にグラファイト３．０部を添加し、続いて打錠成型機により、外径５ｍｍ、内径２ｍｍ、長さ５ｍｍのリング状に成型した。そして、得られた成型物を空気流通下、３８０℃で５時間焼成して触媒を得た。
【００４６】
得られた触媒の酸素以外の元素の組成は、
Ｍｏ12Ｐ1.5Ｖ0.8Ｃｕ0.1Ｓｂ0.3Ｂｉ0.3Ａｓ0.2Ｃｅ0.2Ｋ1
であった。
【００４７】
得られた触媒を反応管に充填し、メタクロレイン５容量％、酸素１０容量％、水蒸気３０容量％および窒素５５容量％からなる原料ガスを常圧下、反応温度２９０℃、接触時間３．６秒で通じた。生成物を捕集し、ガスクロマトグラフィーで分析したところ、メタクロレイン転化率９１．６％、メタクリル酸選択率８９．０％、メタクリル酸収率８１．５％であった。
＜実施例２＞
パラモリブデン酸アンモニウム３６部、メタバナジン酸アンモニウム１．６部および硝酸カリウム６部を純水１４４部に溶解した。これを撹拌しながら、８５％リン酸２．９部を純水３．６部に溶解した溶液を加え、さらに硝酸銅０．４部を純水３．６部に溶解した溶液を加えた。次に、硝酸ビスマス２．５部に６０％硝酸２．５部および水１４．４部を加えて得られた硝酸ビスマスの均一溶液を前記混合液に加えた後、９５℃に昇温した。これに、６０％ヒ酸０．８部を純水３．６部に溶解した溶液を加え、続いて三酸化アンチモン０．７部、二酸化セリウム０．６部を加えた。得られた水性スラリーを加熱撹拌しながら蒸発乾固した後、１３０℃で１６時間乾燥し、粉砕することにより固形物Ａ−２を得た。得られた固形物Ａ−２に含まれるＭｏとＫの含有比（原子比）は１２：３．５であった。
【００４８】
実施例１と同様にして得られた水性スラリーＢ−１に固形物Ａ−２全量を添加し、実施例１と同様にして紛体を得、続いて成型、焼成を行い、触媒を得た。
【００４９】
得られた触媒の酸素以外の元素の組成は、
Ｍｏ12Ｐ1.5Ｖ0.8Ｃｕ0.1Ｓｂ0.3Ｂｉ0.3Ａｓ0.2Ｃｅ0.2Ｋ1
であった。
【００５０】
得られた触媒を反応管に充填し、実施例１と同様にして反応を行った。その結果、メタクロレイン転化率９１．５％、メタクリル酸選択率８８．９％、メタクリル酸収率８１．３％であった。
＜実施例３＞
パラモリブデン酸アンモニウム１０部、メタバナジン酸アンモニウム０．４部および硝酸カリウム４．３部を純水４０部に溶解した。これを撹拌しながら、８５％リン酸０．８部を純水１部に溶解した溶液を加え、さらに硝酸銅０．１部を純水１部に溶解した溶液を加えた。次に、硝酸ビスマス０．７部に６０％硝酸０．７部および水４部を加えて得られた硝酸ビスマスの均一溶液を前記混合液に加えた後、９５℃に昇温した。これに、６０％ヒ酸０．２部を純水１部に溶解した溶液を加え、続いて三酸化アンチモン０．２部、二酸化セリウム０．２部を加えた。得られた水性スラリーを加熱撹拌しながら蒸発乾固した後、１３０℃で１６時間乾燥し、粉砕することにより固形物Ａ−３を得た。得られた固形物Ａ−３に含まれるＭｏとＫの含有比（原子比）は１２：９であった。
【００５１】
別に、水性スラリーに含まれるＭｏとＫの含有比（原子比）が１２：０．２になるように水性スラリーＢ−２を調製した。
【００５２】
パラモリブデン酸アンモニウム１００部、メタバナジン酸アンモニウム４．４部および硝酸カリウム１部を純水４００部に溶解した。これを撹拌しながら、８５％リン酸８．２部を純水１０部に溶解した溶液を加え、さらに硝酸銅１．１部を純水１０部に溶解した溶液を加えた。次に、硝酸ビスマス６．９部に６０％硝酸７．０部および純水４０部を加えて得られた硝酸ビスマスの均一溶液を前記混合液に加えた後、９５℃に昇温した。これに、６０％ヒ酸２．２部を純水１０部に溶解した溶液を加え、続いて三酸化アンチモン２．１部、二酸化セリウム１．６部を加え、撹拌した後、この液状物を７０℃に降温して水性スラリーＢ−２を得た。
【００５３】
このようにして得られた固形物Ａ−３を水性スラリーＢ−２に全量添加し、実施例１と同様にして紛体を得、続いて成型、焼成を行い、触媒を得た。
【００５４】
得られた触媒の酸素以外の元素の組成は、
Ｍｏ12Ｐ1.5Ｖ0.8Ｃｕ0.1Ｓｂ0.3Ｂｉ0.3Ａｓ0.2Ｃｅ0.2Ｋ1
であった。
【００５５】
得られた触媒を反応管に充填し、実施例１と同様にして反応を行った。その結果、メタクロレイン転化率９１．４％、メタクリル酸選択率８８．８％、メタクリル酸収率８１．２％であった。
＜実施例４＞
パラモリブデン酸アンモニウム４２．５部、メタバナジン酸アンモニウム２部および硝酸カリウム６．１部を純水１７０部に溶解した。これを撹拌しながら、８５％リン酸３．５部を純水４．３部に溶解した溶液を加え、さらに硝酸銅０．５部を純水４．３部に溶解した溶液を加えた。次に、硝酸ビスマス３部に６０％硝酸３部および水１７部を加えて得られた硝酸ビスマスの均一溶液を前記混合液に加えた後、９５℃に昇温した。これに、６０％ヒ酸１部を純水４．３部に溶解した溶液を加え、続いて三酸化アンチモン０．９部、二酸化セリウム０．７部を加えた。得られた水性スラリーを加熱撹拌しながら蒸発乾固した後、１３０℃で１６時間乾燥し、粉砕することにより固形物Ａ−４を得た。得られた固形物Ａ−４に含まれるＭｏとＫの含有比（原子比）は１２：３であった。
【００５６】
別に、水性スラリーに含まれるＭｏとＫの含有比（原子比）が１２：０．１５になるように水性スラリーＢ−３を調製した。
【００５７】
パラモリブデン酸アンモニウム１００部、メタバナジン酸アンモニウム４．４部および硝酸カリウム０．７部を純水４００部に溶解した。これを撹拌しながら、８５％リン酸８．２部を純水１０部に溶解した溶液を加え、さらに硝酸銅１．１部を純水１０部に溶解した溶液を加えた。次に、硝酸ビスマス６．９部に６０％硝酸７．０部および純水４０部を加えて得られた硝酸ビスマスの均一溶液を前記混合液に加えた後、９５℃に昇温した。これに、６０％ヒ酸２．２部を純水１０部に溶解した溶液を加え、続いて三酸化アンチモン２．１部、二酸化セリウム１．６部を加え、撹拌した後、この液状物を７０℃に降温して水性スラリーＢ−３を得た。
【００５８】
このようにして得られた固形物Ａ−４を水性スラリーＢ−３に全量添加し、実施例１と同様にして紛体を得、続いて成型、焼成を行い、触媒を得た。
【００５９】
得られた触媒の酸素以外の元素の組成は、
Ｍｏ12Ｐ1.5Ｖ0.8Ｃｕ0.1Ｓｂ0.3Ｂｉ0.3Ａｓ0.2Ｃｅ0.2Ｋ1
であった。
【００６０】
得られた触媒を反応管に充填し、実施例１と同様にして反応を行った。その結果、メタクロレイン転化率９１．１％、メタクリル酸選択率８８．９％、メタクリル酸収率８１．０％であった。
＜実施例５＞
パラモリブデン酸アンモニウム９部、メタバナジン酸アンモニウム０．４部および硝酸カリウム４．７部を純水３６部に溶解した。これを撹拌しながら、８５％リン酸０．７部を純水０．９部に溶解した溶液を加え、さらに硝酸銅０．１部を純水０．９部に溶解した溶液を加えた。次に、硝酸ビスマス０．６部に６０％硝酸０．６部および水３．６部を加えて得られた硝酸ビスマスの均一溶液を前記混合液に加えた後、９５℃に昇温した。これに、６０％ヒ酸０．２部を純水０．９部に溶解した溶液を加え、続いて三酸化アンチモン０．２部、二酸化セリウム０．２部を加えた。得られた水性スラリーを加熱撹拌しながら蒸発乾固した後、１３０℃で１６時間乾燥し、粉砕することにより固形物Ａ−５を得た。得られた固形物Ａ−５に含まれるＭｏとＫの含有比（原子比）は１２：１１であった。
【００６１】
実施例１と同様にして得られた水性スラリーＢ−１に固形物Ａ−５全量を添加し、実施例１と同様にして紛体を得、続いて成型、焼成を行い、触媒を得た。
【００６２】
得られた触媒の酸素以外の元素の組成は、
Ｍｏ12Ｐ1.5Ｖ0.8Ｃｕ0.1Ｓｂ0.3Ｂｉ0.3Ａｓ0.2Ｃｅ0.2Ｋ1
であった。
【００６３】
得られた触媒を反応管に充填し、実施例１と同様にして反応を行った。その結果、メタクロレイン転化率９１．０％、メタクリル酸選択率８８．９％、メタクリル酸収率８０．９％であった。
＜比較例１＞
パラモリブデン酸アンモニウム１００部、メタバナジン酸アンモニウム４．４部および硝酸カリウム４．８部を純水４００部に溶解した。これを撹拌しながら、８５％リン酸８．２部を純水１０部に溶解した溶液を加え、さらに硝酸銅１．１部を純水１０部に溶解した溶液を加えた。次に、硝酸ビスマス６．９部に６０％硝酸７．０部および水４０部を加えて得られた硝酸ビスマスの均一溶液を前記混合液に加えた後、９５℃に昇温した。これに、６０％ヒ酸２．２部を純水１０部に溶解した溶液を加え、続いて三酸化アンチモン２．１部、二酸化セリウム１．６部を加えた。得られた水性スラリーを加熱撹拌しながら蒸発乾固した後、１３０℃で１６時間乾燥し、粉砕することにより固形物Ａ−６を得た。
【００６４】
こうして得られた固形物Ａ−６を実施例１と同様にして成型、焼成を行い、触媒を得た。
【００６５】
得られた触媒の酸素以外の元素の組成は、
Ｍｏ12Ｐ1.5Ｖ0.8Ｃｕ0.1Ｓｂ0.3Ｂｉ0.3Ａｓ0.2Ｃｅ0.2Ｋ1
であった。
【００６６】
得られた触媒を反応管に充填し、実施例１と同様にして反応を行った。その結果、メタクロレイン転化率９０．０％、メタクリル酸選択率８８．２％、メタクリル酸収率７９．４％であった
＜比較例２＞
パラモリブデン酸アンモニウム９０部、メタバナジン酸アンモニウム４部および硝酸カリウム８．６部を純水３６０部に溶解した。これを撹拌しながら、８５％リン酸７．４部を純水９部に溶解した溶液を加え、さらに硝酸銅１部を純水９部に溶解した溶液を加えた。次に、硝酸ビスマス６．２部に６０％硝酸６．３部および水３６部を加えて得られた硝酸ビスマスの均一溶液を前記混合液に加えた後、９５℃に昇温した。これに、６０％ヒ酸２部を純水９部に溶解した溶液を加え、続いて三酸化アンチモン１．９部、二酸化セリウム１．５部を加えた。得られた水性スラリーを加熱撹拌しながら蒸発乾固した後、１３０℃で１６時間乾燥し、粉砕することにより固形物Ａ−７を得た。得られた固形物Ａ−７に含まれるＭｏとＫの含有比（原子比）は１２：２であった。
【００６７】
実施例１と同様にして得られた水性スラリーＢ−１に固形物Ａ−７全量を添加し、実施例１と同様にして紛体を得、続いて成型、焼成を行い、触媒を得た。
【００６８】
得られた触媒の酸素以外の元素の組成は、
Ｍｏ12Ｐ1.5Ｖ0.8Ｃｕ0.1Ｓｂ0.3Ｂｉ0.3Ａｓ0.2Ｃｅ0.2Ｋ1
であった。
【００６９】
得られた触媒を反応管に充填し、実施例１と同様にして反応を行った。その結果、メタクロレイン転化率９０．３％、メタクリル酸選択率８８．３％、メタクリル酸収率７９．７％であった。
＜比較例３＞
パラモリブデン酸アンモニウム６．９部、メタバナジン酸アンモニウム０．３部および硝酸カリウム４．６部を純水２７．６部に溶解した。これを撹拌しながら、８５％リン酸０．６部を純水０．７部に溶解した溶液を加え、さらに硝酸銅０．１部を純水０．７部に溶解した溶液を加えた。次に、硝酸ビスマス０．５部に６０％硝酸０．５部および水２．７部を加えて得られた硝酸ビスマスの均一溶液を前記混合液に加えた後、９５℃に昇温した。これに、６０％ヒ酸０．２部を純水０．７部に溶解した溶液を加え、続いて三酸化アンチモン０．１部、二酸化セリウム０．１部を加えた。得られた水性スラリーを加熱撹拌しながら蒸発乾固した後、１３０℃で１６時間乾燥し、粉砕することにより固形物Ａ−８を得た。得られた固形物Ａ−８に含まれるＭｏとＫの含有比（原子比）は１２：１４であった。
【００７０】
実施例１と同様にして得られた水性スラリーＢ−１に固形物Ａ−８全量を添加し、実施例１と同様にして紛体を得、続いて成型、焼成を行い、触媒を得た。
【００７１】
得られた触媒の酸素以外の元素の組成は、
Ｍｏ12Ｐ1.5Ｖ0.8Ｃｕ0.1Ｓｂ0.3Ｂｉ0.3Ａｓ0.2Ｃｅ0.2Ｋ1
であった。
【００７２】
得られた触媒を反応管に充填し、実施例１と同様にして反応を行った。その結果、メタクロレイン転化率９０．２％、メタクリル酸選択率８８．２％、メタクリル酸収率７９．６％であった。
＜比較例４＞
パラモリブデン酸アンモニウム４０部、メタバナジン酸アンモニウム１．８部および硝酸カリウム６．７部を純水１６０部に溶解した。これを撹拌しながら、８５％リン酸３．３部を純水４部に溶解した溶液を加え、さらに硝酸銅０．５部を純水４部に溶解した溶液を加えた。次に、硝酸ビスマス２．８部に６０％硝酸２．８部および水１６部を加えて得られた硝酸ビスマスの均一溶液を前記混合液に加えた後、９５℃に昇温した。これに、６０％ヒ酸０．９部を純水４部に溶解した溶液を加え、続いて三酸化アンチモン０．８部、二酸化セリウム０．７部を加えた。得られた水性スラリーを加熱撹拌しながら蒸発乾固した後、１３０℃で１６時間乾燥し、粉砕することにより固形物Ａ−９を得た。得られた固形物Ａ−９に含まれるＭｏとＫの含有比（原子比）は１２：３．５であった。
【００７３】
別に、パラモリブデン酸アンモニウム１００部、メタバナジン酸アンモニウム４．４部を純水４００部に溶解した。これを撹拌しながら、８５％リン酸８．２部を純水１０部に溶解した溶液を加え、さらに硝酸銅１．１部を純水１０部に溶解した溶液を加えた。次に、硝酸ビスマス６．９部に６０％硝酸７．０部および純水４０部を加えて得られた硝酸ビスマスの均一溶液を前記混合液に加えた後、９５℃に昇温した。これに、６０％ヒ酸２．２部を純水１０部に溶解した溶液を加え、続いて三酸化アンチモン２．１部、二酸化セリウム１．６部を加え、撹拌した後、この液状物を７０℃に降温して水性スラリーＢ−４を得た。
【００７４】
このようにして得られた固形物Ａ−９全量を水性スラリーＢ−４に添加し、実施例１と同様にして紛体を得、続いて成型、焼成を行い、触媒を得た。
【００７５】
得られた触媒の酸素以外の元素の組成は、
Ｍｏ12Ｐ1.5Ｖ0.8Ｃｕ0.1Ｓｂ0.3Ｂｉ0.3Ａｓ0.2Ｃｅ0.2Ｋ1
であった。
【００７６】
得られた触媒を反応管に充填し、実施例１と同様にして反応を行った。その結果、メタクロレイン転化率９０．１％、メタクリル酸選択率８８．２％、メタクリル酸収率７９．５％であった。
＜実施例６＞
パラモリブデン酸アンモニウム２８．３部、メタバナジン酸アンモニウム０．８部および硝酸セシウム１０．４部を純水１１３．２部に溶解した。これを攪拌しながら、８５％リン酸２．３部を純水２．８部に溶解した溶液を加え、９５℃に昇温した。次いで、硝酸銅１．０部、硝酸第二鉄２．２部、硝酸亜鉛０．４部および硝酸マグネシウム０．５部を純水２２．７部に溶解した溶液を加えた。さらにこの混合液を１００℃で３０分間攪拌した。得られた水性スラリーを並流式噴霧乾燥機により、乾燥機入口温度３００℃、スラリー噴霧用回転盤２００００回転／分の条件で乾燥し、固形物Ａ−１０を得た。得られた固形物Ａ−１０に含まれるＭｏとＣｓの含有比（原子比）は１２：４であった。
【００７７】
別に、水性スラリーに含まれるＭｏとＣｓの含有比（原子比）が１２：０．１５になるように水性スラリーＢ−５を調製した。
【００７８】
パラモリブデン酸アンモニウム１００部、メタバナジン酸アンモニウム２．８部および硝酸セシウム１．４部を純水４００部に溶解した。これを攪拌しながら、８５％リン酸８．２部を純水１０部に溶解した溶液を加え、９５℃に昇温した。次いで、硝酸銅３．４部、硝酸第二鉄７．６部、硝酸亜鉛１．４部および硝酸マグネシウム１．８部を純水８０部に溶解した溶液を加え、よく混合した後、この液状物を７０℃に降温し、水性スラリーＢ−５を得た。
【００７９】
このようにして得られた固形物Ａ−１０を水性スラリーＢ−５に全量添加し、よく混合した後、混合液を１００℃で３０分間攪拌した。得られた水性スラリーを並流式噴霧乾燥機により、乾燥機入口温度３００℃、スラリー噴霧用回転盤２００００回転／分の条件で乾燥した。得られた乾燥物１００部にグラファイト３部を添加し、続いて打錠成形機により、外径５ｍｍ、内径２ｍｍ、長さ３ｍｍのリング状に成形した。そして、得られた成形物を空気流通下、３８０℃で５時間焼成して触媒を得た。
【００８０】
得られた触媒の酸素以外の元素の組成は、
Ｍｏ12Ｐ1.5Ｖ0.5Ｃｕ0.3Ｆｅ0.4Ｍｇ0.15Ｚｎ0.1Ｃｓ1
であった。
【００８１】
得られた触媒を反応管に充填し、実施例１と同様にして反応を行った。その結果、メタクロレイン反応率８９．０％、メタクリル酸選択率８６．８％、メタクリル酸収率７７．３％であった。
＜比較例５＞
パラモリブデン酸アンモニウム１００部、メタバナジン酸アンモニウム２．８部および硝酸セシウム９．２部を純水４００部に溶解した。これを攪拌しながら、８５％リン酸８．２部を純水１０部に溶解した溶液を加え、９５℃に昇温した。次いで、硝酸銅３．４部、硝酸第二鉄７．６部、硝酸亜鉛１．４部および硝酸マグネシウム１．８部を純水８０部に溶解した溶液を加えた。さらにこの混合液を１００℃で３０分間攪拌した。そして、得られた水性スラリーを実施例６と同様にして乾燥を行い、固形物Ａ−１１を得た。
【００８２】
このようにして得られた固形物Ａ−１１を実施例６と同様にして成型、焼成を行い、触媒を得た。
【００８３】
得られた触媒の酸素以外の元素の組成は、
Ｍｏ12Ｐ1.5Ｖ0.5Ｃｕ0.3Ｆｅ0.4Ｍｇ0.15Ｚｎ0.1Ｃｓ1
であった。
【００８４】
得られた触媒を反応管に充填し、実施例１と同様にして反応を行った。その結果、メタクロレイン反応率８７．４％、メタクリル酸選択率８５．８％、メタクリル酸収率７５．０％であった。
【００８５】
【発明の効果】
本発明の新規な製造方法により得られるメタクリル酸合成用触媒は、メタクロレインの気相接触酸化反応において、高活性、高メタクリル酸選択性、高収率でメタクリル酸を生成させるという優れた効果を有する。この触媒によって効率的にメタクリル酸を製造することが可能になり、工業的な価値は極めて高い。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a methacrylic acid synthesis catalyst used for synthesizing methacrylic acid by gas phase catalytic oxidation of methacrolein with molecular oxygen, a catalyst for methacrylic acid synthesis, and production of methacrylic acid using the catalyst. Regarding the method.
[0002]
[Prior art]
Many proposals have been made on a catalyst used for synthesizing methacrylic acid by gas phase catalytic oxidation of methacrolein with molecular oxygen. For example, JP-A-50-101316, JP-A-53-37614, JP-A-54-103819, JP-A-57-120547, JP-A-60-239439, JP-A-2 No. 240043 discloses a catalyst mainly composed of molybdenum and phosphorus. Usually, these catalysts are produced by a series of steps in which an aqueous slurry containing each metal component is dried, shaped as necessary, and then fired. That is, one type of aqueous slurry is prepared and manufactured through a series of steps of drying, molding and firing. However, the catalyst obtained by this method is not necessarily sufficient as an industrial catalyst in terms of activity and selectivity.
[0003]
JP-A-5-177141 discloses a heteropolyacid salt containing at least molybdenum, phosphorus and cesium when preparing a heteropolyacid catalyst containing at least molybdenum, phosphorus and cesium, and a suspension of the heteropolyacid salt. Discloses a method of obtaining a catalyst by adding a catalyst raw material containing at least molybdenum and phosphorus and not containing cesium, and drying and calcining the obtained liquid material, that is, a method of preparing a catalyst in two stages. The catalyst prepared by this method is a catalyst used for the reaction, although a heteropolyacid not containing cesium grows on small particles of the cesium salt of the heteropolyacid and has a structure of a stable cesium salt as a crystal. It is presumed that there is a cesium-free heteropolyacid having a high reaction activity on the particle surface, and it has been reported that the particle surface has higher activity and selectivity than the conventional one-step preparation method.
[0004]
However, the catalyst obtained by this method is not necessarily sufficient as an industrial catalyst in terms of activity and methacrylic acid selectivity, and further improvement in catalyst performance is desired.
[0005]
[Problems to be solved by the invention]
The present invention provides a novel method for producing a catalyst for synthesizing methacrylic acid to be used when synthesizing methacrylic acid by gas phase catalytic oxidation of methacrolein with molecular oxygen, and a highly active, high methacrylic acid selection obtained by this production method It is an object of the present invention to provide a methacrylic acid synthesis catalyst and a method for producing methacrylic acid with a high yield using the catalyst.
[0006]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have found that a catalyst used for synthesizing methacrylic acid by vapor-phase catalytic oxidation of methacrolein with molecular oxygen is highly active and highly methacrylic acid. A new preparation method capable of obtaining a catalyst having selectivity has been completed. The above-mentioned problems of the present invention can be solved by the following present invention.
(1) A method for producing a catalyst for synthesizing methacrylic acid comprising at least molybdenum, phosphorus, and X which is at least one element selected from the group consisting of potassium, rubidium, cesium and thallium, comprising at least molybdenum, Preparing a solid A containing phosphorus and X, preparing an aqueous slurry B containing at least molybdenum, phosphorus and X, mixing the solid A and the aqueous slurry B, solid A and aqueous The content ratio (atomic ratio) of molybdenum and X contained in the solid material A includes the step of drying the liquid material obtained by mixing the slurry B and the step of firing the dried material at 300 to 500 ° C. 12: 2.5 to 12:12, and the content ratio (atomic ratio) of molybdenum and X contained in the aqueous slurry B is 12: 0.05 to 12: 0.4. Method for producing methacrylic acid synthesis catalysts.
(2) A catalyst for synthesizing methacrylic acid obtained by the method for producing a catalyst for synthesizing methacrylic acid of (1).
(3) A method for producing methacrylic acid, comprising subjecting methacrolein to gas phase catalytic oxidation in the presence of the catalyst for synthesizing methacrylic acid according to (2).
[0007]
In the method for producing a catalyst for synthesizing methacrylic acid, the content ratio (atomic ratio) of molybdenum and X contained in the solid A is 12: 2.5 to 12:12, particularly 12: 3.05 to 12:10, It is preferable that it is 12: 3.6-12: 8. Moreover, the content ratio (atomic ratio) of molybdenum and X contained in the aqueous slurry B is 12: 0.05 to 12: 0.4, 12: 0.07 to 12: 0.35, particularly 12: 0. It is preferable that it is 09-12: 0.3.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The catalyst for producing methacrylic acid obtained by the novel production method of the present invention is a catalyst for producing methacrylic acid by vapor-phase catalytic oxidation of methacrolein with molecular oxygen, which has high activity and high methacrylic acid selectivity. have.
[0009]
The method for producing a catalyst for synthesizing methacrylic acid according to the present invention comprises:
(1) preparing a solid A containing at least molybdenum, phosphorus and X;
(2) preparing an aqueous slurry B containing at least molybdenum, phosphorus and X;
(3) mixing the solid A and the aqueous slurry B;
(4) drying the liquid obtained by mixing the solid A and the aqueous slurry B;
(5) a step of firing the dried product at 300 to 500 ° C;
Is included. Here, X represents at least one element selected from the group consisting of potassium, rubidium, cesium and thallium.
[0010]
In the present invention, the method for preparing the solid A is not particularly limited, and various methods such as a coprecipitation method, an evaporation to dryness method, and an oxide mixing method can be used. In particular, a method of preparing an aqueous slurry containing at least molybdenum, phosphorus and X is preferable. At this time, the drying method of the aqueous slurry is not particularly limited, and a general-purpose box dryer, spray dryer, drum dryer, slurry dryer, or the like can be used. Further, it is preferable that the preparation process does not include a process of heat treatment at 300 ° C. or higher. The preparation conditions of the solid A may be appropriately determined according to the method for producing the precursor before heat treatment of the catalyst for synthesizing methacrylic acid containing at least molybdenum, phosphorus and X.
[0011]
The raw material used for preparation of the solid substance A is not specifically limited, The nitrate, carbonate, acetate, ammonium salt, oxide, halide, etc. of each element can be used. For example, ammonium paramolybdate, molybdenum trioxide, molybdic acid, molybdenum chloride, etc. can be used as the molybdenum raw material. The raw material of the catalyst component may be used alone or in combination of two or more for each element.
[0012]
In addition, the solid substance A should just be a solid substance substantially, and it does not prescribe | regulate regarding water content etc. in particular.
[0013]
The shape of the solid A is not particularly limited, but a powder is preferable. Further, the solid A may be pulverized into particles having an appropriate particle size so that the solid A is mixed as uniformly as possible when the solid A is mixed with the aqueous slurry B.
[0014]
The solid A does not necessarily have a heteropoly acid salt structure. In the present invention, the content ratio (atomic ratio) of molybdenum and X contained in the solid A is important. The content ratio (atomic ratio) of molybdenum and X contained in the solid A is 12: 2.5 to 12:12, and 12: 3.05 to 12:10, particularly 12: 3.6 to 12: 8. Preferably there is.
[0015]
Further, the constituent element of the solid A is not particularly limited as long as it contains molybdenum, phosphorus and X, but besides molybdenum, phosphorus and X, copper, vanadium, iron, cobalt, nickel, zinc, magnesium, calcium, Strontium, barium, titanium, chromium, tungsten, manganese, silver, boron, silicon, aluminum, gallium, germanium, tin, lead, arsenic, antimony, bismuth, niobium, tantalum, zirconium, indium, sulfur, selenium, tellurium, lanthanum, Cerium or the like may be included as appropriate.
[0016]
In the present invention, the preparation method of the aqueous slurry B is not particularly limited. What is necessary is just an aqueous slurry containing at least molybdenum, phosphorus and X. The amount of water in the aqueous slurry is not particularly limited, but it must be ensured that all solid A is not redissolved. Specifically, the mass ratio of molybdenum and water contained in the aqueous slurry B is preferably 1: 0.5 to 1:10.
[0017]
The raw material used for the preparation of the aqueous slurry B is not particularly limited, and as with the solid A, nitrates, carbonates, acetates, ammonium salts, oxides, halides and the like of each element can be used. For example, ammonium paramolybdate, molybdenum trioxide, molybdic acid, molybdenum chloride, etc. can be used as the molybdenum raw material. The raw material of the catalyst component may be used alone or in combination of two or more for each element.
[0018]
The content ratio (atomic ratio) of molybdenum and X contained in the aqueous slurry B is 12: 0.05 to 12: 0.4, 12: 0.07 to 12: 0.35, particularly 12: 0.09 to 12: 0.3 is preferred.
[0019]
The constituent elements of the aqueous slurry B are not particularly limited as long as they contain molybdenum, phosphorus and X, but besides molybdenum, phosphorus and X, copper, vanadium, iron, cobalt, nickel, zinc, magnesium, calcium, Strontium, barium, titanium, chromium, tungsten, manganese, silver, boron, silicon, aluminum, gallium, germanium, tin, lead, arsenic, antimony, bismuth, niobium, tantalum, zirconium, indium, sulfur, selenium, tellurium, lanthanum, Cerium or the like may be included as appropriate.
[0020]
In the present invention, the procedure for mixing the solid A and the aqueous slurry B is not particularly limited. In mixing, it is important to put the solid A into the aqueous slurry B. Further, the timing of mixing the solid A into the aqueous slurry B is not particularly limited. For example, after the aqueous slurry B is prepared, the solid A is charged and mixed to be as uniform as possible. Is preferably dried.
[0021]
The ratio (atomic ratio) of molybdenum contained in the solid substance A and molybdenum contained in the aqueous slurry B upon mixing is 1: 1 to 1:30 because a highly active and high methacrylic acid selective catalyst is obtained. It is preferable to do.
[0022]
The method for drying the liquid material is not particularly limited, and a general-purpose box-type dryer, spray dryer, drum dryer, slurry dryer, or the like can be used. What is necessary is just to determine drying conditions suitably.
[0023]
The dried product obtained by drying the mixed liquid of the solid material A and the aqueous slurry B may be subjected to the subsequent firing as it is, but is usually fired after being molded.
[0024]
The method for molding the dried product is not particularly limited, and various molding methods such as ordinary tableting molding, extrusion molding, and granulation can be applied.
[0025]
In molding, a conventionally known additive to the dried product, for example, to control the specific surface area, pore volume and pore distribution of the molded product with good reproducibility, or to increase mechanical strength, barium sulfate, Inorganic salts such as ammonium nitrate, lubricants such as graphite, organic substances such as celluloses, starch, polyvinyl alcohol, stearic acid, hydroxide sols such as silica sol and alumina sol, inorganic fibers such as whiskers, glass fibers, and carbon fibers are added as appropriate. May be.
[0026]
The shape of the molded product is not particularly limited, and the molded product can be molded into an arbitrary shape such as a spherical shape, a cylindrical shape, a ring shape, or a plate shape.
[0027]
In this invention, the obtained molding is baked at the temperature of the range of 300-500 degreeC, and the catalyst for methacrylic acid synthesis | combination of this invention is obtained. The calcining time is not particularly limited, but is preferably 1 hour or longer, and usually 40 hours or shorter, because a good catalyst can be obtained. Firing is usually performed in a stream of oxygen, air or nitrogen.
[0028]
The thus obtained methacrylic acid synthesis catalyst of the present invention preferably contains a heteropolyacid or heteropolyacid salt structure.
[0029]
The catalyst for synthesizing methacrylic acid of the present invention is preferably a composite oxide having a composition represented by the following general formula (I).
[0030]
MoaPbCucVdXeYfOg (I)
Here, in the formula, Mo, P, Cu, V and O each represent molybdenum, phosphorus, copper, vanadium and oxygen, and X is at least one element selected from the group consisting of potassium, rubidium, cesium and thallium Y represents iron, cobalt, nickel, zinc, magnesium, calcium, strontium, barium, titanium, chromium, tungsten, manganese, silver, boron, silicon, aluminum, gallium, germanium, tin, lead, arsenic, antimony, bismuth And at least one element selected from the group consisting of niobium, tantalum, zirconium, indium, sulfur, selenium, tellurium, lanthanum and cerium.
[0031]
a, b, c, d, e, f and g represent the atomic ratio of each element. When a = 12, 0.1 ≦ b ≦ 3, 0.01 ≦ c ≦ 3, 0.01 ≦ d ≦ 3, 0.05 ≦ e ≦ 3, 0 ≦ f ≦ 3, and g is an atomic ratio of oxygen necessary to satisfy the atomic ratio of each component.
[0032]
The existence state of each component of the catalyst produced according to the present invention, particularly the existence state of X, is complicated and has not been grasped strictly. However, the content ratio (atomic ratio) X / Mo of X and molybdenum contained in the solid A is 2.5 / 12 to 12/12. When X / Mo is larger than 3/12, the solid A is simply It is unlikely that a heteropolyacid salt having an X element as a cation is formed. Therefore, the structure of the catalyst as produced by the method disclosed in JP-A-5-177141, that is, the surface of the crystal particles of the heteropolyacid salt containing molybdenum, phosphorus and X is covered with a heteropolyacid containing no X. It is very unlikely that the structure is different, and it is considered that the structure is different. In addition, when X / Mo is 3/12 or less, the solid A may form a simple heteropolyacid salt. It has been found that a catalyst having good catalytic activity and selectivity can be obtained.
[0033]
Next, the manufacturing method of methacrylic acid of this invention is demonstrated. The method for producing methacrylic acid of the present invention is a method for producing methacrylic acid by gas phase catalytic oxidation of methacrolein with molecular oxygen in the presence of the catalyst of the present invention as described above.
[0034]
The reaction is usually carried out in a fixed bed. The catalyst layer may be one layer or two or more layers.
[0035]
The concentration of methacrolein in the raw material gas can be varied within a wide range, but is preferably 1 to 20% by volume, particularly 3 to 10% by volume. The raw material methacrolein may contain a small amount of impurities such as water and lower saturated aldehyde that do not substantially affect the reaction.
[0036]
As the oxygen source for the catalytic oxidation, it is industrially advantageous to use air. However, if necessary, air enriched with pure oxygen can also be used. The molar ratio (volume ratio) of methacrolein to oxygen in the raw material gas is preferably 1: 0.5 to 1: 3.
[0037]
The raw material gas preferably contains water in addition to the reaction raw material and molecular oxygen, and is preferably diluted with an inert gas such as nitrogen or carbon dioxide. The volume ratio of methacrolein to water in the raw material gas is preferably 1: 0.1 to 1:10.
[0038]
The reaction pressure is from normal pressure to several atmospheres. The reaction temperature is preferably in the range of 200 to 450 ° C. The contact time is preferably 2 to 7 seconds.
[0039]
【Example】
EXAMPLES Hereinafter, the preparation method of the catalyst of this invention and the reaction example using the catalyst are demonstrated by an Example.
[0040]
However, “parts” in the following Examples and Comparative Examples means parts by mass. Reaction test analysis was performed by gas chromatography. The catalyst composition was determined from the amount of catalyst raw material charged.
[0041]
Further, the conversion rate of methacrolein as a raw material for reaction in Examples and Comparative Examples, the selectivity and yield of methacrylic acid produced are defined as follows.
[0042]
Conversion rate of methacrolein (%) = number of moles of reacted methacrolein / number of moles of methacrolein supplied × 100
Methacrylic acid selectivity (%) = number of moles of methacrylic acid produced / number of moles of reacted methacrolein × 100
Methacrylic acid yield (%) = number of moles of methacrylic acid produced / number of moles of methacrolein supplied × 100
<Example 1>
22.5 parts of ammonium paramolybdate, 1.0 part of ammonium metavanadate and 5.4 parts of potassium nitrate were dissolved in 90 parts of pure water. While stirring this, a solution in which 1.8 parts of 85% phosphoric acid was dissolved in 2.3 parts of pure water was added, and a solution in which 0.3 part of copper nitrate was dissolved in 2.3 parts of pure water was further added. Next, a uniform solution of bismuth nitrate obtained by adding 1.6 parts of 60% nitric acid and 9 parts of water to 1.6 parts of bismuth nitrate was added to the mixture, and the temperature was raised to 95 ° C. To this was added a solution prepared by dissolving 0.5 parts of 60% arsenic acid in 2.2 parts of pure water, followed by 0.5 parts of antimony trioxide and 0.4 parts of cerium dioxide. The obtained aqueous slurry was evaporated to dryness while stirring with heating, dried at 130 ° C. for 16 hours, and pulverized to obtain solid A-1. The content ratio (atomic ratio) of Mo and K contained in the obtained solid A-1 was 12: 5.
[0043]
Separately, an aqueous slurry B-1 was prepared so that the content ratio (atomic ratio) of Mo and K contained in the aqueous slurry was 12: 0.1.
[0044]
100 parts of ammonium paramolybdate, 4.4 parts of ammonium metavanadate and 0.5 parts of potassium nitrate were dissolved in 400 parts of pure water. While stirring this, a solution in which 8.2 parts of 85% phosphoric acid was dissolved in 10 parts of pure water was added, and a solution in which 1.1 parts of copper nitrate was dissolved in 10 parts of pure water was further added. Next, a uniform solution of bismuth nitrate obtained by adding 7.0 parts of 60% nitric acid and 40 parts of pure water to 6.9 parts of bismuth nitrate was added to the mixture, and the temperature was raised to 95 ° C. To this was added a solution obtained by dissolving 2.2 parts of 60% arsenic acid in 10 parts of pure water, and subsequently 2.1 parts of antimony trioxide and 1.6 parts of cerium dioxide were added and stirred. The temperature was lowered to 70 ° C. to obtain an aqueous slurry B-1.
[0045]
The total amount of the solid A-1 thus obtained was added to the aqueous slurry B-1, the liquid was evaporated to dryness while stirring with heating, and then dried at 130 ° C. for 16 hours. Crushed. To 100 parts of the powder thus obtained, 3.0 parts of graphite was added, and then molded into a ring shape having an outer diameter of 5 mm, an inner diameter of 2 mm, and a length of 5 mm by a tableting machine. The obtained molded product was calcined at 380 ° C. for 5 hours under air flow to obtain a catalyst.
[0046]
The composition of elements other than oxygen in the obtained catalyst is
Mo12P1.5V0.8Cu0.1Sb0.3Bi0.3As0.2Ce0.2K1
Met.
[0047]
The obtained catalyst was filled in a reaction tube, and a raw material gas consisting of 5% by volume of methacrolein, 10% by volume of oxygen, 30% by volume of water vapor and 55% by volume of nitrogen was used at normal pressure, reaction temperature of 290 ° C., and contact time of 3.6 seconds. I communicated with. When the product was collected and analyzed by gas chromatography, methacrolein conversion was 91.6%, methacrylic acid selectivity was 89.0%, and methacrylic acid yield was 81.5%.
<Example 2>
36 parts of ammonium paramolybdate, 1.6 parts of ammonium metavanadate and 6 parts of potassium nitrate were dissolved in 144 parts of pure water. While stirring this, a solution in which 2.9 parts of 85% phosphoric acid was dissolved in 3.6 parts of pure water was added, and a solution in which 0.4 part of copper nitrate was dissolved in 3.6 parts of pure water was further added. Next, a homogeneous solution of bismuth nitrate obtained by adding 2.5 parts of 60% nitric acid and 14.4 parts of water to 2.5 parts of bismuth nitrate was added to the mixture, and the temperature was raised to 95 ° C. A solution prepared by dissolving 0.8 part of 60% arsenic acid in 3.6 parts of pure water was added thereto, followed by 0.7 part of antimony trioxide and 0.6 part of cerium dioxide. The obtained aqueous slurry was evaporated to dryness while stirring with heating, dried at 130 ° C. for 16 hours, and pulverized to obtain solid A-2. The content ratio (atomic ratio) of Mo and K contained in the obtained solid A-2 was 12: 3.5.
[0048]
The total amount of the solid A-2 was added to the aqueous slurry B-1 obtained in the same manner as in Example 1, to obtain a powder in the same manner as in Example 1, followed by molding and firing to obtain a catalyst.
[0049]
The composition of elements other than oxygen in the obtained catalyst is
Mo12P1.5V0.8Cu0.1Sb0.3Bi0.3As0.2Ce0.2K1
Met.
[0050]
The obtained catalyst was filled in a reaction tube, and a reaction was carried out in the same manner as in Example 1. As a result, methacrolein conversion was 91.5%, methacrylic acid selectivity was 88.9%, and methacrylic acid yield was 81.3%.
<Example 3>
10 parts of ammonium paramolybdate, 0.4 parts of ammonium metavanadate and 4.3 parts of potassium nitrate were dissolved in 40 parts of pure water. While stirring this, a solution in which 0.8 part of 85% phosphoric acid was dissolved in 1 part of pure water was added, and a solution in which 0.1 part of copper nitrate was dissolved in 1 part of pure water was further added. Next, a uniform solution of bismuth nitrate obtained by adding 0.7 parts of 60% nitric acid and 4 parts of water to 0.7 parts of bismuth nitrate was added to the mixture, and the temperature was raised to 95 ° C. A solution prepared by dissolving 0.2 part of 60% arsenic acid in 1 part of pure water was added thereto, followed by addition of 0.2 part of antimony trioxide and 0.2 part of cerium dioxide. The obtained aqueous slurry was evaporated to dryness with heating and stirring, then dried at 130 ° C. for 16 hours, and pulverized to obtain a solid A-3. The content ratio (atomic ratio) of Mo and K contained in the obtained solid A-3 was 12: 9.
[0051]
Separately, an aqueous slurry B-2 was prepared so that the content ratio (atomic ratio) of Mo and K contained in the aqueous slurry was 12: 0.2.
[0052]
100 parts of ammonium paramolybdate, 4.4 parts of ammonium metavanadate and 1 part of potassium nitrate were dissolved in 400 parts of pure water. While stirring this, a solution in which 8.2 parts of 85% phosphoric acid was dissolved in 10 parts of pure water was added, and a solution in which 1.1 parts of copper nitrate was dissolved in 10 parts of pure water was further added. Next, a uniform solution of bismuth nitrate obtained by adding 7.0 parts of 60% nitric acid and 40 parts of pure water to 6.9 parts of bismuth nitrate was added to the mixture, and the temperature was raised to 95 ° C. To this was added a solution obtained by dissolving 2.2 parts of 60% arsenic acid in 10 parts of pure water, and subsequently 2.1 parts of antimony trioxide and 1.6 parts of cerium dioxide were added and stirred. The temperature was lowered to 70 ° C. to obtain an aqueous slurry B-2.
[0053]
The total amount of the solid A-3 thus obtained was added to the aqueous slurry B-2 to obtain a powder in the same manner as in Example 1, followed by molding and firing to obtain a catalyst.
[0054]
The composition of elements other than oxygen in the obtained catalyst is
Mo12P1.5V0.8Cu0.1Sb0.3Bi0.3As0.2Ce0.2K1
Met.
[0055]
The obtained catalyst was filled in a reaction tube, and a reaction was carried out in the same manner as in Example 1. As a result, methacrolein conversion was 91.4%, methacrylic acid selectivity was 88.8%, and methacrylic acid yield was 81.2%.
<Example 4>
42.5 parts of ammonium paramolybdate, 2 parts of ammonium metavanadate and 6.1 parts of potassium nitrate were dissolved in 170 parts of pure water. While stirring this, a solution in which 3.5 parts of 85% phosphoric acid was dissolved in 4.3 parts of pure water was added, and a solution in which 0.5 part of copper nitrate was dissolved in 4.3 parts of pure water was further added. Next, a uniform solution of bismuth nitrate obtained by adding 3 parts of 60% nitric acid and 17 parts of water to 3 parts of bismuth nitrate was added to the mixture, and the temperature was raised to 95 ° C. To this was added a solution prepared by dissolving 1 part of 60% arsenic acid in 4.3 parts of pure water, followed by 0.9 part of antimony trioxide and 0.7 part of cerium dioxide. The obtained aqueous slurry was evaporated to dryness while stirring with heating, dried at 130 ° C. for 16 hours, and pulverized to obtain a solid A-4. The content ratio (atomic ratio) of Mo and K contained in the obtained solid A-4 was 12: 3.
[0056]
Separately, an aqueous slurry B-3 was prepared such that the content ratio (atomic ratio) of Mo and K contained in the aqueous slurry was 12: 0.15.
[0057]
100 parts of ammonium paramolybdate, 4.4 parts of ammonium metavanadate and 0.7 parts of potassium nitrate were dissolved in 400 parts of pure water. While stirring this, a solution in which 8.2 parts of 85% phosphoric acid was dissolved in 10 parts of pure water was added, and a solution in which 1.1 parts of copper nitrate was dissolved in 10 parts of pure water was further added. Next, a uniform solution of bismuth nitrate obtained by adding 7.0 parts of 60% nitric acid and 40 parts of pure water to 6.9 parts of bismuth nitrate was added to the mixture, and the temperature was raised to 95 ° C. To this was added a solution obtained by dissolving 2.2 parts of 60% arsenic acid in 10 parts of pure water, and subsequently 2.1 parts of antimony trioxide and 1.6 parts of cerium dioxide were added and stirred. The temperature was lowered to 70 ° C. to obtain an aqueous slurry B-3.
[0058]
The total amount of the solid A-4 thus obtained was added to the aqueous slurry B-3 to obtain a powder in the same manner as in Example 1, followed by molding and firing to obtain a catalyst.
[0059]
The composition of elements other than oxygen in the obtained catalyst is
Mo12P1.5V0.8Cu0.1Sb0.3Bi0.3As0.2Ce0.2K1
Met.
[0060]
The obtained catalyst was filled in a reaction tube, and a reaction was carried out in the same manner as in Example 1. As a result, methacrolein conversion was 91.1%, methacrylic acid selectivity was 88.9%, and methacrylic acid yield was 81.0%.
<Example 5>
9 parts of ammonium paramolybdate, 0.4 parts of ammonium metavanadate and 4.7 parts of potassium nitrate were dissolved in 36 parts of pure water. While stirring this, a solution in which 0.7 part of 85% phosphoric acid was dissolved in 0.9 part of pure water was added, and a solution in which 0.1 part of copper nitrate was dissolved in 0.9 part of pure water was further added. Next, a uniform solution of bismuth nitrate obtained by adding 0.6 parts of 60% nitric acid and 3.6 parts of water to 0.6 parts of bismuth nitrate was added to the mixture, and the temperature was raised to 95 ° C. A solution prepared by dissolving 0.2 part of 60% arsenic acid in 0.9 part of pure water was added thereto, followed by addition of 0.2 part of antimony trioxide and 0.2 part of cerium dioxide. The obtained aqueous slurry was evaporated to dryness with heating and stirring, then dried at 130 ° C. for 16 hours, and pulverized to obtain a solid A-5. The content ratio (atomic ratio) of Mo and K contained in the obtained solid A-5 was 12:11.
[0061]
The total amount of the solid A-5 was added to the aqueous slurry B-1 obtained in the same manner as in Example 1, to obtain a powder in the same manner as in Example 1, followed by molding and firing to obtain a catalyst.
[0062]
The composition of elements other than oxygen in the obtained catalyst is
Mo12P1.5V0.8Cu0.1Sb0.3Bi0.3As0.2Ce0.2K1
Met.
[0063]
The obtained catalyst was filled in a reaction tube, and a reaction was carried out in the same manner as in Example 1. As a result, methacrolein conversion was 91.0%, methacrylic acid selectivity was 88.9%, and methacrylic acid yield was 80.9%.
<Comparative Example 1>
100 parts of ammonium paramolybdate, 4.4 parts of ammonium metavanadate and 4.8 parts of potassium nitrate were dissolved in 400 parts of pure water. While stirring this, a solution in which 8.2 parts of 85% phosphoric acid was dissolved in 10 parts of pure water was added, and a solution in which 1.1 parts of copper nitrate was dissolved in 10 parts of pure water was further added. Next, a uniform solution of bismuth nitrate obtained by adding 7.0 parts of 60% nitric acid and 40 parts of water to 6.9 parts of bismuth nitrate was added to the mixed solution, and then the temperature was raised to 95 ° C. To this was added a solution prepared by dissolving 2.2 parts of 60% arsenic acid in 10 parts of pure water, followed by 2.1 parts of antimony trioxide and 1.6 parts of cerium dioxide. The obtained aqueous slurry was evaporated to dryness with heating and stirring, then dried at 130 ° C. for 16 hours, and pulverized to obtain a solid A-6.
[0064]
The solid A-6 thus obtained was molded and fired in the same manner as in Example 1 to obtain a catalyst.
[0065]
The composition of elements other than oxygen in the obtained catalyst is
Mo12P1.5V0.8Cu0.1Sb0.3Bi0.3As0.2Ce0.2K1
Met.
[0066]
The obtained catalyst was filled in a reaction tube, and a reaction was carried out in the same manner as in Example 1. As a result, methacrolein conversion was 90.0%, methacrylic acid selectivity was 88.2%, and methacrylic acid yield was 79.4%.
<Comparative example 2>
90 parts of ammonium paramolybdate, 4 parts of ammonium metavanadate and 8.6 parts of potassium nitrate were dissolved in 360 parts of pure water. While stirring this, a solution in which 7.4 parts of 85% phosphoric acid was dissolved in 9 parts of pure water was added, and a solution in which 1 part of copper nitrate was dissolved in 9 parts of pure water was added. Next, a uniform solution of bismuth nitrate obtained by adding 6.3 parts of 60% nitric acid and 36 parts of water to 6.2 parts of bismuth nitrate was added to the mixture, and the temperature was raised to 95 ° C. To this was added a solution prepared by dissolving 2 parts of 60% arsenic acid in 9 parts of pure water, followed by 1.9 parts of antimony trioxide and 1.5 parts of cerium dioxide. The resulting aqueous slurry was evaporated to dryness while stirring with heating, dried at 130 ° C. for 16 hours, and pulverized to obtain a solid A-7. The content ratio (atomic ratio) of Mo and K contained in the obtained solid A-7 was 12: 2.
[0067]
The total amount of the solid A-7 was added to the aqueous slurry B-1 obtained in the same manner as in Example 1, to obtain a powder in the same manner as in Example 1, followed by molding and firing to obtain a catalyst.
[0068]
The composition of elements other than oxygen in the obtained catalyst is
Mo12P1.5V0.8Cu0.1Sb0.3Bi0.3As0.2Ce0.2K1
Met.
[0069]
The obtained catalyst was filled in a reaction tube, and a reaction was carried out in the same manner as in Example 1. As a result, methacrolein conversion was 90.3%, methacrylic acid selectivity was 88.3%, and methacrylic acid yield was 79.7%.
<Comparative Example 3>
6.9 parts of ammonium paramolybdate, 0.3 part of ammonium metavanadate and 4.6 parts of potassium nitrate were dissolved in 27.6 parts of pure water. While stirring this, a solution in which 0.6 part of 85% phosphoric acid was dissolved in 0.7 part of pure water was added, and a solution in which 0.1 part of copper nitrate was dissolved in 0.7 part of pure water was further added. Next, a uniform solution of bismuth nitrate obtained by adding 0.5 part of 60% nitric acid and 2.7 parts of water to 0.5 part of bismuth nitrate was added to the mixture, and the temperature was raised to 95 ° C. To this was added a solution prepared by dissolving 0.2 part of 60% arsenic acid in 0.7 part of pure water, followed by 0.1 part of antimony trioxide and 0.1 part of cerium dioxide. The obtained aqueous slurry was evaporated to dryness while stirring with heating, dried at 130 ° C. for 16 hours, and pulverized to obtain a solid A-8. The content ratio (atomic ratio) of Mo and K contained in the obtained solid A-8 was 12:14.
[0070]
The total amount of the solid A-8 was added to the aqueous slurry B-1 obtained in the same manner as in Example 1, to obtain a powder in the same manner as in Example 1, followed by molding and firing to obtain a catalyst.
[0071]
The composition of elements other than oxygen in the obtained catalyst is
Mo12P1.5V0.8Cu0.1Sb0.3Bi0.3As0.2Ce0.2K1
Met.
[0072]
The obtained catalyst was filled in a reaction tube, and a reaction was carried out in the same manner as in Example 1. As a result, methacrolein conversion was 90.2%, methacrylic acid selectivity was 88.2%, and methacrylic acid yield was 79.6%.
<Comparative example 4>
40 parts of ammonium paramolybdate, 1.8 parts of ammonium metavanadate and 6.7 parts of potassium nitrate were dissolved in 160 parts of pure water. While stirring this, a solution in which 3.3 parts of 85% phosphoric acid was dissolved in 4 parts of pure water was added, and a solution in which 0.5 part of copper nitrate was dissolved in 4 parts of pure water was further added. Next, a uniform solution of bismuth nitrate obtained by adding 2.8 parts of 60% nitric acid and 16 parts of water to 2.8 parts of bismuth nitrate was added to the mixture, and the temperature was raised to 95 ° C. To this was added a solution prepared by dissolving 0.9 parts of 60% arsenic acid in 4 parts of pure water, followed by 0.8 parts of antimony trioxide and 0.7 parts of cerium dioxide. The obtained aqueous slurry was evaporated to dryness while stirring with heating, dried at 130 ° C. for 16 hours, and pulverized to obtain a solid A-9. The content ratio (atomic ratio) of Mo and K contained in the obtained solid A-9 was 12: 3.5.
[0073]
Separately, 100 parts of ammonium paramolybdate and 4.4 parts of ammonium metavanadate were dissolved in 400 parts of pure water. While stirring this, a solution in which 8.2 parts of 85% phosphoric acid was dissolved in 10 parts of pure water was added, and a solution in which 1.1 parts of copper nitrate was dissolved in 10 parts of pure water was further added. Next, a uniform solution of bismuth nitrate obtained by adding 7.0 parts of 60% nitric acid and 40 parts of pure water to 6.9 parts of bismuth nitrate was added to the mixture, and the temperature was raised to 95 ° C. To this was added a solution obtained by dissolving 2.2 parts of 60% arsenic acid in 10 parts of pure water, and subsequently 2.1 parts of antimony trioxide and 1.6 parts of cerium dioxide were added and stirred. The temperature was lowered to 70 ° C. to obtain an aqueous slurry B-4.
[0074]
The total amount of the solid A-9 thus obtained was added to the aqueous slurry B-4 to obtain a powder in the same manner as in Example 1, followed by molding and firing to obtain a catalyst.
[0075]
The composition of elements other than oxygen in the obtained catalyst is
Mo12P1.5V0.8Cu0.1Sb0.3Bi0.3As0.2Ce0.2K1
Met.
[0076]
The obtained catalyst was filled in a reaction tube, and a reaction was carried out in the same manner as in Example 1. As a result, methacrolein conversion was 90.1%, methacrylic acid selectivity was 88.2%, and methacrylic acid yield was 79.5%.
<Example 6>
28.3 parts of ammonium paramolybdate, 0.8 part of ammonium metavanadate and 10.4 parts of cesium nitrate were dissolved in 113.2 parts of pure water. While stirring this, a solution prepared by dissolving 2.3 parts of 85% phosphoric acid in 2.8 parts of pure water was added, and the temperature was raised to 95 ° C. Next, a solution prepared by dissolving 1.0 part of copper nitrate, 2.2 parts of ferric nitrate, 0.4 part of zinc nitrate and 0.5 part of magnesium nitrate in 22.7 parts of pure water was added. Further, this mixed solution was stirred at 100 ° C. for 30 minutes. The obtained aqueous slurry was dried by a co-current type spray dryer under the conditions of a dryer inlet temperature of 300 ° C. and a slurry spray rotating disk at 20000 rpm, and a solid A-10 was obtained. The content ratio (atomic ratio) of Mo and Cs contained in the obtained solid A-10 was 12: 4.
[0077]
Separately, an aqueous slurry B-5 was prepared so that the content ratio (atomic ratio) of Mo and Cs contained in the aqueous slurry was 12: 0.15.
[0078]
100 parts of ammonium paramolybdate, 2.8 parts of ammonium metavanadate and 1.4 parts of cesium nitrate were dissolved in 400 parts of pure water. While stirring this, a solution prepared by dissolving 8.2 parts of 85% phosphoric acid in 10 parts of pure water was added, and the temperature was raised to 95 ° C. Next, a solution obtained by dissolving 3.4 parts of copper nitrate, 7.6 parts of ferric nitrate, 1.4 parts of zinc nitrate and 1.8 parts of magnesium nitrate in 80 parts of pure water was added and mixed well. The product was cooled to 70 ° C. to obtain an aqueous slurry B-5.
[0079]
The total amount of the solid A-10 thus obtained was added to the aqueous slurry B-5 and mixed well, and then the mixture was stirred at 100 ° C. for 30 minutes. The obtained aqueous slurry was dried by a co-current type spray dryer under the conditions of a dryer inlet temperature of 300 ° C. and a slurry spray rotating disk of 20000 rpm. 3 parts of graphite was added to 100 parts of the obtained dried product, and then formed into a ring shape having an outer diameter of 5 mm, an inner diameter of 2 mm, and a length of 3 mm by a tableting machine. The obtained molded product was calcined at 380 ° C. for 5 hours under air flow to obtain a catalyst.
[0080]
The composition of elements other than oxygen in the obtained catalyst is
Mo12P1.5V0.5Cu0.3Fe0.4Mg0.15Zn0.1Cs1
Met.
[0081]
The obtained catalyst was filled in a reaction tube, and a reaction was carried out in the same manner as in Example 1. As a result, the methacrolein reaction rate was 89.0%, the methacrylic acid selectivity was 86.8%, and the methacrylic acid yield was 77.3%.
<Comparative Example 5>
100 parts of ammonium paramolybdate, 2.8 parts of ammonium metavanadate and 9.2 parts of cesium nitrate were dissolved in 400 parts of pure water. While stirring this, a solution prepared by dissolving 8.2 parts of 85% phosphoric acid in 10 parts of pure water was added, and the temperature was raised to 95 ° C. Next, a solution in which 3.4 parts of copper nitrate, 7.6 parts of ferric nitrate, 1.4 parts of zinc nitrate and 1.8 parts of magnesium nitrate were dissolved in 80 parts of pure water was added. Further, this mixed solution was stirred at 100 ° C. for 30 minutes. And the obtained aqueous slurry was dried like Example 6, and solid substance A-11 was obtained.
[0082]
The solid A-11 thus obtained was molded and fired in the same manner as in Example 6 to obtain a catalyst.
[0083]
The composition of elements other than oxygen in the obtained catalyst is
Mo12P1.5V0.5Cu0.3Fe0.4Mg0.15Zn0.1Cs1
Met.
[0084]
The obtained catalyst was filled in a reaction tube, and a reaction was carried out in the same manner as in Example 1. As a result, the methacrolein reaction rate was 87.4%, the methacrylic acid selectivity was 85.8%, and the methacrylic acid yield was 75.0%.
[0085]
【The invention's effect】
The catalyst for synthesizing methacrylic acid obtained by the novel production method of the present invention has the excellent effect of producing methacrylic acid with high activity, high methacrylic acid selectivity and high yield in the gas phase catalytic oxidation reaction of methacrolein. Have. This catalyst makes it possible to produce methacrylic acid efficiently, and its industrial value is extremely high.
Claims (9)
少なくともモリブデン、リンおよびＸを含む固形物Ａを調製する工程と、
少なくともモリブデン、リンおよびＸを含む水性スラリーＢを調製する工程と、
固形物Ａと水性スラリーＢとを混合する工程と、
固形物Ａと水性スラリーＢとを混合して得られる液状物を乾燥する工程と、
この乾燥物を３００〜５００℃で焼成する工程とを含み、
固形物Ａに含まれるモリブデンとＸの含有比（原子比）は１２：２．５〜１２：１２とし、
水性スラリーＢに含まれるモリブデンとＸの含有比（原子比）は１２：０．０５〜１２：０．４とすることを特徴とするメタクリル酸合成用触媒の製造方法。A method for producing a catalyst for synthesizing methacrylic acid comprising at least molybdenum, phosphorus, and X, which is at least one element selected from the group consisting of potassium, rubidium, cesium and thallium,
Preparing a solid A comprising at least molybdenum, phosphorus and X;
Preparing an aqueous slurry B comprising at least molybdenum, phosphorus and X;
Mixing the solid A and the aqueous slurry B;
Drying the liquid obtained by mixing the solid A and the aqueous slurry B;
And baking the dried product at 300 to 500 ° C.
The content ratio (atomic ratio) of molybdenum and X contained in the solid A is 12: 2.5 to 12:12,
A method for producing a catalyst for synthesizing methacrylic acid, wherein the content ratio (atomic ratio) of molybdenum and X contained in the aqueous slurry B is 12: 0.05 to 12: 0.4.
ＭｏaＰbＣｕcＶdＸeＹfＯg （I）
（式中、Ｍｏ、Ｐ、Ｃｕ、ＶおよびＯはそれぞれモリブデン、リン、銅、バナジウムおよび酸素を表し、Ｘはカリウム、ルビジウム、セシウムおよびタリウムからなる群より選ばれた少なくとも１種の元素を表し、Ｙは鉄、コバルト、ニッケル、亜鉛、マグネシウム、カルシウム、ストロンチウム、バリウム、チタン、クロム、タングステン、マンガン、銀、ホウ素、ケイ素、アルミニウム、ガリウム、ゲルマニウム、スズ、鉛、ヒ素、アンチモン、ビスマス、ニオブ、タンタル、ジルコニウム、インジウム、イオウ、セレン、テルル、ランタンおよびセリウムからなる群より選ばれた少なくとも１種の元素を表す。ａ、ｂ、ｃ、ｄ、ｅ、ｆおよびｇは各元素の原子比を表し、ａ＝１２のとき、０．１≦ｂ≦３、０．０１≦ｃ≦３、０．０１≦ｄ≦３、０．０５≦ｅ≦３、０≦ｆ≦３であり、ｇは前記各成分の原子比を満足するのに必要な酸素の原子比である。）The catalyst for synthesizing methacrylic acid according to claim 7, which is a composite oxide represented by the following general formula (I).
Mo a P b Cu c V d X e Y f O g (I)
(Wherein Mo, P, Cu, V and O represent molybdenum, phosphorus, copper, vanadium and oxygen, respectively, and X represents at least one element selected from the group consisting of potassium, rubidium, cesium and thallium. , Y is iron, cobalt, nickel, zinc, magnesium, calcium, strontium, barium, titanium, chromium, tungsten, manganese, silver, boron, silicon, aluminum, gallium, germanium, tin, lead, arsenic, antimony, bismuth, niobium Represents at least one element selected from the group consisting of tantalum, tantalum, zirconium, indium, sulfur, selenium, tellurium, lanthanum and cerium, wherein a, b, c, d, e, f and g are atomic ratios of the respective elements. When a = 12, 0.1 ≦ b ≦ 3, 0.01 ≦ c ≦ 3, 0.01 A d ≦ 3,0.05 ≦ e ≦ 3,0 ≦ f ≦ 3, g is the atomic ratio of oxygen required to satisfy the atomic ratio of the respective components.)
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| JP2002233758A JP2002233758A (en) | 2002-08-20 |
| JP4022047B2 true JP4022047B2 (en) | 2007-12-12 |
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| JP2001031407A Expired - Fee Related JP4022047B2 (en) | 2001-02-07 | 2001-02-07 | Method for producing methacrylic acid synthesis catalyst, methacrylic acid synthesis catalyst and methacrylic acid production method |
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Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7732367B2 (en) * | 2005-07-25 | 2010-06-08 | Saudi Basic Industries Corporation | Catalyst for methacrolein oxidation and method for making and using same |
| US7649111B2 (en) * | 2005-07-25 | 2010-01-19 | Saudi Basic Industries Corporation | Catalyst for the oxidation of a mixed aldehyde feedstock to methacrylic acid and methods for making and using same |
| US7649112B2 (en) * | 2005-07-25 | 2010-01-19 | Saudi Basic Industries Corporation | Integrated plant for producing 2-ethyl-hexanol and methacrylic acid and a method based thereon |
| US7273829B2 (en) * | 2005-12-22 | 2007-09-25 | Saudi Basic Industries Corporation | Catalyst for oxidation of saturated and unsaturated aldehydes to unsaturated carboxylic acid, method of making and method of using thereof |
| JP5362370B2 (en) * | 2009-01-14 | 2013-12-11 | 三菱レイヨン株式会社 | Method for producing catalyst for synthesis of methacrylic acid |
| JP5214500B2 (en) * | 2009-03-09 | 2013-06-19 | 住友化学株式会社 | Method for producing catalyst for producing methacrylic acid and method for producing methacrylic acid |
| DE102010010587A1 (en) | 2009-03-09 | 2010-11-18 | Sumitomo Chemical Co. Ltd. | Reproduction of catalyst for methacrylic acid production consists of heteropolyacid compound involves preparing aqueous slurry, drying to obtain solid heteropolyacid compound, preparing another aqueous slurry, drying and baking |
| JP5214499B2 (en) * | 2009-03-09 | 2013-06-19 | 住友化学株式会社 | Method for regenerating catalyst for methacrylic acid production and method for producing methacrylic acid |
| JP4900449B2 (en) * | 2009-10-30 | 2012-03-21 | 住友化学株式会社 | Method for producing catalyst for producing methacrylic acid and method for producing methacrylic acid |
| JP4900532B2 (en) * | 2011-10-14 | 2012-03-21 | 住友化学株式会社 | Method for producing catalyst for producing methacrylic acid and method for producing methacrylic acid |
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