JP3797440B2

JP3797440B2 - Molding catalyst for fluorination and method for producing halogenated hydrocarbon

Info

Publication number: JP3797440B2
Application number: JP32985395A
Authority: JP
Inventors: 崇金村; 聖河野; 圭祐北野; 一博 ▼たか▲橋; 俊柴沼
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 1995-11-24
Filing date: 1995-11-24
Publication date: 2006-07-19
Anticipated expiration: 2015-11-24
Also published as: JPH09141105A

Description

【０００１】
【発明の属する技術分野】
本発明は、フッ素化用成形触媒及びハロゲン化炭化水素の製造方法に関し、特に不均一フッ素化用成形触媒とこの成形触媒を用いるハロゲン化炭化水素の製造方法に関するものである。
【０００２】
【従来の技術】
従来、クロム、酸化クロム、フッ化クロム又は酸化フッ化クロムからなる触媒（以下、これらを総称して「クロム系触媒」と呼ぶ。）は、不均一フッ素化反応に対して有効であることが知られており、既に多数提案されている。例えば、米国特許第２７４５８８６号、同第３２５８５００号、同第３７５５４７７号、同第３８５９４２４号、同第４１５８６７５号、英国特許第９７６８８３号、欧州特許第５０２６０５号、同第６２９４４０号、特公昭４２−３００４号公報、特開平４−２２６９２７号公報などがある。
【０００３】
しかしながら、これらの提案が開示されてから多くの時間を経た今日においても、次の（１）〜（４）に示す如き問題点が克服されていない。
【０００４】
（１）不均一フッ素化反応でよく認められる目的フッ素化生成物質の収率の低さ。
（２）欧州特許第６２９４４０号でも指摘されている、フッ素化反応での反応圧力増加による反応活性低下（目的フッ素化生成物質の収率の低下）。
（３）反応器内の触媒層で生じる圧力損失がもたらす反応圧力増加による反応活性の低下。
（４）短い触媒寿命（触媒の反応活性の経時的な低下）。
【０００５】
一方、先に挙げた全ての提案を含む、これまでに公知となっている不均一フッ素化反応用の成形触媒においては、いずれも、触媒の形状による影響についての検討はなされておらず、粒状、球状、ペレット、又は円柱状で使用されるとか或いは使用可能であると、表現されているのみである。
【０００６】
【発明が解決しようとする課題】
本発明の目的は、従来の円柱状等の触媒に比べて高活性、低圧力損失となり、その結果として触媒寿命も延び、ひいては、ランニングコスト及び設備費の低減、生産能力の向上が可能なフッ素化用成形触媒と、この成形触媒を用いたハロゲン化炭化水素の製造方法を提供することにある。
【０００７】
【課題を解決するための手段】
即ち、本発明は、含塩素炭化水素のフッ素化用成形触媒であって、クロム、酸化クロム、フッ化クロム及び酸化フッ化クロムからなる群より選ばれた少なくとも１種の触媒（クロム系触媒）を主体とし、その形状が中空筒体（特に中空円筒体）であって、この中空筒体の外径が２〜２０ｍｍ、内径が外径の０．１〜０．７倍であり、かつ、長さが外径の０．２〜２．０倍であるフッ素化用（特に不均一フッ素化反応用）成形触媒に係るものである。
【０００８】
また、本発明は、含塩素炭化水素のフッ素化用成形触媒であって、クロム、酸化クロム、フッ化クロム及び酸化フッ化クロムからなる群より選ばれた少なくとも１種（クロム系触媒）が担持された中空筒体（特に中空円筒体）に成形された担体材料を有し、前記中空筒体の外径が２〜２０ｍｍ、内径が外径の０．１〜０．７倍であり、かつ、長さが外径の０．２〜２．０倍であるフッ素化用（特に不均一フッ素化反応用）成形触媒も提供するものである。
【０００９】
本発明者は、触媒の形状と反応条件（温度と圧力）が反応活性と触媒寿命に与える影響に着目し、検討を重ねた。
【００１０】
触媒の形状としては、上述した従来の形状の他に、新たに筒形、特に中空の円筒形についても検討した。その結果、活性に関しては、
（１）クロム系触媒の形状を特定の中空の円筒形にすることにより、同じ組成の球状、円柱状等の触媒や、場合によっては粒状の触媒に比べてさえ高い反応活性を示し、目的フッ素化物質が収率良く得られた。高い反応活性であるということは、言い換えれば、従来に比べて少量の触媒で従来と同じ収率が達成でき、触媒経費の削減につながる。また、このフッ素化反応の多くの場合に、反応温度が低くなると収率は低下するが、本発明による触媒を用いると、目的物質の収率を落とさずに、従来に比べて低温での反応が可能となる。このことは、ランニングコストや設備費の低減をもたらすことになる。
【００１１】
次に、反応器の圧力損失に関して検討した結果、
（２）不均一フッ素化反応用触媒の形状を特定の中空の円筒形にすることにより、反応器への充填時の空間率（触媒層での反応器内容積に占める空間体積の割合）が粒状や円柱状の触媒に比べて大きくなった。その結果、ガス流通時に触媒層で生じる圧力損失が大幅に低減される。反応器の圧力損失の低下は、反応ガス流量の限界を上げ、生産能力の向上につながる。或いは、先に述べたように、フッ素化触媒は一般的に反応圧力の増加により活性が低下することが知られており、圧力損失の大幅な低減による反応圧力の減少は、中空円筒形触媒の更なる活性の上昇をもたらし、上記の（１）と同様に経費の削減につながる。
【００１２】
クロム系触媒による不均一フッ素化反応での触媒の寿命は、反応温度による影響が大きく、反応温度が低いほど寿命は長くなる（触媒の経時的な活性低下速度が遅くなる）ことが明らかとなった。このことより、
（３）本発明による特定の中空の円筒形触媒は上記の（１）、（２）で述べたように、従来よりも高活性の触媒であり、かつ、従来よりも低い温度での反応が可能となったことから、本発明によって触媒の長寿命化が実現できた。長寿命触媒は生産能力の改善をもたらし、触媒に関するコストの低下につながる。
【００１３】
以上のように、本発明によって、高活性で低圧力損失、そして長寿命の触媒が得られるに至った。
【００１４】
本発明による触媒の形状は、上記の（１）〜（３）の結果と工業的に必要な成形性や強度も含めた検討結果から、特に中空の円筒体で、外径が２〜20mmであり、内径が外径の 0.1〜0.7 倍であり、かつ、長さが外径の 0.2〜2.0 倍であることが必須不可欠であり、特に好ましくは、外径が３〜10mmであり、内径が外径の 0.2〜0.5 倍であり、かつ、長さが外径の 0.5〜1.5 倍である。
【００１５】
本発明による触媒の調製方法に関しては、制限はなく、公知の方法、例えば、三フッ化クロム三水和物（ＣｒＦ₃・３Ｈ₂Ｏ）の高温での空気処理；三酸化クロム（ＣｒＯ₃）をアルコールで還元し、加熱脱水する方法；三価のクロム塩から水酸化アンモニウムにより水酸化クロムを沈澱せしめ、次いで加熱焼成する方法；或いは、三酸化クロムの加熱分解；等の方法に基づき、クロム系触媒が調製される際、成形段階で打錠機等の適当な機械で本発明の成形触媒に成形されればよい。或いは、担持段階で中空円筒体に成形された、フッ素化反応に適当な担体材料、例えば、アルミナ、フッ素化アルミナ、活性炭等にクロム系触媒が担持されればよい。
【００１６】
また、本発明によるフッ素化用成形触媒に、クロム、酸素及びフッ素以外であって反応活性改善の効果を持つ元素の少なくとも１種（例えばＺｎなど）が添加又は担持されるのがよい。
【００１７】
本発明が効果を示す反応に関しては、不均一フッ素化反応であれば他の制限はないが、使用反応圧力、温度領域や反応物質の分子径などから、ジクロロメタン、クロロフルオロメタン（ＨＣＦＣ−３１）、パークロロエチレン、トリクロロエチレン、１−クロロ−２，２−ジフルオロエチレン、１，１−ジクロロ−２，２，２−トリフルオロエタン（ＨＣＦＣ−１２３）、１−クロロ−１，２，２，２−テトラフルオロエタン（ＨＣＦＣ−１２４）、１−クロロ−２，２，２−トリフルオロエタン（ＨＣＦＣ−１３３ａ）、１，１−ジクロロ−１−フルオロエタン又は１−クロロ−１，１−ジフルオロエタンを本発明によるフッ素化用成形触媒の存在下でフッ化水素酸（ＨＦ）により気相フッ素化し、対応するハロゲン化炭化水素を得る反応において特に効果がある。
【００１８】
【実施例】
次に、実施例及び比較例によって、本発明による触媒の利点を明らかにする。
【００１９】
実施例１
濃度 5.7％の硝酸クロム水溶液 765Kgに対し、10％水酸化アンモニウム 114Kgを攪拌しながら滴下し、水酸化クロムの沈澱を得た。これを濾別、純水による洗浄の後、その一部を空気中 120℃で12時間乾燥し、得られた固形水酸化クロムを 0.2mm以下の粒径に粉砕し、粉末の水酸化クロムにした。
【００２０】
これに黒鉛３重量％を加え、混合した粉末を外径５mm、内径２mm、高さ（長さ）５mmの中空円筒形に市販の打錠機を用いて圧縮成形した。
【００２１】
これを内径20mmのハステロイＣ製の反応管に充填し、窒素ガス流通下、 400℃で２時間加熱し、次いで、フッ化水素酸と窒素の混合ガスに 200〜360 ℃で２時間接触させた。
【００２２】
こうして得られた本発明のクロム系触媒（酸化フッ化クロム）（触媒Ａ）を用いて、ＨＦによるＨＣＦＣ−１３３ａの気相フッ素化を下記の反応条件１で行った。この時のフッ素化生成物質である１，２，２，２−テトラフルオロエタン（ＨＦＣ−１３４ａ）の収率（ＨＣＦＣ−１３３ａの反応率×生成物中のＨＦＣ−１３４ａの選択率：以下、同様）を、反応器出口ガスを水洗、乾燥後にガスクロマトグラフィーで分析することにより求めた。結果を後記の表−１に示す。
【００２３】

【００２４】
実施例２
触媒Ａを用いて、ＨＦによるＨＣＦＣ−１２３の気相フッ素化を下記の反応条件２で行った。この時のフッ素化生成物質であるＨＣＦＣ−１２４と１，１，２，２，２−ペンタフルオロエタン（ＨＦＣ−１２５）の収率を後記の表−２に示す。
【００２５】

【００２６】
実施例３
触媒Ａを用いて、ＨＦによるジクロロメタンの気相フッ素化を下記の反応条件３で行った。この時のフッ素化生成物質であるＨＣＦＣ−３１とジフルオロメタン（ＨＦＣ−３２）の収率を後記の表−３に示す。
【００２７】

【００２８】
比較例１
実施例１において、中空円筒形ではなく、直径３mm、高さ３mmの円柱状に圧縮成形する以外は全く実施例１と同様に調製したクロム系触媒（触媒Ｂ）を得た。この触媒Ｂを用いて、実施例１と同じ反応条件１でＨＣＦＣ−１３３ａのフッ素化を行った。このときのＨＦＣ−１３４ａの収率を後記の表−１に示す。
【００２９】
比較例２
実施例１において、中空円筒形ではなく、直径６mm、高さ６mmの円柱状に圧縮成形する以外は全く実施例１と同様に調製したクロム系触媒（触媒Ｃ）を得た。この触媒Ｃを用いて、実施例１と同じ反応条件１でＨＣＦＣ−１３３ａのフッ素化を行った。このときのＨＦＣ−１３４ａの収率を後記の表−１に示す。
【００３０】
比較例３
実施例２において、本発明の触媒Ａではなく、触媒Ｂを用いて、反応条件２でＨＣＦＣ−１２３のフッ素化を行った。このときのＨＣＦＣ−１２４及びＨＦＣ−１２５の収率を後記の表−２に示す。
【００３１】
比較例４
実施例３において、本発明の触媒Ａではなく、触媒Ｂを用いて、反応条件３でジクロロメタンのフッ素化を行った。このときのＨＣＦＣ−３１及びＨＦＣ−３２の収率を後記の表−３に示す。
【００３２】
実施例４
触媒Ａを用いて、下記の反応条件４でＨＣＦＣ−１３３ａのフッ素化を行った際の触媒層に生じる圧力損失を測定した。測定結果を後記の表−４に示す。
【００３３】

【００３４】
比較例５
触媒Ｂを用いて、反応条件４でＨＣＦＣ−１３３ａのフッ素化を行った際の触媒層に生じる圧力損失を測定した。測定結果を後記の表−４に示す。
【００３５】
比較例６
触媒Ｃを用いて、反応条件４でＨＣＦＣ−１３３ａのフッ素化を行った際の触媒層に生じる圧力損失を測定した。測定結果を後記の表−４に示す。
【００３６】
実施例５
下記の反応条件５で、触媒ＡによりＨＣＦＣ−１３３ａのフッ素化を行ったときの生成物質であるＨＦＣ−１３４ａの収率の経時変化を調べ、結果を図１に示す。反応開始（収率８％：以下、同様）から収率２％になるまでの時間とその間に得られたＨＦＣ−１３４ａの総生成量を後記の表−５に示す。
【００３７】

【００３８】
比較例７
触媒Ｂを用いて、反応条件５（但し、初期のＨＦＣ−１３４ａの収率が 8.0％となる温度は 351.8℃であった。）でＨＣＦＣ−１３３ａのフッ素化を行ったときの生成物質であるＨＦＣ−１３４ａの収率の経時変化を調べ、結果を図１に示す。反応開始から収率２％になるまでの時間とその間に得られたＨＦＣ−１３４ａの総生成量を後記の表−５に示す。
【００３９】
比較例８
触媒Ｃを用いて、反応条件５（但し、初期のＨＦＣ−１３４ａの収率が 8.0％となる温度は 357.8℃であった。）でＨＣＦＣ−１３３ａのフッ素化を行ったときの生成物質であるＨＦＣ−１３４ａの収率の経時変化を調べ、結果を図１に示す。反応開始から収率２％になるまでの時間とその間に得られたＨＦＣ−１３４ａの総生成量を後記の表−５に示す。
【００４０】

【００４１】

【００４２】

【００４３】

【００４４】

【００４５】
実施例６
実施例１において、外径 3.5mm、内径 1.4mm、高さ 3.3mmに成形した酸化フッ化クロム触媒（触媒Ｄ）を用いた以外は実施例１と同様にして、反応条件１で気相フッ素化を行ったところ、ＨＦＣ−１３４ａが収率14.1％で得られた。
【００４６】
実施例７
触媒Ｄを用いて、反応条件４でＨＣＦＣ−１３３ａのフッ素化を行ったところ、触媒層の圧力損失は 4330mm Ｈ₂Ｏであった。
【００４７】
比較例９
外径 1.8mm、内径 0.5mm、高さ 1.8mmとした以外は触媒Ａと同じとし、反応条件４でＨＣＦＣ−１３３ａのフッ素化を行ったところ、触媒層の圧力損失は13590mm Ｈ₂Ｏであった。
【００４８】
比較例 10
外径10mm、内径８mm、高さ10mmとした以外は触媒Ａと同じとし、反応条件４で圧力損失を測定するため、反応器に触媒を充填した際、強度不足によって全量の４割が割れ、測定不可であった。
【００４９】
比較例 11
外径22mm、内径５mm、高さ22mmとした以外は触媒Ａと同じとし、下記の反応条件６でＨＣＦＣ−１３３ａの気相フッ素化を行った。このときのＨＦＣ−１３４ａの収率は 4.1％であった。
【００５０】

【００５１】
実施例８
触媒Ｄを用い、反応条件６で上記と同様に反応を行ったところ、ＨＦＣ−１３４ａの収率は12.5％であった。
【００５２】
実施例９
水酸化クロムに対して１ mol％のＺｎ（ＮＯ₃）₂・６Ｈ₂Ｏを溶解した水に含浸させた後に、水酸化クロムの乾燥を行う以外は触媒Ｄと同様に調製した触媒（触媒Ｅ）を用いて、下記の反応条件７でＨＣＦＣ−１３３ａの気相フッ素化を行った。このときのＨＦＣ−１３４ａの収率は12.6％であった。
【００５３】

【００５４】
実施例 10
触媒Ｄを用い、反応条件７で上記と同様に反応させたところ、ＨＦＣ−１３４ａの収率は 8.1％であった。
【００５５】
比較例 12
実施例９において、中空円筒形ではなく、３mm×３mmの円柱状に圧縮成形する以外は全く同様の触媒を用い、同じ反応条件で反応させたところ、ＨＦＣ−１３４ａの収率は 8.5％であった。
【００５６】
比較例 13
触媒Ｂを用い、反応条件７で上記と同様の反応を行ったところ、ＨＦＣ−１３４ａの収率は 5.0％であった。
【００５７】
実施例 11
触媒Ａを用い、原料ガスとしてトリクロロエチレンを用い、下記の反応条件８でフッ素化を行った。このときのＨＣＦＣ−１３３ａの収率は85.2％であった。
【００５８】

【００５９】
比較例 14
触媒Ｂを用い、反応条件８で上記と同様に反応を行ったところ、ＨＣＦＣ−１３３ａの収率は77.3％であった。
【００６０】
上記した各結果から明らかなように、本発明に基づいて、中空の円筒体で、外形が２〜20mmであり、内径が外径の 0.1〜0.7 倍であり、かつ、長さが外径の 0.2〜2.0 倍であるクロム系触媒を不均一フッ素化反応に用いることによって、目的物を比較的良い収率でかつ低圧力損失にして得ることができ、しかも触媒寿命も長くすることができる。
【００６１】
【発明の作用効果】
本発明の触媒は、上述した如く、含塩素炭化水素のフッ素化用成形触媒であって、クロム、酸化クロム、フッ化クロム及び酸化フッ化クロムからなる群より選ばれた少なくとも１種の触媒（クロム系触媒）を主体とし、或いはこの触媒を担体に担持し、その形状が中空筒体（特に中空円筒体）であって、この中空筒体の外径が２〜２０ｍｍ、内径が外径の０．１〜０．７倍であり、かつ、長さが外径の０．２〜２．０倍であるフッ素化用（特に不均一フッ素化反応用）成形触媒であるから、従来の円柱状等の触媒に比べて高活性、低圧力損失となり、その結果として触媒寿命も延び、ひいては、ランニングコスト及び設備費の低減、生産能力の向上が可能となり、また、この成形触媒を用いてフッ素化炭化水素を良収率に製造することができる。
【図面の簡単な説明】
【図１】不均一フッ素化反応時の反応時間による目的物の収率の変化を比較して示すグラフである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shaping catalyst for fluorination and a method for producing a halogenated hydrocarbon, and more particularly to a shaping catalyst for heterogeneous fluorination and a method for producing a halogenated hydrocarbon using the shaping catalyst.
[0002]
[Prior art]
Conventionally, catalysts composed of chromium, chromium oxide, chromium fluoride or chromium oxyfluoride (hereinafter collectively referred to as “chromium-based catalysts”) are effective for heterogeneous fluorination reactions. Known and many have already been proposed. For example, U.S. Pat. Nos. 2,745,886, 3,258,500, 3,755,477, 3,859,424, 4,158,675, British Patent No. 976883, European Patent Nos. And JP-A-4-226927.
[0003]
However, even today, a long time has passed since these proposals were disclosed, the following problems (1) to (4) have not been overcome.
[0004]
(1) Low yield of target fluorination product, which is often observed in heterogeneous fluorination reactions.
(2) Reduction in reaction activity due to increase in reaction pressure in fluorination reaction (decrease in yield of target fluorination product) as pointed out in European Patent No. 629440.
(3) Reduction in reaction activity due to increase in reaction pressure caused by pressure loss generated in the catalyst layer in the reactor.
(4) Short catalyst life (decrease in catalytic activity over time).
[0005]
On the other hand, none of the previously known molded catalysts for heterogeneous fluorination reactions, including all the proposals mentioned above, have been studied for the effects of catalyst shape, It is only expressed as being used or usable in the form of spheres, pellets, or cylinders.
[0006]
[Problems to be solved by the invention]
The object of the present invention is to provide high activity and low pressure loss as compared with conventional cylindrical catalysts and the like, and as a result, the catalyst life is extended, and as a result, the running cost and equipment cost can be reduced, and the production capacity can be improved. An object of the present invention is to provide a forming catalyst for chlorination and a method for producing a halogenated hydrocarbon using the forming catalyst.
[0007]
[Means for Solving the Problems]
That is, the present invention is a molding catalyst for fluorination of chlorine-containing hydrocarbons , and at least one catalyst selected from the group consisting of chromium , chromium oxide, chromium fluoride and chromium oxide fluoride (chromium-based catalyst). And the shape thereof is a hollow cylinder (particularly a hollow cylinder), the outer diameter of the hollow cylinder is 2 to 20 mm, the inner diameter is 0.1 to 0.7 times the outer diameter, and The present invention relates to a molding catalyst for fluorination (particularly for heterogeneous fluorination reaction) having a length of 0.2 to 2.0 times the outer diameter.
[0008]
The present invention also provides a molding catalyst for fluorination of chlorine-containing hydrocarbons, which is supported by at least one selected from the group consisting of chromium , chromium oxide, chromium fluoride and chromium oxide fluoride (chromium-based catalyst). A hollow cylindrical body (particularly a hollow cylindrical body) having a carrier material, wherein the hollow cylindrical body has an outer diameter of 2 to 20 mm, an inner diameter of 0.1 to 0.7 times the outer diameter, and The present invention also provides a shaped catalyst for fluorination (particularly for heterogeneous fluorination reaction) having a length of 0.2 to 2.0 times the outer diameter.
[0009]
The inventor of the present invention paid attention to the influence of the catalyst shape and reaction conditions (temperature and pressure) on the reaction activity and the catalyst life, and repeated studies.
[0010]
As the shape of the catalyst, in addition to the above-described conventional shape, a new cylindrical shape, particularly a hollow cylindrical shape was also examined. As a result, regarding activity,
(1) By making the shape of the chromium-based catalyst into a specific hollow cylindrical shape, it shows high reaction activity even when compared with spherical or cylindrical catalysts of the same composition, and in some cases even granular catalysts. The chemical substance was obtained in good yield. In other words, the high reaction activity means that the same yield can be achieved with a small amount of catalyst as compared with the conventional case, leading to a reduction in catalyst cost. In many cases of this fluorination reaction, the yield decreases when the reaction temperature is lowered. However, when the catalyst according to the present invention is used, the reaction at a lower temperature than the conventional one can be achieved without reducing the yield of the target substance. Is possible. This leads to a reduction in running costs and equipment costs.
[0011]
Next, as a result of examining the pressure loss of the reactor,
(2) By making the shape of the catalyst for heterogeneous fluorination reaction into a specific hollow cylindrical shape, the space ratio at the time of filling the reactor (the ratio of the space volume to the reactor internal volume in the catalyst layer) Compared to granular and cylindrical catalysts. As a result, the pressure loss generated in the catalyst layer during the gas flow is greatly reduced. A decrease in the pressure loss of the reactor raises the limit of the reaction gas flow rate and leads to an increase in production capacity. Alternatively, as described above, it is known that the activity of a fluorination catalyst generally decreases with an increase in reaction pressure, and a decrease in reaction pressure due to a significant decrease in pressure loss is the same as that of a hollow cylindrical catalyst. As a result, the activity is further increased and the cost is reduced as in (1) above.
[0012]
It is clear that the life of the catalyst in the heterogeneous fluorination reaction with the chromium catalyst is greatly influenced by the reaction temperature, and that the life becomes longer as the reaction temperature is lower (the rate of decrease in the activity of the catalyst with time is slower). It was. From this,
(3) As described in the above (1) and (2), the specific hollow cylindrical catalyst according to the present invention is a catalyst having a higher activity than the conventional one, and the reaction at a lower temperature than the conventional one. As a result, it was possible to extend the life of the catalyst according to the present invention. Long life catalysts result in improved production capacity, leading to lower costs for the catalyst.
[0013]
As described above, according to the present invention, a highly active, low pressure loss, and long-life catalyst can be obtained.
[0014]
From the results of the above (1) to (3) and the industrially required moldability and strength, the shape of the catalyst according to the present invention is a hollow cylindrical body having an outer diameter of 2 to 20 mm. It is essential that the inner diameter is 0.1 to 0.7 times the outer diameter and the length is 0.2 to 2.0 times the outer diameter, and particularly preferably the outer diameter is 3 to 10 mm and the inner diameter is The outer diameter is 0.2 to 0.5 times, and the length is 0.5 to 1.5 times the outer diameter.
[0015]
The method for preparing the catalyst according to the present invention is not limited, and known methods such as air treatment of chromium trifluoride trihydrate (CrF ₃ .3H ₂ O) at high temperature; chromium trioxide (CrO ₃ ). Is reduced with alcohol and heated and dehydrated; chromium hydroxide is precipitated from trivalent chromium salt with ammonium hydroxide and then calcined; or heat decomposition of chromium trioxide; When the system catalyst is prepared, it may be formed into the formed catalyst of the present invention by an appropriate machine such as a tableting machine at the forming stage. Alternatively, the chromium-based catalyst may be supported on a carrier material suitable for the fluorination reaction, for example, alumina, fluorinated alumina, activated carbon, or the like, which is formed into a hollow cylindrical body at the supporting stage.
[0016]
In addition, it is preferable that at least one element (for example, Zn) other than chromium, oxygen, and fluorine, which has an effect of improving the reaction activity, be added or supported on the molding catalyst for fluorination according to the present invention.
[0017]
Regarding the reaction for which the present invention is effective, there is no other limitation as long as it is a heterogeneous fluorination reaction. However, dichloromethane, chlorofluoromethane (HCFC-31) are used from the reaction pressure used, the temperature range, the molecular diameter of the reactants, and the like. Perchloroethylene, trichloroethylene, 1-chloro-2,2-difluoroethylene, 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123), 1-chloro-1,2,2,2 -Tetrafluoroethane (HCFC-124), 1-chloro-2,2,2-trifluoroethane (HCFC-133a), 1,1-dichloro-1-fluoroethane or 1-chloro-1,1-difluoroethane Reaction to obtain a corresponding halogenated hydrocarbon by gas phase fluorination with hydrofluoric acid (HF) in the presence of a fluorination molding catalyst according to the present invention. Oite is particularly effective.
[0018]
【Example】
Next, the advantages of the catalyst according to the present invention will be clarified by Examples and Comparative Examples.
[0019]
Example 1
To 765 kg of an aqueous chromium nitrate solution having a concentration of 5.7%, 114 kg of 10% ammonium hydroxide was added dropwise with stirring to obtain a chromium hydroxide precipitate. After filtration and washing with pure water, a part of it was dried in air at 120 ° C for 12 hours, and the resulting solid chromium hydroxide was pulverized to a particle size of 0.2 mm or less to form powdered chromium hydroxide. did.
[0020]
3% by weight of graphite was added thereto, and the mixed powder was compression molded into a hollow cylindrical shape having an outer diameter of 5 mm, an inner diameter of 2 mm, and a height (length) of 5 mm using a commercially available tableting machine.
[0021]
This was filled in a Hastelloy C reaction tube having an inner diameter of 20 mm, heated at 400 ° C. for 2 hours under a nitrogen gas flow, and then contacted with a mixed gas of hydrofluoric acid and nitrogen at 200 to 360 ° C. for 2 hours. .
[0022]
Using the chromium-based catalyst (chromium oxyfluoride) (catalyst A) of the present invention thus obtained, gas phase fluorination of HCFC-133a with HF was performed under the following reaction condition 1. Yield of 1,2,2,2-tetrafluoroethane (HFC-134a) as the fluorination product at this time (reaction rate of HCFC-133a × selectivity of HFC-134a in the product: ) Was obtained by washing the reactor outlet gas with water, drying and analyzing it by gas chromatography. The results are shown in Table 1 below.
[0023]

[0024]
Example 2
Using catalyst A, gas phase fluorination of HCFC-123 with HF was performed under the following reaction condition 2. The yields of HCFC-124 and 1,1,2,2,2-pentafluoroethane (HFC-125) as the fluorination product at this time are shown in Table 2 below.
[0025]

[0026]
Example 3
Using catalyst A, vapor phase fluorination of dichloromethane with HF was performed under the following reaction condition 3. The yields of HCFC-31 and difluoromethane (HFC-32), which are fluorination products at this time, are shown in Table 3 below.
[0027]

[0028]
Comparative Example 1
In Example 1, a chromium-based catalyst (catalyst B) prepared in the same manner as in Example 1 was obtained except that it was compression-molded into a cylindrical shape having a diameter of 3 mm and a height of 3 mm instead of a hollow cylindrical shape. Using this catalyst B, HCFC-133a was fluorinated under the same reaction condition 1 as in Example 1. The yield of HFC-134a at this time is shown in Table 1 below.
[0029]
Comparative Example 2
In Example 1, a chromium-based catalyst (catalyst C) prepared in the same manner as in Example 1 was obtained except that it was compression-molded into a columnar shape having a diameter of 6 mm and a height of 6 mm instead of a hollow cylindrical shape. Using this catalyst C, HCFC-133a was fluorinated under the same reaction condition 1 as in Example 1. The yield of HFC-134a at this time is shown in Table 1 below.
[0030]
Comparative Example 3
In Example 2, HCFC-123 was fluorinated under reaction condition 2 using catalyst B instead of catalyst A of the present invention. The yields of HCFC-124 and HFC-125 at this time are shown in Table 2 below.
[0031]
Comparative Example 4
In Example 3, dichloromethane was fluorinated under reaction condition 3 using catalyst B instead of catalyst A of the present invention. The yields of HCFC-31 and HFC-32 at this time are shown in Table 3 below.
[0032]
Example 4
Using the catalyst A, the pressure loss generated in the catalyst layer when HCFC-133a was fluorinated under the following reaction condition 4 was measured. The measurement results are shown in Table 4 below.
[0033]

[0034]
Comparative Example 5
Using catalyst B, the pressure loss generated in the catalyst layer when HCFC-133a was fluorinated under reaction condition 4 was measured. The measurement results are shown in Table 4 below.
[0035]
Comparative Example 6
Using catalyst C, the pressure loss generated in the catalyst layer when HCFC-133a was fluorinated under reaction condition 4 was measured. The measurement results are shown in Table 4 below.
[0036]
Example 5
Under the reaction conditions 5 below, the change over time in the yield of HFC-134a, which is a product obtained when fluorination of HCFC-133a with catalyst A, was examined, and the results are shown in FIG. The time from the start of the reaction (yield 8%: hereinafter the same) to the yield 2% and the total amount of HFC-134a obtained during that time are shown in Table 5 below.
[0037]

[0038]
Comparative Example 7
It is a product obtained when fluorination of HCFC-133a is carried out using catalyst B under reaction condition 5 (however, the temperature at which the initial yield of HFC-134a is 8.0% was 351.8 ° C.). Changes in the yield of HFC-134a over time were examined, and the results are shown in FIG. The time from the start of the reaction to the yield of 2% and the total production amount of HFC-134a obtained during that time are shown in Table 5 below.
[0039]
Comparative Example 8
This is a product obtained when fluorination of HCFC-133a is performed using catalyst C under reaction condition 5 (however, the temperature at which the initial yield of HFC-134a is 8.0% was 357.8 ° C.). Changes in the yield of HFC-134a over time were examined, and the results are shown in FIG. The time from the start of the reaction to the yield of 2% and the total production amount of HFC-134a obtained during that time are shown in Table 5 below.
[0040]

[0041]

[0042]

[0043]

[0044]

[0045]
Example 6
In the same manner as in Example 1 except that a chromium oxyfluoride catalyst (catalyst D) formed to have an outer diameter of 3.5 mm, an inner diameter of 1.4 mm, and a height of 3.3 mm was used in Example 1, gas phase fluorine was obtained under reaction condition 1. As a result, HFC-134a was obtained in a yield of 14.1%.
[0046]
Example 7
When fluorination of HCFC-133a was performed under the reaction condition 4 using the catalyst D, the pressure loss of the catalyst layer was 4330 mm H ₂ O.
[0047]
Comparative Example 9
HCFC-133a was fluorinated under reaction condition 4 except that the outer diameter was 1.8mm, the inner diameter was 0.5mm, and the height was 1.8mm. Under the reaction condition 4, the pressure loss of the catalyst layer was 13590mm H ₂ O. It was.
[0048]
Comparative Example 10
Except for the outer diameter of 10 mm, inner diameter of 8 mm, and height of 10 mm, it is the same as Catalyst A. In order to measure the pressure loss under reaction condition 4, when the reactor is filled with catalyst, 40% of the total amount is cracked due to insufficient strength. Measurement was impossible.
[0049]
Comparative Example 11
Gas phase fluorination of HCFC-133a was performed under the same reaction conditions 6 as below except that the outer diameter was 22 mm, the inner diameter was 5 mm, and the height was 22 mm. The yield of HFC-134a at this time was 4.1%.
[0050]

[0051]
Example 8
When the reaction was performed in the same manner as described above under the reaction condition 6 using the catalyst D, the yield of HFC-134a was 12.5%.
[0052]
Example 9
A catalyst (catalyst E) prepared in the same manner as catalyst D except that 1 mol% Zn (NO ₃ ) ₂ .6H ₂ O dissolved in chromium hydroxide was impregnated with water and then the chromium hydroxide was dried. ) Was used for vapor phase fluorination of HCFC-133a under the following reaction condition 7. The yield of HFC-134a at this time was 12.6%.
[0053]

[0054]
Example 10
When the reaction was conducted in the same manner as described above under the reaction condition 7 using the catalyst D, the yield of HFC-134a was 8.1%.
[0055]
Comparative Example 12
In Example 9, when the reaction was carried out under the same reaction conditions using the same catalyst except that it was compression molded into a 3 mm × 3 mm column instead of a hollow cylinder, the yield of HFC-134a was 8.5%. It was.
[0056]
Comparative Example 13
When the same reaction as described above was carried out under the reaction condition 7 using the catalyst B, the yield of HFC-134a was 5.0%.
[0057]
Example 11
The catalyst A was used, and fluorination was carried out under the following reaction condition 8 using trichlorethylene as a raw material gas. The yield of HCFC-133a at this time was 85.2%.
[0058]

[0059]
Comparative Example 14
When the reaction was performed in the same manner as described above using the catalyst B under the reaction condition 8, the yield of HCFC-133a was 77.3%.
[0060]
As is clear from the above results, based on the present invention, the hollow cylinder has an outer diameter of 2 to 20 mm, an inner diameter of 0.1 to 0.7 times the outer diameter, and a length of the outer diameter. By using a chromium-based catalyst of 0.2 to 2.0 times in the heterogeneous fluorination reaction, the target product can be obtained with a relatively good yield and low pressure loss, and the catalyst life can be extended.
[0061]
[Effects of the invention]
As described above, the catalyst of the present invention is a molding catalyst for fluorination of chlorine-containing hydrocarbons , and is at least one catalyst selected from the group consisting of chromium, chromium oxide, chromium fluoride and chromium oxyfluoride ( Chromium-based catalyst) or the catalyst is supported on a carrier, the shape of which is a hollow cylinder (particularly a hollow cylinder), the outer diameter of which is 2 to 20 mm, and the inner diameter is the outer diameter. Since it is a molding catalyst for fluorination (especially for heterogeneous fluorination reaction) having a length of 0.1 to 0.7 times and a length of 0.2 to 2.0 times the outer diameter, high activity, becomes low pressure loss as compared with the catalyst of the columnar or the like, as a result also extends catalyst life, and thus, reduction of running cost and equipment cost, it is possible to increase production capacity, also using the molded catalyst fluorine Can be produced in good yield. .
[Brief description of the drawings]
FIG. 1 is a graph showing a comparison of changes in the yield of a target product depending on the reaction time during a heterogeneous fluorination reaction.

Claims

A molding catalyst for fluorination of chlorine-containing hydrocarbons , mainly comprising at least one catalyst selected from the group consisting of chromium, chromium oxide, chromium fluoride and chromium oxyfluoride, the shape of which is a hollow cylinder The hollow cylinder has an outer diameter of 2 to 20 mm, an inner diameter of 0.1 to 0.7 times the outer diameter, and a length of 0.2 to 2.0 times the outer diameter. Molding catalyst.

A catalyst for fluorination of chlorinated hydrocarbons, which is a carrier material molded into a hollow cylinder carrying at least one selected from the group consisting of chromium, chromium oxide, chromium fluoride and chromium oxyfluoride The hollow cylinder has an outer diameter of 2 to 20 mm, an inner diameter of 0.1 to 0.7 times the outer diameter, and a length of 0.2 to 2.0 times the outer diameter. Molding catalyst for fluorination.

The molding catalyst for fluorination according to claim 1 or 2, which is a hollow cylindrical body and is used for heterogeneous fluorination reaction.

The fluorination molding catalyst according to any one of claims 1 to 3, wherein at least one element other than chromium, oxygen and fluorine and having an effect of improving reaction activity is added or supported. Molding catalyst.

Using the molding catalyst for fluorination according to any one of claims 1 to 4, dichloromethane, chlorofluoromethane, perchloroethylene, trichloroethylene, 1-chloro-2,2-difluoroethylene, 1,1-dichloro -2,2,2-trifluoroethane, 1-chloro-1,2,2,2-tetrafluoroethane, 1-chloro-2,2,2-trifluoroethane, 1,1-dichloro-1-fluoro A method for producing a halogenated hydrocarbon, comprising fluorinating ethane or 1-chloro-1,1-difluoroethane to obtain a corresponding halogenated hydrocarbon.