JP4055229B2 - Method for epoxidizing allyl halides and regenerating catalyst used - Google Patents

Description

（式中、Ｒ¹ 、Ｒ² 及びＲ³ は水素原子またはＣ₁ 〜Ｃ₂ のアルキル基を示し、それぞれ同一であっても異なっても良い。ＸはＣｌ、Ｂｒ、Ｉより選ばれるハロゲン原子である。）
【００１１】
本発明に用いられる一般式（１）で示される脂肪族オレフィンとは、アリルクロライド、メタリルクロライド、１−クロロ−２−ブテン、１−クロロ−３−メチル−２−ブテン、アリルブロマイド、沃化アリル、１−クロロ−２−ペンテンが挙げられる。また、過酸化水素として通常過酸化水素の水溶液が用いられるが、反応系中で過酸化水素で生成する化合物として例えば水素ー酸素／白金族金属の組み合わせ、尿素の過酸化水素付加化合物あるいはｔ−ブチルハイドロパーオキサイド等を用いても良い。本反応に用いられるチタノシリケート触媒としては、一般式：ｘＴｉＯ₂ ・（１−ｘ）ＳｉＯ₂ （式中のｘは０．００２〜０．２０）で示されるチタン原子含有合成ゼオライト触媒が挙げられるが、チタン原子を分子構造内に結合しているものであればよく、特にチタン原子とケイ素原子との比率を問題とするものではない。チタノシリケートの構造としては、ＭＦＩ構造を有する上記ＴＳ−１、ＭＥＬ構造を有するＴＳ−２、ＢＥＡ構造を有するＴｉ−ベータ、メソ細孔構造を有するＴｉ−ＭＣＭ−４１やＴｉ−ＭＣＭ−４８などが挙げられる。
【００１２】
超音波はその振動数が人間の可聴範囲、すなわち約２０ｋＨｚを超える音波をいう。本発明における超音波照射装置は、任意の周波数および出力を有する装置が使用できる。照射周波数はチタノシリケートの細孔径の大きさやハロゲン化アリルの種類によって異なるが通常、２０〜１００ｋＨｚの周波数、好ましくは２５〜６０ｋＨｚのものが適当である。照射出力は反応サイズにより適当なものを選ぶことが出来る。超音波放射体としては平板型、リング型、円盤型等のいずれの形式でも良い。
【００１３】
本発明者らはまた、すでに報告されているアルカリ金属塩やリン酸塩を中和剤に用いた触媒を焼成により再生する場合、触媒活性が著しく低下するという問題点に鑑み鋭意検討を行った結果、炭酸アンモニウムの添加が有効であるという知見を得た。
【００１４】
本発明によれば、チタノシリケート触媒重量当り０．１〜３．０重量％の炭酸アンモニウムを添加することを特徴とする上記アリルクロライド類のエポキシ化方法が提供される。炭酸アンモニウムの好ましい添加量は１．０〜２．０重量％である。
【００１５】
本発明者らはまた、チタノシリケート触媒の再生処理さらに触媒の洗浄方法について検討した結果、再焼成処理に代る、かつ再焼成処理よりもさらに広範な上記触媒の再生に適用し得る方法を見出した。
【００１６】
本発明によれば、一般式（１）で示される炭素数３〜９の脂肪族オレフィンと過酸化水素、または反応系中で過酸化水素を生成する化合物とをチタノシリケート触媒の存在下で反応後、取り出した上記のチタノシリケート触媒を炭素数１〜５の極性溶媒及び水からなる溶媒より選ばれた少なくとも１種を含む抽出液中で、超音波を照射して溶媒抽出を行なうことを特徴とする触媒の再生方法が提供される。
【００１７】
超音波の周波数は前期のようにチタノシリケートの細孔径やエポキシ化物の種類によって異なるが、通常２０〜１００ｋＨｚの周波数、好ましくは２５〜６０ｋＨｚが適当である。炭素数が１〜５の極性溶媒としては、炭素数が１〜５のアルコール、ハロゲン化物、ニトリル、アミン、または、炭素数が２〜５のケトン類等が挙げられる。例えば、水、メタノール、エタノール、１−プロパノール、２−プロパノール、２−ブタノール、２−メチル−１−プロパノール、２−メチル−２−プロパノール、アセトン、アセトニトリル、メチル−エチルケトン、ヘキサン、シクロヘキサン、ジクロロメタン、１，２−ジクロロエタン、１，１−ジクロロエタン、などがあげられるが、好ましくは、メタノール、ジクロルメタン、アセトン、アセトニトリルである。
【００１８】
【発明の実施の形態】
本発明に使用されるチタノシリケート（チタン原子含有合成ゼオライト）の調製にあたっては、酸化ケイ素、酸化チタン、含窒素有機塩基および水でなる反応混合物を調製する。酸化ケイ素源はテトラアルキルオルトケイ酸エステル、好ましくはオルトケイ酸テトラエチルまたは単にコロイド状のシリカでも良い。酸化チタン源は、テトラアルコキシチタン、好ましくは、テトラエトキシチタン、テトラプロポキシチタン、または、テトラブトキシチタンの中から選ばれる化合物、または、四塩化チタンやオキシ塩化チタンのような無機化合物でも良い。有機塩基は水酸化テトラアルキルアンモニウム、または、臭化テトラアルキルアンモニウムの中から選ばれる化合物、特に好ましくは、水酸化テトラ−ｎ−プロピルアンモニウムである。各試薬の混合物を攪拌し、得られた沈殿より溶媒を除去した後オートクレーブに移し、１３０〜２００℃、自己圧力、１〜３０日の条件で、チタノシリケート前駆体の結晶が形成されるまで水熱処理する。次いでこれらの結晶を母液から分離し水で注意深く洗浄、乾燥した後、空気中で５００〜８００℃で焼成することにより目的とするチタノシリケート触媒が得られる。
【００１９】
一般式（１）で示されるオレフィンに対するチタノシリケート触媒の好ましい仕込み濃度は０．５〜２０重量％であり、２〜１５重量％で最も高いオレフィン基準のエポキシ化選択率、及び収率が得られる。用いる水溶液中の過酸化水素の好ましい濃度は１〜60重量％であるが保存性や操作性の面から10〜40重量％が好ましい。
【００２０】
エポキシ化反応は適当な溶媒の存在下で行うことができる。適当な溶媒としては、水、メタノールやイソプロピルアルコールのような低級アルコール、アセトン等の有機溶媒、またはこれらの混合物が挙げられる。反応温度は０〜１００℃で減圧、常圧、加圧下のいずれでも実施できる。通常はハロゲン化アリル類の沸点以下で行うが、反応速度を早くする場合には加圧して反応温度を上げることも出来るし、低温で還流下に実施した場合には減圧下で反応できる。
【００２１】
超音波の照射は通常反応中に連続的あるいは間欠的に行い、外部照射方式、内部照射方式のいずれでも良い。通常、液相接触酸化反応では、攪拌機、外部循環、ガスの吹き込み等による強制攪拌下に行われるが、本発明において、好ましくは、これらの強制攪拌に超音波照射を組み合わせて実施される。具体的には、過酸化水素水溶液、触媒、ハロゲン化アリル類混合液に必要があれば適当な溶媒を適当量加え、超音波照射する事により本発明を実施し得る。固定床式反応においても、触媒層にハロゲン化アリル類と過酸化水素を供給しながら超音波を照射することにより実施出来る。一度利用した触媒を再び使用する場合も同様である。
【００２２】
使用後のチタノシリケート触媒を再生するには、触媒を遠心分離等の方法で反応系より取り出し、溶媒として水又は前記のような炭素数１〜５の極性溶媒を用い２０〜１００ｋHzの超音波を照射して、抽出温度１０〜８０℃、好ましくは５〜６０℃、抽出時間５分〜５時間、好ましくは１５分〜２時間、洗浄して抽出を行えば良い。
【００２３】
【作用】
本発明に使用する超音波について述べる。超音波振動は微少な空間に作られる高圧力差で生じるキャビテーションによって、極めて優れた混合、分散、脱ガス効果を実現し得る。そのため、ゼオライトのような多孔体を触媒に用いる場合は、細孔内拡散の促進のみならず、触媒表面や細孔内に吸着した生成物やジオールの脱離、及び再吸着の防止等により、反応速度の向上および触媒寿命の延長が期待できる。エポキシ化反応においては、再吸着の防止および拡散の促進により、反応速度の増大および逐次反応によるジオール生成の抑制による選択率の向上が期待される。
【００２４】
【実施例】
以下、実施例及び比較例により本発明を具体的に説明する。
ＴＳ−１触媒の調製
ジムロート、温度計、滴下ロート、および攪拌機を備えた１Ｌ−セパラブルフラスコに、オルトケイ酸テトラエチル２００ｇと２−プロパノール（ＩＰＡ）２００ｇを入れ、これに０．０５Ｎ−塩酸水溶液３５．０ｇを１４０ｇのＩＰＡで希釈した溶液を、窒素気流下、室温、攪拌下で６０分かけて滴下した。さらに、チタン酸テトラブチル１０．９ｇ（Ｔｉ／Ｓｉ ｍｏｌ比＝３０）をＩＰＡ１０９ｇに希釈し滴下した。室温で１時間熟成化後、１ｍｏｌ／Ｌ−水酸化テトラプロピルアンモニウム水溶液（以下ＴＰＡＯＨと略す）４７ｇを滴下し、寒天状沈殿物を７３６ｇ得た。ついで加水分解を促進し且つ遊離したエタノールを留去するため１００℃で１時間加熱攪拌し、さらに減圧加熱下でアルコールを完全に除去し、白色粉末８１．４ｇを得た。得られた白色粉末４０ｇに１ｍｏｌ／Ｌ−ＴＰＡＯＨを３４．０ｇを加えて、攪拌機を備えたオートクレーブのテフロン製内筒に移した。混合物を１７０℃まで加熱し、自己発生圧力下において、この温度で１日間攪拌した。反応後、遠心分離で固形物を取り出し、洗浄液がＮ／１０−ＡｇＮＯ₃ で白濁しなくなるまでイオン水で洗浄し、６０℃で１２時間乾燥することにより、白色のＴＳ−１結晶３７．３ｇを得た。この結晶３２．５ｇを磁性ルツボに入れ、５５０℃で３時間焼成することにより、純白のＴＳ−１触媒の焼成品２６ｇを得た。
【００２５】
実施例１〜５、比較例１（エポキシ化反応）
温度計、還流器、攪拌機を備えたガラス製５０ｍｌの３ツ口フラスコに上記のＴＳ−１触媒２．０ｇ、３５重量％−過酸化水素水溶液１０．４ｇ（１０７ｍｍｏｌ、原料基質に対して０．６当量モル）、原料基質としてメタリルクロライド１６．２ｇ（１７９ｍｍｏｌ）、適当量の助触媒を加え、表１に示す超音波照射下、内温を４０±３℃に保ってエポキシ化を行った。反応液は有機層、水層、触媒の３層からなる。反応液を氷冷した後、メタノールを加え有機層と水層を一層にし、精密ろ過により触媒を除去した。この液にプロピオン酸エチルを内部標準として加え、ＧＬサイエンス（株）社製キャピラリーカラム（ＴＣ−１７０１，３０ｍ）を備えたＦＩＤガスクロマトグラフィーで分析、定量した。また、溶液中に残存した過酸化水素はヨードメトリー法で定量した。結果を表１に示す。
【００２６】
【表１】

註：ａ）炭酸アンモニウムを触媒に対し１．６重量％添加
ｂ）炭酸アンモニウムをａ）と同量添加、過酸化水素１７９ｍｍｏｌ添加
【００２７】
超音波を用いず攪拌のみでは（比較例 1）、過酸化水素の転化率９７％を得るのに４時間を要した。この際の基質基準の選択率は６９．２％と低く、１０．８％のジオール体が生成した。この反応系に、３９ｋＨｚ、２００Ｗの超音波を照射すると（実施例１）、２時間で同転化率が得られ、エポキシ化選択率も８２．８％と向上した。ジオール体への選択率も１％低下した。超音波の出力を４８ｋＨｚ、６０Ｗと弱くした場合（実施例２）も実施例１と同じ結果が得られており、反応速度を向上させるための超音波照射のエネルギー敷居値が、低いことが解る。本反応系に、炭酸アンモニウムを触媒重量に対して１．６重量％添加した場合（実施例３）、反応２時間での過酸化水素転化率は９９．６％にまで達しており、エポキシ化選択率も９３．５％と非常に高い結果を得た。更に、ジオール体の生成はほぼ完全に抑制することが出来た。過酸化水素を基質に対して当量モル数加え、炭酸アンモニウムを添加し、超音波を照射した場合（実施例４）、３時間で９８．２％の転化率が得られ、ジオール体の生成も２．７％にまで抑制出来た。さらに実施例５によれば強制攪拌を行わなくとも反応が促進されることがわかる。
【００２８】
実施例６，７、比較例２，３（触媒の再生）
反応終了後、回収した触媒を有機溶媒中で超音波を照射して再生処理を行い、再び反応に供した際の結果を表２に示す。参考のために調製直後の新触媒の使用例（参考例）、超音波を照射しない例（比較例２，３）を併記する。
【００２９】
【表２】

【００３０】
この反応条件下では、十分な混合が得られるため、超音波照射と同程度の転化率が得られる。未洗浄若しくはメタノールで洗浄したのみ場合は、いずれも触媒活性が３割程度低下した（比較例２、比較例３）。しかしながら、メタノール洗浄時に超音波を照射すれば、活性は完全に回復し（実施例６）、ジクロロエタンを溶媒に用いた場合も超音波照射により調製直後の触媒を用いた場合に対して８３％まで活性が回復した（実施例７）。
【００３１】
【発明の効果】
本発明によれば、チタノシリケートと過酸化水素によるハロゲン化アリル類の直接エポキシ化反応において、（１）超音波を反応系に照射することによる反応速度の改善、（２）超音波照射と共に炭酸アンモニウムを助触媒に用いることのよる選択率の向上、（３）超音波照射下での低温極性溶媒抽出による触媒再生、が可能となる。助触媒として使用される炭酸アンモニウムは反応速度を損なうこと無く、逐次反応を完全に抑制し、安全性、経済性にも優れている。更に触媒の焼成処理を行う場合にも触媒の活性の低下を起こさない。また、触媒の再生工程において、超音波を照射せずに溶媒による加熱抽出で行った場合は、触媒中に捕捉されたオレフィン、エポキシ化合物等の有機物が重合、開環、縮合等の反応を生じ、脱離できなくなり再生効果は著しく低減する。本発明の劣化触媒の再生法によれば、ほぼ新触媒の性能水準にまで回復できるので、触媒の繰り返し使用が可能となり、工業的に触媒のコスト低減に有効である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for epoxidizing allyl halides and a method for regenerating a catalyst used therein.
[0002]
[Prior art]
The epoxidation method of allyl halides is a process developed by Shell in 1945, in which allyl halides are treated with chlorine and water, converted to halohydrin, and then ring-closed to epoxide in the presence of alkali. Are operating in various places. A method of converting allyl alcohol into halohydrin to obtain a similar epoxy compound is currently in operation. However, all of these current methods have large problems in terms of environmental load because they produce a large amount of wastewater.
[0003]
A direct oxidation method using hydrogen peroxide or oxygen as an oxidizing agent is expected as a next-generation process with a low environmental load. Among them, a combination of synthetic zeolite containing titanium in the framework at a certain ratio, so-called titanosilicate, and hydrogen peroxide is actively studied all over the world as a promising oxidation method. As a typical titanosilicate, TS-1 having an MFI structure (5.3 × 5.6 Å), TS-2 having an MEL structure (5.3 × 5.4 Å), BEA structure (7.6) Ti-beta having a (× 6.4 angstrom) and Ti-MCM-41 having an MCM-41 structure (15 to 100 angstrom) have been reported. The number shown after the structure type represents the pore diameter of the zeolite. The crystal structure of titanosilicate can be selected according to the size of the reaction substrate to be used. In general, however, the turnover of active sites decreases as the pore size increases. When an aliphatic olefin having 3 to 9 carbon atoms is oxidized, TS-1 has an appropriate crystal structure. The preparation and application of TS-1 are disclosed in JP-B-1-42889 and JP-B-4-5028, respectively.
[0004]
Titanosilicate catalysts have acid sites on the outer surface of the catalyst and in pores called “channels”. These acid sites hydrolyze the epoxy compound as a product when water is present in the reaction system to give a diol as a ring-opening product. Therefore, the presence of acid sites on the outer surface of the catalyst leads to a decrease in the substrate selectivity of the epoxy product. In addition, at the acid sites in the pores, the by-produced diol form clogs the channel, resulting in loss of the catalyst. Invite life. US Pat. No. 4,824,976 discloses that the acid sites on the outer surface of the catalyst can be neutralized by silylation or the like. Since zeolite such as TS-1 has a small pore diameter as described above, it is impossible to neutralize the acid sites in the pores where epoxidation reaction takes place using a silylating agent having a trimethylsilyl group. Regarding the acid point in the pores, the addition of alkali metal salts such as lithium chloride and sodium nitrate and ammonium dihydrogen phosphate into the reaction system neutralizes the acid points in the pores and improves the selectivity and catalyst life. This is disclosed in JP-A-8-225556 and the above-mentioned US patent.
[0005]
[Problems to be solved by the invention]
However, since zeolite is a porous inorganic compound, the pore size cannot be deformed with a high degree of freedom like a protein found in enzymes. Therefore, when the size of the reaction molecule is close to the pore diameter, the effective diffusion coefficient of the reaction molecule becomes extremely small, and the reaction rate becomes diffusion dominant. When the residence time in the pores is long (diffusion is slow), even if a neutralizing agent is added, the epoxide is susceptible to sequential hydrolysis, leading to a decrease in selectivity and deactivation of the catalyst. When an epoxidation reaction is carried out with a TS-1 catalyst using an aliphatic olefin having 3 to 9 carbon atoms, particularly allyl chloride or betamethylallyl chloride (hereinafter referred to as methallyl chloride) as a raw material, Since the molecular size is very close to the pore size of the MFI structure, clogging is likely to occur, and the influence of diffusion becomes more remarkable. When titanosilicate having a BEA structure with a large pore diameter is used, an epoxide production rate as high as that of the TS-1 catalyst cannot be obtained. In the TS-1 catalyst, it is strongly desired to increase the diffusion rate in order to further increase the epoxidation rate.
[0006]
The method of neutralizing the catalytic acid sites by alkali metal salts, phosphates, or silylation can maintain the initial activity and selectivity of the catalyst immediately after preparation for a relatively long time, but the deterioration of the catalyst performance still remains. Inevitable. Therefore, even if these neutralization methods are used, some catalyst regeneration treatment is required in order to repeatedly use the catalyst twice or more. As a method for regenerating such a deactivated catalyst, a method in which the deactivated catalyst is refired is generally performed. However, in the recalcination treatment of the catalyst used in the neutralization method, the catalyst performance is remarkably reduced as compared with the catalyst immediately after preparation due to the influence of residual alkali metal ions and the like. Become. Searching for a cocatalyst that does not cause a decrease in activity even by the calcination treatment, or establishment of a new catalyst regeneration treatment method that is not affected by the neutralizing agent to be used becomes an essential issue.
[0007]
Accordingly, the present invention provides a novel reaction method that improves the selectivity and reaction rate by promoting diffusion in the pores, and provides a cocatalyst that does not cause a decrease in activity even by a calcination treatment, and neutralization used. It is an object of the present invention to provide a novel catalyst regeneration treatment method that is not affected by the agent.
[0008]
[Means for Solving the Problems]
The present inventors have found that, regardless of the pore size of titanosilicate, irradiation with ultrasonic waves is effective for catalytic action when epoxidizing allyl halides with hydrogen peroxide. Addition of a small amount of ammonium carbonate to the reaction system can completely suppress the ring opening reaction of epoxide, improve the selectivity and reaction rate, and improve the performance level of the new catalyst by re-calcining the reaction removal catalyst. I found that I can recover. Furthermore, as a new catalyst regeneration treatment method, the deactivated catalyst is subjected to recalcination treatment by subjecting the deactivated catalyst to low temperature extraction treatment in a polar solvent such as methanol, dichloromethane, acetone, acetonitrile, water, etc. under ultrasonic irradiation. In the case of re-calcining the reaction removal catalyst in the presence of a neutralizing agent such as an alkali metal salt used in the above neutralization method. In contrast, the present invention has been found to be able to recover to the performance level of the new catalyst.
[0009]
According to the present invention, an aliphatic olefin having 3 to 9 carbon atoms represented by the following general formula (1) and hydrogen peroxide or a compound that generates hydrogen peroxide in the reaction system are present in the presence of a titanosilicate catalyst. In the reaction, there is provided a method for epoxidizing allyl halides characterized by irradiating ultrasonic waves.
[0010]
[Chemical 3]

Wherein R ¹ , R ² and R ³ represent a hydrogen atom or a C ₁ -C ₂ alkyl group, and may be the same or different. X is a halogen atom selected from Cl, Br and I .)
[0011]
The aliphatic olefin represented by the general formula (1) used in the present invention is allyl chloride, methallyl chloride, 1-chloro-2-butene, 1-chloro-3-methyl-2-butene, allyl bromide, iodine. Allyl chloride and 1-chloro-2-pentene. Further, an aqueous solution of hydrogen peroxide is usually used as the hydrogen peroxide, but as a compound generated with hydrogen peroxide in the reaction system, for example, a combination of hydrogen-oxygen / platinum group metal, a hydrogen peroxide addition compound of urea, or t- Butyl hydroperoxide may be used. As the titanosilicate catalyst used in this reaction, a titanium atom-containing synthetic zeolite catalyst represented by the general formula: xTiO _2. (1-x) SiO ₂ (wherein x is 0.002 to 0.20) can be mentioned. However, any material may be used as long as titanium atoms are bonded in the molecular structure, and the ratio of titanium atoms to silicon atoms is not particularly problematic. As the structure of titanosilicate, TS-1 having the MFI structure, TS-2 having the MEL structure, Ti-beta having the BEA structure, Ti-MCM-41 and Ti-MCM-48 having the mesopore structure are used. Etc.
[0012]
Ultrasound refers to sound waves whose frequency exceeds the human audible range, that is, approximately 20 kHz. As the ultrasonic irradiation apparatus according to the present invention, an apparatus having an arbitrary frequency and output can be used. The irradiation frequency varies depending on the size of the titanosilicate pore size and the type of allyl halide, but a frequency of 20 to 100 kHz, preferably 25 to 60 kHz, is appropriate. An appropriate irradiation output can be selected depending on the reaction size. The ultrasonic radiator may be any type such as a flat plate type, a ring type, and a disk type.
[0013]
The present inventors have also intensively studied in view of the problem that the catalytic activity is remarkably lowered when a catalyst using a previously reported alkali metal salt or phosphate as a neutralizing agent is regenerated by calcination. As a result, the knowledge that the addition of ammonium carbonate was effective was obtained.
[0014]
According to the present invention, there is provided a method for epoxidizing allyl chlorides, characterized in that 0.1 to 3.0% by weight of ammonium carbonate is added per weight of titanosilicate catalyst. A preferable addition amount of ammonium carbonate is 1.0 to 2.0% by weight.
[0015]
The inventors of the present invention have also studied a method for regenerating the titanosilicate catalyst and a method for washing the catalyst. As a result, the present inventors have found a method that can be applied to the regeneration of the above-mentioned catalyst in place of the re-firing treatment and wider than the re-firing treatment. I found it.
[0016]
According to the present invention, an aliphatic olefin having 3 to 9 carbon atoms represented by the general formula (1) and hydrogen peroxide or a compound that generates hydrogen peroxide in the reaction system are present in the presence of a titanosilicate catalyst. After the reaction, the extracted titanosilicate catalyst is subjected to solvent extraction by irradiating with ultrasonic waves in an extract containing at least one selected from a polar solvent having 1 to 5 carbon atoms and a solvent comprising water. A method for regenerating a catalyst is provided.
[0017]
The frequency of the ultrasonic wave varies depending on the titanosilicate pore size and the type of epoxidized product as in the previous period, but a frequency of 20 to 100 kHz, preferably 25 to 60 kHz, is appropriate. Examples of the polar solvent having 1 to 5 carbon atoms include alcohols having 1 to 5 carbon atoms, halides, nitriles, amines, and ketones having 2 to 5 carbon atoms. For example, water, methanol, ethanol, 1-propanol, 2-propanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, acetone, acetonitrile, methyl-ethyl ketone, hexane, cyclohexane, dichloromethane, 1,2-dichloroethane, 1,1-dichloroethane and the like can be mentioned, and methanol, dichloromethane, acetone and acetonitrile are preferable.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
In preparing the titanosilicate (titanium atom-containing synthetic zeolite) used in the present invention, a reaction mixture comprising silicon oxide, titanium oxide, nitrogen-containing organic base and water is prepared. The silicon oxide source may be a tetraalkylorthosilicate ester, preferably tetraethylorthosilicate or simply colloidal silica. The titanium oxide source may be a tetraalkoxytitanium, preferably a compound selected from tetraethoxytitanium, tetrapropoxytitanium, or tetrabutoxytitanium, or an inorganic compound such as titanium tetrachloride or titanium oxychloride. The organic base is a compound selected from tetraalkylammonium hydroxide or tetraalkylammonium bromide, particularly preferably tetra-n-propylammonium hydroxide. Stir the mixture of each reagent, remove the solvent from the resulting precipitate, transfer to an autoclave, and form a titanosilicate precursor crystal under the conditions of 130-200 ° C., self-pressure, 1-30 days Hydrothermal treatment. Subsequently, these crystals are separated from the mother liquor, carefully washed with water, dried, and then calcined in air at 500 to 800 ° C. to obtain the intended titanosilicate catalyst.
[0019]
The preferred feed concentration of the titanosilicate catalyst with respect to the olefin represented by the general formula (1) is 0.5 to 20% by weight, and the highest olefin-based epoxidation selectivity and yield are obtained at 2 to 15% by weight. It is done. The preferred concentration of hydrogen peroxide in the aqueous solution to be used is 1 to 60% by weight, but 10 to 40% by weight is preferred from the viewpoint of storage stability and operability.
[0020]
The epoxidation reaction can be carried out in the presence of a suitable solvent. Suitable solvents include water, lower alcohols such as methanol and isopropyl alcohol, organic solvents such as acetone, or mixtures thereof. The reaction temperature is 0 to 100 ° C., and the reaction can be performed under reduced pressure, normal pressure, or increased pressure. Usually, the reaction is carried out below the boiling point of allyl halides. However, when the reaction rate is increased, the reaction temperature can be increased by pressurization. When the reaction is carried out at low temperature under reflux, the reaction can be performed under reduced pressure.
[0021]
Ultrasonic irradiation is usually performed continuously or intermittently during the reaction, and either an external irradiation method or an internal irradiation method may be used. Usually, the liquid-phase contact oxidation reaction is performed under forced stirring by a stirrer, external circulation, gas blowing, or the like. In the present invention, preferably, these forced stirring is performed in combination with ultrasonic irradiation. Specifically, the present invention can be carried out by adding an appropriate amount of an appropriate solvent and irradiating with ultrasonic waves if necessary for an aqueous hydrogen peroxide solution, a catalyst, and an allyl halide mixture. The fixed bed reaction can also be carried out by irradiating ultrasonic waves while supplying allyl halides and hydrogen peroxide to the catalyst layer. The same applies when the catalyst once used is used again.
[0022]
In order to regenerate the titanosilicate catalyst after use, the catalyst is taken out of the reaction system by a method such as centrifugal separation, and ultrasonic waves of 20 to 100 kHz using water or a polar solvent having 1 to 5 carbon atoms as a solvent are used. , And extraction may be carried out by washing at an extraction temperature of 10 to 80 ° C., preferably 5 to 60 ° C., and an extraction time of 5 minutes to 5 hours, preferably 15 minutes to 2 hours.
[0023]
[Action]
The ultrasonic wave used in the present invention will be described. Ultrasonic vibration can realize extremely excellent mixing, dispersion, and degassing effects by cavitation generated by a high pressure difference created in a minute space. Therefore, when a porous body such as zeolite is used for the catalyst, not only the promotion of diffusion in the pores, but also the elimination of the product and diol adsorbed on the catalyst surface and pores, prevention of re-adsorption, etc. Improvement of reaction rate and extension of catalyst life can be expected. In the epoxidation reaction, it is expected that the reaction rate is increased and the selectivity is improved by suppressing the diol formation by the sequential reaction by preventing re-adsorption and promoting diffusion.
[0024]
【Example】
Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.
Preparation of TS-1 Catalyst Into a 1 L-separable flask equipped with a Dim funnel, thermometer, dropping funnel, and stirrer, 200 g of tetraethyl orthosilicate and 200 g of 2-propanol (IPA) were added. A solution obtained by diluting 0.0 g with 140 g of IPA was added dropwise over 60 minutes at room temperature under stirring in a nitrogen stream. Furthermore, 10.9 g of tetrabutyl titanate (Ti / Si mol ratio = 30) was diluted with 109 g of IPA and added dropwise. After aging at room temperature for 1 hour, 47 g of a 1 mol / L-tetrapropylammonium hydroxide aqueous solution (hereinafter abbreviated as TPAOH) was added dropwise to obtain 736 g of an agar-like precipitate. Subsequently, in order to accelerate hydrolysis and distill off the liberated ethanol, the mixture was heated and stirred at 100 ° C. for 1 hour, and the alcohol was completely removed under heating under reduced pressure to obtain 81.4 g of a white powder. 34.0 g of 1 mol / L-TPAOH was added to 40 g of the obtained white powder, and transferred to a Teflon inner cylinder of an autoclave equipped with a stirrer. The mixture was heated to 170 ° C. and stirred at this temperature for 1 day under self-generated pressure. After the reaction, the solid was removed by centrifugation, washed with ionic water until the washing solution became no cloudy with N / 10-AgNO ₃ , and dried at 60 ° C. for 12 hours to obtain 37.3 g of white TS-1 crystals. Obtained. By putting 32.5 g of this crystal in a magnetic crucible and calcining at 550 ° C. for 3 hours, 26 g of a calcined product of pure white TS-1 catalyst was obtained.
[0025]
Examples 1-5, comparative example 1 (epoxidation reaction)
In a 50 ml glass three-necked flask equipped with a thermometer, a reflux condenser, and a stirrer, 2.0 g of the above TS-1 catalyst and 10.4 g of a 35 wt% hydrogen peroxide aqueous solution (107 mmol, 0. 6 equivalent moles), 16.2 g (179 mmol) of methallyl chloride as a raw material substrate, an appropriate amount of a co-catalyst were added, and epoxidation was performed while maintaining the internal temperature at 40 ± 3 ° C. under ultrasonic irradiation shown in Table 1. . The reaction solution consists of three layers, an organic layer, an aqueous layer, and a catalyst. After the reaction solution was ice-cooled, methanol was added to form an organic layer and an aqueous layer, and the catalyst was removed by microfiltration. Ethyl propionate was added to this solution as an internal standard, and analysis and quantification were performed by FID gas chromatography equipped with a capillary column (TC-1701, 30m) manufactured by GL Sciences. Further, hydrogen peroxide remaining in the solution was quantified by iodometry. The results are shown in Table 1.
[0026]
[Table 1]

註: a) 1.6% by weight of ammonium carbonate is added to the catalyst b) Ammonium carbonate is added in the same amount as a), and 179 mmol of hydrogen peroxide is added.
Only stirring without using ultrasonic waves (Comparative Example 1) required 4 hours to obtain a conversion rate of 97% for hydrogen peroxide. The substrate-based selectivity at this time was as low as 69.2%, and 10.8% diol was produced. When this reaction system was irradiated with ultrasonic waves of 39 kHz and 200 W (Example 1), the same conversion rate was obtained in 2 hours and the epoxidation selectivity was also improved to 82.8%. The selectivity to diol was also reduced by 1%. When the output of the ultrasonic wave is weakened to 48 kHz and 60 W (Example 2), the same result as in Example 1 is obtained, and it is understood that the energy threshold value of the ultrasonic irradiation for improving the reaction rate is low. . When 1.6% by weight of ammonium carbonate was added to this reaction system based on the catalyst weight (Example 3), the hydrogen peroxide conversion rate in the reaction of 2 hours reached 99.6%, and epoxidation was achieved. The selectivity was as high as 93.5%. Furthermore, the production of diol was almost completely suppressed. When hydrogen peroxide was added in an equivalent number of moles relative to the substrate, ammonium carbonate was added, and ultrasonic waves were applied (Example 4), a conversion rate of 98.2% was obtained in 3 hours, and the formation of a diol was also achieved. It was suppressed to 2.7%. Furthermore, according to Example 5, it turns out that reaction is accelerated | stimulated even if forced stirring is not performed.
[0028]
Examples 6 and 7, Comparative Examples 2 and 3 (Catalyst regeneration)
Table 2 shows the results when the recovered catalyst was subjected to regeneration treatment by irradiating ultrasonic waves in an organic solvent after completion of the reaction, and subjected to the reaction again. For reference, examples of using the new catalyst immediately after preparation (reference example) and examples of not irradiating ultrasonic waves (comparative examples 2 and 3) are also shown.
[0029]
[Table 2]

[0030]
Under this reaction condition, since sufficient mixing is obtained, a conversion rate comparable to that of ultrasonic irradiation can be obtained. In the case of only washing with no washing or methanol, the catalytic activity decreased by about 30% (Comparative Example 2 and Comparative Example 3). However, the activity was completely recovered by irradiating ultrasonic waves during methanol washing (Example 6), and even when dichloroethane was used as a solvent, up to 83% of the case of using the catalyst immediately after preparation by ultrasonic irradiation. Activity recovered (Example 7).
[0031]
【The invention's effect】
According to the present invention, in the direct epoxidation reaction of allyl halides with titanosilicate and hydrogen peroxide, (1) the reaction rate is improved by irradiating the reaction system with ultrasonic waves, and (2) with the ultrasonic irradiation. The selectivity can be improved by using ammonium carbonate as a promoter, and (3) catalyst regeneration by low-temperature polar solvent extraction under ultrasonic irradiation is possible. Ammonium carbonate used as a cocatalyst completely suppresses the sequential reaction without impairing the reaction rate, and is excellent in safety and economy. Further, the catalyst activity does not decrease when the catalyst is calcined. In addition, when the catalyst is regenerated by heating extraction with a solvent without irradiating ultrasonic waves, organic substances such as olefin and epoxy compounds trapped in the catalyst cause reactions such as polymerization, ring opening, and condensation. As a result, it becomes impossible to detach and the regeneration effect is remarkably reduced. According to the method for regenerating a deteriorated catalyst of the present invention, it is possible to recover almost the performance level of the new catalyst, so that the catalyst can be used repeatedly, and it is industrially effective in reducing the cost of the catalyst.

Claims (9)

In reacting an aliphatic olefin having 3 to 9 carbon atoms represented by the following general formula (1) with hydrogen peroxide or a compound that generates hydrogen peroxide in the reaction system in the presence of a titanosilicate catalyst, A method for epoxidizing allyl halides, characterized by irradiating with sound waves.

Wherein R ¹ , R ² and R ³ represent a hydrogen atom or a C ₁ -C ₂ alkyl group, and may be the same or different. X is a halogen atom selected from Cl, Br and I .)   The aliphatic olefin represented by the general formula (1) is allyl chloride, methallyl chloride, 1-chloro-2-butene, 1-chloro-3-methyl-2-butene, allyl bromide, allyl iodide, or 1- The epoxidation method according to claim 1, which is chloro-2-pentene. The epoxidation method according to claim 1, wherein the titanosilicate catalyst is a compound represented by a general formula: xTiO ₂ · (1-x) SiO ₂ (wherein x is 0.002 to 0.20).   The epoxidation method according to claim 3, wherein the titanosilicate catalyst has a crystal structure of MFI, MEL, BEA, MCM-41, or MCM-48.   The epoxidation method according to claim 1, wherein the ultrasonic frequency is 20 kHz to 100 kHz.   The epoxidation method according to claim 1, characterized in that 0.1 to 3.0% by weight of ammonium carbonate is added per weight of titanosilicate catalyst. The C3-C9 aliphatic olefin represented by the following general formula (1) and hydrogen peroxide or a compound that generates hydrogen peroxide in the reaction system were reacted in the presence of a titanosilicate catalyst, and then taken out. among extract containing at least one of the above titanosilicate catalyst selected from polar solvents, 1 to 5 carbon atoms (which may comprise water), and characterized by performing solvent extraction by ultrasonic irradiation To regenerate the catalyst.

(Wherein R ¹ , R ² and R ³ represent a hydrogen atom or a C ₁ -C ₂ alkyl group, and may be the same or different. X is a halogen atom selected from Cl, Br and I) .)   The reproduction method according to claim 7, wherein an ultrasonic frequency is 20 kHz to 100 kHz. The regeneration method according to claim 7 or 8, wherein the polar solvent having 1 to 5 carbon atoms is an alcohol, halide, nitrile, amine, or ketone having 2 to 5 carbon atoms.