Title of Invention

PROCESS FOR THE REACTION OF AN ORGANIC COMPOUND WITH A HYDROPEROXIDE

Abstract

A process for the reaction of an organic compound with a hydroperoxide comprises at least the steps (i) to (iii) below: (i) reaction of the hydroperoxide with the organic compound to give a mixture comprising the reacted organic compound and unreacted hydroperoxide, (ii) separation of the unreacted hydroperoxide from the mixture resulting from step (i), (iii) reaction of the hydroperoxide separated off in step (ii) with the organic compound.

Full Text

AS ORIGINALLY FILED Process for the reaction of an organic compound with a hydroperoxide The present invention relates to a process for the reaction of an organic compound with a hydroperoxide, during the course of which hydroperoxide is separated off and reacted again with the organic compound. The present invention likewise relates to an apparatus for the reaction of an organic compound with a hydroperoxide. Reactions of organic compounds with hydroperoxides, i.e. with compounds of the formula ROOH, are generally carried out in one step in customary processes of the prior art. In this context, the term "in one step" relates to the hydroperoxide starting material and means that hydroperoxide is added to the respective organic compound only in a single step during the overall process. For example, US-A-5,262,550 describes a process for the epoxidation of alkenes, in which alkene is reacted with hydrogen peroxide or a hydrogen peroxide precursor in one step to give the corresponding alkene oxide. US-A-4,883,260 discloses a process in which alkene is reacted with hydrogen peroxide in one step in a steel autoclave or in a glass autoclave. S.-H. Wang, Process Economics Program, Report 2E, pp. 6-1 to 6-27, SR1International (1994), describes, for example, a process in which an about 17% strength by weight ethylbenzene hydroperoxide solution is reacted with propene in one step over a homogeneous Mo catalyst. A total of 7.2 mol of propene are used per mole of hydroperoxide in this process. The same document discloses, on pages 6-28 to 6-47, a process in which an about 20% strength by weight ethylbenzene hydroperoxide solution is reacted with propene in one step over a heterogeneous TiO/SiCh catalyst, with the alkene being epoxidized. Here, 16.7 mol of propene are used per mole of hydroperoxide. This document likewise discloses, on pages 5-1 to 5-21, a process in which an about 40% strength by weight tert-butyl hydroperoxide solution is reacted with propene in one step over a homogeneous Mo catalyst, with the alkene being epoxidized. Here, 3.7 mol of propene are used per mole of hydroperoxide. The same document discloses, on pages 5-22 to 5-43, a process in which an about 72% strength by weight tert-butyl hydroperoxide solution is reacted with propene over a homogeneous Mo catalyst in two directly successive steps, with the alkene being epoxidized. Here, 1.2 mol of propene are used per mole of hydroperoxide. A disadvantage of these processes is that it is necessary either to employ a relatively high excess of the organic compound to be reacted or to employ a very concentrated hydroperoxide in order to achieve optimal selectivity. It is an object of the present invention to provide a process which allows the excess of organic compound to be reacted to be kept as low as possible and a relatively low-concentration hydroperoxide to be used. We have found that this object is achieved by a process for the reaction of an organic compound with a hydroperoxide, which comprises at least the steps (i) to (iii) below: (i) reaction of the hydroperoxide with the organic compound to give a mixture comprising the reacted organic compound and unreacted hydroperoxide, (ii) separation of the unreacted hydroperoxide from the mixture resulting from step (i), (iii) reaction of the hydroperoxide separated off in step (ii) with the organic compound. Accordingly, the reaction of the organic compound with the hydroperoxide takes place in at least two steps (i) and (iii). In the process of the present invention, it is likewise conceivable for the reaction of the organic compound with the hydroperoxide to take place in more than two steps. Depending on the number of steps in which the reaction takes place, it is of course also conceivable for more than one step in which the hydrogen peroxide used is separated off to be employed in the process of the present invention. An example which may be mentioned is a process in which the reaction of the organic compound with the hydroperoxide takes place in steps (i), (iii) and (v), and the separation of the hydroperoxide takes place in steps (ii) and (iv). In general, from two to five steps in which the organic compound is reacted with the hydroperoxide are employed in the process of the present invention. The present invention therefore also provides a process for the reaction of an organic compound with a hydroperoxide, which comprises the steps (i) to (ix) below: (i) reaction of the hydroperoxide with the organic compound to give a mixture Mi, (ii) separation of the hydroperoxide from the mixture MI resulting from step (i), (iii) reaction of the hydroperoxide separated off in step (ii) with the organic compound to give a mixture Mn, (iv) separation of the hydroperoxide from the mixture MII resulting from step (iii), (v) reaction of the hydroperoxide separated off in step (iv) with the organic compound to give a mixture MIII, (vi) separation of the hydroperoxide from the mixture MIV resulting from step (v), (vii) reaction of the hydroperoxide separated off in step (vi) with the organic compound to give a mixture Miv, (viii) separation of the hydroperoxide from the mixture Miv resulting from step (vii), (ix) reaction of the hydroperoxide separated off in step (viii) with the organic compound. The process of the present invention preferably has from two to four steps in which the organic compound is reacted with hydroperoxide, particularly preferably from two to three steps. The reaction of the organic compound with the hydroperoxide preferably takes place in two steps. The separation of the hydroperoxide in the abovementioned separation steps (ii), (iv), (vi) and (viii) in the process of the present invention can be carried out by all customary methods of the prior art. It is also possible to use different separation methods in different separation steps. The separation of the hydroperoxide in the separation steps is preferably carried out by distillation. Depending on the requirements of the process, separation in one or more distillation columns is possible. Preference is given to using one distillation columns for separating off the hydroperoxide in one separation step. In the process of the present invention, it is conceivable for a dedicated separation apparatus Aj to be provided for each step in which the hydroperoxide is separated off. It is likewise possible, in the case of an appropriate reaction procedure and a plurality of separation steps, for the separations to be carried out in a single separation apparatus. If a plurality of separation steps are provided, it is also possible, by means of a suitable reaction procedure, to carry out two or more separation steps in one separation apparatus. Accordingly, it is quite generally possible for a total of m separation apparatuses to be provided for n separation steps, where 1 £ m s n. Should a further separation of the hydroperoxide be desired subsequent to the last stage in which reaction of the organic compound with the hydroperoxide takes place, for example to recycle any residual hydroperoxide, this is of course likewise possible within the scope of the process of the present invention. In the process of the present invention, not only the hydroperoxide but also the reacted organic compound can be separated off in a separation apparatus from the mixture resulting from a reaction step in which the organic compound is reacted with the hydroperoxide. It is naturally also possible for the remaining reaction product after the hydroperoxide has been separated off to be transferred to a further separation apparatus provided specifically for this purpose and the reacted organic compound to be separated from the reaction product there. In both cases, it is possible, for example, to collect the reacted organic compound in the m separation apparatuses and to separate it off after the reactions of the organic compound with the hydroperoxide are complete. However, the reacted organic compound is preferably separated off in addition to the hydroperoxide in the respective separation apparatus. In the case of separation by distillation, it is possible, for example, to take off the reacted organic compound from the mixture at the top and to separate the hydroperoxide from the mixture at a side offtake. In the process of the present invention, it is naturally likewise possible, when using a distillation unit as separation apparatus, to separate the hydroperoxide from the mixture not at a side offtake but at the bottom. If the hydroperoxide and/or the reacted organic compound are/is separated off in a distillation unit, it is possible, in the process of the present invention, for any high-boiling components of the mixture, which are formed as by-products in the reaction of the organic compound with the hydroperoxide, to be separated off at the bottom. It is also conceivable to lower the temperature at the bottom by, for example, addition of preferably gaseous, low-boiling components, e.g. the organic compound, preferably propene. Examples of such low-boiling components include hydrocarbons having from 1 to 4 carbon atoms, for example methane, ethane, propane, butane, ethene or butenes. It is likewise possible to use, for example, nitrogen or argon. Of course, it is also possible in the process of the present invention to react a plurality of organic compounds with the hydroperoxide. Likewise, it is conceivable for a plurality of hydroperoxides to be used for the reaction. If a plurality of organic compounds and/or a plurality of hydroperoxides are reacted with one another in the respective steps, it is possible for various products resulting from the reactions to be present in the mixtures. If these are again separated off by distillation in the respective separation plurality of distillation columns for the separation. Likewise, the removal of a plurality of hydroperoxides from the mixture by distillation may make a plurality of distillation columns necessary. The reaction of the organic compound with the hydroperoxide in step (i) takes place in a reactor R1which is suitable for this purpose. Starting mateE2als used for the reaction are the organic compound to be reacted, the hydroperoxide and, if necessary, one or more solvents which are appropE2ate and/or necessary in the reaction. Thus, at least the streams E1and E2 flow into the reactor R1in the process of the present invention. If desired, a further stream Ex, for example, can flow into the reactor E2. Here, E1 is the stream compE2sing the compound to be reacted, possibly dissolved in one or more solvents, E1 is the stream compE2sing the hydroperoxide, possibly dissolved in one or more solvents, and E1 is the stream compE2sing one or more solvents. The individual streams E1 are preferably combined to form one stream E1 upstream of the inlet into the reactor R1in the process of the present invention. It is in pE2nciple likewise possible to introduce the individual streams individually into the reactor E2. Furthermore, it is also possible for the individual streams to be combined in appropE2ate combinations before bE1ng introduced into the reactor R*. For example, E1and E1 could be combined upstream of the inlet into the reactor R1and be introduced into the reactor R1into which the stream E2 additionally flows as a separate stream. In the process of the present invention, a stream E[ consisting of the combination of the streams E1, E2 and E2 is preferably introduced into the reactor E2. Here, preference is given to a stream in which the concentrations of the individual components of the stream are selected so that the stream is liquid and consists of a single phase. The hydroperoxide concentrations in E1 are preferably in the range from 0.01 to 10% by wE1ght, particularly preferably in the range from 0.1 to 9% by wE1ght, more particularly preferably in the range from 1 to 8% by wE1ght and in particular in the range from 5 to 7% by wE1ght. The concentration of the organic compound to be reacted is, for example, selected so that the molar ratio of the organic compound to hydroperoxide is in the range from 0.7 to 3.0, preferably in the range from 0.8 to 2.7, more particularly preferably in the range from 0.9 to 2.3 and in particular in the range from 1.0 to 2.0. Depending on the temperature selected for the reaction of the organic compound with the hydroperoxide in the reactor R1, it may be useful in the process of the present invention to preheat the stream or streams pR1or to entry into the reactor R1 The reaction conditions in the reactor R1 in the process of the present invention are selected so that the hydroperoxide conversion is generally in the range from 70 to 95%, preferably in the range from 80 to 94.5% and particularly preferably in the range from 85 to 94%. Furthermore, pressure pi, temperatureT1 and residenceT1me Ati of the reaction M1xture in the reactor R1 are preferably selected so that the M1xture M1 resulting from the reaction is liquid and consists of a single phase. Here, pressures pi which are generally in the range from autogenous pressure to 100 bar, preferably in the range from autogenous pressure to 40 bar and particularly preferably in the range from autogenous pressure to 30 bar, are selected. The temperaturesT1 are generally in the range from 0 to 120°C, preferably in the range from 10 to 100°C, more preferably in the range from 20 to 90°C and particularly preferably in the range from 30 to 80°C. After the reaction in the reactor R[, the resulting M1xture is passed as stream M1 to the separation apparatus A\. There, the hydroperoxide is separated from the M1xture, as descR1bed above. If, in the case of a separation by distillation, unreacted organic compound is also separated off, then the distillation is generally carR1ed out so that at least 50%, preferably at least 60%, more preferably at least 70%, particularly preferably at least 80% and very particularly preferably at least 90%, of the reacted organic compound are separated from M1. The separation is preferably carR1ed out so that a liquid M1xture compR1sing the hydroperoxide is separated off. This M1xture which has been separated off is i herE1nafter designated as M1. It is also possible for the hydroperoxide-containing M1xture which has been separated off to further compR1se, in addition to the hydroperoxide, small amounts of, for example, unreacted organic compound and/or reacted organic compound. Likewise, the M1xture M1 compR1sing the hydroperoxide which has been separated off may further compR1se necessary solvent which has been added via stream E2 or solvent which may have been present in the streams E2and/or E2. If the unreacted organic compound is also separated off in the separation apparatus A1, this separation, from which a liquid M1xture or a liquid/gas M1xture is preferably obtained, results in a stream which is herE1nafter designated as M1. In the process of the present invention, this may compR1se, in addition to the reacted organic compound, the unreacted organic compound and/or small amounts of any necessary solvent which was added via the stream E2 or solvent which may have been present in the streams E2 and/or E1. If, as descR1bed above, the separation is carR1ed out in a distillation unit and high-boiling components are separated off from M1 at the bottom, then this separation results in a stream E2. Such high-boiling components can be, for example, byproducts of the reaction in the reactor R1 which are present in the stream M1. After the steps (i) and (ii) have been carR1ed out in the process of the present invention, the hydroperoxide which has been separated off is once again reacted with the organic compound in step (iii). For example, it is possible to recirculate the stream M2 compR1sing the hydroperoxide to the reactor R1 and to react it there with the organic compound. In the process of the present invention, vaR1ous possible ways of recirculating M1 5 to R1 are concE1vable. Regardless of how the streams E2 to E2 are introduced into the reactor R1, it is possible, for example, for M2 to be introduced as a separate stream into R1 Here, preheating of the stream M1 is possible, as descR1bed above. 10 It is likewise possible, for example, to introduce M1 into the stream E1 before the resulting stream E1 + M2 is introduced into R1 It is likewise possible to M1x M1 into the stream E1 resulting from the combination of E2to E2 or into a suitable stream as descR1bed above resulting from a suitable combination of any two of the 15 streams E2to E2. If a process vaR1ant in which E2 is added to another stream upstream of the inlet into R1 is chosen, then, for the purposes of the process of the present invention, the concentrations of the components of the corresponding streams are preferably set so that the resulting stream remains liquid and continues to consist of a single phase. In a preferred embodiment of the process of the present invention, the stream M2 is introduced into a second reactor Rn. The stream E2 thus represents, in respect of the reactor RII, in a manner analogous to the streams flowing into the reactor R1, the stream EII. Since renewed reaction of the hydroperoxide which has been separated off with the organic compound to be reacted takes place in the reactor RII in step (iii) of the process of the present invention, at least one further stream EII into the reactor RII is necessary. A stream E2, for example, may also be necessary. 30 Here, in a manner analogous to the above-descR1bed streams E2 to E2, E1l is the stream compR1sing the compound to be reacted, possibly dissolved in EII is the stream compR1sing the hydroperoxide, possibly dissolved in one or more solvents, and EIII is the stream compR1sing one or more solvents. Likewise in a manner analogous to the above-descR1bed streamsE1, it is possible for the streams EII to be introduced into the reactor RII E1ther individually or combined in suitable combinations. Preheating of the streams E2 is likewise possible, as descR1bed above. The stream EII is preferably combined with a stream E2 or a stream E2 + E2 and the resulting stream is introduced into RII. The concentrations of the components of the streams EII and EIIare preferably selected so that the stream En flowing into the reactor RII is liquid and consists of a single phase. The concentration of the organic compound to be reacted is selected so that the molar ratio of organic compound to hydroperoxide is preferably in the range from 0.7 to 10.0, more preferably in the range from 0.8 to 8.0, particularly preferably in the range from 0.9 to 6.0 and in particular in the range from 1.0 to 4.0. As in the reactor R1, the reaction in the reactor RII is carR1ed out at a pressure pn, a temperature TII and a residenceT1me ATII of the reaction M1xture such that hydroperoxide conversions which are generally in the range of 90%, preferably in the range of as 92%, more preferably in the range of 95% and particularly preferably in the range from 95 to 99.5%, are achieved. Pressures PII which are selected are generally in the range from autogenous pressure to 100 bar, preferably in the range from autogenous pressure to 40 bar and particularly preferably in the range from autogenous pressure to 30 bar. The temperatures TII are generally in the range from 0 to 120°C, preferably in the range from 10 to 100°C, more preferably in the range from 20 to 90°C and particularly preferably in the range from 30 to 80°C. It is of course also possible in the process of the present invention for the M1xture MII resulting from the reaction in the reactor RII to be taken from the reactor RII and, as descR1bed above, to be ted to a separation apparatus AII or even me separation apparatus Ai and, if desired, for a third reaction to be carR1ed out subsequently. However, two reactors R1 and RII and one separation apparatus A1 are used in a preferred embodiment of the process of the present invention. The present invention accordingly provides a process in which the reactions in steps (i) and (iii) are carR1ed out in two separate reactors. As reactors, it is of course possible to use all concE1vable reactors which are best suited for the respective reactions. In the process of the present invention, a reactor is not restR1cted to a single vessel. Rather, it is also possible to use a cascade of stirred vessels as, for example, reactor R1 or, for example, reactor RII, Preference is given to using fixed-bed reactors as reactors in the process of the present invention. The present invention accordingly provides a process as descR1bed above in which fixed-bed reactors are used as reactors for the reactions. More preferably, fixed-bed tube reactors are used as fixed-bed reactors. In particular, an isothermal fixed-bed reactor is used as reactor R1 in the process of the present invention and an adiabatic fixed-bed reactor is used as reactor RII. The present invention therefore also provides an apparatus compR1sing an isothermal fixed-bed reactor (I), a separation apparatus (II) and an adiabatic fixed-bed reactor (III). The present invention likewise provides for the use of this apparatus for the reaction of an organic compound with a hydroperoxide. Furthermore, the present invention provides for this use in which the steps (i) to (iii) below: (i) reaction of the hydroperoxide with the organic compound to give a M1xture compR1sing the reacted organic compound and unreacted hydroperoxide, (ii) separation of the unreacted hydroperoxide from the M1xture resulting from step (i), (iii) reaction of the hydroperoxide separated off in step (ii) with the organic compound, are carR1ed out for the reaction of the organic compound with the hydroperoxide. As hydroperoxide, all hydroperoxides known from the pR1or art which are suitable for the reaction of the organic compound can be used in the process of the present invention. Examples of such hydroperoxides are tert-butyl hydroperoxide and ethylbenzene hydroperoxide, which are mentioned in the abovementioned SR1 Report 2E "Propylene Oxide". Here, the tert-butyl hydroperoxide is prepared from isobutane and oxygen. The ethylbenzene hydroperoxide is prepared from ethylbenzene and oxygen. In the present process, preference is given to using hydrogen peroxide as hydroperoxide. The present invention therefore also provides a process as descR1bed above in which the hydroperoxide used is hydrogen peroxide. Here, preference is given to using an aqueous hydrogen peroxide solution. To prepare hydrogen peroxide, use can be made of, for example, the anthraquinone process by which virtually the entire world production of hydrogen peroxide is produced. This process is based on the catalytic hydrogenation of an anthraquinone compound to form the corresponding anthrahydroquinone compound, subsequent reaction of this with oxygen to form hydrogen peroxide and subsequent separation of the hydrogen peroxide formed by extraction. The catalysis cycle is closed by renewed hydrogenation of the anthraquinone compound which is obtained back. An overview of the anthraquinone process is given in "UUmann's Encyclopedia of IndustR1al CheM1stry", 5th edition, volume 13, pages 447 to 456. It is likewise concE1vable to obtain hydrogen peroxide by anodic oxidation of sulfuR1c acid to convert it into peroxodisulfuR1c acid with simultaneous evolution of hydrogen at the cathode. Hydrolysis of the peroxodisulfuR1c acid then leads via peroxomonosulfuR1c acid to hydrogen peroxide and sulfuR1c acid, which is thus recovered. It is of course also possible to prepare hydrogen peroxide from the elements. In the individual reactors, it is concE1vable, in the case of an appropR1ate choice of the organic compound, to employ a reaction procedure in which the reaction of the organic compound with the hydroperoxide occurs under the indicated pressure and temperature conditions without addition of catalysts. However, preference is given to a procedure in which one or more suitable catalysts are added to make the reaction more efficient; preference is in tuRII given to using heterogeneous catalysts. The present invention accordingly provides a process as descR1bed above in which the organic compound is brought into contact with a heterogeneous catalyst duR1ng the reaction. It is in pR1nciple possible to use all heterogeneous catalysts which are suitable for the respective reaction. Preference is given to using catalysts which compR1se a porous oxidic mateR1al such as a zeolite. Particular preference is given to using catalysts which compR1se aT1tanium-, vanadium-, chroM1um-, niobium- or zirconium-containing zeolite as porous oxidic mateR1al. Specific examples of suitable zeolites areT1tanium-, vanadium-, chroM1um-, niobium- and zirconium-containing zeolites having a pentasil zeolite structure, in particular the types assigned X-ray-crystallographically to the BEA, MOR, TON, MTW, FER, MFI, MEL, CHA, ER1, RHO, GIS, BOG, NON, EMT, HEU, KFI, FAU, DDR, MTT, RUT, RTH, LTL, MAZ, GME, NES, OFF, SGT, EUO, MFS, MWW or M1xed MFI/MEL structures and also ITQ-4. It is also possible to useT1tanium-containing zeolites having the UTD-1, CIT-1 or CIT-5 structure in the process of the present invention. FurtherT1tanium-containing zeolites which M1ght be mentioned are those having the ZSM-48 or ZSM-12 structure. Particular preference is given to usingT1 zeolites having an MFI, MEL or M1xed MFI/MEL structure in the process of the present invention. Further preference is given, specifically, to theT1-containing zeolite catalysts which are generally designated as "TS-1", "TS-2" and "TS-3", and alsoT1 zeolites having a skeletal structure isomorphous with p-zeolite. Very particular preference is given to using a heterogeneous catalyst compR1sing theT1tanium-containing silicalite TS-1 in the process of the present invention. It is possible to use the porous oxidic mateR1al itself as catalyst in the process of the present invention. However, it is of course also possible to use a shaped body compR1sing the porous oxidic mateR1al as catalyst. To produce the shaped body from the porous oxidic mateR1al, it is possible to use all methods of the pR1or art. Before, duR1ng or after the one or more shaping steps in these methods, noble metals in the form of suitable noble metal components, for example in the form of water-soluble salts, can be applied to the catalyst mateR1al. This method is preferably employed to produce oxidation catalysts based onT1tanium silicates or vanadium silicates having a zeolite structure, making it possible to obtain catalysts which contain from 0.01 to 30% by wE1ght of one or more noble metals selected from the group consisting of ruthenium, rhodium, palladium, osM1um, iR1dium, platinum, rhenium, gold and silver. Such catalysts are descR1bed, for example, in DE-A 196 23 609.6, which, together with the catalysts descR1bed therE1n, is hereby fully incorporated by reference into the present application. Of course, the shaped bodies can undergo a finishing treatment. All methods of comM1nution are concE1vable, for example crushing or breaking the shaped bodies, likewise further cheM1cal treatments, for example as descR1bed above. When using a shaped body or a plurality thereof as catalyst, this can, in the process of the present invention, be regenerated after deactivation by means of a process in which regeneration is carR1ed out by targeted buRIIing-ofF of the deposits responsible for deactivation. This is preferably carR1ed out in an inert gas atmosphere containing precisely defined amounts of oxygen-donating substances. This regeneration process is descR1bed in DE-A 197 23 949.8, which is in this respect fully incorporated by reference into the present application. Among the reactions which are possible in the process of the present invention, the following may be mentioned by way of example: the epoxidation of olefins, e.g. the preparation of propene oxide from propene and H2O2 or from propene and M1xtures which provide H2O2 in situ; hydroxylations such as the hydroxylation of monocyclic, bicyclic or polycyclic aromatics to give monosubstituted, disubstituted or higher-substituted hydroxyaromatics, for example the reaction of phenol and H2O2, or of phenol and M1xtures which provide H2O2 in situ, to form hydroquinone; oxime formation from ketones in the presence of H202, or M1xtures which provide H2O2 in situ, and ammonia (ammonoximation), for example the preparation of cyclohexanone oxime from cyclohexanone; the Baeyer-Villiger oxidation. In the process of the present invention, preference is given to reacting organic compounds which have at least one C-C double bond. The present invention accordingly provides a process as descR1bed above in which the organic compound has at least one C-C double bond-Examples of such organic compounds having at least one C-C double bond are the following alkenes: ethene, propene, 1-butene, 2-butene, isobutene, butadiene, pentene, piperylene, hexenes, hexadienes, heptenes, octenes, diisobutene, tR1methylpentene, nonenes, dodecene, tR1decene, tetradecene to E1cosene, tR1propene and tetrapropene, polybutadienes, polyisobutenes, isoprenes, terpenes, geraniol, linalool, linalyl acetate, methylenecyclopropane, cyclopentene, cyclohexene, norboRIIene, cycloheptene, vinylcyclohexane, vinyloxiran, vinylcyciohexene, styrene, cyclooctene, cyclooctadiene, vinylnorbomene, indene, tetrahydroindene, methylstyrene, dicyclopentadiene, dinvinylbenzene, cyclododecene, cyclododecatR1ene, stilbene, diphenylbutadiene, vitaM1n A, beta-carotene, vinylidene fluoR1de, allyl halides, crotyl chloR1de, methallyl chloR1de, dichlorobutene, allyl alcohol, methallyl alcohol, butenols, butenediols, cyclo-pentenediols, pentenols, octadienols, tR1decenols, unsaturated steroids, ethoxyethene, isoeugenol, anethole, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, malE1c acid, vinylacetic acid, unsaturated fatty acids such as olE1c acid, linolE1c acid, palM1tic acid, naturally occurR1ng fats and oils. lie process of the present invention is preferably carR1ed out using alkenes having rom 2 to 8 carbon atoms. Particular preference is given to reacting ethene, propene nd butene. Very particular preference is given to reacting propene. ^ further advantage of the process of the present invention, apart from the fact that i smaller excess of organic compound to be reacted over hydroperoxide can be ichieved, is that separating off hydroperoxide and reacting it again with the organic compound enables a higher total conversion of the hydroperoxide to be achieved. At the sameT1me, further reactions of the product are reduced. Figure 1 shows a preferred embodiment of the apparatus. In this figure, E1 is a stream compR1sing, for example, liquid propene, aqueous hydrogen peroxide solution and methanol, R1 is an isothermal fixed-bed tube reactor, M1 is a stream resulting from the reaction in reactor R1, Ai is a distillation column for taking off mateR1al at the top, via a side offtake and at the bottom, M1 is a stream which is taken off at the top and compR1ses predoM1nantly propene, propene oxide and methanol, E2 is a stream which is taken off via a side offtake, compR1ses predoM1nantly methanol and aqueous hydrogen peroxide solution and is passed to the reactor RII, M2 is a stream which is taken off at the bottom and compR1ses high-boiling byproducts, for example methoxypropanols and propanetR1ol, from the reaction in reactor R1, M1 is an optional stream introduced into the distillation unit Ai to keep the bottom temperature low, for example gaseous propene, RII is an adiabatic fixed-bed tube reactor, En is a stream which compR1ses liquid propene and methanol and is introduced into the reactor RII, Mn is a stream from reactor RII compR1sing propene, propene oxide and methanol. Figure 2 shows a further preferred embodiment of the apparatus. In this figure, E1 is a stream compR1sing, for example, liquid propene, aqueous hydrogen peroxide solution and methanol, R1 is an isothermal fixed-bed tube reactor, M1 is a stream resulting from the reaction in reactor R1, AI is a distillation column from which mateR1al can be taken off at the top and at the bottom, M1 is a stream which is taken off at the top and compR1ses predoM1nantly propene, propene oxide and methanol, M2 is a stream which is taken off at the bottom, compR1ses predoM1nantly hydrogen peroxide, water, methanol and high-boiling by-products and is passed to the reactor R1I, R1I is an adiabatic fixed-bed tube reactor, E1I is a stream which compR1ses liquid propene and methanol and is introduced into the reactor RII, M1I is a stream from reactor R1I compR1sing propene, propene oxide and methanol. Examples Example 1: Two-stage procedure with intermediate separation Flows of 10.5 g/h of hydrogen peroxide (about 40% strength by wE1ght), 58 g/h of methanol and 10 g/h of propene are passed through a first tube reactor which has a reaction volume of about 50 ml and is charged with 23.1 g of TS-1 extrudates at a reaction temperature of 40°C and a reaction pressure of 20 bar. To analyze the output from the tube reactor, the reaction M1xture was depressuR1zed into a Sambay vapoR1zer against atmospheR1c pressure. The low boilers which were separated off were analyzed on-line in a gas chromatograph. The liquid reaction product was collected, wE1ghed and likewise analyzed by gas chromatography. The hydrogen peroxide yield achieved was 85%. The propene oxide selectivity based on hydrogen peroxide was 95%. The output from the first reactor, which compR1sed methanol, water, propene oxide, by-products, unreacted propene and hydrogen peroxide, was depressuR1zed into a column. The column was operated at atmospheR1c pressure and had about 15 theoretical plates. At a bottom temperature of about 69°C, the propene oxide was separated off from the M1xture to a level of The lower-boiling propene and some methanol together with propene oxide went over at the top. The runback necessary for the separation in the column was condensed at 50°C in a partial condenser at the top. The top product was taken off in gaseous form and passed to work-up. The bottom product was fed to a second tube reactor. The bottom product from the intermediate separation and a propene stream of about 9 g/h were passed through a second tube reactor which had a reaction volume of about 50 ml and was charged with 28 g of TS-1 extrudates at a reaction temperature of 40°C and a reaction pressure of 20 bar. After leaving the reactor, the reaction M1xture was depressuR1zed into a Sambay vapoR1zer against atmospheR1c pressure. The low boilers which were separated off were analyzed on-line in a gas chromatography The liquid reaction product was collected, wE1ghed and likewise analyzed by gas chromatography. The hydrogen peroxide conversion achieved was 96%. The propene oxide selectivity based on hydrogen peroxide was 96%. The overall hydrogen peroxide conversion was 99.4% and the overall propene oxide selectivity was 95-96%. This gave a propene oxide yield based on hydrogen peroxide of 94-95%. Example 2: Single-stage procedure without intermediate separation Flows of 8.3 g/h of hydrogen peroxide (about 40% strength by wE1ght), 49 g/h of methanol and 7.8 g/h of propene were passed through a tube reactor which had a reaction volume of about 50 ml and was charged with 20 g of TS-1 extrudates at a reaction temperature of 40°C and a reaction pressure of 20 bar. After leaving the reactor, the reaction M1xture was depressuR1zed into a Sambay i vapoR1zer against atmospheR1c pressure. The low boilers which were separated off were analyzed on-line in a gas chromatograph. The liquid reaction product was collected, wE1ghed and likewise analyzed by gas chromatography. The hydrogen peroxide conversion achieved was 98.4%. The propene oxide selectivity based on hydrogen peroxide was 80.3%. The propene oxide yield based on hydrogen peroxide was 79%. We claim: 1. A process for the reaction of an organic compound with a hydroperoxide, which -comprises at least the steps (i) to (iii) below: (i) reaction of the hydroperoxide with the organic compound to give a mixture comprising the reacted organic compound and unreacted hydroperoxide, (ii) separation of the unreacted hydroperoxide from the mixture resulting from step (i) (iii) reaction of the hydroperoxide separated off in step (ii) with the organic compound, wherein the hydroperoxide used is hydrogen peroxide, the organic compound is an olefin, the organic compound is brought into contact with a heterogeneous catalyst during the reaction, the heterogeneous catalyst comprises a titanium-containing silicalite, the reactions in steps (i) and (iii) are carried out in two separate fixed-bed reactors and the unreacted hydroperoxide in step (ii) is separated by distillation. 2. An apparatus for carrying out the process as claimed in claim 1, comprising an isothermal fixed-bed reactor (I), a separation apparatus (II) and an adiabatic fixed-bed reactor (III), wherein the separation apparatus comprises one or more distillation columns.

Documents:

in-pct-2001-173-che-abstract.pdf

in-pct-2001-173-che-claims duplicate.pdf

in-pct-2001-173-che-claims original.pdf

in-pct-2001-173-che-correspondence others.pdf

in-pct-2001-173-che-correspondence po.pdf

in-pct-2001-173-che-description complete duplicate.pdf

in-pct-2001-173-che-description complete original.pdf

in-pct-2001-173-che-drawings.pdf

in-pct-2001-173-che-form 1.pdf

in-pct-2001-173-che-form 19.pdf

in-pct-2001-173-che-form 26.pdf

in-pct-2001-173-che-form 3.pdf

in-pct-2001-173-che-form 5.pdf

in-pct-2001-173-che-pct.pdf