The way epoxidation with2- c4olefins

 

(57) Abstract:

Describes how epoxidation C2-C4Olenev, including (a) the reaction of the secondary alcohol C3-C4and molecular oxygen in the liquid phase with the formation of the oxidation mixture consisting of secondary alcohol C3-C4, ketone C1-C4corresponding secondary alcohol C3-C4, and hydrogen peroxide; (b) the allocation of almost all of the ketone C1-C4from the oxidation mixture, and obtaining a stream containing concentrated hydrogen peroxide, comprising a secondary alcohol C3-C4hydrogen peroxide and less than 1 wt.% ketone C3-C4; (C) the reaction stream containing concentrated hydrogen peroxide, with the olefin C2-C4in the presence of a catalyst of titanium silicate. The method differs in that in stage (C) a stream containing concentrated hydrogen peroxide interacts with the olefin C2-C4in the presence of a diluent comprising methanol, with the formation of the epoxidation reaction mixture, containing epoxide C2-C4corresponding to the olefin C2-C4water, methanol and secondary alcohol C3-C4; and further the Oia with the formation of the first stream of the crude alcohol, combine water, secondary alcohol C3-C4, methanol and less than 1 weight. % epoxide C2-C4; (e) the allocation of almost all of the methanol from the first stream of the crude alcohol with the formation of the second stream of the crude alcohol containing water, a secondary alcohol C3-C4and less than 1 wt.% methanol; and (f) recycling at least part of the methanol, isolated on stage (e), for use as at least part of the diluent at the stage (C). Technical result - increase the selectivity of the process. 17 C.p. f-crystals, 1 tab., 1 Il.

The invention concerns a complete technological process of production of epoxides. In particular, this invention relates to a method of epoxidation on the titanium-silicate catalysts, in which the methanol emitted from the reaction mixture formed during epoxydecane, used to dilute the concentrated flow of oxidant used as a source of hydrogen peroxide on stage epoxidation.

To obtain epoxides we developed many different ways. One such method involves the use of silicalite titanium as catalysts for the oxidation of olefins by hydrogen peroxide. This method on the oxide. A mixture of isopropanol with water reacted with oxygen at 135oC, forming a mixture containing hydrogen peroxide. This mixture was then used directly for the epoxidation of propylene in the presence of a titanium-silicate catalyst without intermediate processing or fractionation.

In U.S. patent N 5384418 described the process of obtaining epoxides, which when epoxydecane in the presence of a catalyst - silicalite titanium used hydrogen peroxide produced by the oxidation of isopropanol; but it is argued that the process favored the destruction of almost all of the acetone from the oxidant on the basis of isopropanol prior to use. In the patent, in addition, it is proposed that the isopropanol, the resulting hydrogenation remove acetone, was used for dilution of the oxidant derived from isopropanol to achieve the desired concentration of H2O2in the oxidation mixture fed to the reactor for epoxidation. Under certain conditions it is desirable when epoxydecane to maintain a relatively low i.e., 1-10 wt.%/ the concentration of hydrogen peroxide, since higher concentrations may reduce the selectivity Otara may be present in the form of an azeotrope with isopropanol/.

The authors now discovered that the use of the recirculation stream containing methanol to dilute the hydrogen peroxide supplied to the reaction zone epoxidation, gives you the advantage during the process. The selectivity with respect to epoxides is improved, because, as you can assume, and the dilution effect of the flow, and also the presence in the specified thread exactly methanol, and other solvents that could theoretically be used as diluents. That is, a higher selectivity to epoxide is realized in the case when the diluent is methanol, instead of isopropanol, for example. Moreover, it was found that the operating costs for such a process with the addition of co-solvent are lower than you could expect as isopropanol and methanol can be easily separated from each other after epoxidation and recycling them separately for use at different stages of the continuous process.

This invention relates to a method of epoxidation, which includes:

/a/ reaction of the secondary alcohol C3-C4and molecular oxygen in the liquid phase with formation of oxidative compounds is B>3-C4and hydrogen peroxide;

/b/ Department of practically the entire quantity of the ketone C3-C4from the oxidation mixture, to obtain a stream containing concentrated hydrogen peroxide, which includes a secondary alcohol C3-C4hydrogen peroxide and less than 1 wt.% ketone C3-C4;

/c/ reaction stream containing concentrated hydrogen peroxide, with the olefin C2-C4in the presence of a catalyst - silicalite titanium, and diluent, representing methanol, with the formation of the epoxidation reaction mixture, consisting of epoxide C2-C4corresponding to the olefin C2-C4water, methanol and secondary alcohol C3-C4;

/d/ detect almost all of the epoxide C2-C4from the epoxidation reaction mixture with the formation of the first stream of the crude alcohol consisting of water, a secondary alcohol C3-C4, methanol and less than 1 wt.% epoxide C2-C4;

/e/ selection of almost all of the methanol from the first stream of the crude alcohol with the formation of the second stream of the crude alcohol consisting of water, a secondary alcohol3-C4and less than 1 wt.% methanol; and

/f/ recirculate diluent at the stage of /c/.

The drawing shows in schematic form suitable for use variant implementation of the method proposed in this invention.

Secondary alcohols suitable for use in the present invention include isopropanol /isopropyl alcohol/ and Deut. butanol /Deut.butyl alcohol/.

Secondary alcohol reacts with molecular oxygen /O2/ from a suitable source of oxygen, such as air, with the formation of the oxidation mixture, which typically contains unreacted excess of the secondary alcohol, ketone C3- C4resulting from oxidation of the secondary alcohol and have the same hydrocarbon skeleton, such as alcohol /for example, acetone or 2-butanone, peroxide and water. The original substance is subjected to oxidation, may contain in addition to alcohol small amounts of ketone and/or water. For example, you can successfully use the azeotropic mixture of water and isopropanol /87,8% wt. isopropanol and 12.2 wt.% water/. In one embodiment of the invention the oxidizing mixture contains 5 to 20 wt.% water, 80-95 weight. % isopropanol, less weight.% methanol and less than 3 wt.% of acetone. Generally speaking, the oxidation conditions are selected so that poles.% ketone and from 0 to 35 wt.% water. Is a partial transformation of /for example, from 5 to 50%/ secondary alcohol, so that unreacted secondary alcohol can be used as a carrier or solvent for hydrogen peroxide in the subsequent stages of the process. The residence time in the reactor, retention time or reaction time from 0.25 hours to 4 hours is usually sufficient for this purpose. The oxidation can be either non-catalytic or catalytic /for example, catalysis by adding a small amount of peroxide or hydroperoxide such as tert-butylperoxide/. Typically the oxidation is expediently carried out at temperatures from 50 to 200oC more preferably from 100 to 180oC/ to achieve an acceptable oxidation rates. The preferred range of partial pressure of oxygen in the incoming gas /which may contain in addition to the oxygen inert dilution gas, such as nitrogen/ ranges from 7 to 1724 kPa /1-250 pounds/square inch/, more preferably of 34.5-345 kPa /5-50 psi/, most preferably 69-207 kPa /10-30 pounds/square inch/. The total pressure in the reaction zone of oxidation should be sufficient that the components of the reaction mixture remained in the liquid phase, usually enough pressure from 345 to 6895 kPa /50-1000 pounds/square d is rivate different temperatures. Oxidation of the alcohol can be a continuous process using, for example, the flow reactor with agitator /CSTP/.

Before using on stage epoxidation of the process of the oxidation mixture is allocated or removed ketone. You can use any known method of separation, which is suitable for this purpose, including methods of fractionation.

However, it is preferable to expose the oxidizing mixture fractional distillation, in which the ketone is evaporated and removed from the oxidation mixture in the form of the head of the faction. A stream containing concentrated hydrogen peroxide, the resulting process can be kubovy balance. Such fractionation can be facilitated by the application of heat or vacuum or below atmospheric/ pressure. The concentration of ketone in the thus obtained stream containing concentrated hydrogen peroxide, should be less than 1 wt.%/ preferably less than 0.5 wt.%/. In order to minimize the formation of any ketone adducts with hydrogen peroxide, peroxides, this separation is more preferable to carry out directly after oxidation by molecular oxygen. Therefore, oxidative Ia or keeping. To promote rapid and complete removal of the ketone from the oxidation mixture, it is desirable to select from the top of the column some of the secondary alcohol and/or water. For example, in one of the embodiments of the invention the stream taken from the top of the column can contain from 10 to 80 mol.% ketone, 15 to 60 mol.% secondary alcohol and 5-30 mol.% water. However, for security reasons, you should be careful not to create too high a concentration of hydrogen peroxide as residue and that do not contain appreciable quantities of hydrogen peroxide in the stream leaving from the top of the column. The residence time in the column under distillation is also an important factor. The residence time must be sufficient to basically happened the collapse of any products of the reaction between the ketone and hydrogen peroxide formed during or after oxidation by molecular oxygen to the concentration of peroxides of aliphatic ketones decreased to values less than 0.5 wt.% of the total number of products, however, you should avoid excessive time stay to prevent the decomposition of hydrogen peroxide. In one of the preferred embodiments of the invention the residence time SOS the/SUP>C/. Under these conditions it was found that the desired removal of the ketone and conversion of all present in the mixture of ketone peroxides can be easily achieved with minimal loss <2%/ hydrogen peroxide in the oxidation mixture. The best results can be obtained by careful passivation distillation columns and/or treatment of oxidative mixture in such a way as to remove or neutralize any active centers, which can catalyze the decomposition of hydrogen peroxide or the formation of ketone peroxides. Method of extractive distillation can also be used. You can also use other methods of separation, capable of reducing the content of the ketone in the oxidation mixture without significant loss of the contained hydrogen peroxide. These methods include, for example, absorption, countercurrent extraction, membrane separation, etc., Especially suitable are multistage fractionation methods.

Due to the removal of the ketone from the oxidation mixture, the concentration of hydrogen peroxide increases. Therefore, the stream containing concentrated hydrogen peroxide, typically contains from 5 to 30 wt.% H2O2. In one of the embodiments of the invention the specified item is this invention, a stream containing concentrated hydrogen peroxide comes into contact with the olefin C2-C4and with a catalytically effective amount of titanium silicate at a temperature of 25oC to 120oC more preferably from 40oC to 80oC/, resulting in the substrate is converted to the desired epoxide. In the mixture is present in the diluent, and at least part of the specified diluent is methanol, isolated from the epoxidation reaction mixture. The remainder of the diluent, if present, can be a fresh methanol, secondary alcohol obtained by hydrogenation of the ketone to be removed from the oxidation mixture, or fresh secondary alcohol or another solvent. Preferably the diluent consists mainly of methanol /for example 70% methanol/, mainly from the return of methanol, with fresh methanol is added only in such quantity that it is necessary to compensate for process losses associated with the release of methanol. The amount of diluent should preferably be sufficient to achieve concentrations of methanol from 5 to 60 wt.% in the epoxidation reaction mixture, except the number of the Pris is h, isobutylene, 2-butene, etc., optionally epoxidizing mixture of olefins.

The amount of olefin relative to the quantity of hydrogen peroxide is not critical, but a suitable molar ratio of olefin:hydrogen peroxide may lie in the range from 100:1 to 1:10. More preferably the molar ratio of olefin to hydrogen peroxide in the range from 1:2 to 10:1 most preferably from 1:1 to 6:1/. In one variation of the process described in this invention, the mixture fed to the reactor for epoxidation /excluding epoksidirovaniya olefin/ contains 1-10 wt.% peroxide of hydrogen, 5 to 40 wt.% methanol, 30 to 85 wt.% secondary alcohol and 1-25 wt.% water.

Silicalite titanium, is used as a catalyst under epoxidation, are a class of zeolites, in which the titanium replaces some of the silicon atoms in the crystal lattice, which is the framework of the molecular sieve. Such substances are well known in the art. Especially preferred silicalite titanium classes of molecular sieves, usually denoted by "TS-1" /with topology MF1 similar topology aluminosilicate zeolites ZSM-5/, "TS -2" /having an MEL topology analogous to the topology aluminosilicate is readie molecular sieves, with the structure of the skeleton is isomorphic to beta zeolites. Silicalite titanium preferably do not contain any non-oxygen atoms in addition to titanium and silicon in the crystalline framework, although there may be minor amounts of boron, iron, aluminum, gallium, etc.

The epoxidation catalysts suitable for use in the process described in this invention have a composition corresponding to the following formula x TiO2: /1-x/SiO2where the value of x is in the range from 0.0001 to 0.500. The preferred value of x between 0.01 and 0.125. The molar ratio of Si:Ti in the crystal frame silicalite titanium preferably should be equal to from 9.5:1 to 99:1 (most preferably from 9.5:1 to 60:1/. It may be desirable use of silicalite, relatively rich in titanium.

The amount used of the catalyst is not critical, but it should be sufficient for the epoxidation reaction took place over a relatively short from a practical point of view, the period of time. The optimum amount of catalyst will depend on a number of factors, including the reaction temperature, the reactivity and concentration of the olefin, hydrogen peroxide concentration, type and concentration of the body is.E. periodic or continuous/, but usually with periodic epoxydecane amount of catalyst is from 0.001 to 10 g/mol of olefin. In a reactor with a fixed catalyst bed, the optimum amount of catalyst will depend on the speed of flow of the reactants through the fixed layer /is usually from 1 to 100 moles 2O2per kilogram of catalyst per hour/.

The catalyst may be used in the form of powder, granules, microspheres, extruded, cast or any other appropriate physical form. It might be useful to use a binder or carrier in combination with silicalite titanium. The catalysts on a carrier or binder can be obtained by known methods, which are generally effective for zeolite catalysts. Preferably, binder or carrier which is substantially free of acid groups and not catalyzed selective decomposition of hydrogen peroxide or disclosure of epoxy rings.

The catalyst may be treated with an alkaline substance /the reason/ or silylium agent to reduce surface acidity, as described in U.S. patent N 4937216.

The temperature of the epoxidation reaction is preferably napodano for this process, enough to perform selective conversion of the olefin to the epoxide acceptable for a short period of time with minimal non-selective decomposition of hydrogen peroxide. In General, it is advisable to carry out the reaction until the highest possible conversion of hydrogen peroxide, preferably at least 50%, more preferably 90% and most preferably 99% to be achieved and a high selectivity. The optimum reaction temperature will depend on the concentration and activity of the catalyst, the reactivity of the substrate, concentration of reagents and the type of solvent along with other factors. The reaction time or residence time in the reactor should normally be from 10 min to 48 h depending on the above parameters. The reaction is preferably carried out at atmospheric pressure or at elevated pressure is usually from 1 to 100 at/. In General, it is desirable that the components of the reaction was in the form of a liquid mixture. For example, when using the olefin, such as propylene, having a boiling point at atmospheric pressure lower than the temperature of the epoxidation, you must create a pressure higher than atmospheric and sufficient to maintain the desired end is to oderjivat excess pressure of approximately 1310 kPa to 1517 kPa /190-220 lbs/sq. inch/.

Phase epoxidation described in this invention, it is possible to conduct periodic, continuous or semi-continuous manner using any suitable type of reaction vessel or apparatus, such as a reactor with a fixed catalyst bed reactor, moving bed, slurry reactor with mixing or flow-through reactor with a stirrer. You can also use known methods for epoxidation reactions catalyzed by metals, using hydrogen peroxide. So the reagents can be downloaded all at once or sequentially. For example, hydrogen peroxide, diluent and/or olefin you can add parts or at different points of the reaction zone. However, it is usually advisable to control the addition of various components so that the concentration of unreacted hydrogen peroxide does not exceed 10 wt.% at any point in the reaction zone.

After the selection to the epoxidation reaction mixture by any suitable method, such as filtration /for example, when using a slurry reactor/ allocated catalyst /silicalite titanium/ can be cost-effectively reused for subsequent epoxidation. Where the catalyst once the I, contains almost no catalyst, and the catalyst remains in the epoxidation zone. In some embodiments, the implementation of this process, in which the epoxide receive a continuous way, it may be desirable to periodically or continuously to regenerate all or part of the used catalyst in order to maintain its optimum activity and selectivity. Suitable methods of regeneration are well known and include, for example, annealing and processing solvent.

When the olefin and hydrogen peroxide reacted to the desired degree of conversion, the reaction mixture epoxidation consisting of water, methanol, epoxide C2-C4and secondary alcohol C3-C4, further processed, separating from a mixture of almost all of the epoxide and receiving the first stream of the crude alcohol consisting of water, methanol, secondary alcohol C3-C4and less than 1 weight. % epoxide C2-C4. The first stream of the crude alcohol is processed to obtain a second stream of the crude alcohol by removal of almost all of the methanol with the aid of a suitable method of separation. This separation is most easily accomplished by the methods of distillation /for example, practise, than the boiling point of the resulting epoxide and methanol used as solvent, and therefore it remains as residue. Methanol evaporates and is collected from the top of the column. Since the olefin is usually boil lower than epoxide, a secondary alcohol and methanol, any unreacted olefin in the reaction mixture epoxidation can also be easily removed by distillation. In some embodiments of the invention, the excess olefin may be removed together with the epoxide by flash distillation /single equilibrium distillation/. Then, to separate the olefin from epoxide, using fractional distillation or condensation. In other embodiments of the invention from the reaction mixture epoxidation first removed the olefin, and then the epoxide.

It is important to remove the main number /example >95%, more preferably >99%/ methanol from the first stream of the crude alcohol as methanol, which is carried away together with the secondary alcohol, will turn into formic acid oxidation by molecular oxygen of the secondary alcohol contained in the first stream of the crude alcohol. Usually it is desirable to minimize the formation of acid during the oxidation of Vtorov, when the oxidizing mixture is used as a source of hydrogen peroxide in the reaction of epoxidation.

Under certain conditions during the epoxidation, the formation of minor amounts of by-product-type ketone as a result of oxidation of the secondary alcohol catalyzed by titanium silicate. In cases where this byproduct is the acetone, it can be removed from the first stream of the crude alcohol, if desired, by fractional distillation, etc., before allocating from a mixture of methanol. If the byproduct is a 2-butanone, it can similarly be removed after separation of methanol from the second stream of the crude alcohol. Remote thus a by - product ketone can be converted by hydrogenation back to the secondary alcohol with the purpose of reuse.

The methanol obtained from the first stream of the crude alcohol, then recycle, at least partially, with the aim of its use as a diluent /or at least part of the diluent/ under epoxidation. An important advantage of the process described in this invention is that there is no need for additional about the ü satisfactory results. By fractional distillation is easily achieved almost complete separation of methanol from other components of the specified stream.

The second stream of the crude alcohol can be recycled for use as a source of secondary alcohol at the stage of oxidation. Preferably, the second stream of the crude alcohol is first subjected to further separation by methods such as fractional distillation, so that part of the water corresponding to the water, which was formed from the hydrogen peroxide during the epoxidation, is removed in the form of VAT residue, and purified secondary alcohol /usually in the form of an azeotrope with water is withdrawn from the top of the column.

On stage hydrogenation of a ketone selected from the oxidation mixture is converted back to the corresponding secondary alcohol by reaction with hydrogen in the presence of a hydrogenation catalyst based on transition metals. Methods of transformation of aliphatic ketones, such as acetone and 2-butanone, in the appropriate secondary aliphatic alcohols by catalytic hydrogenation using a catalyst based on transition metals is well known.

The transition metal in the catalyst hydrogenation is no water is present, particularly beneficial use of Renee or Nickel promoted molybdenum. The hydrogenation can be conducted or in the liquid or in the vapor phase.

Temperature, pressure and hydrogen concentration of the catalyst during hydrogenation are chosen in such a way as to carry out mainly /i.e., at least 80% and more preferably at least 95% conversion of the ketone to the secondary alcohol for almost acceptable relatively short reaction time /i.e., from about 15 min to 12 h/ without a greater recovery of the ketone. The optimal conditions of hydrogenation may vary depending on the type of catalyst and the reactivity of the ketone, but they can be easily identified by professionals in this area by conducting a minimum of the experiment, based on known experimental data related to the hydrogenation of ketones. Commonly used temperature of 20oC to 175oC and hydrogen pressure of from 0.05 to 10 MPa /0.5 to 100 at/. Preferably the molar ratio of H2the ketone is in the range from 1:1 to 4:1. The amount of catalyst preferably should be such that average hourly volume-mass feed rate of the ketone was methodological, continuous or semi-continuous manner using any suitable reaction vessel or apparatus in which the flow coming from the top of the distillation column, can be contacted with the hydrogenation catalyst based on a transition metal and hydrogen. Because the catalyst is usually heterogeneous, it is particularly convenient to use a reactor with a fixed catalyst bed or slurry reactors. You can also use the system with jet stream of liquid through the catalyst bed.

The drawing illustrates a variation of the process of epoxidation proposed in this invention, in which propylene catalytically epoxidised with the formation of propylene oxide. Stream consisting of a secondary alcohol, is supplied via line 1 into the zone of oxidation of the alcohol 2, where the secondary alcohol partially reacts with molecular oxygen, forming an oxidation mixture consisting of hydrogen peroxide, ketone and unreacted secondary alcohol. The source of molecular oxygen is air, pure or diluted O2supplied through line 3.

The oxidation mixture containing hydrogen peroxide, a ketone and a secondary alcohol, p is th distillation. The ketone is selected from the upper part of the column /in some cases together with a part of the secondary alcohol/ and is fed into the hydrogenation zone 6 through line 7. VAT residue /i.e., the stream containing concentrated hydrogen peroxide/, which contains hydrogen peroxide and a secondary alcohol, is supplied via line 8 to epoxidation.

Olefin, which should be epoxydecane, is fed to the epoxidation 11 on lines 9 and 10. In a specific embodiment of the invention shown in the drawing, lines 8 and 21 can also feed in line 10 in points, separated from the line 9. However, there are many other ways of introducing different threads in the epoxidation zone 11. For example, the flows on the lines 8 and 21, can be United in a common line before entering the line 10. Alternatively, olefin, recirculating methanol /diluent/ and a stream containing concentrated hydrogen peroxide, can also be entered directly in the epoxidation zone 11. Thus, the exact method by which the various components of the reaction are introduced into the epoxidation zone is not critical, provided that the total effect is the dilution of the stream containing koncentrira what I'm in the zone 11 in the form of a fixed layer, although the configuration of the slurry reactor can also be used. Olefin, a stream containing concentrated hydrogen peroxide, and the diluent is maintained at the desired reaction temperature in contact with silicalite titanium in the zone 11 in a period of time sufficient to convert at least part of the olefins into the corresponding epoxide C3-C4while most or all of the hydrogen peroxide is consumed in the reaction, and water is formed. Thus obtained reaction mixture epoxidation is supplied via line 12 into the area of separation of olefin 13, where unreacted olefin is identified by appropriate methods, such as distillation and recycle in the call epoxidation 11 on lines 14 and 10. Remaining after the separation of the olefin, the reaction mixture epoxidation flows through line 15 to the cleaning zone epoxide 16, where the propylene oxide is identified by appropriate methods, such as distillation and removed through line 17. In the selection of resin and unreacted olefin from the epoxidation reaction mixture is formed with the first stream of the crude alcohol containing isopropanol, methanol and more high-boiling substances such as water, acids, glycols, etc., but contains very mA is Yes 16 through line 18 and is fed to the purification of the crude alcohol 19. In zone 19 methanol is separated from the first stream of the crude alcohol using appropriate methods, such as distillation. Dedicated methanol /which may, for example, be selected during the distillation of the upper part of the column in the form of boiling fraction/ is returned as a diluent in the epoxidation zone 11 through lines 20 and 21. Fresh methanol, if necessary, can be added to the recirculating methanol through line 22.

The second stream of the crude alcohol, which is formed by the removal of methanol from the first stream of the crude alcohol in area 19, is supplied via line 23 to the cleaning zone of the secondary alcohol 24. In the cleaning zone of the secondary alcohol 24 the cleaning process is so that the purified secondary alcohol /or in some embodiments the invention, the azeotrope of the secondary alcohol with water is withdrawn from the upper part of the column and an aqueous stream containing at least a portion of the water is formed from hydrogen peroxide during epoxidation, and more magelonidae by-products of the epoxidation /acids, glycols/ forms VAT residue and removed through line 25. Purified secondary alcohol is returned to the zone of oxidation of the alcohol 2, lines 28 and 1. Fresh secondary alcohol can be served PI 7 in the hydrogenation zone 6, where this stream is reacted with hydrogen /coming on line 26 of/ in the presence of a suitable hydrogenation catalyst, such as applied on the basis of ruthenium or promoted molybdenum Nickel of Renea /preferably placed as a fixed layer in zone 6/, so as to transform at least part, and preferably mainly all /for example, over 95%/ back ketone to the secondary alcohol. The hydrogenation product stream which is removed from zone 6 through line 27 can, if necessary, be subjected to additional cleaning /for example, in the area of cleaning alcohol 24 or an alternative can be fed directly back into the zone of oxidation of the alcohol 2.

From this description specialists in this field can easily identify the main characteristics of this invention and, without departing from the substance of the invention and without going beyond the scope of the invention, can make various changes and modifications of the invention to adapt it to various applications, conditions and options for implementation.

The separation of isopropanol and methanol

In distillation column containing 50 theoretical plates (including reboiler), 5-th plate from the top downloaded raw prodbase propylene. Coming in a column of the product formed by reacting propylene with an oxidizing mixture of hydrogen peroxide and isopropanol and diluted with methanol, and contains the following main components:

Component - Say. %

Water - 33,1

Isopropanol - 42,8

Methanol - 23,5

Impurities which are present in small quantities - balance

The distillation column operates at a molar ratio of irrigation of 0.64. The pressure in the condenser of the column 40 f/inch2(2,812 kg/cm2), the pressure at the bottom of column 50 f/inch2(3,515 kg/cm2) (i.e., the decrease of pressure of 0.2 f/inch2(0,014 kg/cm2) on a plate). The temperature in the lower part of the column (reboiler) 116oC; the temperature of the upper part of the column (condenser) 104oC.

In such conditions, approximately 98% of methanol from entering the column flow out from the top of a shoulder strap.

Thus obtained distillate is suitable for recirculatory as a diluent to the stage epoxidation, while the residue from the distillation in the lower part of the column (after removing the desired amount of water) is used for recirculatory on the stage of oxidation of isopropanol to education oxidative sa this oxidation mixture used in stage epoxidation method according to the invention.

Example 1 (invention) - Epoxidation of propylene using diluted with methanol flow of hydrogen peroxide

The product obtained by (a) the interaction of isopropanol and molecular oxygen in the liquid phase with the formation of the oxidation mixture consisting of isopropanol, acetone and hydrogen peroxide, (b) the allocation of essentially all of the acetone from the oxidation mixture with the production of concentrated hydrogen peroxide stream consisting of isopropanol and hydrogen peroxide, and (C) dilution of the concentrated hydrogen peroxide stream with methanol, simulated by mixing the following substances: methanol (100 g), isopropanol (66 g), 50% aqueous hydrogen peroxide (34 g), acetic acid (0,60 g) and formic acid (0.20 g). Described above is diluted with methanol flow of hydrogen peroxide contained 7.7 wt.% hydrogen peroxide, a specific method iodometric titration.

In the Parr reactor of stainless steel, equipped with a stirrer, was loaded diluted with methanol hydrogen peroxide (33 g; 0,044 mol. H2O2), the catalyst TS-1 (silicalite titanium) (0,37 g) and sodium acetate (3.0 g). The Parr reactor was tightly closed with a lid equipped with a thermocouple, pressure gauge, kletecka and the Parr reactor was immersed in an oil bath with a temperature of 60oC. After one hour, the Parr reactor was removed from the oil bath and immersed in an ice bath. When the internal temperature in the reactor reached 20oC, the reactor was released gas into the gas bag. The contents of the bag were analyzed on the content of the propylene oxide, acetone and oxygen. The liquid in the reactor was subjected to iodometric titration and analyzed by gas chromatography for the presence of oxidized products.

The following results were obtained:

The conversion of hydrogen peroxide, % - 99

The selectivity of*, %:

Propylene oxide - 92

Glycols - 6

Acetone - 1

Oxygen - 1

*in the calculation of the H2O2.

This example demonstrates excellent conversion and epoxide selectivity obtained using the claimed invention in the above applications.

Example 2 (invention) - Epoxidation of propylene using diluted with methanol flow of hydrogen peroxide

The flow of diluted methanol product of hydrogen peroxide containing 9.9 wt.% hydrogen peroxide is obtained in accordance with the method of Example 1, and the product has the following composition:

Methanol - 40 g

Isopropanol - 40g

50% aqueous pane, described in Example 1 was repeated using the following reagents:

Diluted with methanol stream H2O2- 33 (0,056 mol H2O2)

The catalyst TS-1, silicalite titanium - 0.75 g

Sodium acetate - 3.2 mg

Propylene - 20 ml (0.25 mol)

The following results were obtained:

The conversion of hydrogen peroxide, % - 96

The selectivity of*, %:

Propylene oxide - 89

Glycols - 7

Acetone - 2

Oxygen - 2

*in the calculation of the H2O2.

This example also demonstrates that the claimed invention in its application, as described above, is capable of fast conversion of hydrogen peroxide at the same time with high selectivity for propylene oxide.

Example 3 (comparative) - Epoxidation of propylene using undiluted stream of hydrogen peroxide

The product obtained by (a) the interaction of isopropanol and molecular oxygen in the liquid phase with the formation of the oxidation mixture consisting of isopropanol, acetone and hydrogen peroxide, and (b) the allocation of essentially all of the acetone from the oxidation mixture with the provision of concentrated hydrogen peroxide stream containing 17,1% wt. H2Ossnoi acid (0,30 g) and formic acid (0.10 g).

Repeated the epoxidation procedure of Example 1 using the following reagents:

A stream of concentrated hydrogen peroxide product - 33 g (0,097 mol H2O2)

The catalyst TS-1, silicalite titanium - 1.45 g

Sodium acetate - 3.2 mg

Propylene - 25 ml (0.31 mol)

Observed phase separation.

The following results were obtained:

The conversion of hydrogen peroxide, % - 47

Selectivity, %:

Propylene oxide - 62

Acetone - 19

Glycols - 10

Oxygen - 9

This comparative example shows that the use of concentrated (undiluted) containing hydrogen flow in the epoxidation process using a catalyst silicalite titanium not only leads to lower selectivity for propylene oxide and obtaining significant quantities of undesirable by-products, but also receive lower levels of conversion of hydrogen peroxide.

Example 4 (comparative) - Epoxidation of propylene using diluted with isopropanol flow of hydrogen peroxide

The product obtained by (a) the interaction of isopropanol and molecular oxygen in the liquid phase with the formation of acyclical the oxidation mixture with the production of concentrated hydrogen peroxide flow of product, consisting of isopropanol and hydrogen peroxide, and (C) dilution of the concentrated hydrogen peroxide product isopropanol, simulated by mixing the following substances:

Isopropanol - 80 g

50% aqueous hydrogen peroxide - 14 grams

Acetic acid - 0,30 g

Formic acid 0.10 g

The resulting product contained 7.0 wt.% the hydrogen peroxide.

The epoxidation reaction of propylene was carried out as described in Example 1, using the following reagents:

Diluted with isopropanol stream H2O2- 33 g (0.040 mol H2O2)

The catalyst TS-1, silicalite titanium - 0,37 g

Sodium acetate and 3.3 mg

Propylene - 16 ml (0.20 mol)

The following results were obtained:

The conversion of hydrogen peroxide, % - 78

The selectivity of*, %:

Propylene oxide - 87

Glycols - 5

Acetone - 5

Oxygen - 3

*in the calculation of the H2O2.

This example shows that the isopropanol is not as effective as a diluent for concentrated hydrogen peroxide flow of product, which is methanol as isopropanol may not simultaneously provide high conversional catalyst silicalite titanium.

The above examples can be generalized as shown in the table below.

1. The way epoxidation WITH2- C4olefins comprising (a) reaction of the secondary alcohol WITH3- C4and molecular oxygen in the liquid phase with the formation of the oxidation mixture consisting of secondary alcohol WITH3- C4, ketone3- C4corresponding secondary alcohol WITH3- C4, and hydrogen peroxide; (b) the allocation of almost all of the ketone WITH3- C4from the oxidation mixture, and obtaining a stream containing concentrated hydrogen peroxide, comprising a secondary alcohol WITH3- C4hydrogen peroxide and less than 1 wt.% ketone3- C4; (C) the reaction stream containing concentrated hydrogen peroxide, with the olefin WITH2- C4in the presence of a catalyst of titanium silicate, characterized in that in stage (C) a stream containing concentrated hydrogen peroxide interacts with the olefin WITH2- C4in the presence of a diluent comprising methanol, with the formation of the epoxidation reaction mixture, containing epoxide WITH2- C4corresponding to the olefin WITH2- C4water, methanol and WTO WITH4from the epoxidation reaction mixture with the formation of the first stream of the crude alcohol containing water, a secondary alcohol WITH3- C4, methanol and less than 1 wt.% epoxide WITH2- C4; (e) the allocation of almost all of the methanol from the first stream of the crude alcohol with the formation of the second stream of the crude alcohol containing water, a secondary alcohol WITH3- C4and less than 1 wt.% methanol; and (f) recycling at least part of the methanol, isolated on stage (e) for use as at least part of the diluent at the stage (C).

2. The method according to p. 1, characterized in that the ketone3- C4separated from the oxidation mixture in stage (b), hereroense in the secondary alcohol WITH3- C4;

3. The method according to p. 1 or 2, characterized in that the olefin WITH2- C4represents propylene.

4. The method according to any of the preceding paragraphs, characterized in that the secondary alcohol WITH3- C4represents isopropanol.

5. The method according to any of the preceding paragraphs, characterized in that the stream containing concentrated hydrogen peroxide, contains 5 to 30 wt.% of hydrogen peroxide.

6. The method according to any of the previous paragraph is chicosci entire ketone3- C4evaporates and is removed from the oxidation mixture in the form of a stream withdrawn from the top of the column.

7. The method according to any of the preceding paragraphs, characterized in that stage a) is carried out at 50 - 200oC.

8. The method according to any of the preceding paragraphs, characterized in that stage (C) is carried out at 25 - 120oC.

9. The method according to any of the preceding paragraphs, characterized in that it comprises the additional step of recirculatory at least part of the secondary alcohol3- C4the second stream of the crude alcohol for use in stage (a).

10. The method according to p. 9, characterized in that at least part of the water in the second stream of the crude alcohol is separated from the secondary alcohol WITH3- C4before recycling for use on stage, /and/.

11. The method according to p. 1, characterized in that it includes: /a/ reaction of isopropanol and molecular oxygen in the liquid phase at 50 - 200oC with the formation of the oxidizing mixture comprising isopropanol, acetone and hydrogen peroxide; // the distillation of the oxidation mixture, whereby almost all of the acetone is evaporated and removed from the oxidation mixture in the form of a stream ottimi isopropanol, 5 - 30 wt.% of hydrogen peroxide and less than 1 wt.% acetone; // reaction stream containing concentrated hydrogen peroxide with propylene at 40 - 80oC in the presence of a catalyst of titanium silicate, and diluent, representing methanol, with the formation of the epoxidation reaction mixture comprising water, propylene oxide, methanol and isopropanol; /d/ detect almost all of the propylene oxide from the epoxidation reaction mixture by distillation and the formation of the first stream VAT residue comprising water, methanol, isopropanol and less than 1 weight. % of propylene oxide; /e/ selection of almost all of the methanol from the first stream VAT residue by distillation and the formation of the second stream VAT residue comprising water, isopropanol and less than 1 wt.% methanol; /f/ recycling at least part of the methanol, isolated on stage, /e/, for use as at least part of the diluent at the stage /s/; /g/ allocation at least part of the water from the second flow VAT residue with the formation of flow of the crude isopropanol; /h/ hydrogenation of acetone, separated from the oxidation mixture on stage /in/ in isopropanol; and /i/ recycling flow of the crude isopropanol and item, what stage /h/ is carried out in the presence of a hydrogenation catalyst comprising a transition metal selected from palladium, platinum, ruthenium, chromium, rhodium and Nickel, at 20 - 175oC and hydrogen pressure of 0.05 to 10 MPa /0.5 to 100 at/.

13. The method according to p. 11 or 12, characterized in that the molar ratio of propylene: hydrogen peroxide on stage /s/ is from 1 : 2 to 10 : 1.

14. The method according to any of the preceding paragraphs, characterized in that methanol is 5 to 60 wt.% the reaction mixture epoxidation.

15. The method according to any of the preceding paragraphs, characterized in that the amount of diluent sufficient to provide a hydrogen peroxide concentration of 1 to 10 wt.% on stage /s/, based on the total weight of the stream containing concentrated hydrogen peroxide and diluent.

16. The method according to any of the preceding paragraphs, characterized in that the silicate titanium has the topology MF1, MEL or the topology of zeolite BETA.

17. The method according to any of the preceding paragraphs, characterized in that the titanium silicate has a composition corresponding to the chemical formula x TiO2: /1 - x/ SiO2where the value of x is 0.01 - 0,125.

18. The method according to any of the preceding paragraphs, otlichuy the

 

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FIELD: chemical industry; production of hydrogen peroxide and oxiranes.

SUBSTANCE: the invention is dealt with a method of production of hydrogen peroxides and oxiranes. The invention provides for conductance of reaction of olefin with hydrogen peroxide at the presence of a catalyst and organic thinner. At that hydrogen peroxide is present as a water solution of hydrogen peroxide extracted mainly with the help of purified water out of a mixture produced as a result of oxidation at least of one alkylanthrahydroquinone without aftertreatment with a cleansing water and-or purification. The technical result is an increase of an output and selectivity of oxirane.

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17 cl, 5 tbl, 10 ex

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EFFECT: the invention ensures production of the material fit for use as the carrying agent material for titanium dioxide in a heterogeneous catalyst for epoxidation of olefines in alkylene oxide.

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EFFECT: the invention ensures production of zeolite with a catalytic activity in reactions of epoxidation of olefins by hydrogen peroxide.

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