The method of operation of the installation for the epoxidation of olefin (options)

 

Usage: petrochemistry. Epoxidation of the olefin is carried out using multiple capacitive reactors, each containing a fixed bed of heterogeneous catalyst, for example titanium dioxide on the silicon dioxide. The reactors are connected in series. When the catalyst activity in any individual reactor is reduced to an unacceptable level, the reactor is decommissioned and put into operation an additional reactor containing fresh or regenerated catalyst. The specified reactor, in accordance with various variants of the method can be included in the above-mentioned sequence of reactors as the first or last reactor. For example, the input stream may be initially introduced into contact with either the most active or least active portion of the catalyst in the sequence of reactors. While the last option allows you to increase the lifetime of the catalyst, the first option requires a much smaller performance heat exchangers. Effect: method provides a significant reduction of the catalyst consumption compared with the conventional process of epoxidation reactor C3 C.p. f-crystals, 4 tab., 2 Il.

The scope to which the invention relates the Present invention provides a method of operating equipment for epoxidation using a heterogeneous catalyst, which allows to significantly increase the lifetime of the catalyst. More specifically, the present invention relates to a cascade of series-connected reactor with a fixed catalyst bed, in which the individual reactors periodically decommissioned for regeneration or replacement of the catalyst, when the catalyst activity is reduced to an unacceptable level, in effect impose additional reactors containing fresh catalyst, so that the epoxidation can be performed without interruption. An input stream containing the olefin and the connection to active oxygen, is continuously passed through a cascade of reactors, the temperature of the exothermic process, it is expedient to regulate by means of heat exchangers in such a way as to maintain high selectivity to epoxide. According to one embodiments of the invention the input stream first comes into contact with the catalyst having the highest in the cascade activity. According Druget, when the removable reactor include in the tail position of the cascade.

Background of invention In recent decades found that different types of insoluble substances exhibit high activity and selectivity as catalysts for the conversion of olefins, for example propylene, epoxysilane, such as propylene oxide, with the use of compounds containing active oxygen. To one of the classes of such catalysts include silicalite titanium, such as TS-1 and other zeolites containing cellular structure of the titanium atoms, which are effective in cases where the oxidant is hydrogen peroxide and olefin has a relatively low molecular weight. See, for example, U.S. patent 4833260. When a compound containing active oxygen, is an organic hydroperoxide, such as ethylbenzene hydroperoxide, preference is given to using porous amorphous catalysts, for example, products, usually referred to as "titanium dioxide on the silicon dioxide". Epoxidation of olefins using such catalyst is described in General form, for example, in U.S. patent 4367342.

Although freshly heterogeneous epoxidation catalysts show is. the problem is especially serious in the operation of large-scale industrial installations continuous action where it is necessary to provide a continuous process for the epoxidation over a long period of time while maintaining high yields of epoxide. Although the methods of regeneration of such catalysts are known, highly desirable is to develop methods, the use of which would be possible to increase the interval between operations of regeneration. For regeneration should be terminated epoxidation for a time sufficient to restore the activity of the catalyst, and thereby reduce the effective annual performance industrial installations. In alternate ways lost the activity of the catalysts can be replaced with fresh, however, such solutions have the same practical disadvantages. In addition, the cost of catalysts of this type are relatively high, and it is desirable to minimize the amount of fresh catalyst needed to boot into the installation.

Brief description of the invention the Present invention provides a method of operating plants for the epoxidation of an olefin comprising a cascade of at least two after the first thread, containing the olefin and the connection with active oxygen, continuously passes through the above-mentioned cascade of series-connected reactor and contacting in the liquid phase heterogeneous catalyst in each reactor with a fixed bed under conditions which assure the conversion of the olefin to the epoxide. The said method includes the decommissioning of one of the reactors, fixed bed, part of the mentioned cascade of series-connected reactors, at the time when the heterogeneous catalyst in said reactor with a fixed bed is deactivated to an unacceptable level, and commissioning in the above-mentioned cascade of series-connected reactors additional reactor with a porous layer containing heterogeneous catalyst, with the level of activity on epoxydecane higher level of activity of a heterogeneous catalyst, decommissioned. Generally speaking, a reactor with a fixed bed of catalyst selected for decommissioning is the reactor containing the catalyst lowest activity among the reactors included in the cascade, and therefore the reactor is usually the first reactor of the cascade.

According to one of III, each of the subsequent reactors of the cascade switch to the previous position in the sequence and additional reactor with a fixed catalyst bed into operation in the end position in the cascade of series-connected reactors.

According to another variant, the advantage of which is significantly less necessary for the performance of heat exchangers, additional reactor with a fixed catalyst bed into operation in the first position in the cascade of series-connected reactors.

Installation for epoxidation operated in accordance with the present invention, can operate continuously without interruption of the operation for replacement of the catalyst and less sensitive to failures, decrease the activity of the catalyst and increase the resistance of the layer than the installation comprising a reactor with a fixed catalyst bed is relatively large volume, which must periodically be shut down for replacement of the catalyst. In addition, the consumption of the catalyst in the cascade of series-connected reactors smaller than in the case of a single layer of large volume, equivalent to the total volume of the reactors.

Brief OPI the lyst described in more detail in the comparative example 1. Fig. 2 is a diagram of the cascade of series-connected reactors, operated in accordance with the present invention, as described in more detail in examples 2 and 3.

Detailed description of the invention In the method in accordance with the present invention, the olefin is reacted with a compound containing active oxygen, to form the corresponding epoxide. Although as olefin can be used any unsaturated compound of the ethylene series, including olefins, branched structure, normal structure, cyclic, containing a double bond at a terminal or internal atom chain, with particular preference given to monoolefins2-C6. Examples of such monoolefins are ethylene, propylene, n-butene, isobutylene, n-pentan, cyclohexane, etc. In connection with active oxygen can be used any substance that can serve as a source of oxygen atom, passed to the olefin in the process of epoxidation. The number of joints with active oxygen, which is given special preference, include hydrogen peroxide, organic hydroperoxides and their predecessors. Hydrogen peroxide or organiczna to generate in situ epoxidation process.

Generally, it is preferable to conduct the process in a molar ratio of quantities of compounds with active oxygen and the olefin in the range from 1:1 to 1: 30 (more preferably from 1:5 to 1:20).

Hydrogen peroxide, which can be used as oxidant, can be obtained from any suitable for this purpose source. For example, hydrogen peroxide can be obtained by introducing a secondary alcohol, such as alpha-methylbenzylamine alcohol, isopropyl alcohol, 2-butanol or cyclohexanol, into contact with molecular oxygen under conditions ensuring formation of oxidizing a mixture containing a secondary alcohol and hydrogen peroxide (and/or precursors of hydrogen peroxide). In a typical case, this oxidizing the mixture also contains a ketone such as acetophenone, acetone or cyclohexanone, the corresponding secondary alcohol (i.e., having the same carbon skeleton), a small amount of water and variable amounts of other compounds with active oxygen, such as organic hydroperoxides. One or more components of the oxidizing mixture, for example a ketone, can be fully or partially removed before epoxydecane. To generate hydrogen peroxide can be used as the oxide is molekulyarnym oxygen.

Organic hydroperoxides, suitable as compounds with active oxygen in the epoxidation process in accordance with the present invention can be any organic compounds containing at least one hydroperoxide functional group (-UN). But the preference is given to secondary and tertiary hydroperoxides, due to the increased instability of the primary hydroperoxides and related increased risk of their use. Organic hydroperoxide preferably has the following General structure:where R1, R2and R3the same or different groups selected from the group consisting of hydrogen, C1-C10-Akilov (for example, methyl, ethyl, tert-butyl) and C6-C12-arrow (for example, phenyl, alkyl substituted fanilow), provided that the hydrogen atom is not more than one of the groups R1, R2or R3. Examples of organic hydroperoxides are tert-butyl hydroperoxide, hydroperoxide tert-amyl, cumene hydroperoxide, ethylbenzene hydroperoxide, the hydroperoxide of cyclohexyl, hydroperoxide of methylcyclohexyl, the hydroperoxide of tetralin, hydroperoxide isobutyl the p>

The concentration of active oxygen in the input stream, the input to the cascade of series-connected reactor with a fixed catalyst bed, is not considered as a factor of importance. Generally speaking, suitable concentrations are from about 1 to 50 wt.%. The optimum concentration depends on the specific connection with active oxygen and heterogeneous catalyst selected for implementing the method, the concentration of olefin in the liquid phase and from the molar ratio of the amounts of compounds with active oxygen and olefins, as well as other factors. The concentration of compounds with active oxygen, of course, varies along the length of the cascade of series-connected reactors due to the fact that this connection passing through the cascade, reacts.

The ranges of temperature, pressure and concentration of the olefin in the liquid phase, selected for use in the implementation of the present invention, differ somewhat depending on the applied catalyst and compounds with active oxygen. For example, when using titanium silicalite as the catalyst and hydrogen peroxide as the oxidant, it is advisable to work the and the silicon dioxide and organic hydroperoxide (for example, from 80 to 130oC), although it is possible mutual overlap of these ranges.

When the olefin is propylene, and the connection with active oxygen - ethylbenzene hydroperoxide, particularly useful to adjust the temperature of the flux passing through the cascade of series-connected reactor so that the temperature does not exceed 125oC. the temperature control in this way helps to maintain high selectivity to propylene oxide, while at the same time a high degree of conversion of the hydroperoxide. Generally, it is desirable to achieve at least 96% (more preferably at least 98%, most preferably at least 99%) conversion of compounds with active oxygen originally present in the input stream, by passing the flow through a cascade of series-connected reactors. It is advisable to carry out the described process, so that the selectivity to epoxide, calculated with respect to the converted connection with active oxygen, exceeded 90%. If the olefin is propylene, the connection with active oxygen - ethylbenzene hydroperoxide, and heterogeneous kata is p>

As solvents, as a rule, it is preferable to use an organic compound having a boiling point at atmospheric pressure of from about 25 to 300oC. the Solvent or diluent may be an excess of olefin. Examples of other suitable solvents may include ketones (e.g. acetone, methyl ethyl ketone, acetophenone), ethers (e.g. tetrahydrofuran, butyl ether), NITRILES (e.g. acetonitrile), aliphatic and aromatic hydrocarbons (e.g., ethylbenzene, cumene), halogenated hydrocarbons and alcohols (e.g. methanol, ethanol, isopropyl alcohol, tert-butyl alcohol, alpha-methylbenzylamine alcohol, cyclohexanol), but not only these compounds. If the catalyst is a titanium silicalite and connection with active oxygen, hydrogen peroxide, is preferably used as solvents alcohols (special preference is given to methanol and isopropanol). Such reaction systems allow the presence of significant quantities of water without disturbing their work. If you use an organic hydroperoxide, such as ethylbenzene hydroperoxide, in combination with a catalyst (titanium dioxide on the silicon dioxide, prepocessor) and virtually eliminate the presence of water.

The catalyst used in the described process may be any substance which is insoluble in the liquid phase epoxidation reaction mixture and capable of catalyzing the conversion of the olefin to the epoxide. Such catalysts are well known in the art and may be crystalline (e.g., zeolites or amorphous form. Particularly preferred for the purposes of the present invention are titanium containing catalysts.

Examples of catalysts can serve titanium containing molecular sieve comprising the class of zeolites, in which the titanium atoms replace part of silicon atoms in the crystal lattice of the molecular sieve.

Particularly preferred titanium containing molecular sieves include molecular sieves, usually denoted as TS-1 (having an MFI topology similar to the topology of aluminosilicate zeolites ZSM-5; see U.S. patent 4410501).

Titanium containing molecular sieves suitable for use in the described method, the experts in this field is sometimes referred to as "titanium silicalite", "titanosilicates", "titanium silicates, titanates silicon", etc.

Other suitable in this case, the catalytic compositions are substances containing inorganic cesarean (for example, the oxide or hydroxide of titanium). Inorganic oxygen-containing compound of titanium, associated with oxygen-containing silicon compound, preferably is in the highest positive oxidized state (i.e., titanium in it tetravalent). The proportion of inorganic oxygen-containing compounds of titanium contained in the catalyst may vary, but typically, the catalyst composition contains (based on total catalyst composition) of at least 0.1 wt.% titanium, and preference is given to amounts of from about 0.2 to about 50 wt.%, and the greatest preference amounts of from about 0.2 to about 10 wt.%.

Catalysts of this type are well known in the art and described, for example, in U.S. patents 4367342, 4021454, 3829392 and 3923843, publications of European patents 0129814, 0345856, 0492697 and 0734764, the Japan patent 77-07908 (Chem. Abstracts, 87: 135000s), the international application WO 94/23834, the German patent 3205648 and in the work of Castillo and others (Castillo et al., J. Catalysis, 161, 524-529 (1996)), the information from which these references are included in this description in full.

One type of such heterogeneous catalysts, especially suitable for use in the method in accordance with the present invention the titanium (titanium dioxide), deposited on the silica carrier (silicon dioxide). Titanium dioxide on the silicon dioxide can be either in silanizing or asianasian form.

The catalyst is placed in a cascade of series-connected reactor with a fixed catalyst bed. Several (i.e. two or more) reactors with a fixed layer are connected in series so that the input stream is from one side in the first reactor of the cascade takes place in the reactor through a layer of a heterogeneous catalyst, where there is a partial conversion of the olefin and compounds with active oxygen in the epoxide, and then emerges on the other side of the first reactor. Then the flow of the reaction mixture is injected from one side to the next reactor of the cascade, where the reaction occurs during contact of the stream with a fixed bed of catalyst in the reactor, after which the output stream on the other side of the next reactor. This procedure is repeated until the passage of the stream through the reactor with a fixed catalyst bed, which are currently in operation as part of the cascade. The dimensions of each reactor, the amount of catalyst loaded in each reactor, and the conditions (temperature, pressure) is chosen so that A connection with active oxygen while maintaining high selectivity to epoxide.

The heat released in the exothermic reaction between the olefin and the connection with active oxygen that occur during contact them fixed bed of catalyst in each reactor (which, as a rule, leads to a moderate increase in flow temperature within, for example, from 1 to 25oC), can be defined by passing the stream exiting the reactor through the corresponding heat exchanger before flow into the next reactor of the cascade. Exhaust heat is useful for pre-heating of the stream fed to the first reactor.

The number of reactor with a fixed catalyst used for the conversion, you may need to vary in order to achieve an optimal balance between cost of equipment, operating costs (including the consumption of catalyst and operating characteristics, but typically it ranges from 2 to 5. If necessary, replace one of the operating reactors containing the catalyst is deactivated to an unacceptable level, the operation of introducing at least one additional reactor with a fixed catalyst bed. Thus, the setting for Aporrectodea with a fixed bed of catalyst, functionally connected so that they can be consistently put into operation in selected positions within the cascade or withdraw from service for replacement or regeneration of the catalyst. Typically, at any given moment out of operation is not more than one reactor of the above-mentioned cascade, thus, it is possible to maintain a continuous process of conversion in the rest of the reactor, thereby maintaining maximum performance setup epoxidation. The reactors can be connected to each other through a piping system and the locking elements so that the flow of reaction mixture through the reactor can be modified to achieve the desired sequence of reactors and provide separate reactors out of service for replacement of the catalyst without interrupting the epoxidation process occurring in the remaining reactors.

Various preferred embodiments of the present invention can be illustrated, as described below in the example of the cascade of the six reactors fixed bed catalyst (designated as the reactors a, b, C, D, E and F). In each reactor, first download svezhepriobretenny input stream containing propylene, ethylbenzene hydroperoxide and ethylbenzene, comes first in the reactor And passes through a fixed catalyst bed in the reactor And in conditions providing partial conversion of propylene into propylene oxide and partial conversion of ethylbenzene hydroperoxide to the corresponding alcohol, then flow away from the reactor and introduced into the reactor, after which the stream passes successively through the layers of catalyst reactors b, C, D and E in sequence. The reactor F in the first cycle is out of operation. By the end of the first cycle of the catalyst in the reactor And deactivated to a greater extent than the catalyst in the other reactors. At this point the reactor And decommissioned in order to replace or regenerate the catalyst.

According to one variant embodiment of the invention in the second loop reactor is the first reactor of the United appropriately cascade (i.e., the input stream is fed initially into the reactor, the reactor F, containing fresh catalyst loading, put into operation as the last reactor of the cascade (i.e., the last reactor, through which is passed a stream of the reaction mixture). Thus, the sequence of reactors CAS is the purpose of replacement or regeneration of the catalyst is taken out of service the reactor, and the reactor And containing freshly prepared or regenerated catalyst, again put into operation as of the end of the reactor cascade. Thus, in the third cycle, the reactors operate in the sequence C-D-E-F-A. In subsequent cycles repeats the same procedure, namely the output of the cascade reactor, containing most of the deactivated catalyst (first reactor in the sequence), and the inclusion as the final position of the cascade reactor, containing the most active catalyst.

According to another variant embodiment of the invention at the end of the first cycle in operation enter the reactor F (containing freshly prepared catalyst in the first reactor of the cascade. Thus, in the continuation of the second cycle, the stream passes through a cascade of reactors in the sequence F-B-C-D-E. At the end of the second loop reactor (containing the least active catalyst among reactors of the cascade) decommissioned for the renewal of the catalyst, and the reactor (which now contains fresh catalyst) is connected to the cascade as the first in order of the reactor. The flow of the reaction mixture after passing through the reactor And sent to the reactor containing the least active KAAZ, the sequence of reactors in the third cycle corresponds to the order A-C-D-E-F (the reactor was removed from the cascade). Similarly, in the fourth cycle, the reactors are connected in sequence B-D-E-F-A (the reactor was removed from the cascade).

When the activity of the heterogeneous catalyst in a fixed bed, a separate reactor is reduced to an unacceptable level, the reactor is decommissioned and produce the replacement or regeneration of the catalyst. The acceptable level of decontamination separate fixed catalyst layer varies depending on many factors, including the number in the reactors and minimum values of the output of the epoxide and the conversion of compounds with active oxygen, considered as acceptable from an economic point of view; in a typical case, the catalyst is not recovered (not replace), while its activity does not fall below 10% of the initial value.

Regeneration of the catalyst can be produced according to any known method, for example by calcination, leaching solvent and/or treatment of various reagents, for example selenicereus agents, bases, oxidizers, etc., it is Highly desirable to use the methods of regeneration, providing Voss is egodnya for this purpose the methods of regeneration are well known and described, for example, in application laid Japan 3-114536, Perego and others (G. Perego et al. , Proc. 7thIntern. Zeolite Confer., 1986, Tokyo, p. 827), in the European patent 0743094, U.S. patent 5620935, bids US 08/770822 (20 December 1996) and 08/770821 (20 December 1996). After regeneration or replacement of the catalyst reactor with a fixed catalyst bed may be returned to operation in accordance with the present invention. For optimal performance, install the epoxidation appropriate in each moment to keep out of operation not more than one reactor.

After exiting the final reactor of the cascade flow of the reaction mixture (in which the preferred compound containing active oxygen, reacted almost completely with the formation of epoxide) can be subjected to fractional distillation or other processing in accordance with known methods to extract the target product - epoxide. Unreacted olefin can be returned into the cycle.

EXAMPLES Comparative example 1.

Use the usual multi-zone capacitive reactor 1 containing five layers (a, b, C, D, E) catalyst, as shown in Fig.1. Reactors of this type are described in more detail, for example, in U.S. patents 2271646 and 2322366.the silicon oxide, obtained as described in U.S. patent 3829392; the total amount of catalyst 65 kg Input stream containing 286 kg/h of oxidate ethylbenzene and 408 kg/h of propylene, is introduced into the bottom layer of catalyst in the reactor by line 2 and maintain it in a liquid state at an absolute pressure of 800 psi (56 kg/cm2). Oxidat ethylbenzene is produced by oxidation of ethylbenzene with molecular oxygen according to the method described in U.S. patent 4066706; it contains about 35 wt.% cumene ethylbenzene.

In the beginning of the cycle epoxidation input stream has a temperature of approximately 38oWith, and it is not passed through the heat exchangers connected to the reactor. During the epoxidation cycle heat exchangers are used to transfer the input flow of heat released from the exothermic reaction of epoxidation occurring when the flow comes into contact with the catalyst in a fixed catalyst contained in the reactor.

As necessary, the temperature of the stream entering the reactor is gradually increased to maintain the required level of conversion. At the end of the cycle epoxidation (303 days) heat exchangers provide preheating input sweat the layer of catalyst in the reactor at about 121oWith the maximum value of a recognized appropriate in this particular embodiment of the invention. If you exceed this temperature, the selectivity and the yield of propylene oxide is significantly reduced. Flow temperatures of the reaction mixture at the input and output of each of the four heat exchangers to the end of the cycle are given in table.1.

When the degree of conversion of ethylbenzene hydroperoxide drops to values lower than 99%, and all layers of the catalyst to operate at a temperature at the outlet 121oWith the reactor shut down for replacement of the catalyst is fresh in all layers. The spent catalyst or removed as waste or recovered for use in a future cycle epoxidation.

Example 2.

In accordance with the present invention using a cascade of six separate capacitive reactors (a, b, C, D, E, F), connected as shown in Fig.2. At each point in time are connected by pipeline and are in operation for only five reactors. In Fig.2 the cascade of reactors shown in the process of epoxidation cycle in which the input stream is fed initially into the reactor And then the reactor b, C, D in sequence and, finally, the reactor E, with reacted silicon, the amount of catalyst in each layer 13 kg Reactors equipped with locking devices to disable each individual reactor to replace the catalyst layer. The composition and feed rate of the input stream is identical to that specified in comparative example 1. The flow temperature of the reaction mixture introduced into each layer of the catalyst, regulate by means of heat exchangers (HE-1, HE-2, HE-3, HE-4) so that the exit temperature of the layer did not exceed 121oC. That is, the liquid stream withdrawn from one reactor, cooled to the desired degree by using a heat exchanger, thereby fueling the flow of raw material fed to the first reactor) before entering the next reactor of the cascade, in which the temperature of liquid flow again increases the exothermic reaction of epoxidation occurring in the catalyst bed. For example, at the end of the cycle epoxidation shown in Fig.1, the temperature of the input stream entering the reactor And approximately 101oC, and the temperature of the reaction mixture at the inlet and outlet of each of the four operating heat exchangers has the values shown in the table.2.

At the end of the cycle epoxidation, when the total degree of conversion of the hydroperoxide in this case at the output 121oWith the first reactor of the cascade (reactor A), containing the least active catalyst in the cascade, decommissioned to replace the layer of the freshly prepared catalyst or regenerated catalyst. The deactivated catalyst, of course, can also be regenerated in situ (i.e. in the reactor). Then in the cascade include a spare reactor (reactor F) that contains unused catalyst, as the final stage of the above-mentioned cascade. In the next cycle epoxidation reactors operate in the sequence B-C-D-E-F.

Example 3.

In this example, the epoxidation process carried out by the method identical to that described in example 2, with the difference that at the end of the cycle epoxidation first reactor of the cascade (reactor A) is decommissioned and replaced with a spare reactor (reactor F) containing fresh catalyst. As a result, the flow of raw material first enters the reactor, containing a catalyst of higher activity among reactors of the cascade, and not in the reactor containing the catalyst minimal activity, as in example 2. Thus, in the next cycle epoxidation reactors operate in the sequence F-B-C-D-E. In subsequent cycles the reactor containing the least active ka is isator the highest activity among reactors of the cascade, and then through the rest expluatiruem reactors included in cascade in the order of increasing the activity of the catalyst in them. For example, in the third cycle, the reactors are in the sequence A-C-D-E-F and the reactor excluded from exploitation. The life time of the catalyst in this case is somewhat reduced in comparison with example 2, however, the required heat exchange surface is much less than in example 2. This means that in the example 2 to the end of the cycle epoxidation to achieve temperature 121oWith the output of the first reactor of the cascade stream of incoming raw materials in the first reactor must be heated to 101oC. this requires approximately the same heat exchange surface, as in comparative example 1. The method in accordance with example 3 does not require such a significant heat exchange surface, because the temperature increase is largely due to the high amount of heat exothermic reaction resulting from the presence in the first reactor of the cascade fresh, highly active catalyst. The temperature of the reaction mixture at the inlet and outlet of each of the four operating heat exchangers at the end of the first cycle epoxidation matter carried away allaamah of the invention, illustrated by examples 2 and 3, compared with the known method described in comparative example 1 is the reduced consumption of catalyst.

Claims

1. The method of operation of the installation for the epoxidation of an olefin comprising a cascade of at least two serially connected reactors with a fixed layer, each of which contains a heterogeneous catalyst, in which the input stream containing the olefin and the connection with active oxygen, continuously passes through the above-mentioned cascade of series-connected reactor and contacting in the liquid phase heterogeneous catalyst in each reactor with a fixed bed under conditions which assure the conversion of the olefin to the epoxide, characterized in that it includes: (a) the decommissioning of one of the reactors, fixed bed, included in the above cascade of series-connected reactors, at the time when the heterogeneous catalyst in said reactor with a fixed bed is deactivated to an unacceptable level, and (b) the introduction into operation in the above-mentioned cascade of series-connected reactors additional reactor with fixed bed, sovesti heterogeneous catalyst, decommissioned to stage (a).

2. The method according to p. 1, characterized in that a reactor with a fixed catalyst bed, the output of the operation at the stage (a) is a reactor containing a heterogeneous catalyst of lower activity than the heterogeneous catalyst in any of the other reactors with a fixed layer, forming a cascade of series-connected reactors.

3. The method according to p. 1, characterized in that a reactor with a fixed catalyst bed, the output of the operation at the stage (a), is the first reactor with a porous layer in the above-mentioned cascade of series-connected reactors.

4. The method according to p. 1, characterized in that the additional reactor with a fixed bed of the catalyst in stage (b) enter into operation in the final position of the above-mentioned cascade of series-connected reactors.

5. The method according to p. 1, characterized in that the additional reactor with a fixed bed of the catalyst in stage (b) enter into operation in the first position mentioned cascade of series-connected reactors.

6. The method according to p. 1, characterized in that the said cascade series-connected reactors includes from three to five operated Rea is p> 8. The method according to p. 1, characterized in that the connection with active oxygen selected from the group consisting of organic hydroperoxides and hydrogen peroxide.

9. The method according to p. 1, wherein the heterogeneous catalyst is selected from the group consisting of a titanium zeolite and titanium dioxide on the silicon dioxide.

10. The method according to p. 1, wherein the heterogeneous catalyst in the reactor with a fixed bed, extracted from exploitation, regenerate and said reactor with a fixed bed catalyst is then returned to operation within the above-mentioned cascade of series-connected reactors.

11. The method of operation of the installation for the epoxidation of propylene comprising a cascade of series-connected reactors, containing from three to five reactors with a fixed layer, each of which contains a catalyst of titanium dioxide on the silicon dioxide, in which the input stream containing propylene and an organic hydroperoxide, continuously passes through the above-mentioned cascade of series-connected reactor and contacting in the liquid phase with a catalyst (titanium dioxide on the silicon dioxide in each of the reactors fixed bed under conditions which assure the of eector with a fixed layer, part of the mentioned cascade of series-connected reactors, at the time when the catalyst is titanium dioxide on the silicon dioxide in said first reactor with a porous layer is deactivated to an unacceptable level; (b) switching each of the remaining reactor with a fixed catalyst bed at the previous position in the structure of the cascade of series-connected reactors, and (c) commissioning in the final position of the above-mentioned cascade of series-connected reactors additional reactor with a fixed bed containing the catalyst is titanium dioxide on the silicon dioxide having a desired high level of activity on epoxydecane.

12. The method according to p. 11, wherein the organic hydroperoxide is an ethylbenzene hydroperoxide.

13. The method according to p. 11, characterized in that the catalyst is titanium dioxide on the silicon dioxide in the reactor with a fixed bed, extracted from exploitation, regenerate and said reactor with a fixed catalyst bed then return into operation in the final position of the above-mentioned cascade of series-connected reactors.

14. The method according to p. 11, characterized in that the degree COO stage (a) perform, when the catalyst is titanium dioxide on the silicon dioxide in the first reactor with a fixed catalyst bed is reduced to values less than 10% of the initial activity.

16. The method according to p. 11, characterized in that the temperature of the input stream in the cascade of series-connected reactors is maintained at a level no higher than 125oC.

17. The method of operation of the installation for the epoxidation of propylene comprising a cascade of series-connected reactors, containing from three to five reactors with a fixed layer, each of which contains a catalyst of titanium dioxide on the silicon dioxide, in which the input stream containing propylene and an organic hydroperoxide, continuously passes through the above-mentioned cascade of series-connected reactor and contacting in the liquid phase with a catalyst (titanium dioxide on the silicon dioxide in each of the reactors fixed bed under conditions which assure the conversion of propylene to propylene oxide, characterized in that it includes: (a) the decommissioning of one of the reactor with a fixed catalyst bed part of the mentioned cascade of series-connected reactors, at the time when the catalyst - dirona, moreover, the activity of the catalyst is titanium dioxide on the silicon dioxide in the selected decommissioning reactor with a fixed catalyst bed below the activity of the catalyst is titanium dioxide on the silicon dioxide in any of the other reactor with a fixed catalyst bed, and (b) commissioning in the first position mentioned cascade of series-connected reactors additional reactor with a fixed bed containing the catalyst is titanium dioxide on the silicon dioxide having a desired high level of activity on epoxydecane.

18. The method according to p. 17, wherein the organic hydroperoxide is an ethylbenzene hydroperoxide.

19. The method according to p. 17, characterized in that the catalyst is titanium dioxide on the silicon dioxide in the reactor with a fixed bed, extracted from exploitation, regenerate and said reactor with a fixed catalyst bed then return into operation in the first position mentioned cascade of series-connected reactors.

20. The method according to p. 17, characterized in that the reactor with a fixed catalyst bed, the output of the operation is in the second position mentioned cascade posledovatelnostei is at least 98%.

22. The method according to p. 17, characterized in that the flow of the reaction mixture leaving each reactor with a fixed catalyst bed is cooled using a heat exchanger prior to its introduction into the next reactor with a fixed catalyst bed.

23. The method according to p. 22, characterized in that the input stream is introduced into the first reactor with a fixed catalyst bed is heated using the heat exchanger.

24. The method according to p. 17, wherein stage (a) is performed when the catalyst is titanium dioxide on the silicon dioxide in the selected decommissioning of the reactor with a fixed bed of catalyst is reduced to values less than 10% of the initial activity.

25. The method according to p. 17, characterized in that the temperature of the input stream in the cascade of series-connected reactors is maintained at a level no higher than 125oC.

26. The method according to p. 17, characterized in that the flow of the reaction mixture, leaving an additional reactor with a fixed catalyst bed, put into operation at the stage (b), is passed sequentially through the remaining operating reactors in order to increase the activity of the catalyst in these reactors.

 

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The invention relates to a method for epoxydecane vegetable oils, which are used as plasticizers stabilizers of polyvinyl chloride, various non-toxic polymer compositions

The invention relates to a method for producing oxides of perfluorinated olefins, which are of practical use as starting compounds to obtain some valuable organofluorine products

FIELD: updated methods of recuperation of heat in CO2 discharge systems in production of ethylene oxide.

SUBSTANCE: proposed method includes absorption of ethylene oxide from circulating gas flow by washing the gas in scrubber. Washed flow of circulating gas is brought in contact with hot absorbing carbonate solution for absorption of CO2 and flow of circulating gas after absorption of CO2 returning it to ethylene oxide production cycle; proposed method includes also bringing the said washed circulating gas flow in contact with heated liquid after removal of ethylene oxide at first contact stage, transferring the preheated circulating gas to stage of absorption by hot carbonate for removal of CO2, cooling the said circulating gas from stage of absorption by carbonate and removal of carbonate from it by bringing it in contact with said liquid from first contact stage at second contact stage after cooling this liquid, transferring the liquid from second contact stage to first contact stage and transferring the cooled circulating gas from second contact stage to reaction system for obtaining the ethylene oxide.

EFFECT: enhanced operational and economical efficiency of heat recuperation.

1 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to catalyst supports used for epoxidation. Described is an olefin epoxidation catalyst support, wherein said support has pore volume from pores with diameter smaller than 1 mcm of less than 0.20 ml/g and pore volume from pores with diameter greater than 5 mcm of less than 0.2 ml/l, wherein at least 40% of the pore volume consists of pores having diameter from 1 mcm to 5 mcm. Described is an olefin epoxidation catalyst support, having a support and a catalytically effective amount of silver on it, wherein said support has pore volume from pores with diameter smaller than 1 mcm of less than 0.20 ml/g and pore volume from pores with diameter greater than 5 mcm of less than 0.2 ml/l, wherein at least 40% of the pore volume consists of pores having diameter from 1 mcm to 5 mcm. Described is an olefin epoxidation catalyst which has a support and a catalytically effective amount of silver on it, wherein said support has total pore volume of 0.2-0.6 ml/g, surface area from about 0.3 m2/g to about 3 m2/g, at least 40% of the pore volume from pores with diameter ranging from 1 mcm to 5 mcm and average pore diameter from 1 mcm to 5 mcm, an in which pore volume from pores with diameter greater than 5 mcm is less than 0.20 ml/g, and pore volume from pores with diameter smaller than 1 mcm is less than 0.20 ml/g. Described is a method of oxidising ethylene to ethylene oxide, which involves vapour-phase oxidation of ethylene with molecular oxygen in a fixed bet, in a tubular reactor in the presence of the catalyst described above.

EFFECT: high activity, selectivity and stability of the epoxidation catalyst.

19 cl, 4 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing alkylene glycol, which can be used as a raw material in production of polyester fibres, polyethylene terephthalate plastic and resins, as well as in antifreeze liquids. The method involves the following steps: (a) reaction of alkene with oxygen in the presence of a catalyst in a reactor to obtain a gaseous composition which contains alkylene oxide, alkene, oxygen, carbon dioxide and water vapour, and removing contaminants from the gaseous composition; (b) feeding the gaseous composition from step (a) into an alkylene oxide absorber, having a column of vertically stacked plates or having a packed column, feeding the impoverished absorbent into the alkylene oxide absorber, bringing the gaseous composition into contact with the impoverished absorbent in the alkylene oxide absorber in the presence of one or more catalysts which facilitate carboxylation and hydrolysis, and removing the saturated absorbent from the alkylene oxide absorber, where the impoverished absorbent contains at least 20 wt % and less than 80 wt % water, wherein at least 50 wt % alkylene oxide coming into the alkylene oxide absorber is converted in the alkylene oxide absorber and where temperature in the alkylene oxide absorber ranges from 50 to 160°C; (c) optionally feeding a portion or all of the saturated absorbent from step (b) into one or more final treatment reactors and removing the product stream from the one or more final treatment reactors, where at least 90% of alkylene oxide and alkylene carbonate coming into one or more final treatment reactors are converted to alkylene glycol in one or more final treatment reactors; (d) optionally feeding the saturated absorbent from step (b) or the product stream from at least one or more final treatment reactors at step (c) into a flash vessel or into an apparatus for evaporating light fractions, and removing the light fractions; (e) feeding the saturated absorbent from step (b) or (d) or the product stream from step (c) or (d) into a dehydrator, removing water and obtaining a stream of dehydrated product; and (f) purifying the stream of dehydrated product from step (e) and obtaining a product stream of purified alkylene glycol.

EFFECT: method enables to reduce the cost and complexity of the apparatus while ensuring high selectivity.

12 cl, 1 ex, 6 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to olefin epoxidation. method of epoxidising of olefin to olefin oxide comprises the following operations: bringing the load including, at least, oxygen and olefin, in reactor with catalyst including carrier with bimodal pore distribution in sizes, first types of pores with mean diameter of 0.01-5 mcm and second type of pores with mean diameter of pores of 5-50 mcm, catalytically active amount of silver or silver-bearing compound, promoting amount of rhenium or rhenium-bearing compound, and promoting amount of one or more alkaline metals or alkaline metal-bearing compound. Note here that said reactor has, at least, its outlet, while said olefin oxide resulted from aforesaid contact features concentration at reactor outlet of 2.2 vol. % of cesium, lithium and tungsten. It may comprise bringing the load including, at least, oxygen and olefin, in reactor with catalyst including carrier with total volume of pores of 0.41 cm3/g and bimodal pore distribution in sizes, first types of pores making 25% of total volume of pores with mean diameter of 0.7 mcm and second type of pores making 75% of total amount of pores with mean diameter of pores of 15.8 mcm, catalytically active amount of silver or silver-bearing compound, promoting amount of rhenium or rhenium-bearing compound, and promoting amount of one or more alkaline metals or alkaline metal-bearing compound. Note here that said reactor has, at least, its outlet, while said olefin oxide resulted from aforesaid contact features concentration at reactor outlet over about of 2.2 vol. % at 236°C.

EFFECT: higher selectivity and efficiency.

34 cl, 2 tbl, 1 dwg, 2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing plasticiser for polymer materials from renewable material, such as esters of fatty acids. In accordance with invention, plasticiser is obtained by oxidation of alkyl esters of fatty acids of vegetable origin with oxygen-containing gas in presence of homogeneous catalysts - molybdic acid esters, and aliphatic dihydric alcohols. Process of oxidising is preferably carried out at 100-120 °C and atmospheric pressure.

EFFECT: simplified process.

2 cl, 2 tbl, 12 ex

FIELD: technological processes.

SUBSTANCE: present invention relates to a method of producing ethylene glycol, involving following steps: (i) supplying ethylene and oxygen and an organic chloride moderator to an ethylene oxide reactor wherein ethylene and oxygen react in presence of a catalyst to produce ethylene oxide, thereby producing a reactor product stream; (ii) supplying reactor product stream to an ethylene oxide absorber wherein ethylene oxide is recovered from reactor product stream by absorption in water in absorber section, thereby producing a rich absorbent stream; (iii) supplying rich absorbent stream to an ethylene oxide stripper wherein rich absorbent stream is steam stripped, thereby producing a concentrated ethylene oxide stream and a lean absorbent stream; (iv) recirculating lean absorbent stream through ethylene oxide absorber; (v) optionally supplying concentrated ethylene oxide stream to one or more carboxylation reactors wherein ethylene oxide reacts with carbon dioxide to form an ethylene carbonate stream; and (vi) supplying concentrated ethylene oxide stream and/or ethylene carbonate stream to one or more hydrolysis reactors wherein ethylene oxide and/or ethylene carbonate reacts with water in presence of a hydrolysis catalyst selected from one or more basic alkali metal salts to form an ethylene glycol stream. Method includes additional steps: (vii) removing a glycol bleed stream from ethylene oxide stripper and (viii) adding a base to ethylene oxide stripper such that pH in bottom section of stripper is maintained in range of from at least 9.5 to at most 12.0.

EFFECT: proposed method reduces amount of chloroethanol present in reaction, and reduces or completely prevents decomposition of hydrolysis catalyst.

10 cl, 2 dwg

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.

EFFECT: the invention ensures increased output and selectivity of oxirane.

17 cl, 5 tbl, 10 ex

FIELD: chemical industry; production of a catalyst carrier material and the catalyst.

SUBSTANCE: the invention is dealt with the field of chemical industry. The method of production of a catalyst carrier material includes the following stages: (a) treatment of the utilized catalyst of titanium dioxide-on-silicon dioxide to clear from coke; (Ь) washing of the catalyst cleared from the coke by a flushing fluid chosen from a water solution of an inorganic acid, a water solution of an ammonium salt and their combinations; (c) drying and calcination of the catalyst washed out and cleared from the coke with production of the catalyst carrier material. The technical effect - the material produced this way is fit for use as the carrying agent material for titanium dioxide in a heterogeneous catalyst for epoxidation of olefines in alkylene oxide.

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.

12 cl, 4 ex, 1 tbl

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