The method of obtaining cyclic anhydrides or aliphatic nitriles, the method of obtaining maleic anhydride and a method of producing acrylonitrile and methacrylonitrile

 

(57) Abstract:

Use: in organic synthesis. The inventive receiving aliphatic NITRILES and cyclic anhydrides. Reagent 1: hydrocarbon (benzene, naphthalene, ortho-xylene, WITH4- hydrocarbon straight chain in the case of obtaining cyclic anhydride or chosen from propane, isobutene, isobutane, to obtain NITRILES). Reagent 2: oxygen-containing gas, optionally in the presence of ammonia and a catalyst and carbon monoxide. 3 S. and 9 C.p. f-crystals, 2 ill., table 4.

The invention relates to a method for producing a cyclic anhydride or a nitride of hydrocarbon and oxygen-containing gas in the presence of an appropriate catalyst, in particular to a method of reducing or eliminating the risk of explosion or fire in the headspace of the reactor system, in which there is a formation of the anhydride, or nitrile of hydrocarbon and oxygen.

In industry, cyclic and oleinichenko unsaturated NITRILES are obtained by oxidation of the corresponding hydrocarbon in the vapor phase in the presence of appropriate catalysts. For example, maleic anhydride is usually obtained by oxidation in the vapor phase benzene or42), water and small quantities of other partially oxidized by-products. The equipment for carrying out the reaction represents an aggregate of consecutive elements, which consists of a reactor, which forms a cyclic anhydride, or nitrile; scruber, where the anhydride, or nitrile cleared from the stream of gases flowing from the reactor; using water or another solvent for the anhydride, or nitrile followed by treatment of the purified gas stream.

Up to the present time the above method is carried out at a single pass with maximized conversion of hydrocarbons. This assesible. Therefore, the gas flow in Krubera also contains unreacted hydrocarbon and a significant amount of co and CO2. These products are usually calcined, so that the only return received from them is the heat of combustion. In the known methods of gas flow scruber return for recycling, conversion of hydrocarbons is reduced, and the selectivity of hydrocarbon conversion to the anhydride, or nitrile increases. Residual flow out of the system to prevent the increase of CO, CO2and nitrogen introduced into the system, if the source of oxygen is air). The specified improvement of the method leads to lower conversion per pass, but the overall efficiency of the method increases.

The main problem associated with the gas-phase production of anhydrides and NITRILES by oxidation of hydrocarbons using oxygen-containing gas, is that due to high temperature during operation, there is a danger of ignition or explosion in the reactor, equipment or piping connected to the reactor, the decomposition of unreacted hydrocarbons. The trend of uhlendorf with a fluidized or moving bed catalyst. In accordance with this, in the system maintain such concentrations of reactants to the mixture was outside the limits of Flammability. Although nitrogen helps lower Flammability limit of the mixture, if the source of oxygen is air Flammability limits for a mixture of hydrocarbon air are still quite broad. Therefore, usually working reactors with gas-phase production of anhydrides and NITRILES is carried out at low levels of hydrocarbon to the reaction mixture remained outside the Flammability.

It is known that under given temperature and pressure flammable gaseous mixture of a hydrocarbon with oxygen depends on the ratio of the gas components in the mixture. At very low concentrations of hydrocarbon gas mixture is non-flammable, however, at some threshold level of concentration of the hydrocarbon, the so-called lower limit of detonation (NAPs), the mixture is ignited and remains so by increasing the concentration of hydrocarbons up until the concentration of hydrocarbon reaches a certain level, called the upper limit of detonation (VPD) of the gas mixture. The limits of detonation of fuel is to obtain a gaseous cyclic anhydride, or nitrile would be desirable to carry out at concentrations of hydrocarbons within the detonation, the possibility of ignition or explosion of the reactor or associated equipment makes the above production is very dangerous.

The present invention allows to optimize the selectivity and yield of the process, even if this process occurs at concentrations of hydrocarbons within the Flammability of the mixture. To date this optimization is not possible.

The present invention relates to the improvement of the recirculation method and equipment for obtaining cyclic anhydrides and NITRILES. The method consists in the fact that the anhydride, or nitrile are obtained by partial oxidation in the vapor phase hydrocarbon with oxygen in the presence of an appropriate catalyst (as in the case of obtaining nitrile ammonia) followed by separation of the anhydride, or nitrile from the gas stream flowing from the reactor, and returning them for recycling unreacted hydrocarbon in the reaction zone. The present invention provides for maintaining the concentration of carbon monoxide in all parts of the system is high enough, such that the level of combustible components in the mixture is always kept above the level at which cm is whether nitridating flow and recirculation received enriched carbon monoxide stream to the input or output load reactor for oxidation of hydrocarbons. Unreacted hydrocarbons may be returned to the input power of the hydrocarbon reactor with enriched carbon monoxide stream that is returned for recycling. Alternatively, unreacted hydrocarbons may be removed from the stream and returned for recycling to the inlet nozzle of the reactor and enriched with carbon monoxide stream can be recycled from the exit stream from the reactor.

In accordance with one variant of the method of performing the present invention, one or more hydrocarbon starting materials to obtain anhydride, or nitrile, such as benzene, orthoxylene, naphthalene, butane or butene (in the case of obtaining anhydride and propylene or propane (in the case of obtaining nitrile), is subjected to the interaction with the oxygen-containing gas and, if necessary, with ammonia in an appropriate reactor for partial oxidation in the presence of carbon monoxide as the main gas component in order to obtain a gaseous product stream containing a cyclic anhydride, such as maleic anhydride or phthalic anhydride, or nitrile, such as Acrylonitrile or Methacrylonitrile; this particular product will depend on the form of ug which also contains carbon monoxide, carbon dioxide, unreacted hydrocarbon, oxygen and possibly small amounts of other by-products of the reaction. The gas product stream leaving the reactor for the partial oxidation process in a special cleaning devices, such as scrubber, where the anhydride, or nitrile is subjected to interaction with the liquid solvent, which removes almost all products from the gas stream. Then anhydride or matrilateral liquid discharged from the specified cleaning apparatus and process for allocation of the product. Then the whole anhydride or nitrosobenzene gas product stream or part of it is treated in the separator for carbon dioxide, which remove all the carbon dioxide or part of it, as well as some excessive amounts of carbon monoxide greater than required to maintain the system number. The residual gas stream containing primarily carbon monoxide and unreacted hydrocarbon, return for recycling to the inlet of the reactor for partial oxidation of hydrocarbons.

An alternative implementation of the method of the present invention the gas flow of scruber process in sepago thread then the separated unreacted hydrocarbon returned for recycling to the inlet of the oxidation reactor. All uglepodgotovitelnyj stream, or part of it, leaving the hydrocarbon separator, then treated in a separator for separating carbon dioxide to remove the specified carbon dioxide and excess carbon monoxide from the stream and a residual stream already enriched in carbon monoxide, return for recycling either at the entrance or the exit of the reactor for partial oxidation, or, if necessary, and the input and output of the specified reactor.

In the preferred implementation of the present invention, the oxygen-containing gas using pure oxygen. In another embodiment, the preferred embodiment of the present invention, the carbon dioxide is removed from the flow of scruber by adsorption, absorption, or by membrane separation. If the method is used to produce maleic anhydride, the preferred source hydrocarbons are4-hydrocarbons, straight chain, and the most preferred hydrocarbon straight chain is n-butane. To obtain phthalic angerd offered by way of predpochtitaemye, the preferred source hydrocarbons are3-hydrocarbons, straight chain, of which the most preferred is n-propane. To obtain Methacrylonitrile the proposed method, the preferred hydrocarbon is isobutane.

Another distinguishing feature of the present invention is a system in which the proposed method. This system includes a hydrocarbon reactor, a device for allocating a cyclic anhydride or a nitrile, a separator for separating unreacted hydrocarbon, a separator for separating carbon dioxide and connecting piping. The output of the hydrocarbon reactor is connected to the selection anhydride and nitrile. In turn, the outlet for the gas stream emanating from the device to highlight anhydride, or nitrile, connected to the entrance or in a separator for separating unreacted hydrocarbon, or in a separator for separating carbon dioxide, regardless of which of these devices is the first in the described Assembly of the successive elements. A separator for separating unreacted hydrocarbon and a separator for separating dioxide coal is the initial hole for the gas flow, emerging from the last separator in the specified unit, connected to the ventilation pipe. Described by the new system of the present invention, the pipeline for return flow resulting from separator for separating unreacted hydrocarbon, is connected to the input of the hydrocarbon reactor and piping for return flow resulting from the separator dioxide hydrocarbon, is connected to the output of the hydrocarbon reactor.

In Fig.1 presents a block diagram of one embodiment of a system for obtaining a cyclic anhydride, or nitrile in accordance with the proposed method, Fig. 2 is a block diagram of an alternative system is shown in Fig.1.

In accordance with the proposed method, the hydrocarbon in the gaseous state is subjected to a reaction between oxygen and, optionally, with ammonia in a reaction zone containing a suitable catalyst and in the presence of carbon monoxide as the main gas component in order to obtain a product gas stream containing cyclic anhydrite or oleinichenko unsaturated nitrile petrochemical product as by-products, and usually neprology the unreacted hydrocarbons return reused in the reaction zone, and carbon monoxide is returned in re-cycle on the input or output of the hydrocarbon reaction zone.

The hydrocarbon for use in the reaction is selected depending on the type of petrochemical product that you want to receive. If the target product is a cyclic anhydride, hydrocarbon source connection can be used aromatic hydrocarbons or hydrocarbon straight chain. For example, if you want to get phthalic anhydride, the preferred hydrocarbon is o-xylene or naphthalene, and if you want to get maleic anhydride, hydrocarbon typically use benzene or hydrocarbons with straight chain containing 4 carbon atoms, (C4-hydrocarbons). To obtain maleic anhydride using direct4-hydrocarbon is preferable to the use of benzene, which is a very expensive raw material. As WITH4-hydrocarbons with a direct purpose in the present invention can be used n-butane, butene and butadiene. Most preferred for obtaining maleic anhydride is n-butane, because it is less expensive than nenasyschennye other hydrocarbons such as i-butane. However, these impurities are undesirable, because it does not inhibit the production of maleic anhydride from n-butane.

On the other hand, if you want to get unsaturated nitrile, it is preferable to use a saturated straight or ethylenedeamine hydrocarbon. For example, if the target product is Methacrylonitrile, in order to get preferable to use isobutane or isobutene, and if the target product is Acrylonitrile, the hydrocarbon feedstock to obtain preferable to use propane or propylene.

Below describes in detail the method of the present invention relating to the production of maleic anhydride from n-butane and Acrylonitrile from propane, but this does not mean that the proposed method is limited to the described examples.

As the oxygen-containing gas may be air; coloradobased air; mixtures containing oxygen and an inert gas; or mostly pure oxygen. The term "coloradobased air" means air that contains more oxygen than normal air. Examples of mixtures of oxygen-inert gas are SMEs oxygen is preferred because it avoids introducing into the system an inert gas, such as nitrogen and argon, and thus required the removal of excess quantities of these inert gases from the product gas stream to prevent their formation in the system.

For a more visual description of the present invention shown in Fig.1 and 2, in which the same numbers indicate the same or similar items of equipment. Auxiliary equipment, including compressors, heat exchangers and valves, is not as necessary for a better understanding of the invention and is therefore not shown in Fig.1 and 2 and just mentioned in the discussion.

In Fig. 1 shows apparatus for carrying out the method, which includes the reactor 2 for the partial oxidation of a hydrocarbon with a device for supplying raw material 4 and the device yield (pipeline) 6. The pipeline 6 for upcoming product is connected to the device 8 for the regeneration of petrochemical product, which may be a capacitor or Krubera, in which the cleaning liquid enters through the pipe 10, and a liquid product exits through the exhaust manifold 12. The device 8 to highlight Neftehimik the meters of gas, connected to the separator 16 for separating carbon dioxide. The separator 16 is provided with a discharge pipe 18 to a gas stream that is connected via speaker wire for recycling 20 with an input device to feed 4. The system depicted in Fig.1, may also be provided with a bypass pipe 22, controlled by valve 24.

Reactor 2 may be any suitable reactor, but is usually used for this purpose reactor with a fixed, moving, fluidized, or a portable layer of catalyst. Reactor 2 may be provided with a heat exchanger (not shown) for removing heat generated in the reaction, which is exothermic. Specific design details of the respective reactors are well known and they are not part of the present invention. If the device is to highlight the product 8 is a scrubber, i.e., the absorber, usually it is a device with a nozzle, which in the apparatus of the present invention is equipped with means for spraying water or an aqueous or anhydrous liquid product gas, part of this device from the reactor 2. The separator 16 is used to separate carbon dioxide and other inert gases from a gas stream flow is parator 16 is typically a canister or device for membrane separation. In a preferred embodiment of the present invention, the separator 16 is an adsorption device with a pressure difference (PSA) or temperature difference (TSA).

In Fig. 2 shows a diagram of a variant of the system shown in Fig.1. In this embodiment, the Assembly includes a hydrocarbon separator 26 and the modified piping system. Hydrocarbon separator 26 may be any device capable of selective separation of gaseous hydrocarbons from the gas mixture. In preferred embodiments, the implementation of the present invention the separator 26 is PSA or TSA-device. Additional details regarding the separators 16 and 26, described below.

In the pipe system shown in Fig.2, line 14 connects the outlet of the scrubber 8 to the input of the hydrocarbon separator 26. A pipe 28 connects the output of the hydrocarbon separator 26 to the input of the separator 16 for separating carbon dioxide and return line 30 connects the hydrocarbon separator 26 with a device for supplying raw material 4. In addition, the bypass line 22, controlled by valve 24 connects the pipe 28 with the return pipe 20; the bypass Truboprovod the flow rate of liquid through the pipe 20 to the input device 4.

As mentioned above, the separators 16 and 26 can be any suitable device for separating a desired component (unreacted hydrocarbon or carbon monoxide or both) from a gas stream coming from the scrubber. However, the most preferred are the adsorption device with the pressure difference. Adsorption with the differential pressure is a well-known method of separating components of a gas mixture by using the difference in the degree of adsorption of gases in a mixture to the adsorbent of the particles fixed in a stationary layer. Usually two or more of these layers operate in a cyclic process involving adsorption at relatively high pressure and desorption or regeneration layer at a relatively low pressure or vacuum. The desired component or components may be obtained during any of these stages. The cycle may contain other steps in addition to the basic stages of adsorption and regeneration. Usually there are two or more layers of adsorbent with a phase shift of 180aboutto guarantee pseudoepherine flow of the desired product. Although the standard stage adsorption PSA cycle is carried out under pressure, but it can be about the system, is depicted in Fig.1, the raw material containing the corresponding hydrocarbon, oxygen-containing gas and return gas flow is introduced into the reactor 2 through the input device 4, which may contain one inlet pipe through which the mixture of gaseous reactants and diluents enters the reactor 2; or the specified input device may contain several separate inlet conduits for the separate introduction of the reactants into the reactor. The choice of a particular inlet device depends mainly on the type of reactor used for carrying out the present invention. In the reaction system with a fixed bed of the catalyst components are often mixed before introduction into the reactor, after which the resulting mixture was fed into the reactor through a single pipeline, whereas in the reaction system with a fluidized bed of catalyst components are fed into the reactor separately.

The source gases entering the reactor 2, in contact with the catalyst in the reaction to form product gases. The proposed method can be used any of the known catalysts for the oxidation of hydrocarbons to obtain the desired petrochemical product in a specific procatalyse based on vanadium oxide such as vanadium oxide, vanadium oxide/molybdenum, vanadium oxide/phosphorus and vanadium oxide/titanium. For ammoxidation of hydrocarbons to synthesis of NITRILES suitable catalysts are iron oxide and antimony and bismuth oxides and antimony. These catalysts and their use are well known to the specialists in the production of petrochemical products. For the implementation of the proposed method, in particular for the partial oxidation of hydrocarbons, the use of any particular catalyst is not the decisive factor.

Conditions for partial oxidation of hydrocarbons are well known to specialists. As a rule, the reaction of partial oxidation is carried out at a temperature of from about 250aboutWith up to 600aboutWith, but mainly from about 300aboutWith up to 500aboutWith and at low pressure, typically in the range from 13,788 to 344,7 kPa, but mainly from 20,682 to 206,82 kPa. Typically, the reactants are passed through the reactor at a rate from 152,4 to 1524 mm/s Relationship of oxygen to the hydrocarbon and ammonia to hydrocarbon (in the case of obtaining nitrile) in the feed mixture are from about 0.3:1 to 10:1 and about 0.8:1 to 1.3:1 (by volume) respectively.

The stream of product gas emerging from the reactor wakes carbon and carbon monoxide. As mentioned above, typically, the product stream also contains unreacted hydrocarbon and oxygen, and may contain small amounts of other by-products of the impurity gases and unreacted hydrocarbons. The product gas stream flows from the reactor 2 through line 6 and passes through a heat exchanger (not shown) where it is cooled to a temperature of from about 30aboutWith up to 200aboutC. Then cooled product gas stream passes into the device 8 for the regeneration of petrochemical product, where that product is recovered from the gas stream. This product is dissolved in a solvent, which dissolves almost all petrochemical products, after which the solution containing petrochemical product, out of scruber 8 through line 12. To highlight petrochemical product usually spend additional processing. Purified gas stream exits the scrubber 8 (Krubera) through the pipe 14 and enters the separator 16.

The main purpose of the separator 16 is the prevention of the formation of carbon dioxide and other inert gases in the system. For the optimization process, it is preferable to recycling only monoxide opentrace in the system will increase, and eventually dilute the concentration of carbon monoxide until the moment when the mixture is ignited. To avoid this possibility, it is necessary to remove only the amount of carbon dioxide equal to the number of CO2produced in the reactor 2 for each passage.

The separator 16 is also used to remove excess amounts of carbon monoxide, more than necessary for recirculation amount, and other inert gases from the system. During the continuous reaction of partial oxidation of carbon monoxide is a by-product. After uravnoveshivanie carbon monoxide in amounts approximately equal to the quantity produced in a stage of partial oxidation for each passage, is removed by means of the separator 16 in order to prevent the accumulation of carbon monoxide in the system. Other inert gases, like nitrogen and argon (entered into the system using air as the oxygen source), also removed from the system by means of a separator 16. In this situation, the separator 16 may be a single separator or a series of consecutive separators. In order to avoid accumulation of nitrogen and argon in the system when using bozdaktar 2 together with fresh raw materials.

When the system depicted in Fig.1, work with a closed bypass pipeline 22, the return carbon monoxide and all unreacted hydrocarbons emerging from separator 16 through line 20 and is returned to the reactor inlet 2. In some cases, it is preferable that a portion of the gas stream leaving the device 8 for purification of petrochemical product was on bypass the separator 16. This can be accomplished by a partial opening of the valve 24. The alternative is predominant in the case when it is necessary that all carbon monoxide is intended for recycling, passed through line 22. This would allow the separator 16 to work in this mode, in which the flow entering the separator was removed would only unreacted hydrocarbon. Partially adjustable via the bypass (bypass) the separator 16 is particularly preferred when the oxidant within the reactor 2, is essentially pure oxygen, because the flow through the pipe 22, is then largely free from inert gases and not from carbon dioxide.

Gas mixture at all points in the reaction system is maintained nevosplamenimogo p the Finance inflammable gas mixture. In other words, the concentration of carbon monoxide in the system should be high enough, i.e. such that the total concentration of combustible materials (hydrocarbon reactant and carbon monoxide) always remained above the upper limit of detonation (VPD) for the system. In the reaction systems of the present invention, carbon monoxide is present as the main gas component, i.e., carbon monoxide is present in the reaction system in a concentration exceeding the concentration of any gas component. The concentration of carbon monoxide in the system should be maintained preferably at a sufficiently high level so that she alone prevented the system from the formation of the inflammable mixture at any point. The concentration of carbon monoxide required to ensure this effect will vary from system to system, but generally this result can be achieved if the content of carbon monoxide in the system is at least 30% of the volume of all gases in the system. In the most preferred implementation of the present invention, the content of carbon monoxide is at least 40% by volume of all gases in the system. Most were prepotentials at the lowest possible level.

Flammability of the gas mixture at any point in the system depends on the temperature of the gas mixture to such an extent at which the temperature increase leads to an increase of the limits of Flammability. As mentioned above, the temperature at which the oxidation reaction, generally ranges from about 250aboutWith up to 600aboutC. Thus, for the standard way the possibility of ignition or explosion in the reactor oxidation is quite significant. However, it was also discovered that a flammable hydrocarbon gas mixture in the reactor is significantly reduced in the presence in the reactor of a catalyst, so that practically the danger of explosion in the reactor is small.

However, the product gas stream exiting the reactor 2, contains a very small amount of catalyst or in General it does not contain and is very hot due to the partial oxidation reaction. Therefore, there is a significant danger that the flammable components in the product gas stream will be ignited when entering or after leaving the reactor 2 and just before it is cooled, if the flow reactor will not be present in high concentration monoxide ugley the entire system from the danger of ignition or explosion.

Sometimes it is necessary to provide maximum protection in the area immediately after the reaction zone of the partial oxidation of the hydrocarbon while maintaining the maximum flow rate of reactants through the reactor 2. This alternative implementation of the present invention, illustrated in Fig. 2, specially adapted for the above result. In the process performed in the system shown in Fig.2, a part or all of the return flow of carbon monoxide can be introduced into the system in place, located behind the reaction zone of the reactor 2. This alternative is feasible, because, as noted above, the oxidation catalyst itself performs the function of flame retardant in the reactor. This variant embodiment of the invention has the advantage that it ensures the presence of carbon monoxide in the system, where it is most needed, and at the same time allows a greater flow of reactants through the reactor 2, thereby increasing system performance. The introduction of carbon monoxide in the product stream of the reactor serves not only to prevent the formation of the product gas mixture, under opredeleniya mixture, because carbon monoxide itself is cold.

In the proposed method, implemented in the system shown in Fig.2, the gas stream coming from the device 8 to highlight the petrochemical product, process, the hydrocarbon separator 26 to remove basically all unreacted hydrocarbon from the gas stream depleted in petrochemical; and the separated unreacted hydrocarbon in return repetitive cycle on the boot end of the reactor 2 for the partial oxidation of hydrocarbons. Then part or all of depleted hydrocarbon stream coming from the hydrocarbon separator process separator 16 to remove carbon dioxide and excess carbon monoxide from the stream, and the remaining stream already enriched in carbon monoxide comes from separator 16 through line 20 and is returned in re-cycle or at the entrance of the reactor for partial oxidation of a hydrocarbon by opening the valve 32 and closing of the valve 36, or on the output side of the reactor 2 by opening valve 36 and closing valve 32, or on both sides by opening valves 32 and 36. As in the case of the variant of the system shown in Fig.1, part of the PTS 16 by opening valve 24.

In the implementation of the proposed method an additional quantity of carbon monoxide can be first entered into the system with the raw material or a high concentration of carbon dioxide may from the outset be maintained in the system to ensure that the gas mixture remained outside the Flammability. Then, since the concentration of carbon monoxide will increase, additional amounts of carbon monoxide or an excess of carbon dioxide will gradually decrease and disappear when the system reaches a desired equilibrium state. At this stage, carbon monoxide can be easily maintained at a desired level by regulating the amount of recoverable carbon monoxide.

It should be noted that the scope of the present invention includes the use of standard equipment for tracking and automatic regulation of the flow of gases in the system so that it can be fully automated for the effective implementation of continuous process.

An important advantage of the present invention is that it allows the reaction of partial oxidation of hydrocarbons using the initial concentration of hydrocarbon, C partial oxidation of a hydrocarbon or equipment, associated with the specified reactor. Another advantage is that the reaction of partial oxidation can be reliably carried out without the use of an inert gas diluent such as nitrogen. The proposed method also stands out for its simplicity, ease of implementation, low capital and operating costs and a significantly lower probability of ignition. The method may be carried out at a relatively low per pass conversion of the original hydrocarbon in the target product in order to achieve a significantly higher selectivity. In this regard, it should be noted that the system which achieves high selectivity, and therefore an increased overall yield of the target product, has a great advantage.

The present invention is illustrated by the following examples in which all parts, percentages and relationships are based on the total amount, if it is not specifically mentioned.

P R I m e R 1. The sequence of maleic anhydride in the vapor phase was modeled in the reactor with a fluidized bed of catalyst is shown in Fig.1. Similar raw materials supplied to the hydrocarbon reactor, steave use headspace hydrocarbon reactor, containing a fluidized bed of a catalyst of vanadium oxide-phosphorus and the adsorber with the differential pressure, the adsorption layer containing molecular sieves. The speed of the various threads and the results obtained are presented in table.1.

P R I m m e R 2. The process of obtaining Acrylonitrile in the vapor phase was modeled in the reactor to the fluidized bed, is shown in Fig. 1. Similar raw materials supplied to the hydrocarbon reactor contained a fresh source component and the component return flow. The reaction was modeled based on the use of a vapor-phase carbon reactor containing a fluidized bed of catalyst, and the adsorber with the pressure difference adsorption layer containing molecular sieves. The speed of the various threads and the results obtained are presented in table.1-4.

D o p o l n t I l n m s p R I m m e R. Presents a hypothetical vapor phase of the experience of receiving phthalic anhydride in a reactor with a fixed bed of the catalyst obtained by using a reactor system similar to those shown in Fig.1. The initial reaction mixture in the hydrocarbon reactor contains fresh source component and component recycled stream. The OS is a mash of oxides of vanadium and titanium, and vibration absorber high pressure adsorption layer containing molecular sieves. Different feed rate and the results are presented in table.4.

1. The method of obtaining cyclic anhydrides or aliphatic NITRILES, comprising: a) contacting in a reactor in the vapor phase hydrocarbon, oxygen-containing gas and, optionally, ammonia in the presence of a catalyst partial oxidation and carbon monoxide as the main gaseous component under conditions that allow to obtain a gaseous product containing the target product, carbon monoxide and carbon dioxide, with the specified hydrocarbon selected from benzene, naphthalene orthoxylene and C4hydrocarbons (straight chain in the case of obtaining a cyclic anhydride or a specified hydrocarbon selected from propane, propylene, isobutene, isobutane or mixtures thereof, in the case of obtaining aliphatic nitrile; C) the allocation of a specified gaseous product the target product; (C) return the residual gaseous product in the reactor, characterized in that before returning the residual gaseous product in the reaction zone is separated from it the carbon dioxide to maintain a sufficiently high the system, to prevent the presence of inflammable mixture.

2. The method according to p. 1, characterized in that get maleic anhydride, using as hydrocarbon hydrocarbon straight chain containing four carbon atoms.

3. The method according to p. 2, characterized in that said hydrocarbon is n-butane.

4. The method according to p. 1, characterized in that to obtain phthalic anhydride is used as the hydrocarbon orthoxylene.

5. The method according to p. 1, characterized in that the Acrylonitrile using propane, propylene or a mixture thereof as a hydrocarbon.

6. The method according to p. 1, characterized in that Methacrylonitrile, using as hydrocarbon isobutane, isobutene or their mixture.

7. The method according to PP.1 to 6, characterized in that the oxygen-containing gas is substantially pure oxygen.

8. The method according to any of paragraphs.1 to 7, characterized in that the process is conducted in a reactor with a fluidized bed.

9. The method according to PP.1 to 8, characterized in that the carbon dioxide is separated from the specified gaseous product adsorption.

10. The method according to p. 9, characterized in that the carbon dioxide is separated from the specified gr CLASS="ptx2">

11. The method of obtaining maleic anhydride, comprising (a)contacting in a reactor in the vapor phase hydrocarbon straight chain containing four carbon atoms, and essentially pure oxygen in the presence of a fluidized bed of oxidation catalyst and the carbon monoxide as the main gaseous component under conditions that allow to obtain a gaseous product containing a specified anhydride, unreacted hydrocarbons, carbon dioxide and carbon monoxide; (b)the allocation of the specified anhydride from the specified stream of a gaseous product, wherein (c)separating unreacted hydrocarbon and carbon monoxide from a stream of a gaseous product; (d)return the separated unreacted hydrocarbon to the reactor inlet partial oxidation; (e)returning the separated carbon monoxide, which if necessary, remove part or all of the remaining carbon dioxide, or to the input of the partial oxidation reactor or the reactor outlet of the oxidation, and the total concentration of carbon monoxide and hydrocarbons present in the system which provide the specified process, supports a sufficiently high for the specified process is lonitrile, comprising (a)contacting in the vapor phase in the reactor hydrocarbon selected from propane, propylene, isobutane, isobutene or their mixtures, ammonia and substantially pure oxygen in the presence of amoxicillinno catalyst and the carbon monoxide as the main gaseous component under conditions that allow to receive a stream of a gaseous product containing a specified nitrile, unreacted hydrocarbons, carbon dioxide and carbon monoxide; (b)the allocation of the specified nitrile from the specified stream of a gaseous product, wherein (c)separating unreacted hydrocarbon and carbon monoxide from a stream of a gaseous product; (d)return the separated unreacted hydrocarbon to the reactor inlet partial oxidation; (e)returning the separated carbon monoxide, from which previously removed part or all of the remaining carbon dioxide, or to the input of the partial oxidation reactor or the reactor outlet of the oxidation, and the total concentration of carbon monoxide and hydrocarbons present in the system which provide the specified process, support is high enough for this process to prevent the presence of inflammable mixture.


 

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30 cl, 1 dwg, 3 ex

FIELD: chemistry.

SUBSTANCE: mixed metal oxide catalyst based on antimonite in a catalytic active oxidation state has the empirical formula: MeaSbbXcQdReOf, where Me is at least one element from the group: Fe, Co, Ni, Sn, U, Cr, Cu, Mn, Ti, Th, Ce, Pr, Sm, or Nd; X is at least one element from the group: V, Mo, or W; Q is at least one element from the group: Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Sc, Y, La, Zr, Hf, Nb, Ta, Re, Ru, Os, Rh, Ir, Pd, Pt, Ag, Au, Zn, Cd, Hg, Al, Ga, In, Tl, Ge, Pb, As, or Se; R is at least one element from the group: Bi, B, P, or Te; and the indices a, b, c, d, e and f denote atomic ratios: a has a value from 0.1 to 15; b has a value from 1 to 100; c has a value from 0 to 20; d has a value from 0 to 20; e has a value from 0 to 10 and f is a number, taken to fulfill the valency requirements of the metals answering for the oxidation degree they have in the composition of the catalyst. Method of obtaining such a catalyst includes the following stages. At first they are subjected to aqueous suspension of Sb2O3 with HNO3 and with one or more compounds of Me, and voluntarily with one or more compounds from the groups: X, Q or R, for obtaining the first mixture (a). The first mixture is then heated and dried to form a solid product (b). After this the solid product is calcinated forming the catalyst. The particular metal oxide catalyst based on antimonite in the catalytic active oxidation state as per the invention has the empirical formula: Ua'FeaSbbMocBieOf, where the indices a, a', b, c, e and f denote atomic ratios: a has a value from 0.1 to 5; a' has a value from 0.1 to 5; b has a value from 1 to 10; c has a value from 0.001 to 0.2; e has a value from 0.001 to 0.2; and f is a number, taken to fulfill the valency requirements of Sb, U, Fe, Bi, and Mo, answering for the oxidation degree they have in the composition of the catalyst. Method of obtaining such a catalyst includes the following stages. At first they are subjected to aqueous suspension of Sb2O3 with HNO3, oxides or nitrates of bismuth and oxides or nitrates of uranium to form the first mixture (a). The first mixture is then heated under temperature and in a period of time, enough for the induction of the process for the formation of the antimonic oxide crystals and formation of the second mixture (b). An aqueous solution of a ferric compound iss then added to the second mixture for the formation of a third mixture (c). The pH of the third mixture is regulated in the range of 7 - 8.5, a precipitate of a hydrated mixture of oxides in the aqueous phase is formed (d). The precipitate is separated from the aqueous phase (e). An aqueous suspension of precipitate components of hydrated mixed oxides is obtained (f). Molybdate is added to the suspension component of hydrated mixed oxides (g). A suspension of hydrated mixed oxides of Molybdate component in the form of dy particles is formed (h). Later the calcination of the dry particles with the formation of the catalyst is carried out (i).

EFFECT: increase in the activity and selectivity of the catalyst.

30 cl, 2 tbl, 7 ex

FIELD: chemistry.

SUBSTANCE: invention concerns improved method of obtaining at least one product of partial propylene oxidation and/or ammoxidation, propylene selected out of group including propyleneoxide, acrolein, acrylic acid and acrylnitryl, where source substance is propane. Method involves a) at the first stage, homogeneous and/or heterogeneous catalysed dehydration and/or oxydehydration of raw propane in the presence and/or in the absence of oxygen, to obtain gas mix containing propane and propylene; and b) if required, separation of part gas mix 1 obtained at the first stage and its components other than propane and propylene, such as hydrogen, carbon monoxide, or transformation of this part in the other compounds, such as water, carbon dioxide, so that gas mix 1' containing propane and propylene and compounds other than oxygen, propane and propylene is obtained from gas mix 1; and at least one more stage c) heterogeneous catalysed ammoxidation and/or partial gas phase ammoxidation of propylene containing in gas mix 1 and/or gas mix 1' in gas mix 1 or gas mix 1' containing molecular oxygen of gas mix 2, where total C4-hydrocarbon content in gas mix 2 is < 3 volume %.

EFFECT: reduced process performance due to reduced output of target product and enhanced selectivity of carbon oxide generation at the second process stage.

50 cl, 10 ex

FIELD: chemistry.

SUBSTANCE: described is mass of metal oxides, intended as catalyst for heterogeneously-catalysed partial oxidation and/or ammoxidation of at least one saturated and/or unsaturated hydrocarbon, of general stechiometry I MO1VaM1bM2cM3dOn (I), were M1= stands for Te; M2=stands for Nb; M3= stands for at least one of elements from group, which includes Pb, Ni, Co, Bi and Pd; a = 0.05 to 0.6, b= 0.01 to 0.5, c= 0.01 to 0.5, d = 0.0005 to 0.5 and n= equals the number determined by valence and number of different from oxygen elements in (I), whose X-ray diffractogragm has diffraction reflexes h, i and k , whose peaks are at diffraction angles (2Θ) 22.2±0.5° (h), 27.3±0.5° (i) and 28.2±0.5° (k), and - diffraction reflex h in the range of X-ray diffractogram is the most intensive and has peak half-width maximal value 0.5°, intensity Pi of diffraction reflex i and intensity Pk fulfill ratio 0.65≤R≤0.85, in which R is determined by formula R=Pi/(Pi+Pk) intensity ratio, and - half-width of diffraction reflex i and diffraction reflex k each constitute ≤1°, and at least one mass of metal oxides (I) represents such, X-ray diffractogram of which does not have diffraction reflex with peak position 2Θ=50.0±0.3°. Described is mass of metal oxides, which contains equal or more than 80 wt % of at least one mass of metal oxides, indicated above, and whose X-ray diffractogram has diffraction reflex with peak 2Θ=50.0±0.3°.Also described are methods of heterogeneously catalysed partial gas phase oxidation or ammoxidation of at least one saturated or unsaturated hydrocarbon, using as catalytic active mass at least one mass of metal oxides, described above. Described is method of obtaining metal oxides mass by mixing sources of its elementary components, calcination of dry mixture at 350-700°C and washing by organic and/or inorganic acid solution.

EFFECT: increasing target product selectivity.

17 cl, 1 tbl, 16 ex, 17 dwg

FIELD: chemistry.

SUBSTANCE: present invention relates to mixed metal oxide oxidation catalysts and ammonolysis of propane and isobutane, methods of obtaining them and usage. Described is a mixed metal-oxide system, containing molybdenum, vanadium, niobium, antimony, germanium and oxygen or molybdenum, vanadium, tantalum, antimony, germanium and oxygen, with the following stoichiometric ratios of elements: molybdenum to antimony from 1:0.1 to approximately 1:0.5, and molybdenum to germanium from 1:>0.2 to approximately 1:1. Description is given of a catalyst, which is a mixed metal-oxide system, effective in vapour-phase conversion of propane to acrylic acid or acrylonitrile or conversion of isobutane to methacrylic acid or methacrylonitrile. The mixed metal-oxide system has an empirical formula Mo1VaNbbSbcGedOx or Mo1VaTabSbcGedOx, in which a ranges between 0.1 and 0.6, b ranges between 0.02 and 0.12, c ranges between 0.1 and 0.5, d ranges from more than 0.2 to 1, and x depends on the oxidation number of other elements in the mixed metal-oxide system. Described also is a method of obtaining the system described above, involving the following stages: addition into a reaction vessel of precursors Mo, V, Nb or Ta, Ge and Sb in an aqueous solvent to form a reaction medium with initial pH 4 or less, and optional addition of another aqueous solvent into the reaction vessel; sealing the reaction vessel; reaction of the reaction mixture at temperature above 100°C and pressure above atmospheric pressure for a period of time, sufficient for formation of a mixed metal-oxide system; optional cooling of the reaction mixture; and extraction of the mixed metal-oxide system from the reaction mixture. Description is given of a method of converting propane into acrylonitrile and isobutane into methacrylonitrile using the catalyst described above.

EFFECT: simple technology of making catalyst, increased catalyst activity and output of the target product in reactions of oxidative ammonolysis of propane and isobutane.

27 cl, 8 tbl, 50 ex, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method for oxidative ammonolysis in the presence of mixed metal oxide catalysts. The method for oxidative ammonolysis to obtain an unsaturated nitrile involves bringing saturated or unsaturated hydrocarbon or a mixture of saturated or unsaturated hydrocarbon with ammonia and an oxygen-containing gas in the presence of a catalyst composition containing molybdenum, vanadium, antimony, niobium, tellurium, at least one element selected from a group consisting of titanium, tin, germanium, zirconium, hafnium and mixtures thereof, at least one lanthanide selected from a group consisting of lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium and mixtures thereof. Disclosed is a version of the method for oxidative ammonolysis, where the catalyst contains, in addition to the listed elements, lithium and an element selected from sodium, caesium, rubidium and mixture thereof.

EFFECT: catalysts are characterised by very low content of tellurium in the composition, catalyst compositions are effective in gas-phase conversion of propane to acrylonitrile and isobutane to methacrylonitrile.

25 cl, 2 tbl, 15 ex

FIELD: chemistry.

SUBSTANCE: invention relates to hydrocarbon oxidation catalysts. Described is a catalyst for oxidising hydrocarbons during gas-phase contact, containing a mixed oxide of molybdenum (Mo), vanadium (V), tellurium (Te) and niobium (Nb), having chemical formula 1: Mo1.0VaTebNbcon, (l) where a, b or c independently denotes atomic molar ratios of vanadium, tellurium or niobium, provided that 0.01≤a≤1, 0.01≤b≤1, 0.01≤c≤1 and n denotes the atomic molar ratio of oxygen, which is determined by valence and atomic molar ratios of vanadium, tellurium and niobium, and tungsten (W) or tungsten oxide bonded to the mixed metal oxide, where the atomic molar ratio of tungsten bonded to the mixed metal oxide and molybdenum contained in the mixed metal oxide ranges from 0.00001:1 to 0.02:1. Described is a method of producing said catalyst involving steps for: preparing a first mixture of molybdenum (Mo) precursor, a vanadium (V) precursor, a tellurium precursor (Te), a niobium precursor (Nb) and acid; obtaining a mixed oxide of molybdenum (Mo), vanadium (V), tellurium (Te) and niobium (Nb) by calcining the first mixture; preparing a second mixture of mixed metal oxide and the tungsten precursor and calcining the second mixture. Described is a method for gas-phase oxidation of hydrocarbons, involving oxidation of hydrocarbons in the presence of the catalyst described above.

EFFECT: high activity and selectivity of the catalyst.

10 cl, 2 tbl, 12 ex

FIELD: chemistry.

SUBSTANCE: described is a catalyst for oxidising hydrocarbons during gas-phase contact, containing a mixed oxide of molybdenum (Mo), vanadium (V), tellurium (Te) and niobium (Nb), having chemical formula 1: Mo10VaTebNbcOn, (1) where a, b or c independently denotes atomic molar ratios of vanadium, tellurium or niobium, provided that 0.01≤a≤1, 0.01≤b≤1, 0.01≤c≤1 and n denotes the atomic molar ratio of oxygen, which is determined by valence and atomic molar ratios of vanadium, tellurium and niobium, and palladium (Pd) or palladium oxide bonded to the mixed metal oxide, where the atomic molar ratio of palladium bonded to the mixed metal oxide and molybdenum contained in the mixed metal oxide ranges from 0.00001:1 to 0.02:1. Described is a method of producing said catalyst, comprising steps for: preparing a first mixture of a molybdenum (Mo) precursor, a vanadium (V) precursor, a tellurium precursor (Te), a niobium precursor (Nb) and an acid; preparing a mixed oxide of molybdenum (Mo), vanadium (V), tellurium (Te) and niobium (Nb) by calcining the first mixture; preparing a second mixture of mixed metal oxide and a palladium precursor and calcining the second mixture. Described is a method for gas-phase oxidation of hydrocarbons, involving oxidation of hydrocarbons in the presence of the catalyst described above.

EFFECT: high activity and selectivity of the catalyst.

10 cl, 2 tbl, 12 cl

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing acrylonitrile from glycerine. The method involves a first step for gas-phase dehydration of glycerine in the presence of a catalyst having Hammett acidity, denoted by H0, less than +2, at temperature ranging from 150°C to 500°C and at pressure and at pressure ranging from 1 to 5 bar, to obtain acrolein; a second step for ammoxidation of acrolein on an ammoxidation catalyst at temperature ranging from 300°C to 550°C and at pressure ranging from 1 to 5 bar, to obtain acrylonitrile; and an intermediate step for partial condensation of water and heavy byproducts obtained at the dehydration step. The invention also relates to acrylonitrile with 14C content of the order 10-10 wt % with respect to total weight of carbon which can be obtained using the method given above.

EFFECT: method enables to optimise the acrolein ammoxidation step by reducing the amount of water and impurities in a stream rich in acrolein.

3 cl, 2 dwg, 1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to N-[2,4-dioxo-6-(tetrahydrofuran-2-yl)-7-trifluoromethyl-1,4-dihydro-2H-quinazolin-3-yl]methanesulphonamide and N-[6-(1-isopropoxyethyl)-2,4-dioxo-7-trifluoromethyl-1,4-dihydro-2H- quinazolin-3-yl] methanesulphonamide, having antagonistic activity on the AMPA receptor. The invention also relates to a pharmaceutical composition.

EFFECT: use of said compounds to produce drugs for treating AMPA mediated conditions and primarily for treating epilepsy or schizophrenia.

6 cl, 81 ex

FIELD: physics; operation.

SUBSTANCE: invention relates to the chemical industry, particularly to the automatic control systems and can be used for temperature support of the reaction mixture in chemical reactors. The system of automatic temperature profile support in the reactor with distributed constants in maleic anhydride production contains two control systems: cascade automatic control system (ACS) of coolant temperature control in the reactor and ACS of benzene-air mixture fed to the reactor where the correction signal is inleted according to reaction mixture temperature. The correction signal represents the sum of the signals about reaction mixture temperature in the measurement points positioned along the reactor height multiplied to the weight factor determined intuitively or from optimization problem solution. Then the correction signal is compared with assignment signal on the functional generator serving as algebraic adder. The invention allows to increase the temperature support accuracy in the reactor at maleic anhydride production.

EFFECT: increasing of the temperature support accuracy in the reactor.

2 cl, 2 dwg

FIELD: chemistry.

SUBSTANCE: described are 2,4,6-phenyl-substituted cyclic ketoenols of formula (I, in which W, X, Y and CKE are given in invention formula. Also described are esters of acylamino acids of formula (II), substituted derivatives of phenylacetic acid of formula (XXIX), (XXVII), (XXXI), which are intermediate compounds for obtaining formula (I) compound.

EFFECT: obtaining herbicidal preparation containing combinations of biologically active substances, including (a), formula (I) compound and (b') improving compatibility with cultural plants mefenpyr-diethyl, with weight ratio 5-1:1-7.7.

9 cl, 46 tbl, 36 ex

FIELD: chemistry.

SUBSTANCE: method of purifying maleic anhydride involves heating molten initial crude product to 60-65°C and then cooling to 53-54°C and filtering at temperature of 51.5-53°C. Filtration is carried out on a filter with hole size of 0.01-0.05 mm and the molten mass is thermally processed in an atmosphere of dry inert gas or in sealed conditions in an atmosphere of dry inert gas.

EFFECT: high technological effectiveness of the process owing to its short duration and use of lower temperature parametres and higher degree of purification of maleic anhydride.

1 cl, 1 ex

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