Method of preparing mixture of cyclohexanol and cyclohexanone

FIELD: chemistry.

SUBSTANCE: method involves a step for oxidising cyclohexane to obtain cyclohexyl hydroperoxide, a step for catalytic decomposition of cyclohexyl hydroperoxide on a heterogeneous catalyst to obtain a mixture of cyclohexanol and cyclohexanone and a step for distilling cyclohexane, carried out at high temperature and pressure. Said steps form a single circulation loop in which the reaction mixture is circulated through transfer of cyclohexane vapour from the boiler of the distillation apparatus into an oxidation reactor, as well as due to subsequent spontaneous overflow under gravitational forces of the liquid reaction mixture from the oxidation reactor to a decomposition reactor and then into the boiler of the distillation apparatus. The cyclohexane oxidation reactor lies over the cyclohexyl hydroperoxide decomposition reactor which is on the same level as or below the level of the boiler of the distillation apparatus. Conversion of cyclohexane in the oxidation zone is not more than 1.0 mol % and conversion of cyclohexyl hydroperoxide in the decomposition zone is not less than 90.0 mol %.

EFFECT: high selectivity of the cyclohexane oxidation process.

8 cl, 1 tbl, 1 dwg, 15 ex

 

The invention relates to a process of obtaining a mixture of cyclohexanol and cyclohexanone by oxidation of cyclohexane and may find application in the chemical industry. Cyclohexanone and cyclohexanol are intermediates in the production of polyamides of nylon-6 and nylon-6,6.

The most common way of obtaining them is the oxidation of cyclohexane with oxygen. The oxidation of cyclohexane is carried out in such a way that results in Okidata - mixtures containing ketone - cyclohexanone (K), alcohol, cyclohexanol (A) and cyclohexylpropionic (CHHP) in cyclohexane. The product is available from oxidate and consisting of ketone and alcohol, usually called KA-oil.

Describes the different ways of obtaining a mixture of cyclohexanone and cyclohexanol. The most common is the oxidation of cyclohexane with oxygen. Thus get more 60% of the world production of cyclohexanone. The most well-known technology for the oxidation of cyclohexane in the presence of a homogeneous catalyst soluble salts of cobalt (US 3957876, US 4587363, DE 3733782). The disadvantage of this method of producing cyclohexanone and cyclohexanol is the low conversion of cyclohexane (4-6 mol.%) and low selectivity of the conversion of cyclohexane to KA oil-(75-85 mol.%).

Known two-stage method for producing cyclohexanol and cyclohexanone is through the intermediate formation of cyclohexylpiperazine. In the first phase oxidation of cyclohexane is carried out similarly to the above-described method, but without adding to the reaction mixture of soluble salts of cobalt. To increase the output CHHP in the reaction mixture derived phenol (EN 2116290), Na pyrophosphate (K) (CA 1262359) or ester of phosphoric acid (US 4675450).

In the second stage SNR turn in KA-oil using heterogeneous catalysts (EP 659726, US 4503257, US 5004837, JP 63277640, US 4499305)and soluble in the reaction mixture of salts of transition metals (US 4257950, US 4508923, US 4704476, US 5206441, US 4482746, US 4918238, CA 1294984, US 4877903, EP 92876, US 4238415). Reduce the formation of by-products of the decomposition process SNR carried out, as a rule, at 20-40°C lower than the oxidation of cyclohexane.

A known method of producing alcohols and ketones (US 5859301, B01J 23/34, C07C 29/132, 12.01.1999), which includes a step of oxidation of the corresponding alkane and/or alkene with formation of a reaction mixture containing alkylhydroperoxide, the stage of processing of the reaction mixture aqueous alkaline solution and the stage of decomposition of alkylhydroperoxide in the presence of a heterogeneous catalyst, the active component which is an oxide of a metal selected from the range of: Mn, Fe, Co, Ni and Cu, and the carrier consists of a material resistant to the alkaline aqueous phase. The optimum conditions for the oxidation of cyclohexane and laid out what I CHHP differ. Typically, the decomposition is carried out at a lower temperature, which is accompanied by a pressure decrease. According to US 5859301 selectivity of transformation SNR in KA-oil close to 100%, it is obvious that the total selectivity of the process will be determined by the selectivity of the conversion of cyclohexane in CHHP. Such organization of the process and conversion of cyclohexane at the stage of oxidation in the range from 3 to 6 mol.% the total selectivity of the process can not be higher than 80-85 mol.%.

As a prototype we have chosen the way of cyclohexanol and cyclohexanone, which is described in patent US 6703529, C07C 35/08, 9.03.04. The method includes: 1) the oxidation of cyclohexane with the formation of steam and gas waste oxidation of cyclohexane and liquid oxidate, including the main oxidation products of cyclohexanone, cyclohexanol and cyclohexylpropionic in cyclohexane; 2) contacting the steam-waste process for the oxidation of cyclohexane with water, 3) mixing the liquid flows generated in stage 1 and 2, and the separation of mixtures of water and organic phases; 4) decomposition of cyclohexylpiperazine in the organic phase coming from the stage 3 with the formation of cyclohexanone and cyclohexanol; 5) distillation of cyclohexane from its oxidation products and the return of cyclohexane at stage 1; 6) isolation and purification of cyclohexanone and cyclohexanol; 7) non-volatile organically is the residue formed at stage 6, the amount of which reaches 20% of the amount of the resulting ketone and alcohol, is treated with diluted acid solution for hydrolysis products and the processing of the electrolyte solution for the extraction of Cr in the water layer.

The main disadvantage of the prototype (US 6703529) is the formation during the oxidation of cyclohexane large number of products, including organic acids that interact with the walls of the equipment lead to the extraction of chromium from high-alloy steels. Accumulation of chromium in non-volatile organic residue leads to the extraction of chromium before using this non-volatile residue and consequently to a significant complication of technology for cyclohexanone and cyclohexanol.

The invention solves the problem of increasing the selectivity of the oxidation of cyclohexane and reduce by-products, including acids, which lead to the extraction of chromium from the walls of the equipment.

Method for obtaining a mixture of cyclohexanol and cyclohexanone at elevated temperature and pressure comprising phase oxidation of cyclohexane, the stage catalytic decomposition of cyclohexylpiperazine CHHP on the heterogeneous catalyst and the stage distillation; these stages form a single circulatio the economic circuit, in which the circulation of the reaction mixture is performed by moving the vapor of cyclohexane from the cube still in the oxidation reactor, and by subsequent spontaneous flow under gravity of the liquid reaction mixture from the reactor oxidation in the decomposition reactor and then into the cube; the conversion of cyclohexane in the zone of oxidation does not exceed 1 mol.%, and conversion cyclohexylpiperazine in the decomposition zone is not less than 90 mol.%. The oxidation of cyclohexane, the decomposition of cyclohexylpiperazine and the process of distillation of cyclohexane is carried out in similar conditions: at a temperature of 150-200°C and a pressure of 5-15 ATM.

The reactor for the oxidation of cyclohexane is located above the reactor for the decomposition of cyclohexylpiperazine, and a reactor for the decomposition of cyclohexylpiperazine is on the same level with the cube of the distiller or below the level of the cube of the distiller. To bind volatile cube distiller can be added to the basic hydroxide or basic salt.

A pair of cyclohexane can be pre-condensed, and the condensate filed in the reactor oxidation of cyclohexane using a pump.

As a heterogeneous catalyst for the decomposition of cyclohexylpiperazine use a catalyst containing as an active ingredient one of the elements, or any combination of elements, select the data from the group of Co, Fe, Cu, Ni, Mn, Cr, Re, Os, Ru, Au, Pt, Pd supported on a carrier.

As catalyst for the decomposition of cyclohexylpiperazine use preferably a catalyst containing as the active component of gold Au supported on a carrier.

As media use SiO2, Al2O3, TiO2, MgO, carbon or any combination thereof.

The catalyst used in the form of granules and/or in the form of mono-and/or textile materials.

In order to increase the efficiency of conversion of cyclohexane to KA oil and to reduce the number of generated non-volatile by-products, we offer the process of obtaining oxidate (a mixture of cyclohexanone and cyclohexanol in cyclohexane) to implement a scheme providing for the circulation of the reaction mixture in the loop reactor of the oxidation - decomposition reactor - distillation". The driving force of the circulation of the reaction mixture in this circuit is the transfer pair from the distiller to the reactor for the oxidation of cyclohexane. An important condition for the implementation of this scheme is the location of the equipment relative to each other. The reactor oxidation of cyclohexane must be located above the reactor for the decomposition of cyclohexylpiperazine (CHHP). The lower part of the reactor for the decomposition of CHHP should be at the cube level, and the pipe coming out of the reactor for the decomposition of CHHP should fail the change to the bottom of the cube.

The drawing shows a diagram of the receiving oxidate (a mixture of cyclohexanone and cyclohexanol in cyclohexane): 1 - reactor oxidation of cyclohexane, 2 - reactor for the decomposition of cyclohexylpiperazine (CHHP), 3 - distillation column, 4 - cube distiller.

Source cyclohexane and oxygen-containing gas mixture is fed into the reactor for the oxidation of cyclohexane (1). In the reactor (1) also receives a portion of the unreacted cyclohexane in the form of vapor from the distillation (3). The heat released by condensation of the vapor of cyclohexane, is partially removed by using a heat exchanger, and partly goes to heating the incoming source of cyclohexane. In the reactor (1) cyclohexane partially oxidized in cyclohexylpropionic, cyclohexanone and cyclohexanol.

Volatile components of the reaction mixture and a pair of cyclohexane utilized by known methods, and the condensation of cyclohexane returns to the stage of oxidation. Liquid converted reaction mixture from the oxidation reactor (1) by gravity into the reactor for the decomposition (2). In the decomposition reactor (2) cyclohexylcarbamate turns into a KA-oil. From the decomposition reactor (2) the reaction mixture is sent to the cube of the distiller (4). In Cuba (4) cyclohexane and other volatile components of the reaction mixture is evaporated and then enter the distiller (3), which separates the Le is colluci components from cyclohexanone and cyclohexanol and other volatile ingredients oxidation products of cyclohexane. A pair of cyclohexane from the distiller (3) returned to the reactor for the oxidation of cyclohexane (1), and Cuba (4) exited oxidat enriched with cyclohexanol and cyclohexanone. Further oxidat is processed by the known methods for separation of ketone and alcohol (Msherman, Assadian, Amolde and other Production of cyclohexanone and adipic acid by oxidation of cyclohexane. M.: Chemistry, 1967, 240 pages; US 6703529).

A distinctive feature of this method of producing cyclohexanone and cyclohexanol is the low selectivity of the conversion of cyclohexane by-products, and hence the significant decline in the number of generated non-volatile organic residue. So, when the conversion of cyclohexane at the output of the installation is equal to 5 mol.% and the multiplicity of circulation of the reaction mixture in the installation equal to 10, the selectivity of conversion of cyclohexane in the ketone and the alcohol can theoretically reach up to 97 mol.%. In a laboratory setup with the conversion of cyclohexane 5 mol.% and the multiplicity of circulation 10 we were able to achieve selectivity of conversion of cyclohexane in the ketone and alcohol ~ 93 mol.%. It is natural to assume that the installation of more power at higher ratio of reactor volume to the surface of the walls of the reactor selectivity of conversion of cyclohexane in cyclohexylpropionic and later in KA-oil will be higher. Of all IDNO, compared to the prototype considered a method of obtaining a KA-oil leads to a decrease of non-volatile organic residue not less than 3 times. Improving the selectivity of the conversion of cyclohexane into alcohol and ketone is achieved due to the low conversion of cyclohexane in the zone of oxidation, increase the conversion of cyclohexylpiperazine on a heterogeneous catalyst and reduction of the share of thermal decomposition of cyclohexylpiperazine.

The conversion of cyclohexane to KA oil according to the present invention is carried out by the organization of the circulation of the reaction mixture through the reactor of the oxidation of cyclohexane (1), the reactor CHHP decomposition (2) and distillation (3) without any intermediate processing of the mixture. The circulation of the reaction mixture is carried out by transferring the vapor of cyclohexane from the distiller (3) in the oxidation reactor (1), where the conversion of cyclohexane to cyclohexanol, cyclohexanone and cyclohexylpropionic. From the reactor the liquid oxidation reaction mixture by gravity into the reactor decay SNR (2)where SNR turns into a KA-oil. The mixture enters the distiller (3), where the separation of cyclohexane from oxidation products and return it in the form of steam in the reactor oxidation of cyclohexane.

The oxidation of cyclohexane is carried out in the liquid phase in away the ance catalyst at a temperature of 150-200°C and a pressure of 5-15 ATM oxygen, air or other oxygen-containing gas. Preferably the oxidation is carried out at a temperature of 160-180°C and a pressure of 7-10 ATM. For oxidation may be used in any of the known types of reactors, tanks, columns, horizontal. Preferably the process is conducted in multiple column reactor. The reactor oxidation of cyclohexane (1) must be placed above the reactor CHHP decomposition (2) and above cube distiller (4). To prevent decomposition SNR surface equipment, which circulates the reaction mixture should be made of inert material, or passaged by any known method, for example, Na4P2O7. It is important that the conversion of cyclohexane oxidation reactor (1) was not more than 1 mol.%, preferably no more than 0.5 mol.%. The residence time of the reaction mixture in the oxidation reactor (1) is 10-120 minutes, preferably 15-30 minutes

From the top of the oxidation reactor (1), the reaction mixture by gravity into the reactor for the decomposition of CHHP (2). For the decomposition of CHHP you can use reactors of different designs, but preferably the process is conducted in a flow adiabatic reactor on a gold catalyst. The catalyst may be used in the form of granules, and/or in the form of mono-and/or textile materials.

Process conditions the decomposition of CHHP as follows: the temperature is and 130-200°C, pressure 4-15 atmospheres, a contact time of the reaction mixture 0.3-10 minutes Preferably the process is carried out at a temperature of 160-180°C, the pressure 7-10 bar and a contact time of the reaction mixture with the catalyst 1-3 minutes Conversion CHHP should be not less than 90 mol.%, preferably at least 99 mol.%. The reactor CHHP decomposition (2) is located below the reactor oxidation of cyclohexane (1). The bottom of the reactor should be at the same level with the bottom of the cube distiller or below the level of the cube distiller.

The reaction mixture, consisting mainly of cyclohexane, cyclohexanol and cyclohexanone and partially heated by the heat decomposition reaction of cyclohexylpiperazine, from the bottom of the pipe reactor, the decomposition (2) is supplied to the lower nozzle cube distiller (4). In Cuba (4) the reaction mixture is additionally heated by an external heat source, partially evaporates. The pair arrive in the distiller (3)where there is a concentration of light components, mainly cyclohexane. Liquid cubed (oxidate) enriched with oxidation products, mainly cyclohexanol and cyclohexanone. Oxidat from the cube (4) is sent to further processing for selection of the target products by the known methods. Speed selection oxidate cube from a distiller (4) must be equal to the feed rate of cyclohexane oxidation reactor (1). The distillation process of the OS is done at high pressure, which is very slightly greater than the pressure in the reactor of the oxidation of cyclohexane (1). The differential pressure between the distiller and the oxidation reactor is determined by the resistance plate (nozzle) of the distiller and the height of the liquid column in the oxidation reactor (1).

Pair of distiller (3) returned to the reactor for the oxidation of cyclohexane (1). When using a column reactor vapors get into the reactor through the plate / tube sheet located at the bottom of the reactor. Instead of the plate / tube sheet can be used a plate with caps or valve plate. The resistance plate and the height of the liquid column reactor column type determine the difference between the temperature of the liquid in the cube (4) and the temperature at the bottom of the reactor for the oxidation of cyclohexane (1). Typically, this difference does not exceed 2-3°C. the Oxygen-containing gas, it is desirable to apply to the oxidation reactor (1) in conjunction with pairs of cyclohexane. Pre-mixing the vapors coming from the distiller (3) with an oxidizing agent, allows for more uniform distribution of oxygen by volume of the reactor (1) and to reduce the formation of by-products and resin formation. In the lower part of the oxidation reactor (1) is the condensation of the vapor of cyclohexane, which requires heat removal and installation of the heat exchanger in this part of the reactor.

Parameters oxidate output from the cube (4) shall be established as the conversion of cyclohexane oxidation reactor (1), and the rate of circulation of the reaction mixture in the loop reactor oxidation of cyclohexane (1) reactor decomposition of CHHP (2) - distiller (3)". Under magnification circulation, we mean the ratio of the velocity of circulation of the reaction mixture in the circuit (measured in cyclohexane) to the feed rate of the cyclohexane in the installation. So, with the multiplicity of circulation, equal to 10, and the conversion of cyclohexane oxidation reactor (1) 0.5 mol.% the conversion of cyclohexane in the reaction mixture taken from the cube (4), is equal to ~5 mol.%. Thus the selectivity of the conversion of cyclohexane to KA oil-can theoretically reach up to 97 mol.%. With increasing frequency circulation conversion of cyclohexane in the cube will grow.

The selectivity of the conversion of cyclohexane in the target products in the oxidation reactor (1) is largely determined by the efficiency of the distillation process. The less oxidation products from the cube enters the oxidation reactor, the less side products formed in the oxidation of cyclohexane. With the increase of the conversion of cyclohexane to leaving the plant, and hence the concentration of oxidation products of cyclohexane in the cube increases the likelihood of leakage of these products from the cube in the oxidation reactor. However, as shown by experiments in a laboratory setup, increasing the conversion of cyclohexane from 3 to 50 mol.% selectivity to build the value of cyclohexane ketone and alcohol in the installation varies little, from 93 to 89 mol.%.

Pair of distiller (3) pre can be condensed, and the condensate in liquid form sent to the set point of the oxidation reactor (1). This allows you to partially exclude from circulation boiling by-products and to use any known reactors for the oxidation of cyclohexane. Instead of distiller (3) you can use distillation column for separating cyclohexane from its oxidation products. In this case, the selection of liquid cyclohexane can be done with a certain plates of the distillation column. When the circulation of liquid cyclohexane require additional equipment, in particular a pump, regulating the feed rate of the circulating liquid cyclohexane oxidation reactor (1).

To reduce the transfer of volatile impurities, primarily acids, from the distiller to the reactor, cube distiller, you can optionally type in proportion to the number of generated acids inorganic alkali or basic salt. The interaction of the base with the acid contained in the by-products of oxidation, leads to neutralize acids. The concentration of the acid side products warded off the cyclohexane decreases, which, ultimately, leads to the decrease of the concentration of acids in the oxidation reactor (1) and a decrease in the rate of acid RA is the position of the CHHP, consequently, the growth selectivity of the conversion of cyclohexane by-products.

The advantage of this method of obtaining ketone and alcohol is maintained at a high selectivity in the conversion of cyclohexane to KA oil-high conversion of cyclohexane. So, when the conversion of cyclohexane 5 mol.% the selectivity of the formation of by-products does not exceed 7 mol.%. When increasing the conversion of cyclohexane to 50 mol.% the selectivity of side products formation is ~11 mol.%. The proposed method of receiving KA-oil is characterized by relative simplicity of the process. The driving force of the circulation process, the proposed method is to heat the fluid in a cube of distiller. The transfer rate of vapor of cyclohexane from a distiller in the oxidation reactor is governed by the intensity of heating of the reaction mixture in a cube of distiller. As the overflow of the reactor oxidation (1) the reaction mixture from it by gravity into the reactor for the decomposition of CHHP (2) and next cube (4) distiller (3). That is, this process does not need an expensive pumping equipment. In addition, when such an organization process by reducing the time spent by cyclohexylpiperazine at elevated temperature in the intermediate tanks and heat exchangers reduces the share of CHHP, thermally decomposed, and the investigator is about, and increases the selectivity of the conversion of cyclohexane in the ketone and alcohol. The selection of the cyclohexanone and cyclohexanol from oxidate is carried out by known methods (Msherman, Assadian, Amolde and other Production of cyclohexanone and adipic acid by oxidation of cyclohexane. M.: Chemistry, 1967, 240 pages; US 6703529).

The invention is illustrated by the following examples and the drawing.

The oxidation of cyclohexane is carried out in a laboratory setup, consisting of a column reactor for the oxidation of cyclohexane (1), reverse refrigerator (not shown), reactor decomposition of CHHP (2), Cuba (4) and the distillation column (3). Source cyclohexane served in the upper part of the distillation column (3), and the air in the lower portion of the oxidation reactor (1). The removal of the reacted liquid reaction mixture (product) is carried out cube (4). The gaseous mixture after the return of the refrigerator through the pressure regulator discharged into the atmosphere. Together with the gas phase is also reset volatile oxidation products of cyclohexane.

Example 1

During the oxidation of cyclohexane in the installation shown in the drawing, the total pressure is maintained within the range of 8.1 to 8.2 ATM, the temperature in the reactor for the oxidation of cyclohexane 172°C, the decomposition reactor 162°C, the temperature in the distillation 173-174°C, in Cuba the distiller 175-176°C. the residence Time of the liquid is actionnow mixture in the oxidation reactor is 14.8 minutes The molar ratio between fed to the reactor with the oxygen source and the cyclohexane is 0.04. The contact time of the liquid reaction mixture with a catalyst (1.5 wt.% Au/SiO2, SiO2- silicalite with the MFI structure) in the reactor for the decomposition of CHHP is 2.3 minutes Multiplicity of circulation of the reaction mixture in the installation (the ratio of the velocity of circulation of the reaction mixture to the feed speed of the original cyclohexane) is 7.3. The duration of the experiment 15 hours the mixture withdrawn from Cuba, periodically analyze. The results are presented in the table.

You can see that after 8 hours of work characteristic of the exhaust from the cube reaction mixture enters the stationary level. The conversion of cyclohexane is stabilized at the level of 3.0-3.1 mol.%, the selectivity of the conversion of cyclohexane by-products - at the level of 7.4-7.5 mol.%. Cyclohexylpropionic in the oxidation products of cyclohexane is missing.

Example 2

During the oxidation of cyclohexane in the installation shown in the drawing, the total pressure is maintained within the range of 8.1-8.2 ATM, the temperature in the reactor for the oxidation of cyclohexane 172-174°C, the decomposition reactor 162-163°C, the temperature in the distillation 173-174°C, in Cuba the distiller 176-179°C. the residence Time of the liquid reaction mixture in the oxidation reactor is 22.2 minutes Molar ratio between fed to the reactor Kislorodmontage and source cyclohexane is 0.18. The contact time of the reaction mixture with a catalyst (example 1) 3.4 minutes Multiplicity of circulation of the reaction mixture in the installation (the ratio of the velocity of circulation of the reaction mixture to the feed speed of the original cyclohexane) is 45. The duration of the experiment ~86 including the Composition of the mixture withdrawn from Cuba, periodically analyze. The results are presented in the table.

It is seen that in the last ~15 h, the conversion of cyclohexane in the exhaust from the cube reaction mixture is stabilized at the level 45-47 mol.%. Thus the selectivity of the conversion of cyclohexane by-products during the last ~15 h at 10-11 mol.%. Cyclohexylpropionic in the oxidation products of cyclohexane was not found.

Example 3.

The oxidation of cyclohexane is carried out analogously to example 1 except that as the catalyst use of catalyst 2.0% Au/Al2O3. The duration of the experiment is 8 hours the mixture analyzed at the end of the experiment. The results are presented in the table.

Example 4.

The oxidation of cyclohexane is carried out analogously to example 1 except that as the catalyst use of catalyst 0.8% Cu/SiO2(SiO2- silicalite with the MFI structure). The duration of the experiment is 8 hours the mixture analyzed at the end of the experimental is the same. The results are presented in the table.

Example 5.

The oxidation of cyclohexane is carried out analogously to example 1 except that as the catalyst use of catalyst 1.9% Ru/SiO2(SiO2- silicalite with the MFI structure). The duration of the experiment is 8 hours the mixture analyzed at the end of the experiment. The results are presented in the table.

Example 6.

The oxidation of cyclohexane is carried out analogously to example 1 except that as the catalyst use of catalyst (1.7% Au+1.0% Cu)/SiO2(SiO2- silicalite with the MFI structure). The duration of the experiment is 8 hours the mixture analyzed at the end of the experiment. The results are presented in the table.

Example 7.

The oxidation of cyclohexane is carried out analogously to example 1 except that as the catalyst use of catalyst 0.7% Fe2O3/SiO2(SiO2- silicalite with the MFI structure) and the contact time of the reaction mixture with the catalyst in the decomposition reactor is 8 minutes duration of the experiment is 8 hours the mixture analyzed at the end of the experiment. The results are presented in the table.

Example 8.

The oxidation of cyclohexane is carried out analogously to example 1 except that as a catalyst is and use the catalyst (1.5% Au+0.7% Fe 2O3)/(SiO2- silicalite with the MFI structure). The duration of the experiment is 8 hours the mixture analyzed at the end of the experiment. The results are presented in the table.

Example 9.

The oxidation of cyclohexane is carried out analogously to example 1 except that as the catalyst use of catalyst (0.4% Pd/SiO2(SiO2- silicalite with the MFI structure). The duration of the experiment is 8 hours the mixture analyzed at the end of the experiment. The results are presented in the table.

Example 10.

The oxidation of cyclohexane is carried out analogously to example 1 except that as the catalyst use of catalyst (2.5% Au+0.4% Pd/SiO2(SiO2- silicalite with the MFI structure). The duration of the experiment is 8 hours the mixture analyzed at the end of the experiment. The results are presented in the table.

Example 11.

The oxidation of cyclohexane is carried out analogously to example 1 except that as the catalyst use of catalyst 0.6% Au/SiO2(SiO2- fiberglass in the form of fibers). The duration of the experiment is 8 hours the mixture analyzed at the end of the experiment. The results are presented in the table.

Example 12.

The oxidation of cyclohexane is carried out analogues of the but example 1 except as the catalyst used catalyst 1.6%>Au/(SiO2+TiO2) (SiO2+TiO2- titanosilicate with the MFI structure). The duration of the experiment is 8 hours the mixture analyzed at the end of the experiment. The results are presented in the table.

Example 13.

The oxidation of cyclohexane is carried out analogously to example 1 except that as the catalyst use of catalyst 1.1% Au/(SiO2) (SiO2- silicalite, molded pellets with a diameter of ~1.5 mm, is used as a binding SiO2). The duration of the experiment is 8 hours the mixture analyzed at the end of the experiment. The results are presented in the table.

Example 14 (comparative).

The oxidation of cyclohexane is carried out analogously to example 1 except that the schema exclude the distiller. In this case, the reaction mixture is once passed through the oxidation reactor after reactor decomposition of CHHP the finished product is taken for analysis. The duration of the experiment 8 o'clock the Results are presented in the table.

It is seen that during the last 5 h, the conversion of cyclohexane removed from a reactor for the decomposition of the reaction mixture is stabilized at the level of 0.5 mol.%. Thus the selectivity of the conversion of cyclohexane ketone is 53 mol.%, alcohol - 42 mol.%, side the products 5 mol.%. Cyclohexylpropionic products not found.

Example 15 (comparative).

The oxidation of cyclohexane is carried out analogously to example 3 except that the residence time of cyclohexane oxidation reactor is increased to 45 minutes duration of the experiment is 8 o'clock the Results are presented in the table.

It is seen that during the last 4 h, the conversion of cyclohexane removed from a reactor for the decomposition of the reaction mixture is stabilized at the level of ~3.2 mol.%. The total selectivity of the conversion of cyclohexane to cyclohexanone is 42.9 mol.%, in the cyclohexanol 44.9 mol.%, in by-products 13 mol.%". Cyclohexylpropionic products not found.

14td align="center" namest="c4" nameend="c5"> 173 0.51
The conversion of cyclohexane to KA oil.
TimeP (ATM)T (°C)The type field
this (mol %)
The selectivity of the conversion of cyclohexane (mol.%)
The oxidation reactorReactor decayColumn CubeKetoneAlcoholCHHPBy-products
1234561314151617
Example 1
2.08.21721621731750.756.242.01.20.7
4.08.2172 1621741762.048.046.00.15.9
6.08.21721621731752.845.148.60.16.2
8.08.21721621731762.943.149.40.07.4
10.0 8.21721621731763.144.547.50.07.9
12.08.11721621731753.144.248.30.17.4
14.88.11721621741763.044.947.60.0Example 2
2.98.21731631731750.327.368.40.43.9
8.38.31731631731765.447.945.10.07.1
13.28.217416317317710.5 49.245.20.05.6
18.08.017416217417715.849.743.70.06.6
23.37.917416217417821.749.243.10.07.6
28.28.4174162174 17825.649.442.90.07.7
33.28.517416217417827.549.542.50.08.0
38.28.517316217417831.249.542.10.08.4
43.08.0173 16217417732.949.341.90.08.7
48.08.017316217417737.749.241.20.09.6
53.28.317316217517837.648.342.40.09.3
58.1 8.217316217417941.448.342.60.09.1
63.08.117316217517943.246.642.70.010.7
68.27.917316217417747.447.442.80.0 9.8
73.07.917216217417745.147.442.30.010.3
78.08.117216217417946.546.442.60.010.9
Continuation of the table
12345613151617
Example 3
8.08.11731621741773.046.646.40.07.0
Example 4
8.08.31721611731763.144.647.40.08.0
Example 5
8.08.21621741772.930.162.40.07.5
Example 6
8.08.21721621731763.055.937.20.06.9
Example 7
8.08.11721611731752.724.159.8 2.014.1
Example 8
8.08.21721621731763.024.159.80.07.2
Example 9
8.08.21731621741772.837.949.81.011.2
Example 10
8.08.2172162 1741763.044.047.80.08.2
Example 11
8.08.3172162171773.156.236.40.07.4
Example 12
8.08.3172162171773.245.947.10.0 7.0
Example 13
8.08.3172162171772.850.941.60.07.5
Example 14
2.08.1172162--0.4068.730.20.11.0
4.08.1172162--57.237.60.15.1
6.08.2172162--0.5254.740.40.04.9
7.08.1172162--0.5053.441.60.05.0
8.08.1172162-0.5151.044.20.04.8
Continuation of the table
1234561314151617
Example 15
2.08.1172162--0.753.2400.26.6
4.08.0170162--2.045.143.60.111.2
6.08.1171162--3.143.244.4012.4
7.08.2172162--3.241.944.513.6
8.08.2172162--3.141.245.8013.0

1. The method of obtaining a mixture of cyclohexanol and cyclohexanone at elevated temperature and pressure, including phase oxidation of cyclohexane with getting cyclohexylpiperazine, stage catalytic decomposition of cyclohexylpiperazine on a heterogeneous catalyst with a mixture of cyclohexanol and cyclohexanone and the stage of distillation of cyclohexane, characterized in that each of these stages form a single circulation loop, in which the circulation of the reaction mixture is performed by moving the vapor of cyclohexane from the cube still in the oxidation reactor, and by subsequent spontaneous flow under gravity of the liquid reaction mixture from the reactor oxidation in the decomposition reactor and then to the cube of the distiller, in this case the reactor is R cyclohexane is above the reactor for the decomposition of cyclohexylpiperazine, as the reactor for the decomposition of cyclohexylpiperazine is on the same level with the cube of the distiller, or below the level of the cube of the distiller, and the conversion of cyclohexane in the zone of oxidation does not exceed 1.0 mol.%, and conversion cyclohexylpiperazine in the decomposition zone is not less than 90.0 mol.%.

2. The method according to claim 1, characterized in that the oxidation of cyclohexane, as the decomposition of cyclohexylpiperazine, and the process of distillation of cyclohexane is carried out in similar conditions: at a temperature of 150-200°C and a pressure of 5-15 ATM.

3. The method according to claim 1, characterized in that cube distiller add basic hydroxide or basic salt.

4. The method according to claim 1, characterized in that a pair of cyclohexane pre-condensed, and the condensate is fed into the reactor for the oxidation of cyclohexane using a pump.

5. The method according to claim 1, characterized in that as a heterogeneous catalyst for the decomposition of cyclohexylpiperazine use a catalyst containing as an active ingredient one of the elements, or any combination of elements selected from the group of Co, Fe, si, Ni, Mn, Cr, Re, Os, Ru, Au, Pt, Pd supported on a carrier.

6. The method according to claim 5, characterized in that as the catalyst for the decomposition of cyclohexylpiperazine use, preferably, a catalyst containing as the active component of gold Au, deposited on n the Khabibullina.

7. The method according to claim 5, characterized in that as the carrier heterogeneous catalyst decomposition using SiO2, Al2O3, Tio2, MgO, carbon, or any combination thereof.

8. The method according to claim 5, characterized in that the catalyst decomposition is used in the form of granules, and/or in the form of mono-and/or textile materials.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention relates to a method of preparing a mixture of cyclohexanol and cyclohexanone which are intermediate products in production of polyamides nylon-6 and nylon-6.6. The method is realised at high temperature and high pressure and involves the following successive cycles: oxidation of cyclohexane - decomposition of cyclohexylhydroperoxide, wherein oxidation of cyclohexane and decomposition of cyclohexylhydroperoxide are carried out in separate series-connected reactors without intermediate separation of the aqueous phase, whereby in each separate cycle, cyclohexane is oxidised with air or an oxygen-containing gas in liquid phase in the absence of a catalyst until conversion of cyclohexane of not more than 1.5 mol %, and the cyclohexylhydroperoxide formed during oxidation of cyclohexane is decomposed on a heterogeneous catalyst in a separate reactor until conversion of not less than 90 mol %.

EFFECT: method increases overall selectivity of converting cyclohexane to cyclohexanone and cyclohexanol and also considerably reduces formation of by-products.

9 cl, 19 ex, 2 tbl, 1 dwg

FIELD: chemistry.

SUBSTANCE: method involves preparation of a reaction mixture at room temperature consisting of the alcohol to be oxidised, sodium bicarbonate, an organic solvent and a nitroxyl radical. Electrolysis is carried out on platinum electrodes with current of 1 A and temperature of 20-25°C. Potassium iodide is added to the reaction mixture. The organic solvent used is dichloromethane and the nitroxyl radical used is 4-acetylamino-2,2,6,6-tetramethylpiperidine-1-oxyl of formula: with ratio of alcohol to nitroxyl radical equal to 10:1.

EFFECT: invention ensures high output of end products a within short period of time and less expenses on electricity using a high-technology method.

2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing cyclohexanone from cyclohexane, involving the following stages: oxidation of cyclohexane to hydroperoxide of cycohexyl with oxygen in the absence of a catalyst, purification of the reaction medium by washing with water, decomposition of hydroperoxide of cycohexyl to cyclohexanol and cyclohexanone in the presence of a catalyst, extraction of the cyclohexanol/cyclohexanone mixture for separating unreacted cyclohexane and separation of products with boiling point higher than that of the cyclohexanol/cyclohexanone mixture, dehydrogenating cyclohexanol contained in the cyclohexanol/cyclohexanone mixture, in the presence of a dehydrogenation catalyst, distillation of the obtained mixture so as to obtain first run (F1) at the first stage, containing compounds with boiling point lower than that of cyclohexanone, and a last run (Q1) and distillation of the last run (Q1) to obtain a first run (F2) at the second stage, formed from cyclohexanone, and a last run (Q2).

EFFECT: obtaining highly pure cyclohexanone, suitable for use as raw material for synthesis of ε-caprolactam.

6 cl, 1 dwg, 3 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of continuous oxidation of saturated cyclic hydrocarbons using oxygen, into a mixture of hydroperoxide, alcohol and ketones. The method involves feeding into the lower part of a column and in parallel flow, a stream of oxidisable liquid hydrocarbon and a gas stream containing oxygen, and degassing the liquid phase in the upper part of the column by forming a gas dome and extraction of the degassed liquid phase. The gas containing oxygen is let into different compartments of the column, and into the dome and/or liquid phase at the level of the degassing zone, or directly above. A stream of non-oxidising gas with output sufficient for maintaining concentration of oxygen in the gas layer at the level of volume concentration, less than or equal to the upper limiting concentration of oxygen is supplied.

EFFECT: possibility of implementing a method with high selectivity on an explosion safe level.

9 cl, 1 dwg, 1 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for synthesis of 3-bromoadamantyl-1-alkyl(aryl)-ketones of the general formula: , wherein that can be used as intermediate substances for synthesis of some biologically active compounds. Method involves interaction of 1,3-dehydroadamantane with α-bromoketones of the following order: α-bromoacetone, α-bromoacetophenone, α-bromocyclohexanone in the mole ratio of reagents = 1:(2-3), respectively, in absolute diethyl ether medium, at temperature 34-40°C for 3-4 h. Method provides preparing the claimed compounds with high yield.

EFFECT: improved method of synthesis.

3 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to an improved method for synthesis of 2,6-di-(3,3',5,5'-di-tert.-butyl-4,4'-oxybenzyl)-cyclohexane-1-one used as a stabilizing agent of polyolefins and low-unsaturated carbon=chain rubbers. Method involves interaction of cyclohexanone with N,N-dimethyl-(3,5-di-tert.-butyl-4-oxybenzyl)amine in the ratio = (1-1.2):2, respectively, and process is carried out at temperature 125-145°C up to ceasing isolation of dimethylamine. Method provides simplifying technology and preparing the end product with the yield 61-85.4%.

EFFECT: improved method of synthesis.

12 tbl, 23 ex

FIELD: organic chemistry, chemical technology, catalysts.

SUBSTANCE: invention relates to catalytic decomposition of organic hydroperoxides representing important compounds on organic synthesis. Decomposition of cycloalkyl hydroperoxides comprising from 6 to 12 carbon atoms results to formation a mixture of corresponding alcohols and ketones. Process is carried out in the presence of a solvent (alkane, halogen-containing hydrocarbon) at temperature from 20°C to 200°C. Catalyst comprises ruthenium as a catalytically active metal added to a solid carrier chosen from the following group: carbon prepared by pyrolysis of acetylene and metal oxides chosen from the group comprising zirconium, aluminum, lanthanum and manganese. The amount of catalyst expressed as the mole percents of ruthenium to the amount of moles of hydroperoxide to be decomposed is from 0.0001% to 20%. Preferably, the catalyst comprises one additional rare-earth element as a component of alloy. The carrier represents, as a rule, metal oxide with high specific surface above 10 m2/g but preferably, above 100 m2/g that is resistant against oxidation. The hydroperoxide concentration is in the range from 1 to 80 wt.-% with respect to the solution mass. Preferably, hydroperoxide represents cyclohexyl, cyclododecyl, tetraline, ethyl benzene or pinane hydroperoxide and hydrocarbon used in preparing the parent hydroperoxide is used as a solvent. Invention provides the development of the modified catalyst enhancing conversion and selectivity in decomposition of hydroperoxides.

EFFECT: improved method for decomposition.

8 cl, 24 ex

FIELD: organic chemistry, in particular production of carbonyl compounds such as aldehydes and ketones.

SUBSTANCE: claimed method includes reaction of nitrous oxide with alkenes in presence of inert gas as diluent. Reaction is carried out in gas phase at 401-700°C and under pressure of 2-300 atm. Target compounds represent value intermediates for precise and base organic synthesis.

EFFECT: method of high selectivity in relation to target products and improved explosion proofing.

5 cl, 1 tbl, 14 ex

The invention relates to an improved method for producing a mixture of ketones/alcohols using decomposition cycloalkylcarbonyl in the presence of a catalyst containing a catalytically active metal element is immobilized on a solid carrier, and the catalyst obtained by the fixation of ORGANOMETALLIC compounds of General formula III or IIIa:

,

,

in which M denotes a metal ion, or a combination of metal ions, corresponding to the elements belonging to group IB-VIIB or VIII of the Periodic table (CAS version), including the lanthanides; m is an integer from 1 to 6; p denotes an integer from 0 to 4; q represents an integer from 1 to 4; X represents an anion

The invention relates to the production of cyclohexanone by liquid-phase oxidation products of hydrogenation of benzene containing cyclohexene, nitrous oxide or its mixture with an inert gas

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing phenol and acetone through acid-catalysed decomposition of cumene hydroperoxide in series-connected reactors in two steps at high temperature with simultaneous formation of dicumyl peroxide at the first step followed by its decomposition in a reaction medium at the second step. The process is carried out using a catalyst in form of 2-hydroxy- benzene sulphonic acid of general formula , where X and Y denote hydrogen, alkyl, arakyl, halogen, oxyalkyl, sulpho group, alkyl(2-hydroxy benzene sulphonic acid group) in amount of 0.1-1 mmol/l.

EFFECT: method enables to obtain desired products with high output while maintaining low content of hydroxy acetone in the reaction mass.

2 cl, 9 tbl, 7 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of preparing a mixture of cyclohexanol and cyclohexanone which are intermediate products in production of polyamides nylon-6 and nylon-6.6. The method is realised at high temperature and high pressure and involves the following successive cycles: oxidation of cyclohexane - decomposition of cyclohexylhydroperoxide, wherein oxidation of cyclohexane and decomposition of cyclohexylhydroperoxide are carried out in separate series-connected reactors without intermediate separation of the aqueous phase, whereby in each separate cycle, cyclohexane is oxidised with air or an oxygen-containing gas in liquid phase in the absence of a catalyst until conversion of cyclohexane of not more than 1.5 mol %, and the cyclohexylhydroperoxide formed during oxidation of cyclohexane is decomposed on a heterogeneous catalyst in a separate reactor until conversion of not less than 90 mol %.

EFFECT: method increases overall selectivity of converting cyclohexane to cyclohexanone and cyclohexanol and also considerably reduces formation of by-products.

9 cl, 19 ex, 2 tbl, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing cyclohexanone from cyclohexane, involving the following stages: oxidation of cyclohexane to hydroperoxide of cycohexyl with oxygen in the absence of a catalyst, purification of the reaction medium by washing with water, decomposition of hydroperoxide of cycohexyl to cyclohexanol and cyclohexanone in the presence of a catalyst, extraction of the cyclohexanol/cyclohexanone mixture for separating unreacted cyclohexane and separation of products with boiling point higher than that of the cyclohexanol/cyclohexanone mixture, dehydrogenating cyclohexanol contained in the cyclohexanol/cyclohexanone mixture, in the presence of a dehydrogenation catalyst, distillation of the obtained mixture so as to obtain first run (F1) at the first stage, containing compounds with boiling point lower than that of cyclohexanone, and a last run (Q1) and distillation of the last run (Q1) to obtain a first run (F2) at the second stage, formed from cyclohexanone, and a last run (Q2).

EFFECT: obtaining highly pure cyclohexanone, suitable for use as raw material for synthesis of ε-caprolactam.

6 cl, 1 dwg, 3 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to production of phenol, method of extracting phenol from products of splitting cumene hydroperoxide and to a device for extracting phenol from products of splitting cumene. The method of producing phenol involves the following stages: i) oxidation of cumene, obtaining a reaction mixture containing cumene hydroperoxide and unreacted cumene; ii) splitting products obtained from stage i), obtaining a mixture of splitting products containing at least phenol, acetone, hydroxyacetone, unreacted cumene and water; iii) treatment of the mixture of splitting products obtained on stage ii) through distillation, which involves separation of the mixture of splitting products into at least three fractions using a single fractional distillation stage through: putting the mixture of splitting products into a distillation column, removal of the first fraction, containing acetone, from the upper part of the distillation column, removal of the second fraction, containing phenol, from the lower part of the distillation column, and removal of the third fraction, containing at least unreacted cumene, hydroxyacetone and water, in form of an off-stream. The outlet opening of the off-stream is higher the area for putting in the mixture of splitting products into the distillation column, characterised by removal of heat from the distillation column. The section for removing heat is higher than the outlet opening of the off-stream of the third fraction.

EFFECT: increased energy efficiency of methods using old technology, while maintaining quality standards and total output of end products.

25 cl, 6 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: one of method versions is carried out in presence of catalyst with strong acidity in one or several reaction zones with further separation of reaction mixture by means of rectification and possibly partial recycling into reaction zone(s) of one or several components of reaction mixture. Decomposition is carried out in presence of inert easily-boiling solvent, which contains mainly hydrocarbons, whose boiling temperature is lower than 70°C, preferably lower than 40°C, but not lower than minus 1°C, which is partially evaporated directly from reaction zone(s) and partially distilled from obtained reaction mixture, is in liquid state returned to reaction zone(s) with supporting in it (them) temperature from 1 to 70°C, preferably from 10 to 45°C. Second method version is carried out in presence of catalyst with strong acidity in one or several reaction zones with further separation of reaction mixture by means of rectification. Applied is easily-boiling solvent, which after separation from reaction mixture, possibly with part of ketone, is recycled into reaction zone(s), and sulfocationite catalyst in H+ form, resistant in liquid media, containing alkylaromatic hydroperoxides, ketones, phenol and hydrocarbons in large amount, at temperatures up to 70°C, in fine-grain or coarse-grain form, possibly, in form of mass-exchange filling with size from 1.5 to 25 mm.

EFFECT: obtaining phenol and ketones without formation of large amount of by-products and resins and practically without equipment corrosion.

14 cl, 1 dwg, 6 ex

FIELD: chemistry.

SUBSTANCE: H-form of ultrastable dealuminated Y-zeolites HUSY with SiO2/Al2O3 ratio within 5 to 120 is used as catalyst. As a rule, zeolites are combined with a binding agent represented by aluminum oxide, silicon oxide or their mix. Usually the catalyst is preliminarily activated by calcination in air at 300-600°C, while the method is implemented at 20-100°C. As a rule, cumol hydroperoxide concentration in the raw mix varies within 3 to 80%, and acetone, cumol, phenol or their mix with various component ratio are used as solvent.

EFFECT: increased process selectivity in relatively mild conditions.

7 cl, 1 tbl, 11 ex

FIELD: chemistry.

SUBSTANCE: method includes two-stage acid-catalysed decompounding of cumene hydroperoxide in series reactors under heat resulted in simultaneous generation dicumene peroxide in the first stage followed with its decompounding in reaction medium environment in the second stage. Thus any catalytic agent is not used; it is prepared in separate reactor immediately prior to introduce to the first reactor of cumene hydroperoxide decompounding by mixing sulphuric acid with phenol in ratio 2:1 to 1:1000 and keeping produced mixture at temperature 20-80°C within 1-600 minutes.

EFFECT: method allows for considerable yield reduction of hydroxyacetone.

4 cl, 7 tbl, 6 ex

FIELD: chemistry.

SUBSTANCE: invention relates to the method of obtaining phenol and acetone by acid-catalysable decomposition of hydro-peroxide of cumene in the environment of the reaction products at elevated temperatures in one stage. In this case the process is carried out in the presence of a catalyst, prepared immediately before its introduction into the reactor for the decomposition of hydro-peroxide of cumene by mixing sulfuric acid with phenol at the ratio of from 2:1 till 1:1000 and the waiting time from mixing till putting into the reactor for the decomposition of hydro-peroxide of cumene from 1 to 600 minutes at a temperature from 20 to 80°C. As a rule, sulfuric acid has a concentration of higher than 75% or oleum is used.

EFFECT: it makes it possible to decrease the output of the by-product hydroxyacetone, improves the quality of market-grade phenol and decreases the consumption of sulfuric acid.

2 cl, 4 tbl, 4 ex

FIELD: industrial organic synthesis.

SUBSTANCE: invention relates to technology of air oxidation of cyclohexane followed by treatment of oxidation products to decompose contaminating cyclohexyl hydroperoxide. Decomposition of cyclohexyl hydroperoxide into cyclohexanol and cyclohexanone is accomplished in the following steps: washing cyclohexane oxidation end products with water, separation of phases, and treatment of organic phase with alkali aqueous solution wherein water phase-to-organic phase volume ratio is approximately 0.10:100 to 1.00:100. Thereafter, phases are separated once again and organic phase is brought into contact with catalyst containing cobalt salt in alkali aqueous solution. Resulting two-phase product is stirred, and after next separation of phases, cobalt-containing alkali aqueous phase is removed and organic phases is washed with water. Part of alkali aqueous phase may be optionally reused by recycling it to the first reaction product treatment step. Alkali solution can be prepared from alkali hydroxides or alkali carbonates at concentration of alkali solution 2 to 25%, to which cobalt catalyst is added in amount from 5 to 15 ppm.

EFFECT: achieved essentially full conversion of cyclohexane into cyclohexanol and cyclohexanone.

13 cl, 4 ex

FIELD: chemical industry; methods of production of phenol and acetone.

SUBSTANCE: the invention is pertaining to the field of chemical industry, in particular, to the industrial process of production of phenol and acetone by the cumene method. The method is realized by decomposition of the technological cumene hydroperoxide in the in series connected reactors in two stages with formation on the first stage of the dicumylperoxide at the temperature of 40-65°С at presence as the catalytic agent of 0.003-0.015 mass % of the sulfuric acid with its subsequent decomposition on the second stage in the reaction medium at the temperature of 90-140°С. The process is conducted at the excess of phenol in the reaction mixture at the molar ratio of phenol : acetone exceeding 1, preferentially - from 1.01 up to 5. Excess of phenol is formed either by distillation (blowing) of acetone or addition of phenol in the reaction medium. The technical result of the invention is reduction of formation of hydroxyacetone, which one worsens the quality of the commercial phenol.

EFFECT: the invention ensures reduction of formation of hydroxyacetone, which one worsens the quality of the commercial phenol.

5 cl, 4 ex, 8 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to a method of preparing a mixture of cyclohexanol and cyclohexanone which are intermediate products in production of polyamides nylon-6 and nylon-6.6. The method is realised at high temperature and high pressure and involves the following successive cycles: oxidation of cyclohexane - decomposition of cyclohexylhydroperoxide, wherein oxidation of cyclohexane and decomposition of cyclohexylhydroperoxide are carried out in separate series-connected reactors without intermediate separation of the aqueous phase, whereby in each separate cycle, cyclohexane is oxidised with air or an oxygen-containing gas in liquid phase in the absence of a catalyst until conversion of cyclohexane of not more than 1.5 mol %, and the cyclohexylhydroperoxide formed during oxidation of cyclohexane is decomposed on a heterogeneous catalyst in a separate reactor until conversion of not less than 90 mol %.

EFFECT: method increases overall selectivity of converting cyclohexane to cyclohexanone and cyclohexanol and also considerably reduces formation of by-products.

9 cl, 19 ex, 2 tbl, 1 dwg

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