The method of producing cyclohexanone
The invention relates to a method for producing cyclohexanone, which is based on the reaction of liquid-phase oxidation of cyclohexene to cyclohexanone nitrous oxide or its mixture with an inert gas. The process is conducted at a temperature of 150-350oAnd pressure of nitrous oxide is from 0.01 to 100 ATM. Preferably used catalyst and the solvent. Can be used for recycling the exhaust gases. The technical result - a high selectivity for the target product and explosion safety. 10 C.p. f-crystals, 5 PL. The invention relates to a method for producing cyclohexanone, more specifically to a method for producing cyclohexanone by liquid-phase oxidation of cyclohexene nitrous oxide (N2O.Cyclohexanone is an intermediate product for the synthesis of-caprolactam and adipic acid, which are used for the production of polyamide materials nylon-6 and nylon-66. It is also widely used as a solvent of fats, dyes, natural and synthetic resins.The primary method of industrial production of cyclohexanone is in liquid-phase oxidation of cyclohexane with oxygen. The process is conducted in the field 145-180oC at a pressure of 8-12 bar, ICI cyclohexanol, in which the proportion of cyclohexanone is less than 50%.You can also process non-catalytic way. In this case, the reaction mixture was added boric acid, which binds the resulting cyclohexanol in the form of ether, inhibiting in this way the formation of by-products [U. S. Pat. 3932513, 1976, J. L. Russell]. The disadvantage of both variants of the process is the significant drop in the selectivity of the reaction with increasing conversion of cyclohexane. To maintain the total selectivity to cyclohexanone and cyclohexanol at the level of 85-90% conversion per pass should not exceed 3-5%. This leads to high costs for the selection of products and recycling of cyclohexane.Cyclohexanone can be obtained by selective catalytic dehydrogenation of cyclohexanol [U. S. Pat. 3998884, 1976, S. A. Gibson] or by hydrogenation of phenol [U. S. Pat. 3076810, 1963, R. J. Duggan et. al.; U. S. Pat. 4092360, 1978, Jan F. Van Peppen et. al.]. However, these methods are not widely used because of the high cost of raw materials.In the patent GB Pat. 649, 680 (1951) claimed method oxidation of olefins to carbonyl compounds nitrous oxide. According to this method, in particular, it is possible to obtain cyclohexanone by oxidation of cyclohexene. The disadvantage of this is an EP with cyclohexanol limited to one experience, carried out at a temperature of 300oC and a pressure of 500 ATM).The second major disadvantage of this method is the possibility of formation of flammable mixtures. To eliminate the risk, the authors of patent offer to additionally enter into the reaction mixture of saturated hydrocarbons. However, as shown by more recent studies, a mixture of saturated hydrocarbons with N2O almost as explosive as a mixture of olefins. Thus, the maximum concentrations of propylene in N20 is 1.8-26.8 per cent, and the maximum concentrations of propane 2,1-24,8% [G. Panetier, A. Sicard, V Symposium on Combustion, 620 (1955); B. B. Brandt, L. A. Matov, A. I. Raslowsky, C. S. Khailov, Chem. prom. , 1960, 5, S. 67-73]. Therefore, saturated hydrocarbons, in spite of their lower reactivity, can not serve as a means to avoid the explosion.This patent discloses a method of producing cyclohexanone by oxidation of cyclohexene, which does not have these disadvantages. According to the method for improving the selectivity of the reaction are under more mild conditions, when cyclohexane is present in the form of a liquid phase in which the oxidation reaction proceeds with high selectivity. Excessive increase in the temperature and/or pressure N2Is the p> Intrinsically safe working conditions for the proposed method are provided by adding to the reaction mixture an inert gas reacts with N2About, such as nitrogen, argon, helium, carbon dioxide, etc. or their mixture. The role of the inert gas can play the off-gases of the reaction. At different stages of the process depending on the ratio cyclohexen : nitrous oxide, the proportion of inert gas required to provide proof of work can be different and be created by a separate feeder. From the point of view of simplicity and maximum process safety it is advisable to have this dilution nitrous oxide inert gas to the reaction mixture was explosive in any content cyclohexene. This condition is satisfied if the content of N2About in a mixture with an inert gas is not more than 25%. Apply this mixture eliminates the occurrence of hazardous situations at all stages of the process.To reduce the explosion hazard in the reaction mixture can be added flame retardants, such as trifloromethyl, diperchlorate, dibromotetrafluoroethane etc.In accordance with this invention the oxidation of cyclohexene to cyclohexanone can be assest of steel, titanium or other suitable material. This can be used all known technological methods that increase the efficiency of gas-liquid reactions.In the case of a static variant of the process in the autoclave load cyclohexen in such quantity that when the temperature of the reaction he was present as a liquid phase. Then served nitrous oxide or a mixture thereof with an inert gas, reducing the pressure to a predetermined value. The number of N2O pick up so that its pressure at the reaction temperature ranged from 0.01 to 100 ATM. The concentration of inert gas in the mixture with nitrous oxide selected so that it does not exceed 99%. The reaction is carried out at a temperature of 150-350oC. the reaction Time depends on the environment and requirements of process indicators, and may vary from several minutes to several tens hours. If necessary to ensure a deeper conversion of cyclohexene gas phase is replaced by a new portion of the nitrous oxide and the reaction is carried out again. In the case of incomplete conversion of nitrous oxide it in the composition of the recirculating gases can be reused for the reaction.The proposed process can the e can be chosen from a wide range of substances, practices used in organic synthesis. Reaction with high speed proceeds without a catalyst, although it may also be carried out in the presence of a catalyst.The proposed method of producing cyclohexanone does not imply high purity reagents. So, nitrous oxide can be used both in pure form and mixed with various gases, not having a harmful effect on process performance. Cyclohexen may also contain impurities of organic compounds not having a harmful effect on process performance.The essence of the invention is illustrated by the following examples.Examples 1-6 the Results of these examples are shown in table. 1 and show a high selectivity of the reaction liquid-phase oxidation of cyclohexene to cyclohexanone using as oxidant nitrous oxide.Example 1. In a reactor with a volume of 100 cm3(firm Parr), made of stainless steel and equipped with a mixer, pour 25 cm3cyclohexene (Aldrich, 99%). The reactor is rinsed with nitrogen and then brought her up to a pressure of 25 ATM. The reactor was sealed, heated to 250oC and maintained at this temperature for 5 hours. After the reaction, the reaction is graphy and gas chromatography / mass spectrometry. From the obtained data to calculate the conversion of cyclohexene (X) and the reaction selectivity to cyclohexanone (S):where0CyEN- initial concentration of cyclohexene; CCyONthe concentration of cyclohexanone in the reaction products;Cside- total concentration of by-products. In the case of large conversion value X can be calculated also by the difference between the initial and final concentrations of cyclohexene:Example 2 same as example 1 with the difference that the reaction of lead within 12 hours.Example 3 same as example 1 with the difference that the reaction is carried out at 150oC for 23 hours.Example 4 same as example 1 with the difference that the reaction is carried out at a temperature of 198oC for 15 hours.Example 5 same as example 1 with the difference that the reaction is carried out at 220oWith in 12 hours.Example 6 same as example 1 with the difference that the reaction is carried out at 280oC for 3 hours.Example 7 This example is comparative. The experience carried out analogously to example 1 with the difference that was charged to the reactor 4 ml of cyclohexene. Under such load all cyclohe the but of 0.5%. This suggests that under these conditions the reaction in the gas phase is hardly taking place.Examples 8-9 These examples in comparison with examples 4 and 5 demonstrate the effect of the concentration of nitrous oxide in the process indicators (table. 2). The concentration of nitrous oxide in the reaction mixture is set by the size of its initial pressure at room temperature.Example 8 is similar to example 4 with the difference that the initial pressure of nitrous oxide in this experiment, the set of 40 ATM.Example 9 same as example 5 with the difference that the initial pressure of nitrous oxide in this experiment, the set of 10 ATM.Examples 10-12 Examples 10-12, the results of which are given in table. 3, show the possibility of conducting the process in the presence of a catalyst.Example 10 same as example 1 with the difference that the oxidation of cyclohexene are 16.5 hours in the presence of 0.21 g of the zeolite catalyst FeZSM-5. Zeolite (Si02/Al2O3=150, 0.56 wt.% Fe) prepared by hydrothermal synthesis method with the introduction of iron in the original gel in the form FeCl3. After burning a template and translation of the zeolite in the H form the sample calcined in air at 550oC and then subjected thermoprotei activation at 650o[US Pat. 5672777, 1997, Kharitonov et al.]ub>/SiO2(2.8 wt. % Fe2O3). The catalyst is prepared by impregnation of SiO2solution F13, dried at 110oC and calcined in air at 500oC for 2 hExample 12 same as example 4 with the difference that the reaction are 12 hours in the presence of 0.5 g of Rh/ZrO2(1 Mac. % Rh). The catalyst is prepared by impregnation of ZrO2a solution of Rh(NO3)3, dried at 110oC and calcined in air at 500oC for 2 hExamples 13-16
These examples show the possibility of oxidation of cyclohexene using different solvents (table. 4).Example 13 same as example 5 with the difference that in the reactor pour 25 ml of a mixture of cyclohexene and heptane in a volume ratio of 1:1.Example 14 same as example 13 with the difference that instead of using cyclohexane acetonitrile.Example 15 same as example 13 with the difference that instead of cyclohexane using Isobutanol.Example 16 same as example 13 with the difference that instead of cyclohexane using water.Examples 17-22
Examples 17-22 are given in table. 5. These examples show the possibility of reaction with dilute mixtures of nitrous oxide.Example 17 same as example 1 with the difference that instead of Fleet 70%. The initial pressure in the reactor (Ro) set 45 ATM.Example 18 is similar to example 17 with the difference that the concentration of N2O in a mixture with nitrogen is 20%. The experience carried out within 12 hours.Example 19 analogous to example 18 with the difference that the initial pressure in the reactor was set to 80 ATM. The experience carried out at 220oWith in 12 hours.Example 20 is similar to example 19 except that the concentration of N2About in a mixture with nitrogen is 40%. The initial pressure of the mixture in the reactor was set to 40 ATM.Example 21 analogous to example 19, with the difference that as the inert gas instead of nitrogen gas used argon and the concentration of N2O in a mixture with Hypertension is 50%. The initial pressure in the reactor was set to 30 ATM.Example 22 is the same as example 21 with the difference that instead of argon using carbon dioxide.Example 23 analogous to example 19, with the difference that the concentration of N2O in a mixture with nitrogen is 1%. The initial pressure of the mixture in the reactor was set to 200 ATM.Examples 17-23 show that cyclohexen with high selectivity is oxidized to cyclohexanone with nitric acid diluted with an inert gas. The content of N2About in a mixture with an inert gas can izmest hazardous situations under any songs with cyclohexanol. As examples 18 and 19 (table. 5), the oxidation reaction of cyclohexene to cyclohexanone in this area proceeds with high efficiency.Example 24
This example shows the possibility of oxidation of cyclohexene using recirculating gases.Example 24 is similar to example 1 with the difference that instead of pure nitrous oxide into the reactor first served 12.5 ATM N2O-containing gas, formed after oxidation of cyclohexene according to example 5. Then the reactor add pure nitrous oxide, bringing the total pressure of 25 ATM. The experience carried out at 250oC for 5 hours. Experience the conversion of cyclohexene was 22% with a selectivity for 95.8%
In the present invention proposes a new method of producing cyclohexanone, based on the reaction of liquid-phase oxidation of cyclohexene oxide nitrogen or its mixture with an inert gas. The process provides high selectivity, the explosion and is promising for industrial applications.
1. The method of obtaining of cyclohexanone cyclohexene, wherein the process is carried out by contact of the liquid cyclohexene oxide of nitrogen at a temperature of 150-350o3. The method according to any of paragraphs. 1-2, characterized in that the concentration of inert gas in the reaction mixture does not exceed 99%.4. The method according to any of paragraphs. 1-3, characterized in that the concentration of the inert gas is selected so as to exclude the possibility of formation of explosive compositions at each stage of the process.5. The method according to any of paragraphs. 1-4, characterized in that the reaction is carried out at a temperature 150-199oAnd pressure of nitrous oxide is from 0.01 to 100 ATM.6. The method according to any of paragraphs. 1-5, characterized in that the reaction is carried out at a temperature of 150-350oAnd pressure of nitrous oxide is from 0.01 to 20 ATM.7. The method according to any of paragraphs. 1-6, characterized in that the reaction is carried out in the presence of a catalyst.8. The method according to any of paragraphs. 1-7, characterized in that the reaction is carried out in the presence of a solvent.9. The method according to any of paragraphs. 1-8, characterized in that the nitrogen oxide contains traces of other gases without impairing the performance of the process.10. The method according to any of paragraphs. 1-9, characterized in that the reaction is carried out in a static or flow-through version.11. The method according to any of paragraphs. 1-10, characterized in that for carrying out the reaction using recirculating gases.
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
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, 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.
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.
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
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
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.
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
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
FIELD: process engineering.
SUBSTANCE: invention relates to catalyst for dehydration of cyclohexanol to cyclohexane and to method of its production. Proposed catalyst comprises the following components in wt %: calcium carbonate - 16.4-37.0, graphite - 1.0-3.0, and zinc oxide making the rest. Proposed method comprises preparing reaction mix of previously mentioned composition containing sources of zinc oxide and calcium carbonate, moulding, drying, and calcinating. Note here that said mix comprises the following components in wt %: calcium carbonate - 12.4-29.8, carboxymethylcellulose or methylcellulose - 0.1-1.0, and base zinc carbonate making the rest, while graphite is added into amounts sufficient for production of said catalyst.
EFFECT: higher strength, lower costs, simplified production, reduced harmful effects.
3 cl, 2 tbl, 2 ex