SU390713A1 - Method of producing cycloalkanols and cycloalkanones - Google Patents

Description

one

The invention from 1H1s1c to the area of dicycloaliphatic alcohols and ketones, for example, cyclohexanol and cyclohexanone.

The known method of crawling of diclohexanol and cyclohexanone by the oxidation of cyclohexane in the LSD1OK phase with oxygen-containing gas in the presence of a soluble chromium compound as a catalyst.

For decomposition of hydroscopic severity, the oxygen products are heated without additional catalyst addition.

You get a mixture of cyclohexanol and cyclohexanone with a predominant content of cyclohexanol.

The purpose of this work is to obtain a mixture of cycloalkanols ' cycloalkanols enriched in cycloalkanone.

According to the proposed method, the decomposition of cycloalkyl hydroperoxide, dissolved cycloalkane and obtained during the oxidation of cycloalkane, is carried out in a series of located reactors at co-concentration of hydroperoxide in Caladome. Of these, not more than 15%.

In the redakable way, all oxidation products of cycloalkanes containing peroxides and "hydroperoxide features, but mainly oxidation products (oxidates) containing hydroperoxides can be treated, since in this case the percentage of undesirable products in the feedstock is minimal. In practice, it is advisable to proceed from the oxidation products obtained in the oxidation of cycloalkanes with a catalyst-free air, possibly under pressure at a temperature and percentage of conversion of hydroperoxide, selected in such a way that it is possible to limit the formation of undesirable compounds. The work is carried out .in equipment that does not catalyze

decomposition of hydraperoxia, when steel equipment is used, it is subjected to its prior ososivation using, for example, pyrophosphates. When oxidation is carried out specifically to produce hydroperoxides, the percentage

Covers are generally limited to less than 10%, preferably between 2 and 6%. Cycloalkyl hydroxycaroxide oxidation products contain cycloalkanol, cycloalka non and various secondary (nobone) products. The common products can be oxidized and processed to decompose peroxides in a patented process. The mixture of products oxidized (oxidate), before being subjected to processing by the proposed method, to bring to any concentration. But since the reaction is exothermic, in order to avoid overheating, which contributes to a decrease in yield, one should not work with too concentrated solutions. Practically, it is necessary to work with solutions of oxidation products with a concentration of α-peroxides not higher than 15%. Since oxidation is usually carried out under pressure, a simple method of concentrating the mixtures of oxidation products thus obtained is to reduce the pressure of the hot oxydate at the outlet of the oxidation reactor. Such solutions of moxobium oxide products can be successfully obtained according to the method described in French patent 1491518. Before the oxidation products were processed to decompose the peroxides, it was advisable to remove the acids contained in them, at least partially, by washing with water.

The temperature may be the same in all zones of peroxide decomposition, or different in different zones, but as a rule, work is carried out in the range from 80 to. At too low temperatures, the rate of decomposition of hydroperoxide is significantly reduced, while at temperatures above 150 ° C, given the number of peroxide decomposition zones, the selection of the IB process, meaning that cycloalkanones are reduced. Work is carried out preferably in the range from 100 to 130 ° C.

The decomposition of hydroperoxide is carried out in stages as the cyclohexane solution is extended from the first to the last decomposition zone. g.idraperK1ISey.

The selectivity of the process in the direction of producing cycloalkanones increases with an increase in the number of zones of peroxide decomposition, and the more noticeable this effect is, the higher the decomposition temperature of the Sherekia. The selection of the number of zones is determined by the prelude of all Economical and technological considerations, the purpose of which is to ensure good production.

So, for example in the case when cycloalka. the cyclohexane is nome, the work is carried out under the above temperature conditions, in 2-6 successive zones.

Peroxide decomposition zones can be placed in apparatus of various types, commonly used to ensure phase uniformity and the same concentration. You can, for example, work in recirculating columns, simple columns, sleepers with mixing devices, in autoclaves. It is recommended to supply each zone with a device that allows separating water formed during the decomposition of peroxide, which can then be removed from the reaction zone as a double azeotronic mixture with a cycloalkane, possibly with simultaneous action of an inert gas jet. Peroxide decomposition zones can be cascaded.

The catalysts are chromium compounds with a solubility in cycloalkanes of at least 0.1 g1l at room temperature. Among soluble catalysts, for example, chromium (III) carboxylates, such as naphthenates, α -octoates and stearates, carbonyl derivatives, complex compounds, hexavalent chromium carboxilates, for example, tertiary alkyl ethers, can be mentioned.

chromic acid, for example, tertiary butyl chromate; cycloalkyl esters of chromic acid, for example cyclohexyl chromate. Tertiary alkyl or cycloalkyl octoates and chromates are preferred. Since cycloalkanol is contained in various zones of peroxide decomposition, the corresponding chromates can be obtained in the zoops themselves by introducing compounds such as, for example, chromium oxide or its complex compound with pyridine.

The amount of catalyst may vary in the UCh | irok limits, but, as a rule, the amount of metal in the catalyst is from 1 mg to 1 g per 1 kg of peroxide in solution,

processed to decompose peroxides. The catalyst can be introduced by polishing into the first zone of peroxide decomposition, or it is better to p-distribute the zones by any suitable method.

When carrying out (the proposed process, the cycloalkane oxidation products are continuously fed (possibly preheated) to the first peroxide decomposition zone along with some catalyst. The temperature in the zones is controlled in any suitable way, by changing the intensity of the heating or the oxidate supply depending on the percentage selected for this zone peroxide decomposition. In the case when the peroxide decomposition temperature exceeds the boiling point of the mixture, leave the apparatus under its own (autogenous) pressure under certain conditions in combination with the pressure created by the flow

inert gas. Work is conducted, as a rule, under pressure in the range from atmospheric to 25 atm.

The oxidate subjected to partial decomposition of peroxides, along with a certain amount of catalyst, goes continuously to the second zone, in which the remaining hydroperoxide undergoes further partial decomposition and so on to the last zone.

The solution, which is practically free of peroxides, is prepared by conventional methods in order to separate the cycloalkanone from the cycloalkanol. This can be done by distillation. In this case, the last zone of peroxide decomposition can be combined with distillation and preliminary concentration (enrichment) operations. It is recommended that the endotraction of hydroperoxide in the solution entering the last zone

decomposition of peroxides was insignificant; It is advisable to work in such a way that at least 60% of the peroxides contained in the solution entering the first zone are decomposed even before

in the last zone. The described method is applicable to the treatment of products by the oxidation of cycloalkanes containing 5-16 carbon atoms in the cycle, and in particular cycloalkano1B with 6-12 atoms, amy carbon in the cycle. Of particular interest is the conversion of cyclohexane into a mixture of cyclohexanone and cyclohexanol with a significant percentage of cyclohexanium. Example 1. A jagged apparatus is shown schematically in FIG. 1. The apparatus includes three columns, operating according to the reclamation principle A, B, and C, made of stainless steel. The columns are made in the form of cylinders (height 178 cm, internal diameter 5 cm, equipped with internal coaxial cylinders (internal diameter 3 cm), a useful capacity of 3.1 liters and external scrubs containing liquid at 123 ° C. Columns The lower part of column A is fed through a pipeline / harmful and enriched (collapsed) cyclohexane solution heated to 95 ° C, IB with an amount of 13.5 kg / hour, obtained from the stage of cyclohexane oxidation with air without a catalyst, containing 10 evaporation loses, 8% peroxide, 2.43% cyclohexanone and 3.5% of heavy products consisting mainly of acids and esters. At the bottom of each column, each one of the columns is fed simultaneously through the pipeline 2 nitrogen in the amount of 100 l / h through pipeline 3 - 0.03% cyclohexane solution of chromium octoate containing 10.8% by weight of metal, in the amount of 0.8 kg / hour in Li columns and 0.48 kg / hour in column C. Inside each column, a temperature of 115 ° C and a pressure of 2.5 are maintained ATM (relative). Nitrogen and entrained products (water, cyclohexane, cyclohexanol, cyclohexanone) are sent from the top of each of the columns to condenser 4. The condensed products are sent to decanter 5, where water separates (collector 6) from the organic phase 7, while nitrogen leaves through valve 8. The liquid phase leaving the column L is cooled to 40 ° C, the pressure is released to atmospheric, and washed counter-current, while the organic phase is separated (separated) in decanter b, it enters the column 9, in which n given by line 10 8% aqueous solution Ammian .ka Used amount of 4 kg / h. The aqueous phase is removed through runoff 11, while the organic phase is sent to column D (plate), where the decomposition of the remaining peroxides occurs simultaneously and the majority of the cyclohexane is removed. This column is equipped with a lower part of the boiler, which allows the temperature of the liquid in the lower part of the column to be maintained at 115 ° C. The vaporous fraction (cyclohexane-water) is condensed in condenser 12, then sent to decanter 13, where cyclohexane separation takes place (collected 14} and the aqueous phase (collection 15). The mixture of heavy products is collected in collection 16 and distilled. - the quantities of nepeKHcefi, cyclohexanol and cyclohexanone are given at different stages of the process per 100 kg of solution fed through line 1. Example 2. The hardware diagram is shown in Fig. 2. It includes recycled columns L, 5 and C from stainless steel to the national party The columns are made in the form of cylinders, 260 cm in height, with an inner diameter of 5 cm. Inside each column there is a coaxial cylinder with an inner diameter of 3 cm and a useful capacity of 3.1 liters, with an outer jacket in which liquid is circulated at 105 ° C. The columns of the L column are fed through a pipeline (9.64 kg / h) of a cyclohexane solution at 100 ° C obtained at the oxidation stage 1 and cyclohexane with air without a catalyst and subjected to countercurrent washing with water (10% by weight), then drying by distillation azeotropic water-cyclohexane mixtures; the solution contains 9.8 wt. % peroxides, 2.76% cyclohexanol, 1% cyclohexanone and 1% heavy products, consisting mainly of acids and esters. in the lower part of each of the columns is fed through the pipeline 2 nitrogen. in the amount of 200 l / h and through the pipeline 3 0,0825% cyclohexaeic solution of tertiary butyl chromate, at the rate of 0.312 kg / h in each of the columns L, B and C Inside the columns, the temperature is kept at 105 ° C and the pressure is 2.6 atm relative. Nitrogen from the top of the columns and entrained products (mainly water and cyclohex. N) are condensed in condensers 4, 5 and 6, then these products are decanted in decanters 7, 8 and 9, and water is separated through descents 10 , 11 and 12, while the organic phase is returned to the bottom of the corresponding column. The uncondensed gas escapes after bleeding through the gas outlet 13. The liquid phase from column C is directed to the lower part of the plate column D, the pressure descends to atmospheric. In the last column, the remaining peroxides are simultaneously decomposed and the majority of cyclohexane is removed. The column is equipped at the bottom with a boiler that maintains the temperature of the liquid from the IOC. The vaporous fraction (cyclohexane-water) is condensed in condenser-74, collected in decanter J5, in which cyclohexane B is separated: collection / and-water phase in collection 77.

The mixture of heavy products is collected in collection 18 and distilled.

Below, the p1c drive of the number of lerakides at different stages of the process in terms of 100 kg of solution flowing through the pipeline} /.

The solution coming for processing. 9.8 At the exit of L 4.33

  from B1,66

  from C0,53

  from to

 Subject invention

 Cycloalkanol and cycloalkanone oxidation by oxidation of cycloalkane in a liquid aze-oxygen-containing gas with a subsequent decomposition of the solution obtained

cycloalkyl hydroperoxides in cycloalkane

Natetane am temperatura 80-150 ° C

10 npTicyTicTtBH pa1CT1Wori | Mogo chromium compound

as a catalyst and the selection of Celje, Vy (Products by well-known methods, oglyucha-YutsMyys by the fact that, with the purpose of obtaining a mixture

 cycloalkan-nol and cycloalkanone, abraded with 5 NOC of cycloalkanone, decomposed by means of hydroxyl cycloalkyl acid and lead to a follower of

located reactors - at a concentration

 hydrape-isi in of no more

15%.