CA1262359A - Continuous preparation of mixtures containing cyclohexyl hydroperoxide, cyclohexanol and cyclohexanone - Google Patents
Continuous preparation of mixtures containing cyclohexyl hydroperoxide, cyclohexanol and cyclohexanoneInfo
- Publication number
- CA1262359A CA1262359A CA000473196A CA473196A CA1262359A CA 1262359 A CA1262359 A CA 1262359A CA 000473196 A CA000473196 A CA 000473196A CA 473196 A CA473196 A CA 473196A CA 1262359 A CA1262359 A CA 1262359A
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- Prior art keywords
- stage
- molecular oxygen
- cyclohexane
- dissolved
- cyclohexyl hydroperoxide
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C409/00—Peroxy compounds
- C07C409/02—Peroxy compounds the —O—O— group being bound between a carbon atom, not further substituted by oxygen atoms, and hydrogen, i.e. hydroperoxides
- C07C409/14—Peroxy compounds the —O—O— group being bound between a carbon atom, not further substituted by oxygen atoms, and hydrogen, i.e. hydroperoxides the carbon atom belonging to a ring other than a six-membered aromatic ring
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
- C07C29/48—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by oxidation reactions with formation of hydroxy groups
- C07C29/50—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by oxidation reactions with formation of hydroxy groups with molecular oxygen only
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C407/00—Preparation of peroxy compounds
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/27—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation
- C07C45/32—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation with molecular oxygen
- C07C45/33—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation with molecular oxygen of CHx-moieties
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2601/00—Systems containing only non-condensed rings
- C07C2601/12—Systems containing only non-condensed rings with a six-membered ring
- C07C2601/14—The ring being saturated
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- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Abstract of the Disclosure: Mixtures containing cyclohexyl hydroperoxide, cyclohexanol and cyclohexanone and having a high cyclohexyl hydroperoxide content are prepared by a continuous process which comprises the oxidation of cyclo-hexane with molecular oxygen, or with a gas containing this, in the liquid phase, in which 1. in a first stage, molecular oxygen is dissolved in cyclohexane by bringing the latter into contact with molecular oxygen, or with a gas containing this, at from 10 to 110°C and under superatmospheric pressure, and 2. in a second stage, the cyclohexane containing dis-solved molecular oxygen is passed through an elongated, tubular reaction zone at from 130 to 250°C and under superatmospheric pressure, virtually with plug flow and without the formation of a gas phase, the residence time being between a) the time required for the consumption of 50% of the amount of dissolved molecular oxygen and b) 1.2 times the time required for the consumption of 99.9% of the dissolved molecular oxygen.
Description
O.Z. 0~50/36944 Co ~ xtures containin~_cyclohexyl hydr~ DL~-L~hexanol_~
German Laid-Open Application DOS 2,951,956 describes a process for the preparation of m;xtures consisting of cyclohexyl hydroperoxide, cyclohexanol and cyclohexanone an having a high perox;de content, in which the react;on of cyclohexane w;th molecular oxygen ;s carr;ed out ;n the l;qu;d phase ;n several successive stages, the temperature is decreased from stage to stage by not less than 5C
in each case, and molecular oxygen ;s ;ntroduced ;n each stage. The y;elds of cyclohexyl hydroperox;de obta;ned in this procedure are unsatisfactory. German Laid-Open Application DOS 1,593,700 and British Patent 1,085,892 also disclose processes in which molecular oxygen is f;rst dissolved ;n cyclohexane at a relat;vely low temperature, and the cyclohexane contain;ng dissolved molecular oxygen is passed through a tubular reaction zone, at elevated temperatures, in a second stage. However, the procedures described there give mainly cyclohexanol and cyclohexanone and sub-stant;al amounts of ac;ds, but only m;nor amounts of cyclohexyl hydroperox;de. The acids are undesirable byproducts which are formed by further oxidation of cyclohexanone w;th oxygen. In order to obtain a very high yield of useful products, and minimize the amount of by-products, it is necessary to carry out the reaction in such a way that it stops at the stage of the initially formed cyclohexyl hydroperoxide or the latter becomes the principal product~ The cyclohexyl hydroperoxide can then be converted in a further stage, in the absence of molecu-lar oxygen, to give cycLohexanol and cyclohexanone in vir-tually quantitative yield; by reaction in the presence ofolefins, and using suitable catalysts, it is also pos-sible to prepare epoxides.
It is an object of the present invention to carry out the reaction in the oxidation of cyclohexane with mole-cular oxygen in such a way that essentially cyclohexyl hydroperoxide is obtained and the content of cyclohexanone 3~;~
German Laid-Open Application DOS 2,951,956 describes a process for the preparation of m;xtures consisting of cyclohexyl hydroperoxide, cyclohexanol and cyclohexanone an having a high perox;de content, in which the react;on of cyclohexane w;th molecular oxygen ;s carr;ed out ;n the l;qu;d phase ;n several successive stages, the temperature is decreased from stage to stage by not less than 5C
in each case, and molecular oxygen ;s ;ntroduced ;n each stage. The y;elds of cyclohexyl hydroperox;de obta;ned in this procedure are unsatisfactory. German Laid-Open Application DOS 1,593,700 and British Patent 1,085,892 also disclose processes in which molecular oxygen is f;rst dissolved ;n cyclohexane at a relat;vely low temperature, and the cyclohexane contain;ng dissolved molecular oxygen is passed through a tubular reaction zone, at elevated temperatures, in a second stage. However, the procedures described there give mainly cyclohexanol and cyclohexanone and sub-stant;al amounts of ac;ds, but only m;nor amounts of cyclohexyl hydroperox;de. The acids are undesirable byproducts which are formed by further oxidation of cyclohexanone w;th oxygen. In order to obtain a very high yield of useful products, and minimize the amount of by-products, it is necessary to carry out the reaction in such a way that it stops at the stage of the initially formed cyclohexyl hydroperoxide or the latter becomes the principal product~ The cyclohexyl hydroperoxide can then be converted in a further stage, in the absence of molecu-lar oxygen, to give cycLohexanol and cyclohexanone in vir-tually quantitative yield; by reaction in the presence ofolefins, and using suitable catalysts, it is also pos-sible to prepare epoxides.
It is an object of the present invention to carry out the reaction in the oxidation of cyclohexane with mole-cular oxygen in such a way that essentially cyclohexyl hydroperoxide is obtained and the content of cyclohexanone 3~;~
- 2 - O.Z 0050/369~4 and carboxyl;c acids is kept very low.
We have found that this object is achieved by a process for the continuous preparation of a m;xture con-- taining cyclohexyl hydroperoxide, cyclohexanol and cyclo-hexanone and having a high cyclohexyl hydroperoxide con-tent by oxidation of cyclohexane with molecular oxygen, or a gas containing this~ in the liquid phase, in which 1. in a first stage, molecular oxygen is dissolved in cyclohexane by bring;ng the latter into contact with molecular oxygen, or with a gas containing this, at from 10 to 110C and under superatmospheric pressure, and 2. in a second stage, the cyclohexane containing dis-solved molecular oxygen is passed through a tubular reaction zone at from 130 to 250C and under super-atmospheric pressure, wherein the cyclohexane containing dissolved molecular oxygen is passed through an elongated tubular reaction zone virtually with a plug flow and without the formation of a gas phase, the residence time being between a) the time required for the consumption of 50% of the amount of dissolved molecular oxygen and b) 1.2 times the t;me required for the consumption of 99.9% of the dissolved oxygen.
The novel process has the advantages that the yields of cyclohexyl hydroperoxide obtained are higher than those achieved to date, and the content of cyclohexanone and carboxylic acids is kept low.
In a first stage, molecular oxygen is first dis-solved in cyclohexane. In this procedure, cyclohexane is brought into contact with molecular oxygen or a gas con-taining this. As a rule, the gases used contain more than 20%9 advantageously more than 90%, in particular more than 99%, of mole~ular oxygen. The remaining components are inert gases, such as nitrogen, carbon dioxide and noble gases. In this stage, the temperature is kept at from 10 to 110C, in part;cular from 15 to 80C The molecular
We have found that this object is achieved by a process for the continuous preparation of a m;xture con-- taining cyclohexyl hydroperoxide, cyclohexanol and cyclo-hexanone and having a high cyclohexyl hydroperoxide con-tent by oxidation of cyclohexane with molecular oxygen, or a gas containing this~ in the liquid phase, in which 1. in a first stage, molecular oxygen is dissolved in cyclohexane by bring;ng the latter into contact with molecular oxygen, or with a gas containing this, at from 10 to 110C and under superatmospheric pressure, and 2. in a second stage, the cyclohexane containing dis-solved molecular oxygen is passed through a tubular reaction zone at from 130 to 250C and under super-atmospheric pressure, wherein the cyclohexane containing dissolved molecular oxygen is passed through an elongated tubular reaction zone virtually with a plug flow and without the formation of a gas phase, the residence time being between a) the time required for the consumption of 50% of the amount of dissolved molecular oxygen and b) 1.2 times the t;me required for the consumption of 99.9% of the dissolved oxygen.
The novel process has the advantages that the yields of cyclohexyl hydroperoxide obtained are higher than those achieved to date, and the content of cyclohexanone and carboxylic acids is kept low.
In a first stage, molecular oxygen is first dis-solved in cyclohexane. In this procedure, cyclohexane is brought into contact with molecular oxygen or a gas con-taining this. As a rule, the gases used contain more than 20%9 advantageously more than 90%, in particular more than 99%, of mole~ular oxygen. The remaining components are inert gases, such as nitrogen, carbon dioxide and noble gases. In this stage, the temperature is kept at from 10 to 110C, in part;cular from 15 to 80C The molecular
- 3 - O.Z. 0050/36944 oxygen is dissolved in cyclohexane under superatmospheric pressure, advantageously under from 1û to 200, in particu-lar from 15 to 60, bar~
As a rule, the degree of saturation with molecular oxygen is maintained at from 60 to 100%.
It i9 possible, under the particular ~emperature and pressure conditions used, to saturate cyclohexane com-pletely with molecular oxygen. For safety reasons, how-ever, it ;s advisable to keep the degree of saturation be-low 90%, eg. from 60 to 90%, under the part;cular tempera-ture and pressure conditions used.
- Advantageously, the saturation of cyclohexane with molecular oxygen is carried out in apparatuses as are con-ventionally used ;n industry for dissolving gases in li-quids~ for example packed columns or stirred kettles,molecular oxygen being introdu~ed in f;nely divided form.
In a second stage, the cyclohexane containing dis-solved molecular oxygen is then passed through an elongated tubular reaction zone. During this procedure~ the flow is ma;nta;ned as virtually plug flow, ie. care should be taken to ensure that only very little, if any, backmixing takes place. This is achieved by, for example, elon-gated reaction zones having a length:diameter ratio of from 100:1 to 1,000:1, or elongated tubular reaction zones containing baffles, eg. Raschig rings, and having a length:
diameter ratio of from 10:1 to 100:1.
In th~ second stage, the temperature is kept at from 130 to 250C, a temperature of from 150 to 200C
having proven particularly useful. The reaction tempera-ture is preferably decreased along the tubular reactionzone~ This 1s effected, for example, continuously or step-wise, eg~ in from 3 to 6 steps, the drop in temperature from the entrance to the tubular reaction zone to the exit from this zone advantageously being maintained at from 10 to 40C, in particular from 15 to 30C. The tempera-ture is of course not allowed to fall below the lower limit of the reaction temperature, as stated above, as a result of
As a rule, the degree of saturation with molecular oxygen is maintained at from 60 to 100%.
It i9 possible, under the particular ~emperature and pressure conditions used, to saturate cyclohexane com-pletely with molecular oxygen. For safety reasons, how-ever, it ;s advisable to keep the degree of saturation be-low 90%, eg. from 60 to 90%, under the part;cular tempera-ture and pressure conditions used.
- Advantageously, the saturation of cyclohexane with molecular oxygen is carried out in apparatuses as are con-ventionally used ;n industry for dissolving gases in li-quids~ for example packed columns or stirred kettles,molecular oxygen being introdu~ed in f;nely divided form.
In a second stage, the cyclohexane containing dis-solved molecular oxygen is then passed through an elongated tubular reaction zone. During this procedure~ the flow is ma;nta;ned as virtually plug flow, ie. care should be taken to ensure that only very little, if any, backmixing takes place. This is achieved by, for example, elon-gated reaction zones having a length:diameter ratio of from 100:1 to 1,000:1, or elongated tubular reaction zones containing baffles, eg. Raschig rings, and having a length:
diameter ratio of from 10:1 to 100:1.
In th~ second stage, the temperature is kept at from 130 to 250C, a temperature of from 150 to 200C
having proven particularly useful. The reaction tempera-ture is preferably decreased along the tubular reactionzone~ This 1s effected, for example, continuously or step-wise, eg~ in from 3 to 6 steps, the drop in temperature from the entrance to the tubular reaction zone to the exit from this zone advantageously being maintained at from 10 to 40C, in particular from 15 to 30C. The tempera-ture is of course not allowed to fall below the lower limit of the reaction temperature, as stated above, as a result of
4 - O.Z. 0050/369~4 reducing the temperature.
The elongated reaction zone is advantageously in the form of a coiled tube. It is advantageous if a plurality of coiled tubes, eg. as many as 5, preferably of decreasing length, are connected in series. In such an arrangement, it - has proven useful to reduce the temperature from section to section. Another advantageous embodiment of the elongated reaction zone consists of tube bundles containing parallel tubes. Preferably, a plurality of tube bundles, eg. as many as 5, particularly of decreasing length, are connected in series, and it has proven useful to reduce the temperature from tube bundle to tube bundle.
The pressure employed in the second stage is ad-vantageously the same as, or higher than, the saturation pressure. Care is taken to ensure that, at the particular temperature used~ the pressure is sufficiently high to prevent the formation of a gas phase. As a rule, pres-sures of from 40 to 100 bar are maintained, and the pres-sure in the second stage is advantageously at least 10 bar higher than the saturation pressure.
The residence time in the second stage is between a) the time required for the consumption of 50% of the amount of dissolved molecular oxygen and b) 1.2 times the time required for the consumption of 99.9% of the dissolved oxygen.
Advantageously, the residence time maintained is between the time required for the consumption of 80% of the amount of dissolved molecular oxygen and the time required for the consumption of 99~9% of the dissolved molecular oxygen.
In the second zone, the conversion is advantageously maintained at from 1 to 8, in particular from 2 to 6, %
by weight, based on cyclohexane.
It has also proven advantageous for cyclohexane containing molecular oxygen to be introduced in the course of the second stage, at one or more further points, eg.
from 1 to 4 points, which advantageously are located in the
The elongated reaction zone is advantageously in the form of a coiled tube. It is advantageous if a plurality of coiled tubes, eg. as many as 5, preferably of decreasing length, are connected in series. In such an arrangement, it - has proven useful to reduce the temperature from section to section. Another advantageous embodiment of the elongated reaction zone consists of tube bundles containing parallel tubes. Preferably, a plurality of tube bundles, eg. as many as 5, particularly of decreasing length, are connected in series, and it has proven useful to reduce the temperature from tube bundle to tube bundle.
The pressure employed in the second stage is ad-vantageously the same as, or higher than, the saturation pressure. Care is taken to ensure that, at the particular temperature used~ the pressure is sufficiently high to prevent the formation of a gas phase. As a rule, pres-sures of from 40 to 100 bar are maintained, and the pres-sure in the second stage is advantageously at least 10 bar higher than the saturation pressure.
The residence time in the second stage is between a) the time required for the consumption of 50% of the amount of dissolved molecular oxygen and b) 1.2 times the time required for the consumption of 99.9% of the dissolved oxygen.
Advantageously, the residence time maintained is between the time required for the consumption of 80% of the amount of dissolved molecular oxygen and the time required for the consumption of 99~9% of the dissolved molecular oxygen.
In the second zone, the conversion is advantageously maintained at from 1 to 8, in particular from 2 to 6, %
by weight, based on cyclohexane.
It has also proven advantageous for cyclohexane containing molecular oxygen to be introduced in the course of the second stage, at one or more further points, eg.
from 1 to 4 points, which advantageously are located in the
- 5 - O.Z. 0~50/369~4 first half of stage 2.
In order to shorten the induction period in the second stage, it is advantageous to use an initiator, eg.
a peroxideO in particular cyclohexyl hydroperoxide or a reaction mixture containing this, for example in an amount of from 0.1 to 0.5~ by weight, based on cyclohexane.
The surfaces which come into contact with the reac-tion m;xture, in particular those of the second stage, are advantageously enamelled or passivated. The passivation -is achieved by, for example, treatment with pyrophosphates.
Examples of suitable pyrophosphates are Na pyrophosphate and K pyrophosphate. It has proven particularly advan-tageous for small amounts, eg. not more than 10 ppm, of a pyrophosphate to be added to the cyc lohexane either continuously or at intervalsO
In addition to containing unreacted cyclohexane, the resulting reaction mixture contains cyclohexyl peroxide, cyclohexanol, minor amounts of cyclohexanone and small amounts of other oxygen containing oxidation products such as esters and carboxylic acids.
Before further processing, some of the acidic compo-nents are advantageously washed out of the resulting reac-tion mixture with water. Further conversion of the cyclo-hexyl hydroperoxide to cyclohexanol and cyclohexanone in the presence of a catalytic metal compound is carried out, for example~ as described in German Laid-Open Application DOS 2,352,378. Cyclohexanone and cyclohexanol are used for the preparation of adipic acid and caprolac~am.
The Examples which follow illustrate the process accord1ng to the invention.
101 g/hour of cyclohexane are fed into 3 high pres-sure stainless steel vessel equipped with a stirrer and having a capacity of 1,000 cm3, and molecular oxygen (100 vol.~ of oxygen) in finely divided form is passed in at 25C and under 15 bar. The cyclohexane saturated with molecular oxygen in this manner is passed, at a rate 5~
In order to shorten the induction period in the second stage, it is advantageous to use an initiator, eg.
a peroxideO in particular cyclohexyl hydroperoxide or a reaction mixture containing this, for example in an amount of from 0.1 to 0.5~ by weight, based on cyclohexane.
The surfaces which come into contact with the reac-tion m;xture, in particular those of the second stage, are advantageously enamelled or passivated. The passivation -is achieved by, for example, treatment with pyrophosphates.
Examples of suitable pyrophosphates are Na pyrophosphate and K pyrophosphate. It has proven particularly advan-tageous for small amounts, eg. not more than 10 ppm, of a pyrophosphate to be added to the cyc lohexane either continuously or at intervalsO
In addition to containing unreacted cyclohexane, the resulting reaction mixture contains cyclohexyl peroxide, cyclohexanol, minor amounts of cyclohexanone and small amounts of other oxygen containing oxidation products such as esters and carboxylic acids.
Before further processing, some of the acidic compo-nents are advantageously washed out of the resulting reac-tion mixture with water. Further conversion of the cyclo-hexyl hydroperoxide to cyclohexanol and cyclohexanone in the presence of a catalytic metal compound is carried out, for example~ as described in German Laid-Open Application DOS 2,352,378. Cyclohexanone and cyclohexanol are used for the preparation of adipic acid and caprolac~am.
The Examples which follow illustrate the process accord1ng to the invention.
101 g/hour of cyclohexane are fed into 3 high pres-sure stainless steel vessel equipped with a stirrer and having a capacity of 1,000 cm3, and molecular oxygen (100 vol.~ of oxygen) in finely divided form is passed in at 25C and under 15 bar. The cyclohexane saturated with molecular oxygen in this manner is passed, at a rate 5~
- 6 - O.Z. 0050/36944 of 101 g/hour, into a glass tube having an internal dia-meter of 0.5 cm and a Length of S m. The glass tube is heated at 170C over its entire length. In order to avoid the formation of gases, a pressure of about 20 bar is maintained-in the glass tube. The rate of the cyclo-hexane feed g;ves a residence time of 36 minutes, which corresponds to the time required for the consumption of 99.9% of the dissolved molecular oxygen~ In addition to containing cyclohexane, the resulting reaction mixture contains 1.98% by weight of cyclohexyl hydroperoxide, 0.23% by weigh-t of cyclohexanol, 0.095i~ by weight of cyclo-hexanone and 0.08% by weight of carboxylic acid. The selec-tivity with respect to cyclohexyl hydroperoxide is 81.3%, that with respect to cyclohexanone is 4.65%, that with respect to cyclohexanol is 10.8% and that with respect to cyclohexyl hydroperoxide, cyclohexanol and cyclohexanone together is 96.7%, these selectivities being based on cyclohexane con-verted. The proportion of cyclohexyl hydroperoxide among the three last-mentioned products is 0.841.
The procedure descr;bed in Example 1 is followed, except that the glass tube (stage 2) is heated at 180C
and is charged with 198.3 g/hour of cyclohexane which is saturated with molecular oxygen~ The resulting residence t;me is 18 minutes, which corresponds to the time in which 99.9% of the dissolved molecular oxygen is consumed. In addition to containing cyclohexane, the resulting reaction mixture contains 1.89% by weight of cyclohexyl hydro-peroxide, 0.307~ by weight of cyclohexanol, 0.11% by weight of cyclohexanone and 0.05% by weight of carboxylic acids.
The selectivity with respect to cyclohexyl hydroperoxide is 69.0%, that with respect to cyclohexanone is 6.4%, that with respect to cyclohexanol is 20.3% and that with respect to cyclohexyl hydroperoxide, cyclohexanone and cyclohexanol together is 95.6%, these select;vit;es being based on cyclohexane converted. The proportion of cyclohexyl hydro-peroxide among the last three mentioned useful products
The procedure descr;bed in Example 1 is followed, except that the glass tube (stage 2) is heated at 180C
and is charged with 198.3 g/hour of cyclohexane which is saturated with molecular oxygen~ The resulting residence t;me is 18 minutes, which corresponds to the time in which 99.9% of the dissolved molecular oxygen is consumed. In addition to containing cyclohexane, the resulting reaction mixture contains 1.89% by weight of cyclohexyl hydro-peroxide, 0.307~ by weight of cyclohexanol, 0.11% by weight of cyclohexanone and 0.05% by weight of carboxylic acids.
The selectivity with respect to cyclohexyl hydroperoxide is 69.0%, that with respect to cyclohexanone is 6.4%, that with respect to cyclohexanol is 20.3% and that with respect to cyclohexyl hydroperoxide, cyclohexanone and cyclohexanol together is 95.6%, these select;vit;es being based on cyclohexane converted. The proportion of cyclohexyl hydro-peroxide among the last three mentioned useful products
- 7 - O.Z. 0050/36944 is 0.8000 The procedure described in Example 1 is followed, and the glass tube (stage 2) is heated at 170C and the pressure maintained at 20 bar. 114 g/hour of cycLohexane which ;s saturated w;~h molecuLar oxygen are fed in. Dur-;ng a residence t;me of 32 minutes, 56~ of the d;ssoLved oxygen ;s conv0rtedO In add;t;on to conta;ning cyclo-hexane, the res~lt;ng reaction m;xture contains 1.6% by weight of cyclohexyL hydroperoxide, 0.12% by weight of - cyclohexanol, O.OS% by weight of cyclohexanone and 0.04%
by weight of carboxylic acids. The seLectivity with res-pect to cycLohexyL hydroperoxide ;s 87.2%, that w;th res-pect to cyclohexanol ;s 6.8%~ that with respect to cyclo-hexanone ;s 3u5% and that w;th respect to cycLohexyL hydro-perox;de, cyclohexanol and cyclohexanone together ;s 97.5%, these select;v;t;es be;ng based on cyclohexane converted.
The proport;on of cyclohexyL hydroperox;de among the three Last ment;oned products is 0.890.
The procedure descr;bed ;n ExampLe 1 ;s foLLowed, except that the gLass tube (stage 2) ;s repLaced w;th a vessel equ;pped w;th a st;rrer and having a capacity of 100 cm3, 116 g/hour of cyclohexane saturated w;th mole-cular oxygen are fed to the st;rred vessel~ and the tempera-ture is maintained at 170C, the pressure at 20 bar and the mean residence time at 36 m;nutes. The proportion of ryclohexyl hydroperoxide in the resulting react;on m;xture ;s 0.47, based on the cyclohexyl hydroperoxide, cycLohexanol and cyclohexanone formed. The seLectivity is 91~, based on cycLohexane converted.
The procedure described in Comparative Example 1 is followed; in the stirred vessel (stage 2) the temp~ora-ture is maintained at 180C, the pressure at 25 bar andthe residence time at 18 minutesO The proportion of cyclo-hexyL hydroperoxide in the resuLting reaction mixture is ~23~
- - 8 - O.Z~ 0050/36944 0.50, based on the content of cyclohexyl hydroperoxide~
cyclohexanol and cyclohexanone. The selectivity is 44.4%
for cyclohexyl hydroperoxide, 10.3% for cyclohexanone and 34.8% for cyclohexanol, these selectivities being based on cycLohexane converted. This gives an overall selectivity for the three last mentioned compounds of 89.5%.
by weight of carboxylic acids. The seLectivity with res-pect to cycLohexyL hydroperoxide ;s 87.2%, that w;th res-pect to cyclohexanol ;s 6.8%~ that with respect to cyclo-hexanone ;s 3u5% and that w;th respect to cycLohexyL hydro-perox;de, cyclohexanol and cyclohexanone together ;s 97.5%, these select;v;t;es be;ng based on cyclohexane converted.
The proport;on of cyclohexyL hydroperox;de among the three Last ment;oned products is 0.890.
The procedure descr;bed ;n ExampLe 1 ;s foLLowed, except that the gLass tube (stage 2) ;s repLaced w;th a vessel equ;pped w;th a st;rrer and having a capacity of 100 cm3, 116 g/hour of cyclohexane saturated w;th mole-cular oxygen are fed to the st;rred vessel~ and the tempera-ture is maintained at 170C, the pressure at 20 bar and the mean residence time at 36 m;nutes. The proportion of ryclohexyl hydroperoxide in the resulting react;on m;xture ;s 0.47, based on the cyclohexyl hydroperoxide, cycLohexanol and cyclohexanone formed. The seLectivity is 91~, based on cycLohexane converted.
The procedure described in Comparative Example 1 is followed; in the stirred vessel (stage 2) the temp~ora-ture is maintained at 180C, the pressure at 25 bar andthe residence time at 18 minutesO The proportion of cyclo-hexyL hydroperoxide in the resuLting reaction mixture is ~23~
- - 8 - O.Z~ 0050/36944 0.50, based on the content of cyclohexyl hydroperoxide~
cyclohexanol and cyclohexanone. The selectivity is 44.4%
for cyclohexyl hydroperoxide, 10.3% for cyclohexanone and 34.8% for cyclohexanol, these selectivities being based on cycLohexane converted. This gives an overall selectivity for the three last mentioned compounds of 89.5%.
Claims (11)
1. in a first stage, molecular oxygen is dissolved in cyclohexane by bringing the latter into contact with molecular oxygen, or with a gas containing this, at from 10 to 110°C and under superatmospheric pressure, and 2. in a second stage, the cyclohexane containing dissolved molecular oxygen is passed through an elongated tubular reaction zone at from 130 to 250°C and under super-atmospheric pressure, virtually with plug flow and without the formation of a gas phase, the residence time being between a) the time required for the consumption of 50% of the amount of dissolved molecuLar oxygen and b) 1.2 times the time required for the consumption of 99.9% of the dissolved molecular oxygen.
2. A process as claimed in claim 1, wherein, in the first stage, the degree of saturation with molecular oxygen is maintained at from 60 to 100%.
3. A process as claimed in claim 1, wherein, in the second stage, the pressure maintained is at least 10 bar above the saturation pressure.
4. A process as claimed in claim 1, wherein, in the second stage, the residence time maintained is that which is required to consume from 80 to 99.9% of the dissolved molecular oxygen.
5. A process as claimed in claim 1, wherein the tubu-lar reaction zone in the second stage has a length:diameter ratio of from 100:1 to 1,000:1.
6. A process as claimed in claim 1, wherein, in the second stage, the temperature is reduced along the tubular reaction zone.
7. A process as claimed in claim 1, wherein, in the second stage, the temperature is reduced by 10 - 40°C
along the tubular reaction zone.
along the tubular reaction zone.
8. A process as claimed in claim 1, wherein, in the course of the second stage, cyclohexane containing molecu-lar oxygen is fed in at one or more further points.
9. A process as claimed in claim 1, wherein an alkali metal pyrophosphate is added to the cyclohexane used.
10. A process as claimed in claim 1, wherein a peroxide is added to the reaction mixture enter;ng the second stage.
11. A process as claimed in claim 1, wherein cyclohexyl hydroperoxide is used as an initiator.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3403410.2 | 1984-02-01 | ||
| DE19843403410 DE3403410A1 (en) | 1984-02-01 | 1984-02-01 | METHOD FOR THE CONTINUOUS PRODUCTION OF CYCLOHEXYL HYDROPEROXIDE AND MIXTURES CONTAINING CYCLOHEXANOL AND CYCLOHEXANONE |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1262359A true CA1262359A (en) | 1989-10-17 |
Family
ID=6226443
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000473196A Expired CA1262359A (en) | 1984-02-01 | 1985-01-30 | Continuous preparation of mixtures containing cyclohexyl hydroperoxide, cyclohexanol and cyclohexanone |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0150821B1 (en) |
| JP (1) | JPS60190759A (en) |
| AU (1) | AU3824385A (en) |
| CA (1) | CA1262359A (en) |
| DE (2) | DE3403410A1 (en) |
| MD (1) | MD380C2 (en) |
| SU (1) | SU1422995A3 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2562150B2 (en) * | 1986-10-23 | 1996-12-11 | バスフ アクチェンゲゼルシャフト | Post-treatment method for reaction mixture containing cyclohexyl hydroperoxide |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1085892A (en) * | 1964-04-13 | 1967-10-04 | Ici Ltd | Oxidation of organic compounds with gases containing molecular oxygen |
| DE1593700A1 (en) * | 1966-12-07 | 1970-07-16 | Vickers Zimmer Ag | Process for the production of cyclohexanol and cyclohexanone |
| JPS5136747B2 (en) * | 1971-11-01 | 1976-10-12 | ||
| NL7802125A (en) * | 1978-02-25 | 1979-08-28 | Stamicarbon | PROCESS FOR PREPARING CYCLOAL CANNONS AND CYCLOAL CANNONS. |
| DE2951956A1 (en) * | 1979-12-22 | 1981-07-23 | Basf Ag, 6700 Ludwigshafen | METHOD FOR PRODUCING MIXTURES FROM CYCLOHEXYL HYDROPEROXIDE |
-
1984
- 1984-02-01 DE DE19843403410 patent/DE3403410A1/en not_active Withdrawn
-
1985
- 1985-01-25 EP EP85100742A patent/EP0150821B1/en not_active Expired
- 1985-01-25 DE DE8585100742T patent/DE3560109D1/en not_active Expired
- 1985-01-30 JP JP60014611A patent/JPS60190759A/en active Pending
- 1985-01-30 CA CA000473196A patent/CA1262359A/en not_active Expired
- 1985-01-31 AU AU38243/85A patent/AU3824385A/en not_active Abandoned
- 1985-01-31 SU SU853850144A patent/SU1422995A3/en active
-
1994
- 1994-12-23 MD MD95-0034A patent/MD380C2/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| AU3824385A (en) | 1985-08-08 |
| DE3560109D1 (en) | 1987-05-07 |
| JPS60190759A (en) | 1985-09-28 |
| EP0150821A2 (en) | 1985-08-07 |
| EP0150821A3 (en) | 1985-12-18 |
| MD380C2 (en) | 1996-06-30 |
| EP0150821B1 (en) | 1987-04-01 |
| SU1422995A3 (en) | 1988-09-07 |
| DE3403410A1 (en) | 1985-08-01 |
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| Date | Code | Title | Description |
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| MKLA | Lapsed |