CN106349019A - Method for producing cyclohexanol - Google Patents

Abstract

The invention provides a method for producing cyclohexanol by preparing cyclohexyl carboxylate from a cyclohexene raw material and then performing ester exchange reaction under a near critical or supercritical condition. In the ester exchange step of the method, a catalyst is not used, reaction products do not need to be separated in the reaction process, and low alcohol-to-ester ratio can be adopted; furthermore, the method has the characteristics of high reaction rate, high conversion rate, high selectivity and simple aftertreatment.

Description

A kind of method of producing cyclohexanol

technical field

The invention relates to a method for producing cyclohexanol, in particular to a method for firstly preparing cyclohexyl carboxylate with cyclohexene raw material, and then producing cyclohexanol by transesterification under near-critical or supercritical conditions.

Background technique

Cyclohexanol is a widely used chemical raw material and solvent. For example, cyclohexanol can undergo dehydration reaction at high temperature (such as 150°C to 300°C) to prepare cyclohexene. Among the many uses of cyclohexanol, the most important is cyclohexanone, the main intermediate in the production of nylon 6 and nylon 66.

Since the advent of nylon, DuPont, DSM, Monsanto, BASF, Sumitomo, Toray, Asahi Kasei and other world-renowned chemical companies have long been committed to the production technology development of cyclohexanol (ketone). At present, the industrial production methods of cyclohexanol (ketone) include phenol hydrogenation method, cyclohexane oxidation method and cyclohexene hydration method.

The phenol hydrogenation method is the earliest industrial production method of cyclohexanol. Due to the shortage of phenol raw materials, the expensive price of noble metal hydrogenation catalysts and the easy carbon deposition of catalysts and other unfavorable factors, phenol hydrogenation method is generally not used in new plants. Cyclohexane oxidation is currently the main production method of cyclohexanol. There are many problems in this method, such as low conversion rate, poor selectivity, environmental protection and safety. Due to these problems, Asahi Kasei Corporation of Japan has developed a new process for the preparation of cyclohexanol by hydration of cyclohexene. This process has mild reaction conditions, high selectivity, lower hydrogen consumption, and almost no three wastes in the whole process. The defect is that the raw materials High-purity cyclohexene must be used, the operation process is complicated, and the single-pass conversion rate is very low.

Hydrogenation of cyclohexyl acetate is a new production method of cyclohexanol, although compared with the previous production method of cyclohexanol, the reaction conversion rate and selectivity of this method are high, and the process and operation process are also large. For the sake of simplification, the requirements for hydrogenation reaction equipment, investment and operating costs are still relatively high, and the hydrogenation process will inevitably consume hydrogen sources.

CN103232325A discloses a method for preparing cyclohexanol by transesterification under catalytic conditions using cyclohexyl carboxylate as a raw material. Catalyzed transesterification reactions can generally be divided into three types: enzyme-catalyzed, acid-catalyzed and base-catalyzed. The existing literature on catalyzed transesterification mainly focuses on the production of biodiesel. These documents show that biological enzyme catalysis cannot be applied industrially in the short term because it is difficult to solve the problem of high catalyst cost and easy deactivation; the reaction rate of acid catalysis is slow, and the use of acid catalyst will also cause serious equipment corrosion and Pollution emission, alcohol in the reaction system may also undergo etherification reaction under acid catalysis conditions; base catalysis has the advantages of mild reaction conditions and fast rate, but it is only suitable for raw materials with high purity, especially raw materials that cannot contain acid and and/or water, otherwise it will adversely affect the base catalyst. In addition, if homogeneous catalysis is used, there must be post-treatment steps such as neutralization, water washing, and drying, while non-homogeneous catalysis (solid catalyst) is still in the stage of industrial testing, and there is no report on the industrial application of heterogeneous catalysis in the literature. . In addition, the transesterification reaction is an equilibrium reaction. In the process of the catalyzed transesterification reaction, it is necessary to separate part of the reaction products or use a higher alcohol-to-ester ratio to increase the conversion rate of the reaction.

Contents of the invention

Aiming at the above-mentioned deficiencies in the prior art, the present invention provides a method of first preparing cyclohexyl carboxylate with cyclohexene raw material, and then producing cyclohexanol by transesterification under near-critical or supercritical conditions. In the transesterification step of the method, no catalyst is used, no reaction product is separated during the reaction, a lower alcohol-to-ester ratio can be used, and the method has the characteristics of fast reaction rate, high conversion rate, good selectivity and simple post-treatment.

The main contents of the present invention are as follows.

1. A method for producing cyclohexanol, comprising:

(1) Utilize cyclohexene source and carboxylic acid to undergo addition esterification to obtain cyclohexyl carboxylate;

(2) Under near-critical or supercritical conditions, transesterify cyclohexyl carboxylate with C1-C6 monohydric alkanol; separate the reaction product to obtain cyclohexanol and alkanol carboxylate.

2. The method according to 1, characterized in that, in step (1), the carboxylic acid is a C1-C22 linear monocarboxylic acid.

3. The method according to any one of the foregoing, characterized in that, in step (1), the carboxylic acid is formic acid or acetic acid.

4. The method according to any one of the above, characterized in that, in step (1), the C1-C6 monohydric alkanol is methanol or ethanol.

5. according to the aforementioned arbitrary method, it is characterized in that, in step (1), carry out addition esterification reaction in catalytic rectification column, and described cyclohexene source is cyclohexene and cyclohexane and/or Or a mixture of benzene, the mass fraction of cyclohexene is 20% to 80%.

6. The method according to any one of the foregoing, characterized in that it further comprises the step of using benzene to selectively hydrogenate to obtain a cyclohexene source.

7. According to any one of the aforementioned methods, it is characterized in that, in step (2), the reaction conditions are: the reaction temperature is 220°C to 300°C, preferably 260°C to 280°C; the reaction pressure is 2MPa to 25MPa, preferably 4MPa ~10MPa.

8. The method according to any one of the above, characterized in that, in step (2), a continuous reaction is adopted, and the feed volume space velocity is 0.1h ^-1 ~ 10h ^-1 , preferably 0.2h ^-1 ~ 5h ^-1 .

9. The method according to any one of the above, characterized in that, in step (2), the molar ratio of alcohol to ester is 1-50:1, preferably 1-10:1, more preferably 3-6:1.

10. According to any of the aforementioned methods, it is characterized in that, in the reaction product of step (2), contain water and the mass fraction of water is less than 20%; In the reaction product of preferred step (2), contain water and the mass fraction of water It is 0.005%-10%; more preferably, the reaction product of step (2) contains water and the mass fraction of water is 0.01%-5%.

11. The method according to any one of the foregoing, characterized in that it also includes the step of hydrogenating the alkanol carboxylate obtained in step (2) to obtain alkanol.

12. A method for producing cyclohexanone, comprising preparing cyclohexanone from cyclohexanol, characterized in that the cyclohexanol is produced by any one of methods 1 to 11.

13. A method for producing caprolactam, comprising preparing caprolactam from cyclohexanone, characterized in that the cyclohexanone is produced by the method described in 12.

14. A method for producing adipic acid, comprising preparing adipic acid from cyclohexanol, characterized in that the cyclohexanol is produced by any one of methods 1 to 11.

Compared with the prior art, the present invention has the following advantages.

1. Using cyclohexyl carboxylate as raw material, transesterification reaction occurs under near critical or supercritical conditions to produce cyclohexanol, with high reaction rate, conversion rate and selectivity;

2. Using cyclohexyl carboxylate as a raw material, transesterification occurs under near-critical or supercritical conditions to produce cyclohexanol, without using a catalyst, without re-reacting and separating the reaction product at the same time, the alcohol ester is relatively low, and the post-production The treatment process is simple, and there is no need for post-treatment steps such as washing to generate three wastes;

3. The process equipment investment and operating cost of transesterification are lower than the hydrogenation process of cyclohexyl carboxylate;

4. In terms of the overall process route, the hydrogen consumption of the present invention is lower;

5. The present invention can co-produce higher fatty alcohols.

detailed description

In the present invention, the transesterification reaction refers to the transesterification reaction between carboxylate and alcohol.

In the present invention, all pressures are gauge pressures.

In the context of this specification, except for what is explicitly stated, any matters or matters not mentioned are directly applicable to those known in the art without any change. Moreover, any embodiment described herein can be freely combined with one or more other embodiments described herein, and the resulting technical solutions or technical ideas are regarded as a part of the original disclosure or original record of the present invention, and should not be It is regarded as a new content that has not been disclosed or expected in this paper, unless those skilled in the art think that the combination is obviously unreasonable.

The numerical points disclosed in this specification include not only the specifically disclosed numerical points, but also the endpoints of various numerical ranges. The ranges of any combination of these numerical points shall be regarded as the disclosed or recorded ranges or technical characteristics of the present invention, regardless of Whether these value pairs are disclosed one by one in this paper. All the features disclosed in the present invention can be combined arbitrarily, and these combinations should be understood as the content disclosed or recorded in the present invention, unless those skilled in the art think that the combination is obviously unreasonable.

It is known in the art that biodiesel can be produced by transesterification of oil and methanol under supercritical conditions. Generally speaking, the reaction needs to be carried out under supercritical conditions in order to obtain satisfactory results. However, under near-critical (or subcritical) conditions, the reaction rate of transesterification is still slow, such as at 200 ° C to 230 ° C At this time, the temperature did not reach the critical temperature of methanol at 239.4°C, and the transesterification reaction rate at this time was low, and about 68% to 70% of the rapeseed oil was converted into fatty acid methyl esters after one hour; when the temperature reached 270°C, the rapeseed oil The conversion rate of seed oil is still not high; however, when the temperature reaches above 300℃, the reaction rate increases obviously, and the conversion rate can increase to 80%-95% in four minutes. It is also known in the art that cyclohexanol is prone to dehydration reaction, and the dehydration of cyclohexanol to generate cyclohexene is a strong endothermic reaction (heat of reaction is 34.3kJ/mol), so raising the temperature is conducive to the dehydration of cyclohexanol to generate cyclohexene In practice, cyclohexanol is often dehydrated between 150°C and 300°C to prepare cyclohexene in the laboratory or on a small scale. The present inventors have found that when cyclohexyl carboxylate is transesterified under the high temperature conditions of near critical or supercritical reactions, almost no side reactions take place, and even under near critical conditions, the ester of cyclohexyl carboxylate The rate of the exchange reaction was still relatively fast, thus completing the present invention.

The invention provides a method for producing cyclohexanol, comprising:

(1) Utilize cyclohexene source and carboxylic acid to undergo addition esterification to obtain cyclohexyl carboxylate;

(2) Under near-critical or supercritical conditions, transesterify cyclohexyl carboxylate with C1-C6 monohydric alkanol; separate the reaction product to obtain cyclohexanol and alkanol carboxylate.

According to the present invention, existing technologies for preparing cyclohexyl carboxylate by reacting cyclohexene source with carboxylic acid can be adopted, and these technologies include CN 201210559171.9, CN 201210560214.5, CN201310001152.9, CN 201310001078.0, CN 201310512160.X, CN201210559915 .7, CN 201210560665.9, CN 201210559981.4, CN201210560237.6, CN 201210559160.0, CN 201210559175.7, the contents related to the present invention in the above documents should be regarded as recorded in the present invention.

According to the present invention, in step (1), carry out addition esterification reaction in catalytic rectification tower, and described cyclohexene source is the mixture of cyclohexene and cyclohexane and/or benzene, the cyclohexene The mass fraction is 20% to 80%.

According to the present invention, in step (1), in order to ensure the production efficiency of cyclohexanol integral process route, the cyclohexene in the cyclohexene source needs to be reacted completely or basically reacted completely, for this reason carboxylic acid should be compared with cyclohexene excess.

According to the present invention, in step (1), at least two streams are drawn from the reactive distillation column, one is cyclohexyl carboxylate stream; the other is cyclohexane and/or benzene stream. One or both of the two streams may contain carboxylic acid.

According to the present invention, in step (1), the carboxylic acid is preferably a C1-C22 straight-chain monocarboxylic acid, more preferably a C1-C10 straight-chain monocarboxylic acid, further preferably formic acid or acetic acid.

According to the present invention, in step (2), the near-critical or supercritical conditions may be: the reaction temperature is 100°C to 400°C, preferably 150°C to 350°C, more preferably 200°C to 300°C; The pressure is 0.5MPa-40MPa, preferably 1MPa-20MPa, more preferably 2MPa-16MPa. The optimal reaction conditions are as follows: the reaction temperature is 220°C-300°C, preferably 260°C-280°C; the reaction pressure is 2MPa-25MPa, preferably 4MPa-10MPa.

According to the present invention, in step (2), the near-critical conditions are: the reaction temperature is 220°C to 280°C, preferably 240°C to 280°C; the reaction pressure is from 4MPa to less than the critical pressure, preferably from 6MPa to less than the critical pressure pressure.

According to the present invention, the operation mode of step (2) can be either batch or continuous. When a batch reaction is adopted, the reaction time is 0.1h-10h, preferably 0.5h-5h; when a continuous reaction is adopted, the feed space velocity is selected from 0.1h ^-1 to 10h ^-1 , preferably 0.2h ^-1 to 5h ^-1 .

According to the present invention, in step (2), tank reactors or tubular reactors can be used.

According to the present invention, in step (2), the molar ratio of alcohol to ester is 1-50:1, preferably 2-10:1, more preferably 3-6:1.

According to the present invention, the reaction product of step (2) contains water and the mass fraction of water is less than 20%; preferably the reaction product of step (2) contains water and the mass fraction of water is 0.001% to 10%; more preferably The reaction product of step (2) contains water and the mass fraction of water is 0.01%-5%. According to the present invention, the water in the reaction product is brought in by the raw materials and/or produced during the reaction. Usually, part or all of the water in the reaction product is produced during the reaction.

According to the present invention, the method also includes the step of obtaining a source of cyclohexene, for example, the source of cyclohexene can be obtained by dehydrogenating cyclohexane or selective hydrogenation of benzene, preferably by selective hydrogenation of benzene to obtain a source of cyclohexene .

According to the present invention, the method further includes the step of hydrogenating the alkanol carboxylate obtained in step (2) to obtain alkanol. The carboxylic acid in the alkanol carboxylic acid ester is preferably a C8-C22 carboxylic acid, more preferably a C8-C16 carboxylic acid, and aliphatic alcohol with the same carbon number as the carboxylic acid can be obtained after hydrogenation.

The present invention also provides a method for producing cyclohexanone, caprolactam or adipic acid respectively by using cyclohexanol as a raw material. This part of the content belongs to the prior art and will not be described in detail in the present invention.

Below through embodiment, further illustrate the present invention.

Example 1

Cyclohexyl acetate was prepared according to the method described in Example 5 of Chinese patent application CN 103664531 A.

Example 2

Methanol (water content 0.079%) and cyclohexyl acetate (prepared by the method of Example 1, cyclohexyl acetate content is 99.35%, acetic acid content 0.023%) are pumped into the tube according to the ratio of alcohol ester molar ratio 8:1 Type reactor, reacted under the condition of 250 ℃, 5MPa and feeding space velocity of 1h ^-1 , collected the reaction product, analyzed the conversion rate of cyclohexyl acetate was 98.57%, the selectivity of cyclohexanol was 99.38%, the product The water content in the medium is 0.056%, the ether content is 0.02%, and no cyclohexene is detected from the product.

Example 3

Methanol (water content 0.079%) and cyclohexyl acetate (prepared by the method of Example 1, cyclohexyl acetate content is 99.35%, acetic acid content 0.023%) are pumped into the tube according to the ratio of alcohol ester molar ratio 2:1 Type reactor, react under the condition of 200 ℃, 8MPa and feeding space velocity is 0.5h ^-1 , collect reaction product, analyze the conversion rate of cyclohexyl acetate is 94.42%, the selectivity of cyclohexanol is 99.83%, The water content in the product was 0.031%, the ether content was 0.03%, and no cyclohexene was detected from the product.

Example 4

Methanol (water content 0.079%) and cyclohexyl acetate (prepared by the method of Example 1, cyclohexyl acetate content is 99.35%, acetic acid content 0.023%) are pumped into the tube according to the ratio of alcohol ester molar ratio 4:1 Type reactor, react under the condition of 260 ℃, 6MPa and feeding space velocity is 1.0h ^-1 , collect reaction product, analyze the conversion rate of cyclohexyl acetate is 99.23%, the selectivity of cyclohexanol is 99.54%, The water content in the product was 0.043%, the ether content was 0.02%, and no cyclohexene was detected from the product.

Example 5

Methanol (water content 0.079%) and cyclohexyl acetate (prepared by the method of Example 1, cyclohexyl acetate content is 99.59%, acetic acid content 0.149%) are pumped into the tube according to the alcohol ester molar ratio of 5:1 Type reactor, react under the condition of 250 ℃, 7MPa and feeding space velocity is 2.0h ^-1 , collect reaction product, analyze the conversion rate of cyclohexyl acetate to be 99.38%, the selectivity of cyclohexanol is 99.34%, The water content in the product was 0.065%, the ether content was 0.02%, and no cyclohexene was detected from the product.

Under the same reaction materials and proportions and the same reaction conditions as mentioned above, the corrosion of the reaction materials was tested with a carbon steel test piece, and the results showed that the corrosion was less than 0.075mm/a.

Example 6

Methanol and cyclohexyl acetate (prepared according to the method of Example 1) were pumped into the tubular reactor according to the molar ratio of alcohol to ester of 3: ¹ . Under the condition of reaction, the reaction product was collected, and the conversion rate of cyclohexyl acetate was analyzed to be 97.42%, the selectivity of cyclohexanol was 99.47%, the ether content in the product was 0.02%, and no cyclohexene was detected in the product.

Example 7

Methanol and cyclohexyl acetate (prepared according to the method of Example 1) are pumped into the tubular reactor according to the ratio of alcohol ester molar ratio of 10:1, under the conditions of 300°C, 12MPa and feed space velocity of 5h ^-1 Next reaction, the reaction product was collected, and the conversion rate of cyclohexyl acetate was analyzed to be 99.70%, the selectivity of cyclohexanol was 98.35%, the ether content in the product was 0.03%, and no cyclohexene was detected from the product.

Example 8

Methanol (water content 1.253%) and cyclohexyl acetate (prepared by the method of Example 1, cyclohexyl acetate content is 99.59%, acetic acid content 0.149%) are pumped into the tube according to the ratio of alcohol ester molar ratio 5:1 Type reactor, react under the conditions of 260 ℃, 5MPa and feed space velocity of 2h ^-1 , collect the reaction product, analyze the conversion rate of cyclohexyl acetate is 99.57%, the selectivity of cyclohexanol is 99.23%, the product The moisture content in the medium is 0.67%, the ether content is 0.03%, and no cyclohexene is detected from the product.

Example 9

Methanol (water content 1.253%) and cyclohexyl acetate (prepared by the method of Example 1, cyclohexyl acetate content is 99.59%, acetic acid content 0.149%) are pumped into the tube according to the ratio of alcohol ester molar ratio 6:1 Type reactor, react under the condition of 260 ℃, 2MPa and feeding space velocity is 0.5h ^-1 , collect reaction product, analyze the conversion rate of cyclohexyl acetate is 96.37%, the selectivity of cyclohexanol is 99.65%, The moisture content in the product was 0.73%, the ether content was 0.02%, and no cyclohexene was detected from the product.

Example 10

Ethanol (water content 0.434%) and cyclohexyl acetate (prepared by the method of Example 1, cyclohexyl acetate content is 99.35%, acetic acid content 0.023%) are pumped into the tube according to the ratio of alcohol ester molar ratio 4:1 Type reactor, react under the condition of 260 ℃, 6MPa and feeding space velocity is 1.0h ^-1 , collect reaction product, analyze the conversion rate of cyclohexyl acetate to be 98.23%, the selectivity of cyclohexanol is 99.65%, The water content in the product was 0.24%, the ether content was 0.03%, and no cyclohexene was detected from the product.

Example 11

Ethanol (water content 0.434%) and cyclohexyl acetate (prepared by the method of Example 1, cyclohexyl acetate content is 99.59%, acetic acid content 0.149%) are pumped into the pipe according to the ratio of alcohol ester molar ratio 3:1 Type reactor, react under the conditions of 220 ℃, 10MPa and feed space velocity of 3h ^-1 , collect the reaction product, analyze the conversion rate of cyclohexyl acetate is 97.39%, the selectivity of cyclohexanol is 99.78%, the product The water content in the medium is 0.23%, the ether content is 0.04%, and no cyclohexene is detected from the product.

Under the same reaction materials and proportions and the same reaction conditions as mentioned above, the corrosion of the reaction materials was tested with a carbon steel test piece, and the results showed that the corrosion was less than 0.075mm/a.

Example 12

Ethanol (water content 5.264%) and cyclohexyl acetate (prepared by the method of Example 1, cyclohexyl acetate content is 99.35%, acetic acid content 0.023%) are pumped into the tube according to the ratio of alcohol ester molar ratio 4:1 Formula reactor, react under the condition of 280 ℃, 5MPa and feeding space velocity is 1.0h ^-1 , collect reaction product, analyze the conversion rate of cyclohexyl acetate is 93.83%, the selectivity of cyclohexanol is 99.54%, The moisture content in the product was 2.59%, the ether content was 0.03%, and no cyclohexene was detected from the product.

Example 13

Ethanol (water content 5.264%) and cyclohexyl acetate (obtained by the method of Example 1, cyclohexyl acetate content is 99.59%, acetic acid content 0.149%) are pumped into the tube according to the ratio of alcohol ester molar ratio 5:1 Type reactor, react under the conditions of 240 ℃, 8MPa and feeding space velocity of 2h ^-1 , collect the reaction product, analyze the conversion rate of cyclohexyl acetate is 94.11%, the selectivity of cyclohexanol is 99.49%, the product The water content in the medium is 3.26%, the ether content is 0.03%, and no cyclohexene and acetic acid are detected from the product.

Example 14

The methanol used is directly purchased ultra-dry methanol with a water content of 28 μg/g, and the cyclohexyl acetate is cyclohexyl acetate obtained by rectification. First, use sodium carbonate and calcium chloride to remove acid and water, and then decompress Distilled cyclohexyl acetate free of acetic acid and water. Pump ultra-dry methanol and refined cyclohexyl acetate obtained by rectification into the tubular reactor according to the molar ratio of alcohol to ester of 4:1, and react under the conditions of 260 ° C, 6 MPa and feed space velocity of 1 h ^-1 , The reaction product was collected, and the conversion rate of cyclohexyl acetate was analyzed to be 87.63%, the selectivity of cyclohexanol was 99.32%, the water content in the product was 0.003%, the ether content was 0.02%, and no cyclohexene was detected in the product.

Claims (16)

1. a kind of method producing Hexalin, comprising:

(1) utilize cyclohexene source, with carboxylic acid, addition esterification occurs, obtain cyclohexyl carboxylate；

(2) near critical or postcritical under the conditions of, by the unitary chain of cyclohexyl carboxylate and c1～c6 There is ester exchange reaction in alkanol；Product is carried out separate, obtain hexamethylene alcohol and carboxylic acid chain triacontanol ester.

2. method according to claim 1 is it is characterised in that in step (1), described Carboxylic acid is the straight-chain monobasic carboxylic acid of c1～c22.

3. method according to claim 1 is it is characterised in that in step (1), described Carboxylic acid is formic acid or acetic acid.

4. method according to claim 1 is it is characterised in that in step (1), and described c1～ The unitary alkanol of c6 is methanol or ethanol.

5. method according to claim 1 is it is characterised in that in step (1), be catalyzed Carry out addition esterification in rectifying column, and described cyclohexene source be cyclohexene and hexamethylene and/or The mixture of benzene, the mass fraction of cyclohexene is 20%～80%.

6. method according to claim 1 is it is characterised in that also include adding using benzene selective Hydrogen, the step obtaining cyclohexene source.

7. method according to claim 1 is it is characterised in that in step (2), react bar Part is: reaction temperature is 220 DEG C～300 DEG C；Reaction pressure is 2mpa～25mpa.

8. in accordance with the method for claim 1 it is characterised in that in step (2), reaction is warm Spend for 220 DEG C～280 DEG C；Reaction pressure is 4mpa to less than critical pressure.

9. in accordance with the method for claim 1 it is characterised in that in step (2), using even Continuous formula reaction, feed volume air speed is 0.2h^-1～5h^-1.

10. in accordance with the method for claim 1 it is characterised in that in step (2), alcohol and ester Mol ratio be 3～6:1.

11. in accordance with the method for claim 1 it is characterised in that the product of step (2) In, containing water and water mass fraction be less than 20%.

12. in accordance with the method for claim 1 it is characterised in that the product of step (2) In, containing water and water mass fraction be 0.01%～5%.

13. in accordance with the method for claim 1 it is characterised in that also include using step (2) The carboxylic acid chain triacontanol ester hydrogenation obtaining, the step obtaining alkanol.

A kind of 14. methods producing Ketohexamethylene, including Ketohexamethylene is prepared by Hexalin it is characterised in that Described Hexalin is obtained by any one of claim 1 to 13.

A kind of 15. methods producing caprolactam, prepare caprolactam including by Ketohexamethylene, its feature It is, method described in 14 for the described Ketohexamethylene is obtained.

16. a kind of method producing adipic acid, including adipic acid is prepared by Hexalin it is characterised in that Described Hexalin is obtained by any one of claim 1 to 13.