JPH0635399B2 - Method for producing high boiling hydrocarbon oil - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a hydrocarbon oil, and more particularly to a method for producing a high boiling hydrocarbon oil by hydrogenation.

(Prior Art) Conventionally, as a high-boiling hydrocarbon oil, phenylxylylethane, diphenylether or alkyldiphenyl,
Hydrogenated terphenyl, alkylnaphthalene, dibenzyltoluene and the like are known. These hydrocarbon oils are
It has a boiling point of about 290 to 380 ° C at normal pressure, and is used as a relatively high-temperature heat medium, electrical insulating oil, and solvent for pressure-sensitive copying paper.

However, there is no known hydrocarbon-based heat medium having a boiling point of around 400 ° C under normal pressure and which can be stably used. For example,
Phenylxylylethane is It has a structure represented by and its boiling point is about 300 ° C.

In addition, as a method for producing the phenylxylylethane-based compound, 1) sulfuric acid described in JP-A-48-97858 or CF ₃ SO ₃ H-based compound described in JP-A-55-24144 is used. Method using homogeneous acid catalyst, 2) Method using solid acid catalyst such as silica alumina described in JP-A-53-135959, zeolite described in JP-A-55-24145, 3) JP-A-56- A method using an ion exchange resin described in Japanese Patent No. 18928 as a catalyst is known,
Phenylxylylethane can be obtained by aralkylating styrenes with alkylbenzene.

This type of compound has a boiling point of about 300 ° C and cannot be used at too high temperatures. In addition, since phenylxylylethane synthesized by such a method contains a small amount of unsaturated dimer in styrene, in the case of inconvenience such as thermal polymerization causing viscosity increase when used at high temperature. There is.

(Problems to be Solved by the Invention) As described above, until now, it is impossible to easily obtain a hydrocarbon oil having a boiling point of 400 ° C. or higher and high heat stability. In recent years, due to various heat treatment processes and reaction processes
A heat medium that can be used stably at around 400 ° C is desired.
However, the limit is 340 to 380 ° C. in the conventionally known composition.

In addition, in the styrene-alkylbenzene system, in order to increase the production yield of not only phenylxylylethane but also 3 to 4 nuclides having a boiling point of about 400 ° C or higher, the reaction temperature should be lowered and the concentration of styrenes It is necessary to perform operations such as increasing However, depending on reaction conditions, raw material composition, etc., a large amount of unsaturated di-tetramer containing a polymerized double bond is also produced. The presence of such an unsaturated substance may be convenient in some cases, but it is often inconvenient because it causes deterioration of the hue of the product and poor thermal stability. To avoid this, it is necessary to hydrogenate the polymerizable unsaturated double bond.

(Means for Solving Problems) In order to obtain a high boiling point hydrocarbon oil, the present invention reacts alkylbenzene with styrene at an arbitrary ratio using a cation exchange membrane as a catalyst to form a dimer or tetramer of styrene. A mixture of oligomer and styrene-alkylbenzene adduct is prepared.

These mixtures are then added in the presence of a catalyst in order to hydrogenate the polymerizable unsaturated double bonds contained in the mixture.
It is treated with high-pressure hydrogen at 50-100 ℃ to produce colorless and odorless high boiling hydrocarbon oil.

As the alkylbenzene as a raw material, for example, toluene, ethylenebenzene, o-xylene, m-xylene, p-xylene, various trimethylbenzenes, isopropylbenzene and the like can be used. These alkylbenzene raw materials can be used as a single component or as a mixture.

Examples of the other raw material styrene include styrene and α
-Methylstyrene, p-methylstyrene and the like can be used.

The mixing ratio of alkylbenzene and styrenes of these raw materials is arbitrary, and the raw material composition can be changed according to the desired composition of the desired reaction product. Generally, the mixing ratio of alkylbenzene and styrenes can be a weight ratio of 99: 1 to 1:99.

The cation exchange membrane used as a catalyst is a cation exchange membrane having SO ₃ H groups (for example, Nafion-1 from DuPont).
17,324) or equivalent, and in order to exert the effect as a catalyst, it is preferably used in a proportion of 0.1% by weight or more based on the styrenes in the reaction product. Also, by changing the reaction conditions with this catalyst system, it is possible to obtain a desired composition of a high-boiling highly aromatic oil containing linear and cyclic dimers and tetramers of diarylalkane and styrene. . Further, since the catalyst is in the form of a film, the step of removing the catalyst such as the conventional acid catalyst is unnecessary.

Next, examples of the catalyst used for hydrogenating the unsaturated double bond include Ni / diatomaceous earth and Raney nickel.

The high-boiling hydrocarbon oil obtained in this way is distilled, if necessary, and bisected to those with boiling points of 300 ± 20 ° C and 400 to 430 ° C, the former being a high-boiling solvent, electrical insulating oil, etc. It can be used as a heating medium.

(Example) Hereinafter, the Example of this invention is described based on drawing.

As shown in FIG. 1, in the first step, raw material alkylbenzene is stored in a tank 1 and styrene is stored in a tank 2. These raw materials are fed into the line mixer 4 by the pump 3 and mixed, and then fed to the preheater 5 for preheating.

The preheated mixture was fed into a reactor 6 equipped with a catalyst and reacted at a reaction temperature of 30 to 140 ° C. for a residence time of 1 to 8 hours to obtain a distyrene tetramer oligomer and a styrene-alkylbenzene adduct. A mixture is obtained.

Unreacted alkylbenzene and the like are recovered by using the flash drum 7 (recovery rate: 80 to 90%), and the remaining low boiling point components are substantially reduced to 0.1% or less in the evaporator 8. The product thus obtained has a boiling point of 29.
Since it is the above mixture at 0 to 430 ° C., it partially contains unsaturated double bond moieties.

In the second step, the product obtained in the first step is stored in the surge tank 9 and hydrogenated in the hydrogenation reactor 10 under mild conditions. What is important here is the selective partial hydrogenation of only the polymerizable double bonds.

In the product obtained in the first step, hydrogenated structures are present in both the phenyl group and the unsaturated double bond portion. When used as a heating medium or a high boiling point solvent, hydrogenation of only the unsaturated double bond portion gives a product having sufficiently high thermal stability, and the hydrogenated product becomes colorless and odorless. As a result of various studies on such partial hydrogenation, it was found that favorable results were obtained by using a Ni / diatomaceous earth-based or Raney nickel-based catalyst.

Particularly, at 50 to 100 ° C and hydrogen pressure of 10 to 150 kg / cm ² (preferably 50 to 70 ° C and hydrogen pressure of 50 to 100 kg / cm ² ), hydrogen of 0.1% by weight or more based on the raw material is used. Upon addition, unsaturated double bonds can be selectively hydrogenated. In this case, if the temperature is lower than 50 ° C, the hydrogenation reaction rate is slow, and if it exceeds 100 ° C, some phenyl groups are hydrogenated,
The number of polymerizable unsaturated double bonds may increase rather. The hydrogen pressure is not so strict, but the above range is appropriate considering the reaction rate, equipment materials, pressurization cost, and the like.

In the third step, the product obtained in the second step is converted into a vacuum distillation column.
Distilled at 11 and distilled at a boiling point of 300 ± 20 ° C 12 (benzene core 2
A binuclear body containing 3 to 4 nuclei such as phenylxylylethane, a dimer of styrene) and a fraction 13 having a boiling point of 400 to 430 ° C. (3 to 4 nuclei containing 3 to 4 benzene nuclei, eg, a tetramer of styrene, Styrene-alkyl ibenzene trinuclear)). This step is useful for refining high temperature heat transfer media. Depending on the application, the hydrogenated product 14 can also be used as a mixture of di- to tetra-nuclear bodies.

Example 1 200 g of styrene and 800 g of C ₈ fraction (mixed xylene) obtained by refining coke oven gas oil were placed in a three-necked flask having a capacity of 2 and having a condenser and a thermometer inlet, and Nafion was used as a catalyst. (Nafion) -117 added to styrene 1%,
The reaction was carried out at about 100 ° C for 2 hours. As a result of distilling and collecting unreacted components, the reaction rate of styrene at this time was 98.1%.
C (The average molecular weight by gel permeation chromatography was 267.5. The iodine value was 19.3.

To 100 parts of this refined product, 2 parts of Ni / diatomaceous earth catalyst was added, and the initial hydrogen pressure in the autoclave was 100 kg / cm ² , 100
The reaction was carried out at 50 ° C for 50 minutes, and the catalyst was filtered off to obtain 95 parts of a hydrogenated product. The iodine value of this hydrogenated purified product was 3.08.

Gas chromatographs and nuclear magnetic resonance spectra of the obtained hydrogenated products and raw materials were measured and determined. As shown in FIG. 2, from the nuclear magnetic resonance spectrum, before hydrogenation
It was confirmed that the peak of the component of the terminal double bond (δ 6.2 to 6.5 ppm) disappeared in the product of (b) after hydrogenation as compared with (a).

Examples 2 and 3 Water point products were obtained by the same reaction as in Example 1 except that the hydrogenation conditions were changed as shown in Table 1. Table 1 shows the hydrogen consumption (mol of hydrogen / 100 g sample) and the iodine value of the product.

The iodine value before hydrogenation was 19.3.

Comparative Examples 1 and 2 Hydrogenated products were obtained by the same reaction as in Example 1 except that the hydrogenation conditions were changed as shown in Table 1. Table 1 shows the hydrogen consumption (mol of hydrogen / 100 g sample) and the iodine value of the product.

Example 4 20% styrene and 80 mixed xylenes were placed in a flow reactor.
% Mixture at a rate of 200 ml / hour, Example 1
The same catalyst was used in the ratio of catalyst / raw material = 0.01, and the reaction was carried out for a residence time of 3 hours. The resulting reaction product was heated at 70 ° C. for 1 hour and the same catalyst as in Example 1 was used at 0.2% by weight to obtain an initial hydrogen pressure of 10%.
Hydrogenated at 0 kg / cm ² . The iodine value of the obtained hydrogenated product was 3.5.

Example 5 2 kg of styrene and 3 kg of mixed xylene were placed in the reactor of 10 and the same catalyst as in Example 1 was added to 1% of styrene.
The reaction was carried out at about 120 ° C for 3 hours. In the same manner, the reaction was repeated 3 times to obtain 7.7 kg of oligomer oil from 15 kg of raw material (6 kg of styrene) by vacuum distillation. Take 7 kg from this and put it in 20 autoclaves at an initial hydrogen pressure of 100 kg / cm ² , 70
Hydrogenated at 70 ° C with 70 g of Ni / diatomaceous earth catalyst. The hydrogenated product obtained by separating the catalyst particles was colorless and transparent. The total amount of this hydrogenated product was charged into a distillation device of 10 and distilled under reduced pressure, and about 40 mm of light fraction distilled up to about 100 ° C at 10 mmHg.
With the exception of 0 g, 3.2 kg of a product centered on a binuclear distillate at 10 to 5 mmHg at 130 to 140 ° C and 3.3 kg of a bottom residue were obtained. The average molecular weights of the hydrogenated refined product, the binuclear body and the kettle residue (3 to tetranuclear body) were 285.7, 194.2, 375 and 2, respectively.

(Effects of the Invention) As described above, according to the present invention, a high-boiling hydrocarbon oil which has never been obtained,
Particularly, a synthetic hydrocarbon oil useful as a high temperature heat medium, a high boiling point solvent, and an electric insulating oil can be produced very efficiently.

In particular, the composition comprising trinuclear to tetranuclear compounds obtained in the present invention is a mixture of components having a boiling point of 400 to 430 ° C. and is excellent as a high temperature heat medium. Further, the binuclear component obtained at the same time is also used as a heat medium at a relatively low temperature, a high boiling point solvent, and an electric insulating oil. Furthermore, it is a purified product that is not separated by distillation.
The tetranuclear mixture has a high dielectric constant and is excellent as an insulating oil for capacitors.

[Brief description of drawings]

FIG. 1 is a diagram showing a manufacturing process according to an example of the present invention, and FIG. 2 is a graph showing a nuclear magnetic resonance spectrum of a hydrocarbon oil before and after hydrogenation in Example 1, where (a) is before hydrogenation , (B) shows after hydrogenation. 1,2 …… Raw material tank, 3 …… Pump 4 …… Line mixer 5 …… Preheater, 6 …… Reactor 7 …… Flash drum 8 …… Distiller, 9 …… Surge tank 10 …… Hydrogenation reaction Vessel, 11 …… Vacuum distillation column 12 …… Boiling point 300 ± 20 ℃ fraction 13 …… Boiling point 400-430 ℃ fraction 14 …… Hydrogenated product

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location C10G 45/32 2115-4H (72) Inventor Yoshihisa Kono 1 Kawasaki-cho, Chiba-shi, Chiba Kawasaki Steel Stock Corporate Technology Research Division

Claims (1)

[Claims] 1. A cation-exchange membrane is used as a catalyst to react alkylbenzene with styrenes to obtain a mixture containing a styrene di-tetramer oligomer and a styrene-alkylbenzene adduct, and the unsaturated disulfide contained in the mixture. A process for producing a high-boiling hydrocarbon oil in which heavy bonds are hydrogenated with high-pressure hydrogen at 50 to 100 ° C in the presence of a catalyst.