JPS6242938A - Production of high-boiling hydrocarbon oil - Google Patents

Abstract

PURPOSE:To obtain the titled substance, by reacting an alkylbenzene with a styrene by the use of a cation exchange membrane as a catalyst to give a mixture containing a styrene oligomer and a styrene-alkylbenzene adduct and hydrogenating the double bonds in the mixture with high-pressure hydrogen. CONSTITUTION:An alkylbenzene is reacted with a styrene by the use of a cation exchange membrane as a catalyst to give a mixture of an oligomer of dimer-tetramers of the styrene and a styrene-alkylbenzene adduct and then the polymerizable double bond in the mixture is treated with high-pressure hydrogen in the presence of a catalyst (e.g., Raney Ni) at 50-100 deg.C to give the titled colorless, odorless substance. The cation exchange membrane used as the catalyst has a SO3H group and the amount of it used is preferably >=0.1wt% based on the styrene. The prepared high-boiling hydrocarbon is optionally distilled, divided into a component having 300+ or -20 deg.C boiling point and a component having 400-430 deg.C boiling point. The former is usable for a high- boiling solvent, an electrical insulating oil, etc., and the latter is useful as a high-temperature heating medium.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing hydrocarbon oil, and particularly to a method for producing high-boiling hydrocarbon oil by hydrogenation.

(Prior art) Conventionally, high boiling point hydrocarbon oils include ■ phenylxylylethane, ■ diphenyl ether and alkyldiphenyl, ■
Hydrogenated terphenyl, (1) alkylnaphthalene, (2) dibenzyltoluene, etc. 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 that has a boiling point of around 400° C. at normal pressure and can be stably used. For example, phenylxylylethane has a structure represented by i, and its boiling point is about 300°C.

In addition, as a method for producing this phenylxylylethane compound, 1) sulfuric acid described in JP-A-413-97858 and CF35 described in JP-A-55-24144 are used.
o, a method using a homogeneous acid catalyst such as H type, 2) a method using a solid acid catalyst such as silica alumina described in JP-A-53-135959, zeolite described in JP-A-55-24145, 3) A method is known in which ion exchange resin is catalyzed as described in JP-A-56-18928, in which phenylsilylethane can be obtained by aralkylating styrene using alkyl benzene. .

This type of compound has a boiling point of about 300°C and cannot be used at very high temperatures. In addition, the phenylxylylethane synthesized by this method contains some unsaturated dimer of hastyrene, so if it is used at high temperatures, it may cause thermal polymerization and increase viscosity. be.

(Problems to be Solved by the Invention) As mentioned in rtij, to date, it has been impossible to easily obtain a highly thermally stable hydrocarbon oil with a boiling point of 400°C or higher. In recent years, there has been a demand for a heat medium that can be stably used at around 400° C. in various heat treatment processes and reaction processes. However, with conventionally known compositions, 34
The limit was 0 to 380°C.

In addition, in the styrene-alkylbenzene system, in order to increase the yield of not only phenylxylylethane but also tri- to tetranuclear bodies having a boiling point of about 400°C or higher,
Lower the reaction temperature, f1. It is necessary to perform operations such as increasing the concentration of , -ones, etc. +, or j-1, reaction conditions,
Depending on the composition of the raw materials, polymerization - 7-poly viscosity may occur due to unsaturated 2-
There are also many tetramers, 41 formations. Although the presence of this 61,·) unsaturated substance may be advantageous in some cases, it is often disadvantageous as it causes deterioration of the hue of the product, poor thermal stability, and the like.

To avoid this, it is necessary to hydrogenate the polymerizable unsaturated di(11) bond.

(First Step to Solve the Problem) The present invention uses a one-field ion exchange membrane as a catalyst to obtain a high boiling point hydrocarbon oil using alkyl hempine and suji! Nons are reacted in arbitrary proportions to produce a mixture of mono- to tetrameric oligomers of styrene and methyl-1-non-alkylhenzene adducts.

Next, in order to hydrogenate the polymerizable unsaturated double bonds contained in the mixture, these mixtures are treated with high-pressure hydrogen at 50 to 100 °C in the presence of a catalyst, resulting in colorless and odorless high-boiling carbonization. Produce hydrogen oil.

Examples of raw material alkylbenzene include l-luene,
Conidelbenzene, 0-xylene, m-xylene, p-
Xylene, various types of trimethylbenzene, isopropylbenzene, etc. can be used. These alkylbenzene raw materials can be used as a single component or as a mixture.

Examples of the other raw material methylnones include styrene,
α-methylstyrene, p-methylstyrene, etc. can be used.

The mixing ratio of alkylbenzene and styrene as these raw materials is arbitrary, and the desired 3,
(2) The raw material composition can be changed depending on the composition. in general,
The mixing ratio of argylbenzene and styrene is 99:1~1
:99 double star ratio can be achieved.

The cation exchange membrane used as a catalyst is a cation exchange membrane having SO3+1 groups (for example, DuPont's Nafion (N
af 1on)-117,324) or equivalent, and in order to increase the effect as a catalyst, it is preferably used in a proportion of 0.1% by weight or more based on the styrene in the reactant. In addition, by changing the reaction conditions using this catalyst system, it is possible to obtain a high-boiling point, highly aromatic oil containing diarylalkane and linear and cyclic dimers to tetramers of styrene with a desired composition. . Furthermore, since the catalyst is in the form of a film, a catalyst removal step unlike conventional acid catalysts is unnecessary.

Next, examples of catalysts used for hydrogenating unsaturated double bonds include Ni/silica nitride, Raneysonol, and the like.

The high-boiling hydrocarbon oil thus obtained is distilled if necessary to reduce the boiling point to 300'20'C and 400 to 43'C.
In addition to the 0°C one, the +ijj type can be used as a high boiling point solvent, electrical insulating oil, etc., and the latter can be used as a high temperature heat medium.

(Example) Embodiments of the present invention will be described below based on the drawings.

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

The preheated mixture is fed into a reactor 6 equipped with a catalyst and reacted at a reaction temperature of 30 to 140°C and a residence time of 1 to 8 hours to add styrene dimer to tetramer oligomers and styrene-alkylbenzene. You get a mixture of things.

Unreacted alkyl hanzene, etc. are recovered using the flash drum 7 (recovery rate 80-90%), and remaining low-boiling components are collected in the evaporator 8 so that the unreacted components are substantially reduced to 0.1% or less. Make it. The product thus obtained is the above-mentioned mixture having a boiling point of 290 to 430°C, and therefore contains one moiety of saturated double bonds.

In the second step, the product obtained in the first step is stored in a surge tank 9 and hydrogenated in a hydrogenation reactor 10 under mild conditions. What is important in this case is to selectively partially hydrogenate only polymerizable double bonds.

In the product obtained in the first step, hydrogenated structures exist in both the phenyl group and the unsaturated double bond. When used as a heat carrier or a high boiling point solvent, hydrogenation of only the unsaturated double bond portion will yield a product with sufficiently high thermal stability, and the hydrogenated product will be colorless and odorless. As a result of various studies on such partial hydrogenation, it has been found that preferable results can be obtained by using a Ni/diatom-based or Raney-Nikesol-based catalyst.

Especially at 50-100℃ and hydrogen pressure 10-150 kg/
cJ (preferably 50-70°C and hydrogen pressure 50-10
0 kg/cJ) using a catalyst of 0.1% by weight or more based on the raw material, it is possible to selectively hydrogenate unsaturated double bonds. In this case, the temperature is 50
Below 100°C, the hydrogenation reaction rate is slow, and above 100°C, some phenyl groups may be hydrogenated and the number of polymerizable unsaturated double bonds may even increase. Although there are no strict restrictions on the hydrogen pressure, in view of the reaction rate, equipment materials, pressurization cost, etc., the range shown in 2 is appropriate.

In the third step, the product obtained in the second step is distilled in a vacuum distillation column 11, and a fraction 12 with a boiling point of 300±20°C (a trinuclear substance containing two benzene nuclei, such as phenylxylylethane, Dimer of styrene) and fraction 13 with a boiling point of 400-430°C (tri- to tetranuclear substance containing 3-4 benzene nuclei, e.g. styrene tetramer, trinuclear substance of styrene-alkylhenzene) do. This process is useful for purifying high temperature heat transfer media. Depending on the application, the hydrogenated product 14 can also be used as a mixture of di- to tetranuclear bodies.

1. Into a 2p volume three-bottle flask equipped with a Tsuji cooler and a thermometer insertion port, 800 g of a C8 fraction (mixed xylene) obtained by refining 1 coke oven light oil (200 g of styrene) was charged, and Nafion was added as a catalyst. 117 was added in an amount of 1% based on styrene, and the mixture was reacted at about 100°C for 2 hours.

As a result of distilling and recovering the unreacted components, the reaction rate of styrene was 98.1%, the average molecular weight by GPC (gel permeation chromatography) was 267.5, and the iodine value was 19. It was 3.

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

Gas chromatography and nuclear magnetic resonance spectra were measured on the obtained hydrogenated purified products and raw materials to determine the results. As shown in Figure 2, the nuclear magnetic resonance spectrum shows that before hydrogenation (
It was confirmed that in the product after hydrogenation (b), the peak of the component at the terminal double bond (66.2 to 6.5 ppm) disappeared compared to a).

Examples 2 and 3 A hydrogenated product was obtained by reacting in the same manner as in Example 1, except that the hydrogenation conditions were changed as shown in Table 1. Table 1 shows the amount of hydrogen consumed at this time (a sample of 7100 g of hydrogen moles) and the iodine value of the product.

Note that the iodine value before hydrogenation was 19.3.

Comparative Examples 1 and 2 Hydrogenated products were obtained by reacting in the same manner as in Example 1, except that the hydrogenation conditions were changed as shown in Table 1. Table 1 shows the amount of hydrogen consumed (hydrogen moles/100 g sample) and the iodine value of the product at this time.

A mixture of 20% styrene and 80% mixed xylene was passed through a flow reactor at a rate of 200 mff/hour,
The same catalyst as in Example 1 was used in the same ratio of catalyst/raw material as before, and the reaction was carried out for a residence time of 3 hours. The obtained reaction product was
Hydrogenation was carried out at 0° C. for 1 hour using 0.2% by weight of the same catalyst as in Example 1 at an initial hydrogen pressure of 100 kg/c+J. The obtained hydrogenated product had an iodine value of 3.5.

2 kg of styrene and 3 k of mixed xylene were added to the reactor of 1 ton [10 β].
The same catalyst as in Example 1 was added in an amount of 1% based on styrene, and the mixture was reacted at about 120° C. for 3 hours. Repeat the reaction 3 times in the same way to produce 15 kg (6 kir of styrene)
7.7 k of oligomer oil was obtained by vacuum distillation from the original lit.
I got g. I took about 7 kg from this and made it to 2011! Initial hydrogen pressure 100kg/c, 70゛C in an autoclave.
Hydrogenation was carried out using 70 g of Ni/diatomaceous earth catalyst.

The hydrogenated product obtained by separating the catalyst particles was transparent and colorless. The entire amount of this hydrogenated product was charged into an Ion distillation apparatus, distilled under reduced pressure, and heated to approximately 100°C at 1
Excluding the 400 g of light products distilled up to this point, the total amount of
3.2 kg of a product mainly consisting of trinuclear bodies distilled at 40° C. and 10 to 50 Hg and 3.3 kg of bottom residue were obtained. The average molecular weights of the hydrogenated purified product, the trinuclear product, and the residue (tri- to tetranuclear product) were 2B5.7.1.94.2 and 375.2, respectively.

(Effects of the Invention) As described above, according to the present invention, an unprecedented high boiling point hydrocarbon oil,
In particular, synthetic hydrocarbon oils useful as high-temperature heat carriers, high-boiling solvents, and electrical insulating oils can be produced extremely efficiently.

In particular, the composition comprising tri- to tetra-nuclear bodies 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. Furthermore, the trinuclear component obtained at the same time is also used as a heat medium at relatively low temperatures, a high boiling point solvent, and an electrical insulating oil. Furthermore, the di- to tetranuclear mixture, which is a purified product that is not separated by distillation, has a high dielectric constant and is excellent as an insulating oil for capacitors.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the manufacturing process according to an example of the present invention. FIG. 2 is a graph showing nuclear magnetic resonance spectra of hydrocarbon oil before and after hydrogenation in Example 1. , (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 reactor 11 ... Vacuum distillation column 12 ...
Boiling point: 300±20°C Fraction 13: Boiling point: 400-430°C Fraction 14: Hydrogenated product

Claims (1)

[Claims] 1. React alkylbenzene and styrene using a cation exchange membrane as a catalyst to obtain a mixture containing styrene dimer to tetramer oligomers and styrene-alkylbenzene adducts, and remove unsaturated double bonds contained in this mixture. , a method for producing high-boiling hydrocarbon oils by hydrogenating with high-pressure hydrogen at 50-100°C in the presence of a catalyst.