JPH0747730B2 - Heat carrier oil - Google Patents

Description

TECHNICAL FIELD The present invention relates to heat carrier oils, and more particularly to heat carrier oils that produce less carbonaceous material when used at high temperatures.

2. Description of the Related Art Heat carrier oil is most commonly used as a heat carrier for indirect heating. The required performance of this heat carrier oil is
(1) Good thermal stability, withstanding long-term use at high temperature, (2) No problem with physical properties such as specific gravity, viscosity, thermal conductivity, vapor pressure, etc. (3) No toxicity (4) There are some things that are not corrosive.

Currently, refined mineral oil, diphenyl, diphenyl ether, alkylbenzene, alkylnaphthalene, 1-phenyl-1-xylylethane and the like are widely used as heat carrier oil. However, since the heat carrier oil is generally used at a high temperature, when used for a long time, the oil deteriorates and carbonaceous matter is generated, which causes sludge generation. Therefore, development of a heat carrier oil that is less likely to undergo thermal deterioration at high temperatures and is free of carbonaceous matter is becoming an important issue.

On the other hand, the existence of hydrogen-donating substances has long been known,
It is often used for coal liquefaction, heavy oil cracking, visbreaking, etc. The most typical hydrogen donating substance is tetralin (tetrahydronaphthalene), which has two or more aromatic rings or one aromatic ring and a five-membered ring.
It is already known that a hydride of a compound having both a hydrogen atom and a hydrogen atom has a hydrogen donating property.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, there is no attempt to apply these hydrogen-donating substances to prevention of carbonaceous substance generation when using a heat carrier oil, and there is no experimental report for such purpose. The present inventor has noticed that the carbonaceous production mechanism in operations involving reduction of molecular weight such as coal liquefaction and heavy oil decomposition and the carbonaceous production mechanism when using a heat carrier oil are essentially the same. Through the experiments, they found that the presence of a hydrogen-donating substance is effective for the production of carbonaceous matter when using a medium oil, and completed the present invention.

An object of the present invention is to provide a heat carrier oil that produces less carbonaceous matter when used at high temperatures.

Means for Solving the Problems The present invention provides (i) 100 parts by weight of a mineral base oil and / or a synthetic base oil as an essential component, and (ii) thermal decomposition, catalytic cracking or catalytic reforming of petroleum. To hydrogenate hydrocarbons with a boiling point of 250 ° C or higher obtained from
The present invention provides a heat carrier oil to which 0.1 to 20 parts by weight of hydrogenated oil having a hydrogen donating ability at 50 ° C. or higher is 3 times or more that of the above-mentioned mineral oil base oil and / or synthetic base oil.

Hereinafter, the content of the present invention will be described in more detail.

As the mineral base oil and synthetic base oil of the present invention, any oil may be used as long as it has a viscosity similar to that of an oil generally used as a lubricating oil. Specific examples of the mineral oil-based base oil include 70 pale oil, SAE10 and SAE2.
Various grades such as 0, SAE30, SAE50 and bright stock are used.

Further, as the synthetic base oil, specifically, for example, polybutene, α-olefin oligomer, alkylbenzene, alkylnaphthalene, diester, polyol ester,
Polyglycol, polyphenyl ether, tricresyl phosphate, silicone oil, perfluoroalkyl ether, normal paraffin, diphenylalkane, etc. are used.

Among these, one of the diphenylalkanes, the formula 1-phenyl-1-xylylethane represented by is particularly preferably used.

The hydrogenated oil added to the base oil in the present invention must have excellent hydrogen donating ability to the base oil. And it must be a substance that donates hydrogen under conditions such that a carbonaceous substance is produced from a base oil or a polymer substance is produced at high temperature. On the other hand, the base oil is selected to have properties suitable for each use of the heat carrier oil. When a large amount of hydrogenated oil is added to the base oil, the properties originally possessed by the base oil are impaired and the performance as a heat carrier oil is lost. Therefore, it is preferable that the amount of hydrogenated oil added to the base oil be small and effective. From a practical point of view, the amount of hydrogenated oil added to the base oil must be 0.1 to 20 parts by weight, preferably 1 to 15 parts by weight, more preferably 2 parts by weight, based on 100 parts by weight of the base oil. ~ 10 parts by weight. In this case, the hydrogen donating ability of the hydrogenated oil added to the base oil is 3 times or more, preferably 5 times or more, more preferably the base oil.
It must be 10 times or more. The present inventor has found that as a hydrogenated oil satisfying the above-mentioned conditions, a hydrogenated oil obtained by hydrogenating a hydrocarbon having a boiling point of 250 ° C. or higher obtained from an apparatus for thermally decomposing, catalytically cracking or catalytically reforming petroleum is effective Found. This hydrogenated oil contains a large amount of a compound having two or more aromatic rings and a compound having both a part of the aromatic ring and one unsaturated five-membered ring. become.

Specifically, naphtha pyrolysis device cracked residual oil, FCC device (catalytic cracking device) cycle oil, slurry oil and decanted oil (DCO), naphtha catalytic reforming device reformed residual oil, crude oil pyrolysis device cracked tar, or, These mixtures are illustrated.

Usually, it is known that the base oil also contains the polycyclic aromatic compound, but the content of the compound having a good hydrogen donating property is extremely small, and the hydrogen donating property of the base oil is extremely low. Confirmed by experiments.

The method for hydrogenating a hydrocarbon having a boiling point of 250 ° C. or higher obtained from an apparatus for thermally cracking, catalytically cracking or catalytically reforming petroleum is arbitrary, but normally, hydrogen gas is used in the presence of a catalyst having a hydrogenating function. A method of hydrogenating is used. The catalyst having a hydrogenating function is not particularly limited, and a known catalyst used for hydrotreating petroleum fractions can be used. Specifically, at least one metal element selected from Groups V to VIII of the Periodic Table, in particular, a sulfide or oxide of at least one metal element selected from nickel, cobalt, molybdenum, vanadium and tungsten is alumina. , Silica, silica-alumina, those supported on an inorganic carrier such as cation-substituted zeolite or an aromatic ring nuclear hydrogenation catalyst such as nickel, nickel oxide, nickel-copper, platinum, platinum oxide, platinum-rhodium, platinum-lithium, Metals such as rhodium, palladium, cobalt, Raney-cobalt and ruthenium are activated carbon, alumina, silica-alumina,
Examples thereof are those supported on diatomaceous earth and an inorganic carrier such as zeolite. The conditions for hydrogenating a feedstock in the presence of a catalyst having these hydrogenation functions are 300 ° C to 400 ° C in the case of a catalyst used for hydrotreating the petroleum fraction.
C, preferably 30 atm to 150 atm, and in the case of an aromatic ring nuclear hydrogenation catalyst, 150 ° C to 300 ° C, 30 atm to 150 atm.
Atmospheric pressure is desirable. The reactor is also not particularly limited, and a hydrogenated oil having a good hydrogen donating property can be prepared by using a general fixed bed reactor. In the hydrogenated oil thus obtained, as a hydrogen-donating substance, specifically, for example, dihydronaphthalene, tetrahydronaphthalene, dihydroanthracene,
Dihydrophenanthrene, tetrahydroanthracene,
Tetrahydrophenanthrene, octahydroanthracene, octahydrophenanthrene and the like are included, and although these substances can be used alone, they are not preferable from the economical point of view.

In the present application, the method for evaluating the hydrogen donating ability of these hydrocarbons is performed by the following method. This is a method of obtaining from the trapped amount of migratory hydrogen using a hydrogen acceptor.
That is, a sample and a hydrogen acceptor such as anthracene are reacted under certain conditions, and the amount of hydrogen acceptor hydrogenated after the reaction is analyzed by gas chromatography or the like.

Specifically, a predetermined amount of hydrocarbons sample and a predetermined amount of anthracene (sample / anthracene = 1/2 weight ratio) are stored in an autoclave with a stirrer, and the temperature is 350 ° C or higher, for example, 350 ° C.
~ 450 ℃ temperature, pressure 50kg / cm ² · g (N ₂ pressure), 3 without catalyst
Let react for 0 minutes. Before and after the reaction 9,10-dihydroanthracene, 1,4,5,8-tetrahydroanthracene, 1,2,3,4-
The amounts of tetrahydroanthracene, 1,2,3,4,5,6,7,8-octahydroanthracene as well as residual anthracene are analyzed by gas chromatography. The hydrogen used for hydride generation of these anthracenes is supplied from hydrocarbons having hydrogen donating properties, so the amount of hydrogen transferred from these hydrocarbons to anthracene (hydrogen atom / mol anthracene) is calculated. Is measured as a hydrogen-donating property.

This method is based on Yokono T., Marsh H. and Yokono.
The method is based on the method described in M., Fuel, 60 , 607 (1981).

As a method of adding such a substance to the base oil, it can be added at the stage of producing the base oil at the refinery, or can be added by the user side at the stage of using the heat carrier oil.
Further, at the stage of producing a base oil, it has two or more aromatic rings obtained from a device for thermally decomposing, catalytically cracking or catalytically reforming petroleum, or has both one aromatic ring and one five-membered ring. It is also possible to hydrogenate the oil containing the compound with the base oil to produce the base oil and at the same time obtain the hydride.

In addition, various additives are added to the ordinary heat carrier oil to improve its performance. There is no problem in adding such an additive to the heat carrier oil of the present invention. Examples of such additives include antioxidants, detergent dispersants, viscosity index improvers, pour point depressants, corrosion inhibitors, metal deactivators,
Examples include rust preventives, defoamers, and coloring agents. For details of these various additives, see, for example, "Lubricant Science", Vol. 15,
No. 6 "or" Toshio Sakurai "," Petroleum Product Additives "
(Koshobo) ”, etc. The total addition amount of these various additives is 10 parts by weight or less, preferably 5 parts by weight or less, particularly preferably 3 parts by weight or less, relative to 100 parts by weight of the base oil. It is desirable to have.

EXAMPLES The present invention will be described in more detail by the following experiments, comparative experiments, examples and comparative examples.

Examples 1 to 3 and Comparative Experiments 1 to 3 In order to compare the hydrogen donating properties of the heat carrier oil base oil and the hydrogenated oil, the following experiments were conducted. As the heat transfer oil base oil, SAE10, SAE30, and SAE50 (all hydrotreated) from Arabian crude oil are used as examples of hydrogenated oil, and naphtha thermal cracker cracked residual oil and naphtha catalytic reformer reformed Residual oil and FCC
A hydride of the equipment decanted oil was used. The experimental method was performed by the method described above.

That is, the sample and anthracene are reacted under certain conditions,
According to the method of determining the hydrogen transfer amount from the amount of hydrogen added to anthracene. After reacting the base oils of SAE10, SAE30 and SAE50 with anthracene under certain conditions (Table 1),
Amount of 9,10-dihydroanthracene, 1,2,3,4-tetrahydroanthracene, 1,4,5,8-tetrahydroanthracene and 1,2,3,4,5,6,7,8-octahydroanthracene Was analyzed by gas chromatography. As a result, the amount of hydrogen transferred from each base oil to anthracene can be known. The results are shown in Table 3. On the other hand, naphtha pyrolysis unit cracked residual oil, naphtha catalytic reformer reformed residual oil and FCC unit decanted oil were hydrogenated under certain conditions (Table 2) and anthracene was reacted under the conditions of Table 1, before and after the reaction. 9,10-dihydroanthracene, 1,4,5,8-tetrahydroanthracene, 1,2,3,4-tetrahydroanthracene, 1,2,3,4,5,
The amount of 6,7,8-octahydroanthracene as well as anthracene was analyzed by gas chromatography. Calculate the increase and decrease of these before and after the reaction, and transfer the amount of hydrogen transferred from hydride of naphtha pyrolysis unit cracked residual oil, naphtha catalytic reformer reformed residual oil and FCC device decanted oil to anthracene (hydrogen atom / mol anthracene) I asked. Amount of hydrogen transferred from each base oil to anthracene, naphtha thermal cracker cracked residual oil, naphtha catalytic reformer reformed residual oil and FC
Table 3 summarizes the amount of hydrogen transferred from the hydride of decanted oil in the C unit to anthracene.

As a result, the amount of hydrogen transferred from each base oil is very small,
On the other hand, in the case of hydrogenated oil, the transfer amount of hydrogen is quite large,
That is, the hydrogen donating ability is 3 times or more that of each base oil, for example 10
It turns out that there is ~ 30 times.

Example 1, Comparative Example 1 The SAE50 base oil shown in Comparative Experiment 3 in Comparative Example 1 and the same SAE50 in Example 1 in 100 parts by weight of the base oil were shown in Experiment 1 using an internal stirring type autoclave experimental apparatus having an internal volume of 100 ml. Naphtha pyrolysis unit Add 5 parts by weight of hydride of cracked residual oil to the above autoclave and put them at 400 ° C for 72 hours
Internal stirring was continued. The gas phase is nitrogen and the initial pressure is 5 kg / cm.
^After pressurizing at ² (normal temperature), the temperature was raised. After 72 hours, the contents were taken out and the formation of carbonaceous material was observed, and then the toluene insoluble content was measured. The results are shown in Table 4.

Example 2, Comparative Example 2 In the internal closed thermostat (made of stainless steel) shown in the figure, the SAE30 base oil shown in Comparative Experiment 2 in Comparative Example 2 and 100 parts by weight of the same SAE30 base oil in Example 2 were used for the experiment. The naphtha catalytic reforming apparatus shown in 2 and 7 parts by weight of the hydride of the reformed residual oil were added to the internal closed thermostatic bath. In each case, a nichrome wire having a surface temperature of about 800 ° C was immersed in the liquid, the liquid was stirred, and the constant temperature bath was heated so that the temperature of the liquid was maintained at 200 ° C. The gas phase was replaced with nitrogen. After continuing this state for 1,500 hours, the liquid was sampled, the production of carbonaceous matter in the liquid was observed, and then the toluene insoluble content was measured.
The results are also shown in Table 4.

The following points are clear from each of the above embodiments.

(1) The hydrogen donating property of the heat carrier oil base oil is small.

(2) The hydrogen donating ability of the hydrides of the products obtained from the petroleum thermal cracking unit, catalytic cracking unit and catalytic reforming unit is much higher than that of the heat carrier oil base oil.

(3) When the hydride of the product obtained from the above-mentioned petroleum thermal cracking device, catalytic cracking device and catalytic reforming device is added to the heat carrier oil base oil, the production of carbonaceous matter is greatly reduced.

(4) Many hydrides of products obtained from the above-mentioned petroleum thermal cracking device, catalytic cracking device, and catalytic reforming device are not required, and in the above example, a few% of them show a sufficient effect.

Effects of the Invention As described above, by adding a small amount of a hydrocarbon having a predetermined hydrogen donating property, which has a boiling point of 250 ° C. or more, obtained from a device for thermally decomposing, catalytically cracking or catalytically reforming petroleum to a heat carrier oil. It is understood that the precipitation of carbonaceous substances when the heat carrier oil is used is limited, and that the base oil can be used without impairing the properties of the base oil.

[Brief description of drawings]

FIG. 1 is a schematic view showing a test device used in an example of the present invention. (1): Stainless steel thermostat, (2): Stirrer,
(3): Nichrome wire, (4): Thermometer.

Claims (2)

[Claims] 1. A boiling point obtained from a device for thermally decomposing, catalytically cracking or catalytically reforming petroleum as an essential component for (i) 100 parts by weight of a mineral base oil and / or a synthetic base oil. Hydrogenates hydrocarbons above 250 ° C, 3
A heat carrier oil comprising 0.1 to 20 parts by weight of a hydrogenated oil having a hydrogen donating ability at 50 ° C. or higher that is 3 times or more that of the mineral base oil and / or synthetic base oil. 2. A hydrocarbon having a boiling point of 250 ° C. or higher obtained from a device for thermally decomposing, catalytically cracking or catalytically reforming petroleum,
Naphtha pyrolysis device Decomposition residual oil, FCC device (contact cracking device)
The heat carrier oil according to claim 1, which is a cycle oil, a slurry oil and a decanted oil (DCO), a naphtha catalytic reformer reformer residual oil, a crude oil thermal cracker cracker tar, or a mixture thereof.