JPH0438083B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing electrical insulating oil, which comprises treating a pyrolysis oil fraction from a pyrolysis process of petroleum heavy residual oil. In recent years, due to the depletion of petroleum resources, heavier crude oil has been used, and as a result, the amount of by-product heavy residual oil such as distillation residue oil has also tended to increase.
However, this heavy residual oil has low industrial utility value due to its high viscosity and high sulfur and metal content. On the other hand, the only form of utilization of such heavy residual oil is as a raw material for thermal decomposition processes such as coking. The coking process of this heavy residual oil yields liquid material, ie, pyrolysis oil, along with coke and gas, but the yield of pyrolysis oil in normal coking is quite high, and a large amount of pyrolysis oil can be obtained. Become. However, conventional methods for utilizing the pyrolysis oil produced in large quantities have been to perform further processing such as fluidized catalytic cracking, since this oil is relatively rich in aliphatic hydrocarbons and may not have a sufficient octane number. Unless otherwise available, it could not be used as gasoline for automobiles, and could only be used as simple fuel for boilers. Therefore,
The utilization of this large amount of by-product pyrolysis oil is becoming a major industrial problem. By the way, petroleum-based light hydrocarbons such as naphtha
By pyrolysis at 750-850℃, ethylene,
The production of basic raw materials for the petrochemical industry, such as propylene, is widely practiced as so-called naphtha cracking. At this time, it is difficult to make a general statement because it varies depending on the type of feedstock oil supplied to the pyrolysis equipment, cracking conditions, etc., but the amount of pyrolysis by-product oil containing a large amount of aromatic hydrocarbons is relative to the amount of ethylene produced.
0.5 to 3.0% by weight is produced as a by-product. In addition, in order to improve the octane number or to obtain aromatic hydrocarbons by increasing the content of aromatic hydrocarbons such as benzene, toluene, and xylene, naphtha and the like are converted into Pt or Pt-Re/Al ₂ in the presence of hydrogen.
The reformed oil obtained in large quantities from catalytic reforming in which it is brought into contact with a noble metal catalyst such as O ₃ naturally also contains a large amount of aromatic hydrocarbons. Furthermore, residual oil from which benzene, toluene, and xylene are separated and removed from the above-mentioned thermal decomposition by-product oil and reformed oil by separation means such as solvent extraction is C ₉ ,
Although it is a distillate mainly composed of aromatic hydrocarbons such as _C10 , its industrial use has not been sufficient due to the fact that it is a mixture of many components and it is difficult to separate each component. isn't it. As a result of intensive research into the effective use of fractions, which are not fully utilized industrially as described above, the inventors of the present invention have found that the pyrolysis oil fraction obtained from the pyrolysis of heavy residual oil has been Excellent low-temperature properties comparable to electrical insulating oils are obtained through acid catalyst treatment of raw materials that are a mixture of by-product oil fractions, reformed oils, pyrolysis by-product oil fractions, and aromatic residual oils from reformed oils. The present invention was completed by discovering that a high boiling point fraction can be obtained. That is, the present invention provides (A) 400% petroleum-based heavy residual oil.
A pyrolysis oil fraction obtained from a pyrolysis process that is thermally decomposed at temperatures above ℃ but not exceeding 600℃,
Pyrolysis oil fraction 20 whose main component is hydrocarbons with a boiling point in the range of 120 to 290℃ and also contains aliphatic olefins.
~95% by weight and (B) (a) petroleum light oil at a temperature of 750 to 850.
Pyrolysis by-product oil fraction obtained by pyrolysis at ℃ and then treatment to reduce unsaturation, (b) boiling point 50~
A reformed oil fraction obtained by catalytically reforming light petroleum oil at 250°C and then optionally undergoing treatment to reduce unsaturated content, and (c) the pyrolysis byproduct oil of (a) above. and/or one or more aromatic fractions with a boiling point of 150 to 250°C selected from the group consisting of aromatic fractions mainly containing aromatic hydrocarbons separated and obtained from the reformed oil fraction of (b) as a raw material. It is characterized by forming a reaction product with a boiling point of 315°C or higher that has excellent low-temperature properties by treating a fraction of 80 to 5% by weight in the liquid phase in the presence of acid contact at a reaction temperature of 30 to 330°C. Regarding electrical insulating oil. The petroleum heavy residual oil to be thermally cracked in item (A) of the present invention refers to atmospheric distillation residue oil, vacuum distillation residue oil, thermal cracking or catalytic cracking residue oil, and various Refers to petroleum refining residues such as furfural, propane, bentane extraction residues, reformer residues, etc., and mixtures thereof. It is necessary that the decomposition temperature of the thermal decomposition process of the present invention is 400°C or higher and does not exceed 600°C.
No thermal decomposition occurs at decomposition temperatures lower than 400℃;
In addition, when the temperature exceeds 600℃, aromatic hydrocarbons, which are themselves highly reactive, become excessive in the resulting pyrolyzed oil regardless of the decomposition time, and acid-catalyzed treatment results in high polymers such as resin components. This is not preferable because it tends to result in the formation of olefins and the amount of aliphatic olefins with boiling points in the range of 120 to 290°C is too small. The decomposition temperature is preferably 400-550°C. The decomposition time can be changed as appropriate depending on the main purpose of the thermal decomposition process, such as coke production, viscosity reduction of raw material heavy oil, etc., and can be adopted in the range of 10 seconds to 50 hours, for example. Water vapor or other non-reactive gaseous media can also be present during the decomposition. The decomposition pressure is usually relatively low, at reduced pressure or 50Kg/cm ²
That's about it. Typical thermal cracking processes for heavy residual oil include Hydrocarbon Processing,
As described in Vol. 61, No. 9, September 1982, pp. 160-163, there are the visbreaking method and the coking method. That is, the visbreaking method is a process in which the raw material is thermally decomposed under relatively mild conditions while suppressing the generation of coke in a superheating furnace tube, mainly for the purpose of reducing the viscosity of the raw material, and there are two types: a coil type and a soaker type. Normally, cracked oil leaving the cracking furnace is rapidly cooled to crack it and suppress coke. This includes
Examples include the Lummus method and the Shell method. In addition, the coking method is a process that simultaneously produces coke, but after heating the residual oil in a heating furnace for a relatively short period of time, it is sent to a coke drum.
Here, delayed coking (UOP method, Foster
Wheeler method, MWKellogg method, Lummus method and
CONOCO method, etc.), fluid coking method (Exxon method, etc.) in which residual oil is cracked on high-temperature fluidized coke, flexi coking method (Exxon method), which combines fluid coking method with gasification process of produced coke, , the EUREKA process, which produces pitch by thermal decomposition and steam stripping at relatively low pressures such as normal pressure. Among these thermal cracking processes, as a result of the sulfur content and metal content in the residual oil being concentrated in the produced coke, the cracked oil contains relatively few of these impurities.
Therefore, purification after acid catalytic treatment is also a comparative vessel. Further, the coking method is preferable because the high boiling point contains a relatively large amount of aliphatic olefin. Furthermore, among these, delayed coking is operated on a large scale because it produces lump coke that is useful as a carbon source for graphite for electrodes, and as a result, it produces particularly large amounts of cracked oil as a by-product. Therefore, it is an advantageous caulking method because the benefits will be great if the present invention makes effective use of it. The composition of the pyrolysis oil obtained from the above pyrolysis process varies depending on the type of pyrolysis process, pyrolysis conditions, type of raw heavy oil, etc., but it usually contains almost all aromatic olefins. In addition to paraffins such as normal paraffin and iso-paraffin, it also contains highly reactive aliphatic olefins such as normal olefin and iso-olefin, and also includes alkyl-substituted monocycles such as alkylbenzene, alkylindanes, and alkyltetralins. It includes aromatic hydrocarbons having an alkyl-substituted complex ring such as, and an alkyl-substituted condensed ring such as alkylnaphthalene. Among the pyrolysis oils obtained from the various pyrolysis processes mentioned above, in the present invention, boiling points of 120 to 290
℃, more preferably a pyrolysis oil fraction whose main component is hydrocarbons in the range of 150 to 260℃. A fraction whose main component is a hydrocarbon having a boiling point outside of the above range is not preferred because an industrially useful reaction product cannot be obtained. Furthermore, the pyrolysis oil fraction to be treated in the present invention needs to contain aliphatic olefins. The typical composition of the target pyrolysis oil fraction is 30 to 70% by weight of paraffin and 10 to 10% of aliphatic olefin.
40% by weight, aromatic hydrocarbons 5-20% by weight.
However, as long as the above-mentioned conditions for the target fraction are satisfied, there is no problem in appropriately fractionating the pyrolysis oil or diluting it with unreacted oil or the like. (a) Pyrolysis by-product oil fraction, (b) reformed oil fraction, and (c) aroma as the components of section (B) to be mixed with the pyrolysis oil fraction of section (A) above. The group fractions are as follows. That is, the pyrolysis by-product oil fraction (a) is a pyrolysis by-product oil fraction obtained when petroleum light oil is pyrolyzed at a temperature of 750 to 840°C for the purpose of producing ethylene, proprene, etc. In particular, it is a distillate that has been treated to reduce unsaturation such as diolefins and monoolefins. Petroleum-based light oils include naphtha, kerosene, LPG,
Examples include various petroleum light oils such as butane. Considering the properties of the resulting thermal decomposition by-product oil fraction, naphtha and kerosene are preferred as the thermal decomposition raw materials because they are more suitable for the purpose of the present invention. There are no particular limitations on the thermal decomposition method, and various commonly used thermal decomposition methods at 750 to 850°C, such as a tubular decomposition furnace method using a tubular decomposition furnace, a thermal medium decomposition method using pyrolysis, etc. can be used as appropriate. The thermal decomposition byproduct oil fraction, which is obtained by removing the target products such as olefins and diolefins such as ethylene, propylene, and butadiene, from the products of this thermal decomposition is determined by the type of petroleum light oil used as the raw material, the thermal decomposition conditions, etc. It contains a relatively large amount of aromatic hydrocarbons, and contains paraffins 2 to
10% by weight of naphthenes, 3-10% by weight of naphthenes, 55-85% by weight of aromatic hydrocarbons, 2-10% by weight of aliphatic olefins, 2-15% by weight of aromatic olefins with a carbon number of 6-10. It is a distillate. Among these, in the present invention, a fraction with a boiling point of 150 to 280° C. is used by mixing it with the thermally cracked oil fraction of (A). However, the thermal decomposition byproduct oil fraction of the present invention is a fraction that has been further treated to reduce the unsaturated content to 0.5% or less, preferably 0.1% or less. This treatment is achieved by a conventionally known catalytic hydrogenation treatment. For example, Pt, Pd, Ni, Co, Mo, W, Co-Mo,
A metal contact such as Ni-W or a catalyst in which these are supported on a carrier such as alumina can be used. The conditions for this treatment are usually the reaction temperature
200-400°C, hydrogen pressure 20-150 Kg/cm ² , hydrogen/oil molar ratio 0.5-20, and LHSV 0.1-10. In addition, the reformed oil fraction in (b) above has a boiling point of 50 to 250°C.
It is a reformed oil fraction obtained by catalytically reforming light petroleum oil, such as naphtha such as straight-run naphtha. Catalytic reforming is widely used in the oil refining and petrochemical fields to improve octane number and to obtain benzene, toluene, xylene, etc.
This catalytic reforming is carried out in the presence of hydrogen at a reaction temperature of 450-510°C.
The catalyst is platinum supported on alumina or silica-alumina, platinum-rhenium,
Metal catalysts such as molybdenum oxide and chromium oxide. Industrial methods include fixed-bed UOP platform homing and Standard Oil Company's ultrahoming, as well as fluidized bed and mobile methods. In catalytic reforming, dehydrogenation and cyclization reactions mainly occur, as well as isomerization reactions, which increase the content of BTX such as benzene, toluene, and xylene, and improve the octane number. However, the resulting reformed oil is characterized by having a bromine number of about 3.8 or less and a very low unsaturated content compared to the thermal decomposition by-product oil of (A). A more preferred reformate has a bromine number of about 2 or less. The typical composition of this catalytic reforming oil fraction is paraffin
30-35% by weight, 65-70% by weight of aromatic hydrocarbons, and 0-2% by weight of olefins. In the present invention, the boiling point
A catalytic reforming oil fraction of 150-280°C is used. As mentioned above, the fraction usually has a low amount of unsaturation, but if necessary, it can be treated to reduce unsaturation. This treatment can be carried out in the same manner as the treatment for reducing the unsaturated content of the thermal decomposition by-product oil (a) described above. Furthermore, using these catalytically reformed oils, the pyrolysis by-product oils, or mixtures thereof as raw materials, an aromatic fraction mainly composed of aromatic hydrocarbons obtained by an appropriate separation means is used as described in (c) above. Can be used as an aromatic fraction. This separation is carried out on a large scale in the field of petrochemistry to obtain BTX from catalytic reforming oil or pyrolysis by-product oil, and is usually carried out by solvent extraction or extractive distillation. . Typical solvent extraction methods include the Udex method (DOW method), which uses diethylene glycol, triethylene glycol, etc. as an extraction solvent, and the sulfolane method (Shell method), which uses sulfolane. In addition,
In this extraction, in order to avoid blockage of the apparatus due to polymerization of unsaturated components, unsaturated components are usually removed by hydrogenation or the like as a pretreatment. In this way, among the aromatic fractions mainly consisting of aromatic hydrocarbons obtained by separation from catalytic reforming oil and pyrolysis byproduct oil, the fraction with a boiling point of 150 to 250°C ((c) of the present invention)
(aromatic fraction) consists of hydrocarbons having 9 to 10 carbon atoms, but mainly contains alkylbenzenes, polyalkylbenzenes, naphthalene, and many other aromatic hydrocarbons. Although it is obtained in large quantities along with BTX fraction, there was no effective way to use it. In the present invention, the pyrolysis oil fraction of (A) is added to the pyrolysis oil fraction of (B).
(a) thermal decomposition by-product oil fraction, (b) reformed oil fraction, and (c) aromatic fraction are mixed and subjected to acid catalyst treatment. The fractions (a) to (c) can be appropriately mixed and used as the fraction (B). The mixing ratio of both is (A) pyrolysis oil fraction 20-95
The fraction (B) is 80 to 5% by weight. When the obtained reaction product is used as an electrical insulating oil, a more preferable mixing ratio is 70 to 90% by weight of the fraction (A) and the fraction of B, since it provides excellent low-temperature properties.
It is 30-10% by weight. As the acid catalyst, solid acid catalysts, mineral acids, so-called Friedel-Crafts catalysts, organic acids, etc. are preferably used. For example, specifically, acid clay minerals such as acid clay and activated clay, amorphous or crystalline silica-alumina, AlF ₃・Al ₂ O ₃ , solid acid catalysts such as strong acid type ion exchange resins, HF ，
AlCl ₃ , BF ₃ . Friedel-Crafts catalysts such as _SnCl4 , inorganic or organic acids such as sulfuric acid, para-toluenesulfonic acid, trifluoromethanesulfonic acid. The reaction format of the treatment may be batch type, semi-batch type or flow type, but when using a solid acid, it is preferable to use flow type. The aerated acid catalyst is added to the fraction in an amount of 0.2 to 20% by weight in a batch system, preferably 1 to 10% by weight, and the LHSV is 0.1 to 20, preferably 0.5 to 10 in a flow system. Process with. Reaction temperature is 30~
The temperature is 300°C, preferably 50-250°C. Although the treatment time varies depending on the reaction conditions, that is, the amount of catalyst, reaction temperature, raw material composition, etc., a sufficient time is required to complete the reaction, and it can usually be selected within the range of 2 to 24 hours. The reaction pressure may be any pressure necessary to maintain the liquid phase. In the present invention, the above acid catalyst treatment is carried out at a boiling point.
Carry out so that a reaction product with a temperature of 315°C or higher is obtained. The reaction product is mainly a reaction product of aliphatic olefins, and is mainly composed of oligomers of aliphatic olefins and alkylates of aliphatic olefins and aromatic hydrocarbons. A reaction product with a boiling point lower than 315°C has a low flash point, etc., and is not valuable as an insulating oil, and there is no point in acid catalyst treatment, so it is not preferred. In the present invention, as mentioned above, a fraction of a specific composition from a specific source is used as a raw material and is subjected to a specific treatment, so that virtually no high molecular weight compounds that adversely affect various physical properties are generated. The reaction product has a relatively low viscosity. Therefore, depending on the application, it is possible to use it as an insulating oil by simply separating the unreacted fraction (raw material fraction), for example, by distillation, without further separating the heavy fraction. Of course, the product can be divided into suitable boiling range fractions if desired. Although the unsaturated content of the pyrolysis oil fraction is reduced by the above treatment, for example, the bromine number is reduced, the reaction product contains oligomers of aliphatic olefins as described above, so it is preferable to By performing catalytic hydrogenation treatment, unsaturation is reduced or eliminated. In addition, the catalytic hydrogenation treatment can also be performed on the separated reaction product or a fraction containing a large amount of the reaction product, or the pyrolysis oil fraction itself that has been subjected to the acid catalyst treatment. can. Any conventionally known catalyst can be used for the catalytic hydrogenation treatment. For example, Pt, Pd, Ni, Co,
Metal catalysts such as Mo, W, Co-Mo, Ni-W, etc. can be used. The conditions for this treatment are usually a reaction temperature of 250 to 400°C, a hydrogen pressure of 20 to 100 kg/cm ² , a hydrogen/oil molar ratio of 0.5 to 20, and a LHSV of 0.1 to 10. This hydrogenation treatment is carried out under conditions in which hydrogenation of the aromatic hydrocarbons does not substantially occur. After the catalytic hydrogenation treatment, reaction products and, if necessary, gas components are separated by appropriate means such as distillation. Of course, the hydrogenation reaction product may be further separated into appropriate fractions. The hydrogenation reaction product thus obtained has a boiling point of 315°C or higher, a viscosity of 25 cst or lower at 75°C, a pour point of -40°C or lower, and a flash point of 140°C or higher. Although its composition varies depending on the boiling point range of the raw materials, mixing ratio, etc., it contains almost no normal paraffins, and contains isoparaffins, aromatic hydrocarbons containing alkyl-substituted monocycles or complex rings, etc. It consists of The features of the present invention are summarized as follows. (1) According to the present invention, the cracked oil from the pyrolysis process of heavy residual oil and the pyrolysis by-product oil of petroleum light oil, or the high boiling point fraction (bp 150 to 250°C) in catalytically reformed gasoline, is available for use. That is, the industrial value is low, and the industrial value is high because it is possible to effectively utilize a large amount of surplus heavy residual oil. At the same time, products with high industrial value can be obtained by using high-boiling fractions with low industrial value that are by-produced during the production of high value-added benzene, toluene, xylene, etc. (2) Since the raw material is a fraction of a specific structure of a specific raw material, and a specific treatment is carried out, virtually no high-molecular weight substances that would adversely affect physical properties are produced, and only relatively low-viscosity substances are produced. can get. Therefore, if possible, it has the advantage that it can be used as an inexpensive electrical insulating oil by simply distilling the unreacted oil fraction. Furthermore, even though pyrolysis oil from heavy residual oil is used as a raw material, electrical insulating oil with low unsaturated content, metal content, and sulfur content can be obtained. Next, the present invention will be explained in detail with reference to Examples. Example 1 Delayed coking equipment for coking vacuum distillation residue oil with properties shown in Table 1 obtained from Minas crude oil (decomposition temperature 496°C, residence time 24 hours, decomposition pressure 4
Kg/cm ² ) Pyrolysis oil was obtained together with gas and coke at the yield shown in Table 2. Of these, the boiling point is 160~
The fraction at 260°C is designated as fraction A, and its composition is shown in Table 3.

【table】

【table】

[Table] Aromatic olefin content −

Claims (1)

[Scope of Claims] 1 (A) A pyrolysis oil fraction obtained by thermally decomposing petroleum heavy residual oil at a temperature of 400 to 600°C, which has a boiling point
Pyrolysis oil fraction whose main component is hydrocarbons in the range of 120 to 290℃ and also contains aliphatic olefins.
(B) (a) A thermal decomposition by-product oil fraction obtained by thermally decomposing petroleum light oil at a temperature of 750 to 850°C and then performing a treatment to reduce unsaturated content, (b) A reformed oil fraction obtained by catalytically reforming light petroleum oil with a boiling point of 50 to 250°C, and then optionally subjected to treatment to reduce unsaturated content, and (c) the above (a) One or more types selected from the group consisting of aromatic fractions mainly consisting of aromatic hydrocarbons separated and obtained using the thermal decomposition byproduct oil of (b) and/or the reformed oil fraction of (b) as raw materials. boiling point of
A reaction product having a boiling point of 315°C or higher is obtained by treating 80 to 5% by weight of a fraction of 150 to 250°C in the liquid phase in the presence of an acid catalyst at a reaction temperature of 30 to 330°C. Manufacturing method of electrical insulating oil. 2. The method of claim 1, wherein the pyrolysis process is a coking process. 3 (A) A pyrolyzed oil fraction obtained by thermally decomposing petroleum heavy residual oil at a temperature of 400 to 600°C, which has a boiling point
Pyrolysis oil fraction whose main component is hydrocarbons in the range of 120 to 290℃ and also contains aliphatic olefins.
(B) (a) A thermal decomposition by-product oil fraction obtained by thermally decomposing petroleum light oil at a temperature of 750 to 850°C and then performing a treatment to reduce unsaturated content, (b) A reformed oil fraction obtained by catalytically reforming petroleum-based light oil with a boiling point of 50 to 250°C, and then optionally subjected to treatment to reduce unsaturation, and (c) the above (a) One or more types selected from the group consisting of aromatic fractions mainly consisting of aromatic hydrocarbons separated and obtained using the thermal decomposition byproduct oil of (b) and/or the reformed oil fraction of (b) as raw materials. boiling point of
A reaction product with a boiling point of 315°C or higher is produced by treating 80-5% by weight of a fraction of 150-250°C in the liquid phase in the presence of an acid catalyst at a reaction temperature of 30-330°C, and then aromatic A method for producing electrical insulating oil, characterized by carrying out catalytic hydrogenation treatment under conditions in which nuclear hydrogenation of hydrocarbons does not substantially occur. 4. The method of claim 3, wherein the pyrolysis process is a coking process.