JPS61120896A - Preparation of naphthenic lube base oil - Google Patents

Abstract

PURPOSE:To obtain the title base oil with excellent oxidation stability by the nuclear hydrogenation of hydrocarbon oil obtd. by hydro (thermally) cracking a coal-base raw material such as coal tar (pitch) or coal liquid. CONSTITUTION:A coal-base raw material such as coal tar (pitch), coal liquid or coal liquefaction pitch is subjected to hydro (thermal) cracking in the pres ence of a catalyst comprising at least one metal component selected from Group VI and/or Group VIII metals of the periodic table, such as Mo, W, Ni or Co, supported on a carrier such as Al2O3 under conditions including a pressure of 20-300kg/cm<2> G, a temp. of 250-500 deg.C, a liquid space velocity of 0.01-100hr<-1> and a liquid/gas ratio of 100-5,000lH2/l oil, to obtain a hydrocar bon oil of a boiling range of 200-600 deg.C and of S and N content each <=1,000ppm contg. 50wt% or more condensed polycyclic component with 2-10 rings. Then it is refined by sulfuric acid washing and/or solid adsorption after nuclear hydrogenation in the presence of a metal catalyst such as Ni or Pt at 50-300 deg.C and 10-200kg/cm<2> G.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing naphthenic lubricating base oil using coal tar, coal tar pitch, coal liquefied oil or Ishikawa liquefied pitch as a raw material.

[Conventional technology]

Naphthenic lubricating base oil is made from a special naphthenic crude oil with low wax content, which is distilled at normal pressure to remove light valves, and the resulting atmospheric distillation residue is distilled under reduced pressure to provide light lubricating oil. Each fraction except the oil fraction, medium V1 lubricating oil fraction, and vacuum distillation residue (asphalt) is subjected to IIA acid treatment, white clay treatment, or solvent extraction and purification. In cases where even higher quality oil is required, it is manufactured by refining such as hydrogenation depending on the application.

These naphthenic lubricating base oils not only have a lower viscosity index and better low-temperature fluidity than paraffinic lubricating base oils, but also have high solubility due to their large number of naphthene rings.
Characteristics include that the deteriorated precipitated carbon is soft. For this reason, these naphthenic r! Lubricating oils are in high demand for relatively special uses such as insulating oils, cable oils, refrigeration oils, compressor oils, and low-humidity lubricating oils.

However, as special naphthenic crude oil tends to be depleted worldwide, it is becoming increasingly difficult for countries to secure this special naphthenic crude oil, resulting in a stable supply of naphthenic lubricating base oil. It is becoming impossible to do so.

In order to deal with this situation, various attempts have been made to develop substitutes for naphthenic lubricating base oils. A method for producing WIJ naphthenic lubricating base oil by hydrogenating an extract containing 1% or more by weight at high temperature and pressure in the presence of a special catalyst (Japanese Patent Publication No. 53-10.
082 Publication and Special Publication No. 53-47.24.3)
The first raffinate and A first extract is obtained, and then in a second extraction zone the first Rough Ine-1 is treated with an extraction solvent having preferential solubility for aromatic components to obtain a second Rough Ine-I. A method for producing a naphthenic lubricating base oil by obtaining a second extract and refining the second extract 1 to Raku 1 (Japanese Patent Publication No. 54-102, 8
No. 23 and Japanese Patent Publication No. 55-55,430) have been proposed.

[Problems and effects to be solved by the invention] As described above, most naphthenic lubricating base oils, with the exception of some special synthetic lubricating oils, are produced by refining crude oil. Due to the soaring price of crude oil and the instability of its supply, the use of coal as an alternative raw material to crude oil has become essential in terms of securing resources.

However, a method for producing lubricating base oils from coal-based feedstocks such as coal tar, coal tar pitch, and coal liquefied oil has not yet been established, and coal-based feedstocks are less effective than petroleum-based feedstocks. The bath has a high nitrogen content, has a structure with few straight-chain alkyl groups, and is mainly composed of fused polycyclic aromatic compounds. The problem is that the refined oil produced by this method has extremely poor oxidation stability and is difficult to use as a lubricating oil.

[Means and effects for solving the problems] The present invention was devised in view of this point of view, and the present invention is made by converting coal-based raw materials selected from coal tar, coal tar pitch, coal liquefied oil, and coal liquefied pitch into hydrogen. Hydrocarbon oil obtained by chemical cracking or thermal decomposition is desulfurized and denitrified if necessary to reduce the sulfur content and nitrogen content to 1,000 OOIII'1 m or less, respectively, and then nuclear hydrogenated to produce naphthenes with excellent oxidation stability. This is a method for producing lubricating base oil.

-〇- In the present invention, the hydrocarbon oil used as a raw material is obtained by hydrocracking or thermally decomposing a coal-based raw material such as lutal, coal tar pitch, coal liquefied oil or coal liquefied pitch,
Alternatively, it is obtained by hydrogenolysis and thermal decomposition, preferably contains 50% or more, preferably 60% of fused polycyclic components having 2 to 10 rings, and has a boiling point range. is 200-6. 0°C or higher. As such a hydrocarbon oil, for example, =1-
There are hydrocarbon oils produced when coal tar pitch is hydrogenated, and pyrolysis oils produced when coal tar pitch is converted into alcohol.

Since this hydrocarbon oil is derived from coal, it usually contains 0.02 to 2% by weight of sulfur compounds converted to elemental sulfur content, and contains nitrogen compounds of 0.02 to 2% by weight in terms of elemental sulfur content. The content is 0.1 to 3% by weight calculated as 0.1% to 3% by weight. In the present invention, when these sulfur and nitrogen contents are high, it is preferable to reduce these sulfur and nitrogen contents to 1.0% by hydrorefining, respectively. oooppm or less, preferably sulfur content is 100 pu+ or less, nitrogen content is 10011jlllJ
Put it under your eyes.

The hydrorefining performed for this purpose is HOLH, Ni, C.

etc., carried out in a batch method or a liquid flow method in the presence of a catalyst in which at least one metal component selected from Group 6 Ma and/or Group 8 metals is supported on a carrier such as alumina or silica. However, it is preferably a liquid flow type, in which case the reaction temperature is 250 to 500°C, preferably 350 to 430°C, and the reaction pressure is 20 to 300 Kg/cd-
G1 preferably 50 to 200 Kg/cM-G, liquid hourly space velocity (1-HS V ) 0 .

(It is best to perform this under 1-oil conditions.

If necessary, desulfurization and denitrification are performed to reduce the sulfur content and nitrogen content to 1. The hydrocarbon oil reduced to below OOOrll)m is then subjected to nuclear hydrogenation. In this nuclear hydrogenation, 70 to 90% of the carbon in the obtained nuclear hydrogenated hydrocarbon oil is naphthenic carbon, and 0.
It is preferable to carry out the process so that ~20% is aromatic carbon and the remainder is paraffinic carbon, and more preferably, the process is carried out until the aromatic hydrocarbons in the hydrocarbon oil become naphthenic hydrocarbons as much as possible.

This nuclear hydrogenation of hydrocarbon oil is carried out using a catalyst in which metals from group 8 of the periodic table, such as N1, Pl, and Pd, are supported on diatomaceous earth, alumina, magnesia, boria, silica, etc., and a large excess of hydrogen gas is present. Although the reaction can be carried out in a batch manner or in a liquid flow manner, a batch method is preferable; in this case, the reaction m
a 50-300℃ and reaction pressure 10-200KFl/
This can be carried out under conditions in the range of r:d.G. In addition, regarding the reaction time, it is preferable to carry out the reaction until the absorption of hydrogen is completed.

In the present invention, in order to remove impurities remaining in the hydrocarbon, purification treatment by sulfuric acid washing and/or solid adsorption is preferably performed before or after nuclear hydrogenation. Either one or both of the sulfuric acid cleaning and/or solid adsorption may be performed. Moreover, when performing both, the order is also arbitrary, and either one may be performed before nuclear hydrogenation, and the other may be performed after nuclear hydrogenation.

Regarding the processing conditions for the above-mentioned sulfuric acid cleaning, 80-98% sulfuric acid is mixed at a sulfur/oil ratio of 0.01-10.0 (volume ratio), preferably 0.1-1.0, and the preparation range is room temperature to 80℃
It is best to stir the mixture for 15 to 150 minutes. In addition, regarding the processing conditions for the solid adsorption mentioned above, in a solid adsorbent such as activated clay, activated alumina, or silica alumina, the mixture range is 0 to 150°C rl-H8V0.1 to 50hr-', and the preferable t'L
It is preferable to circulate at a rate of 5 to 1 Qhr.

The resulting oil, which has been nuclear hydrogenated in this way and treated by sulfuric acid washing and/or solid adsorption, is separated into oils with appropriate boiling point ranges by a vacuum heat surface, and then converted to kinematic viscosity (
Naphthenic lubricating base oils with a QIC of 3t can be obtained. The naphthenic lubricating base oil obtained here has a pour point of -10°C or less.

〔Example〕

Hereinafter, the method of the present invention will be explained in detail based on Examples.

Example 1 Soft pitch obtained by heating coal tar was hydrogenated in the presence of a hydrogenation catalyst, and the hydrogenated pitch was thermally decomposed in a dilate coker to produce hydrocarbon oil as a raw material. Manufactured. This hydrocarbon oil has a boiling point of 270-500℃,
Sulfur content 1. , 200 p, pm and nitrogen content 7.6.0
It contained Oppm.

This raw material hydrocarbon oil was converted into a commercially available N i 0-MoO3/A
Charged into a flow type high pressure reactor filled with p203 catalyst, reaction temperature 1σ400°C1 hydrogen pressure 180Kg/cd-G,
Liquid hourly velocity 0, 3 br-1 and liquid-gas ratio 400~
3, OO, Of-l 2-(1/ (l Oi
Hydrorefining was carried out under the conditions of 1. The recovery rate of the hydrotreated oil was 99%, the sulfur content was reduced to 0.5 ppm, and the nitrogen content was reduced to t; t 30 pI) Ill.

Next, 10% by weight of a nickel catalyst was added to the above hydrotreated oil and reacted for 4 hours in a crepe at 230° C. and a water digging force of 100 KFI/art-G in column P1. A nuclear hydrogenated hydrocarbon oil in which the group rings were hydrogenated as much as possible was obtained.

98% rli in this nuclear hydrogenated hydrocarbon oil! After adding 10 m% of acid and contacting for 30 minutes, the nuclear hydrogenated hydrocarbon oil and sulfuric acid were separated, neutralized with 5% NaO+-1 aqueous solution, washed with water, and further heated at 130°C. , L l-I SV
Solid adsorption treatment was carried out by passing through activated clay for 1 hr-% to obtain nuclear hydrogenated refined oil. The yield of this nuclear hydrogenated refined oil is 40%, with a sulfur content of 3.0 ppm and a nitrogen content of 0.5 ρ.
It was pnl.

- The boiling point of the hydrogenated refined oil is 250 to 350 depending on the heat temperature.
℃ distillation and 350 to 1! It was fractionated into a 100'C fraction to produce a naphthenic lubricating base oil. The yield of naphthenic lubricating base oil with a boiling point of 250-350℃ is 24%,
The yield of naphthenic lubricating base oil at 4% was obtained.

Example 2 The same raw material hydrocarbon oil used in Example 1 was hydrorefined in the same manner as in Example 1, and then subjected to nuclear hydrogenation in the same manner as in Example 1, without being subjected to sulfuric acid washing treatment. , solid adsorption treatment with activated clay in the same manner as in Example 1, followed by fractional distillation to obtain a fraction with a boiling point of 250-350°C and a fraction with a boiling point of 350-350°C.
A naphthenic lubricating base oil distilled at 400°C was obtained.

2 12 1 The yield of nuclear hydrogenated refined oil obtained by solid adsorption treatment is 72
%, sulfur content 0.5ppm and nitrogen content 0.3nr1
It was m. Boiling point 250-350 obtained by fractional distillation
The yield of naphthenic lubricating base oil in the 'C fraction is 43%, and the yield of naphthenic lubricating base oil in the boiling point 350-400°C fraction is 1.
It's 2%.

Example 3 A naphthenic lubricating base oil was produced in the same manner as in Example 2 above, except that the order of nuclear hydrogenation and solid adsorption treatment using activated clay was reversed. The yield of the nuclear hydrogenated refined oil was 71%, with a sulfur content of 0.5 ppm and a nitrogen content of 0.5 ppm.
It was 2r+pm. Boiling point 250 obtained by fractional distillation
The yield of the naphthenic lubricating base oil in the ~350°C fraction was 47%, and the yield of the naphthenic lubricating base oil in the boiling point fraction of 350~400°C was 8%.

Comparative Example 1 A lubricating group) Ill was produced in the same manner as in Example 1 except that the nuclear hydrogenation was omitted. The obtained refined oil was fractionally distilled to obtain a fraction with a boiling point of 250 to 350°C and a fraction with a boiling point of 350 to 400°C.

Comparative Example 2 A lubricating base oil was produced in the same manner as in Example 2 except that nuclear hydrogenation was omitted. The iq refined oil was fractionally distilled to obtain a fraction with a boiling point of 250-350°C and a fraction with a boiling point of 350-400°C.

Next, the viscosity, viscosity index, pour point,
Total acid value, oxidation stability bits K by rotating cylinder type
2514, 3.3), the general properties of flash point, specific gravity and hue were investigated. The results are shown in Table 1.

As is clear from the results in Table 1, the naphthenic lubricating base oils obtained in each example had a
It was found that Poka has excellent oxidation stability and has a low pour point, making it excellent in terms of performance.

[Efficacy of invention Song Dynasty]

According to the method of the present invention, conventional petroleum-based hydrocarbon oil is used as raw material because it has a higher aromatic carbon content than petroleum-based hydrocarbon oil and also contains a large amount of nitrogen as an impurity. A naphthenic lubricating base oil with excellent oxidation stability can be produced by using coal-based hydrocarbon oil, to which the method for producing naphthenic lubricating oil cannot be applied, as raw ore.

Claims (8)

[Claims] (1) Oxidation characterized by hydrocracking or thermal cracking of a coal-based raw material selected from coal tar, coal tar pitch, coal liquefied oil, and coal liquefied pitch, and subjecting the obtained hydrocarbon oil to nuclear hydrogenation. A method for producing naphthenic lubricating base oil with excellent stability. (2) After hydrocarbon oil is desulfurized and denitrified by hydrorefining to reduce the sulfur content and nitrogen content to 1000 ppm or less,
A method for producing a naphthenic lubricating base oil according to claim 1, wherein the naphthenic lubricating base oil is subjected to nuclear hydrogenation. (3) A method for producing a naphthenic lubricating base oil according to claim 2, in which hydrocarbon oil is desulfurized and denitrified by hydrorefining to reduce the sulfur content and nitrogen content to 100 ppm or less. (4) The method for producing a naphthenic lubricating base oil according to any one of claims 1 to 3, wherein after nuclear hydrogenation, purification treatment is performed by washing with sulfuric acid and/or solid adsorption. (5) After hydrorefining hydrocarbon oil, washing with sulfuric acid and/or
Alternatively, the method for producing a naphthenic lubricating base oil according to any one of claims 1 to 3, which comprises performing a refining treatment by solid adsorption and then nuclear hydrogenation. (6) Hydrocarbon oil contains 50 fused polycyclic components having 2 to 10 rings.
The method for producing a naphthenic lubricating base oil according to any one of claims 1 to 5, wherein the naphthenic lubricating base oil contains at least % by weight and has a boiling point range of 200 to 600°C. (7) Hydrorefining is carried out in Group VI and/or VII of the periodic table.
In the presence of a catalyst containing at least one metal component selected from Group I metals, the reaction temperature is 250 to 500°C, the reaction pressure is 20 to 300 Kg/cm^2 G, and the liquid hourly space velocity is 0.
．． 01~10.0hr^-^1, liquid-gas ratio 100~5
, 000H_2-l/l-oil. The method for producing a naphthenic lubricating base oil according to any one of claims 2 to 6. (8) Nuclear hydrogenation is carried out at a reaction humidity of 50 to 300°C and a reaction pressure of 10 to 200 kg in the presence of a catalyst containing at least one metal component selected from group VIII metals of the periodic table.
A method for producing a naphthenic lubricating base oil according to any one of claims 1 to 7, which is carried out under the conditions of /cm^2·G.