JPH06100870A - Preparation of base of light diesel oil good in hue and hue stability - Google Patents

Abstract

PURPOSE:To provide a process for preparing a base of light diesel oil having a hue of at least -10 (reference value of hue) in terms of Saybolt color and an excellent hue stability from gas oil prepd. by oil cracking and having poor hue and hue stability, a sulfur content of at most 0.5wt.%. and a b.p. of 150 to 400 deg.C. CONSTITUTION:Gas oil prepd. by oil cracking and having a sulfur content of at most 0.5wt.% and a b.p. of 150 to 400 deg.C is brought into contact with hydrogen in the presence of a catalyst for the hydrogenation treatment thereof under a pressure of 20 to lower than 45/cm at 200 to 300 deg.C to prepare a base of light diesel oil having a good hue of at least -10 in terms of Saybolt color and a good hue stability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a diesel gas oil base material having good hue and hue stability.

[0002]

2. Description of the Related Art At present, diesel gas oil in Japan is mainly produced by mixing straight-run gas oil, straight-run light oil fraction, straight-run kerosene fraction, etc. with desulfurized light oil fraction processed by a general desulfurization reactor. is doing. The JIS standard does not specify the hue of diesel diesel oil, but each oil company has its own Saybolt color, AS
Quality control is performed by setting a constant hue reference value such as TM color and APHA color. The petroleum industry tends to increase the capacity of heavy oil crackers in order to cope with the recent trend toward white oil. As a result, the gas oil fraction produced from the cracker (called petroleum gas oil) is expected to increase significantly in the future. However, petroleum-decomposed gas oil is rarely used in high-value-added diesel gas oil bases because of its extremely poor hue and hue stability, and almost all petroleum-decomposed gas oil is currently used as low-value-added heavy oil. Is. Therefore, in order to increase the added value of petroleum-decomposed gas oil having extremely poor hue and hue stability, petroleum-decomposed gas oil is required to have improved hue and hue stability.

[0003]

SUMMARY OF THE INVENTION The object of the present invention is to obtain a hue with a Saybolt color value from petroleum cracked gas oil having poor hue and hue stability, a sulfur content of 0.5% by weight or less and a boiling point of 150 to 400 ° C. It is to provide a method for producing a diesel gas oil base material having a hue stability of -10 or more (hue reference value) and good hue stability.

[0004]

DISCLOSURE OF THE INVENTION As a result of intensive studies for solving the above problems, the present inventors have found that diesel gas oil having good hue and hue stability can be obtained by hydrotreating petroleum cracked gas oil under specific conditions. The inventors have found that a base oil can be produced and completed the present invention. That is, in the present invention, a petroleum cracked gas oil having a sulfur content of 0.5% by weight or less and a boiling point of 150 to 400 ° C. is heated at a temperature of 200
The present invention relates to a method for producing a diesel gas oil base material having a Saybolt color value of -10 or more and having good hue and hue stability when brought into contact with hydrogen under conditions of ℃ to 300 ℃ and pressure of less than 20 to 45 kg / cm ² .

The petroleum cracked gas oil used in the present invention has a sulfur content of 0.
It is a petroleum-decomposed light oil having a boiling point of 150 to 400 ° C. and 5% by weight or less. Examples of the petroleum cracked gas oil include light oil obtained by distillation of fluid catalytic cracking (FCC) oil of petroleum such as heavy oil or light oil obtained by distillation of thermally cracked oil, or a mixed oil of these cracked light oils. When gas oil obtained by distillation of fluid catalytic cracking (FCC) oil and gas oil obtained by distillation of pyrolysis oil are mixed, the mixing ratio thereof is preferably 1:99 to 99: 1. In the present invention, gas oil obtained by distillation of fluid catalytic cracking (FCC) oil having a sulfur content of 0.1 to 0.5% by weight and a boiling point of 200 to 400 ° C is preferably used.

In the hydrotreatment of the present invention, the hue and hue stability of petroleum cracked gas oil are mainly improved, and as a result, some hydrodesulfurization is performed. The hydrotreating temperature of the present invention is 200 to 300 ° C, preferably 220 to 280.
C., particularly preferably in the range of 230 to 250.degree. Two
If the temperature is lower than 00 ° C, the hue is Seybolt color value -10
It is difficult to achieve the above (hue reference value). Thirty
If it exceeds 0 ° C, the hue and hue stability of the petroleum-decomposed gas oil will be poor. The hydrotreating temperature is the temperature at the outlet of the reaction bed catalyst layer. Hydrotreating pressure is 20 ~ 45kg / c
It is less than m ² , preferably in the range of 25-40 kg / cm ² . When it is lower than 20 kg / cm ² , the hue and color stability are not improved. Hydrotreating pressure is hydrogen partial pressure. Amount of petroleum-decomposed gas oil supplied (liquid space velocity) (L
HSV) is preferably 0.1 to 12 h ^-1 , particularly 4 to 8 h
^-1 is the preferred range. Hydrogen / oil ratio is 200-500
0 scf / bbl is preferable, especially 500 to 3000 s
cf / bbl is the preferred range.

As the hydrotreating catalyst, a catalyst usually used for hydrorefining petroleum distillate can be used. For example, alumina, silica, titania, boria,
Zirconia, silica-alumina, silica-magnesia,
Alumina-Magnesia, Alumina-Titania, Silica-
A catalyst in which a hydrogenation active metal is supported on a porous inorganic oxide such as titania, alumina-boria or alumina-zirconia is used. As the hydrogenation active metal, V
At least one metal selected from Group I, Group VI, and Group VIII iron group metals is used. Among these, at least one kind of hydrogenation active metal selected from the group consisting of chromium, molybdenum, tungsten, cobalt and nickel is preferable. These metals can be present on the support in the form of metals, oxides, sulfides or mixtures thereof.

In the present invention, it is particularly preferable to use a catalyst in which an active material of cobalt-molybdenum or nickel-molybdenum is supported on an alumina carrier. The amount of the active metal supported is preferably in the range of 1 to 30% by weight as an oxide. Particularly, the range of 3 to 20% by weight is preferable. The shape of the catalyst may be granular, tablet, or columnar. The hydrotreating catalyst may be pre-sulfided by a known method before use in hydrotreating.

The form of the hydrotreating reaction tower may be any of a fixed bed, a fluidized bed and an expansion bed, but a fixed bed is particularly preferable. Contact between hydrogen, petroleum distillate and the catalyst may be carried out in any of a cocurrent upflow, cocurrent downflow and countercurrent systems. After hydrotreating, the produced oil is gas-liquid separated by a separator as necessary, and the liquid substance is stripped,
Light components such as sulfur compounds such as hydrogen sulfide and nitrogen compounds such as ammonia may be separated.

[0010]

EXAMPLES The present invention will be described in more detail by way of examples, but the invention is not limited to the examples without departing from the gist of the present invention. Example 1 As a petroleum-decomposed gas oil, sulfur content 0.23% by weight, boiling point 15
Hydroprocessing was performed under the reaction conditions shown in Table 1 using light oil obtained by fluid catalytic cracking (FCC) in the range of 0 to 400 ° C. As the hydrotreating catalyst in the reaction tower, a commercially available catalyst in which 5 wt% CoO and 15 wt% MoO ₃ were supported on an alumina carrier was used. The catalyst was presulphurized by known methods. The results are shown in Table 1.

Example 2 As a petroleum-decomposed gas oil, sulfur content 0.23% by weight, boiling point 15
Hydroprocessing was performed under the reaction conditions shown in Table 1 using light oil obtained by fluid catalytic cracking (FCC) in the range of 0 to 400 ° C. As the hydrotreating catalyst in the reaction tower, a commercially available catalyst in which 5 wt% NiO and 15 wt% MoO ₃ were supported on an alumina carrier was used. The catalyst was presulphurized by known methods. The results are also shown in Table 1.

Example 3 As a petroleum-decomposed gas oil, a gas oil obtained by fluid catalytic cracking (FCC) having a sulfur content of 0.23% by weight and a boiling point in the range of 150 to 400 ° C. was used to produce hydrogen under the reaction conditions shown in Table 1. The chemical treatment was performed. For the hydrotreating catalyst in the reaction tower, 5 wt% CoO and 15 wt% MoO ₃ were used on an alumina carrier.
The commercially available catalyst carrying was used. The catalyst was presulphurized by known methods. The results are also shown in Table 1.

Example 4 As a petroleum-decomposed gas oil, sulfur content 0.23% by weight, boiling point 15
Hydroprocessing was performed under the reaction conditions shown in Table 1 using light oil obtained by thermal decomposition in the range of 0 to 400 ° C. For the hydrotreating catalyst of the reaction tower, 5 wt% NiO on an alumina carrier was used.
And a commercially available catalyst supporting 15% by weight of MoO ₃ was used. The catalyst was presulphurized by known methods. The results are also shown in Table 1. All the produced oils of Examples 1 to 4 retain the ASTM color L0.5 even after being left for 20 days in the dark at 50 ° C., and have good hue stability.

Comparative Example-1 In Comparative Example-1, a comparative experiment was carried out when the pressure in the reaction column did not satisfy the conditions of the present invention. The results are also shown in Table 1. As a result, the obtained oil hue did not pass the standard value. In order to pass the hue to the target value, pressure 20
More than kg / cm ² is required.

Comparative Example-2 In Comparative Example-2, a comparative experiment was conducted when the temperature of the reaction tower did not satisfy the conditions of the present invention. The results are also shown in Table 1. As a result, the obtained oil hue did not pass the standard value. To pass the hue to the target value, the temperature should be 20
0 ° C is required.

Comparative Example-3 In Comparative Example-3, a comparative experiment was carried out when the temperature of the reaction tower did not satisfy the conditions of the present invention. The results are also shown in Table 1. As a result, the obtained oil hue did not pass the standard value. In order to pass the hue to the target value, the temperature should be 30
0 ° C or lower is required. Light oils obtained by distillation of fluid catalytic cracking (FCC) oils were used as feedstocks for Comparative Examples 1 to 3.

Comparative Example-4 In Comparative Example-4, a comparative experiment was carried out in the case where the pressure and temperature of the reaction tower did not satisfy the conditions of the present invention. The results are also shown in Table 1. As a result, the obtained oil hue did not pass the standard value. In the hydrotreatment method of the present invention, a pressure of 20 kg /
cm ² or more, and the reaction temperature is 200 ° C. to 300 ° C.
It is necessary to set in the range of.

Comparative Example-5 In Comparative Example-5, a comparative experiment was carried out when the hydrogenation catalyst in the reaction column did not satisfy the conditions of the present invention. The results are also shown in Table 1. Diesel oil obtained by distillation of pyrolysis oil was used as the feedstock oil of Comparative Examples 4-5. As a result, in the case where the hydrotreating catalyst in the reaction tower is a noble metal-based catalyst, when hydrogen sulfide (0.2 vol% of hydrogen sulfide is present) is present in the reaction system, the hue improving effect is not recognized, and the hydrotreating method of the present invention has The hue improvement effect cannot be exhibited. Comparative Examples 1 to 5 All produced oils are 50
As a result of being left for 20 days in the dark at 0 ° C., the ASTM color of all the oils produced in Comparative Example deteriorated to L2.0, and the present invention is also effective for improving the hue stability.

As is clear from the examples and comparative examples, the commercially available diesel diesel oil has improved the hue and the hue stability of petroleum distillate distillates having significantly poor hue and hue stability under the commercial operating conditions. The hue improving method of the present invention is effective as a method for producing a substrate.

[0020]

[Table 1]

[0021]

According to the present invention, hue and hue stability are poor, sulfur content is 0.5% by weight or less, and boiling point is 150 to 400 ° C.
It is possible to produce a diesel gas oil base material having a hue with a Saybolt color value of −10 or more (hue reference value) and good hue stability from petroleum-decomposed gas oil in the range of ≦ 4.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ken Ushio 8 Chidori-cho, Naka-ku, Yokohama-shi Kanagawa Japan Central Oil Research Institute (72) Inventor Masaru Sato 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Central Research Institute of Nippon Oil Co., Ltd.

Claims (3)

[Claims] 1. A sulfur content of 0.5% by weight or less and a boiling point of 150 to
Petroleum cracked gas oil in the range of 400 ° C. in the presence of a hydrotreatment catalyst, temperature 200 ° C. to 300 ° C., pressure 20 to 45 kg
A method for producing a diesel gas oil base material having a hue of -10 or more in terms of Saybolt color value and having good hue and hue stability when contacted with hydrogen under a condition of less than / cm ² . 2. The fluid catalytic cracking (FC)
The method according to claim 1, which is C) a light oil obtained by distilling oil, a light oil obtained by distilling a pyrolysis oil, or a mixed oil of these cracked light oils. 3. The hydrotreating catalyst is a porous inorganic oxide carrier on which at least one hydrogenation-active metal selected from the group consisting of chromium, molybdenum, tungsten, cobalt and nickel is supported. The method described in 1.