JPH0625677A - Production of low-sulfur diesel gas oil - Google Patents

Abstract

PURPOSE:To produce a diesel gas oil having a sulfur content of 0.05wt.% or below (target sulfur content) and a hue of 0 or above (in terms of Saybolt color) (standard hue) from a petroleum distillation residue having a sulfur content of 0.5-2.0wt.% and a boiling point in the range of 200-400 deg.C. CONSTITUTION:This production process comprises the step 1 of bringing the above petroleum distillation residue into contact with hydrogen under conditions of a temperature of 371-450 deg.C and a pressure of 10 to <45kg/cm<2> in the presence of a hydrotreatment catalyst to decrease the sulfur content to 0.05wt.% or below and the step 2 of bringing the hydrotreated oil from the step 1 into contact with hydrogen in the presence of a hydrotreatment catalyst under conditions of a temperature of 200-300 deg.C and a pressure of 10 to <45kg/cm<2> to decrease the sulfur content to 0.05wt.% or below and to increase the hue to 0 or above in terms of Saybolt color.

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 diesel gas oil having a low sulfur content and a good hue from petroleum distillate.

[0002]

2. Description of the Related Art Conventionally, in the production of diesel gas oil in Japan, a straight-run gas oil fraction, a straight-run gas oil fraction, and a straight-run kerosene fraction are mainly processed by a general desulfurization reactor. Gas oil fractions obtained from the cracker are mixed to give sulfur content of 0.4-
It produces 0.5% by weight of diesel fuel oil. However, due to recent domestic environmental problems, reduction of NOx and particulate matter in exhaust gas of diesel vehicles is required.

Therefore, the sulfur content in diesel gas oil is changed from the current 0.4 to 0.5 wt% to 0.2 wt% (first stage desulfurization target value), and then 0.05 wt% (second stage). The petroleum industry is required to gradually reduce the desulfurization target value). In addition, although the hue standard is not specified, each oil company has its own Saybolt color, ASTM color, APH color.
Quality control is performed by setting a constant hue reference value for A color and the like.

A two-stage hydrotreatment method has been proposed in order to achieve a sulfur content in diesel gas oil of 0.2% by weight, which is the first stage desulfurization target value (JP-A-3-86793). Under the reaction conditions of this method, it is difficult to achieve the target sulfur content of 0.05% by weight in the second stage desulfurization. Furthermore, at a temperature within the range of 150 to 325 [deg.] C. of the second reaction column, particularly below 200 [deg.] C., the sulfur content of 0.
It is difficult to improve the hue of desulfurized oils treated at higher temperatures to achieve 05% by weight.

[0005]

The object of the present invention is to obtain a sulfur content of 0.5 to 2.0% by weight and a sulfur content of 0.05% by weight or less (from a petroleum distillate having a boiling point of 200 to 400 ° C). It is intended to provide a method for producing a diesel gas oil having a desulfurization target value) and a hue of 0 or more (Sauebol color value) (hue reference value).

[0006]

[Means for Solving the Problems] As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a petroleum distillate distillate is subjected to a two-stage hydrotreatment under specific conditions to obtain a low sulfur content,
Moreover, they have found that diesel light oil having a good hue can be produced and completed the present invention.

That is, the present invention has a sulfur content of 0.5 to 2.0.
% Petroleum distillate having a boiling point of 200 to 400 ° C. in the presence of a hydrotreating catalyst at a temperature of 371 to 450
The presence of a hydrotreating catalyst in a first step of bringing the sulfur content into 0.05 wt% or less by bringing it into contact with hydrogen under the conditions of ° C and a pressure of less than 10 to 45 kg / cm ^2. Under temperature 200 ~ 300 ℃, pressure 10 ~ 45 Kg /
The present invention relates to a method for producing a low-sulfur diesel gas oil, which comprises a second step of bringing the sulfur content into 0.05% by weight or less and the hue to a Saybolt color value of 0 or more by contacting with hydrogen under a condition of cm ² .

The petroleum distillate used in the present invention is a petroleum distillate having a sulfur content of 0.5 to 2.0% by weight and a boiling point of 200 to 400 ° C. Examples of the petroleum distillate distillate oil include distillate oil obtained by atmospheric distillation or reduced pressure distillation of crude oil, distillate oil obtained by fluid catalytic cracking (FCC), distillate oil obtained by thermal cracking, and the like. In the present invention, a distillate oil having a sulfur content of 0.5 to 2.0% by weight and a boiling point of 200 to 400 ° C. obtained by atmospheric distillation of crude oil is preferably used.

In the present invention, the petroleum distillate distillate oil is mainly hydrodesulfurized in the first step, and the hue of the desulfurized oil is mainly improved in the second step.

The hydrotreating temperature in the first step of the present invention is 37.
It is in the range of 1 to 450 ° C, preferably 371 to 420 ° C. When the temperature is lower than 371 ° C, it is difficult to achieve the target sulfur content of 0.05% by weight in the second stage desulfurization. 45
When the temperature exceeds 0 ° C, the hydrotreated oil is highly colored, and the hue in the second step is 0 or more in the diesel color value (hue reference value)
Is difficult to achieve. The hydrotreating temperature of the first step is the reaction tower average temperature (WABT).

[0011] First hydrotreatment pressure steps 10-45 below Kg / cm ^2, preferably in the range of 25~35Kg / cm ^2. When it is lower than 10 kg / cm ^2, it is difficult to achieve the sulfur content of 0.05% by weight as the second stage desulfurization target value. The hydrotreating pressure in the first step is the hydrogen partial pressure.

The feed amount (liquid hourly space velocity) (LHSV) of petroleum distillate in the first step is preferably ¹ to 10 h ^-1 , and particularly preferably 4 to 10 h ^-1 . Hydrogen in the first step /
The oil ratio is preferably 200 to 3000 scf / bbl, and particularly preferably 400 to 3000 scf / bbl.

As the hydrotreating catalyst in the first step, 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-titania, alumina-boria, alumina-
A catalyst in which an active metal is supported on a porous inorganic oxide carrier such as zirconia is used.

Examples of the active metal include VI and VI of the periodic table.
At least one metal selected from Group VIII iron group metals is used. Examples thereof include vanadium, chromium, molybdenum, tungsten, cobalt, nickel and the like. 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 a cobalt-molybdenum active metal is supported on an alumina carrier. The supported amount of the active metal is preferably in the range of 3 to 20% by weight as an oxide.

The shape of the catalyst may be granular, tablet, or columnar. The hydrotreating catalyst in the first step may be pre-sulfurized by a known method before use for hydrotreating.

The form of the hydrotreating reaction tower in the first step may be any of a fixed bed, a fluidized bed and an expanded bed, but a fixed bed is particularly preferable. The contact of hydrogen, petroleum distillate and oil in the first step and the catalyst may be carried out by any method of cocurrent upflow, cocurrent downflow and countercurrent. In the present invention, the sulfur content can be reduced to 0.05% by weight or less by the hydrogenation treatment in the first step.

After the hydrotreatment in the first step, the produced oil is directly supplied to the second step for hydrotreatment. If necessary, stripping or separation of light components may be performed before feeding to the second step.

The hydrotreating temperature in the second step of the present invention is 20.
It is in the range of 0 to 300 ° C, preferably 200 to 280 ° C. When the temperature is lower than 200 ° C., it is difficult to achieve a hue of 0 or more (Hue reference value) in the second step. If the temperature exceeds 300 ° C., it is difficult to achieve a hue of 0 or more (Hue reference value) in the second step.

The hydrotreating temperature in the second step is the temperature of the highest temperature part of the reaction column (generally near the outlet of the reaction column).

[0020] Second hydrotreatment pressure steps 10-45 below Kg / cm ^2, preferably in the range of 25~35Kg / cm ^2. Further, the pressure in the second step is preferably equal to or higher than that in the first step. If it is lower than 10 kg / cm ^2, it is difficult to achieve a hue of 0 or more (Hue reference value) in the second step. The hydrotreating pressure in the second step is the hydrogen partial pressure.

The hydrogen partial pressure in the second step is preferably equal to or higher than that in the first step. Supply amount (liquid hourly space velocity) (LHSV) of petroleum distillate distillate in the second step is ^{1 to} 20 h ^-1
Is preferable, and 4 to 20 h ^-1 is particularly preferable.
The hydrogen / oil ratio of the second step is 200 to 3000 scf / bb
1 is preferable, and 400 to 3000 scf / bbl is a particularly preferable range.

As the hydrotreating catalyst in the second step, the same catalyst as that used in the first step can be used. The hydrotreating catalyst in the second step may be pre-sulfided before use in hydrotreating.

The form of the hydrotreating reaction column in the second step may be any of a fixed bed, a fluidized bed and an expansion bed, but a fixed bed is particularly preferable. In the second step, the contact between hydrogen, petroleum distillate and the catalyst may be carried out in any of a cocurrent upflow, cocurrent downflow and countercurrent systems. Although the present invention uses the first step and the second step in series, it is not limited to the continuous operation, and the operation corresponding to the first step and the operation corresponding to the second step can be separately performed.

When the hydrogen partial pressures of the first step and the second step are almost the same, the temperature of the second step is lower than the temperature of the first step, but the hydrogen partial pressure of the second step is higher than that of the first step. This is not the case if is high. After the hydrotreatment in the second step, the produced oil may be subjected to stripping or separation of light components, if necessary. INDUSTRIAL APPLICABILITY According to the present invention, a diesel diesel oil having a sulfur content of 0.05% by weight or less and a hue with a Seybold color value of 0 or more can be produced by the first step and the second step. The present invention will be described in more detail below, but the present invention is not limited to these examples without departing from the gist of the present invention.

[0025]

【Example】

Examples-1 to 3 As petroleum distillation distillate oil, sulfur content 1.1% by weight, boiling point 20
Two-stage hydrotreatment was carried out under the reaction conditions shown in Table 1 using atmospheric straight-run light oil in the range of 0 to 400 ° C. For the hydrotreating catalyst in the first step and the second step, 5 wt% C was added to the alumina carrier.
A commercially available catalyst supporting oO and 15 wt% MoO ₃ was used. The catalyst was presulphurized by known methods. The reaction towers of the first step and the second step were arranged in series and continuously hydrotreated. The results are shown in Table 1. According to this, the obtained product gas oil passed the desulfurization target value of sulfur content and the standard value of hue.

Comparative Examples-1 to 4 As petroleum distillate, 1.1% by weight of sulfur and 20 in boiling point
Two-stage hydrotreatment was carried out under the reaction conditions shown in Table 1 using atmospheric straight-run light oil in the range of 0 to 400 ° C. For the hydrotreating catalyst in the first step and the second step, 5 wt% C was added to the alumina carrier.
A commercially available catalyst supporting oO and 15 wt% MoO ₃ was used. The catalyst was presulphurized by known methods. The reaction towers of the first step and the second step were arranged in series and continuously hydrotreated. The results are also shown in Table 1.

[0027]

[Table 1]

Comparative Example 1 was conducted to clarify the effect of the low temperature treatment in the first step. As a result, the hue of the obtained product light oil passed the standard value, but the sulfur content failed the desulfurization target value. In Comparative Example-2, the sulfur content of the product gas oil obtained passed the desulfurization target value, but the hue failed the standard value. In Comparative Example-3, the hue of the obtained product gas oil passed the standard value, but the sulfur content failed the desulfurization target value. Further, the degree of desulfurization is inferior to Comparative Example-2, and the superiority of the two-stage hydrotreatment method is not recognized. In Comparative Example-4, the sulfur content of the obtained product gas oil passed the defluent target value, but the hue failed the standard value.

As is clear from the examples and comparative examples,
In order to pass the sulfur content of 0.05% by weight or less of the desulfurization target value, the reaction temperature of the first step must be 371 ° C or higher, and in order to pass the hue to the reference value, the reaction temperature of the second step. Is required to be 200 ° C. or higher.

[0030]

Industrial Applicability According to the present invention, a petroleum distillate having a sulfur content of 0.5 to 2.0% by weight and a boiling point of 200 to 400 ° C. and a sulfur content of 0.05% by weight or less (desulfurization target value), Further, it is possible to produce a diesel gas oil having a hue of 0 or more in terms of the Saybolt color value (hue reference value).

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

Claims (1)

[Claims] 1. A sulfur content of 0.5 to 2.0% by weight and a boiling point of 20.
Petroleum distillation distillate oil in the range of 0 to 400 ° C., in the presence of a hydrotreatment catalyst, temperature 371 to 450 ° C., pressure 10 to 45
Under a condition of less than Kg / cm ² , the first step to bring the sulfur content to 0.05 wt% or less by contacting with hydrogen, and the hydrotreated oil of the first step in the presence of a hydrotreatment catalyst at a temperature of 200 to 30.
Low-sulfur diesel consisting of a second step of bringing hydrogen into contact with hydrogen under conditions of 0 ° C. and a pressure of 10 to less than 45 kg / cm ² to make the sulfur content 0.05 wt% or less and the hue to be 0 or more in the Saybolt color value. A method for producing light oil.