JP5032805B2 - Method for producing ultra-low sulfur kerosene with excellent hue - Google Patents

Description

  The present invention relates to a method for producing an ultra-low sulfur kerosene excellent in hue by hydrogenation of a kerosene fraction.

Regulations to reduce the sulfur content of fuels, especially diesel fuels, have become more stringent in order to regulate SO _X and PM emissions from fuel combustion and to optimize the performance of exhaust gas treatment catalysts. In Japan, regulations to reduce the sulfur concentration of diesel oil, a diesel feedstock, to 50 mass ppm or less will begin in 2005, and regulations to lower to 10 mass ppm or less will begin in 2008. Since kerosene itself is used as a fuel and also as a blend base of light oil, it is required to reduce the sulfur concentration of kerosene to 10 ppm by mass or less at the same timing as light oil.

  Although the hue of kerosene is stipulated by JIS K 2203 as a Saybolt color of +25 or more, the actual situation is that each oil refinery company sets its own standards for Saybolt color and performs quality control. Many oil refining companies use Saybolt +30 or more as a standard.

  In general, desulfurized kerosene is a hydrocarbon oil with a 95 vol% distillation temperature in crude oil of 300 ° C or lower (so-called kerosene fraction) together with hydrogen under a pressure of 1.0 to 5.0 MPa and a temperature of 270 to 340 ° C. Processed and manufactured in contact with a hydrotreating catalyst. In kerosene hydrotreating, if the reaction temperature is raised to reduce the sulfur concentration in the product oil, there is a problem that the hue of the resulting product oil is significantly deteriorated. The target of kerosene desulfurization treatment is also set to a sulfur concentration of 50 ppm by mass or less, preferably 10 ppm by mass or less, and a hydroprocessing method that does not deteriorate the hue of the produced oil is required. The following prior art is disclosed with respect to such a subject.

  Patent Document 1 discloses that 95% by volume distillation temperature of 450 ° C. or less and 0.1% by mass or more of sulfur using a catalyst containing a Group 6B metal component, a Group 8 metal component and an organic additive on a support. Is disclosed in which a feed oil containing is hydrotreated in two stages to obtain a product oil having a sulfur content of less than 200 ppm by mass. According to this, a catalyst containing a Group 6B metal component, a Group 8 metal component, and an organic additive is effective in reducing the sulfur content of hydrocarbon oil to 200 ppm by mass or less. However, this document does not disclose a specific example of the two-stage hydrotreatment, and does not mention any improvement in the hue of the product oil.

  In Patent Document 2, a catalyst having nickel and / or cobalt, molybdenum and phosphorus supported on a refractory inorganic oxide support in the first reaction zone and having an average pore diameter of 70 to 150 mm is disposed. After the second reaction zone, nickel and / or cobalt, molybdenum and phosphorus are supported on the refractory inorganic oxide support, and the average pore diameter is 20 from the average pore diameter of the catalyst in the reaction zone immediately before the reaction zone. A gas oil hydrotreating method characterized in that a catalyst having a size of ~ 120 mm is arranged is disclosed. The reference also mentions a raw oil obtained by mixing a portion of kerosene with light oil, but does not mention only kerosene. In addition, there is no mention of the hue of the product oil.

Patent Document 3 discloses that diesel diesel oil is brought into contact with hydrogen in the presence of a hydrotreating catalyst at a specific temperature and a specific pressure, and has a sulfur content of 0.05% by weight or less and a hue of Saybolt color value. The present invention relates to a method comprising a first step of obtaining a product oil exceeding 10 and a second step of obtaining a product oil whose hue exceeds the Saebold color value of the hue of the first step. According to this, a diesel light oil having a low sulfur content and good hue and hue stability can be produced by subjecting the feedstock to a two-stage hydrotreatment under specific conditions. However, here too, the feedstock mentioned in the document is diesel light oil, and no mention is made of the kerosene fraction. Moreover, a pressure is 45-100 kg / cm < ² > among reaction conditions, Furthermore, it does not mention the low pressure conditions.

In Patent Document 4, a hydrotreated oil having a poor hue with a sulfur content of 0.4% by weight or less and containing a hue-degrading substance of −15 or less is hydrogenated in the presence of a hydrotreating catalyst. A method is disclosed in which a hydrotreated oil having a good hue with a Saybolt color of +15 or more is obtained. This is because a product oil having a poor hue desulfurized by a conventionally known hydrotreating catalyst is brought into contact with a conventionally known hydrotreating catalyst at a temperature lower than that in the first stage, so that the Saybolt color is +15 or more. An improved product oil is obtained. However, there is no mention of an ultra-deep desulfurization with a sulfur concentration of 10 mass ppm or less or a method for advanced hue improvement of Saybolt color +30 or more.
As mentioned above, although the method of reducing sulfur concentration by performing hydrodesulfurization in two stages is disclosed, the method for producing kerosene that reduces the sulfur concentration of the produced oil to 10 mass ppm or less and does not deteriorate the hue of the produced oil is disclosed. There are no examples.
JP 2000-313890 A JP 2004-43579 A JP-A-10-88153 JP-A-7-102267

  The subject of this invention is providing the manufacturing method of the kerosene which improves a hue significantly, keeping the sulfur concentration of produced | generated oil at 10 mass ppm or less. The kerosene produced by the method of the present invention is not only used as a fuel itself but also includes a so-called kerosene base material that can be used as a blend base material for petroleum products.

  As a result of the study, the present inventors have found a method for producing kerosene having excellent hue and ultra-low sulfur by combining a specific hydroprocessing catalyst with a specific kerosene fraction and performing hydroprocessing in two stages. The present invention has been completed.

  That is, according to the present invention, in the production of kerosene, a raw material oil containing 95% by volume or more of a kerosene fraction having a 95% by volume distillation temperature of 300 ° C. or lower is first periodically displayed in an inorganic porous carrier in the presence of hydrogen. Contact with a hydrotreating catalyst (first catalyst) containing a Group 6 metal component, a Group 9 metal component and an organic additive, and then the Group 6 metal component and Group 10 metal of the periodic table on the inorganic porous support It is the manufacturing method of the ultra-low sulfur kerosene excellent in the hue characterized by making it contact with the hydroprocessing catalyst (2nd catalyst) containing a component and an organic additive.

In the above production method, the volume ratio of the second catalyst is 10 to 70% by volume of the total volume of the first catalyst and the second catalyst.
Moreover, this invention is a manufacturing method of the kerosene which reduces the sulfur concentration of a kerosene fraction to 10 mass ppm or less, and is a manufacturing method of the kerosene whose Saybolt color is +30 or more.
Further, the above-described production method is characterized in that the hydrogenation treatment is performed at a hydrogen partial pressure of 2 to 5 MPa, a temperature of 270 ° C. or more, and T ° C. or less determined by the following formula.
T = 19.6 × ppH ₂ +256
[Wherein, ppH ₂ is a hydrogen partial pressure (MPa). ]

  By applying the kerosene production method of the present invention, it is possible to economically achieve ultra-deep desulfurization with a sulfur concentration of 10 mass ppm or less without consuming excessive hydrogen, and to obtain kerosene excellent in hue with a Saybolt color of +30 or more. It becomes possible to manufacture over a long period of time.

  Examples of the hydrotreating catalyst applied to the present invention include inorganic porous materials mainly composed of γ-alumina and the like obtained in JP-A-8-332385, JP-A-8-332386, or JP-A-2000-313890. Examples of the catalyst include molybdenum, tungsten, cobalt, nickel, phosphorus, etc. supported on a carrier, containing an organic additive, and dried only under the condition that the additive remains in the catalyst.

In the present invention, the catalyst (first catalyst) which is first brought into contact with the raw material oil among the above catalysts is a catalyst containing a Group 6 metal component and a Group 9 metal component of the periodic table, and then a Group 6 metal of the periodic table A catalyst containing the component and the Group 10 metal component (second catalyst) is brought into contact with the raw material oil.
Examples of the inorganic porous carrier used in the first catalyst and the second catalyst include alumina, silica, silica-alumina simple substance, composite oxides such as alumina and magnesia, boria, titania, zirconia, zinc oxide and phosphoric acid. A mixture of these compounds can be used, but those mainly composed of alumina are preferred. Regarding the form of alumina, α, θ, δ, κ, η, γ, χ type transition alumina, bayerite, gibbsite, boehmite, pseudo-boehmite, etc. These can be used alone or as a mixture. However, γ-alumina is preferred from the viewpoint of economy and practicality.

Examples of combinations of Group 6 metal components and Group 9 metal components of the first catalyst include molybdenum-cobalt, tungsten-cobalt, and molybdenum-tungsten-cobalt. From the viewpoints of activity and economy, molybdenum-cobalt. Is preferred.
On the other hand, examples of the Group 6 metal component and Group 10 metal component in the second catalyst include molybdenum-nickel, tungsten-nickel, and molybdenum-tungsten-nickel. From the viewpoint of activity and economy, molybdenum -Nickel combinations are preferred.

  The supported amount of the Group 6 metal component of the periodic table used in the first catalyst and the second catalyst is 5 to 50% by mass, preferably 15 to 30% by mass as an oxide with respect to the oxide catalyst not containing an organic additive. %. Similarly, the 9th and 10th group metal components of the periodic table also carry 1 to 10% by mass, preferably 2 to 8% by mass as oxides.

The organic additive contained in the first catalyst and the second catalyst is a polyvalent such as ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol (average molecular weight 200 to 600), polyvinyl alcohol, glycerin and the like. Alcohols and their ethers, esters, glucose, fructose, galactose, maltose, lactose, sucrose and other monosaccharides, disaccharides, formic acid, acetic acid, succinic acid, malonic acid, succinic acid, maleic acid, fumaric acid, tartaric acid, citric acid Acids, organic acids such as malic acid, gluconic acid and their salts, or ethylenediamine, ethylenediaminetetraacetic acid (EDTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), nitro B is selected from various chelating agents such as triacetic acid (NTA). These organic additives can be used alone or in combination of a plurality of compounds.
The organic additives contained in the first catalyst and the second catalyst may be different types of compounds as long as they are within the range of the above compounds.

  The added amount of the organic additive is 0.01 to 3 times the total number of moles of the Group 6 metal and the Group 9 and 10 metals of the periodic table, preferably 0.1 to 2.5 times the amount. is there. When the amount is less than 0.01 moles, the effect of improving the catalyst performance is not observed. When the amount exceeds 3 moles, the addition becomes difficult due to the thickening of the solution. In addition, catalyst activity is reduced due to excess carbon deposition during presulfidation.

  When preparing hydrogenated active metal solutions, mineral acids such as boric acid, nitric acid, sulfuric acid, hydrochloric acid, hydrofluoric acid, and phosphoric acid are added to improve the liquid stability and hydrogenation activity. Also good. When using a non-volatile mineral acid such as sulfuric acid, boric acid, phosphoric acid, the oxide can be added in an amount of 0.5 to 15% by mass, preferably 1 to 10% by mass based on the oxide catalyst. .

Usually, the first catalyst and the second catalyst are packed in a reaction tower. As a filling method, a method in which a first catalyst is packed in a front stage of a single reaction tower and a second catalyst is packed in a rear stage, a plurality of reactions A method of packing the first catalyst and the second catalyst separately in each column can be exemplified. In the latter method, when the first catalyst and the second catalyst are packed in the same reaction tower, for example, the first catalyst is packed in the first reaction tower and the first stage of the second reaction tower connected to the same tower. In addition, a case where the second catalyst is packed in the rear stage of the second reaction column is also included.
The filling volume ratio of the first catalyst to the second catalyst is such that the volume ratio of the second catalyst is 10 to 70% by volume, preferably 20 to 60% by volume, particularly preferably 30% of the total volume of the first catalyst and the second catalyst. ~ 50% by volume.
If the amount is less than 10% by volume, there is no effect in improving the hue of the produced oil. If the amount exceeds 70% by volume, the hydrogen consumption is increased, making economical operation difficult.

  The upper limit of the raw material oil applied to the present invention is 0.1 to 1.0% by mass of sulfur, Saebold color +20 to 35, and 95% by volume distillation temperature of 300 ° C. or lower, preferably 270 ° C. or lower. It is a kerosene fraction. As kerosene fractions, in addition to straight-run kerosene, kerosene fractions obtained from thermal cracking equipment, hydrocracking equipment, distillate oil, residual oil hydrotreating equipment, and the like can be used. A kerosene fraction having a 95% by volume distillation temperature exceeding 300 ° C. may be mixed in the feedstock at a rate of 5% by volume or less.

  The first catalyst and the second catalyst are preferably presulfurized and used by a known method before being used for the hydrotreatment. Examples of the reaction tower used for the hydrogenation treatment include a fixed bed, a moving bed, and a boiling bed, but a fixed bed type reaction tower is preferred.

The hydrotreating conditions applied to the present invention are not particularly limited, and generally applied hydrodesulfurization conditions for kerosene, for example, hydrogen partial pressure of 1 to 6 MPa, preferably 2 to 5 MPa, liquid space velocity of 0. Examples include ^{1 to} 10 hr ⁻¹ , preferably ¹ to 7 hr ⁻¹ , hydrogen / feed oil ratio of 40 to 200 Nm ³ / kl, preferably 50 to 150 Nm ³ / kl. In addition, about reaction temperature, a driving | running upper limit temperature is determined by the coloring temperature of the product oil (temperature in which the Saebold color of product oil becomes less than +30). This coloring temperature is strongly influenced by the hydrogen partial pressure, and in the region where the hydrogen partial pressure is 2 to 5 MPa, the following relationship is generally found between the coloring temperature of the product oil and the hydrogen partial pressure. The operation upper limit temperature can be estimated from the pressure.
T = 19.6 × ppH ₂ +256
[T: coloring temperature (° C.), ppH ₂ : hydrogen partial pressure (MPa)]

In addition, about the minimum reaction temperature, 270 degreeC or more, Preferably 280 degreeC or more is mentioned. This is because if the temperature is lower than 270 ° C., the desulfurization reaction proceeds slowly and it becomes difficult to produce an ultra-low sulfur kerosene having a sulfur concentration of 10 mass ppm or less.
In addition, the first-stage hydrotreating performed using the first catalyst and the second-stage hydrotreating performed using the second catalyst are performed under different conditions as long as they are within the above conditions. May be.

  After the hydrogenation treatment, the product oil is gas-liquid separated with a separator, and the liquid substance is stripped to separate light components such as sulfur compounds such as hydrogen sulfide and nitrogen compounds such as ammonia, and the sulfur concentration is 10 mass. A kerosene having a good hue with a ppm or less and a Saybolt color of +30 or more is obtained. In order to improve the desulfurization performance and the color of the treated oil, it is preferable to perform a hydrogenation treatment under conditions of a high hydrogen partial pressure and a high hydrogen flow rate, and this also applies to the present invention.

  EXAMPLES Examples will be described below to clarify the effects of the present invention, but these do not limit the present invention.

[Example 1]
(1) Preparation of the first catalyst 313 g of molybdenum trioxide, 90 g of cobalt carbonate, 68 g of 85% phosphoric acid, and 146 g of polyethylene glycol (# 200) (0.25 mol per mol of molybdenum and cobalt) were dissolved in water. The impregnating solution thus obtained was impregnated into 1 kg of a γ-alumina molded carrier, and then dried at 100 ° C. for 16 hours to be used as a first catalyst, a CoO—MoO ₃ catalyst (MoO ₃ = 22% by mass, CoO = 4). Mass%, P ₂ O ₅ = 3 mass%).

(2) Preparation of second catalyst Impregnating solution obtained by dissolving 324 g of molybdenum trioxide, 111 g of nickel carbonate, 143 g of 85% phosphoric acid, and 81 g of diethylene glycol (0.25 moles with respect to molybdenum and nickel) in water. Is impregnated in 1 kg of a γ-alumina molded carrier, and dried at 100 ° C. for 16 hours to be used as a second catalyst. NiO—MoO ₃ -based catalyst (MoO ₃ = 22 mass%, NiO = 4 mass%, P ₂ O ₅ = 6% by mass) was prepared.

(3) Catalyst filling and hydrogenation treatment In a fixed bed flow reactor, the CoO-MoO ₃ catalyst and the NiO-MoO ₃ catalyst at a volume ratio of 7: 3, and the CoO-MoO ₃ catalyst in the previous stage The NiO—MoO ₃ catalyst was packed in the subsequent stage.
Next, preliminary sulfidation was performed with a sulfurized oil obtained by adding dimethyl disulfide as a sulfur content to a kerosene fraction (sulfur concentration: 0.26 mass%, 95 vol% distillation temperature 265 ° C) as a sulfur content.
Next, as a raw material oil, a hydrogenation test was conducted by passing a kerosene fraction having a sulfur content of 0.33 mass% and a Saybolt color +24.

The reaction conditions of the hydrotreatment are such that the hydrogen pressure is 4.0 MPa, the hydrogen / oil ratio is 100 Nm ³ / kl, the liquid space velocity is 7.0 hr ^−1, and the product oil having a sulfur concentration of 7 mass ppm is obtained in both the first and second stages. The reaction temperature was adjusted.
Table 2 shows the test results 14 days after the start of the test when the catalyst performance was stable. The sulfur concentration and Saybolt color of the product oil were analyzed using the same analysis method and apparatus as the raw material oil.

[Comparative Example 1]
A fixed bed flow reactor was filled with only the same CoO—MoO ₃ catalyst as in Example 1, and the same hydrotreating test as in Example 1 was performed. The results are shown in Table 2.

  From Table 2, it was found that in Example 1 based on the present invention, kerosene having a very good hue with a Saybolt color of +30 or more was obtained even when the same ultra-deep desulfurization was carried out as compared with Comparative Example 1. Furthermore, since Example 1 achieves ultra-deep desulfurization at a temperature 6 ° C. lower than that of Comparative Example 1, using the method of the present invention, an ultra-low sulfur kerosene excellent in hue over a long period of time compared to the conventional method. It can be seen that the production of

Claims (4)

In the production of kerosene, a feedstock containing 95% by volume or more of a kerosene fraction having a 95% by volume distillation temperature of 300 ° C. or lower is first added to the inorganic porous carrier in the presence of hydrogen, and a periodic table Group 6 metal component; Contacting with a hydrotreating catalyst (first catalyst) comprising a Group 9 metal component and a polyhydric alcohol ;
Next, the inorganic porous carrier is contacted with a hydrotreating catalyst (second catalyst) containing a Group 6 metal component, a Group 10 metal component and a polyhydric alcohol in the periodic table,
Here, the volume ratio of the second catalyst is 30 to 50 % by volume of the total capacity of the first catalyst and the second catalyst. A method for producing an ultra-low sulfur kerosene excellent in hue. Method for producing a kerosene of claim 1 wherein for reducing the sulfur concentration of the kerosene fraction below 10 mass ppm. The method for producing kerosene according to any one of claims 1 and 2 , wherein the kerosene has a Saybolt color of +30 or more. The method for producing kerosene according to any one of claims 1 to 3 , wherein the hydrogenation treatment is performed at a hydrogen partial pressure of 2 to 5 MPa, a temperature of 270 ° C or more, and T ° C or less determined by the following formula. .
T = 19.6 × ppH ₂ +256
[Wherein, ppH ₂ is a hydrogen partial pressure (MPa). ]