JP2008101214A - Method for producing environmentally friendly light oil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an environmentally friendly light oil having sufficiently low sulfur and aromatic contents and being ensured to have practically sufficient low temperature performance and calorific value, and a method for producing it. <P>SOLUTION: The environmentally friendly light oil has a density of 0.78 g/cm<SP>3</SP>or higher, a sulfur content of 1 ppm by mass or less, a clouding point of -10°C or lower, a clogging point of -5°C or lower, a 10% distillation temperature of 200°C or higher, a 90% distillation temperature of 340°C or lower, a 10-13C normal paraffin content of 2.0% by mass or less, a 14-21C normal paraffin content of 8.0% by mass or less, a 24C or larger normal paraffin content of 0.1% or less, and an aromatic content of 5% by mass or less. The method for producing such the environmentally friendly light oil as this comprises performing catalytic hydrocracking and isomerizing a normal paraffin raw material and fractionating the thus generated oil to obtain a light oil fraction with a 10% distillation temperature of 200°C or higher and a 90% distillation temperature of 340°C or lower. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an environmentally friendly light oil with reduced environmental impact and a method for producing the same, and more specifically, a light oil that ensures sufficient low-temperature characteristics and heat generation while considering environmental problems by reducing sulfur content and aromatic content. And a manufacturing method thereof.

  In recent years, various ideas have been added to the diesel automobile technology due to increasing environmental problems, and there is a demand for reduction of sulfur and aromatics in light oil used as fuel. It is difficult to reduce the sulfur content to 1 mass ppm or less and the aromatic content to 5 mass% or less from petroleum gas oil by the existing hydrorefining technology.

  On the other hand, according to the Fischer-Tropsch method, the main component is normal paraffin from synthesis gas (consisting of hydrogen and carbon monoxide) obtained by reforming natural gas and the like, and hardly contains sulfur and aromatics. Hydrocarbons can be synthesized. In recent years, the production of synthetic light oil using this synthesized hydrocarbon as a raw material has attracted attention (see, for example, Patent Documents 1 to 7). However, although such synthetic light oil has a sufficiently low sulfur content and aromatic content, the low temperature performance is not sufficient and the calorific value is low as compared with petroleum light oil.

Japanese National Patent Publication No. 11-513729 Japanese National Patent Publication No. 11-513730 JP-T-2001-511207 Special table 2001-522382 gazette Special table 2002-507635 gazette Japanese translation of PCT publication No. 2002-526636 Japanese translation of PCT publication No. 2002-526637

  The present invention solves such problems, and provides an environment-friendly diesel oil having a sufficiently low sulfur content and aromatic content, and having a practically sufficient low-temperature performance and calorific value, and a method for producing the same. Is an issue.

  The present inventors have produced such a problem by producing light oil using a specific fraction of the product oil obtained by hydrocracking and isomerizing a normal paraffin as a raw material using a specific catalyst. The present invention has been completed.

  The method for producing an environmentally-friendly light oil according to the present invention includes a step of obtaining a product oil from a normal paraffin raw material by hydrocracking and isomerization using a catalyst in which a hydrogenation active metal is supported on a support containing silica alumina, A method for producing an environmentally-friendly light oil comprising a step of fractionating a product oil to obtain a light oil fraction having a 10% distillation temperature of 200 ° C. or higher and a 90% distillation temperature of 340 ° C. or lower, in particular, the normal paraffin The raw material is preferably synthesized by the Fischer-Tropsch method.

Moreover, the environmentally friendly light oil according to the present invention has a density of 0.78 g / cm ³ or more, a sulfur content of 1 mass ppm or less, a cloud point of −10 ° C. or less, a clogging point of −5 ° C. or less, and a 10% distillation temperature. Is 200 ° C or higher, 90% distillation temperature is 340 ° C or lower, C10-13 normal paraffin content is 2.0 mass% or less, and C14-14 normal paraffin content is 8.0 mass% or less. The content of normal paraffin having 24 or more carbon atoms is 0.1% or less and the aromatic content is 5% by mass or less.

  The environment-friendly light oil according to the present invention has specific properties, has specific distillation characteristics, and has a specific normal paraffin content distribution, and therefore has a particularly low sulfur content and aromatic content, At the same time, since it has sufficient low-temperature performance and calorific value, the present invention makes it possible to provide environmentally friendly light oil that is excellent in practical performance and excellent in environmental conservation.

[Normal paraffin raw materials]
As the normal paraffin raw material used in the production method of the present invention, light normal paraffin is low in hydrocracking and isomerization reactivity. Specifically, it is preferable to use a raw material having an initial boiling point of 300 ° C. or higher, particularly 310 ° C. or higher, and a 10% distillation temperature of 350 ° C. or higher, particularly 360 ° C. or higher. In addition, since the heavy component of the normal paraffin raw material is converted into normal paraffin of a light oil fraction by decomposition, it is preferable to cut a fraction that is too heavy by distillation or the like. Is preferably 590 ° C. or lower, and the 90% distillation temperature is preferably 560 ° C. or lower, particularly 550 ° C. or lower. By these, the reaction rate of hydrocracking and isomerization and the light oil yield can be increased.

The normal paraffin content in the normal paraffin raw material is preferably 85% by mass or more, particularly preferably 95% by mass or more. The impurity content is preferably a sulfur content of 500 ppm or less, particularly 50 ppm or less, and a nitrogen content of 100 ppm or less, particularly 10 ppm or less.
As the normal paraffin raw material, those having the above properties can be preferably used. Although there is no particular limitation on the type, slack wax obtained from a petroleum refining process, for example, a solvent dewaxing process, which is one of lubricating oil production processes, or a synthetic wax synthesized by the Fischer-Tropsch method is used. Can do. There are various types of these waxes, but they may be used singly or in combination of two or more, or a mixture of slack wax and synthetic wax may be used. In particular, it is preferable to use a synthetic wax by Fischer-Tropsch method alone. Note that the Fischer-Tropsch method is a method in which carbon monoxide and hydrogen are reacted using a catalyst to synthesize mainly normal paraffin or a small amount of olefin or alcohol.

〔catalyst〕
The catalyst used in the method for producing environmentally friendly light oil of the present invention is a catalyst in which a hydrogenation active metal is supported on a carrier containing silica alumina. For example, a catalyst disclosed in JP-T-2002-523231 or Patent No. 291047 is preferably used.

  In the production method of the present invention, a carrier that can be preferably used is a carrier made of an inorganic porous oxide containing silica alumina. Silica alumina is preferably formed on a carrier using alumina as a binder. Silica alumina can be amorphous or crystalline, but is preferably amorphous. The range of the silica / alumina molar ratio of amorphous silica alumina is preferably 3-8. The support preferably contains no oxide other than aluminum and silicon, but may contain magnesia, zirconia, boria, calcia, and the like.

  Although there is no restriction | limiting in particular in the hydrogenation active metal carry | supported, It is preferable that 1 type, or 2 or more types of metal components chosen from the 6th group, the 9th group, and the 10th group of a periodic table are included. Examples of the metal selected from Group 6, Group 9, and Group 10 include molybdenum, tungsten, cobalt, rhodium, iridium, nickel, platinum, and palladium, and particularly non-noble metals such as molybdenum, tungsten, cobalt, and nickel. It is preferably used as a hydrogenation active component. The supported amount of the hydrogenation active metal is preferably added and supported so that the total amount of metal elements is 0.05 to 35% by mass, particularly 0.1 to 30% by mass.

[Hydrolysis and isomerization]
In the hydrocracking and isomerization used in the production method of the present invention, the reaction temperature is 300 to 400 ° C., particularly 320 to 350 ° C., the hydrogen pressure is 1 to 20 MPa, particularly 3 to 9 MPa, and the hydrogen / oil ratio is 100 to 100. It is preferable to perform the reaction under the reaction conditions of 2000 NL / L, particularly 300 to 1500 NL / L, and the liquid space velocity (LHSV) is 0.5 to 5 hr ⁻¹ .

  In the normal paraffin raw material, the ratio of components higher than 360 ° C. is defined as the decomposition rate, and in order to increase the isomerization rate and yield of the gas oil fraction, the decomposition rate is 50-85. Mass% is preferred. When the decomposition rate exceeds 85% by mass, the light oil fraction causes secondary decomposition.

[Light oil fraction]
In the production method of the present invention, light oil having a 10% distillation temperature of 200 ° C. or higher, preferably 240 ° C. or higher, and a 90% distillation temperature of 340 ° C. or lower, preferably 330 ° C. or lower, from the oil produced by the hydrocracking and isomerization steps. Fraction distillate. A fraction heavier than this diesel oil fraction can be used again as a raw material.

[Combination]
In the production method of the present invention, the above light oil fraction can be used as a light oil as it is or as a light oil base for preparing a product light oil by mixing with another light oil base. Examples of other light oil base materials include base materials for blending kerosene, light oil, semi-finished products, intermediate products, and the like produced by refining crude oil. Moreover, vegetable oil methyl ester etc. can be mix | blended as another light oil base material. When preparing a light oil by blending the light oil fraction of the present invention with another light oil base, it can be blended in an appropriate ratio so as to be a light oil of a desired quality. The ratio is preferably 20% by mass or less, particularly 5 to 15% by mass.

As additives to light oil, known fuel additives such as low-temperature fluidity improvers, wear resistance improvers, cetane number improvers, antioxidants, metal deactivators, and corrosion inhibitors may be added. Good. As the low temperature fluidity improver, an ethylene copolymer or the like can be used. In particular, a vinyl ester of a saturated fatty acid such as vinyl acetate, vinyl propionate or vinyl butyrate is preferably used. As the wear resistance improver, a long chain (for example, having 12 to 24 carbon atoms) fatty acid or fatty acid ester thereof is preferably used. The wear resistance is sufficiently improved by the addition amount of 10 to 500 ppm, preferably 50 to 100 ppm.

[Environmentally friendly diesel]
The environment-friendly light oil according to the present invention has a density (15 ° C.) of 0.78 g / cm ³ or more, preferably 0.785 to 0.815 g / cm ³ , a sulfur content of 1 mass ppm or less, and an aromatic content of 5 mass%. Hereinafter, it is preferably 2% by mass or less.

  The low temperature characteristics of the environmentally friendly light oil according to the present invention have a cloud point of −10 ° C. or lower, preferably −15 ° C. to −35 ° C., and a clogging point of −5 ° C. or lower, preferably −15 ° C. to −30 ° C. The pour point is preferably −10 ° C. or lower, particularly preferably −25 ° C. to −50 ° C.

  The distillation properties of the environment-friendly light oil according to the present invention have a 10% distillation temperature of 200 ° C or higher, preferably 250 ° C to 290 ° C, and a 90% distillation temperature of 340 ° C or lower, preferably 300 ° C to 335 ° C.

  The normal paraffin content of the environment-friendly light oil according to the present invention is such that the normal paraffin content of 10 to 13 carbon atoms is 2.0 mass% or less, preferably 1.0 mass% or less, and the normal paraffin content of 14 to 21 carbon atoms. Is 8.0 mass% or less, preferably 5.0 mass% or less, and the content of normal paraffin having 24 or more carbon atoms is 0.1 mass% or less, preferably including normal paraffin having 24 or more carbon atoms. Not.

EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is limited and is not interpreted by this Example.

[Preparation of catalyst A]
Silica alumina powder and pseudo boehmite powder were mixed, kneaded, formed into a cylinder, dried, and fired at 600 ° C. to prepare a carrier. This carrier was composed of 80% by mass of silica alumina and 20% by mass of alumina on a dry carrier basis, and had a cylindrical shape having a diameter of about 1.6 mm. As the silica-alumina powder, a powder having a silica / alumina molar ratio of 4.4, an agglomerated particle diameter of 1 to 10 μm, 94.4% by mass and ignition loss of 16.9% by mass was used.

  This support was impregnated with an aqueous solution containing ammonium metatungstate and an aqueous solution containing nickel nitrate, dried, and calcined at 500 ° C., whereby 11.0% by mass of tungsten and 1.0% of nickel were added to the catalyst. Catalyst A containing mass% was prepared.

[Preparation of catalyst B]
A carrier was prepared by mixing and kneading mordenite powder and pseudoboehmite powder, forming into a cylindrical shape, drying, and firing at 600 ° C. This carrier was composed of 7% by mass of mordenite and 93% by mass of alumina on a dry carrier basis, and was in the shape of a cylinder having a diameter of 1.4 mm. As the mordenite powder, a powder having a silica / alumina molar ratio of 210 and a zeolite pore major diameter of 7.0 angstroms was used.
This support was impregnated with an aqueous solution containing ammonium molybdate, an aqueous solution containing nickel nitrate, and an aqueous solution containing phosphoric acid, dried, and calcined at 500 ° C., so that 12% by mass of molybdenum and 4% of nickel were contained in the catalyst. Catalyst B containing 2.5% by mass and 2.5% by mass of phosphorus was prepared.

[Hydrolysis / Isomerization]
After charging the catalyst A into a fixed bed flow reactor having a catalyst filling amount of 100 mL and presulfiding, a normal paraffin raw material described later is used, pressure is 4 MPa, hydrogen / feed oil supply ratio is 660 NL / L, LHSV = 1.0 h ^{− 1. A} hydrocracking / isomerization reaction was performed under reaction conditions of a reaction temperature of 330 ° C., and a light oil fraction was fractionated from the resulting oil to obtain a light oil A (Example) of the present invention.

  A light oil B (Comparative Example 1) was obtained in the same manner as in the case of the catalyst A except that the catalyst B was used instead of the catalyst A and the reaction temperature was 362 ° C.

  As a normal paraffin raw material, SX-50 manufactured by SMDS (Shell Middle Distillate Synthesis) was used. This has a density of 0.81 g / mL in terms of 15 ° C., an initial distillation point of 316 ° C., a 10% distillation temperature of 379 ° C., a 90% distillation temperature of 457 ° C., and an end point of 489 ° C., and is synthesized by the Fischer-Tropsch method. It is a thing.

  Table 1 shows the properties of the obtained light oils A and B and the commercially available light oil shown as Comparative Example 2. Regarding the property measurement, the density is JISK 2249, the sulfur content is JIS K 2541, the cloud point and the pour point are JIS K 2269, the clogging point is JIS K 2288, the distillation property is JIS K 2254, and the calorific value is the true calorific value. Was measured according to JIS K 2279. Aromatic content and normal paraffin content were analyzed by gas chromatography.

  From Table 1 above, light oil A has a sulfur content of 1 ppm or less and an aromatic content of 1% by mass or less, which is extremely lower than commercially available light oil. Furthermore, compared with light oil B and commercially available light oil, the calorific value is almost the same, It can be seen that it is particularly excellent in low-temperature characteristics such as cloud point, clogging point, and pour point.

Claims (2)

  A step of obtaining a product oil from a normal paraffin raw material by hydrocracking and isomerization using a catalyst in which a hydrogenation active metal is supported on a support containing silica alumina, and a 10% distillation by fractionating the product oil A method for producing environmentally friendly light oil, comprising a step of obtaining a light oil fraction having a temperature of 200 ° C or higher and a 90% distillation temperature of 340 ° C or lower.   The method for producing environmentally friendly diesel oil according to claim 1, wherein the normal paraffin raw material is synthesized by a Fischer-Tropsch process.