JPH0377836B2 - - Google Patents

Description

[Detailed description of the invention]

FIELD OF THE INVENTION The present invention relates to a method for processing petroleum. More specifically, it is a dewaxing treatment method in which a petroleum fraction with a high pour point is brought into contact with a special crystalline silicate, and a hydrocarbon conversion method in which the wax content is selectively converted into gasoline. Normally, when a petroleum fraction contains 1 to several percent of wax content, as the temperature decreases, the low-temperature fluidity of the oil as a whole is lost. For liquid hydrocarbon fuels with a boiling point of 200℃ or higher, low-temperature fluidity is important from a practical standpoint, and it is one of the important product specifications for jet fuel, plain oil, A heavy oil, B heavy oil, and lubricating oil. , must have a pour point below +10°C or -30°C. However, some of these products obtained by distillation of crude oil often contain significant amounts of long-chain paraffin content, or wax content, which causes them to fail to meet product specifications.
It is not uncommon for pour points to exceed +50°C. In view of the above-mentioned requirements for product quality, several methods for removing long-chain paraffin, ie, wax content, have been proposed and are in industrial use. One of them is the solvent dewaxing method, which is
This method involves mixing light oil with a suitable solvent such as methyl ethyl ketone to selectively dissolve and remove the wax content in the solvent, but the process is complicated and not economically advantageous, so it is rarely used at present. Another method is catalytic dewaxing with a catalyst, which can selectively accept waxes but not other branched paraffins, naphthenes or aromatics. This method uses a crystalline aluminosilicate having pores as a catalyst for contact treatment at high temperatures to selectively and effectively remove wax content. In addition, the decomposition products obtained by decomposing the wax by this method are
LPG and naphtha. Mordenite zeolite and ZSM-5 type zeolite have been proposed as crystalline aluminosilicate suitable for the purpose of this catalytic dewaxing method. Mordenite is manufactured by British Petroleum Co. in Special Publications No. 1856-1856 and Special Publication No. 1856,
- It is a dewaxing catalyst specified in Publication No. 48482,
It is said that a catalyst consisting of decationized mordenite supported with metals from groups of the periodic table is effective.
ZSM-5 type zeolite is a crystalline alumina silicate that has never been found in nature, and was specified by Mobil Oil Company in Japanese Patent Publication No. 10064/1983.
±0.2) M2 _/o O: _W2O3 :5-100A zeolite expressed by the oxide molar ratio _{of YO2} : _ZH2O , where M is a cation and n is an atom of the cation M. Value, W
is selected from the group consisting of aminium or gallium, Y is selected from the group consisting of silicon and germanium, and Z has a value from 0 to 40. ZSM−
The catalytic dewaxing method using 5 zeolite was published in
This is clearly disclosed in Japanese Patent Laid-open No. 34444 and Japanese Patent Application Laid-open No. 17401/1983, and the effect of lowering the pour point is clear. However, from an industrial point of view, with conventional catalysts, the by-product decomposition products contain a large proportion of LPG and an insufficient proportion of the more valuable gasoline. There are defects that lead to
On the other hand, due to the adhesion of carbonaceous matter onto the catalyst, activity is lost in a short period of time, and the regeneration cycle is short. However, recently, a certain type of crystalline silicate synthesized for the first time by the present inventors has been shown to be suitable for use as a catalytic dewaxing catalyst, and also to be used as a catalyst for heavy aromatic dewaxing, which is a precursor of coke in the decomposition of wax components. It has been found that this method has the revolutionary effect of suppressing the adhesion of coke onto the catalyst and greatly improving the durability of the catalyst compared to conventional crystalline aluminosilicate. This phenomenon is due to the fact that, compared to conventional crystalline aluminosilicate, the crystalline silicate has catalytic active sites not of Al but of metals such as La, Ce, and Bi, which have not been previously known as zeolite constituents. This is thought to be due to the presence of oxides. For this reason, this crystalline silicate has somewhat different hydrocarbon decomposition performance, and has the characteristic of being able to selectively produce low fluidity fuel oil and gasoline as products. The present invention provides a dewaxing method using this crystalline silicate. That is, the present invention is capable of producing low pour point fuel and high quality gasoline from petroleum fractions containing wax content, at a reaction temperature of 200 to 500°C, a reaction pressure of 500 kg/cm ² or less, and an LHSV of 0.01 to 500°C. 100h ^-1 ,
Under conditions of H ₂ /oil ratio of 5000 Nm ³ /Kl or less, the above petroleum fraction is expressed as the molar ratio of the oxide in the dehydrated form: (0.1 to 2) R _2/o O・M ₂ O ₃・ySiO ₂ [In the above formula, R: one or more monovalent or divalent cations n: valence of R M: one or more metals selected from lanthanum, cerium, and bismuth y: ≧12] This invention relates to a method for catalytic dewaxing of petroleum fractions, which is characterized by contacting a crystalline silicate with a composition and an X-ray diffraction pattern shown in Table 1 below.

【table】

[Table] The crystalline silicate having the above chemical composition used in the present invention is a reaction mixture containing the following silica source, one or more sources of lanthanum, cerium, and bismuth, an alkali source, water, and a special organic compound. It is synthesized by a hydrothermal synthesis reaction using as a starting material an acid for controlling the pH of the mixture and the reaction mixture. In addition, iron, the source of alumina, which is well known as a constituent metal of crystalline silicate,
Sources of trivalent transition metals such as chromium, vanadium, etc. can also be added. If the source of silica is silica or silica compounds commonly used in zeolite synthesis,
Any source of silica may be used, for example silica powder, colloidal silica, or silicates such as water glass. As sources of lanthanum, cerium, or bismuth, compounds such as sulfates, nitrates, and chlorides of these metals are used. As the alkali source, a hydroxide of an alkali metal such as sodium, or an alkaline earth metal such as calcium, or a compound with aluminic acid or silicic acid is used. As a special organic compound that is one of the raw materials for hydrothermal synthesis of crystalline silicate, the following can be used. (1) Organic amines Primary amines such as n-propylamine and monoethanolamine, secondary amines such as dipropylamine and diethanolamine, tertiary amines such as tripropylamine and triethanolamine, or ethylenediamine, Various organic compounds such as diglycolamine, mixtures of the above compounds and halogenated hydrocarbons (propyl bromide, etc.) are illustrative, and the present invention is not limited thereto. In addition, monovalent or divalent cations (R) in the present invention include alkali metal ions, alkaline earth metal ions, ions of the above-mentioned organic compounds, or hydrogen ions formed by treatments such as calcination and ion exchange. Point to ion. The crystalline silicate used in the present invention has a conventional zeolite structure in which part or all of Al- is replaced with lanthanum, cerium, or bismuth, and further has a SiO ₂ /M ₂ O ₃ ratio of 12 It is characterized by the above characteristics and is produced starting from a reaction mixture having the following molar composition. _SiO2 / _{M2O3 12-3000} (preferably 20-200) ^OH- / _SiO2 0-1.0 (preferably 0.2-0.8) _H2O / _SiO2 2-1000 (preferably 10-200) Organic compound / _{M2O3 1} ~100 (preferably 5~
50) The crystalline silicate used in the present invention is synthesized by heating the raw material mixture at a temperature and time sufficient to generate the crystalline silicate.
Hydrothermal synthesis temperature is 80~300℃ preferably 130~200℃
The hydrothermal synthesis time is from 0.5 to 14 days, preferably from 1 to 10 days. Although the pressure is not particularly limited, it is preferable to use it freely. The hydrothermal synthesis reaction is continued by heating the raw material mixture to the desired temperature and, if necessary, stirring, until crystalline silicate is formed. After crystals have thus formed, the reaction mixture is cooled to room temperature, filtered, washed with water, and the crystals are separated. Even more normal
Drying is performed at 100°C or higher for about 5 to 24 hours. The crystalline silicate produced by the above-mentioned method can be molded into an appropriate size as it is or mixed with a binder etc. conventionally used for catalyst molding, using well-known techniques, and used as a catalyst. can be used. The crystalline silicate used in the present invention is a regularly porous crystalline material having a certain crystal structure, and generally exhibits an X-ray diffraction pattern shown in Table 1 below.

【table】

TABLE Standard techniques were used to obtain the data in Table 1 above. The irradiation is copper Kα radiation. I ₀ is the intensity of the strongest peak and I/I ₀ is the relative intensity. Preferably, the crystalline silicate is activated by heating in air at a temperature ranging from 400 to 700°C for 2 to 48 hours before use as a catalyst. The alkali metals present in this crystalline silicate can be exchanged with one or more other cations by conventional methods to form the H form or Ca, Mg, Zn, Ga,
Crystalline silicates of other metal cation types such as Pt, Pd, Ni, and Fe can be provided. For example, a method for ion-exchanging the crystalline silicate into H-type is to remove organic compounds by firing the crystalline silicate produced by the method described above, and then immerse it in a strong acid such as hydrochloric acid to directly convert it into H-type. Alternatively, there is a method in which the material is immersed in an aqueous solution of an ammonium compound to form the NH ₄ form, and then baked to form the H form. Additionally, for catalytic purposes, the crystalline silicates can be impregnated with compounds of one or more metals. Suitable metals are those belonging to the periodic group and group Cr, Mo, W, and the platinum group Pd, PtRh, Ir, Ru and metals.
Fe, Co, and Ni belong to the iron family with Os. The impregnated silicate preferably contains 0.1 to 20% by weight of metal. The compounds of the metals used are those which decompose on application of heat to give the corresponding oxides and which are soluble in water, such as nitrates or chlorides, as well as metal carbonyl compounds which are soluble in organic solvents. , metal acetylacetone. Crystalline silicates are therefore prepared by impregnating with aqueous solutions of compounds of these metals and drying and calcining. When Ni, Co, and Mo, which are known as hydrodesulfurization active metals, are used for metal impregnation, they are preferred catalysts because they not only dewax but also hydrodesulfurize the feedstock oil and reduce the sulfur content of the product. Crystalline silicates include alumina, silica,
It can be used in combination with refractory oxides such as silica alumina and titania. In particular, in a catalyst preparation method involving metal impregnation, it can be preferably used to facilitate metal support and, in some cases, to further enhance the catalytic effect. These refractory oxides are mixed with the crystalline silicate in the form of a sol or gel or as an oxide, and the amount thereof is usually 5 to 80% by weight, preferably from 5 to 80% by weight, based on the total amount of crystalline silicate and refractory oxide. It ranges from 10 to 50% by weight. Although the feedstock hydrocarbon oil to be subjected to catalytic dewaxing treatment using the catalyst of the present invention may have any carbon number and boiling point, one of the objects of the present invention is to selectively remove wax from wax-containing hydrocarbon oil. The purpose of this method is to lower the pour point of the feed stock by decomposing the wax content into lighter hydrocarbons. It is particularly effective in petroleum fractions with pour points higher than 0°C. In addition to straight-run kerosene, gas oil, or vacuum gas oil obtained by distilling crude oil, this raw material oil can also be desulfurized oil obtained by treating these with a hydrodesulfurization catalyst such as a cobalt-molybdenum-alumina catalyst or a nickel-molybdenum-alumina catalyst. can be used.
In some cases, the present invention can also be applied to hydrocarbon oils derived through processes such as thermal cracking, hydrocracking, and catalytic cracking. For example, heavy gas oil has a carbon number of 11~
30, boiling point range 220-440℃, wax content 5-15% by weight,
The sulfur content is 1.5 to 2% by weight, and the pour point is +5 to +
It exhibits a temperature of 30°C and is suitable as a raw material oil for the present invention. Next, the conditions for catalytic dewaxing are that the temperature range is 200 to 500.
℃ preferably 250~350℃, pressure range 1~500℃
Kg/cm ² preferably 1~50Kg/cm ² , LHSV 0.01~
100h ^-1 preferably 0.1 to 10h ^-1 , gas supply amount in gas-feedstock oil ratio 0 to 5000Nm ³ /Kl preferably 100 to
It is 1000Nm ³ /Kl. The gas mixed with the raw material oil and supplied to the reactor is not particularly limited, and for example, in addition to hydrogen and nitrogen, the gas after removing the liquid fraction from the product flowing out from the reactor outlet may be recycled. can be used. The degree of catalytic dewaxing is controlled by changing the above conditions, e.g. by increasing the reaction temperature or by increasing the LHSV
Although the decomposition of the wax component increases by decreasing the amount, the processing conditions are ultimately determined by the desired product. Next, the present invention will be explained in detail with reference to examples, but the present invention is not limited to the following examples unless the gist thereof is exceeded. Example 1 Crystalline silicate was synthesized as follows. Water glass, lanthanum chloride, cerium chloride, sodium chloride, water to 36Na ₂ O・(0.5La ₂ O ₃・
The molar ratio of 0.5Ce ₂ O ₃ )・80SiO ₂・1600H ₂ O was prepared, and an appropriate amount of hydrochloric acid was added to the mixture so that the pH of the mixture was around 9. Propyl was added as an organic compound. Amine, propyl bromide
20 times the total number of moles of La ₂ O ₅ and Ce ₂ O ₃ was added, mixed well, and placed in a 500 c.c. stainless steel autoclave. While stirring the above mixture at approximately 500 rpm,
The reaction was carried out at 160°C for 3 days. After cooling, filter out the solid content and wash thoroughly with water until the pH of the washing water is approximately 8.
It was dried at 110°C for 12 hours and fired at 550°C for 3 hours. The crystal grain size of this product is around 1μ, and the composition excluding organic compounds is expressed in dehydrated form.
It was 0.4Na ₂ O・(0.5La ₂ O ₃・0.5Ce ₂ O ₃ )・80siO ₂ . This is called crystalline silicate 1. In the above preparation method, the same operation as in the case of crystalline silicate 1 was performed except that the amounts of lanthanum chloride and cerium chloride were converted into the molar ratio of La ₂ O ₃ and Ce ₂ O ₃ and changed as shown in Table 2. Crystalline silicates 2 to 6 as shown in Table 2 were prepared repeatedly.

[Table] Furthermore, even when silica sol was used in place of water glass in Crystalline Silicate 2, Crystalline Silicate 2 (B) having the same composition was obtained. Example 2 Crystalline bismuth silicate was synthesized in exactly the same manner as in Example 1 except that bismuth chloride was used instead of lanthanum chloride and cerium chloride. The crystal grain size of the product obtained by firing at 550°C for 3 hours is around 1μ, and the composition excluding organic compounds is expressed in dehydrated form as 0.6Na ₂ O・Bi ₂ O, 80siO ₂
It was hot. This is called crystalline silicate 7.
When synthesizing this crystalline silicate 7, the same results can be obtained even if nitric acid is used instead of hydrochloric acid, bismuth nitrate is used instead of bismuth chloride, or silica sol is used instead of water glass among the raw materials. silicate was obtained. In addition, aluminum chloride was added when preparing raw materials for crystalline bismuth silicate, and 0.6NaO.
The product synthesized by repeating the above preparation procedure except for using a raw material mixture of (0.9Bi ₂ O ₃ .0.1Al ₂ O ₃ ).80SiO ₂ is referred to as crystalline silicate 8. Example 3 Crystalline silicates 1 to 6 synthesized in Example 1 were
After calcining at 530°C for 5 hours, it was subjected to the following hydrochloric acid treatment twice to obtain a proton type catalyst. This hydrochloric acid treatment consisted of immersing it in 1N hydrochloric acid and treating it at 80°C for 3 days, followed by washing and drying at 110°C for 12 hours. After the catalyst thus obtained was shaped, it was subjected to a reaction with heavy gas oil having the properties shown in Table 3. Reaction conditions are 325℃, 30Kg/cm ² G, LHSV=1.5h ^-1 H ₂ /oil
The test was carried out at 500Nm ³ /Kl, and the results shown in Table 4 were obtained. Table 3 Properties of raw material heavy gas oil Specific gravity (15/4℃) 0.8684 Heavy viscosity (50℃oSt) 5.165 Flash point (℃) 140 Pour point (℃) +10 Sulfur content (wt%) 1.56 Distillation properties IBP (initial 198°/C 5% 251 10% 295 30% 326 50% 343 70% 359 90% 382 95% 391 Recovery 98 Residue 2

【table】

[Table] Example 4 After mixing 100 g of crystalline silicate 2 protonated in Example 3 and 130 g of alumina boehmite gel with an alumina content of 77% by weight, 200 ml of 5% nitric acid solution was added, and the mixture was thoroughly mixed with a kneader. Knead. after that,
It was molded to a diameter of 1.5 mm using an extruder, dried at 120°C for 6 hours, and then fired at 550°C for 3 hours. The matrix thus obtained consisted of 50% by weight crystalline silicate and 50% alumina. Next, 200 g of the base material described above was immersed in 420 ml of an aqueous solution containing 69 g of ammonium molybdate.
After soaking for 24 hours, filter and dry at 120℃ for 6 hours,
It was baked at 550°C for 4 hours. followed by cobalt nitrate 85
It was immersed for 24 hours in 420 ml of an aqueous solution containing g.
Thereafter, it was filtered, dried at 120°C for 6 hours, and fired at 550°C for 4 hours. The catalyst obtained by the above preparation method has a
Molybdenum MoO ₃ as 6.7% by weight, cobalt
It was 1.9% by weight as CoO. This catalyst was cured for 2 hours at 250° C. in a mixed gas of hydrogen and hydrogen sulfide, and then subjected to a reaction via the heavy substance used in Example 3 and having the properties shown in Table 3. The reaction conditions were temperature 350℃ and 375℃, pressure 30Kg/cm ² G,
Table 5 shows the results obtained at LHSV 1.5h ^-1 and H ₂ /oil 500Nm ³ /Kl. It can be seen from Table 5 that desulfurization progresses effectively as the pour point decreases.

【table】

[Table] Example 5 The crystalline silicates 7 and 8 synthesized in Example 2 were protonated by the same hydrochloric acid treatment as in Example 3, and the resulting dry powder was molded. Heavy gas oil having the properties shown in Table 3 was subjected to the reaction. Reaction conditions: 300℃, 30Kg/cm ² G, LHSV
= 1.5h ^-1 , _H2 /oil ^500Mm3 /Kl, and the results are shown in Table 6, 6-1 and 6-2. Example 6 Crystalline silicate 7, which had been protonated by the method of Example 3, was subjected to exactly the same method as in Example 4 to obtain a support having the same amount of alumina as a matrix, and then impregnated with molybdenum and cobalt. The final catalyst was 8% by weight as molybdenum MoO ₃ and 1% by weight as cobalt as CoO. This catalyst was sulfurized in a mixed gas of hydrogen and hydrogen sulfide at 250°C for 2 hours, and then the third catalyst used in Example 3 was used.
Heavy menstrual oil having the properties shown in the table was subjected to the reaction. The reaction conditions were: temperature 350℃, pressure 30Kg/cm ² G, LHSV 1.5h ^-1 ,
The results obtained using H ₂ /oil 500Nm ³ /Kl are shown in Table 6.
Shown in 3.

【table】

【table】

Claims (1)

[Claims] 1. When producing a low pour point fuel oil from a petroleum fraction containing a wax content, the petroleum fraction is expressed as a molar ratio of oxides in a dehydrated form: (0.1 to 2) R _2/o O・M ₂ O ₃・ySiO ₂ [In the above formula, R: one or more monovalent or divalent cations n: valence of R M: one selected from lanthanum, cerium, and bismuth A catalytic dewaxing method for a petroleum fraction, characterized in that the metal is brought into contact with a crystalline silicate having a chemical composition of y:12] and an X-ray diffraction pattern shown below. [Table] [Table] [Table]