JPS59147085A - Dewaxing of hydrocarbon fraction - Google Patents

Abstract

PURPOSE:A hydrocarbon fraction such as petroleum is broght into contact with a catalyst mainly composed of a zeolite having a specific X-ray diffraction pattern and mesitylene adsorption in the presence of hydrogen to effect dewaxing of high recovery rate economically and advantageously. CONSTITUTION:A hydrocarbon fraction is brought into contact with a catalyst mainly composed of a zeolite which has an X-ray diffraction pattern shown in the table (d is lattice interval; 100 I/I0 is relative intensity; VS means very strong, S, strong; M, medium) and more than 1.6wt% of mesitylene adsorption in the presence of hydrogen. The zeolite can be preferably represented by the formula: (1.0+ or -0.2)M2/nO.Al2O3.XSiO2.YH2O [M is alkali or alkaline earth me tal; n is valency of M; X is 15-60; Y is 0-25]. EFFECT:The above catalyst permits the long-hours of use with high activity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for improving the fluidity of hydrocarbon fractions, and more particularly to a method for dewaxing hydrocarbon fractions, typified by petroleum fractions.

Recently, the proportion of kerosene, light oil, and A heavy oil called middle distillates in petroleum demand has been increasing, while the demand for B and C heavy oils has been decreasing. An effective method for increasing the overall yield of middle distillates as described above is a method of lowering the pour point, etc. of light oil and heavy oil A base materials. In general, when using hydrocarbon fractions for various purposes, being able to improve their fluidity during storage, transportation, and combustion not only increases the yield of middle distillates, but also increases the flexibility of crude oil selection in oil refining. The effects can be said to be extremely significant, such as an increase in sex and a drastic improvement in the handling of petroleum products during the winter.

From this point of view, a method has been proposed to selectively decompose and remove the wax content in the hydrocarbon fraction by using zeolite as a total catalyst as a method of lowering the pour point etc. of the hydrocarbon fraction. Three types of zeolites are known as shown below.

(1)? +-Paraffin can be completely adsorbed, but is the molecular size larger than isoparaffin? Zeolites that do not adsorb hydrocarbons: A-type zeolite (Japanese Patent Publication No. 45-30963), erionite (Japanese Patent Publication No. 47-32723).

(2) Zeolite that can adsorb n-paraffin and monomethyl-substituted crude oil, but does not adsorb hydrocarbons containing quaternary carbon atoms such as 2,2-dimethylbutane: ZsM-5
Zeolite (Special Publication No. 49-34444).

(3) Mordenite (Sho Kosho No. 45-31856) is a zeolite that can adsorb hydrocarbons containing all quaternary carbon atoms, such as neopentane, but has a smaller pore diameter than Y-type zeolite.

In these conventional techniques, wax is the main component? L
-i<Since the molecular diameter of rough-in is about 5λ, the main focus is on increasing the selectivity of the n-paraffin decomposition reaction by using zeolite sound with a relatively small pore diameter. It is thought that the pores of the above-mentioned zeolites are suitable for adsorbing monomethyl-substituted paraffins, and various attempts have been made to improve catalysts based entirely on zsu-5 zeolite.Recently, the above-mentioned ( ZSM-23,35 zeolite having a pore size intermediate between 1) and (2) has been proposed (Japanese Patent Application Laid-open No. 131091/1983).

However, in these conventional techniques, the catalyst used is very expensive, the catalyst activity is insufficient, the reaction temperature is high, the operating time until catalyst regeneration is not long enough, or the recovery rate of dewaxed oil is low. Due to these drawbacks, there is a need for the development of catalysts with higher activity, higher selectivity, and longer life. 〃
・In view of this situation, the inventors of the present invention have been conducting intensive research on dewaxing methods for hydrocarbon fractions. :, As a result, surprisingly, contrary to the teachings of Japanese Patent Publication No. 49-34444, etc., te, 2,
It has been found that pentasil-type zeolite, which has a relatively large pore size that adsorbs hydrocarbons containing quaternary carbon atoms such as 2-dimethylbutane, provides a highly active catalyst. When using a zeolite that exhibits a specific mesitylene (1,3,5-)limethylbenzene adsorption property, the reaction activity increases because the diffusion of the reactant to the active site and the desorption of the reaction product become easier. The present invention was achieved based on the knowledge that the secondary side reactions of the product are reduced, and the present invention has the X-ray diffraction nodules shown in Table 1. A zeolite that has all the characteristics of adsorbing mesitylene at 1.6% by weight or more? This paper proposes a new dewaxing method characterized by contacting a catalyst, which is the main component, with a hydrocarbon fraction in the presence of hydrogen.

The zeolite used in the present invention needs to have an X-ray diffraction pattern shown in Table 1 in an alkaline form, and more specifically, it is desirable to have an X-ray diffraction pattern as shown in Table 2. . Measurement of the X-axis diffraction pattern is carried out according to conventional methods. In other words, X-ray irradiation is performed on copper using a Geiger counter spectrometer equipped with a recording device using alpha rays, and the diffraction pattern (Kuhn's total is obtained) shows the relative intensity of 0. line) and the lattice spacing d (unit: angstrom A).

Table I X-ray diffraction pattern 11.2±0.28 10.1±0.2 S3.86±o
, os vs3.72±o, os
s3.66±0.05
M Table 2 X-ray diffraction pattern 10.1±0.2 89.8±0.2
M 6.37±o, i w558±0.
I W 2.00±0.05 W However, relative strength (100I/To) is expressed as VS = very strong, S = strong, M = intermediate strength, W - weak.

The zeolite used in the present invention has the general formula in alkaline form: (1,0±0.2)M2AO=At203・XSs
Q2・YH20 However, M is an alkali metal and/or alkaline earth metal, n is the valence of M, and X is 15 to 60
．． YII'i0 to 25 are all represented.

Further, the zeolite used in the present invention must be capable of totally adsorbing 1.6% by weight or more of mesitylene under the following conditions in the acid form. It is preferable that 1.8 ff% or more of mesitylene be adsorbed on the back.

The adsorption amount of mesitylene is measured by a method according to JIS K-1412. The obtained zeolite is thoroughly dealkalized with an aqueous ammonium chloride solution.

The sample is then molded without binder to a size of 20-32 meshes and fired in air at 550°C for 16 hours.

The zeolite thus obtained was subjected to an adsorption test under the measurement conditions described below.

Adsorbent amount: Approximately 41 Adsorption concentration: 25°C Carrier gas: N2,80ON - Mesitylene partial pressure: 0.51Hf Adsorption time: 6 hours As is clear from the examples below, the catalyst used in the present invention is suitable for recovering dewaxed oil. It has the characteristics of high efficiency and high activity. With conventional catalysts, considerable amounts of LPG, naphtha, and gasoline components are produced as by-products during the dewaxing reaction, but the added value of these components fluctuates greatly depending on the oil supply and demand balance and other factors. A high recovery rate increases the economic stability of the dewaxing process, which has great industrial significance. In addition, since the catalyst of the present invention has high catalytic activity, the reaction temperature can be set lower than that of conventional catalysts, enabling long-term operation, and furthermore, thermal deterioration of hydrocarbon oil is suppressed, improving color tone and stability. Dewaxing oil with excellent properties such as? Obtainable.

The zeolite used in the present invention may be produced by any method as long as it has the above characteristics.

One of the specific examples is shown below. That is, a silica source, an alumina source, an alkali source, and an organic compound containing a carboxyl group (respectively fLsio2T At203.0ff
- and A) expressed in molar ratio, the following composition range 5in2/At 203
20~60H20/SiO25~100 0H/S Z 02 0.1~0.35A
/A, 1203 0 to 100, and can be produced by reacting until crystals are formed.

As the silica source, for example, silica sol, silica gel, silica airgel, silica hydrogel, silicic acid, silicate ester, sodium silicate, etc. are used.

Alumina sources include sodium aluminate, aluminum sulfate, aluminum nitrate, alumina sol, alumina gel,
Activated alumina, gamma-aluminum 9-alpha alumina, etc. are used.

As the alkali source, caustic soda, caustic potash, etc. are used, and caustic soda is preferred.

These alkali sources are added so that 011- is present in the system preferably in the above composition.

As the organic compound containing a carboxyl group, various carboxylic acids such as aromatic, aliphatic 117j group, and alicyclic carboxylic acids are used. Further, the organic compound having a carboxyl group may contain a functional group other than the carboxyl group, such as a hydroxyl group or an amino group.

Typical examples are succinic acid, tartaric acid, citric acid,
Examples include toluic acid and tolylic acid. It is thought that these become alkali metal salts in the reaction system.
However, it goes without saying that it can be used in advance as an alkali metal salt.

The aqueous reaction mixture thus prepared is made into a slurry as uniform as possible and crystallized by placing it in a closed container, such as an autoclave made of iron, stainless steel, or lined with fluororesin. The reaction conditions for the crystal F are a reaction temperature of 80 to 2500. Preferably 100~
The reaction time is 5 hours to 30 days, preferably 10 hours to 10 days.

The reaction mixture is preferably kept in a homogeneous state by stirring continuously or periodically during crystallization.

After cooling, the crystallized reaction product is taken out from the closed container, washed with water, passed through the mouth, and dried if necessary. The crystalline aluminosilicate thus synthesized has the X-ray diffraction pattern shown in Table 2.

The amount of mesitylene adsorbed can be increased to 1.6% by weight or more by appropriately selecting the ratio of the starting materials silica and alumina and the types of organic compounds used.

The crystalline aluminosilicate synthesized in this way is alkaline as it is and does not have sufficient solid acidity. When used in the reaction of the present invention, it is necessary to completely impart solid acidity to the crystalline aluminosilicate to make it into an acid form. As is well known, acid type crystalline aluminosilicate has polyvalent cations of divalent or higher valence, such as hydrogen ions, ammonium ions, or rare earth ions, as cations in crystalline aluminosilicate, and these are usually sodium ions. It can be obtained by ion-exchanging at least a portion of the alkali metal ions of a crystalline aluminosilicate having a monovalent alkali metal ion such as, for example, with a dihydrogen ion, an ammonium cation, or a polyvalent cation. This ion exchange is preferably carried out using a solution containing acid and/or ammonia 1 and salt compound 2 to completely introduce hydrogen ions and/or hydrogen ion precursors into the crystalline aluminosilicate. Ion exchange treatment is
It is generally carried out in an aqueous solution. Acids that can be used include inorganic acids and organic acids, with inorganic acids being more common. Examples of the inorganic acid include hydrochloric acid, nitric acid, phosphoric acid, carbonic acid, etc., but of course other inorganic acids may be used as long as they contain hydrogen ions.

When using an inorganic acid, it is not preferable to treat it with a solution with too high a concentration because this will cause structural changes. The concentration of the acid preferably used varies greatly depending on the type of acid, so it is difficult to determine it unambiguously, and when using it, it is necessary to be careful not to cause large changes.

As ammonium salt compounds, inorganic ammonium salts such as ammonium nitrate, ammonium chloride, ammonium sulfate, ammonium carbonate, aqueous ammonia, etc., or ammonium salts of organic acids such as ammonium formate, ammonium acetate, ammonium citrate, etc. can be used, but more Inorganic ammonium salts are preferred. The ammonium salt used is preferably used as a 0.05 to 4N solution, more preferably about 0.1 to 2N solution. As the method of ion exchange treatment of crystalline aluminosilicate with an acid and/or ammonium salt solution, any of the batch method and flow method is preferably used. In the case of batchwise treatment, the solid-liquid ratio is preferably at least an amount that allows the crystalline aluminosilicate to come into sufficient contact with the liquid, specifically at least about 1 t/Kq. A treatment time of about 0.1 to 72 hours is sufficient, preferably about 0.5 to 24 hours. Although the treatment temperature may be lower than the boiling point, it is preferable to heat it to fully accelerate the ion exchange rate. When processing with a single stream system, a fixed bed system, a fluidized bed system, etc. can be used, but
It is necessary to take measures to prevent uneven flow of the fluid and to prevent uneven ion exchange treatment. The ion exchange treated crystalline aluminosilicate is then washed with water. Distilled water is preferably used as the washing liquid, and the washing may be carried out by either a batch type or a flow type. In this way, hydrogen ions and/or ammonium ions, which are hydrogen ion precursors, are introduced into the τ crystalline aluminosilicate to impart solid acidity. Crystalline aluminosilicate may contain hydrogen ions and/or cations other than their precursors [7], and the type and amount thereof are not particularly limited.

Equipment that can be used for the reaction of the present invention includes fixed bed 1. Although either fluidized bed method may be used, a fixed bed method is preferably used because the apparatus is simple and operation is easy. In the case of a fixed bed system, the smaller the catalyst particle size is, the more preferable it is from the point of view of the catalyst effectiveness coefficient, but if the particle size becomes too small, pressure loss increases, which is not preferable. Therefore, there is a preferable range for the catalyst particle size. Preferably used particle size is 0.0
It is between 5 and 10, more preferably between 0.3 and 3. The synthesized crystalline aluminosilicate is usually in a powder state. Therefore, in order to obtain a catalyst having such a preferable range, it is necessary to mold the catalyst.

Examples of the molding method include compression molding and extrusion molding. In the case of extrusion molding, what is its moldability? It is preferable to use it in a binder to improve the strength of the molded product or to add strength to the molded product. Of course, it goes without saying that there is no need to use a binder if it can be sufficiently molded without a binder. Examples of binders include all naturally occurring clays such as kaolin, bethonite, and montmorillonite, as well as synthetic products such as silica sol, alumina sol, and aluminisogel.

The amount of binder added is 70% by weight or less, preferably 30% by weight or less.
% by weight or less. Such molding may be performed before ion exchange treatment of the crystalline aluminosilicate, or ion exchange may be performed after molding. Hydrogenation components such as nickel, palladium, platinum, rhenium, molybdenum, and tungsten may be added to the catalyst of the present invention in order to improve activity, selectivity, and lifetime. Methods for adding these hydrogenated components include kneading, impregnation, and physical mixing of powders, but are not necessarily limited to these methods. However, since it is more preferable for activity and selectivity to disperse these components more uniformly throughout the catalyst, a kneading method or an impregnation method that provides good dispersibility is preferred.

The catalyst prepared as described above is dried prior to use and subsequently calcined. Drying at 50-250℃ TO, 1 hour or more, preferably tL,
<iio, carried out for 5 to 48 hours. Firing is 300-7
0.1 hour or more at 00°C, preferably 400-600°C
It is carried out for 0.5 to 24 hours. Firing is performed in air, inert gas, or an atmosphere consisting of these and water vapor. In addition, through such firing, the ammonium ions introduced in the ion exchange process are converted to hydrogen ions, and the hydrogen ions even change to the firing temperature? As the temperature increases, the catalyst converts to a decationization type, but it is of course possible to use catalysts in the following forms.

The catalyst prepared as described above is used under the following reaction conditions. That is, the reaction operating temperature is 200
-500°C, preferably 250-450°C. The reaction operating pressure is from atmospheric pressure to 100 Kf/crlG, preferably from 10 K9/crlG to 50 Kf/adG. The liquid time-space velocity (l
ll5V) is 0.1 to 10 hr-', preferably 0.
5-4. Ohr-'. Is the ratio of hydrogen to hydrocarbon 100 to 1000 N-rr? /lr! , preferably 20
0~80ON-7? //This is GaI.

As feedstocks, various hydrocarbon fractions including waxes obtained from crude oil, tar sands, oil sands, coal, etc. can be used.

The entire implementation of the present invention will be explained below with reference to side sounds. In this example, the catalyst performance was evaluated under the reaction conditions shown below.

1. Raw material name Desulfurized vacuum gas oil Gas oil boiling point (10-90%) (℃) 320-490 277-
359 pour point (℃) +32.5
+12.5 total sulfur (wt%) o
, o 8 0.5 s2, reaction conditions LH8V (hr-”) 2.0 reaction pressure (Kfl crlG) 35H2
/Fe ed (# -me/ml!)
500 reaction parts distilled the reaction product, boiling point 165℃
The pour point of the above fractions was varied depending on the catalyst activity so that it would reach a predetermined temperature.

Example 1 9.22 grams of solid caustic soda and 12.5 grams of tartaric acid were dissolved in 344.2 grams of water. 17.5 grams of sodium aluminate solution was added to this solution to form a homogeneous solution. 66.0 grams of silicic acid was gradually added to this mixture while stirring thoroughly to prepare a homogeneous slurry-like aqueous reaction mixture. The composition ratio (molar ratio) of this reaction mixture was as follows: ○ S Z Q z/A', 2()a 25
H20/';1o220 0H-/:Es Q2 0.169"L
2031.0 This mixture was placed in a 500-volume autoclave and sealed. Thereafter, the mixture was heated to 160° C. with stirring and crystallized for 72 hours. Cool after crystallization and then produce the product?
It was taken out from the auto-crepe tube, washed with distilled water until 71H was almost neutral, passed through the mouth, and dried overnight at 11.0°C. The obtained product was a zeolite having the X-ray diffraction pattern shown in Figure 1, and the amount of mesitylene adsorbed was 2.111.
)t%. The thus obtained zeolite powder was heated to 80 to 90° C. with an ammonium chloride aqueous solution having an i0.187 normality at a solid-liquid ratio of 5 (t/Kg), and subjected to ion exchange treatment in a batchwise manner for 30 minutes. Thereafter, it was thoroughly washed with distilled water and dried at 110°C overnight. To this dealkalized zeolite powder, 15% by weight of alumina sol as a total binder was added in terms of alumina (Al2O2) and thoroughly kneaded. After kneading, the mixture was formed into particles having a size of 10 to 24 mesh (JIS sieve), dried at 110°C overnight, and then calcined at 500°C for 2 hours in the presence of air. The catalytic performance of the catalyst thus obtained was evaluated using desulfurized vacuum gas oil. 10 days after the start of the reaction, the reaction temperature at which the pour point becomes -15 °C is 334 °C) 9, this pour point ffi,
The reaction temperature increase rate required to maintain t(II) is 5.8
°C/day. The production rate of fractions with a boiling point of 165°C or higher is 85
．． 311)j%, and the bromine number of this distillate is 1.8.

Also, according to the results of evaluating this catalyst using light oil, the reaction temperature at which the pour point reaches -20°C 10 days after the start of the reaction is 327°C, and the reaction temperature increase rate required to maintain this pour point at all is 6. 7 days at 0°C. The yield of fractions with a boiling point of 165'c or higher was 86.4'%.

Implementation procedure 2゜In the same manner as in Example 1, the following carboxylic acid was used instead of tartaric acid. Seven zeolite syntheses were carried out using this method. The composition ratio (molar ratio) of the reaction mixture was as follows.

A Cono-phosphoric acid Q-) Ruinon n
Citric acid Salicylic acid sio□/Al, 0330
30 30 30II20/S♂02
20 20 20 200H-/S
iOO, 140, 170, 140, 17A/Al 20
The product obtained was a zeolite with an X-ray diffraction pattern essentially the same as in FIG. Also, the mesitylene adsorption amount is 1.8, 1.8, 2.0, 1.9 from the left of the table, respectively. It was a buttock.

The zeolite thus obtained was acidified and molded into a catalyst in the same manner as shown in Example 1, and the catalyst performance was evaluated using desulfurized vacuum gas oil. For each zeolite, the reaction temperature at which the pour point reaches -15°C on the 10th day after the start of the reaction, the temperature increase rate necessary to maintain this pour point, and the production rate of one fraction with a boiling point of 165°C or higher are as follows. It was like that.

Reaction temperature (C) 344 341 336
337 Comparative Example 1゜In Example 1, the composition ratio (mole ratio) of the aqueous reaction mixture
Zeolite was synthesized with the following changes.

SiO2/Al2O395 H20/5i0225 01.1/5iC)2 o, d 2
A/A12037.0 The product obtained is a zeolite with basically the same X-ray diffraction pattern as in Figure 1, and the amount of mesitylene adsorbed is 0.
．． The zeolite thus obtained was acidified and molded into a catalyst in the same manner as shown in Example 1, and the catalyst performance was evaluated using desulfurized vacuum gas oil. . Ten days after the start of the reaction, the reaction temperature at which the pour point reaches -15'C is 395°C, and the rate of temperature increase required to maintain this pour point is 7
．． IC/day. The production rate of the fraction with a boiling point of 165° C. or higher is 79.3 wt%, and the bromine number of this fraction is 4.3.

Comparative example 2゜Synthesis of zeolite ZSM-5
It was carried out according to the method described in No. Synthesis conditions are shown in the table below○ Starting component ('f') Hydrous silicic acid 68.3B,
Sodium aluminate solution 10.5 Reaction mixture composition ratio (molar ratio) SiO2 1.00 A12030.02 Na20 0.034CCC
113CH2C1-12), A7] 20
(131I2020 B'C was added to starting component C to make a homogeneous solution. Starting components A-e were gradually added to this mixed solution and stirred to prepare a homogeneous slurry-like reaction mixture. This reaction mixture was autoclaved. and heated to 160℃ while stirring,
Crystallization was carried out for 72 hours. After the crystallization was completed, it was washed with water in a neutral trench, and then dried at 120° C. for 15 hours.

The obtained zeolite is ZSM-5, which shows the X-ray diffraction pattern shown in Figure 2, and the amount of mesitylene adsorbed is Q, 8u.
It%.

The thus obtained ZSM'-5 zeolite was molded, calcined, ammonium ion exchanged, and calcined in the same manner as in Example 1 to obtain a catalyst. The performance of this catalyst was evaluated using desulfurized vacuum gas oil. 10 days after the start of the reaction, pour point -15'
The reaction temperature at which C was reached was 374°C, and the rate of reaction temperature increase necessary to maintain this pour point was 8.3°C/day. In addition, the production rate of fractions with a boiling point of 165°C or higher was 77.8%.
The bromine number of this fraction is 4.1.

Comparative example 3゜synthetic mordenite (manufactured by Twotone, Zeolon xooNA
) A catalyst was prepared by acidification and molding in the same manner as shown in Example 1, and the catalyst performance was evaluated using desulfurized vacuum gas oil. In this catalyst, even if the reaction temperature is raised to 400°C, the pour point does not fall below -10°C. In addition, the mesitylene adsorption amount of this mordenite is 2.3 weight ratio,
Although -C satisfies the requirements of the present invention, the lattice spacing d (degrees angstroms) Fi determined from the X-ray diffraction pattern is less than or equal to that shown in Table 1.

ct, (X)7.02. 6.55. 4.53. 4
．． 00. 3.48°3.39. 3.21°

[Brief explanation of drawings]

FIG. 4 shows the X-ray diffraction pattern of the zeolite used in Example 1, and FIG. 2 shows the X-ray diffraction pattern of the zeolite used in Comparative Example 2. Procedural amendment April 8, 1980 Kazuo Wakasugi, Commissioner of the Patent Office1, Indication of the case, Patent Application No. 19629, filed in 19822, Name of the invention: Dewaxing method for hydrocarbon fractions3, Person making the amendment Relationship to the case Name of special contract applicant (315) Higashi Co., Ltd. Name of Tomito Oil Co., Ltd. Drawings attached to the application (Figs. 1 and 2) 6. Toshi 8!41 of the self-answer attachment for amendments and Correct Figure 2.・Nー゛-pa＼, -, #r↑, 655-

Claims (1)

[Claims] A hydrocarbon fraction is brought into contact in the presence of hydrogen with a catalyst having an X-ray diffraction pattern shown in Table 1 and having a mesitylene adsorption amount of 1.6 weight or more as a main component of a zeolite. Dewaxing method for hydrocarbon fractions.