JPS60135486A - Method for dewaxing hydrocarbon fraction - Google Patents

Abstract

PURPOSE:To dewax efficiently a hydrocarbon fraction and to lower pour point, by bringing the hydrocarbon fraction in the presence of hydrogen into contact with a catalyst composed of a mixture of a mordenite type zeolite and a specified pentacil type zeolite. CONSTITUTION:A mordenite type zeolite is uniformly mixed with a pentacil type zeolite having an X-ray diffraction pattern (S being intense, VS being very intense, M being medium intense) shown in Table. The monovalent alkali metal ion of the resulting zeolite mixture powder is subjected to an ion exchange treatment with hydrogen ion or ammonium ion to thereby convert it into an acid type. Pref. further a binder such as alumina sol is added thereto and the mixture is shaped into a particle having the desired size, dried and calcined to obtain a catalyst. A hydrocarbon fraction such as gas oil or kerosene is brought into contact with the catalyst in the presence of hydrogen at 200-500 deg.C to dewax it.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a method for improving the fluidity of hydrocarbon fractions.

More specifically, this article concerns a method for dewaxing hydrocarbon fractions, typically petroleum fractions.

[Prior art and its problems]

Recently, the proportion of kerosene, light oil, and heavy oil, which are called middle distillates, in oil demand has been increasing, and on the other hand, there has been a noticeable decline in demand for B and C heavy oils, as mentioned above. An effective way to increase the yield of middle distillates is to lower the pour point of the base material of 2-gas oil and A-heavy oil.In general, when hydrocarbon fractions are used for various purposes, storage, It is possible to improve the fluidity during transportation and combustion by simply increasing the yield of the second middle distillate, which increases the flexibility of crude oil selection in petroleum refining and makes it possible to handle petroleum products in the winter. It can be said that the effects are very significant.

From this point of view, a method has been proposed in which the wax content in the hydrocarbon fraction is selectively decomposed and removed by using it as a zeolite a-catalyst as a method to lower the pour point etc. of the hydrocarbon fraction. As an example, the following zeolites are known: (1) Zeolite that can adsorb n-halafine but does not adsorb hydrocarbons with a molecular diameter larger than imparaffin: A-type zeolite (Japanese Patent Publication No. 45
-30963), Erionite (Special Publication No. 47-327
No. 23) (2i Zeolite that can adsorb n-halafine and monomethyl-substituted paraffin, but does not adsorb hydrocarbons containing quaternary carbon atoms such as 2,2-dimethylbutane: ZSM-5
Zeolite (Special Publication No. 49-34444).

(3) Mordenite (Japanese Patent Publication No. 31856/1983) is a zeolite that can adsorb hydrocarbons containing all quaternary carbon atoms, such as neopentane, but has a smaller pore size than Y-type zeolite.

In these conventional techniques, n-
Since the molecular diameter of paraffin is about 5A, the main focus is on increasing the selectivity of the n-paraffin decomposition reaction by using zeolite (1), which has a relatively small pore diameter. In the three types of zeolites mentioned above, it is thought that pores large enough to adsorb monomethyl-substituted paraffin are suitable.
Various attempts have been made to improve catalysts based on ZSM-5 zeolite '2, and recently ZS'M-23, -35 zeolite r, which has a pore size between (1) and (2) above, has been proposed. (Japanese Unexamined Patent Publication No. 131091/1983). On the other hand, due to the recent crude oil situation, the use of high pour point heavy oils has been increasing in particular. The dewaxing activity of this high pour point heavy oil cannot be said to be sufficient in the prior art.

As a result of intensive investigation into the cause, it was found that the n-paraffin component contained in the wax component decreases as the hydrocarbon fraction has a higher pour point. Most of the components hJ are n-paraffins. High pour point hydrocarbon fraction includes wax components,
The number of n-balaf acids has decreased, and branched paraffins, naphthenic hydrocarbons, or aromatic hydrocarbons are the main components.

Judging from this wax component, mordenite type zeolite with a relatively large pore diameter is considered to be preferable as a catalyst component, but when evaluated as a catalyst, mordenite type zeolite has a low dewaxing activity and cannot be used. Therefore, in order to selectively decompose and remove a wide range of wax components from n-paraffins to aromatic hydrocarbons, conventional catalysts are insufficient in both activity and selectivity.

[Purpose of the invention]

The object of the present invention is to provide a novel catalyst that is highly effective in the dewaxing of hydrocarbon fractions, especially in the dewaxing reaction of heavy hydrocarbon fractions with high pour points. [Structure] The present invention has four features: a catalyst consisting of a mixture of mordenite zeolite and pentasil zeolite having an X-ray diffraction pattern shown in Table 1, in the presence of hydrogen, is brought into total contact with a hydrocarbon fraction. This article relates to a method of dewaxing.

Mordenite-type zeolite, which is the first component of the catalyst used in the present invention, can be either a synthetic product or a natural product, and of course a mixture thereof may also be used, but natural products contain impurities, and from the viewpoint of catalytic activity. And the power of synthetic products is more preferable. Especially silica/alumina (5i02/At20a
) High silica type mordenite with a ratio of 12 or more is preferred from the viewpoint of dewaxing activity.

High-silica mordenite can be obtained by acid-treating ordinary mordenite, but high-silica mordenite obtained by synthesis is more flexible in terms of activity selectivity. The synthesis method is disclosed in, for example, Japanese Patent Application Laid-Open No. 58-910329, and is synthesized as follows. An aqueous reaction mixture consisting of an alcohol source, an alumina source, an alkali source, and an organic compound contained in a carboxyl group (indicated by 5102.At203J0H- and A, respectively) has the following composition range 5iOz/Aj2039~100 expressed in molar ratio. 50
H20/5jOz 5~100 1()-5010"-
50OH-/5i020.10□50 0.14~0.
40 0.15~0351V'kL20s 0.05~
100 0.10-50 0.10-20 and carry out the reaction formula until zeolite crystals are formed, thereby making it possible to completely synthesize mordenite as zeolite.

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

Sources of alumina include aluminated soda, aluminum chloride, aluminum nitrate, and alumina sol.

Alumina gel, activated alumina, gamma alumina, alpha alumina, etc. are increasingly used.

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

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

As the organic compound containing a carboxyl group, various types of carboxylic acids such as aromatic, aliphatic, and aliphatic carboxylic acids and their salts can be used.

Examples include lactic acid, tartaric acid, salicylic acid and salts thereof.

The aqueous mixture thus prepared is made into a slurry as uniform as possible and placed in a closed container, such as an autoclave made of iron, stainless steel, or lined with porcelain or fluororesin, and the crystallization is carried out. . The reaction conditions for the crystallization tank are a reaction temperature of 8()-250°C, preferably 14°C.
( ) -200°C, and one reaction time is from 5 hours to 30 days, preferably from 10 hours to 10 days. It is desirable to keep the mixture in a uniform state by stirring it 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. On the other hand, the pentasil type zeolite, which is the second component of the catalyst used in the present invention, is It is desirable that the mold be a zeolite having an X-ray diffraction pattern as shown in Table 1, and more specifically an X-ray diffraction pattern as shown in Table 2.

The general formula is (1,0±02)M2/nO At203FistXS]02
・Yf-(20 (where M is an alkali metal and/or an earth metal, n is the valence of M, and X is 1'5
~200. Measurement of the nX-ray diffraction pattern represented by Y=O~25) is carried out according to a conventional method. That is, X-ray irradiation is performed using a Geiger counter spectrometer equipped with a recording device to obtain a diffraction pattern. This diffraction pattern has a relative intensity of 100I/IMAX (IM
AX is the strongest line) and the lattice spacing d (unit: angstrom A) is determined.

However, the relative strength (100I/IMAX) is expressed as VS-very strong, S-'J', M-intermediate strength, and W-weak.

Table 1 X-ray diffraction pattern 11.20,28 10.1±0.28 a86 i 0.08 VS 3.72±0088 366±0.05 M Margin below Table 2 X-ray diffraction pattern 11.2 ±0.28 10.1±0.28 9.8±0.2 M a37±0.1 W 6.00±0.1 W 5.71±0.1 W 5.58 ± 0.1 W 4 .37±o, os w 427±o, os w a8610.08 VS 3.82±o, os vs a75 0.08' 5 372±o, os s 3.66±0.05 M 3.00± 0.05 M 2.00 0.05 W The pentasil type zeolite used as the second component of the catalyst used in the present invention may be produced by any method as long as it has the above characteristics. Typically, silica source, alumina source,
This can be achieved by preparing an aqueous reaction mixture containing an alkali source and crystallizing it under reaction conditions that allow the synthesis of zeolite.

Various additives may also be added to the aqueous reaction mixture. As an additive, for example, 2
10064, a compound containing a quaternary alkyl ammonium ion, a compound containing a quaternary alkyl ammonium ion disclosed in JP-A-50-54598, or a compound containing a primary alkyl amine % disclosed in JP-A-50-54598 or JP-A-52-
Examples include alcohol, which was disclosed in No. 43800.

Particularly preferred are the carboxyl group-containing organic compounds disclosed in Japanese Patent Publication No. 58-91032.

The pentasil type zeolite having the X-ray diffraction pattern shown in Table 1 is preferably produced, for example, as follows.

That is, a silica source, an alumina source, an alkali source, and various compounds containing carboxyl groups (5 iOz, At
The aqueous reaction mixture consisting of 20a+ OH- and A) is represented by the composition ratio and has the following composition range: 8102~'tt20s 5 or more 20 or more 25-5
00HzO/SiO2! y"loo 5~100'1
0~50OH7SiO0,01~1.0 0.05-(
1,400,10135A/AtzOa 0.05 or more 0.10-200 0.10-.100, and can be produced in the same manner as the mordenite described above. Note that even in a composition range in which pentasil-type zeolite is likely to be produced, mordenite-type zeolite may be produced depending on the crystallization conditions. In particular, when the crystallization temperature is high, mordenite type zeolite tends to form. When the silica/alumina ratio (SiO2/At20 g) of the reaction mixture composition ratio is the same, a lower alkalinity (0H-/5102) tends to result in a pentasil type zeolite, and a higher alkalinity results in a mordenite type zeolite. silica/
As the alumina ratio increases, the alkalinity of the pentasil-type zeolite produced also increases.

The 1-mordenite type zeolite thus produced and the pentasil type zeolite having all the X-ray diffraction patterns shown in Table 1 are uniformly mixed. As for the mixing ratio, the weight ratio of 2-mordenite zeolite and pentasil-type zeolite having the X-ray diffraction pattern shown in Table 1 is usually 1:100 to 100:1%, preferably 1:io to 10:1. It is preferable to mix in a ratio of 3:7 to 7:3, and it is preferable to mix as uniformly as possible.

Therefore, it is appropriate to mix zeolite in powder form.
In order to use pentasil type zeolites having a diffraction pattern in the present invention, it may be necessary to convert these zeolites into acid form. The zeolite may be made into an acid beforehand and then mixed, or it may be made into an acid form after mixing and further after shaping. Acid type zeolite is well known.

The cations in zeolite may include divalent or higher polyvalent cations such as hydrogen q ions, ammonium ions, or rare earth ions. Part of it is obtained by ion exchange with all hydrogen ions, ammonium ions, or polyvalent cations.

This ion exchange treatment is preferably an ion exchange treatment in which hydrogen ions and/or hydrogen ion precursors are introduced into the zeolite by treatment with a solution containing acid and/or ammonium chloride.

Also as an additive in aqueous reaction mixtures.

In the case of zeolites synthesized using compounds containing quaternary alkylammonium ions or primary alkyl amines, since they contain cations containing nitrogen at the time of production, acid and/or ammonium salt compounds Even without an ion exchange treatment using a solution containing ion, acid type zeolite can be obtained by decomposing the organic element-containing cations by calcination and converting them into hydrogen ions. If necessary, it is of course also possible to convert the alkali metal ions such as sodium present during zeolite production into acid form by ion exchange treatment with hydrogen and/or its precursor ammonium ion. It is.

Ion exchange treatment is generally performed 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, and carbonic acid, but of course other acids containing hydrogen ions may be used as long as they are δ.

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. 07'-
The correct concentration of acid to be used varies greatly depending on the type of acid, so it is difficult to determine it unambiguously.
Great care must be taken to avoid major structural changes.

As ammonium salt compounds, inorganic ammonium salts such as ammonium nitrate, ammonium chloride% ammonium sulfate, ammonium carbonate, aqueous ammonia, etc., or organic W ammonium salts such as ammonium formate, ammonium acetate, ammonium citrate, etc. can be used as well. , is an inorganic ammonium salt. The ammonium salt used is preferably used as a clear solution of 0.05 to 4N, more preferably as a solution of about 6.1 to 2N. As a method for total ion exchange treatment of zeolite with an acid and/or ammonium salt solution, either a batch method or a flow method is preferably used. In the case of batch treatment, the solid-liquid ratio is at least an amount that allows the zeolite to come into sufficient contact with the liquid, specifically about 1 t/1 (preferably 7 or more). The processing time is about 0.
1 to 72 hours is sufficient, preferably about 0.5 to 24 hours. The processing temperature should be below the boiling point, but
Preferably, heating is used to promote the rate of ion exchange. When processing with a flow 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 uneven ion exchange treatment. Zeolite I-Q was exchanged at a processing plant and then washed with water. Distilled water is preferably used as the washing liquid, and the washing may be carried out in either a batch type or a flow type. In this way, hydrogen ions and/or ammonium ions as hydrogen ion precursors are introduced into the zeolite, giving it solid acidity.Cations other than hydrogen ions and/or their precursors are present in the zeolite. The type and amount thereof are not particularly limited. The apparatus that can be used for the reaction of the present invention may be either a fixed bed or a fluidized bed, but a fixed bed system is simpler and easier to use.
It is preferably used because it is easy to operate. 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 is too small, pressure loss increases, which is not preferable. Therefore, there is a preferable range for the catalyst particle size. Preferably used particle size 1-r 0
．． 05 to 10m+++, more preferably 0.3
~3 Swallow in your throat. Synthetic zeolites are usually obtained in powder form. 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. Particularly in the case of extrusion molding, it is best to use a binder to improve the moldability or to impart strength to the molded product.

Of course, if it can be molded without a binder.

Needless to say, there is no need to use a binder. Examples of the binder include naturally occurring clay resins such as tuolin, bentonite, and montmorillonite, and synthetic products such as silica sol, alumina sol, and alumina gel. ) The amount of inder added is 70 lbs.
Preferably it is 30% by weight or less. The catalyst of the present invention has high activity and selectivity.

Nickel and palladium to improve lifespan.

A hydrogenation component such as platinum, rhenium, molybdenum, or tungsten may be added. Methods for adding these hydrogenation components include a kneading method, an impregnation method, a method of physically mixing powders together, but are not necessarily limited to these methods. However, the kneading method or the impregnation method, which has good dispersibility, is preferred because it allows these components to be more uniformly dispersed throughout the catalyst and is more favorable for activity and selectivity.

The catalyst prepared as described above is dried before use, and then calcined.
It is carried out for 5 to 48 hours.

Firing is carried out at 300-70°C for 0.1 hour or more, preferably at 400-600°C for 05-24 hours. Firing is performed in air, inert gas, or an atmosphere consisting of these and water vapor. By this kind of calcination, the ammonium ions introduced in the ion exchange process are converted to hydrogen ions, and as the calcination temperature is increased, the hydrogen ions are converted to a decationized form. However, of course, catalysts in this form can also be used satisfactorily.

The catalyst prepared as described above can be used completely under the following reaction conditions:
The temperature is 0 to 500°C, preferably 250 to 450°C. The reaction operating pressure is from atmospheric pressure to 100 to 9/ad Q, preferably from 10 Kg/cnlG to 50 Kr/cnI G
It is. The liquid hourly space velocity (LH8V), which means the contact time of the tail, is 0.1 to 10 br-', preferably α5 to 4. There is Qhr T. The ratio of hydrogen to hydrocarbon is 1
00~1000 N-++//m”, 200 in 1 inch
~800 N-n? /n? It is.

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

〔Effect of the invention〕

The catalyst used in the present invention has particularly excellent catalytic activity towards high pour point heavy oil hydrocarbon fractions. Furthermore, the naphtha and gasoline components that are produced as by-products have high octane numbers, which overall contributes to the high loading power and value of the product. EXAMPLES The present invention will be described in more detail below with reference to Examples.

In this example, the catalyst performance was evaluated under the reaction conditions shown below.

(1) Raw material name Desulfurized vacuum gas oil boiling point (10-90%) ('C): 320-490 pour point C℃) + 32.5 Total sulfur (wt s5 o, os (2) Reaction conditions LHS V (hr) 2 .0 Reaction pressure (Kg/cJ G) 35 H2/Feed-(N-'mVml 500 Example 1
6 grams of solid caustic soda 1a, 1 and 8 grams of tartaric acid were dissolved in 335 grams of total water. 202 grams of sodium aluminate solution was added to this solution to form a homogeneous solution. 66.0 g of silicic acid powder was gradually added to this mixture with stirring to prepare a uniform slurry-like aqueous reaction mixture.

The composition ratio (molar ratio) of this reaction mixture was determined as follows.

SiO2/At203 20 1-ho/5iO220 OH, 0.25 A/At20g 2.5 The reaction mixture was placed in a 5oonl autoclave and sealed, and then reacted at 160°C for 72 hours with stirring.

After the reaction, the product was taken out from the autoclave, washed with distilled water until the pH became almost neutral, filtered through the mouth, and washed at 120°C.
It was dried overnight at ℃.

The product obtained has a molar ratio of 0.9 in the anhydrous state.
8 Na2OA 420g Mordenite having a composition ratio of 15.48 iOz. This mordenite v,
Abbreviated as II A I''.

Next, 923 grams of solid caustic soda, 12.5 grams of tartaric acid
A homogeneous slurry aqueous reaction mixture was prepared in the same manner from 341 grams of water, 175 grams of sodium aluminate solution, and 66.0 grams of silicic acid powder. The compositional ratio (molar ratio) of this reaction mixture is β in the following column.

SiO2/At20a 30 IhO/5iO220 01 (7/5i020.17 AZA4z0a 2.5 The zeolite synthesized in the same manner as the mordenite described above had the X-ray diffraction pattern shown in Table 3. This zeolite is abbreviated as k"13". .

Table 3 X-ray diffraction pattern 11.30 49 10.09 33 9.82 11 116 515 142 758 596 409 a04. 12 5.75 10 5.61 13 5.40 2 5.17 3 5.028 634 4.52 3 4.39 10 4.29 8 4.12 3 008 3.86 100 a83 82 &76 50 a74 55 a66 27 d (in) 100I/IMAX a62 5 a50 8 4.47 15 338 9 a33 8 a27 2 323 2 320 2 a16 2 3.06 10 2.99 16 289 3 284 2 2.75 4 z62 3 258 2 2 .50 6 Z42 4 240 3 204 3 2.02 9 2.00 11 1.97 3 L95 3 1.92 2 1.88 3 Mordenite powder "A" and zeolite powder "B"
e The powder thus obtained, which was mixed at a weight ratio of 3:7, was heated to 80 to 90°C with a 0187 normal ammonium chloride aqueous solution at a solid-liquid ratio of 5 (LA9) for 30 minutes. Batch ion exchange treatment was performed.

Thereafter, it was thoroughly washed with distilled water and dried at 110°C overnight.

To this dealkalized powder was added 1% of alumina sol f binder (15v) in terms of alumina (Atzos) and thoroughly kneaded. After kneading 10 to 24 meters (JI)
The particles were molded into thick particles using an S 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. If the reaction field is set at a reaction humidity of 270°C, the pour point will be 8 at -15°C. The production rate of the fraction with a boiling point of 165° C. or higher was 82.5 wt%, and the octane number of this fraction was 87.

Example 2 Mordenite powder "A"' and zeolite powder "B"' were synthesized in the same manner as in Example 1. This A″ and”
Example 1: Mix B "' in a weight ratio of 1:10.
Oxidized and molded into a catalyst using the same method as shown in
Catalyst performance was evaluated using desulfurized vacuum gas oil. When the reaction was carried out at a reaction temperature of 270°C, the pour point was -10°C. The production rate of fractions with a boiling point of 165°C or higher is s o, o w
t%, and the octane number of this distillate was 87, a.

Example 3 Moltenite powder Pa′'' and zeolite powder “B” synthesized in the same manner as in Example 1 in a weight ratio of 6:40.
They were mixed in the same proportions, acidified and molded into a catalyst in the same manner as in Example 1, and the catalyst performance was evaluated in the same manner as in Example 1. When the reaction temperature is set at 270°C, the pour point is -10°C. 7! The production rate of the fraction heated to 165° C. or higher was 79.5 wt%, and the octane number of the single fraction b was 88.

Comparative Example 1 Synthesis of Zeolite ZS#i-5
This was carried out according to the method described in No. 4. The synthesis conditions are shown in the table below.

Starting components (gl A, hydrated silicic acid 683 B, sodium aluminate solution 10.5 C0 tetrapropylammonium high 439.4 droxide semen (
2! Brown water solution) Reaction mixture composition ratio (molar ratio) SiCh LOO At20g 0.02 Na20 0.034 [(CHsCH2CH4)4N120 0.31202
0 Starting component C was added to B' to form a homogeneous solution. The starting component At was gradually added to this mixed solution and stirred to prepare a homogeneous slurry-like reaction mixture. This reaction mixture was completely automated.
Pour into a crepe and heat to 160℃ while stirring, 7
Crystallization was carried out for 2 hours.

After crystallization, wash with water until it becomes neutral, then wash for 12 hours.
It was dried at 0°C for 15 hours. The obtained zeolite was analyzed using ZSM-5, which showed the X-ray diffraction pattern shown in FIG.

ZSM-5 zeolite thus obtained Example 1
A catalyst was prepared by molding, calcination, ammonium ion exchange, and calcination in the same manner as in 2009.The performance of this catalyst was evaluated using desulfurized vacuum gas oil.When placed in a reaction field at a reaction temperature of 270°C, the pour point was 0°C. The production rate of fractions with a boiling point of 165°C or higher is 8
The octane number of this distillate was 82, which was 2.3 wt%.

[Brief explanation of the drawing]

Figure 1 shows the X of ZSM-5 zeolite used in Comparative Example 1.
The line diffraction pattern is shown. Patent Applicant: Toshi Co., Ltd., Fudo Oil Co., Ltd., Agent, Patent Attorney: Masaru Ohno, Rei No, Ryunosuke, Ohno

Claims (1)

[Claims] (1) Desorption of a hydrocarbon fraction characterized by contacting a hydrocarbon fraction in the presence of hydrogen with a catalyst consisting of a mixture of Mordenai) W zeolite and a zeolite having an X-ray diffraction pattern shown in Table 1. Deaf law.