JP2549332B2 - Method for producing crystalline aluminosilicate - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a crystalline aluminosilicate having excellent hydrothermal stability, which can be suitably used for catalytic cracking of hydrocarbon oil, and more specifically,
It relates to a method for producing the above crystalline aluminosilicate by subjecting a stabilized Y zeolite to a constant thermal load.

[0002]

2. Description of the Related Art Generally, in petroleum refining, it is an important subject to produce gasoline in good yield, and for the purpose of producing gasoline, diesel oil obtained by atmospheric distillation or vacuum distillation of crude oil is used. A method of catalytically cracking a distillate, an atmospheric distillation residual oil or a vacuum distillation residual oil using a catalyst composed of a stabilized zeolite such as X or Y zeolite or USY zeolite (ultra-stable Y zeolite) and an inorganic matrix is adopted. ing.

Many techniques have already been proposed for the catalyst for the above purpose. For example, regarding the stabilized Y zeolite, US Pat. Nos. 3,293,192 and 3,3,192 have been proposed.
No. 402,996.

[0004]

However, when catalytically cracking hydrocarbon oils using a catalyst containing stabilized Y zeolite, the hydrothermal stability of the stabilized Y zeolite is low.
The crystal structure collapses and the decomposition activity decreases. Also,
When the content of the stabilized Y zeolite in the catalyst is increased for the purpose of maintaining a high decomposition activity, the amount of the inorganic matrix is relatively decreased and the wear resistance of the catalyst is reduced.

In order to solve such a problem, the present inventors previously proposed a method for producing a crystalline aluminosilicate having a high hydrothermal stability by applying a thermal load to the stabilized Y zeolite. (See Japanese Patent Application No. 2-172500, hereinafter referred to simply as "previous proposal"). However, according to this production method, when a thermal load is applied to the stabilized Y zeolite, the crystallinity of the zeolite may be reduced, and the crystalline aluminosilicate obtained by this method is used as a hydrocarbon. When used as a catalyst for catalytic cracking of oil, there is concern that the cracking activity will decrease.

Therefore, the present invention minimizes the destruction of the crystal structure by applying a thermal load under the condition that the crystal structure of the crystalline aluminosilicate is not destroyed, as compared with the prior proposal. It is an object of the present invention to propose a method for producing a crystalline aluminosilicate having even more excellent properties than the previously proposed catalyst as a catalyst for catalytic cracking of hydrogen oil.

[0007]

Means for Solving the Problems The inventors of the present invention have made extensive studies in order to achieve the above-mentioned object, and as a result, the conditions for applying a thermal load to the stabilized Y zeolite, specifically, the temperature rising rate, The present invention has been completed by finding that the crystal structure of the obtained crystalline aluminosilicate can be less destroyed by making it looser than that of the previous proposal.

That is, the method for producing a crystalline aluminosilicate excellent in hydrothermal stability of the present invention is SiO ₂ / Al ₂
O ₃ molar ratio is 5-11, unit cell size is 24.50-2
4.72Å, alkali metal content is 0.0 in terms of oxide
Stabilized Y zeolite, 2-1% by weight, at 1-15 ° C
The temperature is increased to 600 to 1200 ° C. at a rate of / minute, and at this temperature,
It is characterized in that the stabilized Y zeolite is calcined for 5 to 300 minutes at a crystallinity reduction rate of 15% or less.

In the present invention, the stabilized Y zeolite used as the starting material is so-called Y zeolite at high temperature,
After steaming several times, treat with at least one of mineral acids such as hydrochloric acid, bases such as sodium hydroxide, salts such as potassium fluoride, and chelating agents such as ethylenediamine acetic acid (EDTA). And shows resistance to deterioration of crystallinity. Of course, as the stabilized Y zeolite, Y zeolite is used as ammonium hexafluorosilicate [(NH ₄ ) ₂ SiF ₆ ].
Those obtained by treatment with a silicon compound such as or silicon tetrachloride (SiCl ₄ ) may be used, or treatment with a silicon-free compound such as EDTA or phosgene (COCl ₂ ) may be used. There is no problem even if the obtained product is used.

The above-mentioned stabilized Y zeolite is SiO ₂ /
Al ₂ O ₃ molar ratio is 5-11, preferably 5-8, unit cell size is 24.50-24.72Å, preferably 2
4.50 to 24.70Å, the alkali metal content is 0.02 to 1% by weight in terms of oxide, and preferably 0.05 to 0.
It means Y zeolite which is 8% by weight. This stabilization Y
Zeolites have basically the same crystal structure as natural faujasite and have the compositional formula shown in Chemical Formula 1 as an oxide.

[0011]

Embedded image

The stabilized Y zeolite as a raw material used in the present invention has a low R _{2 / m 2} O content, and as shown in Chemical formula 1, has a coefficient of 0.002 to 0.2. Is. That is, the stabilized Y zeolite used in the present invention is a crystalline aluminosilicate having the properties shown in Table 1.

[0013]

[Table 1]

In the production method of the present invention, when a constant thermal load (hereinafter, also referred to as heat shock) is applied to the stabilized Y zeolite, it takes a certain time (that is, a constant temperature rise). One point is to raise the firing temperature (in speed). Thermal load is about 600-120
At a temperature of 0 ° C, preferably about 600-1000 ° C, about 5
The calcining may be performed for about 300 minutes, preferably for about 5 to 100 minutes, and under the conditions that the crystallinity reduction rate of the stabilized Y zeolite is about 15% or less, preferably about 10% or less.

At this time, it is important that the temperature rising rate up to the above-mentioned firing temperature is about 1 to 15 ° C./min, preferably about 2 to 10 ° C./min. That is, if the rate of temperature rise is too fast, the crystal structure collapses, and if it is too slow, the productivity of the crystalline aluminosilicate deteriorates. As described above, a crystalline aluminosilicate having good productivity, high cracking activity and high hydrothermal stability required as a catalyst for catalytic cracking of hydrocarbon oils can be produced by heat shock while preventing the collapse of the crystal structure. In order to achieve this, it is essential to keep the temperature within the above range.

If the calcination temperature is too low, the desired product cannot be obtained. Conversely, if the calcination temperature is too high or the calcination time is too long, the crystal structure of the zeolite will collapse. Furthermore, even if the calcination conditions are the same, if the temperature rising time is too short, the crystal structure of zeolite will collapse. Usually, firing is performed in an electric furnace or a firing furnace under an atmospheric pressure in an air or nitrogen atmosphere, but the firing is performed by leaving it in an electric furnace in an air or nitrogen atmosphere with a water vapor partial pressure of 0 to 0.5 atm. May be. Moderate humidity easily causes dealumination, and heat shock can be generated even at a relatively low temperature within the above temperature range.

Furthermore, under heat shock conditions, it is desirable that the crystal structure of the zeolite is not collapsed as much as possible, and the crystallinity reduction rate of the stabilized Y zeolite is about 15% or less, preferably 10% or less. Do under conditions. The crystallinity of stabilized Y zeolite is ASTM
D-3906 (Standard Test Meth)
od for Relative Zeolite D
It is calculated according to the effect Intensities method. That is, the standard sample is a Y-type zeolite (Si / Al ratio of 5.0, unit cell size of 24.58Å,
The amount of Na ₂ O is 0.3% by weight), and the intensity ratio of the relative X-ray diffraction between the test sample and the standard sample is obtained. The rate of decrease in crystallinity of the stabilized Y zeolite due to the heat shock of the present invention is obtained from the formula shown in Formula 1.

[0018]

[Equation 1]

In the above formula, heat shock crystalline aluminosilicate means a crystalline aluminosilicate obtained by subjecting stabilized Y zeolite to a heat shock, and hereinafter referred to as "heat shock crystalline aluminosilicate". When this means.

By the way, the heat shock crystalline aluminosilicate obtained in the present invention is mixed with an inorganic oxide matrix and used as a catalyst for catalytic cracking of hydrocarbon oil, as described later. When used as this catalyst,
The heat shock may be applied either before or after mixing with the inorganic oxide matrix, but it is preferably before mixing. The heat shock in the present invention is distinguished from the heat treatment under severe conditions for simulated equilibration performed prior to the catalyst performance evaluation test.

Further, in the present invention, heat-stabilized Y zeolite is heat-treated to obtain a heat-shock crystalline aluminosilicate, but when Y-zeolite is heat-treated to directly produce the heat-shock crystalline aluminosilicate, crystals are obtained. The structure collapses and the purpose cannot be achieved. The reason for this is not clear in detail, but it is possible to heat-treat the Y zeolite to produce the stabilized Y zeolite, wait for the crystal structure to settle down in this state, that is, stabilize, and then perform the heat treatment again. It is presumed that it is necessary.

The heat shock crystalline aluminosilicate obtained by the present invention has the following characteristics. That is, bulk SiO ₂ / by chemical composition analysis
The Al ₂ O ₃ molar ratio is about 5-11, preferably 5-8. Also, the unit cell size is less than about 24.47Å, preferably less than 24.45Å. The unit cell size can be measured according to ASTM D-3942 / 85, and can be calculated by using the peak of X-ray diffraction. If this value is too large, the hydrothermal resistance deteriorates. The molar ratio of Al in the zeolite framework to total Al is about 0.3 to 0.6, preferably about 0.3 to 0.55. This value is calculated by the formulas (1) to (3) shown in Formula 2 from the SiO ₂ / Al ₂ O ₃ molar ratio and the unit cell size by the above chemical composition analysis (HK Beyer et al., J. Che
m. Soc. , Faraday Trans. l, 19
85, 81, 2899).

[0023]

[Equation 2]

In addition, A in the zeolite skeleton with respect to all Al
The molar ratio of 1 can be calculated by other formulas, but when other formulas are used, it does not reach the above value.

When the bulk SiO ₂ / Al ₂ O ₃ molar ratio is the same, if the Al molar ratio in the zeolite framework to the total Al is too small, the catalytic activity required for catalytic cracking is lost. When the ratio of Al outside the skeleton, that is, amorphous Al, becomes high, the selectivity also behaves like an amorphous catalyst,
Hydrogen generation, coke production, and olefin content in gasoline are increased. On the other hand, if the molar ratio of Al in the zeolite skeleton to the total Al is too large, the amount of olefins in gasoline decreases, but the hydrothermal resistance of the catalyst decreases, and the amount of coke produced also increases.

The content of alkali metal or alkaline earth metal is about 0.02 to 1.0% by weight, preferably about 0.05 to 0.8% by weight in terms of oxide. When the content of alkali metal or alkaline earth metal is less than about 0.02% by weight in terms of oxide, the crystal structure is likely to collapse, and the catalytic activity tends to decrease when catalytically cracking nitrogen-containing hydrocarbon oil. Is increased, which is not preferable. In addition, when a large amount of alkali metal is present in the heat shock crystalline aluminosilicate, the decomposition activity of the catalyst is lowered, and nickel and vanadium, which are heavy metals often contained in the feed oil, particularly heavy oil feed oil, are reduced. When such a substance adheres, there is a problem that activity deterioration is likely to occur.

One of the major characteristics of the heat shock crystalline aluminosilicate obtained according to the present invention is that the unit cell size is less than about 24.47Å, which is compared to about 24.50 to 24.72Å of stabilized Y zeolite. It is becoming smaller.

Another characteristic is ²⁷ Al-MA.
S (Magic Angry Spinning) N
According to the MR spectrum, the stabilized Y zeolite shows two peaks (see FIG. 2), while the heat shock crystalline aluminosilicate obtained by the present invention shows three characteristic peaks (see FIG. 1). That is.

The peaks shown in FIGS. 1 and 2 are peaks due to 4-coordinate Al, that is, due to Al in the crystal lattice, the peaks are those of pentacoordinate Al, and the peaks are those of hexacoordinate A.
l, that is, a peak due to Al outside the crystal lattice is shown. The pentacoordinated Al that appears in this peak is described in, for example, J. Am. C
hem. Soc. , 1986, 108, 6158-61
As described on page 62, it is inferred that the morphology of Al in an unstable state is in the process of transitioning from 4-coordinate Al in the crystal lattice to 6-coordinate Al outside the lattice. By the way, after the heat shock according to the present invention, a peak due to pentacoordinated Al appears even after a long time has passed, but it is hidden by the peak when it is in a hydrated state, and the pentacoordinated peak cannot be detected.
The above-mentioned hydrated state means a state in which the heat shock crystalline aluminosilicate reaches in about 1 week after being left in the air at room temperature.

Since the heat shock crystalline aluminosilicate obtained in the present invention has the above-mentioned characteristics, it is presumed that the bottom cracking performance is particularly good and that the heat shock crystalline aluminosilicate shows a unique effect as described later. The properties of the heat shock crystalline aluminosilicate produced according to the present invention are summarized in Table 2.

[0031]

[Table 2]

Further, the heat shock crystalline aluminosilicate obtained by the present invention substantially has the X-ray diffraction pattern shown in FIG. The X-ray diffraction pattern has values as shown in Table 3 as a typical example. That is, the strongest intensities (1, 2 and 3 in FIG. 3) were measured with lattice spacings (d) of 14.1 ± 0.2Å, 5.61 ± 0.1Å and 3.72 ± 0. It is 1 Å.

[0033]

[Table 3]

To carry out the catalytic cracking of hydrocarbon oils using the heat shock crystalline aluminosilicate obtained according to the invention, the heat shock crystalline aluminosilicate is mixed with an inorganic oxide matrix and this mixture is used. May be contacted with a hydrocarbon oil. Here, as the inorganic oxide matrix, for example, silica, alumina, boria, chromia, magnesia, zirconia, titania, silica-alumina, silica-magnesia, silica-zirconia, chromia-alumina, titania-alumina, titania-silica, titania. -Zirconia, alumina-zirconia, etc.,
Alternatively, it may be a mixture of these and may further contain at least one clay mineral such as montmorillonite, kaolin, halloysite, bentonite, attapulgite, and bauxite.

The above-mentioned mixture (that is, a mixture of a heat shock crystalline aluminosilicate and an inorganic oxide matrix, hereinafter referred to as "catalyst") can be produced by a conventional method, and typically, a suitable method. As the inorganic oxide matrix, for example, silica-alumina hydrogel,
It is possible to obtain catalyst particles by using an aqueous slurry of silica sol or alumina sol, adding the above heat shock crystalline aluminosilicate to it, thoroughly mixing and stirring, and then spray drying. In this case, the heat shock crystalline aluminosilicate in the catalyst is about 5-60% by weight,
It is preferably added in an amount of about 10 to 50% by weight and an inorganic oxide matrix of about 40 to 95% by weight, preferably about 50 to 90% by weight.

The catalytic cracking of hydrocarbon oil using the above catalyst can be carried out by a known catalytic cracking method. For example, a hydrocarbon oil boiling above the boiling point range of gasoline may be brought into contact with the catalyst. The hydrocarbon oil (hydrocarbon mixture) boiling above the boiling point range of gasoline means a light oil fraction obtained by atmospheric distillation or vacuum distillation of crude oil, atmospheric distillation residual oil and vacuum distillation residual oil, and of course, coker Light oil,
Solvent deasphalted oil, solvent deasphalted asphalt, tar sand oil,
It also includes shale oil oil and coal liquefied oil.

Catalytic cracking on a commercial scale is usually carried out by continuously circulating the above catalyst in a catalytic cracking unit consisting of two vessels, a vertically installed cracking reactor and a catalyst regenerator. . The hot regenerated catalyst exiting the catalyst regenerator is mixed with the hydrocarbon oil to be cracked and directed upward in the cracking reactor. As a result, the catalyst, which is generally called "coke" and deactivated by depositing carbonaceous matter on the catalyst, is separated from the decomposition products, stripped, and transferred to a catalyst regenerator. The spent catalyst transferred to the catalyst regenerator is regenerated by burning the coke on the catalyst with air, and is recycled to the cracking reactor.

On the other hand, the decomposition products are dry gas and LP.
G, gasoline fraction, and, for example, light cycle oil (LC
O), heavy cycle oil (HCO) or slurry oil and separated into one or more heavy fractions. Of course, it is also possible to further promote the cracking reaction by recycling these heavy fractions to the cracking reactor.

The operating conditions of the cracking reactor in the above catalytic cracking apparatus are that the pressure is about atmospheric pressure to 5 Kg / c.
m ² , preferably about atmospheric pressure to 3 Kg / cm ² , temperature about 4
00 ° C to 600 ° C, preferably about 450 ° C to 550 ° C,
A catalyst / feedstock hydrocarbon oil weight ratio of about 2 to 20, preferably about 5 to 15, is suitable.

[0040]

In the above-mentioned method for producing a heat shock crystalline aluminosilicate proposed by the present inventors, the heating rate up to the firing temperature is about the same as the heating rate during heat treatment of ordinary zeolite. It was about 17 to 20 ° C./minute. As a result of subsequent studies by the present inventors, it was found that the crystallinity was considerably lowered at the temperature raising rate as previously proposed, even if the firing temperature was the same.

On the other hand, in the present invention, as a result of various studies in order to find a method that does not decrease the crystallinity in the temperature rising process until the firing temperature is reached, it is most preferable to make the temperature rising rate gentle. After obtaining the knowledge that it is an economical method and further studying it, the rate of 1 to 15 ° C./minute was selected.

In the present invention employing such a temperature rising rate, the crystallinity of the stabilized Y zeolite as a raw material does not decrease even during the temperature rising process up to the firing temperature, and the crystallinity decrease rate is 15%. Even in the calcination step of the present invention carried out with the content controlled to be not more than%, a crystalline aluminosilicate having a stable crystal structure and having excellent properties as a catalyst for catalytic cracking of hydrocarbon oil can be obtained.

[0043]

EXAMPLES The contents of the present invention will be specifically described below with reference to Examples and Comparative Examples. Example 1 SiO ₂ / Al ₂ O ₃ molar ratio was 7, alkali metal content was 0.2 wt% in terms of oxide, and unit cell size was about 24.
Hydrothermal stability was obtained by heating 60 Å stabilized Y zeolite in an electric furnace in an air atmosphere under atmospheric pressure at a rate of 3.75 ° C./min up to 750 ° C. and then firing at 750 ° C. for 10 minutes. An excellent heat shock crystalline aluminosilicate was obtained. When the produced component was analyzed, it showed the main X-ray diffraction pattern of Y zeolite and had the physical property values shown in Table 4. Further, the crystallinity is 110% after the heat shock with respect to 110% of the stabilized Y zeolite as the raw material.
% (Decrease in crystallinity 8.1%). This heat shock crystalline aluminosilicate is designated as HZ-1.

[0044]

[Table 4]

Example 2 Except that the temperature rising rate up to the firing temperature was 2.5 ° C./min.
A heat shock crystalline aluminosilicate was produced in the same manner as in Example 1. When the product was analyzed, it showed the main X-ray diffraction pattern of Y zeolite and had the physical properties shown in Table 5. Further, the crystallinity was 105% after the heat shock with respect to 110% of the stabilized Y zeolite as the raw material (the crystallinity decrease rate was 4.5%). This heat shock crystalline aluminosilicate is designated as HZ-2.

[0046]

[Table 5]

Comparative Example 1 A heat shock crystalline aluminosilicate was produced in the same manner as in Example 1 except that the temperature rising rate up to the firing temperature was 22.5 ° C./min. When the product was analyzed, it showed a major X-line pattern of Y zeolite and had the physical properties shown in Table 6. In addition, the crystallinity was 87% after the heat shock with respect to 110% of the stabilized Y zeolite as the raw material (the crystallinity decrease rate was 20.9%). This heat shock crystalline aluminosilicate is referred to as HZ-3.

[0048]

[Table 6]

As is clear from Examples 1 and 2, and Comparative Example 1, even if the firing conditions are the same, if the rate of temperature increase to the firing temperature is high (temperature raising time is short) as in Comparative Example 1, formation occurs. It can be seen that the crystal structure of the object collapses.

Examples 3 to 4 and Comparative Example 2 [Preparation of catalyst] Content of the products HZ-1, HZ-2 and HZ-3 obtained in Examples 1 and 2 and Comparative Example 1 in the final catalyst. To 35 wt% and kaolin was added to the silica sol so that the content in the final catalyst was 45 wt%. After thoroughly stirring these slurries, they were dried and atomized with a spray dryer. Let each be catalysts A, B, and C.

[Evaluation of catalytic decomposition characteristics]: ASTM standard fixed bed micro-activity test (Micro-Activit)
y Test) device, the catalytic cracking characteristics of the catalysts A to C were tested under the same raw material oil and the same measurement conditions. Prior to the test, each of the test catalysts A to C was set at 80% for simulated equilibration.
It was treated at 0 ° C. for 6 hours in a 100% steam atmosphere.
Desulfurized vacuum gas oil was used as the feedstock, and the test conditions were as shown in Table 7. Table 8 shows the test results. The conditions in Table 7 are the conditions in the fixed bed microactivity test apparatus adopted in this example, and do not necessarily match the conditions preferable in the industrial fluid catalytic cracking apparatus described in the text.

[0052]

[Table 7]

[0053]

[Table 8]

As is clear from Table 8, the catalysts A and B are
The conversion is higher than that of catalyst C, and the middle distillate (gasoline,
The yield of LCO) is also high, and the yield of heavy fraction (HCO) is low. That is, it can be seen that catalytic cracking of a hydrocarbon mixture using the catalyst containing the crystalline aluminosilicate obtained according to the present invention exhibits a remarkable effect of achieving high cracking activity.

[0055]

EFFECTS OF THE INVENTION According to the present invention, the stabilized Y zeolite is subjected to a thermal load under a specific condition (particularly, a condition that the temperature rising rate up to the calcination temperature is moderated), so that the crystal structure is not destroyed. It is possible to obtain a heat shock crystalline aluminosilicate having a characteristic of exerting a remarkable effect when used as a catalyst for catalytic cracking of hydrocarbon oil. Specifically, high catalytic activity can be achieved by catalytically cracking a hydrocarbon mixture using the catalyst composition containing the heat shock crystalline aluminosilicate. Further, since this heat shock crystalline aluminosilicate is excellent in hydrothermal stability, it can be expected that the life of the catalyst is extended and a stable product yield is obtained.

[Brief description of drawings]

FIG. 1 is a ²⁷ Al-MAS spectrum of a heat shock crystalline aluminosilicate obtained in Example 1 of the present invention.

FIG. 2 is a ²⁷ Al-MAS spectrum of the stabilized Y zeolite used in Example 1 of the present invention.

FIG. 3 is an X-ray diffraction pattern of the heat shock crystalline aluminosilicate obtained in Example 1 of the present invention with copper K-α rays.

Claims (1)

(57) [Claims] 1. A method for producing a crystalline aluminosilicate having excellent hydrothermal stability, wherein the SiO ₂ / Al ₂ O ₃ molar ratio is 5 to 11, and the unit cell size is 24.50 to 24.7.
2Å, alkali metal content is 0.02-1 in terms of oxide
Stabilized Y zeolite, which is wt%, is heated to 600 to 1200 ° C. at a rate of 1 to 15 ° C./minute, and at this temperature, 5 to 3
Decrease rate of crystallinity of the stabilized Y zeolite is 1 for 00 minutes
A method for producing a crystalline aluminosilicate, which comprises firing at 5% or less.