JPH05178610A - Production of crystalline aluminosilicate - Google Patents

Abstract

PURPOSE:To provide a producing method of a crystalline aluminosilicate excellent in hydrothermal stability and suitable as a catalyst for catalytic decomposition of hydrocarbon oil. CONSTITUTION:The crystalline aluminosilicate is produced by raising temp. of a stabilized Y-zeolite, having 5-11 molecular ratio of SiO2/Al2O3, 24.50-24.72Angstrom unit lattice dimension and 0.02-1wt.% alkali metal content expressed in temp. of the oxides, up to 600-1200 deg.C in a rate of 1-15 deg.C/min and by calcining at this temp. for 5-300min in <=15% crystallinity decreasing rate. Decrease in crystallinity of the produced zeolite is suppressed without breaking the crystalline structure in temp. raising process till the calcining temp. if raising temp. is in a rate of 1-15 deg.C/min and the product having excellent property as a catalyst for catalytic decomposition of hydrocarbon is obtained.

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 the stabilized Y zeolite to a constant thermal load.

[0002]

2. Description of the Related Art Generally, in petroleum refining, it is an important issue to produce gasoline in good yield, and for the purpose of producing gasoline, light 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 and 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 decrease, 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, and thus carbonization is performed. 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 conducted extensive studies 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 discovering 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, which is 2-1% by weight, at 1-15 ° C.
The temperature is increased to 600 to 1200 ° C. at a rate of / min, and at this temperature,
It is characterized by being calcined for 5 to 300 minutes at a crystallinity reduction rate of 15% or less of the stabilized Y zeolite.

In the present invention, the stabilized Y zeolite used as a starting material is so-called Y zeolite at high temperature,
After several steam treatments, 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 ethylenediamineacetic acid (EDTA). And is resistant to deterioration of crystallinity. Of course, as the stabilized Y zeolite, Y zeolite can be used as ammonium hexafluorosilicate [(NH ₄ ) ₂ SiF ₆ ].
Or obtained by treating with a silicon compound such as silicon tetrachloride (SiCl ₄ ) may be used, or treated with a compound containing no silicon such as EDTA or phosgene (COCl ₂ ). 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]

[Chemical 1]

The stabilized Y zeolite used as a raw material in the present invention has a low content of R _{2 / m 2} O, and has a coefficient of 0.02 to 1.0 as shown in Chemical formula 1. 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 temperature (at speed) to the firing temperature. Thermal load is about 600-120
At a temperature of 0 ° C, preferably about 600-1000 ° C, about 5
The calcining may be carried out 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 will collapse, and conversely, if it is too slow, the productivity of the crystalline aluminosilicate will deteriorate. In this way, a crystalline aluminosilicate having good 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 crystal structure from collapsing. In order to achieve this, it is indispensable 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 raising time is too short, the crystal structure of zeolite will collapse. Normally, firing is performed in an electric furnace or a firing furnace under atmospheric pressure or normal pressure in a nitrogen atmosphere. However, firing is performed by leaving it in an electric furnace in an air or nitrogen atmosphere with a steam partial pressure of 0 to 0.5 atm. May be. Moderate humidity easily causes dealumination, and can cause heat shock even in the vicinity of a relatively low temperature within the above temperature range.

Moreover, under heat shock conditions, it is desirable to prevent the crystal structure of the zeolite from collapsing 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 obtained 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 equation 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, which is performed prior to the catalyst performance evaluation test.

Further, in the present invention, the heat-shock crystalline aluminosilicate is obtained by heat-treating the stabilized Y zeolite, but if the heat-treatment of the Y zeolite is attempted to directly produce the heat-shock crystalline aluminosilicate, the crystal is 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. Presumably because 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 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 from the SiO ₂ / Al ₂ O ₃ molar ratio by the chemical composition analysis and the unit cell size by the formulas (1) to (3) shown in Formula 2 (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 the other formulas are used, the above values are not obtained.

When the bulk SiO ₂ / Al ₂ O ₃ molar ratio is the same, if the Al molar ratio in the zeolite skeleton to the total Al is too small, the catalytic activity required for catalytic cracking is lost. When the proportion of Al outside the skeleton, that is, the proportion of amorphous Al, becomes higher, 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 will decrease, but the hydrothermal resistance of the catalyst will decrease, and the amount of coke produced will also increase.

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. Further, 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 those of tetracoordinate Al, that is, the peaks due to Al in the crystal lattice, the peaks are those of pentacoordinate Al, and the peaks are those of hexacoordinate A.
1 that is, a peak due to Al outside the crystal lattice. 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 presumed that the form of unstable Al on the way 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 pentacoordinate Al appears even after a long time elapses, but it is hidden by the peak when it is in a hydrated state, and the pentacoordinate peak cannot be detected.
In addition, the above-mentioned hydrated state means a state in which the heat shock crystalline aluminosilicate reaches in about 1 week after leaving it 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 according to the present invention has substantially 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) have the measured lattice spacing (d) of 14.1 ± 0.2Å, 5.61 ± 0.1Å, and 3.72 ± 0. It is 1 Å.

[0033]

[Table 3]

To carry out catalytic cracking of hydrocarbon oils using the heat shock crystalline aluminosilicate obtained according to the present 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, the mixture of the heat shock crystalline aluminosilicate and the 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,
The catalyst particles can be obtained 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,
The inorganic oxide matrix may be added in an amount of preferably about 10 to 50% by weight, and 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, the 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 cracking reactor and a catalyst regenerator, which are vertically installed. .. 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 substances 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 one or more heavy fractions such as slurry oil. 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 normal 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 previously 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 study by the present inventors, it was found that the crystallinity was considerably lowered at the temperature rising 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 investigations in order to find a method that does not decrease the crystallinity in the temperature rising process until the firing temperature is reached, the slowest heating rate is the most. After obtaining the knowledge that it is an economical method, and further studying it, 1 to 15 ° C./minute was selected as this rate.

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 in 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 which is carried out with the content controlled to be not more than%, the crystalline structure is stably maintained, and a crystalline aluminosilicate 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 properties shown in Table 4. Further, the crystallinity is 110% after the heat shock, compared to 110% of the stabilized Y zeolite as the raw material.
% (Decrease in crystallinity of 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.
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. Further, the crystallinity was 87% after the heat shock against 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 heating rate up to the firing temperature is high (the heating 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, 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. Of 35 wt% and kaolin were 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 microactivity test (Micro-Activit)
y Test) device, the catalytic cracking characteristics of the catalysts A to C were tested under the same feedstock 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. The test results are shown in Table 8. 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 fluidized 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 when catalytic cracking of a hydrocarbon mixture is carried out using a catalyst containing the crystalline aluminosilicate obtained by the present invention, a remarkable effect that a high cracking activity can be achieved is exhibited.

[0055]

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 cracking activity can be achieved by catalytically cracking a hydrocarbon mixture using the catalyst composition containing this 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 the 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 copper K-α ray of the heat shock crystalline aluminosilicate obtained in Example 1 of the present invention.

Claims (1)

[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% by weight, is heated to 600 to 1200 ° C. at a rate of 1 to 15 ° C./min, and at this temperature, 5 to 3 ° C.
Decrease rate of crystallinity 1 of the above-mentioned stabilized Y zeolite for 1 hour
A method for producing a crystalline aluminosilicate, which comprises firing at 5% or less.