JPH0245501B2 - TANKASUISONORYUDOSETSUSHOKUBUNKAIYOSHOKUBAISOSEIBUTSU - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a catalyst composition useful for fluid catalytic cracking (FCC) of hydrocarbons, and more particularly to a fine zeolite coated with a single metal oxide and a dispersion thereof. FCC composed of a silica-based matrix containing
The present invention relates to a catalyst composition for use. As a catalyst for hydrocarbon FCC, porous inorganic oxides such as silica-alumina, silica-zirconia, silica-magnesia, and even silica-
Catalyst compositions in which fine zeolite is dispersed in a clay matrix have been known. However, in general, with this type of catalyst composition, there is a risk that the pores of the zeolite will be encapsulated by the matrix component, especially by the silica component in the matrix, and if this encapsulation occurs, the catalyst will not function properly. It is regrettable that the performance of the system will be significantly degraded. The present invention prevents the above-mentioned encapsulation by coating zeolite dispersed in a matrix with a single metal oxide, and has excellent decomposition activity, gasoline selectivity, hydrothermal stability, and resistance to metal poisoning. Ta
Provides a catalyst composition for FCC. That is, the catalyst composition according to the present invention consists of fine zeolite coated with a single metal oxide and a silica-based matrix containing the fine zeolite in a dispersed state. In the catalyst composition of the present invention, the zeolite coated with a single metal oxide includes both natural zeolites and synthetic zeolites. Preferred specific examples of synthetic zeolites include zeolite X,
Examples include Y, A, L, T, ultra-stabilized zeolite, mordenite, and ZSM-5. In particular, zeolite Y, which is widely used for catalytic cracking of hydrocarbons, is preferred as the zeolite of the present invention. Zeolite Y with a SiO ₂ /Al ₂ O ₃ ratio of 4 to 7 is S
Hydrothermal stability and metal resistance are inferior to zeolites such as mordenite and ZSM-5, which have a high iO ₂ /Al ₂ O ₃ ratio, so the effect of coating zeolite with a single metal oxide is significant. It is expressed in In the present invention, "zeolite" not only means crystalline aluminosilicate, but also substances in which part or most of the aluminum has been replaced with gallium, and materials in which part or most of the silicon of aluminosilicate has been replaced with germanium. It also includes substances that have been Zeolites generally have pore diameters greater than 3 Å, but particularly useful in FCC are zeolites with pore diameters greater than 4 Å. In addition, it is preferable that the zeolite used in the present invention has most of its alkali cations replaced by metals or mixtures of metals from Groups B of the Periodic Table through ion exchange. Particularly preferred zeolites are those in which a part of the alkali cations have been exchanged with metals other than alkali metals, in particular rare earth metal ions, and the remainder with hydrogen or hydrogen precursors. The zeolite coating material may be of any type as long as it is composed of a single type of metal oxide, but alumina, zirconia, magnesia, titania, etc. are generally preferred. And the metal oxide content of zeolite coated with a single type of metal oxide is 3~
Approximately 20wt% is allowed. In the present invention, when coating zeolite with metal oxide,
A fine zeolite is suspended in an acidic aqueous solution of a water-soluble metal salt corresponding to the metal oxide, preferably sulfate, nitrate, acetate, etc., and a basic solution, typically aqueous ammonia, is added to this suspension. In addition, a method is generally employed in which the metal in the liquid is deposited, for example, in the form of hydroxide, on the surface of the zeolite, and then the zeolite is separated from the liquid and dried at a relatively mild temperature. Taking the case of coating zeolite with alumina as an example, aluminum sulfate is used as the water-soluble metal salt, and the aqueous solution of aluminum sulfate is mixed with the zeolite treated with a colloid mill.
The pH of the mixed solution at this time is 3-4. Next, add ammonia water to this mixture while stirring,
After raising the pH of the liquid to about 9 and depositing aluminum hydroxide on the zeolite surface, it is aged at 80°C for 2 hours. The aluminum hydroxide coated zeolite is then separated from the liquid, washed with hot water, and then dried at 120° C. for about 12 hours. Note that if the thus dried coated zeolite is calcined in air at a temperature of 500° C. or higher, alumina will be detached from the zeolite surface during the preparation of the catalyst composition, leading to unfavorable results. Rare earth metal exchanged Y coated with 4.6wt% aluminum compound in terms of alumina by the above method
Transmission electron microscopy (180,000x magnification) revealed that in type zeolite, alumina precursors exist in a layered form with a thickness of 150 to 200 Å on the zeolite surface. In addition, the change in specific surface area was 561 m ² /g for Y-type zeolite before coating and 545 m ² /g after coating.
The residual rate of zeolite crystals was 98%. Furthermore, regarding the amount of Na ions in zeolite,
The zeolite containing 5.0 wt% (dry basis) sodium as Na ₂ O is coated with the above coating to reduce the sodium content to 2.25 wt % as Na ₂ O, but this is due to the process of preparing the catalyst composition for FCC. It is effective in easily removing sodium from the catalyst composition after spray drying. Just to be sure, depending on the conditions when zeolite is coated with a metal oxide, there is a possibility that metal may be newly incorporated into the zeolite lattice.
For example, when coating zeolite with zirconia,
When a highly acidic zirconium sulfate aqueous solution is used as a water-soluble metal salt aqueous solution, dealumination may occur from the zeolite crystal lattice when mixed with zeolite, and zirconium may be newly incorporated into the zeolite lattice. The situation is not necessarily disadvantageous to the present invention. The catalyst composition for FCC of the present invention is prepared by dispersing the metal oxide-coated zeolite described above in a silica-based matrix at a ratio of 5 to 40 wt%. Here, silica-based matrix refers to all materials that contain silica and are used as matrices of conventional FCC catalysts, including silica-alumina, silica-alumina-zirconia,
In addition to silica-alumina-magnesia, matrices containing clays of various compositions are included. Although the metal oxide-coated zeolite can be dispersed in the silica matrix by any known method, it is generally preferable to use a spray drying method. The method for preparing the catalyst composition of the present invention by spray drying using silica sol and kaolin as matrix precursors is as follows. The silica sol is prepared by rapidly adjusting the pH of a sodium silicate solution to a range of about 1.8 to about 3.0. Kaolin is added to the sodium silicate solution before the silica sol is prepared, or added to the silica sol. On the other hand, the zeolite coated with metal oxide is made into an aqueous slurry, and its pH is about 3 to about 4.5.
to hold. This aqueous slurry is then mixed with the kaolin-containing silica sol described above and the mixture is spray dried. Thereafter, the spray-dried composition is washed with water and then ion-exchanged with ammonium sulfate to remove Na from the composition, thereby obtaining the FCC catalyst composition of the present invention. Example 1 Y-type zeolite ion-exchanged with rare earth metals
An aqueous slurry was prepared by adding 8169 g of pure water to 3500 g (dry basis) and homogenized by passing it through a colloid mill twice. Next, 29.37 kg of a 2% aqueous aluminum sulfate solution was added to this aqueous slurry, and after stirring and mixing, 17.53 kg of a 2% aqueous ammonia solution was gradually added thereto while stirring was continued. The addition time was 4.5 hours and the final PH of the mixture
was 8.8. This mixture was aged at 80°C for 2 hours, filtered to collect a filter cake, washed with warm water, and heated at 120°C for 16 hours.
Dry for an hour. The resulting coated zeolite contained 6.2 wt% alumina on a dry basis. 1260 g (dry basis) of this coated zeolite was made into an aqueous slurry, passed through a colloid mill and homogenized, and then a 65% aqueous sulfuric acid solution was added thereto to adjust the pH of the slurry to 3.7. On the other hand, an acidic silica sol with a pH of 2.40 was prepared by quickly adding a 65% sulfuric acid aqueous solution to 12.15 kg of JIS No. 3 standard water glass (SiO ₂ concentration 9.88%), and this acidic silica sol was mixed into the above-mentioned aqueous slurry with a pH of 3.7. , followed by diyodiakaolin
1540g was added. of the mixed slurry at this point.
The pH was 2.9. This mixed slurry is heated with hot air at
Spray drying was performed at 220°C to obtain a dry composition. Next, the above dry composition is washed with warm water, and further
% ammonium sulfate solution. The washed cake was then ion-exchanged in a 2% ammonium sulfate solution for 20 minutes to remove Na ⁺ ions in the zeolite.
exchanged for NH ₄ ⁺ ions. After washing the ion-exchanged composition with 0.5% ammonia water and warm water, it was heated to 120°C.
and dried for 16 hours. The zeolite content of the resulting catalyst composition is approximately
The amount of residual sodium and sulfate ions were as follows. Na ₂ O: 0.25%, SO ₄ : 0.02% Example 2 29.37 kg of 2% aluminum sulfate aqueous solution used to coat the zeolite in Example 1 was replaced with 8750 g of 2% zirconium acetate aqueous solution, and 2. % ammonia aqueous solution usage from 17.53Kg
A catalyst composition was obtained in exactly the same manner as in Example 1 except that the weight was reduced to 10.0 kg. The amounts of residual sodium and sulfate ions in this composition were as follows. Na ₂ O: 0.35%, SO ₄ : 0.02% Comparative Example A catalyst composition was obtained in exactly the same manner as in Example 1, except that the zeolite was not coated with alumina.
The amounts of residual sodium and sulfate ions in this composition were as follows. Na ₂ O: 0.25%, SO ₄ : 0.02% Example 3 8169 g of pure water was added to 3500 g of Y-type zeolite (dry basis) with a SiO ₂ /Al ₂ O ₃ ratio of 4.8 that had been ion-exchanged with rare earth metals to make an aqueous slurry. was prepared and homogenized by passing it twice through a colloid mill. Next, 54.58 kg of a 2% aqueous magnesium acetate solution was added to this aqueous slurry, and after stirring and mixing, 27.4 kg of a 2% aqueous ammonia solution was gradually added thereto while stirring was continued. The addition time was 6.2 hours and the final PH of the mixture was 8.5. This mixture was aged at 80°C for 2 hours, filtered to recover a filter cake, washed with warm water, and dried at 120°C for 16 hours. The resulting coated zeolite contained 8.3 wt% magnesia on a dry basis. A catalyst composition was prepared in the same manner as in Example 1 using this magnesia-coated zeolite. The amounts of residual sodium sulfate ions in this composition were as follows. Na ₂ O: 0.91% SO ₄ : 0.02% Example 4 Implemented except that 26.25 kg of 2% titanium sulfate aqueous solution was used in place of 29.37 kg of 2% aluminum sulfate aqueous solution used to coat the zeolite in Example 1. A coated zeolite was obtained in exactly the same manner as in Example 1.
The resulting coated zeolite was 4.6wt% on a dry basis.
of TiO ₂ . Using this coated zeolite, a catalyst composition was obtained in the same manner as in Example 1. The amounts of residual sodium and sulfate ions in this composition were as follows. Na ₂ O: 0.33wt% SO ₄ : 0.02wt% Catalyst performance test 1 Using the ASTM standard microactivity test (ASTM MAT) equipment, the same feedstock oil,
The decomposition activity of each catalyst composition of Examples 1 to 4 and Comparative Example was tested under the same measurement conditions. Prior to the test, each test catalyst was calcined at 600℃ for 1 hour and then heated at 770℃ for 6 hours.
Processed in a steam atmosphere for 100% of the time and further heated to 600℃
The firing process was carried out for 1 hour. Kuwait desulfurized vacuum gas oil was used as the raw material oil, and the test conditions were as follows. The test results are shown in Table 1. Decomposition temperature: 482℃ WHSV: 16hr ^-1 Catalyst/Feedstock oil: 3.0 (weight ratio)

[Table] As is clear from Table 1, the catalyst compositions of Examples 1 to 4 have higher conversion rates and gasoline yields than those of Comparative Examples, and are excellent in gasoline selectivity. Catalytic Performance Test 2 The catalyst's resistance to nickel poisoning and vanadium poisoning was tested using the same equipment, feedstock oil, and measurement conditions as in Performance Test 1 above. For metal poisoning of the catalyst, nickel naphthenate and vanadium naphthenate are used. The catalyst is impregnated with a predetermined amount of metal in advance and dried. Then, the catalyst is calcined at 600℃ for 1 hour, and then heated at 770℃ for 6 hours.
It was buried in a steam atmosphere for 100% of the time, then fired at 600°C for an additional hour, and then used for testing. The test results are shown in Tables 2, 3 and 4.

[Table] Yield decrease rate

[Table] Rate of decrease in yield

【table】

[Table] * Percentage of decrease in each yield with respect to the conversion rate and gasoline yield in Table 1 As is clear from the test results shown in Tables 2 and 3, the catalysts of Examples 1 to 4 were The percentage decrease in yield is small. Furthermore, from the results in Table 4, it can be seen that even when the catalysts of Examples 1 to 4 were poisoned with vanadium, the rate of decrease in conversion rate and gasoline yield was small.

Claims (1)

[Scope of Claims] 1. In a catalyst composition for hydrocarbon fluid catalytic cracking comprising fine zeolite dispersed in a silica-based matrix, the zeolite is coated with a single metal oxide in the matrix. A catalyst composition for fluid catalytic cracking of hydrocarbons, characterized in that the composition is dispersed in: 2. The catalyst composition according to claim 1, wherein the zeolite coated with a single metal oxide has a metal oxide content of 3 to 20 wt%. 3. The catalyst composition of claim 1, wherein the content of zeolite coated with a single metal oxide is 5 to 40 wt% of the composition.