JPH0356781B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for preparing a hydrocarbon conversion catalyst, and more particularly to a method for preparing a hydrocarbon conversion catalyst comprising a crystalline aluminosilicate zeolite and an alumina-magnesia matrix. This method is characterized by adsorbing a basic compound onto zeolite before mixing. A catalyst consisting of crystalline aluminosilicate zeolite and alumina-magnesia matrix can be used for catalytic cracking of hydrocarbons, hydrocracking, alkylation, polymerization, hydrodemetallization, isomerization, disproportionation of toluene, etc. It is particularly suitable as a catalyst for the catalytic cracking of heavy oils containing 0.5 ppm or more of heavy metals such as nickel, vanadium, and iron. In normal catalytic cracking, petroleum hydrocarbons are cracked by contacting them with a catalyst to obtain a large amount of light components such as LPG and gasoline and a small amount of cracked light oil, and then the coke deposited on the catalyst is burned off with air. The catalyst is recycled and reused. In this case, so-called distillate oils such as light gas oil (LGO), heavy gas oil (HGO) from atmospheric distillation towers, and vacuum gas oil (VGO) from vacuum distillation towers are traditionally used as feedstock oils. . However, recently, the world's crude oil has become heavier,
In addition, as the demand structure in Japan has changed, there has been a tendency for heavy oils to be in surplus from both the supply and demand perspective, so it has become necessary to target heavy oils containing distillation residues as raw materials for catalytic cracking. However, heavy oil containing distillation residue contains much higher amounts of metals such as nickel, vanadium, iron, copper, and sodium than distillate oil, and these metals are not present on the catalyst. It is known that it accumulates and significantly inhibits the activity and selectivity of degradation. In other words, as metals accumulate on the catalyst, the decomposition rate decreases, making it practically impossible to achieve the desired decomposition rate, while the amount of hydrogen and coke generated increases significantly, making it difficult to operate the equipment. At the same time, the yield of the desired liquid product is reduced. An object of the present invention is to provide a method for preparing a catalyst suitable for a conversion reaction of hydrocarbon oil. In particular, heavy metals such as nickel, vanadium, and iron are 0.5ppm.
The purpose of the present invention is to provide a method for preparing a catalytic cracking catalyst with high metal resistance that can suppress the amount of hydrogen and coke produced without reducing the yield of gasoline and middle distillates when cracking heavy oil containing the above. shall be. The present inventors have previously discovered that a catalyst composed of crystalline aluminosilicate zeolite and an alumina-magnesia matrix serves as a catalytic cracking catalyst with high metal resistance (Japanese Patent Application No. 58-22901). The catalyst can be obtained by mixing alumina/magnesia hydrogel and zeolite, drying and calcining, or by mixing calcined alumina/magnesia and zeolite in an aqueous or non-aqueous solvent and evaporating to dryness. However, magnesia or magnesium hydroxide shows basicity in water, so if zeolite, which is a solid acid, and magnesia or magnesium hydroxide are mixed in water, some of the acidic points in the zeolite may be poisoned by the magnesium. . This results in a decrease in the number of acidic sites, which are active sites of the catalytic cracking catalyst, which is undesirable and leads to a decrease in catalytic activity. The present invention has been researched and developed to improve the above-mentioned drawbacks. In the present invention, when preparing a catalyst containing 3 to 40 wt% of crystalline aluminosilicate zeolite and 60 to 97 wt% of alumina-magnesia matrix,
The present invention provides a method for preparing a hydrocarbon conversion catalyst, characterized in that a basic compound is adsorbed on the zeolite in advance before mixing the zeolite and alumina/magnesia. The alumina/magnesia matrix referred to in the present invention is a synthetic product mainly composed of alumina (Al ₂ O ₃ )/magnesia (MgO) or a processed product of naturally occurring clay minerals, and has a magnesia content of 2 to 2. 50 wt%, preferably 4 to 30 wt% is used. When the magnesia content in the matrix is less than 2 wt%, the characteristic effects seen in the present invention do not appear. Furthermore, if the magnesia content is more than 50 wt%, sufficient catalytic activity cannot be obtained. The above matrix can be prepared by any method. An example of this is as follows. A mixed aqueous solution of an aluminum salt and a magnesium salt is reacted with ammonia to form an alumina/magnesia hydrogel slurry. The type of salt at this time is not particularly limited, but chlorides, nitrates, and sulfates are preferred. Next, the hydrogel slurry is aged, filtered, washed with a sufficient amount of pure water, dried at, for example, 110°C for a day and night, and air-calcined at 500-600°C for 4-10 hours. The specific surface area of the matrix thus obtained is 50-300 m ² /g, and the pore volume is 0.1-1.2
cc/g, and the average pore diameter is 10-200 Å. The crystalline aluminosilicate zeolite used dispersed in the matrix of the present invention is a natural or synthetic crystalline aluminosilicate having a three-dimensional framework structure and a uniform pore size ranging from about 4 to about 15 Å. It is a porous material. Natural zeolites include gmelinite, siabasite, dachyaldofutuite, clinoptilolite, hojiasite, kiftuite, houfutuite, levinite, erionite, sodalite, cancrinite, ferrierite, brillustafutuite, offretite, sodafutuite, mordenite, etc. Any one of these may be used, but hojasite is most preferred.
As synthetic zeolites, zeolites X, Y, A,
L, ZK-4, B, E, F, HJ, M, Q, T,
Any of W, Z, alpha, beta, ZSM type, omega, etc. zeolites may be used, but Y type and X type zeolites or mixtures thereof are most preferred. It is well known that when using zeolite as a highly active catalytic cracking catalyst, it is desirable to reduce the Na ₂ O content in the zeolite as much as possible. Zeolites with high Na ₂ O content not only have low activity but also poor heat resistance, which shortens catalyst life. Na ions in zeolite can be exchanged with other cations, and the ion exchange method can reduce the Na ₂ O content in zeolite. Calcium, magnesium, hydrogen, rare earth elements, platinum, and palladium are suitable as cations, and when used as a catalytic cracking catalyst, hydrogen and rare earth elements or mixtures thereof are particularly suitable. The method for producing the zeolite is not particularly limited, and the zeolite can be produced, for example, by the following method.
Mix Na-Y type zeolite, rare earth element chloride, and ammonium chloride, and mix this mixture for 60~
Stir at 100°C for 2 to 10 hours to perform ion exchange.
The above ion exchange operation is repeated 2 to 5 times as necessary. Next, the filtered zeolite is dried at 80-150°C for a day and night, and then air-calcined at 400-650°C for 2-10 hours. The content of Na ₂ O in the zeolite thus obtained is 0.5 to 2.0 wt%,
By further ion exchange after air firing,
The Na ₂ O content is less than 1wt%. The basic compound to be adsorbed to the crystalline aluminosilicate zeolite as used in the present invention is such that when the basic compound is adsorbed to the zeolite and then the catalyst is air-calcined, the basic compound is desorbed from the catalyst or burned and remains in the catalyst. Preferably one without. For example, aliphatic amines (methylamine, butylamine, etc.), aromatic amines (aniline, toluidine, etc.),
Examples include organic basic compounds such as cyclic amines (pyridine, piperidine, etc.) or ammonia. The method for preparing the catalyst of the present invention involves adsorbing a basic compound onto a crystalline aluminosilicate zeolite and then mixing it with an alumina-magnesia matrix. The method for adsorbing the basic compound onto the zeolite may be either gas phase adsorption or liquid phase adsorption, and is carried out to the extent that the acidic points of the zeolite are neutralized. In gas phase adsorption, the vapor of a basic compound is collected at a temperature of 20 to 100℃.
It is adsorbed onto the zeolite for a contact time of 5 minutes to 2 hours. In liquid phase adsorption, the zeolite is immersed in an aqueous or non-aqueous solvent containing a basic compound at a temperature of 20 to 20°C.
After standing at 50°C for a contact time of 5 minutes to 2 hours, the solvent is removed. By adsorbing a basic compound on the zeolite in advance in this manner, the acidic sites of the zeolite are protected even after the zeolite and alumina-magnesia matrix are mixed, making it possible to obtain a highly active catalyst. The zeolite adsorbed with basic compounds is then mixed with an alumina-magnesia matrix.
The zeolite content at this time is 3 to 40 wt%, preferably 5 to 30 wt%. If the zeolite content is less than 3 wt%, the catalyst activity will be low, which is not preferable. In addition, the content of zeolite
If it is more than 40 wt%, the catalyst activity is too high, causing over-decomposition and reducing the yield of the desired product. The method of mixing the zeolite adsorbed with the basic compound of the present invention and the matrix is not particularly limited. For example, the zeolite slurry may be heated and mixed with a matrix using an aqueous or non-aqueous solvent and then dried, or the zeolite and the matrix may be simply mixed mechanically. Alternatively, in the matrix manufacturing process, the zeolite slurry may be mixed with an aged, filtered, and washed hydrogel slurry of the matrix, and the mixture may be spray-dried and then air-calcined at 500-600°C for 4-10 hours. In this case, a binder such as alumina sol or silica sol may be added, and this is also within the scope of the present invention. Example 1 (A) An alumina-magnesia matrix was prepared as follows. 92g of aluminum nitrate and
Dissolve 16g of magnesium nitrate in 1 part of pure water. Add the above mixed solution dropwise into 4N ammonia water while stirring vigorously so that the final pH is 10. Filter the resulting precipitate and wash with a sufficient amount of pure water. (B) La, H-Y type zeolite was prepared from Na-Y type zeolite as follows. Put 20g of Na-Y type zeolite, 83g of lanthanum chloride, and 15g of ammonium chloride into a beaker from Step 2, and add pure water to the beaker so that the total volume is 1. This is heated to about 80°C and stirred with a magnetic stirrer for 3 hours, then filtered and washed with pure water from Step 1. After repeating the above operation three times, it was dried in an oven at 110°C for a day and night, and then air-baked at 540°C for 3 hours. Finally, the above ion exchange operation is performed one more time, and after washing and drying, the product is baked at 500°C for 2 hours. The La exchange rate of the La, H-Y type zeolite obtained in this way is 77%.
The amount of residual Na ₂ O was 0.81wt%. Let the zeolite prepared in (B) adsorb 2.65 g of ammonia gas at room temperature for 30 minutes. By this operation, all the acidic points of the zeolite are neutralized by ammonia. Next, pure water is added to the zeolite pre-adsorbed with ammonia to form a slurry, and the slurry is kneaded with the entire amount of the alumina-magnesia hydrogel prepared in (A). After adjusting the viscosity of the gel by adding pure water, it is spray-dried.
It is then air fired at 500°C for 4 hours. The composition of the final composition is shown in Table 1. Next, the activity and selectivity of the above catalyst was determined by ASTM (D
-3907) Evaluated by MAT (microactivity test). In addition, in order to examine the nickel resistance of the catalyst, 1wt% nickel was added to the catalyst.
Mitchell's method (Ind.Eng.Chem., Prod.Res.
Dev., 19 , 209 (1980). That is, the catalyst is impregnated with a toluene solution of nickel naphthenate, the solvent is evaporated, and then this is
Air firing was performed at 550°C for 3 hours. In addition, in order to make the performance of the catalyst obtained in this way the same as that of the equilibrium catalyst,
The catalyst was steamed at 770°C for 6 hours before being subjected to MAT. The reaction conditions for MAT are WHSV16hr ^-1 ,
The catalyst/oil ratio was 3, the reaction temperature was 482℃, and the feedstock oil was
It is an ASTM standard oil. The MAT results are shown in Table 1. Here, the decomposition rate in the table is defined as follows. Decomposition rate = Feedstock oil - fraction with a boiling point of 216°C or higher / Feedstock oil × 100 (wt%) Examples 2 to 3 and Comparative Example 1 2.65 g of zeolite prepared in (B) of Example 1
- After leaving it in saturated vapor of butylamine or piperidine for 30 minutes at room temperature to adsorb these basic compounds, it is mixed with a matrix prepared in the same manner as in Example 1, and a catalyst is prepared in the same manner as in Example 1. We conducted an evaluation. As a comparative example, a catalyst prepared without pre-adsorbing a basic compound onto zeolite was also evaluated. As a result, as shown in Table 1, it is found that the catalytic activity is significantly increased by adsorbing a base on zeolite in advance. In addition, the strength of these bases is determined from the pKb values shown in Table 2.
The order is n-butylamine>ammonia, which agrees well with the order of activity. That is, in order to obtain a highly active catalyst, it is preferable that the strength of the base to be adsorbed is strong.

【table】

【table】

Claims (1)

[Claims] 1 Crystalline aluminosilicate zeolite from 3 to
40wt%, alumina/magnesia matrix
A method for preparing a hydrocarbon conversion catalyst, characterized in that, in preparing a catalyst containing 60 to 97 wt%, a basic compound is previously adsorbed on the zeolite before mixing the zeolite and alumina/magnesia.