JP2740800B2 - Catalyst composition for catalytic cracking of hydrocarbons - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a catalyst composition for catalytic cracking of hydrocarbons, and more particularly to a catalyst for heavy hydrocarbons containing metal contaminants such as hydrocarbons, particularly vanadium. The present invention relates to a catalyst composition for hydrocarbon catalyst decomposition, which is used for cracking and has a small decrease in activity and selectivity of the catalyst and has excellent vanadium resistance.

[Prior art and its problems]

Conventionally, in the catalytic cracking of heavy hydrocarbons containing metal contaminants such as vanadium, vanadium deposited on the catalyst destroys the crystal structure of the crystalline aluminosilicate zeolite that is the active component, resulting in a significant decrease in catalyst activity It is also known that in order to inactivate metal contaminants such as vanadium deposited on the catalyst, various compounds are contained as a metal scavenger to improve the metal resistance. It has been proposed (for example,
-149241, JP-A-62-38242).

However, although alkaline earth metals, especially calcium compounds, have an excellent effect of inactivating metal contaminants,
In a catalyst composition in which this is dispersed in an inorganic oxide matrix as a metal scavenger, calcium migrates during use of the catalytic cracking reaction of the catalyst composition, lowering the thermal stability of the crystalline aluminosilicate zeolite and reducing the crystal structure. There is a problem that the activity of the catalyst for destroying the catalyst decreases, or the octane value (RON) of the gasoline product obtained by the catalytic cracking reaction decreases because it is incorporated by ion exchange into the crystalline aluminosilicate zeolite. .

Therefore, when a calcium compound is used as a metal scavenger, a specific calcium compound such as CaSnO ₃ is used as disclosed in JP-A-62-38242,
Alternatively, it has been proposed that catalyst particles containing a crystalline aluminosilicate zeolite and particles made of calcium oxide and alumina are physically mixed and used (for example, JP-A-61-204042).

[Object of the invention]

The present invention is a catalyst composition in which a calcium compound is dispersed as a metal scavenger in an inorganic oxide matrix, which is used for catalytic cracking of heavy hydrocarbons to use the catalyst for its activity, selectivity and octane number of gasoline products. An object of the present invention is to provide a catalyst composition for catalytic cracking of hydrocarbons, which has a small decrease in (RON) and is excellent in metal resistance, particularly in vanadium resistance.

Another object of the present invention is to provide a catalyst composition using a calcium compound which can be obtained at low cost as a metal scavenger dispersed in an inorganic oxide matrix.

[Summary of the Invention]

The present invention relates to a catalyst composition for catalytic cracking of hydrocarbons, comprising a crystalline aluminosilicate zeolite and a crystalline calcium aluminate dispersed in an inorganic oxide matrix.

[Specific description of the invention]

 Hereinafter, the present invention will be described specifically.

The catalyst composition for catalytic cracking of hydrocarbons according to the present invention contains 5 to 50% by weight, preferably 5 to 40% by weight of crystalline aluminosilicate zeolite and 3 to 50% by weight, preferably 5 to 5% by weight of crystalline calcium aluminate. It is desirable to contain 30% by weight and an inorganic oxide matrix in the range of 10 to 90% by weight, preferably 20 to 90% by weight.

The catalyst composition of the present invention can be produced by mixing a crystalline aluminosilicate zeolite and a crystalline calcium aluminate with an inorganic oxide matrix precursor and spray-drying the crystalline aluminosilicate zeolite. X-type zeolites, Y-type zeolites, mordenites, synthetic and natural zeolites such as ZSM-type zeolites, etc., can be used, as in the case of ordinary catalyst decomposition catalyst compositions, from hydrogen, aluminum and polyvalent metals. Used in ion-exchanged form with the selected cation. Y-type zeolites, especially superstable Y
Type zeolites are preferred because of their excellent hydrothermal stability.

The crystalline calcium aluminate in the present invention is a general term for a compound in which calcium oxide and alumina are bonded, and contains a crystal that can be detected by X-ray diffraction.
In particular, those having a molar ratio of CaO / Al ₂ O ₂ of 1 or less are preferable.

Such a crystalline calcium aluminate can be obtained, for example, by calcining a mixture of calcium oxide or calcium carbonate and alumina at a temperature of 1000 ° C. or more for 0.2 hours or more, preferably 0.5 to 10 hours. Specific examples of the crystalline calcium aluminate in the present invention include CaAl ₂ O ₄ (CaO, Al ₂ O ₃ ) and Ca ₃ Al ₂ O ₆ (3CaO, Al ₂ O ₃ )
In addition to the above, there are substances having a molar ratio of CaO to Al ₂ O ₃ different from that described above. In particular, alumina cement is inexpensive and preferable.

The crystalline calcium aluminate in the present invention is preferably one in which calcium is incorporated in the crystal structure and free calcium does not exist. Calcium incorporated into the crystal structure does not migrate when dispersed in an inorganic oxide matrix, so vanadium traps without adversely affecting catalyst activity, selectivity, gasoline product octane number (RON), etc. It has excellent effects as an agent.

The crystalline calcium aluminate of the present invention is preferably in the form of particles, and the average particle diameter is preferably 60 μm or less, and more preferably 0.1 to 30 μm. When the particle size exceeds 60 μm, the catalyst composition finally obtained is not desirable as a catalyst for a fluidized bed because the average particle size is generally in the range of 40 to 100 μm.

Further, the inorganic oxide matrix of the present invention, silica,
Silica-alumina, alumina, silica-magnesia, alumina-magnesia, phosphorus-alumina, silica-zirconia, silica-magnesia-alumina and other conventional matrix components used in conventional catalytic cracking catalysts that act as binders. Such matrix components include inorganic oxides other than crystalline calcium aluminate,
For example, kaolin, halloysite, montmorillonite, and the like are also contained.

The catalyst composition of the present invention was obtained by adding a crystalline aluminosilicate zeolite and a crystalline calcium aluminate to a precursor of the aforementioned inorganic oxide matrix, for example, silica hydrosol, silica-alumina hydrogel, etc., and uniformly dispersing the resultant. It can be manufactured by spray drying the mixture slurry as usual. Then, the spray-dried particles are washed as necessary, and after the washing, they are dried or dried and fired again.

It is also possible to introduce a rare earth into the catalyst composition of the present invention by an ordinary method.

The catalyst composition of the present invention is particularly suitable for use in catalytic cracking of heavy hydrocarbons containing metal contaminants such as vanadium, but can also be used for catalytic cracking of hydrocarbons containing no metal contaminants. For the catalytic cracking using the catalyst composition, ordinary catalytic cracking conditions are employed.

〔Example〕

 Hereinafter, the present invention will be described specifically with reference to Examples.

CaCO ₃ 100 g of fine powder having a crystal structure of Example -1 aragonite
Of fine powder of bauxite 118 having an Al ₂ O ₃ content of 86.6% by weight
Mix well with g. The mixture was calcined at 1380 ° C. for 1 hour to melt, and then cooled to obtain a solid. Next, the solid was pulverized to obtain fine calcium aluminate having an average particle diameter of 30 μm. The fine calcium aluminate is Ca
The O / Al ₂ O ₃ molar ratio was 1.0, and a peak corresponding to a crystal of calcium aluminate and another crystal peak were shown by X-ray diffraction. Next, 5% by weight of sulfuric acid was added to water glass and adjusted.
350 g (dry basis) of Y-type crystalline aluminosilicate zeolite (NH ₄ Y zeolite) obtained by exchanging 4000 g of silica hydrosol containing SiO ₂ at an exchange rate of 95% with ammonium ion and 400 g (dry basis) of kaolin clay were added. Was added to obtain a mixed slurry.

This mixed slurry was spray-dried, washed, and dried to obtain a catalytic cracking catalyst composition of the present invention. This catalyst composition contains 5% by weight of crystalline calcium aluminate particles, 35% by weight of NH ₄ Y zeolite, and 60% by weight of an inorganic oxide matrix as a metal scavenger.
It was 68 μm. This catalyst composition is referred to as catalyst B.

In the same manner as above, using kaolin clay as a balance material, the amount of crystalline calcium aluminate particles added was changed to 0 (a catalyst containing no crystalline calcium aluminate particles: control catalyst) and 10, 20, and 50% by weight. A catalyst was prepared.

 These catalyst compositions are referred to as A, C, D, and E, respectively.

Example 2 Using CaCO ₃ and bauxite used in Example 1, mixing was performed so that the molar ratio of CaO / Al ₂ O ₃ would be 0.1, 0.5, 0.7, and 1.5, respectively, and further 5 hours at 1100 ° C. Calcination gave a solid. Grind each solid and average particle size 10μ
m of calcium aluminate particles were obtained. Each of these crystalline calcium aluminate particles showed a peak corresponding to a crystal of calcium aluminate and another crystal peak by X-ray diffraction.

Then, in exactly the same manner as in Example 1, a catalytic cracking catalyst composition containing 20% by weight of each of the above calcium aluminate particles was prepared.

The catalyst compositions corresponding to the CaO / Al ₂ O ₃ molar ratio of 0.1, 0.5, 0.7, 1.5 are designated as F, G, H, I.

The reference catalysts A prepared in Comparative Example 1 in Example 1 was impregnated with an aqueous CaCl ₂ solution such that 5% by weight of the catalyst composition as CaO.

Then, after drying at 120 ° C., it is calcined at 600 ° C. for 2 hours to obtain Ca
A catalyst composition J having O was prepared.

Comparative Example 2 Catalyst composition K containing 20% by weight of θ-alumina particles in exactly the same manner as in Example 1, except that θ-alumina particles having an average particle diameter of 10 μm were used instead of the crystalline calcium aluminate particles. Was prepared.

Comparative Example-3 An example using a magnesium silicate mineral (sepiolite) instead of the crystalline calcium aluminate particles
In exactly the same manner as in Example 1, a catalyst composition L containing 20% by weight of sepiolite particles was prepared.

Comparative Example-4 A mixture of sodium aluminate having an alumina concentration of 2.6% by weight and an aluminum sulfate aqueous solution having an alumina concentration of 1.3% by weight was mixed.
An alumina mixture slurry having an alumina concentration of 2% by weight and a pH of 9.5 was obtained. The prepared alumina slurry was filtered and washed to obtain a pseudo-boehmite gel having an alumina concentration of 5% by weight.

This pseudo-boehmite gel CaCl ₂ aqueous solution is added so that the CaO / Al ₂ O ₃ molar ratio becomes 1.0, and the mixture is aged by stirring at 80 ° C. for 3 hours, then dried at 110 ° C., and calcined at 600 ° C. for 2 hours. give CaO-Al ₂ O ₃ oxide (X) Te.

The CaO-Al ₂ O ₃ by crushing part of the oxide (X) to give the oxide particles having an average particle diameter of 10 [mu] m. The oxide particles are X
No peak corresponding to the crystal of calcium aluminate was observed in -line diffraction.

Using this CaO-Al ₂ O ₃ oxide particles were prepared CaO-Al ₂ O ₃ oxide catalyst composition comprising 20 wt% of particles M in exactly the same manner as in Example 1.

Example 3 The CaO—Al ₂ O ₃ oxide (X) prepared in Comparative Example-4 was further calcined at 1380 ° C. for 1 hour and then pulverized to obtain an average particle diameter of 10 μm
m of calcium aluminate particles were obtained.

The calcium aluminate particles showed a peak corresponding to a crystal of calcium aluminate by X-ray diffraction.

Using the crystalline calcium aluminate particles, a catalyst composition N containing 20% by weight of the crystalline calcium aluminate particles was prepared in the same manner as in Example 1.

Example-4 [Use Example] For each of the catalysts A to N of the example and the comparative example,
Performance evaluation by ASTM MAT was performed.

First, in order to examine the metal resistance, nickel and vanadium, Ni + V amount (V / Ni = 2) 1 were added to each catalyst as follows.
0,000 ppm was deposited. That is, each catalyst is pre-
After calcination for 1 hour, a predetermined amount of a benzene solution of nickel naphthenate and vanadium naphthenate was absorbed by each catalyst, then dried at 110 ° C., and then calcined at 600 ° C. for 1.5 hours.
Thereafter, each catalyst was subjected to a steam treatment at 770 ° C. for 6 hours and calcined again at 600 ° C. for 1 hour for pseudo equilibrium. Also,
The respective catalysts on which nickel and vanadium had not been deposited were also steamed at 770 ° C. for 6 hours for pseudo-equilibration, and then calcined at 600 ° C. for 1 hour.

ASTM MAT was performed using the catalysts thus pretreated.
An evaluation test was performed. The results are shown in Table 1. The reaction conditions are as follows.

Feed oil: Degassed vacuum gas oil Reaction temperature: 482 ° C Space velocity: 16hr ^-1 Catalyst / oil ratio: 3 (weight) [Effects] The catalyst composition of the present invention is used for catalytic cracking of heavy hydrocarbons. As can be seen from Table 1, even when metal contaminants such as vanadium and nickel are deposited, high conversion and high gasoline yield are obtained. Indicates the rate.

In the case of the catalyst composition of the present invention in which calcium aluminate added as a metal scavenger is crystalline (for example, catalyst N), excellent metal resistance is obtained as compared with the case of amorphous calcium aluminate (catalyst M). Show.

Further, the catalyst J in which θ-alumina was added as a metal scavenger shows a high addition rate like the catalyst of the present invention, but the amount of hydrogen coke generated is larger than that of the catalyst of the present invention, and the gasoline yield is lower. .

Claims (1)

(57) [Claims] 1. A catalyst composition for catalytic cracking of hydrocarbons comprising a crystalline aluminosilicate zeolite and a crystalline calcium aluminate dispersed in an inorganic oxide matrix.