JPS6178897A - Catalytic cracking of heavy hydrocarbon oil - Google Patents

Abstract

PURPOSE:To effect catalytic cracking of a stock oil efficiently, maintaining high yields of gasoline for a long period of time, by bringing a heavy hydrocarbon oil into contact with a mixture of particles comprising a specified cracking catalyst and alumina powders under cracking conditions. CONSTITUTION:A high-grade heavy hydrocarbon oil or a low-grade heavy hydrocarbon oil having a metal content of about 50ppm (on a metal basis) is brought into contact with a mixture of particles which consists of 80-20wt% cracking catalyst obtained, for example, by dispersing at least 10wt%, based on the mixture of particles, crystalline aluminosilicate in a matrix comprising a porous inorganic oxide, and 20-80wt% Al2O3 particles having an average particle diameter of 20-80mum and a bulk density of 0.60-1.20g/ml, prepared by burning Al(OH)3 of an average particle diameter of 20-80mum, obtained by the Bayer process, under cracking conditions, such as 460-540 deg.C, a WHSV of 4-20hr<-1>, and a ratio of cat/oil of 4-12, to cause catalytic cracking. After cracking, the mixture of particles is treated at 600-750 deg.C for about 50min to be regenerated, and is repeatedly used (about 15 times).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for catalytic cracking of heavy hydrocarbon oils, and more particularly to vanadium.

The present invention relates to a method of catalytically cracking a low-grade heavy hydrocarbon oil containing a large amount of metals such as nickel and iron in the presence of a mixture of a crystalline aluminosilicate-containing cracking catalyst and alumina particles.

Conventionally, catalytic cracking of hydrocarbon oil for the purpose of producing gasoline is carried out using a cracking catalyst consisting of crystalline aluminosilicate dispersed in a matrix. As long as the raw material is a hydrocarbon oil with a relatively small amount of metal contaminants, even if the raw material oil is a heavy hydrocarbon oil, some results have been achieved.6 However, the deterioration of the oil situation in recent years has led to This creates a situation where low-grade heavy hydrocarbon oil containing large amounts of metals such as vanadium, nickel, and iron must be subjected to catalytic cracking. In this case, the conventional catalytic cracking methods described above do not necessarily give good results.

In other words, when a low-grade heavy hydrocarbon oil containing a large amount of metal contaminants is treated with a conventional crystalline aluminosilicate-containing Clarakin catalyst, the cracking activity of the catalyst is only impaired by metal deposition. Instead, the dehydrogenation reaction is promoted due to the increased amount of metal deposited, and as a result, the amount of hydrogen and coke produced increases, resulting in a decrease in gasoline yield. When a large amount of metal is deposited on the catalyst, the crystalline aluminosilicate may undergo crystal destruction, further deteriorating the cracking activity.

For this reason, conventional measures for catalytic cracking of heavy hydrocarbon oils containing large amounts of metals include increasing the amount of cracking catalyst used in order to keep the amount of metal deposited per catalyst particle low. Alternatively, a method is adopted in which a used cracking catalyst with a relatively small amount of metal deposits is used in combination, and an antimony compound is added to the feedstock oil to suppress the decrease in cracking catalyst activity caused by metal deposition. methods have also been adopted. However, these conventional methods are not always successful due to the high operating costs. In addition, for the purpose of increasing cracking activity,
Increasing the content of crystalline aluminosilicate in the catalyst is undesirable because it promotes the by-production of coke and gaseous components and reduces gasoline yield.

The present invention is a method that is different from the conventional methods described above, and is capable of catalytically cracking even low-grade heavy hydrocarbon oil containing a large amount of metal while maintaining a high gasoline yield over a long period of time. This method proposes a method for catalytic cracking of low-grade heavy hydrocarbon oil containing large amounts of metals, and when alumina particles are mixed with a conventional cracking catalyst, metal contamination in the feedstock oil is reduced. This is based on the new findings that the metal contaminants are preferentially captured by the alumina particles, and that the cracking catalyst that coexists with the alumina particles is significantly less poisoned by metal contaminants.

In the catalytic cracking method for heavy hydrocarbon oil according to the present invention, a cracking catalyst containing crystalline aluminosilicate and alumina particles are added to a particle mixture in a weight ratio of 80/20 to 20/80. It consists of contacting heavy hydrocarbon oils under cracking conditions.

In the present invention, any conventional cracking catalyst in which crystalline aluminosilicate is dispersed in a matrix made of porous inorganic oxide can be used as the crystalline aluminosilicate-containing cracking catalyst, but the most commonly used cracking catalyst is A catalyst is used in which ammonium ion-exchanged or rare earth-exchanged faujasite is dispersed in silica or silica-alumina. The amount of crystalline aluminosilicate dispersed in the matrix ranges from 10 to 50% by weight for conventional catalysts, more typically from 20 to 40% by weight.
That's about it. but.

In the present invention, since alumina particles are used together with a cracking catalyst, the mixing ratio of both (1) (this will be described later)
Taking into account the amount of crystalline aluminosilicate, based on the mixture of cracking catalyst and aluminum particles,
0% by weight, preferably 20-40% by weight,
It is possible to adjust the amount of crystalline aluminosilicate in the cracking catalyst in advance.

The alumina particles used in combination with the cracking catalyst may be activated alumina commonly used as a fluidized catalyst, but
What is its average particle size and bulk density?

It is preferable that the alumina particles of the present invention have an average particle diameter of 20 to 80μ, preferably 40 to 70μ.
It is suitable that the bulk density is in the range of 0.60 to 1.20 g/mQ.

Preferably, the alumina particles have an oil absorption of at least 0.2 cc/g. Such alumina particles can be prepared by, for example, preparing alumina hydrate through a neutralization reaction between a sodium aluminate aqueous solution and an aluminum sulfate aqueous solution, removing by-product salts from this by washing, and then converting the alumina hydrate into alumina hydrate as needed. It can be easily obtained by peptizing it with an acid, then spray drying it, and then calcining it.

Further, calcined aluminum hydroxide having an average particle diameter of 20 to 80 μm obtained by the Bayer method is also suitable as the alumina particles of the present invention, and this material is advantageous in that the manufacturing cost is low.

In the present invention, it is necessary that the mixing ratio of the 2-cracking catalyst and the alumina particles is in the range of 80/20 to 20/80 in weight ratio. If the amount of alumina particles is less than this range, the metal contaminants in the M feed oil cannot be sufficiently captured preferentially by the alumina particles, and conversely, if the amount of cracking catalyst is less than this range, naturally Therefore, the cracking activity decreases and the feedstock oil cannot be sufficiently catalytically cracked. Therefore, when carrying out the method of the present invention, the amount of metal contaminants contained in the feedstock oil should be taken into account.7 If the amount is large, the proportion of alumina particles in the mixture of cracking catalyst and alumina particles should be increased.

It is possible to compensate for the decrease in cracking activity that would occur with a relative decrease in the amount of cracking catalyst by increasing the amount of crystalline alumina silicate dispersed in the cracking catalyst.

As cracking conditions, cracking conditions conventionally used in the industry can be adopted in the present invention, and typical examples of such cracking conditions are as follows: 0 reaction temperature 460-540°C + WHS V
4 to 20 hr -', cat10il ratio 4 to 12° Also, in the catalytic cracking method of hydrocarbons, the cracking catalyst that has been inactivated by coke precipitation is regenerated by carbon burning and reused in the cracking reaction. Although it is customary.

The method of the present invention also uses conventional regeneration equipment and regeneration conditions to regenerate and reuse spent cracking catalyst and alumina particles. This playback is usually 6
It is carried out at a temperature of 00 to 750°C.

Although the catalytic cracking method of the present invention is effective even when relatively high-grade heavy hydrocarbon oil with a low content of metal contaminants is used as feedstock oil, the advantage of the present invention is most notably cursed. According to the method of the present invention, when low-grade heavy hydrocarbons containing a large amount of metal contaminants are catalytically cracked.

Gasoline can be obtained in high yield from heavy hydrocarbon oil with a total metal content of about 50 ppm (metal equivalent).

To explain this point in more detail, the alumina particles mixed with the cracking catalyst are 1 bit more vanadium, nickel, etc. Because of its strong affinity with gold ELxt, metals in the feedstock oil are preferentially deposited on alumina particles, and are inactivated by reacting with the alumina during exposure to high temperatures. Therefore, the dehydrogenation reaction caused by the deposited metal is suppressed, and as a result, the production of coke, hydrogen, and other gaseous components is suppressed. On the other hand, from the cracking catalyst side, due to the coexistence of alumina particles, metal deposition on the catalyst is significantly reduced, and therefore the original catalytic activity of the cracking catalyst can be maintained at a high level for a long period of time. It can be done.

The present invention will now be described in more detail with reference to Examples.

Example 1 [Preparation of Cracking Catalyst] Commercially available 3 water glass was diluted to prepare a water glass solution with a concentration of 12.73% Sin. This water-glass solution and concentration 25
% sulfuric acid was poured into the same container at a rate of 20 Ω/min and 5.6 Ω/min for 0 min to obtain silica hydrosil.

This silica hydrosil is mixed with 30% kaolin based on the weight of the final composition, and rare earth exchanged Y-type zeolite (
A 30 wt % aqueous slurry with an exchange rate of 67% was mixed so that the amount of zeolite was 50% based on the weight of the final composition, and this mixture was spray dried, washed and dried to obtain cracking catalyst A. The average particle diameter of this catalyst was 57μ, and the bulk density was 0.80g/mα.

[Preparation of alumina particles]

Hyaluminum hydroxide with an average particle size of 70μ obtained by the Bayer method was calcined at 550°C for 3 hours to obtain a bulk density of 0.76g.
/m Q and an oil absorption of 0.42 cc/H were obtained.

[Catalytic cracking]

The above-mentioned cracking catalyst and alumina particles are each sieved to remove cracking catalyst particles with a size of 55μ or more,
After removing alumina particles of 55μ or less, the remaining particles were treated in 100% steam at 770°C for 6 hours.
Then, it was fired in air at 600°C for 1 hour. After that,
These cracking catalysts and alumina particles were mixed at a predetermined ratio, and the following catalytic cracking reaction was carried out using the particle mixture.

Hydrotreated reduced pressure 1 oil (DSVGO) to which nickel naphthenate and vanadium naphthenate were added so that the nickel and vanadium contents were 200 ppm each was used as the feedstock oil.

The reaction conditions are reaction temperature: 482°C, space velocity: 16h.
r −”, a particle mixture/feedstock oil weight ratio of 3 was adopted to carry out the decomposition reaction for 75 seconds, and then the particle mixture in the reaction zone was treated in air at 630 °C for 50 minutes to regenerate, and then regenerated again. The reaction-regeneration operation for performing the above catalytic cracking reaction was repeated 14 times, the results of the catalytic cracking in the 15th reaction were evaluated2, and the total flexural deposition in the particle mixture was further determined at the end of the 15th reaction. The results are shown in Table 1.

Table 1 *C5゛Gasoline: boiling point range C5~204℃Example 2 Contact was carried out under exactly the same conditions and procedures as in Example 1, except that the following catalyst was used in place of the cracking catalyst used in Example 1. A decomposition reaction was carried out. The results are shown in Table 2.

[Preparation of cracking catalyst]

Kaolin was added to the silica hydrosil prepared as in Example 1 by 52% and 33%, respectively, based on the weight of the final composition.
%, cracking catalysts B and C were prepared in the same manner as catalyst A except that they were changed to 25%.

E was prepared. A cracking catalyst was also prepared by adding only rare earth-exchanged Y-type zeolite to silica hydrosil without adding kaolin so that the final composition was 90% by weight.

(Left below) Table 2 As can be seen from Table 2, when comparing the activities with a constant amount of zeolite in the mixture of cracking catalyst and alumina particles, the method of the present invention shows that the amount of total deposition on the cracking catalyst is Since the amount is small, there is little decrease in activity.

Comparative Example A catalytic cracking reaction was carried out under exactly the same conditions and procedures as in Example I, except that the following silica particles, used cracking catalyst, or silica-alumina particles were used in place of the alumina particles used in Example 1. . The results shown in Table 3 were obtained. However, the particle mixing ratio was 50150 in all cases.

[Silica particles]

Sin, a water-glass aqueous solution with a concentration of 12.73 wt% and a concentration of 2
Silica hydrosil was prepared by mixing 5% sulfuric acid, which was spray-dried, washed and dried, then heated at 550 °C for 3
After firing for a time, the average particle size is 70μ, and the bulk density is 0.71g/m.
Silica particles of Q were obtained.These silica particles were sieved to 5
Remove particles of 5μ or less and store the rest in 100% water vapor.
After being treated at 0°C for 6 hours, it was subjected to an experiment in which it was fired in air at 600°C for 1 hour.

[Used cracking catalyst]

In actual M21f, used cracking catalyst (average particle size 75 μ, bulk density 0.81 g/m Q) was heated at 600°C.
It was baked for 1 hour and used in experiments. This used catalyst contained 235 ppm of nickel and 438 ppm of vanadium.

[Preparation of silica-alumina particles]

A water strand solution having a Sin2 concentration of 11.2% was prepared by diluting a commercially available 3-volume water vitreous solution. Separately, a 10.5% aluminum sulfate solution was prepared. A gel was prepared by mixing the water vitreous solution and the aluminum sulfate solution at a rate of 20 Q/min and 10 Q/min, respectively. This gel was heated at 65°C for 3
．． The mixture was heated for 5 hours and stabilized with water glass to a p)l value of 5.8. This gel was spray dried with hot air at 220°C, washed and dried to prepare silica-alumina particles.

The silica-alumina particles were sieved to remove particles of 55 μm or less, and the remaining particles were treated in 100% steam at 770° C. for 6 hours, then calcined in air for 1 hour, and used for experiments.

Claims (1)

[Claims] 1. Heavy hydrocarbon oil is added to a particle mixture of a cracking catalyst containing crystalline aluminosilicate and alumina particles in a weight ratio of 80/20 to 20/80 under cracking conditions. A method for catalytic cracking of heavy hydrocarbon oils. 2. The method of claim 1, wherein the amount of crystalline aluminosilicate contained in the particle mixture is at least 10%, based on the weight of the particle mixture. 3. The alumina particles in the particle mixture have an average particle diameter of 20 to 80μ and a bulk density of 0.60 to 1.20.
Claim 1 using alumina that is g/ml
The method described in section.