DE1144860B - Process for the production of a small-spherical silica-alumina cracking catalyst suitable for a fluidized bed process - Google Patents

Description

INTERNAT.KL. Clog

GERMAN

PATENT OFFICE

A32213IVc / 23b

REGISTRATION DAYS

NOTICE THE REGISTRATION AND ISSUE OF THE EXCLUSIVE LETTER:

June 9, 1959

MARCH 7, 1963

The invention relates to a process for the production of a small-spherical, suitable for a fluidized bed process Silica - Alumina - Cracking Catalyst.

It is characterized in that one by co-precipitation in an aqueous medium hydrated silica and 10 to 70 percent by weight based on the weight of the catalyst, an inorganic, silica-containing additive with an average particle size ίο of not more than 20 microns intimately binds a hydrated alumina on top of this intimately connected mixture precipitates and the product becomes a catalyst with a silicon dioxide content between 65 and 85 percent by weight and an aluminum oxide content between 15 and 35 percent by weight, without the additional material, spray-dried.

The cracking catalyst contains significant amounts of inexpensive inorganic additives and can be used in conventional manufacturing facilities for synthetic Catalysts are produced. The cracking catalyst should have a good particle size distribution, and the particle shape should be uniform. The additives are said to work with the catalyst material exist in intimate connection, whereby the heat distribution is improved.

Under the expression "precipitate on", as it is used here to denote the coating of silica gel is used, it should be understood that in the reaction of an aluminum salt with an alkaline Means likely to be more of a link or complex between silica and Aluminum oxide takes place as the formation of practically pure aluminum hydroxide.

The expression "intimate connection" should be understood to mean that in the end product the parts of the Additive are in direct contact with the silicon dioxide-aluminum oxide gel or from this be enclosed, as the microscopic examination shows. This intimate connection is according to the invention by precipitation of the silica gel and the alumina gel in the presence of the additive achieved.

The additives used are in finely divided form in order to achieve the required degree of intimate connection. In order to achieve the level of intimate bonding necessary to impart the desired and required properties to the final catalyst product, the additive material should have an average particle size of no more than 20 microns, preferably no more than 8 microns. Such additives are in the process of manufacture
of a small-spherical silica-alumina cracking catalyst suitable for a fluidized bed process

Applicant:

American Cyanamid Company,
New York, NY (V. St. A.)

Representative: Dr. F. Zumstein,

Dipl.-Chem. Dr. rer. nat. E. Assmann

and Dipl.-Chem. Dr. R. Koenigsberger,

Patent Attorneys, Munich 2, Bräuhausstr. 4th

Claimed priority:
V. St. v. America, June 16, 1958 (No. 742 004)

William Beveridge Innes, Maiden Ward Michael,

Stamford, Conn.,

and Nicholas Chomitz, Yonkers, NY (V. St. A.),
have been named as inventors

Commercially available in appropriate average particle size. If not, you can get the right distribution the particle size by grinding or other suitable means. If you fail to do that Regulating the particle size results in a very finely divided material and poor abrasion properties. This is due to uneven shrinkage as it dries, which in turn causes cracking or breakage of the particles. To achieve the best physical and catalytic properties the finely divided, inorganic additive material in amounts of 10 to 70, preferably about 40 to 60 weight percent based on the weight of the final catalyst is used.

The abrasion resistance is measured as a percentage of the material continued above. This value is obtained by placing a known amount of catalyst of a certain weight, for example 50 g, in a hollow cylinder. An air flow of a very specific flow rate, for example 0.425 m ³ / hour, is then measured in

309 538/376

a measuring device supplied. In certain time- pH of a low acidic value in the

intervals, for example 10, 20, 45 or more hours, the range given above.

a collection system, usually a bottle, temperatures of, for example, below 15 ° C

removed and emptied and the weight of the on one require an extraordinarily long response time

Particle size of 12 microns or less reduces 5 and results in a low porosity product with poorer properties adorned catalyst determined. This weight becomes stability. Higher temperatures, for example above

then to calculate the percentage of the above half 65 ° C, lead to products with lower bulk

continued material used. Such a dense, poor abrasion properties and extra-

Factor gives an indication of the abrasion resistance - quite high porosity. Preferably be

ability of the catalyst. The lower the percentage io temperatures between 25 and 40 ⁰ C used,

of the material carried overhead, the higher it does not matter which order of addition or

is the abrasion resistance of the catalyst. which type of addition is used,

It is essential for the method according to the invention that the final solids content is the initial

drive that the finely divided, inorganic additive intimately mixed slurry between 3 and

material, the silica gel and the aluminum 15 9%> preferably about 6.5%. It

oxide gel in intimate connection with one another, it was found that in one procedure

in order to achieve a suitable catalyst product within this range the end product is best

obtain. can be kept under control.

According to the invention, finely divided, inorganic from the procedures listed above is used

Additive material, such as kaolin, to any water - the first preferred because of the particularly good, intimate properties

amount that is, for example, in a precipitation tank connection and because of the good further processing

is located, added and then a suitable alkali possibility, including washing and filtering for

Silicate solution added to this. A removal of the impurities such as alkali metals,

suitable acid, for example sulfuric acid or count, which the final catalyst material

Hydrochloric acid, add poison to the mixture in the precipitation 25 while stirring and reduce its activity. Thereafter

tank added to a hydrated silicon dioxide, silicon dioxide hydrate and inorganic additives

or silicon dioxide gel on the finely divided, dispersible material, which are intimately connected to each other,

yawed, inorganic additive material to precipitate and filtered and washed. If necessary, will

to establish such an intimate connection. slurried again and the process step

The intimate connection between silicon dioxide gel 30 is repeated until the product is practically free of alkali

and additives can also be made to remove salts and other undesirable contaminants

one is a suitable precipitating agent for alkali silicate.

and an additive in any amount of water that will be virtually alkali-free, intimate mixture gives and then with stirring for the purpose of even parauf with hydrated aluminum oxide or with Precipitation adding an alkali silicate. For example 35 alumina gel coated. This covering can be an inorganic additive such as kaolin, or the precipitation of hydrated aluminum together with a suitable precipitating agent, oxide to the mixture of silicon dioxide and additives such as an acid, or aluminum sulfate, in water material can be accomplished in several ways are present and an alkali silicate solution is added. For example, one can use commercially available thereby redissolving the hydrated silica to 40 alum or aluminum sulfate inorganic additive material is precipitated. slurried mixture of silica and

On the other hand, you can also add a slurry of additional material and then an alkali aluminate, an alkali silicate and a finely divided, inorganic such as sodium aluminate, to the composition up to Pour additional material into a precipitation tank that has a pH of 3.5 to 6. Within a suitable precipitating agent, for example an acid 45 of this pH range, is the hydrated aluminum or Aluminum sulphate. oxide precipitated from the solution and on the intimate

Regardless of which procedure is chosen, associated particles of silicon dioxide and additive

an intimate bond between the material is always achieved.

inorganic additional material and the precipitated, on the other hand you can also use alum or aluminum

hydrated silicon dioxide. 50 miniumsulfat for the aqueous slurry of

To achieve the required intimate bond, add silica and additive and place on top it is essential that the additive material be aqueous in an ammonia or other suitable alkali Add medium, such as in a precipitation tank, until the pH is between 3.5 and 6. In At the time of precipitation of the hydrated silica this pH range the hydrated aluminum or of the silica gel in suspended form 55 oxide precipitated and in intimate connection with the is present. Substrate made of silicon dioxide and additional material

The precipitation of hydrated silica brought about.

on the finely divided inorganic additive material. Third, general, for coating the material Can be made of silicon dioxide and additional material with hydrati-60 ° C at a pH value between 2.5 and 10 at 20 be made. This is true, a procedure that can be used in the same way as alumina valid which of the procedures listed above can be a suitable acid, such as sulfuric acid or is used. With an addition of acid to a hydrochloric acid, to an aqueous slurry of alkaline medium namely the pH value of silicon dioxide, additional material and one to one falls highly alkaline to a pH of sludge-added alkali aluminate, such as sodium-8 to 9, the precipitation range for the hydrated 65 aluminate, can be added, increasing the pH Silicon dioxide. With the addition of an alkali silicate solution adjusted to 3.5 to 6 and the hydrated AIuallein or together with an inorganic miniumoxide on the base material of silicon additive to an acidic medium, the dioxide gel and additional material rises.

5 6

The temperature during the coating with more effective use of the spray-drying device hydrated aluminum oxide or with aluminum allows a higher throughput • oxide gel is preferably between 20 and 60 ⁰ C, can be achieved in a given time,
usually between 25 and 40 ° C. As mentioned before, it is essential to manufacture

resulting slurry contains 3 to 9, preferably 5 of the new, microspheroid catalysts in which ■ about 6.5% solids. Additive material, silicon dioxide and aluminum oxide

Temperature, solids content and pn range are intimately connected with the addition of all three essential factors for obtaining the material in the precipitation of the silica gel ■ the required degree of intimate connection, both in an aqueous medium. If you use others when the silica is precipitated in the presence of procedures, there is no intimate connection an inorganic elongation material or achieved and also the physical state Coating this intimate mixture with hydrati- these mixtures and the nature of their connection sated aluminum oxide. such that the during the alkali and sulfate

Besides, it is both ionic removal during precipitation in different stages of the verse Silicon dioxide on which the finely divided, inorganic filtration losses that occur are so great that Additional material as well as during the coating that the process is technically unsuitable. Would essential that the slurries are continuously agitated, for example a composition of hy, mixed or stirred to a uniformly-dratized silicon dioxide and aluminum oxide evenly Coating and mixing a uniform particle compartment with an inactive additive, size to get. 20 for example silicon dioxide, which leads to a

After the intimately connected Si addition of hydrochloric acid to a sodium silicate solution has been coated with silicon dioxide and inorganic additive material with precipitated, washed silicon dioxide hydrogel hydrated aluminum oxide, the losses would be during the period, the resulting slurry is filtered and filtration is extracted in a conventional filter device ; this process eventually becomes usually high and prohibitive again.
fetches, and then it is dried. The washing of the new catalytic converters will be like others

Slurry can be made, for example, in a conventional, commercially available silica-alumina-cracking rotary filter. The catalyst in the fluidized bed conversion process washing of the residue is necessary in order to be used, in which high-boiling petroleum hydrocarbons remove desired sulfate and other impurities to substances catalytically to gasoline with a high octane content. The strength of washing can be cracked by the tray. It is known that one dermann can be determined. Thereafter, the washed-like process will present the catalyst particles in an alumina gel-coated silica gel suspension state in a vaporous carbon additive composition to form microspheroid hydrogen streams and spray dried the cracking between catalyst particles. On the other hand, it is 35,370 and 595 ^° C., preferably between 480 and 540 ^° C., it is often desirable that the aluminum gel coated is carried out.

Silica gel additive composition The joint precipitation of kaolin and hy-

ύογ spray-dry washing, since then less dratized silicon dioxide is known per se, and Water to remove practically the same amount of the same applies quite generally to precipitation Contamination, such as sulfate ions, is required. 40 of hydrated alumina on a support

The spray drying is done by spraying the too. The spray-drying of catalysts from composition through a nozzle or by spraying hydrated aluminum oxide and silicon dioxide from a spray wheel in contact with hot gases has already been carried out as such in US Pat. No. 2,768,145. This drying can be described in; However, this does not apply to the drying of the aluminum oxide-containing catalysts (see, for example, US Pat. No. 2,644,516). It, the inorganic additive siliziumdioxydhaltiges Can gas inlet temperatures up to 705 ⁰ C comparison mateiial included.

Find a turn. Preferably, however, the US Pat. No. 2,763,622 discloses only

temperature of the joint precipitation of kaolin and emerging drying gases between about 205 and 50 hydrated silicon dioxide, but not the after-540 ^° C., so that this is in intimate connection with the subsequent precipitation of hydrated aluminum additive material Silicon dioxide-aluminum hydroxide. The oxide hydrogel produced in accordance with this USA patent specification in solidified, partially dehydrated, prepared catalysts have a getinger microspheroid gel particle is converted. The abrasion resistance compared to the spray drying according to the invention generally gives a product with 55 catalysts. The superior abrasion • a moisture content between 7 and 15% • resistance of the manufactured according to the invention

It is an essential advantage of the catalyst according to the invention that the method of the invention achieves the additional gel material due to the type of drying in the process according to the invention.
Composition in the spray dryer with a U.S. Patent 2,768,145 relates only

Solids content of 9.5 to 12% can be given 60 to another method of spray drying. The catalysts prepared during customary catalyst compositions, that is to say according to the process of this US patent specification, customary silicon dioxide-aluminum oxide gel cracking catalysts have a lower catalyst composition, generally with an aluminum oxide content. They are more uneconomical to manufacture with an optimal solids content of approximately 8%, which is what is introduced in a bulk product. Although this is only a special 65 of considerable importance.
Embodiment of the method according to the invention In the following examples all parts and

represents, this implementation is given in high percentages in weight units, if Dimensions desirable and very important, as nothing else is listed.

7 8

Example 1 contains before modification with the kaolin 75%

Silica and 25% alumina, calculated

An aqueous dispersion of finely divided paper based on incineration.

maeherkaolin with an average particle size The combination of kaolin and silica size of 0.77 microns is placed in a precipitation tank 5 alumina hydrogel is mixed vigorously and added. Theoretically, the added amount of kaolin is then homogenized, so that 55% of the particles have a catalyst product that is sufficient for a 50% kaolin content in the final size of less than 325 mesh, so as to be a valid catalyst product. Then an aqueous sodium silicate solution 4ioxyd-aluminum oxide hydrogel is to be achieved for kaolin- an intimate connection between additive and silicon-water-suspension,
added in sufficient amount to obtain a solid io

content of 6.5 ° / _0, based on the total content, manufacturing Example 4

to be supplied. To ensure an even

The dispersion is agitated carefully. 1.13 kg of untreated Georgia kaolin clay

Sulfuric acid is then added to a sulfuric acid solution to the precipitation tank to a pH of 9.5 with good agitation. It is constantly given 15, which _{moves 0.45 kg of 95% H 2} SO ₄ and 1.32 kg in order to maintain the uniformity of the mixture with water. Ensure containing a sodium silicate solution. Additional sulfuric acid, 2.40 kg of sodium silicate (28.5% SiO ₂ and 8.9% Na ₂ O) is then added up to a ρπ value of 3. For safety to 10.9 kg of water is added slowly with good ordering of completeness and uniformity of movement at 5O ⁰ C until reaching a p _H -value coating the mixture continues to move moderate, ao of 5 was added to the acid. One 1.72 kg of water and

An alum solution containing 8% Al ₂ O ₃ is added to alum containing 1.32 kg of alum (17.3% Al ₂ O ₃ ) . The coating is carried out by adding a 14% strength solution, then adding a sodium aluminate solution to the ammonia solution with vigorous agitation until the pat value is adjusted to 4.7. The addition of the 25 pH value of 5.0 is complete. The Si-sodium aluminate obtained is continuously agitated to form silicon dioxide - aluminum oxide - kaolin - sludge ensuring uniform precipitation of the mung is repeatedly filtered and washed to remove the hydrated aluminum oxide or the aluminum content of Na ₂ O and sulfate prior to spray drying To greatly reduce the KaoUn silicon dioxide gel inventory.

part and an intimate connection with this constituent 30 The final catalyst product contains 65 parts by weight made. Alum and sodium aluminate percent kaolin. Without kaolin, the catalyst contains are in sufficient quantity to achieve a 75% silicon dioxide and 25% aluminum content by weight of 6.5% health solids used. minium oxide.

Then this is done with silicon dioxide-aluminum example 5

oxide gel coated, finely divided kaolin filtered and 35

practically free of sodium and sulfate ions. A sodium silicate solution that wash 2.40 kg of sodium. With a solids content of silicate (28.5% SiO ₂ and 8.9% Na ₂ O) and 10.9 kg of approximately 10%, the batch is fed to the spray dryer. The water containing is mixed with 0.91 kg acid washed spray dryer with an inlet temperature of kaolin (99% of kaolin with a particle size 400 ° C. The product obtained has 86% 40 under 325 meshes) with good agitation. Solids on and is in the form of microspheroid 25% sulfuric acid solution slowly becomes the particle. Silicate kaolin slurry with good agitation

The catalyst contains 41% kaolin, based on added up to a pH of 5.0 at 50 ° C. After solids, at 1000 ° C after combustion. Without this for 15 minutes, a solution of 1.72 kg of water and 1.09 kg of kaolin is added to the catalyst which contains 75% silicon dioxide, 45 alum (17.3% Al ₂ O ₃ ) and 25% aluminum oxide. Gel slurry. Plating is through

Addition of ammonia up to a pH value of

Example 2 5.0 completed. The obtained silicon dioxide

Alumina kaolin slurry that is soluble

A procedure similar to that of Example 1 containing 5 ° salts is spray-dried. After Sprühmit the modification is used that instead of fine-drying, the soluble salts are used by wiederverteiltem Papiermacherkaolin finely divided silica repeatedly filtering and washing prior to the final drying, from the 95% particle size at 200 ⁰ C,
have less than 20 meshes. The final catalyst product contains 50% by weight

The end product, a microspheroid catalyst, 55 percent kaolin. Without kaolin, the catalyst contains intimately bound silica, silicon dioxide and 75 percent by weight silicon dioxide and 25 percent by weight aluminum oxide, contains 50% silica. Without percent aluminum oxide.
Silica contains the catalyst 87.5% silicon dioxide and 12.5% aluminum oxide. Example 6

60

Example 3 100.3 kg of sodium silicate become 953 kg of water,

containing 56.7 kg of kaolin in one with a turbine

Given a tank agitated to achieve 45 weight percent kaolin. To this mixture in one Endkatalysatorprodukt sufficient kaolin about 56.2 kg of 25% strength acid to a becomes a silica-alumina hy- p 65 _H value of 8.5 and holding for 15 minutes at this drogel high alumina content added and pH. The gelation of the silicon dioxide takes place vigorously mixed. The silica-aluminum- within a period of 15 minutes. The high alumina hydrogel slurry contains 5% gel solids.

Table I.

Sample designation

Art

additive

lot
(Weight
percent)

admitted

Particle size *)

to the dryer

(Weight percent)

-90 μ

-44 μ

SAT *

structure

PV *** cc / g

ABD ** g / ccm

Particle size

(Weight percent)

MM sieve

-20 μ

Above draining

Particle
(Weight percent)

5h

Hours.

Hours.

Catalyst properties
AGC test

A. G 63 1.3 23 1.2 79 1.2 20th 1.1 66 1.4 19th 1.2 60 1.3 58 1.2 120 1.2 32 1.2 28 1.6 16 1.2

Example 3.
Example 3 (S)

example 1
Example 1 (S)

Example 2 ...
Example 2 (S)

Example 4 ...

Example 5

Catalyst A

Catalyst A (S).

kaolin
kaolin

kaolin
kaolin

Silica
Silica

kaolin
kaolin

none
none

45
45

41
41

50
50

56
50

0
0

.,Gel
gel

silicate
silicate

silicate
silicate

acid
silicate

68

70

69

70

65

55

318

59 346 109 54 328 106 30th 310 45 250

Catalyst B ....
Catalyst B (S).

519

184 81

0.39 0.44

0.48 0.56

0.41 0.55

0.65 0.65

0.37 0.47

0.63 0.68

3
4th
4th

27

12th

3
4th
8th

48
14th

17th

10
11
11

20th

64
18th
22nd

12th
13th
16

33

1.6 1.3

1.5 1.3

2.0 1.4

1.6 1.5

1.4 1.4

3.2 1.8

F = freshly calcined for 1 hour at 595 ^° C.

S = Wasserdampfbeharldlung 17 hours at 75O ⁰ C at atmospheric pressure. The accelerated test determines the stability. Numbers under "S" are measured after 1 hour in a cracking system according to "American Cyanamid's Manual of Test Methods for Synthetic Fluid Cracking Catalysts", 1957.

SA * = effective surface.
ABD ** = bulk density.
PV *** = pore volume.

g Catalyst A = A 25% alumina-silica-alumina fluidized bed cracking catalyst. S Catalyst B = A commercially available natural fluidized bed catalyst.

12th

84.8 kg of a 7.5% aluminum sulfate solution diluted with 68.0 kg of water is added to the hydrogel formed above. The obtained pH value is 3,1.11,1 kg 29 ° / ₀ strength sodium aluminate solution containing approximately 20% excess alkali, may be added, wherein the _pH value rises to 4.0. The pn value is adjusted to 4.5 with more alkali before filtering and washing.

The coated slurry is then washed free of sodium and sulfate ions and spray dried. The catalyst contains 70 percent by weight kaolin. Without kaolin, the catalyst contains 25% aluminum oxide and 75% by weight silicon dioxide. ■ .;

The microspheroid catalyst obtained has sufficient abrasion resistance, activity and stability.

Table I shows the test results of catalysts prepared according to Examples 1 to 5 with the results of a commercially available fluidized bed - silicon dioxide - aluminum oxide - catalysis ao i-butane high alumina sators (Catalyst A) and a natural fluidized bed clay catalyst, made from halloysite, referred to as catalyst B, compared.:.

The values given under "Catalyst properties" are determined in the following way: The Conversion of a standard oil mixture is carried out at an hourly space velocity (volume) of 1.4 for one hour by the catalyst or catalysts of "unknown properties" to be tested and at the same time carried out under the same conditions by a standard reference catalytic converter. The factor ^ is the activity "of the catalyst to be tested and is determined as a percentage by Resilience and effective surface is characterized and in terms of yields in terms of gasoline components is equivalent to commercially available flow operations used in the petroleum industry and synthetic fluid bed catalysts. The comparison results are shown in the table below II, where the symbols F and S have the same meaning as in Table I.

Tables
Relative yield information

component Example 3 S. 1.0. example 1 I ^s Example 2 ^s Kataly
sator port I ^s F. F. 1.1 F. 1.0 F. 1.1 C ₅ shares - 1.0 0.95 0.9 1.0 204 ° C 1.0 1.0 1.4 1.0 n-butane .... 1.1 1.3 0.7 1.3 0.8 1.0 0.5 i-butane 0.6 0.9 1.0 1.0 1.1 0.6 0.8 Butene 1.1 I ₅ O 0.6 1.1 0.9 0.9 0.5 propane 0.9 0.9 0.8 0.9 0.9 0.5 0.9 Propene 1.6 1.20 0.9 1.0 0.8 0, £ 1.0 C ₂ and easier 0.8 1.3 1.0 1.5 1.1 2.0 carbon 1.4 1.9 2.3

= ¹ hour process duration;
Duration of proceedings.

other values for 1 hour

The values in Table II indicate that the with Kaolin modified, strongly aluminum oxide catalysts according to the invention practically the commercial silicon dioxide catalysts with a high content of aluminum with the following exceptions are comparable. The ratio of the hourly space velocity catalyst produced according to the invention gives somewhat more normal butane and coke speed, based on weight, with that of the standard and a little less propane and less light-weight catalyst compares with the same conversion.

The gas factor (G) is the ratio of the volume of the gas produced by the catalyst to be tested under standard conditions (dry gas 20 ° C, 29.92 in Hg) to the gas produced by the standard catalyst with the same conversion. The carbon factor (C) is the ratio of the carbon yield from the catalyst under test to that with the standard catalyst with the same conversion
aimed.

Table I clearly shows that the abrasion losses are gasoline. The gasoline yield increases with steam treatment while the isobutane yield may drop.

The comparison with the natural clay catalyst identified as Catalyst B in Table II shows that the catalyst prepared according to the invention has higher yields of normal and isobutane and gives lower yields of light gasoline as well as lower carbon yields than such natural, commercially available fluidized bed catalysts. When using the catalytic converter according to the invention

lower when using the method according to lysators obtained gasoline component has a better the invention according to example 1, 2, 4 and 5 than with ver Octane number than with natural, commercially available halogen.
intimate mixture is produced with a hydrogel. As an alternative to the inventive method, the effective surface of the inventive drive could be proposed, either low-priced catalysts go approximately linearly with aluminum oxide-containing silicon dioxide - aluminum the content of additional material, while the porous oxide catalysts, for example, with about 13% volume of a Additive containing catalyst 55 aluminum oxide content to modify or simply lysators is higher than one should assume, based on average catalysts in place of the inventive basis. Catalysts prepared by the process, modified catalysts to Verdes Example 1 have to turn. With respect to the first procedure, a larger average pore diameter, it is evident that such a modification than a commercial 25% alumina catalyst contains a low alumina catalyst which is calculated according to the following formula to a significant extent

PD (pore diameter) = A [V (pore volume) / S (effective surface)] · 10 *

One of the main advantages of the invention The process consists in obtaining a catalyst which, by virtue of its good activity and wear and tear, results in a relatively low activity of the catalyst becomes, since the amount of aluminum oxide and thus the active catalytic sites contained therein is slight be reduced below the permissible limit. It would also be a special and essential benefit of the catalyst according to the invention are lost. This advantage lies in the fact that the inventive

according to procedures a modification of a flowing, highly aluminous silica-alumina cracking catalyst material is accessible, whereby a final catalyst product is conveniently and inexpensively obtained, which is a high Has number of catalytically active sites.

As already mentioned, the catalyst according to the invention is less expensive to manufacture than silica-alumina catalysts with relatively low alumina content, for a number of obvious reasons. So it is in the manufacture of silicon dioxide - aluminum oxide - hydrogel, which has a high aluminum oxide content not necessary, the hydrogel ingredients so thoroughly to achieve a certain alkali and Sulfate ion content, based on the final catalyst product, to filter and wash.

Claims (10)

PATENT CLAIMS: 20 1. A process for the preparation of a small-spherical silica-alumina-cracking catalyst suitable for a fluidized bed process, characterized in that a hydrated silica and 10 to 70 percent by weight, based on the weight of the catalyst, of an inorganic, silicic acid-containing one by co-precipitation in an aqueous medium Additive material with an average particle size of not more than 20 microns is intimately bound together, a hydrated aluminum oxide is precipitated on this intimately bound mixture and the product is converted into a catalyst with a silicon dioxide content between 65 and 85 percent by weight and an aluminum oxide content between 15 and 35 percent by weight, without that Additional material that is spray-dried. 2. The method according to claim 1, characterized in that the hydrated silicon dioxide from an alkali silicate solution in the presence of a precipitant such as an acid or aluminum sulfate, is precipitated. 3. The method according to claim 1 or 2, characterized in that the hydrated alumina is precipitated from an aluminum sulfate and / or alkali aluminate solution. 4. The method according to any one of the preceding claims, characterized in, that the hydrated alumina is based on the intimate mixture of hydrated silica and finely divided, inorganic, silicic acid-containing additive material from an alum solution is precipitated in the presence of alkali. 5. The method according to any one of claims 1 to 3, characterized in that hydrated Aluminum oxide is precipitated from an alkali aluminate solution in the presence of acid. 6. The method according to any one of the preceding claims, characterized in, that the intimate mixture of finely divided, inorganic, silicic acid-containing additive, hydrated silica and hydrated alumina, either washed and then washed spray dried or first spray dried and then washed. 7. The method according to any one of the preceding claims, characterized in, that kaolin or silica is used as an additional material. 8. The method according to any one of the preceding claims, characterized in, that the hydrated silica contributes to the inorganic siliceous additive a ρκ value of 2.5 to 10 is precipitated. 9. The method according to any one of claims 1 to 8, characterized in that the hydrated Aluminum oxide is precipitated at a pn value of 3.5 to 6. 10. The method according to any one of the preceding claims, characterized in that the method between 20 and 6O ⁰ C is carried out. Considered publications:
U.S. Patent Nos. 2,763,622, 2,768,145. © 309 538/376 2.63