DE1187589B - Process for the preparation of a cracking catalyst from silicon dioxide and zirconium dioxide - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

BOIj

German class: 12 g -4/01

Number: 1187 589

File number: S 67898IV a / 12 g

Filing date: April 2, 1960

Opening day: February 25, 1965

The manufacture of catalysts from silicon dioxide and zirconium dioxide is known. So is suggested been made by impregnating silica gel with silica-zirconia catalysts To produce zirconium nitrate and then to decompose the metal salt into zirconium dioxide. Pressed mixtures of silica and zirconia precipitates are also used as hydrocarbon conversion catalysts has been proposed. Although those obtained using such catalysts Results have shown that silica and zirconia compositions are effective in catalytic Promote the conversion of hydrocarbons are useful in themselves, they point in the Comparison with the known silica-alumina hydrocarbon conversion catalysts no noticeable improvement in activity, so compositions continued in the art made of silicon dioxide and aluminum oxide are used as cracking catalysts.

According to another known procedure for the preparation of a catalyst from silicon hydroxide and zirconium hydroxide becomes the silicon hydroxide before or after it is mixed with the zirconium hydroxide washed and dried, a silicon hydroxide-zirconium hydroxide mixture being added to the calcination that is practically completely free of alkali metal ions. Here, if necessary, a Mixture of precipitated zirconium hydroxide and silicon hydroxide precipitated from an alkali metal silicate solution by treatment with an aqueous acid or an aqueous solution of an ammonium salt or an freed polyvalent metal salt with subsequent washing in water of alkali metal ions will. However, even with this procedure, no cracking catalyst is achieved in terms of its activity and selectivity meets modern technical requirements.

According to the invention is a method of making a cracking catalyst from silica and Zirconia, which has excellent selectivity and activity in the cracking of hydrocarbons distinguishes, provided, which is characterized in that a water-soluble zirconium compound and converts an alkali silicate or an organic silicate ester into a gellable sol which is im consists essentially of silicon dioxide and zirconium dioxide, has a pH value above 6 and in which optionally about 2 to 40 percent by volume (based on the dried gel product) of a solid powdery Dispersed material that is insoluble in the sol and at the calcination temperature of the Process for the preparation of a cracking catalyst from silicon dioxide and zirconium dioxide

Applicant:

Socony Mobil Oil Company, Inc.,

New York, N.Y. (V. St. A.)

Representative:

Dr. E. Wiegand, Munich 15, Nussbaumstr. 10
and Dipl.-Ing. W. Niemann, Hamburg 1,
Patent attorneys

Named as inventor:
Charles Joseph Plank, Woodbury, NJ;
Edward Joseph Rosinski, Sewell, NJ;
Robert Bruce Smith, Glassboro, NJ (V. St. A.)

Claimed priority:

V. St. v. America April 2, 1959 (803 552)

Gel is infusible and has an average particle diameter between about 1 and 5 μ, determined by weight, the sol can be solidified to form a silicon dioxide-zirconium dioxide gel, the pH of the gel is reduced below 5, the gel at a pH value below 5 at a temperature in the range from approximately 66 to 104 ⁰ C for a time of about one hour, essentially under conditions of atmospheric pressure, brings into contact with an aqueous medium, the gel washes free of soluble material, dried and calcined.

The zirconium dioxide content, based on dry matter, is preferably about 2 to 20 percent by weight, especially about 5 to 15 percent by weight in the gellable sol.

Activation by treatment of silica-zirconia gel in an aqueous medium under the specified conditions and the regulation of the pH value during gel formation and one such activation step results in the unusually effective selectivity and activity of the silica-zirconia cracking catalyst according to the invention. The conditions used in the activation stage are related to achievement the desired catalyst selectivity is very critical. This is how the pH is during the activation stage

509 510/403

3 4

substantially less than 5 and preferably less than a few seconds to several hours

of 3. The pH of gelation, on the other hand, ranges depending on the pH of

significantly above 6, but not higher than 10, temperature and the solids concentration without

thereby achieving a silica-zirconium addition of any substance to the hydrosol or

Dioxyd-Gels is made possible by especially 5 without deducting any substance from the hydrosol

advantageous gel properties as well as to settle or solidify to a hydrogel,

short settling and solidification times, d. H. If one follows the teaching according to the invention,

generally less than 2 hours and ins- the gel time can be very rapid, i. H. fewer

particular less than 2Q seconds. Hydrogels that last as 20 seconds, which allows the

are produced at a pH value above 6, io gel is produced directly in the form of spherical particles

are much more amenable to activation than those which are put into a product with improved

those made below 6. The physical properties and to be specific

Activation treatment is preferably used during technical advances in the manufacture of the catalyst

carried out at least 2 hours. lead sators. Besides achieving quick gelation

The intermediate hydrogel state, which is found in the production of the high pH, leads to gel formation

position of the catalysts according to the invention was created to a more selective catalyst, such as

is of a gelatinous precipitate in relation to a comparable gel

to distinguish. Real, all-encompassing hydrogels whose pH value was below 6,

take the entire volume of the solution from which it is showing.

be formed, one and possess a certain, ao The silica-zirconia hydrogel that is based on

rigid structure. If, it is broken, one shows this way is obtained, is treated afterwards,

real hydrogel has a conchoidal or snail so that its pH value is below 5 and ins-

linear break, as compared with a particular one to less than 3, but higher than 1,

shows irregular, jagged edge breakage, which is wrinkled in the. To do this, the hydrogel is used

Case of gelatinous precipitates is obtained. 25 essentially immediately after being formed with a

The latter only take up part of the volume of acid medium brought into contact. Can do this

the solution a ₄ from which they are formed and have a short time needed, it is generally

no rigidity in structure. In addition, however, it may be desirable that the pH of the silicon dioxide

Due to the tendency of gelatinous low-zirconia hydrogels, hydrogels appear immediately as they form

suggest peptizing when washing, generally lowering 3 ° less than 5. When you get the hydrogel

more easily washed free of soluble contaminants for a noticeable period of time below pH

will. A special and further advantage of conditions in which the formation is carried out,

Hydrogels consists in that they hold due to their rigidity, this is, as has been found, for selectivity

Structure to spheroidal particles of high quality of the final catalyst is disadvantageous. In general

can be shaped. 35 is the hydrogel with an aqueous solution of a

The water-soluble zirconium compound, which is sufficient in the acid or acid salt Method used according to the invention is concentration to affect the pH of the hydrogel water-soluble mineral acid salt of zircon, such as sam to reduce to less than 5, in contact z. B. zirconium nitrate, zirconium sulfate and zirconyl chloride. brought. Generally used for this purpose From this group, zirconium sulfate is preferred, since it is an inorganic acid and, in particular, a deterioration comparable formation conditions Catalyst-thin solution of a mineral acid, for example gates made using this salt are nitric, hydrochloric or sulfuric acid, in the form of a 1, the greatest improvement in terms of activity up to 10 weight percent solution for use and show selectivity. Zircon sand is a suitable one.

Source of a zirconium compound. The zirconium content is then reduced in pH

Dioxide in such a sand can be activated by caustic by placing the same under the

Melting at temperatures that reduce pH-

538 ⁰ C, and subsequent leaching while it is in contact with a

with sulfuric acid converted into zirconium sulfate aqueous medium located at a temperature about

will. 50 in the range from 66 to 104 ^° C., in particular

The silicate reactant is generally between about 80 ° and 104 ° C, at substantially

an alkali silicate and especially sodium silicate, atmospheric pressure during at least one

although silicates of other alkali metals, for example hour and generally not for about 48 hours

wise potassium silicate, used in a similar way, keeps going beyond. This stage is to achieve the

can be. An organic silicate ester, e.g. B. 55 improved silica-zirconia compound

Ethyl orthosilicate can also be used as a silica settlement according to the invention. According to this

source can be applied. Step is the hydrogel in a suitable manner with a

The solutions of the zirconium compound and the silicate-acidic solution are covered to adjust the pH of the hydro-reactive component are intimately gels in such proportions during activation approximately within the mixed so that a gellable sol with a 60 range from 1 to 5 and preferably from 1 to 3 results Keep zirconium dioxide content between. While the hydrogel after treatment see about 2 and 20, preferably between about 5 and to reduce its formation pH, such as 15 percent by weight and a pH above described, in an aqueous medium, which, as above 6, generally not stated above about 10, going at the elevated temperature results. 65 is held, can be transferred or brought in,

The resulting product is a hydrosol of which is generally preferable to the activation of the

Silica and Zirconia, which have the ability to reduce hydrogels in the same solution

asked to perform in the course of an appropriate period of time applied to the pH.

5 6

In a preferred embodiment, the appropriate period of time turns into a hydrogel or Post-BiI silica-zirconia hydrogel solidifies and the resulting hydrogel becomes dung at a pH value above 6 in a then at a temperature below the aqueous, dilute solution of an acid or a melting point of the incorporated powder Acid salt passed, in which the pH of the hydrogel 5 dried a gel. It was found that a is brought immediately below 5, and the hydrogel silica-zirconia gel, which becomes when it goes down then in such a solution with a setting or solidification of a sol, the powdered temperature between about 66 and 104 ° C during a material in the particle size mentioned above Maintained sufficient length of time to obtain the desired contains, and while drying the resulting hydro-activation to achieve. The pH of the hydrogel ίο gels at a temperature below the melting point the activation treatment is an important point of transition of the added material, Factor that opposes a much greater resistance to the final catalyst activity has direct influence, and after the process abrasion or wear and improved diffusion according to According to the invention, it should be lower than 5, as shown in comparison with lower than 3, shows a catalyst of 15 talking silica-zirconia gels, to obtain high cracking activity. which do not contain such an added powder.

After the activation treatment, the powdered material can be dispersed exchangeable or zeolitic impurities, if added to an already produced hydrosol present, from the hydrogel in any run, or the powder may preferably, if that removed in an unlikely manner. While in a practical way ao Hydrosol is characterized by a short gelation time or a large proportion of such zeolitic is traced to one or more of the reaction impurities in the course of the activation components which are added or may be used in the formation of the hydrosol treatment with the aqueous medium that is used containing acidic compound can be removed in the form of a separate stream with streams of the any remaining zeolitic material 25 hydrosol-forming reactants in one in a known manner by base exchange with water mixing nozzle or by other means by which the erigen solutions of mineral acids removed, such as. B. Reaction components in intimate contact with salt or sulfuric acid, solutions of ammonium are brought in. Except for the pre-salted, which act in such a way that they particle size called metal impurities should be solid through the powder Ammonium, which later decomposes by calcination, that of the silicon dioxide-zirconium dioxide hydrosol is removed, replace, and solutions of polyvalent ones are incorporated, in them necessarily insoluble Metal salts, in particular a zirconium salt, that is, and it should also be characterized by same or different zirconium salt than that at the hydrogel drying temperature and that can be that is fusible at the original. That in the silica-zircon formation of the hydrogel was used. In the case of the base 35 dioxide sol according to the embodiment described Exchange of the silica-zirconia hydrogel according to the invention incorporated powder can be a with an acid must obviously be a limited catalytically active or an inert material. As or controlled amount applied, as detailed above, the particular is powdered Avoid redissolving the zirconium dioxide. Material that is incorporated into the hydrosol, so out of the case Exchanges with ammonium compounds are chosen 4 ° that it is insoluble in them and some when dry Excess in the final stages of the heating temperature is infusible. With attention Catalyst production by calcination from these features include suitable, typical mag gears, and when using any zirconium material with an average particle salt by weight, that the catalytic properties are not after a diameter of 1 to 5 μ dry gels or gelatinous influenced, excesses applied 45 tinous precipitates, such as. B. those of and left in the composition. Silicon dioxide, aluminum oxide, magnesium oxide,

After the removal of zeolitic impurities such as chromium oxide, molybdenum oxide, zirconium dioxide and thorium oxide, the hydrosol is washed with water free of solvent oxide or titanium oxide including the excess ions. The settlements of the same. Thus, a particularly resulting catalyst composition of silicon comprises 50 preferred, powdered material for the incorporation of dioxide and zirconium dioxide is then by drying leibung in the sol powdered silicon dioxide-zirin air or superheated steam at a temperature of condioxide gel fines with a weight between about 93 and 204 ° C for a period of time mean particle diameter of 1 to 5 μ. Other between 4 and 24 hours and / or by suitable materials are zircon sand (zirconium silicate) calcination at a temperature between 427 and 55 or other metal silicates, metals and metal oxides, 982 ⁰ C for about 2 to 8 hours or more including aluminum oxide, chromium trioxide, Movollendet, lybdenum oxide, magnesium oxide, manganese oxide, zirconium

In some cases it may be desirable to use the dioxide and silicon dioxide in their different ways

Silica-Zirconia Hydrosol a lot of forms and modifications. So it has been found

of a solid, powdered material which is insoluble in it that the introduction of alumina powder into

borrowed, with an average particle by weight, the silica-zirconia sol is a product

supplies diameters between 1 and 5 μ, especially with improved properties,

between 2 and 4 μ. The amount of the catalyst can be in any desired,

powdered material introduced in this way is mechanical form according to the particular purpose,

between 2 and 40 percent by volume and in particular 65 for which it is intended. He can

between about 15 and 30 percent by volume of the dried either before or after calcination to form lumps,

neten gel product. The powdery silicon lumps or grains are broken up, or

Dioxyd-Zirkondioxyd-Sol sets itself after the course of a he can into a fine powder, which for the application

in the case of the suspension-like process or in the case of solution B, which is obtained by adding 300 cm ^{3 of} Zr (SO ₄ I ₂ ·

Process with tuidized solids (fluidized bed 4 H ₂ O solution with a content of 0.05 g

method) is suitable to be ground. On the other hand ZrO ₂ / cm ³ and 35 cm ³ H ₂ SO ₄ (48.85 weight

the catalyst can be used for working percent aqueous solution) to 1470 cm ^{3 of} water

wise in a fixed bed or a compact, moving 5 was made. Bed of mines, pellets or other suitable shapes, preferably before the calcination step, solutions A and B became rapidly with stirring be shaped. In this case the catalytic one is mixed. The resulting hydrogel had one Mixture partially dried to a powder with pH 8.5. Gelation occurred to one a particle size preferably smaller than the solid hydrogel in 10 to 15 seconds with a sieve of about 120 mesh at a temperature of about 24 ° C.

Mill square centimeters and rub the resulting hydrogel after

Suitable lubricants combined, for example left standing for 30 minutes at about the temperature previously specified with graphite, hydrogenated coconut oil, stearin standing in cube acid or resin, and cut by ejecting, pressing or 15 and transferred into containers in which the formed by other means known in the art. Cubes with 1 percent by weight aqueous solution particles with dimensions in the range of approximately H ₂ SO _{4 were brought} into contact, with 3.175.3.175 mm to 12.7-12.7 mm being the general pH value of the hydrogel to drop to 1.7 mine satisfactory. The molded particle was brought out. The hydrogel was then further dried and / or activated, as described above, by calcining it. Held at about 8O ⁰ C solution for about 24 hours

With bucket AmKhrungsform according to the invention was; during this time the pH rose is the originally produced hydrosol in form 2.0.

of cows into a water immiscible. The treated hydrogel then became a

Medium emgsÄhrt, for example in a column of a 25 base exchange subjected to zeolitic Versadt Waster immiscible liquid, e.g. B. to remove impurities by using a Ölmeditm, in which the spheres of the hydrosol are 2 percent by weight, aqueous solution of Ammo-ZU spherical, pearl-like hydrosol particles abnium chloride was brought into contact, wherein set or solidify. Other sizes are three 2-hour treatments and one treatment usually included within the range of about 0.397 to 30 overnight and about 1 volume-12.7 mm in diameter, while the smaller proportion of ammonium chloride solution per gel volume area ©, which was generally applied as microspheres for each treatment, within the range of about the base exchanged hydrogel

10 to 100 μ in diameter. The use of was then washed with water until the wesentkugelförmig shaped gel particles is borrowed particularly 35 was free of chloride ion, overnight at about advantage in hydrocarbon cracking process, eventually turn 138 ° C dried and for 10 hours at about 649 ⁰ C of Mobile catalyzed process,
sstorbett, the fluidized bed process (fluidized) and example 2

other processes in which the spherical silicon

40 A silica-zirconia catalyst was subjected to internal agitation. When used in the stationary bed made from the following reaction components: the _T. . ,. """,.." _τ .

day-like gel catalyst particles through solution A, which is composed of 690 cm ^{3 of} dilute sodium

avoidance of channel formation effective contact removal with a content of 0.193 g

between the reaction components and the Ka- 45 2> iU ₂ / cm existed.

catalyst. Solution B, which by adding 300 cm ³ Zr (SO ₄ V

The resulting improved silica-4H ₂ O solution at a content of 0.05 g

• Zirconium dioxide catalyst is used with numerous ZrO ₂ / cm ³ and 47 cm ³ H ₂ SO ₄ (48.85 weight

drive for the cracking of hydrocarbons percent aqueous solution) to 1485 cm ^{3 of} water

useful. For example, it has been found that 50 was made. that he is involved in the cracking of heavy petroleum, such as

z. B. Gas oils »heavy gasoline, to lighter solutions A and B were with rapid stirring

Materials that boil in the gasoline sector, with common, | mixed quickly. The resulting hydrosol had catalytic cracking conditions including a pH of 6.3. It gelation took place at a temperature in the range of about 427 to 566 ⁰ C 55 solid hydrogel at room temperature of about 24 ° C and eineaa pressure is usually between about 1 and about 30 seconds.

Atmospheres abs. is very effective. The resulting hydrogel was after standing-

The invention is described below with reference to some leave overnight at approximately the above

Examples mower veraoieäiaulicht nen temperature cut into cubes and

60 containers in which the cubes with oil weight

■ '_. -Ii percent aqueous solution of H ₂ SO ₄ in contact

öeispie l were brought, with the pH value of the hydrogel

A silica-zirconia catalyst was caused to drop to 1.7. The hydrogel

made from the following reaction components: 7 ™ *? ^then ^ άψ ** - activated that it is 24 hours

65 was kept in solution at about 80 C; wan-

Solution A, which consists of 690 cm ^{8 of} diluted sodium, rend this time, the pH rose to 2.5. Süicaflösung with a content of 0.193 g. The treated hydrogel was then a

SiO ^ ⁸ consisted *. Subjected to base exchange, washed and according to

Example 1 dried and then calcined ^{at about 538 ° C. for 10 hours.}

Example 3

A silica-zirconia catalyst was prepared from the following reactants manufactured:

Solution A, which consisted of 2070 cm ^{3 of} dilute sodium silicate solution with a content of 0.193 g SiO ₂ / cm ³ .

Solution B, which is obtained by adding 900 cm ^{3 of} Zr (SO ₄ ) ₂ · 4 HnO solution with a content of 0.05 g ZrO ₂ / cm ³ and 68.3 cm ^{3 of} H ₂ SO ₄ (95.2 percent by weight) to 4530 cm ^{3 of} water was made.

Solutions A and B were mixed with rapid mechanical stirring. The resulting hydrosol had a pH of 3.6. Gelation to a solid hydrogel occurred in about 8 hours Room temperature of around 24 ° C.

The resulting solid hydrogel, after standing overnight at about the temperature given above, was cut into cubes and transferred to containers in which the cubes were covered with water and held at a temperature of about 80 ^° C. for 24 hours.

The treated hydrogel was then base exchanged, washed, dried and calcined according to Example 1.

The cracking properties of the above-specified catalysts according to Examples 1, 2 and 3 determined by subjecting each of these catalysts to the CAT-C test. With this one The test is a mid-continent gas oil of a wide range, which starts at about 232 ° C up to 95%

ίο boiling at about 510 ° C, under standard conditions including an hourly space velocity of 2, a catalyst to oil ratio of 3, and a temperature of about 482 ° C, passed over the catalyst sample. In order to observe the differences in the selectivity of the individual silica-zirconia catalyst samples regardless of the level of conversion, each catalyst is compared with a standard technical silica-alumina cracking catalyst which contains about 10 percent by weight of aluminum oxide and 90 percent by weight of silicon dioxide and has the same conversion as the corresponding silica. Zirconia catalyst there. The results according to Examples 1, 2 and 3 are given in Table I below. In this comparison, each of the catalysts before cracking test at about 649 ⁰ C under atmospheric pressure, was treated with 100% steam for 10 hours, to bring the activity to a reproducible height.

Table I. example

Educational pH

Gel time pH during the
Activation treatment

conversion

Volume percentage

Difference * compared to SiO ₂ -Al ₂ O ₃

Gasoline percentage by volume

Coke weight percent

1
2
3

8.5
6.3
3.6

10 to 15 seconds 30 seconds 8 hours 1.7 to 2.0
1.7 to 2.5
3.6

52.1
48.4
46.8

+3.9 +3.7 +1.8

Value for SiO ₂ -ZrO ₂ catalyst minus value for SiO ₂ -Al ₂ O ₃ for the same conversion.

-0.5 +0.3 +0.8

From the data given above and Examples 1 and 2 it can be seen that the formation of the Silica-zirconia hydrogels at the higher pH and the subsequent lowering of the pH value during the activation treatment versus a comparable formation of the hydrogel starting at a low pH as illustrated in Example 3 has several advantages. First of all, the gel time is noticeably shortened. This allows the hydrogel to be produced in particulate form directly from the hydrosol without intermediate formation of a gel mass, which is then broken up and closed Particles of suitable size and shape is formed. Second is the activity of the catalysts according to the Steam treatment, d. H. the steam stability, in the case of the catalysts according to Examples 1 and 2, which are used in pH values of 8.5 and 6.3 are established higher. Third, there will be more with the latter catalysts Gasoline and less coke formed.

A number of silica-zirconia catalysts were prepared by procedures analogous to that used in the preparation of the catalyst according to Example 1 to determine the effect of the zirconia content on the catalytic activity of the catalyst product. In this series (Examples 4 to 7) an activation was carried out in that the silicon dioxide-zirconium dioxide gel formed at a pH of 8.5 with 1 percent by weight aqueous solution of H ₂ SO ₄ for 24 hours at a temperature of about 93 ° C in contact. The treated hydrogel was then base exchanged to remove zeolitic impurities by contacting it with a 2 weight percent aqueous solution of ammonium chloride, including three 2 hour treatments and one overnight treatment and about 1 volume ammonium chloride solution per volume of gel with each treatment was applied. The base-exchanged hydrogel was then washed with water until it was essentially free of chloride ion, ^{dried overnight at about 138 °} C. and ^{calcined at 538 °} C. for 10 hours. The only variation within this series was the level of zirconia in the final catalyst. The CAT-C ratings of these catalysts are given in Table II below.

509 510/403

Table II

example

5 I 6

description

ZrO ₂ in the hydrogel, ° / o · · · ·
Physical Properties

Pore volume, cm ⁸ / g

Density, g / cm ⁸
fresh or unchanged.
steamed ¹ ).

Surface area, m ^a / g
fresh or unchanged.
steamed ¹ ).

Chemical composition
ZrO ₂ , weight percent

Well, percent by weight

SO ₄ , percent by weight

Conversion, percent by volume

Gasoline, volume percentage

Difference compared to SiO ₂ -Al ₂ O ₃ C ² )

Gasoline, volume percentage

Coke, weight percent

Conversion, percent by volume

Gasoline, volume percentage

Difference to SiO ₂ -Al ₂ O ₃ ( ² )

Gasoline, volume percentage

Coke, weight percent

0.43

0.61
0.70

686

354

3.94
0.01
0.10

10
0.40

0.67
0.77

625
351

7.51
0.01
0.10

0.67 0.83

535 333

14.6 <0.01 0.27

25 0.29

0.77 0.86

475 250

25.7 0.02 0.33

Cat-C rating for fresh or

unchanged catalysts 56.9 70.9

47.2 53.0

+3.0 +1.7

-0.9 0.0

Cat C rating on steam treated catalysts

49.6
44.1

+4.1
-0.5

58.9
49.4

+4.0
-0.9

60.7 50.0

+3.7 -1.4

62.5 48

+0.8 +0.8

C ¹ ) Treated for 20 hours at about 663 ⁰ C with 100% steam at atmospheric pressure. (") Value for SiO _r ZrO" catalyst minus value for SiO ₂ -Al ₃ O ₃ for the same conversion.

From the above data it can be seen that the gasoline yield for each of the catalysts according to FIGS Examples 4 to 6 are about the same, i.e. H. +4 volume percent. The conversion level of the catalyst according to Example 4 containing 4% zirconia is about 10 volume percent less than that with the catalysts according to Examples 5, 6 and 7, each containing 7.5 to 25% zirconium dioxide. The steam treated catalysts show increased coke yield with increasing Zirconia content from 5 to 15%; however, the coke gain is lost at 25% zirconia. Everyone the catalysts according to Examples 4 to 6 led to a substantial improvement in terms of of the percentage of gasoline volume versus corresponding silica-alumina catalysts. Thus, the catalysts according to the invention are desirably characterized by a zirconium dioxide content between about 2 and 20 and in particular between about 5 and 15 percent by weight

Another line of silica-zirconia catalysts was made to illustrate the conditions for activation. These catalysts were prepared according to the following Working method generated.

Example 8

It became a silica-zirconia gel by mixing the streams of

(1) sodium silicate solution and

(2) Acid Zirconium Sulphate Solution
manufactured.

The sodium silicate solution was 40 weight percent water and 60 weight percent sodium silicate composed.

The acid-zirconium sulfate solution contained 6.61 percent by weight zirconium sulfate, 89.7 percent by weight water and 3.69 percent by weight sulfuric acid. This solution contained 0.0227 g ZrO ₂ / cm ³ .

368 cm ³ / min of sodium silicate solution and 392 cm ³ / minute of the acid zirconium sulfate solution were mixed in a mixing nozzle, so that a sol was formed which on a dry basis, contained 10 weight percent zirconium dioxide and in 2.1 seconds at about 18.3 ° C settled or solidified to form a hydrogel. The gel was formed into spherical hydrogel beads by placing beads of the sol in an oil medium. The resulting hydrogel particles, pH 8.5, were contacted with a 2 weight percent aqueous solution of H ₂ SO ₄ for 2 hours at about 93 ° C. The treated hydro

gel particles were then base-exchanged, washed, dried and as in the Examples 4 to 7 calcined.

The catalysts according to Examples 9 and 10 were the same as in Example 8 Manner, but made with the exception that the time used for activation in the has been varied to the extent illustrated below. The CAT-C rating of these catalysts is in the Table III below:

Table III

example
9

10

Description of the hydrogel

activation

solution

Time, hours

Temperature, ⁰ C

pH (away)

Physical Properties
Pore volume fresh or unchanged, cm ³ / g.

Density, g / cm ³

fresh or unchanged

treated with steam ^)

Surface area, m ² / g

fresh or unchanged

treated with steam ^)

Chemical properties

ZrO ₂ , weight percent

Well, percent by weight

SO ₄ , percent by weight

Conversion, percent by volume

Gasoline, volume percentage

Difference to SiO ₂ -Al ₂ O ₃ ( ^a )

Gasoline, volume percentage

Coke, weight percent

Conversion, percent by volume

Gasoline, volume percentage

Difference to SiO ₂ -Al ₂ O ₃ ( ² )

Gasoline, volume percentage

Coke, weight percent

10% ZrO ₂ beads formed at pH 8.5
V ₂ V / V pearls

2% H ₂ SO ₄

about 93
2.1

0.35

0.82
0.98

591
314

4th
93
2.3

0.37

0.79
0.94

590
314

7.97 7.83

0.01 0.01

0.11 0.22

Cat C rating
with fresh or unchanged catalysts

19th
93

2.4

0.45

0.75
0.82

352

71.0 70.3 68.2 54.1 54.2 53.8 +2.8
-0.1 +3.2
-0.5 +3.6
-0.9 at with Cat C rating
Steam ( ^x ) treated t catalysts 61.0 58 50.4 48.8 +3.9
-1.0 +4.0
-1.7 60.9 51.1 +4.6
-1.3

C ¹ _{) Treated with 100 ° / 0} steam at atmospheric pressure at about 663 ° C for 20 hours. ( ² ) Value for SiO ₂ -ZrO ₂ catalyst minus value for SiO ₂ -Al ₂ O ₃ for the same conversion.

From the above data it can be seen that activation for 4 hours at about 93 ° C. improves the selectivity of the catalyst somewhat more than the corresponding activation at 2 hours. A further increase in the activation time to 19 hours shows a decrease in the level of conversion and in gasoline gain. In this case, however, the coke recovery was improved. The particular period required for activation will depend in part on the type, concentration, and temperature at which such steps are performed and may range from one hour progressively to 48 hours or more. Generally the activation time will be greater than 2 hours and will usually be within the range of 2 to 24 hours. Another comparative series of silica-zirconia catalysts was prepared to illustrate the need for high temperature during the activation step. The catalysts according to Examples 11 and 12 were prepared by a method analogous to Example 8. The catalyst according to Example 11- was treated at room temperature while the catalyst example 12 to an activation treatment was subjected at about 93 ⁰ C in accordance with. The results are shown in Table IV below.

Table IV

Example 11 I 12

description

activation

Time, hours

Temperature, ⁰ C ...

Solution ..
pH (away)

Physical Properties
. Pore volume, cm ^s / g

Apparent density,

g / cm ⁸
fresh or unchanged
treated with steamC ¹ )

Surface area,

m ⁸ / g

friseatew. unchanged
treated with steamf ¹ )

Chemical
composition
ZrOg, percent by weight

Well, weight bar
percent ......

SO ₄ , percent by weight

Conversion,

Volume percentage

Gasoline, volume percentage
Difference compared to

Gasoline, volume percentage.
Coke, weight percent

Conversion, percent by volume

Gasoline, volume percentage

Difference compared to
Sil

Gasoline, volume percentage
Coke, weight percent

formed at pH 8.5

24

Room temperature

2% H ₈ SO ₄ 1.2

0.33

0.87 1.01

532 293

8.65

0.02

<0.10

24 about

2 ° / oH ₂ S0 ₄ 2.1

From the above data it can be seen that treatment in dilute acid solution at room temperature was not sufficient to obtain the desired gasoline and coke recovery as obtained with the catalyst prepared by the process according to the invention. According to the above-described operation is desirable that activation is carried out at a temperature approximately within the range 66-104 ⁰ C.

Example 13

0.43

0.74 0.84

642 351

7.81

0.008

0.11 Silica-zirconia hydrogel in bead form was prepared by a method analogous to Example 8. In this example, the beads were activated by treatment in an aqueous 2% H ₂ SO ₄ solution at about 66 ^{° C. for 8 hours.} The treated hydrogel was evaluated in a gas oil cracking test after base exchange, washing and drying according to Example 8 and after annealing for 5 hours at about 871 ° C, followed by steaming. At a conversion of 55.6%, the gasoline gain (volume percent) versus SiO ₂ -Al ₂ O _{3 was} 4.4%. This result shows that about 66 ° C is a satisfactory activation temperature. It also illustrates the unusual stability of this type of catalyst when exposed to high temperatures. The following example is provided to illustrate the use of zircon sand as a source of a zirconium compound. For example, the zirconium dioxide content of zirconium sand can be converted into zirconium sulfate by caustic fusing at around 566 to 621 ° C and leaching in sulfuric acid.

Cat C rating

with fresh

or unchanged

Catalysts

67.7 50.6

0.6 +0.1

67 52.0

2.3 -1.0

Cat-C rating

steamed ( ^x )

Catalysts

51.9 44.6

+3.2 +0.8

57.6 48.3

+3.7 -1.2

(*) 20 hours at about 663 ° C with 100% steam at atmospheric Pressure treated

(«) Value for SiO, -ZrO, .catalyst minus value for OAIO on the same conversion.

Example 14

375 g of NaOH pellets were added to 250 g of zirconium sand (67 ° / ₀ ZrO _2). The mixture was heated at about 566 ° C. for 3/2 hours. The resulting product was contacted with 41% of water at room temperature overnight and then filtered and washed. The residue from the washing was ^{brought into contact with 800 cm 3 of} a solution of 73H ₂ SO ₄ and V ₃ H ₂ O for 72 hours at a reflux temperature of about 149 ° C. The resulting solution was filtered and diluted to a total volume of 51 with water. The final, dilute solution of zirconium sulfate contained 0.034 g ZrO ₂ / cm ³ .

Solution A was prepared by adding 300 cm ^{3 of} NaOH solution with a content of 25 percent by weight NaOH to 2800 cm ^{3 of} dilute sodium silicate solution with a content of 0.193 g SiOa / cm ³ .

Solution B was prepared by diluting 1764 cm ^{3 of} the zirconium sulfate solution prepared as described above with a content of 0.034 g ZrO ₂ / cm ³ with 5136 cm ³ H ₂ O.

Solution A was mixed with solution B with rapid stirring. The resulting hydrosol had a pH of 8.5. Gelation to a solid hydrogel occurred within about 15 seconds. The hydrogel was cut into cubes and transferred to containers in which the cubes were brought into contact _{with 1 g weight percent aqueous solution of H 2} SO _4; that led to the

The pH of the hydrogel dropped to 2.2. The hydrogel was heated in this solution ^{at about 93 ° C. for 24 hours.}

The treated hydrogel was then base exchanged, washed, dried and

calcined as in Examples 4-7. The Cat-C rating at | the fresh or unchanged and the steamed catalyst is illustrated in Table V below.

Table V

conversion

Volume percentage

petrol

Volume percentage

Difference compared to
SiO ₂ -Al ₂ O ₃ C ² )

coke
Weight percent

petrol

Volume percentage

Fresh or unchanged catalyst
Steamed catalyst ^) ..

65.9
54.9

54.4
47.5

+5.1
+4.4

C ¹ _{) Treated with 100 ° / 0} steam at atmospheric pressure at about 663 ° C for 20 hours.

( ² ) Value for SiO ₂ -ZrO ₂ catalyst minus value for SiO ₂ -Al ₂ O ₃ for the same conversion.

-1.6
-0.9

The following example is provided to illustrate the use of ethyl orthosilicate as the source of silica and of zirconyl chloride as the source of zirconia in the manufacture of the silica-zirconia catalyst.

Example 15

A silica-zirconia catalyst was prepared from the following reactants.

Solution A was obtained by mixing 5220 cm ^{3 of} tetraethylorthosilicate ethyl alcohol with a content of 0.104 g SiO ₂ / cm ³ and 1200 cm ^{3 of} ZrOCl ₂ · 8H ₂ O / ethyl alcohol solution with a content of 0.05 g ZrO ₂ / cm ³ and 60 cm ^{3 of} 4n-HNO ³ produced.

Solution B consisted of 1080 cm ^{3 of} 3.06N NH ₄ OH solution.

Solutions A and B were mixed together with rapid stirring. The resulting hydrosol had a pH of 8.5 and gelled to a solid hydrogel within 90 seconds. The hydrogel was cut into cubes and transferred to containers in which the cubes were brought into contact with HCl ^{at about 93 ° C. for 24 hours.}

The pH was controlled approximately within the range of 2 to 3 by adding HCl.

The treated hydrogel was then base exchanged, washed, dried and calcined as in Examples 4-7. The CAT-C score for the fresh or unchanged and the steamed catalyst is illustrated in Table VI below.

Table VI

conversion
Volume percentage

petrol
Volume percentage

Difference compared to
SiO ₂ -Al ₂ O ₃ C ² )

petrol
Volume percentage

Fresh or unchanged catalyst
Steamed catalyst ( ^x ) ..

66.2
48.8

50.6
41.6

Treated C ¹⁾ 20 hours at about 663 ⁰ C with 100% steam at atmospheric pressure.

C ² ) value for SiO ₂ -ZrO ₂ catalyst minus value for SiO ₂ -Al ₂ O ₃ for the same conversion.

+1.3
+2.1

Another line of silica-zirconia catalysts was used made to illustrate that solutions of sulfuric acid and zirconium sulfate or zirconium sulfate alone as well as Sulfuric acid can be applied to activate the hydrogel.

Example 16

It became a silica-zirconium dioxide gel by mixing the streams of

(1) sodium silicate solution and

(2) Acid Zirconium Sulphate Solution
manufactured.

The sodium silicate solution was 40 weight percent water and 60 weight percent sodium silicate composed.

The acid-zirconium sulfate solution contained 3.16 percent by weight zirconium sulfate, 91.4 percent by weight H ₂ O and 5.44 percent by weight H ₂ SO ₄ . This solution contained 0.01 g ZrO ₂ / cm ³ .

400 cm ³ / min of sodium silicate solution and 418 cm ³ / minute of the acid zirconium sulfate solution were mixed in a mixing nozzle, so that a sol was formed which, on a dry basis, containing 5 percent by weight of zirconium dioxide. The sol was formed into spherical hydrogel beads by placing beads of the sol in an oil medium.

509 510/403

were led. The hydrosol beads settled or solidified to form a hydrogel within 2.1 seconds at about 15.6 ° C. The resulting hydrogel having a pH value of 8.5 were placed for 24 hours at about 93 ⁰ C with a 2gewichtsprozentigen aqueous solution of H ₃ SO ₄ in contact. The treated hydrogel particles were then base exchanged, washed, dried and calcined as in Examples 4-7. The catalysts according to Examples 17, 18 and 19 were prepared in exactly the same way as in Example 16, with the exception that the hot activation solution in each case

(a) from a ₂ percent by weight aqueous solution of H 2 SO ₄ and 1 percent by weight Zr (SO ^ ₂ · 4 H ₂ O,

(b) consisted of a ₂ weight percent aqueous solution of H 2 SO ₄ and 5 weight percent Zr (SOi) ₂ · 4 H ₂ O and (c) a 5 weight percent aqueous solution of Zr (SO _{4 I 2} · 4 H ₂ O).

The CAT-C ratings of these catalysts are given in Table VII below.

Table VII

example
17 I 18

19th

description
Activation ■

I.
formed at pH 8.5

Zr (SOJ ₈ ^ H ₂ O ₅ ⁰ A.

Time, hours.

Temperature, ° C

End pH

Physical Properties
Pore volume, cm * / g

Apparent density, g / cm ⁸
fresh or unchanged
treated with steam (*)

Surface area
fresh or unchanged.

composition

ZrO ₂ , weight percent.
Well, percent by weight.
SO ₄ , percent by weight.

3.9
0.65

0.57
0.65

5.4
0.04
<0.09

2
1

3.0
0.60

0.61
0.73

2
5

about 93 ⁰ C
1.8

0.47

0.66 0.78

638

6.3
0.02
<0.09

655

7.6 0.006 <0.09

2.5

0.57

0.62 0.76

630

8.9

0.004

0.21

CAT-C rating for steam treated catalysts

Conversion, percent by volume

Gasoline, volume percentage

Difference to SiOyAl ₂ O ₃ ( ^a )

Gasoline, volume percentage

Coke, weight percent

42.6
39.1

+3.3
-0.2

47.2
42.3

+3.6
-0.4

47.4 42.5

+3.5 -0.8

49.1 43.7

+4.0 -0.9

C ¹ ) Treated with 100% steam at atmospheric pressure at about 663 ° C for 20 hours.

P9 value for SiOa-ZrOa catalyst minus value for SiO _a -AlaO ₃ with the same conversion.

The following example illustrates the preparation of a silica-zirconia catalyst With improved diffusion properties through the incorporation of 40 weight percent zircon sand (based on the final catalyst), which is ground to a particle size of 1 to 5 μ.

Example 20 g ₀

It became a silica-zirconia catalyst in bead form by mixing streams the end

(1) Dilute sodium silicate solution with a content of suspended fines and

(2) Acid Zirconium Sulphate Solution
manufactured.

The sodium silicate solution was prepared by dispersing about 3.3 kg of a slurry of zircon sand fines in about 7.7 kg of sodium silicate diluted with about 3.2 kg of water. the Fines were dried for 24 hours and in 50 weight percent water sludge for 72 hours Grind to a diameter of 1 to 5 μ. These Solution contained 54.4% sodium silicate, 11.6% fines, and 34% on a weight basis Water.

The acid-zirconium sulfate solution was prepared by adding about 0.7 kg of 95 weight percent H ₂ SO ₄ to a solution of about 1.26 kg of zirconium sulfate in about 17.1 kg of water. This solution contained 6.61 percent by weight of Zr (SOi) ₂ · 4 H _2, 0.89.7 percent by weight of water and 3.69 percent by weight of H ₂ SO ₄ . Of the

21 22

The zirconium dioxide content of this solution was 0.0227 g.

ZrO ₂ / cm ³ . yaw of about 3.3 kg of a 20 weight percent

356 cm ³ / minute of the sodium silicate fine material sludge aqueous sludge of silicon dioxide-zirconium dimes and 386 cm ³ / minute of the acid-zirconium sulfate oxide gel fines with a solution by weight were mixed in a mixing nozzle so that 5 ler particle diameters of 1, 5 μ a sol was formed in about 10.5 kg, which is produced within 2.3 Se- dilute sodium silicate solution. The final customer at about 22 ° C settled to a hydrogel valid solution with a specific gravity of or solidified. The sol was formed into spherical hydrobases containing 55.4 percent by weight sodium silicate, 39.85 percent gel beads by introducing 1.230 percent by weight sol beads into an oil medium. The resulting hydrogel, water and 4.75% silica-zirconia particles, pH 7.7, became fines for 24 hours.

long at about 93 ° C with 1 percent by weight aqueous The acid-zirconium sulfate solution was

Solution of H ₂ SO _{4 brought} into contact. The solution of about 3.8 kg of zirconium sulfate in about 39.6 kg of treated hydrogel particles was then base-exchanged with water and added about 1.79 kg of sulfuric acid, washed and dried. The final solution with a spe- and calcined according to Examples 4 to 7. contained a specific weight of 1.084 at about 15.6 ° C,

The physical and catalytic properties on a weight basis, 87.81% water, 8.36% of the resulting silica-zirconia-zirconium sulfate, and 3.83% sulfuric acid.
Pearl catalyst are in the following Ta- 432 cm ³ / minute of the sodium silicate fine material sludge

Belle VIII illustrates. 20 mes and 392 cm ³ / minute of the acid zirconium sulfate

Solution were mixed in a mixing nozzle so that

Table VIII a sol was formed, which within 2 to

3 seconds at about 11.1 ° C to a hydrogel Physical properties settled or solidified. The sol was

Pore volume, cm ³ / g 0.44 25 conduction of sol spheres in an oil medium to form spherical

a,. , - ..,, "shaped like hydrogel beads. The resulting

Apparent density, g / cm ^{3 of} hydrogel particles with a pH of 7.2 were made

fresh or unchanged 0.83 for 4 hours at a room temperature of about

treated with steam ( ^x ) 0.88 21 ° C with water and then with a solution of a

Surface area, m ² / g ³ ° 3 weight percent sulfuric acid for 3 hours

". ,, -j -, * ■ * ■ brought into contact at about 93 C m. The treated

fresh or unchanged 355 hydrogel particles were then im

steamed C ¹ ) 224 washed substantially free of sulfate ion, at about

Analysis at 121 to 149 ° C, dried in steam for 5 hours

ZrO ₂ , percent by weight 32.5 ³ S ^be ! ^{about 76} 9 ° ^C f ^air and calcined for 10 hours

Well, weight percent 0.01 ^for ™ ^Dri J ^{ck v} ™ ^e * ^wa } & ^ata ™ ^d . T ₁ J ^? "

SO ₄ , percent by weight <0.10 P £ ^rature ™? ^about f ⁴ ? ^c , ^with ? ^on | ^f treated. the

physical and catalytic properties of the

CAT-C rating of steamed (*) J ^ch . giving product are in the following

Catalyst ⁴ ° ^{Table IX} illustrates.

Conversion,% by volume 46.3 Example 22

Gasoline, volume percent 42.0 It was gin silicon dioxide-zirconium dioxide gel with

,. , .., _._., _ ". a content of finely divided aluminum oxide

Difference from SiO ₂ -Al ₂ O ₃ ( ² ) 45 _Ver mixing the streams of

Gasoline, percentage by volume +4.0 .... _XT . ., ..-, ·, · ^ , _l4 .

Coke, weight percent -0.2 W emem sodium silicate ^{sludge containing}

on aluminum oxide fibers and

i ¹ ) for 20 hours at a temperature of about 663 ° C in _{// Vv} ".. ^ - ■, _{1 £} . _T ..

100 · / “Steam treated at atmospheric pressure. ( ² ) Acid-zirconium sulfate solution

( ² ) Value for SiOrZrOa catalyst minus value for ⁵ ° produced.

SiO ₂ -Al ₂ O ₃ with the same conversion. _ - _T. ....,,,, τ ^.

The sodium silicate sludge was dispersed

Examples 22 and 23 given below yaw from about 12.3 kg of a 25 weight percent each illustrate the production of silicon-aqueous sludge from aluminum oxide fines Dioxyd-zirconium dioxide and silicon dioxide-zirconium dioxide catalysts with a weight average particle diameter-aluminum oxide by means of a jointing knife of 4.4 μ. in about 14.5 kg of sodium silicate, the Exercise of finely ground silicon dioxide-zirconium was diluted with about 0.37 kg of water. oxide gel fines and oc aluminum oxide in the final solution with a specific Ge hydrosols during education. weight of 1.309 at about 24 ° C, based on

60 weight basis, 53.18% sodium silicate, 20.3% aluminum example 21 minium oxide fines and 26.52% water.

A silicon dioxide-zirconium dioxide gel was used. The acid-zirconium sulfate solution was

by mixing the streams of dissolve about 7.4 kg of zirconium sulfate into about 78.5 kg

, _1λ . _xT,. ... ,, ... _,,,. Water and addition of about 4.7kg sulfuric acid

(1) a sodium silicate sludge made with a grade _{6 The} final solution with a spean silicon dioxide-zirconium dioxide substance and ^ c _{116n weight of lj095 contained} at about 15.6 ° C,

(2) Acid Zirconium Sulphate Solution on a weight basis, 86.75% water, 8.20% manufactured. Zirconium sulfate and 5.05% sulfuric acid.

378 cm ^s / minute of the silicate slurry and 359 cm ³ / minute of the acid-zirconium sulfate solution were mixed in a mixing nozzle, so that a sol was formed, which within 3 to 4 seconds at about 12.8 ° C to a hydrogel settled or solidified. The sol was formed into spherical hydrogel beads by introducing small sol balls into an oil medium. The resulting hydrogel particles, pH 6.9, were contacted with water at room temperature of about 21 ° C for 4 hours and then with a solution of a weight percent sulfuric acid for 3 hours at about 93 ° C. The final pH of the hydrogel was 2.1. The treated hydrogel particles were then washed substantially free of sulfate ions for a period of about 60 hours, steam dried at about 121-149 ° C, standing at about 760 ° for 5 Calcined and treated with steam for 10 hours at a pressure of 1.05 atmospheres and a temperature of about 649 ° C. The physical and catalytic properties of the resulting product are illustrated in Table IX below.

Table IX at
21 game
22nd 50.9
40.5 0.70
0.78 0.91
1.05 +5.3
-0.6 Physically
Apparent density, g / ca ^s
fresh or unchanged ...
treated with steam C ¹ ) ... 179 14 ₅ 8 Surface area, m ^a / g
fresh or unchanged
treated with steam (*} ...
Difiusionsvetmögen
cm ^ second x 16 ^a Gas oil cracking
valuation (*) 42 ^ 5
35.2 Conversion, percent by volume
Gasoline ·, votaa percent
Difference compared to +4.1
-0.3 Gasoline, volume percentage
Coke, weight percent ....

35

40

45

M catalyst, calcined for 5 hours at about 760 ° C and 10 stands at about 649 ° C at 1.05 atm Danrpf treated.

P) Value for SiOa-ZrOa catalyst minus the value for SiCVAl _a Qs in the case of dmseftiem conversion.

55

The above results illustrate that according to the procedure given above, a selective or active silica-zirconia cracking catalyst can be produced with improved properties of the dissertation property. Of the Catalyst according to Example 22 compared to the DißusioQSverraögen toi * had about 1 for a silicon dioxide-zirconium dioxide catalyst, containing no added powdered material, a diffusivity of 14.8. The catalysts showed good gasoline selectivity with less coke formation than a silica-alumina cracking catalyst took place in the same conversion. The gas oil crack test as used in evaluating these catalysts was the same as the CAT-C test, except that a temperature of about 875 ° C, a space velocity of 1.5 and a catalyst to oil ratio of 4.0 were used became.

Claims (6)

Patent claims: 1. A process for the preparation of a cracking catalyst from silicon dioxide and zirconium dioxide, characterized in that one water-soluble zirconium compound and an alkali silicate or an organic silicate ester converts a gellable sol which has a pH value above 6 and in which, if necessary, about 2 to 40 percent by volume (based on the dried gel product) of a solid powdery Dispersed material is insoluble in the sol and at the calcination temperature of the gel is infusible and a mean particle diameter determined by weight between has about 1 and 5 μ, the sol can be solidified to form a silicon dioxide-zirconium dioxide gel, reduces the pH of the gel below 5, the gel at a pH below 5 at a temperature in the range of approximately 66-104 ° C for a period of about one hour, essentially under atmospheric pressure conditions brings it into contact with an aqueous medium, washes the gel free of soluble material, dries and calcined. 2. The method according to claim 1, characterized in that a gellable sol with a zirconium dioxide content, on a dry matter basis, from about 2 to 20 weight percent is used. 3. The method according to any one of claims 1 and 2, characterized in that the gellable sol a pH above 6 but not higher than 10 and the gel has a pH below 5 but above 1 having. 4. The method according to any one of claims 1 to 3, characterized in that as water-soluble Zirconium compound is a zirconium salt of a mineral acid and ethyl orthosilicate is used as a silicate will. 5. The method according to any one of claims 1 to 4, characterized in that beads of the sol are introduced into a column of a water-immiscible liquid in which the sol-spherules solidified into spherical hydrogel particles. 6. The method according to any one of claims 1 to 5, characterized in that washed free of soluble material, dry gel at a Temperature of about 427 to 982 ° C is calcined. Documents considered: German Patent No. 972 724. 509 510/403 2.65 © Bundesdruckerei Berlin