DE1067159B - Process for the production of fission catalysts - Google Patents

Description

BUNDKSKEPUBLIK GERMANY

GERMAN

kl. 23 b 1/04

INTERNATIONAL KL.

PATENT OFFICE BOIj; C 10g

EDITORIAL 1 067 159

N 14597 IVc / 23 b

REGISTRATION DATE: JANUARY 22, 1958

NOTICE THE REGISTRATION AND ISSUE OF THE EDITORIAL: OCTOBER 15, 1959

The so far technically to the catalytic! Catalysts used in columns of hydrocarbon oils are either treated clay catalysts or synthetic silica-alumina compounds, which contain about 12 to 25% aluminum oxide in bound form.

So far it has been held that a dissociation catalyst works the better, the larger its free inner surface per unit weight. The best commercially available synthetic silica-alumina composite catalysts of this type therefore have effective surface areas in the fresh state on the order of 500 to 600 m ² / g.

It has now been found that cracked catalysts can be produced which only have a relatively small effective surface area of about 200 m ² / g. up to about 400 m ² / g , but nevertheless have a high effectiveness per unit of surface, with the selectivity being significantly improved at the same time. This improvement in selectivity enables a substantial increase in gasoline production, and it causes a decrease in coke and gas formation.

The new method according to the invention is based on the surprising finding that it is necessary to achieve the particular technical efficacy described, the structural design of the cleavage catalysts to deviate from the previous state of the art and in particular to ensure that the Si O ₂ -Emunities are particularly strongly aggregated and any excess of unbound aluminum oxide is avoided. The silicon dioxide hydrogel which forms the basic structure of the catalyst body is therefore produced under certain controlled conditions, and at the same time its reaction with the aluminum salts and their hydrolysis are precisely regulated.

According to the invention, the production of the new cleavage catalysts with a small effective surface area is based on strongly alkaline sodium silicate solutions which have a p _FI value of at least 10. These water glass solutions are mixed with such amounts of aqueous solutions of one or more salts of magnesium and / or calcium that about ¹ Ao to Vs mole of the metal salt or metal salts per mole of SiO ₂ is present in the silicate solution, while at the same time the entire concentration of SiO _{2 should be} between 3 and 9 percent by weight after the addition of the metal salts. The p _H of the mixture -Wcrt must not fall below 10 during the addition of the magnesium and / or calcium salt solutions. This regulated addition of the zwci process for the production of fission catalysts

Applicant:

N. V. De Bataafsche Petroleum Maatschappij, The Hague

Representative: Dr. K. Schwarzhans, patent attorney, Munich 19, Romanplatz 9

Claimed priority: V. St. v. America January 24, 1957

Ross Edwin van Dyke, Orinda, Calif.,

and John Norton Wilson, Berkeley, Calif. (V. St. Α.),

have been named as inventors

Valuable metal ions counteracts the negatively charged double layer which forms in the concentrated waterglass solutions and allows the _{van der Waals forces that promote aggregation of the SiO 2} units to come into play, which promotes the crosslinking of these units and a strong aggregation is achieved. The special structure of the silicon dioxide hydrogel obtained by this novel measure is also noticeable in its external appearance. In contrast to the masses usually obtained by adding acid and forming a solid jelly, the hydrogel produced according to the invention in the manner described is a soft thixotropic substance which does not solidify even when left to stand. A solution of the water-soluble salt of aluminum is then added to the reaction mixture obtained by adding the magnesium and / or calcium salts at such a rate that the pn value of the liquid is between 9.0 and 10.5, at least during the addition an aqueous ammonia solution is also added to the last part of this metal salt solution. This controlled addition ensures that really all of the aluminum is _{bound to the SiO 2} aggregate of the hydrogel, so that the finished catalyst does not have any excess aluminum salt. At the same time it is also ensured that the finished catalyst has a relatively small free inner space

3 4

Having surface, but much more selective acts 0.5 molar, and that the p _H of the silicate solution -Wcrt

than the best cracking catalysts known to date. during this addition to a value of min-

The Al ₂ O ₃ -Si O ₂ hydrogel obtained in this way is then at least 10, preferably between 10 and 10.5,

is separated from the liquid by filtration, held,

wash and dry. 5 The resulting cream-like material can be used for

The expression »mol SiO ₂ * used here refers to securing the equilibrium for a few minutes, e.g. B.

on the total amount of silicon dioxide for about 15 minutes.

depending on whether this is in hydrated form under the conditions described or is present as a silicate. / ^ - Magnesium and / or calcium completely in that

In and of itself, processes for the production of ^ Siiciumdioxydaggregat have already been implemented. The Reaktionsvon dissociation catalysts by treatment of CAI ^ ^ mixture has in this stage, a _pH value of mincium- and / or magnesium silicates with aluminum \ Vjigstens 10.0, preferably contains about 5% Gesamtsalzlösungcn known, but there are always Pro "" -silica and has the shape of a very soft

Duktc with a relatively large effective top gel that is thixotropic, but does not dissolve when standing

surface received, and these differ therefore 15 solidified into a solid gel. If the overall

not only with regard to their structural structure, silicon dioxide concentration in this stage

but also in terms of their selectivity of about 9%, a catalyst is obtained from

Catalysts prepared according to the invention, such as undesirably low apparent density. If you

later comparison searches will have to be confirmed. on the other hand, is below about 3%, is the apparent

For example, it has been recommended that a density of 20 be too high. At 5% concentration it is

stoichiometric composition of crystalline CaI- apparent density of the finished catalyst normal-

cium silicate in a magnesium or aluminum salt manner about 0.30 to 0.60, and it is then for use

Solution to slurry and very suitable for a while with increased dung in the suspension state.

To digest temperature in it. If the _pH value is at this stage about 10.5,

A method is also described; according to FIG. 25, it is preferably set to the range from 10.0 to which one reduced from a water glass solution with 10.5 therein, z. B. by adding an aqueous on slurried solid MgO by adding an acid solution of an acid such as sulfuric acid or salt solid gel crushed and this gel lump acid.

then soaked in an aluminum salt solution. In the working method described above,

Here, too, it is a common Hydrogcl 30 follows the implementation of the magnesium and / or CaI-

with few aggregated SiO ₂ units, which contain a lot of ciums in the silica aggregate at a very high level

Can bind to aluminum and therefore catalytic converters high _pH value, so that the latter, if necessary,

torcn with high effective surfaces. by adding acid to 10.0 to 10.5 hcrab-

Finally, a mode of operation is known in which it is possible to set. According to another execution

In a conventionally prepared hydrochloride form of the process, the same men-

SiO ₂ and Al ₂ O _{3 are} then used with a Magnesia- gen of these reaction components, the

slurry, a magnesium salt solution or acid, but before the magnesium and / or calcium

dry magnesia is treated. This catalyst salt solution was added. In this way of working

satorcn also have a different internal structure, the magnesium and / or calcium in one

and other properties than the present invention in more detail p 40 lying at 10 to 10.5 _H -Wcrt to the reaction

manufactured products. brought. According to another variant, you can use the

The starting material for the production of the acid and the magnesium and / or calcium salt

bcsscrtcn catalysts according to the invention is to supply solution at the same time. In none of these cases

Sodium silicate. You could also VCR potassium silicate so you can the _pH value of the reaction mixture

turn around; but this is much more expensive. The 45 when adding the magnesium and / or calcium

Let the ratio of SiO ₂ to Na ₂ O in the sodium silicate salt solution drop below 10.0,

can vary from about 1: 1 to about 4: 1; After a short aging time it is at a p _n value

usually between 3: 1 and 4: 1. above 10, preferably between 10 and 10.5

The sodium silicate is first treated with water to an aqueous solution of an aluminum salt, e.g. B. a Gcsamt-Si O ₂ concentration between about 6% 5 ° 0,4molare a solution of aluminum sulphate, switched on and about 15 weight percent or set in such training, until the _pH value _is a value of about 9, 5 diluted to the extent that the total silicon dioxide concentration is sufficient. In this stage, an aqueous ammonia hydration immediately before the addition of the aluminum solution (e.g. an omolar solution) is at the same time as the salt solution between about 3 and 9%, e.g. 5%. the aluminum salt solution is added to verhin-Der P ₁₁ value of the diluted sodium silicate is 55 to that of the p _H -Wcrt falls below 9.0, and around it normally about 11.5. preferably to hold at 9.5. At this work

The main amount of silicon dioxide is then added to the sodium silicate solution

Stir a dilute solution of a soluble salt - but not the total amount - with the AIu-

of magnesium and / or calcium, such as. B. aggregated mineral oxide.

gncsiumchlorid, magnesium sulfate, calcium chloride, 60 of the p _H value, wherein the hydrolysis of the AIu-

Calcium nitrate, calcium acetate, or a solution of a minium salt is of decisive importance.

dicscr salts, in which case magnesium or the meaning, and it must be at least 9.0;

Calcium hydroxide has been dissolved, with stirring the preferred value is 9.5. At a higher one

added. It is Wese ntlich that the magnesium p _H value of about 10.0 is shown that the obtained and / or to-CalciumsaTziosung to the silicate solution contains 65 catalyst large amounts of sodium, which only

is given and not the other way around, or that the case is difficult without impairing the properties of the

the solutions are to be removed at the same time as a catalyst in a mixing vessel. On the other hand, at

be guided. It is also essential that the p _H values below 9.0, the magnesium and / or CAI

Solution of the magnesium and / or calcium salt removes cium to a large extent from the catalyst is diluted, preferably between 0.05 and 70 distant.

The ρ ,, - value of the silicon dioxide can be determined by the Addition of an aqueous solution of an acid prior to the addition of the aluminum salt, pressed down to 9.5 hours will. The aluminum salt solution is then simultaneous with the ammonia solution at such a rate admitted that the p ^ value no longer changes. In this case it will be the most essential the total amount of silica aggregated before the alumina was incorporated.

The amount of aluminum incorporated into the catalyst can be up to 35 percent by weight of Al ₂ O ₃ , calculated on the finished catalyst. However, the amount is preferably below 30%, e.g. B. between 12 and 30 per cent.

The stated amounts of magnesium and / or calcium correspond to about 1 to 9 percent by weight of MgO and CaO, calculated on the finished catalyst. _{In order to obtain increased yields of valuable C 3} and C ₄ olefins in addition to the improved gasoline yield by means of the cleavage catalysts produced according to the invention, it is essential that at least about 3% MgO and / or CaO are present in the finished catalyst.

In some cases it is advantageous to use a salt, e.g. B. an alkali or ammonium salt to add to the sodium silicate solution, since this reduces the apparent density of the catalyst and increases its pore volume. This addition is particularly advantageous if the sodium silicate used has a high ratio of SiO ₂ to Na ₂ O, e.g. B. over 3, has. The salt can be dissolved in the sodium silicate solution in any concentration up to about 0.1 mole per mole of SiO ₂ .

After aggregation of the silicon dioxide and incorporation of the aluminum oxide in the manner described, the aqueous product is filtered, washed and dried. The catalyst is expediently treated with an ammonium salt solution, e.g. As the nitrate, chloride or acetate, at a high _pH value, for example. B. 9.5, washed to remove sodium salts •.

The material can be dried and then ground ■ or into pieces of the desired size and shape Form to be converted for use in a fixed bed or in a moving bed, or it can be spray dried to produce a microspheroidal powder suitable for use is suitable in the technique of the fluidized catalyst. Before using the catalyst it is expediently calcined to bring the moisture content to a value of 15% or ■ bring something below this value.

The catalyst according to the invention does not have the unfavorable electrostatic properties of the commercial ones Silica-magnesia cracking catalyst and can therefore easily be suspended hold (fluidize). It can also be mixed with natural clay catalysts or the common synthetic silica-aluminum • oxide catalysts be used.

The catalyst prepared according to the invention is for cracking all types of hydrocarbon oils which are commonly used as a starting material for catalytic cleavage, in particular for the catalytic cracking of very heavy hydrocarbon oils with molecular weights over 300 and at Columns in higher than usual degrees of conversion, e.g. B. up to 60% or more. "Conversion" is defined as 100 minus the percentage of the recovered oil boiling above 232 ° C. the catalytic cracking can be carried out by putting the vapors of the oil to be cracked in a suitable reactor with the catalyst at temperatures from about 450 to about 575 ° C and at Pressing from 1 to 4 atü brings into contact.

example

Catalyst # 1

516 g of sodium silicate with an SiO ₂ : Na ₂ O ratio of 3.2 and an SiO ₂ content of 29.1% were diluted to 2.5 l with water. About 500 ecm of a 0.664 molar magnesium sulfate solution was added to the silicate solution with stirring over the course of about 20 minutes at about room temperature. In the mixture obtained, the Mg: Si atomic ratio was about 0.13. The _pH value of the slurry obtained was quenched by adding

ao 32 ecm of a 6.1 η sulfuric acid was reduced to 10.45, and the sludge was stirred for 45 minutes. At this stage the material was in the form of a soft gel. The _pH value of the gel was then reduced by the addition of 0.2761 a 0.4 molar AIuminiumsulfatlösung to 9.5. At this time, a 6molaren solution of ammonia in water was begun along with the remaining 0.644 1 of aluminum sulfate solution at a rate such that the _pH value was maintained at 9.4 to 9.5 with the addition. The obtained silica-alumina Magncsiumoxyd mixture was filtered from the mother liquor, washed with water, washed again then washed with 0.2 molar ammonium nitrate solution at _pH value 9.5 with water, then dried, and 4 hours at 565 ° C calcined. The resulting catalyst contained 6% MgO, 19% Al ₂ O ₃ , the remainder being silica. The effective surface area was 308 m ² / g and the pore volume

0.56 cc / g . ^ i / 4r'r _v $ o _% I ^ C _v ^ « [ff4

Catalyst # 2

516 g of sodium silicate having a SiO _2: Na ₂ O ratio \ ^f on 3.2 and having a SiO ₂ content of 29.1% was diluted to 2.5. 1 About 500 ecm of a 0.541 molar calcium chloride solution were added to the dilute sodium silicate solution over the course of 20 minutes with stirring. The p _u value of the sludge obtained, which contained 0.11 atoms of Ca per atom of Si, was then reduced to 10.5 by adding 46 ecm of 6.1N sulfuric acid. This slurry was stirred for 45 minutes at room temperature. The _pH value of the slurry was reduced by the addition of 0.29 1 of a 0,4molaren aluminum sulfate solution to 9.5. Then ammonia solution (6 molar) was added simultaneously with the remaining 0.63041 aluminum sulfate solution at a rate such that the p _H was kept -Wcrt to 9.4 to 9.5. The resulting gel, which contained 0.16 mol Al ₂ O ₃ per mol SiO ₂ , was filtered off, washed with water, then with 0.2 molar ammonia nitrate solution at a p ^ value of 9.5 and then again with water, dried and Calcined at 565 ° C. for 4 hours.

The catalyst obtained contained 4.3% CaJD,

19% Al ₂ O ₃ ;

the rest was SiO ₂ . Its effective "

The surface area was 277 m ² / g and its pore volume was 0.78 ccm / g. The difference between the amount of calcium used in manufacture and the calcium content in the finished catalyst is important

attributable to the fact that part of the calcium dissolved during the _{alkaline treatment stage of the reaction mixture corresponding to a p u} value of 9.5 and was then removed with the filtrate.

Catalyst # 3

516 g of sodium silicate with an SiO ₂ : Na ₂ O ratio of 2.3 and an SiO ₂ content of 29.1% were diluted to 1.5 l with water. 140 ecm of a 1 molar solution of Na ₂ SO _{4 were} added to this solution. 1.5 1 of a dilute 0.2026 molar solution of magnesium sulfate, corresponding to 0.12 mol per mol of SiO ₂ were added to the solution of sodium silicate and sodium sulphate in "stirring at room temperature in the course \ ^r on 20 minutes was then further. stirred for 10 minutes in order to lead the reaction to linden. the resulting mixture contained 0.12 Mg atoms per atom of Si. the p _H -Wcrt of the mixture was then stopped by adding 22 of a 6.1 n-Schwefelsäurc ecm to 10, 5 reduced .. the _pH value of the mixture was then reduced by the addition of 0.207 l of a 0,4molaren aluminum sulfate solution to 9.5. then together the aluminum sulfate solution omolare ammonia solution was added at such a rate remaining 0.7881 that the P ₁₁ value was kept at 9.5 to 9.55. The gel containing 0.16 mol Al ₂ O. per mol of SiO ₂ was filtered with water, with 0.5 molar ammonia solution at Pn 9.5 and again with water washed, dried and 4 hours at 565 ° C cal ciniert.

The catalyst obtained contained 4.5% MgO, 19% Al ₂ O.,; the rest was SiO ₂ . The surface area and the pore volume were 315 m ² / g and 0.52 ccm / g, respectively.

Catalyst # 4

1100 g of sodium silicate with an SiO ₂ : Na "O ratio of 3.2 and an SiO ₂ content of" 27.3% were diluted to 2.41 with AVasscr. 292 ecm of a 1 molar magnesium sulfate solution were diluted to 3.61 . This diluted solution was added to the diluted sodium silicate solution while stirring at room temperature over 15 minutes. the _pH value of the slurry obtained was then quenched by addition of 196 cc of a 6.1 n-Schwcfelsäure reduced to about 10.5. one allowed the sludge to age for 1 hour _{at this p n value. The p u} value of the sludge was then determined by adding 70 ecm

ίο a 0, ^ 7 molar aluminum sulfate solution reduced to 9.5 with stirring. Ammonium hydroxide was then added simultaneously with a further 533 ecm of the 0.97 molar aluminum sulfate solution at such a rate that the p _lt -A value was kept at 9.35 to 9.5. The resulting gel was filtered off, washed with water, then with 0.5 molar ammonium nitrate at p _IT 0.5 and then again with water, dried and calcined at 565 ° C. for 4 hours.

so The catalyst obtained contained 2.2% MgO and 17% Al ₂ O ₃ ; the remainder was SiO ₀ . Its effective surface area was 310 m ² / g.

The catalysts Nos. 1 to 4 were each 20 hours at 576 ° C under a vapor pressure of

as 1 at subdued to such a short period of use to imitate under practical working conditions. They then became catalytic splitting of a flash distillate from West Texas crude oil with a molecular weight of 319 at 500 ° C., 1 atm and for 60 minutes used.

A commercially available cracking catalyst which contains silicon dioxide and aluminum oxide is used as the comparative catalyst. This is one of the newer so-called high-aluminum catalysts, which contains about 25% Al ₂ O ₃ . The fresh surface area was about 515 m ² / g. The freshly purchased standard catalyst was subjected to the same steam pretreatment as described above. The results are compiled in the following table.

Catalyst no.

I I

Space velocity L

(Litcr / Litcr / Stundc)

% implemented

Products, percent by weight

gas

petrol

C _s and C ₄ olefins

coke

Relative fuel yield

Relative yield of C ₃ and C ₄ olefins

Relative coke yield

Relative activity

2.35
53.6

17.3
34.9
9.3
1.40

106

95

65

112

1.61
60.2

21.7
36.1
11.3
2.36

107

105

67

115

2.32
52.6

18.9
33.3
10.0
1.35

102

105

68

106

i, 62
60.9

22.8
35.3
11.5
2.81

105

106

104

2.33
56.9

20.3
34.4
10.4
2.19

103

100

80

105

The information on the relative yield of gasoline, C _{1 and C 4} olefins and coke and the effectiveness in the lower part of the table for the cracking catalysts according to the invention in comparison with the corresponding results for the standard catalyst show the superior effect of the former. The yield of this known standard catalyst obtained with the same degree of conversion was set at 100 in each case. The relative activity is based on a liquid hourly space velocity and indicates the relative amount of cleavage products which is catalyzed by a unit of the catalyst surface, a value of 100 again being assumed for the Stanclard catalyst.

It should be noted that in all cases the amount of coke produced by the new catalyst is only 65 to 80% was that which was produced with the same degree of conversion by the Stanclard catalyst. On the other hand was the amount of gasoline produced in all

Claims (8)

Cases much higher. The amount of valuable C3 and C4 olefins was generally much higher, especially at the higher degrees of conversion. In addition to the improvements made in the catalytic cracking process itself, it can be mentioned that the present process for preparing the catalyst enables the use of relatively concentrated solutions of sodium silicate and substantially reduces the consumption of sulfuric acid. P STENT AMSI'K OC H IS 1. A method for producing a Sjjaltkatalysators by mixing together a calcium and / or magnesium silicate and an aluminum salt solution, characterized in that an aqueous Lös'ung of sodium silicate prepared and this sodium silicate solution while maintaining a p _H -value of at least 10, a dilute aqueous solution one or more salts of magnesium and / or calcium is reacted, this dilute solution being added in such an amount that it ^{provides about 1} Ao to Vs mole of the metal salt or metal salts per mole of SiO ₂ in the sodium silicate solution, and that the entire concentration of SiO ₂ after the addition of 3-9 percent by weight, and in that a water soluble salt of aluminum and an aqueous ammonia solution are added at least during the final stages of the feeding of the aluminum salt solution at such a rate to the obtained reaction mixture, a solution, that the p _H -Value of the liquid in the area I is between 9.0 and 10.5, whereupon the resulting hydrogel is separated from the liquid by filtration, washed and dried. 2. The method according to claim I _1, characterized in that a 0.05 to 0.5 molar solution of one or more salts of magnesium and / or calcium, based on these salts, is used. 3. The method according to any one of claims 1 and 2, characterized in that prior to, simultaneously with and / or after the addition of the solution of one or more salts of magnesium and / or calcium for adjusting the p _H -value of the mixture from 10 to 10.5, an aqueous solution of an acid to the solution of Sodium silicate is added. 4. The method according to any one of claims 1 to 3, characterized in that the water-soluble aluminum salt is maintained the _pH value at least 9.0 and preferably to 9.5 during the addition of the solution. 5. The method according to any one of claims 1 to 4, characterized in that prior to the addition of the solution of the aluminum salt to the mixture of sodium silicate solution and magnesium and / or calcium salt solution to reduce the p _H -value of said mixture to 9.5, an aqueous acid solution is added, and in that the aluminum salt solution and the ammonia solution are added simultaneously at a rate such that the _pH value is maintained at 9.5. 6. The method according to any one of claims 1 to 5, characterized in that the amount of aluminum oxide incorporated into the catalyst is between 12 and 30 percent by weight, calculated as Al ₂ O ₃ on the finished catalyst. 7. The method according to any one of claims 1 to 6, characterized in that the amount of the dem Magnesium and / or calcium incorporated into the catalyst between 1 and 9 percent by weight, calculated than MgO and CaO on the finished catalyst. 8. The method according to any one of claims 1 to 7, characterized in that the sodium silicate solution before the addition of the magnesium and / or calcium salt solution, one or more alkali or Ammonium salts are added. Considered publications:
German Patent No. 712 505;
Italian Patent No. 384 741;
U.S. Patent Nos. 2,472,830, 2,529,283. © 909 638/343 10