DE2235846A1 - ZEOLITE AND ITS USE AS A COMPONENT FOR A CRACK CATALYST FOR THE PRODUCTION OF ENGINE FUEL WITH HIGH AROMATIC CONTENT - Google Patents

Description

DR. ULRICH GRAP STOLBERG DIPL.-ING. JÜRGEN SUCHANTKE

(US 166,243 -prio 26.7.Tl ^USA . ■ A / 19083 - 9558)

Hamburg, July 20, 1972

Zeolite and its use as a component for a cracking catalyst for the production of motor fuels with a high aromatic content

The present invention relates to zeolite-containing cracking catalysts their use obtained high yields of aromatic gasoline fractions with an increased octane number will.

It is well known that stabilized zeolites, in particular a synthetic faujasite subjected to ion exchange, suitable catalysts for the recovery of gasoline fractions from petroleum feedstocks such as gas oil. These cracked gasoline fractions are usually with additives to increase the octane number such as tetraethyl lead added to motor fuels with a high octane value obtain.

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There is a great need for high octane motor fuels that are free of such additives, and for this purpose high aromatic gasolines are particularly valuable. Unfortunately, however, gasoline fractions which using normal, amorphous or crystalline zeolite-containing cracking catalysts obtained by catalytic cracking of gas oil, a relatively low aromatic content, regardless of whether the zeolite has a low silica content with a silica: alumina ratio of up to 3: 1 or a more stable zeolite with higher silica content (Type Y) having a silica: alumina ratio greater than about 3 ^ 1.

It has now been found that in the catalytic cracking of petroleum gasoline fractions with an unusually high aromatic content can be obtained if a synthetic faujasite with a silicon dioxide: aluminum oxide ratio of more than about 3 * 0 is used as a catalyst which has been subjected to an ion exchange, so that it is 1 to 20, preferably about 1 to 10 wt.? Silver ions (expressed as Ag ₂ O) and 1 to 15, preferably about 3 to 15 wt. Contains rare earth ions (expressed as SEpO,). It has also been found that the silver and rare earth exchanged paujasite of type Y (Ag-SE-Y) when used as a hydrocarbon cracking catalyst or catalyst component leads to the formation of only small amounts of undesired coke and / or dry gas fractions.

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The subject of the present invention is accordingly a zeolite of the faujasite type with a silicon dioxide: aluminum oxide ratio of more than about 3 »-which is characterized by a silver carbonate content of about 1 to 20 wt. (calculated as Ag ₂ Q) and a content of rare earth cations 1-15 wt.% (calculated as SEPO,). The invention also relates to a composition for cracking petroleum to obtain aromatic hydrocarbons, which contains a zeolite which is stabilized by removing the sodium cations and has a silicon dioxide / aluminum oxide ratio of more than 3, in a mixture with an inorganic oxide, which thereby is characterized in that it zeolite of silver (calculated as Ag ₂ O) in an amount of 1 to 20 wt.% and rare earth metals in an amount of 1 to 15 wt.% (calculated as SEpO-.) are the cations.

Finally, the subject matter of the invention is a process for the production of motor fuels (gasoline) with a high aromatic content by catalytic cracking of a petroleum feedstock, the process being characterized in that the catalyst used is a zeolite which has a silicon dioxide: aluminum oxide ratio of at least 3 _% Silver cation content of 1 to 20 wt. % (Calculated as AgpO) and a content of rare earth cations of 1 to 15 wt. JS (calculated as SEpO).

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The Ag-SE-Y catalyst can be classified according to either of the two produce the following particularly preferred working methods. The first method consists of the following steps:

1) A sodium faujasite with a silicon dioxide: aluminum oxide ratio of more than about 3 is exchanged with an ammonium salt solution, e.g. an ammonium sulfate or ammonium chloride solution, to bring the sodium faujasite content of sodium oxide (Na ₂ O) to about 1.5 to ¹ I. Weight % to decrease.

2) The faujasite exchanged with the ammonium salt solution is then exchanged with a solution of rare earth salts, preferably a solution of chlorides or sulphates of rare earths, in order to obtain an SE _? O-content of about 0.3 to 15 percent by weight can be achieved.

3) The rare earth exchanged faujasite is then placed at a temperature of about 371 to 87 ° C Calcined for 0.1 to 3 hours.

The calcined exchanged faujasite is then exchanged again with an ammonium salt solution the sodium oxide content to less than about 1 wt humiliate.

5) The re-exchanged faujasite is now preferably contacted with a silver ion solution, with a silver nitrate solution, calculated by a silver content (as to reach Agpo) of about 1 to 20 wt.%.

6) The faujasite exchanged with silver eventually becomes at

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a temperature of about 260 to 76O ⁰ C. 1 to 10 hours calcined.

A second suitable for the preparation of the Ag-SE-Y catalyst Method consists of the following general way of working:

1) A synthetic sodium faujasite with a silicon dioxide: aluminum oxide ratio of more than about 3 is exchanged with a solution which contains a mixture of silver ions and rare earth ions, preferably a rare earth nitrate, the pH value being about 3, 0 to 3.5. Thus, a rare earth content of from about 1 to 12 percent is.% (Calculated as SEPO,) and a silver content of 1 to 15 wt.% (Calculated as Ag ₃ O) is reached.

2) The exchanged faujasite is then calcined at a temperature of about 427 to 76O ⁰ C for about 1 to 3 hours.

3) The calcined, exchanged with silver and rare earth faujasite is now replaced an ammonium sulfate solution with an ammonium salt solution, for example, to bring the sodium oxide content to below about 0.5 wt.%.

4) The exchanged product is now calcined at a temperature of about 2βΟ to 76O ⁰ C for 1 to 10 hours. ·

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In both methods, the sodium content of the catalyst should be below 0.5% by weight at the end.

Optionally, the catalysts prepared as described above can be reduced prior to use 1/2 to 10 hours in a hydrogen atmosphere at a temperature of about 204-649 ⁰ C.

The catalysts used for the cracking process can consist of practically 100% of the Ag-SE-Y catalyst or they can contain the Ag-SE-Y catalyst in a mixture with an inorganic oxide. If it is desired to obtain the catalyst in a form suitable for fluidized bed beds or as pellets, the synthetic sodium zeolite of type Y used as starting material can already be present in a corresponding form. These particles are subjected to the above exchange and calcination steps to obtain a catalyst which is essentially all Ag-SE-Y.

If a catalyst is to be obtained which contains Ag-SE-Y in the room with an inorganic oxide as matrix, the Ag-SE-Y is mixed in finely divided form with a suitable inorganic oxide as a matrix component. Suitable Matrix components include inorganic hydrogels such as

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.-Silicic acid, alumina and silica / alumina hydrogels. In general, these hydrogels are essentially in amorphous form and can be easily mixed with the strong Mix crystalline Ag-SE-Y component. The matrix components such as clay or combinations of clay with amorphous inorganic hydrogels can be made with the Ag-SE-Y catalyst component unite. · .-- ..

Containing silver and rare earths as metal cations Catalysts can be obtained in a form which is suitable for fluidized beds, e.g. in the form of finely divided ones spray dried microspheres having a particle size in the range of 10 to 150 / µm by using conventional catalyst preparation techniques applies. Catalysts suitable for fluidized bed or fixed bed operation with a catalyst particle size in the range of about 4 to 0.42 mm clear mesh size can also be achieved with the aid of conventional catalyst production processes to win.

The novel catalysts according to the invention are used for the catalytic cracking of heavy petroleum feedstocks. Preferably, the catalysts are used in a conventional manner by the petroleum feedstock such as gas oil with a catalyst bed at a temperature from 427 to 538 ⁰ C in contact wird..Die contact time between oil feedstock and catalyst will depend on the

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specific application of catalytic processes; however, it has been found that contact times range from down to 5 seconds and up to 300 seconds with benefit application can find when the highly active catalysts are used according to the invention.

If the present catalyst in combination with a a typical semi-synthetic matrix, i.e. a matrix of a silica / alumina hydrogel and clay, is used, with the Ag-SE-Y component in amounts of about 5-15 Weight? If it is present, the catalyst shows a microactivity on the order of about 60 to 85% when it is below it Standard conditions tests. The distribution of the products obtained using the present catalyst shows that high yields of gasoline fractions (Cj. up to and including Cq) can be obtained. These gasoline fractions have a unusually high aromatic content, which can easily be detected using conventional NMR methods. It will also found that the present catalysts give a cracked product, which only small amounts of undesirable Dry gas (hydrogen, C. and Cp hydrocarbons) and contains even small amounts of coke. This result is completely unexpected since it is generally found that the addition of metals, such as silver, to common catalysts

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usually the formation of dry gas and coke to such an extent that the corresponding catalysts for technical cracking processes are out of the question.

The present invention is to be explained in more detail below with the aid of examples, which include the production the novel catalyst and, on the other hand, its use for cracking hydrocarbons.

example 1

A sample of 200 g of a commercially available zeolite Y in the sodium form with a NapQ content of 1J>% and a silicon dioxide: aluminum oxide ratio of 5> 1 was dispersed in 2 liters of demineralized water which contained 200 g of ammonium sulfate. The mixture was heated to the boil and held at this temperature for one hour. After the ion exchange, the solid product was collected on a filter, rinsed with demineralized water and then exchanged again with 2 liters of ammonium sulfate solution which contained 200 g of ammonium sulfate. The solid product was isolated and mixed with 1 liter of a rare earth chloride solution containing the equivalent of 12 grams of rare earth oxides. It was a commercial mixture of chlorides of rare earth metals. The solution was heated to boiling for 30 minutes, after which the solids were isolated. The solid product was washed free of sulfate and chloride and then calcined ^{at 76O 0 C for 3 hours.} The calcined product

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was twice with an ammonium sulfate solution as above described, exchanged and then washed free of sulfate. One half of the obtained product was mixed with 25 g of silver nitrate dissolved in 250 ml of water at 60 C, whereby the product designated as Sample No. 1 in Table I below was obtained. The other half of the calcined Product was made in a similar manner with 50 g of silver nitrate solution exchanged and gave the product, which is designated in Table I below as sample no.

The resulting products, exchanged with silver were calcined for 3 hours at 76o C ^0. The surface area of these products was 551 and 544 m / g, respectively.

Example 2

The Ag-SE-Y products obtained above were examined for their silver content and their rare earth content. The analytical values can be found in Table I. These Ag-SE-Y samples were combined with a semi-synthetic cracking catalyst matrix which contained 30 parts by weight of kaolin clay and 60 parts by weight of silica / alumina hydrogel. The hydrogel in turn contained 25 wt. Clay. The Ag-SE-Y component was combined with the synthetic matrix in an amount of 10% by weight, and pellets of 0.3 mm were formed. These pellets were heated l6 hours in an atmosphere of 100 # steam at 1.05 kg / cm to 732 ⁰ C to simulate a technical deactivation. The steam-treated pellets were then used for cracking gas oil at a temperature of 493 C and a throughput rate of 4.3 wt / hour in an apparatus

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temperature to determine the "'standard microactivity use. The cracked gas oil was analyzed using the NMR technique Aroma content investigated.

The analysis values for the catalysts and the distribution in the cracked product "can be found in the following Table I. Sample No. 3 in Table I is a conventional calcined, Zeolite type Y (CSEY) exchanged with rare earths is listed together with the product distribution obtained, the catalyst obtained in a similar manner; however, this zeolite used for comparison does not contain any silver. The following results clearly show that the Ag-SE-Y catalyst results in a gasoline with a noticeably higher aromatic content. This aroma content is clearly related to the higher octane values.

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Table I.

Sample no.

Composition of the molecular sieve

Microactivity Results

% Aromatic Protons

Conversion .. %: ■ Coke in Vol.?

lo. 2 4th .1 0 .06 71 .1 4th 1 15.9 13- 4th 4th .1 0 .06 69 .0 3- 7th 15.7 0 16 71 .5 14.5

CJl CO

To the. Determining the influence of a reducing treatment of the above catalysts with hydrogen prior to their use have been reduced samples of the catalysts listed in Table I in a hydrogen stream for 2 hours at 48O ⁰ C, before being subjected to the steam treatment. The microactivity values found can be found in Table II below.

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Table II

Sample no.

Composition of the molecular sieve

Microactivity Results

! ^ Aromatic protons

O CO OO O

% Ag ₂ O

Conversion to Vol. *

4 5

9.5

12.6

4.1 4.1 16

73.7 72.0

73.5

17.4

16.8
15.5

The above results show that the reducing Treatment of the catalyst with hydrogen improves the ability to increase the aromatics yield.

Example 3

A sample of 100 g of a commercial type Y sodium faujasite with a sodium oxide content of 13% and a silicon dioxide: aluminum oxide ratio of about 5.1 was dispersed in a solution containing 39> 9 g of lanthanum nitrate (LaNO,), 6H ₂ O, corresponding to 15.0 g of La ₂ O ₅ and 2.9 ¹ l g of silver nitrate corresponding to 2.0 g of AgpO in 250 g of water. The pH of the lanthanum nitrate / silver nitrate solution was increased to 3 »! By adding nitric acid. set. The dispersion of the sodium zeolite of type Y in the silver / lanthanum nitrate solution was heated to boiling for 1 hour, after which the solid products were separated off by filtration. The solid product was washed with demineralized water until no more traces of silver could be detected. The exchanged product was then calcined for 3 hours at 536 ° C. and then exchanged again twice with a boiling solution of 100 g of ammonium sulfate in one liter of water. Finally, the product was washed free of sulfate and dried at 121 ° C. overnight.

example k

The type Y zeolite produced in Example 3 in the form loaded with silver ions and rare earth ions (AgrSE-Y) was purified with a semi-synthetic matrix containing 30 Ge. parts by weight of kaolin clay and 60 parts by weight of the 25 % clay containing Kiorjela'iüro / Tonorde-Gomiaches of Example 2 contained. D.io Λ /; ·; · - ^] ν- · Υ-Κυΐ: ιρπιιοηί.ο in rinor amount of 10 wt. #

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was associated with the matrix. This product was molded into pills, steamed and finally in the microactivity test described in example 2 checked. The results obtained can be found in Table III below.

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Table III

Sample no.

Composition of the molecular sieve

Microactivity Results

^ Aromatic protons

% Ag ₂ O

co
O 7th (Ag-SE-Y) 7th .0 12th .5 9807 / 8th (CSEY) ' O 16 .0 - *

Conversion to V0I.5 &

75.0 75.0

18.6
I6.2

The above values clearly show that in comparison with a conventional one loaded only with rare earth metals A catalyst containing zeolite as a promoter significantly increases the amount of the silver-containing zeolites of the present invention of aromatics, as the higher content of aromatic protons proves.

Example 5

Samples of the Ag-SE-Y catalysts in a mixture with a matrix which 30 parts by weight of clay and 60 parts by weight of silica / alumina (25% AlpO-.) As indicated in Example 2, were subjected to a test in a pilot plant, with two different types of gas oil were used. The West Texas gas oil (WTGO) had a specific gravity of 27.7 API (dj | 0.889) and a boiling range from 321 to 493 ⁰ C. The Sunoil gas oil (Sun) had a specific gravity of 30.7 API (d ■ * 0.8724) and

15th

a boiling range from 177 to 527 ^° C. Catalysts with a similar activity were used for comparison, which contained various amounts of zeolite type Y in the rare earth / hydrogen form in the framework with a synthetic silica / alumina matrix (26% AlpO,) and were used under similar conditions The test results obtained in a semi-industrial plant can be found in Table IV below.

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I. . Tabel 493 " WTGO. 92.8 Ht ^v C.
10 wt.
Ag-SE-Y 2235846 3.0 A-
10 wt.
Ag-SE-Y 4.0 65.5 78.2 IV S-13 _S 5 catalyst Throughput - 20
swiftly
speed weight / hour 1.65 22nd B '
6 wt.
SE-HY • D
? 3.5 wt.
SE-HY Steam deactivation
tion Conditions in
the test facility Input product 9.7. 82 S-20 ^ 493 S-20 Temp, in ⁰ C Conversion to VoI? 14.4 5.7 4.0 Cat./Oil-Ver
ratio C ₁ + C ₂ KW in
Weight % 9.4 ? Steam 493 2Ö. 493 C-, KW in total
-in VoI? PP. Cr + gasoline fraction
⁵ in VoI? PF 49.0 % Water vapor U ₅ O Sun ■ 4.0 Cu KW in total
in VoI? PF RON (ASTM) 20 ■■■ _ = - 64.5 20th Total C ₁₁ KW in
VoI? FF MOZ (ASTM) WTGO 1.34 Sun Aniline point ⁰ C 66.5 10.1 63.0 Bromine number 1.12 14.7 1.20 Coke by weight? FP 8.3 8.3 7.8 (1) 732 ⁰ C; 100 9.3 47.0 9.9 ⁽²⁾ 827 ° C: 20 4.0 90.4 57.0 77.9 53.5 88.8 21 86.7 77.1 47 76.1 32 0.6 28 51 - K5 ; 12 hours : 12 hours

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From the above values it can be seen that the catalysts A and C according to the present invention provide gasoline fractions with a significantly higher octane rating than the catalysts B and D with a zeolite type Y exchanged only with rare earths. It is also shown that with the aid the catalysts A and C larger amounts of unsaturated C ₁ .- hydrocarbons are obtained than with the catalysts B and D used for comparison. The increase in the formation of unsaturated C 1 -C hydrocarbons is completely unexpected. The content of unsaturated hydrocarbons is particularly valuable for refineries because these compounds are used in alkylation processes to produce high-octane gasoline.

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Claims (1)

Patent claims fl; Paujasite type zeolite with a SiIi ciumdi oxide; Aluminum oxide ratio of more than about 3> characterized by a content of silver cations of about 1 to 20 wt. (calculated as Ag ₂ O) and a rare earth metal content of 1 to 15 wt. (calculated as SE ₃ O,). 2. Zeolite according to claim 1, characterized by a sodium cation content less than 0.5 wt. (calculated as Na "0). 3 · Catalyst composition for cracking crude oil with the formation of aromatic hydrocarbons, which contains a zeolite stabilized by removing the sodium cations with a silicon dioxide: aluminum oxide ratio of more than 3 in a mixture with an inorganic oxide, characterized in that the cations of the zeolite silver in an amount of 1 to 20 wt.? (calculated as Ag ₃ O) and rare earth metals in an amount of 1 to 15 wt.? (calculated as SE ₂ O,) are. ¹ J. Catalyst according to claims 1, 2 or 3 »characterized in that the paujasite is produced with the aid of a process comprising the following steps: a. Replacing a Natriumfaujasit with an ammonium salt to lower the sodium content to about 1.5 to H wt. ^, b. Exchanging the paujasite with rare earth metal ions to achieve the desired rare earth metal content, 309807/1177 22358A6 as . c. Calcining the rare earth exchanged faujasite at a temperature of 371 to 871 ⁰ C for a period of about 0.1 to 3 hours, d. Exchange of the calcined paujasite with an ammonium salt solution to reduce the sodium oxide content to less than about 1 wt.?, e. Exchange the faujasite with a silver salt solution to achieve this the desired silver content and f. calcining the silver-exchanged faujasite at a. Temperature from about 260 to 76O ⁰ C. 5. Catalyst according to claims 1, 2 or 3, characterized in that that the faujasite is produced using a process comprising the following steps: a. Replacing a sodium faujasite with a solution of Ions of rare earths and silver ions at a pH value of around 3.0 to 3> 5 to achieve the desired silver content and rare earths b. Calcining the exchanged faujasite at a temperature of 427 to 76O C for a period of about 1 to 3 hours and c. Replacing the calcined faujasite with an ammonium salt solution to reduce the sodium oxide content to less than about 0.5 wt. *. 6. Catalyst according to claims 1 to 5, characterized in that it was ^{reduced at 200 to 65O 0} C for 0.5 to 10 hours in a hydrogen atmosphere. 309807/1 1 77 7 · Use of a catalyst according to claims 1 to 6 for the catalytic cracking of crude oil feedstocks for recovery of motor fuels with a high aromatic content. coll: we 309807/1177