DE1667059C3 - Catalyst for the conversion of hydrocarbons - Google Patents

Description

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The present invention relates to a catalyst for the conversion of hydrocarbons, which has a molecular sieve as one of the active components and is particularly suitable for use in fluidized bed systems. One of the best when using Molecular sieve catalysts in fluidized beds encountered difficulties is that the powdery zeolite has a very fine particle size and must be embedded in an amorphous oxide for the production of hard microspherical particles, which then contains less than about 25% zeolite.

Catalysts which contain more than this amount of powdered zeolite generally have a high attrition index. This is based on that the mass used as a binder cannot hold the zeolite. Since the according to conventional Process-made molecular sieves are made up of small particles that easily turn into cracking catalysts can be incorporated, was in the previous method for incorporating zeolitic molecular sieves in Cracking catalysts add the zeolite at some point in the preparation of the catalyst.

In the older DE-PS 15 67 568 the production an abrasion-resistant zeolite. This zeolite has a particle size in the range from 5 to 200 μm and is in the form of microspheres. The procedure consists in having at least a portion of the Manufactures mixture containing silica and aluminum oxide components, the mixture into particles in the Size range of 50-200 μm dries, the dried mixture at a temperature of 425 ° to I 100 "C calcined, the particles treated with an alkali solution, aged and subjected to a hydrothermal conversion and the product obtained desired molecular sieve washes and dries. The DE-PS also describes how to make a zeolite

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Wl Z-12 in microsphere shape with CaCb to the Caleiumform of the zeolite with a sodium content of 6.28% calculated as NaaO.

With the present invention, a catalyst for converting petroleum hydrocarbons is now proposed, which consists of an abrasion-resistant crystalline ion-exchanged aluminosilicate in microsphere shape with a particle size in the range of 50 to 200 μπι is obtained and which thereby is characterized in that the alkali ions in the crystalline aluminosilicate against ammonium, magnesium or rare earths up to one as alkali oxide calculated alkali ion content of less than 10% have been replaced and that these aluminosilicate microspheres with an inorganic oxide in the form of a microsphere, which is composed of silicon dioxide-aluminum oxide, Silica-alumina-magnesia, alumina, silica-zirconia, a clay or a semi-synthetic material made of silica-alumina and clay, are mixed, the crystalline aluminosilicate constitutes from 2 to 90 percent by weight of the mixture.

The catalyst of the invention has many advantages. For example, it can access any of the refinery or another consumer of the catalyst tailored to the desired properties will. For example, if a refinery has a high content of any component in its product would like to have, the composition of the catalyst can be chosen so that a catalyst mixture is obtained which, for example, a product with the highest possible content of heating oil, gasoline or other desired components in the catalytic) cracking of hydrocarbons.

The first step in obtaining the catalysts of the invention is to prepare a very abrasion-resistant microspherical molecular sieve according to the process of DE-PS 15 67 568. The molecular sieve can consist of a silica-alumina cracking catalyst or of alumina and silica made from clays such as kaolin or halloysite.

In making the microspherical molecular sieve from a commercially available spray-dried amorphous silica-alumina cracking catalyst, the catalyst is selected to provide the required amount of silica-alumina in the finished product. To prepare a Type X molecular sieve, a suitable amount of silica-alumina cracking catalyst having an alumina content of about 28% is calcined at 538 ° C. for about 3 hours. An amount of sodium hydroxide solution corresponding to the desired sodium content in the finished product is then added. The mixture is aged for a sufficient time at room temperature and then heated to complete hydrothermal conversion. The product is filtered, washed with water and dried.

When using clay to produce the zeolite, it is slurried with a solution of colloidal silica and then additionally treated with sodium silicate. The slurry obtained thereafter is spray-dried. The spray-dried microspheres are aged and then subjected to a crystallization process.

In the next stage, the sodium or other alkali metal content of the microspherical molecular

sieves lowered by ion exchange. The one to turn in Base exchange required for the desired exchange ions is carried out under such time, temperature and concentration conditions that at least about 40% of the alkali metal originally contained in the aluminosilicate are exchanged and the The alkali content of the product obtained is reduced below about 10% by weight (calculated as alkali oxide). For This base exchange can be numerous cations exchangeable for alkali ions either alone or in Combination can be used with each other. Inorganic salts are preferred for reasons of price. Suitable substitutes are soluble compounds of magnesium and related elements, the Rare earths like cerium, lanthanum, praseodymium, neodymium, samarium and other rare earths as well as these Ions and mixtures thereof with other ions such as solutions containing ammonium. the Ammonium salts can also be used for this exchange. Organic salts can also be used of metals such as acetates and formates as well as very dilute or weak acids are used.

The concentration of the exchange compound in the base exchange solution can vary depending on the nature of the particular ions used to replace the alkali metal in the aluminosilicate treatment. However, the total concentration of the exchange ions must be so high under the treatment conditions that the alkali metal content of the original alkali aluminosilicate, based on the dry substance, is reduced to below 10% by weight. The concentration of the exchange bond in the exchange solution can be between 0.2 and 30% by weight. Other concentrations ¹ can also be used, provided that the alkali content is reduced to below 10 π % by weight and preferably below 2.5% by weight.

The temperature at which the base exchange is carried out can be between room temperature and The boiling point of the treatment solution. The base exchange solution is used in excess and the excess is removed from the crystalline aluminosilicate after a suitable time. The exposure time of the replacement solution or the replacement solutions on the crystalline aluminosilicate must in any case be sufficient to remove the alkali ions in the aluminosilicate up to to be exchanged below about 10% by weight and preferably below 3% by weight. After the exchange and washing process, the microspherical aluminosilicate is washed in a conventional manner and dried and then ready for use as a catalytic material. In the next Stage is the microspherical aluminosilicate with the other component, an inorganic oxide, mixed. The other component can, but need not, be an active cracking catalyst. For obvious reasons, it is desirable to use an active cracking catalyst in some cases. This component is also in micro m> to facilitate the mixing of the two components spherical shape used. The resulting mixed catalyst is then for use in cracking stones ready to use. It can be used in a conventional fluid bed or fixed bed cracking system and if necessary, usual treatment methods under- <v> be thrown.

The invention is explained in more detail by the following description of a particular embodiment.

example 1
a) Production of the starting material

The following describes the preparation of a type X molecular sieve for use in the catalyst according to the invention. A commercially available spray dried amorphous silica-alumina was used. This material consisted of a silica-alumina petroleum cracking catalyst with an alumina content of 28%. This product was calcined at 538 ° C. for 3 hours, after which 200 g was added to 756 ml of water containing 153.7 g of sodium hydroxide. The mixture was aged at 25 ° C for 2 days and then heated to 100 ° C for 6 hours. The product was filtered, washed with water and dried at 110 ° C.

The product had essentially the same X-ray diffraction pattern as the Type X molecular sieve and contained no detectable impurities. The internal surface area of the product, determined by the BET method, was 824 m ² / g. According to the microscopic examination, the product consisted of spherical particles with diameters in the range from 50 to 200 μm.

b) ion exchange

The abrasion-resistant microspherical molecular sieve thus produced was in a catalytically active material transferred:

The wet product (with about 50% moisture) was treated with a 95 ° C solution of mixed rare earth chlorides for 15 minutes. The weight ratio of molecular sieve to rare earth chloride to water in the mixture was 1: 0.5: 5.0. After the mixture was stirred for about 15 minutes, the solution was filtered off and the molecular sieve was treated with a fresh solution of rare earth chlorides. The solution was heated to a temperature of 95.degree. C. and kept at this temperature during the treatment period of 15 minutes. The solution used for the second treatment contained twice the amount of rare earth chlorides and water, so that the ratio of molecular sieve to rare earth chloride to water was 1: 1:10. The solution was then filtered off from the molecular sieve as above and the product was washed free of chloride and calcined at 538 ° C. for 2 hours. The product then contained 2.5% Na ₂ O. After calcination, the product was treated with an ammonium sulfate solution heated to 95 ° C. for 15 minutes. The weight ratio of molecular sieve to ammonium sulfate to water was 1: 1:20. After this treatment, the solution was filtered off and the treatment with ammonium sulfate solution was repeated. After the second treatment with ammonium sulfate solution, the product was washed sulfate-free and dried. The product obtained in this way could be used for the preparation of a number of mixture catalysts according to the invention. It had the following analytical data:

Inner surface 760 m ² / g Moisture content 22.15% Sodium content as Na /) (based on dry matter) 0.36% Rare earth (based on dry matter) 23.86%

In this way, a total of 410 g of microspherical, swirlable «molecular sieve manufactured,

c) mixing stage

The product obtained in room b) was treated with a commercially available silica-alumina cracking catalyst mixed with 13% aluminum oxide to form an active mixed catalyst.

1500 g of a fluidized bed cracking catalyst based on silica-alumina with an alumina content of 13% and a moisture content of 21.24% were obtained with 195.4 g of that in step b) Product mixed · The two components were mixed thoroughly to give a swirlable Mixture containing about 11.5% fluidizable molecular sieve catalyst. The catalyst mixture was compared with commercially available catalysts with regard to their abrasion properties.

d) Testing of abrasion resistance

The abrasion properties of the one obtained from stage c) Product were determined according to the following procedure:

The abrasion resistance of the fluidizable molecular sieve became that of the commercially available one Compared silica-alumina cracking catalyst. For this purpose, 100 g of the obtained in stage c) were Catalyst mixture kept fluidized in a stream of air at room temperature. This condition was maintained for 144 hours. In this case, abrasion occurred as a result of the collision of the particles of the microspherical particles instead. The airflow was adjusted so that the particles with a diameter below 20 μm were removed and for Analysis could be collected. The zeolite content of this collected fraction was determined by X-ray analysis determined.

To carry out the abrasion test, 100 g of the mixture were poured into a vertical glass tube with a clear Given a width of 4.5 cm. The mixture became porous through a porous one located at the bottom of the tube Glass pane held. An air flow was passed through the tube at a rate of 7.4 liters each Minute sent, whereby the mixture was kept in a lively agitated state and the particles with a diameter below 20 μm from the tube out and could be collected in a porous paper tube. In this test were determined the following values:

Table 1

Zeil in the fluidized bed Loss at Board height in Fine particles X-ray movement diagram of fine particles at the Ab steering angle of 6 ° 0 to I hours 7.1g 0 mm 1 to 3 '/ ₄ hours 8.8 g 18 mm 3V ₂ to 24 hours 11.7 g 37 mm 24 to 48 hours 7.2 g 41 mm 48 to 96 hours 7.8 g 4 i, 5 mm 96 to 120 hours 0.7 g - 120 to 144 hours 0.5 g -

The 100 g mixture shells before abrasion Band height in the X-ray diffraction diagram boi dem Deflection angle of 6 ° of 45 mm, while the non-abraded portion after 144 hours Had a band height of 47 mm. This shows that the attrition occurring in the fluidized bed is responsible for the molecular sieve component was less than that consisting of the commercial petroleum cracking catalyst Component which is generally considered to be very resistant to abrasion.

e) Catalylic activity

The catalytic activity of the catalyst was measured according to the "Indiana Relative Activity" test (IRA test) after the catalyst had been used for 16 hours at a temperature of 650 ^° C. mi! Steam had been activated. The method of the IRA test is briefly summarized as follows: A normal unfractured gas oil (414 ml) is passed down through a weighed sample of the catalyst (80 ml bulk volume) over a reaction period of 50 minutes at 500 ° C The liquid product is recovered and distilled to determine the degree of conversion and the yield of carbon and gas. The relative activity (IRA activity) determined by this test is the amount of the reference catalyst, in grams, required to produce the same Cracking degree as achieved with 100 g of the test catalyst under otherwise identical conditions. The activity is therefore given in units that are proportional to the weight of the catalyst. For example, 200 g of a catalyst with 50% activity gives the same cracking result as 100 g of one obtained catalyst with 100% activity. the catalyst was pretreated for 16 hours at 650 ⁰ C and 1 atmosphere pressure with steam. the for the IRA-aktivi The values determined are shown in the following table.

Table 2

IRA activity

Gas formation factor

Carbon formation factor

106.8
0.86
0.56

The values for the gas formation factor and the carbon formation factor are to those with a Reference catalyst obtained gas and carbon quantities, which are set equal to 1 in both cases became. These factors are a measure of the stability.

The activity of the catalyst was also determined by a test known as the "D + L" test. In this test, the conditions prevailing in the technical application of the catalyst are imitated. For this purpose, the catalyst is subjected to strong deactivation by means of heat and steam and then tested for its cracking activity. Entaklivierung to the fresh catalyst is aiü 5 hours by steam to 204 ⁰ C, then for 3 hours with steam at 566 ° C and finally for 24 hours in a steam atmosphere of 4.20 and heated 566 ° C. Another part of the same catalyst is subjected to heat treatment at 816 ° C. for 3 hours.

Following the deactivation by heat and steam, the cracking activity of the catalyst becomes certainly. For this purpose, 200 ml of the deactivated catalyst are poured into the reactor, which is kept at 454.degree given. Then 238 ml of unfractionated gas oil

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with a boiling range of 260-37 Γ C with a Speed of 120 ml per hour guided over the catalyst. This corresponds to a space velocity of 0.6 ml per ml of catalyst per hour. The cracked products are collected and the carbon deposited on the catalyst is determined. The "D +! .." activity is confirmed by attempts at distillation the collected liquid products determined. It is the fraction distilled over at 204 ° C and the Distillation loss determined and as a "D +!." Factor specified.

The values determined in this test are in the reproduced in the following table:

Table 3 treatment I Λ ί
WtMtI ₁ M
hehiindliinp
hoi 56h ( i-.r.Ukü-.icrür.g 55.6
0.88 44.6
1.09
1.13 D + L factor at 60 (
Gas formation factor
Carbon formation
Iactor

As in the above f-'all, the values for the, Gas formation factor and the carbon formation factor iiiif the gas- and carbon stiffeners. which in both Traps equal to 1 were set. The high Catalonian activity of the invention results from these values Catalyst clearly. The conventional .silicon-1 Dioxide-Alumina Cracking Catalyst with 13 "·" Alumina would have a "D - I." activity of about 35 after deactivation with steam at 566 ° C. The IRA activity vuti catalysts of this type is eiwa 85.

Example 2

The product obtained according to Example 1, step b) was subjected to a series of steam treatments and steaming plus heat treatments. The product contained 23.8% by weight rare earth oxides and 0.36% by weight. The deactivation was carried out for 8 hours at 27 ° C. with 20% steam same manner mixed with steam treated semisynthetic catalyst. This catalyst consisted of a mixture of a conventional silica-alumina cracking catalyst having an alumina content of 13% with sound. the micro-spherical product obtained after stage 6 was ■ mixed with the semi-synthetic catalyst to a physical mixture, which 7 wt .-% (based on the silicon dioxide-aluminum oxide content) contained the fluidizable zeolite.

The catalyst was tested in a fixed fluidized bed cracker. As Ausgangsmate- t rial a heavy gas oil was used in this case. 150 g of catalyst were used in each experiment: the weight ratio of catalyst to oil was 4. The system was operated at 493 ° C. and with throughput rates (weight per hour per ton of space) of 5 and 20. after the deactivation described above are given in the following table:

059 8th 10 5 Table 4 20th 68 70.5 Throughput speed 62 57.5 (Gew./Sld./Raum) 61.5 0.91 0.81 Conversion (vol%) 58 2.6 4.9 C ₅ + gasoline (VoI .- "/,) 0.94 C <+ gasoline / conversion 2.2 Coke. Wt%

The excellent crack activity of the catalyst mixture and its selectivity for C -, + gasoline formation can be clearly seen from the values given in the table above.

line further testing of the cracking activity of this catalyst was carried out in a test. Before the semisynthetic cracking catalyst deactivated at 827 C with 20% di ~ ipf. which al "mixing material in the preparation of the catalyst erfindungsgemäC'p · helical was was compared with the catalyst hybrid, which contained 7 wt.% of the product obtained after step b.

The T "· · was running at a throughput speed carried out by IO (weight / hour / room). Of simplicity For the sake of this, in Table 5 the “Is mixed material used K '·: ι. ·!:!. cuiiys-Mor with“ Catalyst A ”and the cifindgemälJe Catalyst mixture labeled "Catalyst B". The ones obtained in this experiment Values are given in the following table:

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Catalyst A Catalyst B

Conversion (Vol-%) 48
Cc + gasoline 41.5

C \ + gasoline / conversion 0.87
Coke (wt%) 3.2

Conversion / coke 15.1

C <+ gasoline / coke 13.0

68

62
0.91
2.6

26.1

23.8

From these values it can be seen that the hydrocarbon conversion when using the catalyst according to the invention in comparison to that with the than "Catalyst A" designated semisynthetic catalyst increased conversion achieved by about 40% will. The conversion to gasoline is increased by about 50% and the conversion to coke by about 20 ° Λ lowered. These values clearly show that the catalyst of the present invention is excellent Has cracking activity and selectivity

Example 3

The following describes the preparation of the microspherical zeolite component from a spray-dried Mixture of kaolin. Sodium silicate and colloidal silica are described.

To 250 g (dry basis) kaolin (Al ₂ O ₃ : 2 SiO ₂ : 2 H ₂ O) were added 135 g of colloidal silica in the form of a _{slurry containing about 40% SiO 2} and 2i g of sodium silicate solution (28.6% SiO ₂ and 9 , 4% Na ₂ O) with so much water that a pumpable slurry was obtained. The slurry was sprayed at a temperature of over 425 ° C using an air pressure of 133 kg.

dries. The spray-dried microspheres were ^{calcined at 370 °} C. for 3 hours. A portion of this product (38 g) was then mixed with 40.3 g of NaOH in 337 g of water and aged for 75 hours at room temperature and then boiled for 16 hours to crystallize. The product obtained was filtered, washed and dried. The X-ray analysis of the product showed the X-ray diffraction pattern of zeolite type X. The inner surface area determined by the BET method was 735 m ² / g.

The abrasion properties of the microspherical molecular sieve were examined by the standard method known as the roller test. The abrasion index is obtained by exposing the catalyst to a jet of air at high speed after heating it for 3 hours at 538 ° C. The weight of the particles formed in this test with a diameter of less than 20 μm is used as a criterion for the resistance of the catalyst to the

Formation of ultrafine particles which are not retained in a flowing catalyst cracking system can, for sure. The abrasion index is according to the formula

100

AWAY

obtained, where A is the content of particles from 0-20 μm after abrasion in g. B is the content of particles from 0-20 μm before abrasion in g and C is the content of particles> 20 μm before abrasion in g.

According to this, the abrasion index of the product according to the invention was 10.7. This value is compared to ii those normally used in fluid bed processes commercial catalysts very well. A commercially available silica-alumina cracking catalyst with an aluminum oxide gchali of! 3% ha! bcispicls have a graduation index of around 20.

Claims (2)

Patent claims: 1. Catalyst for the conversion of petroleum hydrocarbons, obtained from an abrasion-resistant crystalline ion-exchanged aluminosilicate in microsphere shape with a particle size in the range from 50 to 200μπι, characterized in that the alkali ions in the crystalline Aluminosilicate against ammonium, magnesium or. Rare earths have been replaced up to an alkali ion content calculated as alkali oxide of less than 10% and that these aluminosilicate microspheres with an inorganic oxide present in the form of a microsphere, consisting of silicon dioxide-aluminum oxide, Silica-magnesia, silica-alumina-magnesia, alumina, silica-zirconia, a clay or any one of them Silica-alumina and clay is made up of semi-synthetic material, mixed together with the crystalline aluminosilicate making up from 2 to 90% by weight of the mixture. 2. Use of the catalyst according to claim 1 for cracking hydrocarbons. 10