DE4114532B4 - A β-zeolite, a Y-zeolite and a matrix-comprising cracking catalyst for hydrocarbon batches - Google Patents

Abstract

Catalyst comprising:
a. 20 to 95% by weight of at least one matrix,
b. 1 to 60% by weight of at least one Y zeolite with a faujasite structure,
c. 0.01 to 30% by weight of at least one β-zeolite in hydrogen form, synthesized in a fluoride environment, with an overall Si / Al atomic ratio of more than 2.5, a fluorine content between 0.005 to 2% by weight and a nitrogen adsorption capacity, measured at 77K greater than 0.08 cm ³ (liquid) · g ^-1 under a relative pressure P / P _s of 0.19.

Description

The invention relates to a catalyst for converting batches of hydrocarbons containing a Y zeolite of faujasite structure in association with a beta zeolite in the hydrogen form and a usually amorphous or poorly crystallized matrix.

The catalyst according to the invention is specially designed and adjusted for the cracking of petroleum fractions to produce a significant amount of compounds with three and / or four carbon atoms in their molecule and especially propylene and isobutane. The catalyst according to the invention is particularly suitable for the Cracking heavy petroleum fractions.

The invention also relates to a process for cracking heavy petroleum fractions in the presence of the The catalyst defined above and with processes for the preparation of this catalyst. Cracking the hydrocarbon batches allows, increased Obtaining yields of very good quality automotive gasoline has become a problem the petroleum industry since the beginning of the 1930s enforced, Introducing of processes that work in a fluidized bed (FCC or Fluid Catalytic Cracking) or in a mobile bed (e.g. the TCC) which the catalyst permanently between the reaction zone and the Regenerator circulates where it comes from the coke by burning in the presence of a hydrogen-containing gas is released into one quite remarkable progress in terms of technology with fixed Bed led. The fluidized bed (FCC) units are now much wider more common than the one with a movable bed. Cracking is usually done at approximately 500 ° C below a total pressure adjacent to atmospheric pressure and in the absence of Performed hydrogen.

The most used catalysts Zeolites have been in the cracking units since the early 1960s, usually of faujasite structure. These zeolites that are in an amorphous matrix are incorporated, for example consisting of amorphous silicon oxide-aluminum oxide, and which can contain variable proportions of clays are characterized through cracking activities across from Hydrocarbons that are a thousand to ten thousand times higher than those of the silica-alumina catalysts are rich of silicon dioxide until the late 1950s were used.

Brought towards the end of the 1970s the lack of availability of crude oil and the increasing need for high octane gasoline the refineries more and more heavy crude oils to use. Treating these latter poses a difficult task Problem for the refineries because of their elevated Levels of catalyst poisons, especially nitrogenous ones Connections and on metallic connections (especially nickel and vanadium) if you are more unusual Values on Conradson carbon and especially on asphaltenic Connections.

• – thermisch und hydrothermisch stabilere Katalysatoren, die gegenüber Metallen verträglicher sind,
• – die Herstellung von weniger Koks bei gleicher Umsetzung,
• – der Erhalt eines Benzins mit erhöhter Oktanzahl, und
• – verbesserte Selektivität an mittleren Destillaten.

This need to process heavy batches and other recent problems, such as the progressive but general suppression of lead-based additives in gasoline, the slow but sensitive development in various countries of demand for middle distillates (kerosene and gas oils) have also prompted the refineries to look for improved catalysts that make it possible to achieve the following goals in particular:

• Thermally and hydrothermally more stable catalysts which are more compatible with metals,
• - the production of less coke with the same implementation,
• - obtaining a gasoline with an increased octane number, and
• - Improved selectivity on middle distillates.

EP 0 186 446 A2 describes a process for hydrocracking hydrocarbon batches to increase yields of C ₃ and C ₄ olefins which comprises a catalyst made from a beta zeolite or a zeolite with a faujasite structure or a combination of both, these zeolites in the acid or rare earth form can be present and the zeolite with faujasite structure can be a Y zeolite. Also called EP 0 186 446 A2 the dealumination of the zeolite β as an advantageous method for establishing a favorable Si / Al ratio.

US 4,837,396 A. describes a method for stabilizing a zeolite, also made of β. and an ultra-stable Y zeolite with faujasite structure existing catalyst with the addition of aluminum-containing hydroxychloride compounds. These stabilize the catalyst with regard to the reaction conditions, which can deactivate it.

In certain cases there is also a considerable demand for light hydrocarbons with 2 to 4 carbon atoms in the molecule or for certain thereof, such as the C ₃ and / or C ₄ hydrocarbons and in particular the propylene and the isobutane.

The preservation of propylene is special desirable in certain developing countries, where there is a significant need for this product.

• 1) das Cracken der schweren Moleküle bei guter Selektivität an Kohlenwasserstoffen mit 3 und/oder 4 Kohlenstoffatomen zu ermöglichen und
• 2) ausreichend beständig gegen ernste Bedingungen des Wasserdampfpartialdrucks und der Temperatur, die im Regenerator einer industriellen Crackeinrichtung herrschen, zu sein,

gilt es daher einem Katalysator zu verleihen, der eine überragende Kombination aus Crack- und Stabilitätseigenschaften, insbesondere hinsichtlich der Ausbeute an Propylen und Isobutan besitzt.The properties,

• 1) enable the cracking of the heavy molecules with good selectivity on hydrocarbons with 3 and / or 4 carbon atoms and
• 2) to be sufficiently resistant to serious conditions of the water vapor partial pressure and the temperature which prevail in the regenerator of an industrial cracking device,

it is therefore important to lend a catalyst which has an outstanding combination of cracking and stability properties, in particular with regard to the yield of propylene and isobutane.

These requirements are met by meets the catalyst of claim 1.

Important research that carried out on numerous zeolites resulted in a zeolite that is characterized by the fact that it is synthesized in a fluoride environment has been. This allows you to have a catalyst with excellent stability get a good selectivity to hydrocarbon production with 3 and 4 carbon atoms. The use of such a β-zeolite enables to obtain a cracking catalyst that allows a gas fraction and in particular to get propylene and isobutane which is larger than with prior art catalysts.

The β-zeolite in the hydrogen form, as used according to the invention, differs from β-zeolites of the prior art in that it was synthesized in a fluoride environment according to the production process as described in IN EP 419 334 A1 was claimed. This zeolite in the hydrogen form, which is used according to the invention, corresponds to the β-zeolite, which in EP 419 334 A1 is described and claimed and a partial description of which is incorporated here with express reference.

• a) die angenäherte allgemeine Formel: M_2/nO, Al₂O₃, xSiO₂ wo M ein Proton und/oder ein metallisches Kation, n die Valenz von M, x eine Zahl zwischen 5 und 800 bedeutet,
• b) ein Beugungsdiagramm der Röntgenstrahlung, dargestellt in Tafel I der EP 419334 A1 , wobei diese Tafel I untenstehend hier aufgenommen ist, und
• c) einen Gehalt an Fluor zwischen etwa 0,005 und 2,0 Gew.-%, vorzugsweise zwischen 0,01 und 1,5 Gew.-%, wobei dieser Zeolith im übrigen in Fluoridumgebung synthetisiert war.

The in EP 419 334 A1 Zeolite described and claimed is characterized by:

• a) the approximate general formula: M _{2 / n} O, Al ₂ O ₃ , xSiO ₂ where M is a proton and / or a metallic cation, n is the valence of M, x is a number between 5 and 800,
• b) a diffraction diagram of the X-rays, shown in Table I of the EP 419334 A1 , this table I being included here below, and
• c) a fluorine content of between approximately 0.005 and 2.0% by weight, preferably between 0.01 and 1.5% by weight, this zeolite being otherwise synthesized in a fluoride environment.

The identification of the zeolites of the β type can be so easily starting from the x-ray diffraction pattern respectively. This diffraction pattern can be obtained by means of a diffractometer in which the classic powder method with the Cu-K α radiation was applied.

An internal calibration makes it possible to precisely determine the values of the angles 2 θ which are assigned to the diffraction peaks. The different interstitial _distances d _hkl , characteristics of the sample, are calculated on the basis of the Bragg relationship. The measurement error estimate (d _hkl ) versus d _{hkl is} calculated as a function of the absolute error Δ (2 θ, with) which the 2 θ measurement is affected by the Bragg relationship. In the presence of an internal calibration, this error is minimized and generally assumed to be ± 0.05 °. The relative intensity I / Io with which each value of d _{hkl is} afflicted is estimated from the height of the corresponding diffraction peak.

The latter can be determined based on from a "cliche", obtained with the help a Debye-Scherrer chamber. A scale of is often used Symbols to this intensity to characterize: FF = very strong, F = strong, mF = medium to strong, m = medium, mf = medium to low, f = low, ff = very low.

Table I shows the diffraction pattern of the X-rays, a characteristic of the β-type zeolite EP 419 334 A1 In the column of the d _hkl one has plotted the extreme values which the different inter- _{lattice distances} d _hkl can have. Each of these values is said to have the measurement error, which is generally between ± 0.007 and ± 0.0002 corresponding to the value of 2 θ (d _hkl is expressed in nanometers) TABLE I

• a) Man bildet ein Reaktionsgemisch in Lösung mit einem pH-Wert kleiner etwa 9, vorzugsweise zwischen etwa 4 und etwa 9 (und noch weiter bevorzugt zwischen etwa 6 und etwa 9), und umfassend: Wasser, wenigstens eine Siliciumdioxidquelle, wenigstens eine Aluminiumquelle, wenigstens eine Quelle eines Mobilisatormittels, welches Fluoridionen (F^–) enthält, wenigstens eine Quelle eines Strukturbildnermittels, das gewählt ist aus der Gruppe die gebildet ist durch Diazabicyclo-1,4 (2,2,2)oktan und ein Gemisch von Diazabicyclo-1,4 (2,2,2)oktan und Methylamin, wobei dieses Strukturbildnermittel gegebenenfalls organische Kationen liefern kann, wobei dieses Reaktionsgemisch eine Zusammensetzung, ausgedrückt als Molverhältnis zwischen den folgenden Werteintervallen hat: Si/Al: 3-200, vorzugsweise 3-100, beispielsweise 4-20, F^–/Si: 0,1-8, vorzugsweise 0,2-6, beispielsweise 0,5-4, H₂O/Si: 4-30, vorzugsweise 5-20, beispielsweise 5-12, (R+R')/Si: 0,5-4, beispielsweise 0,9-2,1, R/R': 0,1-unendlich, vorzugsweise 0,2-unendlich, beispielsweise 0,3-unendlich, wo R der DABCO (Diazabicyclo-1,4(2,2,2)oktan) und R' das Methylamin ist (R' = 0 für den Fall, wo Methylamin nicht verwendet wird),
• b) man hält dieses Reaktionsgemisch bei einer Heiztemperatur zwischen etwa 50 und 250°C, vorzugsweise zwischen etwa 80 und etwa 220°C, bis man eine kristalline Verbindung erhält, und
• c) man kalziniert diese Verbindung bei einer Temperatur größer als etwa 350°C und vorzugsweise größer als etwa 450°C.

The β-zeolite in the hydrogen form, synthesized in the fluoride environment, was prepared according to the procedure as described in EP 419 334 A1 a method, a partial description of which is given below for reference:

• a) A reaction mixture is formed in solution with a pH of less than about 9, preferably between about 4 and about 9 (and even more preferably between about 6 and about 9), and comprising: water, at least one source of silicon dioxide, at least one source of aluminum, at least one source of a mobilizing agent which contains fluoride ions (F ^- ), at least one source of a structuring agent which is selected from the group formed by diazabicyclo-1,4 (2,2,2) octane and a mixture of diazabicyclo-1 , 4 (2,2,2) octane and methylamine, this structuring agent optionally being able to supply organic cations, this reaction mixture having a composition, expressed as a molar ratio between the following value intervals: Si / Al: 3-200, preferably 3-100, for example 4-20, F ^- / Si: 0.1-8, preferably 0.2-6, for example 0.5-4, H ₂ O / Si: 4-30, preferably 5-20, for example 5-12, (R + R ') / Si: 0.5-4, for example 0.9-2.1, R / R': 0.1-u finite, preferably 0.2-infinite, for example 0.3-infinite, where R is DABCO (diazabicyclo-1,4 (2,2,2) octane) and R 'is methylamine (R' = 0 if where methylamine is not used),
• b) this reaction mixture is kept at a heating temperature between about 50 and 250 ° C., preferably between about 80 and about 220 ° C., until a crystalline compound is obtained, and
• c) this compound is calcined at a temperature greater than about 350 ° C. and preferably greater than about 450 ° C.

To use this beta zeolite according to the invention the calcination stage c) is preferably between about 500 and about 600 ° C in air, for example at about 550 ° C in air. The calcination level c) enables to obtain a zeolite in the hydrogen form.

• – Da die Synthese im allgemeinen in Abwesenheit von Alkalikationen durchgeführt wird, erhält man die Wasserstofform durch einfache Kalzinierung, vorzugsweise unter Luft zwischen etwa 500 und etwa 600°C, beispielsweise bei etwa 550°C (Eliminierung der organischen Kationen);
• – die sauren Eigenschaften des Zeoliths werden durch das Vorhandensein, nach der Kalzinierungsstufe c), von Fluor, verbessert;
• – die Kristalle haben eine höhere Abmessung (wenigstens eine Dimension zwischen 0,1 und 10 μm) als die eines β-Zeoliths der gemäß dem Stand der Technik in alkalinem Milieu synthetisiert wurde. Diese Eigenschaft verleiht den β-Zeolithen, die im Fluoridmilieu synthetisiert wurden, eine verbesserte thermische Stabilität.

The zeolite beta, synthesized in a fluoride environment according to EP 419 334 A1 has several peculiarities that give it numerous advantages, based on β-zeolites, which were synthesized in the alkali environment. Among these advantages one can mention in particular:

• Since the synthesis is generally carried out in the absence of alkali cations, the hydrogen form is obtained by simple calcination, preferably in air between about 500 and about 600 ° C., for example at about 550 ° C. (elimination of the organic cations);
• - The acidic properties of the zeolite are improved by the presence, after the calcination step c), of fluorine;
• - The crystals have a higher dimension (at least one dimension between 0.1 and 10 microns) than that of a β-zeolite which was synthesized according to the prior art in an alkaline environment. This property gives the β-zeolites, which were synthesized in the fluoride environment, an improved thermal sta bility.

• – Die Globalatomverhältnisse Si/Al werden durch X-Fluoreszenzanalyse bestimmt.
• – Der Gehalt an Fluor wird bestimmt durch das Dosieren mit Hilfe einer spezifischen Elektrode.
• – Die Kristallinität wird bewertet durch qualitative Prüfung des Beugungsspektrums der Röntgenstrahlen. Es ist zur Zeit nicht möglich, die Parameter des Gitters der Elementarzelle des β-Zeoliths zu bestimmen (unabhängig von dem Synthesemilieu des Zeoliths).
• – Die Adsorptionsfähigkeit des β-Zeoliths am Stickstoff wird bestimmt bei 77 K für einen Relativdruck P/P_s = 0,19 (P_s ist der Sättigungsdampfdruck bei der Temperatur von 77 K).

The different properties of the β-zeolites are measured using the method as follows:

• - The global atomic ratios Si / Al are determined by X-fluorescence analysis.
• - The fluorine content is determined by dosing using a specific electrode.
• - The crystallinity is assessed by qualitative examination of the diffraction spectrum of the X-rays. It is currently not possible to determine the parameters of the lattice of the unit cell of the β-zeolite (regardless of the synthesis milieu of the zeolite).
• - The adsorption capacity of the β-zeolite on nitrogen is determined at 77 K for a relative pressure P / P _s = 0.19 (P _s is the saturation vapor pressure at the temperature of 77 K).

The beta zeolite in the hydrogen form, of use to the catalyst according to the present invention is a β-zeolite synthesized in a fluoride environment, the one calcination, preferably in air, between about 500 and about 600 ° C, for example at about 550 ° C has experienced, this calcination possibly a Dealuminization treatment follows.

The beta zeolite in the hydrogen form, the use according to the invention finds, is thus dealuminated or not dealuminized, preferably dealuminated.

The β-zeolite may optionally be subjected to partial or total defluorination treatment by NH ₄ OH after the calcination step, as in EP 419 334 A1 described.

• – Ein Globalatomverhältnis Si/Al höher als 2,5, gegebenenfalls 5 bis 1000 und vorzugsweise etwa 10 bis 500,
• – einen Fluorgehalt zwischen 0,005 und 2 Gew.-%, üblicherweise zwischen 0,01 und 1,5 Gew.-%,
• – eine Stickstoffadsorptionskapazität, gemessen bei 77 K unter einem Relativdruck P/P_s von 0,19 größer als 0,08, vorzugsweise bei 0,10 cm³ (flüssig)·g^–1

The β-zeolite in the hydrogen form according to the invention is characterized by the following properties:

• A global atomic ratio Si / Al higher than 2.5, optionally 5 to 1000 and preferably approximately 10 to 500,
• A fluorine content between 0.005 and 2% by weight, usually between 0.01 and 1.5% by weight,
• A nitrogen adsorption capacity, measured at 77 K under a relative pressure P / P _s of 0.19 greater than 0.08, preferably at 0.10 cm ³ (liquid) · g ⁻¹

The zeolite in the hydrogen form according to the invention Furthermore by describing that was synthesized in a fluoride environment. It generally does not contain anything Alkalization, the synthesis medium generally contains none of this.

The beta zeolite is preferably dealuminized.

• 1. Nach der Kalzinierungsstufe wird der β-Zeolith einer thermischen Behandlung in Anwesenheit von Wasserstoff ausgesetzt, die durch die Technik des "self-steaming" (Kalzinierung in begrenzter Atmosphäre) durchgeführt werden kann. Die Temperatur liegt gewöhnlich zwischen 300 und 800°C und vorzugsweise zwischen 400 und 700°C während eines Zeitraumes, im allgemeinen oberhalb von 10 Minuten und vorzugsweise von mehr als 20 Minuten. Die Kalzinierungsatmosphäre enthält wenigstens 1% und vorzugsweise wenigstens 5% Wasserdampf. Im Falle des "self-steamings" wird die Atmosphäre im wesentlichen aus Wasser und Ammoniak gebildet. Das so erhaltene Produkt kann einer sauren Behandlung ausgesetzt werden, die darauf zielt, Aluminium aus dem Feststoff zu extrahieren: Diese Behandlung kann durchgeführt werden, indem man das Produkt in eine mineralische oder stark organische Säure von einer Normalität taucht, die gewöhnlich zwischen 0,1 und 12 N liegt, und zwar bei einer Temperatur üblicherweise zwischen 20 und 150°C und vorzugsweise zwischen 80 und 150°C, während eines Zeitraumes, der im allgemeinen mehr als 10 Minuten beträgt.
• 2. Nach der Kalzinierungsstufe nimmt man eine saure Behandlung vor mit dem Ziel, das Aluminium aus dem Feststoff zu extrahieren. Diese Behandlung kann wie bei 1, durchgeführt werden, indem man den Feststoff in eine mineralische oder stark organische Säure von einer Normalität taucht, die gewöhnlich zwischen 0,1 und 15 N liegt, und zwar bei einer Temperatur zwischen 20 und 120°C während eines Zeitraumes von mehr als 10 Minuten.

There are various methods for obtaining the dealuminated beta zeolite; the β-zeolite in hydrogen form is preferably exposed to one of the following two treatments:

• 1. After the calcination step, the β-zeolite is subjected to a thermal treatment in the presence of hydrogen, which can be carried out by the technique of "self-steaming" (calcination in a limited atmosphere). The temperature is usually between 300 and 800 ° C and preferably between 400 and 700 ° C for a period, generally above 10 minutes and preferably more than 20 minutes. The calcining atmosphere contains at least 1% and preferably at least 5% water vapor. In the case of "self-steaming", the atmosphere is essentially formed from water and ammonia. The product so obtained can be subjected to an acidic treatment aimed at extracting aluminum from the solid: this treatment can be carried out by immersing the product in a mineral or strongly organic acid of a normality, usually between 0.1 and 12 N, at a temperature usually between 20 and 150 ° C and preferably between 80 and 150 ° C, for a period which is generally more than 10 minutes.
• 2. After the calcination step, an acid treatment is carried out with the aim of extracting the aluminum from the solid. This treatment can be carried out as in 1, by immersing the solid in a mineral or strongly organic acid of a normality, usually between 0.1 and 15 N, at a temperature between 20 and 120 ° C during a Period of more than 10 minutes.

Surprisingly point the β-zeolites, which are synthesized in the fluoride environment and, for example, accordingly the procedures described above were dealuminated, a special texture. Texture analysis using an electron microscope with transmission on ultra-thin Section shows the presence of mesopores in the middle of the crystals. These mesopores have a very special morphology: they act are cylinders that are in planes perpendicular to the c axis of the crystal to run. These mesopores open directly outside the crystals of the β-zeolite: they ensure an improved Diffusion of the reactants in the middle of the crystals.

Other methods of dealuminating can be considered, such as attack by hydrofluoric acid, hydrochloric acid in the gaseous phase or treatment by a fluorosilicate or any other method known in the art.

The catalyst according to the invention contains also a Y zeolite with faujasite structure (Zeolite Molecular Sieves Structure, chemistry and use, Donald W. BRECK, John WILLEY & Sons 1973). Among the zeolites that if you want to use a stabilized one is preferred Y zeolite, which is generally called ultra stable or USY, either at least partially with the metallic cations exchanged form, for example cations of the alkaline earth metals and / or cations of rare earth metals with an atomic number of 57 to 71 or in the form of hydrogen.

The catalyst according to the invention contains also usually at least one amorphous or poorly crystallized matrix, for example chosen is from the group aluminum oxide, silicon dioxide, magnesium oxide, Clay, titanium oxide, zirconium oxide, the combinations of at least two of these compounds and the combination of aluminum oxide and boron oxide.

The matrix is preferably selected the group formed by silica, alumina, Magnesium oxide, the silica-alumina mixtures, the silica-magnesia mixtures and the sound.

• a) 20 bis 95%, vorzugsweise 30 bis 85% und noch vorteilerhafterer Weise 50 bis 80 Gew.-% wenigstens einer Matrix,
• b) 1 bis 60%, vorzugsweise 4 bis 50% und noch vorteilhafterer Weise von 10 bis 40 Gew.-% wenigstens eines Y-Zeoliths mit Faujasitstruktur und
• c) 0,01 bis 30%, vorzugsweise 0,05 bis 20% und meist noch mehr bevorzugt 0,1 bis 10% wenigstens eines β-Zeoliths in Wasserstofform, gegebenenfalls entaluminisiert, der die im folgenden angegebenen Eigenschaften hat.

The catalyst according to the invention contains:

• a) 20 to 95%, preferably 30 to 85% and more advantageously 50 to 80% by weight of at least one matrix,
• b) 1 to 60%, preferably 4 to 50% and more advantageously 10 to 40% by weight of at least one Y zeolite with a faujasite structure and
• c) 0.01 to 30%, preferably 0.05 to 20% and usually even more preferably 0.1 to 10% of at least one β-zeolite in hydrogen form, optionally dealuminized, which has the properties indicated below.

The beta zeolite in hydrogen form, of use in the preparation of the catalyst according to the invention found as described above is a beta zeolite in the hydrogen form, the alumino-silicate backbone in general is formed solely from aluminum atoms and silicon atoms. you however can be used to produce the catalyst according to the invention a beta zeolite use in the hydrogen form as described above, in which a part of the aluminum and / or the silicon of the Alumino-Slikat framework is replaced will exit from synthesis by other elements, metals or metalloids, such as B, P, Ti, V, Cr, Fe, Mn, Ga, Ge and Zr,

The catalyst according to the invention can be prepared by methods well known to those skilled in the art.

So can the catalyst by at the same time the beta zeolite in the hydrogen form (optionally dealuminated) and the Y zeolite according to the usual Process for the preparation of the cracking catalysts containing a zeolite built in, preserved.

The catalyst can also pass through mechanical mixing of a first product, which is a matrix and the Y zeolite with Faujasite structure includes and a second product which contains the β-zeolite in hydrogen form (optionally dealuminated), as described above, and wherein it is, for example, a mixture of this zeolite of the hydrogen form with a structure acts which is identical or different to that in this first product can be obtained. This mechanical mixture can usually be carried out with dried products. Drying the products is advantageous for example by atomization (spray drying) carried out at a temperature of about 100 to 500 ° C, generally for about 0.1 to 30 seconds.

After drying by atomization can these products still contain about 1 to 30% by weight of volatile material (water or Ammonia).

The mixture of the beta zeolite in hydrogen form (optionally dealuminated and matrix) usually contains 1 up to 90 wt .-% and advantageously 5 to 60 wt .-% β-zeolite based on the total weight this mixture.

The mixture of the Y zeolite and Matrix as it is used to produce the catalyst according to the invention is used is a common cracking catalyst in general State of the art (for example a commercial cracking catalyst); the beta zeolite in hydrogen form (optionally dealuminated), such as it has been described above can therefore be regarded as an additive which is what it is in terms of its mixture with the usual Crack catalyst defined above can be used or previously be built into a matrix, the entirety of matrix-β-zeolite then forms an additive that is defined with the classic one above Cracking catalyst mixes, for example after adequate shaping, by mechanical Mixing the beta zeolite grains containing the hydrogen form and the grains of the usual Cracking catalyst.

The general conditions of the catalytic cracking reaction are particularly well known and need not be repeated here in the context of the invention (see for example US 3,293,192 A. . US 3,449,070 A . US 4,415,438 A . US 3,518,051 A. and US 3,607,043 A ).

The greatest possible amount of gaseous hydrocarbons with 3 and 4 carbon atoms and in particular propylene and isobutane it is sometimes advantageous to slightly generate the Increasing temperature where you do the cracking, for example from about 10 to about 50 ° C. The catalyst after However, invention is in the greatest number of cases sufficiently active so that such an increase in temperature is not becomes necessary. The other cracking conditions are related to the used unchanged in the prior art.

The following examples illustrate the Invention without limiting it:

EXAMPLE 1

Production of a beta zeolite in the hydrogen form with an Si / Al atomic ratio equal to about 11.

The β-zeolite is synthesized in a fluoride medium according to the in EP 419 334 A1 described synthetic method.

• – Stufe von zwei Stunden bei 550°C, Stickstoffdurchsatz = 2 l/h/g, Luftdurchsatz = 0,4 l/h/g;
• – Stufe von zwei Stunden bei 550°C, Luftdurchsatz = 2 l/h/g.

The calcination treatment (step c)) was carried out in air at 550 ° C according to the following protocol:

• - Two hour step at 550 ° C, nitrogen flow = 2 l / h / g, air flow = 0.4 l / h / g;
• - Step of two hours at 550 ° C, air flow = 2 l / h / g.

The β-zeolite obtained (called β 1) has the approximate chemical formula:
H ₂ O, Al ₂ O ₃ , 22 SiO ₂ .

Its weight percentage of fluorine lies at 0.49%. Its gamma ray diffraction pattern is characteristic for the of the zeolite beta and corresponds to that of Table I of the description.

Its nitrogen adsorption capacity, measured at 77 K under a relative pressure P / P _s of 0.19, is 0.185 cm ³ (liquid) · g ⁻¹ .

EXAMPLE 2

Production of a beta zeolite in the hydrogen form of a total Si / Al atomic ratio equal to about 18.

The starting zeolite is the beta zeolite in the hydrogen form of a total Si / Al atomic ratio of about 11 according to example 1.

This β-zeolite in the hydrogen form is immersed in a normal solution of 0.5 N nitric acid. The ratio of the volume of the liquid to the mass of the beta zeolite is 5 cm ³ / g and the treatment time is 4 hours at a temperature of 100 ° C. After three washes :: with distilled water and subsequent filtration, the product is dried at 110 ° C for 24 hours.

The β-zeolite obtained (called β 2) has an X-ray diffraction pattern on which is characteristic of the beta zeolite is and corresponds to that of Table I of the description.

Its total atomic ratio Si / Al is around 18; its fluorine weight content of about 0.30%.

Its nitrogen adsorption capacity, measured at 77 K under a relative pressure P / Ps of 0.19, is 0.210 cm ³ (liquid) · g ⁻¹ .

EXAMPLE 3

Production of a beta zeolite in the hydrogen form with a total Si / Al atomic ratio equal to about 32.

The starting beta zeolite is as in Example 2 the beta zeolite in the hydrogen form with a total weight ratio Si / Al of about 11 made according to Example 1.

Acid treatment with HNO _{3 is} identical to that described in Example 2, regardless of the fact that the normality of the acid is 1 N.

• – ein Röntgenstrahlbeugungsdiagramm, das charakteristisch für den β-Zeolith ist und dem dem Tafel I der Beschreibung entspricht;
• – ein Atomgesamtverhältnis Si/Al von etwa 32;
• – einen Fluorgewichtsgehalt von 0,25 %;
• – eine Stickstoffadsorptionskapazität, gemessen bei 77 K unter einem Partialdruck P/P_s von 0,19 gleich 0,24 cm³ (flüssig)·g^–1.

After washing with distilled water and drying at 100 ° C for 24 hours, a β-zeolite (called β 3) is obtained, which is characterized by:

• An X-ray diffraction pattern characteristic of the zeolite β and corresponding to Table I of the description;
• An overall atomic Si / Al ratio of about 32;
• - a fluorine weight content of 0.25%;
• A nitrogen adsorption capacity, measured at 77 K under a partial pressure P / P _s equal to 0.19 0.24 cm ³ (liquid) · g ^-1 .

EXAMPLE 4

Manufacture of cracking additives based on β-zeolite.

The various products β 1 to β 3 that according to Examples 1 to 3 were used to Cracking additives by mechanical mixing in the usual way with 30 wt .-% β-zeolite in the hydrogen form in the dry state and 70% by weight amorphous Silicon dioxide that was previously calcined from a granulometry produce comparable to that of the β-zeolites in the hydrogen form was.

The various additives obtained in this way are brought into the form of lozenges and then comminuted into small aggregates with the aid of a comminution machine. The portion of the grains measuring between 4 x 10 ^-5 m and 2 x 10 ^-4 m (40 to 200 microns) is then collected by sieving. These additives are called AB1, AB2 and AB3 and each contain the β-zeolites in the hydrogen form β1, β2, β3 in a proportion of 30% by weight.

EXAMPLE 5

Manufacture of cracking catalysts according to the invention and catalytic test conditions for these catalysts.

The three additives AB1 to A33 obtained according to Example 4 are mixed mechanically in a conventional manner in a proportion of 20% by weight with a new catalytic industrial cracking catalyst, CAT for short. The CAT catalyst contains a matrix of silicon dioxide-aluminum oxide and 30% by weight of an ultrastabilized Y zeolite (USY) with a crystal parameter a of 2.45 nm, in which the opening of the main dodecahedral channels at 7.4 × 10 ^-10 m (W.MEIER and D. HOLSON, Atlas of Zeolite Structure Types 1978). The catalyst (CAT) and the various additives were previously calcined for 6 hours at 750 ° C. in the presence of 100% water vapor.

That from the mixture of the catalyst CAT and the Additicen AB1 to AB3 resulting catalysts thus: 24% by weight of the ultrastabilized zeolite Y (USY), 6% by weight of β-zeolite in the hydrogen form and 70% by weight matrix.

The catalyst CAT, each of the catalysts resulting from the mixture of the catalyst CAT and the additives AB1 to AB3 are then introduced into the reactor of a catalytic test micro unit MAT. Each catalyst's ability to convert a heavy hydrocarbon batch is then determined under the following conditions:
Amount of catalyst = 6 g
Weight ratio catalyst / batch = C / O = 6
Batch injection time = 40 seconds
WHSV = mass space velocity = 15 h ^-1
Temperature = 510 ° C.

The batch used has the following properties:
Density 15 ° C = 0.932
% By weight S = 1.8
% By weight N = 0.2
Conradson carbon% = 3.2
Ni + V = 8 ppm
Viscosity 60 ° C = 46.2 mm ² / s
I _R (60 ° C) = 1.5061 (diffraction index of the batch)
saturated proportions = 44.5% by weight
Olefins = 1.7% by weight
Aromatics = 43.9% by weight
Resins = 8.6% by weight
Asphaltenes (insoluble in or in C ₅ ) = 1.3% by weight.

comparison of catalytic performance

• – Umwandlung der Charge in Gew.-%,
• – Gasausbeute in Gew.-% (H₂ + C₁ bis C₄ Kohlenwasserstoffe),
• – Verteilung der Gase in Gew.-% (H₂ + C_l bis C₄ Kohlenwasserstoffe),
• – Benzinausbeute C₅ in Gew.-% bei 220°C,
• – LCO-Ausbeute (mittlere Destillate: 220-380°C) in Gew.-%,
• – Ausbeute an Koks in Gew.-%.

The results obtained in Table II are expressed as follows:

• Conversion of the batch into% by weight,
• Gas yield in% by weight (H ₂ + C ₁ to C ₄ hydrocarbons),
• Distribution of the gases in% by weight (H ₂ + C ₁ to C ₄ hydrocarbons),
• - Gasoline yield C ₅ in% by weight at 220 ° C,
• LCO yield (average distillates: 220-380 ° C.) in% by weight,
• - Coke yield in% by weight.

TABLE II

These results show that use of additives based on β-zeolites in the hydrogen form, synthesized in a fluoride environment it allows big amount of to produce propylene, butylene and isobutane. At the same time the quality of gasoline, expressed as octane number, improved.

Claims (10)

Catalyst comprising: a. 20 to 95% by weight of at least one matrix, b. 1 to 60% by weight of at least one Y zeolite with a faujasite structure, c. 0.01 to 30% by weight of at least one β-zeolite in hydrogen form, synthesized in a fluoride environment, with an overall Si / Al atomic ratio of more than 2.5, a fluorine content between 0.005 to 2% by weight and a nitrogen adsorption capacity, measured at 77K greater than 0.08 cm ³ (liquid) · g ^-1 under a relative pressure P / P _s of 0.19. The catalyst of claim 1 comprising: a. 30 up to 85% by weight of the matrix, b. 4 to 50% by weight of the Y zeolite with fauja structure and c. 0.05 to 20 wt% of the zeolite beta in hydrogen form. Catalyst according to one of claims 1 and 2, characterized in that that these Matrix chosen is from the group formed by alumina, silicon um (di) oxide, magnesium oxide, clay, titanium oxide, zirconium oxide, in combinations of at least two of these compounds and the combination of aluminum oxide / boron oxide. Catalyst according to one of claims 1 to 3, characterized in that this Y zeolite is an ul trastable Y zeolite is in the hydrogen form and / or in the form in which an at least partial exchange by the cations of the rare earth metals of atomic number 57 to 71 has taken place. Catalyst according to one of Claims 1 to 4, characterized in that this β-zeolite in the hydrogen form has a total Si / Al atomic ratio of 5 to 1000, a fluorine content between 0.01 and 1.5% by weight and a nitrogen adsorption capacity, measured at 77K, of more than 0.10 cm ³ (liquid) · g ^{- 1} under a relative pressure P / P _s of 0.19. Catalyst according to one of claims 1 to 5, characterized in that that this beta zeolite in the hydrogen form, a dealuminated β-zeolite in the hydrogen form is. Catalyst according to one of claims 1 to 5, characterized in that that this beta zeolite in the hydrogen form, a dealuminated β-zeolite in the hydrogen form is in a form in which at least a partial exchange by Cations of rare earth metals with atomic numbers 57 to 71 have taken place Has. A method of manufacturing one of the claims 1 to 7 defined catalyst, characterized in that it is the includes the following stages: a. Preparation of a dried mixture by atomizing the beta zeolite in the hydrogen form and a matrix b. Making one dried mixture by atomizing the Y zeolite with faujasite structure and a matrix and c. Mix the dried product from stage a. With the dried product of stage b. Process for producing a catalyst according to a of claims 1 to 7, characterized in that the β-zeolite in the hydrogen form and this Y zeolite with a faujasite structure can be worked into a matrix at the same time. Use of a catalyst according to one of claims 1 to 7 or produced according to one of claims 8 and 9 in a catalytic Cracking process of a hydrocarbon batch under cracking conditions to get an elevated one Proportion of product containing propylene and isobutane.