DE3031102A1 - CHROMOSILICATE CATALYST AND ITS USE FOR CONVERTING HYDROCARBONS - Google Patents

Description

The present invention relates to a new variety of crystalline silicates containing chromium oxide and processes for their preparation. These products are useful as catalysts for hydrocarbon conversion processes, particularly dewaxing and for olefin production.

Molecular sieves made of crystalline zeolites are aluminosilicates, which consist of a rigid three-dimensional latticework of SiOj, - and AIO ^ -Tetrahedra exist, which have common oxygen atoms are connected. The inclusion of aluminum atoms in the latticework leads to a lack of electrical charge, which must be locally neutralized due to the presence of additional positive ions in the product. In natural zeolites and In many synthetic zeolites, these ions usually consist of alkali metal or alkaline earth metal cations, which are very are mobile and can be easily exchanged for other cations to varying degrees in conventional processes can. The cations occupy channels and connecting cavities that are formed by the geometry of the lattice.

US Pat. No. Z> 702,886 describes a new class of crystalline zeolites which have been given the designation ZSM-5. The composition of the ZSM-5 zeolites can be shown in the molar ratio of the oxides as follows:

0.9 + 0.2M ₂ Z _n O: WgO,: 5-100YO ₂ ^ H ₂ O

where M is at least one cation, η its valence, W aluminum or potassium, Y silicon or germanium and ζ represent a number between 0 and 40. Representatives of this ZSM-5 class have a X-ray diffraction spectrum of the powder form (random powder X-ray diffraction pattern) with the following significant lines:

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Table 1 Interplanar distance d (A): relative intensity

11.1 + 0.2 strong

10.0 + 0.2 strong

7.4 + 0.15 weak 7.1 + 0.15 weak

6.5 +0.1 weak

5 * 97) ± ⁰ ^ ¹ weak

5.56 + 0.1 weak

5.01 +0.1 weak

4.60 + 0.08 weak

4.25 + 0.08 weak

3.85 + 0.07 very strong

5.71 + 0.05 strong

3.04 + 0.03 weak

2.99 + 0.02 weak

2.94 + 0.02 weak

The above values were determined by conventional methods which are described in the cited patent.

According to the US patent mentioned, the ZSM-5 zeolites prepared by making a reaction mixture of tetrapropylammonium hydroxide, sodium oxide and an oxide of aluminum or gallium and an oxide of silicon or germanium crystallized hydrothermally.

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U.S. Patent 3,9,1,871 discloses a crystalline organometallic silicate the following composition in an anhydrous state:

0.9 + 0.2 [XR ₂ O + (1-X) M ₂ ^ _n Ol]: ^ .0.005 Al ₃ O ₅ : ^ ISiO ₃

where M is a metal not belonging to Group IIIA, η its Valence, R is an alkylammonium radical and χ is a number between 0 and 1. The products are synthesized by a reaction mixture of alkyl ammonium oxides, sodium oxide, water and oxides of non-Group IIIA metals hydrothermally crystallized. Alumina appears in small amounts in the product due to contamination of the reactants and / or the equipment used for the synthesis. the Powder X-ray diffraction analysis shows the following significant lines:

Table 2 Interplanar distance d (A): ReI. intensity

11.1 + 0.2 strong

10.0 + 0.2 strong

7.4 + 0.15 weak

7.1 + 0.15 weak

6.5 +0.1 weak

5'97] ± O "weak ¹

5.56 +0.1 weak

5.01 + 0.1 weak

4 / 7- + / 08 weak

4.25 + 0.08 weak

3.85 + 0.07 very strong

5.71 + 0.05 strong

3.04 + 0.03 weak

2.99 +0.02 weak

2.94 + 0.02 weak

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US Pat. No. 4,061,724 describes a crystalline silica, which is referred to as "silicalite". Silicalite is produced by hydrothermal crystallization of a reaction mixture, the water, silicon oxide and an alkylonium compound such as tetraethylammonium hydroxide, tetrapropylammonium hydroxide or contains the corresponding salts such as, for example, tetrapropylammonium bromide. Silicalite shows after calcination for one hour in air at 600 ° C the following X-ray diffraction pattern:

Table 3 d-A relative intensity

11.1 +0.2 very strong

10.0 + 0.2 very strong

3.85 + 0.07 very strong

3.82 + 0.07 strong

3.76 + 0.05 strong

3.72 + 0.05 strong

Table 4 contains the result of an X-ray diffraction analysis of a silicalite with 51 * 9 moles of SiO ₂ per mole of tetrapropylammonium oxide after calcination:

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Table 4

d-A right! .intensity d-A

relative intensity

lljl 100 4.35 5 10.02 64 7th 9.73. 16 4.08 3 8.99 1 4.00 3 8.04 0.5 3.85 59 · 7.42 1 3.82 32 7.06 0.5 3.74 24 6.68 5 3.71 27 6.35 9 3.64 12th 5.98 14th 3.59 • ⁰ J ⁵ 5.70 7th 3.48 3 5 ⁵ ' ₃ " 8th 3 ₇ 44 5 2 3.34 11 5, 'll 2 3 _τ 30 7th 5.01 4 · 3.25 3 4 _Τ 98 5 3.17 0.5 4.86 0.5 ³ ) ¹³ 4 j 60 3 3.05 5 4j44 0.5 ² J ⁹⁸ 10

All of the products described have a pore diameter of about 6 angstroms · they are all suitable for use in certain hydrocarbon conversions. The ZSM-5-esque ones However, aluminosilicates are overly active in hydrogenating Cracking, e.g. when cracking normal paraffins in one Load to be dewaxed. The high activity leads

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too high gas generation and low yields of liquid products. In contrast, silicalite itself is much less active; it is mainly used as an absorbent for oil Oil / water mixtures are used.

It is therefore an object of the invention to provide a new product which is useful for hydrocarbon dewaxing mixing with high yields of liquid products, for the production of olefins and for use in others Hydrocarbon conversions «

The accompanying drawing shows the ESCA spectra for chromium in CZM chromosilicates according to the invention and in with chromium impregnated silicalite according to Example 5

The present invention relates to a new crystalline chromosilicate which is made by hydrothermal crystallization a chromium-containing reaction mixture is obtained · The inventive Chromosilicates have a molar ratio of chromium oxide to silicon oxide greater than about 20: 1 and a X-ray diffraction grating, which is characterized by the following diffraction lines:

Table 5

d-A relative intensity

11.1 +0.2 very strong

10.0 __ + 0.2 very strong

3.85 + 0.07 very strong

3.82 + 0.07 strong

3.76 + 0.05 strong

5.72 +0.05 strong

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The chromosilicates, which are abbreviated as CZM below, have the following composition, given in moles of the oxides in an anhydrous state:

RgO raMgOIbCr ₂ O, rcSiOg

wherein RpO is a quaternary alkyl ammonium oxide, preferably Tetrapropylammonium oxide, M one of the alkali metals lithium, sodium, potassium or mixtures thereof and preferably sodium, a is a number between 0 and 1.5, c is a number equal to or greater than 12 and c / b is a number greater than 20. The relationship c / b is usually in the range between 20 and J5,000 and preferably in the range from 50 to 1,000. This chromosilicate shows X-ray diffraction lines of the powder form (random powder X-ray diffraction lines) according to table 6:

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Table 6

Interplanar distance 2Θ (doubled Bragg normalized d (Angstrom) angle) intensities

11.2 + 0.2 7.90 100

10.05 ± 0.12 8.80 70

9.75 + 0.11 9.07 17

8.99 + 0.09 9.84 1

7.44 + 0.06 11.90 1

6.71 + 0.05 13.20 7

6 * 36 + 0.05 13.92 11

5.99 + 0.04 14.78 14

5.71 + 0.04 15.53 7 5.57 + 0.04 15.91 10 5.36 + 0.03 16.54 3 5.14 + 0.03 17.25 1 5.02 + 0.03 17.65 5

4.98 + 0.03 17.81 5 4.61 + 0.02 19.25 4 4.36 + 0.02 20.37 5 4.25 + 0.02 20.88 8 4.08 + 0.02 21.78 2 4.01 + 0.02 22.18 3 3.86 + 0.02 23.07 52 5.82 + 0.02 23.29 32 3.75 + 0.02 23.73 17

3.72 + 0.02 23.73 26 3.65 + 0.02 24.40 12 3.60 + 0.01 24.76 2 3.48 + 0.01 25.58 2 3.44 + 0.01 25.88 4 3.40 + 0.01 26.24 1 3.35 + 0.01 26.60 3 3.31 + 0.01 26.95 6 3.25 + 0.01 27.43 2 3.05 + 0.01 29.28 4

2.99 + 0.01 - «£ & £ &,., - ** -> ,? 2.961 · 0.01 13 (g ©; ^ / 116 6 4

.99 +. 01
2.961 x 0.01

The X-ray diffraction spectra were made according to standard methods determined using an X-ray tube with a copper target, a graphite crystal monochromator for sanctioning the Kgj, doublet radiation from copper and a proportional counter tube, that the reflected K ^ doublet radiation s & ektiv measures. The spectra were recorded with a line chart recorder and the peak intensities were converted to a scale from 0 to 100. The interplanar distances d (in Angstrom units) j corresponding to the recorded diffraction peaks, were calculated.

The crystalline chromosilicate is produced by hydrothermal Crystallization of an aqueous reaction mixture containing quaternary alkyl ammonium oxide, chromium oxide, silicon oxide and lithium, sodium or potassium oxide or a mixture of these alkali oxides and preferably sodium oxide. The reaction mixture preferably has the following composition, based on moles of the oxides:

D,: cSiQ ":

where a is a number greater than O, but less than 5, c is a Number from 1 to 100, the ratio c / b is greater than 12, but less than 800 and d is a number in the range from 70 to 500. A preferably denotes a number in the range from 0.05 to 1, c a number in the range from 2 to 20, the ratio c / b is in the range from J50 to 600 and d means a number in the range from 100 to 300. The hydrothermal crystallization is preferred at a temperature in the range from 100 to 200 C,

ο particularly preferably from 125 to 175 C and especially at 150 ° C. The crystallization is expediently carried out under the autogenous pressure of the reaction mixture.

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CZM is useful as a hydrocarbon conversion catalyst, especially for dewaxing and olefin production.

In such processes, a hydrocarbon feed, e.g. a reformate, brought into contact with the CZM catalyst under conversion conditions.

The normal paraffins in the reformate are raked and delivered considerable amounts of olefins, even in the presence of hydrogen.

Preferably, the reformate with the CZM catalyst in the presence of hydrogen at a hydrogen partial pressure in the range 10 to 27 atmospheres and at a temperature in the range of 450 to 510 ⁰ C is brought into contact. These conversion conditions allow the catalyst to be arranged in such a way that it either absorbs the entire output of the reformer in a separate boiler downstream of it, or it is present as a catalyst layer in the last reforming reactor. Preferably, the liquid space velocity should be in the range of 0.5 to 2 / hour. be maintained.

The CZM catalyst according to the invention can be used with or without a matrix or binder. When using a Matrix you can use the CZM. combine with it in a conventional manner in a weight ratio of catalyst to matrix about 95: 5 to 1: 100. In such cases, the matrix should consist essentially of non-acidic materials such as clay or Made of silica. A preferred binder is alumina, which is peptized, kneaded with the catalyst and extruded.

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ns

The chromosilicates according to the invention are crystalline
Structures represent the X-ray diffraction powder spectra
(random powder X-ray diffration patterns) similar to that
Show ZSM-5 aluminosilicates and silicalite. According to the invention, chromium oxide must be present in the reaction mixture during the hydrothermal crystallization. The silica ratio
to chromium oxide in the product composition is more than 20 and preferably 50 to 1,000.

CZM is hydrothermally crystallized from a reaction mixture that has suitable sources of chromium? Contains silicon and sodium oxide, water and quaternary alkylammonium cations of the formula (Rj ₄ N) +, in which R is an alkyl radical having 1 to 4 carbon atoms.

R is preferably the isthyl, propyl or n-butyl radical
and especially the propyl radical. Examples of compounds which provide such a cation in solution are tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide and salts corresponding to these hydroxides, such as chloride, bromide and iodide.

Suitable sources of silica for the reaction mixture include alkali metal silicates such as sodium silicate solution and reactive forms of silica sols, silica gels and fumed silica. Silica sols such as the commercial grade "Ludox brand" with JO wt.% SiO ₂ are particularly preferred. Since alumina is easily incorporated into the crystal lattice, care should be taken to keep alumina contamination to a minimum. Commercial

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Usual silica sols typically contain 500 to 700 ppm AlpO ,, and at least some of this clay will are present in the end product.

In general, sodium, potassium and lithium are added to the reaction mixture added in the form of the hydroxides or the corresponding salts. Alkali metal silicates can also reduce the total amount or contribute part of these metals, in addition to their puncture as a source of silica. Preferred sources of alkali are Sodium hydroxide, sodium nitrate and sodium silicate solution or water glass.

Suitable sources of chromium include soluble chromium salts such as chromium chloride, chromium sulfates and chromium nitrates, the latter being the latter are particularly preferred. The chromium silicates according to the invention are preferably obtained from a basic reaction mixture crystallizes with a pH in the range from 10 to 13. In order to achieve a mixture within this pH range, it may be necessary, depending on the starting material, to adjust the pH with additional base (e.g. ammonium hydroxide or alkali metal hydroxide) to increase or to lower it to the desired value with an acid (e.g. mineral acids). To increase the pH Particularly suitable are sodium, lithium or potassium hydroxide, dg (these alkali metals also as participants in the reaction are required during the crystallization process.

The reaction mixture should preferably, expressed in molar amounts of the oxides, contain 0.05 to 5 mol of sodium, potassium or lithium oxide, 1 to 100 mol of SiO ₂ and 70 to 500 mol of water and a molar ratio of silica to chromium oxide equal to or more than 12 : Have 1. Preferred reaction mixtures

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ι?

contain 0.5 to 1 mole of sodium, potassium or lithium oxide and preferably sodium oxide, 2 to 20 moles of silica, 100 to 300 moles of water and a molar ratio of silica Chromium oxide in the range from 30 to 600.

After the reaction mixture has been put together, it is ^{heated to a temperature in the range from 100 to 200 °} C., preferably from 125 to 175 ^° C. and particularly preferably to a temperature of 150 ^° C. and kept at this temperature and the autogenous pressure until the hydrated forms of the CZM. The crystalline hydrated CZM usually arises and separates out of the reaction mixture over the course of 6 hours to 6 days and especially within 48 hours. The crystals are separated from the mother liquor, for example with cooling to room temperature, filtering and washing. From the crystals thus synthesized, low-sodium forms or dehydrated forms of the product can be prepared in a conventional manner.

example 1

A reaction solution is prepared by adding 47.9 S of tetrapropylammonium bromide in 35 ml of ^Was §fg _s i§ ^s t ¹ ^ d to the solution 7 * 2 g of sodium hydroxide in 30 ml /. Then, 8 g of Cr (NO ₃₎ ,. 9HgO dissolved in 20 ml of water, undll6g "Ludox brand" -Kiselsäuresol (30 wt.% SiOg) was added with rapid stirring. The entire reaction mixture is placed in an open Teflon bottle in an autoclave and heated for 48 hrs. Under the autogenous pressure to I50 C ^0. After this hydrothermal

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Crystallization are filtered off the product crystals and washed with water, dried overnight at 121 C and then for 8 hours. Calcined at 450 ⁰ C. They give the X-ray diffraction pattern according to Table 6, the molar composition of the oxides is 0.6 Na _{9 OiCr 9} O '«280 SiO ₀ after washing 2 * with aqueous ammonium nitrate solution.

Example 2

2.2 g of sodium nitrate, dissolved in 10 ml of water, and 5 * 5 g of Cr (NO,),. 9HpO, dissolved in 10 ml of water, are successively converted into 100 g of a 25% strength by weight solution of tetrapropy ammonium hydroxide under vigorous · stirring Then added are added to the above solution 80 g "Ludox brand" -Kieselsäuresol (30 wt. # SiO) and the mixture is autoclaved 2 days in steam pressure of the solution at 144 ⁰ C. The product crystals are filtered off, exchanged with ammonium nitrate, washed with water, dried overnight at 121.degree. C. and calcined at 450.degree. C. for 8 hours. The X-ray diffraction analysis gave the diffraction spectrum according to Table 6.

The crystals had the following composition, given in moles of the oxides

0.5 Na ₂ O: Cr ₂ O _:

example

A sample of the chromosilicate is used to test the CZM catalyst according to example 2 mixed with a binder (peptized Ziegler clay catapal) in a weight ratio of 1: 1,

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the mixture is extruded, exchanged with ammonium acetate, dried and calcined at 450 ° C. for 8 hours. Exchange process and calcination are repeated twice. The clay-free one Part of the catalyst had the following composition, expressed in moles of oxides:

0.01 Na ₂ OrCr ₂ O: 225SiO ₂ .

A charge of 585 ° C + isosplitter residue with a stick point of + 33 ° C is with hydrogen under a pressure of 68 atmospheres at a temperature of 350 ° C and a space velocity of the liquid of 2 / hour. passed over the catalyst. The hydrogen supply to the reactors
was kept at 17.8 L / L feed. Under these conditions, a 370 ° C + product yield of 83.8 wt. %
achieved with a pour point of -30 ° C. For comparison, an analogous test was carried out with the same weight ratio of silicalite (produced in accordance with US Pat. No. 4,061,724) to
Catapal binder. In order to achieve a comparable C ^ H product, an operating temperature of 406 C was required, which clearly shows the increased activity of the chromosilicate compared to the catalysts from the prior art.

Example 4

Comparing trials have been carried out to determine the effectiveness of To investigate CZM, silicalite and a silicalite which, after synthesis using Cr (NO,), is impregnated with chromium had been.

The CZM catalyst was made as follows: the product
according to Example 2 was five times exchanged with 25 #iger ammonium acetate solution at 80 ⁰ C, washed with water, overnight

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dried at 121 ° C. and calcined at 450 ° C. for 8 hours. Replacement, drying and calcination were repeated.

The silicalite was produced according to the specification of US Pat. No. 4,061,724. The catalyst was prepared by exchanging the silicalite four times with 20 #iger ammonium nitrate solution at 80 ⁰ C, washing with water, drying overnight at 121 ° C for 8 hours and calcining at 450 ⁰ C.

The imjiagnierte with chromium silicalite was prepared by mixing the above catalyst with a solution of Cr _(NO,) - ₅ was impregnated T9HpO after Porenfüllmethode. The catalyst was then ^{dried at 121 °} C. overnight and calcined at 450 ^° C. for 8 hours. The analysis resulted in the following values for the three catalysts:

Table 7

Al (ppm) Na (ppm) Cr (wt. %)

CZM 380 <£ 50 0.56

Silicalite 400 · <50 0

Silicalite impregnated with chromium 400 100 0.5

The catalysts were bound with Catapal alumina, extruded, dried and calcined for 8 hrs. At 450 ⁰ C. Samples Each catalyst was treated in porcelain boats in a brazier in a 100 # steam atmosphere at 76O ° C.

Steam treated and untreated catalyst samples were then tested in a "Dekan impact crack test" to determine the Determine effectiveness in cracking. The following test procedure was used: 0.1-0.5 g of catalyst was added with 1 g of

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Acid-washed and neutralized alundum mixed and poured into a tubular reactor made of 4.8 mm thick stainless steel, the remaining space being filled with alundum. The reactor contents were ^{calcined at 450 °} C. for 1 hour. This reactor was then placed in a clamshell oven and the reactor outlet was connected to the inlet of a gas chromatograph. The inlet was connected to the carrier gas line of the GasChromatograph. Helium was passed through the system at a rate of 30 cm / min. Through a partition above the reactor n-decane amounts of 0.04 milcroliter were injected and the reaction products were determined by conventional gas chromatographic analysis. Zero tests with Alumdum showed no conversion under the test conditions, as did a catalyst made from 100 % Catapal clay.

A pseudo-1st order cracking rate constant k was calculated using the formula

^K -1r- ^ln

where A is the weight of the zeolite in grams and χ is the proportion of conversion into products boiling below decane.

Table 8 shows the values for the logarithm of k as a function of the steam treatment at J6O C.

Table 8

Ln k after steam treatment

at 760 ° C

0 hours 6 hours 24 hours

CZM
Silicalite

Silicalite impregnated with chrome

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> o 40 -1, 85 -2, 70 -1, 00 -4, 35 ^ o -2, 65 -4, 20th

Without steam treatment, both were chromium-containing Catalysts very active. After 6 hours of steam treatment CZM was about three times as effective as silicalite, while silicalite impregnated with chromium was only about 1.4 times was so effective. After 24 hours of steam treatment was CZM 5 times as effective as silicalite, which was impregnated with chromium However, silicalite would have improved its effectiveness only slightly. These values illustrate the vastly different catalytic effect of CZM chromosilicates and aluminosilicates that have not been impregnated with chromium.

Example 5

ESCA analysis of Cr-silicalites

A series of tests was carried out to determine the differences to show that exist between the chromium in CZM chromosilicates and silicalite impregnated with chromium.

Samples from CZM and according to the procedure of Example 4 manufactured, with chromium-impregnated silicalite (without steam treatment) were in a Hewlett-Packard 595OA ESCA spectrometer (electron spectroscopy for chemical analysis) examined. The samples were not in a binder. Both samples were powder, they were attached in the spectrometer by sputtering on both sides sticky tape. Al Kqk radiation, which passed through a monochromator. 2 eV electrons from an electron surge anode with a Emission settings of 0.5 mAmp were used to control the to compensate for effects caused by the use of samples. The pressure in the spectrometer was about during the analysis

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-8th
2x10 "Torr. A 50 eV window of 256 points was sampled for chromium, while 20 eV windows of 256 points were sampled for silicon, carbon and oxygen. The various windows were sampled multiple times, then the signals were averaged to get a good one The analyzer was calibrated by setting the Au (4f 7/2) binding energy (BE) to 34.0 +0.1 eV. After taking into account the effects of using the sample, the Cr (2pj5 / 2 ) BE 2 eV lower with CZM than with chromium-impregnated silicalite, while the Si (2p) and 0 (ls) BE values of the two samples were the same within the experimental accuracy (+ 0.1 eV). st the difference between the Cr (2P ") lines for CZM and silicalite impregnated with chromium. The large difference between the Cr BE values shows that, surprisingly, the chromium is present in the two samples in a different oxidation state.

The visual examination of CZM and the chromium-impregnated silicalite also confirms the differences between the rehearsals. After the calcination stage in the production (8 hours at 450 ° C) the CZM sample is light green, during the chrome-impregnated silicalite is yellow. This shows the increased stability of the chromium in the CZM chromosilicate in comparison to the chrome-impregnated silicalite.

The synthetic chromosilicates can be used as they are produced during synthesis or thermally post-treated (calcined). It is usually desirable to remove and transfer alkali metal ions by ion exchange Substitute hydrogen, ammonium, or any desired metal ion. The chromosilicate can be used in Combination with hydrogenating components such as tungsten, vanadium,

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Molybdenum, rhenium, nickel, cobalt, chromium, manganese or an edimetal such as palladium or platinum in such cases, in which a hydrogenation / dehydrogenation function is desired. Typical metal cations are the rare earths, metals of groups IIA and VIII and mixtures thereof, with cations of metals such as rare earths, Mn, Ca, Mg, Zn, Cd, Pt, Pd, Ni, Co, Ti, Al, Sn, Pe and Co are particularly preferred.

Hydrogen, ammonium ion and metallic components can be introduced into the chromosilicate by exchange. That Chromosilicate can also be impregnated with the metals, or the metals can be physically mixed with it, where known standard procedures are to be used.

Typical ion exchange processes consist of bringing the synthetic chromium silicate into contact with a solution brings containing a salt of the replacement cation or cations. Numerous salts can be used, however chlorides will be used and other halides, nitrates and sulfates are particularly preferred. Ion exchange processes are described in numerous patents, see e.g. US-PSS 3,140,249, 3,140,251 and 3,140,253. The ion exchange can take place before or after the calcination of the zeolite.

After contact with the salt solution of the replacement cation, the chromosilicate is typically washed with water and dried at a temperature of 65 to about 315 ° C. After washing, calcination can be carried out in air or inert gas at temperatures of about 200 to 820 ^° C. for 1 to 48 hours or longer, a catalytically active product, in particular for hydrocarbon conversions, being obtained.

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The spatial arrangement remains independent of the cations present in the synthesized form of the chromosilicate of the atoms that make up the basic crystal lattice are essentially unchanged. The exchange of cations has if at all, only little influence on the lattice structures.

The chromosilicates can be produced in various physical forms. Generally speaking, they can be made as Powder, granulate or shaped body such as an extrudate with Particle sizes such that a sieve with a mesh size of 9 mm is passed, but the product passes through a sieve of 0.0 ^ 7 mm clear mesh size is recorded. Is the catalyst shaped, e.g., by extrusion using an organic binder, it can be extruded before drying or dry or partially dry and then extrude.

The chromosilicate can be combined with other materials that are resistant to temperatures and other conditions organic conversion processes are stable. These matrix materials include active and inactive Substances and synthetic or naturally occurring zeolites as well as inorganic materials such as clays, silicic acid and Metal oxides. The latter can be in the naturally occurring form or in the form of gelatinous precipitates, brines or have gels and include mixtures of silica and metal oxides. In certain organic conversion processes The use of an active material together with the synthetic chromosilicate leads to an improvement in the degree of conversion and the activity of the catalyst. Inactive materials serve as a diluent to control the conversion in a given case, leaving no other means of control

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the speed of reaction an economical ■ process flow is secured. The chromosilicates can be incorporated into naturally occurring clays such as bentonite and kaolin will. These materials, i.e. clays, oxides and the like, in part act as binders for the catalyst. It is advisable to produce a catalyst with good crush resistance, since the catalysts at the oil refinery are often heavily used. The catalyst can break down into a powdery material, which can cause procedural problems.

The naturally occurring clays that are produced with the Chromosilicates that can be combined include the groups of montmorillonites and kaolins, including the sub-bentonite and the kaolin, known under the names Dixie, McNamee, Georgia and Florida clays and the like whose main mineral component is halloysite, kaolinite, dickite, nacrite or anauxite. Fibrous Clays such as sepiolite and attapulgite can also be used as carriers. These clays can be mined in raw form or after calcination, acid treatment or chemical modification.

Furthermore, the chromosilicates can be combined with porous matrix materials and mixtures of matrix materials such as Silica, alumina, titanium dioxide, magnesia, silica / alumina, Silica / magnesia, silica / zirconia, kfeselic acid / thorium earth, Silica / Beryllium Oxide, Silica / Titanium Dioxide, TSandioxide / Zirconia or with ternary mixtures such as silica / alumina / thorium earth, silica / alumina / zirconia, silica / alumina / magnesia and silica / magnesia / zirconia. The matrix can be in the form of a Co-Gel.

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The chromosilicates can also be combined with other zeolites will be like with synthetic ucfn natural faujasites, erionites and mordenites. You can also be combined with synthetic zeolites.

The quantitative ratio between crystalline chromium silicate according to the invention and gel matrix made of inorganic oxide can vary considerably. The chromium silicate content may be from about 1 to about 90 wt.%, But ^ is usually in the range of 2 to about 50 wt..

Chromosilicates are suitable for use in hydrocarbon conversions. Hydrocarbon conversions are chemical and catalytic processes in which carbonaceous compounds are converted into other carbonaceous compounds will. Examples of hydrocarbon conversion reactions are catalytic cracking, hydrogen cracking and formation of olefins and aromatics. The catalysts are also useful in other petroleum processing reactions and hydrocarbon conversions such as the isomerization of normal paraffins and naphthenes, polymerization and oligomerization of olefinic or acetylenic compounds such as isobutylene and 1-butene, in reforming, alkylation, Isomerization of polyalkyl-substituted aromatics (e.g. o-xylene) and disproportionation of aromatics (e.g. toluene), being a mixture of benzene, xylenes and higher methylbenzenes receives.

The chromosilicates can be used to process hydrocarbons containing charges can be used. Hydrocarbons Charges contain carbon compounds; they can be of various origins, e.g. unprocessed

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Petroleum fractions, circulated. Petroleum fractions, shale oil, liquefied coal, tar sand oil and in general any carbonaceous liquid product that responds to zeolite catalyzed reactions. Depending on the procedure to which the hydrocarbonaceous feed is subjected, it can be metallic or metal-free, it can also have a high or low content of nitrogen or sulfur Have impurities. In general, the processing becomes more efficient (and the catalyst is more active), the lower the nitrogen content of the feed.

The conversion of hydrocarbonaceous feeds can be done in any suitable way, e.g. in the fluidized bed, in progressive layers or in fixed bed re ^ ctors, depending on the desired behavior. The formation of the catalyst particles depends on the conversion process and the operating mode.

Using hydrogenation catalysts Chromosilikaten containing heavy petroleum residues, cycle oils and other hydrogenating crackable feedstocks at temperatures of 300-525 ⁰ C with molar ratios of hydrogen to hydrocarbon charge from 1 to 100 can be cracked. The pressure can be from 1.7 to 350 kg / cm and the space velocity of the liquid from 0.1 to 30 per hour. In these cases, the chromosilicates can be combined with mixtures of inorganic oxidic carriers or with faujasites such as X and Y, for example.

The chromosilicates can also be used for catalytic cracking at temperatures of about 260 to 625 C, pressures of negative pressure to several hundred atmospheres and other standard conditions can be used.

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The chromosilicates can also be used for dewaxing of hydrocarbonaceous feeds, with selectively removing straight-chain and slightly branched paraffins will. The process conditions are as in the case of hydrogenative dewaxing, a mild hydrogenative cracking, or it is carried out at lower pressures in the absence of hydrogen. Significant amounts arise during dewaxing Amounts of olefins from the cracked paraffins.

The chromosilicates can also be used in reforming reactions at temperatures from 56O to 600 C, printing from Normal pressure up to J56 kg / cm and a space velocity of Fluid from 0.1 to 20 per hour. The molar ratio of hydrogen to hydrocarbon is generally from 1 to 20.

The catalyst can also be used for the hydrogenative isomerization of normal paraffins if one is present Hydrogenation component such as platinum. The hydrogenating isomerization generally takes place at temperatures of 200 up to 575 ° C and liquid space velocities from 0.01 to 5 per hour. The hydrogen to hydrocarbon molar ratio is from 1: 1 to 5: 1. Furthermore, the catalyst can also be used for isomerizing olefins at temperatures of 140 to 320 C can be used.

Other reactions that take place with catalysts according to the invention which may contain a metal such as platinum are hydrogenation / dehydrogenation reactions, nitrogen removal and desulfurization.

Chromosilicates can be used in hydrocarbon conversion reactions together with active or inactive carriers, with organic

13 0 013/1166

or inorganic binders and with or without additives other metals can be used. These reactions and the reaction conditions suitable for them are known.

For: Chevron Research Company, San Francisco, CA., V.St.A.

Dr.H.Chjr.Beil Lawyer

130 01-3- / 1 1β6

Claims (16)

ADE!. · '■ "■■ .-" ■ "3'. 068 Chevron Research Company-San Francisco, CA ,, V * St.A. Chromosilicate catalyst and its use for the conversion of hydrocarbons Patent claims: 1. Crystalline chromosilicate with a molar ratio the oxides SiO ₃ : Cr ₂ O, of more than about 20: 1 and the X-ray diffraction lines of the powder form: d-A ReI.Intensity 11.1 + 0.2 very strong 10.0 + 0.2 very strong 3.85 + 0.07 very strong 3.82 + 0.07 strong 5.76 + 0.05 strong 5.72 + 0.05 strong 130013/1166 2. Crystalline chromosilicate, characterized by a molar composition of the oxides in the anhydrous state corresponding R ₂ O raMgO rbCrgO, rcSiOg where RpO is ^a quaternary alkylammonium oxide, M is one of the alkali metals lithium, sodium or potassium or a mixture thereof, a is a number greater than O but less than 1.5, c is a number greater than or equal to 12 and c / b is a number greater than 20 and an X-ray diffraction pattern (powder) d-A ReI. intensity 11.1 +0.2 very strong 10.0 +0.2 very strong 3.85 + 0.07 very strong 3.82 + 0.07 strong 3.76 + 0.05 strong 3.72 + 0.05 strong 3 · Crystalline chromosilicate according to claim 2, characterized characterized that RpO tetrapropylammonium oxide and M mean sodium. 4. Process for the production of crystalline chromosilicate, characterized in that a reaction mixture containing a quaternary alkylammonium oxide, lithium, Sodium or potassium oxide or mixtures thereof, chromium oxide and silicon oxide in molar amounts of the oxides according to R ₂ O: aM ₂ OXbCr ₃ O: 0SiO ₃ rdHgO where RpO is a quaternary alkyl ammonium oxide, M is one of the 130013/1166 Alkali metals lithium, sodium or potassium or a mixture thereof, a number greater than 0, however less than 5 * c a number in the range from 1 to 100, c / b represent a number greater than 12 and d represent a number in the range from 70 to 500, hydrothermally crystallized. 5. The method according to claim 4, characterized in that tetrapropylammonium oxide and M is sodium. 6.. Method according to claim 5, characterized in that a is a number in the range from 0.05 to 1, c is a number im Range from 2 to 20, c / b a number in the range of J50 to 600 and d is a number in the range from 100 to 300. 7. The method according to claim 6, characterized in that one the hydrothermal crystallization at a temperature carries out in the range of 100 to 200 ° C. 8. The method according to claim 7, characterized in that the hydrothermal crystallization under the autogenous Printing. 9. Obtained by the method of any of claims ^ · to 8 crystalline chromosilica c. 10. A method for converting hydrocarbons, characterized in that a hydrocarbon-containing Bringing charge under conversion conditions with a chromosilicate according to claim 1 in contact. 11. The method according to claim 10, characterized in that the method for hydrogenating cracking, dewaxing, 130013/1 166 Reforming, olefin polymerization or oligomerization, isomerization, disproportionation, alkylation or catalytic cracking is carried out. 12. The method according to claim 10 for improving a normal paraffin containing reformate, characterized in that the reformate with the catalyst according to claim 1 under conversion conditions contacts house Cracking a proportion of normal paraffins to lighter gaseous products. 13 · The method according to claim 12, characterized in that the gaseous products contain olefins. 14. The method according to claim 13, characterized in that one works in the presence of hydrogen 15 · The method according to claim 14, characterized in that at a hydrogen partial pressure in the range of 1 to 30 atmospheres and a temperature in the range from 400 to 550 ⁰ C works. 16. The method according to claim 15, characterized in that the space velocity in the range from 0.1 to 10 hours. " lies. 130013/1186