DK143973B - CATALYST FOR ISOMERIZATION AND HYDROCRAFTING OF CARBON HYDROIDS AND PROCEDURES FOR MANUFACTURING AND APPLICATIONS OF THIS CATALYST - Google Patents

Description

(19) DENMARK (w ^ (12) PUBLICATION WRITING (11) 11 (-3973 Β

DIRECTORATE OF THE PATENT 06 BRAND

(21) Application No. 1703/72 (51) Int.Ci.3 B 01 J 2 3/40 (22) Filing day 7- Apr. 1972 (24) Race day 7 Apr 1972 (41) Aim. available Oct 10 1972 (44) Presented 9 Nov. 1981 (86) International application no. - (86) International filing day - (85) Continuation day - (62) Master application no. -

(30) Priority 9 Apr 1971 in 22966/71, IT

(71) Applicant £> NAM PROGETTI S.P.A., Milan, IT.

(72) inventor Marco Taramasso, IT: Orfeo Forlani, IT: Bruno Notari, IT.

(74) Plenipotentiary International Patent-Bure au.

(54) Catalyst for isomerization and hydrocracking of hydrocarbons and processes for the preparation and uses of this catalyst.

The present invention relates to a catalyst for the isomerization and hydrocracking of paraffinic hydrocarbons or hydrocarbon mixtures and methods of preparation and processes for using this catalyst.

The catalyst is suitable for such isomerizations and hydrocrackings to obtain some products which have the properties required by certain

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industrial exploits. Examples of isomerizations that can be carried out by the catalyst of the invention include a) selective isomerization of 2,2-dimethylbutane to 2,3-dimethylbutane, and b) selective isomerization of heavy normal paraffins.

Isomerization and hydrocarbon hydrocracking are operations widely used in the art.

ISLAND

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By isomerizations, highly branched saturated hydrocarbons, mixed with other hydrocarbons, can increase the anti-banking value of the paraffinic hydrocarbons, thereby avoiding or at least greatly restricting the use of additives based on alkyl lead compounds or of other nature.

Mixing of branched hydrocarbons with hydrocarbons for use as fuel for internal combustion engines enables rapid increase of the octane number of the mixtures in a very simple and economical way.

However, during isomer excitation reactions, secondary reactions with hydrocracking also occur, leaving hydrocarbons at an undesirably low molecular weight.

By hydrocracking, it is possible to obtain from light distillates or gas oils some light fractions which are rich in isoparaffins and which can therefore be used as gasoline.

The above-described treatment is carried out according to well known techniques in which an appropriate petroleum fraction is reacted in the presence of high pressure hydrogen with one catalyst in a reactor maintained at the desired temperature.

It is further necessary to point out that the operating conditions under which the known catalysts work are quite critical, especially in the isomerization processes, due to the limited range of temperatures and pressures where optimum conversion and selectivity are obtained.

However, a catalyst has now been found for the isomerization and hydrocracking of paraffinic hydrocarbons or hydrocarbon mixtures, enabling very high selectivity at conversion levels to be achieved very close to those obtainable thermodynamically.

The catalyst of the invention is characterized in that it comprises a material with a crystal matrix of planar and non-porous material having on the surface similar centers of acidity, adapted to obtain the desired selectivity, and platinum and / or palladium finely distributed, is either caused by charge displacement, or is of a protonic nature or is of the Lewis acid type.

As the flat and non-porous crystal matrix material, the invention has proved particularly suitable for natural or synthetic clay-type minerals, and among these, in particular, high charge density phyllosilicates (0.4 to 1 electron charge per semicell Sx tetrahedral structure.

Such minerals especially belong to the families: smectites of the type "beidellite" (beidellites, non-tronites), and minerals with limited expansion of the "vermiculite" type (vermiculites, hydrobioites, illites).

The specified catalyst can be prepared in various ways, and the invention also relates to three processes for preparing the catalyst.

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The first of these processes, in which the acidity is caused by charge shear, is characterized in that the centers of acidity are formed by neutralizing charge deficiencies in the material with crystal matrix and plane and non-porous structure, after comminution of the material into particles of less than 40 µm. with cations of the elements of the groups Hib, IVb, VIb, Vllb and VIII of the periodic system, preferably lanthanum, cerium, titanium and manganese.

Under the mentioned elements from groups Xllb, IVb, VIb, Vllb and VIII of the periodic table also belongs the lanthanide series (Handbook of chemistry and physics - 49th edition 1968 - 1969 - Chemical Rubber Publishing Company).

The second method by which protonic acidity is obtained is characterized by forming the centers of acidity by subjecting the material with crystal matrix and planar non-porous structure ion exchange with ammonium ions and subsequent heating to a temperature between 300 and 600 ° C. preferably 450 ° C for 10 hours. With this heating, ammonia develops.

The third process by which Lewis acid type acidity is obtained is that the acidity of the centers is obtained by heating the material with planar and non-porous structure to a temperature between 300 ° C and 450 ° C. a partial dehydration of aluminum hydroxyl groups bonded to the octahedral layer of the aforementioned materials. Such acidity is found especially, but not exclusively, in metakaolinite obtained by heating kaolinite mineral to between 350 and 450 ° C.

The platinum and / or palladium present on the surface of the catalyst of the invention is preferably present in an amount of between 0.01 and 5% by weight. It can be applied to the catalyst surface by impregnation with a compound of this metal.

In the case of platinum, the impregnation can be carried out with ³PtCl ^ 'beers Pt (NH 3) 4 (OH) 2.

The application of platinum and / or palladium is carried out in all cases, regardless of the type of acidity present on the catalyst surface and no matter the method used to obtain this acidity.

The catalyst of the invention results in a transformation and selectivity that is very interesting in the industry. Moreover, it is remarkably inexpensive compared to conventional catalysts, both because of the cheap minerals used in its manufacture, and because of its manufacturing, which is very simple and inexpensive, and because the catalyst gives results of industrial interest even with very little small amounts of precious metals which, in case of isomerization, are preferably 0.15%, i.e. much lower than the amounts required by conventional catalysts. In addition, it is necessary to note that it is possible to obtain catalysts of different acidity simply by changing the starting material, the nature of the cation used for ion exchange, and the method of preparation.

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With the same starting material with a certain lack of charge as mentioned above, different catalysts having different artificial acidity can be obtained by using different cations and different reaction products can be obtained from the same charge material and under the same reaction conditions.

Another distribution of reaction products can also be obtained by changing the starting material and using the same cation. Various acidities are also obtained using different preparation methods as shown above.

The invention also relates to a particular method for isomerizing saturated hydrocarbons using the catalyst described above.

This process is characterized in that the saturated hydrocarbon, or a mixture of such hydrocarbons, is contacted in the gas phase with the catalyst at a temperature between 100 and 600 ° C, preferably between 300 and 450 ° C, and at a pressure between 1 and 160 kg / cm, with the specific volumetric velocity being kept between 0.1 and 20 h. The specific volumetric velocity (HSLV) here means the ratio of volumetric flow per volume. per hour of liquid hydrocarbons added and the catalyst volume.

The present process can be carried out either in a continuous or discontinuous manner. It is used in particular, and preferably, for the conversion of 2,2-dimethylbutane to 2,3-dimethylbutane due to the higher octane number of the last product.

The isomerization process with 2,2-dimethylbutane is preferably carried out continuously in two zones. The freshly applied product is isomerized in a first reaction zone containing the catalyst of the invention. From there, a mixture is obtained in thermodynamic equilibrium of aliphatic hydrocarbons from which 2,2-dimethylbutane is separated by distillation.

This compound is sent to another reaction zone containing the catalyst of the invention where the isomerization of 2,2-dimethylbutane to 2,3-dimethylbutane takes place.

The reaction products are sent to a separation column from which the top is obtained 2,2-dimethylbutane which has not reacted, which compound is sent back to the second isomerization reactor, while from the bottom of the column is obtained 2,3-dimethylbutane together with a controlled amount of 2-methyl pentane.

In this process 2,3-dimethylbutane is obtained as the dominant product.

It should be noted that in both reaction zones the catalyst of the invention is used.

However, it is also possible in the first zone to use a catalyst of the second type, e.g. that described in Italian Patent No. 743,088. But in all cases, it is imperative that the catalyst of the invention be used in the second zone.

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The invention further relates to a particular process for hydrocracking liquid saturated hydrocarbons using the catalyst of the invention. This process is characterized in that the saturated hydrocarbon, or a mixture of such hydrocarbons, is contacted in the liquid phase with the catalyst at a temperature between 150 and 450 ° C and at pressures between 35 and 150 atmospheres and a specific volumetric rate of 0.1 to 10 h The products of the reactor are treated in a conventional manner with debutanisation and fractionation.

The invention is further explained by the following examples in which results obtained with the catalyst according to the invention are given.

In the examples, the conversion ratio is the number of reacted molecules number of charged molecules and the selectivity ratio of number of molecules of the desired product number of reacted molecules.

Example1 1

Selective isomerization of 2,2-dimethylbutane. Beidellite, characterized by an equivalent surface of 54 A °, was used. By "equivalent surface" is meant the area available for a single monovalent cation.

10 g of beidellite was ion exchanged by the usual procedure with a 2 N aqueous solution of lanthanum nitrate.

The process was repeated 3 times at a temperature of 60-70 ° C in such a way as to ensure complete ion exchange.

The material thus produced, after careful washing to remove other foreign ions present, was impregnated with solution of chloroplatinic acid in such an amount as to give a final catalyst with a platinum content (after drying and calcination at 350 ° C) of 0.157. .

The control of the degree of hydration of the catalyst under the operating conditions was carried out by adding an appropriate amount of water dissolved in hydrocarbon feed (50 to 100 ppm water). The catalyst thus prepared was tested in a micro-flow reactor with isomerization of 2,2-dimethylbutane.

The conditions for the reaction were as follows:

Temperature 390 ° C

2

Pressure 20 kg / cm catalyst g 1.5 specific volumetric velocity (HLSV) 1 H 2 / hydrocarbon ratio 5 ppm 1 0 0 fed. 50 6 143973 Table 1 shows the results obtained.

Table 1

React composition- Sample A Sample B Sample C

tions products __________.______ 2.2-DM-butane 73.6 73.5 78.6 2.3-DM-butane 21.9 22.8 18.1 2- Methyl-pentane 2.3 2.0 1.7 3- Methyl pentane 2.2 1.7 1.6 n-Hexane trace trace trace

Conversion% 26.4 26.5 21.6

Selectivity% * 83.0 86.0 84.0

Since the desired product in this case is 2,3-DMB, the selectivity must be the ratio - x 100 2,3-DMB + 2 MP + 3 MP + nC6 (DMB = dimethylbutane, MP = methylpentane, Cg = hexane) and there exists. practically not cracking or hydrocracking products.

Example 2

Vermiculite with an equivalent surface of 37 A ° was used. The vermiculite material had been finely ground to obtain particles less than 40 microns in diameter. The material thus obtained, after several times washing to remove possible soluble contaminants, was subjected to cation exchange with a 2 N solution of lanthanum nitrate as in Example 1. It was then similarly impregnated with chloroplatinic acid to give 0.15¾ platinum in the finished catalyst. Also in this case, an appropriate amount of water was added to hydrocarbon feed.

The reaction conditions were as follows: 9

Pressure 20 kg / cm

Catalyst 1.5 g HLSV 1

Hydrogen / hydrocarbon ratio 5 ppm H 2 O in feed. 50 7 143973

Table 2

React composition- Sample A Sample B Sample C Sample D

t Ion products_T = 390 ° C T = 390 ° C T = 410 ° C_T = 390 ° C

2.2- Dimethylbutane 78.7 75.5 69.0 73.7 2.3- Dimethylbutane 20.2 22.6 27.5 23.0 2- Methylpentane 0.6 1.0 1.8 1.7 3- Methylpentane 0, 0.9 0.9 1.6

Conversion ° L 21.3 24.5 31.0 26.3

Selectivity% 95.0 92.5 89.0 88

Example 3

For the purpose of showing the great importance of the particular combination of trivalent cations and clay minerals to obtain high selectivity of the desired product 2,3-dimethylbutane, in this example, the results obtained using ver miculite are given as in Example 2. The vermiculite had been ion-exchanged with an ammonium salt (nitrate or acetate) and further calcined between 400 and 500 ° C to remove NH ^8 then protonic acid formation.

In particular, 10 g of vermiculite was subjected to ion exchange with ammonium acetate solution according to normal practice. After ion exchange and washing, the obtained material was heated for 3 hours to a temperature of 450 ° C. Then 0.15% Pt was introduced as described in the previous example.

The reaction conditions were as follows.

2

Pressure 20 kg / cm

Catalyst 1.5 g HLSV 1

Hydrocarbon ratio 5

Table 3

Reaktionsprodukt_400 ° C_420 ° C

2.2-DMB 91.7 30.9 2.3-DMB 6.0 11.6 2 Methylpentane 1.4 26.2 3 Methylpentane 0.7 16.4 n-C6 0.2 14.9

Conversion% 8.3 69.1

Selectivity 7 »72.5 16.4 8 143973

Example 4 10 g of caolinite purified by sedimentation and subsequent washing for the purpose of removing possible dissolved impurities and adding an appropriate amount of platinum (see Examples 1.2 and 3) were heated to temperature 420 ° C for 15 hours. In this way, a catalyst consisting of metastable caolinite containing 0.15% platinum was obtained by partial dehydration.

The reaction conditions were as follows: 2

Pressure 20 kg / cm

Catalyst 15 g

Hydrocarbon ratio 5

Table 4

Reaction product T = 420 ° C T = 450 C T = 420 C

HLSV = 1 HLSV = 0.5 HLSV = 0.5 2.2- DMB 91.6 83.4 63.7 2.3- DMB 6.8 14.6 24.4 2 Methylpentane 0.9 1.6 8.2 n- Hexane - - 0.6

Conversion% 8.4 16.6 36.3

Selectivity% 80.9 87.9 87.2

Example 5

Selective isomerization of normal hexadecane with 20 g of catalyst consisting of 0.15% platinum supported on 99.85% vermiculite, which was ion exchanged with titanium.

The operating conditions and the data obtained are given below: Reaction conditions: T = 330 ° C P = 50 kg / cm 2 HLSV = 1 ^ / hydrocarbon ratio = 5 The following data were obtained:

Reaction product:

Hydrocarbon C ^-C ^ (mol?) 15%

Content iso-C., -85% total

With C ^-C ^,. hydrocarbons are meant all the products obtained by the hydr ocracking reaction which are desired to be kept within relatively narrow limits.

Products of interest in this case are hydrocarbons having the same molecular weight as the added but branched structure. Therefore, the reaction expressed by the hydro cracking percentage and the ratio of iso-hexadecanes to the sum of all train compounds.

Example 6

Selective isomerization of heavy paraffinic hydrocarbons.

20 g of catalyst consisting of 0.15% platinum supported on 99.85% vermiculite, which had been ion-exchanged with titanium, was used for selective isomerization of normal heavy paraffins with a boiling point of 250 to 350 ° C with the aim of reducing the flow point of the mixture.

The reaction conditions and product characteristics are given below.

u

Reaction conditions: T = 340 ° C P = 50 kg / cm 2 HLSV = 1 10 / hydrocarbon ratio = * 5 Reaction products a) with a boiling temperature up to 250 ° C = 22 wt%.

b) with a boiling temperature higher than 250 ° C (250 ° C +) = 78% by weight. Produktkarateristika

Supply material (250 ° C +): d ^ = 0.804, floating point = + 19 ° C Product (250 C +: d ^, = 0.795, floating point = + 3 ° C.

Example1 7

Hydro cracking of normal hexadecane.

20g of catalyst consisting of vermiculite ion exchange with titanium with a platinum content of 0.15% was tested by a hydrocracking reaction of normal hexadecane. The data obtained are given below:

Reaction conditions: T = 350 ° C P = 50 kg / cm 2 HLSV = 0.5 H2 / hydrocarbon ratio = 10 Product characteristics:

Conversion = 80%

Molar distribution of the reaction products:

Claims (5)

1Λ3973 ίο ~ Product Characteristics C4 = 8.3% n C. C5 = 12% C4 / o 'C6 = 15.8% C? = 12.7% C "= 10.8% η 0ς 8 -7 = 3 <5 3 C9 = 10.4% C5 / o C10 = 8.5% 0 .. = 6.7% n C, C -187 - ^% = 36.0 c12 - 1.8 /. C6 C16 = 6'5 * where C3, C4> and so on are isoparaffinic and paraffinic hydrocarbons having the indicated number of carbon atoms indicated. Claims. Catalyst for the isomerization and hydrocracking of paraffinic hydrocarbons or hydrocarbon mixtures, characterized in that it comprises a material of crystal matrix of planar and non-porous material having on the surface similar centers of acidity adapted to achieve the desired selectivity, and platinum and / or palladium finely distributed 'as this acidity is either caused by charge displacement, or is of a protonic nature or is of the Lewis acid type. Catalyst according to claim 1, characterized in that the flat and non-porous crystal matrix material is a natural or synthetic clay-type mineral. Catalyst according to claim 1 or 2, characterized in that platinum and / or palladium are present in amounts between 0.01 and 0.5% by weight. Process for preparing a catalyst as claimed in any one of the preceding claims, characterized in that the centers of acidity are formed by neutralization of charge deficiencies in the material with crystal matrix and plane and non-porous structure, after comminution of the material into smaller particles. than 40 μ, with cations of the elements in the groups Hib, IVb, VIb, VHb and VIII of the periodic system, preferably lanthanum, cerium, titanium and manganese. Process for preparing a catalyst as claimed in any one of claims 1-3, characterized in that the centers of acidity are formed by subjecting the material with crystal matrix and planar non-porous structure ion exchange with ammonium ions and subsequently heating to a temperature between 300 and 600 ° C, preferably 450 ° C for 10 hours.