DE4206270A1 - CRACKING OF HYDROCARBON OR TARGED BATCHES, THEIR STARTING AND ENDING POINTS ARE BETWEEN 50 AND 220 (DEGREES) C. - Google Patents

Description

The present invention relates to use of a conversion catalyst in coal cracking batches containing hydrogen or tar containing a zeolite y which is usually amorphous or poorly crystallized matrix.

The present invention relates to the cracking process of tar-containing fractions, their start and end boiling points are between 50 and 220 ° C, especially from naphthenic compounds and / or paraffins are sufficient Fractions such as light petroleum from the hydro crack to a substantial amount of compounds that 3 and / or have 4 carbon atoms in their molecule produce, and especially propylene, butylene and Isobutane.

One understands naphthenic connections and / or Paraffins are rich in hydrocarbons or tars Fractions petroleum fractions, the total content of naphthe African compounds and / or paraffins (i.e. the sum of the Content of naphthenic compounds and the content of Paraffins) greater than 50% by weight, usually at least Is 80% by weight. The content of these fractions each Paraffins and naphthenes are between 25 and 45%, preferably between 35 and 45% and between 50 and 65%, preferably between 50 and 60%.

The petroleum fractions with start and end boiling points between 50 and 220 ° C, and especially those rich in naphthenic compounds and / or paraffins, such as Example own the light petroleum from the hydrocrack usually very moderate combustion properties (bad Octane values). The primary way to convert this to naphthenic compounds and / or paraffins are sufficient for 50 up to 220 ° C petroleum fractions is catalytic reforming,  which leads to aromatic forms, the content of which in the Gasoline, in the medium or long term, is doomed itself to diminish very considerably.

In certain, special cases, there is an important need for light hydrocarbons which have 2 to 4 carbon atoms in their molecule, or for certain of these, such as C ₃ and / or C ₄ hydrocarbons, and very particularly for propylene, butylene and isobutane.

Obtaining a substantial amount of isobutane is particularly interesting in the case where the refiner establishes an alkylation unit in which this compound is used as an alkylating agent, for example C ₃ -C ₄ fractions containing olefins for the purpose of a to produce an additional amount of high octane gasoline.

Obtaining propylene is particular in certain Developing countries where there is significant Shows need for this product.

The catalytic cracking process of naphthenic Compounds and / or paraffins range from 50 to 220 ° C Fractions, such as light petroleum from the Hydrocracking may have such a need to some extent meet, on the condition, in particular, the catalyst to adapt for the purpose of this production.

An effective way, the catalyst, the one Zeolites Y and one usually amorphous or poor contains crystallized matrix, is to adapt the rare earth content of the zeolite Y, which in the Catalyst is included to adapt in a new form like this:

• 1) Cracking of the hydrocarbon or tar-containing molecules from the family of naphthenes and paraffins to coals Hydrogen with 3 and / or 4 carbon atoms, esp special to propylene, butylene and isobutane;
• 2) Limit the formation of aromatic compounds naphthenic compounds by reaction of hydrogen Transfer between these naphthenes and those from the Cracks of these same naphthenes and paraffins Olefins.

The US-PS 49 69 987 describes the conversion of an naphthe African compounds and paraffins are rich in hydrocarbons Fractions containing substances or tar. The described Catalysts are made from zeolites and matrices. The Zeolites described are particularly by values of Characterized compulsory indices, like this one in the "Journal of Catalysis, 67, pages 218-222, 1981 "between about 1 and about 12 lying.

The catalyst used in the present invention is is known and is generally used for the catalytic cracking of conventional hydrocarbon or tarry fraction nen, d. H. with start and end boiling points between 300 and 700 ° C are used. This is, for example, in the EP-A-01 24 716.

The significant research carried out by the applicant on numerous zeolites has led to the finding that, surprisingly, the use of a catalyst in the cracking of hydrocarbon or tar-containing fractions with starting and ending boiling points between 50 and 220 ° C, the a zeolite Y (compulsory index equal to 0.4 according to the "Journal of Catalysis, 67, pages 218-222, 1981"), which contains a rare earth content, expressed in% by weight of rare earth oxides T ₂ O ₃ in with respect to the zeolite Y (T is a rare earth of atomic number 57 to 71 inclusive), less than 10%, preferably less than 6%, such that the parameter of the elemental mesh size of the zeolite Y of the catalyst in equilibrium state within the catalytic cracking unit smaller than 2.435 nm (1 nm = 10 ^-9 m) and preferably smaller than 2.430 nm, enables the production of C3 and / or C4 compounds Settings to the maximum and the production of undesirable aromatic compounds to the minimum.

The catalyst used in the present invention contains a zeolite Y of the faujasite structure (zeolite Molecular Sieves Structure, chemistry and use, D.W. Breck, J. Willey and Sons, 1973). Among the zeolites Y that one can be used, one is preferably a stabilized Use zeolites Y, usually ultra stable or USY called, either in partially exchanged form with Cations of rare earths with atomic numbers 57 to 71 finally, so that its rare earth content, out depresses in% by weight of rare earth oxides than 10%, preferably less than 6%, or in Hydrogen form is present. The rare earth content of the in Zeolites Y used in the invention is therefore such chosen that the zeolite Y of the catalyst in the same weight condition within the catalytic cracking unit a parameter value of the elementary mesh size character is less than 2.435 nm and preferably is characterized smaller than 2.430 nm.

The catalyst used in the present invention also contains at least one, usually amorphous or poorly crystallized matrix selected from, for example the group by silicon oxide, aluminum oxide, magnesium oxide, silicon oxide-aluminum oxide mixtures, silicon oxide Magnesium oxide mixtures and clay is formed.

So the catalyst mentioned contains:

• a) about 25 to 99, preferably about 40 to 95 and in a particularly advantageous manner 50 to 85% by weight at least one matrix,
• b) about 1 to 75, preferably about 5 to 60 and in particularly advantageously 15 to 50% by weight at least of a zeolite Y with faujasite structure, the content of Rare earths expressed in% by weight of oxides Rare earths related to zeolite Y, less than 10%, is preferably less than 6%.

The catalyst, as described above, can be used on all be produced in a manner known to the person skilled in the art.

For example, the catalyst can be mixed mechanically first product, the zeolite Y and a matrix contains. This mechanical mixing takes place usually dry, preferably by atomization ("spray Drying "), for example at a temperature of about 100 up to 500 ° C, usually for 0.1 to 30 seconds. After The product obtained can also be dried by atomization about 1 to 30% by weight of volatile substances (Water and ammonia) included.

The catalytic cracking process according to the invention, the is used to work on naphthenic compounds and / or Paraffins rich in hydrocarbons or tars Fractions such as light petroleum from the hydro cracking, selectively implementing is usually either in a fluid bed (like the FCC or "Fluid Catalytic Cracking") or carried out in a fluid bed (like the TCC), in which the catalyst according to the invention constantly between the reactor zone and the regenerator circulates where it passes through Presence of an oxygen-containing gas from combustion coke is exempted. One understands naphthenic Compounds and / or paraffins are hydrocarbon-rich or tar-containing fractions such hydrocarbon or tar-containing fractions, their total naphthenic content  Compounds and / or paraffins (i.e. the sum of the salary naphthenic compounds and their content Paraffins) at least 50% by weight, usually at least Is 80% by weight.

The general conditions of catalytic cracking reactions are well known in detail to be here under the lying invention not to be repeated (see Example, the US-PS 32 93 192, US-PS 34 49 070, US-PS 36 07 043 and US-PS 44 15 438).

However, the goal is to get the greatest possible amount of gas-containing hydrocarbons with 3 and 4 carbon atoms in their molecule, and especially propylene, butylene and Isobutane, often beneficial to produce temperatures in the Use reaction zone that is between 400 and 800 ° C, preferably between 500 and 700 ° C. It can also weight analysis ratio of the weight of the catalyst to the weight of the batch advantageously between 3 and 15 lie.

The following examples illustrate the invention, without restricting the protection area.

EXAMPLE 1 Catalyst in accordance with the invention and test conditions

The cracking catalyst is here by weight analysis table content of zeolite Y close to 35% and by a weight analytical content of matrix of 65% rized. The weight analysis content of rare earths of this zeolite Y, expressed in% by weight of oxides Rare earth with respect to the zeolite Y is approximately 2% and its parameter is the elementary mesh size 2.460 nm.

This catalyst is designated CAT ₁ .

The catalyst CAT ₁ is subjected to a hydrothermal treatment under 100% steam at 700 ° C and for a period of 15 hours until the aging to which the catalyst in the catalytic cracking unit is exposed is simulated.

The crystal parameter of the zeolite Y of the catalyst CAT ₁ is 2.428 nm after the hydrothermal treatment.

The aged catalyst is then introduced into the reactor of a MAT catalytic test microunit. The ability of the catalyst to convert a batch rich in naphthenic compounds and paraffins is then determined based on the following conditions:
Mass of the catalyst = 5 g
Weight analysis ratio catalyst / batch = K / O = 6.2 for CAT ₁
Duration of loading the batch = 9 seconds
Temperatures = 530, 560 and 600 ° C.

The composition (in% by weight) of the batch used is shown in Table 1.  

Table 1

EXAMPLE 2 Not consistent with the invention catalyst

The cracking catalyst is here by weight analysis table content of zeolite Y of close to 20% and a weight analysis matrix content of close to 80% characterized. The rare earth content of this Zeolites Y, expressed in% by weight of oxides Rare earth with respect to the zeolite Y is approximately 15.6% and its parameter is the elementary mesh size 2.468 nm.

This catalyst is designated CAT ₂ .

The catalyst CAT ₂ is subjected to a hydrothermal treatment under 100% steam at 730 ° C. and for a period of 15 hours until the aging to which the catalyst in the catalytic cracking unit is exposed is simulated.

The crystal parameter of the zeolite Y of the catalyst CAT ₂ is 2.436 nm after the hydrothermal treatment.

The aged catalyst is then introduced into the reactor of a MAT catalytic test microunit. The ability of the catalyst to convert a batch rich in naphthenic compounds and paraffins is then determined using the same conditions as those used for the CAT ₁ catalyst described in Example 1, except for the fact that the weight is analytical Catalyst / batch ratio (= K / O) here is 10. The two catalysts were examined under two different K / O ratios in such a way that the zeolite / batch weight analysis ratio was the same.

EXAMPLE 3 Comparison of the catalytic performance of the CAT ₁ and CAT ₂ catalysts

The results are summarized in Table 2.

These results show very clearly that the yields, starting from the same hydrocarbon or tar-containing batch and the same catalytic test conditions, from isobutane and from C ₃ - and C ₄ compounds are significantly improved when a catalyst with a zeolite Y used, whose rare earth content, expressed in% by weight with respect to the zeolite Y, is less than 10%, preferably less than 6%.

Table 2

EXAMPLE 4 Comparison of the catalytic performance of the Catalyst according to the invention in a conventional Batch and a 50 to 220 ° C fraction

The catalyst CAT ₁ of Example 1 according to the invention is used.

The ability of the catalyst to convert a batch is determined based on the following conditions:
Mass of the catalyst: 5 g
Weight analysis ratio catalyst / batch: K / O = 6.2
Batch loading time: 9 seconds
Temperature: 530 ° C.

The MAT test is carried out on a conventional batch (Initial fraction of a raw Kirkuk with a start boiling point higher than 350 ° C), then at a 50 to 220 ° C Fraction (whose composition is shown in Table 1) by.

The results are summarized in Table 3.

Table 3

It is observed that the conservation of isobutane in the case of Use according to the invention is significantly improved.

Claims (7)

1. Catalytic cracking process of a batch containing hydrocarbons, in particular tar, the start and end boiling points of which are between 50 and 220 ° C, characterized in that this is carried out in the presence of a catalyst, comprising:

• a) about 25 to 99% by weight of at least one matrix,
• b) about 1 to 75% by weight of at least one zeolite Y having a faujasite structure, the content of rare earths, expressed in% by weight of rare earth oxides with respect to the zeolite Y, being less than 10%.

2. The method according to claim 1, characterized in that the catalyst

• a) about 40 to 95% by weight of a matrix,
• b) contains about 5 to 60% by weight of said zeolite Y.

3. The method according to any one of claims 1 and 2, characterized in that said zeolite Y has a Rare earth content expressed in% by weight of Rare earth oxides related to zeolite Y, from owns less than 6%. 4. The method according to any one of claims 1 to 3, characterized in that the matrix from the group which is selected by silicon oxide, aluminum oxide, Magnesium oxide, silicon oxide-aluminum oxide mixtures, Silicon oxide-magnesium oxide mixtures and clay is formed. 5. The method according to any one of claims 1 to 4, characterized in that said batch is rich in is naphthenic compounds and / or paraffins.   6. The method according to any one of claims 1 to 5, characterized in that the working temperature between 400 and 800 ° C is. 7. The method according to any one of claims 1 to 6, characterized in that the weight analysis Ratio of the weight of the catalyst to the weight of the batch is between 3 and 15.