FR2658507A2 - Use of an aluminosilicate-type catalyst containing gallium in the aromatisation of light petroleum fractions (cuts) largely containing hydrocarbons containing 2 carbon atoms per molecule - Google Patents

Abstract

The invention relates to the use of a zeolite catalyst in the aromatisation of a light C2 gas fraction in the presence of olefins. The aromatisation process is carried out in at least one moving-bed reactor, in the presence of a catalyst in the bead form, the catalyst generally having the following composition expressed by weight: a) 0.01 to 10% by weight of gallium b) 0.1 to 99.49% of matrix c) 0.5 to 99.89% of a zeolite with the following approximate chemical formula: M2/nO.Al2O3.xSiO2 where M represents a proton and/or a metal cation, n is the valency of the said cation, x is a number between 12 and 1000, the said zeolite having am MFI structure and additionally being synthesised in fluoride medium and having a fluorine content of between 0.01 and 1.5% by weight incorporated during the synthesis.

Description

 The present addition relates to the use of a catalyst of the aluminosilicate type comprising a zeolite with an MFI structure, synthesized in a fluoride medium, containing silicon, aluminum, and gallium, in the aromatization reactions of light cuts containing in mainly 2 carbon atoms per molecule in the presence of olefins, and inert gases such as methane, nitrogen, carbon monoxide and hydrogen. The aromatization is carried out in at least one reactor with a circulating catalyst bed. It is then advisable for the catalyst to be used in the form of beads.

The present addition also relates to the use in aromatization of cuts with a high C2 content (ethane and ethylene) of a catalyst of the aluminosilicate type of the following composition expressed by weight a) 0.01 to 10% by weight of gallium, preferably 0.3 to 7%, b) 0.1 to 99.49% (and preferably 10 to 40%) of a chosen matrix
in the group formed by alumina, silica, magnesia, a
clay and any combination of at least two of the above compounds
and c) 0.50 to 99.89% (and preferably 60 to 90%) of a zeolite
synthetic in fluoride medium with approximate chemical formula
usually the following
M2 / nO, A1203, xSi02, where
M represents a proton and / or a metal cation
n is the valence of the cation
x is a number between 12 and 1000 (molar ratio
Si02 / A1203), the zeolite having a fluorine content of between
0.01 and 1.5% by weight, preferably 0.1 to 1% by weight, fluorine
being incorporated during the synthesis, the so-called zeolite being also
characterized by an X-ray diffraction diagram presented in the
Table 1 of the main patent.

 Using the techniques of the present addition, very stable aromatics selectivities have been found under long operating conditions of the order of 500 hours or more depending on the operating conditions used.

Claims (3)

1) Use according to claim 1 of the main patent, for  the flavoring of a cup consisting for the most part  of hydrocarbons with 2 carbon atoms per molecule of a  catalyst containing by weight  a) 0.01 to 10% of gallium,  b) 0.1 to 99.49% of a matrix chosen from the group made up  by alumina, silica, magnesia, clay and all  combination of at least two of the above-mentioned compounds,  c) 0.50 to 99.89% of a zeolite synthesized in a fluoride medium,  of SiO / Al 0 molar ratio between 12 and 1000, said  2 23  zeolite further having a fluorine content of between  0.01 and 1.5% by weight, the fluorine being incorporated during the  synthesis of the so-called zeolite, which has a diagram of  X-ray diffraction in accordance with Table 1 of the main patent. 2) Use according to claim 1 of a catalyst containing  10 to 40% of matrix and 60 to 90% of zeolite. 3) Use according to claim 1 of a catalyst in the form  of beads, the flavoring being carried out in at least one  circulating catalyst bed reactor.