Mineral oils: processes and products – Chemical conversion of hydrocarbons – Reforming
Patent
1997-12-15
2000-04-04
Griffin, Walter D.
Mineral oils: processes and products
Chemical conversion of hydrocarbons
Reforming
208134, 208135, 208136, 208137, 208138, 585418, 585419, 585420, 585421, C10G 3506, C10G 35085
Patent
active
060456892
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention concerns a process for catalytic conversion of hydrocarbons into aromatic compounds, which can be used in particular for the reforming of gasolines and the production of aromatics.
More precisely, it concerns a process of this type using as catalyst a multi-functional catalyst with an alumina matrix.
2. Description of the Background
Catalytic reforming is a process which makes it possible to improve the octane number of the oil fractions and in particular of the heavy petroleum from distillation by conversion of n-paraffins and naphthenes into aromatic hydrocarbons.
The operation of catalytic reforming thus consists on the one hand of transforming C.sub.7 -C.sub.10 n-paraffins into aromatics and light paraffins and on the other hand C.sub.7 -C.sub.10 naphthenes into aromatics and light paraffins. These reactions are illustrated in particular by the conversion by dehydrogenation of cyclohexanes and the dehydroisomerization of alkylcyclopentanes to yield aromatics, methylcyclohexane yielding for example toluene, and also by conversion by cyclization of n-paraffins into aromatics, n-heptane for example yielding toluene.
During catalytic reforming, cracking reactions also take place of heavy n-paraffins into light paraffins leading in particular to C.sub.1 -C.sub.4 products essentially of propane and isobutane: these reactions are detrimental to the yield of reformed product.
Finally, there is also the formation of coke through condensation of aromatic nuclei forming a solid product, rich in carbon which is deposited on the catalyst.
The reforming catalysts are very sensitive, apart from coke, to various poisons which can reduce their activity: in particular sulphur, nitrogen, metals and water.
By being deposited on the surface of the catalyst, the coke brings about a loss in activity with time which leads to higher operating temperatures, a lower yield of reformed products, and a higher gas yield.
Because of this and considering the regeneration of the catalyst, the catalytic reforming process can be put into operation in two different ways: in a semi-regenerating or cyclic manner and in a continuous manner. In the first case, the process is carried out with a fixed bed, in the second with a mobile bed.
In the semi-regenerating process, to compensate for the loss of activity of the catalyst, the temperature is raised progressively and then the installation is stopped in order to carry out the regeneration of the catalyst by eliminating the coke. In cyclic reforming which in fact is a variation of the semi-regenerating process, the installation comprises several reactors in series and each is closed down in turn, the coke deposits are eliminated from the catalyst out of action and the catalyst regenerated while the other reactors continue to operate.
In continuous reforming, the reactors put into operation are moving-bed reactors operating at low pressure (less than 15 bars), which makes it possible to raise considerably the yields of reformed products and hydrogen by encouraging aromatization reactions instead of cracking, but on the other hand the formation of coke is greatly accelerated. The catalyst passes through the reactors then a regenerating action.
The processes for production of aromatics involve conversion reactions of the paraffinic and naphthenic hydrocarbons into aromatic compounds.
In these processes of conversion of hydrocarbons, bi-functional catalysts are generally used containing, for example, platinum and a support of chlorinated alumina, which associate the acidic function of the chlorinated alumina necessary for the reactions of isomerization of cyclopentanic naphthenes and the cyclization of paraffins with the dehydrogenating function of the platinum necessary for the dehydrogenation reactions. Catalysts of this type also including another metal such as rhenium, tin or lead have been described in U.S. Pat. No. 3,700,588 and U.S. Pat. No. 3,415,737.
As it can be seen above, the catalytic reforming processes can
REFERENCES:
patent: 3177136 (1965-04-01), Lang et al.
patent: 3915845 (1975-10-01), Antos
patent: 3972805 (1976-08-01), Wilhelm
patent: 3972806 (1976-08-01), Antos
patent: 4032587 (1977-06-01), Antos
patent: 4039477 (1977-08-01), Engelhard et al.
patent: 4165276 (1979-08-01), Antos
patent: 4190557 (1980-02-01), Antos
patent: 4290921 (1981-09-01), Antos
patent: 4966682 (1990-10-01), Baird, Jr. et al.
patent: 4966879 (1990-10-01), Baird, Jr.
patent: 4966880 (1990-10-01), Baird, Jr. et al.
patent: 4966881 (1990-10-01), Baird, Jr.
patent: 4968408 (1990-11-01), Baird, Jr.
patent: 5013704 (1991-05-01), Baird, Jr. et al.
patent: 5015614 (1991-05-01), Baird, Jr. et al.
patent: 5227357 (1993-07-01), Sun et al.
patent: 5665223 (1997-09-01), Bogdan
U.S. application No. 08/973,406, filed Dec. 15, 1997.
U.S. application No. 08/973,407, filed Dec. 15, 1997.
U.S. application No. 08/973,403, filed Dec. 15, 1997.
U.S. application No. 08/973,404, filed Dec. 15, 1997.
Alario Fabio
Deves Jean-Marie
Euzen Patrick
Griffin Walter D.
Institut Francais du Pe'trole
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