Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Plural component system comprising a - group i to iv metal...
Reexamination Certificate
1999-10-06
2002-02-26
Myers, Helane (Department: 1764)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Plural component system comprising a - group i to iv metal...
C502S234000, C502S334000, C502S203000, C502S300000, C502S303000
Reexamination Certificate
active
06350715
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention pertains to a process for the preparation of an activated catalyst composition, in particular an isomerisation catalyst using an inert gas in the absence of hydrogen, to the use of this activated catalyst composition for the conversion of a hydrocarbon feedstock, in particular for isomerisation, and to an activated catalyst composition obtainable by said process.
2. Description of the Prior Art
The preparation of activated isomerisation catalysts is known in the art. U.S. Pat. No. 5,654,254 describes a process in which a catalyst comprising a Group VII metal, a hydrocarbon-substituted aluminum chloride, and an alumina carrier is activated by first heating the catalyst in an inert gas atmosphere at a temperature of about 630°-750° C. and subsequently treating the resulting material with a hydrogen chloride-containing gas at a temperature of 630°-750° C. and cooling the resulting mixture in an inert gas atmosphere to ambient temperature.
The gas composition thus is changed twice in the process disclosed in U.S. Pat. No. 5,654,254, viz. from inert gas to a mixture of halogen-containing gas and inert gas and from this mixture to inert gas. Furthermore, if a halogen-containing gas is applied, excess halogen-containing gas which has not reacted with the catalyst during the activation step has to be removed via, e.g., an adsorption tower. The process of U.S. Pat. No. 5,654,254 thus is technically quite complicated. It is therefore an object of the present invention to obtain a technically simple activation process.
The halogen-containing gas is applied in U.S. Pat. No. 5,654,254 at a temperature above 630° C. At such high temperatures, halogen-containing gases have a highly corrosive effect on the process equipment. It is therefore a further object of the present invention to reduce or avoid the corrosive effect of the halogen-containing gas during the activation process.
Another reference dealing with the activation of an isomerisation catalyst optionally in the presence of a halogen-containing gas is WO 9719752. In the process described in this reference, a catalyst composition comprising a Group VIII noble metal and a hydrocarbon-substituted aluminum compound on an alumina carrier containing up to 20 wt % of other components is activated by being contacted with a hydrogen-containing gas at a temperature above 500° C., with the proviso that at least when the hydrocarbon-substituted aluminum compound present in the catalyst composition does not comprise halogen, the catalyst composition to be activated is contacted with a halogen-containing gas either prior to or during the treatment with the hydrogen-containing gas. However, though it is possible to prepare activated isomerisation catalysts with the process of this reference, there is still a need to further increase the activity of these catalysts in order to ensure highly effective hydrocarbon conversion. It is therefore another object of the present invention to prepare catalysts with high activity in hydrocarbon conversion reactions, such as the isomerisation of hydrocarbons.
Like WO 9719752, EP 0409679 deals with an activation process in which preferably hydrogen is present during the activation step and which is carried out at a temperature of 300°-475° C.
Further, GB 952,348 discloses the activation of a catalyst composition comprising a Group VIII noble metal, a non-halide hydrocarbon-substituted aluminum compound, and an alumina carrier, wherein the activation is carried out by contacting the catalyst composition with a mixture of a halogen-containing gas and an inert gas at a temperature below 260° C. (500° F.) and optionally further contacting the resulting catalyst composition with hydrogen or nitrogen, preferably hydrogen, at a temperature of 204°-371° C. (400°-700° F.), preferably 232°-343° C. (450°-650° F.).
Finally, U.S. Pat. No. 5,707,921 discloses an activation process wherein first a high temperature treatment in inert gas is carried out, subsequently a halogen-containing gas in admixture with hydrogen is applied, and finally, the resulting catalyst is cooled to room temperature in an inert gas.
Surprisingly, it has been found that the above problems can be solved and objectives achieved by the unique process of the present invention.
SUMMARY OF THE INVENTION
Accordingly, in one embodiment, the present invention is a process for preparing an activated catalyst composition which process comprises the sequential steps of
(a) contacting a catalyst composition comprising a Group VIII noble metal and a hydrocarbon-substituted aluminum compound on an alumina carrier containing up to 20 wt % of other components with an inert gas in the absence of hydrogen at a temperature above 400° C., wherein at least when the hydrocarbon-substituted aluminum compound is a non-halide hydrocarbon-substituted aluminum compound, the catalyst composition is contacted with a halogen-containing gas either prior to the treatment with the inert gas or during the treatment with the inert gas,
(b) cooling down to ambient temperature in an inert gas optionally containing hydrogen or containing, at a temperature below 400° C., a halogen-containing gas; or if a halogen-containing gas is present during the treatment with the inert gas, alternatively cooling down in a mixture of an inert gas, a halogen-containing gas, and, optionally, hydrogen.
In a second embodiment, the present invention comprises an activated catalyst composition obtained by the process of the first embodiment.
In a third embodiment, the present invention comprises a process for using the activated catalyst composition of the second embodiment.
Other objectives and embodiments of the present invention encompass details about catalyst compositions, reactants and reaction conditions all of which are hereinafter disclosed in the following discussion of each of the facets of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
It has been found in the present invention that when activation step (a) is carried out in the presence of the inert gas and in the absence of a halogen-containing gas, the activity of the resulting catalyst is comparable to that obtained according to the process of U.S. Pat. No. 5,654,254, where an additional high-temperature halogen treatment is carried out subsequent to the treatment with the inert gas. Thus, it is possible in the process of the present invention to avoid such a high-temperature halogen treatment, while maintaining the catalyst's high activity.
Surprisingly, it has further been found in the present invention that when the halogen-containing gas is applied prior to the treatment with the inert gas, the activity of the resulting catalyst is significantly higher than when a halogen-containing gas is applied subsequent to the treatment with the inert gas as disclosed in U.S. Pat. No. 5,654,254.
Furthermore, it has surprisingly been found in the present invention that when steps (a) and (b) as described above are both carried out in the presence of a mixture of the inert gas and the halogen-containing gas, the activity of the resulting catalyst is significantly higher than that of a catalyst according to U.S. Pat. No. 5,654,254. In other words, a catalyst with an even higher activity can be obtained while, in contrast to U.S. Pat. No. 5,654,254, the gas composition remains unchanged. Thus the undesired corrosive effect resulting from the high-temperature halogen treatment in this embodiment of the present invention is compensated by the technical simplicity of the process and by a higher catalytic activity than results from the process of U.S. Pat. No. 5,654,254.
It must be noted that in the case of the isomerisation of hydrocarbon feeds, generally small amounts of halogen compounds are present in the hydrocarbon feed. These isomerisation processes are generally carried out at temperatures below 330° C. Consequently, the corrosive effect of the halogen compound in this case is much smaller than when the halogen compound is applied at high temperatures of, e.g., abov
Morris Louis A.
Myers Helane
Total Raffinage Distribution , S.A.
LandOfFree
Preparation of an activated catalyst using an inert gas in... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Preparation of an activated catalyst using an inert gas in..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Preparation of an activated catalyst using an inert gas in... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2977891