US 5,393,717 AGranted

Regeneration of noble metal containing zeolite catalysts via partial removal of carbonaceous deposits

AssigneeMobil Oil Corporation

InventorsMinas R. Apelian, Anthony S. Fung, George H. Hatzikos, Clinton R. Kennedy, Chung-Hur Lee, Thomas R. Kiliany, Poh K. Ng, David A. Pappal

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Abstract

There is provided a process for regenerating a coked catalyst comprising a zeolite and a noble metal such as platinum. The process involves treating the coked catalyst under somewhat mild oxidation conditions, whereby a sufficient portion of the coke is removed from the catalyst to restore the hydrocarbon sorption properties of the zeolite component to the level observed in the non-coked form. Surprisingly, the original activity of the catalyst is substantially restored, even though a substantial amount of coke remains on the regenerated catalyst.

Claims25

Dependent claims

A process for regenerating a catalyst which has been deactivated during a hydrocarbon processing step by coke deposition thereon, said catalyst comprising a zeolite and a noble metal, said process also providing a means for selecting oxidation conditions for subsequent regenerations, said process comprising the steps of:

(a) contacting said catalyst with an oxygen containing gas under sufficient oxidation conditions to progressively remove said coke from said catalyst in a controlled manner;
(b) removing samples of said catalyst during the course of the progressive removal of coke achieved in accordance with step (a);
(c) measuring at least one of the following properties for each sample removed in accordance with step (b):
(1) the sorption rate of a probe molecule into said sample;
or (2) the amount of noble metal agglomeration in the sample;
(d) determining at least one of the following aspects of the process:
(1) the point during course of progressive removal of coke in step (a) when the maximum sorption rate of said probe molecule is reached for samples measured as per step (c);
or (2) the point during course of progressive removal of coke in step (a) when the rate of noble metal agglomeration increases significantly for samples measured in step (c);
(e) discontinuing the oxidation conditions of step (a);
and
(f) recovering said catalyst having coke removed therefrom.

8 more elements

A process for regenerating a catalyst which has been deactivated during a hydroisomerization step by coke deposition thereon, said catalyst comprising a zeolite and a noble metal, said process comprising the steps of:

(i) contacting said catalyst with an oxygen containing gas under sufficient oxidation conditions to progressively and only partially remove said coke from said catalyst;
(ii) discontinuing said oxidation conditions of step (i) at a point when the catalyst contains at least 1 weight percent of coke, as measured by elemental analysis of carbon, based upon the weight of the fresh catalyst;
and
(iii) recovering said catalyst containing at least 1 percent by weight of coke,
wherein said oxidation conditions employed in step (i) and said point which these conditions are discontinued as per step (ii) are determined by monitoring a test regeneration of a batch of said catalyst, said monitoring comprising the steps of:
(a) contacting a batch of said catalyst with an oxygen containing gas under sufficient oxidation conditions to progessively remove said coke from said catalyst;
(b) removing samples of said catalyst during the course of the progressive removal of coke achieved in accordance with step (a);
(c) measuring at least one of the following properties for each sample removed in accordance with step (b):
(1) the sorption rate of a probe molecule into said sample;
or (2) the amount of noble metal agglomeration in the sample;
(d) determining at least one of the following aspects of the test process:
(1) the point during course of progressive removal of coke in step (a) when the maximum sorption rate of said probe molecule is reached for samples measured as per step (c);
or (2) the point during course of progressive removal of coke in step (a) when the rate of noble metal agglomeration increases significantly for samples measured in step (c);
and
(e) using the determinations of step (d) to set the conditions of step (i) and the point at which these conditions are discontinued as per step (ii).

12 more elements

Dependencies are inferred from the claim text.