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US 6,294,498 B1Granted
Protection of catalysts by deposition of a protective layer
AssigneeEuropeenne de Retraitement de Catalyseurs Eurecat
InventorsJoan Darcissac, Franck Labruyere, Nilanjan Brahma, Pierre Dufrense
Life of this patent
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Abstract
Process for passivation of a heterogenous catalyst of refining reactions or hydrocarbon hydroconversion reactions, characterized in that the external surface of the particles of said heterogeneous catalyst is coated with a protective layer that is made of a particularly inert material which can be eliminated in the reaction zone under the conditions of the reaction.
Claims21
A process comprising:
- a) providing an inert coating material capable of functioning as a protective layer against oxygen and water and also being removable during refining or a hydrocarbon conversion reaction;
- b) applying said coating material on heterogeneous porous hydrocarbon conversion catalyst particles, said catalyst comprising a support and a pair of catalyst metals selected from the group consisting of CoMo, NiMo and NiW under conditions wherein the coating material is present in a quantity corresponding to less than about half of the catalyst pore volume;
- c) wherein said coating material is
- 1. atomized or dispersed on the catalyst by continuously stirring the catalyst and keeping it at a temperature that is below the crystallization point of the coating material, or
- 2. a solution that contains the material is atomized, sprayed or dispersed by continuously stirring the catalyst at a temperature that is above the boiling point of the solvent of said solution;
- and
- d) wherein the coating on the particle exhibits a concentration gradient which decreases from the periphery of the particle towards the center of the particle.
4 more elements
A process comprising:
- a) providing an inert coating material capable of functioning as a protective layer against oxygen and water and also being removable during refining or a hydrocarbon conversion reaction;
- b) applying said coating material on heterogeneous porous hydrocarbon conversion catalyst particles, said catalyst comprising a support and a pair of catalyst metals selected from the group consisting of CoMo, NiMo and NiW under conditions wherein the coating material is present in a quantity corresponding to less than 30% by weight relative to the catalyst;
- c) wherein said coating material is
- 1. atomized or dispersed on the catalyst by continuously stirring the catalyst and keeping it at a temperature that is below the crystallization point of the coating material, or
- 2. a solution that contains the material is atomized, sprayed or dispersed by continuously stirring the catalyst at a temperature that is above the boiling point of the solvent of said solution;
- and
- d) wherein the coating on the particle exhibits a concentration gradient which decreases from the periphery of the particle towards the center of the particle.
4 more elements
Dependencies are inferred from the claim text.