Abstract: The invention provides a process for limiting self-heating of activated particle catalysts wherein the catalyst particles are placed in motion inside a hot gas flow that passes through them and a liquid composition containing one or several film forming polymer(s) is pulverized onto the particles in motion until a protective layer is obtained on the surface of said particles containing said film forming polymer and having an average thickness of less than or equal to 20 ?m. The invention also provides the use of this process to reduce the quantities of toxic gases that may be emitted by the activated catalysts, as well as an activated catalyst for the hydroconversion of hydrocarbons covered with a continuous protective layer that are obtained by this process.

Abstract: The invention provides a process for limiting self heating of activated particle catalysts wherein the catalyst particles are placed in motion inside a hot gas flow that passes through them and a liquid composition containing one or several film forming polymer(s) is pulverized onto the particles in motion until a protective layer is obtained on the surface of said particles containing said film forming polymer and having an average thickness of less than or equal to 20 ?m. The invention also provides the use of this process to reduce the quantities of toxic gases that may be emitted by the activated catalysts, as well as an activated catalyst for the hydroconversion of hydrocarbons covered with a continuous protective layer that are obtained by this process.

Abstract: A process for ex-situ treatment of a catalyst that contains at least one hydrogenating phase, and at least one amorphous silica-alumina or a zeolite that contains acid. The process includes: a stage for introducing nitrogen by contact at a temperature that is less than 100° C., with at least one basic nitrogen-containing compound that is ammonia or a compound that can be decomposed into ammonia, the compound being introduced at a rate of 0.5-10% by weight (expressed in terms of N), and a sulfurization/activation stage with a gas that contains hydrogen and hydrogen sulfide at a temperature of at least 250° C., with this stage being carried out before or after the stage for introducing said nitrogen-containing compound, and optionally drying the catalyst that is obtained. This treatment allows a rapid, effective start-up on the hydrocracking unit.

Abstract: The present invention relates to a method for preparing a supported metal catalyst for the selective hydrogenation of unsaturated hydrocarbons, characterized in that it comprises the following steps: a) electroplating a layer of nickel on a metallic support, and then b) electroplating a top layer of platinum and/or palladium. The present invention also relates to the supported metal catalyst obtained by this process, and the use thereof in hydrogenation reactions of unsaturated hydrocarbons, in particular for the selective hydrogenation of light olefins.

Abstract: The invention provides a process for limiting self heating of activated particle catalysts wherein the catalyst particles are placed in motion inside a hot gas flow that passes through them and a liquid composition containing one or several film forming polymer(s) is pulverized onto the particles in motion until a protective layer is obtained on the surface of said particles containing said film forming polymer and having an average thickness of less than or equal to 20 ?m. The invention also provides the use of this process to reduce the quantities of toxic gases that may be emitted by the activated catalysts, as well as an activated catalyst for the hydroconversion of hydrocarbons covered with a continuous protective layer that are obtained by this process.

Abstract: The present invention relates to a method for preparing a supported metal catalyst for the selective hydrogenation of unsaturated hydrocarbons, characterized in that it comprises the following steps: a) electroplating a layer of nickel on a metallic support, and then b) electroplating a top layer of platinum and/or palladium. The present invention also relates to the supported metal catalyst obtained by this process, and the use thereof in hydrogenation reactions of unsaturated hydrocarbons, in particular for the selective hydrogenation of light olefins.

Abstract: The invention relates to a process for ex-situ treatment of a catalyst that contains at least one hydrogenating phase, and at least one amorphous silica-alumina or a zeolite that contains acid sites, whereby said process comprises: A stage for introducing nitrogen by contact at a temperature that is less than 100° C., with at least one basic nitrogen-containing compound that is ammonia or a compound that can be decomposed into ammonia, with said compound being introduced at a rate of 0.5-10% by weight (expressed in terms of N), and A sulfurization/activation stage with a gas that contains hydrogen and hydrogen sulfide at a temperature of at least 250° C., with this stage being carried out before or after the stage for introducing said nitrogen-containing compound, and the catalyst that is obtained is optionally dried. This treatment allows a rapid, effective start-up on the hydrocracking unit.