Disclosed are a process and system that are capable of performing selective hydrogenation on aromatic fractions by configuring a catalyst bed through staged loading of a plurality of hydrogenation catalysts with different catalytic properties, or configuring a catalyst system in which a plurality of hydrogenation catalysts are arranged using a plurality of reactors in such a way as to be equivalent with the staged loading, and as a result, are capable of suppressing aromatic loss while improving the selective removal of unsaturated hydrocarbons in the aromatic fraction and durability compared to the case of using a single catalyst.

Disclosed are a process and system that are capable of performing selective hydrogenation on aromatic fractions by configuring a catalyst bed through staged loading of a plurality of hydrogenation catalysts with different catalytic properties, or configuring a catalyst system in which a plurality of hydrogenation catalysts are arranged using a plurality of reactors in such a way as to be equivalent with the staged loading, and as a result, are capable of suppressing aromatic loss while improving the selective removal of unsaturated hydrocarbons in the aromatic fraction and durability compared to the case of using a single catalyst.

A process for activating a hydrogenation catalyst comprising nickel to produce a selective hydrogenation catalyst, comprising contacting the hydrogenation catalyst with a mixed gas comprising and hydrogen sulfide and periodically increasing the temperature of the mixed gas in increments until the mixed gas reaches a temperature that facilities the efficient catalytic hydrogenation of both acetylene and butadiene by the modified catalyst, while the modified catalyst is simultaneously characterized by low selectivity for the hydrogenation of ethylene. The disclosure further claims a process that utilizes the modified catalyst to selectively hydrogenate acetylene and butadiene contaminants in a raw light olefin stream produced by thermal cracking, thereby extending the useful catalytic lifespan of a downstream oligomerization catalyst that converts the light olefins stream to a liquid transportation fuel, or a blend stock thereof.

Catalyst comprising a nickel-based active phase and an alumina support, characterized in that: the nickel is distributed both on a crust at the periphery of the support, and in the core of the support, the thickness of said crust being between 2% and 15% of the diameter of the catalyst; the nickel density ratio between the crust and the core is strictly greater than 3; said crust comprises between 40% and 80% by weight of nickel element relative to the total weight of nickel contained in the catalyst.

Catalyst comprising nickel and sulfur on an alumina support, said catalyst being characterized in that: the nickel is distributed both on a crust at the periphery of the support, and in the core of the support, the thickness of said crust being between 2% and 15% of the diameter of the catalyst; the nickel density ratio between the crust and the core is strictly greater than 3; said crust comprises more than 25% by weight of nickel element relative to the total weight of nickel contained in the catalyst, the size of the nickel particles in the catalyst, measured in oxide form, is between 7 and 25 nm.

Catalyst comprising nickel and sulfur on an alumina support, said catalyst being characterized in that: the nickel is distributed both on a crust at the periphery of the support, and in the core of the support, the thickness of said crust being between 2% and 15% of the diameter of the catalyst; the nickel density ratio between the crust and the core is strictly greater than 3; said crust comprises more than 25% by weight of nickel element relative to the total weight of nickel contained in the catalyst, the size of the nickel particles in the catalyst, measured in oxide form, is between 7 and 25 nm.

A process for preparing a selective hydrogenation catalyst comprising nickel, copper and a support comprising at least one refractory oxide, comprising the following steps: bringing the support into contact with a solution containing at least one copper precursor and one nickel precursor; drying the catalyst precursor at a temperature of less than 250° C.; reducing the catalyst precursor by bringing said precursor into contact with a reducing gas at a temperature of between 150° C. and 250° C.; bringing the catalyst precursor into contact with a solution comprising a nickel precursor; a step of drying the catalyst precursor at a temperature of less than 250° C.; reducing the catalyst precursor by bringing said precursor into contact with a reducing gas at a temperature of between 150° C. and 250° C.

Disclosed are a process and system that are capable of performing selective hydrogenation on aromatic fractions by configuring a catalyst bed through staged loading of a plurality of hydrogenation catalysts with different catalytic properties, or configuring a catalyst system in which a plurality of hydrogenation catalysts are arranged using a plurality of reactors in such a way as to be equivalent with the staged loading, and as a result, are capable of suppressing aromatic loss while improving the selective removal of unsaturated hydrocarbons in the aromatic fraction and durability compared to the case of using a single catalyst.

A process for the hydrogenation of a polyunsaturated compound contained in a hydrocarbon feedstock in the presence of a catalyst comprising a porous support and an active phase comprising a group VIII metal, said catalyst being prepared according to the following steps: a) an organic compound containing oxygen and/or nitrogen, but not comprising sulfur, is added to the porous support; b) said porous support is brought into contact with a solution containing a salt of a precursor of the active phase; c) the porous support obtained at the end of step b) is dried;
characterized in that step a) is carried out before or after steps b) and c) and is carried out by bringing together said porous support and said organic compound under conditions of temperature, pressure and duration such that a fraction of said organic compound is transferred in the gaseous state to the porous support.

A process for the hydrogenation of a polyunsaturated compound contained in a hydrocarbon feedstock in the presence of a catalyst comprising a porous support and an active phase comprising a group VIII metal, said catalyst being prepared according to the following steps: a) an organic compound containing oxygen and/or nitrogen, but not comprising sulfur, is added to the porous support; b) said porous support is brought into contact with a solution containing a salt of a precursor of the active phase; c) the porous support obtained at the end of step b) is dried;
characterized in that step a) is carried out before or after steps b) and c) and is carried out by bringing together said porous support and said organic compound under conditions of temperature, pressure and duration such that a fraction of said organic compound is transferred in the gaseous state to the porous support.