Provided is a hydrophilic phosphorus ligand with the structure of formula 1. ##STR00001##
X is ##STR00002##
Y is ##STR00003##
m is an integer from 1 to 20, A independently is *—O(CH.sub.2).sub.n—, n is an integer from 1 to 5, *— is a bond close to triphenylphosphine, and — is a bond away from triphenylphosphine.

Provided is a hydrophilic phosphorus ligand with the structure of formula 1. ##STR00001##
X is ##STR00002##
Y is ##STR00003##
m is an integer from 1 to 20, A independently is *—O(CH.sub.2).sub.n—, n is an integer from 1 to 5, *— is a bond close to triphenylphosphine, and — is a bond away from triphenylphosphine.

The present invention addresses to a method of maintaining the activity of pre-reform catalysts in hydrogen production units, in order to avoid deactivation by oxidation or coke deposition of pre-reform catalysts in the absence of hydrogen in the feed consisting of hydrocarbon and water vapor.

The present invention addresses to a method of maintaining the activity of pre-reform catalysts in hydrogen production units, in order to avoid deactivation by oxidation or coke deposition of pre-reform catalysts in the absence of hydrogen in the feed consisting of hydrocarbon and water vapor.

In accordance with one or more embodiments of the present disclosure, a method for regenerating and rejuvenating a spent catalyst comprising coke and contaminant metals includes washing the spent catalyst with a solvent; drying, at least partially, the spent catalyst; partially combusting the spent catalyst to remove a portion of the coke, thereby producing a partially de-coked catalyst; acid washing the partially de-coked catalyst; and fully combusting the partially de-coked catalyst, thereby producing a regenerated and rejuvenated catalyst. The portion of the coke removed during the partial combustion is greater than or equal to 10 wt. % and less than or equal to 60 wt. %. No rare earth elements are added to the partially de-coked catalyst prior to the fully combusting the partially de-coked catalyst.

In accordance with one or more embodiments of the present disclosure, a method for regenerating and rejuvenating a spent catalyst comprising coke and contaminant metals includes washing the spent catalyst with a solvent; drying, at least partially, the spent catalyst; partially combusting the spent catalyst to remove a portion of the coke, thereby producing a partially de-coked catalyst; acid washing the partially de-coked catalyst; and fully combusting the partially de-coked catalyst, thereby producing a regenerated and rejuvenated catalyst. The portion of the coke removed during the partial combustion is greater than or equal to 10 wt. % and less than or equal to 60 wt. %. No rare earth elements are added to the partially de-coked catalyst prior to the fully combusting the partially de-coked catalyst.

The invention concerns a method for rejuvenating an at least partially used catalyst originating from a hydroprocessing and/or hydrocracking process, the at least partially used catalyst being derived from a fresh catalyst comprising at least one group VIII metal (in particular, Co), at least one group VIB metal (in particular, Mo), an oxide support, and optionally phosphorus, the method comprising the steps: a) regenerating the at least partially used catalyst in a gas stream containing oxygen at a temperature between 300° C. and 550° C. so as to obtain a regenerated catalyst, b) then placing the regenerated catalyst in contact with phosphoric acid and an organic acid, each having acidity constant pKa greater than 1.5, c) performing a drying step at a temperature less than 200° C. without subsequently calcining it, so as to obtain a rejuvenated catalyst.

The invention concerns a method for rejuvenating an at least partially used catalyst originating from a hydroprocessing and/or hydrocracking process, the at least partially used catalyst being derived from a fresh catalyst comprising at least one group VIII metal (in particular, Co), at least one group VIB metal (in particular, Mo), an oxide support, and optionally phosphorus, the method comprising the steps: a) regenerating the at least partially used catalyst in a gas stream containing oxygen at a temperature between 300° C. and 550° C. so as to obtain a regenerated catalyst, b) then placing the regenerated catalyst in contact with phosphoric acid and an organic acid, each having acidity constant pKa greater than 1.5, c) performing a drying step at a temperature less than 200° C. without subsequently calcining it, so as to obtain a rejuvenated catalyst.

The invention relates to a process for the rejuvenation of an at least partially spent catalyst resulting from a hydrotreating process, said at least partially spent catalyst resulting from a fresh catalyst comprising a metal from group VIII, a metal from group VIb, an oxide support, and optionally phosphorus, said at least partially spent catalyst additionally comprising carbon in a content of between 2% and 20% by weight, with respect to the total weight of the at least partially spent catalyst, and sulfur in a content of between 1% and 8% by weight, with respect to the total weight of the at least partially spent catalyst, said process comprising the following stages: a) said spent catalyst is brought into contact with an impregnation solution containing a compound comprising a metal from group VIb, b) a drying stage is carried out at a temperature of less than 200° C.

The invention relates to a process for the rejuvenation of an at least partially spent catalyst resulting from a hydrotreating process, said at least partially spent catalyst resulting from a fresh catalyst comprising a metal from group VIII, a metal from group VIb, an oxide support, and optionally phosphorus, said at least partially spent catalyst additionally comprising carbon in a content of between 2% and 20% by weight, with respect to the total weight of the at least partially spent catalyst, and sulfur in a content of between 1% and 8% by weight, with respect to the total weight of the at least partially spent catalyst, said process comprising the following stages: a) said spent catalyst is brought into contact with an impregnation solution containing a compound comprising a metal from group VIb, b) a drying stage is carried out at a temperature of less than 200° C.