A method for activating an oxidic fresh hydroprocessing catalyst or the catalytically active material of a spent hydroprocessing catalyst comprising a refractory oxide support and one or more base metals selected from Ni, Co, Mo and W comprises optionally regenerating the catalyst, adjusting an aqueous activating solution, which contains an organic acid, to pH > 3 with an alkaline additive, impregnating the catalytically active material with the pH-adjusted aqueous activating solution, and heat-treating the catalyst at a temperature of 120-450° C.

A catalytic upgrading process includes introducing a feed comprising crude oil to a steam cracking unit, thereby producing pyrolysis fuel oil (PFO). The PFO is introduced to a first catalytic depolyaromatization reactor to remove polyaromatics from the feed, thereby producing polyaromatics adsorbed to the catalyst and depolyaromatized PFO. The depolyaromatized PFO is introduced to a hydrocracking unit. The resulting benzene-toluene-xylenes (BTX) and liquid petroleum gas (LPG) are separated, and the BTX is introduced to a BTX complex to produce refined BTX. The LPG can then be introduced to the steam cracking unit. After depolyaromatization, a wash solvent is introduced into the first catalytic depolyaromatization reactor to remove the polyaromatics, regenerate the catalyst, and produce a mixture comprising the wash solvent and the polyaromatics. The wash solvent is separated from the polyaromatics.

The invention concerns a synthesis process of a compound of the following formula (I) or one of the salts thereof,

##STR00001## wherein R represents a COOH, CH.sub.2OH or CHO group, comprising the step according to which the but-3-ene-1,2-diol (BDO) is subjected to an oxidation in the presence of a catalyst, said catalyst comprising an active phase based on at least one noble metal selected from palladium, gold, silver, platinum, rhodium, osmium, ruthenium and iridium, and a support containing alkaline sites.

The invention also concerns the application of this reaction to the preparation of bioavailable compounds of methionine used, in particular, in animal nutrition.

A oxygen transfer agent useful for the oxidative dehydrogenation of saturated hydrocarbons includes at least one mixed oxide derived from manganese or compounds thereof, as well as a promoter, such as tungsten and/or phosphorus. The oxygen transfer agent may also include an alkali metal or compounds thereof, boron or compounds thereof, an oxide of an alkaline earth metal, and an oxide containing one or more of one or more of manganese, lithium, boron, and magnesium. A reactor is at least partially filled with the oxygen transfer agent in the form of a fixed or circulating bed and provides an unsaturated hydrocarbon product, such as ethylene and/or propylene. The oxygen transfer agent may be regenerated using oxygen.

A process for rejuvenating an at least partially spent catalyst resulting from a hydrodesulfurization process of a sulfur-containing olefinic gasoline cut, where the at least partially spent catalyst result is from a fresh catalyst a metal from group VIII, a metal from group VIb, and an oxide support, where the process includes a) regenerating the at least partially spent catalyst in an oxygen-containing gas stream at a temperature between 350° C. and 550° C., b) the regenerated catalyst is brought into contact with an impregnation solution containing a compound containing a metal from group VIb, the molar ratio of the metal from group VIb added per metal from group VIb already present in the regenerated catalyst being between 0.15 and 2.5 mol/mol, c) a drying stage is carried out at a temperature of less than 200° C., and
the use of the rejuvenated catalyst in a hydrodesulfurization process.

A process for regenerating a deactivated vanadium-titanium-phosphorous catalyst which has been used in the production of unsaturated carboxylic acid is disclosed. The process comprises contacting the deactivated vanadium-titanium-phosphorous catalyst with a regeneration stream comprising steam as a regeneration agent at a temperature which is the same or similar to that used in the production of the unsaturated carboxylic acid.

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.

A catalytic upgrading process includes introducing a feed comprising crude oil to a first catalytic deasphalting reactor to deasphalt the feed, thereby producing polymerized asphaltenes and deasphalted oil (DAO). The DAO is introduced to a steam cracking unit, thereby producing pyrolysis gas (PG), which is introduced into a selective hydrogenation unit, thereby producing an olefin-free product, which can then be introduced to a separation unit. The resulting benzene-toluene-xylenes (BTX)-containing stream and liquid petroleum gas (LPG) are separated, and the BTX-containing stream is introduced to a BTX complex to produce refined BTX. After deasphalting, a wash solvent may be introduced into the first catalytic deasphalting reactor to remove the polymerized asphaltenes, regenerate the catalyst, and produce a mixture comprising the wash solvent and the polymerized asphaltenes. The wash solvent is separated from the polymerized asphaltenes.

A catalytic upgrading process includes introducing a feed comprising crude oil to a steam cracking unit, thereby producing pyrolysis fuel oil (PFO). The PFO is introduced to a first catalytic depolyaromatization reactor to remove polyaromatics from the feed, thereby producing polyaromatics adsorbed to the catalyst and depolyaromatized PFO. The depolyaromatized PFO is introduced to a hydrocracking unit. The resulting benzene-toluene-xylenes (BTX) and liquid petroleum gas (LPG) are separated, and the BTX is introduced to a BTX complex to produce refined BTX. The LPG can then be introduced to the steam cracking unit. After depolyaromatization, a wash solvent is introduced into the first catalytic depolyaromatization reactor to remove the polyaromatics, regenerate the catalyst, and produce a mixture comprising the wash solvent and the polyaromatics. The wash solvent is separated from the polyaromatics.

A catalytic upgrading process includes introducing a feed comprising crude oil to a first catalytic deasphalting reactor to deasphalt the feed, thereby producing polymerized asphaltenes and deasphalted oil (DAO). The DAO is introduced to a steam cracking unit, thereby producing pyrolysis gas (PG), which is introduced into a selective hydrogenation unit, thereby producing an olefin-free product, which can then be introduced to a separation unit. The resulting benzene-toluene-xylenes (BTX)-containing stream and liquid petroleum gas (LPG) are separated, and the BTX-containing stream is introduced to a BTX complex to produce refined BTX. After deasphalting, a wash solvent may be introduced into the first catalytic deasphalting reactor to remove the polymerized asphaltenes, regenerate the catalyst, and produce a mixture comprising the wash solvent and the polymerized asphaltenes. The wash solvent is separated from the polymerized asphaltenes.