A process for hydrogenation of an unsaturated hydrocarbon feedstock at an elevated temperature and pressure in a hydrogenation zone by (a) contacting the feedstock, in the presence of hydrogen, with a hydrogenating catalyst containing at least one noble metal on an alumina support and containing no essentially irreversibly sulfided metal (such as nickel, cobalt, or molybdenum), and (b) adding a chloride to the hydrogenation zone and reacting the chloride with the catalyst in an amount sufficient to increase hydrogenation activity of the catalyst.
The invention concerns a process for the hydrogenation of aromatic compounds contained in feeds with an initial boiling point of more than 100.degree. C. and which contain at least 10% by weight of aromatic compounds. It consists of introducing chlorine in a concentration of 0.5-500 ppm by weight with respect to the feed at a temperature of between 200.degree. C. and 450.degree. C., a pressure in the range 1 MPa to 25 MPa, an HSV of between 0.1 h.sup.-1 and 10 h.sup.-1 and a volume ratio of hydrogen to feed of 100-2000. The catalyst used is a noble metal type and contains less than 1% of at least one halogen. Preferably, the catalyst is fluorinated or chlorinated.
The invention concerns a process for the hydrogenation of aromatic compounds contained in feeds with an initial boiling point of more than 100.degree. C. and which contain at least 10% by weight of aromatic compounds. It consists of introducing chlorine in a concentration of 0.5-500 ppm by weight with respect to the feed at a temperature of between 200.degree. C. and 450.degree. C., a pressure in the range 1 MPa to 25 MPa, an HSV of between 0.1 h.sup.-1 and 10 h.sup.-1 and a volume ratio of hydrogen to feed of 100-2000. The catalyst used is a noble metal type and contains less than 1% of at least one halogen. Preferably, the catalyst is fluorinated or chlorinated.
Aromatic hydrocarbons, particularly monocyclic hydrocarbons, are hydrogenated without substantial hydrocracking in the presence of a Group VIII metal hydrogenating component supported on a porous support such as alumina, while adding continuously or intermittently to the reaction zone a small proportion of carbon tetrachloride as a catalyst activator.
Disclosed is a process for selective hydrogenation in liquid phase of an effluent originating from an ethane steam cracker in which said effluent is contacted with a catalyst consisting of at least supported palladium characterized in that it is carried out in the presence of a liquid phase containing at least part of the hydrogenated gasoline cut, condensed and recycled, of said effluent. Said effluent (1), said liquid phase (8) and possibly hydrogen (13) pass through the hydrogenation reactor (4). The product obtained is fractionated (5) into a gaseous cut at the top (7) containing ethylene and a liquid gasoline cut at the bottom which is partially recycled (8). The process may be used for production of ethylene and for production of gasoline.
