Hydrodesulfurizing a highly olefinic gasoline containing cyclic sulfur compounds

Claim 1

A METHOD OF DESULFURIZING A HIGHLY OLEFINIC HYDROCARBON FRACTION, WHICH COMPRISES BRINGING HYDROGEN AND A HYDROCARBON FRACTION CONTAINING MORE THAN 1% BY WEIGHT OF SULFUR IN THE FORM OF CYCLIC SULFUR COMPOUNDS, AND A VOLUME OF OLEFINS GREATER THAN THE VOLUME OF PARAFFINS AND NAPHTHENES THEREIN, SAID VOLUME OF OLEFINS BEING MORE THAN 20% BY VOLUME OF SAID HYDROCARBON FRACTION AND IMPARTING TO SAID HYDROCARBON FRACTION A HIGH OCTANE NUMBER INTO CONTACT WITH A PROMOTED SILICEOUS CATALYST CONSISTING ESSENTIALLY OF A MAJOR WEIGHT PROPORTION OF SILICA, A MINOR WEIGHT PROPORTION OF AT LEAST ONE DIFFICULTY REDUCIBLE METAL OXIDE AND A CATALYST PROMOTER COMPRISING AN ELEMENT SELECTED FROM THE CLASS CONSISTING OF THE METALLIC ELEMENTS OF GROUPS VA, VIA AND VIII OF THE PERIODIC TABLE IN A REACTION ZONE MAINTAINED AT A TEMPERATURE IN THE RANGE OF 775 TO 925* F., THE CONTACT OF SAID HYDROGEN AND SAID HYDROCARBON FRACTION RESULTING IN A NET CONSUMPTION OF HYDROGEN, PASSING SAID HYDROCARBON FRACTION THROUGH THE REACTION ZONE AT A SPACE VELOCITY IN THE RANGE OF ABOUT 0.5 TO 5 LIQUID VOLUMES PER HOUR PER VOLUME OF SAID PROMOTED SILICEOUS CATALYST, MAINTAINING THE PARTIAL PRESSURE OF HYDROGEN IN SAID REACTION ZONE IN THE RANGE OF 20 TO 100 P. S. I., AND RECOVERING FROM THE RESULTING REACTION EFFLUENT A HIGHLY OLEFINIC HYDROCARBON FRACTION CONTAINING LESS THAN 0.3% BY WEIGHT OF SULFUR AND A MAJOR PORTION OF SAID OLEFINS AND HAVING A HIGH OCTANE NUMBER.

Claim 2

A METHOD OF DESULFURIZING A HIGHLY OLEFINIC HYDROCARBON FRACTION, WHICH COMPRISES BRINGING HYDROGEN AND A HYDROCARBON FRACTION CONTAINING MORE THAN 1% BY WEIGHT OF SULFUR IN THE FORM OF CYCLIC SULFUR COMPOUNDS, AND A VOLUME OF OLEFINS GREATER THAN THE VOLUME OF PARAFFINS AND NAPHTHENES THEREIN, SAID VOLUME OF OLEFINS BEING MORE THAN 20% BY VOLUME OF SAID HYDROCARBON FRACTION AND IMPARTING TO SAID HYDROCARBON FRACTION A HIGH OCTANE NUMBER INTO CONTACT WITH A PROMOTED SILICEOUS CATALYST CONSISTING ESSENTIALLY OF A MAJOR WEIGHT PROPORTION OF SILICA, A MINOR WEIGHT PROPORTION OF AT LEAST ONE DIFFICULTY REDUCIBLE METAL OXIDE AND A CATALYST PROMOTER COMPRISING AN ELEMENT SELECTED FROM THE CLASS CONSISTING OF THE METALLIC ELEMENTS OF GROUPS VA, VIA AND VIII OF THE PERIODIC TABLE IN A REACTION ZONE MAINTAINED AT A TEMPERATURE IN THE RANGE OF 775 TO 925* F., THE CONTACT OF SAID HYDROGEN AND SAID HYDROCARBON FRACTION RESULTING IN A NET CONSUMPTION OF HYDROGEN, PASSING SAID HYDROCARBON FRACTION THROUGH THE REACTION ZONE AT A SPACE VELOCITY IN THE RANGE OF ABOUT 0.5 TO 5 LIQUID VOLUMES PER HOUR PER VOLUME OF SAID PROMOTED SILICEOUS CATALYST, MAINTAINING THE PARTIAL PRESSURE OF HYDROGEN IN SAID REACTION ZONE IN THE RANGE OF 20 TO 100 P. S. I., AND RECOVERING FROM THE RESULTING REACTION EFFLUENT A HIGHLY OLEFINIC HYDROCARBON FRACTION CONTAINING LESS THAN 0.3% BY WEIGHT OF SULFUR AND A MAJOR PORTION OF SAID OLEFINS AND HAVING A HIGH OCTANE NUMBER.