Petroleum refining process

Claim 1

PETROLEUM REFINING PROCESS WHICHY COMPRISES THE COMBINATION OF STEPS OF SEPARATING FROM PETROLEUM BY A TOPPING DISTILLATION A BRAOD RANGE FRACTION INCLUDING SUBSTANTIALLY ALL OF THE NORMALLY LIQUID HYDROCARBONS PRESENT BOILING UP TO ABOUT 300 TO 400* C. AND CONTAINING PENTANES, GASOLINE ,NAPHTHA, KEROSENE AND OTHER OILS BOILING UP TO SAID TEMPERATURE RANGE, CONTACTING SAID BROAD RANGE FRACTION IN A HYDRODESULFURIZATION ZONE WITH A HYDROGEN CONTAINING GAS OBTAINED AS HEREAFTER SPECIFIED AND WITH A HYDROSULFURIZATION CATALYST UNDER A PRESSURE BETWEEN ABOUT 30 AND 65 KG./CM.2 WHEREBY PART OF THE HYDROGEN IS CONSUMED, COOLING THE CONTACTED MIXTURE DOWN TO A TEMPERATURE OF AT LEAST ABOUT 40* C. UNDER SUBSTANTIALLY THE HYDRODESULFURIZATION PRESSURE AND PASSING THE COOLED MATERIAL TO A FIRST PHASE SEPARATOR, WITHDRAWING GAS RICH IN HYDROGEN FROM SAID FIRST SEPARATOR AND RECYLING THE SAME TO THE HYDRODESULFDURIZATION ZONE, EXPANDING THE LIQUID PHASE FROM SAID FIRST PHASE SEPARATOR INTO A SECOND PHASE SEPARATOR MAINTAINED AT A LOWER SUPERATMOSPHERIC PRESSURE BETWEEN ABOUT 15 AND 30 KG./CM.2 AND AS FURTHER SPECIFIED BELOW, WITHDRAWING GAS FROM SAID SECOND PHASE SEPARATOR, ADDING TOD SAID LAST-MENTIONED GAS