Hydrorefining of heavy mineral oils

Claim 1

A PROCESS FOR HYDROREFINING A FEEDBACK WHICH IS ESSENTIALLY A FULL-RANGE CRUDE OIL, WHICH COMPRISES FIRST SUBJECTING SAID FEEDSTOCK TO PARTIAL VAPORIZATION IN EQUILIBRIUM WITH (1) HYDROGEN-RICH RECYCLE GAS DERIVED FROM THE HYDROREFINING STEP HEREINAFTER DEFINED, AND (2) FRESH MAKEUP HYDROGEN REQUIRED FOR SAID HYDROREFINING STEP, SAID PARTIAL VAPORIZATION BEING CARRIED OUT AT A TEMPERATURE WITHIN ABOUT 100*F., AND AT A PRESSURE WITHIN ABOUT 300 P.S.I.G. OF THE TEMPERATURE AND PRESSURE PREVAILING IN THE HYDROREFINING STEP HEREINAFTER DEFINED, THEREBY PRODUCING A GAS PHASE COMPRISING BETWEEN ABOUT 75% AND 99% OF SAID FEED OIL AND A LIQUID PHASE COMPRISING ABOUT 1% TO 25% THEREOF, SEPARATING SAID LIQUID PHASE AND SUBJECTING THE SAME TO LIQUID-LIQUID EXTRACTION WITH A LOWER PARAFFINIC SOLVENT TO PRODUCE A HIGHLY ASPHALTIC RAFFINATE AND A NONASPHALTIC EXTRACT, RECOVERING DISSOLVED OIL FROM SAID EXTRACT, BLENDING SAID RECOVERED OIL WITH SAID GAS PHASE, AND THEN SUBJECTING THE RESULTING BLEND TO HYDROREFINING AT A TEMPERATURE BETWEEN ABOUT 600* AND 875*F., A PRESSURE BETWEEN ABOUT 100 AND 5000 P.S.I.G. AND A HYDROGEN RATIO BETWEEN ABOUT 300 AND 8000 STANDARD CUBIC FEET PER BARREL OF LIQUID FEED, AND IN THE PRESENCE OF A HYDROREFINING CATALYST, COOLING THE PRODUCT FROM SAID HYDROREFINING STEP AND CONDENSING THE MAJOR PORTION THEREOF AT SUBSTANTIALLY THE PRESSURE PREVAILING IN SAID HYDROREFINING ZONE, THEREBY PRODUCING A SUPERNATANT HYDROGEN-RICH RECYCLE GAS PHASE, AND CONTACTING AT LEAST A PORTION OF SAID RECYCLE GAS PHASE WITH SAID INITIAL FEED TO EFFECT PARTIAL VAPORIZATION AS ABOVE DESCRIBED.