Hydrodenitrification of oil with countercurrent hydrogen

Claim 1

IN A PROCESS COMPRISING PASSING A HIGH BOILING HYDROCARBON OIL CONTAINING ORGANIC NITROGEN COMPOUNDS DOWNFLOW THROOUGH AT LEAST ONE BED OF SULFACTIVE HYDROGENATION CATALYST PARTICLES COMPRISING A REACTION ZONE AND PASSING AT LEAST 1,000 STANDARD CUBIC FEET OF HYDROGEN-RICH GAS PER BARREL OF OIL UPFLOW THROUGH AT LEAST THE SAME REACTION ZONE, AT REACTION CONDITIONS OF TEMPERATURE AND PRESSURE FOR CONVERTING ORGANIC NITROGEN COMPOUNDS TO AMMONIA, WHEREIN DOWNFLOWING PURIFIED HYDROCARBON OIL EFFLUENT IN WITHDRAWN FROM THE BOTTOM OF SAID REACTION ZONE, WHEREIN UPFLOWING VAPORS CONTAINING ESSENTIALLY ALL THE AMMONIA PRODUCED ARE WITHDRAWN FROM THE REACTION ZONE AND COOLED TO CONDENSE AND SEPARATE NORMALLY LIQUID HYDROCARBON OIL CONTAINED THEREIN FROM HYDROGEN-RICH GAS WHICH IS RECYCLED TO THE REACTION ZONE, AND WHEREIN THE NET AMOUNT OF AMMONIA PRODUCED IS REMOVED FROM THE SYSTEM BUT THE HYDROGEN-RICH GAS AVAILABLE FOR RECYCLING CONTAINS A SMALL EQUILIBRIUM CONCENTRATION OF AMMONIA OF FROM ABOVE 0.02% TO ABOUT 1% BY VOLUME HAVING A NEGILIGIBLE EFFECT ON THE HYDROGEN PARTIAL PRESSURE, THE IMPROVED METHOD OF OPERATION WHICH COMPRISES CONTROLLING THE REACTION CONDITIONS IN SAID REACTION ZONE TO CONVERT MORE THAN 90% OF THE ORGANIC NITROGEN ORIGINALLY CONTAINED IN THE OIL TO AMMONIA, AND REMOVING AMMONIA FROM THE HYDROGEN-RICH GAS TO MAINTAIN THE CONCENTRATION OF AMMONIA IN THE GAS INTRODUCED INTO THE REACTION ZONE BELOW THE CATALYST FOR PASSAGE UPWARDS THERETHROUGH BELOW 0.02% BY VOLUME AND LESS THAN THE EQUIVALENT OF 2.5% OF THE INITAL NITROGEN CONTENT OF THE OIL.