Concurrent deposition of lead sulfide and mercaptan conversion in hydrocarbon oils

Claim 1

IN A PROCESS FOR THE SWEETENING OF SOUR HYDROCARBON FRACTIONS BY CONVERSION TO POLYSULFIDES OF MERCAPTANS WHEREIN A MIXTURE OF SOUR HYDROCARBON FRACTIONS BOILING BELOW ABOUT 650* F. WITH CAUSTIC, OXIDIZING GAS AND SULFUR IS CONTACTED WITH A SUPPORTED LEAD SULFIDE CATALYST AND WHEREIN ACTIVITY OF SAID CATALYST DECLINES WITH CONTINUED OPERATION; THE IMPROVED METHOD FOR MAINTAINING ACTIVITY OF SAID CATALYST WHILE SUSTAINING RATE OF FEED OF SOUR HYDROCARBON FRACTION TO THE PROCESS, WHICH IMPROVED METHOD COMPRISES ADMIXING CAUSTIC AND OXIDIZING GAS WITH A SOUR HYDROCARBON FRACTION, PASSING A MINOR PORTION OF THE RESULTANT CAUSTIC, OXIDIZING GAS, AND HYDROCARBON BLEND IN CONTACT WITH A SOLID SOURCE OF LEAD SELECTED FROM THE GROUP CONSISTING OF METALLIC LEAD AND LEAD COMPOUNDS WHICH REACT IN ALKALINE MEDIUM WITH MERCAPTANS TO FORM LEAD MERCAPTIDE, AND PASSING THE TOTAL QUANTITY OF SAID RESULTANT LEAD-CONTAINING CAUSTIC AND HYDROCARBON BLEND, AFTER HAVING MIXED SAID BLEND WITH ELEMENTAL SULFUR, IN CONTACT WITH SAID SUPPORTED LEAD SULFIDE CATALYST SO AS TO DEPOSIT FRESH LEAD SULFIDE CATALYST ON THE CATALYST SUPPORT.