Coking of pyrolysis tars

Abstract

Abstract PYROLYSIS TARS WHICH ARE FORMED IN THE HIGH TEMPERATURE CRACKING, GENERALLY IN THE PRESENCE OF AN INERT DILUENT, OF A HYDROCARBON DISTILLATE OR AS FRACTION TO PREPARE OLE FINS SUCH AS ETHYLENE, PROPYLENE, BUTENE, STYRENE, EC., CAN BE SUBJECTED TO AN IMPROVED COKING PROCESS ACCORDING TO THIS INVENTIONL THIS INVENTIO COMPRISES THE PRETREATING OF THE PYROLYSIS TARS PRIOR TO COKING BY A HYDROGENATION TREATMENT, PREFERABLY AT MILD CONDITIONS, WHICH CAN BE EFFECTED IN THE PRESENCE OR ABSENCE OF A CATALYST AND/ OR INERT DILUENT FOR THE TAR. THE HYDROGENATION CONDITIONS CAN INCLUDE TEMPERATURES FROM ABOUT 250* TO ABOUT 800*F. AND, WHEN CATALYST ARE EMPLOYED. LIQUID HOURLY SPACE VELOCITIES FROM 0.5 TO ABOUT 10 VOLUMES PER VOLUME PER HOUR. THE HYDROGENATION OS EFFECTED TO CONSUME FROM 100 TO ABOUT 2000 CUBIC FEET OF HYDROGEN PER BARREL OF FEEDSTOCK. FOLLOWING THIS HYDROGENATION, THE RESULTING PARTIALLY HYDROGENATED PYROLYSIS TAR IS THEN COKED IN A CONVENTIONAL DELAYED COKING OPERATION EMPLOYING COKE DRUM TEMPERATURES FROM 775* TO ABOUT 900*F. AND PRESSURES FROM ATMOSPHERIC TO ABOUT 250 P.S.I.G. TO OBTAIN AN IMPROVED YIELD OF DISTILLATE PRODUCT, REDUCED YIELD OF COKE, AND A COKE OF HIGHER QUALITY THAN CAN BE OBTAINED IN THE ABSENCE OF SUCH HYDROGENATION.

Inventors

• 👤 H Folkins

Bibliographic Details