Desulfurization of hydrocarbon extracts

Claim 1

A PROCESS FOR THE HYDROCATALYTIC DESULPHURIZATION OF A SULPHUR-AND-NAPHTHENE-CONTAINING AROMATIC EXTRACT OF HYDROCARBON OIL, WHICH PROCESS IS SELF-SUPPORTING WITH RESPECT TO THE HYDROGEN NEEDED AND IS PRODUCTIVE OF A DESULPHURIZED AROMATIC EXTRACT HAVING, EXCEPT FOR LOWERED SULPHUR CONTENT, PROPERTIES AND BOILING RANGE SUBSTANTIALLY THE SAME AS THE FEEDSTOCK, COMPRISING THE STEPS OF: PASSING A FEEDSTOCK CONSISTING OF THE AROMATIC EXTRACT TO BE DESULPHURIZED TO A REACTION ZONE AND CONTACTING THE FEEDSTOCK THEREIN WITH A DEHYDROGENATION-HYDROGENATION CATALYST AND WITH HYDROGEN DERIVED SOLELY FROM THE FEEDSTOCK SAID CATALYST BEING RESISTANT TO SULPHUR POISONING AND COMBINING ACTIVITY FOR THE DEHYDROGENATION OF NAPHTHENES IN SAID FEEDSTOCK TO AROMATICS WITH ACTIVITY FOR THE HYDROGENATION OF ORGANICALLY COMBINED SULPHUR IN SAID FEEDSTOCK TO HYDROGEN SULPHIDE; MAINTAINING A SELECTED TEMPERATURE IN SAID ZONE BETWEEN ABOUT 700* F. TO ABOUT 800* F. AT WHICH HYDROGEN IS CONTINUOUSLY PRODUCED FROM SAID FEEDSTOCK; MAINTAINING A SELECTED PRESSURE IN SAID ZONE BETWEEN ABOUT 50 TO ABOUT 250 LBS./SQ. IN. GAUGE, SAID SELECTED TEMPERATURE AND PRESSURE BEING CORRELATED TO PROVIDE, FROM THE DEHYDROGENATION OF NAPHTHENES CONTAINED IN SAID FEEDSTOCK, A NET PRODUCTION OF HYDROGEN AT LEAST SUFFICIENT TO CONVERT ORGANICALLY COMBINED SULPHUR IN THE FEEDSTOCK INTO HYDROGEN SULPHIDE AND TO MAINTAIN SAID SELECTED PRESSURE; SEPARATING HYDROGEN SULPHIDE AND A HYDROGEN-RICH GAS MIXTURE FROM THE DESULPHURIZED FEEDSTOCK; RECYCLING SAID HYDROGEN-RICH GAS MIXTURE TO THE REACTION ZONE TO CONSTITUTE THE WHOLE OF THE HYDROGEN SUPPLIED TO SAID ZONE, THE HYDROGEN RECYCLE RATE BEING SUFFICIENT TO MAINTAIN THE NECESSARY PARTIAL PRESSURE OF HYDROGEN IN SAID ZONE; AND, RECOVERING THE DESIRED DESULPHURIZED AROMATIC EXTRACT FROM THE RESIDUE OF SAID SEPARATING OPERATION.