Molecular sieve process for upgrading naphtha wherein the desorbed straight chain hydrocarbons are dehydrogenated and used as desorbing agents

Claim 1

A PROCESS FOR UPGRADING A LIGHT VIRGIN NAPHTHA CONTAINING NORMAL PARAFFINS IN THE C5 TO 175*F. BOILING RANGE WHICH COMPRISES: CONTACTING SAID NAPHTHA WITH A MOLECULAR SIEVE ADSORBENT HAVING PORE DIAMETERS OF ABOUT 5 A., SELECTIVELY ADSORBING SAID NORMAL PARAFFINS UPON SAID MOLECULAR SIEVE AND DESORBING OLEFINS ADSORBED THEREON, SAID OLEFINS HAVING THE SAME NUMBER OF CARBON ATOMS PER MOLECULE AS SAID NORMAL PARAFFINS, WITHDRAWING AND RECOVERING A PRODUCT STREAM CONTAINING SAID DESORBED OLEFINS AND UNADSORBED CONSTITUENTS OF SAID NAPHTHA, DESORBING SAID NORMAL PARAFFINS FROM SAID ADSORBENT AND CONCOMITANTLY ADSORBING OLEFINS HAVING THE SAME NUMBER OF CARBON ATOMS PER MOLECULE AS SAID NORMAL PARAFFINS THEREON, DEHYDROGENATING AT LEAST PART OF THE SAID DESORBED NORMAL PARAFFINS TO THE CORRESPONDING OLEFINS IN A DEHYDROGENATION ZONE, AND THEREAFTER PASSING THUS FORMED OLEFINS AND UNCONVERTED NORMAL PARAFFINS FROM SAID DEHYDROGENATION ZONE TO SAID NORMAL PARAFFIN DESORPTION STEP.