Molecular sieve separation process

Claim 1

AN INTEGRATED PROCESS FOR REMOVAL OF AN ADSORBABLE HYDROCARBON CONSTITUENT FROM A FEED MIXTURE COMPRISING SAID ADSORBABLE HYDROCARBON CONSTITUENT IN ADMIXTURE WITH NONADSORBABLE HYDROCARBONS OF OTHER TYPES, USING A SOLID ABSORBENT COMPRISING A MOLECULAR SIEVE ZEOLITE HAVING PORE SIZES IN THE RANGE OF FROM ABOUT 3 TO ABOUT 15 ANGSTROMS ADAPTED TO SELECTIVELY ADSORB SAID ADSORBABLE HYDROCARBON, WHICH COMPRISES PASSING SAID FEED MIXTURE AT A RELATIVELY LOW TEMPERATURE THROUGH A FIRST ADSORPTION ZONE CONTAINING A BODY OF SAID ADSORBENT, WHEREBY SAID CONSTITUENT IS SELECTIVELY ADSORBED, WITHDRAWING FROM SAID FIRST ZONE A RAFFINATE THAT IS SUBSTANTIALLY FREE OF SAID CONSTITUENT, SAID FIRST ZONE THUS BEING IN AN ADSORPTION STAGE, SIMULTANEOUSLY PASSING HEATED DESORBATE THROUGH A SECOND ZONE CONTAINING A BODY OF SAID ADSORBENT THAT HAS BEEN SATURATED TO A PREDETERMINED DEGREE WITH SAID ADSORBATE WHILE SAID SECOND ZONE WAS JUST PREVIOUSLY IN AN ADSORPTION STAGE, SAID SECOND ZONE THUS PRESENTLY BEING IN A HEATING STAGE, SAID DESORBATE HAVING BEEN OBTAINED BY DESORPTION OF A QUANTITY OF SAID CONSTITUENT FROM A BODY OF SAID ADSORBENT, SIMULTANEOUSLY APPLYING VACUUM TO A THIRD ZONE CONTAINING A BODY OF SAID ADSORBENT THAT HAS JUST PREVIOUSLY BEEN IN A HEATING STAGE, THEREBY REMOVING TRACES OF SAID ADSORBED CONSTITUENT THEREFROM, SAID THIRD ZONE THUS PRESENTLY BEING IN AN EVACUATION STAGE, SIMULTANEOUSLY COOLING A FOURTH ZONE CONTAINING A BODY OF SAID ADSORBENT THAT HAS JUST PREVIOUSLY BEEN IN AN EVACUATION STAGE, SAID COOLING BEING ACCOMPLISHED BY CIRCULATING RAFFINATE THROUGH SAID FOURTH ZONE, AND THEREAFTER PERIODICALLY CHANGING EACH OF SAID ZONES IN A CONSECUTIVE MANNER FROM THE ADSORPTION STAGE, THE HEATING STAGE, THE EVACUATION STAGE AND THE COOLING STAGE.