Method of guarding selective adsorption separation systems

Claim 1

A PROCESS FOR TREATING A GASEOUS MIXTURE COMPRISING C1 TO MORE THAN C5 HYDROCARBONS AND OTHER LOW-BOILING NORMALLY GASEOUS MATERIALS COMPRISING PASSING SAID MIXTURE TO AN OIL ABSORPTION ZONE; RECOVERING AND PASSING A RICH OIL STREAM CONTAINING C5 AND HIGHER BOILING HYDROCARBONS FROM SAID ADSORPTION ZONE TO A STRIPPING ZONE; PASSING STRIPPING GAS TO THE LOWER PORTION OF SAID STRIPPING ZONE; RECOVERING STRIPPED C5 AND HIGHER BOILING HYDROCARBONS FROM SAID STRIPPING ZONE; PASSING STRIPPED ABSORPTION OIL FROM THE LOWER PORTION OF SAID STRIPPING ZONE TO SAID ABSORPTION ZONE; PASSING GASEOUS EFFLUENT FROM SAID ABSORPTION ZONE TO A FIRST GUARD ZONE CONTAINING A FIXED BED OF SOLID ADSORBENT WHEREIN ANY UNABSORBED C5 AND HIGHER BOILING HYDROCARBONS ARE ADSORBED; PASSING UNADSORBED C4 AND LOWER BOILING HYDROCARBONS FROM SAID GUARD ZONE TO A SELECTIVE ADSORPTION SEPARATION ZONE WHEREIN HIGHER BOILING SAID HYDROCARBONS ARE SEPARATED FROM LOWER BOILING SAID HYDROCARBONS; RECOVERING SAID SEPARATED HYDROCARBONS; PASSING A HEATED PORTION OF THE HIGHER BOILING HYDROCARBONS RECOVERED FROM SAID SELECTIVE ADSORPTION SEPARATION ZONE TO A SECOND GUARD ZONE CONTAINING A FIXED BED OF SOLID ADSORBENT AND DESORBING C5 AND HIGHER BOILING HYDROCARBONS ADSORBED THEREIN; PASSING GASEOUS EFFLUENT FROM SAID SECOND GUARD ZONE TO SAID STRIPPING ZONE; AND TRANSFERRING SAID GASEOUS EFFLUENT FROM SAID ADSORPTION ZONE TO THE SAID SECOND GUARD ZONE AND SAID HEATED PORTION OF THE HIGHER BOILING HYDROCARBONS RECOVERED FROM SAID SELECTIVE ADSORPTION SEPARATION ZONE TO SAID FIRST GUARD ZOEN WHEN SAID FIRST GUARD ZONE BECOMES SUBSTANTIALLY SATURATED WITH C5 AND HIGHER BOILING HYDROCARBONS.