Continuous adsorption process

Claim 1

A PROCESS FOR THE SEPARATION OF A MIXTURE OF LOW-BOILING HYDROCARBON GASES COMPRISING MAINTAINING A GRAVITATING ELONGATED COLUMN OF GRANULAR ACTIVATED CHARCOAL OF UNIFORM HORIZONTAL CROSS-SECTION; CONTACTING THE INTERMEDIATE SECTION OF SAID COLUMN OF CHARCOAL WITH A COUNTERCURRENT STREAM OF THE LOW-BOILING HYDROCARBON MIXTURE TO BE SEPARATED SO AS TO SELECTIVELY ADSORB THE HIGHER MOLECULAR WEIGHT HYDROCARBON AND ALLOW THE RESIDUAL HYDROCARBON TO PASS UPWARDLY THROUGH THE REMAINDER OF THE BED; WITHDRAWING A STREAM OF RESIDUAL HYDROCARBON FROM THE UPPER END OF SAID COLUMN; CONTACTING THE LOWER SECTION OF SAID COLUNM OF CHARCOAL CONTAINING THE ADSORBED HYDROCARBON WITH A HOT GASEOUS STREAM COMPRISING RECYCLED DESORBED HYDROCARBON TOGETHER WITH STEAM SO AS TO DESORB THE ADSORBED HYDROCARBON, SAID GASEOUS STREAM SUPPLYING BY DIRECT HEAT EXCHANGE ALL OF THE HEAT FOR THE DESORPTION STEP; RECOVERING A STREAM OF DESORBED HYDROCARBON FROM THE UPPER END OF SAID LOWER SECTION, HEATING A PORTION THEREOF, AND RECYCLING SAME TO SAID LOWER SECTION AS A PORTION OF SAID GASEOUS STREAM; MAINTAINING A COOLING SECTION IN THE UPPER END OF SAID COLUMN OF CHARCOAL SOLELY BY RECYCLING A COOLED PORTION OF THE UNADSORBED HYDROCARBON IN DIRECT HEAT EXCHANGE WITH THE CHARCOAL THEREIN; AND RECYCLING CHARCOAL FROM THE LOWER END OF SAID COLUMN TO THE TOP THEREOF.