Adipic acid process

Claim 1

IN A PROCESS FOR THE PREPARATION OF ADIPIC ACID FROM CYCLOHEXANE, THE STEPS WHICH COMPRISE OXIDIZING CYCLOHEXANE WITH AIR AT A TEMPERATURE BETWEEN 50* AND 175* C. AND UNDER A PRESSURE BETWEEN 50 AND 250 P. S. I. UNTIL FROM 0.5 TO 2 MOLES OF OXYGEN REACT PER MOLE OF CYCLOHEXANE ATTACKED, SEPARATING THE UNOXIDIZED CYCLOHEXANE FROM THE REACTION MIXTURE AND NITRIC ACID OXIDIZING THE CYCLOHEXANE-FREE REACTION PRODUCT UNDER TWO TEMPERATURE STAGES BY CONDUCTING A STREAM OF THE CYCLOHEXANE-FREE REACTION PRODUCT AS A FEED AND A STREAM OF NITRIC ACID INTO A RAPIDLY MOVING STREAM, FLOWING IN A CLOSED CIRCUIT, CONTAINING NITRIC ACID, CATALYST, WATER AND PARTIALLY NITRIC ACID OXIDIZED FEED, MAINTAINED AT A TEMPERATURE BETWEEN 40* AND 90* C., WITHDRAWING A PORTION OF THE PARTIALLY NITRIC ACID OXIDIZED FEED AND HEATING IT IN A SECOND STAGE AT A HIGHER TEMPERATURE.