Process for the catalytic oxidation of olefins with a group viii noble metal catalyst and oxygen to aldehydes, acetals and unsaturated esters

Claim 1

THE OXIDATION OF A HYDROCARBON OLEFIN HAVING 2 TO ABOUT 20 CARBON ATOMS TO AN OXYGENATED PRODUCT SELECTED FROM THE CLASS CONSISTING OF: (A) ALDEHYDES; (B) ACETALS; AND (C) CARBOXYLIC ACID ESTERS OF UNSATURATED ALCOHOLS; WHEREIN THE OLEFIN IS CONTACTED, IN A REACTION ZONE, AT A TEMPERATURE FROM 30* TO 300*C. AND A PRESSURE FROM ATMOSPHERIC TO ABOUT 100 ATMOSPHERES AND SUFFICIENT TO MAINTAIN LIQUID PHASE CONDITIONS AND IN THE PRESENCE OF A REACTION MEDIUM SELECTED FROM THE CLASS CONSISTING OF: (A) AQUEOUS ACIDS HAVING A PH FROM 1 TO ABOUT 7; (B) SUBSTANTIALLY ANHYDROUS ALKANOLS HAVING 1 TO ABOUT 20 CARBONS; AND (C) SUBSTANTIALLY ANHYDROUS CARBOXYLIC ACIDS HAVING 1 TO ABOUT 8 CARBONS; TO PREPARE ALDEHYDES WHEN SAID MEDIUM IS SELECTED AS SAID AQUEOUS ACID, TO PREPARE ACETALS WHEN SAID MEDIUM IS SELECTED AS SAID ALCOHOL AND TO PREPARE SAID ESTERS WHEN SAID MEDIUM IS SELECTED AS SAID CARBOXYLIC ACID; THE IMPROVEMENT THAT COMPRISES: (1) INTRODUCING SAID OLEFIN, OXYGEN AND LIQUID REACTION MEDIUM INTO MUTUAL CONTACT IN A FIRST REACTION ZONE PACKED WITH A FINELY DIVIDED SOLID INERT TO SAID OXIDATION, INSOLUBLE IN SAID REACTION MEDIUM AND HAVING A SPECIFIC SURFACE AREA FROM 2 TO 1000 SQUARE METERS PER GRAM AND CONTAINING IMPREGNATED THEREON BETWEEN ABOUT 0.1 AND 5.0 WEIGHT PERCENT OF A PLATINUM GROUND METAL; (2) WITHDRAWING A LIQUID PHASE OXIDATE FROM SAID FIRST REACTION ZONE; (3) INTRODUCING SAID LIQUID OXIDATE INTO A SECOND REACTION ZONE THAT IS ALSO PACKED WITH INERT SOLID; (4) PASSING SAID LIQUID OXIDATE THROUGH SAID REACTION ZONE WHILE MAINTAINING SAID SECOND REACTION ZONE SUBSTANTIALLY FREE OF OXYGEN; (5) WITHDRAWING A REDUCED CRUDE OXIDATE PRODUCT FROM SAID SECOND REACTION ZONE; AND (6) WHEN THE OXYGEN ABSORPTION RATE IN SAID FIRST REACTION ZONE DECREASES TO A VALUE FROM 10 TO 75 PERCENT OF THE OXYGEN ABSORPTION RATE INITIALLY OBSERVED, PERIODICALLY SWITCHING SAID INTRODUCTION OF OLEFIN, OXYGEN AND REACTION MEDIA FROM SAID FIRST TO SAID SECOND REACTION ZONE AND REVERSING THE FLOW OF SAID REACTION MEDIUM THROUGH SAID FIRST AND SECOND REACTION ZONES.