Abstract: The liquid and gaseous products formed by reacting oxygen with isobutane in an oxidation reactor are separately processed; the liquid reaction product being charged to a distillation zone and separated into a lower boiling isobutane fraction and a higher boiling fraction comprising tertiary butyl alcohol and tertiary butyl hydroperoxide; the gaseous reaction product comprising inert gases and vaporized and/or entrained isobutane being cooled by an amount sufficient to condense isobutane contained therein for recycle to the oxidation reactor; the remaining gases, including isobutane being charged to a tertiary butyl alcohol absorber to obtain a solution of isobutane in tertiary butyl alcohol that is recycled to the distillation zone.