inert gas such as nitrogen and then with increasing concentrations of oxygen while controlling the temperature between 200 u00b0 and 350 u00b0 c the initial dilute concentrations of oxygen usually from about 0 01 to 1 0 percent oxygen in an inert carrier gas are conveniently provided by mixing the appropriate amount of air with a stream of nitrogen not only does the nitrogen serve as a diluent for the air but by using cool nitrogen it also serves as a coolant to control the temperature of the exothermic reaction between the catalyst and the oxygen in a typical regeneration procedure a mixture of air and nitrogen such that the concentration of oxygen is about 0 3 percent is passed over the catalyst bed until the initial exotherm dissipates the temperature is controlled below 350 u00b0 c primarily by the flow of the large volume of nitrogen afterwards the concentration of oxygen is gradually increased until no significant exotherm is observed catalyst regenerated in this manner exhibits activity approaching that of fresh catalyst the present invention is illustrated by the following examples however the examples should not be interpreted as a limitation upon the scope of the present invention 1 3 diaminopropane dap and liquid pivalic acid pa were preheated to 290 u00b0 c and fed to a vertical tubular reactor r 1 1 5 inch diameter 48 inch length filled with 800 milliliters ml of alumina catalyst grain size 1 4 mm diameter the reactor was kept at 290 u00b0 c the pa.