product stream suitable ferritic oxidative dehydrogenation catalysts are also described in miklas m ethod o f a ctivating z inc f errite o xidative d ehydrogenation c atalyst u s pat no 3 953 370 apr 27 1976 which relates to use of steam at a temperature of from 371 704 u00b0 c 700 1300 u00b0 f to activate a zinc ferrite oxidative dehydrogenation catalyst for preparation of butadiene from c 4 c 8 hydrocarbons as well as bajars et al d ehydrogenation w ith m agnesium f errite u s pat no 3 284 536 u s pat no 4 083 844 to purdy entitled calcium oxide modified zinc ferrite oxidative dehydrogenation catalysts and use as well as catalytic oxidative dehydrogenation process u s pat no 4 658 074 the disclosures of which are incorporated herein by reference the oxidative dehydrogenation catalyst bed is preheated to a temperature which is sufficient to initiate the oxidative dehydrogenation reaction the butadiene rich reactor effluent details as to feed compositions and operating temperatures appear in welch et al butadiene via oxidative dehydrogenation hydrocarbon processing november 1978 pp 131 136 the disclosure of which is incorporated herein by reference the butadiene enriched product stream exiting the reactor is cooled through a quench column in which heat is removed from the butadiene enriched product stream and steam content thereof condensed after passing through the.