Ethane oxidative dehydrogenation process

A process for the production of ethylene by oxidative dehydrogenation of ethane, comprising:

• a) contacting ethane and oxygen in a first oxidative dehydrogenation zone which is formed by multiple reactor tubes each containing a catalyst bed containing a first mixed metal oxide catalyst, resulting in multiple effluent streams,
• wherein the multiple reactor tubes are cooled by a coolant;
• b) mixing at least a portion of the multiple effluent streams to produce a mixture comprising ethylene, unconverted ethane and unconverted oxygen having a volume average oxygen concentration, at least 90 vol. % of said mixture having an oxygen concentration which equals the volume average oxygen concentration, or which deviates from the average volume oxygen concentration by at most 1%;
• c) contacting at least a portion of the mixture from step b) in a second oxidative dehydrogenation zone which is formed by multiple reactor tubes each containing a catalyst bed containing a second mixed metal oxide catalyst, resulting in a stream comprising ethylene, unconverted ethane, and less than 500 ppmv of unconverted oxygen.