Oxidative Dehydrogenation of Ethane to Ethylene in an Oxygen-Ion-Transport-Membrane Reactor: A Proposed Design for Process Intensification

Recent major discoveries of gas and oil in the United States in shale plays have significantly increased the amount of ethane available for steam-cracking to produce ethylene; and numerous large petrochemical companies have built new ethane crackers on the U.S. Gulf Coast since 2016. Steam-cracking, however, is energy intensive; and there is a need to develop more-energy-efficient processes to produce ethylene. Oxidative dehydrogenation of ethane to ethylene in an oxygen-ion-transport-membrane reactor is thought to be one such process; and experimental work has demonstrated that (1) a mixed ionic and electronic conducting membrane with the stoichiometry BaFe0.9Zr0.1O3−δ is capable of splitting steam into gaseous hydrogen and oxygen ions on the feed gas–membrane interface, and (2) the oxygen ions can diffuse through the membrane to react with ethane on the fuel-side gas–membrane interface, producing ethylene in yields ranging from 46 to 77% at ethylene selectivities as high as 98%.