Ethane conversion involving lattice oxygen of oxide systems

Chemical looping beyond combustion – a perspective

“…85 Encouraging results for ethane CL-ODH were also obtained with Mo-based redox catalysts, which gave ethylene selectivties of 93-95% and conversion up to 66.5% at 600 1C. 297,316 The oxygen storage capacity of these Mo-based redox catalysts was relatively low (o0.4 wt%), resulting in a decreasing conversion of ethane with time. Nonetheless, in a continuously operating riser reactor system, an ethane conversion of 12% at ethylene selectivities 490% was obtained with a mixed Mo-Te-V-Nb oxide supported on g-Al 2 O 3 when the contact time of ethane feed and redox catalysts was 1-2 s at 500-575 1C.…”

“…[290][291][292] The overall reaction is therefore facilitated by the migration of oxygen anions through the lattice and/or on the surface. The most common redox-active heterogeneous catalysts for ODH of light alkanes are based on vanadium oxide [293][294][295] with different supports, such as alumina, [296][297][298][299] alumina modified with zirconia 300,301 or silica. [302][303][304][305] Nickel oxides 306,307 and cobalt oxides 308,309 have also been examined.…”

Chemical Looping Conversion of Gaseous and Liquid Fuels for Chemical Production: A Review

“…Currently, almost exclusively ethylene is produced from the mature ethane steam cracking technology (C 2 H 6 ↔ C 2 H 4 + H 2 ; Δ H 850 °C = 143 kJ/mol), in which ethane is first preheated and diluted with steam and then this gaseous mixture is fed to external high-temperature reactor tubes to be converted into ethylene, hydrogen, and other light hydrocarbons through a complex homogeneous gas-phase cracking reaction. ,,− Although ethane cracking is a well-established commercial process, it exposes multiple drawbacks from the perspective of process efficiency, economy, and emission control. On one hand, the highly endothermic cracking reaction (143 kJ/mol), high reaction temperatures (up to 1100 °C), and complex downstream separations make this commercial process highly energy- and pollution-intensive. ,, Production of each ton of ethylene consumes approximately 16 GJ of thermal energy and results in the emission of 1–1.2 tons of CO 2 and significant amounts of NO x . , On the other hand, the steam reactor needs to be periodically shutdown for coke removal, and the single-pass ethane conversion is equilibrium-limited .…”

Co and Mo Co-doped Fe2O3 for Selective Ethylene Production via Chemical Looping Oxidative Dehydrogenation

“…Nevertheless, introducing O 2 incurs safety hazards and complexity in downstream product separation. 2,3 More importantly, the requirement of pure O 2 and, hence, an air separation unit (ASU) would raise the capital investment. 4 Chemical looping, which splits a one-step redox reaction process into two sub-steps via a solid intermediate, has been recognized as a promising way for energy conversion and upgradation.…”

“…By contrast, direct oxidative dehydrogenation (ODH) with ethane and O 2 co-feeding provides a new route for ethylene production, which can alleviate the thermodynamic equilibrium limitation by in situ combustion of H 2 . Nevertheless, introducing O 2 incurs safety hazards and complexity in downstream product separation. , More importantly, the requirement of pure O 2 and, hence, an air separation unit (ASU) would raise the capital investment …”