Molten-salt-mediated carbon dioxide capture and superequilibrium utilization with ethane oxidative dehydrogenation

Liu, Junchen; Gao, Yunfei; Wang, Xijun; Li, Fanxing

doi:10.1016/j.xcrp.2021.100503

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DOE OSTI · 1896958

Molten-salt-mediated carbon dioxide capture and superequilibrium utilization with ethane oxidative dehydrogenation

Liu, Junchen·Gao, Yunfei·Wang, Xijun·Li, Fanxing

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Abstract

Existing CO 2 -mediated oxidative dehydrogenation (CO 2 -ODH) of ethane has yet to demonstrate >60% single-pass CO yield due to the intrinsic equilibrium limitations. We report a unique approach with mixed molten carbonates as a reaction medium for CO 2 -ODH, which strategically partitions the CO 2 -ODH reactions into gas and molten-salt phases and facilitates integrated CO 2 capture from power plant flue gases. An 89% CO yield was achieved at 770°C, doubling the equilibrium limitation of conventional CO 2 -ODH. The high CO yield in turn enhances ethylene formation. Further characterizations confirmed that molten-salt mediated ODH (MM-ODH) proceeds through a gas-phase cracking and molten-salt mediated reverse water-gas-shift reaction pathway. Based on this understanding, thermodynamic analysis and ab initio molecular dynamics simulations were conducted to develop general principles to optimize the molten-salt reaction medium. Process analyses confirm that MM-ODH has the potential to be significantly more efficient for CO 2 capture and utilization than conventional CO 2 -ODH.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY CO2 capture CO2 oxidative dehydrogenation CO2 utilization chemical looping ethane ethylene molten salt oxidative dehydrogenation process intensification sorbent

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Liu, Junchen, Gao, Yunfei, Wang, Xijun, Li, Fanxing. 2021-07-14. Molten-salt-mediated carbon dioxide capture and superequilibrium utilization with ethane oxidative dehydrogenation. https://doi.org/10.1016/j.xcrp.2021.100503

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