Layered double hydroxide derived bifunctional Ca-Fe-Mg material for integrated CO2 capture and utilization via chemical looping strategy

Abstract

As a powerful process intensification strategy, chemical looping shows a promising future to achieve an integrated CO2 capture and utilization for reducing CO2 emissions and energy-cost penalties. Herein, a bifunctional Ca-Fe-Mg material derived from layered double hydroxide (LDH) was synthesized and used in chemical looping reforming process for integrated CO2 capture and utilization. Reactivity tests and detailed characterization techniques are performed to examine and explain the performance of this material. 900 °C is determined as a suitable reforming temperature, since more syngas production is obtained (2.5 times of at 800 °C). The presence of Ca induces a synergetic interaction between Ca and Fe to implement an enhanced performance of syngas contents and stable H2/CO ratio. The activity deactivation of the material derives from the phase transition of Ca2Fe2O5 to MgFe2O4, crystal size variation and particle agglomeration. Compared to a reference coprecipitated material, LDH derived Ca-Fe-Mg material shows an enhanced syngas production, due to its highly dispersion of CO2 sorption and reforming active sites. This work provides a new route to rationally design bifunctional material for integrated CO2 capture and utilization.