A dual functional sorbent/catalyst material for in-situ CO2 capture and conversion to ethylene production

Abstract

The coupling technology (CaLODHE) of calcium looping (CaL) and oxidative dehydrogenation of ethane (ODHE) has recently attracted numerous attentions. However, the optimization of the CaO-based sorbent in CaLODHE has not been extensively reported to date. In this work, a comparative study of the CO2 capture performances of the CaO-based sorbents by different synthesis methods (i.e., dry-mixing, wet-mixing, sol–gel, and coprecipitation) tested in CaL and CaLODHE conditions was conducted. The results show that the sorbent by the sol–gel method in CaLODHE condition has the highest cyclic capture performances of around 0.6 g/g during 20 cycles, attributed to the porous structure and homogeneously dispersed CeO2. In addition, the dual functional material (DFM) with CaO-based sorbent and MgGaAlO4 catalyst was first synthesized and the performances of DFM with different mixing ratios of sorbent and catalyst were investigated. The results show that the DFM with the sorbent and catalyst of the same quality has a balanced performance, and the CO2 uptake capacity and conversion are 0.27 g/g and 57%, and the ethane conversion and ethylene selectivity are 56.9% and 74.2%, respectively. In addition, the reaction mechanism of CaLODHE was also proposed in depth.