(36c) Oxidative Dehydrogenation of Ethane to Ethylene over Dual-Function Adsorbent/Catalyst Materials
Greenhouse gases and especially CO2 emissions have greatly contributed into global warming issue. Combined CO2 capture and utilization has been considered as one of the promising technological solution not only for mitigating CO2 emissions but also producing good commodity such as chemicals and fuel. In this study, we performed in-situ CO2 capture and utilization process for ethylene production through oxidative dehydrogenation of ethane in a single bed and semi-isothermal condition with adsorption at 600 oC and reaction at 700 oC over dual function materials (DFMs) consisting of K-Ca double salt as adsorbent and Cr nanoparticles as catalyst, incorporated on three different supports (SiO2, H-ZSM-5 SiO2:Al2O3 200-400 (H-ZSM-5-1), and SiO2:Al2O3 50 (H-ZSM-5-2). The properties of DFMs were investigated by N2 physisorption, XRD, XPS, SEM, EDS, NH3-TPD, H2-TPR, and thermalgravimetric analysis. The (K-Ca)40%-(Cr10%@SiO2)60% was found to exhibit the highest C2H4 yield of 35.6% followed by (K-Ca@CaO)40%-(Cr10%@H-ZSM-5-1)60% and (K-Ca)40%/Cr10%@H-ZSM-5-2)60% with 30.1% and 25.1%, respectively. These results are in line with Cr6+/Cr3+ ratio obtained by XPS analysis which showed that Cr6+/Cr3+ ratio follows the trend Cr10%@SiO2 > H-ZSM-5-1 > H-ZSM-5-2. Overall, this study demonstrated the utility of a combined capture-utilization process for producing light olefins directly from waste CO2.