(514c) Capture and Methanation of CO2 Using Sodium Promoted MgO Based Catalytic Sorbent

Authors: 
Park, S. J., Georgia Institute of Technology
Jones, C. W., Georgia Institute of Technology
A combined cycle of capture and conversion of CO2 performed under isothermal conditions may be an advantageous process intensification approach compared to traditional CO2 capture and sequestration in that the combined cycle can remove energy intensive temperature or pressure swing steps and minimize process units.1 Furthermore, the produced fuel source from conversion of CO2 can be directly used again as an energy source for power generation. A first generation of catalytic sorbents, such as Ru+CaO/Al2O3, for such an application has previously been reported.1,2 In this work, sodium promoted MgO and loaded with ruthenium metal was used for capture and methanation of CO2 in a combined cycle. The MgO support with various NaNO3 and NaNO2 promoter loadings was tested for CO2 capture at 250 °C. MgO_NaNO3 (1:0.1 molar ratio) showed adsorption capacity of 7.6 mmol CO2/g in 12 h. MgO_NaNO3_NaNO2 (1:0.1:0.1 molar ratio) showed adsorption capacity of 8.6 mmol CO2/g in 12 h. To evaluate performance of these materials in a capture and methanation cycle, the methanation capacity, which is equivalent to number of moles of methane produced per mass of catalytic sorbents in a cycle of capture and methanation, was measured for the prepared catalytic sorbents. It was found that a physical mixture of MgO_NaNO3 and Ru supported MgO showed the highest methanation capacity at 250 °C with 1.1 mmol CH4/g. This methanation capacity is comparable to the highest methanation capacity reported up to date, making sodium promoted MgO sorbent promising materials for such applications.




Reference:

(1) Duyar, M. S.; Treviño, M. A. A.; Farrauto, R. J. Dual Function Materials for CO2 Capture and Conversion Using Renewable H2. Appl. Catal. B Environ. 2015, 168–169, 370–376.

(2) Duyar, M. S.; Wang, S.; Arellano-Treviño, M. A.; Farrauto, R. J. CO2 Utilization with a Novel Dual Function Material (DFM) for Capture and Catalytic Conversion to Synthetic Natural Gas: An Update. J. CO2 Util. 2016, 15, 65–71.