Ageing study of Li-Ru/Al2O3 dual function material during the integrated CO2 capture and methanation with SO2-containing flue gas

A Dual Function Material containing Ru (1% wt.) and Li (3% wt.) dispersed by sequential impregnations onto Al2O3 spheres was extensively tested in the integrated CO2 capture and methanation process to assess the effects of the main species (O 2 and H2O) as well as of poisonous impurities (SO2) in realistic flue gases. The DFM designed in this work was benchmarked against the state-of-the-art formulation (Ru and Na) in terms of intrinsic methanation activity as well as CO2 capture capacity, CH4 production and selectivity across more than 100 repeated cycles performed in a fixed bed reactor operated in the temperature range 260-320 & DEG;C with alternate feed conditions. The ageing study with up to 100ppmv SO2 demonstrated a remarkable tolerance to sulfur poisoning coupled with a slow loss of CO2 capacity due to long-term S-accumulation. A detailed characterization of the fresh and S-aged DFM was performed to get insights into mechanistic aspects behind the peculiar self-regeneration characteristic of the catalytic sites in the DFM.