Sulfur tolerance and self-regeneration mechanism of Na-Ru/Al2/O3 dual function material during the cyclic CO2 capture and catalytic methanation

The combined CO capture and methanation with Dual Function Materials (DFM) is emerging as a vibrant field of research for its potential to increase the efficiency and reduce the cost of current multistage CCU processes. In this work, we set out to investigate for the first time the impact of sulfur poisoning over a Na-Ru/AlO DFM operated in a fixed bed reactor with alternate feeds under realistic conditions including the presence of SO, HO and O in the process gas stream. The results of the extensive characterization of the fresh and sulfated (reaction-aged) DFM evidenced a remarkable intrinsic tolerance of the combined CO capture and methanation process to high concentrations of SO in the feed due to a self-regeneration mechanism of the Ru catalytic sites.