<i>In Situ</i> Tar Removal in Biomass Gasification Using Ni-Perovskite-Based Oxygen Carriers

To integrate the advantages of catalytic cracking and chemical looping partial oxidation for tar elimination, a series of perovskite-type oxygen carriers were synthesized and evaluated for in situ tar removal in biomass gasification. The effects of pre-reduction treatment, Ni doping at the B site, and La doping at the A site of perovskite oxygen carriers on the structure and catalytic activity have been systematically investigated. Results indicate that pre-reduction treatment facilitates the formation of active Ni0 particles on the surface of La0.4Sr0.4Ni0.2Ti0.8O3, which significantly improves the tar removal ratio. Ni doping at the B site and La doping at the A site of the perovskite oxygen carriers both significantly enhance the tar removal ratio. After optimization, the oxygen carrier with the highest tar removal ratio (88.7%) is La0.2Sr0.6Ni0.2Ti0.8O3. Furthermore, the oxygen carrier La0.2Sr0.6Ni0.2Ti0.8O3 demonstrates satisfactory redox cycle stabilities, maintaining over 88.0% tar removal ratio after 10 oxidation–reduction cycles. This paper explores the composition and preparation methods of perovskite-type oxygen carriers as well as their effects on tar removal performances. The findings offer references for the optimization of biomass gasification technology and oxygen carrier design, thereby promoting the further development and application of biomass energy.