Upgraded syngas through selective partial oxidation of tar using Ni-doped LaFeO3 with tuned oxidation potential

A novel approach is presented for the conversion of tar under a syngas atmosphere using chemical looping partial oxidation, aiming to enhance the production of effective syngas components, H2 and CO. By partially substituting Fe in the LaFeO3 oxygen carrier with a small amount of Ni, the conversion of tar into H2 and CO can be achieved at 800 °C, without depleting the original H2 and CO in the syngas. Compared to the LaFeO3 oxygen carrier, the LaNi0.06Fe0.94O3-λ oxygen carrier exhibits a 63.0 % increase in tar conversion rate, with H2 and CO production increased by 590.53 ml and 1,648.71 ml, respectively, achieving a 97.1 % tar removal rate within a 30-minute reaction period. Experimental result reveals that LaNi0.06Fe0.94O3-λ shows the most significant lattice oxygen activation peak and the highest lattice oxygen content within the 750–830 °C temperature range under a syngas atmosphere. However, increasing the Ni doping ratio and reaction temperature leads to decreased tar conversion rates and syngas production. This work demonstrates that LaNi0.06Fe0.94O3-λ can achieve targeted tar conversion in a reducing syngas atmosphere while preventing the complete oxidation of both the oxygen carrier and tar, highlighting its potential for converting tar-laden syngas into effective syngas components. © 2024 Elsevier B.V.