Low-temperature biomass tar model reforming over perovskite materials with DBD plasma: Role of surface oxygen mobility

Tar conversion or removal is one of the most troublesome issues limiting biomass or solid waste gasification technology's industrialization. A cost-effective and energy-efficient way of conversion of tar is indispensably dreamed. In this work, an efficient conversion of biomass tar was demonstrated in an integrated catalytic-DBD plasma process to address this. The role of lattice oxygen species for biomass tar model reforming reaction over various perovskite structured La8Ce2-M5Ti5Ox (M = Fe, Co, Ni and Cu) materials was evaluated in an integrated catalytic-DBD plasma process. The tar reforming activity was discussed by considering the production of gaseous products such as H-2, CH4 and CO, which are the main components to achieve high calorific values for the product. Among all the perovskite materials, Co-containing La8Ce2-Co5Ti5Ox gave a superior catalytic performance in oxidative toluene reforming reactions. At 250 degrees C and 90 W discharge power, La8Ce2-Co5Ti5Ox catalyst showed 98% of toluene conversion and the product gas yield of 60 vol% and 27 vol% for CO and H-2 gases, respectively. The energy content of the syngas is enhanced from 36 kJ/h for plasma only reaction to 62 kJ/h and 68 kJ/h for LC-Fe5Ti5Ox and LC-Co5Ti5Ox catalysts, respectively. Besides, LC-Fe5Ti5Ox catalyst showed enhanced H-2 yields with the addition of small amounts of H2O by maintaining similar toluene conversion. The catalytic performances of the perovskite materials were correlated with the oxygen mobility nature of the materials. XRD analysis revealed that the stable perovskite structure is present for all the materials before and after the exposure to plasma energy. O-2-TPD and XPS results revealed that the O species present in La8Ce2-Co5Ti5Ox materials are more mobile than other materials. Finally, the high surface oxygen mobility nature and stable perovskite structure were the possible reasons for the best performance of LC-Fe5Ti5Ox and La8Ce2-Co5Ti5Ox catalysts over other catalysts.