Chemical Looping Catalytic Steam Gasification (CLCSG) of Algae Over La <sub>1-X</sub>Ba <sub>x</sub>FeO <sub>3</sub> Perovskites for Syngas Production

Abstract

Multifunctional perovskite-type oxides (ABO3) with flexible chemical tailoring characteristics and unique physical properties, are attracting an ever-increasing attention of scientists in the field of biomass chemical looping gasification process. Barium substituted lanthanum ferrite La1-xBaxFeO3 (x=0, 0.3, 0.5, 0.7, 0.9, 1.0) with perovskite structure was used as oxygen carrier for algae chemical looping catalytic steam gasification (CLCSG) process for the first time. The effects of the Ba-substitution, mass ratio of perovskite and algae (P/A), temperature and water injection rate on the gasification performance were investigated. Results showed that the activity of LaFeO3 was dramatically improved by Ba substitution due to the formation of Fe4+/Fe3+ and oxygen vacancies. Among all the doped LaFeO3 perovskites, La0.3Ba0.7FeO3 (L3B7F) exhibited the best performance and gave highest syngas yield, carbon conversion and gasification efficiency. A maximum syngas yield of 1.00 m3/kg‧Algae, carbon conversion of 98.86% and gasification efficiency of 96.71% were obtained at 900 oC with a water injection rate of 0.3 ml/min. Continuous high syngas yield and carbon conversion were observed during the cyclic redox tests.