Reactivity investigation on biomass chemical looping conversion for syngas production

Chemical looping gasification (CLG) is regarded as an innovative and promising technology for producing syngas. In this work, CLG of straw was conducted in a fixed bed reactor with Fe2O3 as the oxygen carrier, whose results led to conclusions that Fe2O3, the oxygen carrier, proved advantageous to the secondary gasification reaction and the formation of CO and CO2. It was also found that CO was further oxidized to CO2 at high Fe2O3/C molar ratio, which resulted in a decreased gasification efficiency and low heat value of syngas. Therefore, a conclusion was drawn that the most optimized Fe2O3/C molar ratio was 0.2. In addition, the alkali metals in the biomass evaporated as chlorine salts into gas phase and retained as alkali metal oxide at high temperature, resulting in coking, slagging and heating surface corrosion. In the mean time, the oxygen carrier mainly converted to Fe and sintering phenomenon was serious at high temperature despite the fact that high temperature promoted gas yield, carbon conversion efficiency and gasification efficiency. Therefore, the most optimized temperature was set to 800 degrees C in order to maximize gas yield and gasification efficiency. (C) 2018 Energy Institute. Published by Elsevier Ltd. All rights reserved.