Study on changes in product characteristics and reaction kinetics of deoxygenation for biomass at low temperatures

The low temperature deoxidation processes of cotton stalk and corn stalk ranged from 200℃ to 390℃ were studied. The product characteristics and the kinetics of the deoxidation processes were analyzed to provide a theoretical basis for further exploration of the reaction mechanism of low temperature deoxidation of biomass. The results showed that compared with the raw biomass, after 390℃ low temperature deoxidation reaction, the O/C and H/C of cotton stalk dropped 78.5% and 60.9%, the O/C and H/C of corn stalk dropped 71.8% and 59.7%, the effect on deoxidation is obvious, and the calorific value of cotton stalk and corn stalk increased 36.4% and 31.9%. The weightlessness of cotton stalk and corn stalk during 290-390℃ were increased by 28.22% and 52.28% over the weightlessness during 200 and 290℃. The pyrolysis process of both cotton stalk and corn stalk can be described by hierarchical reaction model, the activation energy of cotton stalk and corn stalk during low temperature deoxidation are 120.91, 109.27 kJ/mol. The pyrolysis process of biomass three components can be described by first order model, the activation energy of hemicellulose, cellulose, lignin during low temperature deoxidationare 77.19, 238.99, 28.42 kJ/mol. © 2019, Editorial Board of Acta Energiae Solaris Sinica. All right reserved.