Thermodynamic Analysis and Synthesis Gas Generation by Chemical-Looping Gasification of Biomass with Nature Hematite as Oxygen Carriers

Zhen Huang, Fang He, Anqing Zheng, Kun Zhao, Sheng Chang, Xinai Li, Haibin Li, Zengli Zhao

Key Laboratory of Renewable Energy and Gas Hydrate of Chinese Academy of Sciences, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou, China.

DOI: 10.4236/jsbs.2013.31004                

Abstract

Thermodynamic parameters of chemical reactions in the system were carried out through thermodynamic analysis. According to the Gibbs free energy minimization principle of the system, equilibrium composition of the reactions of chemical-looping gasification (CLG) of biomass with natural hematite (Fe₂O₃) as oxygen carrier were analyzed using commercial software of HSC Chemistry 5.1. The feasibility of the CLG of biomass with hematite was experimental verified in a lab-scale bubbling fluidized bed reactor using argon as fluidizing gas. It was indicated the experimental results were consistent with the theoretical analysis. The presence of oxygen carrier gave a significant effect on the biomass conversion and improved the synthesis gas yield obviously. It was observed that the gas content of CO and H₂ was over 70% in CLG of biomass. The reduced hematite particles mainly existed in form of FeO. It was showed that the reduction of natural hematite with biomass proceeds in a stepwise manner from Fe₂O₃ →Fe₃O₄→ FeO. Reduction product of natural hematite can be restored the lattice oxygen by oxidation with air.

Keywords

Thermodynamics; Synthesis Gas; Natural Hematite; Oxygen Carriers; Biomass Chemical Looping Gasification

Conflicts of Interest

The authors declare no conflicts of interest.

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