Insights into synergistic effects of oxygen content and reaction temperature on gas product emissions and solid product deposition behaviors during biomass gasification process

In this study, a comprehensive study of biomass gasification behaviors via using a fixed-bed tube reactor was conducted. The effects of reaction temperature and oxygen content in the gasifying agent on different products yields, gas emissions, and solid product characteristics were investigated. The results indicated that with increasing gasification temperature, the gaseous product yield increased while the solid product yield illustrated a reverse trend. By contrast, the liquid yield first increased rapidly, then decreased gradually. Elevating oxygen concentration in the gasifying agent resulted in a decrease of solid yield. During the whole gasification process, the emission of CO was a bit earlier than CO 2 regardless the gasification temperature used. The increasing oxygen concentration resulted in an increase of CO 2 yield while the CO yield showed an opposite trend due to combustion reactions. Compared with low temperature ashes (400 and 600 °C), the high temperature ash (800 °C) showed a much denser structure with agglomeration, indicating that the elevated gasification temperature could aggravate the ash deposition tendency in the practical applications on account of the fusion of low melting point eutectics containing a large amount of alkali species. The effects of oxygen contents on ash deposition were insignificant. Herein, the results of ash characteristics could provide theoretical and practical insights into both ash deposition and its potential applications.