| Summary: | An external thermal high-temperature continuous feed moving bed tubular reactor was used for the gasification of high moisture content lignite (30.41 wt.%) under CO<sub>2</sub> and an auto-generated steam atmosphere. The objectives of this study are to illustrate the synergistic gasification characteristics of high moisture content lignite and CO<sub>2</sub> in the tubular reactor; CO<sub>2</sub> and auto-generated steam (steam released from the lignite) were used as gasification agents for lignite gasification. The effects of temperature and CO<sub>2</sub> flow rate were also investigated. Experimental results showed that when the gasification temperature increased from 800 °C to 1000 °C, the H<sub>2</sub> yield also increased from 8.45 mol kg<sup>−1</sup> to 17.86 mol kg<sup>−1</sup>. This may indicate that the H<sub>2</sub>O-CO<sub>2</sub> gasification of semi-coke was enhanced with the rise in temperature. At 900 °C, the gas yield increased with the increase in CO<sub>2</sub> flow rate, while the yield of char and liquid product showed an opposite trend. The lower heating value of the H<sub>2</sub>-rich syngas varied from 11.73 MJ m<sup>−3</sup> to 12.77 MJ Nm<sup>−3</sup>. The experimental results proved that the high moisture content lignite in-situ CO<sub>2</sub> gasification process is an effective methodology for the clean and efficient utilization of lignite.
|
|---|