Mechanism analysis of synergy behavior during blended char co-gasification of bituminous coal and rice straw

The gasification reactivity of Shenfu bituminous coal char, rice straw char and their blended char and the synergy behavior in blend were studied using TGA. Additionally, inductively coupled plasma emission spectrometer and scanning electron microscopy coupled with energy disperse spectroscopy were employed to explore the active AAEM transformation characteristics in co-gasification process, so as to correlate and explain the synergy behavior variations during co-gasification. The results show that the addition of rice straw char to coal char was favorable for promoting the overall char gasification reactivity compared with individual coal char gasification. The synergy behavior at different co-gasification conversions changes from the gradually decreasing inhibition effect at the early stage of co-gasification to the gradually enhanced synergistic effect when reaching a turning conversion that is increased at higher gasification temperature. The synergy behavior variations during blended char co-gasification are attributed to the combined effect of active K and Ca transformation characteristics in co-gasification process. Furthermore, the overall synergy behavior of blended char co-gasification is shown as a positive synergistic effect, and it is weakened with the increase of gasification temperature.