Study on reactivity characteristics and synergy behaviours of rice straw and bituminous coal co-gasification

Co-gasification of rice straw (RS) and Shenfu bituminous coal (SF) was conducted in a thermogravimetric analyzer (TGA) to explore the effects of gasification temperature and blend ratio on reactivity characteristics and synergy behaviours of co-gasification. Moreover, the relationship between the synergy and the K/Ca transformation in co-gasification was studied using flame atomic absorption spectrum (FAAS) and in-situ heating stage microscope. The results showed that the whole reactivities increased with increasing RS proportion and gasification temperature. The transformation of water-soluble and ion-exchanged (ws-ie) calcium was enhanced in whole co-gasification and the ws-ie potassium transformation was obviously inhibited in mid-late reaction. Hence, synergy behaviours were synthetically determined by the enhancement of Ca deactivation and the strengthening of K catalysis. The inhibiting effect was occurred in initial co-gasification and was converted to the synergistic effect at a characteristic conversion, which decreased with increasing RS proportion and decreasing gasification temperature.