Ash Sintering Behavior of Lignite in Catalyzed Steam Gasification with Kaolin as Additive

Abstract

An investigation of the ash sintering characteristics of LLI lignite with kaolin additive during K2CO3‐catalyzed steam gasification was conducted in this study. The ash samples were prepared using a catalytic gasification system at 1073 K under steam atmosphere. Experiments on the sintering behavior were performed using a pressure‐drop sintering device under inert N2. Results showed that when increasing the concentration of K2CO3 from 0 to 10 wt %, the ash sintering temperature decreased and the ash molten degree become more serious. The potassium‐containing compounds arcanite and kaliophilite can trigger the occurrence of sintering on reactions with other minerals to facilitate the formation of liquid phases and then result in a lower ash sintering temperature. Besides, kaolin can increase ash sintering temperature and ease the melt degree of ashes. Kaolin can react with other minerals to generate more refractory silicon oxide and decrease the fluxing arcanite and amorphous materials in ashes.