Progress in the change of ash melting behavior and slagging characteristics of co-gasification of biomass and coal: A review

The gasification process is considered one of the most effective methods for harnessing energy from biomass. As a promising renewable energy source, biomass offers energy-saving, low-carbon, clean, and efficient conversion of raw materials through gasification. Biomass ash is crucial for ensuring stable coal and biomass co-gasification operations and has thus become a noteworthy point in gasification research. This review provides an overview of global research on biomass and coal co-gasification, focusing on the change of ash melting behavior and slagging characteristics of biomass and coal co-gasification. The key areas include the similarities and differences between biomass ash and coal ash, the viscous temperature and melting characteristics of mixed biomass and coal ash, and the impact of alkali/alkaline earth metals on co-gasification reactivity and slagging behavior during the sintering process. Based on the above induction, analysis, and discussion, the review summarizes and analyzes the effect of adding different biomass types on the melting flow and sintering behavior of mixed ash, presents prediction models and methods for determining melting and slagging properties of mixed ash between biomass and coal, identifies future research priorities for biomass and coal co-gasification,and provides more solutions to avoid agglomeration and slagging during the gasification process.