Co-Gasification of Biomass and Coal: Overview, Challenges and Recommendations

Co-gasification of biomass and coal is a promising technique to improve gasification performance besides reducing emission from individual gasification of coal. In this review, the current status of co-gasification, including challenges and possible solutions are discussed. It is found that co-gasification improves carbon conversion, syngas quality and heating value while reducing the slagging temperature and pollutants emission. The higher reactivity of co-gasification is the results of synergistic effect due to dominant alkali and alkaline earth materials (AAEM) present in biomass ash. The co-gasification challenges include non-uniform particle size of biomass, inhomogeneous mixing of particles, the temperature difference between coal and biomass particles, and the higher moisture content in biomass and agglomeration. However, these challenges can be mitigated by torrefaction of biomass using waste energy and optimum blending ratio.