Study On Desulfuration And Ash Fusion Characteristics Of Co-combustion Biomass And High-sulfur Low Grade Coal

In the next few decades, coal is still in the main position in China's energy supply, since the large-scale development of hydropower, nuclear power, wind power and other electric powers is restricted by some constraints. In China's coal reserves, high-sulfur coal reserve accounts for 20%, so it is a very important issue that how to mak full use of this part resource, and also can reduce the emission of pollutants. Biomass with a high volatile, high activity, low ash and low nitrogen, almost no sulfur features, mixed with the coal burning helps reduce the emissions of NOx and SO2, which prevents the formation of "acid rain". Therefore, strengthening research the technology of co-firing biomass and coal, particularly in the field of co-combustion high-sulfur coal and biomass, has a certain academic significance and applications.In this paper, the sulfur fixation characteristics and ash fusion characteristics were researched that co-combustion five common crops and low grade coal with high-sulfur respectively by experimental methods. Investigate the influence of different mixing ratios, temperature and the composition of biomass ash to sulfur fixation ratio, explore the influence law of ash fusion performance by types and mixing ratio of biomass, and analyze the reasons which caused the change of ash fusion characteristics.The sulfur fixation performance research of co-combustion biomass and high-sulfur coal indicate that temperature has major impact on sulfur fixation ratio, the total sulfur fixation ratio decreases with temperature rising, and factual sulfur fixation ratio actually increased slightly with temperature fluctuations. In the same temperature, higher content of biomass makes better sulfur fixation effect. Sulfur fixation effect is different by using different biomass. The contents of chlorine and alkali metal in biomass have large influence in sulfur fixation effect.The ash fusion performance research of co-combustion biomass and high-sulfur coal show that co-combustion biomass can reduce the ash fusion point, the higher proportion of biomass, the greater decrease of ash fusion point. Since the content of ash in biomass is much lower than in high-sulfur coal, the mixed ash curve of TG-DSC can reflect the ash fusion characteristics with low mixing ratio; with higher proportion of co-combustion, biomass has more significant impact to mixed ash curve of TG-DSC.The sulfur fixation characteristics and ash fusion characteristics of co-combustion five common crops and low grade coal with high-sulfur respectively were investigated by experiments. The results show that the impact of sulfur fixation performance is related to temperature and sulfur fixation ratio. The research of sulfur fixation performance by co-combustion biomass and low grade coal with high-sulfur provide scientific basis and technology for industrial applications.