Synergistic effect of additives and blend on sulfur retention, NO release and ash fusibility during combustion of biomass briquettes

摘要

Even though biomass is carbon-neutral renewable energy, the utilization of biomass results in sulfur oxides (SO (x) ), nitrogen oxides (NO (x) ) and particles emissions. Biomass briquetting and doping with additives are potential methods to ease these emissions. However, additives may increase the price for biomass application. Hence, another method is mixing different kind of biomass which possesses significant difference in ash composition, i.e. using synergistic effect to ease these emissions. In this study, the effect of blending of tree bulk and wheat straw and additives on SO2, NO emissions from briquettes combustion were studied. Experimental results indicate that the emission of SO2 and NO from the mixed briquettes would decrease due to the synergistic effect. An appropriate weight mixing ratio between tree bulk and wheat straw was recommended. The method of mixing raw materials would potentially save additives and reduce the cost of biomass briquettes. The SO2 and NO emission would further decrease and the ash fusibility could be improved obviously for the mixed briquettes modified by CaO, CaCO3, and NH4H2PO4. The NO emissions for the briquettes are much lower during the combustion temperature of 800 degrees C 1000 degrees C. This study may contribute to modification, additives, clean combustion, and economy for the utilization of biomass fuel.