For the purpose of investigating desulfuration characteristics and mechanism of black liquor coal slurry

three combustion experiments were performed in thermobalance

test furnace and industrial boiler

respectively

and sulfur dioxide emission in the combustion fume was compared between black liquor coal slurry and the raw coal

qualitatively and quantitatively.The desulfuration mechanism of black liquor coal slurry was investigated by means of energy spectroscopy

electron probe microanalyzer and X-ray diffraction analysis of typical combustion ash samples from test furnace and industrial boiler.The result indicated that most of sulfur dioxide was absorbed by sodium hydroxide and fixed in fly ash and slag during the combustion of black liquor coal slurry

and the sulpharization process of sodium carbonate in the high temperature environment could also absorb part of sulfur dioxide.Sodium hydroxide and sodium carbonate are two principal desulfuration agents with the mechanism different from coal’s calcium-base desulfuration.The occurrence form of the desulfuration phase in fly ash and slag of black liquor coal slurry was mainly thenardite

sodium sulfate and aphthitalite.