Liquor-to-liquor differences in combustion and gasification processes: Dust composition and melting properties

The behaviour and properties of the inorganic droplet residues (carry over) and condensed dust (fume)formed during combustion of liquors front eight mills are studied. Based on elemental analyses of the liquors, analyses of the char residues obtained by single-particle pyrolysis tests and advanced chemical modelling of the formation and conversion of the inorganic material in combustion, the composition of the droplet residues and condensed dust formed under typical boiler conditions, and the melting behaviour of carry over and fume particles art, predicted. Melting range estimates are based on the alkali salt melting equilibrium model. The predicted sticky, temperature (T-15) varies between 590 and 740degreesC for carryover particles, and between 540 and 860degreesC for fume particles. Electrostatic precipitator dust samples and short-term superheater deposit samples were collected from the boilers. There was generally good agreement between the measured compositions and melting properties of these samples and predicted fume and carryover compositions.