Features of Structure and Chemical Ccomposition of Agglomerated Particles During Biomass Combustion in Fluidized Bed

Agglomeration of the bed materials is one of the significant problems in the biomass fluidized bed combustion, especially for agricultural waste with a very high content of sodium and potassium oxides in the ash, which can form fusible eutectic with silicon oxides. The study of the agglomeration conditions of the bed materials for four types of biomass was carried out. The influence of temperature on the proportion of formed agglomerates was established. It is shown that at concentrations of alkaline elements in the bed (more than 0.4 %) agglomeration occurs even at low temperatures of 750-800 o C. Replacement of sand (part of sand) with iron oxides leads to a sharp decrease in the proportion of formed agglomerates even under conditions of potassium and sodium concentration of more than 1 %.  The microstructure and chemical composition of agglomerated particles were studied using a scanning electron microscope equipped with an energy dispersive microanalysis system. New data on the structure of the surface layer of agglomerated particles are obtained.