ASH FUSION TEMPERATURE AND CONCENTRATION OF ELEMENTS IN THE ASH OF BIOMASS AND COAL

摘要

This study has provided extremely useful information on combustion quality of a wide range of biomass materials. Ash fusion temperature was higher for non-grass biomass than for grasses. It was also higher than that of sub-bituminous coal, and slightly higher than that of bituminous coal. Ash fusion temperatures were similar for grasses and sub-bituminous coal. Concentration of ash in biomass was similar to that in sub-bituminous coal, but generally lower than that in bituminous coal. On average, concentration of sulfur in biomass samples was only 51% of that in sub-bituminous coal, and 14% of that in bituminous coal. Volatile concentration in biomass was more than double that in coal. Results also suggest that relationships between ash composition and ash fusion temperature are different for coal and biomass, and data do not support the contention that high levels of calcium and potassium in biomass are the cause of low ash fusion temperatures. There was a strong negative relationship between ash fusion temperature and silica concentration in the ash of biomass samples, and silica concentration was several times higher in the ash of grasses than in that of non-grass materials. In general, results from this study do not support the common perception that biomass has considerably inferior combustion quality when compared to coal. However, the effect of contamination of biomass with soil on ash fusion temperature needs to be investigated.