Prediction of ash fusion temperatures of high calcium lignites originated from the Ptolemais-Amyntaio basin, North Greece

Abstract

ABSTRACT This study aims to investigate the lignite ash behavior during combustion for electricity generation and to predict the Ash Fusion Temperatures (AFTs) using ash chemical composition. The studied lignite samples were collected from the area of Ptolemais-Amyntaio at Western Macedonia district of Northwest Greece. Ash chemical composition and its AFTs were determined for all collected samples. Results indicated that the chemical composition of the ash varies significantly and is rich in CaO. AFTs, as well as, slagging and fouling indices derived from the chemical analysis results, showed the tendency for slagging and fouling fluctuates also significantly. The varying chemical composition and AFTs, requires frequent sampling and laboratory analysis. Since AFTs determination is a time-consuming laboratorial procedure, multiple linear regression models, capable to predict AFTs from ash chemical composition, were developed. The adjusted regression coefficients of the prediction models were around to 0.90, while the relative root mean square error was approximately 4%.