Qualitative analysis of coal combusted in boilers of the thermal power plants in Bosnia and Herzegovina

In this paper we have looked into the qualitative analysis of coals in Bosnia and Herzegovina (B-H). The analysis includes the following characteristics: moisture (W), ash (A), combustible matter (Vg) and lower heating value (Hd). From the statistic parameters we have determined: absolute range (R), arithmetic mean (X), standard deviation (S) and variations coefficient (Cv). It has been shown that the coal characteristics (W, A, Vg, Hd) have normal distribution. The analysis show that there are considerable deviations of ash characteristics: moisture (36.23%), ash (34.21%), combustible matter (16.15%) and lower heating value (25.16%) from the mean value which is shown by the variations coefficient (Cv). Large oscilations of mass portions: W, A, Vg and Hd around the mean value can adversely influence the function of a boiler plant and an electric filter plant in thermal power plants in B-H in which the mentioned types of coal burn. Large ash oscilations (34.21%) around the mean value point out to the inability of application of dry procedures of desulphurisation of smoke gasses (FGD) due to the additional quantity of ash. It has been shown that the characteristics of Bosnian types of coal do not deviate a lot from the characteristics of coal in the surrounding countries (coals of Serbia and Monte Negro). The results can be used in analysis of coal combustion in thermal power plants, optimisation of electrical-filtre, reduction of SO2 in smoke gas and other practical problems.