Lab-Scale Tests as Support to Selection of Sustainable Coal Combustion Technology - Case Study: Support to Design of TPP Kakanj Unit 8 -

Abstract

In the Laboratory for coal and biomass combustion at the Mechanical Engineering Faculty - University of Sarajevo, extensive research was carried out on the characteristics of combustion of mixtures of coals from Middle Bosnian basin. The aim of the research was to obtain reliable data for further analysis and optimization of the combustion system relied on these coal blends, and the answer to the question of whether it is possible to efficiently burn these coals in boilers with dry ash bottom. Combustion of various coal blends from coal mines Kakanj, Breza and Zenica were investigated at various temperatures (950–1350 °C) and under various technological conditions in the combustion chamber. The following parameters were varied: fraction of individual coals in the mixture, combustion temperature, thermal load of the combustion chamber, air distribution including the combustion air staging system. During the study the composition of flue gas, in particular CO2, CO, NOx and SO2 emissions, then combustion efficiency, solid ash sample characteristics, reactivity of CaO and binding of sulfur to alkaline compounds of the coal ash were analyzed. Summary of the results of this research is given in this paper. It has been shown that high efficiency combustion can be established under certain conditions. It is also estimated that pulverized coal combustion with dry ash bottom furnace is acceptable and sustainable technology for treated coals/blends.