Samples of bottom ash and fly ash coming from the combustion of lignite with the addition of limestone, from the cocombustion of lignite and wood residue with limestone and from co-combustion of lignite, wood residue, biological sludges from the waste water treatment plant and municipal waste as well with the addition of limestone were examined. Scanning electron microscopy with X-ray microanalyser were used for study of morphology and chemical composition of ash particles. The results were compared with average composition of bottom ashes, fly ashes and input materials found by X-ray fluorescence spectrometry and with phase composition found by X-ray diffraction method. There were proved no significant differences in the character and the structure of individual samples coming from various regimes of combustion., Vladimír Tomášek, Ondřej Šustai, Jana Seidlerová, Zdeněk Klika, Martin Stach, Zdeněk Weiss and Václav Roubíček., and Obsahuje bibliografii
Most of natural materials contain traces of chlorine and it enters also to the combustion process. Chlorine products of combustions are usually inorganic hydrogen chloride vapors and chloride salts, nevertheless smaller amount of organic chlorine compounds are formed. Simpler of these organic compounds can act as greenhouse and ozone depleting gases; more complex compounds are directly dangerous for their mutagenity or extreme toxity like so called dioxines. Non-fossil natural materials and fuels derived of them can contain more chlorine than common coal. From the published research studies is evident that the formation of organochlorine compounds is limited to the temperature range 300-800 °C. At the higher temperatures, these compounds are destroyed. In the stage of flue gas cooling some chlorine may be by a "de novo" synthesis introduced to the organic form. Well-controlled combustion of alternative fuels need not contribute to the increase of amount of emissions of dangerous chlorine compounds. In our research were moreover studied the fuels with lower chlorine content. The experimental tests of the emissions from large-scale industrial fluid bed boiler indicated that substitution of large percentage of coal by alternative fuels had no significant effect., Kamil Wichterle, Jan Cieslar, Antonín Klečka, Zdeněk Klika and Václav Roubíček., and Obsahuje bibliografii
Combustion of coal with limestone (a) and co-combustion of coal with limestone with wood, sewage sludge, soap and PTP (b) were performed in CFB. Inorganic matter composition and properties of all input materials were characterized. For this, chemical and coal petrography analyses of solid samples as well as their leaching tests, unburned carbon, and other properties were determined. There are not striking differences in composition of bottom and fly ashes from combustion/co-combustion data. In fly ash samples higher concentrations of Hg (about 2 ppm), As (about 800 ppm) and chlorine (about 400 ppm) are present than they are in bottom ash (0.002 ppm Hg, 250 ppm As, and 220 ppm Cl). Also relating concentrations of above elements determined in emissions are very similar for combustion/co-combustion regimes (about 0.010 mg.m-3 Hg, 0.027 mg.m-3 As and 24 mg.m-3 Cl). Content of unburned carbon in BA is below 2 wt.% and in FA below 0.6 wt.% in all combustion/co-combustion data. In FA samples the concentration of Hg, As, Se, etc. increases with increasing unburned carbon content, i.e. with decreasing grain size of FA. No significant differences in composition of emissions, bottom and fly ashes as well as in composition of water leachates were found from the combustion regimes I, II, III and IV., Martin Stach, Zdeněk Klika, Martina Nováčková and Václav Roubíček., and Obsahuje bibliografii
Review article presents utilisation of coal in industry, coal in power generation, gas production, Czech energy policy and outlook and application of clean coal technology in the Czech power stations. The further exploitation and utilisation of Czech coal resources requires the implementation of development programme aimed at the application of the new, economically effective technologies, of coal mining, utilisation, gasification. Emissions of GHG in CR., Václav Roubíček, Pavel Kolat and Jaroslav Buchtele., and Obsahuje bibliografii