Original title: Srovnání instrumentálních metod pro technickou analýzu popelů z biomasy.
Translated title: Comparison of Instrumental Techniques for Analysis of Ashes from Biomass.
Authors: Farták, J. ; Jiříček, I. ; Pohořelý, Michael
Document type: Papers
Conference/Event: Sborník přednášek konference CHEO 12, Praha (CZ), 20180904
Year: 2018
Language: cze
Abstract: [cze] [eng]
V příspěvku jsou porovnány různé metody pro stanovení obsahu nespáleného uhlíku v popelech z různých vzorků biomasy. TGA metoda s použitím Boudouardovy reakce byla poměrně přesná, ale nelze ji považovat za univerzální vzhledem k možnému spékání vzorků. Právě spékání může být způsobeno vyšším obsahem draslíku, jak je ukázáno v případě vzorku č. 4 a 6. Na základě předložených údajů navrhujeme metodu TGA s kontrolovanou atmosférou dusíku a vzduchu jako nejběžnější pro stanovení nedopalu. Unburned carbon (UC) in six different combustion residues from solid biofuels has been examined using several methods of analysis, such as Loss On Ignition (LOI) and Thermogravimetric Analysis (TGA). Most of the samples came from the heating plants and local heat utilities in the Czech Republic. The amount of unburned carbon in the residues varied widely over an order of magnitude and in several samples accounted for about 7% of the ash mass. Experimental results have shown that LOI overestimated unburned carbon in nearly all samples. Some of these findings can be associated with previously identified thermal decomposition of minerals present in ash. Volatile organic compounds also appear to play a role in the final UC value. Out of TGA methods, first, we used strongly endothermic Boudouard reaction method as an advanced TGA method. However, this reaction was affected by the high potassium content in the samples which could cause incomplete conversion of carbon during Boudouard reaction, because of sintering and formation of the deposits of glass at high temperatures. The second method was a simple TGA method with a controlled atmosphere of nitrogen or air. For ashes, which tend to form a glassy coating and undergo a sintering process, it is not suitable to carry out the measurement at high temperatures, because the Boudouard reaction does not proceed entirely. For these types of samples, it is more appropriate to use TGA methods with a controlled atmosphere of nitrogen or air.
Keywords: analysis; biomass; unburned carbon
Host item entry: Sborník přednášek konference CHEO 12, ISBN 978-80-7592-028-7
Note: Související webová stránka: http://hdl.handle.net/11104/0291933
Rights: This work is protected under the Copyright Act No. 121/2000 Coll.

Institution: Institute of Chemical Process Fundamentals AS ČR (web)
Original record: http://hdl.handle.net/11104/0291933

Permalink: http://www.nusl.cz/ntk/nusl-391520


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