Air and oxy-fuel combustion kinetics of low rank lignites

Autor: Hüsnü Atakül, Berrin Engin
Rok vydání: 2018
Předmět:
Zdroj: Journal of the Energy Institute. 91:311-322
ISSN: 1743-9671
DOI: 10.1016/j.joei.2016.11.004
Popis: The air and oxy-fuel combustion processes of two low-grade lignite coals were investigated by thermogravimetric analysis (TGA) method. Coals were provided from two different coal mines in the Aegean region of Turkey. Oxy-fuel combustion experiments were carried out with three different gas mixtures of 21% O 2 –79% CO 2 ; 40% O 2 –60% CO 2 and 50% O 2 –50% CO 2 at 950 °C and heating rates of 10 °C/min, 20 °C/min and 40 °C/min. The kinetics of the oxy-fuel combustion of coals were studied by using four different methods namely, Coats-Redfern (model-fitting method), Friedman (FR), Flynn–Wall–Ozawa's (FWO) and Kissinger–Akahira–Sunose's (KAS) methods. The apparent activation energies of combustion process calculated by FWO method are slightly but systematically higher than that calculated by the KAS and FR methods for the oxy-fuel atmospheres. Combustion behavior of both coals in the oxy-fuel combustion environment could vary significantly, likely due to their characteristics such ash and volatile matter contents.
Databáze: OpenAIRE