Combustion of pre-dried brown coal in enriched with oxygen atmosphere

Abstract

Brown coal is considered to be a competitive primary energy source for power generation for many countries. In order to keep its competitive edge, the improvement of the power plant efficiency is absolutely required. This could be accomplished by using clean coal technologies. The main aspects of the introduction of the clean coal technologies as oxy-combustion are investigation taking into account the fuel characteristics and investigation of coal combustion in atmosphere enriched with oxygen. An important issue is also the improvement of the fuel quality, which can be achieved by the installation of external brown coal dryers. The influence of pre-drying of the raw fuel in an external dryer is of great importance to the optimization of lignite utilization. This work is mainly focused on the investigation of the behavior of pre-dried brown coal with different moisture content, during ignition, pyrolysis and combustion in atmosphere at different ratio O2/CO 2 is studied. The investigations of ignition time and intensity at selected O2/CO2 ratio for different coal particle size were carried out. Base on thermogravimetry analysis kinetic data in atmosphere at different ratio of oxygen/ carbon dioxide were determined. Also at various moisture content in pre-dried brown coal the tests of oxy-combustion were carried out taking into account the emission pollutants as NOx and SO 2. © Tsinghua University Press, Beijing and Springer-Verlag Berlin Heidelberg 2012.