Explosion of different ranks coal dust in oxy-fuel atmosphere

Significant impact of the coal power generation onto the environment causes that new technological solutions aimed to reduce the impact of coal combustion onto the environment have currently been sought. Oxy-fuel is one of the technologies which reduces conventional pollutants such as NOx, SO2 and contribute to the elimination of CO2. The strategy for the implementation of this technology has currently been connected with two directions: (1) retrofitting of existing power plants to fit new combustion conditions or (2) design of new units. When air is replaced with CO2/O2, it leads to lots of doubts and concerns on boiler construction solutions. The article presents the results of research studies on four coals, on four coals, two bituminous coals and two lignite. The laboratory studies analysed the impact of CO2/O2 atmosphere onto explosion risks in fuel handling/preparation installations. These research studies were performed with the application of 20-litre sphere and TGA/DTG. It was found that the impact of the oxy-fuel atmosphere onto increased explosion risks is lower than it could be concluded from an increase in oxygen concentration in the system. The TGA/DTG studies showed, however, that devolatisation and fuel ignition in the oxy-fuel atmosphere occur at lower temperatures compared to the air atmosphere. •We present research studies on dust explosion in the oxy-fuel atmosphere.•We use two atmospheres i.e. air and 30%O2/70%CO2.•In OXY atmosphere dust explosions parameters are lower than in air atmosphere.•No significant differences in the devolatisation and combustion processes were observed for both atmospheres.•Higher heat capacity of the OXY atmosphere is the probable cause of the reduced parameters of explosiveness of coal dust.