Parametric study on the particulate matter emissions during solid fuel combustion in a drop tube furnace

•Study of combustion and oxy-combustion of coal and woody biomass in a drop tube furnace.•Measurements of particulate matter.•Determination of number size distribution of PM1.•Influence of parameters as temperature, residence time, atmosphere and nature of the coals.•Combustion of mixture of coal and biomass.

Investigations on particulate matter (PM) emissions from solid fuel combustion are important due to their negative impacts on human health and the environment. A full parametric study of the amount and size distribution of particle emissions from solid fuel combustion have been performed using a drop tube furnace (DTF). Different operating conditions have been experimented for coals or biomass, including combustion atmosphere (air or oxy-fuel conditions), particle residence time and temperature. First, the gas atmosphere has a significant effect on PM1 emissions from coal combustion but not from biomass combustion. Second, when the particle residence time increases, the amount of PM1 tends to increase with biomass combustion but to decrease with coal combustion. Third, increasing temperature during biomass combustion tends to increase ultrafine particle emissions such as PM0.1. Fourth, the type of coal greatly affects the PM1 emissions during combustion. Finally, coal co-burning with biomass optimizes the amount of PM1 emitted when the biomass mass ratio is around 25% in the blend.