Operating conditions

In this experiment, baseline data was first obtained for single combustion of 100% British bi­tuminous coal. Also, single combustion of other biomass fuels was carried out to investigate their combustion characteristics in comparison to coal during the co-combustion study. Co­combustion tests at biomass fractions of 30%, 50%, and 70% were performed. For each bio­mass fraction, excess air was varied from 30% to 70% at 20% intervals. For each excess air condition, air staging combustion was applied where the total secondary air is maintained at 65 l/min (about 10-20% to total air ratio). In order to study the impact of fuel property changes (volatiles, ash, and combustibles), heat input was fixed at the design value of the experimental rig i. e. 10 kW. The combustion tests were operated in the bed temperature range of 700-950 °С and superficial velocity range of 0.63 – 1.12 m/s.