Experimental Study on Performance of Downdraft Gasifier Reactor under Varied Ratios of Secondary and Primary Air Flows

Experimental investigation is carried out in open top downdraft biomass gasifier for studying reaction front propagation rate and variation in gas quality in the packed bed reactor. The study includes conditions both with and without secondary air in to the reactor. It is established that in at certain range of ratios of primary to secondary air flows, entry flame front stabilized near the secondary air nozzle. Effect of moisture content in the fuel is studied for different secondary to primary air ratio. It is found that the propagation rates are lower for fuel with higher moisture content. Variation in gas composition with different ratios of secondary to primary air for a range of moisture content in the fuel is studied. The effect of the ratio of secondary to primary air on gas calorific value is evaluated. The results of the work is presented with their associated observations.