Biomass gasification in a laboratory-scale AFBG: influence of the location of the feeding point on the fuel-N conversion

The influence of the feeding point on the conversion of fuel-nitrogen (fuel-N) was studied in an atmospheric fluidized bed gasifier. A comparison between feeding into the bed and feeding from the top of the reactor was made for different temperatures and equivalence ratios. Special emphasis was given to the distribution of fuel-N into NH3, HCN and char. The results show no influence of the feeding point on the nitrogen conversion to HCN and on the amount of nitrogen in char. Top feeding, however, results in lower conversion of fuel-N to NH3. The feeding points, and therefore the contact between the fuel particles and the surrounding oxygen-containing gas, as well as the oxygen concentration itself, are of great importance for the formation and destruction of NH3.