AbstractA study was conducted to quantify tar formation in a stratified downdraft gasifier using wood pellets. The effect of biomass flow rate on tar concentration was also analyzed, and more than thirty compounds in tar were quantified. Among the different compounds in tar, tertiary condensed products such as toluene, o/p-xylene, naphthalene, phenol, styrene, and indene were observed in significant amounts. Tar concentration in the syngas was found to be in the range of 340 to 680 mg/Nm3. These concentrations were found to be much higher when compared to a similar gasifier using woodchips.