Comparison of physicochemical features of biooils and biochars produced from various woody biomasses by fast pyrolysis

The objective of this study was to characterize biooils and biochars produced from four different woody biomasses (two hardwoods: oak, eucalyptus and two softwoods: pitch pine, Japanese cedar). Fast pyrolysis was performed at 500 °C for ca. 2 s using fluidized bed reactor. The mass balances of essential pyrolytic products (biooil, biochar and gas) were influenced by the types of feedstocks. The yields of biooils and biochars were determined to ca. 62–68% and 11–14% based on dry weight of feedstock, respectively. However, physical properties of biooils such as pH, water content, and heating value were almost similar regardless of feedstocks. All biooils were acidic (pH 1.7–2.4) and water contents were estimated between 20% and 26%. The heating values were determined to 15.5–19 MJ/kg. X-ray fluorescence (WDXRF) spectrometry and scanning electron microscopy analyses of biochars showed that considerable amounts of mineral components, which could play an important role for plants growth, were detected in the biochars.