Characterization of energy carriers obtained from the pyrolysis of white ash, switchgrass and corn stover - Biochar, syngas and bio-oil

The pyrolysis of three representative sources of biomass, namely, white ash, switchgrass and corn stover were investigated using a fixed-bed reactor to observe and compare the characterizations of three energy carriers, biochar, syngas and bio-oil. The characteristics of biochar were determined by Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffractometer (XRD) and Scanning Electron Microscopy Energy Dispersive Spectroscopy (SEM-EDS), Gas Chromatography (GC) and Gas Chromatography Mass Spectrometry (GC-MS).The results showed that the carbon content of biochar increased with the increase of pyrolysis temperature. More than 52 wt.% of the carbon was captured in the biochar. The infrared spectra of char samples illustrated that various bands in the spectra were identified, corresponding to stretches -NH-, aliphatic stretches -CH-, stretches conjugate -CC-, -CH3 and stretches -CO-. The surface morphology of biomass sample changed after pyrolysis and carbon fiber can be formed at the temperature of 500 °C. The content of combustible gas CH4, H2 and CO was changed from 50% to 70%. The GC-MS analysis of bio-oil showed that most of the chemical compounds detected were phenolic ones. This study provides a useful reference for energy carriers from the pyrolysis of biomass.