Assessment of miscanthus biomass (Miscanthus sacchariflorus) for conversion and utilization of bio-oil by fluidized bed type fast pyrolysis

Liquid bio-oils were produced from miscanthus (Miscanthus sacchariflorus) by fast pyrolysis at various temperature ranges (350-500 °C) with a short residence time and their physicochemical properties were determined to evaluate the potentials for biofuel utilization. Before operating fast pyrolysis, miscanthus was subjected to ICP-ES (inductively coupled plasma emission spectrometer) analysis and TGA (thermogravimetric analysis). It was learned that miscanthus was thermally unstable due to large amounts of inorganic constituents including potassium (5643.8 ppm), calcium (711.0 ppm) and magnesium (1403.1 ppm). With fast pyrolysis, the yield of bio-oil gradually decreased with increasing temperature and residence time. The maximum yield of bio-oil was ca. 58.9 wt% at 350 °C with a residence time of 1.9 s. The HHV (higher heating value) of bio-oil was determined up to 18.0 MJ/kg produced at 400 °C with a residence time of 1.9 s. The water content of bio-oil was ranged from 21.1 to 56.9 wt%. GC/MS (gas chromatography/mass spectrometry) analysis showed that bio-oil was mostly composed of carbohydrate derivatives and lignin derivatives. 1-(Acetyloxy)-2-butanone, furfural, dihydro-methy-furanone and levoglucosan were the predominant low molecular weight compounds that originated from carbohydrate and those from lignin were guaiacol 4-vinylphenol and syringol.