Pyrolysis of safflower (Charthamus tinctorius L.) seed press cake in a fixed-bed reactor: part 2. Structural characterization of pyrolysis bio-oils

Biomass in the form of agricultural residues is becoming popular among new renewable energy sources, especially given its wide potential and abundant usage. Pyrolysis is the most important process among the thermal conversion processes of biomass. In this study, the various characteristics of bio-oils acquired under different pyrolysis conditions from safflower seed press cake (SPC) were identified. The elemental analyses and calorific values of the bio-oils were determined, and then the chemical compositions of the bio-oils were investigated using chromatographic and spectroscopic techniques such as column chromatography, ¹H NMR, FTIR and GC. The fuel properties of the bio-oil such as kinematic viscosity, flash point, density, water content and ASTM distillation were also determined. Chemical compositions of bio-oils showed that some quantities of hydrocarbons were present, while oxygenated and polar fractions dominated. The bio-oils obtained from safflower seed press cake were presented as an environmentally friendly feedstock candidate for biofuels and chemicals.