Separation and extensive evaluation of properties of fuel and non-fuel portions of pyrolytic bio-oil obtained from Erythrina indica biomass

Abstract

Pyrolytic conversion of Erythrina indica under inert conditions at 600 °C and 1 bar pressure resulted in 26.873 wt. % of bio-oil, 42.870 wt. % of biochar, and 30.257 wt. % of non-condensable gases. The fuel phase separation was performed at 10%, 20%, 30%, and 40% (on volume basis) of a solvent-to-bio-oil ratio using dichloromethane and n-hexane, which depicted significant improvement in its physiochemical properties. However, the fuel phase obtained using n-hexane had better physiochemical properties than that obtained by dichloromethane, indicating n-hexane as a better solvent. The fuel phase extraction utilizing 30 and 40 vol. % of n-hexane showed that they were close to regular gasoline in terms of density, viscosity, and calorific value, which turned out to be the best accomplishment of this work. The calorific value of the fuel phases, extracted by dichloromethane and n-hexane, respectively, were discovered to range between 14.360 and 23.670 MJ/kg and 26.290 and 39.730 MJ/kg. Gross calorific values of corresponding biochar and the non-condensable gases were found to be 28.030 MJ/kg and 14.486 MJ/N m3, respectively. The composition of non-condensable gases revealed that 16.822 vol. % of hydrogen is present, and thus, it can be a good source of green hydrogen. Biochar produced from the pyrolytic conversion of E. indica is equivalent to conventional coal based on comparison of their physical, fuel, and other relevant properties.