Decolorization of Biopetroleum and Analysis of Colored Components

Abstract

Biopetroleum, mainly composed of alkanes, cycloalkanes, and aromatic hydrocarbons, was prepared from biomass by direct deoxyliquefaction. The distillation fractions were obtained after distilling at different temperatures and may become dark brown in color after storage in air. To produce a visually high-grade fuel, acid-activated bentonite was selected as the adsorbent to remove the color-induced components, such as unsaturated carbonyl groups, polycyclic aromatic hydrocarbons, quinones, heterocyclic and nitrous compounds, which can be determined by using GC/MS. The raw and acid-activated bentonites were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TG) and Fourier transform infrared (FTIR) spectra, respectively. The colored distillation fractions were decolorized by acid-activated bentonite. The results showed that the acid-activated bentonite was effective in removing the color-induced components from the distillation fractions, and the maximum decolorization efficiency was 86.31%. The adsorption equilibrium data were fitted to the Freundlich isotherm equation. Moreover, the product treated by the acid-activated bentonite proved to be a high-grade fuel, which is similar to −10# diesel oil (freezing point ≤ −10 °C), not only in composition but also in color.