Assessing yield and properties of distillate from biocrude and blend after hydrothermal liquefaction of microalgae

Abstract

This paper is on assessing yield and properties of distillate derived from biocrude, and blend stream of biocrude and conventional petroleum. Biocrude was produced from hydrothermal liquefaction of a halophytic microalga Tetraselmis sp. at 350^oC, 5min with 16w/v% solids content. The resultant biocrude was coprocessed with petroleum using fractional distillation. The result of the study shows that similar yield and quality distillate were obtained from petroleum and blended stream. Distillate fraction obtained from the blend had similar properties such as higher heating values (HHV), H/C atomic ratio and elemental composition to those of petroleum crude. The energy density of biocrude-distillate significantly improved from 72.4MJ/kg to 86.9MJ/kg with about 97% reduction in oxygen content. Recovery of gasoline fractions with normal boiling point range of 190^oC to 290^oC were found higher in petroleum and blend compared to biocrude. This finding is important as coprocessing blend of biocrude and petroleum would address the issues with heteroatoms, which could be of great economic importance. However further studies are necessary on distillate fractions, in order to assure compatibility with petroleum derived fuels.

Keywords: Biocrude; Coprocessing; Microalgae; Hydrothermal liquefaction