To obtain drop-in fuel properties from 3rd generation biomass, we herein report the catalytic

hydrotreatment of microalgae biocrude, produced from hydrothermal liquefaction (HTL) of Spirulina.

Our contribution focuses on the effect of temperature, initial H2 pressure, and residence time on the

removal of heteroatoms (O and N) in a batch hydrotreating setup. In contrast to common experimental

protocols for hydrotreating at batch scale, we devised a set of two-level factorial experiments and

studied the most influential parameters affecting the removal of heteroatoms. It was found that up to

350 C, the degree of deoxygenation (de-O) is mainly driven by temperature, whereas the degree

of denitrogenation (de-N) also relies on initial H2 pressure and temperature-pressure interaction.

Based on this, complete deoxygenation was obtained at mild operating conditions (350 C), reaching

a concurrent 47% denitrogenation. Moreover, three optimized experiments are reported with 100%

removal of oxygen. In addition, the analysis by GC-MS and Sim-Dis gives insight to the fuel quality.

The distribution of heteroatom N in lower (<340 C) and higher (>340 C) fractional cuts is studied

by a fractional distillation unit following ASTM D-1160. Final results show that 63–68% of nitrogen is

concentrated in higher fractional cuts.