Catalytic Hydrotreatment of Microalgae Biocrude from Continuous Hydrothermal Liquefaction: Heteroatom Removal and Their Distribution in Distillation Cuts

    Elsa Calmette Cirasuolo
    By Elsa Calmette Cirasuolo

    General information

    Author(s) :
    Muhammad Salman Haider, Daniele Castello, Karol Michal Michalski, Thomas Helmer Pedersen and Lasse Aistrup Rosendahl
    Journal or conference :
    Energies
    Publication date :
    2018-12-01
    Summary :

    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.

     

    Type of publication :
    DOI: :
    doi:10.3390/en11123360