(178c) Demetallation of Biocrude from Hydrothermal Liquefaction of Microalgae
We hydrothermally treated microalgae using different processing conditions (isothermal, rapid heating and non-isothermal conditions, different temperatures and times) and determined the metal content in the biocrude oil as well as in the other product phases. We then studied the ability of different interventions to reduce this metal content. Process options explored include treatment in supercritical water in the absence of catalyst, use of different solvents for biocrude oil recovery after HTL, and use of heterogeneous catalysts during hydrothermal treatment. The Fe and Na content was reduced over 70% by use of specific organic solvents and reduced over 98% via application of heterogeneous catalysts. Additional catalytic studies with Fe model compounds permitted post-reaction catalyst characterization via techniques such as scanning electron microscopy and Mössbauer Spectroscopy.