We describe a pilot plant for continuous hydrothermal processing of biomass. Results were obtained for two microalgae strains, Chlorella and Spirulina, across a range of biomass loadings (1-10 wt%), temperatures (250-350 °C), residence times (3-5 minutes) and pressures (150-200 bar). Overall, the biocrude yields were found to increase with higher biomass loading, higher temperature and longer residence time. More severe reaction conditions also reduced the oxygen content of the bio-crude, while the nitrogen content was found to increase with higher temperatures, indicating an increase in the bio-crude production from the protein fraction of the algae. The maximum bio-crude yield obtained was 41.7 wt% for processing Chlorella with a solids loading of 10 wt% at 350 °C and 3 minutes residence time. The present results suggest maximal yields may be obtained in much shorter residence times under continuous flow hydrothermal processing than batch studies have suggested. The maximal yield, however, may not be optimal in terms of properties.A substantial fraction of the feedstock carbon reported to the aqueous phase -this was up to 60% but decreased to 30% at the highest biomass loadings. Gas production (>90 mol% CO 2 ) increased with severity of processing, reaching up to 5% of the feedstock carbon. Finally, the solid yields consistently decreased with increasing temperatures and residence times.

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We have examined the effect of spin contamination in single determinant wave function at the Hartree-Fock and density functional theory in studying adsorption on graphite. Particularly, we examined NO adsorption on a single-layer graphene where some carbon atoms were left unsaturated to simulate the active sites in char. Upon comparison with the results from the restricted open-shell Hartree-Fock (ROHF) method, we found that UHF has a large spin contamination. Consequently, this yields large errors in the Hartree-Fock ground-state wave function, energy-level splitting, and adsorption energy. Interestingly, the spin contamination using unrestricted density functional theory was small, and the energetic information was almost unaffected.

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