Numerical simulation of hydrothermal liquefaction of algae in a lab-scale coil reactor

A computational fluid dynamics (CFD) model of a coil type hydrothermal liquefaction (HTL) reactor with feedstock of algae has been developed using reaction kinetics reported in the literature. The CFD model is applied to understand the effects of thermal conductivity, heat capacity, molar mass, and viscosity of both the reactants and products on the HTL reactions in terms of residence time and mass fractions, for this coil reactor. It is found that the heat conductivity, heat capacity, and molar mass have negligible effects on the HTL reaction in this reactor. However, the viscosity, particularly of the dominant reactants such as the protein, was found to have the most significant effect on the residence time and mass fractions, particularly when the viscosity of protein is reduced from values of the base case. This highlights the need for better measurements of viscosity in future work.