| Project Detail |
Low nitrogen biocrude with hydrothermal liquefaction Biofuels produced using microalgae as a feedstock is a promising alternative to fossil fuels for the transport industry. The steps are straightforward: microalgal growth, biomass harvesting and drying, lipid extraction, and conversion. Current processes are not economically feasible for large-scale production. Hydrothermal liquefaction avoids the energy-intensive drying step and produces bio-oil at mild temperatures. However, it produces biocrudes with high nitrogen and oxygen content, problems difficult to solve simultaneously. With the support of the Marie Sklodowska-Curie Actions programme, the CatHyMiNi project will attempt to do so with nitrogen-selective catalysts that also promote deoxygenation reactions. The transport industry is going through a revolutionary moment in its quest to reduce its carbon footprint, with biofuels being one of the viable options. High productivity, lipid content and its ability to capture CO2 make microalgae a competitive biomass. New technologies such as hydrothermal liquefaction (HTL) has recently attracted the attention in research as it avoids the energy-costly drying step and produces bio-oil at mild temperatures. Nonetheless, conventional HTL process suffers from bio-crudes high nitrogen content, mainly caused by protein content. Furthermore, the biocrude’s high oxygen content reduces its calorific value making biocrude unattractive in addition to its high NOx emissions during combustion. Since nitrogen and oxygen in biocrude respond differently to processing temperature, an approach that would favor simultaneous reduction of both would be revolutionary. The nitrogen removal before the main HTL process could be the solution. In this perspective, the combination of microwave pretreatment and HTL process can be promising. However, this non-selective method may compromise bio-oil yield. In MicroWCatHydroN, we investigate nitrogen-selective catalysts to specifically target nitrogen compounds and maintain the trade-off between desired bio-oil yield and properties. The catalytic activity of nickel can promote hydroisomerization and deoxygenation reactions, thereby improving bio-oil’s cold flow properties and heating value. Overall, this green chemistry-compatible route is economically and technically feasible. Industrial scale-up of algae conversion requires a complete characterization of its complex degradation mechanisms and phenomena occurring during the process in order to understand how nitrogen compounds are formed and consumed. In this sense, MicroWCatHydroN aims to develop a new chemical kinetic model for ParaChlorella kessleri liquefaction. In conclusion, research is expected to increase the production of high-quality bio-oil. |
