Ecosystem simulation and environmental impact analysis of transforming microalgae to produce jet fuel

Dunaliella salina is a fast-growing microalgae with excellent environmental adaptability but a low lipid content, which absorbed organics in wastewater. On basis of systematical data about previous work, an ecosystem model converting microalgae to jet fuel using catalysts HTL method is constructed, in which the bio-oil yield significantly increased to 49.09%. The heat-integration in separation section optimization reduced 46.1% of electricity and 63.4% of the heating energy, which reduced the impact categories of Acidification/Eutrophication and Fossil fuels, by 65.44% and 122.86%, respectively. Through life cycle assessment (LCA) of aqueous phase separation, the results showed that the impact categories of Acidification/Eutrophication, Climate change, Ecotoxicity and Ozone layer reduced by 18.87%, 18.14%, 17.72% and 18.31%, respectively. The system achieved the utilization of organic carbon in wastewater (40.92 kg C/100 kg dry microalgae), and also realized the fixed carbon (2.89 wt % of final product) from fossil energy carbon, which highlighted the importance of technological innovation for environmental protection and provided guidance on microalgae utilization.