Techno-economic analysis of bioactive-rich oil production from Nannochloropsis oculata

Carotenoids and polyunsaturated fatty acids (PUFAs) from microalgae have applications in food, pharmaceuticals, cosmetics, and aquaculture. However, the large-scale use of these compounds is limited by high production costs associated with microalgae harvest and extraction. Microalgae such as Nannochloropsis oculata are also recognized for their capacity to capture CO₂ and remove nutrients from wastewater, positioning them as promising tools for pollution mitigation within circular bioeconomy models. In this article, a techno-economic analysis was performed for three plant sizes (720 kg h^-1, 360 kg h^-1, 180 kg h^-1), considering the downstream processing of cultivated biomass for oil extraction using ethanol as solvent. All unit operations of the process were studied, and mass and energy balances were performed using experimental and literature data. The estimated net present value indicated positive economic feasibility for all plant sizes, and the plant with the highest capacity demonstrated the most favorable profitability metrics. Sensitivity analysis revealed that the net present value of cash flow after tax remained positive for minimum oil selling prices ranging from US$ 90.45 kg⁻¹ to US$ 90.73 kg⁻¹, highlighting the high added value of bioactive compound-rich oil. By demonstrating economically viable production routes, this study supports the deployment of microalgae-based systems that simultaneously valorize biomass and contribute to pollution mitigation, aligning with the goals of sustainable water management and climate action.