Sustainable Pathways for Fish Waste Oil Valorization into Biofuel: Process Synthesis and Case Study

Biodiesel is a promising, sustainable alternative to fossil fuels such as petrol and diesel. Currently, biodiesel can be produced from edible plant oils and non-edible sources and wastes. Notably, fish waste oil is a sustainable resource for transesterification reactions to produce biodiesel. This research proposes a general process design methodology to investigate the potential of biodiesel production from fish waste oil as a pathway for waste-to-energy. The methodology integrates Pinch Analysis principles and process simulation to optimize the energy efficiency of a process design. Real data are collected on fish waste from fish industries in Egypt, focusing on three regions in northern Egypt with a total capacity of 7.5 tons per day (t/d). The research methodology is applied to the design of a biodiesel production plant with a fish waste oil capacity of 547.5 tons/year. The production process involves a transesterification reaction using methanol and NaOH as catalysts. The annual expected yields are 495.2 tons of biodiesel and 51.4 tons of glycerol. The base design indicates total heating and cooling energies of 6889.6 kW and 11,470.1 kW, respectively, and CO 2 emissions of 19,343 tons/year. An improved design using Pinch Analysis achieves substantial energy savings of 47% in heating, 69% in cooling, and, 9202 tons of CO 2 cut. The novelty of the work lies in developing and applying an integrated process design and energy minimization methodology. The work provides a transferable methodology that can be applied to other wastes.