Biomass from grey wastewater featuring iron oxide for hydrogen production via hydrothermal gasification with...

The demand for alternative fuel is progressively increasing in various energy concerns due to pollution-free, improved energy, and better performance. The present innovation is to synthesize the hydrogen from the source of microalgae by using waste grey water. The varied percentages of iron oxide (Fe₂O₃) nanoparticles are integrated with grey water to enhance the specific growth of algae. The impact of Fe₂O₃ on the specific growth of microalgae is investigated. The highest growth of 0.98 μm/day is noted at 0.15% of Fe₂O₃, which is involved in further hydrogen production via the hydrothermal gasification process under different loading rates (0.05, 0.1, and 0.15 g/mL), varied gasification temperatures (500, 550, and 600 °C), and different concentrations (5, 10, and 15%) of potassium hydroxide (KOH) featured catalyst. The 0.2% concentration of Fe₂O₃ is recorded by the maximum specific growth of microalgae (0.98 µ/day). The effect of process parameters on functional behaviour, including molar fraction, hydrogen yield, gasification efficiency (GE), and hydrogen efficiency (HE), is evaluated. The system functioned at a 0.15 g/mL feedstock concentration with 600 °C, processing microalgae with 15% KOH catalyst action, yielding GE, HE, and lower heating values of 62.4%, 66.9%, and 8.4 MJ/Nm³. The higher processing temperature influences a superior hydrogen yield of 41.4 mol/kg.