Decarbonization potential of bioethanol fuel blend systems using Hydrodictyon indicum : A Life Cycle perspective of algal bioenergy

This study approaches an integrated biomass conversion of Hydrodictyon indicum into liquid biofuels. The algal biomass was collected from the high altitude lake of Uttarakhand. The study looks at how to produce and use bioethanol from Hydrodictyon indicum algae in a way that is good for the environment, using a process that involves breaking down the algae with enzymes and then fermenting it with yeast. Hydrodictyon indicum has α-cellulose content of 59.38%, and it produced a bioethanol yield of 1.42 g/L. Blended fuels combining algal bioethanol with conventional fuel were prepared using an inline blending technique. The blended fuel exhibited a cloud point of 6°C, a pour point of −8°C, and a flash point of 51°C. Additionally, it demonstrated a high calorific value of 9985 kcal/kg. Emission analysis revealed a significant decrease in CO₂ and SO₂ emissions compared to standard diesel. The measured levels of CO (4.71 ppm) and CO₂ (2.16 ppm) indicate efficient fuel combustion. LCA, performed using ReCiPe 2016 midpoint methodology, quantified the environmental performance per Lbe20. The results indicated an extremely low CCI (0.125 g CO2-eq L−1), Moderate AI (0.85 g SO2-eq L−1) and reduced FDP (0.42 g Oil-eq L−1). The present study reveals an achievable way to decarbonize the transportation industry by proving that algae-based bioethanol could potentially be used in cleaner fuel compositions.