Comparative Study Using Life Cycle Approach for the Biodiesel Production from Microalgae Grown in Wastewater and Fresh Water

Abstract

Use of bio fuels is a sustainable solution in the current energy scenario, which is marked by unsustainable use of fossil fuels. Production of biodiesel requires microalgae as feedstock. The micro algae require nutrients, CO2 & light source for its growth. An approach where waste water treatment plant can act as source of nutrients for the growth of microalgae would be beneficial. Hence the present work was carried out to understand the life cycle assessment of biodiesel production from microalgae grown in waste water and associated impacts compared with biodiesel production from fresh water. The system boundary considered in the process includes cultivation of microalgae, flocculation, centrifugation, extraction, and transesterification. The functional unit considered for the study is 1 MJ of energy produced from biodiesel. The life cycle assessments (LCA) for the present case was carried out using Umberto NXT software and inventory was taken from Eco invent database v3.0 and literature. Results has shown that the microalgae grown in waste water requires lesser energy as compared to algae grown in fresh water.