Life Cycle Energy Analysis of a Microalgal Based Bioreactor

Abstract

Biofuels which are derived from microalgae can be considered as a substitute for fossil and petroleum fuels in the near future. The dependence and viability of microalgal based fuels is highly dependent on the sustainability and environmental impacts of microalgae to biofuel conversion process in terms of energy analysis and Greenhouse gas emissions. Life Cycle Assessment (LCA) has been considered as a tool to evaluate the sustainability of any system. LCA is done pertaining to the system boundaries, life cycle inventories, process efficiencies and the functional units of the system. Life cycle energy analysis (LCEA) evaluates the overall energy input to the system and the useful output. The paper presents life cycle energy analysis of a micro algal based bioreactor set up at Forbes Marshall's lab at IIT Bombay. This study proposes a detailed engineering model for the species Chlorella Vulgaris used in the bioreactor. The paper aims at the evaluation of Net Energy Ratio (NER) of oil and biodiesel production. There has been an effort to compare life cycle GHG emissions in a vehicle technology with and without a mix of biodiesel with the conventional fuel.