Comparative LCA of Flocculation for the Harvesting of Microalgae for Biofuels Production

Abstract

In recent years, the use of Life Cycle Analysis (LCA) to evaluate environmental benefits resulting from the production of biofuel from microalgae has continued to evolve. Literature in this field shows that one of the main challenges associated with the effect of biofuel production on the environment is the high energy consumption necessary in the microalgae harvesting phase to achieve the level of dewatering required to the next steps. Moreover, detailed LCAs specifically focused on the assessment of alternative technologies for the harvesting of microalgae have yet to be presented. As such, the aim of this paper is to analyze the potential environmental benefits and shortcomings arising from the use of flocculation for the harvesting of microalgae in the biofuel production process, with particular attention to the Canadian context.The method employed is a comparative LCA, where two alternative scenarios based on the application of two harvesting technologies are taken into account: (1) flocculation and centrifugation and (2) direct centrifugation (without flocculation). The calculations of environmental impact and the sensitivity analysis are performed with the SimaPro software.