Details

Title:

Life Cycle Assessment of Bioethanol from Microalgae

Author(s):

Kohl, M., Iribarren, D., Petrakopoulou, F., Dufour, J.

Document(s):

Abstract:

Liquid biofuels, such as biodiesel and bioethanol, are expected to play a leading role in achieving a more secure, reliable and sustainable energy sector. Microalgae are seen as a possible feedstock for future bioenergy systems, due to their high productivity and potentially high oil or carbohydrate content. In the present study, the life-cycle environmental performance of a hypothetical “microalgae-to-ethanol” system was evaluated. The system includes cultivation of the carbohydrate-rich microalgal strain Chlorella vulgaris in open raceway ponds, flocculation, centrifugation, dilute acid hydrolysis, fermentation with Zymomonas mobilis bacteria, and distillation. The main processes contributing to the potential environmental impacts were identified. Improvement actions should focus on minimizing the nutrient and energy needs of the cultivation stage, as well as on optimizing the energy demand of the hydrolysis process and its consumption of chemicals. When compared to conventional first-generation bioethanol, microalgal ethanol showed a worse life-cycle performance. However, in comparison with microalgal biodiesel under a well-to-wheels perspective, microalgal ethanol could be a more appropriate biofuel. Further research is needed in order to provide a sustainable microalgal ethanol system.

Keywords:

bioethanol, biofuel, life cycle assessment (LCA), microalgae, environmental impact

Topic:

Biomass Policies, Markets and Sustainability

Subtopic:

Sustainability assessment and criteria

Event:

21st European Biomass Conference and Exhibition

Session:

5DO.12.5

Pages:

1818 - 1822

ISBN:

978-88-89407-53-0

Paper DOI:

10.5071/21stEUBCE2013-5DO.12.5

Price:

FREE