Microalgae Biorefinery Alternatives And Hazard Evaluation

JAVIER PINEDO; CARLA V. GARCÍA PRIETO; AGUSTIN D´ALESSANDRO; RAQUEL IBAÑEZ; STELLA TONELLI; MARIA SOLEDAD DIAZ; ANGEL IRABIEN

CHEMICAL ENGINEERING RESEARCH & DESIGN

INST CHEMICAL ENGINEERS

Lugar: Amsterdam; Año: 2015 vol. 104 p. 200 - 209

0263-8762

Biodiesel production based on microalgae and using carbon dioxide as feedstock consti-tutes an attractive biofuel alternative. Technology development and process optimization are necessary to minimize the overall production cost. Moreover, in the framework of pro-cess sustainability, social and environmental impacts should include process safety aspects. In this context, the objective of this work is to develop a biodiesel production process based on microalgae and the subsequent estimation of the associated risks, thus contributing to more sustainable and safe processes.The biodiesel biorefinery is optimized, taking into account alternative configurations for algae cultivation and lipid extraction. Algae cultivation options are open ponds and tubular photobioreactors. Regarding lipid extraction, dewatering and subsequent n-hexane extrac-tion, and combined ethanol/n-hexane extraction are the studied alternatives. Numerical results showed that open ponds and n-hexane extraction provide maximum net present value. However, n-hexane consumption dramatically rises, and industrial hazards have not been considered in the optimization process. To overcome this issue, a preliminary hazard analysis is carried out to identify hazardous materials and operations. Event trees are for-mulated to derive the frequencies of different accident scenarios, further determining the consequences. The major consequences of accidents involve toxic releases of high quanti-ties of n-hexane. By comparing the proposed alternatives, this work aims to highlight the need to consider not only economic but also safety and environmental objectives in the development of a biodiesel production project.