Microalgae biorefinery alternatives and hazard evaluation

Biodiesel production based on microalgae and using carbon dioxide as feedstock constitutes an attractive biofuel alternative. Technology development and process optimization are necessary to minimize the overall production cost. Moreover, in the framework of process 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 extraction, 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 formulated to derive the frequencies of different accident scenarios, further determining the consequences. The major consequences of accidents involve toxic releases of high quantities 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.The authors are grateful for the financial support provided by CONICET and the Spanish MICINN under projects CTQ2013-48280-C3-1-R and CTM2014-57833-R. J. Pinedo would also like to thank the financial support provided by “Becas Iberoamérica JPI España 2014”

What to Do with Unwanted Catches: Valorisation Options and Selection Strategies

27 pages, 8 figures, 7 tables.-- This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International LicenseThe European Common Fisheries Policy (CFP) has established a landing obligation (LO) and the need for proper management of bycatches without incentivising their capture. Food use is the priority option but only unwanted catches (UWC) above minimum conservation reference size (MCRS) can be used for direct human consumption. As a result, other options, such as animal feeds, industrial uses or energy, should be considered to valorise landed < MCRS individuals. Two approaches have been developed to help select the best available option for processing UWC. The first methodology is based on a multi-criteria decision analysis (MCDA) using an analytic hierarchy process (AHP) that considers technical, economic and market criteria. As a sample case, we chose the Basque fleet fishing in the Bay of Biscay, developed within the H2020 DiscardLess project. The second approach is based on the simultaneous analysis of both economic and environmental aspects. This was applied to the case of Spanish bottom trawlers operating in ICES sub-Divisions VIIIc and IXa. Finally, various food products and bio compounds from typical UWC biomass were obtained in a pilot food processing plant developed within the LIFE iSEAS projectDiscardLess project has received funding from the European Union’s Horizon 2020 Framework Programme for Research and Innovation under grant agreement no. 633680. Life iSEAS has been co-funded under the LIFE+Environment Program of the European Union (LIFE13 ENV/ES/000131)Peer reviewe