Enhancing the sustainability of biodiesel fuels by inherently safer production processes

Biodiesel is an emerging green fuel that is finding increasing applications. The further improvement of the sustainability of biodiesel production processes is a key element in the energy transition scenario. Among the social pillars of sustainability, safety is a specific requirement. However, several major accidents were experienced in biodiesel facilities, involving the inventory of hazardous substances. In the present study, an inherent safety methodology is proposed as a specific design criterion for the screening of technology alternatives, supporting the selection of the safest and most sustainable production process. Four reference process alternatives for the transesterification of rapeseed oil to produce biodiesel were conceptualized. Inherent Safety Key Performance Indicators (IS-KPIs) were defined to assess the safety performance of the alternative process technologies and to support the selection of the safest design option. A sensitivity analysis was performed in order to verify the robustness of the results with respect to possible uncertainties. The results allowed the comparative assessment of the inherent safety performance of the main biodiesel production technologies, enabling a deeper understanding of the safety-critical aspects of the novel processes proposed for industrial application. The IS-KPIs were integrated in a wider system of KPIs, addressing also the environmental and economic aspects, obtaining an overall assessment of the sustainability performance of the alternative design options considered. •Alternative technologies for biodiesel production were compared in terms of inherent safety.•Inherent Safety Key Performance Indicators (IS-KPIs) were used for the ranking.•Base catalysed transesterification resulted the inherently safest process.•IS-KPIs were compared to environmental and economic KPIs for sustainability assessment.•Holistic sustainability performance of process alternatives is obtained including IS-KPIs.