Hazard assessment of edible oil refining: Formation of flammable mixtures in storage tanks

This work presents a methodology for the assessment of hazards due to the formation of flammable mixtures in edible oil refineries, with particular focus on storage tanks. Safety issues in these plants are due to the presence of residual volatile flammable solvents deriving from the extraction processes, which may accumulate in the storage tanks and generate flammable vapour mixtures. The methodology, based on the application of a thermodynamic model for the estimation of vapour phase composition in oil storage tanks as a function of operating conditions (i.e. temperature and residual solvent content), allows the identification of potential hazards due to formation of flammable mixtures inside the tanks. The model was first validated using available experimental data and then extended to case-studies representative of state-of-the-art industrial storage applications. The results of the case-studies were then used to calculate specific hazard indexes, providing a quick tool for preliminary assessment of hazards due to the formation of flammable mixtures in edible oil storage plants.