Consequence modeling of hazardous accidents in a supercritical biodiesel plant

• Jet fire was identified as the most likely incident in the case of flammable material release.
• It was recommended to minimize the number of workers and the work hours in vicinity the possible source of release.
• For equipment and structure protection, it was recommended to minimize the flammable material inventory.
• Provide proper isolation systems and using fireproofing coatings.

Biodiesel is going to be one of the most preferable fuels because of fossil fuel sources depletion and rising environmental issues. This type of fuel is produced mainly by transesterification of triacylglycerol compounds such as vegetable oils and animal fats in a catalyzed or non-catalyzed reaction media. Energy, cost and environmental investigations for conventional (catalyzed) and modern (non-catalyzed) methods show that non-catalyzed method in supercritical process conditions is more advantageous but more unsafe because of high pressure and high inventories of flammable materials. Thus, this paper is aimed at identifying and analyzing the severity of process incidents in a supercritical biodiesel plant using consequence modeling and analysis approach. Following this approach, pressurized liquid inventories were identified as the most hazardous sources and subsequently jet fire was identified as the most likely incident in the case of flammable material release. Then, destructive effects of jet fire were simulated for three different leakage sizes from 0.5 to 1.5 inch. The results showed long effect distances, the ranges of which were 61–159 m and 70–190 m for the structures and humane respectively. According to these results, in the case of jet fire, structures and humane in a long distance around the source of release would be affected. Thus, all human in these areas shall leave the mentioned distances in less than few seconds which seems to be impossible. Also, structures and equipments would be damaged if flame impingement duration lasts more than 2 s. Therefore, sufficient protections should be provided to decrease the level of Jet Fire damage on near structures and personnel. Besides, supercritical biodiesel plants should be designed in a low production capacity in order to decrease the hazardous radios and the duration of feeding the release source in the case of any risk.