Background: Due to the high volume of the substance in the methyldiethanolamine (MDEA) tanks and the chemical properties, inflammability, and toxicity of the substance as well as the presence of hydrogen sulfide gas in the equipment around this tank, it is important to model its accidents. In this study, the rupture scenario of the MDEA tank in two seasons, cold and hot, with the presence of a protective wall and the absence of a protective wall, was modeled.
Methods: At first, the dimensional data of the volume of the tank, the chemical and thermodynamic information of the substance, and the geographic maps of the desired area were defined for the software. Besides, the average weather conditions were inquired from reliable authorities and given to the software so that after performing the calculations, the results of the reservoir rupture scenario would be stated. In this study, the PHAST software was used for calculating the information.
Findings: The area under the pool fire radiation in the hot season was 96.5 meters in the wind direction, which was 93 meters in the cold season. Besides, the minimum distance from the center of the fire, where the probability of death is 99%, was 35 meters in the direction of the wind. The concentration of toxic substances up to a distance of 1825 meters in the direction of the wind had a 99% probability of death, and after that it decreased and reached about zero up to a distance of 1865 meters. In the hot season, the pool evaporation rate increased from 1.3 kg/s to 1.6 kg/s. In the cold season, the evaporation rate of substance was 0.3 kg/s. In the absence of a protective wall for a pool fire, the maximum heat radiation was at a distance of 124 meters; this amount of radiation was about 10 meters in the case of the presence of the protective wall.
Conclusion: According to the obtained results, during the occurrence of any of the consequences, which will be in the worst case of these results, the safe distance of the tank can be determined by warning signs. Moreover, in case of accidents, how far the rescue team can approach the danger center and what measures they will have to control the crisis is of great importance.
