Modeling the Consequence of Vinyl Chloride Accidental Release from Tanks in a Petrochemical Plant

Each year, many accidents occur in processing industries such as oil, gas, and petrochemicals. Processing industries mostly work with hazardous chemicals and units in high temperature and high-pressure conditions like reactors and storage tanks. The study aimed to model the consequences of a complete tank rapture (explosion and fire) and specify the intensity caused by the events.

The applied method in this study was based on the Quantitative Risk Assessment method. This method is used for risk assessment in chemical, petroleum, gas, and petrochemical processes and transport industries. Initially, the process associated with the monomer vinyl-chloride storage tank was identified. At the next stage, the scenarios and probable hazards were identified and defined and the PHAST Risk 7.11 was run for modeling the consequences.

The most dangerous consequences of vinyl-chloride storage tanks include sudden fire and explosion in a complete tank rapture. In a full tank-explosion, the radiation of the explosion wave was once recorded as 79 meters with the death probability of 99 percent.

Each explosion or probable rapture in monomer vinyl-chloride tanks may cause terrible consequences. The vinyl-chloride monomer storage process is a high-risk process that is not tolerable. To reduce the risk, the consequence intensity, the consequence probability, and the exposure amount should be reduced. To this end, it is highly recommended to use smaller tanks, modify operational variables (capacity, pressure, temperature, etc.), and reduce the level of exposure in similar projects.