Consequence modeling and analysis of explosion and fire hazards caused by methane emissions in a refinery in cold and hot seasons

Methane is one of the gaseous materials with high potential of damage. Today, it is widely used in process, chemical industries and human environments. This study thus aimed to predict the emissions and the probable effects of liquid methane using ALOHA software in order to perform appropriate safety measures and consequently to reduce the plausible adverse effects.

Considering the results of HAZOP studies, the worst case scenario was chosen and, using ALOHA software, possible methane gas leak scenarios from the reservoir were modeled. During the study, all the moral standards were observed.

Based on the results obtained, gas concentrations of liquid methane would reach 400000 ppm in a distance of 39 meters around the reservoir, which is in the range of PAC-3 demonstrating risk of death threatening the lives of surrounding people. In the event of a full leakage of 238 meters around the reservoir, the methane gas concentration is predicted to be 50000 ppm, which is equivalent to the low explosive charge (LEL) of methane gas. Wave pressure of vapor cloud caused by methane leaks exceeds 1 psi in a distance of 270 meters.

The consequences of methane toxicity in the studied refinery are one of the most serious threats to the personnel. Therefore, preparing a reaction plan for emergency conditions will have an effective role in limiting the harmful effects of the toxic and dangerous materials emissions.