The Effect of Storage Temperature on Threat Zone Caused by an Ammonia Release from a Storage Tank

Abstract

In this study, the threat zone that may occur as a result of an accidental release of an-hydrous ammonia, a flammable and highly toxic substance (Flammability:1, Health:3, NFPA 704), which has many uses, was investigated. A fire can be prevented by taking precautions such as not keeping ignition sources in the environment as a result of the ac-cidental release of ammonia gas. However, although its ignition is prevented, it can cause harm to humans and the environment due to its highly toxic nature. Therefore, the toxicity of ammonia was taken into account in this study. A common type of storage of anhydrous ammonia is in a horizontal cylindrical tank at ambient temperature and its vapor pres-sure. Therefore, in this type of storage, storage is carried out at different temperatures in different seasons. This study aims to examine the effect of storage temperature on the size of the threat zone, taking into account the knowledge that the storage temperature will change in seasonal conditions. Areal Locations of Hazardous Atmosphere (ALOHA) and DOW’s Chemical Exposure Index (DOW CEI) methods were used to determine the size of the threat zone, and the results obtained from these two methods were compared. The advantages and disadvantages of the two methods were presented. It is thought that this study will guide the relevant people such as operators who use these methods in calculating the hazard distances in the establishments that store ammonia and will provide awareness that the storage temperature affects the size of the threat zone.