A Quantitative Risk Analysis Due to Leakage of Ammonia Storage Tank at PUSRI IIB Factory

Abstract

Ammonia products in industry are usually stored in a cold state which is maintained
at a temperature of -33 C in a liquid state (refrigerated storage tank). One of the
chemical industry companies that produces ammonia and has been established in the
mid-20th century is PT Pupuk Sriwijaya Palembang. One method that can be used to
predict the scenario of an ammonia tank leak is by quantitative risk analysis. The
purpose of this study is to identify the effect of the leakage of the ammonia storage tank
at the Pusri IIB factory, calculate the concentration of ammonia scattered per unit
distance and calculate the distance affected by thermal radiation and toxic gases from
the source of the leak, and compare the calculation results (manual) with the simulation
results with the device. ALOHA software. The tool used in the ALOHA simulation is a
laptop with the following specifications: Lenovo Thinkpad T440p, Intel® CoreTM i5-
400M, 8 GB RAM, 64-bit OS. The effects of ammonia storage tank leaks or accidents
due to tank leaks that may occur after the ALOHA simulation are pool fire, BLEVE,
toxic vapor cloud, and flammable area of vapor cloud. In scenario 1 for the impact of
pool fire thermal radiation (>10 kW/m2), the resulting red zone is 36 m. Probit analysis
of the impact of pool fire was also carried out, with probit 1st degree burns it could
allow 261 people to be exposed at a distance of 45 meters and 14-16 people at a
distance of 75 meters. For the BLEVE impact, the resulting red zone is up to 1.2 km
with probit analysis of 1st degree burns in the dry season scenario, the possibility of
people being exposed is 9,007 people at a distance of 1,000 meters and 3,126-4,002
people at a distance of 2,000 meters. While the spread of toxic gas (toxic vapor cloud),
the red zone (ERPG-3) produced is 269 m. The worst impact for the occurrence of a
pool fire can reach 58 meters from the source of emission or tank leakage, BLEVE
reaches 2.7 km, toxic area reaches 2.3 km, and flammable area reaches 60 meters. The
recommendations given in this study are checking the instruments on the tank,
installing a lightning rod on the tank, and risk analysis is needed to anticipate tank
leaks and avoid making densely populated settlements within 2 km of the ammonia
tank.