A Survey on Environmental Pollutants Emission Sources in Process Industries: A Comprehensive HAZOP and Bow-tie Study on a Sulfur Recovery Unit

The process industry is known for its hazardous and complex nature, and thus, hazard identification and risk management are crucial to ensure safety. Implementing hazard identification methods and incident modeling concurrently is essential to prevent adverse events. This study aims to identify potential hazards in a sulfur recovery plant from an environmental perspective using the Hazard and Operability (HAZOP) study method and to model the identified hazards using the Bow-tie technique.

This descriptive cross-sectional study involved five research steps to gather necessary information on the sulfur recycling unit. The HAZOP study was utilized to identify process hazards, which were subsequently modeled using the Bow-tie method in Bow-tie Pro software. The statistical analysis and important variable values of these two methods were described.

The findings of the study conducted on the sulfur recycling unit revealed the identification of 10 nodes, 95 deviations, 158 causes, 186 consequences, 95 safeguards, and 92 recommendations through the HAZOP study. Additionally, the Bow-tie study recognized 19 top events, 19 threats, 90 controls, 69 consequences, and 162 escalation factors.

The results demonstrate that any faults or deficiencies in control devices can significantly impact the consequences of environmental pollution in process industries. However, efficient monitoring of process deviations and the implementation of recommended measures can effectively eliminate or reduce such impacts.