Analysis and Simulation of Severe Accidents in a Steam Methane Reforming Plant

Severe accidents of process industries in Iran have increased significantly in recent decade. This study quantitatively analyzes the hazards of severe accidents imposed on people, equipment and building by a hydrogen production facility. A hazard identification method was applied. Then a consequence simulation was carried out using PHAST 6.54 software package and at the end, consequence evaluation was carried out based on the best-known and different criteria. Most hazardous jet fire and flash fire will be occurred in desulfurization and reformer units respectively. The most dangerous vapor cloud explosion will be caused by a rupture in desorfurizing reactor. This incident with an overpressure of 0.83 bars at a distance of 45 m will kill all people and will destroy all buildings and equipments that are located at this distance. The safety distance determined by TNO Multi-Energy model and according to the worst consequence is equal to 260 m. Vapor cloud explosion will have the longest harmful distance on both human and equipment compared to jet fire and flash fire. Atmospheric condition will have a significant influence on harmful distance, especially in vapor cloud explosion. Therefore, the hydrogen production by natural gas reforming is a high-risk process and should always be accompanied by the full implementation of the safety rules, personal protection and equipment fireproofing and building blast proofing against related to fire and explosions.