Risk Assessment of the Ammonia Leak in Cooling Section of the New Ammonia Plant for the Plan for Emergency Response Control for Commissioning and Start-up of the New Plant Ammonia of the Moron Petrochemical Complex Using the Simulation Tool PHAST 6.7

Based on the premise of "only what is known can be controlled," This paper aims to develop the risk assessment of the more severe scenario considered during the development of the Plan for emergency response control for Commissioning and start-up of the new plant ammonia of the Moron Petrochemical Complex.

 During the preparation of the Plan for emergency response control for Commissioning and start-up of the new Fertilizer plant of Morón petrochemical complex, it was evaluated for the ammonia plant, the main points of attention in terms of identify 13 potential hazards and emergency operational scenarios for the development of ammonia plant emergency plannings.

The main points of attention regarding potential hazards are:

• Shut off of natural gas to the primary and secondary fuel burners arc. (Upper primary reformer)
• Valve in main inlet pipe natural gas to the plant. (Piperack - west battery limit plant)
• Transfer line - Reformation area. (East of the plant between primary and secondary reformer Side).
• Synthesis reactor V-105D.
• Pipes, process vessels and valves cooling section. (South west side of the plant).

The scenarios originally identified and qualitatively assessed under the criterion of experience and expertise in operations, processes, instrumentation, fire, health and safety personnel, are:

• Rupture of Primary Reformer catalyst tubes with Fire (Medium risk; Emergency Planning: AMO-03).
• Rupture of transfer line - reformation section with fire. (Medium risk; Emergency Planning: AMO-04).
• Rupture of output line - Secondary Reformer with fire. (Medium risk; Emergency Planning: AMO-05).
• Rupture of Internal coil of the starting burnout furnace, synthesis section, with fire. (Medium risk; Emergency Planning: AMO-06).
• Rupture of lines or opening of safety valves cooling section with ammonia leak. (High Risk; Emergency Planning: AMO-07).

 According to the event considered more severe for the preparation of pre-planning AMO-07, and according to the design principle of opening or actuating safety valves in that section is to send the gases and vapors of ammonia to the flare, it is decided to conduct the assessment of the Ammonia leak from ruptured line.

Evaluating the equipments of the cooling section, its contents and operating conditions, it is established that the most representative and relevant in that section is the Unified exchanger (chiller) V-120-C and the cooling stages. Therefore it is decided to perform a risk assessment using the PHAST 6.7 for the Simulation of a leak of Liquid Ammonia  by rupture of ammonia Line V-120-CF1 to the pumps V-124J/JA, line NH-1016 at a height of 10m above the ground and a sense of Horizontal leakage, naming the study as a Risk Assessment of the Ammonia Leak in Cooling Section of the New Ammonia Plant for the Plan for emergency response control for Commissioning and start-up of the new plant ammonia of the Moron Petrochemical Complex using the simulation tool PHAST 6.7