Abstract
Many of the existing chemical processes require the storage of hazardous substances, and/or demand that severe operating conditions are maintained during production. The operation of this type of processes requires high standards of safety. In this context it is introduced the Inherent Safety (IS), which focuses on eliminating or reducing the hazards associated with a set of conditions, seeking to remove the hazard at its source, rather than accepting it and later on trying to mitigate its effects. The application of IS analysis is more effective in the early stages of the project (research and conceptual phases), where it is still possible to make huge changes in the process (e.g. substitution of solvents). As the process moves through the life cycle (Front End Engineering Design (FEED) and Detailing Engineering) it becomes more difficult, but it is still possible. The FEED phase for example stablishes the following points where IS principals can be applied: the critical operating parameters and safe operating envelope of temperature and pressure; selection of construction materials; unit layout. This paper aims to demonstrate how IS strategy can be applied in the FEED phase of a project with focus in the unit layout definition. A good layout with sufficient spacing between hazards, equipment and units can reflect in several benefits. The study case was done in a real petrochemical unit that had an accident that burned down one entire section of the plant. Toward in finding a safer solution for the new design, an IS methodology was proposed and applied. The results showed the advantages of using inherent safety to design the unit layout in the FEED phase and how it can contribute to build a safer design and operation by minimizing the risks, such as domino effect.
