Process route selection for inherently safer design based on consequences analysis

Abstract

Increased public awareness of safety and stringent requirements by the authority has led to the consideration of inherent safety in the design of processing plants. Inherent safety approach ensures the safety of a process by eliminating or minimizing the hazard from a process rather than implementing engineering control to manage the hazard. The opportunity for such an approach is the highest at the early stages of the design. In addition, the effectiveness of the hazard reduction measures by employing the inherent safety principles must also be assessed at the early stages of the process design so that the design engineers can make an informed decision on the process design. This paper describes the methodology for integrating the assessment of fire hazards with process simulation at the early stage of process design. The methodology was illustrated by comparing process routes for dimethyl ether (DME) production plant using substitution principle. The process design simulation was carried out in iCON® process simulator, while assessment of the fire hazards was carry out in Excel® using a seamless two-way data transfer facility that is available in iCON®. The results from the case study showed that the potential consequences of a fire can be reduced by employing the substitution principle of inherent safety. The methodology that has been developed in this work enables simultaneous technical and safety assessments at the early stages of the process design.