Towards inherently safer design of the Propane Dehydrogenation (PDH) plants: A comprehensive index analysis

Propane Dehydrogenation is a booming method of propylene production. Significant attention has been given to various process aspects of this method, but it has remained less attended in the process safety aspect. Inherently Safer Design (ISD) is a fundamental branch of process safety that is concerned with the recognition and avoidance of hazards rather than controlling them. Inherent Safety Metrics (ISMs) are ISD tools to quantify various hazardous parameters. Comprehensive Inherent Safety Index (CISI) is a competent tool for assessing ISD due to the inclusion of various process conditions and equipment design. Implementing CISI on an industrial PDH design, reveals the parts with the highest safety concerns. The fractionation section, followed by the feed treatment section, which acquire huge distillation towers and multiple passes high-flow streams are the most hazardous subunits. The reactor section and the reactor effluent section are also of high indexes due to their high flow and drastic process conditions. This study shows the robust capability of the utilized method and demonstrates the process equipment and subunits with the highest safety concerns in a propane dehydrogenation unit that can be subject to further safety studies and improvements.