Engineering aspects of the preparation for managing accidental Hydrogen Sulphide releases at a process site

The scope of documentation that deals with siting and laying out process facilities is often limited to combustible gases and flammable or combustible liquids. Generic documentation for siting and laying out process facilities with respect to airborne toxic materials, and how to approach the management of inadvertent releases, is usually not readily available. Barring an inherent safety solution; i.e., substitution of the toxic material with a non-toxic material, there are two basic approaches when dealing with Hydrogen Sulphide (H2S): evacuation and shelter-in-place. This paper deals with several engineering aspects of a holistic safety management approach that covers both evacuation and shelter-in-place. The engineering aspects include dispersion modeling and functional safety aspects of the gas detection systems as well as (potential) problems with their application.