Risk Index Approach for the Optimal Layout of Chemical Processes Minimizing Risk to Humans

Abstract

Chemical processes are constructed within very compact areas in the consideration of limited resources, including land, although many of their units are dangerous and vulnerable to accidents. Even the safety among units is secured by modifying the layout of process to ensure the safety distance, this situation can get worse if the process site is near residential areas or the workspace of employees because of the risk to humans from the process. In this study, such risk to humans as well as the risk to the equipment itself are quantitatively considered to give more reliable layout of chemical processes. Modified individual risk index has been adopted, counting for the direct risk that a person near the dangerous equipment can take. With this index, optimal process layout is designed by minimization of cost and land area to consider the limitation of resources. The proposed methodology can provide a guideline to designing safe layout of a chemical process concerning the various safety distance measures including equipment–equipment distance, equipment–workspace distance, and equipment–public area distance.