Using integrated toxic release consequences analysis tool for inherently safer design of process plant at preliminary design stage

Toxic release is one of major accidents in process plant that caused many fatalities. Some examples of major disaster due to the toxic release are the tragedy of TCDD release in Seveso, Italy (1976) and MIC release in Bhopal, India (1984). Common and popular practices to prevent such accidents are by installation of add-on protective system and to follow safe operation procedure. Even though these techniques are proven effective to minimize the probability of accidental release of toxic materials; however, the hazard is still remained in the process plant. This study reports on an alternative design approach to avoid or minimize the toxic release accidents by utilizing an inherent safety concept. A process design tool was developed by the integration of process design simulator, iCON from PETRONAS with toxic release consequence model created in MS-Excel spreadsheet. The consequence model was based on the method recommended by Center for Chemical Process Safety. This unique prototype tool allows the consequence analysis of potential toxic release to be done early in preliminary design stage. If the design fails to meet the limitation of toxic release criteria, the improvement can be done using an inherent safety concept to avoid or minimize the toxic released consequence. A case study of ammonia release from a purification column was conducted, and the results show that the toxic release consequence can be avoided or minimized during the process simulation stage. More studies are currently carried out to explore the full capabilities of the developed prototype tool for inherently safer design options before commercial applications. © Springer-Verlag Berlin Heidelberg 2012.