Inherent safety tool for explosion consequences study

The lack of formal integration between process design stages with risk and consequence estimation is a hurdle to designing inherently safe process plants. Conventional risk assessment methodologies are often not carried out concurrently with process design. Therefore, process designers lack the information about risk levels and consequence that may result from the process conditions being considered in a particular process route until the design is completed. Hence, effects of changes in process conditions on risk levels and consequence cannot be studied in a time effective manner during the design stages. Few studies have been identified on the possibility and viability of integrating risk estimation with process design. But viable framework and methodology for doing so has not yet been reported. This paper presents a feasible framework in which risk and consequences estimation can be part of design stages. A demonstrative tool named as integrated risk estimation tool (iRET) was developed by using process simulation software, HYSYS and spreadsheet, MS Excel as the platforms. iRET estimates risk due to explosions by using TNT equivalence method and the TNO correlation method. iRET has a potential to be extended to include all forms of risk such as fire, explosion, toxic gas releases and boiling liquid expanding vapour explosion (BLEVE). The paper also presents case studies to demonstrate the functionality and viability of using iRET in conjunction with process design. The results of these case studies have successfully shown that the risk due to explosion can be assessed during the initial design stage ensuring a safer plant. The framework and iRET there by presented here provide systematic methodology and technology to design inherently safer plants.