(55bb) Safety Analysis for Process Intensification Involving Heat Integration

Process Intensification (PI) is a sustainable technology concept that aims to achieve more economic, more sustainable, and safer processes in chemical manufacturing. More economic processes can result from lower energy consumption or waste reduction, which is a primary objective of continuous industrial process improvement. The recent trend towards industrial decarbonization has accelerated the development and implementation of sustainable technology such as process intensification and the use of assessment tools such as life cycle analysis (LCA).

Central to the theory of PI is the hypothesis that intensified processes are more economical, more sustainable, and/or safer. A much-debated question is whether safety is improved in these intensified processes compared to their conventional counterparts. Recent years have seen interest in the development and application of multi-objective optimization of productivity, environmental impact, and safety for intensifying conventional processes. Over the same timeframe, there have also been multi-criteria comparison methodologies developed for comparing process performance.

Risk assessment is a standard approach in safety analysis. Risk is composed of failure frequencies and consequences. For quantitative analysis, empirical data is used for failure frequencies, and different matrices maybe used for measuring the consequences. A commonly used consequence index is the Fire and Explosion Damage Index (FEDI) where the optimization is to minimize the process toxicity, flammability, and/or explosiveness. Another commonly used consequence index is the Individual Risk (IR) indicator, which is a function of the distance between the epicenter of the accident and the location of the potential harm to personnel. FEDI and IR are used to select the optimal design within the process intensification options.

However, the results of these analyses are conflicting. Some quantitative risk assessments have shown that intensified process options are safer, some have shown that the intensified processes are only as safe as conventional processes, while others have shown that safety performance could be worsened.

In this work, we discuss the limitations of the safety analysis of intensified processes using a case study of a heat-integrated process from the literature. We use the concept of hierarchy of controls with the aim of developing a framework for digital twins that can be used to enhance safety analysis of heat integrated processes.