Automated evaluation of safety at the conceptual stage: An index-based methodology for units and processes

Safety analysis is traditionally performed after the detailed design is concluded, and process modifications at this stage lead to extra expenses. Implementing safety indices at the conceptual stage allows to guide engineers towards an inherently safer design. Although the progress made in the field, there are still some lacks to address to help spread the utilization of such metrics. Here we leverage the tool for stream safety we presented in an earlier work to calculate units and process indices, all ranging over a fixed scale from 0 to 10. Three different analysis stages (streams, units, process) allow for a thorough analysis, comprehensive of all parameters available at the conceptual design stage. The index is fully automated, since the code retrieves the needed information either from the process simulator or a built-in Excel database. The indices are tested on two alternatives of the same methane pyrolysis process (Configuration 1 and 2), and compared to three existing indices. The automatization of our code returns the results for each Configuration (made of 40 streams and 15 units) in less than 40 s of computation time versus multiple hours required to compute state-of-the-art indices.