Evaluating process safety at conceptual stage: A stream-based index approach

Incorporating safety indexes during the conceptual design stage is essential for ensuring the safety and efficiency of chemical processes. Despite many advances in the field, there are still areas that can be improved. Here we present a new Stream Safety Index: a fully automated, stream-based safety index coupled with a process simulator. The index ranges over a simple scale from 0 to 10 and provides immediate feedback on safety performance, facilitating safer design decisions. It is constructed starting from various sub-indexes, based on continuous, optimized functions. The index is tested on a methanol production process flowsheet and compared to two existing indexes, Process Stream Index (PSI) and Comprehensive Inherent Safety Index (CISI). Stream Safety Index (SSI) identifies the same sensitive zones as CISI, but its calculation is automatized and almost instantaneous. While Stream Safety Index does not completely eliminate subjectivity, it can be easily adapted to fit the specific parameters of the end user.