A HAZOP-like risk analysis method for intensified and multi-scale processes
Résumé
Technology under development for process intensification using multi-scale equipment will contribute significantly to provide a safer design by going from batch/semi-batch to continuous operation while reducing inventory of hazardous substances in critical stages. On the other hand, the shift to higher space-time-yields adds new risks such as runaway reactions with hot spot formation or handling an explosive atmosphere in the presence of potential permanent ignition sources, etc. A new method was developed for preliminary risk assessments, called HAZOP-LIKE study, to cover the characteristic and specific features of micro-designed equipment that are relatively unimportant when employing conventional equipment. Another advantage is that the method can be employed in the early stages of development of the process to point out as early as possible the areas of concern in terms of safety. The method uses a guide-word approach with ranking the risks in terms of probability and severity. It was developed as part of the European research project IMPULSE (Integrated Multiscale Process Units with Locally Structured Elements) whose overall objective was the effective and targeted integration of innovative process equipment such as micro-reactors, compact heat exchangers and other micro- and/or meso-structured components to attain radical performance enhancement for whole process systems in chemical production. The risk analysis method is described in detail and case studies are presented concerning a generic liquid-liquid reaction and the production of vinyl acetate to demonstrate the method. The results show that the created generic templates support comprehensive risk analysis studies with hidden deviations not obviously following traditional HAZOP studies.