A HAZOP Gap Query Approach for Hazard Assessment in Multi-Product Facilities

Batch, multi-product chemical processing facilities present special challenges for conducting thorough & timely hazard assessments. A technique has been developed to expand traditional HAZOP methodology to include additional parameters for process operational intent, chemicals, and affected upstream/downstream equipment. Integrated Layer of Protection Analysis (LOPA) is then applied as required to assess existing or proposed Independent Protection Layers (IPLs), and to compare resulting mitigated risk to established risk criteria limits. The resulting HAZOP/LOPA for each unit then becomes a baseline hazard assessment, to which subsequent processes/configurations can be compared, without having to repeat the full HAZOP for each new process. For new products, an operational intent template is created by selecting the chemicals and equipment to be used, as well as the operational intent (e.g., reaction, stripping, product isolation, etc.) and conditions for each step in a semi-batch process. The unit HAZOP file is then electronically queried using programmed search logic to identify matching process intent/equipment/chemicals parameters that were considered during the base HAZOP exercise. A condensed Process Hazard Review (PHR) is then conducted to review the query results, ensure the identified items are applicable to the proposed new process, and to evaluate new items that were not previously covered under the base HAZOP.