Vulnerability of process and instrument air supply utilities to volcanic ash

Among other consequences of volcanic activity, recent events confirmed that the hazards caused by volcanic ash have a potential impact also at relevant distances from the emission point. The fallout of volcanic ashes may affect several utilities and services at industrial sites, potentially causing Natech events with relevant end-point consequences, e.g., operational failures, business interruption, and environmental contamination. The present study focuses on the vulnerability of process and instrument air intake utility systems to volcanic ash. A detailed model, based on an in-depth characterization of ash properties, is developed to provide accurate time to clogging estimations under varying conditions. A surrogate model is also proposed to enable a real-time assessment using a limited set of input parameters, supporting both preventive planning and real-time decision-making in emergency management. A tailored risk matrix is developed to provide a scenario-specific vulnerability ranking of critical utilities due to volcanic ash accumulation. A novel quantitative approach for the assessment of risk due to filter clogging has also been developed to support the management of the vulnerabilities and critical scenarios identified by the matrix screening. The analysis of test cases confirmed the value of the novel approach in supporting risk management and resilience against volcanic hazards, aimed at the mitigation of operational disruptions and/or more severe process safety accidents.