CHEMICAL ENGINEERING TRANSACTIONS VOL. 67, 2018 A publication of The Italian Association of Chemical Engineering Online at www.aidic.it/cet Guest Editors: Valerio Cozzani, Bruno Fabiano, Davide Manca Copyright © 2018, AIDIC Servizi S.r.l. I SBN 978-88-95608-64-8; I SSN 2283-9216 Ageing Assessment and Management at Major-Hazard Industries Maria Francesca Milazzo a , Paolo Bragatto b , Giuseppa Ancione a , Giuseppe Scionti a a Dip.Inge. - Department of Engineering, University of Messina, Messina, Italy b INAIL, Dipartimento Innovazioni Tecnologiche, Centro Ricerca, via Fontana Candida, 1, Monteporzio, Italy mfmilazzo@unime.it As a consequence of the obligations of the Directive Seveso III, there is a need of methods and tools that support industrial managers and the auditors, respectively, to manage and to verify the ageing status of critical equipment. Risk-Based Inspection methods (RBI) are usually used, as well as some other recommended practices (ASME, API or RIMAP). Criticalities are associated with RBI methods as these were born to optimise inspections’ costs by comparing them with safety levels, thus an effort is always necessary to adapt the method in order to manage ageing. This work describes an under-development system that supports industrial managers and auditors in controlling and managing ageing. It can be considered as a virtual sensor, made up by hardware and software. It collects information about process variables (recorded by control systems), external variables, inspection information and other data, then it processes collected information and predicts the numeric value of a performance indicator based on the approach for the ageing assessment, which was developed by an Italian working group on ageing. Based on such an indicator the prediction of the ageing state of the equipment is possible as well as its management based on the levels of industrial risk acceptance. The software is a dynamic model indicating factors that accelerate and those that slow down the degradation processes. The model is expected to build a “digital twin” of a complex plant by using a huge amount of data, which is valuable to understand how the plant will age in the next future. 1. Introduction Ageing of equipment and facilities in the process industries has become a relevant issue in recent years. The problem is particularly recognised in Europe, where industrial sites have a century of life and to build new plants appears very difficult, given scarce available resources as well as difficulties in obtaining the authorisation due to very congested lands. A few national regulators, designed for the implementation of the EU Directives for the prevention of chemical accidents, have recognised the relevance of this issue over the last ten years and more. The first one was the British Competent Authority (HSE), which published in 2006 the guideline for the safe management of ageing plants under the COMAH regulation (Wintle et al., 2006). According to the HSE’s report, the first step to manage aged plants is the awareness that ageing is not about how old the equipment is but is about what is known about its condition and the factors that influence the onset, evolution and mitigation of its degradation; this means that ageing management is a process that starts at the time of the facility’s installation. The importance of the ageing phenomenon was definitely recognised in 2012, when the Directive UE/2012/18 (Seveso III) was published. It imposes the plant manager to adopt a plan to control the hazard related to ageing and corrosion (art.8 Annex III point b.iii) and the inspectors to verify the adequateness of the activities planned by the plant management to guarantee a safe ageing (art. 20). Thus, managers have the obligation to demonstrate the adequateness of the management of such an issue. The application of the newest Directive in EU countries started in 2015. The huge impact of an inadequate management of ageing on workers’ safety, industrial assets and environment has been clearly demonstrated in technical and scientific literature. Indeed, the EU Commission published an exhaustive report about corrosion-related accidents in the refineries (Wood et al., 2013), whereas the OECD reported about accidents collected in all process industries (OECD, 2017); other investigations that evidences the relevance of the occurrence of accidents due to ageing are given by De DOI: 10.3303/CET1867013 Please cite this article as: Milazzo M.F., Bragatto P., Ancione G., Scionti G., 2018, Ageing assessment and management at major-hazard industries, Chemical Engineering Transactions, 67, 73-78 DOI: 10.3303/CET1867013 73