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Emergency response is a procedural safety barrier of paramount importance for the mitigation of fire scenarios and the prevention of escalation. However, in Natech scenarios, emergency response may be affected by the natural event impacting the site. Indeed, when contrasting Natech accidents, emergency responders have to face both the natural event and the cascading technological scenario. Despite the criticality of the issue, limited attention was devoted to date to the analysis of emergency response in cascading sequences triggered by natural events. The present study provides a novel and technically sound methodology to assess the performance of emergency response and the required intervention time in Natech scenarios. An expert survey combined with a Bayesian Network model was used to assess the performance of the emergency response. The routing and setup phases were identified as those mostly affected by natural events. Monte Carlo simulations were used to obtain baseline data and specific probability distributions for the time required to carry out the emergency response considering the factors that may hinder the response during natural events. In Natech accidents, the time for effective mitigation resulted higher of at least a factor 2 with respect to that expected in the case of conventional accidents. The methodology developed may be used to support the improvement of the emergency management of Natech scenarios, allowing for a detailed definition of site-specific emergency response plans. Moreover, the results may be used to provide a more accurate assessment of the fire-driven escalation probability in Natech events., Safety and Security Science

Natural events are a widely recognized hazard for industrial sites where relevant quantities of hazardous substances are handled, due to the possible generation of cascading events resulting in severe technological accidents (Natech scenarios). Natural events may damage storage and process equipment containing hazardous substances, that may be released leading to major accident scenarios called Natech events. The need to assess the risk associated with Natech scenarios is growing and methodologies were developed to allow the quantification of Natech risk, considering both point sources and linear sources as pipelines. A key element of these procedures is the use of vulnerability models providing an estimation of the damage probability of equipment or pipeline segment as a result of the impact of the natural event. Therefore, the first aim of the PhD project was to outline the state of the art of vulnerability models for equipment and pipelines subject to natural events such as floods, earthquakes, and wind. Moreover, the present PhD project also aimed at the development of new vulnerability models in order to fill some gaps in literature. In particular, a vulnerability model for vertical equipment subject to wind and to flood were developed. Finally, in order to improve the calculation of Natech risk for linear sources an original methodology was developed for Natech quantitative risk assessment methodology for pipelines subject to earthquakes. Overall, the results obtained are a step forward in the quantitative risk assessment of Natech accidents. The tools developed open the way to the inclusion of new equipment in the analysis of Natech events, and the methodology for the assessment of linear risk sources as pipelines provides an important tool for a more accurate and comprehensive assessment of Natech risk.

Deliberate attacks (security attacks) pose a significant threat to offshore Oil&Gas critical infrastructures as they have the potential of triggering major event scenarios with severe consequences on people, property, and the surrounding environment. The standards API RP 70 and API RP 70I address security issues in the offshore Oil&Gas sector, providing a semi-quantitative approach to evaluate the actual level of security risk. However, as the credibility of security attacks grows, security risk assessments should be approached in a more systematic and quantitative way to measure vulnerabilities and determine the level of protection available in the site. In this context, the present study introduces a systematic quantitative procedure using Bayesian Network (BN) to calculate the probability of success of physical attacks and the role of preventive and mitigative response strategies. The procedure is applied to a case study allowing to show its potential for improving security in the offshore Oil&Gas industry., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Safety and Security Science

Fire is one of the main accident scenarios occurring in chemical and process plants, and it can lead to domino effects due to thermal radiation. Emergency response is necessary to prevent fire escalation, in addition to safety barriers. In major industrial fire accidents, backup is usually required in emergency response, due to the lack of emergency response capacity of a single emergency response department. A method addressing the optimal allocation of emergency response forces, specifically considering the front-line departments, is developed in the present study. The emergency response of the front-line departments can reduce the thermal radiation received by the equipment adjacent to the primary fire and thus prolong the time to failure of the equipment, such that the backups have more time to get to the fire scene. The allocation analysis of emergency response teams is carried out considering the dynamic ttf of an adjacent equipment item resulting from the change in time of the thermal radiation received. A timed colored hybrid Petri-net (TCHPN) approach is proposed to model the emergency response process. The probability of preventing fire escalation is obtained from the TCHPN model and the optimal allocation of firefighting forces is determined. A case study illustrates the proposed approach, two scenarios are compared and results show that if a request for backup can be issued immediately according to the fire state, fewer emergency forces can be deployed on the front line department, such as the reduction from 6 emergency response teams to 3 teams to maintain the success probability of 0.91. The influence of other factors such as the position of fire departments and the layout of tanks on the allocation of emergency forces is also discussed., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Safety and Security Science

Energy transition is the response of humankind to the concerning effects of fossil fuels depletion, climate change and energy insecurity, and calls for a deep penetration of renewable energy sources (RESs) in power systems and industrial processes. Despite the high potentials, low impacts and long-term availability, RESs present some limits which need to be overcome, such as the strong variability and difficult predictability, which result in scarce reliability and difficult applicability in steady-state processes. Some technological solutions relate to energy storage systems, equipment electrification and hybrid systems deployment, thus accomplishing distributed generation even in remote sites as offshore. However, all of these actions cannot disregard sustainability, which represents a founding principle for any project, bringing together economics, reliability and environmental protection. To entail sustainability in RESs-based innovative projects, previous knowledge and tools are often not tailored or miss the novel objectives. This research proposes three methodological approaches, bridging the gaps. The first contribute adapts literature-based indicators of inherent safety and energy efficiency to capture the specificities of novel process plants and hybrid systems. Minor case studies dealing with novel P2X processes exemplify the application of these novel indicators. The second method guides the conceptual design of hybrid systems for the valorisation of a RES in a site, by considering the sustainability performances of alternative design options. Its application is demonstrated through the comparison of two offshore sites where wave energy can be valorised. Finally, “OHRES”, a comprehensive tool for the sustainable optimisation of hybrid renewable energy systems is proposed. “OHRES” hinges on the exploitation of multiple RESs, by converting ex-post sustainability indicators into discrimination markers screening a large number of possible system configuratio

Nowadays, the chemical industry has reached significant goals to produce essential components for human being. The growing competitiveness of the market caused an important acceleration in R&D activities, introducing new opportunities and procedures for the definition of process improvement and optimization. In this dynamicity, sustainability is becoming one of the key aspects for the technological progress encompassing economic, environmental protection and safety aspects. With respect to the conceptual definition of sustainability, literature reports an extensive discussion of the strategies, as well as sets of specific principles and guidelines. However, literature procedures are not completely suitable and applicable to process design activities. Therefore, the development and introduction of sustainability-oriented methodologies is a necessary step to enhance process and plant design. The definition of key drivers as support system is a focal point for early process design decisions or implementation of process modifications. In this context, three different methodologies are developed to support design activities providing criteria and guidelines in a sustainable perspective. In this framework, a set of key Performance Indicators is selected and adopted to characterize the environmental, safety, economic and energetic aspects of a reference process. The methodologies are based on heat and material balances and the level of detailed for input data are compatible with available information of the specific application. Multiple case-studies are defined to prove the effectiveness of the methodologies. The principal application is the polyolefin productive lifecycle chain with particular focus on polymerization technologies. In this context, different design phases are investigated spanning from early process feasibility study to operative and improvements assessment. This flexibility allows to apply the methodologies at any level of design, providing supporting gu

The severe accidents deriving from the impact of natural events on industrial installations have become a matter of growing concern in the last decades. In the literature, these events are typically referred to as Natech accidents. Several peculiarities distinguish them from conventional industrial accidents caused by internal factors, such as the possible occurrence of multiple simultaneous failures, and the enhanced probability of cascading events. The research project provides a comprehensive overview of Natech accidents that occurred in the Chemical and Process Industry, allowing for the identification of relevant aspects of Natech events. Quantified event trees and probability of ignition are derived from the collected dataset, providing a step forward in the quantitative risk assessment of Natech accidents. The investigation of past Natech accidents also demonstrated that wildfires may cause technological accidents. Climate change and global warming are promoting the conditions for wildfire development and rapid spread. Hence, ensuring the safety of industrial facilities exposed to wildfires is paramount. This was achieved defining safety distances between wildland vegetation and industrial equipment items. In addition, an innovative methodology for the vulnerability assessment of Natech and Domino scenarios triggered by wildfires was developed. The approach accounted for the dynamic behaviour of wildfire events and related technological scenarios. Besides, the performance of the emergency response and the related intervention time in the case of cascading events caused by natural events were evaluated. Overall, the tools presented in this thesis represent a step forward in the Quantitative Risk Assessment of Natech accidents. The methodologies developed also provide a solid basis for the definition of effective strategies for risk mitigation and reduction. These aspects are crucial to improve the resilience of industrial plants to natural hazards, especially

Offshore Oil&Gas facilities are attractive targets of intentional malicious attacks (security attacks) that may trigger cascading events (e.g., the release and dispersion of hazardous material and/or energy, fires, explosions) with consequences on people, environment, and assets. The severity of these consequences is potentially similar to those arising from major accident scenarios originated by conventional safety-related causes. Current practice in managing the risk of security attacks mostly relies on qualitative or semi-quantitative procedures developed over the years in the offshore Oil&Gas industry. In the present study, a systematic quantitative procedure is developed, based on a Bayesian Network (BN) approach, for calculating the probability of success of physical security attacks, taking into account both preventive and mitigative security intervention strategies. The procedure addresses the specific framework of the offshore Oil&Gas industry. A case study concerning an offshore fixed Oil&Gas platform allowed us to demonstrate the quality of the results that can be achieved and their potential towards the improvement of the security of the installations considered., Safety and Security Science

Dynamic Risk Assessment and Management of Domino Effects and Cascading Events in the Process Industry provides insights into emerging and state-of-the-art methods for the dynamic assessment of risk and safety barrier performance in the framework of domino effect risk management. The book presents methods and tools to manage the risk of cascading events involving the chemical and process industry. It is an ideal reference for both safety and security managers, industrial risk stakeholders, scientists and practitioners. In addition, laymen may find the state-of-the-art methods concerning domino effects (large-scale accidents) and how to prevent their propagation an interesting topic of study. Includes dynamic hazard and risk assessment methods Presents methods for safety barrier performance assessment Addresses the effect of harsh environment on domino risk assessment Relates physical security in relation to domino effects Includes innovative methods and tools

Dynamic Risk Assessment and Management of Domino Effects and Cascading Events in the Process Industry provides insights into emerging and state-of-the-art methods for the dynamic assessment of risk and safety barrier performance in the framework of domino effect risk management. The book presents methods and tools to manage the risk of cascading events involving the chemical and process industry. It is an ideal reference for both safety and security managers, industrial risk stakeholders, scientists and practitioners. In addition, laymen may find the state-of-the-art methods concerning domino effects (large-scale accidents) and how to prevent their propagation an interesting topic of study. Includes dynamic hazard and risk assessment methods Presents methods for safety barrier performance assessment Addresses the effect of harsh environment on domino risk assessment Relates physical security in relation to domino effects Includes innovative methods and tools

Dynamic Risk Assessment and Management of Domino Effects and Cascading Events in the Process Industry provides insights into emerging and state-of-the-art methods for the dynamic assessment of risk and safety barrier performance in the framework of domino effect risk management. The book presents methods and tools to manage the risk of cascading events involving the chemical and process industry. It is an ideal reference for both safety and security managers, industrial risk stakeholders, scientists and practitioners. In addition, laymen may find the state-of-the-art methods concerning domino effects (large-scale accidents) and how to prevent their propagation an interesting topic of study. Includes dynamic hazard and risk assessment methods Presents methods for safety barrier performance assessment Addresses the effect of harsh environment on domino risk assessment Relates physical security in relation to domino effects Includes innovative methods and tools

The interaction between natural hazards and chemical and process installations might lead to severe technological scenarios involving hazardous materials. These events are termed as Natech accidents and have several peculiarities that fall beyond the features of industrial accidents caused by internal factors. Indeed, natural events can simultaneously trigger multiple technological scenarios, leading to complex situations hard to be managed by emergency teams. Moreover, natural hazards can affect utilities and lifelines required to guarantee the correct operation of processes and of the implemented safety measures. This impairment can produce peculiar scenarios if specific classes of substances are handled, and can influence the possibility of accident escalation and domino effect, eventually leading to complex cascading events. This thesis is aimed at developing the tools for a more comprehensive quantification of the Natech risk, with a specific focus on the possibility that utilities and safety barriers might be impacted during the accident. A novel paradigm is presented for the description of the dynamics of Natech events, to highlight the central role of utilities and safety barriers in accident chain progression. Subsequently, a complete approach to assess the modification of barrier performance during natural hazards is described and embedded in an approach to assess the modification of Natech escalation likelihood. Then, a set of quantitative risk assessment methodologies is presented, enabling the evaluation of Natech risk including the possibility of barrier depletion and accident escalation also via domino effects. The tools presented in this thesis will hopefully enhance the comprehension of complex Natech events and foster the development of effective strategies for risk reduction and management, pivotal issues to be addressed to improve the resilience of chemical and process sites to natural hazards also in the light of the possibility that their sever

Accidents triggered by natural events are becoming an increasing issue for policy-makers and industrial practitioners in the last decades. These events are called Natech (natural hazards triggering technological disasters), and their study is critical due to an increase in both the frequency and the magnitude of the consequences. Considering the possible failure of safety systems and the several equipment items potentially involved in the accidents due to the occurrence of multiple simultaneous failures and cascading events, the emergency response results to be a crucial aspect in the risk assessment and management of Natech events. Despite this, the emergency response can also be affected by the occurrence of natural events. The purpose of the present work is to understand the effects of natural events on emergency response. To reach this goal, some relevant past accidents are studied. The result of the analysis allows highlighting the effects of the natural events on the emergency response. Moreover, lessons learned on the critical elements of the emergency response are derived when considering Natech accidents and related cascading events., Safety and Security Science

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Safety and Security Science

Wildfires are uncontrolled fires involving the combustion of wild vegetation. When a wildfire front approaches the Wildland-Industrial Interface there can be a serious threat for process and storage equipment items located at the plant boundary. Ensuring the integrity of such equipment prevents the fire from spreading inside the plant site and causing major accidents such as fire, explosion, and toxic gas dispersion. The provision of adequate clearance areas is paramount since the early stages of the plant design. Once the facility is built, the implementation of safety measures can protect industrial items and ensure tank integrity. A tailored methodology for the calculation of safety distances between wild vegetation and tanks accounting for the safety system was developed and applied to a case study. The outcomes provide useful information on the effectiveness of safety measures for the protection of industrial items exposed to wildfire., Peer Reviewed, Postprint (published version)

The interaction between natural hazards and chemical and process installations might lead to severe technological scenarios involving hazardous materials. These events are termed as Natech accidents and have several peculiarities that fall beyond the features of industrial accidents caused by internal factors. Indeed, natural events can simultaneously trigger multiple technological scenarios, leading to complex situations hard to be managed by emergency teams. Moreover, natural hazards can affect utilities and lifelines required to guarantee the correct operation of processes and of the implemented safety measures. This impairment can produce peculiar scenarios if specific classes of substances are handled, and can influence the possibility of accident escalation and domino effect, eventually leading to complex cascading events. This thesis is aimed at developing the tools for a more comprehensive quantification of the Natech risk, with a specific focus on the possibility that utilities and safety barriers might be impacted during the accident. A novel paradigm is presented for the description of the dynamics of Natech events, to highlight the central role of utilities and safety barriers in accident chain progression. Subsequently, a complete approach to assess the modification of barrier performance during natural hazards is described and embedded in an approach to assess the modification of Natech escalation likelihood. Then, a set of quantitative risk assessment methodologies is presented, enabling the evaluation of Natech risk including the possibility of barrier depletion and accident escalation also via domino effects. The tools presented in this thesis will hopefully enhance the comprehension of complex Natech events and foster the development of effective strategies for risk reduction and management, pivotal issues to be addressed to improve the resilience of chemical and process sites to natural hazards also in the light of the possibility that their sever

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Safety and Security Science

Accidents triggered by natural events are becoming an increasing issue for policy-makers and industrial practitioners in the last decades. These events are called Natech (natural hazards triggering technological disasters), and their study is critical due to an increase in both the frequency and the magnitude of the consequences. Considering the possible failure of safety systems and the several equipment items potentially involved in the accidents due to the occurrence of multiple simultaneous failures and cascading events, the emergency response results to be a crucial aspect in the risk assessment and management of Natech events. Despite this, the emergency response can also be affected by the occurrence of natural events. The purpose of the present work is to understand the effects of natural events on emergency response. To reach this goal, some relevant past accidents are studied. The result of the analysis allows highlighting the effects of the natural events on the emergency response. Moreover, lessons learned on the critical elements of the emergency response are derived when considering Natech accidents and related cascading events., Safety and Security Science

Domino Effect: Its Prediction and Prevention, Volume Five in the Methods in Chemical Process Safety series, focuses on the process of learning from experience, including elements of process safety management, human factors in the chemical process industries, and the regulation of chemical process safety, including current approaches. Users will find this book to be an informative tool and user manual for process safety for a variety of professionals. This new release focuses on Domino effect – Case histories and accident statistics, the state-of-the-art in domino effect modeling, Fire Driven Domino Effect, Mitigation of Domino Effect, and much more. Acquaints readers/researchers with the fundamentals of process safety Provides the most recent advancements and contributions from a practical point-of-view Gives readers the views/opinions of experts on each topic

Domino Effect: Its Prediction and Prevention, Volume Five in the Methods in Chemical Process Safety series, focuses on the process of learning from experience, including elements of process safety management, human factors in the chemical process industries, and the regulation of chemical process safety, including current approaches. Users will find this book to be an informative tool and user manual for process safety for a variety of professionals. This new release focuses on Domino effect – Case histories and accident statistics, the state-of-the-art in domino effect modeling, Fire Driven Domino Effect, Mitigation of Domino Effect, and much more. Acquaints readers/researchers with the fundamentals of process safety Provides the most recent advancements and contributions from a practical point-of-view Gives readers the views/opinions of experts on each topic

The use of liquefied natural gas (LNG) as an alternative ship fuel marks a fundamental step towards the reduction of emissions linked to maritime transportation of goods and passengers. Despite the positive safety record of the LNG shipping industry, natural gas is a hazardous substance and safety concerns for its use onboard passenger ships demand a thorough evaluation. This study aims at a comprehensive safety and sustainability assessment of marine LNG technologies, focusing on small-scale applications, seeking to fill the current knowledge gap in this field. An in-depth evaluation of the safety of existing technologies for LNG bunkering and onboard fuel gas supply systems is performed, providing key information about the credible accident scenarios and their expected consequences. The safety criticalities are identified based on the application of specifically developed models for the evaluation of the inherent safety performance of LNG bunkering and propulsion technologies. Another part of the work is dedicated to the development of a computational fluid dynamic (CFD) setup to model the behaviour of cryogenic tanks exposed to accidental hydrocarbon fires, overcoming the limitations of the previous modelling approaches, and providing precise data for further analysis of the tank structural integrity under extreme conditions. Furthermore, a preliminary CFD modelling of LNG fire scenario consequences occurring inside the fuel preparation room of gas-fuelled ships is carried out to evaluate the heat flux received by the ship structure. The obtained results represent a first step towards a wider approach aimed at enhancing the safety of the entire LNG supply for maritime propulsion. Furthermore, these results can make a valuable contribution to support the decision-making process for shipowners and port authorities in the design and safety assessment of such systems, both in port areas and onboard ships, also providing guidance for emergency responders.

There has been a strong need to enhance the utilization of renewable energy systems (RESs) from onshore to offshore applications where oil and gas companies are pivoting to integrate such renewable energy options into their offshore operations to lower their carbon footprint, extend the lifetime of their assets, and expand their market. In this regard, innovative hybrid energy systems, such as “Power to Gas? (P2G) and “Power to Liquid? (P2L) options, as well as novel integration strategies for “Gas to Power? (G2P) systems, offer the opportunity to implement solutions energy transition, paving the way to offshore RES deployment. Hybrid Energy Systems for Offshore Applications delivers a comprehensive presentation of state of the art and perspective developments of offshore RES exploitation strategies and technologies, and provides a unique portfolio of decision-making methodologies supporting the selection of the most suitable options for offshore renewable energy production at a specific site. System modeling and analysis along with the definitions of multicriteria methodologies and strategies based on sustainability, environmental impact, and safety performance indicators are addressed in an integrated fashion. Rounding out with both research and practical applications explained, this book gives academicians and industrial professionals fundamentals and methods for integrated performance analysis of innovative systems addressing offshore RES exploitation, sustainable chemical and power production, better efficiency, lower costs, lower environmental impact, and higher inherent safety. Harmonized presentation of RESs Unique coverage on hybrid energy systems and their offshore applications Comprehensive thermodynamic analysis and evaluation of the developed systems Process and system modeling, analysis, and decision-making methodologies for offshore P2G, P2L, and G2P solutions Sustainability modeling and assessment studies for various offshore applications Distinct pa

The use of liquefied natural gas (LNG) as an alternative ship fuel marks a fundamental step towards the reduction of emissions linked to maritime transportation of goods and passengers. Despite the positive safety record of the LNG shipping industry, natural gas is a hazardous substance and safety concerns for its use onboard passenger ships demand a thorough evaluation. This study aims at a comprehensive safety and sustainability assessment of marine LNG technologies, focusing on small-scale applications, seeking to fill the current knowledge gap in this field. An in-depth evaluation of the safety of existing technologies for LNG bunkering and onboard fuel gas supply systems is performed, providing key information about the credible accident scenarios and their expected consequences. The safety criticalities are identified based on the application of specifically developed models for the evaluation of the inherent safety performance of LNG bunkering and propulsion technologies. Another part of the work is dedicated to the development of a computational fluid dynamic (CFD) setup to model the behaviour of cryogenic tanks exposed to accidental hydrocarbon fires, overcoming the limitations of the previous modelling approaches, and providing precise data for further analysis of the tank structural integrity under extreme conditions. Furthermore, a preliminary CFD modelling of LNG fire scenario consequences occurring inside the fuel preparation room of gas-fuelled ships is carried out to evaluate the heat flux received by the ship structure. The obtained results represent a first step towards a wider approach aimed at enhancing the safety of the entire LNG supply for maritime propulsion. Furthermore, these results can make a valuable contribution to support the decision-making process for shipowners and port authorities in the design and safety assessment of such systems, both in port areas and onboard ships, also providing guidance for emergency responders.

With the aim of extracting lessons learned, this study investigated a large oil spill at an ironworks factory in Saga prefecture, during the severe flooding that hit southwestern Japan in late August 2019. The oil spill dispersed by the flood waters contaminated adjacent crops, irrigation canals and citizens homes in a large area of Omachi town. Many citizens had practiced vertical evacuation. Due to the oil spill, the pumping of flood waters had to be stopped to prevent further contamination, resulting in oil stagnating in the area for several days. This meant that residents had to be rescued from their homes in the middle of strong oil vapours. The oil spil s possible long-lasting impact in terms of health and environmental pollution requires monitoring and further investigation. The study found that oil spills caused by floods had already occurred at the same site, highlighting the need to improve risk management of chemical hazards, develop flood risk maps that consider the potential for these types of secondary events and other compound disasters, and propose more effective strategies for emergency planning and response.

Against a backdrop of rapidly increasing worldwide population and growing energy demand, the development of renewable energy technologies has become of primary importance in the effort to reduce greenhouse gas emissions. However, it is often technically and economically infeasible to transport discontinuous renewable electricity for long distances to the shore. Another shortcoming of non-programmable renewable power is its integration into the onshore grid without affecting the dispatching process. On the other hand, the offshore oil & gas industry is striving to reduce overall carbon footprint from onsite power generators and limiting large expenses associated to carrying electricity from remote offshore facilities. Furthermore, the increased complexity and expansion towards challenging areas of offshore hydrocarbons operations call for higher attention to safety and environmental protection issues from major accident hazards. Innovative hybrid energy systems, as Power-to-Gas (P2G), Power-to-Liquid (P2L) and Gas-to-Power (G2P) options, implemented at offshore locations, would offer the opportunity to overcome challenges of both renewable and oil & gas sectors. This study aims at the development of systematic methodologies based on proper sustainability and safety performance indicators supporting the choice of P2G, P2L and G2P hybrid energy options for offshore green projects in early design phases. An in-depth analysis of the different offshore hybrid strategies was performed. The literature reviews on existing methods proposing metrics to assess sustainability of hybrid energy systems, inherent safety of process routes in conceptual design stage and environmental protection of installations from oil and chemical accidental spills were carried out. To fill the gaps, a suite of specific decision-making methodologies was developed, based on representative multi-criteria indicators addressing technical, economic, environmental and societal aspects of alternative opti

Against a backdrop of rapidly increasing worldwide population and growing energy demand, the development of renewable energy technologies has become of primary importance in the effort to reduce greenhouse gas emissions. However, it is often technically and economically infeasible to transport discontinuous renewable electricity for long distances to the shore. Another shortcoming of non-programmable renewable power is its integration into the onshore grid without affecting the dispatching process. On the other hand, the offshore oil & gas industry is striving to reduce overall carbon footprint from onsite power generators and limiting large expenses associated to carrying electricity from remote offshore facilities. Furthermore, the increased complexity and expansion towards challenging areas of offshore hydrocarbons operations call for higher attention to safety and environmental protection issues from major accident hazards. Innovative hybrid energy systems, as Power-to-Gas (P2G), Power-to-Liquid (P2L) and Gas-to-Power (G2P) options, implemented at offshore locations, would offer the opportunity to overcome challenges of both renewable and oil & gas sectors. This study aims at the development of systematic methodologies based on proper sustainability and safety performance indicators supporting the choice of P2G, P2L and G2P hybrid energy options for offshore green projects in early design phases. An in-depth analysis of the different offshore hybrid strategies was performed. The literature reviews on existing methods proposing metrics to assess sustainability of hybrid energy systems, inherent safety of process routes in conceptual design stage and environmental protection of installations from oil and chemical accidental spills were carried out. To fill the gaps, a suite of specific decision-making methodologies was developed, based on representative multi-criteria indicators addressing technical, economic, environmental and societal aspects of alternative opti

The security of critical infrastructures is of paramount importance nowadays due to the growing complexity of components and applications. This paper collects the contributions to the industry dissemination session within the 14th International Conference on Critical Information Infrastructures Security (CRITIS 2019). As such, it provides an overview of recent practical experience reports in the field of critical infrastructure protection (CIP), involving major industry players. The set of cases reported in this paper includes the usage of serious gaming for training infrastructure operators, integrated safety and security management in the chemical/process industry, risks related to the cyber-economy for energy suppliers, smart troubleshooting in the Internet of Things (IoT), as well as intrusion detection in power distribution Supervisory Control And Data Acquisition (SCADA). The session has been organized to stimulate an open scientific discussion about industry challenges, open issues and future opportunities in CIP research.

The security of critical infrastructures is of paramount importance nowadays due to the growing complexity of components and applications. This paper collects the contributions to the industry dissemination session within the 14th International Conference on Critical Information Infrastructures Security (CRITIS 2019). As such, it provides an overview of recent practical experience reports in the field of critical infrastructure protection (CIP), involving major industry players. The set of cases reported in this paper includes the usage of serious gaming for training infrastructure operators, integrated safety and security management in the chemical/process industry, risks related to the cyber-economy for energy suppliers, smart troubleshooting in the Internet of Things (IoT), as well as intrusion detection in power distribution Supervisory Control And Data Acquisition (SCADA). The session has been organized to stimulate an open scientific discussion about industry challenges, open issues and future opportunities in CIP research.

Managing Wildland-Urban-Interface (WUI) fires is a challenging task due to the inherent complexity of the WUI environment. To ensure the success of strategies for the protection of population and structures, safety measures have to be implemented at different scales (landscape, community and homeowner). The present study is focused on the homeowner scale and deals with the threat related to the presence of LPG domestic tanks in a WUI fire scenario. Recent accidents have demonstrated that the risk associated with this type of installation is real, but often disregarded by residents. A methodology was developed, providing a set of indicators that may easily be compared with risk acceptance criteria, assessing whether the integrity of an LPG tank exposed to WUI fire scenarios is compromised or not. The methodology is applicable to a vast range of situations and at a different level of detail according to available data. A number of case studies were carried out, showing that WUI fire scenarios impacting on domestic LPG tanks complying with regulations currently adopted in several Mediterranean countries cannot be deemed safe. The methodology proposed represents an advanced tool to assist on safety distances sizing to be prescribed by standards, driving regulators towards better-informed decision-making., Peer Reviewed, Postprint (author's final draft)

Preprint

Domino effects triggered by fire can cause extremely severe damages to the chemical and process plants. In the need of a more effective prevention of fire domino effects, the present study focuses on firefighting which has received less attention compared to passive and active fire protection systems. Considering both the vulnerability and recoverability phases during fire domino effects, we have introduced a methodology for optimal identification of firefighting strategies so as to increase the resiliency of process plants in dealing with fire escalation scenarios. The area above the resilience curve (AARC), which is equal to the accumulation of loss of resilience over time, was considered as the metric to identify the optimal firefighting strategies. In other words, the strategy leading to the lowest AARC can be selected as the optimal strategy from a resiliency perspective, Safety and Security Science

Manufacturing processes involving chemical agents are evolving at great speed. In this context, managing chemical risk is especially important towards preventing both occupational accidents and major accidents. Directive 89/391/EEC and Directive 2012/18/EU, respectively, are enforced in the European Union (EU) to this end. These directives may be further complemented by the recent ISO 45001:2018 standard regarding occupational health and safety management systems. These three management systems are closely related. However, scientific literature tackles the researching of these accidents independently. Thus, the main objective of this work is to identify and analyse the links and transitional spaces between the risk management of both types of accident. Among the results obtained, three transitional spaces can be pointed out which result from the intersection of the three systems mentioned. Similarly, the intersection of these spaces gives shape to a specific transitional space defined by the individual directives linked to Directive 89/391/EEC. These results are limited from a regulatory and technical perspective. Thus, the results are a starting point towards developing models that integrate the management systems studied.

Before the tragedy of 9/11, the perception of risk in process plants was mainly focused on accidental events caused by technical failures, human errors or natural events. However, since then, the risk of deliberate actions against process facilities - also known as security risk - has also become a concern. Security risk assessment of engineering systems and infrastructures constitutes a complex task since a significant multitude of technical and socio-political information is needed to reasonably predict the risk of intentional malevolent acts. In the present study, a methodology based on Bayesian network (BN) has been applied to increase the security of critical infrastructures via cost-effective allocation of security measures. Using the probability updating feature of BN, the proposed methodology can be employed to investigate the effect of vulnerabilities on adversaries' preferences while planning security scenarios. Moreover, the proposed methodology is capable of efficiently identifying an optimal defensive strategy given a security scenario (i.e., an attack) through maximizing defenders' expected utility., Safety and Security Science

Manufacturing processes involving chemical agents are evolving at great speed. In this context, managing chemical risk is especially important towards preventing both occupational accidents and major accidents. Directive 89/391/EEC and Directive 2012/18/EU, respectively, are enforced in the European Union (EU) to this end. These directives may be further complemented by the recent ISO 45001:2018 standard regarding occupational health and safety management systems. These three management systems are closely related. However, scientific literature tackles the researching of these accidents independently. Thus, the main objective of this work is to identify and analyse the links and transitional spaces between the risk management of both types of accident. Among the results obtained, three transitional spaces can be pointed out which result from the intersection of the three systems mentioned. Similarly, the intersection of these spaces gives shape to a specific transitional space defined by the individual directives linked to Directive 89/391/EEC. These results are limited from a regulatory and technical perspective. Thus, the results are a starting point towards developing models that integrate the management systems studied., Safety and Security Science

Security threats are becoming an increasing concern for chemical sites and related infrastructures where relevant quantities of hazardous materials are processed, stored or transported. In the present study, security related events that affected chemical and process sites, and related infrastructures, were investigated. The aim of the study is to frame a clear picture of the threats affecting the chemical and process industry, and to issue lessons learnt from past events. A database of 300 security-related accidents was developed and populated, starting from European and American sources. Threat categories that caused such events were identified and analyzed. The attack modes were investigated. Important differences were found with respect to geographical areas and industrial sectors affected. The use of explosives (both military and improvised explosive devices) is by far the more frequent attack mode, although armed attacks and arson are also frequent events and may result in an in-depth penetration of the attackers. In recent years, cyber-attacks are also posing important threats. Lessons learnt call for the implementation of a specific security management system in the chemical and process industry, aiming at the physical and cyber protection of industrial sites., Safety and Security Science

The possible occurrence of accidental fires impacting vessels for transportation and storage of hazardous materials represents a key safety issue in the process industry. In these situations, the vessel heats up, pressurizes and can fail catastrophically, generating devastating consequences. Such scenarios have been extensively investigated in the past decades to improve vessel design and emergency response planning. Numerous field studies and laboratory scale tests were carried out and several models were developed to predict the thermal and mechanical response of vessels exposed to fire. However, previous modeling approaches suffer several limitations and need to be improved and experimental data is not sufficient to effectively support the development of advanced modelling tools such as CFD. With the aim of overcoming these limitations, a novel research program was proposed. This combines fire tests, carried out by means of an innovative experimental apparatus, and a CFD based modelling approach. The present work focuses mainly on the modelling part (the experimental setup is briefly described and preliminary analysis of the data from tests is presented). Starting from previous approaches presented in literature, an improved CFD modelling setup was developed. Conditions of several fire tests involving LPG and water tanks were simulated and the results are compared with experimental measurements highlighting strengths and limitations of the modelling. In the last part of the work, an alternative approach is presented, based on models developed for the study of subcooled boiling flows that showed promising results in other fields of application. The aim was to explore the possibility of extending this approach to the case of fired vessels. The work proves that CFD is a powerful tool for the development of models able to accurately describe and predict the response of a pressure vessel exposed to fire. However, further work is needed especially regarding submodels f

The propagation of fire-induced domino effects in chemical plants largely depends on the primary fire scenario, on separation distances between the units, and on the presence of fire protection barriers. Passive and active safety barriers are widely employed to prevent or delay the initiation or propagation of domino effects. In the present study, a methodology has been developed based on Bayesian network to account for the impact of such safety barriers on the propagation of fire domino scenarios. The Bayesian network has been extended to a limited memory influence diagram in order to identify a cost-effective allocation of additional safety barriers to further mitigate the fire propagation. The application of the methodology has been demonstrated using a chemical tank farm. The results are in good agreement with the results of a graph theoretic approach developed in a previous study, proving the reliability of the developed methodology in cost-effective protection of process plants., Safety and Security Science

Manufacturing processes involving chemical agents are evolving at great speed. In this context, managing chemical risk is especially important towards preventing both occupational accidents and major accidents. Directive 89/391/EEC and Directive 2012/18/EU, respectively, are enforced in the European Union (EU) to this end. These directives may be further complemented by the recent ISO 45001:2018 standard regarding occupational health and safety management systems. These three management systems are closely related. However, scientific literature tackles the researching of these accidents independently. Thus, the main objective of this work is to identify and analyse the links and transitional spaces between the risk management of both types of accident. Among the results obtained, three transitional spaces can be pointed out which result from the intersection of the three systems mentioned. Similarly, the intersection of these spaces gives shape to a specific transitional space defined by the individual directives linked to Directive 89/391/EEC. These results are limited from a regulatory and technical perspective. Thus, the results are a starting point towards developing models that integrate the management systems studied.

The possible occurrence of accidental fires impacting vessels for transportation and storage of hazardous materials represents a key safety issue in the process industry. In these situations, the vessel heats up, pressurizes and can fail catastrophically, generating devastating consequences. Such scenarios have been extensively investigated in the past decades to improve vessel design and emergency response planning. Numerous field studies and laboratory scale tests were carried out and several models were developed to predict the thermal and mechanical response of vessels exposed to fire. However, previous modeling approaches suffer several limitations and need to be improved and experimental data is not sufficient to effectively support the development of advanced modelling tools such as CFD. With the aim of overcoming these limitations, a novel research program was proposed. This combines fire tests, carried out by means of an innovative experimental apparatus, and a CFD based modelling approach. The present work focuses mainly on the modelling part (the experimental setup is briefly described and preliminary analysis of the data from tests is presented). Starting from previous approaches presented in literature, an improved CFD modelling setup was developed. Conditions of several fire tests involving LPG and water tanks were simulated and the results are compared with experimental measurements highlighting strengths and limitations of the modelling. In the last part of the work, an alternative approach is presented, based on models developed for the study of subcooled boiling flows that showed promising results in other fields of application. The aim was to explore the possibility of extending this approach to the case of fired vessels. The work proves that CFD is a powerful tool for the development of models able to accurately describe and predict the response of a pressure vessel exposed to fire. However, further work is needed especially regarding submodels f

Manufacturing processes involving chemical agents are evolving at great speed. In this context, managing chemical risk is especially important towards preventing both occupational accidents and major accidents. Directive 89/391/EEC and Directive 2012/18/EU, respectively, are enforced in the European Union (EU) to this end. These directives may be further complemented by the recent ISO 45001:2018 standard regarding occupational health and safety management systems. These three management systems are closely related. However, scientific literature tackles the researching of these accidents independently. Thus, the main objective of this work is to identify and analyse the links and transitional spaces between the risk management of both types of accident. Among the results obtained, three transitional spaces can be pointed out which result from the intersection of the three systems mentioned. Similarly, the intersection of these spaces gives shape to a specific transitional space defined by the individual directives linked to Directive 89/391/EEC. These results are limited from a regulatory and technical perspective. Thus, the results are a starting point towards developing models that integrate the management systems studied., Safety and Security Science

The propagation of fire-induced domino effects in chemical plants largely depends on the primary fire scenario, on separation distances between the units, and on the presence of fire protection barriers. Passive and active safety barriers are widely employed to prevent or delay the initiation or propagation of domino effects. In the present study, a methodology has been developed based on Bayesian network to account for the impact of such safety barriers on the propagation of fire domino scenarios. The Bayesian network has been extended to a limited memory influence diagram in order to identify a cost-effective allocation of additional safety barriers to further mitigate the fire propagation. The application of the methodology has been demonstrated using a chemical tank farm. The results are in good agreement with the results of a graph theoretic approach developed in a previous study, proving the reliability of the developed methodology in cost-effective protection of process plants., Safety and Security Science

Security threats are becoming an increasing concern for chemical sites and related infrastructures where relevant quantities of hazardous materials are processed, stored or transported. In the present study, security related events that affected chemical and process sites, and related infrastructures, were investigated. The aim of the study is to frame a clear picture of the threats affecting the chemical and process industry, and to issue lessons learnt from past events. A database of 300 security-related accidents was developed and populated, starting from European and American sources. Threat categories that caused such events were identified and analyzed. The attack modes were investigated. Important differences were found with respect to geographical areas and industrial sectors affected. The use of explosives (both military and improvised explosive devices) is by far the more frequent attack mode, although armed attacks and arson are also frequent events and may result in an in-depth penetration of the attackers. In recent years, cyber-attacks are also posing important threats. Lessons learnt call for the implementation of a specific security management system in the chemical and process industry, aiming at the physical and cyber protection of industrial sites., Safety and Security Science

Before the tragedy of 9/11, the perception of risk in process plants was mainly focused on accidental events caused by technical failures, human errors or natural events. However, since then, the risk of deliberate actions against process facilities - also known as security risk - has also become a concern. Security risk assessment of engineering systems and infrastructures constitutes a complex task since a significant multitude of technical and socio-political information is needed to reasonably predict the risk of intentional malevolent acts. In the present study, a methodology based on Bayesian network (BN) has been applied to increase the security of critical infrastructures via cost-effective allocation of security measures. Using the probability updating feature of BN, the proposed methodology can be employed to investigate the effect of vulnerabilities on adversaries' preferences while planning security scenarios. Moreover, the proposed methodology is capable of efficiently identifying an optimal defensive strategy given a security scenario (i.e., an attack) through maximizing defenders' expected utility., Safety and Security Science

Security of chemical and oil & gas facilities became a pressing issue after the terrorist attacks of 9/11, due to relevant quantities of hazardous substances that may be present in these sites. Oil & gas pipelines, connecting such facilities, might be potential targets for intentional attacks. The majority of methods addressing pipeline security are mostly qualitative or semi-quantitative, based on expert judgment and thus potentially subjective. In the present study, an innovative security vulnerability assessment methodology is developed, based on Discrete-time Bayesian network (DTBN) technique to investigate the vulnerability of a hazardous facility (pipeline in this study) considering the performance of security countermeasures in place. The methodology is applied to an illustrative gas pipeline in order to rank order the pipeline segments based upon their criticality., Safety and Security Science

Acid gases, such as sulphur dioxide and hydrogen halides and – in a broad sense – carbon dioxide, are typical pollutants generated by combustion processes. Their removal by means of solid sorbents represent an efficient and cost-effective approach in dry acid gas treatment systems for waste incineration flue gas, while for CO2 capture the process is exploratively studied as a promising alternative to amine scrubbing. The present study addressed both aspects. In waste incineration flue gas cleaning, acid gas removal by sorbent injection is a well-established process. Nonetheless, a thorough understanding of the gas-solid reactions involved in the process has not been reached yet and, thus, the operation of dry treatment systems is still highly empirical. In the present study, the process was analysed using different levels of detail: from the microscopic level of a lab-scale experimental campaign and phenomenological description of the kinetic and mass transfer phenomena governing the gas-solid reaction to the macroscopic level of techno-economic and environmental assessment of alternative full-scale dry treatment systems. With respect to CO2 capture technologies, the process is still in the development stage and research is focused on the identification of highly-efficient sorbents. The present study analysed the enhancement of CO2 uptake potential of magnesium oxide, a promising sorbent for intermediate-temperature carbon capture, by means of coating with alkali metal molten salts. The joint analysis of gas-solid reaction for flue gas cleaning in two diverse contexts allowed the identification of common issues and of possible shared solutions.

The PhD research project is aimed at developing and applying an innovative framework toward Risk Assessment of cascading events within the chemical and process industry, addressing both domino and security-based events. Cascading events are catastrophic accidents, triggered by external hazard factors, including safety-based (i.e., domino) and security-based events. In the chemical industry domain, barriers provide a crucial role for the prevention, control and mitigation of cascading events. Therefore, it is necessary to apply innovative techniques, aimed at the evaluation of barriers technical performance and at their optimal economic allocation, to be inserted within Quantitative Risk Assessment (i.e., QRA). Concerning barriers technical performance, the research activity is aimed at applying Bayesian Networks to safety barriers performance assessment, regarding domino events. Starting from a conventional approach, preliminary applications have been aimed at implementing a Bayesian approach to barriers performance assessment concerning major accidents. Therefore, the approach has been extended to domino accident analysis, in purpose to evaluate the effect of barriers introduction within modelling. The case studies demonstrated that the application of a Bayesian approach provides a very accurate barriers performance assessment within QRA, with reference to external hazard factors driven accidents (i.e., domino events), offering a realistic risk picture. Concerning barriers optimal economic allocation, the research activity is aimed at developing and applying an original economic model for the prevention of security-based cascading events. The model includes security upgrades performance and costs assessment, evaluation of benefits and definition of threat and vulnerability probabilities. The application of economic techniques, by means of cost-benefit and cost-effectiveness analyses, enables barriers optimal allocation within budgets constraints. Validation of the

The PhD research project is aimed at developing and applying an innovative framework toward Risk Assessment of cascading events within the chemical and process industry, addressing both domino and security-based events. Cascading events are catastrophic accidents, triggered by external hazard factors, including safety-based (i.e., domino) and security-based events. In the chemical industry domain, barriers provide a crucial role for the prevention, control and mitigation of cascading events. Therefore, it is necessary to apply innovative techniques, aimed at the evaluation of barriers technical performance and at their optimal economic allocation, to be inserted within Quantitative Risk Assessment (i.e., QRA). Concerning barriers technical performance, the research activity is aimed at applying Bayesian Networks to safety barriers performance assessment, regarding domino events. Starting from a conventional approach, preliminary applications have been aimed at implementing a Bayesian approach to barriers performance assessment concerning major accidents. Therefore, the approach has been extended to domino accident analysis, in purpose to evaluate the effect of barriers introduction within modelling. The case studies demonstrated that the application of a Bayesian approach provides a very accurate barriers performance assessment within QRA, with reference to external hazard factors driven accidents (i.e., domino events), offering a realistic risk picture. Concerning barriers optimal economic allocation, the research activity is aimed at developing and applying an original economic model for the prevention of security-based cascading events. The model includes security upgrades performance and costs assessment, evaluation of benefits and definition of threat and vulnerability probabilities. The application of economic techniques, by means of cost-benefit and cost-effectiveness analyses, enables barriers optimal allocation within budgets constraints. Validation of the

Acid gases, such as sulphur dioxide and hydrogen halides and – in a broad sense – carbon dioxide, are typical pollutants generated by combustion processes. Their removal by means of solid sorbents represent an efficient and cost-effective approach in dry acid gas treatment systems for waste incineration flue gas, while for CO2 capture the process is exploratively studied as a promising alternative to amine scrubbing. The present study addressed both aspects. In waste incineration flue gas cleaning, acid gas removal by sorbent injection is a well-established process. Nonetheless, a thorough understanding of the gas-solid reactions involved in the process has not been reached yet and, thus, the operation of dry treatment systems is still highly empirical. In the present study, the process was analysed using different levels of detail: from the microscopic level of a lab-scale experimental campaign and phenomenological description of the kinetic and mass transfer phenomena governing the gas-solid reaction to the macroscopic level of techno-economic and environmental assessment of alternative full-scale dry treatment systems. With respect to CO2 capture technologies, the process is still in the development stage and research is focused on the identification of highly-efficient sorbents. The present study analysed the enhancement of CO2 uptake potential of magnesium oxide, a promising sorbent for intermediate-temperature carbon capture, by means of coating with alkali metal molten salts. The joint analysis of gas-solid reaction for flue gas cleaning in two diverse contexts allowed the identification of common issues and of possible shared solutions.

Security of chemical and oil & gas facilities became a pressing issue after the terrorist attacks of 9/11, due to relevant quantities of hazardous substances that may be present in these sites. Oil & gas pipelines, connecting such facilities, might be potential targets for intentional attacks. The majority of methods addressing pipeline security are mostly qualitative or semi-quantitative, based on expert judgment and thus potentially subjective. In the present study, an innovative security vulnerability assessment methodology is developed, based on Discrete-time Bayesian network (DTBN) technique to investigate the vulnerability of a hazardous facility (pipeline in this study) considering the performance of security countermeasures in place. The methodology is applied to an illustrative gas pipeline in order to rank order the pipeline segments based upon their criticality., Safety and Security Science

Production of energy from biomassis an attractive alternative to conventional fossil fuels. Use of solid organic wastes to produce biofuel is seen as a promising route from the sustainability point of view. Pyrolysis is one of the possible thermochemical methods to convert solid biomasses to valuable liquid and gas products. In this study, the slow pyrolysis process of poultry litter was investigated using different experimental and analytical techniques. A fixed bed reactor was used for the simulation of the slow pyrolysis process up to a constant temperature (400-800°C) under nitrogen flow. Yields of the different product fractions were determined. Several analytic methods were used to characterise the products. On-line FTIR techniques were used to detect the most significant compounds in the evolved gas. GC-MS results allowed the identification of the most important categories of compounds in the liquid condensate. HCNS composition of the products was revealed by elemental analysis and the fate of nitrogen and sulphur, present in relevant amounts in the original substrate, was studied. The energy transfer from the original biomass substrate to the different product fractions was also investigated. However, the bio-oil obtained from pyrolysis can be used as biofuel only after an upgrading step. A suitable method for upgrading bio-oil is catalytic cracking of the pyrolysis products, which converts high molecular weight compounds of the bio-oil into lower-weight molecules. Therefore, in the following step of the present study in-situ catalytic pyrolysis of poultry litter was studied by zeolites (zsm-5) catalyst. In order to study the effect of influential factors (temperature and catalyst to biomass ratio) on the obtained products, experimental design techniques were used. Overall, the results achieved shed some light on the potential use of the slow pyrolysis process for sanitation and waste-to-energy valorization of poultry litter.