Search Results (95)

The maritime transport of liquefied gases poses significant safety and environmental hazards such as fire, explosion, toxic gas emissions, and air pollution. The main objective of this study was to systematically identify, analyze, and prioritise the potential risks associated with the operation of liquefied gas tankers using a hybrid methodological framework. This framework integrates Fuzzy Delphi, Fuzzy DEMATEL, and Fault Tree Analysis (FTA) techniques to provide a comprehensive risk assessment. Initially, 20 key risk factors were identified through expert consensus using the Fuzzy Delphi method. The causal relationships between these factors were then assessed using Fuzzy DEMATEL to understand their interdependencies. Based on these results, accident probabilities were further analyzed using FTA modelling. The results show that fires, explosions, and large gas leaks are the most serious threats. Equipment failures—often caused by corrosion and operational errors by crew members—are also significant contributors. In contrast, cyber-related risks were found to be of lower criticality. The study highlights the need for improved crew training, rigorous inspection mechanisms, and the implementation of robust preventive risk controls. It also suggests that the prioritisation of these risks may need to be reevaluated as autonomous ship technologies become more widespread. By mapping the interrelated structure of operational hazards, this research contributes to a more integrated and strategic approach to risk management in the LNG/LPG shipping industry. Full article

In response to global concerns about climate change and decarbonization across every sector, pressure has mounted on the maritime industry to reduce its environmental impacts, specifically its greenhouse gas (GHG) emissions, representing around 2.8% of the global total. As such, it prompts new alternative fuels that align with the International Maritime Organization (IMO)’s 2050 net-zero target. In recent years, several alternative fuels, such as hydrogen, ammonia, and methanol, have been proposed. However, alternative fuels face many challenges regarding cost, safety, and efficiency compared to traditional fossil fuels. Currently, methanol is considered one of the most promising alternatives since it is available, easy to store, and can take full advantage of existing infrastructure in situ. Moreover, methanol has a lower carbon intensity than conventional fossil fuels. However, its usage poses related risks of toxicity and flammability; thus, this area still needs in-depth research regarding hazard control. This study implements a systematic five-step methodology. Through a comprehensive literature review, the predominant hazards are delineated. To systematically analyze these risks, this study introduces a novel hazard-based coding system developed to categorize hazards into three classifications: toxicity, flammability, and explosivity. This system is specifically designed to analyze qualitative reports from thirty methanol accident investigations utilizing MAXQDA software. Subsequently, safety barriers related to methanol are identified, followed by a gap analysis to evaluate the effectiveness of existing safety measures. The findings indicate that physical hazards, including flammability and explosivity, represented the majority of identified risks. Furthermore, tank explosions emerged as a prominent sub-hazard, frequently linked to the highest number of reported fatalities. A gap analysis delineates the identified barriers related to Equipment and Personal Protective Equipment (PPE), Human Error Reduction, the Legal Framework, and First Aid, comparing them against the current measures outlined in IMO Circular 1621 and other legislative frameworks. Consequently, the analysis highlights critical gaps in technical guidelines and operational procedures related to methanol use. The study recommends the development of fuel-specific safety protocols, mandatory training for seafarers, and regulatory updates to address the unique hazards of methanol. These measures are necessary to create higher safety standards and make methanol a viable alternative fuel by ensuring its safe integration into the industry. Full article

Gas accumulation triggered by coal and gas outbursts is the core cause of secondary disasters in coal mines. This study focuses on the risk assessment of gas accumulation during disaster scenarios, proposing a multidimensional evaluation method integrating the analytic hierarchy process (AHP), information entropy theory, kernel density estimation, and dynamic risk propagation modeling. A unified intelligent prevention system encompassing “monitoring–prediction–decision making” is established. Leveraging the TFIM3D simulation platform and case studies from the Qunli Coal Mine accident, this research reveals spatiotemporal evolution patterns of gas concentration and explosion risk thresholds. A ventilation optimization strategy based on risk classification is proposed. The results demonstrate that the dynamic risk index (DRI), derived from the coupling of the roadway air volume stability coefficient and gas concentration information entropy, can accurately identify high-risk zones. The findings provide theoretical foundations and practical pathways for dynamic risk management in ventilation systems during coal and gas outburst disasters. Full article

Human reliability is a key factor in long-term sustainability, especially for tasks that are critical to safety. It is also evident that human behavior is often the main or significant cause of system failures. Identifying human error is challenging, particularly when it comes to determining the exact moment when an error occurred that led to an accident, as errors develop over time. It is essential to understand the causes and mechanisms of human errors. This finding is not new; for over 30 years, it has been recognized that human operations in safety-critical systems are so important that they should be modeled as part of risk assessment in operation. This article discusses various HRA methodologies and argues that further research and development are necessary. An example of selected HRA techniques will be demonstrated through a case study on acetylene filling activities. When filling acetylene into pressure vessels or cylinders, it is critically important to analyze the reliability of the human factor, as this process involves handling a highly explosive gas. Irresponsibility, lack of training, or incorrect decision-making can lead to severe accidents. Any deficiencies in this process can result in not only equipment damage but also endanger the health and lives of people nearby. This case may also suggest potential improvements to existing guidelines, international standards, and regulations, which often require the consideration of a wider range of ergonomic factors in the risk assessment process. Full article

Gas distribution stations (GDSs), pivotal nodes in long-distance natural gas transportation networks, are susceptible to catastrophic fire and explosion accidents stemming from system failures, thereby emphasizing the urgency for robust safety measures. While previous studies have mainly focused on gas transmission pipelines, GDSs have received less attention, and existing risk assessment methodologies for GDSs may have limitations in providing accurate and reliable accident probability predictions and fault diagnoses, especially under data uncertainty. This paper introduces a novel dynamic accident probability assessment framework tailored for GDS under data uncertainty. By integrating Bayesian network (BN) modeling with fuzzy expert judgments, frequentist estimation, and Bayesian updating, the framework offers a comprehensive approach. It encompasses accident modeling, root event (RE) probability estimation, undesired event (UE) predictive analysis, probability adaptation, and accident diagnosis analysis. A case study demonstrates the framework’s reliability and effectiveness, revealing that the occurrence probability of major hazards like vapor cloud explosions and long-duration jet fires diminishes significantly with effective safety barriers. Crucially, the framework acknowledges the dynamic nature of risk by incorporating observed failure incidents or near-misses into the assessment, promptly adjusting risk indicators like UE probabilities and RE criticality. This underscores the importance for decision-makers to maintain a heightened awareness of these dynamics, enabling swift adjustments to maintenance strategies and resource allocation prioritization. By mitigating assessment uncertainty and enhancing precision in maintenance strategies, the framework represents a significant advancement in GDS safety management, ultimately striving to elevate safety and reliability standards, mitigate natural gas distribution risks, and safeguard public safety and the environment. Full article

The global demand for liquefied natural gas (LNG) has led to a significant increase in the number of LNG carriers (LNGCs), consequently elevating the risk of operational accidents. Unlike conventional vessels, LNGCs present a high risk of fire and explosion and involve extensive repair times and costs due to the complex structure of the cargo containment system (CCS). This study investigates the effects of seawater exposure on the uni-axial compressive properties of plywood used in LNGC CCS structures, with the goal of establishing material strength criteria that could reduce repair requirements. The analysis focuses on the NO96 CCS, which incorporates the highest volume of plywood among existing designs. In this configuration, compressive strength is a critical design parameter. Therefore, the mechanical response of plywood was evaluated under both room temperature and cryogenic conditions (−163 °C), simulating the LNG operating environment. The results demonstrate that plywood exhibited increased compressive strength after three hours of seawater and saltwater immersion, although the rate of improvement diminished with extended exposure. In contrast, specimens immersed in distilled water showed a consistent reduction in compressive strength. Furthermore, cryogenic temperatures significantly enhanced the compressive strength compared to ambient conditions. This study establishes a methodology for assessing the mechanical performance of plywood under marine and cryogenic conditions, contributing to its reliable application in LNG carrier structures. Full article

Gas explosions are the most serious type of accident in coal mines in China. This study analyzed 125 gas explosion accidents that occurred between 2010 and 2020. The results showed that the number of gas explosion accidents and deaths in 2010–2020 was stable and decreasing. The number of larger gas explosion accidents in 2010–2020 is the largest, but the death toll from major accidents was much greater. Coal faces, headings, and roadways are the main locations where gas explosions are initiated. The coal mines in which gas explosions occur in coal faces and headings are mainly “township” enterprises and private mines, all of which engage in illegal operations. The main cause of gas accumulations in roadways is ventilation system failure; these failures can be reduced with improved ventilations system management. The number of gas explosion accidents and related deaths in the Sichuan, Guizhou, and Heilongjiang provinces are very high. The annual change in the frequency of gas explosion accidents, the quarterly distribution of gas explosion accidents, and time during a mining shift when gas explosion accidents occur are closely related to national policies and regulations, company annual production goals, and the mental status of miners, respectively. Full article

This article offers a concise overview of the best practices for safety in offshore oil and gas operations, focusing on the risks associated with various types of equipment, particularly on the risk of fire. It identifies specific machinery and systems that could pose hazards, assesses their potential impact on safety, and explores conditions that may lead to accidents. Some of the largest accidents were analyzed for their associations with fire hazards and specific equipment. Two primary regulatory approaches to offshore safety are examined: the prescriptive approach in the United States (US) and the goal-oriented approach in Europe. The prescriptive approach mandates strict compliance with specific regulations, while in the goal-oriented approach a failure to adhere to recognized best practices can result in legal accountability for negligence, especially concerning human life and environmental protection. This article also reviews achievements in safety through the efforts of regulatory authorities, industry collaborations, technical standards, and risk assessments, with particular attention given to the status of Mobile Offshore Drilling Units (MODUs). Contrary to common belief, the most frequent types of accidents are not those involving a fire/explosion caused by the failure of the Blowout Preventer (BOP) after a well problem has already started. Following analysis, it can be concluded that the most frequent type of accident typically occurs without fire and is due to material fatigue. This can result in the collapse of the facility, capsizing of the platform, and loss of buoyancy of mobile units, particularly in bad weather or during towing operations. It cannot be concluded that accidents can be more efficiently prevented under a specific type of safety regime, whether prescriptive or goal-oriented. Full article

The safety engineering design of hydrogen systems and infrastructure, worker education and training, regulatory compliance, and engagement with other stakeholders are significant to the viability and public acceptance of hydrogen farms. The only way to ensure these are accomplished is for the field of hydrogen safety engineering (HSE) to grow and mature. HSE is described as the application of engineering and scientific principles to protect the environment, property, and human life from the harmful effects of hydrogen-related mishaps and accidents. This paper describes a whole hydrogen farm that produces hydrogen from seawater by alkaline and proton exchange membrane electrolysers, then details how the hydrogen gas will be used: some will be stored for use in a combined-cycle gas turbine, some will be transferred to a liquefaction plant, and the rest will be exported. Moreover, this paper describes the design framework and overview for ensuring hydrogen safety through these processes (production, transport, storage, and utilisation), which include legal requirements for hydrogen safety, safety management systems, and equipment for hydrogen safety. Hydrogen farms are large-scale facilities used to create, store, and distribute hydrogen, which is usually produced by electrolysis using renewable energy sources like wind or solar power. Since hydrogen is a vital energy carrier for industries, transportation, and power generation, these farms are crucial in assisting the global shift to clean energy. A versatile fuel with zero emissions at the point of use, hydrogen is essential for reaching climate objectives and decarbonising industries that are difficult to electrify. Safety is essential in hydrogen farms because hydrogen is extremely flammable, odourless, invisible, and also has a small molecular size, meaning it is prone to leaks, which, if not handled appropriately, might cause fires or explosions. To ensure the safe and dependable functioning of hydrogen production and storage systems, stringent safety procedures are required to safeguard employees, infrastructure, and the surrounding environment from any mishaps. Full article

In coal mines, the mixture of coal dust and gas is more ignitable than gas alone, posing a high explosion risk to workers. Using the explosion tube, this study examines the explosion propagation characteristics and flame temperature of low-concentration gas and coal dust mixtures with various particle sizes. The CPD model and Chemkin-Pro 19.2 simulate the reaction kinetics of these explosions. Findings show that when the gas concentration is below its explosive limit, coal dust addition lowers the gas’s explosive threshold, potentially causing an explosion. Coal particle size significantly affects explosion propagation dynamics, with smaller particles producing faster flame velocities and higher temperatures. Due to their larger surface area, smaller particles absorb heat faster and undergo thermal decomposition, releasing combustible gases that intensify the explosion flame. The predicted yield of light gases from both coal types exceeds 40 wt% daf, raising combustible gas concentrations in the system. When accumulated reaction heat elevates the gas concentration to its explosive limit, an explosion occurs. These results are crucial for preventing gas and coal dust explosion accidents in coal mines. Full article

Hydrogen, as one of the most promising renewable clean energy sources, holds significant strategic importance and vast application potential. However, as a high-energy combustible gas, hydrogen poses risks of fire and explosion in the event of a leakage. Hydrogen production plants typically feature large spatial volumes and complex obstacles, which can significantly influence the diffusion pathways and localized accumulation of hydrogen during a short-term, high-volume release, further increasing the risk of accidents. Implementing effective hydrogen leakage monitoring measures can mitigate these risks, ensuring the safety of personnel and the environment to the greatest extent possible. Therefore, this paper uses CFD methods to simulate the hydrogen leakage process in a hydrogen production plant. The study examines the molar fraction distribution characteristics of hydrogen in the presence of obstacles by varying the ventilation speed of the plant and the directions of leakage. The main conclusions are as follows: enhancing ventilation can effectively prevent the rapid increase in hydrogen concentration, with higher ventilation speeds yielding better suppression. After a hydrogen leak in a confined space, hydrogen tends to diffuse along the walls and accumulate in corner areas, indicating that hydrogen monitoring equipment should be placed in corner locations. Full article

As unconventional building structures, container houses are now widely used in urban tourism to create characteristic buildings. Nowadays, natural gas accidents occur frequently in cities and towns; however, the development of laws and influencing factors of natural gas accidents in container buildings have rarely been studied. In this paper, a natural gas explosion test was carried out in an ordinary container house, and a numerical simulation was carried out according to the test results. The influence of methane proportion, ignition position, pressure-relief area, and pressure-relief intensity on the explosion load was analyzed. Research shows that natural gas will gather from top to bottom during the process of leakage and diffusion, and vertical stratification will occur. The most unfavorable working condition is 9.5% methane. Using the roof of the container house as a pressure-relief panel can effectively control the influence range of natural gas explosion accidents and help reduce accident losses. It is suggested that the stacking of container buildings should be reduced as much as possible, and the roof strength should be weakened to ensure structural safety. The research results have certain reference values for the disaster prevention and reduction design of urban characteristic buildings. Full article

Accidental leakage from oil–gas storage tanks can lead to the formation of liquid pools. These pools can result in vapor cloud explosions (VCEs) if combustible vapors encounter ignition energy. Conducting accurate and comprehensive consequence analyses of such explosions is crucial for quantitative risk assessments (QRAs) in industrial safety. In this study, a methodology based on the SLAB-TNO model to calculate the overpressure resulting from a VCE is presented. Based on this method, the consequences of the VCE accident considering the gas cloud concentration diffusion are studied. The probit model is employed to evaluate casualty probabilities under varying environmental and operational conditions. The effects of key parameters, including gas diffusion time, wind speed, lower flammability limit (LFL), and environment temperature, on casualty diffusion are systematically investigated. The results indicate that when the diffusion time is less than 100 s, the VCE consequences are significantly more severe due to the rapid spread of the gas cloud. Furthermore, increasing wind speed accelerates gas dispersion, reducing the spatial extent of casualty isopleths. The LFL is shown to have a direct impact on both the mass and diffusion of the flammable gas cloud, with higher LFL values shifting the explosion’s epicenter upward. The environmental temperature promotes gas diffusion in the core area and increases the mass of the combustible gas cloud. These findings provide critical insights for improving the safety protocols in oil and gas storage facilities and can serve as a valuable reference for consequence assessment and emergency response planning in similar industrial scenarios. Full article

The Yamal-Nenets Autonomous District, especially the Yamal Peninsula located in the permafrost zone, stores Russia’s largest oil and gas resources. However, development in the area is challenging because of its harsh climate and engineering–geological features. Drilling in oil and gas fields in permafrost faces problems that are fraught with serious accident risks: soil heaving leading to the collapse of wellheads and hole walls, deformation and breakage of casing strings, gas seeps or explosive emissions, etc. In this respect, knowledge of the permafrost’s structure is indispensable to ensure safe geological exploration and petroleum production in high-latitude regions. The extent and structure of permafrost in West Siberia, especially in its northern part (Yamal and Gydan Peninsulas), remain poorly studied. More insights into the permafrost’s structure have been obtained by a precise sTEM survey in the northern Yamal Peninsula. The sTEM soundings were performed in a large oil and gas field where permafrost is subject to natural and anthropogenic impacts, and its degradation, with freezing–thawing fluctuations and frost deformation, poses risks to exploration and development operations, as well as to production infrastructure. The results show that permafrost in the western part of the Yamal geocryological province is continuous laterally but encloses subriver and sublake unfrozen zones (taliks) and lenses of saline liquid material (cryopegs). The total thickness of perennially frozen rocks is 200 m. The rocks below 200 m have negative temperatures but are free from pore ice. Conductive features (<10 Ohm﮲m) traceable to the permafrost base may represent faults that act as pathways for water and gas fluids and, thus, can cause a geohazard in the oil and gas fields (explosion of frost mounds, gas blow during shallow drilling, etc.). Full article

Mine gas accidents have received widespread attention at home and abroad, because mine gas accidents often cause casualties and property losses once they occur. This study was conducted in order to have a more comprehensive understanding of the research status of and research hotspots in coal mine gas management at home and abroad, and to provide references for relevant researchers’ studies and literature searches. Using the Web of Science (WOS) core database as the data source, this paper analyzed the data from the period of 2000–2023 under the headings of “gas governance”, “Gas Control Technology”, “Pre-mining gas methods in coal mines”, “Methods of Gas Mining in Coal Mines”, “Post-mining gas”, and “Post-mining gas methods in coal mines”. “Methods in Coal Mines”, “Methods of Gas Mining in Coal Mines”, and “Post-mining Gas Methods in Coal Mines” were searched, and the CiteSpace tool was utilized to provide a multi-dimensional visual presentation of the literature, including authors, the number of journals issued, countries of issue, keywords, etc., in order to explore the research hotspots in this field. The analysis results show the following: the development process in the field of gas prevention and control is mainly divided into the three stages of initial exploration, steady development, and explosive surge; China, Australia, and the United States are the top three countries in terms of the number of articles published, and they have a greater influence in the field, but there is a closer connection between the regions in Europe; a certain group size has been formed by the researchers and research institutes in this field, the China University of Mining and Technology is more active in this field, ranking as the first in terms of the number of articles issued, and it has a cooperative relationship with many universities; Kai Wang and Enyuan Wang are the core authors in this field, while C. Ozgen Karacan also has a large body of research in the field, and his research results are widely recognized; the main journals issued in this field are Fuel and Energy Policy, while other journals have been frequently cited, and these journals have an important role in the field. In these journals, “Coal mine methane: A review of capture and utilization practices with benefits to mining safety and to greenhouse gas reduction” is one of the most important articles in the field. Thin coal seams, coal mining workings, and coal and gas protrusion are current research hotspots. Full article