Academic literature on the topic 'Flammable Substance'

One of the current key problems is forecasting flammable properties of substances. The lack of information about the applied substance prevents developing complete fire-prevention systems. To solve this problem authors suggest a forecasting method based on molecular descriptors and artificial neuron networks. As an example of the method they predicted the self-ignition point of anthraquinone and anthraquinone-based colorants. Average absolute error did not exceed 13,1 °C.

Assessment of the mobile risk sources is not yet established in the European Union by law and therefore there is not enough pressure to manage and reduce risks. However, the transport of dangerous goods poses a special risk in terms of the nature of the transported material, especially for densely populated urban areas. The release of toxic or flammable substances into the air may endanger the health and life of many inhabitants. The assessment of consequences of the mobile accident hazards has been dealt with only seldom and not in details. The aim of this paper is to assess the risks associated with the transport of dangerous flammable substance. Authors would like to point out that the mobile resources represent a significant source of risk through the transport of dangerous goods in the event of an emergency occurrence associated with their leakage.

The transitions between the vibrational energetic states of atoms represent the infrared absorption spectra, which is a band spectrum over which the transitions between energetic rotational states overlap. One of the most important uses of infrared absorption spectrometry is the identification in quantitative terms of the structure of compounds from a substance, the analytes being either solid, liquid or vaporous. The FTIR-TGA Coupling is a technique that permanently controls the mass loss in a sample, as a function of temperature and time, as well as the identification and recording of various compounds occurring during the combustion process. Research on hydraulic oils has consisted of their analysis using the FTIR-TGA coupling in order to identify flammable substances that can generate explosive events.

Auto-ignition temperature (AIT) is usually defined as the lowest temperature at which a substance will produce hot-flame ignition in air at atmospheric pressure without the aid of an external energy source such as spark or flame. Its principal applications include: defining the maximum acceptable surface temperature in a particular area, usually for electrical classification purpose, to prevent fire and explosion hazards; determining the possible hazardous consequence associated with leakage of flammable chemicals in risk assessment methods. Although AIT is indispensable for safely handling and operating flammable substance, the AITs data are, however, very much diverse in different data compilations. In present work the AITs of three ketones are measured in compliance with the ASTM E659 test method. The measured AITs are (461.7 ± 9.2) °C, (397.8 ± 8.0) °C and (399.0 ± 8.0) °C for Methyl Ethyl Ketone, Methyl Isoamyl Ketone and 2-Heptanone, respectively. It is found that the AIT compiled in DIPPR 2009 is beyond the experimental reproducibility in Methyl Ethyl Ketone and Methyl Isoamyl Ketone, and the difference is found to be of 54 °C and 207 °C and 6 °C for Methyl Ethyl Ketone Methyl and Isoamyl Ketone, respectively. The AIT reported in The Chemical Database also deviates from that obtained in present work with certain degree, and the difference is found to be of 54 °C, 57 °C and 133 °C for Methyl Ethyl Ketone, Methyl Isoamyl Ketone and 2- Heptanone, respectively.

This paper explains the interest in urban organic solid wastes, the relevance of these wastes to municipal solid waste management, the main ways in which organics are reused, and the problem that arise from the wish to ensure safe and effec�tive reuse as part of sustainable development in cities in Romania. Wastes are substances resulting from biological or technological processes that can no longer be used as such, some of which are reusable. Dangerous substances are any substance or product which, when used in apparently non-hazardous quantities, concentrations or conditions, presents a significant risk to humans, the environment or material goods (eg explosives, oxidizing, flammable, toxic, harmful, corrosive, irritant, mutagenic. Urban administrations nowadays are seeking ways to divert organic wastes from municipal solid waste streams for a variety of reasons, as noted below. Recommenda�tions are made for separation at source so that safe composting can be carried out. Private companies are being encouraged to undertake composting, often via forms of public-private partnerships. More attention is being paid to the role of non-govern�mental organizations in promoting citizen awareness of organic waste issues, and co-operation with separation at source. This paper draws attention to the many informal ways that organic wastes are currently reused, which are rarely taken into account in official plans for managing organic wastes.

The article presents the possibilities for the contemporary application of Styrofoam in the elements of building structures. Having in mind that Styrofoam belongs to a group of highly flammable materials, 5 % of combustion retarder - so called "retardant" - needs to be added to the amount when produced for structural building elements. That kind of Styrofoam is called "self-extinguishing" contrary to "normal" that does not contain that substance. The Article also shows the way in which building elements are constructed (external and interfloor construction), made out of Styrofoam using "Plastbau" technology. A possibility to use exterior wall panels ‘Plastbau’ under weather conditions of Saint-Petersburg has been considered. Temperature distribution along a wall’s section as well as a heat flow going through a building enclosure ‘Plastbau’ have been also analyzed herein.

COG have been widely used together with blast furnace gas and blast furnace oxygen gas in the steel industry in Moravian-Silesian region of Czech Republic. COG is a flammable and explosive substance. Most explosion characteristics published so far are valid for pure compounds and limited experimental conditions, mostly ambient. There have been no explosion characteristic exists for COG-air mixtures which cover industrial conditions up to 423 K. Experimental tests have been carried out in a 20-L closed explosion chamber adopted for the explosion tests. The element potential approach in the thermochemical equilibrium calculations applied in the Chemkin subroutine has been used for explosion pressure calculations. Different explosion characteristics have been reported in a range from 298 K up to 423 K and from 0.5 bar(a) up to 1.0 bar(a).

Furan is colorless, highly volatile and flammable liquid with a specific ether odor. In nature it occurs in some species of wood, it is formed during burning process of wood, tobacco, fuels and also in thermal food processing. In industry furan is used as an intermediate in organic synthesis, resins solvent, during production of lacquer, drugs, stabilizers, insecticides and also in production of chemical compounds which have polymeric and coordination structure. Carcinogenic effect on animals was a base of recognition that furan is a substance which is probably also carcinogenic on humans. The aim of this study was to develop and validate a method of determining furan in workplace air. Developed determination method of furan relies on vapor absorption of this substance on coconut shell charcoal. Furan was extracted by 5% butan-1-ol solution in toluene. Obtained solution was analyzed with chromatography. The study was performed with gas chromatograph coupled with mass spectrometer (GC-MS), equipped with non-polar HP-PONA capillary column (length 50 m, diameter 0.2 mm and the film thickness of the stationary phase 0.5 µm). Developed method is linear in the concentration range of 0.05–1.0 µg/ml, which is equivalent to the range of 0.005–0.1 mg/m3 for 10-L air sample. The analytical method described in this paper makes it possible to determine furan in workplace air in the presence of comorbid substances. The method is precise, accurate and it meets the criteria for procedures for determining chemical agents listed in Standard No. PN-EN 482. The developed method of determining furan in workplace air has been recorded as an analytical procedure (see Appendix). This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

Docetaxel (DCT) is a plant derived cytotoxic from taxane family - mitosis inhibitors. It is used in the treatment of breast, lung and prostate cancer, squamous cell carcinoma of the head and neck, and gastric adenoma. Docetaxel is a highly flammable liquid and health-threatening substance classified as mutagenicity category 2 and reproductive toxicity category 1B. This paper presents a method for measuring docetaxel in the workplace air with HPLC with diode array detector (DAD). The method is based on the adsorption of inhalable fraction of docetaxel aerosol on glass fiber filter, desorption with water and chromatographic analysis. The analysis was performed in reverse phase on C18 column and mobile phase – acetonitrile: ammonium acetate solution (45: 55). The measurement range was 0.6 – 10 µg/m3 for 480-L air sample. The limit of detection (LOD) was 0.0065 µg/ml and the limit of quantification (LOQ) was 0.0195 µg/ml. The developed method of docetaxel determination has been recorded as an analytical procedure (see appendix).

With the industrial and technological development of the present-day society, the presence of flammable and toxic substances has increased in a growing number of activities. Dispersion of hazardous gas releases occurring in transportation or storage installations represent a major threat to health and environment. Therefore, forecasting the behaviour of a flammable or toxic cloud is a critical challenge in quantitative risk analysis. The main aim of this dissertation has been to provide new insights that can help technological risks analysts when dealing with complex dispersion modelling problems, particularly those problems involving dispersion scenarios with barriers or semi-confined. A literature survey has shown that, traditionally, empirical and integral models have been used to analyse dispersion of toxic/flammable substances, providing fast estimations and usually reliable results when describing simple scenarios (e.g. unobstructed gas flows over flat terrain). In recent years, however, the use of CFD tools for simulating dispersion accidents has significantly increased, as they allow modelling more complicated gas dispersion scenarios, like those occurring in complex topographies, semi-confined spaces or with the presence of physical barriers. Among all the available CFD tools, FLACS® software is envisaged to have high performance when simulating dispersion scenarios, but, as other codes alike, still needs to be fully validated. This work contributes to the validation of FLACS software for dispersion analysis. After a literature review on historical field tests, some of them have been selected to undertake a preliminary FLACS performance examination, inspecting all possible sources of uncertainties in terms of reproducibility capacity, grid dependence and sensitivity analysis of input variables and simulation parameters. The main outcomes of preliminary FLACS investigations have been shaped as practical guiding principles to be used by risk analysts when performing dispersion analysis with the presence of barriers using FLACS software or tools alike. Although the literature survey has shown some experimental data available, none of the works include detailed exercises giving new insights of how to perform accurate CFD simulations nor giving precise rates of FLACS performance. Therefore, new experiments have been performed in order to offer new sets of cloud dispersion data for comprehensive validation studies. Propane cloud dispersion field tests (unobstructed and with the presence of a fence obstructing the flow) have been designed and undertaken at Can Padró Security and Safety training site (Barcelona) by which intensive data on concentration has been acquired. Four tests were performed, consisting on releases up to 0.5 kg/s of propane during 40 seconds in a discharge area of 700 m2. FLACS software has been challenged against the experimental data collected during the field tests. In general terms, the CFD-based simulator has shown good performance when simulating cloud concentration. FLACS reproduces successfully the presence of complex geometry and its effects on cloud dispersion, showing realistic concentration decreases due to cloud dispersion obstruction by the existence of a fence. However, simulated clouds have not represented the whole complex accumulation dynamics due to wind variation, since they have diluted faster than experimental clouds.
Com o atual desenvolvimento industrial e tecnológico da sociedade, a presença de substâncias inflamáveis e/ou tóxicas aumentou significativamente em um grande número de atividades. A possível dispersão de gases perigosos em instalações de armazenamento ou em operações de transporte representam uma grande ameaça à saúde e ao meio ambiente. Portanto, a caracterização de uma nuvem inflamável e/ou tóxica é um ponto crítico na análise quantitativa de riscos. O objetivo principal desta tese foi fornecer novas perspectivas que pudessem auxiliar analistas de risco envolvidos na análise de dispersões em cenários complexos, por exemplo, cenários com barreiras ou semi-confinados. A revisão bibliográfica mostrou que, tradicionalmente, modelos empíricos e integrais são usados na análise de dispersão de substâncias tóxicas / inflamáveis, fornecendo estimativas rápidas e geralmente confiáveis ao descrever cenários simples (por exemplo, dispersão em ambientes sem obstruções sobre terreno plano). No entanto, recentemente, o uso de ferramentas de CFD para simular dispersões aumentou de forma significativa. Estas ferramentas permitem modelar cenários mais complexos, como os que ocorrem em espaços semi-confinados ou com a presença de barreiras físicas. Entre todas as ferramentas CFD disponíveis, consta na bibliografia que o software FLACS® tem bom desempenho na simulação destes cenários. Porém, como outras ferramentas similares, ainda precisa ser totalmente validado. Após a revisão bibliográfica sobre testes de campo já executados ao longo dos anos, alguns testes foram selecionados para realização de um exame preliminar de desempenho da ferramenta CFD utilizado neste estudo. Foram investigadas as possíveis fontes de incertezas em termos de capacidade de reprodutibilidade, de dependência de malha e análise de sensibilidade das variáveis de entrada e parâmetros de simulação. Os principais resultados desta fase foram moldados como princípios práticos a serem utilizados por analistas de risco ao realizar análise de dispersão com a presença de barreiras utilizando ferramentas CFD. Embora a revisão bibliográfica tenha mostrado alguns dados experimentais disponíveis na literatura, nenhuma das fontes encontradas incluem estudos detalhados sobre como realizar simulações de CFD precisas nem fornecem indicadores precisos de desempenho. Portanto, novos testes de campo foram realizados a fim de oferecer novos dados para estudos de validação mais abrangentes. Testes de campo de dispersão de nuvem de propano (com e sem a presença de barreiras obstruindo o fluxo) foram realizados no campo de treinamento da empresa Can Padró Segurança e Proteção (em Barcelona). Quatro testes foram realizados, consistindo em liberações de propano com vazões de até 0,5 kg/s, com duração de 40 segundos em uma área de descarga de 700 m2. Os testes de campo contribuíram para a reavaliação dos pontos críticos mapeados durante as primeiras fases deste estudo e forneceram dados experimentais para serem utilizados pela comunidade internacional no estudo de dispersão e validação de modelos. Simulações feitas utilizando-se a ferramenta CFD foram comparadas com os dados experimentais obtidos nos testes de campo. Em termos gerais, o simulador mostrou bom desempenho em relação às taxas de concentração da nuvem. O simulador reproduziu com sucesso a geometria complexa e seus efeitos sobre a dispersão da nuvem, mostrando claramente o efeito da barreira na distribuição das concentrações. No entanto, as simulações não foram capazes de representar toda a dinâmica da dispersão no que concerne aos efeitos da variação do vento, uma vez que as nuvens simuladas diluíram mais rapidamente do que nuvens experimentais.
Amb el desenvolupament industrial i tecnològic de la societat actual, la presència de productes tòxics i inflamables s'ha vist incrementada àmpliament en diferents sectors. La dispersió de fuites de substàncies perilloses que poden tenir lloc durant el transport o emmagatzematge d'aquestes, pot representar un risc important per a les persones i pel medi ambient. Per això, poder predir el comportament d'un núvol tòxic o inflamable representa un dels reptes més importants de l'anàlisi quantitativa del risc. El principal objectiu d'aquesta tesi és el d'aportar nous coneixements que siguin d'interès pels analistes de risc tecnològic a l'hora d'enfrontar-se a problemes de modelització dispersió de certa complexitat, com ara aquells que ocorren en escenaris semi-confinats o amb presència de barreres. La revisió bibliogràfica ha permès detectar que, tradicionalment, els models que més s’han emprat per analitzar la dispersió de fuites han estat els de naturalesa empírica i integral, ja que aquests poden donar bones prediccions i de manera més àgil en escenaris senzills sense obstruccions i en terreny pla. Tanmateix, en els darrers anys, l’ús d’eines CFD (Computational Fluid Dynamics) per a simular la dispersió accidental s’ha vist incrementat, ja que aquests programaris permeten modelitzar escenaris més complexos, pel que fa a la topografia o a la presència d’elements que puguin obstruir el flux de material. D’entre totes les eines CFD disponibles, el programari FLACS® és el que mostra més potencial a l’hora de simular aquesta tipologia d’escenaris, però, com altres eines de la seva tipologia, encara requereix estudis complerts de validació. Aquesta tesi contribueix a la validació de FLACS per a realitzar anàlisis de dispersió. Després de revisar amb cura els estudis experimentals de la bibliografia, alguns d’ells han estat seleccionats per a dur a terme una avaluació inicial de les prestacions de FLACS, en la que s’han investigat totes les possibles fonts d’incertesa que poden aparèixer en les simulacions. Se n’ha estudiat la reproductibilitat, la dependència del domini i mida de cel·les i la sensibilitat de la concentració a variacions en les variables d’entrada i en els paràmetres de simulació. Els principals resultats d’aquesta anàlisi preliminar s’han presentat en forma de ―principis guia‖ que podran ser utilitzats per analistes de risc per tal que puguin simular de manera acurada escenaris complexes de dispersió amb l’eina FLACS o amb d’altres programaris similars. Tot i que a la bibliografia hi ha algunes dades experimentals disponibles, cap dels treballs inclou exercicis de validació suficientment complets. Tampoc s’hi inclou informació sobre com cal plantejar adequadament els escenaris de simulació ni tampoc s’hi troben valoracions quantitatives de la fiabilitat de FLACS. Per aquest motiu, en el marc d’aquesta tesi, s’ha dut a terme experiments per tal de tenir noves dades que permetin realitzar estudis de validació complets. Les proves han consistit en fuites de propà (lliures i amb obstruccions) i s’han dut a terme al centre de seguretat Can Padró (Sant Vicenç de Castellet, Barcelona). Amb aquests experiments s’ha pogut obtenir una gran quantitat de dades de concentració dels núvols experimentals. S’han dut a terme un total de 4 proves, amb cabals de 0.5 kg/s en una àrea de descàrrega de 700 m2. Les prestacions de FLACS ha estat provades tot simulant les proves experimentals. A nivell general, el programari ha tingut un bon rendiment a l’hora de simular la concentració dels núvols de propà. A més, ha pogut reproduir de manera adequada la presència d’una obstrucció i els seus efectes en la dispersió, donant resultats de descens de concentració realistes. Tanmateix, els núvols simulats no han representat en la seva totalitat la dinàmica d’acumulació dels experiments reals degut a la gran variabilitat del vent i han mostrat temps de dilució inferiors als reals.

Safety study of refuelling station. Diploma thesis, Institute of Metrology and Quality Assurance Testing, Brno University of Technology. This Diploma thesis deal with quantitative risk assessment of exposure. It means for population, animals and environment stocking, transport and manipulation with vairous fuel at refuelling station in particular area and influence of other industrial effects in close area of this refuelling station. There is more specified a Method of Dow´s fire and explosion Index, method of Guidelines for Quantitative Risk Assessment and method FMEA (Failure Mode and Effect Analysis).

Dissertação de Mestrado em Química Forense apresentada à Faculdade de Ciências e Tecnologia
O fogo, um dos elementos mais usado e mencionado desde os primórdios da civilização, é atualmente parte integrante dos incêndios, uma problemática que assola o nosso país ano após ano. Estes ocorrem em meio natural e urbano, sendo os incêndios rurais aqueles que têm uma maior expressão no número de ocorrências/ano. No entanto, são os incêndios urbanos os principais responsáveis pelas vítimas resultantes de incêndios em Portugal, bem como pelo elevado número de amostras que chegam para análise ao Laboratório de Polícia Científica.Os incêndios florestais são a subcategoria dos incêndios rurais com maior expressão a nível nacional e internacional, destacando-se, a nível europeu, países como Portugal e Espanha como aqueles que registam um maior número de ocorrências por ano, contrastando com todos os planos e ações de sensibilização em vigência para esta problemática.Este paradoxo torna imprescindível a investigação forense sobre a origem e as causas associadas a episódios como este. As ciências forenses são as responsáveis por esta investigação, uma vez que a recolha e análise dos resíduos tem de ser efetuada com métodos, normas e procedimentos cientificamente aprovados. Apesar da evolução desta investigação, ainda aproximadamente metade dos incidentes são classificados como causas indeterminadas. No entanto, naqueles em que é possível determinar uma causa, os incidentes de origem criminosa são os responsáveis por mais de metade das ocorrências, estando outra metade associada a ações de uso negligente do fogo.Neste tipo de investigação é necessária a identificação de acelerantes de combustão, quimicamente definidos como hidrocarbonetos. Trata-se de compostos derivados do petróleo que são utilizados em ambiente doméstico e, por isso, são facilmente encontrados nas superfícies comerciais. O mundo dos acelerantes de combustão é bastante vasto, tendo este trabalho incidido sobre a identificação de acendalhas em cenários onde tenha ocorrido um incêndio. Foram, para isso, utilizados neste estudo 5 tipos de acendalhas (ecológicas, géis, líquidas, diferentes e clássicas) em dois cenários distintos, antes e depois de serem expostos ao processo de queima. A técnica analítica utilizada foi a Cromatografia Gasosa acoplada com Espectrometria de Massa (GC MS).Através do estudo por comparação cromatográfica foi possível distinguir com clareza os 5 grupos estudados, tendo sido analisados os compostos presentes na amostra, o padrão de eluição e a aparência dos cromatogramas. Foi ainda possível, a formação de 4 subgrupos dentro do grupo das amostras clássicas, tendo sido esse agrupamento corroborado através de uma análise quimiométrica. As amostras sujeitas ao processo de queima permitiram uma análise mais detalhada acerca deste tipo de acelerante, e qual seria o seu comportamento cromatográfico numa amostra problema real, num caso de investigação, após a ocorrência de incêndio. Através deste estudo pormenorizado da identificação de acendalhas por GC-MS foi possível a construção de uma ficha técnica identificativa para cada amostra analisada, onde é possível encontrar toda a informação recolhida referente à mesma. Esta base de dados tem como principal objetivo auxiliar na análise por comparação efetuada às amostras de rotina que chegam ao LPC.
Fire, one of the most used and mentioned elements since the dawn of civilization, is now an integral part of fires, a problem that plagues our country year after year. These occur in natural and urban environments, but rural fires are those that have a greater expression in the number of occurrences/year. However, it is the urban fires that are mainly responsible for the victims resulting from fires in Portugal, and as well as the largest number of samples that arrive for analysis to Laboratório de Polícia Científica.Forest fires are the subcategory of rural fires with greater expression at national and international level, highlighting, at European level, countries such as Portugal and Spain as those with the highest number of occurrences per year, in contrast to all of plans and awareness actions about this issue.This paradox makes forensic investigation very important to assess about the origin and causes associated to episodes such as this. Forensic sciences are responsible for this research as residues collection and analysis must be done with scientifically approved methods, standards and procedures. Despite the progress of this investigation still approximately half of the incidents are classified as undetermined causes. However, in cases where a cause can be determined, incidents of criminal cause are responsible for more than half of the occurrences, while the other half are associated to negligent fire actions.In this type of investigation, it is necessary to identify combustion accelerants, chemically defined as hydrocarbons. These are petroleum-derived compounds that are used in home environment and are therefore easily found on commercial surfaces.The world of combustion accelerants is quite large, and this work has focused on identifying firelighters in scenarios where a fire occurred. Five types of firelighters were used (Ecological, Gels, Liquid, Different and Classic), and they were used in two different scenarios, before and after exposed to the burning process. The identification technique used was Gas Chromatography – Mass Spectrometry (GC-MS).Through the chromatographic comparation study it was possible to clearly distinguish the 5 groups studied, having analyzed the compounds present in the sample, the elution pattern and appearance of the chromatograms. It was also possible to form 4 subgroups within the Classic samples group, which was corroborated by chemometric analysis. The samples subjected to the firing process allowed a more detailed analysis of this type of accelerant, and what would be the chromatographic behavior in a real problem sample in a case of investigation after the occurrence of fire.Through this detailed study of the identification of firelighters by GC-MS it was possible to construct an identifiable datasheet for each sample analyzed, where it is possible to find all the collected information about it. The main objective of this database is to assist in comparative analysis performed on routine samples arrived at the LPC.

Product engineers are often challenged to estimate: 1. the properties of new or obscure classes of material that have not been extensively studied before, or have never been made before; 2. the property changes on a material due to physical and chemical modifications; 3. the properties under a variety of ambient conditions, such as temperatures, pressures, electromagnetic fields, and prolonged environmental exposures and weathering. When theoretical understanding is insufficient and quantitative correlations are not available, we can often make useful qualitative estimations by using fragmentary empirical structure–property relations. The principal tools are observations of associations and trends, which are often the only methods available in biological, health, safety, and environmental properties. Association is based on analogy, or the probabilistic assumption that “similar substances have similar properties.” Does x◦, the material in question, resemble a known substance x1 or a class of substances {x1, x2, . . ., xi , . . .} that have known properties and structure? If we can find such a match, then we can use it to make qualitative property estimates for x◦.We know that metals are nearly always solids at room temperature, but mercury is an exception. Trend is based on the study of the variation of properties among the substances {x1, x2, . . ., xi, . . .} and how they depend on structure variations, which amounts to qualitative and empirical structure–property relations. For example, we know that a larger molecule tends to have higher melting and boiling points, but chlorobenzene has lower melting point than benzene. Thomas Midgley used qualitative trend analysis to help him to discover the chlorofluorocarbons as refrigerants. He did not have a well-organized database, nor did he have an established method of analysis and prediction, and his method was ad hoc and empirical. What he did know was that sulfur dioxide and ammonia were in use as refrigerants. He looked at the periodic table of nonmetallic elements and observed the trend that small compounds of these elements tend to become less flammable when we move from the left to the right of the table, which is certainly true in the sequence CH4, NH3, H2O, and HF.

Ballast Water Treatment Systems (BWTS) particularly in tankers are faced with very unique and specific challenges with regards to the classification of hazardous areas and their installation requirements. Hazardous areas are defined as areas in which a flammable or explosive gas and air mixtures is, or may normally be expected to be, present in quantities such as to require special precautions for the construction and use of electrical equipment and machinery. Given that the ballast tanks in tankers are typically located adjacent to a cargo oil tanks, by definition ballast water is considered a hazardous substance. Therefore, BWTS installation in tankers will be subject to specific hazardous area installation requirements. This paper will identify specific installation requirements and considerations for BWTS installations in hazardous areas, and will provide installation scenarios which will highlight compliance with this specific requirements and various interpretations of different Flag States and Classification societies.

Large reserves of natural gas exist worldwide, particularly in areas in which there is no market or where the resources exceed the demand; this natural gas is liquefied for shipping to areas where there is a demand. As the liquefied natural gas is a flammable substance, a leakage in this process may cause undesired events like fires and explosions. The consequence analysis is used to define the extent and nature of effects caused by undesired events and thus to quantify the damage caused by such events. Specific models are used to analyze the spills or jets of gas and liquid, gas dispersion, explosions and fires. The central step in the analysis of consequences is to determine the concentration of the vapor cloud of hazardous substances released into the atmosphere, in space and time. Gaussian and integral tools are extensively used in risk analysis, mainly to develop analysis about gas flow over flat terrain, providing fast dispersion estimations. Recently, with the computational advances, computational fluid dynamics (CFD) tools are used to short and medium range gas dispersion scenarios. However the advantages and disadvantages of each approach according with the scenario evaluated have not been widely discussed. This paper evaluates, using a CFD model, the cloud dispersion of a LNG leakage. Then the results are compared with the results previously obtained by UDM (Unified Dispersion Model) and some advantages and disadvantages of each model are discussed. This study contributes to the decision making about the choice of most appropriated model to evaluate the consequences analysis.

Abstract Over the next few decades air travel is predicted to grow, with international agencies, manufacturers and governments predicting a considerable increase in aviation use. However, based on current fuel type, International Civil Aviation Organization (ICAO) project emissions from aviation are estimated to be seven to ten times higher in 2050 than in 1990. These conflicting needs are problematic and have led to the EU Flightpath 2050 targeting dramatic emissions reductions for the sector (75% CO2, 90% NOX by 2050). One proposed solution, decreasing carbon emissions without stunting the increase in air travel, is hydrogen propulsion; a technology with clear environmental benefits. However, enabling the safe application of this fuel to aviation systems and industrial infrastructure would be a significant challenge. High-profile catastrophic incidents involving hydrogen, and the flammable and cryogenic nature of liquid hydrogen (LH2) have led to its reputation as a more dangerous substance than existing or alternative fuels. But, where they are used (in industry, transport, energy), with sufficient protocols, hydrogen can have a similar level of safety to other fuels. A knowledge of hazards, risks and the management of these becomes key to the integration of any new technology. Using assessments, and a gap analysis approach, this paper examines the civil aviation industry requirements, from a safety perspective, for the introduction of LH2 fuel use. Specific proposed technology assessments are used to analyze incident likelihood, consequence impact, and ease of remediation for hazards in LH2 systems, and a gap analysis approach is utilized to identify if existing data is sufficient for reliable technology safety assessment. Outstanding industry needs are exposed by both examining challenges that have been identified in transport and industrial areas, and by identifying the gaps in current knowledge that are preventing credible assessment, reliable comparison to other fuels and the development of engineering systems. This paper demonstrates that while hydrogen can be a safe and environmentally friendly fuel option, a significant amount of work is required for the implementation of LH2 technology from a mass market perspective.

The consequence analysis is used to define the extent and nature of effects caused by undesired events being of great help when quantifying the damage caused by such events. For the case of leaking of flammable and/or toxic materials, effects are analyzed for explosions, fires and toxicity. Specific models are used to analyze the spills or jets of gas or liquids, gas dispersions, explosions and fires. The central step in the analysis of consequences in such cases is to determine the concentration of the vapor cloud of hazardous substances released into the atmosphere, in space and time. With the computational advances, CFD tools are being used to simulate short and medium scale gas dispersion events, especially in scenarios where there is a complex geometry. However, the accuracy of the simulation strongly depends on diverse simulation parameters, being of particular importance the grid resolution. This study investigates the effects of the computational grid size on the prediction of a cloud dispersion considering both the accuracy and the computational cost. Experimental data is compared with the predicted values obtained by means of CFD simulation, exploring and discussing the influence of the grid size on cloud concentration the predicted values. This study contributes to optimize CFD simulation settings concerning grid definition when applied to analyses of consequences in environments with complex geometry.

The evaporation of pools of volatile liquids under dynamic conditions is gaining interest as an engineering subject. Indeed there is an increasing need to optimize the control of thermal or chemical processes and to cope with more and more stringent Environmental, Health and Safety (EHS) regulations applicable to the handling of hazardous liquids, especially those relating to stationary gas turbine installations. A specific issue, tied with flammable substances, comes from the fact that the transition from a flame to an explosion is not sufficiently well controlled due to the difficulty in modeling complex installations. Therefore, the current approach used to address explosion risks consists in quantifying the flux of vapors emitted by the pool and evaluating the mechanical effect entailed by a potential ignition of the flammable cloud generated. It is therefore of paramount importance to accurately know, under variable vaporizing conditions, how much of the volatile matter is extracted by the ventilation stream from the liquid pool and how these vapors get diluted downstream of the source. A survey of the literature shows that while pool evaporation of water has been extensively covered by experimentation, most organic liquids including hydrocarbons, alcohols, ethers, etc. have been insufficiently studied. In order to fill this gap, the authors have combined an experimental approach enabling to quantify the source of vapors with a dedicated Computational Fluid Dynamics (CFD) approach describing the mixing/dilution phenomena in the gas phase. This dual approach has proved very fruitful as it leads to realistic spatial distributions of the species downstream of the source. Therefore it has been utilized to develop experimentally verified data for the evaporation rate of single and multicomponent liquids. This paper presents the original experimental rig developed to quantify the vaporization rates. The elaboration of the CFD model and the results obtained when coupling both approaches will be the matter of a next paper.

The transfer under dynamic conditions of volatile species from a liquid pool to the surrounding air is gaining interest in the engineering community. In particular, increasingly stringent regulations and standards apply to all types of flammable substances. This is especially the case in stationary gas turbine applications, where the vaporization of accidentally occurring pools of liquid fuels attracts increasing attention. Since the flame-to-explosion transition cases are insufficiently controlled, the current, only practicable approach to assess the explosion risks arising from a fuel pool in an enclosure consists in quantifying the amount of vapor that leaves the pool and minimizing, by means of a proper dilution strategy, the potential damages entailed by the ignition of the resulting cloud. This approach requires two steps: (1) The accurate assessment of vaporization rates under given ventilation conditions, a task that calls for skills in thermal and mass transfers. (2) The reliable prediction of the transport of the vapors in the ventilation stream, a task specifically focused on fluid dynamics. The three teams involved in this paper have joined their efforts to achieve this multidisciplinary objective. As a first task, the LRGP team (Laboratoire des Reactions et Génie des Procédés) and GE Energy have experimentally validated a vaporization model initially devised for water pools. This work has been reported in a recent paper. Concurrently, EURO/CFD and GE Energy have developed a CFD approach devoted to the mixing/dilution processes in defined enclosure geometries and under specified ventilation conditions. Finally both approaches havebeen coupled by EURO/CFD to produce predictive isopleth pictures of the vapor clouds generated under given temperature and velocity conditions. The present paper covers the integration of the liquid pool vaporization model in thecommercial CFD software ANSYS Fluent and sets out the results obtained. This dual, concerted approach is a first of the kind to the authors’ knowledge and proves fruitful for the prediction of the spatial distributions of the volatile species developed when a volatile pool vaporizes in a ventilated enclosure. It fills a gap in the analysis of safety scenarios arising from spillages of liquid fuels and provides a rational tool in zone classification studies.