查看更多>>摘要：Chemical and process plants storing large quantities of hazardous materials (flammable and/or toxic) may be attractive targets of intentional malicious attacks threatening the life and health of workers and po-pulation, as well as the environment and the availability of critical infrastructures. Quantification of the vulnerability of industrial facilities against shooting attacks received scarce attention in the context of Security Vulnerability Assessment (SVA) or Security Risk Assessment (SRA) methodologies. Specific damage models for projectile impact on equipment items storing relevant quantities of hazardous materials are not available in the literature. The current study aims at filling this gap by reviewing a wide set of empirical and analytical perforation models and validating them against experimental data from ballistic experimental tests. According to specific statistical parameters, the most suitable perforation models were selected in order to be used in the definition of quantitative methods for the analysis of the shooting attacks to at-mospheric storage equipment. The application of the selected models to the assessment of the vulnerability to perforation of steel atmospheric storage tanks showed important differences between handguns and rifles as regards the thickness that can be successfully perforated. The results allowed for the definition of inherent safety thresholds for the perforation thickness that can be used in the context of vulnerability assessment of critical assets within SVA/SRA.(c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：There are many people in urban construction areas, and natural gas leakage can potentially cause serious accident consequences. Predicting the consequences of gas dispersion is important to react rapidly and adequately in the event of an incident. Currently, computational fluid dynamics (CFD) models are an important tool to predict gas dispersion. However, in most cases, considering computational cost, the building layouts is ignored, so the flow field influence near the building area cannot be considered. In this research process, a realizable k-epsilon turbulence model is used to simulate the natural gas leakage process in a typical building layout (enclosed building layout), while focusing on wind speed and the leakage position. The validity of realizable k-epsilon turbulence model is verified by experimental data. The results show that under conditions of high wind speed (wind speed >= 6 m/s), the reverse vortex formed by the shear flow of wind can cause the natural gas cloud to sink. When the leak hole is located in the influence area of the turbulent vortex, it easily induces R-H instability. When combined with the stronger K-H instability at high wind speeds, natural gas clouds may accumulate. This then leads to serious leakage accidents, knowledge of which may be the key component of emergency management during an accidental natural gas leakage. The research results can guide the building layout plan and gas pipeline construction to prevent accidents.
Neto, Salvio Lima de CarvalhoViviani, Juliano Cesar ToledoWeschenfelder, Silvio EdegarRodrigues da Cunha, Maria de Fatima...
10页
查看更多>>摘要：This work aims to evaluate the use of petroleum as a solvent in the liquid-liquid extraction of oil and grease content from oilfied produced water. Initially, tests were performed with synthetic effluent, using cyclo-hexanecarboxylic acid as model compound through the study of physical-chemical parameters: pH, tem-perature, stirring speed and time, petroleum type and concentration, and initial concentration of naphthenic acids. Afterwards, the process was evaluated for the removal of oil and grease content from a real oilfield produced water sample. The pH and petroleum concentration proved to be significantly in-fluential in removing cyclohexanecarboxylic acid from the synthetic produced water (ANOVA). The greater the amount of petroleum present, the greater the efficiency. By acidifying the synthetic effluent, the effi-ciency of removing these naphthenic acids from the synthetic produced water was increased. Response surface methodology (RSM) evaluated these two factors. On the other hand, the initial concentration of cyclohexanecarboxylic acid and petroleum type did not presented great influence on the obtained results, indicating robustness of the process. The methodology carried out with synthetic effluent proved to be efficient in removing the oil and grease content from real effluent (' 60% of removal at pH range 2-5). (c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
Liu, AoboDelichatsios, Michael A.Levendis, Yiannis A.
12页
查看更多>>摘要：Liquid nitrogen (LN2) can be used to supplement or replace currently used fire extinguishers in challenging fire situations. This environmentally-benign cryogenic fluid can be produced readily from deep refrigeration of air. This manuscript addresses the application of liquid nitrogen to fires through a nozzle. Its aim is to investigate the survivability of LN2 droplets, following breakup of the jet exiting the nozzle, and the amount of liquid that reaches a target. Numerical simulations were carried out to explore the effects of relevant parameters, such as the initial droplet size and velocity, the droplet injection angle, and the thermal radiation on the droplet flight distance and the liquid droplet mass. The results indicate that all these parameters influence the fate of the LN2 droplets. Coarse atomization, high initial velocities, short nozzle-to-target distances, and shallow jet angles maximize the amount of the cryogen delivered to the target. A small-scale experiment was performed to test the results of the calculations. The comparison of the experimental results and the theoretical calculations was deemed satisfactory. In both cases the reach of the liquid droplets was in the order of 1 m from the nozzle, for an initial droplet velocity in the neighborhood of 20 m/s as measured in the experiments. (C) 2022 Published by Elsevier Ltd on behalf of Institution of Chemical Engineers.
查看更多>>摘要：The delay of ignition (DOI) affects engine performances and the fundamental reasons that affect DOI have not been fully explained. In this paper, taking biodiesel mixed with methanol as an example, the effect of the hydroxyl (-OH) functional group in the fuel on the DOI was studied. Through thermogravimetric ana-lyzer and constant volume combustion chamber (CVCC), the activation energy and DOI of different blending ratios (0%, 10%, 20% and 30%) of biodiesel/methanol mixed fuel were determined. Using the fictitious hydroxyl (FOH-) method, the low-temperature oxidation of biodiesel/methanol/FOH- and the reaction path of ignition in the cylinder were analyzed. The results show that when the methanol blending ratio is less than 30%, as the blending concentration of FOH- groups increases, the low-temperature oxidation reaction activity of the mixed fuel increases, and the activation energy decreases. The physical and chemical effects of -OH can prolong and shorten DOI, respectively, and the influence of physical effects is more important than chemical effects. For every 10% increase in -OH functional group concentration, the DOI of biodiesel/methanol mixed fuel increases by 1.4%. (C) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：This paper designs and evaluates an innovative multigeneration system based on a heliostat solar field that is a combination of closed Brayton cycle, absorption refrigeration cycle, humidification and dehumidifica-tion desalination, and proton exchange membrane electrolyzer. Thermodynamic and exergoeconomic analyses are performed for the performance assessment. Moreover, the grey wolf optimization algorithm in different multi-objective optimization scenarios is implemented to obtain the optimum operating conditions and desirable performances. According to the obtained results, the simulation at the base operating conditions is led to generating 8.32 MW of power, 3.16 kg/s of freshwater, 8.37 MW of cooling load, and 0.22 kg/h of hydrogen with 39.15% exergy efficiency and 8.81 $/GJ sum unit cost of products. Moreover, the lowest payback period and maximum profitability are related to the electricity price of 0.07 $/kWh, with a payback period of 2.93 years. Also, at the optimum point, the exergetic efficiency with SUCP and freshwater production rate are considered obtained to be 45.09%, 8.27 $/GJ, and 3.89 kg/s. Finally, the proposed system performance was evaluated for a case study of Dubai, UAE. It is resulted that the maximum net power obtained in May during a yearly operation by about 7.40 MW with exergetic efficiency of 38.70%. (C) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：The photochemical behavior of a model PAH, naphthalene, was investigated under simulated sunlight ir-radiation with different dissolved organic matter (DOM) in seawater. The results revealed that naphthalene was prone to direct photolysis (Phi(d) = 1.34 x 10(-3)) and could be degraded by (DOM)-D-3*/O-1(2)-induced reactions with fulvic acid (FA) and humic acid (HA) at low concentrations. However, the DOM at a high level dramatically decreased the k(obs) due to the higher light attenuation and radical competition effect. The presence of FA resulted in lower (DOM)-D-3*/O-1(2) generation and quantum yield compared with HA, but it achieved higher degradation kinetics due to the higher reactivity between (3)FA* and naphthalene and their lower binding effect. The naphthalene degradation in natural water with different depths and DOM were modeled based on the experimental results, which revealed the important role of indirect photolysis initiated by inorganic constituents. Moreover, several degradation intermediates were identified by GC-MS and three possible pathways were proposed. The Quantitative Structure Activity Relationships (QSAR) evaluation revealed that some intermediates are more toxic than original naphthalene. This study offers further insights into the photochemical behavior of PAHs, which will facilitate our understanding of the persistence and ecological risks of organic contaminants in natural waters. (C) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：The possibility of inducing severe security-related events with damage to people, property, and the environment by deliberate malicious attacks to chemical and process plants handling large quantities of hazardous materials received an increasing attention in recent years. The identification of the credible security scenarios is required by Security Vulnerability/Risk Assessment (SVA/SRA) methodologies. However, the current availability of supporting tools is limited. This may hinder a proper management of the risks, especially in the European context where security threats are only marginally recognized under the Seveso legislation. The present study aims at supporting a harmonized identification of the scenarios triggered by deliberate malicious physical attacks to chemical and process plants. An approach based on Bow-Tie formalism is proposed to identify reference security scenarios. The Bow-Tie diagram is used to link the attack modes (Attack Tree) to the relevant release scenarios (Security Events) and to the physical damage scenarios (Event Tree). Reference Bow-Tie diagrams were defined considering substances commonly present in process plants (e.g. flammable substances and oxidizing solids). The validation of the reference scenarios (both attack scenarios and physical damage scenarios) was provided by the analysis of more than 20 security-related incidents that occurred in chemical and process facilities worldwide in the last 50 years. Application to a case-study proved the effectiveness of the results achieved in supporting SVA/SRA studies and in promoting integration among safety and security management.(c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：Burgeoning industrialization has escalated the energy demand and amplified the insistence on depleting petroleum-based reservoirs. Subsequently, this has imposed a study to pinpoint renewable alternative sources. Employing renewable resources promotes energy production coupled with environmental sus-tainability. Microbial fuel cells (MFCs) have an encouraging role in producing sustainable and viable elec-trical energy. It transforms chemical energy into electrical energy with the assistance of microorganisms acting as biocatalysts. It is an emerging technology that has the potential to treat wastewater with bioe-lectricity production simultaneously. However, scaling up this technology is a major challenge as a plethora of technical constraints limits its application in the real world. This review highlights MFC performance in terms of power generation by utilizing various wastewaters as substrate. Moreover, it sheds light on dif-ferent MFC designs, mechanisms, and parameters affecting MFC performance along with their pros and cons to generate maximum power output. It concludes possible ways to combat its drawbacks and discusses its future prospects. (c) 2022 The Author(s). Published by Elsevier Ltd on behalf of Institution of Chemical Engineers. CC_BY_4.0
查看更多>>摘要：With the rapid growth of the demand for lithium-ion batteries (LIBs), the treatment challenges of spent LIBs continue to increase. The dissociation characteristics of the electrode materials by impact crushing and shear crushing were studied. The liberation characteristics of each size particles and over crushing rule of aluminum (Al) foil were analyzed. The results show that both shear crushing and impact crushing can achieve effective liberation of electrode materials. The rapid liberation of cathode material can be achieved by shear crushing in 5 s, the particle size of the shear crushed products is mainly concentrated in + 2 mm and - 0.074 mm, and the degree of liberation increases to 69.29% at 40 s. Meanwhile, the liberation caused by impact crushing mainly occurs within 5-20 s, the liberation degree increases sharply from 1.36% to 49.51%, and final liberation degree can reach 62.68% with 40 s crushing. In addition, the over crushing of Al foil is inevitable in impact crushing and shear crushing, and the Al content of - 0.074 mm crushing products of shear crushing and impact crushing fluctuates within 2.4%- 3.5%. This study provides a feasible technical approach for the safe and environmentally friendly dissociation of electrode materials in spent LIBs.(c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
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