当前期刊: Process Safety and Environmental Protection Go to current issue    加入关注   
显示样式:        排序: 导出
我的关注
我的收藏
您暂时未登录!
登录
  • 更新日期:2020-01-26
  • Understanding Loss of Containment of Non-radiological Chemotoxic Materials in the Civil Nuclear and Process Industries
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-25
    Matt Clay; Moray Kidd; Andrew Gale; Tim Boardman; Jim Murphy; Tony Wynn; Steven Naylor; Jo Ellwood

    Loss of containment of toxic and flammable inventories from process plant is associated with a long history of major accidents including fires, explosions and toxic releases. Such accidents affect both workers and the offsite public. These issues are often associated with the onshore process industries which incorporate a very wide range of segments including pharmaceutical manufacture, tank storage, downstream oil & gas, fine and speciality chemical manufacture as well as many others. What may be less well appreciated is that while the Civil Nuclear sector has a key focus on containment of radiological materials, it also maintains significant inventories of flammable and toxic materials, which it terms ‘chemotoxic’ hazards. It follows that a very broad range of industries have a desire to prevent and mitigate the potential for loss of containment events which release chemotoxic materials. Existing sources of loss of containment intelligence include the Health & Safety Executive (HSE) and other databases which can be interrogated to glean process safety insights. Such systems incorporate some limited coding of data, but often feature much greater detail within unstructured free text. Systematic interrogation of such free text fields could yield greater detail within process safety insights as well as a potentially larger number of records with which to draw insight. The Discovering Safety Programme is a multidisciplinary initiative funded by the Lloyd’s Register Foundation. The programme aims to improve plateaued safety performance through better insight via data analysis tools including text mining and natural language processing. This paper describes the early stages of a project within the Discovering Safety Programme to obtain process safety insights from HSE’s regulatory database. This work includes analysis of coded information, proposals to extract intelligence from unstructured free text and also exploration of whether process safety intelligence can be extracted from a subset of occupational safety incidents. The paper describes the findings from industry consultation, including the civil nuclear sector.

    更新日期:2020-01-26
  • L-Histidine doped-TiO2-CdS nanocomposite blended UF membranes with photocatalytic and self-cleaning properties for remediation of effluent from a local waste stabilization pond (WSP) under visible light
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-24
    Hadis Zangeneh; Zahra Rahimi; Ali Akbar Zinatizadeh; Sayed Hossein Razavizadeh; Sirus Zinadini

    In this study, a dual photocatalyst of TiO2-CdS doped by C, N nonmetals with the aid of L-Histidine (C, N-doped TiO2-CdS) was synthesized and then incorporated into polyethersulfone (PES) ultrafiltration (UF) membrane matrix in order to endow photocatalytic and self-antifouling properties. The resulting photocatalytic nanocomposite was first characterized by analyses of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FE-SEM), photoluminescence (PL), and UV–Vis diffuse reflectance spectroscopy (DRS). The fabricated membranes were identified through tests of SEM, contact angle and Atomic force analysis (AFM). The membranes performance was evaluated in terms of pure water flux (PWF) and antifouling experiments in a dead end set up. To find out optimum conditions and investigate photocatalytic properties under continuous visible light irradiation, the impacts of two operating variables, i.e. working pressure (P, 1-5 bar) and cross flow rate (Q, 50-150 L/h) at three levels on four responses were investigated in a continuous regime using filtration of effluent from waste stabilization pound (WSP). From the results, the highest PWF, FRR and Rr were found to be 80.37 kg/m2h, 80. 2 %, and 56. 1 % for the membrane modified by 0.5 wt. % C, N doped TiO2-CdS contrast to 60.69 kg/m2h, 33 % and 15.6 % obtained for the control membrane. At optimum conditions, i.e. 3 bar and 150 L/h, the values of PWF, FRR and COD removal were 150.6 kg/m2h, 89.5 % and 65.26 %, respectively. An improvement of 1.4, 1.5 and 1.3 times in PWF, FRR, and COD removal, respectively, were achieved for the 0.5 wt.% membrane under visible light irradiation compared to the control one. These results were attributed to super hydrophilicity, photocatalytic properties and self-antifouling.

    更新日期:2020-01-24
  • Simplifying COSHH and Improving Chemical Safety
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-24
    Stuart Morgan; Mark Stewart; Tasha Bennett

    At Heineken UK, we have applied 5S principles to the legislation and guidance set out by the Health and Safety Executive (HSE) to develop a set of procedures and training materials to simplify the entire COSHH process and ensure compliance with HSE regulations. Most notably, we have complete visibility of all COSHH assessments and safety data sheets through “COSHH Boards” and “COSHH Tubes” on each of our production lines for ease of access to critical information in an emergency. We have found these procedures and the application of 5S to drastically save time, improve COSHH assessment quality and chemical control across an entire site. The engagement and awareness of our colleagues on chemical safety has dramatically increased on our journey to a zero accident workplace.

    更新日期:2020-01-24
  • Agent-Based Model to Predict the Fate of the Degradation of Organic Compounds in the Aqueous-Phase UV/H2O2 Advanced Oxidation Process
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-23
    Robert Zupko; Divya Kamath; Erica Coscarelli; Mark Rouleau; Daisuke Minakata
    更新日期:2020-01-23
  • Agglomeration Behaviour of Caprolactam Solution Concentrates Triggered by Cyclic Dimers in the Recovery Process: Characterisation, Mechanism, and Process Optimisation
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-23
    Chunwang Yi; Ce Yang; Jie Li; Juan Chen; Shen Zhang; Huan Sun

    The cyclic dimer 1,8-diazacyclotetradecane-2,9-dione is one of the most important components of caprolactam solution concentrates and triggers significant agglomeration during the recovery process in industrial polyamide-6 plants. For this reason, the agglomeration behaviour and morphology changes of cyclic dimers in solution concentrates were investigated. Precipitates separated from an ∼80 wt.% solution concentrate were explored. Cyclic dimers aggregated in the solution concentrates at lower temperatures to form larger, thicker, and compacted structures or multi-layers structures. An appropriate increase in the solution temperature and addition of fresh caprolactam aid in avoiding agglomeration, but high temperatures (over 140 ℃) initiate the hydrolytic polymerisation of caprolactam in the solution concentrate, which aggravates blockages. Based on these results, an optimised process model is introduced to avoid aggregation.

    更新日期:2020-01-23
  • Root causes of coal mine accidents: Characteristics of safety culture deficiencies based on accident statistics
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-22
    Jiangshi Zhang; Jing Fu

    Coal mine accidents pose a serious threat to miners and the surrounding environment. Despite a recent downward trend in the numbers of major accidents and casualties in Chinese coal mining enterprises, accident reoccurrence remains an on-going issue for the industry. This paper aims to identify the root causes, namely, the characteristics of safety culture deficiencies driving typical coal accidents. Using the accident analysis pathway of the 24Model and the logical thought of Why Because Analysis (WBA), 67 typical major accidents (gas explosion, gas outburst, flooding and fire) are analysed to identify the deficiencies in safety culture based on the determinations of the safety culture dimension and statistics of recurrent accident patterns. The related elements and occurrence frequencies of the deficiencies in safety culture can be inferred as follows: ignored safety laws and regulations (frequency is 100%), unrealized safety priority (100%), limited role of functional departments (86.6%), and insufficient attention to safety education for special operation personnel and mining workers (80.6%), among others. These characteristics are not concerned with accident types, and the most prominent characteristics are manifested in four aspects: unrealized safety priority, flaws in management actions towards safety, passive safety compliance and participation of employees, and imperfect work conditions. Specifically, we emphasize the role of departments, safety communication, safety participation and supervision climate in influencing and improving the safety culture to further reduce industrial accidents.

    更新日期:2020-01-22
  • Leak Frequency Analysis for Hydrogen-based Technology using Bayesian and Frequentist Methods
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-22
    Mahesh Kodoth; Shu Aoyama; Junji Sakamoto; Naoya Kasai; Yehia Khalil; Tadahiro Shibutani; Atsumi Miyake

    Dealing with hazardous environments such as hydrogen poses considerable risks to property, people, and the environment. Leak frequency analysis is a method of understanding the characteristics of risks at hydrogen refueling stations (HRSs). This paper proposes leak rate estimation using time-based evaluation methods that utilize historical HRS accident information. In addition, leak frequency estimates from another two methods (non-parametric and leak-hole-size) were examined. In the non-parametric approach, the leak frequency is estimated based on a Bayesian update. The results from these three approaches are summarized to understand the trend of leak rate data. The leak rate data from the time-based method displays a similar trend to the leak size based method. However, the non-parametric method tends to be conservative due to high failure observations (new evidences) during the Bayesian update. Finally, the unrevealed leak time was calculated as a function of the leak frequency. The quantitative insights of this study can be used to set performance standards for the availability and reliability in the operation and maintenance of HRSs.

    更新日期:2020-01-22
  • Study on sealing effect of pre-drainage gas borehole in coal seam based on Air-Gas mixed flow coupling model
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-21
    Hao Wang; Enyuan Wang; Zhonghui Li; Xiaoran Wang; Qiming Zhang; Bing Li; Muhammad. Ali

    The low gas extraction concentration is one of the main factors that affect the prevention and control effect of coal and gas outburst. Based on this, the factors of air leakage around the roadway and borehole are analyzed. The effect of extraction time, seal length and air leakage on the gas concentration is discussed by the fluid-solid coupling model, which is proved by the borehole environmental parameter instrument.The research findings show :(1) Influenced by roadway excavation and drilling, a large number of cracks are created inside the coal around the roadway and the boreholes, which are the main air leakage channels for the air to flow from roadway into borehole; (2) Inside the borehole, the closer it is to the bottom of the borehole, the fewer the cracks in the coal seam, the higher the gas concentration. The critical point of air leakage in which the gas concentration is 100% moves continuously to the bottom of the borehole with extraction time, until it is stable. The effective sealing length must exceed the position of critical point of air leakage; (3) The gas concentration is related to the sealing length and the amount of air leakage. Increasing the sealing length, and reducing the air leakage can greatly improve the extraction efficiency. Based on the above results, combined bag-type segmented grouting technique, which is to inject different sealing materials into different regions divided by the stress, is proposed to block the air leakage channel by comparing the crack characteristics of the coal surface in the abnormal stress zone and the normal stress zone by SEM technology. According to the field test results, the application of the new sealing technology blocks the crack channel, improves gas concentration and reduces the risk of coal and gas outburst. The results have important guiding significance for improving gas utilization rate, reducing greenhouse gas emission and enhancing safety in production.

    更新日期:2020-01-22
  • Study on Explosion Characteristics of the Inert Substances at Longkou Oil Shale of China
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-20
    Bo Liu; Yuyuan Zhang; Xiangbao Meng; Jinshe Chen; Junfeng Wang; Xiang Wang; Yansong Zhang

    According to the chemical analysis, we found the inert substances of fossils in Longkou oil shale in China are mainly calcium carbonate (CaCO3) and quartz (SiO2). Their influence on the explosive characteristics of oil shale dust, through the macroscopic explosion experiments and microscopic analysis, was investigated. We found that CaCO3 has better explosion suppression effect than SiO2. There are two suppression effects during the oil shale dust explosion: adhesion and isolation of inert substances; inerting effect of carbon dioxide (CO2) generated from the complex reaction of CaCO3 and SiO2. Due to the existence of two suppression effects, the combustion of oil shale particles stops when the heat generated by the two combustion paths is less than the heat dissipated, i.e., the explosion either comes to an end or fails to occur.

    更新日期:2020-01-21
  • Solvothermal co-liquefaction of sugarcane bagasse and polyethylene under sub-supercritical conditions: optimization of process parameters
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-18
    Humair Ahmed Baloch; M.T.H Siddiqui; Sabzoi Nizamuddin; N.M Mubarak; Mohammad Khalid; M.P Srinivasan; G.J Griffin
    更新日期:2020-01-21
  • 更新日期:2020-01-21
  • Gas-phase aromatic compounds degradation by a partially TiO2 coated photoreactor assisted with ozone
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-18
    Bárbara Maria Borges Ribeiro; Tânia Miyoko Fujimoto; Bianca Gvozdenovic Medina Bricio; Ursula Luana Rochetto Doubek; Edson Tomaz
    更新日期:2020-01-21
  • Assessment of gas emission hazard associated with rockburst in coal containing methane
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-18
    Mingyao Wei; Enyuan Wang; Xiaofei Liu

    The stress field and gas seepage field of methane react upon each other in the process of rockburst in coal seam containing methane. Therefore, it is important to reveal the coupling mechanism between them. Due to the fact that volumetric strain describes the development of fracture, damage evolution equation for coal is built by accounting volumetric strain as an internal factor. The evolution models for porosity and permeability are built by considering the effect of shear dilation on fracture deformation. A gas-solid simulation software called TOUGH2(CH4)-FLAC is developed based on effective stress equation and permeability model which is coupled by linking two existing simulators (TOUGH2 and FLAC3D). A simulation case for gas flow in process of rockburst is carried out. The simulated result indicates that several bands of failure zone were caused by dynamic disturbance forming spall in deep coal. Methane in sorption state turns into desorption and flows out rapidly through damage-induced path that result in a rise of methane concentration in roadway shortly. The simulation results reveal the mechanism of extreme gas emission after disturbance induced by rockburst.

    更新日期:2020-01-21
  • 更新日期:2020-01-17
  • Runaway inhibition of styrene polymerization: A simulation study by chaos divergence theory
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-14
    Lei Ni; Jiawei Cui; Juncheng Jiang; Yong Pan; Hao Wu; Chi-Min Shu; Zhirong Wang; Shanjun Mou; Ning Shi

    We attempted to prevent the thermal risk of a runaway reaction of polymerization in a batch reactor and to realize online monitoring and emergency inhibition of the thermal runaway behavior. Styrene thermal initiation of bulk polymerization was studied. A full-size model of the styrene polymerization reactor was constructed by referring to the reactor model of the Mettler Toledo automatic calorimeter, which was combined with the kinetic and thermodynamic models of styrene polymerization. The DIV thermal runaway critical criterion based on chaos divergence theory was used to judge the thermal runaway reaction. The critical point of the runaway reaction was determined and used to inhibit the thermal runaway of styrene polymerization by injecting cooling diluents at the liquid surface. The influence of injection rate (vc=0.5、0.8、1m/s), injection position (in-1、in-2、in-3), and amount of cooling diluents (no add、50%、70%、100%) injected on the thermal runaway inhibition of the reaction was investigated and elucidated. The results indicated that a better inhibiting effect can be obtained by injecting the inhibitors at higher rates near the edge of the paddle blade. Moreover, appropriately increasing the injection amount of the inhibitors can achieve better inhibition of the runaway reaction.

    更新日期:2020-01-15
  • Thermal stability and flammability assessment of 1-ethyl-2, 3-dimethylimidazolium nitrate
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-14
    Bin Zhang; Shang-Hao Liu; Jie Liu; Zhi-He Zhang; Bin Laiwang; Chi-Min Shu

    1-Ethyl-2, 3-dimethylimidazolium nitrate [C2mmim][NO3] is a typical solvent for industrial applications. Under inappropriate temperatures, [C2mmim][NO3] may present a flammability hazard due to thermal decomposition. This study investigated the thermal stability and flammability of [C2mmim][NO3] via simultaneous thermogravimetric analyzer, homemade combustion test device (CTD) with high speed camera, and thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR). The thermal decomposition of [C2mmim][NO3] was divided into two parts based upon the dynamic experiments, and the maximum operating temperature was determined to comprehensively estimate the thermal stability of [C2mmim][NO3]. CTD experiments indicated that [C2mmim][NO3] could produce intense combustion when heated. Further TG-FTIR experiments confirmed that [C2mmim][NO3] decomposed to produce a large number of flammable gases, such as ethylene, which might be the reason that [C2mmim][NO3] has prominent flammability.

    更新日期:2020-01-14
  • Toward an efficient multi-step separation protocol to recover metallic components from waste leachates
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-13
    E. Rivas; M.A. Martín-Lara; G. Blázquez; M.J. Muñoz-Batista; A. Pérez; M. Calero

    This work presents a study of the separation and recovery of metal elements, through a multi-step protocol based on solvent extraction, stripping and chemical precipitation processes. The waste leachate was produced during the treatment of the mixed solid waste from the decommissioning of a coal-fired power plant. The organophosphorus acid, di-(2-ethylhexyl) phosphoric acid (DEHPA) was investigated as organic extracting agent during the solvent extraction (Step 1). A factorial design with three levels for the organic phase/aqueous phase ratio (O/W), DEHPA concentration and contact time were carried out and a prediction model obtained using a neural-fuzzy approach. Optimized extraction values for Ti (93.4 %), (V) 94.6 % and (Zn) 89.8 % were obtained using 60 min of contact time, a DEHPA concentration of 0.5 M and O/W ratio of 4. Stripping tests were performed using HCl, H2SO4, NaOH and KOH as stripping agents. The stripping step (step 2) showed optimum results (82% of Zn and 31% of V) using 1 M H2SO4 solution as stripping agent. A selective precipitation step (step 3) allowed the final separation of metals in aqueous solutions produced in Step 1 and 2. The results showed that an effective separation of Mn and Ni could be carried out at pH 9, while the best separation results for the solution obtained during the stripping step, which contains V and Ti, was obtained at pH 12.

    更新日期:2020-01-14
  • Advanced Treatment Technologies Efficacies and Mechanism of Per- and Poly-Fluoroalkyl Substances Removal from Water
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-13
    Mohammad Boshir Ahmed; Md. Masruck Alam; John L. Zhou; Bentuo Xu; Md Abu Hasan Johir; Aneek Krishna Karmakar; Md Saifur Rahman; Jewel Hossen; A.T.M. Kamrul Hasan; Mohammad Ali Moni
    更新日期:2020-01-13
  • 更新日期:2020-01-13
  • 更新日期:2020-01-13
  • Analysis of the Corrosion Failure of a Semiconductor Polycrystalline Distillation Column
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-11
    Peipei Sun; Zhirong Wang; Yawei Lu; Shuoxun Shen; Rongrong Yang; Anxue Xue; Trent Parker; Jian Wang; Qingsheng Wang

    Distillation column is a fundamental device for the production of the semiconductor polysilicon. Therefore, investigating corrosion leakage protection of the distillation column is of great significance because of the undetectable yet very significant consequences of corrosion leakage to the column. In this work, corrosion investigation of a polycrystalline silicon rectification tower is presented. The composition and crack morphology of the distillation column (316 L austenitic stainless steel) were detected and analysed using component and hardness analysers. The effects of pH and temperature on the corrosion rate were studied by conducting electrochemical experiments. According to the macroscopic test results, the surface of the tower was covered with a large number of pits and cracks of different depths. Furthermore, based on the metallographic analysis, SEM analysis, and energy spectrum analysis results, it was determined that the crack morphology was mostly intergranular and transgranular. Combined with the test data and process environment, it has been determined that the main forms of corrosion for rectification towers are pitting corrosion and stress corrosion caused by chloride ions. According to the results of electrochemical experiments, the corrosion rate of 316 L stainless steel is negatively correlated with pH value for a pH range of 4 to 6 at constant temperatures. However, the corrosion rate is positively correlated with temperature for the range of 60 °C to 90 °C at constant pH values. From the analysis of the corrosion morphology, the corrosion failure mode of 316 L stainless steel is largely attributed to pitting corrosion when the column is operated at low temperatures (60 °C and 70 °C). However, at high temperatures (90 °C), a transformation from pitting corrosion to stress corrosion occurs along the crystalline form. To ensure the stable operation of the polysilicon rectification tower, this paper proposes corrosion protection measures based on the results of the analysis as described.

    更新日期:2020-01-13
  • Bioconversion of Chicken Feather Wastes by Keratinolytic Bacteria
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-11
    Samira Alahyaribeik; Seyed davood Sharifi; Fatemeh Tabandeh; Shirin Honarbakhsh; Shokoufeh Ghazanfari
    更新日期:2020-01-13
  • A New Simplified Calculation Model of Geometric Thermal Features of a Vertical Propane Jet Fire Based on Experimental and Computational Studies
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-11
    Hossein Mashhadimoslem; Ahad Ghaemi; Amir Hossein Behroozi; Adriana Palacios

    Jet fires and their consequences are one of the significant factors responsible for catastrophic events in industrial process units. In this research, various types of turbulence models were investigated to simulate a vertical propane jet fire using computational fluid dynamics (CFD). CFD was applied to evaluate the following turbulence models of k-ε, SST, BSL, BSL RS and the Realizable k-epsilon (RNG k-ε), the Eddy Dissipation Concept (EDC) for combustion, and the Monte Carlo model for radiation. All the above-mentioned turbulence models are used for a temperature range of 1500 to 1700 K. The results showed that the SST turbulence model is the best option, with average error of 4.7% for a jet fire simulation, with a lower computational time. The simulation of the jet fire shape at surface temperature of 800 K was also compared with the experimental data obtained under the same conditions. By taking into account the time parameter in the simulation, the predicted ratio of flame length and equivalent flame diameter results are in good agreement with the experimental jet fire data.

    更新日期:2020-01-13
  • Empirical analysis of a steam explosion in a slag yard based on a field investigation and 3D explosion damage simulation
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-11
    Jae Joon Lee; Hong Sik Yun; Young Jae Cho; Jae Hyeok Park

    Many types of explosions often occur in industrial settings, and research is being conducted to identify the causes and establish preventive measures. The aim of this study is to investigate slag yards, where metal residues are cooled in the steel industry, often causing steam explosions. The cause of accidents and explosion simulation analyses were used to investigate the sources of steam explosions in a slag yard. The explosion intensity of 4 kg of TNT was measured for the purpose of predicting the intensity of a steam explosion. This was compared with a simulation of explosion damage that occurred in 2017. These results could not be produced from small-scale experiments, and they indicate that damage resulting from actual explosions poses a potential risk to pipes that cannot be directly observed. We conclude that this damage can lead to a domino accident, and this study provides results for estimating the possibility of future damage.

    更新日期:2020-01-13
  • Organic ultraviolet-absorbing materials in street dust from Hefei, China: concentrations, profiles, and human health risks
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-11
    Xiangyang Xing; Xue Han; Lei He; Jiali Cheng; Fuyong Zhong; Jiazheng Sun; Zhenwu Tang

    Organic ultraviolet absorbents (UVAs) are widely found in the environment. However, little is known about UVA distributions in street dust and the risks they pose to human health. We determined the concentrations of 12 UVAs in street dust from cultural, residential, traffic, and industrial areas in Hefei, China. 4-Methylbenzylidene camphor was not detected in the street dust samples. The total concentration range of the 11 other UVAs (Σ11UVAs) in the street dust samples was 6.42–94.2 ng/g. Octocrylene was the dominant UVA, contributing 53.8% of the Σ11UVA concentrations. The UVA concentrations were higher in dust from the industrial area than in dust from cultural, residential, and traffic areas. Source analysis was performed, and industrial activities and the use of cosmetics and personal care products were found to be the main sources of UVAs in street dust. The health risks posed to humans exposed to UVAs in street dust in Hefei were generally low. More research is required to improve our understanding of the health risks posed to humans exposed to UVAs through other pathways.

    更新日期:2020-01-13
  • Risk Assessment of Gas Explosion in Coal Mines Based on Fuzzy AHP and Bayesian Network
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-11
    Min Li; Hetang Wang; Deming Wang; Zhenlu Shao; Shan He

    Gas explosion is one of the most deadly hazards in underground coal mining. Risk assessment has played an effective role in avoiding gas explosions and revising coal mine regulations. However, the traditional methods are deficient in quantitative evaluation, dynamic control and dealing with uncertainty. In this paper, a method of quantitative assessment the risk of gas explosion in underground coal mine using Bayesian network was proposed. A fuzzy analytic hierarchy process (FAHP) method based on subjective and objective information of experts was developed in the process of fuzzification. Through the Bayesian inference, the probability of occurrence of potential risk events and the probability distribution of risk factors can be calculated in real time according to on prior knowledge and evidence updating. Meanwhile, the most likely potential causes of accidents can be determined. A sensitivity analysis technique was utilized to investigate the contribution rate of each risk factor to a risk event, so as to determine the most critical risk factor. Taking Babao Coal Mine in China as the case, this study conducted a gas explosion risk assessment. The results show that the mothed of fuzzy AHP and Bayesian Network is feasible and applicable. It can be used as a decision-making tool to prevent coal mine gas explosions and provide decision makers with a technical guide for managing the coal mine gas explosion risk.

    更新日期:2020-01-13
  • Risk-based safety measure allocation to prevent and mitigate storage fire hazards
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-11
    Long Ding; Faisal Khan; Jie Ji

    Fire is a main threat to property and human safety in materials storage of process industry plants as well as other industrial sectors, and risk management of materials storage fires is challenging due to potential accident causes and various safety measures. Complex accident causes, severe consequences, and effective safety measures have been the main concerns of industrial companies and researchers. However, for storage fires, a generic risk management model is absent. Bow-tie is an effective method to reveal causal relationships of accident causes, safety barriers, and possible accident consequences. In this study, based on bow-tie analysis, a generic framework for quantitative risk management of storage fires is established via analysis of previous storage fires. Pertinent safety measures are presented, allocation and efficacy of these safety measures to reduce storage fires risk is investigated. Finally, the methodology and proposed generic framework is applied to a major storage fire accident for a case study, the probabilities of fire accident and consequences are reduced significantly, which shows the efficacy and applicability of the proposed approach. The generic framework established in the present study can be tailored to various storage fire accidents with limited manipulation; and also, allocation and implementation of pertinent safety measures can reduce storage fires risk significantly.

    更新日期:2020-01-13
  • Effect of Fe2+ adding period on the biogas production and microbial community distribution during the dry anaerobic digestion process
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-11
    Shaona Wang; Rongfang Yuan; Chengchen Liu; Beihai Zhou

    Fe2+ is essential for the improvement of biogas production and the growth of anaerobic microorganisms; however, it is often excessively added to anaerobic digesters, leading to the inhibition of biogas production. In this study, the dosing frequency of Fe2+ for the mesophilic and thermophilic biogas fermentation of high-solid swine manure was optimized. The most significant enhancing effect (13.44%-33.22%) induced by Fe2+ addition was observed with dosing frequency of 400 mg/L for every 5 d, and the maximum efficiency for unit concentration of Fe2+ occurred when the dosing frequency was 400 mg/L for every 15 d. Maximum biogas production was obtained in the group with dosing frequency of 400 mg/L for every 5 d, and biogas production potential was 465.24 mL/(g volatile solid (VS)) based on modified Gompertz predicted model with a maximum rate of 16.72 mL/(gVS·d), which was higher than that of the control group (6.78 mL/(gVS·d)). In addition, Fe2+ dosing displayed a stimulatory effect on SCOD removal, the SCOD removal with dosing frequency of 400 mg/L for every 5 d were highest in all reactors. The optimum dosing frequency of Fe2+ positively affected the microbial community structure. 16S rRNA gene sequencing revealed that the abundances of Firmicutes and Euryarchaeota were increased, which could enhance the hydrolysis-acidification and methanogenesis process during anaerobic digestion process.

    更新日期:2020-01-13
  • Regional evaluation of fire apparatus requirements for petrol stations based on travel times
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-11
    Dingli Liu; Zhisheng Xu; Zhengyang Wang; Chuangang Fan
    更新日期:2020-01-13
  • Biomethane Recovery from Source-Diverted Household Blackwater: Impacts from Feed Sulfate
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-11
    Mengjiao Gao; Bing Guo; Lei Zhang; Yingdi Zhang; Najiaowa Yu; Yang Liu
    更新日期:2020-01-13
  • 更新日期:2020-01-13
  • Assessment of low-temperature oxidation characteristics of coal based on standard oxygen consumption rate
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-09
    Yueping Qin; Yipeng Song; Wei Liu; Jun Wei; Qianlong Lv

    To investigate the low-temperature oxidation characteristics of coal, programmed heating and oxidation experiments were conducted on single-particle-size coal samples from different mines. The inlet and outlet oxygen concentrations of the coal sample tank were measured to calculate the standard oxygen consumption rate (SOCR) of each coal sample at different temperatures. The relationship between the SOCR and temperature was fitted by an exponential function, and two regression coefficients ( A and B) related to the spontaneous combustion characteristics of coal were obtained, and the effects of both A and B on the spontaneous combustion of coal was analyzed. The results show that the A and B values are related to the physical structures and chemical properties of coal, respectively. Accordingly, taking the A and Bvalues of single-particle-size coal samples as the basic parameters, a new identification index describing the spontaneous combustion of coal is proposed. Compared with the chromatographic oxygen absorption method, the newly proposed identification index can reflect the degree of difficulty of spontaneous coal combustion more truly and intuitively. This research is of theoretical and practical significance for evaluating the characteristics of spontaneous coal combustion.

    更新日期:2020-01-11
  • Micro-pilot test for optimized pre-extraction boreholes and enhanced coalbed methane recovery by injection of liquid carbon dioxide in the Sangshuping coal mine
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-09
    Hu Wen; Xiaojiao Cheng; Jian Chen; Chunru Zhang; Zhijin Yu; Zhenbao Li; Shixing Fan; Gaoming Wei; Bangkai Cheng

    The extraction efficiency of high-gas coal seams is low in China with a large number of pre-drainage boreholes. In this study, we analyze the coal seam gas displacement mechanism using liquid carbon dioxide by combining theoretical analysis, experiments, and field tests. Changes of gas displacement efficiency with time under different displacement flow and pressure conditions are determined. We propose a coalbed methane displacement method using liquid carbon dioxide and apply the model in a field test carried out in well No. 2 of the Sangshuping coal mine. The results show that the injection of liquid carbon dioxide in coal seams is a pressure swing adsorption process. The effective displacement radius from the in-situ tests reaches 20 m. The maximum CH4 extraction concentration in the test area is 65%, which is 2.41 times higher than that of the original coal seam (27%). The maximum methane extraction flux rate is 0.884 m3/min, which is 2.34 times that of original coal seam (0.377). Implementation of liquid carbon dioxide displacement coalbed methane technology optimizes borehole arrangement and enhances coalbed methane extraction.

    更新日期:2020-01-11
  • Influence of high atmospheric pressure on flame spread over electric wire at different inclinations
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-09
    Yanli Zhao; Jian Chen; Xiao Chen; Youjie Sheng; Shouxiang Lu; Shengfeng Luo; Jun Deng

    A series of experiments of the upward flame spread over polyethylene-coated wire with copper core were conducted in a newly designed high-pressure chamber to study the effects of the wire inclination angles and ambient pressures. The angle of inclination changed from 0° to 75° and the pressure ranged from 100 kPa to 400 kPa. The results show that the flame spread rate increases with the inclination angle and the pressure. The characteristic lengths including the flame length, the flame base width and the pyrolysis length present an increasing trend with increasing inclination angles, while the elevated pressure results in that the flame length and flame base width decreases and the pyrolysis length increases. Moreover, a simplified heat transfer analysis model considering the convective, radiant and conductive heat feedback is proposed to discuss the flame spread mechanism. Based on the theoretical analysis, convective heat transfer from flame and conductive heat transfer from wire core play significant roles in heating the unburned insulation with the increase of inclination angles. For the cases with higher pressure, the heat transfer from flame including heat convection and heat conduction plays a dominant role in increasing the heat feedback to the unburned wire.

    更新日期:2020-01-11
  • Occurrence, impacts and general aspects of pesticides in surface water: A review
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2020-01-02
    Renata Mariane de Souza; Daiana Seibert; Heloise Beatriz Quesada; Fátima de Jesus Bassetti; Márcia Regina Fagundes-Klen; Rosângela Bergamasco
    更新日期:2020-01-02
  • The effects of vent area and ignition position on pressure oscillations in a large L/D ratio duct
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-31
    Huadao Xing; Qiming Xu; Xianzhao Song; Yongxu Wang; Bin Li; Lifeng Xie

    Experiments were conducted in a 2 m large duct with an internal diameter of 70 mm, to investigate the effects of the vent area and ignition position on pressure oscillations with different methane concentrations. The results showed that violent pressure oscillations occurred when methane concentrations were between 9.5 and 12 vol. % in the closed duct. End ignition was shown to dampen the pressure oscillations to a significant extent. In addition, vented explosions could also reduce the pressure oscillations where the amplitude of the pressure oscillations decreases with increasing vented area. For a vent area of 38.5 cm2, no pressure oscillations occurred in all tests. Central ignition produced the larger pressure peak only when the vent area was small.

    更新日期:2019-12-31
  • Experimental Investigation of Potential Confined Ignition Sources for Vapour Cloud Explosions
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-31
    Jason Gill; Graham Atkinson; Edmund Cowpe; Herodotos Phylaktou; Gordon Andrews

    Electrical control boxes are common on high vapour cloud hazard sites, and in the case of the Buncefield explosion the ignition source was inside such a box, that was sited in an emergency pump house building. There has, however, been relatively little previous research into this type of ignition mechanism and its effect on the explosion severity. Commercially available electrical control boxes measuring 600 mm high, 400 mm wide and 250 mm deep were used to explore the pressure development, venting processes and flame characteristics of stoichiometric propane/air explosions using aluminium foil and the supplied doors as vent coverings. In some tests, the boxes were empty in order to establish a baseline for the effect of the internal congestion of the boxes. In other tests a congestion array was added. It was found that, in both the empty and congested box tests, the door produced a flat petal shaped flame, which differed drastically from the mushroom flame shape and associated rolling vortex bubble venting that is traditionally observed with large orifice vented explosions.

    更新日期:2019-12-31
  • Study on the Propagation Characteristics of Hydrogen/Methane/Air Premixed Flames in Variable Cross-Section Ducts
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-30
    Jian Wang; Yong Wu; Ligang Zheng; Minggao Yu; Rongkun Pan; Weiwei Shan

    The flame propagation characteristics of hydrogen/methane/air mixtures with different hydrogen addition ratios (φ = 0, 10%, 20%, 30%, 40% and 50%) in different variable cross-section ducts were studied. A high-speed camera and pressure sensors were used to collect flame images and determine the overpressure dynamics. The results show that the smooth flame front will be twisted and folded, when the flame propagates to the abrupt position of the cross-section area of the duct. The larger the abrupt change rate of the duct cross-section is, the more obvious the disturbance to the flame and the more severe the turbulence. With increasing hydrogen addition ratio, the flame propagation speed and overpressure in the four kinds of variable cross-section ducts studied increase. The time for the flame front to reach the downstream end is gradually shortened, and the flame propagation time when the flame propagates from the smaller cross-section tube to the larger cross-section tube is more severely shortened with increasing hydrogen addition ratio than that when the flame propagates from the larger cross-section tube to the smaller cross-section tube. The increase of the overpressure caused by the addition of hydrogen is more significant when the flame propagates from the smaller cross-section tube to the larger cross-section tube. When the flame propagates from the smaller cross-section tube to the larger cross-section tube or from the larger cross-section tube to the smaller cross-section tube, the larger the abrupt change rate of the duct cross-section is, the larger the maximum overpressure.

    更新日期:2019-12-30
  • Emergency rescue capability evaluation on urban fire stations in China
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-30
    Mengmeng Chen; Kai Wang; Xiangluan Dong; Haili Li

    Fire station plays an important role in ensuring the safety of people, property and environment. In order to improve the emergency rescue capability of the fire station, its influence factors are distinguished and a capability evaluation system is established in the present paper. The system is composed of goal layer, criteria layer and sub-criteria layer. The goal layer is the evaluation objective, namely, the emergency rescue capability of urban fire station. The criteria layer and sub-criteria layer contain five indexes and 25 indexes, respectively. Within the established evaluation system, the fuzzy comprehensive evaluation (FCE) method is chosen to analyze the decision problem. The weight of each index included in the system is determined based on the Analytical Hierarchy Process (AHP) method. Thus, the level of the emergency rescue capability of the fire station can be evaluated quantitatively. At last, a fire station in Zhengzhou city is taken as an example to verify the effectiveness of the established system. The results reveal that the emergency rescue capability of the fire station is in general level. Accordingly, the measures to strengthen the rescue capacity of the referred fire station are put forward.

    更新日期:2019-12-30
  • 更新日期:2019-12-29
  • What Went Right
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-28
    Paul R. Amyotte

    Learning from process industry case histories is most often centred on management system elements, equipment components (including safety devices), and the actions of personnel that led to failure in achieving intended outcomes. Hence there can be a tendency to focus on things that went wrong. In this paper we explore the idea of focusing on things that went right – on events, resources, and concepts in which there is strong evidence of process safety success. It is concluded that learning lessons in this manner can serve as a helpful complement to the more traditional avenue of learning from process safety failure.

    更新日期:2019-12-29
  • ‘Knock on nanocellulose’: Approaching the laminar burning velocity of powder-air flames
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-27
    Audrey Santandrea; Marine Gavard; Stéphanie Pacault; Alexis Vignes; Laurent Perrin; Olivier Dufaud

    Due to their low sedimentation rate, nano-objects offer the opportunity to study flame propagation at low turbulence. The burning velocity was then estimated by flame visualization in two apparatuses: a vertical 1 m long tube with a square cross-section and a 20 L sphere equipped with visualization windows and a vent. This works aims to study the laminar burning velocity of nanocellulose by a direct visualization of the flame propagation within these devices. A high-speed video camera was used to record the flame propagation, and an estimation of the unstretched burning velocity was obtained through linear and nonlinear relationships relating the flame stretching and the flame velocities. Although these methods were initially established for gases, the organic nature of nanocellulose implies a fast devolatilization, which makes the application of the methods possible in this work. Similar results were obtained in both apparatuses in different turbulence conditions, proving the laminar burning velocity was approached. The laminar burning velocity for the nanocellulose was determined to be 21 cm s−1. This value, estimated through flame propagation visualization, was then compared to the value calculated by applying a semi-empiric correlation to the pressure-time evolution recorded during standard explosion tests in the 20 L vessel.

    更新日期:2019-12-27
  • Comparing hexacyanoferrate loaded onto silica, silicotitanate and chabazite sorbents for Cs extraction with a continuous-flow fixed-bed setup: methods and pitfalls
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-26
    Agnès Grandjean; Yves Barré; Audrey Hertz; Virginie Fremy; Jérémy Mascarade; Eric Louradour; Thierry Prevost

    Radioactive 137Cs is one of the most common and problematic radionuclides in nuclear wastes. Decontamination typically involves passing the waste in continuous flow through an agitated or fixed bed reactor containing an efficient sorbent. There are many articles in the literature describing a broad spectrum of highly efficient sorbents. However,their properties is often difficult, mainly because the experimental conditions used differ. We describe the series of experiments that need to be performed to characterize Cs sorbents and illustrate by comparing three of these that, for the extraction of trace elements, the kinetics and selectivity of the exchange process are far more important than the maximum extraction capacity of the material.

    更新日期:2019-12-27
  • Numerical Investigation of Coal Self-heating in Longwall Goaf Considering Airflow Leakage from Mining Induced Crack
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-26
    Jian Zhang; Jingyu An; Zhihui Wen; Kaixuan Zhang; Rongkun Pan; Nahid Akter Al Mamun
    更新日期:2019-12-27
  • Combustion Behaviors and Residues Characteristics in Hydrogen/Aluminum Dust Hybrid Explosions
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-24
    Xiaozhe Yu; Jianliang Yu; Xinyan Zhang; Wentao Ji; Xianshu Lv; Yujie Hou; Zhiyong Li; Xingqing Yan

    Hybrid explosion experiments of hydrogen/aluminum dust in open space were performed. Aluminum dust with a median diameter of 56.18 μm was mixed with hydrogen at different volume concentrations (0%, 5% and 10%). Flame propagation was recorded by a high-speed camera. The explosion residues were observed by a scanning electron microscope, and their compositions were analyzed by X-ray photoelectron spectroscopy. The flame propagation velocities and structures, explosion residues and the combustion reaction mechanisms of hydrogen/aluminum dust mixtures were elucidated. The results show that the addition of hydrogen can increase the flame brightness and improve the continuity of the flame front. In the flame propagation process of a hydrogen/aluminum dust hybrid explosion, a micro-diffusion flame and asymmetric flame appeared simultaneously. Compared with pure aluminum dust combustion in air, when 5% hydrogen-air mixtures were used to disperse the dust, the flame propagation velocities decreased by 0.11-0.15 m/s. Attributable to a variety of intermediate products competing for oxygen and absorbing heat, the hybrid explosion residues cooled faster, porous oxide layers and incompletely oxidized aluminum spheres with small particle sizes were formed. The XPS showed that Al2O3, Al(OH)3, AlO(OH) and other complex products appeared in the combustion reactions. On this basis, a combustion model of hydrogen/aluminum dust hybrid explosion was established.

    更新日期:2019-12-25
  • Investigation on the overpressure of methane-air mixture gas explosions in straight large-scale tunnels
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-24
    Yunfei Zhu; Deming Wang; Zhenlu Shao; Xiaolong Zhu; Chaohang Xu; Yutao Zhang

    To investigate the overpressure of methane-air explosions in straight large-scale tunnels, the computational fluid dynamics (CFD) code of Flame Accelerator Simulator (FLACS) was used and validated against experiments conducted at three different scales, and the effects of the volume concentration of methane in air, the blockage ratio (BR), the tunnel length, and the cross-section were studied. When analysed using the GaussAmp mathematical model, the maximum peak overpressure appears at a volume concentration of 10.30% of methane in air. Blockage ratios (BR) of 0.15 and 0.3 resulted in the combustion of methane-air mixtures with the volume concentration of 6.5% and 14.0% of methane in air, producing a fatal overpressure of 21 kPa. When the BR increases up to 0.75, both the lean and rich mixtures cause a peak overpressure of over 60 kPa. Combustion of the same methane-air mixture produces the same overpressure, which decays approximately linearly at the same slope owing to a smooth wall roughness before travelling near the outlet, independent of the specific tunnel length. A method to characterise the cross-sections was proposed, and the maximum peak overpressure of different lengths of methane-air mixtures in different cross-sectional tunnels was found, presenting various regimes from a hump shape to a wave-like uplift and bowl shape. The cross-section parameters determine the degree of confinement and further control the maximum peak overpressure in the modelled tunnels. An exponential asymptotic model can be used to conveniently obtain the maximum peak overpressure. These phenomena indicate that approximately square-shaped cross-sections should be selected to avoid an extremely high overpressure in large-scale tunnels with the potentially significant accumulation of methane-air mixtures.

    更新日期:2019-12-25
  • Utilization of nickel-electroplating wastewaters in manufacturing of photocatalysts for water purification
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-23
    Alexander Gorokhovsky; Maria Vikulova; Jose Ivan Escalante-Garcia; Elena Tretyachenko; Igor Burmistrov; Denis Kuznetsov; Diana Yuri

    A new route of purification/revalorization of nickel electroplating wastewaters is proposed. It is shown that chemical treatment of different nickel-electroplating wastewaters with aqueous dispersion of layered structure amorphous potassium polytitanate (PPT) successfully removed the nickel from the effluents. Moreover, the resulting solid products, obtained with optimal PPT doses, showed excellent and consistent photocatalytic properties in the visible range of solar radiation, which are independent on the characteristics of the wastewater i.e. pH, nickel contents or the presence of other heavy metals. On the other hand, after proper dilution, the resulting treated effluents can be returned to the municipal wastewater collectors. The mechanisms of the processes taking place during the treatment are analyzed.

    更新日期:2019-12-23
  • Process Safety Assessment Considering Multivariate Non-linear Dependence Among Process Variables
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-23
    Arko Ghosh; Salim Ahmed; Faisal Khan; Risza Rusli

    Nonlinear dependencies among highly correlated variables of a multifaceted process system pose significant challenges for process safety assessment. The copula function is a flexible statistical tool to capture complex dependencies and interactions among process variables in the causation of process faults. An integration of the copula function with the Bayesian network provides a framework to deal with such complex dependence. This study attempts to compare the performance of the copula-based Bayesian network with that of the traditional Bayesian network in predicting failure of a multivariate time dependent process system. Normal and abnormal process data from a small-scale pilot unit were collected to test and verify performances of failure models. Results from analysis of the collected data establish that the performance of copula-based Bayesian network is robust and superior to the performance of traditional Bayesian network. The structural flexibility, consideration of non-linear dependence among variables, uncertainty and stochastic nature of the process model provide the copula-based Bayesian network distinct advantages. This approach can be further tested and implemented as an online process monitoring and risk management tool.

    更新日期:2019-12-23
  • 更新日期:2019-12-23
  • Insight into the application of hydrogen-rich energy in iron ore sintering: parameters optimization and function mechanism
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-23
    Zhiyun Ji; Haoyu Zhou; Xiaohui Fan; Min Gan; Qian Liu; Xiaoxian Huang; Xuling Chen; Haorui Li
    更新日期:2019-12-23
  • Research-scale three-phase jet foam generator design and foaming condition optimization based on Box-Behnken design
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-23
    Gang Fu; Juncheng Jiang; Lei Ni

    Three-phase foam, namely surfactant-particle stabilized foam is a promising material in pool fire extinguishment. However, its effectiveness hasn’t been validated. In this study, a research-scale three-phase jet foam generator, which allowed adjustments of foam slurry composition, nozzle type, air flow rate and screen aperture, was developed. In order to optimize the foaming condition, a three-factor three-level Box-Behnken design (BBD) was adopted. Fly ash (FA) particles were used as the solid phase to generate three-phase foams. As a result, the FA supported foam exhibited better stability over conventional fire-fighting foam, especially when the particle concentration exceeded a threshold value. In addition, the BBD results presented a good agreement between experimental data and fitted models. The optimal foaming condition was determined by numerical optimization. Small-scale fire extinguishing experiments were carried out and three-phase foam manifested better burnback performance compared to conventional fire-fighting foam. The design in this work can be used to study the firefighting efficiency of different three-phase foams and serve as a prototype to develop better generators for both lab research and practical application.

    更新日期:2019-12-23
  • On Reliability Challenges of Repairable Systems Using Hierarchical Bayesian Inference and Maximum Likelihood Estimation
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-23
    Ahmad BahooToroody; Mohammad Mahdi Abaei; Ehsan Arzaghi; Guozheng Song; Filippo De Carlo; Nicola Paltrinieri; Rouzbeh Abbassi

    Failure modelling and reliability assessment of repairable systems has been receiving a great deal of attention due to its pivotal role in risk and safety management of process industries. Meanwhile, the level of uncertainty that comes with characterizing the parameters of reliability models require a sound parameter estimator tool. For the purpose of comparison and cross-verification, this paper aims at identifying the most efficient and minimal variance parameter estimator. Hierarchical Bayesian modelling (HBM) and Maximum Likelihood Estimation (MLE) approaches are applied to investigate the effect of utilizing observed data on inter-arrival failure time modelling. A case study of Natural Gas Regulating and Metering Stations in Italy has been considered to illustrate the application of proposed framework. The results highlight that relaxing the renewal process assumption and taking the time dependency of the observed data into account will result in more precise failure models. The outcomes of this study can help asset managers to find the optimum approach to reliability assessment of repairable systems.

    更新日期:2019-12-23
  • 更新日期:2019-12-23
  • Advanced oxidation processes for the removal of organophosphorus pesticides in aqueous matrices: A systematic review and meta-analysis
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-23
    Mohammad Malakootian; Armita Shahesmaeili; Maryam Faraji; Hoda Amiri; Susana Silva Martinez

    The advanced oxidation processes (AOPs), as an alternative technology to eliminate pesticides from aqueous environments, consist of several groups of technologies that have been used with high efficiency in the treatment of water and wastewater in recent decades. A systematic review of the scientific literature to evaluate the most common advanced oxidation processes (AOPs) for the removal of organophosphorus pesticides in aqueous matrices is addressed in this study. Meta-analysis is also performed to provide a precise and robust summary estimate after a systematic and rigorous integration of the available evidence. In the current study, 9 sub-groups of AOPs were reviewed, such as electrochemical, UV/H2O2 photolysis, photocatalysis, Fenton-type, plasma, gamma irradiation, sulfate-based catalyst, sonolysis and ozonation technology for organophosphorus pesticides degradation. The random effects model was used to estimate the pooled measurements and 95% confidence intervals (95% CI). In total, six studies were included in this review. All studies, except one, used the photocatalytic process as AOP. The average pooled percentage of AOP for pesticide degradation was 66.8 (95% CI: 58.1-75.6). In addition, the most studied pesticides are chlorpyrifos and diazinon which, according to the results of the meta-analysis, the photocatalytic process has the highest efficiency of diazinon elimination with an average percentage of 79.2 (95% CI: 76.8-81.5).

    更新日期:2019-12-23
  • Effect of admixed solid inertants on dispersibility of combustible dust clouds in a modified hartmann tube
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-23
    Yajie Bu; Zepeng Ma; Chang Li; Paul Amyotte; Wenbo Yuan; Chunmiao Yuan; Gang Li
    更新日期:2019-12-23
  • Bayesian Network and Game Theory Risk Assessment Model for Third-Party Damage to Oil and Gas Pipelines
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-23
    Yan Cui; Noor Quddus; Chad V. Mashuga

    Tremendous amounts of oil and gas products are transported in pipelines worldwide resulting in increasing interest to identify the hazards and evaluate the associated risks associated with this critical infrastructure. Third-party intrusion is one of the least quantifiable factors being considered during the pipeline hazard assessment stage despite the substantial contributing to the total number of oil and gas pipeline incidents. This is because a probabilistic risk assessment cannot reliably model human actions and be applied to intentional acts. Due to the distinctive motivations of third-party damage, an unintentional third-party damage Bayesian Network model and a game-theoretic model on malicious intrusion will therefore be built, to examine the mechanism of pipeline failure caused by this mode. This study is conducted aiming at investigating pipeline risk resulting from third-party damage, and will formulate risk assessment models to identify threats, prioritize risks and determine which integrity plan should apply to different pipeline segments given the condition of third-party interference (both the accidental damage and malicious acts).

    更新日期:2019-12-23
  • Experimental Investigation of LNG Release Underwater and Combustion Behavior under Crosswinds
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-23
    Yixiang Zhang; Jianlu Zhu; Youmei Peng; Cunyong Song; Yuxing Li

    Liquefied natural gas (LNG) trade has increased globally; therefore, assessments of the hazards of its accidental release and associated consequences must be conducted to ensure LNG security during marine transportation. This study aims to understand the dynamic behavior occurring when an LNG jet is released underwater and the combustion behavior of a flammable vapor cloud on the water’s surface with airflows from 0 to 4 m/s. A series of controlled LNG vertical jet release experiments were conducted using a cryogenic storage tank with three orifices. Various instruments were employed to measure the flow rate and pressure in pipelines during different leakage scenarios, and the emanating LNG vapor clouds were immediately ignited with the mass loss rate of 0.016, 0.037, and 0.049 kg/s in three orifices, respectively. The flame behavior was recorded by a video camera. With respect to flame length rapidly decreased with crosswinds of 0-2 m/s and then gradually decreased to a constant value with the velocities increase to 4 m/s. A dimensionless number of Ri was employed to analyze the relative magnitude between the buoyancy force and transverse flow. The flame tilt angle was found in accordance trend with flame length for first increased and further reach to become constant at Ri-1 increase to 2. As existing correlations provide an overestimation, a new correlation was established to describe the flame length as a function of crosswind speed, and a good prediction was found for measured tilt angles with the correlated values.

    更新日期:2019-12-23
  • Degradation of pesticide thiamethoxam by heat – activated and ultrasound – activated persulfate: Effect of key operating parameters and the water matrix
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-23
    Hafida Lebik-Elhadi; Zacharias Frontistis; Hamid Ait-Amar; Farid Madjene; Dionissios Mantzavinos
    更新日期:2019-12-23
  • Characterization of pore structure and the gas diffusion properties of tectonic and intact coal: Implications for lost gas calculation
    Process Saf. Environ. Prot. (IF 4.384) Pub Date : 2019-12-23
    Zhenyang Wang; Yuanping Cheng; Liang Wang; Hongxing Zhou; Xinxin He; Minghao Yi; Chuanpeng Xi

    Accurate calculation of the amounts of lost gas from coal are of great importance in underground mining. In this study, the effects of pore structure and the gas diffusion properties on the lost gas from tectonic and intact coals were investigated by the mercury intrusion porosimetry method (MIP), N2 (77 K) and CO2 (273 K) adsorption methods, and gas adsorption equilibrium/desorption tests. The results indicated that mesopore and macropore volumes increased after tectonic damage, as did the specific surface areas (SSA) and porosities. However, there was little change for the micropore volumes. Additionally, the desorption experiments indicated that the initial desorption and gas flow capacities of tectonic coal were greater than those of intact coal. Both laboratory and field results demonstrate that there is more higher lost gas for tectonic coal, which is directly influenced by the developed mesopore and macropore structure and by the initial gas desorption capacity. The logarithmic function method is a relatively better choice. When the gas content is determined in coal mines, the sampling exposure times should be kept as short as possible. From the perspective of engineering, this study provides a reference for the calculation of lost gas in tectonic coals.

    更新日期:2019-12-23
Contents have been reproduced by permission of the publishers.
导出
全部期刊列表>>
2020新春特辑
限时免费阅读临床医学内容
ACS材料视界
科学报告最新纳米科学与技术研究
清华大学化学系段昊泓
自然科研论文编辑服务
加州大学洛杉矶分校
上海纽约大学William Glover
南开大学化学院周其林
课题组网站
X-MOL
北京大学分子工程苏南研究院
华东师范大学分子机器及功能材料
中山大学化学工程与技术学院
试剂库存
天合科研
down
wechat
bug