• Title/Summary/Keyword: hazardous gas

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A Study on Risk Mitigation Measures of NaTech Damage Effect of Hazardous Chemical Storage Tank - Focus on Triggered by Earthquake - (화학물질 저장탱크의 NaTech 피해영향 저감방법 연구 - 지진으로 인한 사고 중심으로 -)

  • Lee, Tae-Hyung;Lee, Hyun-Seung;Yoo, Byung-Tae
    • Journal of the Korean Institute of Gas
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    • v.22 no.5
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    • pp.79-88
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    • 2018
  • This study presents an evaluation method to estimate the damage scale of chemical storage tank of petrochemical plant due to the earthquake that is likely to occur among NaTech damage types. Based on this, the risk for damage reduction of chemical storage tanks was evaluated. As a result of the study, the risk of the storage tank increased greatly considering the earthquake, and the risk was greatly reduced as a result of evaluating the proposed measures to mitigate the damage impact on the earthquake. This study is expected to contribute to the research on the reduction of NaTech damages such as typhoons and thunderstorms as well as earthquakes, and to establish an emergency response plan. In the future, it is necessary to systematically study and institutionalize the risk reduction measures considering earthquakes.

A Study on application of F-N curve to OCA (장외영향평가 F-N curve 적용에 관한 연구)

  • Lee, Dong Hyeok;Yoo, Byung Tae
    • Journal of the Korean Institute of Gas
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    • v.22 no.5
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    • pp.31-37
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    • 2018
  • The distrust about chemical plant safety have been increased by occurring the major industrial accidents. Chemical plants have become more and more enlarged and sophisticated to increase production amount and decrease cost. So hazard of industrial accidents also have been increased. In this situation, quantitative risk assessment is activated by introducing OCA(Off-site Consequence Analysis). So it is possible to analyze the objective hazard of chemical plant. Currently OCA focus on the end point of hazardous area by fire/explosion/dispersion. But in this case, it is possible to analyze the industrial accident effect to near the chemical plant but hard to consider the actual hazard by frequency and population density. This study analyzes the validity about application of F-N curve to OCA by compare end point with F-N curve about accident.

Condensation and coagulation of metallic species with fly ash particles in a waste incinerator (폐기물 소각시 생성되는 유해 중금속물질과 연소실내 비산재와의 응축, 응집 현상에 대한 연구)

  • Yu, Ju-Hyeon;Hwang, Jeong-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.2
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    • pp.264-274
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    • 1997
  • A numerical analysis on condensation and coagulation of the metallic species with fly ash particles pre-existing in an incinerator was performed. Waste was simplified as a mixture of methane, chlorine, and small amounts of Pb and Sn. Vapor-phase amounts of Pb- and Sn -compounds were first calculated assuming a thermodynamic equilibrium state. Then theories on vapor-to-particle conversion, vapor condensation onto the fly ash particles, and particle-particle interaction were examined and incorporated into equations of aerosol dynamics and vapor continuity. It was assumed that the particles followed a log-normal size distribution and thus a moment model was developed in order to predict the particle concentration and the particle size distribution simultaneously. Distributions of metallic vapor concentration (or vapor pressure) were also obtained. Temperature drop rate of combustion gas, fly ash concentration and its size were selected as parameters influencing the discharged amount of metallic species. In general, the coagulation between the newly formed metal particles and the fly ash particles was much greater than that between the metal particles themselves or between the fly ash particles themselves. It was also found that the amount of metallic species discharged into the atmosphere was increased due to coagulation. While most of PbO vapors produced from the combustion were eliminated due to combined effect of condensation and coagulation, the highly volatile species, PbCl$_{2}$ and SnCl$_{4}$ vapors tended to discharge into the atmosphere without experiencing either the condensation or the coagulation. For Sn vapors the tendency was between that of PbO vapors and that of PbCl$_{2}$ or SnCl$_{4}$. To restrain the discharged amount of hazardous metallic species, the coagulation should be restrained, the number concentration and the size of pre-existing fly ash particles should be increased, and the temperature drop rate of combustion gas should be kept low.

A Case Study of Bottom Liner Construction Using Composite Liner Technology in a Solid Waste Landfill (복합차수층 조성기술을 이용한 폐기물매립지 바닥차수층 시공사례)

  • Lee, Kyu-Jung;Lee, Nam-Hoon;Park, Soo-Young;Jeon, Won-Pyo;Lee, Chae-Young
    • Journal of the Korea Organic Resources Recycling Association
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    • v.15 no.3
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    • pp.90-96
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    • 2007
  • Modern waste management units, so-called "landfills" protect human health and environment from hazardous leachate and gas. Accordingly, it must be constructed with a bottom liner system that includes a gas collection layer. Leachate is the contaminated liquid that drains from the waste material pollutes ground water. For this reason. bottom liner system must have durability and low hydraulic conductivity (in case of compacted clay liner, no more than $1{\times}10^{-7}cm/sec$ ). P county in Kangwon province constructed a solid waste landfill with bottom liner system. In this study. it is mainly introduced that the test results on construction and quality control of bottom liner system by "Multiple composite liner construction technology", which is selected for bottom liner system in P solid waste landfill.

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A Study on the System Design of Chemical Process using Quantitative Risk Assessment Methodology (정량적 위험성평가기법을 이용한 화학공정 시스템 구축에 관한 연구)

  • Byun, Yoon Sup
    • Journal of the Korean Institute of Gas
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    • v.18 no.6
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    • pp.32-39
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    • 2014
  • To ensure the reliability of the safety system so that handing large quantities of hazardous materials in chemical plant is considered basic information in chemical process design. However, the reliability of the production system may be reduced when the reliability of the safety system emphasized in order to ensure the safety of chemical process. It is necessary to balance the reliability of the production system and reliability of the safety. In this study, a quantitative risk assessment was performed by selecting the furnace process, which is widely used in the chemical plant in order to suggest a way to ensure the safety and productivity of chemical process, based on the quantitative data. Quantitative risk assessment methodology have been used directed graph analysis methodology. It is possible to evaluate the reliability of the safety system and the production system. In this study, the optimum system design requirement to improve the safety and the productivity of the furnace is two-out-of-three logic for TT and PT.

A Study on the Damage Range of Chemical Leakage in Polysilicon Manufacturing Process (폴리실리콘 제조 공정에서 화학물질 누출 시 피해범위에 관한 연구)

  • Woo, Jongwoon;Shin, Changsub
    • Journal of the Korean Institute of Gas
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    • v.22 no.4
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    • pp.55-62
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    • 2018
  • There is growing interest in solar power generation due to global warming. As a result, demand for polysilicon, which is the core material for solar cells, is increasing day by day. As the market grows, large and small accidents occurred in the production process. In 2013, hydrochloric acid leaked from the polysilicon manufacturing plant in SangJu. In 2014, a fire occurred at a polysilicon manufacturing plant in Yeosu, and in 2015, STC(Silicon Tetrachloride) leaked at a polysilicon manufacturing plant in Gunsan City. Leakage of chemicals in the polysilicon manufacturing process can affect not only the workplace but also the surrounding area. Therefore, in this study, we identified the hazardous materials used in the polysilicon manufacturing process and quantitatively estimate the amount of leakage and extent of damage when the worst case scenario is applied. As a result, the damage distance by explosion was estimated to be 726 m, and the damage distance to toxicity was estimated to be 4,500 m. And, if TCS(Trichlorosilane), STC(Silicon Tetrachloride), DCS(Dichlorosilane) leaks into the air and reacts with water to generate HCl, the damage distance is predicted to 5.7 km.

Development of composite catalyst for hazardrous gas treatment using the heat of aviary heating equipment (계사용 온풍기를 이용한 유해가스처리 복합촉매시스템 개발)

  • Jang, Hyun-Tae;Cha, Wang-Seog
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.10
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    • pp.2779-2785
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    • 2009
  • Among the livestock, chickens are raised because of the merit ingested protein in low-priced cost of production and are primary livestock increased the consumption of meat. The factors of influencing condition, odor is the most important factor. Odor substances are ammonia, amines, hydrogen sulfide and mercaptan which come from night soil. Livestock are prevented from rearing by means of these odor substances. Though the henhouse is heated using hot air type heater in the winter season, it is ventilated for the control of odor because of the increase of odor concentration. In the present work, composite catalytic system combined the existing facilities(hot air type heater) with catalytic system was developed, it could controled odor and hazardous gas using the oxidation/reduction reaction without extra operating cost. Moreover, the purpose of this work is to develop the catalysts which are cost competitive and can maximize energy efficiency. The catalysts are noble metal(Pt-Rh) and composite transition metal(Mn) type.

Research Trend on the Accumulation Routes of Microplastics in Soil and Their Analytical Methodologies (토양 내 미세플라스틱의 축적경로 및 분석기법 연구 동향)

  • Choi, Hyung-Jun;An, Jinsung;Choi, Suk Soon
    • Applied Chemistry for Engineering
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    • v.31 no.4
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    • pp.360-367
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    • 2020
  • In this study, the accumulation and distribution routes of microplastics in soil environment were examined, and their analytical methodologies were summarized. Density separation and removal process of inhibition materials were introduced for the separation of microplastics in soil and the basic principles and limitations of quantitative and qualitative analyses including pyrolysis gas chromatography mass spectrometry, µ-Raman spectrometry, fourier transform infrared spectrometry, and microscopes were investigated. Chemical extraction methods for the analysis of mediated hazardous substance (additives and sorbed matters) in microplastics were also discussed with focusing on in vitro bioaccessibility assay for the human oral exposure route. Based on the described methodologies for the analysis of microplastics in soil, it is expected that these methods enable to select appropriate analysis techniques in consideration of medium state, contamination level and sample quantity.

Working Environment and Risk Assessment of Biphenyl in Workplace (Biphenyl 취급사업장의 작업환경 및 유해성 평가)

  • Kim, Hyeon-Yeong
    • Journal of the Korean Institute of Gas
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    • v.18 no.2
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    • pp.55-61
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    • 2014
  • In this study, we evaluated the measurement of working environment, the amount of exposure, the hazards and risks of biphenyl, that was registered as 2A in IARC. Based on the exposure scenario, it was calculated that the exposure amounts are $1.0{\times}10^{-2}$, $4.2{\times}10^{-4}$, $7.0{\times}10^{-6}mg/m^3$, respectively, and the $RfC_{work}$ is 0.21, 2.13, 0.53 $0.31mg/m^3$ as carcinogenicity, target toxicity (oral), target toxicity (inhalation), developmental toxicity, respectively. According to these hazards evaluation and risk assessments, it was estimated that 0.57, 0.39 as carcinogenicity and non-carcinogenicity (developmental toxicity), respectively. It was also estimated relatively lower risks below 1. But since biphenyl is hazardous used much amounts, and could be exposed to workers directly, it was determined to require exposure monitoring to protect workers' health.

Structural Response of Offshore Plants to Risk-Based Blast Load

  • Heo, YeongAe
    • Architectural research
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    • v.15 no.3
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    • pp.151-158
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    • 2013
  • Offshore oil and gas process plants are exposed to hazardous accidents such as explosion and fire, so that the structural components should resist such accidental loads. Given the possibilities of thousands of different scenarios for the occurrence of an accidental hazard, the best way to predict a reasonable size of a specific accidental load would be the employment of a probabilistic approach. Having the fact that a specific procedure for probabilistic accidental hazard analysis has not yet been established especially for explosion and fire hazards, it is widely accepted that engineers usually take simple and conservative figures in assuming uncertainties inherent in the procedure, resulting either in underestimation or more likely in overestimation in the topside structural design for offshore plants. The variation in the results of a probabilistic approach is determined by the assumptions accepted in the procedures of explosion probability computation, explosion analysis, and structural analysis. A design overpressure load for a sample offshore plant is determined according to the proposed probabilistic approach in this study. CFD analysis results using a Flame Acceleration Simulator, FLACS_v9.1, are utilized to create an overpressure hazard curve. Moreover, the negative impulse and frequency contents of a blast wave are considerably influencing structural responses, but those are completely ignored in a widely used triangular form of blast wave. An idealistic blast wave profile deploying both negative and positive pulses is proposed in this study. A topside process module and piperack with blast wall are 3D FE modeled for structural analysis using LS-DYNA. Three different types of blast wave profiles are applied, two of typical triangular forms having different impulse and the proposed load profile. In conclusion, it is found that a typical triangular blast load leads to overestimation in structural design.