• Title/Summary/Keyword: Sulfur dioxide

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Corrosion Behavior of Carbon Steel in Diluted Sulfuric Acid based on Seawater

  • Kim, Mun Su;Jeong, Jin-A
    • Corrosion Science and Technology
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    • v.18 no.3
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    • pp.78-85
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    • 2019
  • The International Maritime Organization (IMO) will administer a new 0.5% global sulfur cap on fuel content from 1 January 2020, lowering from the present 3.5% limit. Seawater $SO_x$ (sulfur oxide) scrubbing is especially spray scrubbing and a promising alternative to complying with the IMO regulation. However, the ionization of $SO_2$ (sulfur dioxide) and the $H_2SO_4$ (sulfuric acid) formed from $SO_3$ (sulfur trioxide) is proposed to accelerate corrosion of the internal seawater pipe. Apparently, the corrosion of the scrubber seawater piping system occurs in a severe and frequent manner. Hence, in this study, electrochemical measurement and weight loss of carbon steel (used as seawater pipe in most of the ships) in diluted sulfuric acid solution were investigated to determine corrosion rate, corrosion current density, corrosion potential, electrochemical behavior, and impressed-current density. Accordingly, the corrosion rate of carbon steel sheet in various diluted sulfuric acid solutions was observed to be greater than that in natural seawater, thus suggesting the fundamental data to deal with corrosion problems in scrubber seawater pipe.

Desirable pH of Slurry in Desulfurization Absorber for a 1000 MW Coal Fired Power Plant (1000 MW급 석탄화력발전용 탈황흡수탑의 적정슬러리 pH)

  • Park, Jeong-kee;Yoo, Hoseon
    • Plant Journal
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    • v.15 no.1
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    • pp.38-44
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    • 2019
  • This research is an experimental investigation to find the desirable pH of slurry in the desulfurization absorber for a 1000 ㎿ coal fired power plant, operating in compliance with the Air Environmental Conservation Act and the plant's internal regulations. In case the average sulfur dioxide concentration in inflow flue gas, ${\bar{C\;in}}$ [ppm] changed to 500 ppm, 550 ppm, 600 ppm and 635 ppm after fixing inflow flue gas flow rate, generator output, pressure drop in the absorber, and oxidation air flow rate, the desirable pH of the slurry in the absorber, was 5.0, 5.2, 5.3 and 5.4. Thus, it is recommended that the desirable pH of slurry is calculated using the correlation equation, $RpH=0.0018{\times}{\bar{C\;in}}+4,2031$ when the average sulfur dioxide concentration in the inflow flue gas is in the range of 500 ppm to 635 ppm.

Trend and Prospect of Scrubber Technology for Regulatory on Sulfur Content in Marine Fuel Oil (선박 연료의 황 함유량 규제에 따른 스크러버 기술의 동향과 전망)

  • Eom, Hanki;Park, Byung Hyun;Jeong, Soon-Kwan;Kim, Sung Su
    • Prospectives of Industrial Chemistry
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    • v.22 no.5
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    • pp.1-13
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    • 2019
  • 국제해사기구(IMO, international maritime organization)는 2015년부터 배출규제해역(ECA, emission control area)을 운항하는 선박은 황 함유량이 0.1%(m/m) 이하로 강화된 기준을 만족하는 연료를 사용해야 하며, 2020년부터는 모든 선박에 대해 황 함유량이 0.5%(m/m) 이하인 연료를 사용하거나 동등 이상의 성능을 갖는 배출가스 후처리 장치의 설치를 의무화하였다. 이에 따라, 선박에서 배출되는 오염물질을 제어할 수 있는 다양한 기술이 개발되고 있으며, 후처리 관점에서 습식 스크러버(wet scrubber)는 선박의 디젤 엔진에서 배출되는 이산화황(sulfur dioxide)을 저감시키기 위한 가장 적합한 해결책으로 알려져 있다. 습식 스크러버는 해수를 사용하는 개방형 스크러버(open loop scrubber)와 화학세정수를 사용하는 폐쇄형 스크러버(closed loop scrubber)로 구분된다. 습식 스크러버는 오염물질의 효율적인 처리가 가능하지만 유지보수비가 비싸고, 폐수 발생으로 인한 2차 오염발생 및 부식에 매우 취약한 단점이 있다. 따라서 최근에는 스크러버 내부의 부식을 방지하기 위한 내부식성 재질에 관한 연구와 흡수제(absorbent)의 고도화 연구가 활발히 진행되고 있다. 또한, 하이브리드형 스크러버(hybrid scrubber)는 개방형과 폐쇄형 스크러버의 장점을 결합한 기술로 황산화물의 배출을 규제하는 배출규제해역에서는 폐쇄형 스크러버를 가동하고, 선박이 공해상으로 진입할 경우 개방형 스크러버로 전환함에 따라 황산화물 배출 및 반응 후 세척수의 폐수배출 기준을 동시에 만족할 수 있다.

Monitoring and Safety Assessment of Pesticide Residues and Sulfur Dioxide on Functional Rice Products (기능성 쌀의 잔류농약 및 이산화황 안전성 실태조사)

  • Lee, You-Jin;Park, Myung-Ki;Kim, Ki-Yu;Park, Eun-Mi;Kang, Heung-Gyu;Lim, Ji-Hyun;Cho, Wook-Hyun;Kim, Youn-Ho;Lee, Sun-Young;Yong, Kum-Chan;Yoon, Mi-Hye
    • Journal of Food Hygiene and Safety
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    • v.32 no.6
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    • pp.493-499
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    • 2017
  • This study was conducted to monitor the current status of pesticide residues and sulfur dioxide in a total of 91 functional rice products from February to October 2016. Multi class pesticide multiresidue methods of 220 pesticides was performed by the GC/ECD, GC/NPD, GC/TOF/MS, LC/PDA, and LC/FLD. As a result of analysis, the pesticides were detected in 3 samples, representing a detection rate of 3.3%. The kind of pesticides was propiconazole and isoprothiolane used for germicide in agriculture or plant growth regulator purposes. The detected levels were 0.0340~0.0566 mg/kg, which were under the MRL (Maximum Residues Limits). The contents of sulfur dioxide in 91 samples by the Monier-Williams method were not detected. Risk assessment of pesticides evaluated using human health exposure with the ratio of EDI (Estimated daily intake) to ADI (Acceptable daily intake). %ADI (the ratios of EDI to ADI) were 0.24~1.25% with safety level.

Odor Thresholds and Breathing Changes of Human Volunteers as Consequences of Sulphur Dioxide Exposure Considering Individual Factors

  • Kleinbeck, Stefan;Schaper, Michael;Juran, Stephanie A.;Kiesswetter, Ernst;Blaszkewicz, Meinolf;Golka, Klaus;Zimmermann, Anna;Bruning, Thomas;Van Thriel, Christoph
    • Safety and Health at Work
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    • v.2 no.4
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    • pp.355-364
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    • 2011
  • Objectives: Though sulfur dioxide (SO2) is used widely at workplaces, itseffects on humans are not known. Thresholds are reportedwithout reference to gender or age and occupational exposure limits are basedon effects on lung functioning, although localized effects in the upper airways can be expected. This study's aim is to determine thresholds with respect to age and gender and suggests a new approach to risk assessment using breathing reflexes presumably triggered by trigeminal receptors in the upper airways. Methods: Odor thresholds were determined by the ascending method of limits in groups stratified by age and gender. Subjects rated intensities of different olfactory and trigeminal perceptions at different concentrations of $SO_2$. During the presentation of the concentrations, breathing movements were measured by respiratory inductive plethysmography. Results: Neither age nor gender effects were observed for odor threshold. Only ratings of nasal irritation were influenced bygender. A benchmark dose analysis on relative respiratory depth revealed a 10%-deviation from baseline at about 25.27 mg/$m^3$. Conclusion: The proposed new approach to risk assessment appearsto be sustainable. We discuss whether a 10%-deviation of breathingdepth is relevant.

The Effect of Fuel Sulfer on Particulate Matter of Diesel Engine Equipped with Oxidation Catalyst (경유 중 황이 산화촉매 장착 디젤엔진의 입자상 물질에 미치는 영향)

  • 조강래;신영조;류정호;김희강
    • Journal of Korean Society for Atmospheric Environment
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    • v.13 no.6
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    • pp.487-495
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    • 1997
  • The most desirable diesel oxidation catalyst (DOC) should have the properties of oxidizing CO, HC and SOF effectively at low exhaust gas temperature while minimizing the formation of sulfate at high exhaust gas temperature. Precious metals such as platinum and palladium have been known to be sufficiently active for oxidizing SOF and also to have high activity for the oxidation of sulfur dioxide $(SO_2)$ to sulfur trioxide $(SO_3)$. There is a need to develop a highly selective catalyst which can promote the oxidation SOF efficiently, on the other hand, suppress the oxidation of $SO_2$. In this study, a Pt-V catalyst was prepared by impregnating platinum and vanadium onto a Ti-Si wash coated ceramic monolith substrate. A prepared Pt-V catalytic converter was installed on a heavy duty diesel engine and the effect of fuel sulfur on particulate matter (PM) of heavy duty diesel engine was measured. The effect of fuel sulfur on PM of Pt-V was also compared with that of a commercialized Pt catalyst currently being used in some of the heavy duty diesel engines in advanced countries. Only 1 $\sim$ 3% of sulfur in the diesel fuel was converted to sulfate in PM for the engine without catalyst, but almost 100% of sulfur conversion was achieved for the engine with Pt catalyst at maximum loading condition. In the case of Pt-V catalyst, there was no big difference in conversion with the base engine even at maximum loading condition. The reason of SOF increase according to the increase of suflate emission was identified as the washing off effect of bound water in sulfate.

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Sulfur Isotopic Ratios in Precipitation around Chonju-city, Korea and Its Availability as a Tracer of the Source of Atmospheric Pollutants (전주지역 강수의 황동위원소비와 대기오염원의 추적자로서 그 유용성)

  • Na, Choon-Ki;Kim, Seon-Young;Jeon, Sir-Ryeong;Lee, Mu-Seong;Chung, Jae-Il
    • Economic and Environmental Geology
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    • v.28 no.3
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    • pp.243-249
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    • 1995
  • In order to investigate the origin of sulfate in rain waters and to evaluate the feasibility of using sulfur isotope method as a tracer of atmospheric pollutants, the sulfur isotopic ratio of sulfate in rain waters collected in Chonju city from October 1994 to March 1995 was monitored and was compared with those of possible sources proposed by previous works. The pH of rain waters shows an intermediate acidic range from 4.45 to 6.88 and their daily variation appears to be well correlated with to the amount of precipitation. The sulfur isotopic ratios of sulfate in rain waters show a highly restricted range from 0.0 to + 1.8‰. The ${\delta}^{34}S$ values are similar to those of soil and pine tree surrounding Chonju city, but largely deviate from those of China. D-parameter($d={\delta}D-8{\delta}^{18}O$) of rain waters varies from 9.4 to 28.8. The values indicate that the rain waters in Chonju city are originated from the rainy front of China continent. All data obtained from this study suggested that sulfate in the rain waters collected in Chonju city was mainly derived from the sulfur dioxide gas emitted by the petroleum combustion. Therefore, sulfur isotopic study for the precipitation provided an excellent tool for environmental assessment in this region and for tracing the source of atmospheric pollutants.

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Effects of Sulfur Dioxide on Bark Acidity, Leaf Acidity and Water Soluble Sulfur Contents of Prunus yedoensis and Ligustrum obtusifolium Seedlings (아황산가스가 왕벚나무와 쥐똥나무 유묘의 수피산도, 엽중산도 및 엽내 수용성 황 함량에 미치는 영향)

  • 주영특;이상덕;김홍률
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.4 no.4
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    • pp.219-223
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    • 2002
  • This study investigated effects of bark acidity, leaf acidity and water soluble sulfur contents by SO$_2$, 1-2 seedling of Prunus yedoensis and Ligustrum obtusifolium were treated 5 level (0. 0.5, 1, 2, 4 ppm) of SO$_2$. The tallowing results were obtained; In the case of bark and leaf acidities, pH values decreased as SO$_2$ concentration was high. Prunus yedoensis compare with Ligustrum obtusifolium had high relative susceptibility because rates of increase in bark and leaf acidities were high according to SO$_2$ concentration. Water soluble sulfur contents in the leaves also increased as SO$_2$ concentration was high. Prunus yedoensis compare with Ligustrum obtusifolium had high relative susceptibility because increase rates of water soluble sulfur contents in the leaves were high according to SO$_2$ concentration.

Photochemical Conversions of Reduced Sulfur Compounds to SO2 in Urban Air (도시의 환원 황 화합물의 이산화황으로의 광화학적 변환)

  • Shon, Zang-Ho;Kim, Ki-Hyun
    • Journal of Korean Society for Atmospheric Environment
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    • v.20 no.5
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    • pp.647-654
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    • 2004
  • This study examines the local oxidation chemistry of reduced sulfur compounds (RSC) in the urban air. The chemical conversion of RSC (such as DMS, $CS_2,\;H_2S,\;DMDS,\;and\;CH_3SH)\;to\;SO_2$ was modeled using a photochemical box model. For our model prediction of the RSC oxidation, measurements were carried out from an urban monitoring station in Seoul (37.6$^{\circ}$N, 127.0$^{\circ}$E), Korea for three separate time periods (Sep. 17~18; Oct 23; and Oct. 27~28, 2003). The results of our measurements indicated that DMS and $H_2S$ were the dominant RSC with their concentrations of 370${\pm}$140 and 110${\pm}$60 pptv, respectively. The conversion of DMDS to $SO_2$ can occur efficiently in comparison to other RSC, but it is not abundant enough to affect their cycles. The overall results of our study indicate that the photochemical conversion of the RSC can contribute ≶ 20% of the observed $SO_2$.

Random Coefficient Models for Environmental Kuznets Curve Hypothesis in Seoul Metropolitan Region (확률계수모형을 이용한 수도권지역의 환경쿠즈네츠가설에 관한 재고찰)

  • Kim, Ji Uk
    • Environmental and Resource Economics Review
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    • v.11 no.3
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    • pp.377-396
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    • 2002
  • This paper investigates whether an inverted U relationship between pollution and economic development could be found in the Seoul metropolitan region using a panel data for the period of 1985~1999. We uses a model with a more flexible random coefficients specification which allows for a greater degree of regional heterogeneity. The emissions of sulfur dioxidetotal($SO_2$), suspended particulates(TSP), nitrogen dioxide($NO_2$), and carbon monoxide(CO) were selected as four major pollutants. We found that the emissions of these pollutants per capita except sulfur dioxidetotal exhibited inverted U shapes with per capita gross regional domestic product (GRDP). We also noted that the turning points for Seoul metropolitan region occured at a range of incomes, from $3,000 to $5,000 per capita.

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