• Title/Summary/Keyword: NOx(Nitrogen oxide)

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Simulation of Magnetic Field and Removal Characteristic of Nitrogen Oxide Using Wire-Plate Type Plasma Reactor (선 대 평판형 플라즈마 반응기를 이용한 자계 시뮬레이션과 질소산화물제거 특성)

  • 이현수;박재윤
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.9
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    • pp.407-411
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    • 2003
  • The purpose of this paper is to study the removal of nitrogen oxide(NOx) using a wire-plate type plasma reactor with magnet attached for indoor air purification. In order to produce a more effective reactor, we conducted magnetic field simulations. The results of the magnetic field simulations show that NOx can be removed more effectively. The results from the magnetic field simulation show that when 7 magnets were applied to the reactor, the magnetic flux density was at its highest amount than when using 0, 3, or 5 magnets. From the data obtained by the simulation results a plasma reactor was made and thus, several experiments were conducted. The best removal efficiency was obtained with 14 W AC power to the reactor with 5 magnets.

Evaluation of the Removal Performance of Nitrogen Oxides of Foam Composites Using Activated Carbon and Titanium Dioxide (활성탄소와 이산화 타이타늄을 활용한 폼 복합체의 질소산화물의 제거 성능 평가)

  • Choi, Hyun-Chul;Choi, Young-Cheol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.6
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    • pp.120-127
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    • 2022
  • Nitrogen oxide(NOx) is a major cause of air pollution, exists in the form of nitrogen monoxide and nitrogen dioxide, and is harmful to the human body. Recently, a number of studies to reduce NOx in the atmosphere have been conducted, and these efforts have been the same in the field of construction materials. It is known that NOx can be efficiently removed by using a photocatalytic reaction. In this study, the NOx removal performance of the foam composite using activated carbon(AC) and titanium dioxide(TiO2) was investigated. AC was used to enhance the photocatalytic reaction of TiO2 by increasing the internal specific surface area of the foam composite. In this study, foam composites were prepared using the substitution rate of AC as the main variable. The NOx removal performance of specimen was evaluated according to the test method presented in ISO-22197-1. The specific surface area of the foam composite showed a tendency to increase according to the AC content, but decreased at 15% or more. Also, when the AC substitution rate was 15%, the NOx removal efficiency was the highest.

Biological Removal of Nitrogen Oxides from Combustion Flue Gases (연소배가스 중 질소산화물(NOx) 제거를 위한 생물학적 기술)

  • Lee, Ki-Say
    • Applied Chemistry for Engineering
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    • v.21 no.3
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    • pp.243-251
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    • 2010
  • Nitrogen oxides (NOx) in combustion flue gas are currently mitigated by chemical processes such as catalytic reduction, absorption and adsorption. However, development of environmentally sustainable biological processes is necessary in the near future. In this paper, the up-to-dated R&D trend of biological methodologies regarding NOx removal was reviewed, and their advantages and disadvantages were discussed. The principles and applications of bacterial system including nitrification and denitrification and photosynthetic microalgae system were compared. In order to enhance biological treatment rate and performance, the insoluble nitric oxide (NO) should be first absorbed using a proper solubilization agent, and then microbial degradation or fixation is to be followed. The use of microalgal system has a good prospect because it can fix $CO_2$ and NOx simultaneously and requires no additional carbon for energy source.

R&D Status of NOx and Flue-gas Treatment Technologies in KIER (KIER의 NOx 및 연소배가스 처리기술 개발현황)

  • Min, Byoung-Moo;Choi, Sang-Il
    • 한국연소학회:학술대회논문집
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    • 2003.05a
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    • pp.295-300
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    • 2003
  • In Korea, the emission standards for air pollutants will be more tighten from Jan. 2005. Especially, the new emission standards is focused on the nitrogen oxide. From this trend of standards, nitrogen oxide emission is hot issue in energy fields. Also, we have a new environmental problem, the carbon dioxide emission, which are related to the global warming. To solve the environmental problems, we must define the situation of clean-up technologies level in Korea and decide the direction of R&D for flue gas cleaning technologies. Now, this paper discus briefly on the De-NOx R&D activities and the large scale testing facility for flue gas clean-up technologies in Korea Institute of Energy Research. These discussions are contribute to the increasing of the R&D activities for flue gas clean-up technologies in Korea.

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Effect of NH3 Uniformity Index on SCR System According to Urea Spray Characteristics (요소수 분무특성이 SCR시스템 내 분무균일도에 미치는 영향)

  • Kim, Se Hun;Ko, Jin Seok;Ko, Jae Yu;Cho, Young Jun;Lee, Dong Ryu
    • Journal of ILASS-Korea
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    • v.24 no.4
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    • pp.178-184
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    • 2019
  • Diesel engines have the advantages of higher thermal efficiency and lower CO2 emissions than gasoline engines, but have the disadvantages that particulate matter (PM) and nitrogen oxides (NOx) emissions are greater than those of gasoline engines. In particular, nitrogen oxides (NOx) emitted from diesel engines generates secondary ultrafine dust (PM2.5) through photochemical reactions in the atmosphere, which is fatal to humans. In order to reduce nitrogen oxides (NOx), pre-treatment systems such as EGR, post-treatment systems such as LNT and Urea SCR have been actively studied. The Urea SCR consists of an injection device injecting urea agent and a catalytic device for reducing nitrogen oxides (NOx). The nitrogen oxide (NOx) reduction performance varies greatly depending on the urea uniformity in the exhaust pipe. In this study, spray characteristics according to the spray hole structure were confirmed, and the influence of spray uniformity on spray characteristics was studied through engine evaluation.

Removal Characteristics of Nitrogen Oxide in Electromagnetic-Catalytic Plasma Reactor (전자계-촉매형 플라즈마 반응기의 질소 산화물 제거 특성)

  • 이현수;박재윤;이동훈;한병성
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.7
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    • pp.640-648
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    • 2002
  • This study is to develop electromagnetic-catalyst application plasma reactors for indoor air purification. Nitrogen Oxide(NOx) removal characteristics are measured in the electromagnetic catalyst application plasma reactors with various parameters and the effect of catalyst or/and magnetic field are investigated on the NOx removal. And AC or DC high voltage is applied for corona discharge, flow rates are 150~1500 $\ell/min$ and NO initial concentration is about 10 ppm. $Mn0_2$ and $TiO_2$ catalysts to increase NOx removal rate are used. In the results, NOx removal rate by AC power is about 10 % higher than that by DC power under the experimental condition of 700 $\ell/min$, 5 magnets, $MnO_2$ and $Ti)_2$ catalysts. When magnet is applied to the reactor, NOx removal rate increased. Also, the reactor with $MnO_2$ and $Ti)_2$ catalyst and magnet have the best removal rate.

A Study on NOx Emission Characteristics of An Industrial Gas Turbine (산업용 가스터빈의 NOx 배출 특성에 관한 연구)

  • Jeong, Jai-Mo;Park, Jung-Kyu
    • Journal of the Korean Society of Combustion
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    • v.9 no.1
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    • pp.11-17
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    • 2004
  • The purposes of this study are to analyze nitrogen oxides(NOx) formation mechanism and to reduce abnormal NOx emissions in gas turbines. Industrial gas turbines emissions have potential to negative affect to the atmosphere in many different ways such as photochemical smog, acid rain and global warming. In conventional gas turbine combustors, one of the main pollutants such as nitrogen oxide(NOx) species, are principally formed from combustion process of fuel with oxygen in the primary combustion zone, and their emission levels are highly depend on peak temperatures in the combustor. In order to examine the characteristics and the effect of NOx formation, we used gas turbine of which commercial operating in Korea. From the examination, it has been found that NOx emissions are relatively high at low load(output) and during combustion mode change. Also, the effect of Air/Fuel ratio was considered. As the Air/Fuel ratio was increased in Lean-Lean mode, the NOx emission was decreased. The results of this study indicated that NOx emission levels are highly depend on peak temperature and pressure of combustion process in the combustor.

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Influence of changing combustor pressure and secondary fuel injection on flame stabilization and NOx emission (연소실 압력변동과 2차 연료분사가 화염안정화와 NOx 배출에 미치는 영향)

  • Kim, Jong-Ryul;Choi, Gyung-Min;Kim, Duck-Jool
    • 한국연소학회:학술대회논문집
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    • 2006.10a
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    • pp.128-133
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    • 2006
  • Influence of changing combustor pressure on flame stabilization and nitrogen oxide (NOx) emission in the swirl-stabilized flame with secondary fuel injection was investigated. The combustor pressure was controlled by suction at combustor exit. Pressure index ($P{\ast}=P_{abs}/P_{atm}$), where $P_{abs}$ and $P_{atm}$ indicated the absolute pressure and atmosphere pressure, was controlled in the range of $0.7{\sim}1.3$ for each equivalence ratio conditions. The flammable limits of swirl flames were largely influenced by changing combustor pressure and they showed different tendency compared with laminar flames. Emission index showed maximum value near atmospheric condition and decreased with decreasing pressure index for overall equivalence ratio conditions. R.m.s of pressure fluctuations also showed similar tendency with nitric oxide emission. By injecting secondary fuel into flame zone, the flammable limits were extended significantly. Emission index of nitric oxide and r.m.s. of pressure fluctuations were also controlled by injecting secondary fuel. The swirl flames were somewhat lifted by secondary fuel with high momentum, hence low nitric oxide emission. This NOx reduction technology is applicable to industrial furnaces and air conditioning system by adopting secondary fuel injection.

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NOx Reduction Characteristics of Ship Power Generator Engine SCR Catalysts according to Cell Density Difference (선박 발전기관용 SCR 촉매의 셀 밀도차에 따른 NOx 저감 특성)

  • Kyung-Sun Lim;Myeong-Hwan Im
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.7
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    • pp.1209-1215
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    • 2022
  • The selective catalytic reduction (SCR) is known as a very efficient method to reduce nitrogen oxides (NOx) and the catalyst performs reduction from nitrogen oxides (NOx) to nitrogen (N2) and water vapor (H2O). The catalyst, which is one of the factors determining the performance of the nitrogen oxide (NOx) ruduction method, is known to increase catalyst efficiency as cell density increases. In this study, the reduction characteristics of nitrogen oxides (NOx) under various engine loads investigated. A 100CPSI(60Cell) catalysts was studied through a laboratory-sized simulating device that can simulate the exhaust gas conditions from the power generation engine installed in the training ship SEGERO. The effect of 100CPSI(60Cell) cell density was compared with that of 25.8CPSI(30Cell) cell density that already had NOx reduction data from the SCR manufacturing. The experimental catalysts were honeycomb type and its compositions and materials of V2O5-WO3-TiO2 were retained, with only change on cell density. As a result, the NOx concentration reduction rate from 100CPSI(60Cell) catalyst was 88.5%, and IMO specific NOx emission was 0.99g/kwh satisfying the IMO Tier III NOx emission requirement. The NOx concentration reduction rate from 25.8CPSI(30Cell) was 78%, and IMO specific NOx emission was 2.00g/kwh. Comparing the NOx concentration reduction rate and emission of 100CPSI(60Cell) and 25.8CPSI(30Cell) catalysts, notably, the NOx concentration reduction rate of 100CPSI(60Cell) catalyst was 10.5% higher and its IMO specific NOx emission was about twice less than that of the 25.8CPSI(30Cell) catalysts. Therefore, an efficient NOx reduction effect can be expected by increasing the cell density of catalysts. In other words, effects to production cost reduction, efficient arrangement of engine room and cargo space can be estimated from the reduced catalyst volume.

Removal Effect of Nitrogen Oxide Using Magnetic Field (자계를 이용한 질소산화물의 제거 효과)

  • Lee, H.S.;Park, J.Y.;Park, S.H.;Lee, D.H.
    • Proceedings of the KIEE Conference
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    • 2002.06a
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    • pp.64-66
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    • 2002
  • This study is to develop electromagnetic plasma reactors for indoor air purification, Removal effect of nitrogen oxide using magnetic field are investigated. And AC or DC high voltage is applied for corona discharge, flow rates are 150${\sim}$1500${\ell}$/min and NO initial concentration is about 10 ppm. In the results, NOx removal rate by AC power is about 10 % higher than that by DC power under the experimental condition of 700 ${\ell}$/min, 5 magnets. When magnet is applied to the reactor, NOx removal rate increased.

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