• Title, Summary, Keyword: selective removal

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A Study on Characteristic of NO Reduction by High Level O2Gas in Selective Non-Catalystic Reaction (High Level O2배가스중 NO 저감에 대한 선택적비촉매환원 반응특성에 관한 연구)

  • 이강우;정종현;오광중
    • Journal of Environmental Science International
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    • v.11 no.6
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    • pp.577-582
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    • 2002
  • Selective catalytic reduction and selective non-catalytic reduction processes are mainly used to treat nitrogen oxidants generated from fossil-fuel combustion. Especially, the selective non-catalytic reduction process can be operated more economical and designed more simply than the selective catalytic reduction. For this reason, many researchers carried out to increase the removal efficiency of nitrogen oxidants in the condition of low oxygen concentration by using the selective non-catalytic reduction process. However, this study was flue gas contained high oxygen concentration of 20(v/v%) with ammonia as a reducing agent. Moreover, it carried out experiment with many factors that are reaction temperature, retention time, initial NO concentration, NSR(normalized stoichiometric ratio). It was determined optimal operating conditions to improve NO removal efficiency with SNCR process. The De-NOx efficiency was increased with NSR, initial NO concentration and retention time increasement. This study has NO removal efficiency over 80% in the high oxygen concentration as well as low oxygen concentration. The injection of reducing agent may be considered for SNCR process and facility operation in 850$\^{C}$ of optimal condition.

Study of Development of Selective Removal Adsorption Ion Exchange Resin Materials for Fabricated with Chemical-biological Cloth by QFD (QFD 기법을 이용한 특정 유해가스 노출제어 이온선택성 보호복 소재개발연구)

  • Song, Hwa Seon;Koo, Il Seob;Kim, In Sik
    • Journal of the Korean Society for Quality Management
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    • v.43 no.3
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    • pp.359-372
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    • 2015
  • Purpose: Through studying the expert's and non-experts panel responses to the questions regarding the attributes of chemical-biological protection cloth quality in terms of the levels of customer demand and technical factors has been studied. We are applied to a QFD matrix with find out the relationship between the selective removal efficiency of chemical-biological cloth and the guidelines of technical approach. Methods: We fabricated several composite of ion-exchange resins with selectively permeable performance designed to facilities water vapor transport and selective adsorption of the harmful gases. With these materials, we characterized on the selectively permeable performance to identify ion-exchange resin with chemical-biological protective cloth. Results: Results showed that ion exchange materials possessed performance with selectively efficiencies as NH3, SOx, NOx and HCl gas. The selective adsorption amount of ammonia and hydrogen gases were $90-80{\mu}g/g$ with TRILITE SCR-BH sulfonated ion exchange resin. The PP non-woven/ion exchange resin adsorbent materials possessed performance with water vapor permeability were 1,100-1,350 g/m2/day, it's was two times high value compare with activated carbon. With these materials, we characterized selectively removal efficiency to identify new ion-exchange material with chemical-biological protective capability. Conclusion: This study shows that a QFD aids in deciding with of the adsorption parameters to optimized with chemical-biological protection cloth manufacturing.

Selective nitrification and denitrification in fixed bed biofilm reactors

  • Yun, Ho-Jun;An, Seung-Ho;Kim, Dong-Jin
    • 한국생물공학회:학술대회논문집
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    • pp.278-281
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    • 2001
  • A fixed bed biofilm reactor filled with ceramic media were used to remove nitrogen by selective nitrification (ammonium to nitrite). The effects of experimental conditions (nitrogen load, dissolved oxygen, nitrite ratio, C/N ratio) on denitrification were investigated. The reactor showed more than 80% average T-N removal efficiencies at T-N loading in the range of $1.1{\sim}3.3$ kg $T-N/m^3{\cdot}d$ C/N at the C/N ratio of 1. T-N removal efficiencies increased as nitrite ratio.

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A Study of NOx Removal in Flue Gas by Selective Catalytic Reduction (선택적 촉매환원법에 의한 배기가스중 NOx 저감에 관한 연구)

  • 박해경;김경림;최병선;이인철;최익수
    • Journal of Korean Society for Atmospheric Environment
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    • v.4 no.2
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    • pp.38-46
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    • 1988
  • NOx is an important air pollution material which is generated when fossil fuels are burning, NOx removal in flue gas by selective catalytic reduction was studied over various catalysts in a fixed bed continuous flow reactor. The ranges of experimental conditions were at the temperatures between $200^\circ$C and $350^\circ$C, the $NH_3/NOx$ mole ratios between 0.8 and 1.4, oxygen concentrations between 1.5% and 3% and the space velocities between 5, 000 $hr^-1$ and 12, 500 $hr^-1$. The efficiency of NOx removal in the ranges of experimental conditions was highest at the temp. of 300$^\circ$C, oxygen concentration of 2.5-2.6% and $NH_3/NOx$ mole ratios of 1.0-1.2. The catalyst with high activity for NOx removal in flue gas was found to be $MoO_3-V_2O_5/TiO_2$.

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Removal of Iron from Ilmenite through Selective Chlorination Using PVC (PVC에 의한 일메나이트 광석 중 선택염화에 의한 Fe의 제거)

  • Son, Yongik;Ring, Rie;Sohn, Ho-Sang
    • Journal of the Korean Institute of Resources Recycling
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    • v.25 no.3
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    • pp.74-81
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    • 2016
  • Study on chlorination of ilmenite ore were carried out by using PVC(polyvinyl chloride) as the chlorinating agent in a static bed reactor for selective removal of iron. The effect of amount of PVC and reaction temperature were investigated. It was found that the removal ratio of iron increased with amount of PVC and temperature. After reaction with HCl gas generated from PVC, porous surface of the specimens were observed. As a result, HCl gas could react with iron in the central portion of ilmenite particle through these pores. Examination of data using kinetic model suggest that the selective chlorination rate is controlled by chemical reaction at the interface of particles. The activation energy for the selective chlorination of ilmenite using PVC was calculated as 20.47 kJ/mol.

A development of diesel engine De-NOx system using the selective catalytic reduction method (선택적 촉매 환원법을 이용한 디젤엔진의 De-NOx 시스템 개발에 관한 연구)

  • 정경열;김재윤;오상훈;박정일;류길수
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • pp.187-191
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    • 2001
  • In the paper, an approach to the development of the selective catalytic reduction process of NOx is presented. The reduction process can be efficiently controlled using a conventional combination of feed-forward and feed-back control structures. The aim of this paper is to test and verify an approach to the SCR process which is based on an industrial pilot plant of combustion and nitric oxide formation. The systems are based on measurements of a NOx removal ratio and the fuel flow rate, and NH$_3$slip which are usually available as a part of de-NOx control system.

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Cleaning Method for Selective Removal of Stains from Historic Textiles and Stains Change by Long Period Storage -Focused on Blood Soil- (복식유물 오구의 선택적 제거를 위한 세척방법 및 장기간 보관에 따른 오구 변화 -혈액오구를 중심으로-)

  • Roh, Eui Kyung;Ryu, Hyo-Seon;Chae, Jeongmin
    • Journal of the Korean Society of Clothing and Textiles
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    • v.41 no.2
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    • pp.341-351
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    • 2017
  • This study evaluates a cleaning method to maintain and minimize the change of blood soil for the selective removal of stains from textiles with historical significance and special meaning. Cotton and silk fabrics were soiled with blood, aged artificially and then washed by wet cleaning or dry cleaning (water, nonionic surfactant; Triton, natural surfactant; saponin, organic solvent; n-Decane). The washed fabrics were stored at room temperature for four years. The change of the blood soil was evaluated by SEM, weight, thickness, and color differences. Subsequently, the shape and the amount of blood adsorption on the fabric varied depending on fiber type and fabric structure characteristics; in addition, long term storage affected changes to blood soil. It was difficult to remove artificially aged blood soil from fabrics by wet or dry cleaning. However, the changes of the blood soil by these cleanings can be explained by the changes on SEM, weight, thickness and fabric color. The changes (especially color) showed over time. Wet cleaning showed that the changes of those factors were slightly lower than those by dry cleaning.

Selective Adsorption Properties of Carbonyl Compounds in Cigarette Mainstream Smoke by Hydrazine Impregnated Adsorbent (Hydrazine 첨착 흡착제에 의한 담배 주류연 중 카보닐 화합물의 선택 흡착 특성)

  • Park Jin-Won;Rhee Moon-Soo;Lee John-Tae;Hwang Keon-Joong;Hwang Taek-Sung
    • Journal of the Korean Society of Tobacco Science
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    • v.27 no.2
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    • pp.178-188
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    • 2005
  • To use the filter materials for selective removal of carbonyl compounds in cigarette mainstream smoke, hydrazine such as 2,4-dinitrophenylhydrazine and dansylhydraznie impregnated adsorbents were prepared with perchloric acid or phosphoric acid as a accelerator in hydrazone formation reaction. The change of morphology of adsorbents in various of impregnator were investigated by SEM. Impregnation amount caused by reaction time, acid type and impregnation reagent, and the adsorption properties of carbonyl compounds in cigarette mainstream smoke were investigated. Amounts of impregnation was increased as increasing reaction time. The removal amount for vapor phase carbonyl compounds by 2,4-DNPH impregnated adsorbent was higher than that of dansylhydrazine impregnated adsorbent. The selectivity of 2,4-DNPH impregnated polyacrylic type adsorbent was superior to those of other adsorbents. This results indicated that the 2,4-DNPH impregnated polyacrylic adsorbent was applicable to cigarette filter material because of its fast reactivity and porosity.

Comparison of Selective Removal of Nitrate Ion in Constant Voltage and Constant Current Operation in Capacitive Deionization (축전식 탈염에서 정전압과 정전류 운전에 따른 질산 이온의 선택적 제거율 비교)

  • Choi, Jae-Hwan;Kim, Hyun-Ki
    • Korean Chemical Engineering Research
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    • v.53 no.3
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    • pp.269-275
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    • 2015
  • The adsorption characteristics of ions were evaluated for the nitrate-selective carbon electrode (NSCE) in accordance with power supply methods. The NSCE was fabricated by coating the surface of a carbon electrode with anion-exchange resin powders with high selectivity for the nitrate ion. Capacitive deionization (CDI) experiments were performed on a mixed solution of nitrate and chloride ion in constant voltage (CV) and constant current (CC) modes. The number of total adsorbed ions in CV mode was 15% greater than that in CC mode. The mole fraction of adsorbed nitrate ion showed the maximum 58%, though the mole fraction was 26% in the mixed solution. This indicates that the fabricated NSCE is highly effective for the selective adsorption of nitrate ions. The mole fraction of adsorbed nitrate was nearly constant value of 55-58% during the adsorption period in CC mode. In the case of CV mode, however, the values increased from the initial 30% to 58% at the end of adsorption. We confirmed that the current supplied to cell is important factor to determine the selective removal of nitrate.