• 제목, 요약, 키워드: selective removal

검색결과 286건 처리시간 0.038초

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

  • 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.

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

  • 송화선;구일섭;김인식
    • 품질경영학회지
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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

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

  • 박해경;김경림;최병선;이인철;최익수
    • 한국대기환경학회지
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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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PVC에 의한 일메나이트 광석 중 선택염화에 의한 Fe의 제거 (Removal of Iron from Ilmenite through Selective Chlorination Using PVC)

  • 손용익;링리에;손호상
    • 자원리싸이클링
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    • v.25 no.3
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    • pp.74-81
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    • 2016
  • 고정층 반응기에서 PVC를 염화제로 사용하여 일메나이트 광석 중 철을 선택적으로 제거하기 위한 염화반응에 대하여 조사하였다. 철의 제거율에 미치는 PVC첨가량과 반응온도의 영향에 대하여 조사하였다. 철의 제거율은 PVC 첨가량과 온도가 증가할수록 상승하였다. PVC에서 생성된 HCl가스와 반응한 후의 시편 표면에는 많은 기공이 관찰되었다. 이러한 기공에 의해서 일메나이트 입자의 중앙부분에 있는 철과 반응할 수 있었던 것으로 생각된다. 선택적 염화반응을 속도론적 모델에 의해 조사한 결과 입자 계면에서의 화학반응에 의해서 율속되는 것으로 생각된다. PVC를 사용한 일메나이트의 선택적 염화반응에서 활성화 에너지는 20.47 kJ/mol로 계산되었다.

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

  • 정경열;김재윤;오상훈;박정일;류길수
    • 한국마린엔지니어링학회:학술대회논문집
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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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복식유물 오구의 선택적 제거를 위한 세척방법 및 장기간 보관에 따른 오구 변화 -혈액오구를 중심으로- (Cleaning Method for Selective Removal of Stains from Historic Textiles and Stains Change by Long Period Storage -Focused on Blood Soil-)

  • 노의경;유효선;채정민
    • 한국의류학회지
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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.

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

  • 박진원;이문수;이존태;황건중;황택성
    • 한국연초학회지
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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.

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

  • 최재환;김현기
    • Korean Chemical Engineering Research
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    • v.53 no.3
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    • pp.269-275
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    • 2015
  • 질산이온 선택성 탄소전극(NSCE, nitrate-selective carbon electrode)에서 전원공급 방식에 따른 이온들의 흡착특성을 분석하였다. 질산이온에 선택성이 높은 음이온수지 분말을 탄소전극에 코팅하여 NSCE를 제조하였다. 질산과 염소이온의 혼합용액에 대해 정전압(CV, constant voltage)과 정전류(CC, constant current) 모드에서 축전식 탈염(CDI, capacitive deionization)을 실시하였다. 이온들의 총 흡착량은 CV 모드로 운전한 경우 CC 모드에 비해 약 15% 증가하였다. 혼합용액에서 질산이온의 비율은 26%로 낮았지만 흡착된 질산이온의 몰비율은 최대 58%로 나타나 NSCE가 질산이온을 선택적으로 제거하는데 효과적임을 확인하였다. CC 모드에서 운전한 경우 흡착된 질산이온의 몰비율은 흡착기간 동안 55~58%로 일정하였다. 반면 CV 모드에서는 30~58%로 큰 차이를 보였다. 이를 통해 셀에 공급되는 전류가 질산이온의 선택적 제거율을 결정하는데 중요한 인자임을 알 수 있었다.