• 제목/요약/키워드: Environmental catalysis

검색결과 96건 처리시간 0.031초

SCR 시스템의 효율적인 운영을 위한 Soot Blowing 방법에 대한 해석적 연구 (Computational Study on the Soot Blowing Method for Enhancing the Performance of the SCR System)

  • 서문혁;장혁상
    • 한국입자에어로졸학회지
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    • 제8권3호
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    • pp.99-110
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    • 2012
  • In the SCR (selective catalytic reduction) system which is used for controlling the NOx emission from the Diesel engines, the soot deposited on the catalysis causes degradation of the system performance. Numerical study was done to evaluate the performance of soot blower which is proposed as a method for removing the soot on the catalysis. The spray conditions and the effect of the compressed air from the AIG (air inlet gun) were analyzed numerically to evaluate the overall effective method of the soot blowing. The characteristics of the final velocity distribution and velocity waves across the inlet section of the catalysis were evaluated with respect to the geometries of the AIG outlets and pressure conditions. An experimental model was used to validate the results of the numerical calculation that is used for finding the effective removal blowing momentum transfer quantities of soot the inlet section of the catalysis, and it is proposed that the required minimum blowing momentum transfer quantities are over than 0.499 $kg/m{\bullet}t_{eff}$ in the current study.

악취물질인 유기산 제거를 위한 DBD 플라즈마 촉매 복합공정의 적용 (Application of DBD Plasma Catalysis Hybrid Process to remove Organic Acids in Odors)

  • 홍은기;서정민;최금찬
    • 한국환경과학회지
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    • 제23권9호
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    • pp.1627-1634
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    • 2014
  • Odor control technology include absorption, adsorption, incineration and biological treatments. But, most of processes have some problems such as secondary organic acids discharge at the final odor treatment facility. In order to solve the problems for effective treatment of organic acids in odor, it is necessary to develop a new type advanced odor control technology. Some of the technology are plasma only process and plasma hybrid process as key process of the advanced technology. In this study, odor removal performance was compared DBD(Dielectric Barrier Discharge)plasma process with PCHP(plasma catalysis hybrid process) by gaseous ammonia, formaldehyde and acetic acid. Plasma only process by acetic acid obtained higher treatment efficiency above 90%, and PCHP reached its efficiency up to 96%. Acetic acid is relatively easy pollutant to control its concentration other than sulfur and nitrogen odor compounds, because it has tendency to react with water quickly. To test of the performance of DBD plasma process by applied voltage, the tests were conducted to find the dependence of experimental conditions of the applied voltage at 13 kV and 15 kV separately. With an applied voltage at 15 kV, the treatment efficiency was achieved to more higher than 13 kV from 83% to 99% on ammonia, formaldehyde and acetic acid. It seems to the odor treatment efficiency depends on the applied voltage, temperature, humidity and chemical bonding of odors.

Electrochemical degradation of Orange G in K2SO4 and KCl medium

  • Hamous, Hanene;Khenifi, Aicha;Bouberka, Zohra;Derriche, Zoubir
    • Environmental Engineering Research
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    • 제25권4호
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    • pp.571-578
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    • 2020
  • In this work, a detailed study on the electrochemical degradation of an azo dye, Orange G is performed using a platinum electrode. Indeed, the influence of the dye concentration (50-150 mg/L), the pH of the medium and the density of the electric current is studied on the rate of discoloration, the rate of mineralization, the efficiency of the electric current and the energy consumption. The UV-visible spectra of OG plotted against the degradation time show the decrease of the intensity of the characteristic dye peaks. In an environment rich in chlorides, all peaks disappear after 15 min of degradation. However, the peaks at wavelengths of 200 and 290 nm appeared after one hour of treatment. In K2SO4, the eliminated percentages are respectively 46, 54 and 61% for wavelengths of 245, 330 and 480 nm. This suggests that the degradation mechanisms in K2SO4 and KCl environments are not the same. In the middle rich in chlorides, the eliminated percentage of OG did not seem to be affected by the concentrations increase. These results confirm the hypothesis that electrochemical oxidation process is very favorable for concentrated pollutants discharge.

금속착물로부터 HCN 생성에 대한 촉매반응연구 (Catalysis Reaction for the Formation of Hydrogen Cyanide from Metal Complex)

  • 박흥재
    • 한국환경과학회지
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    • 제3권4호
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    • pp.439-443
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    • 1994
  • In aqueous acid solution ${[Cr(CN)_6]}^{3-}$ aquates via a series of stepwise stereospecific reactions to give ${[Cr{(H_2O)}_6]}^{3+}$as the final product.Some of the intermediate cyanoaquo complexes in the sequence have been isolated.These complexes aquate by both acid independent and acid denpendent pathways, the latter involving protonation of the cyano ligands followed by aquation of the singly protonated species. The kinetic data for the aquation of {[CrCN{(H_2O)}_5]}^{2+}$ are consistent with the transition state structure ${[{(H_2O)}_4Cr(CN)-OH-Cr{(H_2O)}_5]}^{3+}$. Addition of $Cr^{2+}$ to solutions of cyanocobalt(III) complexes produces the metastable intermediate${[CrNC{(H_2O)}_5]}^{2+}$ This isomerizes to in a $Cr^{2+}$-catalyzed reaction which occurs by a ligand-bridged electron-change mechnism. From acid catalysis on these aquation reactions, it product HCN. Especially, $HSO_3$-ions do the role of catalyst in the formation of HCN from $CrCN^{3-}$

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브롬촉매와 암모니아의 오존산화 반응시 pH의 영향에 관한 연구 (The Effect on the pH in ozonation of ammonia with Br catalysis)

  • 박문숙;안재동;노봉오
    • 환경위생공학
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    • 제19권1호
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    • pp.1-7
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    • 2004
  • This study was conducted to supply basic informations on development of water treatment process for the ozonation of ammonia depend on pH variation with or without bromide catalysis. The results were as follows: The oxidation rate of ammonia increased depend on pH increase at ozone/bromide process. It was found that overall kinetics was zero order with respect to reaction time and reaction velocity constant of zero order increased depend on pH increase from 4.9 to 9.5 and the equation of linearization was $k_{o}$ = 0.00565 ${\times}$ [pH] + 0.0069 at ozone/bromide process. The denitrification reaction of ammonia was superior as the pH increase in the presence of bromide.

하수종말처리장의 인 처리시설에 티탄염 응집제 적용 및 슬러지 재활용 (Application of Ti-salt Coagulant and Sludge Recycling for Phosphorus Removal in Biologically Treated Sewage Effluent)

  • 김종범;박희주;이기원;조아라;김명완;이영준;박세민;이광영;손호경;김종호
    • Korean Chemical Engineering Research
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    • 제51권2호
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    • pp.257-262
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    • 2013
  • 부영양화 방지를 위하여 규제되는 총인(Total-phosphorous, T-P) 농도가 0.2~2 mg/L 이하로 변경됨에 따라, 응집 처리 과정에서 인의 제거를 시도하게 되었다. 따라서 본 연구는 실제 하수종말처리장의 생물학적 처리수를 시료로 하여 티탄염 농도, pH 등의 인자가 인 제거에 미치는 특성에 대하여 검토하였다. 또한 실제 현장에서 가장 많이 사용되는 침강식 침전조와 가압부상식 침전조에 티탄염을 적용하여 인 제거 효율 및 슬러지 활용 가능성을 조사하였다. 응집제로 티탄염을 사용하는 경우 인 제거효율이 기존에 사용하는 황산 알루미늄($Al_2(SO_4)_3$, Alum)과 유사하였다. 하향 침강방식의 침전조와 가압부상방식의 침전조 모두 기준치 이하로 모두 현장 적용이 가능하였다. 생성된 산화티탄의 성분은 원수에 포함된 무기물과 투입된 티탄염 성분으로 구성되었다. 티탄염 응집 후 생성된 슬러지를 소성하여 산화티탄을 제조하였다. 시판되고 있는 P-25 제품과 유사한 광촉매 활성을 가지고 있어 슬러지에서 생성된 산화티탄도 기존에 사용하는 제품시장에 대체 사용이 가능할 것으로 판단된다.

물 속 유기물의 고도 특성 분석 (Advanced Characterization Techniques of Organic Matter in Aqueous Solutions)

  • 손호경;;;김종범;김종호
    • 공업화학
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    • 제22권1호
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    • pp.1-14
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    • 2011
  • 물은 인간에게 가장 소중한 자원이지만 여러 유기물에 의해 오염되어 있다. 이러한 유기물은 인간과 환경에 큰 영향을 끼칠 수 있으므로 물 속 유기물의 특성 분석이 중요하다. 본 총설에서는 물 속 유기물의 자세한 분석 방법과 특성을 고찰하였다. 각 유기물의 물리적, 화학적, 생물학적면에 의거하여 전통적인 방법과 고도 특성 분석을 정리하였다.