• Title, Summary, Keyword: selective removal

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Development of Oil-water Separator for the Effective Application of Highly Selective Membranes (고선택성 유수분리막 적용성 향상을 위한 유수분리장치 성능 개선 연구)

  • Choi, Kwang-Soon;Lee, Donghun;Uhm, Sunghyun
    • Applied Chemistry for Engineering
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    • v.30 no.1
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    • pp.39-42
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    • 2019
  • We report on the design of oil-water separators and the selection of materials for the effective application of highly selective membranes fabricated by commercial PET (polyester) fabrics. The waterproof ability of PET fabrics was optimized to improve the separation selectivity. The density of individual PET fabrics should be over $60g/m^2$, and the multi-layered structure is more favorable for the waterproof ability together with maintaining the removal efficiency. For the continuous adsorption and removal process, the rotating perforated cylinder was selected, and covered with membranes. Furthermore, more improved and stable removal efficiency was obtained by installing floating baffles which forces the oil content to move toward membranes.

Preparation of Hydrazine Impregnated Adsorbents and Selective Adsorption Properties for Carbonyl Compounds in Cigarette Mainstream Smoke (Hydrazine 첨착 흡착제의 제조 및 담배 주류연 중 카보닐 화합물의 선택 흡착 특성)

  • Lee, John-Tae;Park, Jin-Won;Lee, Jeong-Min;Rhee, Moon-Soo;Hwang, Keon-Joong;Hwang, Taek-Sung
    • Polymer Korea
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    • v.30 no.3
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    • pp.210-216
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    • 2006
  • To use the filter materials for selective removal of carbonyl compounds in cigarette mainstream smoke, hydrazine such as 2,4-dinitrophenylhydrazine (2,4-DNPH) and dansylhydrazine (DAH) impregnated adsorbents were prepared with perchloric acid or phosphoric acid as an accelerator in hydrazone formation reaction. Changes of molecular structure and morphology of adsorbents in various of impregnator were investigated by FTIR/ATR and SEM. Impregnation amount caused by reaction time, acid type and impregnation reagent, and the adsorption properties of carbonyl compounds in cigarette mainstream smoke were studied. Amounts of impregnation increased with 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 result indicates that the 2,4-DNPH impregnated polyacrylic adsorbent is applicable to cigarette filter material because of its fast reactivity and porosity.

Reduced graphene oxide supported V2O5-WO3-TiO2 catalysts for selective catalytic reduction of NOx

  • Lee, Minwoo;Ye, Bora;Jeong, Bora;Chun, Hye-yeon;Lee, Duck Hyun;Park, Sam-sik;Lee, Heesoo;Kim, Hong-Dae
    • The Korean Journal of Chemical Engineering
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    • v.35 no.10
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    • pp.1988-1993
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    • 2018
  • We present a reduced-graphene-oxide (rGO)-supported $V_2O_5-WO_3-TiO_2$ (VWTi) catalysts for the efficient selective catalytic reduction of NOx. The rGO support provides well-dispersed functional sites for the nucleation of nanoparticles, allowing the formation of VWTi catalysts with high specific surface areas. The dispersion of the nano-particles, as observed by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS), confirmed the uniform dispersion of the particles on the rGO surface. Detailed Fourier-transform infrared (FT-IR) and $NH_3$ temperature-programmed desorption ($NH_3-TPD$) analyses indicated that the high density of acidic sites provided by the rGO is key to the observed enhancement of NOx removal efficiency, and the rGO-supported catalysts exhibit improved NOx removal efficiencies with smaller amounts of $V_2O_5$ and $WO_3$ compared with the commercially available $V_2O_5-WO_3-TiO_2$ catalysts.

Numerical Study of SNCR System for the NOx removal in a Municipal Soild Waste Incineratior (NOx 저감을 위한 SNCR 시스템의 전산해석연구)

  • 나혜령;박병수;주지선;서정대;김현진
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • pp.229-232
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    • 2000
  • 산업 현장에서 연소 과정중 발생되는 NOx를 제거하기 위한 방법으로 현재 연구 및 상업 화 대상에서 가장 널리 사용되고 있는 것이 SCR(Selective Catalytic Reduction)과 SNCR((Selective non-catalytic reduction)이다. 그러나, SCR의 경우 높은 장치비와 유지비 가 소요되어, 최근에는 로 내에 요소용액을 직접 분사하여 NOx를 질소와 수증기로 환원시켜 제거하는 방법인 SNCR에 대한 연구가 활발히 진행되고 있는 추세이다.(중략)

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A Circulating Fluidized Bed Scrubbing Technology for Dry Removal of the SOx and NOx of Coal Combustion Gases (석탄연소가스내의 SOx/NOx 동시처리를 위한 순환유동식 건식세정기술)

  • 이상권;조경민
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • pp.69-74
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    • 1999
  • 각종 산업체의 공정에서 혹은 석탄 혹은 석유를 사용하는 화력발전설비에서 다량 발생되는 질소산화물(NOx), 황산화물(SOx)의 배출규제가 점점 강화되어 감에 따라 배출량 절감이 절실히 요구된다. 기존의 배기가스 정화장치는 처리대상에 따라 다양한 방법들이 사용되는데 황산화물의 경우 습식, 반건식, 건식세정법에 의해, 질소산화물은 선택적 촉매환원법(Selective Catalytic Reduction)과 선택적 무촉매환원법(Selective Non Catalytic Reduction)이 널리 이용되고 있다.(중략)

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Selective Adsorption of Uranium Ionsin High Concentration of Chemical Salts

  • Jung, Chong-Hun;Won, Hui-Jun;Kim, Gye-Nam;Park, Wangkyu;Wonzin Oh
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • pp.119-120
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    • 2004
  • A study on the selective adsorption of uranium(VI) from a high concentration of chemical salts has tern peformed to investigate the uranium removal mechanisms and the application conditions of the electrosorption technique using the activated carbon fiber(ACF) as a good conductive electrosorption adsorbent. Electrosorption test were carried out using an electrochemical cell.(omitted)

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Removal of Cd(II) from water using carbon, boron nitride and silicon carbide nanotubes

  • Azamat, Jafar;Hazizadeh, Behzad
    • Membrane Water Treatment
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    • v.9 no.1
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    • pp.63-68
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    • 2018
  • Molecular dynamics simulations were used to study the removal of Cd(II) as a heavy metal from wastewater using armchair carbon nanotube, boron nitride nanotube and silicon carbide nanotubes under applied electric field. The system contains an aqueous solution of $CdCl_2$ as a heavy metal and a (7,7) nanotube as a nanostructured membrane, embedded in a silicon nitride membrane. An external electric field was applied to the considered system for the removal of $Cd^{2+}$ through nanotubes. The simulation results show that in the same conditions, considered armchair nanotubes were capable to remove $Cd^{2+}$ from wastewater with different ratios. Our results reveal that the removal of heavy metals ions through armchair carbon, boron nitride and silicon carbide nanotubes was attributed to the applied electric field. The selective removal phenomenon is explained with the calculation of potential of mean force. Therefore, the investigated systems can be recommended as a model for the water treatment.

Development of solid absorbents for the removal of NOx (NOx 제거용 고체흡수제 개발)

  • Sahn, Jong-Rack
    • Proceedings of the KIEE Conference
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    • pp.709-712
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    • 1997
  • Selective removal of NOx by binary oxide systems of Ba-Cu and Mn-Zr was investigated. These mixed oxides were effective in removing NOx at $400^{\circ}C$ by absorption in or on the solid as nitrate. The reaction was investigated by oxidation of NO which was promoted in the presence of $O_2$ on Mn or Cu sites. Then, the oxidized species were stored in the solid as nitrate ions on Ba or Zr sites.

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Overlook of carbonaceous adsorbents and processing methods for elemental mercury removal

  • Bae, Kyong-Min;Kim, Byung-Joo;Park, Soo-Jin
    • Carbon letters
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    • v.15 no.4
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    • pp.238-246
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    • 2014
  • People have been concerned about mercury emissions for decades because of the extreme toxicity, persistence, and bioaccumulation of methyl Hg transformed from emitted Hg. This paper presents an overview of research related to mercury control technology and identifies areas requiring additional research and development. It critically reviews measured mercury emissions progress in the development of promising control technologies. This review provides useful information to scientists and engineers in this field.

Electroconvective Instability on Undulated Ion-selective Surface (파상형 이온 선택 표면상의 전기와류 불안정성)

  • Lee, Hyomin
    • Korean Chemical Engineering Research
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    • v.57 no.5
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    • pp.735-742
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    • 2019
  • In this work, the electrokinetic interactions between the undulated structure of an ion-selective membrane and electroconvective instability has been studied using numerical analysis. Using finite element method, electric field-ionic species transport-flow field were analyzed by fully-coupled manner. Through the numerical study, the Dukhin's mode as the mechanism of undulated surface for the electroconvective instability were proven. The Dukhin's mode which competes with Rubinstein's mode has roles of (i) decreasing transition voltage to overlimiting regime and (ii) non-linearly increasing of overlimiting current. Also, (iii) the mixing efficiency is enhanced by removal mechanism of high-frequency Fourier mode of the electroconvective instability. Conclusively, the undulated ion-selective surface would provide energy-efficient mechanism for ion-selective transport systems such as electrodialysis, electrochemical battery, etc.