NEWS & INFORMATION FOR CHEMICAL ENGINEERS, Vol. 30, No. 3, 2012…377
Removal of phosphate from aqueous solutions by iron nano-particle resin Lewatit (FO36)
Lida Rafati, Ramin Nabizadeh, Amir Hossein Mahvi†, and Mohamad Hadi Dehghani
Department of Environmental Health Engineering, School of Public Health and Institute for Environmental Research, Tehran University of Medical Sciences, P. O. Box 14155-6446, Tehran, Iran
(Received 8 September 2010 • accepted 13 August 2011)
Lewatit FO36 resin was covered with Fe (III) nano-particles, and it was used as a new way to eliminate phosphate. Column experiments were carried out in 11 stages in fixed bed columns with constant flow rate of 9 ml/min and the empty bed contact time (EBCT) of 2.1min. The adsorption capacity was calculated for different concentration of phosphate solutions.
After resin was regenerated by using NaOH and NaCl solutions, the adsorption capacity of resin was computed for 6mg/L of phosphate, typically. The adsorption capacity of resin was checked again a typical concentration of phosphate. The adsorption capacity measurements of regenerated resin show that the concentration of phosphate reached to 1.6mg/g after an 8.5% decrease when the initial concentration of phosphate is 6 mg/L. Competition of anions with phosphate was analyzed using chloride, sulfate, bicarbonate and a combination of these anions. Finally the effect of resin in phosphate removal was studied for a typical real sample, and the data was analyzed using statistical software (SPSS 13). The statistical results indicated that Cl-, SO43-
, HCO3
-and combined competing anions did not have a strong influence on the phosphate removal efficiency.
Low-temperature growth of highly conductive and transparent aluminum-doped ZnO film by ultrasonic-mist deposition
Seung-Woo Seo*, Sung Ho Won**, Heeyeop Chae*, and Sung Min Cho*,***,†
*School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Korea
**Department of Biochemical Engineering, Dongyang Mirae University, Seoul 152-714, Korea
***Advanced Materials and Process Research Center for IT, Sungkyunkwan University, Suwon 440-746, Korea (Received 7 May 2011 • accepted 9 August 2011)
Aluminum-doped ZnO (AZO) thin films are grown by ultrasonic-mist deposition method for the transparent conducting oxides (TCO) applications at low temperatures. The AZO films can be grown at a temperature as low as 200 ℃ with zinc acetylacetonate and aluminum acetylacetonate sources. The lowest resistivity of grown AZO films is 1.0×10-3Ω ·cm and the lowest sheet resistance of 1 mm thick films is 10 Ω/ , which is close to that of commercial indium tin oxide (ITO) or Asahi U-type SnO2: F glass. The highest carrier concentration and mobility are 5.6×1020cm-3and 15 cm2/V·sec, respectively. Optical transmittance of the AZO films is found over 75% for all growth conditions. We believe that the properties of grown AZO films in this study are the best among all reported previously elsewhere by solution processes.
Development of non-precious oxygen reduction reaction catalyst for polymer electrolyte membrane fuel cells based on substituted cobalt porphyrins
Singaram Vengatesan, Eunae Cho†, and In-Hwan Oh
Center for Fuel Cell Research, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, P. O. Box 131, Cheongryang, Seongbuk-gu, Seoul 136-791, Korea
(Received 28 June 2011 • accepted 27 August 2011)
Active and stable cobalt-based non-precious metal catalysts for the oxygen reduction reaction (ORR) in PEM fuel cells were developed through high-temperature pyrolysis of metal-porphyrins supported on carbon. The roles of substituted porphyrins, carbon support, and catalyst loading on ORR activity were studied using rotating disc electrode (RDE) measurements. It was observed that the carbon support plays a major role in improving the catalytic activity. The results showed that among the supported catalysts, the homemade mesocarbon-supported cobalt-porphyrin catalyst with 20 wt%
loading displayed higher ORR activity; the cell performance showed maximum current density of 1.1 A cm–2at 0.13 V in H2/O2fuel cells.
Editor’s Choice
Optical application of poly(HEMA-co-MMA) containing silver nanoparticles
and N,N-dimethylacrylamide
A-Young Sung†and Tae-Hun Kim
Department of Ophthalmic Optics, Daebul University, Jeonnam 526-702, Korea (Received 12 August 2011 • accepted 5 September 2011)
High functional ophthalmic lens materials, poly(HEMA-co-MMA)s, were prepared by the copolymerization of HEMA, MMA, NVP, EDGMA, and N,N-dimethylacrylamide in the presence of silver nanoparticles. Silver nanoparticles have antimicrobial properties and a hydrophilic monomer N,N-dimethylacrylamide has excellent biocompatibility and oxygen transmissibility. The water content was in the range of 36.63-44.45%, indicating the characteristics of general water-content contact lenses, and the refractive index was measured to be in the range of 1.423-1.435. Meanwhile, the oxygen transmissibility ranged from 10.63×10Å|11 to 18.85×10–11(cm2/sec)(mlO2/ml×mmHg) increasing with increasing the addition ratio of N,N-dimethylacrylamide. The polymeric materials satisfied the basic characteristics required for ophthalmic contact lenses. The polymers can be used to fabricate antimicrobial hydrogel contact lenses with high oxygen transmissibility.
이온 오염에 의한 고분자전해질 연료전지의 성능저하
송
송진진훈훈··우우명명우우··김김세세훈훈*··안안병병기기*··임임태태원원*··박박권권필필†† 순천대학교 화학공학과, 540-742 전남 순천시 매곡동 315
*현대자동차 환경기술연구소, 446-912 경기도 용인시 기흥구 마북동 104 (2011년 7월 6일 접수, 2011년 7월 30일 채택)
고분자전해질연료전지(PEMFC)에서 음극 공기에 의한 이온오염은 막전극 합체(MEA)의 성능을 심각하게 열화시킨다.
본 연구에서는 산업단지, 길가, 해변의 공기 중 이온농도를 측정하였다. 이들 지역에서 Na+, K+, Ca2+와 Fe3+이온 농도가 비 교적 높았다. 가습수로부터 이들 이온이 cathode에 유입되어 MEA 성능에 미치는 영향에 대해 연구하였다. 수돗물을 가습 수로 사용해 170시간 운전한 후 MEA 성능이 초기의 11%로 감소하였다. 이들 오염 이온들이 수소이온보다 전해질 막의 슬 폰산기와 친화력이 더 강해 전해질 막에 쉽게 이온 교환된 결과다. MEA 중에서 전극/막 계면에서 이온 오염이 MEA 성능 저하에 미치는 영향이 제일 컸다.
국내 초임계 석탄화력발전소에 연소 후
CO
2포집공정 설치 시 성능 및 경제성 평가이
이지지현현··곽곽노노상상··이이인인영영··장장경경룡룡··심심재재구구†† 한전전력연구원, 사업화기술개발실, 305-760 대전시 유성구 문지로 65
(2012년 1월 21일 접수, 2012년 2월 16일 채택)
국내 초임계 석탄화력발전소에 연소 후 CO2포집공정을 설치하였을 경우에 예상되는 발전단가와 CO2저감비용(Costof CO2avoided)을 산출하였다. 본 연구에서 고려된 연소 후 CO2포집기술은 이미 상업적으로 적용이 가능하고, 기존의 화력 발전에 적용이 용이한 아민 화합물을 이용한 화학 흡수법을 기초로 하였으며, 경제성 평가를 위해 연간 발생하는 비용 및 발 전량을 연간 균등화(Levelized)하여 발전단가를 산정하는 수명기간 중 발전단가 분석(LCCA: Life CycleCost Analysis) 방식을 활용하여 분석하였다. 경제성 평가에서 가장 중요한 항목 중 하나인 설비 투자비(건설비 등) 및 운영비 산출을 위해, 기존의 CO2포집 설비가 없는 기준 석탄화력발전소의 건설비는 IEA(국제에너지기구)에서 제시하는 국내 초임계석탄화력 발전소(순출력 767 MW급)의 데이터를 활용하였으며, 석탄화력발전소에 CO2포집설비가 추가된 경우에도 IEA에서 제시 하는 기준 석탄화력발전소와 CO2포집설비 설치 후의 OECD 평균 순공사비(Overnight cost) 증감분을 참조하여 계산하였 다. 상기 데이터를 이용하여 기존 석탄화력발전소 및 CO2포집 설비 설치 후의 발전 단가 및 CO2포집비용을 분석한 결과 CO2포집설비 설치 후 발전 효율은 기존 초임계 석탄화력발전소의 발전효율 41%에서 31.6%로 약 9.4%가 저하되었으며, 발전단가는 기존의 45.5 USD/MWh에서 73.9 USD/MWh로 약 62%가 증가되었고 CO2포집비용은 41.3 USD/tCO2로 산 출되었다.
378…NICE, 제30권 제3호, 2012
