Korean J. Chem. Eng., 29(10), 1285-1288 (2012) DOI: 10.1007/s11814-012-0074-4
One-step synthesis of mesoporous sulfated zirconia nanoparticles with anionic templateHongping Pu, Liuyi Zhang, Dongquan Du, Caiyun Han, Hongyin Li, Jiangyan Li, and Yongming Luo† †
Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650093, P. R. China
(Received 1 February 2012·accepted 22 May 2012)
Abstract - Mesoporous sulfated zirconia nanoparticles (MSZNP) with high surface area have been synthesized by using sodium dodecyl sulfate (C1
2
H
25
OSO
3
Na, SDS), both as a template and a sulfating agent via one-step route. On the basis of FT-IR, EDS together with NH
3
-TPD analyses, the SO
4
2- anion, originated from the hydrophilic head of SDS, can be incorporated into ZrO2 to form MSZNP with super-acidity. The phase transition of ZrO
2
from tetragonal to monoclinic phase was effectively inhibited by the presence of SO
4
2-, and the formation mechanism was illustrated in detail.
MSZNP(550) achieved far higher activity than CSZ(550) in transesterification of soybean oil with methanol due to the synergistic effect of strong acidity, high BET surface area and the formation of mesostructure.
Korean J. Chem. Eng., 29(10), 1321-1328 (2012) DOI: 10.1007/s11814-012-0025-0
Convective heat transfer of alumina nanofluids in laminar flows througha pipe at the thermal entrance regime
Seokwon Kim, Hansol Yoo, and Chongyoup Kim† †
Department of Chemical and Biological Engineering, Korea University, Anam-dong, Sungbuk-gu, Seoul 136-713, Korea (Received 10 January 2012 . accepted 29 February 2012)
Abstract - The convective heat transfer characteristics of aqueous alumina nanofluids were investigated experimentally under forced laminar tube flows. The particles had different shapes of cylinders, bricks and blades, and particle loading was between 0-5 volume%. The nanofluids were characterized rheologically, and the heat transfer system was validated by using water without particles. In calculating Nusselt and Peclet numbers to assess heat transfer enhancement of nanofluids, physical properties of water were used so as not to exaggerate the amount of heat transfer. It was found that heat transfer coefficients of nanofluids are almost the same or a little smaller than that of water. The heat transfer coefficient can be reduced by the lowering the thermal conductivity of the nanofluid under shearing conditions and particle depletion by the cluster migration from the wall to the tube center. The reduction in thermophysical properties also contributes to the reduction in heat transfer coefficient. It has been concluded that nanofluids from metal particles with appropriate stabilizing agents can satisfy the requirements to be a practically usable nanofluid.
Korean J. Chem. Eng., 29(11), 1483-1486 (2012) DOI: 10.1007/s11814-012-0115-z
Photocatalytic reduction of carbon dioxide using Co
3
O
4
nanoparticles under visible light irradiationJoseph Albert Mendoza, Hye Kyoung Kim, Hoey Kyung Park, and Kyun Young Park† †
Department of Chemical Engineering, Kongju National University, 275, Budae-dong, Seobuk-gu, Cheonan, Chungnam 331-717, Korea
(Received 15 January 2012·accepted 19 July 2012)
Abstract - Photocatalytic reduction of carbon dioxide under visible light irradiation was carried out with Co
3
O
4
powders suspended in water. A Pyrex glass batch reactor of 10mL in volume was used with a 21 W LED lamp of 510 to 620 nm in wave length as light source, and the reaction time was held at 4 h. The major products were formic acid and formaldehyde;
the production rates were 4.53 μ mol g-1h-1 and 0.62 μ mol g-1h-1 for formic acid and formaldehyde, respectively. Carbon monoxide and methane were detected in trace amounts. The occurrence of the photo-reduction with Co
3
O
4
is against the expectation from the valence band edge of Co
3
O
4
in the literature. Possible causes for the contradictory result are discussed.
Editor’s Choice
(2)
NEWS & INFORMATION FOR CHEMICAL ENGINEERS, Vol. 30, No. 6, 2012 … 791 Korean J. Chem. Eng., 29(11), 1500-1507 (2012)
DOI: 10.1007/s11814-012-0048-6
Energy efficiency improvement of dimethyl ether purification process by utilizing dividingwall columns
Le Quang Minh, Nguyen Van Duc Long, and Moonyong Lee† † School of Chemical Engineering, Yeungnam University, Gyeongsan 712-749, Korea
(Received 6 December 2011 . accepted 5 April 2012)
Abstract - The alternative fuel, dimethyl ether (DME), which can be synthesized from natural gas, coal or biomass syngas, has been traditionally used as a diesel substitute or additive. DME purification processes with a conventional distillation sequence consume a large amount of energy. We used dividing wall columns (DWCs) to improve the energy efficiency and reduce the capital cost of the DME purification process. Various possible DWC arrangements were explored to find the potential benefits derived from thermally coupled distillations. The results show that utilizing DWCs can significantly reduce both the energy consumption and investment cost of the DME purification process. The lower energy consumption also results in the reduction of the CO
2
emission.
Korean Chem. Eng. Res., Vol. 50, No. 5, October, 2012, pp. 759-765 http://dx.doi.org/10.9713/kcer.2012.50.5.759
1,3-프로판디올의 생물학적 생산을 위한 분리공정 홍
홍 연 연 기 기 † †
한국교통대학교 화공생물공학과 380-702 충북 충주시 대학로 50 (2012년 4월 3일 접수, 2012년 5월 10일 채택) 요
요약 약 - 바이오 디젤 생산량 증가에 따라 공정 중에 부산물로 발생하는 글리세린의 과잉공급 및 가격 하락이이 루어지고 있다. 이에 따라 글리세린에 기반한 다양한 화학제품생산과 관련된 연구가 활발히 진행되고 있으며 글리세린을 탄소원으로 한 1,3-프로판디올의 생물학적 생산은 그 중 하나이다. 1,3-프로판디올은 지금까지 화 학적인 방법을 통해 생산되어 왔으나 생물학적인 방법을 통해 생산될 경우 공정의 친환경성 및 경제성 확보와 더불어 1,3-프로판디올을 중합원료로 하는 PTT (Poly(trimethylene terephthalate))의 바이오폴리머로서의 활용을 가능하게 한다. 그럼에도 글리세린 유래 1,3-프로판디올의 생물학적 생산의 경제성에 있어 핵심은 경제적인 분 리공정의 수립에 있다. 본 총설에서는 1,3-프로판디올을 분리하기 위한 공정들에 대한 연구 동향을 소개하고 최 근 에너지 절감과 더불어 1,3-프로판디올 분리와 부산물 제거를 동시에 달성할 있는 공정으로 주목받고 있는 수 상이성분계 추출에 대한 연구개발 동향 및 전망을 제시하고자한다.
Korean Chem. Eng. Res., Vol. 50, No. 5, October, 2012, pp. 866-873 http://dx.doi.org/10.9713/kcer.2012.50.5.866
