Editor’s Choice

Editor’s Choice

592

Korean Journal of Chemical Engineering, Vol.34, No.9, 2355-2365, 2017

Soft-, shape changing materials toward physicochemically powered actuators Shim TS, Kim JM

Abstract - A shape changing material (SCM) morphs its shape upon external stimulus, and it offers a design of complex 3-dimensional structures remotely, which can be potentially useful for biomedical tools, drug delivery, and soft robotics. To actuate such structures through a physicochemical stimulus, stimuli-responsive materials have been studied over the past few decades. Several SCMs have been reported by combining novel stimuli responsive materials, micropatterning techniques and a unique actuation cue. In this review, we introduce a recent development in SCMs within the aspects of their materials and structures to describe how the materials can be designed and actuated on demand. Finally, we iscuss the future direction and challenges for SCMs as physicochemically-powered actuators.

Korean Journal of Chemical Engineering, Vol.34, No.9, 2374-2382, 2017

Enhanced CO methanation over Ni-based catalyst using a support with 3D-mesopores Cao HX, Zhang J, Ren XK, Guo CL

Abstract - Ni-based catalysts supported on a support with 3D-mesopores, including Ni/KIT-6(EG), Ni/KIT-6(PS) and Ni/KIT-6(DS), were prepared by adding ethylene glycol, direct synthesis and post synthesis methods, respectively, and their catalytic properties were investigated for CO methanation as one of the core technologies of synthetic natural gas production in a continuous flow fixed-bed reactor. The catalysts were characterized by N2 adsorption-desorption, X-ray diffraction (XRD), transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDS), hydrogen temperature-programmed reduction (H

-TPR), hydrogen temperature-programmed desorption (H2-TPD) and thermal gravimetric analysis (TGA), respectively. The results showed that Ni/KIT-6(EG) exhibited the best catalytic performance with CO conversion of almost 100% and CH4 yield of 75% at 450 °C, atmospheric pressure and 60,000 mL/g/h due to the higher dispersion of Ni species, stronger reducibility of NiO and formation of smaller Ni nanoparticles fixed into 3D-mesopores, indicating that adding ethylene glycol was effective to improve catalytic performance of Ni-based catalyst for CO methanation. Moreover, compared with Ni/Al

O

(EG) prepared using Al

O

as a support, Ni/KIT- 6(EG) showed better catalytic performance owing to the higher specific surface area, stronger reducibility of NiO and confinement effect of 3D-mesopores promoting to produce more active sites. After 60h lifetime test of Ni/KIT-6(EG) at 500 °C, atmospheric pressure and 60,000mL/g/h, 3D-mesopores were still maintained and no obvious agglomeration of Ni nanoparticles was observed, meaning that Ni species were still well dispersed into 3D-mesopores. As a consequence, Ni/KIT-6(EG) exhibited superior catalytic performance and stability, which makes it a promising candidate for CO methanation.

Korean Journal of Chemical Engineering, Vol.34, No.9, 2418-2422, 2017

Removal of polycyclic aromatic hydrocarbons from contaminated soil in a two-phase partitioning bioreactor

Lee JY, Kwon TS, Lee YC

Abstract - A two-phase partitioning bioreactor was employed to remediate soil contaminated by a mixture of polycyclic aromatic hydrocarbons consisting of phenanthrene, anthracene, and pyrene. In this study, the transfer of three PAHs into the water-immiscible liquid phase (silicone oil or paraffine oil) from the soil was investigated during the first 24 h. And then, phenanthrene and anthracene were degraded by approximately 90% and 80%, respectively, compared with initial concentration in soil, but pyrene was not degraded during seven days of operation period. In addition, the feasibility of a soil slurry sequencing batch reactor system in terms of continuously operating a two-phase partitioning bioreactor was investigated.

Phenanthrene and anthracene were degraded semi-continuously and repeatedly during two operating cycles. Pyrene was still

not degraded and was just transferred into the water-immiscible liquid phase considering its solubility.

NEWS & INFORMATION FOR CHEMICAL ENGINEERS, Vol. 35, No. 5, 2017 …

593 Korean Journal of Chemical Engineering,

Vol.34, No.9, 2507-2513, 2017

Efficient photocatalytic removal of aqueous Cr(VI) by N-F-Al tri-doped TiO2 Wang S, Xie Y, Cheng W, Gao J

Abstract - As chromium is a common heavy metal contaminant in water, we have prepared N-F-Al tri doped TiO

catalyst for Cr(VI) removal under visible light. The sample was prepared via a sol-gel method and was characterized by XRD, BET, UV-vis DRS, XPS and SEM techniques. In the photocatalytic experiments, effects of Al/Ti ratio, F/Ti ratio, calcination temperature and different dopants were investigated. The optimum Al/Ti molar ratio, F/Ti ratio and calcination temperature proved to be 0.01, 0.1 and 500 °C, respectively, which is in accordance with the characterization analysis. Catalysts prepared under this condition showed a high photoactivity for Cr(VI) removal in water.

Korean Journal of Chemical Engineering, Vol.34, No.10, 2559-2569 2017

Separation of oil from oily wastewater using low cost ceramic membrane Bipul D, Bandana C, Pranab B

Abstract - Safe disposal of oily wastewater is a global issue across the industrial world. Stable oil-in-water emulsion has been separated by dead end filtration using low cost ceramic membrane. The efficiency of separation at different oilwater emulsion concentrations was evaluated at different trans-membrane pressures. Maximum rejection of oil 95.4% was observed for membrane sintered at 850

C for oil concentration of 250mg/L at 137.89 kPa. The permeate oil concentration was within the permissible range of environmental tolerance (<12mg/L). The flux decline data was compared with various pore blocking models and it was appraised that cake filtration model best represents the fouling mechanism within the experimental range of pressure and oil-in-water concentration. Solvent permeation studies revealed that nonpolar solvents were more permeable than the polar solvents. The selection parameter of 14.78×10 −6m

/m

·s indicates a good combination of flux permeation, declination and rejection for the membrane sintered at 900

C.

Korean Journal of Chemical Engineering, Vol.34, No.10, 2610-2618 2017

Reductive amination of ethanol to ethylamines over Ni/Al

O

catalysts Park JH, Hong E, An SH, Lim DH, Shin CH

Abstract - Ni(x)/Al

O

(x=wt%) catalysts with Ni loadings of 5-25 wt% were prepared via a wet impregnation method on an γ-Al

O

support and subsequently applied in the reductive amination of ethanol to ethylamines. Among the various catalysts prepared, Ni(10)/Al

O

exhibited the highest metal dispersion and the smallest Ni particle size, resulting in the highest catalytic performance. To reveal the effects of reaction parameters, a reductive amination process was performed by varying the reaction temperature (T), weight hourly space velocity (WHSV), and NH

and H

partial pressures in the reactions. In addition, on/off experiments for NH

and H

were also carried out. In the absence of NH

in the reactant stream, the ethanol conversion and selectivities towards the different ethylamine products were significantly reduced, while the selectivity to ethylene was dominant due to the dehydration of ethanol. In contrast, in then absence of H

, the selectivity to acetonitrile significantly increased due to dehydrogenation of the imine intermediate. Although a small amount of catalyst deactivation was observed in the conversion of ethanol up to 10 h on stream due to the formation of nickel nitride, the Ni(10)/Al

O

catalyst exhibited stable catalytic performance over 90 h under the optimized reaction conditions (i.e., T=190

C, WHSV=0.9 h −1, and EtOH/NH

/H

molar ratio=1/1/6).

Korean Chemical Engineering Research, Vol.55, No.4, 483-489, 2017

Deposition of Functional Organic and Inorganic Layer on the Cathode for the Improved Electrochemical Performance of Li-S Battery

Sohn HS

Abstract - The loss of the sulfur cathode material through dissolution of the polysulfide into electrolyte causes a significant

capacity reduction of the lithium-sulfur cell during the charge-discharge reaction, thereby debilitating the electrochemical

594

performance of the cell. We addressed this problem by using a chemical and physical approach called reduction of polysulfide dissolution through direct coating functional inorganic (graphene oxide) or organic layer (polyethylene oxide) on electrode, since the deposition of external functional layer can chemically interact with polysulfide and physically prevent the leakage of lithium polysulfide out of the electrode. Through this approach, we obtained a composite electrode for a lithium-sulfur battery (sulfur: 60%) coated with uniform and thin external functional layers where the thin external layer was coated on the electrode by solution coating and drying by a subsequent heat treatment at low temperature (~80°C). The external functional layer, such as inorganic or organic layer, not only alleviates the dissolution of the polysulfide electrolyte during the charging/discharging through physical layer formation, but also makes a chemical interaction between the polysulfide and the functional layer.

As-formed lithium-sulfur battery exhibits stable cycling electrochemical performance during charging and discharging at a reversible capacity of 700~1187 mAh/g at 0.1 C (1 C = 1675 mA/g) for 30 cycles or more.

Korean Chemical Engineering Research, Vol.55, No.4, 561-566, 2017

굴곡 융착면을 이용한 고밀도폴리에틸렌 관의 버트 융착 공정에서의 열유체 거동 수치모사

Numerical Simulation of Heat and Flow Behaviors in Butt-fusion Welding Process of HDPE Pipes with Curved Fusion Surface

유재현, 최선웅, 안경현, 오주석

Abstract - 폴리머 재질의 관을 융착 시키기 위해서는 버트 융착 공정을 거치는데, 최근 융착면에 굴곡을 주어 융착 강도를 높이고자 하는 시도가 있었다. 본 연구에서는 융착면의 굴곡이 폴리머의 열유체 거동 및 융착 강도에 어떠한 영향을 미칠 것인지 2차원 축대칭 평면에서 유한요소법을 사용하여 살펴보았으며, 고밀도폴리에틸렌 관을 대상으로 하였다. 열유화 단계에서 융착면의 형상을 따라 굴곡진 상경계면이 나타남을 확인할 수 있었다. 접합 단계에서는 굴곡진 상경계면과 융착면 사이에서의 멜트의 압착 흐름이 나타남을 확인할 수 있었으며, 굴곡융착부의 낮은 전단율은 관의 축과 수직 방향 배향을 완화시켜 융착부 강도 향상에 도움을 줄 수 있을 것으로 예상된다.

Korean Chemical Engineering Research, Vol.55, No.4, 567-573, 2017

WOx/SBA-15 촉매와 과산화수소를 이용한 선박용 경유의 산화 탈황 연구

Oxidative Desulfurization of Marine Diesel Using WOx/SBA-15 Catalyst and Hydrogen Peroxide 오현우, 김지만, 허관선, 우희철

Abstract - 선박용 경유(황 농도 약 230 ppmw)의 황화합물 제거를 위해 산화텅스텐(WOx)을 실리카로 이루어진 다공성 물질인 SBA-15에 담지한 산화 촉매를 제조하였으며 산화제로 과산화수소를 이용한 산화공정과 추출 용매로 아세토니트릴을 이용한 추출공정을 통해 촉매의 산화성능을 확인하였다. XRD 및 XRF, XPS 분석과 BET 이론을 통해

제조한 촉매의 물리적 특성에 대해 조사하였다. 담지된 WOx는 삼산화텅스텐(WO

)으로 존재하였으며 실제 담지율이 약

10 wt% 부근일 때 단일층을 형성하는 것으로 판단된다. 제조한 촉매의 산화성능을 확인한 결과, 0.1 g의 13 wt% WOx/

SBA-15 촉매와 과산화수소(산소/황 몰 비=10)를 도입하여 90 °C에서 3시간 동안 반응이 이루어졌을 때 76.3%의 가장

높은 황제거율을 나타냈다. 연속반응 비교 실험을 통해 1회의 산화반응으로 황 화합물의 산화가 충분히 일어났음을

확인하였다. 또한 5회의 추출공정을 통해 최대 94.4%의 황 제거율을 나타냈다.