Wonik Materials Co

Cheongwon

Wonik Materials Co

Cheongwon
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Hwang B.W.,Kyungpook National University | Lee S.C.,Kyungpook National University | Ahn J.H.,Kyungpook National University | Kim S.Y.,Kyungpook National University | And 4 more authors.
Journal of Nanoelectronics and Optoelectronics | Year: 2017

A SnO2-based thick film gas sensor promoted with Fe2O3 and ZnO (SnFeZn) was developed in this study for the detection of 1 ppm H2S gas at 350 °C. The SnFeZn was prepared by physical mixing of SnO2 with Fe2O3 and ZnO. The SnFeZn sensor showed not only a high response of about 4.5, but also complete recovery on detection of H2S. Moreover, the response of SnFeZn sensor was maintained during multiple cycles of detection and recovery without deactivation, unlike the response magnitude of a SnO2 sensor. These results were due to the effect of the Fe2O3 and ZnO promoters. The Fe2O3 promoter played an important role in the improvement of sensor recovery, and the ZnO promoter played an important role in the enhancement of sensor response. © 2017 by American Scientific Publishers.


Lee W.S.,Kyungpook National University | Ju D.G.,Korea Institute of Industrial Technology | Jung S.Y.,Wonik Materials Co. | Lee S.C.,Korea Institute of Energy Research | And 3 more authors.
Topics in Catalysis | Year: 2017

Ni-Al-based catalysts prepared by impregnation, co-precipitation, and polymer-modified incipient methods, referred to as NA-IM, NA-CM, and NA-PM, respectively, were applied to autothermal reforming (ATR) of n-dodecane, since this hydrocarbon exhibits properties similar to those of diesel fuel and can be used as its surrogate. The corresponding catalytic performances were evaluated in terms of H2 yield and n-dodecane conversion at 750 °C and 12,000 h−1 in a fixed-bed reactor at an S/C molar ratio of 1.23 and an O2/C molar ratio of 0.25. NA-CM and NA-PM exhibited similar performances in terms of H2 yield (1.4) and n-dodecane conversion (90%); however, the performance of NA-IM was inferior to those of other catalysts. The differences between the prepared catalysts were investigated by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller analysis, with the obtained results indicating the importance of well-dispersed Ni species in NA-PM for efficient ATR. © 2017 Springer Science+Business Media New York


Lim E.J.,Kyungpook National University | Jung S.Y.,Wonik Materials Co. | Park C.G.,Poohung Photo Chemical Co. | Lee S.C.,Kyungpook National University | Kim J.C.,Kyungpook National University
Adsorption | Year: 2016

Molybdenum–nickel-based catal-sorbents were prepared with gamma-alumina (γ-Al2O3) via an impregnation (MNAI30) method, and tested for the simultaneous removal of H2S and NH3 gases in a fixed-bed reactor system. The NH3 and H2S breakthrough times of the MNAI30 catal-sorbents were 200 and 225 min, respectively. The NH3 breakthrough time was shorter than that of H2S because the NH3 decomposition ability was decreased when α- and β-NiMoO4, NiO, and MoO3 were converted into Ni3S2 and MoS2, which were ineffective in decomposing NH3 in the presence of H2 gas. NiAl2O4 was also observed in the MNAI30 catal-sorbent and was reduced during the decomposition of NH3 at a low temperature, a phenomenon that improved the NH3 decomposition ability of the catal-sorbent during the H2S absorption process. © 2016 Springer Science+Business Media New York


Chae H.J.,Kyungpook National University | Lee S.C.,Kyungpook National University | Lee S.J.,Korean Intellectual Property Office | Cho M.S.,Kyungpook National University | And 6 more authors.
Journal of Industrial and Engineering Chemistry | Year: 2016

The SO2 sorption properties of dry potassium-based sorbents, prepared by impregnation of various supports with potassium carbonate, were investigated at the various water vapor concentrations at a level of 5000ppm of SO2. It was found that alkali metal-based sorbents promoted with potassium carbonate could be used as a sorbent for SO2 sorption at low temperatures (between 30°C and 60°C). In particular, the potassium-based sorbents showed an excellent SO2 sorption capacity of about 310mg SO2/g sorbent in the presence of water vapor, while in the absence of water vapor, their SO2 sorption capacities decreased. © 2016 The Korean Society of Industrial and Engineering Chemistry.


Kim Y.L.,Wonik Materials Co | Park S.J.,Wonik Materials Co | Choi H.,Wonik Materials Co | Baek J.-M.,Wonik Materials Co | And 3 more authors.
Journal of Chemical and Engineering Data | Year: 2014

Isothermal vapor-liquid equilibrium (VLE) data were measured for the binary systems of octafluoropropane + octafluorocyclobutane and hexafluoropropylene oxide + octafluorocyclobutane system at the temperature range from 263.15 K to 303.15 K. The experiments were carried out with a circulating-type equilibrium apparatus including online gas chromatography analysis. The VLE data were correlated well by the Peng-Robinson equation of state using the Wong-Sandler mixing rules involving the NRTL model. All the binary parameters of these systems and the average absolute deviations (AADs) in terms of saturated pressure and vapor phase composition between the experimental and calculated values are represented. © 2014 American Chemical Society.


Cho W.-S.,Soongsil University | Cho W.-S.,Seoul Waterworks Research Institute | Lee K.-H.,Soongsil University | Chang H.-J.,Wonik Materials Corporation | And 2 more authors.
Korean Journal of Chemical Engineering | Year: 2011

The separation/concentration of SF6, a strong greenhouse gas, of 1.3% in N2 was investigated using pressure-temperature swing adsorption (PTSA) with activated carbon. To screen an effective adsorbent to be used for PTSA, adsorption isotherms on the selected adsorbents were obtained. Among the studied adsorbents, AC-1, a coconut-shell based commercial activated carbon, showed the largest adsorption amount of 3.5 mmol-SF6/g-carbon at 303.65 K and 3 atm and the highest selectivity among the adsorbents tested. Its adsorption isotherm was well fit into Langmuir-Freundlich model. Before feasibility test of PTSA, a series of experiments were performed to investigate the effect of operating parameters including adsorption pressure, feed flow rate, desorption temperature and evacuation time on the PTSA performance using the 3-step PTSA cycle (pressurization, adsorption and regeneration-recovery). As the adsorption pressure, desorption temperature and evacuation time were increased, respectively, purity and recovery increased. Increasing the feed flow rate resulted in low purity and recovery. The maximum purity of 19.5% and recovery of 50.1% were obtained with adsorption pressure of 2.5 atm, desorption temperature of 200 °C and evacuation of 1 hour. © 2011 Korean Institute of Chemical Engineers, Seoul, Korea.


Choi H.Y.,Wonik Materials Co | Park S.J.,Wonik Materials Co | Seo D.,Wonik Materials Co | Baek J.-M.,Wonik Materials Co | And 4 more authors.
International Journal of Hydrogen Energy | Year: 2015

Ammonia borane (NH3BH3), as a source material for energy generation and hydrogen storage, has attracted growing interest due to its high hydrogen content. We have investigated the synthesis of ammonia borane from diborane (B2H6) and ammonia (NH3) utilizing a low-temperature process. From our results, a maximum synthetic yield of 92.2% was obtained, for an ammonia borane complex of 0.35M. The diammoniate diborane (DADB) was detected in about 5-10mol% within the solid ammonia borane by solid-state 11B-NMR analysis. The synthesized solid ammonia borane products were studied to characterize hydrogen release upon thermal dehydrogenation. © 2015 Hydrogen Energy Publications, LLC.

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