• 한국분말재료학회지
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• 제25권3호
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• pp.203-207
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• 2018

Plastic pollution is threatening human health and ecosystems, resulting in one of the biggest challenges that humanity has ever faced. Therefore, this study focuses on the preparation of macroporous carbon from biowaste (MC)-supported manganese oxide ($MnO_2$) as an efficient, reusable, and robust catalyst for the recycling of poly(ethylene terephthalate) (PET) waste. As-prepared $MnO_2/MC$ composites have a hierarchical pore network and a large surface area ($376.16m^2/g$) with a narrow size distribution. $MnO_2/MC$ shows a maximum yield (98%) of bis(2-hydroxyethyl)terephthalate (BHET) after glycolysis reaction for 120 min. Furthermore, $MnO_2/MC$ can be reused at least nine times with a negligible decrease in BHET yield. Based on this remarkable catalytic performance, we expect that $MnO_2$-based heterogeneous catalysts have the potential to be introduced into the PET recycling industry.

• 한국대기환경학회지
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• 제17권4호
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• pp.363-370
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• 2001

In this study, TiO$_2$, the popular photocatalyst, was used to decompose ethanol. TiO$_2$was prepared by the sol -gel method and coated on pyrex stick. A 15W, UV-A lamp was used as the UV light source and il gas chromatography (HP 5890) was used to confirm the concentrations of ethanol, $CO_2$and the intermediates. Variation of preparation parameters and calcination temperature for TiO$_2$photocatalysts in the sol -gel method caused changes of ethanol decomposition activity. The best ethanol photodecomposition activity was obtained on the sample when prepared with 0.14 mol of HCI, a mol of ethanol and 1.3 mol of TTIP ware mixed in sol-gel process and calcinated at 50$0^{\circ}C$ for 3 hours. Acetaldehyde was detected as an intermediate and decomposed to carbon dioxide and water at the end of the reaction.

• 대한화학회지
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• 제4권1호
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• pp.51-57
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• 1957

Hydroquinone-formaldehyde resin prepared from hydroquinone, formaldehyde and hydrochloric acid as a catalyst was shown to be oxidized with ferric chloride solution and regenerated by stannous chloride solution. The influence of various conditions of preparation on the capacity of oxidation was studied. Results show that the concentration of a solution of hydroquinone has not any effects below 14 parts of water to 1 part of hydroquinone, by the after-heat-treatment for 5-6 hours at 100-120 deg. C. the capacity of oxidation is exhibited a maximum, and decreased as the mole ratio of hydroquinone to formaldehyde increase. The optimum conditions for the preparation of this resin are as follows: hydroquinone 1 part to distilled water 10 parts, mole ratio of formaldehyde 1.2 to hydroquinone 1, and 5 hours of after-heat-treatment at 120 deg. C. The maximum capacity under the above conditions is 13.99 meq/g-ersin.

• 한국세라믹학회지
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• 제26권4호
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• pp.471-478
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• 1989

In this study we investigated the gelation time of sol which containing mixtures of TEOS with H2O, ethanol, HCl in the preparation of monolithic silica glass through Sol-Gel method. In this case apparent activation energies were observed by Arrhenius equation. We investigated the conversion from gel to glass in drying and heat treatment stages using DT-TG, FT-IR, XRD analysis and dried gel conversed to glass by heat treatment up to 85$0^{\circ}C$. The results of this experiment showed that the gelation time of solutions were promoted when increasing the amount of addition of H2O and HCl catalyst for TEOS and high reaction temperature of solution.

• International journal of advanced smart convergence
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• 제4권1호
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• pp.154-161
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• 2015

A novel process has successfully been developed by overcoming major difficulties through the elimination of number of process steps involved in the Classical Transesterification reaction during the preparation of Fatty Acid Methyl/Ethyl Ester (FAME.FAEE) called biodiesel. The Classical process with cost intensive process steps such as the utilization of excess alcohol, needing downstream distillation for the recovery and reutilization of excess alcohol/cosolvent, unrecoverable homogenous catalyst which consumes vast quantity of fresh distilled water during the purification of the product and downstream waste water treatment before its safe disposal to the surface water body. The Novel Process FAME/FAEE is produced from any vegetable oil irrespective of edible or inedible variety using sonication energy. The novelty of the finding is the use of only theoretical quantity of alcohol along with a co-solvent and reduced quantity of homogeneous catalyst. Under this condition neither the homogeneous catalyst goes to the FAME layer nor is the distillation needed. The same ester also has been prepared in high pressure high temperature reactor without using catalyst at sub critical temperature. The quality of prepared biodiesel without involving any purification step meets the ASTM standards. Blended Biodiesel with Common Diesel Fuel (CDF) and FAME is prepared, characterized and used as fuel in the Kirloskar make CI Engines. The evaluation of the engine performance result of pure CDF, B05 biodiesel, B10 biodiesel of all types of biodiesel prepared by using the feedstock of Soybean (Glycine max) and Karanja (Pongamia pinnate) oil along with their mixed oil provides useful information such as brake power, brake thermal efficiency, brake specific fuel consumption, etc, and established it as ideal fuel for unmodified CI engine.

• 한국응용과학기술학회지
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• 제8권1호
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• pp.9-20
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• 1991

In the preparation of acrylic water repellent(EDLWC). quaternized 2-diethylarrunoethylmethacrylate-stearylmethacrylate copolymer (DSACC) and quaternized 1-Iaurovlbis(aminoethyl)-2-dodecylimidazoline(LDDIC) were selected as a basic resin and the improving agent such as softening effect and hydrostatic pressure of the water repellent. EDLWC was prepared by blending waxes and emulsifier for waxes with various ratio to DSACC and LDDIC. As the results of the measurement of water repellency, washable, tear strength and crease recovery to polyester-cotton(P/C) blended fabrics treated with EDLWC only or addition of textile finishing resin, the physical properties were increased. Sodium acetate was the most effective catalyst in the water repellency among the various kinds of catalyst. and the reasonable concentration of the catalyst was 1. 4 wt%. EDLWC was confirmed as durable water repellent with the results of making little difference of water repellency as ${\pm}5$ point after and before washing. The reaction mechanism between P/C blended fabrics and EDLWC in the presence of catalyst was proposed. And also, the longitudinal view of the P/C blended fabrics treated with water repellent was observed with scanning electron microscope.

• Carbon letters
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• 제6권1호
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• pp.41-46
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• 2005

Plasma carbon blacks of 20~30 nm diameter were synthesized by direct decomposition of natural gas using a hybrid plasma torch system with 50 kW direct current and 4 MHz of radio frequency. The insulating rector which inside diameter of 400 mm and length of 1500 mm, respectively was kept at 300~$400^{\circ}C$ during the preparation. The ultimate analysis of plasma carbon blacks reveals that the raw plasma carbon blacks contains a large quantity of volatile which is mainly consist of hydrogen. Therefore devolatilization of raw plasma carbon blacks were carried out at $900^{\circ}C$ for one hour under nitrogen atmosphere. The devolatilization leads to the decrease in electrical resistivity and surface oxygen functional groups of plasma carbon black significantly. In order to investigate the plasma carbon as a catalyst support, devolatilized plasma black at $900^{\circ}C$ (DPB) supported PtAu catalyst was synthesized by sodium boronhydride reduction method. Electrochemical measurements and direct formic acid fuel cell test indicated that catalytic activity of DPB supported PtAu catalyst for formic acid oxidation was similar to that of Vulcan XC-72 of commercial carbon black supported one.

• 공업화학
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• 제24권1호
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• pp.82-86
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• 2013

기능성 용매인 1-buthyl-3-methylimidazolium trifluoromethanesulfonate ([Bmim][$CF_3SO_3$])를 이용하여 팔라듐 입자를 제조하였다. 제조된 입자의 형상은 기능성용매의 농도에 영향을 받았다. 또한 hexafluoropropylene 수소화 반응용 촉매를 제조하기 위하여 탄소 담지 팔라듐 입자를 제조하였다. 촉매 제조 시 기능성용매의 농도와 소성온도를 변화해 가면서 최적의 촉매제조 조건을 구하고자 하였다. 수소화 촉매의 반응활성의 상기의 두 가지 제조조건에 따라서 크게 달라지는 것이 관찰되었다. 동일한 반응조건에서 기능성용매와 팔라듐 전구체의 몰 비가 동일하고 소성온도가 $500^{\circ}C$에서 제조된 촉매가 가장 우수한 반응성을 보였다.

• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.325-334
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• 2018

Lactose is a reducing disaccharide consisting of two different monosaccharides such as galactose and glucose. The hydrogenation of lactose to lactitol is a formidable challenge because it is a complex process and several side products are formed. In this work, we synthesized Ru-Ni bimetallic nanohybrids as efficient catalysts for selective lactose hydrogenation to give selective lactitol. Ru-Ni bimetallic nanohybrids with $Ru-NiO_x$ (x = 1, 5, and 10 wt%) are prepared by impregnating Ru and Ni salts precursors with $TiO_2$ used as support material. Ru-Ni bimetallic nanohybrids (represented as $5Ru-5NiO/TiO_2$) catalyst is found to exhibit the remarkably high selectivity of lactitol (99.4%) and turnover frequency i.e. ($374h^{-1}$). In contrast, monometallic $Ru/TiO_2$ catalyst shows poor performance with ($TOF=251h^{-1}$). The detailed characterizations confirmed a strong interaction between Ru and NiO species, demonstrating a synergistic effect on the improvement on lactitol selectivity. The impregnation-reduction method for the preparation of bimetallic $Ru-NiO/TiO_2$ catalyst promoted Ru nanoparticles dispersed on NiO and intensified the interaction between Ru and NiO species. $Ru-NiO/TiO_2$ efficiently catalyzed the hydrogenation of lactose to lactitol with high yield/selectivity at almost complete conversion of lactose at $120^{\circ}C$ and 55 bar of hydrogen ($H_2$) pressure. Moreover, $Ru-NiO/TiO_2$ catalyst could also be easily recovered and reused up to four runs without notable change in original activity.

• 청정기술
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• 제29권4호
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• pp.321-326
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• 2023

최근 탄소중립과 관련하여 연소 시 이산화탄소 배출이 없어 청정한 수소에너지에 대한 관심이 증가하고 있다. 이에 따라 수소 생산에 관련된 연구가 계속되고 있으며 본 연구에서는 폐기물을 처리함과 동시에 고순도 수소를 생산하기 위해 폐기물 유래 합성가스를 수성가스전이반응에 적용하였다. 마그네슘을 세륨과 함께 지지체로 사용하여 고온수성가스전이(HT-WGS)반응에서 촉매의 활성을 향상시키고자 하였다. HT-WGS 반응의 활성물질로 구리를 사용해 Cu-CeO₂-MgO 촉매를 제조하였으며, 제조방법에 따른 촉매활성 연구를 진행하였다. HT-WGS 반응 결과 함침법으로 제조된 Cu-CeO₂-MgO 촉매가 가장 높은 활성을 보였으며, 이는 가장 높은 산소 저장능과 많은 활성 Cu 종을 가지는 특성에 기인한 결과이다.