• 한국가스학회:학술대회논문집
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• 2005.10a
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• pp.83-87
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• 2005

The kinetics of the direct synthesis of DME was studied under different conditions over a temperature range of $220\~280^{\circ}C$, syngas ratio $1.2\~ 3.0$ All experiment were carried out over hybrid catalyst, composed to a methanol synthesis catalyst (Cu/ZnO/$Al_2O_3$) and a dehydration Catalyst ($\gamma$-Al_2O_3$) The observed reaction rate qualitatively follows a Langmiur-Hinshellwood type of reaction mechanism. Such a mechanism is considered with three reaction, methanol synthesis, methanol dehydration and water gas shift reaction. From a surface reaction with dissociative adsorption of hydrogen, methanol and water, individual reaction rate was determined

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.41-49
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• 2012

This study was aimed at the development of catalysts for the direct methanol synthesis by partial oxidation of methane. Mo-Bi-V-Al mixed oxide catalysts were prepared and characterized and used in the direct methanol synthesis reaction. The catalysts prepared by the sol-gel method had much larger surface areas than those prepared by the co-precipitation method. The larger the surface area was, the less the methanol selectivity was. The catalysts having larger surface area facilitate the complete oxidation of methane, decreasing the selectivity of methanol. The catalysts prepared by the sol-gel method showed higher methanol selectivity of 13% at $20^{\circ}C$ lower temperature than those prepared by the co-precipitation method. Through XRD analysis, it was revealed that the structures of the catalysts prepared by the two methods were different. In the reaction, methanol selectivity increased and carbon dioxide selectivity decreased with pressure due to the suppression of complete oxidation reaction at a high pressure.

• Clean Technology
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• v.22 no.3
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• pp.196-202
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• 2016

In this study, ceria- based catalysts were prepared for dimethyl carbonate (DMC) synthesis and reaction conditions were evaluated for finding the optimal reaction route. In order to find optimal catalysts for DMC synthesis, calcination temperature and Cu(II) impregnation amount were evaluated. The oxidative carbonylation using methanol, carbon monoxide and oxygen and the direct synthesis using methanol and carbon dioxide were introduced for producing DMC. Following the law of Le Chatelier, the dehydration reaction was applied for enhancing the reactivity (methanol conversion) as removing water during the reaction. 2-cyanopyridine, as a chemical dehydration agent, was used. In the case of the oxidative carbonylation, methanol conversion rate increased from 15.1% to 38.7% and the DMC selectivity increased from 0% to 98.8%. In the case of the direct synthesis, methanol conversion rate increased from 1.0% to 77.8% and the DMC selectivity increased from 41.2% to 100.0%.

• Bulletin of the Korean Chemical Society
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• v.30 no.3
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• pp.683-686
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• 2009

Slurry phase reaction of elemental silicon with methanol has been studied in the presence of copper using a small amount of cuprous chloride as an activator in DBT (dibenzyltoluene) at various temperatures from 200 ${^{\circ}C}$ to 320 ${^{\circ}C}$. Trimethoxysilane (1a) with a Si-H unit was obtained as the major product and tetramethoxysilane (1b) as the minor product. The reaction worked well using a 0.5 wt % CuCl as an activator. The optimum temperature for this direct synthesis of 1a was 240 ${^{\circ}C}$. Methoxysilanes were obtained in 95% yield with 81% selectivity to 1a from 85% conversion of elemental silicon.

• Journal of the Korean Applied Science and Technology
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• v.31 no.3
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• pp.446-452
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• 2014

Methanol was directly produced by the partial oxidation of methane with four-component mixed oxide catalysts. Four-component(Mo-Bi-Cr-Si) mixed oxide catalysts were prepared by the co-precipitation and sol-gel methods. The catalyst prepared by the sol-gel method showed about eleven times higher surface area than that prepared by the co-precipitation method. From the $O_2$-TPD experiment of the prepared catalysts, it was proven that there exists two types of oxygen species, and the oxygen species that participates in the partial oxidation reaction is the lattice oxygen desorbing around $750^{\circ}C$. The optimum reaction condition for methanol production was $420^{\circ}C$, 50 bar, flow rate of 115 mL/min, and $CH_4/O_2$ ratio of 10/1.5, providing methane conversion and methanol selectivity of 3.2 and 26.7%, respectively.

• 한국전기화학회:학술대회논문집
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• 2002.07a
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• pp.201-202
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• 2002

• 한국전기화학회:학술대회논문집
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• 2000.04a
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• pp.53-53
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• 2000

• 한국전기화학회:학술대회논문집
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• 2003.07a
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• pp.233-238
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• 2003

• Applied Chemistry for Engineering
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• v.17 no.2
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• pp.125-131
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• 2006

Dimethyl ether (DME) is a new clean fuel as an environmentally-benign energy resource. DME can be manufactured from various energy sources including natural gas, coal, biomass and spent plastic. In addition to its environmentally friendly properties, DME has similar characteristics to those of LPG. Therefore, it is considered as an excellent substitute fuel for LPG, fuel cells, power plant, and especially diesel and is expected to be the alternative fuel by 2010. The experimental study of the direct synthesis of DME was investigated under various conditions over a temperature range of $220{\sim}280^{\circ}C$, syngas ratio 1.2~3.0. All experiments were carried out with a hybrid catalyst, composed of a methanol synthesis catalyst ($Cu/ZnO/Al_2O_3$) and a dehydration catalyst (${\gamma}-Al_2O_3$). The observed reaction rate follows qualitatively a Langmiur-Hinshellwood model as the reaction mechanism. Such a mechanism is considered with three reactions; methanol synthesis, methanol dehydration and water gas shift reaction. From a surface reaction with dissociative adsorption of hydrogen, methanol, and water, individual reaction rate was determined.

• Journal of Hydrogen and New Energy
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• v.15 no.4
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• pp.283-290
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• 2004

The single-step process for conversion of syngas to DME give higher conversion than the syngas-to-methanol process. This arises because of a synergy among the three simultaneous reaction, methanol synthesis, methanol dehydration and water gas shift reaction, in the process. we would find the optimal condition of the process which these advantages. The optimal condition of DME synthesis reaction over a commercial $Cu/Zn/Al_2O_3$ catalyst and Hybrid catalyst in a fixed bed reactor. The syngas-to-dimethyl ether conversion was examined on various reaction condition (Temperature 473~553K, $H_2/CO$ ratio 1~3, Pressure 30'50atm, GHSV 1000~4000).