• 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

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.3
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• pp.258-261
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• 2006

The addition of zeolite particles enhances the stability of mRNA molecules in a cell-free protein synthesis system. When $20{\mu}g/{\mu}L$ of zeolite (Y5.4) is added to a reaction mixture of cell-free protein synthesis, a substantial increase in protein synthesis is observed. The stabilizing effect of zeolite is most dearly observed in an in vitro translation reaction directed by purified mRNA, as opposed to a coupled transcription and translation reaction. Upon the addition of zeolite in the in vitro translation reaction, the life span of the mRNA molecules is substantially extended, leading to an 80% increase in protein synthesis. The effect of zeolite upon the mRNA stability appears be strongly related to the cation exchange (potassium to sodium) reaction. Our results demonstrate the possibility of modifying this biological process using heterogeneous, non-biological substances in a cell-free protein synthesis system.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.888-888
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• 2009

A simulation study on SCR (Steam Carbon dioxide Reforming) process in gas-to-liquid (natural gas to Fischer-Tropsch synthetic fuel) process was carried out in order to find optimum reaction conditions for GTL (gas-to-liquid) process reaction. Optimum SCR operating conditions for synthesis gas to FT (Fischer-Tropsch) process were determined by changing reaction variables such as feed temperature and pressure. During the simulation, overall synthesis process was assumed to proceed under steady-state conditions. It was also assumed that physical properties of reaction medium were governed by RKS (Redlich-Kwong-Soave) equation. SCR process was considered as reaction models for synthesis gas in GTL proess. The effect of temperature and pressure on SCR process $H_2$/CO ratio and the effect of reaction pressure on SCR reaction were mainly examined. Simulation results were also compared to experimental results to confirm the reliability of simulation model. Simulation results were reasonably well matched with experimental results.

• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.927-930
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• 2004

• Korean Journal of Metals and Materials
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• v.49 no.10
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• pp.790-796
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• 2011

To reduce the heat released during intermetallic reaction, Ni-50at%Al powder compact has been previously annealed at several conditions before the reaction. The effects of the pre-annealing conditions on the reaction synthesis process have been investigated. Experimental results show that the heat released during the reaction synthesis decreased proportionally with increase of the pre-annealing temperature and duration time. The reaction duration period was significantly increased when the intermetallics were formed in the powder compact during the pre-annealing. This was attributed to the fact that the reaction occurred by solid-state diffusion between the un-reacted elemental atoms and that the $NiAl_3$ phase formed predominantly during pre-annealing.

• Korean Chemical Engineering Research
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• v.56 no.3
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• pp.416-420
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• 2018

A comprehensive kinetic study has been conducted on dimethyl carbonate synthesis by transesterification reaction of ethylene carbonate with methanol. An alkali base metal (KOH) was used as catalyst in the synthesis of DMC, and its catalytic ability was investigated in terms of kinetics. The experiment was performed in a batch reactor at atmospheric pressure. The reaction orders, the activation energy and the rate constants were determined for both forward and backward reactions. The reaction order for forward and backward reactions was 0.87 and 2.15, and the activation energy was 12.73 and 29.28 kJ/mol, respectively. Using the general factor analysis in the design of experiments, we analyzed the main effects and interactions according to the MeOH/EC, reaction temperature and KOH concentration. DMC yield with various reaction conditions was presented for all ranges using surface and contour plot. Furthermore, the optimal conditions for DMC yield were determined using response surface method.

• Journal of Powder Materials
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• v.2 no.2
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• pp.158-164
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• 1995

Synthesis of the NiTi shape memory alloy using the thermal explosion mode of the self-propagating high-temperature synthesis has been investigated. The significant fractions of intermetallics phases were found to form at the Ti/Ni powder interface during the heating to the ignition temperature and seemed to influence the relative fraction of phases in the final products. As the heating rate to the ignition temperature was increased, the combustion temperature and the fraction of NiTi in the final reaction products were increased. The synthesis reaction under 70 MPa compressive pressure yielded a reaction product with 98% theoretical density.

• Journal of the Korean Society of Safety
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• v.27 no.5
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• pp.77-87
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• 2012

Compared to a batch reactor, where all reactants are initially charged to the reactor, the semi-batch reactor presents serious advantages. The feed of at least one of the reactants provides an additional way of controlling the reaction course, which represents a safety factor and increases the constancy of the product quality. The aim of this study was to investigate the characteristics of thermal hazard such as a feed time, catalysis concentration and solvent concentration in methylthioisocyanate(MTI) synthesis reaction process. The experiments were carried out by the Multimax reactor system and Accelerating rate calorimeter(ARC). The MTI synthesis reaction process has many reaction factors and complicated reaction mechanism of multiphase reaction. Through this study, we can use as a tool for assessment of thermal hazard of other reaction processes by applying experiment method provided.

• Transactions on Electrical and Electronic Materials
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• v.13 no.5
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• pp.225-228
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• 2012

In order to synthesize LED phosphor materials, we have applied three novel synthesis techniques, "melt synthesis", "fluidized bed synthesis" and "vapor-solid hybrid synthesis", in contrast with the conventional solid state reaction technique. These synthesis techniques are also a general and powerful tool for rapid screening and improvements of new phosphor materials.

• Bulletin of the Korean Chemical Society
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• v.27 no.5
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• pp.769-772
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• 2006