• International Journal of Automotive Technology
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• 제7권4호
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• pp.501-508
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• 2006

The effect of chemical additives, such as dimethyl ether(DME), ethanol, carbon disulfide on the soot formation were examined numerically. ill this study, the Frenklach soot mechanism was used as a base mechanism to predict the soot formation in the ethane flame. The combination of Westbrook's DME mechanism, Marinov's ethanol mechanism, and chemical kinetic mechanism for hydrogen sulfide and carbon disulfide flames was made with the base mechanism because the DME, ethanol, $CS_2$ additives are added into the ethane fuel. CHEMKIN code was used as a numerical analysis software to simulate the effect of chemical additives on reduction of the polycyclic aromatic hydrocarbons(PAH's) which are soot precursors. From the numerical results it is observed that addition of DME, ethanol and $CS_2$ into ethane fuel can reduce PAH species significantly. That means theses additives can reduce soot formation significantly. Results also strongly suggest suppression of soot formation by these additives to be mainly a chemical effect. Hand OH radicals may be the key species to the reduction of PAH species for additives.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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• pp.279-281
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• 2012

A short chemical mechanism was developed with the chemical model reduction strategy based on the use of Simulation Error Minimization Connectivity Method(SEM-CM). We examined the accuracy resulting from using this mechanism, as compared with the full mechanism, for premixed flames and auto-ignition of methane-air mixture under high pressures. These comparisons are in good agreement, but it has a little divergence to predict the ignition delay time at high pressure conditions as compared with experiment results.

• 대한화학회지
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• 제47권4호
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• pp.432-436
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• 2003

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2791-2796
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• 2014

The capture of $SO_2$ at or close to the temperatures of real flue gas is much more attractive in application. In this work, two kinds of ionic liquids (ILs) based on lactate anion were used to absorb $SO_2$ at high temperatures from 100 to $120^{\circ}C$. The ILs show high absorption capacities of over one mol $SO_2$ per mol IL at $110^{\circ}C$. The absorption of $SO_2$ by the ILs based on lactate anion is reversible and the ILs can be reused for the capture of $SO_2$ at high temperatures with high absorption capacity and thermal stability. Furthermore, the absorption mechanism of $SO_2$ by the ILs was studied by FT-IR, $^1H$ NMR and $^{13}C$ NMR spectra. It has been found that there are strong chemical interactions between the ILs and $SO_2$. Also the absorption mechanism is different when there is water present in ILs compared to when there is not.

• 한국연소학회지
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• 제16권2호
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• pp.16-22
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• 2011

It is a challenging task to apply large detailed chemical mechanisms of fuel oxidation in simulation of complex combustion phenomena. There exist a few systematic methodologies to reduce detailed chemical mechanisms to smaller sizes involving less computational load. This research work concerns generation of a skeletal chemical mechanism by a directed relation graph with specified accuracy requirement. Two sequential stages for mechanism reduction are followed in a perfectly stirred reactor(PSR) for high temperature chemistry and to consider the autoignition delay time for low and high temperature chemistry. Reduction was performed for the detailed chemical mechanism of n-heptane consisting of 561 species and 2539 elementary reaction steps. Validation results show acceptable agreement for the autoignition delay time and the PSR calculation in wide parametric ranges of pressure, temperature and equivalence ratio.

• Bulletin of the Korean Chemical Society
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• 제24권1호
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• pp.65-69
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• 2003

The kinetic and chemical mechanisms of AChE-catalyzed hydrolysis of short-chain thiocholine esters are relatively well documented. Up to propanoylthiocholine (PrTCh) the chemical mechanism is general acid-base catalysis by the active site catalytic triad. The chemical mechanism for the enzyme-catalyzed butyrylthiocholine(BuTCh) hydrolysis shifts to a parallel mechanism in which general base catalysis by E199 of direct water attack to the carbonyl carbon of the substrate. [Selwood, T., et al. J. Am. Chem. Soc. 1993, 115, 10477- 10482] The long chain thiocholine esters such as hexanoylthiocholine (HexTCh), heptanoylthiocholine (HepTCh), and octanoylthiocholine (OcTCh) are hydrolyzed by electric eel acetylcholinesterase (AChE). The kinetic parameters are determined to show that these compounds have a lower Michaelis constant than BuTCh and the pH-rate profile showed that the mechanism is similar to that of BuTCh hydrolysis. The solvent isotope effect and proton inventory of AChE-catalyzed hydrolysis of HexTCh showed that one proton transfer is involved in the transition state of the acylation stage. The relationship between the dipole moment and the Michaelis constant of the long chain thiocholine esters showed that the dipole moment is the most important factor for the binding of a substrate to the enzyme active site.

• Bulletin of the Korean Chemical Society
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• 제22권10호
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• pp.1123-1126
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• 2001

• Korean Chemical Engineering Research
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• 제53권5호
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• pp.531-539
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• 2015

클로로알카리 산업은 염화나트륨 수용액의 전기분해로 연간 약 7천만 톤의 가성소다 및 염소를 생산하는 전 세계적으로 가장 큰 전기화학 공정 중 하나이다. 클로로알카리 공정에서는 DSA(Dimensionally Stable Anodes) 전극인 $RuO_2$ 및 $IrO_2$를 주로 사용하여 염소를 생산하며 상업적으로 사용되고 있는 전극에 비하여 염소 발생 효율이 높은 전극을 개발하려는 연구가 계속되고 있다. 그러나 보다 염소 발생 효율이 좋은 전극을 개발하기 위해서는 DSA 전극에서의 염소 발생 메커니즘에 대한 이해가 뒷받침되어야 한다. 따라서 본 글에서는 기존 연구를 중심으로 DSA 전극에서 염소 발생 메커니즘 연구가 현재까지 어떻게 발전되어 왔는지 검토하고 염소 발생 메커니즘의 핵심적인 요인들을 분석 및 정리하여 DSA 전극에서 염소 발생을 체계적으로 이해하는데 도움이 되고자 한다.

• 한국자동차공학회논문집
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• 제21권2호
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• pp.37-44
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• 2013

Generally, a reduced chemical mechanism of n-heptane is used as chemical fuel of a 3-D diesel engine simulation because diesel fuel consists of hundreds of chemical components and various chemical classes so that it is very complex and large to use for the calculation. However, the importance of fuel in a 3-D simulation increases because detailed fuel characteristics are the key factor in the recent engine research such as homogeneous charged compression ignition engine. In this study, normal paraffin, iso paraffin and aromatics were selected to represent diesel characteristics and n-dodecane was used as a representative normal paraffin to describe the heavy molecular weight of diesel oil (C10~C20). Reduced kinetics of iso-octane and toluene which are representative species of iso paraffin and aromatics respectively were developed in the previous study. Some species were selected based on the sensitivity analysis and a mechanism was developed based on the general oxidation scheme. The ignition delay times, maximum pressure and temperature of the new reduced n-dodecane chemical mechanisms were well matched to the detailed mechanism data.

• 대한기계학회논문집B
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• 제32권2호
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• pp.133-140
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• 2008

A reduced chemical kinetic mechanism is developed in order to predict the flame phenomena in premixed $CO/H_2/Air$ flames at atmospheric pressure, aimed at studying the coal gas combustion for the IGCC applications. The reduced mechanism is systematically derived from a full chemical kinetic mechanism involving 11 reacting species and 66 elementary reactions. This mechanism consists of four global steps, and is capable of explicitly calculating the concentration of 7 non-steady species and implicitly predicting the concentration of 3 steady state species. The fuel blend contains two fuels with distinct thermochemical properties, whose contribution to the radical pool in the flame is different. The flame speeds predicted by the reduced mechanism are in good agreement with those by the full mechanism and experimental results. In addition, the concentration profiles of species and temperature are also in good agreement with those by the full mechanism.