• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.455-456
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• 2003

광화학 스모그 현상을 재현하기 위한 메카니즘은 약 20,000개의 반응식과 수천개의 종이 포함되어야 하므로 자세한 반응 메카니즘을 포함하는 데는 한계가 있다(Dodge, 2000). 최근에 morphecule이라 부르는 대리종(surrogates)을 사용하는 방법(morphecule approach)이 개발되었다. 이 메카니즘은 반응 속도, 생성율, 생성물의 형태를 포함하여 lumped surrogates와 관련된 인자들이 모사하는 전체 시간 중 각 t시간 동안 일정하고 그 시간이후에는 인자들이 변화한다고 가정한다. 또한 특성이 비슷한 유기 화합물의 다양한 그룹을 표현할 때 morphecule이라 부르는 특정 화학종들을 사용한다. (중략)

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.449-452
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• 2007

The present study numerically investigate the effects of the Syngas chemical kinetics on the basic flame properties and the structure of the Syngas diffusion flames. In order to realistically represent the turbulence-chemistry interact ion and the spatial inhomogeneity of scalar dissipation rate. the Eulerian Particle Flamelet Model(EPFM) with multiple flamelets has been applied to simulate the combustion processes and NOx formation in the syngas turbulent nonpremixed flames. Due to the ability for interactively describing the transient behaviors of local flame structures with CFD solver, the EPFM model can effectively account for the detailed mechanisms of NOx format ion including thermal NO path, prompt and nitrous NOx format ion, and reburning process by hydrocarbon radical without any ad-hoc procedure. validation cases include the Syngas turbulent nonpremixed jet and swirling flames. Based on numerical results, the detailed discussion has been made for the sensitivity of the Syngas chemical kinetics as well as the precise structure and NOx formation characteristics of the turbulent Syngas nonpremixed flames.

• Journal of the Korean Applied Science and Technology
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• v.29 no.4
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• pp.570-576
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• 2012

In this study, we investigated the characteristics of NO oxidation using un-divided electrolyzed seawater as oxidant. The concentration of available chlorine and the temperature of electrolyzed seawater are increased with electrolysis time in the closed-loop constant current electrolysis system. While NO gas flow through bubbling reactor which is filled with electrolyzed seawater, the oxidation rate of NO to $NO_2$ is increased with the concentration of available chlorine and the temperature. $NO_2$, generated by oxidation reaction, is dissolved in electrolyzed seawater and existed as $HNO_3{^-}$ ion.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.746-751
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• 2002

Fluidized bed combustion is a coal combustion technology that can reduce both SOx and NOx emission; SOx is removed by limestone that is fed into the combustion chamber and the NOx is reduced by low temperature combustion in a fluidized bed combustor and air stepping, but $N_2O$ generation is quite high. $N_2O$ is not only a greenhouse gas but also an agent of ozone destruction in the stratosphere. The calcium oxide(CaO) is known to be a catalyst of $N_2O$ decomposition. This study of $N_2O$ decomposition reaction in fixed bed reactor packed over CaO bed has been conducted. Effects of parameters such as concentration of inlet $N_2O$ gas, reaction temperature, CaO bed height and effect of $CO_2$, NO, $O_2$ gas on the decomposition reaction have been investigated. As a result of the experiment, it has been shown that $N_2O$ decomposition reaction increased with the increasing fixed bed temperature. While conversion of the reaction was decreased with increasing $CO_2$ concentration. Also, under the present of NO, the conversion of $N_2O$ decomposition is decreased. From the result of kinetic study gained the heterogeneous reaction rate on $N_2O$ decomposition. In the case of $N_2O$ decomposition over CaO, heterogeneous reaction rate is. $\frac{d[N_2O]}{dt}=\frac{3.86{\times}10^9{\exp}(-15841/R)K_{N_2O}[N_2O]}{(1+K_{N_2O}[N_2O]+K_{CO_2}[CO_2])}$. In this study, it is found that the calcium oxide is a good catalyst of $N_2O$ decomposition.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.2
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• pp.188-193
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• 2015

It has been generally recognized that $N_2O$(Nitrous Oxide) emission from marine diesel engines has a close correlation with $SO_2$(Sulfur Dioxide) emission, and diversity of fuel elements using ships affects characteristics of the $N_2O$ emission. According to recent reports, in case of existence of an enough large NO(Nitric Oxide) generated as fuel combustion, effect of the $SO_2$ emission in exhaust gas on the $N_2O$ formation is more vast than effect of the NO. Therefore, $N_2O$ formation due to the $SO_2$ element operates on a important factor in EGR(Exhaust Gas Recirculation) systems for NOx reduction. An aim of this experimental study is to investigate that intake gas of the diesel engine with increasing of $SO_2$ flow rate affects $N_2O$ emission in exhaust gas. A test engine using this experiment was a 4-stroke direct injection diesel engine with maximum output of 12 kW at 2600rpm, and operating condition was set up at a 75% load. A standard $SO_2$ gas with 0.499%($m^3/m^3$) was used for changing of $SO_2$ concentration in intake gas. In conclusion, the diesel fuel included out sulfur elements did mot emit the $SO_2$ emission, and the $SO_2$ emission in exhaust gas according as increment of the $SO_2$ standard gas had almost the same ratio compared with $SO_2$ rate in mixture inlet gas. Furthermore, the $N_2O$ element in exhaust gas was formed as $SO_2$ mixture in intake gas because increment of $SO_2$ flow rate in intake gas increased $N_2O$ emission. Hence, diesel fuels included sulfur compounds were combined into $SO_2$ in combustion, and $N_2O$ in exhaust gas should be generated to react with NO and $SO_2$ which exist in a combustion chamber.

• Clean Technology
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• v.25 no.4
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• pp.316-323
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• 2019

In order to enhance combustion efficiency and reduce atmosphere pollutants, it is essential to measure carbon monoxide (CO) concentration precisely in combustion exhaust. CO is the important gas species regarding pollutant emission and incomplete combustion because it can trade off with NOx and increase rapidly when incomplete combustion occurs. In the case of a steel annealing system, CO is generated intentionally to maintain the deoxidation atmosphere. However, it is difficult to measure the CO concentration in a combustion environment in real-time, because of unsteady combustion reactions and harsh environment. Tunable Diode Laser Absorption Spectroscopy (TDLAS), which is an optical measurement method, is highly attractive for measuring the concentration of certain gas species, temperature, velocity, and pressure in a combustion environment. TDLAS has several advantages such as sensitive, non-invasive, and fast response, and in-situ measurement capability. In this study, a combustion system is designed to control the equivalence ratio. Also, the combustion exhaust gases are produced in a Liquefied Petroleum Gas (LPG)/air flame. Measurement of CO concentration according to the change of equivalence ratio is confirmed through TDLAS method and compared with the simulation based on Voigt function. In order to measure the CO concentration without interference from other combustion products, a near-infrared laser at 4300.6 cm^-1 was selected.