• Proceedings of the KSME Conference
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• 2001.06d
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• pp.989-994
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• 2001

Numerical simulations of high temperature catalytic combustion have been performed for the application to a gas turbine combustor. Dependences of inlet temperature and pressure on the distributions of temperature and species concentrations were investigated using plug flow model with detailed homogeneous and heterogeneous chemistries of methane-air mixtures. Honeycomb typecombustor deposited with Pt catalyst of 100mm in length and 26mm in diameter is used. The results show that rapid increase of temperature profile occurs earlier with the increase of inlet temperature and the decrease of inlet pressure. The condition which catalytic combustion is stabilized exists at certain range of inlet temperature and pressure. The state of catalytic combustion is also confirmed by the distributions of species concentration.

• 한국연소학회:학술대회논문집
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• 2004.11a
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• pp.181-186
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• 2004

Catalytic combustion is one of the suitable methods which is applicable to micro heat source due to high energy density and no flame quenching. And hydrogen can be oxidized at room temperature with platinum catalyst. So hydrogen-fueled micro catalytic combustor with platinum catalyst can be good and easy-handling heat source for another micro devices. In this work we focused on general catalytic combustion characteristics of hydrogen-air premixed gas in 10mm scale catalytic combustor for the further application to micro scale. Platinum was coated on dense ceramic monolith which can be installed in simple-structured catalytic combustor. We investigated the effect of flow rate, heat loss and platinum percentage in catalyst-coated monolith on catalytic combustion performance by temperature distribution in the combustor. By those results we confirmed catalytic reactivity and estimated reaction area. And we simulated micro scale catalytic reaction by sliced monolith. The results of this work will be important design factors for micro scale catalytic combustor.

• Clean Technology
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• v.25 no.4
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• pp.331-335
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• 2019

Interest in environmental pollution is increasing all over the world, and technology development to solve it is actively carried out. In areas where heat is used, especially, combustion is causing countless pollutants in the air environment. Combustion catalyst is a technology that reduces NOx and CO by lowering combustion temperature and enabling complete combustion. Traditional combustion catalysts are expensive and complex in the synthesis process using precious metal catalyst. In this study, hexaaluminate, a high-temperature combustion catalyst, was manufactured using urea, and the properties were investigated according to the synthesis time. The combustion performance and characteristics were evaluated using this catalyst. As the temperature increased, the changing methane conversion rate was shown in two patterns. The conversion rates for 1 hour, 9 hours, and 12 hours were similar, while the conversion rates for 3 hours and 6 hours showed similar patterns. Methane combustion performance increased rapidly as the synthesis time increased from 6 hours to 9 hours, whereas the temperature at T50 was approximately 745 ℃. The performance of the synthesized combustion catalyst for 9 hours was optimum as the NOx emission of this combustion catalyst was not present and the maximum emission of CO was 72 ppm.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.5
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• pp.541-549
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• 2003

A basic experimental study was conducted in order to find the optimum combustion control technology to decrease the thermal NO$_{x}$, by applying the catalytic combustion method with natural gas. NO$_{x}$ emission increased with increasing space velocity due to temperature rising in the furnace. In order to overcome the low resistance to high temperature, secondary air was supplied to the CST combustor. The following secondary fuel formed combustible mixture in part, which resulted in steep increase of the exiting temperature of the 2nd catalyst bed. It led to the more generator of NO$_{x}$, 30∼60% of the 1 st catalyst bed. It might be due to the potential increase of thermal NO$_{x}$.

• 한국연소학회:학술대회논문집
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• 2002.11a
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• pp.71-79
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• 2002

The characteristics of the catalytically supported combustion with Pd and Pd/Pt based catalyst using the bench-scaled high pressure combustor have been investigated up to 5atm. This study aimed to investigate combustion characteristics of the stable flame attached to the exit of catalyst bed and NOx emissions with respect to the position of axial and radial direction in the combustor. NOx emissions were increased along the axial distance after the catalyst bed exit and radially decreased from the center to the wall of the combustor. At the higher pressure, the NOx emission decreased slightly due to the lower flame temperature in the combustor at the high pressure.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.281-290
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• 2018

As the internal combustion engine vehicles of high fuel efficiency and low emission are demanded, it becomes important to procure technologies for improving low-temperature performance of automotive catalyst systems. In this study, we showed that the combustion rate of diesel particulate matter is greatly enhanced at low temperature by applying fuel-borne catalyst and perovskite catalyst concurrently. It was tried to examine the correlation between elemental composition of perovskite catalyst and combustion activity of mixed catalyst system. To achieve this goal, we applied temperature-programmed oxidation technique in testing the combustion behavior of perovskite-mixed particulate matter bed which contained the element of fuel-borne catalyst or not. We tried to explain the synergetic action of two catalyst components by comparing the trends of concentrations of carbon dioxide and nitrogen oxide in temperature-programmed oxidation results.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.4
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• pp.324-330
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• 2018

In this study a numerical study was conducted to show flow, temperature and gas distributions in a high temperature CO shift reactor which was designed specially for energy saving and then evaluated with the related experiment. Mole fractions of syngas at the end of the catalyst bed were predicted with various assumed pre-exponential factors, were compared with the corresponding experimental results and $10^8$ was finally selected as the value. With the selection, a base case was examined. It was calculated that the inlet duct attached asymmetrically to the CO shift reactor affects on the distribution of the upward momentum (+z directional). In addition, CO conversion ratio is achieved up to 90% in the catalyst bed and especially it reached up to 70% at the initial part of catalyst bed.

• Journal of Energy Engineering
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• v.6 no.1
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• pp.34-40
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• 1997

This study aims to investigate the application possibility on natural gas in relation to the catalytic combustion of methane on Pd/cordierite catalyst which is currently used as an automobile converter catalyst. The surface area of the catalyst tested was determined to be about 18.7㎡/g and to keep stable condition in structure at mid-high temperatures. The activation energy for methane combustion reaction was estimated to be 19.2 kcal/mol and a hysterisis on the catalyst activity was observed in terms of the catalyst deactivation as the reaction temperature was varied for the methane combustion. On Pd/cordierite catalyst, The characteristics of methane combustion were studied as functions of space velocity and air/fuel ratios below 700$^{\circ}C$.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.3
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• pp.193-200
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• 2010

Anode off-gas of high temperature fuel cell still contains combustible components such as hydrogen, carbon monoxide and hydrocarbon. In this study, a catalytic combustor has been applied to the high temperature fuel cell so that the combustion of anode-off gas can be boosted up. Since the performance of catalytic combustor directly depends on the combustion catalyst, this study is designed to perform the experimental investigation on the combustion characteristics of the three commercial catalysts with a different composition. Screening tests with three catalysts are preceded before the performance examination since it is necessary to determine the most suitable catalyst for design configuration of the catalytic combustor. The performance analysis shows that methane conversion rate strongly depends on gas hourly space velocity (GHSV) as well as inlet gas temperature. Additionally, the GSHV optimization results show that the optimum GHSV will be in the range between 18,000 $hr^{-1}$ and 36,000 $hr^{-1}$. It is also shown that the minimum inlet temperature of catalytic reaction of methane is from $100^{\circ}C$ to $150^{\circ}C$.

• 한국연소학회:학술대회논문집
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• 2001.11a
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• pp.73-82
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• 2001

The characteristics of the catalytically supported thermal combustion with Pd-based catalyst using the bench scale high pressure combustor has been investigated up to 7 atm. The emission of $NO_{\chi}$ depends on the preheating temperature and the excess air ratio. Most $NO_{\chi}$ emission seems to come from the pre-burner for the preheating of the inlet gas. Decreasing excess air ratio in the inlet gas below 1.5 results in the stable catalytically supported thermal combustion in the post combustion region while the $NO_{\chi}$ emission increased up to 15 ppm. Further, the increase of the pressure shows the dramatic increase of the emission CO and THC. However, the $NO_{\chi}$ emission decreased slightly due to the lower combustion temperature at the high pressure.