• Journal of the Korean Society of Combustion
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• v.19 no.4
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• pp.49-55
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• 2014

Design criterion for the size of micro Pt-catalytic combustor is investigated in terms of heat release rate. One-dimensional plug flow model is applied to determine the surface reaction constants using the experimental data at stoichiometric butane-air mixture. With these reaction constants, the mass fraction of butane and heat release rate predicted by the plug flow model are in good agreement with the experimental data at the combustor exit. The relationship between the size of micro catalytic combustor and mixture flowrate is introduced in the form of product of two terms-the effect of fuel conversion efficiency, and the effect of chemical reaction rate and mass transfer rate.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2003.05a
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• pp.579-587
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• 2003

A lot of VOCs that is noxious ate exhausted at drying process of enamel coating device. This VOC gas can be incinerated perfectly through catalytic combustion, and heat that is occurred in incineration process ran be again used in drying process. By using VU catalytic combustion technology, in this study, we developed a enamel coating machine that have an excellent environment improvement and energy saying effect. As basic research for this development characteristics ana performance of catalytic combustion for VOC gas was evaluated and numerical analysis for drying oven was calculated. According to the result, VOCs combustion characteristics of metal form catalysis was excellent in high temperature, and it was seen that enamel coating machine should be designed as a precious controllable structure of recirculating supply rate and suction rate.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.12
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• pp.1681-1690
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• 1998

The aim of this paper is to investigate combustion characteristics of lean premixed mixture stabilized by catalytic surface reaction. The catalytic combustor consisted of a catalyst bed and a thermal combustor. The catalyst bed was made of two stage, Pd catalyst in the first stage and Pt catalyst in the second stage. Auto ignition of lean mixture took place in the thermal combustor. Ignition temperature was about $810{\sim}820^{\circ}C$ at the fuel-air ratio of 1.5~3.0 % and the mixture velocity of 11~18m/sec. The position of flame front in the thermal combustor moved toward back as preheat temperature increased and fuel-air ratio decreased. The f1ame supported by surface reaction was stabilized without any flame stabilizers. NOx emissions from the catalytic combustor were below 2.0 ppm ($O_2$ 15 %) when gas temperature was limited below $1350^{\circ}C$. This result demonstrates that NOx emission from the catalytic combustor is much low comparing with conventional combustors.

• Journal of Institute of Convergence Technology
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• v.9 no.1
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• pp.7-12
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• 2019

The aim of this study is to improve the durability performance of catalysts for a catalytic combustor and to obtain operating conditions for stable combustion of the catalytic combustor. It was attempted to improve the durability of the catalysts by adding a promoter in order to reduce the cost of replacing Pt catalyst while maintaining stability. The main catalyst used in the study was Pt and the promoters were Ni and La. Pure Pt3/γ-Al₂O₃ catalyst without promoter was promoted to fast sintering states under harsh conditions and catalytic combustion was turned off, whereas the catalysts added La, Ni as promoter were showed relatively slow sintering states. It can be concluded that the promoter La, Ni effectively contributes to the improvement of the durability of the Pt catalyst, and it is possible to get longer durability and more stable duration than the conventional catalytic combustor.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.4
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• pp.375-381
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• 2010

In this paper, the heat-transfer characteristics of steam reforming in an annular reactor are presented. Heat is supplied by the catalytic combustion of syn-gas. The thermal behaviors of exothermic and endothermic reactions in a directly coupled concentric-tube packed-bed reactor were investigated experimentally. The gas mixture supplied for catalytic combustion consisted of the off-gas emitted from MCFC anode. Methane in steam at a suitable S/C (steam-to-carbon) ratio was used in the reforming reactions. On the basis of the experimental results, a simple simulation was performed to predict the temperature profile required in the reforming side of the reactor to achieve optimum hydrogen yield. The results of this study may be utilized as reference data in future studies for further development of coupled reactors.

• Korean Chemical Engineering Research
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• v.56 no.3
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• pp.349-355
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• 2018

$BaMnAl_{11}O_{19}$ was prepared by urea-induced homogeneous precipitation and characterized by X-ray diffraction and scanning electron microscopy. At increased precipitant concentrations, AlOOH replaced $Al(OH)_3$ as an Al precursor. $BaMnAl_{11}O_{19}$ exhibited enhanced catalytic combustion performance and inhibited CO generation. Catalytic performance was also enhanced by the presence of $BaAl_2O_4$ and $BaMnAl_{11}O_{19}$. Compared to $BaAl_2O_4$, $BaMnAl_{11}O_{19}$ exhibited superior catalytic combustion activity.

• Applied Chemistry for Engineering
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• v.24 no.5
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• pp.507-512
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• 2013

Perovskite-type oxides were successfully prepared using microwave-assisted process, and by XRD, XPS, BET, and $H_2-TPR$. Their catalytic activities for the combustion of benzene were also examined. Most of catalysts studied showed the perovskite crystalline phase with the particle size of 21~35 nm. The $LaMnO_3$ catalyst showed the highest activity and the conversion reached almost 100% at $250^{\circ}C$. The catalysts prepared by microwave-assisted process showed higher activity compared to those prepared sol-gel method. In addition, the catalytic activity was increased with an increase of calcination temperature of $LaMnO_3$-type catalyst. The TPR results on the measurement of redox property showed a good correlation with the order of catalytic activity on the benzene combustion reaction.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.4
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• pp.443-448
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• 2010

The objective of this study was to assess the catalytic activities of manganese oxide (MnO, $MnO_2$, $Mn_2O_3$, and $Mn_3O_4$) catalysts for odors (acetaldehyde and propionaldehyde) removal. We used a fixed bed reactor as the experimental apparatus and the catalytic performance were carried out over the temperature range of $200{\sim}470^{\circ}C$. The properties and performance of catalysts were characterized by the X-ray diffraction (XRD) and Brunauer Emmett Teller (BET). The catalytic activities of manganese oxide catalysts for acetaldehyde combustion were in the order of MnO < $MnO_2$ < $Mn_2O_3$ < $Mn_3O_4$, and it is similar to that of propionaldehyde combustion. We also confirmed that the reactions have well followed the kinetic model of Power-Rate Law and the reaction order (n) is 1 for both of the acetaldehyde and propionaldehyde combustion. In addition, the reaction activation energy of acetaldehyde and propionaldehyde combustion over $Mn_3O_4$ were found to be $72.42\;kJmol^{-1}$ for 487~503 K and $51.14\;kJmol^{-1}$ for 473~533 K, respectively.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.6
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• pp.800-809
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• 2011

The reaction characteristics of an integrated reactor with steam reformer and catalytic combustor using anode offgas for high temperature fuel cells such as MCFC and SOFC have been experimentally investigated in the present study. The coupled reactor had a coaxial cylindrical shape, and the inner and the outer tube was packed with combustion catalysts and reforming catalysts, respectively. Thus, the endothermic steam reforming could proceed by absorbing heat from catalytic combustion of anode offgas. Results show that increasing inlet temperature and decreasing excess air ratio increased the reformer temperature, which led to the increase in $H_2$ yield. The reforming performance for SOFC conditions was better than that for MCFC conditions since the composition of flammable components became smaller for MCFC cases. Measured reformate composition under various test conditions correlated well with thermal equilibrium composition.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.4
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• pp.237-242
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• 2011

In this study, the catalytic activity of Mn-Phthalocyanine (Mn-PC) for VOCs (acetadehyde, propionaldehyde and toluene) combustion was determined. The reaction was carried out in a fixed bed reactor at the temperature range of $200{\sim}380^{\circ}C$. We investigated the physicochemical properties of Mn-PC before and after the pretreatment (air, $450^{\circ}C$, 1 hr, 60 cc/min) by TGA (Thermogravimetric Analyzer), BET (Brunauer Emmett Teller), EA (Elemental Analyzer), XRD (X-ray Diffractometer) and SEM (Scanning Electronic Microscope). By TGA analysis, 88 wt.% mass loss of Mn-PC was found at $419^{\circ}C$. The BET surface area of Mn-PC increased after the pretreatment. The decomposition and combustion of organic components in Mn-PC were observed by EA analysis. We also confirmed that Mn-PC had transformed into a new manganese oxide phase ($Mn_3O_4$) after the pretreatment by XRD analysis. By SEM analysis, many of the micropores generated during the pretreatment were found. The catalytic activity of Mn-PC with the pretreatment for propionaldehyde combustion was higher than that of $Mn_3O_4$ and fresh Mn-PC. It showed the catalytic activity of Mn-PC with the pretreatment for VOCs combustion by the order of toluene < acetadehyde < propionaldehyde.