• Transactions of the Korean hydrogen and new energy society
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• v.15 no.3
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• pp.244-249
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• 2004

Pd catalyst have been used in hydrogenation, oxidation, and low temperature combustion reaction. Recently, it has been candidated as a possible reagents in the partial oxidation of methanol reformers of the fuel cell. Pd catalysts, even though it is very precious and expensive, catalytic functioning is good, but it still need to be improved in the matter of durability and low catalytic activity after calcination. In this study, we synthesize the improved Pd catalyst and study their chemical functioning.

• Journal of Sensor Science and Technology
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• v.17 no.3
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• pp.178-182
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• 2008

Planar type micro catalytic combustible gas sensor was developed by using nano crystalline $SnO_2$ Pt thin film as micro heater was deposited by thermal evaporation method on the alumina substrate. The thickness of the Pt heater was around 160 nm. The sensor showed high reliability with prominent selectivity against various gases(Co, $C_3H_8,\;CH_4$) at low operating temperature($156^{\circ}C$). The sensor with nano crystalline $SnO_2$ showed higher sensitivity than that without nano crystalline $SnO_2$. This can be explained by more active adsorption and oxidation of hydrogen by nano crystalline $SnO_2$ particles. The present planar-type catalytic combustible hydrogen sensor with nano crystalline $SnO_2$ is a good candidate for detection of hydrogen leaks.

• Journal of the Korean Society of Combustion
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• v.12 no.4
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• pp.39-46
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• 2007

The technique of $NH_3$ SCR (selective catalytic reduction) assisted by plasma oxidation has been applied to a 2,000 cc diesel engine. The present combined $deNO_x$ process consists of two steps. The first step is that about 50% of emitted NO from the engine is oxidized to $NO_2$ in a plasma oxidation process. The second step is that NO and $NO_2$ are simultaneously reduced to $N_2$ in the $NH_3$ SCR process. The engine test results showed that the $deNO_x$ rates of the present combined process are higher than those of conventional SCR process by 20%. Such a high performance of the combined process is noticeable especially, when the exhaust temperature are relatively low, i.e., $170-220^{\circ}C$. To provide a feasibility of the present technique the effects of operating conditions, such as an electrical input energy, an exhaust gas temperature, an initial NO concentration, and the amount of hydrocarbon addition, were discussed.

• 한국연소학회:학술대회논문집
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• 2006.10a
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• pp.260-265
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• 2006

An experimental study on the catalytic reformer adopted in the auxiliary power unit system of solid oxide fuel cell was conducted. A 3-fluid nozzle, by which liquid fuel such as diesel, water and air are sprayed and uniformed mixed, was designed and used in this study. An electrically heated monolith inserted in the reformer was used for the vaporization of fuel and water in the transient state of reformer. The reformer uses the partial oxidizing reaction at the catalyst and the supply of water prevents the flame combustion in the spraying zone and lessens the deactivation of catalyst. The result showed that the reforming of liquid fuel can be started by the electrically heated monolith and the 3-fluid nozzle can give the uniform mixing of fuel, water and air. It was also found that the reformer fueled by n-hexadecane can make the reformate, at best, containing $H_2$ at 15.5% and CO at 11.5% that are used as fuel in the solid oxide fuel cell.

• Bulletin of the Korean Chemical Society
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• v.23 no.6
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• pp.799-803
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• 2002

Partial oxidation of methane has been conducted over $CeO_2$and it has been found that $CeO_2$has an extraordinary catalytic activity in the reaction. Its activity was strongly dependent on the $CH_4/CO_2$ ratio. Total combustion was dominant with stoichiometric feed ratio$(CH_4/O_2=$ 2.0) but partial oxidation was achieved between the $CH_4/O_2$ ration of 3.8 4.3 and the period depended upon the feed composition. The proposed raaction mechanism it that oxygen vacancies in raduced deria are supplied with oxygen molecules from the reactant, and then activate adsorbed oxygen, followed by releasing activated axygen species reacting with methane to produce $H_2$ and CO.

• Resources Recycling
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• v.27 no.3
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• pp.93-99
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• 2018

Effective extraction of platinum group elements by dissolving waste platinum scrap from the display industry and solvent extraction, was studied. The extracted platinum solution was prepared as a precursor solution for diesel automotive exhaust gas purification catalyst and its catalytic activity was tested. The behavior of aqueous species of platinum was investigated through solution chemistry and based on the existence and behavior of these chemical species, the possibility of extraction and separation was established. By dissolving waste scrap by electrochemical method, the dissolution time of scrap was shortened and the extraction efficiency was increased. Through separation and removal of rhodium component, solvent extraction by TBP, and stripping by hydrochloric acid, Pt-Chloride-$H_2O$ solution was prepared. And then, an platinum amine complex solution through amination reaction with this solution as a raw material was prepared. The possibility of producing high-value platinum compounds from platinum group waste scrap was investigated by preparing platinum amine complex solution and then examining the catalytic activity with this amine precursor on the combustion reaction of carbon black.

• 한국연소학회:학술대회논문집
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• 2002.11a
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• pp.237-240
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• 2002

Micro catalytic reactors are alternative propulsion device that can be used on a nano satellite. When used with a monopropellant, $H_2O_2$, a micro catalytic reactor needs only one supply system as the monopropellant reacts spontaneously on contact with catalyst and releases heat without external ignition, while separate supply lines for fuel and oxidizer are needed for a bipropellant rocket engine. Additionally, $H_2O_2$ is in liquid phase at room temperature, eliminating the burden of storage for gaseous fuel and carburetion of liquid fuel. In order to design a micro catalytic reactor, an appropriate catalyst material must be selected. Considering the safety concern in handling the monopropellants and reaction performance of catalyst, we selected hydrogen peroxide at volume concentration of 70% and perovskite redox catalyst of lantanium cobaltate doped with strondium. Perovskite catalysts are known to have superior reactivity in reduction-oxidation chemical processes. In particular, lantanium cobaltate has better performance in chemical reactions involving oxygen atom exchange than other perovskite materials. In the present study, a process to prepare perovskite type catalyst, $La_{0.8}Sr_{0.2}CoO_3$, and measurement of its propellant decomposition performance in a test reactor are described.

• Journal of the Korean Society of Combustion
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• v.12 no.3
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• pp.16-23
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• 2007

Employing an after-treatment system has almost become a mandatory requirement for Diesel vehicles, which results from a reinforced exhaust regulations as the number of vehicles powered by a Diesel engine increases. The Diesel Particulate Filter (DPF) system is considered as one of the most efficient method to reduce particulate matter (PM); however, the improvement of a regeneration performance at any engine operation point presents a considerable challenge by itself. Temperature, gas composition and flow rate of exhaust gas are important parameters in DPF evaluation processes, especially during a regeneration process. Engine dynamometer and segment tester are generally used in DPF evaluation so far. These test methods, however, could not completely evaluate the effect of various parameters on real DPF, such as oxygen concentration, amount of soot and exhaust gas temperatures. The evaluation of DPF systems using a dump combustor has been verified experimentally and this dump combustor system is likely to be appropriate for the DOC (Diesel Oxidation Catalyst) and SCR (Selective Catalytic Reduction) assessments test, too.

• Journal of Wellbeing Management and Applied Psychology
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• v.6 no.1
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• pp.17-22
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• 2023

Purpose: VOCs (volatile organic compounds) are all the organic compounds that react with solar rays and increase the concentration of ozone in the troposphere and are partially also known as carcinogens. The adsorption using activated carbon is usually applied to remove VOCs. Research design, data and methodology: The 20 places of surface coating facilities were selected to evaluate the emission amount of VOCs in Seoul. In addition, the removal efficiency of VOCs in 25 places of automobile coating facilities was evaluated. Results: The average emission amount of VOCs was 10.903 kg/hr from automobile coating facilities, while 3.520 kg/hr from other surface coating facilities. The removal efficiency in adsorption with the combustion catalytic process has the mean value of 87.9% and the regeneration efficiency of activated carbon has the mean value of 95.0%. Conclusions: The removal efficiency in adsorption with the biofiltration process has the mean value of 89.8% and the regeneration efficiency of activated carbon has the mean value of 94.8%. The removal efficiency in the plasma catalyst process has the mean value of 79.3%.

• Journal of Power System Engineering
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• v.3 no.2
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• pp.20-25
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• 1999

Experiments were carried out to investigate the characteristics of formaldehyde emission from the small gasoline engine and its reduction technologies. Catalytic converters used are Pt/Rh, Pd/Rh, Pd/Pt, $62cell/cm^2$ monolith type. The measurement of formaldehyde was conducted by using the method of DNPH-GC. From the experimental results, formaldehyde emission increased in a lean mixture due to incomplete combustion of the hydrocarbons. The order of catalytic activity of formaldehyde oxidation was Pt/Rh > Pd/Rh > Pd/Pt. As the distance from the exhaust manifold to the inlet of the catalyst became far, in spite of lower catalyst temperature, formaldehyde concentration decreased because of the adsorption of formaldehyde.