• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.7
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• pp.634-640
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• 2003

This paper is to be researched into ozone generation character of Bi-Ti-Si type high dielectric yield ceramic catalyst discharge tube. And conditions of basic experiment are the outside diameter of discharge tube : 52 mm, the length of discharge tube : 350 mm, the frequence : 900 Hz, the temperature of cooling water : 25 $^{\circ}C$, quantity of flow : 5, 10, 20 l/min, pressure : 1.2, 1.4, 1.6 atm, and distance of discharge gap : 0.4, 0.6, 0.8 mm. Ozone generation characteristics were measured to consumption power. At quantity of flow : 20 l/min, discharge gap : 0.6 mm, pressure : 1.6, and consumption power : 150 W, Maximum ozone generation efficiency of 175 g/kWh was obtained. Maximum ozone generation efficiency was measured below the flow quantity of 20 l/min at below pressure of 1.6 atm. However, Maximum ozone generation efficiency was measured over the flow quantity of 20 l/min at over pressure of 1.6 atm.

• Korean Chemical Engineering Research
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• v.56 no.5
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• pp.752-760
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• 2018

The lowering of temperature for combustion of diesel particulate matters (or diesel soot) is one of the important tasks in automotive industry that is searching for a way to meet up "high-fuel efficiency, low-emission" standard. In this study, it was discussed how the use of ozone over platinum-based catalyst promotes a low-temperature soot oxidation occurred at $150^{\circ}C$. The use of platinum catalyst did not increase oxidation rate largely but was very effective in improving the selectivity of carbon dioxide. The pre-oxidation of NO into $NO_2$ using ozone was rather crucial in improving the oxidation rate of soot at $150^{\circ}C$.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1678-1683
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• 2003

DBD(Dielectric Barrier Discharge) plasma in air is well established for the production of large quantities of ozone and is more recently being applied to aftertreatment processes for HAPs(Hazardous Air Pollutants). Although DBD high electron density and energy, its potential use as nano and sub-micron sized particle charging are not well known. Aim of this work is to determine design and operating parameters of a two-stage ESP with DBD. DBD and ESP are used as particle charger and precipitator, respectively. We measured particle precipitation efficiency of two-stage ESP and estimated ozone decomposition of both pelletized $MnO_2$ catalyst and pelletized activated carbon. To examine the particle precipitation efficiency, nano and sub-micron sized particles were generated by a tube furnace and an atomizer. AC voltage of $7{\sim}10$ kV(rms) and 60 Hz is used as DBD plasma source. DC -8 kV is applied to the ESP for particle precipitation. The overall particle collection efficiency for the two-stage ESP with DBD is over 85 % under 0.64 m/s face velocity. Ozone decomposition efficiency with pelletized $MnO_2$ catalyst or pelletized activated carbon packed bed is over 90 % when the face velocity is under 0.4 m/s in dry air.

• Applied Chemistry for Engineering
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• v.32 no.4
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• pp.483-486
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• 2021

Catalytic ozonation of methyl ethyl ketone (MEK) has been examined over mesoporous MnO_x/Al₂O₃ (MA) catalysts developed by a solvent deficient method using two different manganese precursors including manganese chloride (C) and manganese sulfate (S) at room temperature. The maximum catalytic activities of MA with C (MEK removal efficiency and ozone decomposition of 98.4 and 93.7%, respectively) were higher than those of MA with S (MEK removal efficiency and ozone decomposition of 96 and 68%, respectively). Also the catalytic stability of MA with C was much higher than that of MA with S. The physico-chemical properties of catalysts are well correlated with the activity results, which confirmed that fine dispersion of MnO_x species with high ratios of Mn³⁺/Mn⁴⁺ and more acid sites are attributed to the higher catalyst stability for the MA-C catalyst.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.6
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• pp.130-136
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• 2002

A novel ozonizer has been developed using a high frequency surface discharge and a high purity Ti-Si-Al ceramic catalyst as its dielectric component. A cylindrical thin compound ceramic catalyst in reactor is adhered to inside of the film-like outside electrode. And, when experiment condition are oxygen gas temperature of 20 ［$^{\circ}C$］, inner reactor pressure of 1.6 atm 600［Hz］ and flow late of 2［l/min］. the ozonizer can easily produce ozone concentration(50～60［g/㎥］for oxygen) and power efficiency(180［g/kWh］for oxygen) without using a special enrichment means. At 2［l/min］, 20［$^{\circ}C$］, 1.6［atm］, 600［Hz］and 40［W］, the result of simulation to gas temperature of reactor using general code Phoenics, the maximum temperature of reactor was 132［$^{\circ}C$］in reactor. Ant the result electric field simulation of Ti-Si-Al type reactor using general code Flux 2D, maximum electric field was 0.131E.08［V/m］.

• Journal of Industrial Technology
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• v.39 no.1
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• pp.1-5
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• 2019

In this study, we examined the effect of NO addition on the ozone-induced soot oxidation activity of $LaMnO_3$ perovskite catalysts. The addition of 10~20% NO ($NO_2$) with respect to the concentration of ozone effectively enhanced the rate of ozone-induced soot oxidation rate over $LaMnO_3$. However, the excessive addition of NO ($NO_2$) was detrimental to ozone-induced soot oxidation activity. It is supposed nitrogen oxides would adsorb on the catalyst and then react with carbon-oxygen species developed on soot surface, but an excessive addition of nitrogen oxide would inhibit the formation of carbon-oxygen species, which is a key intermediate in the reaction, and consequently suppress the oxidation rate of soot.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.6
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• pp.577-585
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• 2014

A series of experiments using atmospheric-pressure non-thermal plasma coupled with transition metal catalysts were performed to remove ethylene from agricultural storage facilities. The non-thermal plasma was created by dielectric barrier discharge, which was in direct contact with the catalyst pellets. The transition metals such as Ag and $V_2O_5$ were supported on ${\gamma}-Al_2O_3$. The effect of catalyst type, specific input energy (SIE) and oxygen content on the removal of ethylene was examined to understand the behavior of the hybrid plasma-catalytic reactor system. With the other parameters kept constant, the plasma-catalytic activity for the removal of ethylene was in order of $V_2O_5/{\gamma}-Al_2O_3$ > $Ag/{\gamma}-Al_2O_3$ > ${\gamma}-Al_2O_3$ from high to low. Interestingly, the rate of plasma-catalytic ozone generation was in order of $V_2O_5/{\gamma}-Al_2O_3$ > ${\gamma}-Al_2O_3$ > $Ag/{\gamma}-Al_2O_3$, implying that the catalyst activation mechanisms by plasma are different for different catalysts. The results obtained by varying the oxygen content indicated that nitrogen-derived reactive species dominated the removal of ethylene under oxygen-lean condition, while ozone and oxygen atoms were mainly involved in the removal under oxygen-rich condition. When the plasma was coupled with $V_2O_5/{\gamma}-Al_2O_3$, nearly complete removal of ethylene was achieved at oxygen contents higher than 5% by volume (inlet ethylene: 250 ppm; gas flow rate: $1.0Lmin^{-1}$; SIE: ${\sim}355JL^{-1}$).

• Applied Chemistry for Engineering
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• v.26 no.4
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• pp.463-469
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• 2015

Bisphenol A (BPA) in aqueous solution was measured using HPLC technique, which was established by acetonitrile analysis and KDP solution analysis methods. In these experiments the decomposition characteristics of BPA were compared using the ozone alone, ozone/pH 10, and ozone/hydrogen peroxide processes. About 70% of 10 mg/L of BPA was removed during 60 min by the ozone alone process, while 10 mg/L of BPA was completely removed by the ozone/pH 10 and ozone/hydrogen peroxide processes in 40 min and 60 min, respectively. The final decomposition efficiency drawn from results of TOC and HPLC analyses showed that the ozone/hydrogen peroxide process was the best among them, whereas the concentrations of TOC and reaction intermediates when using the ozone/pH 10 process were higher than those of the ozone alone process after 60 min of reaction. The ozone/hydrogen peroxide process was the most efficient among them when oxidizing organic carbons in water to $CO_2$ and $H_2O$.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.206-208
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• 2002

A novel ozonizer has been developed using a high frequence surface discharge and a high purity ceramic as its dielectric component. And A cylindrical thin compound ceramic catalyst in reactor is adhered to inside of the film-like outside electrode. An ac exciting voltage with frequency to 0.6 kHz from 1.0 kHz and $4{\sim}6$ kV of peak-to-peak is applied between the electrodes to produce a stable high-frequency silent discharge for generation of ozone. A substantial reduction of the exciting voltage is also enabled by using a thin ceramic. As a result, the ozonizer can easily produce ozone concentration(50 $g/m^3$ for oxygen) and power efficiency(240 g/kWh for oxygen) without using a special enrichment means.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.989-994
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• 2005

The treatment efficiency and the degradation characteristics of humic acid were investigated in three processes-GAC adsorption, Ozone alone and Ozone/GAC hybrid process, in which $UV_{254}$, DOC, molecular size distribution and surface change of GAC were evaluated. DOC removal rate in Ozone/GAC hybrid profess(ca. 80%) was higher than the arithmetic sum of Ozone alone(38%) and GAC adsorption(19%). This result approves that the combined Ozone/GAC hybrid process brings synergistic effects on DOC removal from the HA containing water. $UV_{254}$ decrease rate was also at the highest in Ozone/GAC hybrid process from the three processes. It may be interpreted that the granular activated carbon in Ozone/GAC hybrid process acts as not only an adsorbent but also a catalyst for ozonation, and futhermore offers an additional reaction site between adsorbed organic matter and ozone. In the study of molecular sire distribution, there was no significant change of molecular size distribution in the GAC adsorption process during the reaction time of 120 min. In Ozone alone process, the fraction of molecular size over 30 kDa was decreased a little at the beginning and left constant after 10 min. But in Ozone/GAC hybrid process, the molecules size over 30 kDa of HA was significantly decreased from 36.3% to 3.9%. And also the fraction of smaller molecular size below 0.5 kDa was increased from 4.8%(untreated HA) to 12.3%(in Ozone alone) and 40.1%(in Ozone/GAC) respectively at the reaction time of 120 min.