• Proceedings of the KAIS Fall Conference
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• 2011.12b
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• pp.496-498
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• 2011

본 논문에서는 알루미늄 드로스를 재활용하여 생성 된 수산화알루미늄을 이용하여 질소산화물 제거 SCR 촉매를 제조하였다. 현재 상용중인 촉매와 화학적 특성과 질소산화물 제거 효율을 비교하기 위해 동일 타입의 하니컴 형태의 $V_2O_5-WO_3-TiO_2-Al_2O_3$ SCR 촉매를 제조하였으며, XRF와 BET를 사용하여 화학적 특성을 평가 비교하였다. 또한 MR(Micro Reactor)을 이용하여 $350^{\circ}C$와 $450^{\circ}C$에서 질소산화물 제거 평가를 실시하였으며, 평가 결과 80~90%의 제거 효율을 확인하였다.

• Resources Recycling
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• v.29 no.2
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• pp.55-61
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• 2020

Selective catalytic reduction (SCR) has been a promising technology to reduce the air pollution caused by nitrogen oxides (NOx) in several industries. The consumption of SCR catalysts increases every year as technology evolves, however those have a limited lifespan and usually end up in landfills after they deactivate. Currently, the most widely used catalyst for and stationary applications is V₂O₅-WO₃/TiO₂ which can contain around 50% wt V₂O₅ and 7-10% wt of WO₃. The vast uses for both vanadium and tungsten and the worldwide interest in recycling methods that allow for the extraction of metals from secondary sources represent the major motivation for this research. The extraction time, pH dependency, extraction concentration studies were carried out using Aliquat 336 in exxol D80 as the extractant. It was determined that to optimize the extraction of both metals 30min of contact time with an organic phase containing 0.5mol/L of Aliquat 336 are needed at a slightly acidic pH (~5.0). In addition, counter McCabe-Thiele studies allowed us to determine that one stage is necessary for the removal of 99% of vanadium while 2 stages are necessary for the extraction of tungsten and counter current simulations proved that the theoretical approach was correct.

• Applied Chemistry for Engineering
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• v.19 no.1
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• pp.80-85
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• 2008

Catalytic filter is capable of performing shallow bed dust filtration plus a catalytic reaction, promoted by a catalyst deposited in its inner structure. Such a feature may allow potential cost and space reduction in several environmental applications. Dust filtration and halogenated volatile organic compound (1,2-dichlorobenzene) destruction were carried out in a lab-scale reactor. $WO_3-V_2O_5/TiO_2$ supplied by MaGreen, which showed high catalytic acitivity at low temperature, was used as a catalyst. P-84 that can be operated under $250^{\circ}C$ was used as a felt. The catalytic activity and filtration efficiency of catalytic filters were investigated under the operating conditions, including temperature, face velocity, and dust concentration. The catalytic activity of catalytic filter increased with increasing temperature and the amount of catalyst loaded. The test results showed that the filtration efficiency was primarily affected by the face velocity. Pressure drop variations as a function of time were investigated for a variety of conditions. In case of virgin filter, a dramatic decrease in the pulse interval and a slightly increase in the base line pressure drop were observed. A relatively slow pressure drop build-up was recorded for the catalytic filter due to smooth and slippery surface characteristics of nanofiber. The catalytic filter indicated that high filtration efficiency over 99.98% and high catalytic activity over 90% at 1 m/min and $210^{\circ}C$.

• Applied Chemistry for Engineering
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• v.33 no.6
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• pp.600-605
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• 2022

In this study, nitrogen oxide (NO_x) removal experiments were performed using a graphene based ceramic filter coated with a V₂O₅-WO₃-TiO₂ catalyst. Graphene oxide (GO) was prepared by Hummer's method using graphite, and the reduced graphene oxide was produced by reducing with hydrazine (N₂H₄). Vanadium (V), Tungsten (W), and Titanium (Ti) were coated by the sol-gel method, and then a metal oxide-supported filter was prepared through a calcination process at 350 ℃. A NO_x removal efficiency test was performed for the catalytic ceramic filters with UV light in a humid condition. When graphene oxide (GO) and reduced graphene oxide (rGO) were present on the filter, the NOx removal efficiency was superior to that of the conventional ceramic filter. Most likely, this is due to an improvement in the adsorption properties of NOx molecules on graphene coated surfaces. As the concentration of graphene increased, higher NO_x removal efficiency was confirmed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1209-1215
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• 2022

The selective catalytic reduction (SCR) is known as a very efficient method to reduce nitrogen oxides (NOx) and the catalyst performs reduction from nitrogen oxides (NOx) to nitrogen (N₂) and water vapor (H2O). The catalyst, which is one of the factors determining the performance of the nitrogen oxide (NOx) ruduction method, is known to increase catalyst efficiency as cell density increases. In this study, the reduction characteristics of nitrogen oxides (NOx) under various engine loads investigated. A 100CPSI(60Cell) catalysts was studied through a laboratory-sized simulating device that can simulate the exhaust gas conditions from the power generation engine installed in the training ship SEGERO. The effect of 100CPSI(60Cell) cell density was compared with that of 25.8CPSI(30Cell) cell density that already had NOx reduction data from the SCR manufacturing. The experimental catalysts were honeycomb type and its compositions and materials of V₂O₅-WO₃-TiO₂ were retained, with only change on cell density. As a result, the NOx concentration reduction rate from 100CPSI(60Cell) catalyst was 88.5%, and IMO specific NOx emission was 0.99g/kwh satisfying the IMO Tier III NOx emission requirement. The NOx concentration reduction rate from 25.8CPSI(30Cell) was 78%, and IMO specific NOx emission was 2.00g/kwh. Comparing the NOx concentration reduction rate and emission of 100CPSI(60Cell) and 25.8CPSI(30Cell) catalysts, notably, the NOx concentration reduction rate of 100CPSI(60Cell) catalyst was 10.5% higher and its IMO specific NOx emission was about twice less than that of the 25.8CPSI(30Cell) catalysts. Therefore, an efficient NOx reduction effect can be expected by increasing the cell density of catalysts. In other words, effects to production cost reduction, efficient arrangement of engine room and cargo space can be estimated from the reduced catalyst volume.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.330-336
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• 2005

The ozone injection method was proposed to improve the catalytic process for the removal of nitrogen oxides ($NO_x$). Nitric oxide (NO) in the exhaust gas was first oxidized to nitrogen dioxide ($NO_2$) by ozone produced by dielectric barrier discharge, and then the exhaust gas containing the mixture of NO and $NO_2$ was directed to the catalytic reactor where both NO and $NO_2$ were reduced to $N_2$ in the presence of ammonia as the reducing agent. A commercially available $V_2O_5-WO_3/TiO_2$ catalyst was used as the catalytic reactor. The $NO_2$ content in the mixture of NO and $NO_2$ was changed by the amount of ozone added the exhaust gas. The effect of reaction temperature, initial $NO_x$ concentration, feed gas flow rate, and ammonia concentration on the removal of $NO_x$ at various $NO_2$ contents was examined and discussed. The increase in the content of $NO_2$ by the ozone injection remarkably improved the performance of the catalytic reactor, especially at low temperatures. The present ozone injection method appears to be promising for the improvement of the catalytic reduction of $NO_x$.