• Proceedings of the Membrane Society of Korea Conference
• /
• 1993.04a
• /
• pp.39-40
• /
• 1993

부분 산화반응에 주촉매로 사용되는 바나듐($V_2O_5$)을 담체 내부에 코팅하기위한 방법과 조건을 찾고, 제도된 바나듐막의 구조적 전자적 특성과 투과도 특성을 알아보며 이 바나듐막을 코팅한 막반응기를 이용하여 탄화수소의 부분 산화반응을 수행하여 그 반응특성을 알아보았다.

• Proceedings of the KAIS Fall Conference
• /
• 2004.11a
• /
• pp.265-268
• /
• 2004

Methyl methacrlate와 cyclopentadiene을 반응하여 Methyl 5-methylbicyclo(2.2.1)hept-2-ene-5-carboxylate(MMBHC)를 합성코자 하였다. 합성된 MMBHC의 온도, solvent 변화와 촉매($AlCl_3$)의 사용 유무에 따른 endo, exe의 비율을 관찰하였다. 온도가 낮은 경우 온도가 높은 쪽 보다 endo 비율이 높았고 촉매($AlCl_3$)를 사용하였을 때(약 endo : exo = 63 : 37) 촉매를 사용하지 않은 반응(endo : exe = 34 : 66)보다 endo의 비율이 높았다. methyl acrylate를 사용한 경우 같은 조건에서 endo : exe의 비율이 93.5 : 6.5로 MMA를 사용한 경우보다 endo의 비율은 좋았다. 온도가 높은 경우 수율은 좋았지만 exe의 비율이 높았고 solvent에 따라 endo, exe의 선택도는 큰 차이를 보이지 않음을 알 수 있었다.

• Resources Recycling
• /
• v.27 no.1
• /
• pp.64-73
• /
• 2018

This study aims to analysis the environmental impact on waste catalyst recycling technology using entire life cycle assessment. Environmental impacts consist of the five categories of impacts: global warming, resource depletion, acidification, eutrophication, and photochemical oxide production. The waste catalyst recycling presently have a GWP 3.53 ton $CO_2$ equivalent/ton, a ADP 0.017 ton Sb equivalent/ton, a AP 0.051 $SO_2$ equivalent/ton, a EP 0.0092 $PO{_4}^{3-}$ equivalent/ton, a 0.0019 ton $C_2H_4$ equivalent/ton. The smelting reduction process is the greatest contributor to all categories of environmental impacts in waste catalyst recycling. Electricity used in the smelting reduction process is the major contributor of all impact categories.

• Applied Chemistry for Engineering
• /
• v.22 no.6
• /
• pp.648-652
• /
• 2011

Passive autocatalytic recombiner (PAR) is considered as an explosive gas control system in operating NPP plants. This work investigates and evaluates hydrogen recombination performance over manufactured $Pt/TiO_2$ catalysts. When the space velocity increases, the hydrogen conversion decreased, while hydrogen depletion rate (g/sec) increases highly in $35000{\sim}100000hr^{-1}$ Gas Hourly Space Velocity (GHSV). Hydrogen conversion and depletion rate with Pt loading is investigated. As a result, there were no differences in the hydrogen conversion, but exothermic heating rate (K/sec) is increases as Pt loading increases. The catalyst showes a high hydrogen conversion efficiency of 80% under atmospheric conditions.

• Air Cleaning Technology
• /
• v.15 no.2 s.57
• /
• pp.24-32
• /
• 2002

• JOURNAL OF ELECTRICAL WORLD
• /
• s.407
• /
• pp.83-85
• /
• 2010

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.27 no.1
• /
• pp.1-8
• /
• 2017

Catalytic synthesis and properties of ${\beta}-Ga_2O_3$ nanowires grown by metal organic chemical vapor deposition are reported. Au, Ni and Cu catalysts were suitable for the growth of $Ga_2O_3$ nanowires under our experimental conditions. The $Ga_2O_3$ nanowires grown by using Au, Ni and Cu catalysts showed different growth rates and morphologies in each case. We found the $Ga_2O_3$ nanowires were grown by the Vapor-Solid (VS) process when Ni was used as a catalyst while the Vapor-Liquid-Solid (VLS) was a dominant process in case of Au and Cu catalysts. Also, we found nanowires showed different optical properties depend on catalytic metals. On the other hand, for the cases of Ti, Sn and Ag catalysts, nanowires could not be obtained under the same condition of Au, Cu and Ni catalytic synthesis. We found that these results are related to the different characteristics of each catalyst, such as, melting points and phase diagrams with gallium metal.

• Applied Chemistry for Engineering
• /
• v.8 no.2
• /
• pp.211-219
• /
• 1997

Liquid or gas phase alkylation of isobutane with 1-butene for i-octane production was carried out over Cs- or $NH_4$-exchanged $H_3PW_{12}O_{40}$. Pretreatment temperature of the catalyst played an important role on the catalytic activity of heteropoly acids in the liquid phase alkylation. Cation-exchanged $H_3PW_{12}O_{40}$ showed a better total yield and i-octane selectivity than the mother acid in the liquid phase alkylation, and $(NH_4)_{2.5}H_{0.5}PW_{12}O_{40}$ was more efficient than $Cs_{2.5}H_{0.5}PW_{12}O_{40}$ in terms of i-octane selectivity. It was found that the acidic property (deactivation of acid sites) of the catalyst was closely related to the catalytic activity of Cs- or $NH_4$-exchanged $H_3PW_{12}O_{40}$ in the gas phase alkylation. $C_5-C_7$ were mainly formed in the early stage of gas phase alkylation due to the strong acidic property of the catalyst, whereas $C_8$ and $+C_9$ were mainly produced as the reaction proceeded due to the deactivation of acid sites. $Cs_{2.5}H_{0.5}PW_{12}O_{40}$ showed the highest total yield in the gas phase alkylation among the catalysts examined.

• Applied Chemistry for Engineering
• /
• v.28 no.3
• /
• pp.279-285
• /
• 2017

In this study, the study of the selective catalytic oxidation (SCO) for controlling the $NH_3$ at $200{\sim}350^{\circ}C$ range was investigated. Physicochemical properties of the catalysts were determined using XRD and XPS analysis. In the case of catalytic activity according to thermal treatment condition, the reduction catalyst showed better activity than that of using the calcination catalyst. It was confirmed that the valence state of reduction catalyst was mainly $Pt^{2+}$ and $Pt^0$ as analyzed by XPS. Also, when comparing the reaction activities of $Pt/TiO_2$ catalysts according to the reduction temperature, the $NH_3$ conversion of the catalyst reduced at $700^{\circ}C$ showed the most excellent activity. However, the best activity of $NH_3$ conversion to $N_2$ was obtained for the catalyst reduced at $600^{\circ}C$.

• Korean Chemical Engineering Research
• /
• v.44 no.6
• /
• pp.650-658
• /
• 2006

The recycling of TDA from solid waste of TDI plant(TDI-R) by near-critical hydrolysis reaction had been studied by means of a statistical design of experiment. The main and interaction effects of process variables had been defined from the experiments in a batch reactor and the correlation equation with process variables for TDA yield had been obtained from the experiments in a continuous pilot plant. It was confirmed that the effects of reaction temperature, catalyst type and concentration, and the weight ratio of water to TDI-R(WR) on TDA yield were significant. TDA yield decreased with increases in reaction temperature and catalyst concentration, and increased with an increase in WR. As a catalyst, NaOH was more effective than $Na_2CO_3$ for TDA yield. The interaction effects between catalyst concentration and temperature, WR and temperature, catalyst type and reaction time on TDA yield had been defined as significant. Although the effect of catalyst concentration on TDA yield at $300^{\circ}C$ as subcritical water was insignificant, the TDA yield decreased with increasing catalyst concentration at $400^{\circ}C$ as supercritical water. On the other hand, the yield increased with an increase in WR at $300^{\circ}C$ but showed negligible effect with WR at $400^{\circ}C$. The optimization of process variables for TDA yield has been explored with a pilot plant for scale-up. The catalyst concentration and WR were selected as process variables with respect to economic feasibility and efficiency. The effects of process variables on TDA yield had been explored by means of central composite design. The TDA yield increased with an increase in catalyst concentration. It showed maximum value at below 2.5 of WR and then decreased with an increase in WR. However, the ratio at which the TDA yield showed a maximum value increased with increasing catalyst concentration. The correlation equation of a quadratic model with catalyst concentration and WR had been obtained by the regression analysis of experimental results in a pilot plant.