• 한국응용과학기술학회지
• /
• 제31권2호
• /
• pp.313-319
• /
• 2014

This study was performed to obtain high conversion efficiency of $NH_3$ and minimize generation of nitrogen oxides using metal-supported catalyst with Ag : Cu ratio. Through structural analysis of the prepared catalyst with Ag : Cu ratio ((10-x)Ag-xCu ($0{\leq}x{\leq}6$)), it was confirmed that the specific surface area was decrease with increasing metal content. A prepared catalysts showed Type II adsorption isotherms regardless of the ratio Ag : Cu of metal content, and crystalline phase of $Ag_2O$, CuO and $CuAl_2O$ was observed by XRD analysis. In the low temperature($150{\sim}200^{\circ}C$), a conversion efficiency of AC_10 recorded the highest(98%), whereas AC_5 (Ag : Cu = 5 : 5) also showed good conversion efficiency(93.8%). However, in the high temperature range, the amounts of by-products(NO, $NO_2$) formed with AC_5 was lower than that of AC_10. From these results, It is concluded that AC_5 is more environmentally and economically suitable.

• 한국대기환경학회지
• /
• 제27권4호
• /
• pp.379-386
• /
• 2011

Catalyst-assisted plasma system with a DBD (Dielectric Barrier Discharge) reactor was used to remove hydrogen sulfide, which is one of the odorous species in this study. The ${\gamma}-Al_2O_3$ and ${\beta}$-Zeolite catalysts impregnated by Ag, Cu and Mn species were employed as catalysts and their $H_2S$ removal characteristics under plasma irradiation were investigated. From the experimental study, we found that the $H_2S$ removal efficiency increases with decreasing space velocity in the system and increasing specific input energy. Furthermore, ${\beta}$-Zeolite catalysts are efficient to remove $H_2S$ than ${\gamma}-Al_2O_3$ catalysts. Especially, the catalysts impregnated by Ag have higher removal efficiency than other catalysts (Cu, Mn).

• 한국가스학회지
• /
• 제19권5호
• /
• pp.20-28
• /
• 2015

탄화수소 선택적 촉매환원공정에서 ${\gamma}$-알루미나에 지지된 금속 산화물 촉매의 크기 및 형태에 따른 질소산화물 ($NO_x$) 저감 특성에 대해 조사하였다. 환원촉매로는 Ag, Cu 및 Ru를 사용하였으며, n-heptane을 환원제로 사용하였다. Ag/${\gamma}$-$Al_2O_3$ 촉매의 경우 온도범위 $250{\sim}400^{\circ}C$에서 20 nm>50 nm>80 nm 순으로 Ag의 크기가 작을수록 $NO_x$ 전환효율이 높게 나타났다. 금속 산화물 촉매의 형태에 따른 영향은 구형과 선형에 대해 살펴보았다. Ag와 Cu는 동일한 조건에서 선형이 구형보다 $NO_x$ 전환효율이 높은 것으로 나타났으나, Ru의 경우에는 형태에 따른 영향이 거의 관찰되지 않았다. 사용된 금속산화물 촉매 중에서 Ag를 사용했을 때 $NO_x$ 저감효율이 가장 높았으며, 선형의 Ag를 사용했을 때 $300^{\circ}C$의 반응온도에서 대부분의 $NO_x$를 제거할 수 있었다. Cu와 Ru 촉매상에서는 NO가 환원되기보다는 $NO_2$로의 산화반응이 우세하여 전체적으로 $NO_x$ 저감효율이 낮게 나타났다.