Jin-Gul Kim

Effect of Change of Hydrogen Rich Reductant on HC-SCR over Co-Pt/ZSM5 Catalyst

HC-SCR was conducted over Co-Pt/ZSM5 catalyst coated over 200 cpsi cordierite in the condition of atomspheric pressure and 200℃-500℃. Weight ratio of Co/Pt determined from EDX analysis was 8/2, which was almost equal to the weight ratio at preparation step . XPS showed that nitrates within cobalt precursor and chlorine withn Pt precursor were removed. TEM result demonstrated that crystallite size of cobalt and Pt was under 5nm. Among these tested hydrocarbon reductants, isobutane (i-C4H10) showed the highest de-NOx yield of 80% under the condition of the mole ratio of reductant/NOx =1.0 at 180℃. De-NOx yield from HC-SCR was increased as the carbon number of hydrocarbon reductant was increased. The decrease of bonding energy between C and H of HC reductant played a role to increase of de-NOx yield, which indicated that the dissociation step of C-H bond of hydrocarbon molecule might be the rate determining step of HC-SCR. The increase of oxygen concentration in the feed resulted in the decrease of de-NOx yield but the increase of CO and N2O yield.

Effect of Fe Addition on Hydrogen Rich NSR Kinetics over Pt/Co/Ba/Al 2 O 3 Catalyst

Abstract >> Thermal aging effect on NSR kinetics was studied over Pt/Co/Fe/Ba/Al 2 O 3 catalyst. The amount ofNO x uptake over Pt/Co/Ba/Al 2 O 3 calcined at 400℃ increased with increasing NSR temperature from 200℃ to400℃, where amount of NO x uptake is the highest at 400℃ with mol ratio of NO x /Ba = 0.5. Thereafter, theamount of NO x uptake at 400℃ decreased with the higher calcination temperature, where Pt/Co/Ba/Al 2 O 3 catalystcalcined at 700℃ showed an amount of NO x uptake with the mol ratio of NO x /Ba=0.062. Result of XRD and NSR showed that Fe addition into Pt/Co/Ba/Al 2 O 3 suppressed sintering of Pt crystallites andmake NO x uptake larger, compared to no addition of Fe into Pt/Co/Ba/Al 2 O 3 catalyst. From BET result, it wasfound that the change of specific surface area was relatively small by the thermal aging process. Therefore, it was found that the sintering of Pt crystallites caused the decrease of NO x uptake during NSR reaction and Feplayed a role to suppress the sintering process of Pt crystallites caused by thermal aging.

Evaluation of ZSM-5 supported metal catalyst for NO x removal

Abstract NOx reduction of stationary exhaust was performed at atmospheric condition and the temperature ranging from 200 o C to 500 o C over ZSM-5 supported metal catalyst. The characteristics of the prepared catalysts were investigated using the analytical techniques such as SEM, XRD, EDX, ICP and ITR. The results of EDX and ICP analysis demonstrated that the most part of transition metal existed on the exterior surface of support. Maximum de-NOx yield over Fe/ZSM-5 shown between 380 o C and 400 o C was presumed to be due to the maximum H 2 reduction rate at 400 o C of ITR. Key Words : HC-SCR, Fe/ZSM-5, de-NO x , Reduction, ITR * 교신저자 : 유승준(sjyoo001@hanmail.net)접수일 09년 05월 21일 수정일 09년 06월 15일 게재확정일 09년 08월 19일 1. 서론 1.1 분석결과 오존층 파괴, 지구의 온난화, 산성비, 그리고 광화학 스모그 등 지구의 환경 문제가 날로 심각해짐에 따라 이의 원인 물질에 대한 규명과 오염원 제거를 위한 기술개발에 대한 연구가 활발히 진행되고 있다. 자동차 엔진이나 발전소, 공장 보일러, 가정용 난방기구와 같은 고온 열원에서 배출되는 배기가스의 주성분인 CO, CO 2 , 불완전 연소에 의해 생성된 탄화수소, NO x , SO x 그리고 분진 등이 지구의 환경을 오염시키는 주원인 물질 중의 일부이다. 한편, 스모그 형성과 산성비 그리고 인체에 해로운 영향을 미치는 NO

Synergy Effect of Fe/ZSM-5 and Co-Pt/ZSM-5 for NOx removal

Abstract In the condition of GHSV=30000 hr -1 , NO x removal yield was higher as mole ratio of SiO 2 /Al 2 O 3for Fe/ZSM-5 was lower regardless of preparation method such as CVD (chemical vapor deposition) and dry impregnation. In addition to this, Fe/ZSM-5 catalyst showed about 50% NOx removal yield between 350 o C - 400 o C while CO formed significantly. To remove newly formed CO over Fe/ZSM-5, Co-Pt/ZSM-5 was used in conjunction with Fe/ZSM-5 in the series and this demonstrated over 90% removal yield of both NOx and CO at 250 o C and GHSV=13000 hr -1. Key Words : Fe/ZSM-5, CVD, i-butane, NO x removal, Co-Pt/ZSM-5 * 교신저자 : 유승준(sjyoo001@hanmail.net)접수일 09년 05월 29일 수정일 (1차 09년 07월 20일, 2차 09년 08월 07일) 게재확정일 09년 09월 16일 1. 서론 지금까지 질소산화물, 일산화탄소와 같은 유독가스는 물론, 온실효과의 주원인이 되는 이산화탄소 그리고 오존층을 파괴하는 프레온가스 등에 대한 연구가 진행되어 오고 있다. 프레온 가스 이외의 배기물은 대부분 연소 장치로부터 배출되고 있기 때문에 화석연료를 사용하는 이상은 근본적으로 완전히 제거하는 것은 어려운 문제이다. 이러한 환경오염원을 제거하는 배기가스 정화용 촉매의 개발 연구가 1970년대 이후 세계적으로 이루어지고 있다[1-5]. 연소 후 배기가스 중에 포함된 NO