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나노 입자 이산화티탄 촉매원료 및 세라믹 하니컴 촉매 압출성형에 관한 연구

The Nano-scale TiO2 Powder for Catalyst Applications and Extrusion of Ceramic Honeycomb Catalyst,

윤대현 (Yoon, Dae Hyun, 경상대학교 대학원)

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초록/요약moremore
Nano-scale titanium dioxide(TiO_(2)) powders with anatase phase were prepared from meta-titanic acid (MTA) for the application of photo-catalyst decomposing toxic organics and SCR catalyst removing NOx with NH_(3). In order to obtain a titanium dioxide for the photocatalyst application, the sulfat...
Nano-scale titanium dioxide(TiO_(2)) powders with anatase phase were prepared from meta-titanic acid (MTA) for the application of photo-catalyst decomposing toxic organics and SCR catalyst removing NOx with NH_(3). In order to obtain a titanium dioxide for the photocatalyst application, the sulfates and impurities contained in the meta-titanic acid needed to be removed. For removing the these undesirable sulfates and impurities, a washing and neutralization process were employed. After the wash, a metal oxide was added to the meta-titanic acid. Then, the resulting compound was dried at 120℃ for 24 hours. The dried compound were sintered to obtain a titanium dioxide powder showing anatase phase crysatlline at various temperature. The titanium dioxide powder showing a specific surface area of about 100 ㎡/g and anatase phase purity of 97 wt% can be used as a photocatalyst. The degree 4CP decomposition capability depended on the non-stochiometry of the TiO_(2) samples and the total area of all the particles in slurry. To optimize the TiO_(2)/WO_(3)/V_(2)O_(5) powder for SCR catalyst, the effects of SO_(3), WO_(3) and V_(2)O_(5) on the activity were examined. Sulfated titanium oxides with 2 wt% V_(2)O_(5) and 10 wt% WO_(3) was prepared by impregnating the different precursors and loading methods. On the viewpoint of SO_(3) content, the maximum NOx removal efficiency was shown at the 3 wt% of SO_(3) content. WO_(3) containing TiO_(2) powder was prepared by impregnating ammonium metatungstate (AMT) dissolved in water onto TiO_(2) particle. The TiO_(2)/WO_(3) powder prepared by such wet chemical process showed the higher activity then the dry mixing technique. Extrusion formed ceramic honeycomb for De-NOx via selective catalytic reduction (SCR) was developed using the powder containing mainly TiO_(2), Al_(2)O_(3) and V_(2)O_(5). The optimum organic contents of water, MC and PEG for this system were 40, 3.5 and 3.5 part, respectively, with respect to the weight of starting powder. An extruded honeycomb was dried in the chamber controllable humidity and temperature. The stepwise drying process with the drying time longer than 10 days was developed to prevent any cracking. One inch honeycomb with cell density of 35 cpsi was successfully dried prior to firing. The product showed a nearly 98% catalytic activity in a wide temperature range from 250℃ to 450℃. The plasticity of dough and the catalytic activity of honeycomb were evaluated as a function of sulfate content. A modified vicat needle was designed to evaluate the plasticity of dough for the green honeycomb extrusion. The TiO_(2) powder containing 1 wt% sulfate showed a nearly 97% of NOx reduction efficiency and high formability while extruding.
목차moremore
제1장 서론 1
제2장 이론적배경, 관련연구 4
2.1 광촉매 이산화티탄 4
...
제1장 서론 1
제2장 이론적배경, 관련연구 4
2.1 광촉매 이산화티탄 4
2.2 SCR 촉매담체용 이산화티탄 8
2.3 SCR(Selective Catalytic Reduction) 촉매 11
2.4 광촉매 활성과 비화학양론성의 관계 17
2.5 압출배토의 가소성 평가 34
제3장 이산화티탄 40
3.1 광촉매용 이산화티탄 40
3.1.1 서론 40
3.1.2 실험방법 42
3.1.2.1 메타티탄산 42
3.1.2.2 수세효과 44
3.1.2.3 열처리효과 44
3.1.3 결과 및 고찰 44
3.1.3.1 메타티탄산 44
3.1.3.2 수세효과 51
3.1.3.3 열처리 효과 54
3.1.4 결론 60
3.2 SCR용 이산화티탄 61
3.2.1 서론 61
3.2.2 실험방법 62
3.2.2.1 SO3 함량에 따른 활성 62
3.2.2.2 텅스텐산화물 담지조건에 따른 활성 63
3.2.2.3 바나듐산화물 담지조건에 따른 활성 64
3.2.2.4 WO3/V2O5/TiO2 분말 제조 64
3.2.2.5 고정층 탈질촉매능 평가 64
3.2.3 결과 및 고찰 68
3.2.3.1 SO3 함량에 따른 활성 68
3.2.3.2 WO3 첨가 68
3.2.3.3 H2WO4 첨가 72
3.2.3.4 AMT 첨가 74
3.2.3.5 V2O5 첨가 79
3.2.3.6 W 및 V 담지 TiO2 SCR 분말의 촉매능 84
3.2.4 결론 86
제4장 SCR 촉매압출 성형 88
4.1 서론 88
4.2 실험방법 93
4.2.1 촉매원료 조합 93
4.2.2 성형첨가제 최적 조합비 93
4.2.2.1 결합제 95
4.2.2.2 가소제 95
4.2.2.3 수분함량 95
4.2.3 건조방법 및 조건 96
4.2.4 하소 96
4.2.5 SO3 영향 98
4.2.6 탈질활성 측정 98
4.3 결과 및 고찰 100
4.3.1 최적 첨가제 조합비 100
4.3.2 건조조건 확립 100
4.3.3 하소조건 확립 101
4.3.4 탈질활성 101
4.3.5 SO3 영향 107
4.4 결론 112
제5장 종합결론 113
References 115