http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Tackling the Problem of Sulfur Poisoning of Perovskite Catalysts for Natural Gas Combustion
Rosso, Ilaria,Saracco, Guido,Specchia, Vite 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.2
LaMn_0.5Mg_0.5O_3 y MgO and LaCr_0.5-xMn_xMg_0.5O_3 y MgO catalysts(x=0-0.25, y=0-17) were prepared, characterized (XRD, BET, SEM-EDS, TEM, FTIR, chemical and atomic absorption analyses), tested for high-temperature methane combustion and aged in presence of SO_2 to investigate sulfur effect on catalytic activity. Different roles of manganese and chromium in the perovskite structure have been assessed:(i) manganese improves the activity of catalysts in the fresh state, whereas chromium worsens it;(ii) owing to its basic nature, manganese makes perovskites more prone to adsorb SO_2 and so less resistant to sulfur poisoning, whereas chromium, owing to its acidic nature, has opposite effects; (iii) the partial solubility of chromium oxide in basic media renders Cr-catalyst regeneration by NH_3 leaching less effective. MgO promotes catalytic activity of fresh LaCr_0.5Mg_0.5O_3 y MgO catalysts and slows down sulfur poisoning of LaMn_0.5Mg_0.5O_3 y MgO and LaCr_0.5Mn_0.5O_3 17 y MgO catalysts only.
Diesel Particulate Traps Regenerated by Catalytic Combustion
Fino, Debora,Fino, Paolo,Saracco, Guido,Specchia, Vito 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.3
The development of catalytic means for the regeneration of particulate-laden traps for diesel exhaust cleaning is the main topic of this paper. All the steps of the catalytic trap preparation are dealt with, including: the synthesis and choice of the proper catalyst and trap materials, the development of in situ catalyst deposition, and the bench testion of the derived catalytic traps. Two different traps were considered(i.e., silicon carbide and cordierite wallflow monoliths operating via a shallow-bed filtration mechanism), whereas the best catalyst selected was the perovskite LaCr_0.9O_3. The filtration efficiency and the pressure drops of the catalytic and non-catalytic monoliths were evaluated on a diesel engine bench under various operating conditions. On the basis of the obtained results the catalysed SiC converter was found to be the most satisfactorty converter to be placed on the exhaust line of the modern commonrail diesel-engine cars.
Mobile and Non-mobile Catalysts for Diesel-Particulate Combustion : A Kinetic Study
Fino, Debora,Russo, Nunzio,Badini, Claudio,Saracco, Guido,Specchia, Vito 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.3
One of the potential ways to solve the problem of diesel particulate emission from both stationary and mobile sources is the use of traps carrying a suitable catalyst for promoting particulate combustion as soon as it is filtered. A Cu-K-V based catalyst, considered among the most promising in the literature, the KVO_3+C_sCl and the K_0.7Cu0.3VO_3+KCl catalysts were prepared and investigated. Their performance was compared to a reference V_2O_5 catalyst. The superior performance of the Cu-K-V catalyst is based on the grounds of both microreactor(temperature programmed combustion) and catalytic trap tests. Based on experimental data and modelling calculations, this paper elucidates how the mobility of catalyst components is the main reason for such an outcome performance and is a prerequisite to achieve an activity sufficient for trap self-regeneration.