توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Development of Synergic Mixed Metal Oxides for the Combined Catalytic–Absorptive Removal of Nitric Oxide from Diesel Exhaust
نویسنده(ها): ، ، ، ، ،
اطلاعات انتشار: Iranian Journal of Chemistry and Chemical Engineering (IJCCE)، سي و دوم،شماره۱(پياپي ۶۵)، ۲۰۱۳، سال
تعداد صفحات: ۱۲
The NO removal over oxide sorbents (K2O\Al2O3 , CaO\Al2O3 and BaO\Al2O3) at a loading of up to 25 wt.% was investigated using a synthetic diesel exhaust gas containing 1,000 ppm NO, 1000 ppm iso–butane (i–C4H10), 8% O2 and N2 balance. The reactor was operated at 250 oC to 450 oC for the activity study. NO was effectively stored (removal efficiencies between 30–60 %) as nitrate under experimental conditions after surface oxidation to NO2; and the maximum removal efficiency decreased in the order of K2O\Al2O3 (55.4 %) > BaO\Al2O3 (39.0 %) > CaO\Al2O3 (37.0 %). K2O\Al2O3 had higher mobility; but loadings higher than 15 wt.% were detrimental to the morphological properties. Despite higher basicity, CaO\Al2O3 showed lower removal efficiency of NO compared to BaO(10)\Al2O3 due to low catalytic NO2 formation activity. Unlike K2O(10)\Al2O3, BaO(10)\Al2O3 showed increasing NO removal between 350 oC and 450 oC. K2O(5)BaO(5)\Al2O3 resulted in better surface area and volume leading to about 65 % of NO removal. This was attributed to synergic effects between physicochemical, catalytic and NO removal properties of the components. The high performance of K2O(5)BaO(5)\Al2O3 was successfully elucidated based on the characteristics of the sorbent.

۲Alkaline Earth Metal Oxide Catalysts for Biodiesel Production from Palm Oil: Elucidation of Process Behaviors and Modeling Using Response Surface Methodology
نویسنده(ها): ، ، ، ، ،
اطلاعات انتشار: Iranian Journal of Chemistry and Chemical Engineering (IJCCE)، سي و دوم،شماره۱(پياپي ۶۵)، ۲۰۱۳، سال
تعداد صفحات: ۱۴
Four different alkaline earth metal oxides i.e. MgO, CaO, SrO and BaO were used as heterogeneous catalysts for biodiesel production from palm oil. Effects of critical process variables i.e. reaction time, methanol to oil ratio and temperature were investigated. The results were then fitted to a historical design to study the Analysis of Variance (ANOVA), to characterize interactions between variables and to simulate the process. MgO did not show good catalytic activity while CaO produced undesired products at longer reaction time. BaO showed the best biodiesel result with a yield of up to 95 %, followed by SrO with a yield of 91 %. A methanol to oil ratio of 9:1 and 60 ºC were found to be the optimum conditions. The experimental data were satisfactorily predicted at 99 % confidence level under various conditions with R2 values higher than 0.92. Characterizations of the catalysts before and after the transesterification process were also performed using a surface analyzer, scanning electron microscopy, Hammett indicator and Atomic Absorption Spectrophotometeric (AAS) methods. The catalytic activity was in the order of BaO > SrO > CaO. However, due to lixiviation of BaO in the product, SrO was found to be the most potential catalyst
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