توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱One–dimensional heterogeneous plug flow model was employed to model an adiabatic fixed bed reactor
نویسنده(ها): ، ، ،
اطلاعات انتشار: ششمین کنگره بین المللی مهندسی شیمی، سال
تعداد صفحات: ۵
One–dimensional heterogeneous plug flow model was employed to model an adiabatic fixed bed reactor for the catalytic ndehydration of methanol to dimethyl ether. Longitudinal temperature and conversion profiles predicted by this model were compared to those experimentally measured in a bench scale reactor. The reactor was packed with 1.5–mm γ– Al2O3 pellets as dehydration catalyst and operated in a temperature range of 543–603 K at an atmospheric pressure. Also, the effects of weight hourly space velocity (WHSV) and temperature on methanol conversion were investigated. According to the obtained results, the maximum conversion is obtained at T=603.15 K and WHSV=72.87 h–1.<\div>

۲Effects of Gamma–Alumina Grain Size on Methanol Dehydration to Dimethyl Ether at Different Temperature and Weight Hourly Space Velocity
نویسنده(ها): ، ،
اطلاعات انتشار: پانزدهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۴
In this paper the effects of catalyst grain size, feed temperature and weight hourly space velocity on dimethyl ether production by dehydration of methanol are investigated. Commercial gamma alumina is used as dehydration catalyst in an adiabatic fixed bed reactor. Catalyst grain sizes are changed from 0.063 up to 2 mm, and the feed temperatures are changed from 200 up to 320 °C. Another parameter which is changed is weighthourly space velocity. This parameter is changed from 10 up to 90 h–1. Experimental design was optimized by the Taguchi method. The obtained results show that methanol conversion is increased by decreasing of catalyst grain sizes. But, the slip of changes converges to a fixed value, gradually. This phenomenon can be explained by mass transfer effects. Also, the experimental obtained results show that conversion values are increased by increasing feed temperature and decreased by increasing weight hourly space velocity. So that, by increasing temperature from 230°C to 320°C at 10h–1, the methanol conversion increased from 20 to 70%, and when weight hourly space velocity is changed from 10 to 90h–1 at 260°C the methanol conversion decreased from 65 to 15%.<\div>

۳A comparative study of LaCoO3 and LaCo0.3Zn0.7O3 perovskite–type nanocatalysts for carbon monoxide emission control
نویسنده(ها): ، ،
اطلاعات انتشار: پانزدهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۴
The nanostructured LaCoO3 and LaCo0.3Zn0.7O3 perovskite–type catalysts were synthesized by the polymerized complex method based on the Pechini process. The prepared catalysts were characterized by XRD and SEM and their catalytic activity was evaluated in the CO oxidation reaction. The SEM pictures of the synthesized nanocatalysts showed that the particles sizes were close to 100 nm. According to the obtained results, the synthesized LaCoO3 nanocatalyst showed a superior performance as compared to the LaCo0.3Zn0.7O3 nanocatalyst, however, for both nanocatalysts, the conversion of CO increased with increasing reaction temperature. The catalytic activity of the prepared nanocatalysts was measured at different temperatures from 100 to 400°C with an inlet gas mixture containing 95% N2, 1% CO and 4% O2. The effect of temperature and gas hourly space velocity (GHSV) was investigated. According to the results of catalytic activity measurements, although the both nanocatalysts showed nearly complete CO conversion at 400°C, LaCoO3 depicted a superior catalytic activity and can be considered as a potential candidate for developing catalytic converters to remove carbon monoxide from automobile exhaust gas<\div>
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