惰性粒子對奈米觸媒在液相氫化反應之影響

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Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/3590

Title:	惰性粒子對奈米觸媒在液相氫化反應之影響
Authors:	謝潼穎;Tong-Ying Hsieh
Contributors:	化學工程與材料工程研究所
Keywords:	液相氫化反應;加強效應;奈米觸媒;惰性粒子;硝基苯;糠醛;liquid hydrogenation;enhancement effect;nanocatalyst;solid;nitrobenzene
Date:	2000-06-16
Issue Date:	2009-09-21 12:18:30 (UTC+8)
Publisher:	國立中央大學圖書館
Abstract:	奈米觸媒由於具有等方向性及大量的表層原子，因此反應活性相當優異。但由於觸媒本身的粒子介於奈米級之間（ <100 nm），因此在進行液相的反應時易於因本身的凡得瓦力的影響而聚集，造成在反應器內的分佈不均，而降低其反應性。故一般都需要將轉速提高至高轉速的高耗能狀態，方能使奈米粒子達到完全分散的目的，且克服反應時外部質傳的問題。本研究旨在探討惰性粒子，如氧化鋁、氧化矽、氧化鋯以及活性碳等，對硼化鎳奈米觸媒在液相氫化反應的影響，其中包括了改變惰性粒子的成分、轉速、溶劑及不同的氫化反應，藉著這些的變化來更進一步地瞭解惰性粒子在液相氫化反應中所扮演的角色。，進行硝基苯的氫化反應且使用環己烷最為溶劑時，可發現加入惰性粒子確實可以增強奈米觸媒的催化活性，其增強效果大小如下：氧化鋁>氧化矽>氧化鋯>活性碳。而比較加入的惰性粒子/硼化鎳觸媒的重量比所產生增強效應的最佳比例，對於氧化鋁而言是10，對於氧化矽而言是7.5。當進一步進行轉速效應的研究後，對於在低轉速時加入惰性粒子後的增強效應最好，平均可提高硝基苯的轉化率100 ％以上，最高可以達到280 ％附近；但在高轉速區的增強效果較差，但最少也有55 ％的增強效應。當改變溶劑為甲醇時，加入惰性粒子並沒有增強效應的產生，甚至產生反效果；在糠醛的選擇性氫化反應中，加入惰性粒子亦可以有效地提升奈米觸媒的催化活性。而在糠醛的氫化反應中不論是在低轉速區或是在高轉速區，惰性粒子的增強效應都差不多。 Ultrafine catalysts had good activity owing to their isotropic and amount surface atoms. But those nanoparticles were agglomerated for van der wall force and their adhesion to the metallic surface of the reactor wall. Therefore, the agitation of liquid reaction was increased for high stirring speed to make nanoparticles dispersed well and overcome external mass transfer. The effects of inert solids such as alumina, silica, zirconia and charcoal activated in liquid hydrogenation were discussed in this paper. The rule of solid in liquid hydrogenation were research by varied some parameters such as compounds of solid, agitated speed, solvent and different reactions. The enhancement of inert solid was find significantly in nitrobenzene hydrogenation when solvent was cyclohexane. The enhancements of solids were listed: alumina> silica> zirconia> charcoal activated. The optimum weight ratio of Al2O3/Ni-B was 10 and SiO2/Ni-B was 7.5. For farther research for effect of agitated speed, the best enhancement of inert solid was existed in low agitated speed. The conversion was average increased over 100 %, and maximum enhancement was 281 %. But high-agitated speed had low enhancement, the conversion only increased for 55 %. When changed solvent as methanol, the enhancement of inert solid was not existence even had disutility. The enhancement of inert solid also was exited in furfural selectivity hydrogenation. Both high-agitated speed and low-agitated speed in furfural hydrogenation, the enhancement of inert solid was distributed in 60 %~ 80 %.
Appears in Collections:	[National Central University Department of Chemical & Materials Engineering] Electronic Thesis & Dissertation

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