(3.227.235.183) 您好!臺灣時間:2021/04/13 22:30
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果

詳目顯示:::

我願授權國圖
: 
twitterline
研究生:李珠瑤
研究生(外文):Li, Ju-Yau
論文名稱:三液相相轉移催化反應系統的相轉換現象研究
論文名稱(外文):Characteristics of Phase Inversi on in a Phase Transfer Catalysis  System with Three Liquid Phases
指導教授:江建利
指導教授(外文):Chiang Chien-Lih
學位類別:碩士
校院名稱:國立成功大學
系所名稱:化學工程學系
學門:工程學門
學類:化學工程學類
論文種類:學術論文
論文出版年:1996
畢業學年度:84
語文別:中文
論文頁數:145
中文關鍵詞:相轉換第三液相相轉移催化反應Phase InversionThird Liquid PhasePhase Transfer Catalysis
相關次數:
  • 被引用被引用:8
  • 點閱點閱:113
  • 評分評分:系統版面圖檔系統版面圖檔系統版面圖檔系統版面圖檔系統版面圖檔
  • 下載下載:0
  • 收藏至我的研究室書目清單書目收藏:0
  相間轉移觸媒催化反應系統的研究,一直是近年來化工界研究的重點
對於某些相間轉移觸媒催化反應系統,在反應過程中,會有第三液相出現
。此第三液相的生成,可使得反應速率大幅增加;另一方面,它也使得產
物的分離步驟簡化。因此這一方面的應用研究,在化工界具有很大的潛力
。而在工業界的應用方面,系統的穩定性是很重要的設計條件,當分散相
愈多,質傳面積愈大,液滴聚合速率加快,即有可能產生相轉換,亦即分
散相變為連續相。因此,本文針對溴化四丁基銨催化溴正丁烷與酚鈉的反
應系統,在批次攪拌槽內,透過電導度法來探討三液相相間轉移催化反應
系統的相轉換特性。我們發現在沒有第三液相生成的系統中,觸媒傾向於
使系統成為O/Wtype,而觸媒與酚鈉形成的離子對將使得相轉換不易發
生,並使過渡區變大。當系統出現第三液相時,系統容易形成W/Otype
的分散型式,由其是添加NaOH所造成相轉換Hold-up 下降的效應極為顯著
;添加NaBr則有助於形成O/Wtype的分散。此外,溫度,觸媒濃度與反
應物濃度也會影響系統的相轉換Hold-up 。一般而言,有第三液相生成系
統的液滴結合時間(Tc)較兩相的系統長;當系統中有NaOH或KOH 出現時,
Tc會變短。對於W/Otype的分散,相轉換Hold-up 值愈低的系統,其遲
滯相轉換時間(Td)愈長。有第三液相生成的系統,Td相當敏感。對所有的
系統而言,Td隨轉速的增加而增加。照相拍攝的結果顯示,在有第三液相
生成系統中的液滴均極細小,而無第三液相生成的系統,其液滴大小與界
面張力有關,且W/Otype系統的分散中通常有Complex Drops 形成。

Recently many researches have been dedicated to the phase
transfer catalysisreaction systems. In some of these systems,
the formation of the third liquidphase(TLP) dramatically
accelerates the reaction rate and simplifies the sepa-ration
process. Studies on this field will be of great potential in the
indus-try. In view of the industrial application, the stability
of the system, invo-lving two or three immiscible liquids,is of
much importance in the operations.Increasing the volume fraction
of the dispersed phase will result in the incr-ease of the mass
transfer areas, promote the drops coalescence rate and event-
ually lead to the phase inversion, i.e. the dispersed phase
becomes the conti-nuous phase and vice versa. In this study,the
characteristics of phase invers-ion in a phase transfer
catalysis system with three liquid phases are examinedin a batch
vessel using the conductivity-measuring method, in which the
react-ion of n-butyl bromide with phenyl benzoate is
catalyzed by the tetrabutyl-ammonium bromide. It is found that,
without the formation of TLP, an increasein the catalyst
concentration tends to make water the continuous phase
,whilethe ion-pairsformed by catalyst and reactant retards the
happening of phaseinversion andenlarges the ambivalent region.
The W/O disersions are likely tobe formed if TLP are present in
the systems. The addition of NaOH will reducethe phase
inversion hold-up remarkably , while the presence of NaBr will
helpwater to be continuous. Temperature , catalyst
concentrations and reactantsalso affect the phase inversion
hold-up. Systems with TLP would have longerTc (
CoalescenceTime) than those without TLP. When NaOH or KOH is
added intothe system , Tc will be shortened. Delayed phase
inversion time (Td) is foundto be longer for the systems with
lower phase inversion hold-ups,and much moresensitive to
thesystems with TLP. Also , it increases with increasing
rotorspeeds for all the systems. Photographs indicate that
the drop sizes in asystem containing TLP are quite tiny.
Interfacial tension is relevant to thedrop size in the systems
without TLP. Complex drops are observable in most ofthe W/O
type dispersions.

QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top
無相關期刊
 
系統版面圖檔 系統版面圖檔