聚雙苯氧基磷化偶氮烯薄膜於滲透蒸發程序之應用

Poly[bis(phenoxy)phosphazene] Membranes for Application in Pervaporation Process

陳元凱(Yuan-Kai Chen)

指導教授 ： 孫一明

元智大學/工程學院/化學工程與材料科學學系/碩士(1996年)

摘要

本研究是使用聚雙苯氧基磷化偶氮烯膜(poly[bis(phenoxy)phos-
phazene]，簡稱PPOP)，利用滲透蒸發(pervaporation)程序來分離苯/環
己烷，並利用連續式微量天平的實驗裝置，探討苯與環己烷的吸脫附動力
學模式與吸附平衡量，並計算吸附濃度、擴散係數與溶解度，進而得到滲
透係數，用吸附實驗結果來輔助解釋滲透蒸發的實驗結果。在滲透蒸發實
驗中，對於苯/環己烷的分離係數最大值在苯進料濃度約為40%時，其分離
係數為3。在變溫實驗中，其標準化通量隨著溫度的升高而增加，而分離
係數降低，利用Arrhenius equation計算出苯與環己烷的滲透活化能分別
為22.9 KJ/mol與28.6 KJ/mol。在吸脫附實驗中，苯的吸附濃度比環己烷
大許多，就擴散係數而言，苯大於環己烷，兩者的擴散係數均隨著活性係
數的增加而增加。在變溫實驗中，吸附濃度隨著溫度的升高而降低，擴散
係數隨著溫度的升高而增加，由擴散係數計算苯與環己烷的擴散活化能，
苯的平均擴散活化能為71.9 KJ/mol，環己烷的平均擴散活化能為77.1
KJ/mol，對溶解度而言，兩者的溶解度均隨著溫度的升高而降低，由Vant
Hoff方程式得到苯與環己烷於PPOP膜中溶解熱分別為-47.6 KJ/mol
與-37.8 KJ/mol。對滲透蒸發與吸脫附實驗中所求得的滲透係數而言，由
液體本身接觸到膜表面的滲透蒸發程序其滲透係數比吸脫附實驗得到的滲
透係數大許多，由滲透蒸發求得的滲透係數苯為1500~4500 barrer，環己
烷為730~3600 barrer，但在吸脫附實驗中，苯的滲透係數最大不到400
barrer，而環己烷最大值也只有10 barrer。

關鍵字

薄膜 ； 滲透蒸發

並列摘要

Poly[bis(phenoxy)phosphzene] (PPOP) membranes were tested in
the pervaporation process for the separation of benzene and
cyclohexane. A continuous micro-balance was used the obtain the
sorption kinetics and equilibrium data. Diffusivities and
solubilities can be determined and thus the permeabilities can
be estimated by the solution-diffusion model. The results
obtained from both experiments were compared in this study.In
the pervaporation experiments, there was a maximum separation
factor of 3 when the feed concentration of benzene was about 40
%. In the temperature effect study, the normalized flux
increased but the separation factor decreased with temperature.
The activation energies of permeabilities for benzene and
cyclohexane were 22.9 and 28.6 KJ/mol, respectively. In the
sorption experiments, benzene showed larger solubilities than
cyclohexane. The diffusivities for benzene and cyclohexane
increased with their vapor activities. In temperature effect
study, the solubilities decreased and diffusivities increased
with temperature. The heats of sorption for benzene and
cyclohexane were -47.6 and -37.8 KJ/mol, respectively. The
activation energies for the averaged diffusivities for benzene
and cyclohexane were 71.9 and 77.1 KJ/mol.The permeabilities for
benzene and cyclohexane in pervaporation were 1500-4500 and
730-3600 Barrer, respectively. The estimated permeabilities for
benzene and cyclohexane from sorption experimental data were
less than 400 and 10 Barrer, respectively. The PPOP membranes
contacted with liquid feed directly so that the permeabilities
obtained from pervaporation were much larger than those from
sorption experiments.

並列關鍵字

membrane ； pervaporation