混合醇胺 MEA/TEA 水溶液之三成份擴散係數量測研究

Ternary diffusion coefficient measurements for monoethanolamine (MEA) + Triethanolamine (TEA) + water (H2O) system

張文豪(Wen-Hao Chang)

指導教授 ： 李夢輝

中原大學/工學院/化學工程學系/碩士(2007年)

https://doi.org/10.6840/cycu200700475

摘要

本論文使用泰勒分散法 (Taylor dispersion method) 量測三成份
醇胺水溶液之擴散係數， 實驗系統為Ethanolamine (MEA) +
Triethanolamine (TEA) + H2O，溫度範圍為30、35、40 oC；總濃度範
圍為2、3 kmol·m-3，本實驗在每個濃度中都量測有三個不同的濃度比
例的三成分數據點。利用載體與溶質濃度的不同，引發擴散形成濃度
差分布，使得分子發生擴散的現象，而這就是泰勒分散法的原理。最
後在毛細管出口處由折射偵測器(RI detector)偵測濃度分布並轉換變
成折射指數分布的訊號，再利用折射指數分布訊號透過非線性回歸來
計算出三成分之擴散係數。除此之外在計算擴散係數方面，我們利用
活性係數來估計擴散係數，以方便與實驗數據來相互驗證。累積有關
擴散係數數據，未來就可以找出多種醇胺之間的關係，另外本論文量
測結果也是使用在吸收二氧化碳設備(濕壁柱)之計算上的基礎數據。

關鍵字

MEA+TEA ； 三成份擴散係數

並列摘要

The ternary diffusion coefficients of aqueous blended alkanolamine
systems Ethanolamine (MEA) + Triethanolamine (TEA) + water were
measured to use the Taylor dispersion method for 30、35 and 40 oC. The
ternary diffusion coefficients were reported for solutions containing the
total amine concentrations, 2 and 3 kmol·m-3 for three amine
concentration ratios. The corresponding mutual diffusion coefficients of
aqueous MEA and aqueous TEA solutions were also measured. In the
Taylor dispersion experiment, a solution is injected into a laminar carrier
stream of reference fluid which flows in a long capillary tube and the
injected solutes spread out as the mixed flow along the capillary tube.
The concentration profiles of diffused solutes were determined by a
refractive index detector. Final using regression procedure to calculate the
ternary diffusion coefficients from the concentration profiles of mixed
solutions. The main diffusion coefficients (D11 and D22) and the cross
coefficients (D12 and D21) were related to functions of temperature and
concentration of alkanolamines. The correlation between the diffusion
coefficients on the compositions and the temperature and viscosity were
discussed. Final using the Onsager model to calculate of the main
diffusion coefficients (D11 and D22) and the cross coefficients (D12 and
D21) from the activity and the partial molar volume of components were
also performed. The experimental results can be used to determent the
effect of presence of diffusivities alkanolamine on diffuse of the mixtures
and the values can be directly applied in modeling CO2 absorption in the
wetted wall column.

並列關鍵字

MEA+TEA ； Ternary diffusion coefficient

參考文獻

Alizadeh, A.; Nieto de Castro, C. A.; Wakeham, W. A. The Theory Of The

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Int. J. Thermophys. 1980, 1, 243-284.

Diffusion In Aqueous Solutions. J. Phys. Chem. B 2006, 110,

Aris, R. On The Dispersion of a Solute In a Fluid Flowing Through a