混合醇胺水溶液 MEA/MDEA 之三成分交互擴 散係數之量測研究-根據泰勒分散法

Taylor dispersion technique for the measurements of ternary mutual diffusion coefficient of aqueous monoethanolamine / N-methyldiethanolamine solutions

柯智強(Chic-Chung Ko)

指導教授 ： 李夢輝

中原大學/工學院/化學工程學系/碩士(2006年)

https://doi.org/10.6840/cycu200600418

摘要

本論文利用泰勒分散法(Taylor dispersion method)量測醇胺水溶液之三成分擴散係數，本實驗系統為 monoethanolamine (MEA) + N-methyldiethanolamine (MDEA) + H2O；溫度範圍為30至50 oC；總濃度範圍為2.5至4 kmol沸-3，每個濃度下，均包含四個不同之醇胺莫耳比例。 MEA 和MDEA之雙成分醇胺水溶液擴散係數亦被量測，泰勒分散法(Taylor dispersion method)之實驗，是取適量的溶質經由六向閥以脈衝方式瞬間注入毛細管中，其濃度分佈經由載體溶液的帶動而進行擴散程序，溶質的濃度分佈流至管末端經由折射率偵測器測定其折射指數轉換成電子訊號由電腦紀錄。從折射指數分佈訊號經由非線性迴歸程序來計算出三成分之擴散係數。其中主擴散係數(D11和D22)與交叉擴散係數(D12和D21)與醇胺水溶液之濃度、溫度和黏度之關係將於本文詳細討論，此外並利用與部分莫爾體積及物質之活性相關的Onsager模式來估算本實驗系統。本量測結果可用來計算二氧化碳與混合醇胺水溶液之反應動力學基礎數據。

關鍵字

醇胺 ； 泰勒分散法 ； 三成分擴散係數

並列摘要

The objective of this study was to measure the ternary diffusion coefficients of aqueous blended alkanolamine systems monoethanolamine (MEA) + N-methyldiethanolamine (MDEA) + water using the Taylor dispersion technique for temperatures 30 to 50 oC. The ternary diffusion coefficients are reported for solutions containing the total amine concentrations, 2, 3, and 4 kmol•m-3 for various amine concentration ratio. The corresponding mutual diffusion coefficients of aqueous MEA and aqueous MDEA solutions were also measured. In a Taylor experiment, a delta function of solution is injected into a laminar carrier stream of reference fluid which flows in a long capillary tube. The injected solutes spread out as they flow along the tube. The concentration profiles of dispersed solutes are determined by a differential refractometer. A regression procedure is used to calculate the ternary diffusion coefficients from the refractive index profiles. The main diffusion coefficients (D11 and D22) and the cross coefficients (D12 and D21) are reported as function of temperature and concentration of alkanolamines. The dependence of the diffusion coefficients on the compositions and the temperature were discussed. Based on the theoretical model, the calculations 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 reported. A fairly good result was obtained between the calculated and the measured values of ternary mutual diffusivity.

並列關鍵字

ternary diffusion coefficient ； taylor dispersion method ； alkanolamine

參考文獻

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