混合醇胺水溶液(三級醇胺DEEA + 多元胺DETA)吸收二氧化碳之反應動力學數據量測

The reaction kinetics study for the absorption of carbon dioxide into the aqueous amine (tertiary amine DEEA + polyamine DETA)solutions

許展禎(Chan-Chen Hsu)

指導教授 ： 李夢輝

中原大學/工學院/化學工程研究所/碩士(2015年)

https://doi.org/10.6840/cycu201500413

摘要

本研究主要探討CO2與Diethylethanolamine (DEEA)混合Diethylenetriamine (DETA)水溶液的化學吸收反應動力學研究，實驗裝置是使用濕壁柱來量測CO2化學吸收，同時量測醇胺水溶液在不同溫度下的密度、黏度、亨利常數和擴散係數，雙成分系統濃度範圍是DEEA (5~40wt%) + H2O和DETA (5~40wt%) + H2O；三成分系統濃度範圍是DEEA (35wt%) + DETA (5wt%) + H2O、DEEA (30wt%) + DETA (10wt%) + H2O、DEEA (25wt%) + DETA (15wt%) + H2O及DEEA (20wt%) + DETA (20wt%) + H2O，溫度是30、35和40C。
研究中DEEA與CO2的化學反應以擬一級反應表示，DETA與CO2反應是以兩性離子反應機構表示，可由此兩者的量測數據以數值迴歸得到反應速率常數。
實驗結果發現在混合溶劑中DEEA有助於增加物理溶解度，但隨著混合溶劑中DEEA濃度增加，化學反應速率卻相對降低，DETA物理溶解度不佳，隨著增加DETA濃度卻能有效提升化學反應速率。
在酸性氣體吸收的化工程序設計上，亨利常數、擴散係數與反應速率常數是設計程序必須參考的重要數據，本研究可提供DEEA + DETA水溶液吸收酸性氣體上設計反應器時所需的動力學數據與實際操作的參考方法。

關鍵字

二氧化碳吸收 ； 多元胺 ； 三級醇胺 ； 反應動力學

並列摘要

The reaction kinetics of absorption of CO2 into the aqueous DEEA + DETA solutions was studied using a wetted wall column to measure the CO2 absorption rate. The density, viscosity, Henry’s constant and diffusivity coefficient of CO2 in the aqueous amine solutions at different temperature were measured. The compositions of the studied binary systems were DEEA (5~40wt%) + H2O and DETA (5~40wt%) + H2O. For the ternary systems, measurements were done at DEEA (35wt%) + DETA (5wt%) + H2O, DEEA (30wt%) + DETA (10wt%) + H2O, DEEA (25wt%) + DETA (15wt%) + H2O and DEEA (20wt%) + DETA (20wt%) + H2O. Temperatures considered were 30, 35 and 40C for all property measurements.
The pseudo-first order reaction mechanism was applied for the reaction of CO2 with DEEA while the zwitterion mechanism was used for absorption of CO2 into DETA. The reaction rate constants were determined from the measured specific absorption rate data.
Results show that the DETA increases the chemical absorption rate in mixed aqueous DEEA + DETA solutions.
The results can be used as a process design data using aqueous DEEA + DETA solutions as the CO2 absorbents for the CO2 absorption process.

並列關鍵字

carbon dioxide absorption ； tertiary amine ； polyamine ； reaction kinetics study

參考文獻

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