- 學位論文
二氧化碳吸收劑三級醇胺 (3DMAP)/ 多元胺 (DETA) 水溶液之反應動力學量測研究
The Reaction Kinetics of the Carbon Dioxide in the Aqueous Tertiary Amine (3DMAP) / Polyamine (DETA) Solutions
摘要
本研究目的是探討CO2 與3-dimethylamino-1-propanol (3DMAP) 混合Diethylenetriamine (DETA) 水溶液的化學吸收反應動力學的研究，實驗裝置使用濕壁柱來測量CO2的化學吸收，同時測量醇胺水溶液在不同的溫度下密度、黏度、亨利常數及擴散係數，雙成分系統濃度範圍為3DMAP (5~30 wt%) + H2O；三成分系統為3DMAP (25wt%) + DETA (5wt%) + H2O、3DMAP (20wt%) + DETA (10wt%) + H2O及3DMAP (15wt%) + DETA (15wt%) + H2O，溫度為30、35及40C。 本實驗的研究結果3DMAP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，在混合溶劑中3DMAP有助於增加物理溶解度，但隨著混合溶劑中3DMAP濃度增加，化學反應速率卻隨之降低，DETA物理溶解度雖然不佳，但增加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裡，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3DMAP + DETA水溶液吸收酸性氣體上設計反應器時需要的動力學數據。
關鍵字
二氧化碳並列摘要
The reaction kinetics of the CO2 absorption into aqueous solutions of 3-dimethylamino-1-propanol (3DMAP) and into mixed aqueous solutions of 3DMAP and Diethylenetriamine (DETA) were investigated by a wetted wall column at 30, 35, and 40oC. The systems studied were: 3DMAP (5, 10, 15, 20, 25, 30wt%) + H2O and 3DMAP (25%) + DETA (5%) + H2O, 3DMAP (20%) + DETA (10%) + H2O, 3DMAP (15%) +DETA (15%) + H2O. The physical properties such as density, viscosity, Henry’s law constant and diffusivity of the studied systems were also measured. Due to the reactivity of CO2 to the amine solutions, the N2O analogy was used to estimate the solubility and diffusivity of CO2 in the aqueous amine solutions. The reaction rate constants were calculated by applying a hybrid model which combines a pseudo-first order reaction mechanism for the reaction of CO2 with 3DMAP while the zwitterion mechanism for the absorption of CO2 into DETA. The results of this research data can be used to design for the absorption process of which the aqueous 3DMAP + DETA solutions used as the CO2 absorbents.