本研究主要探討利用中空纖維薄膜接觸器(PVDF hollow fiber membrane contactor),結合醇胺水溶液來捕捉二氧化碳,選用吸收液為AMP/ PZ及MDEA/ PZ,溫度控制為30 ℃。探討重點包括:(1)探討氣體流速、液體流速對有效氣液接觸面積之影響;(2)操作參數之效能評估,包括氣體流率、液體流率、吸收液的種類及PZ的濃度對二氧化碳吸收率之影響;(3)建立質傳基本資料,包括修改氣相質傳關係式 及計算吸收液滲入膜孔之比例;(4)質傳阻力之分析,分析主要的阻力落於哪一相,於不同操作條件下,探討各相質傳阻力之消長。結果顯示混合醇胺水溶液可有效降低膜相及液相之阻力(< 25 %)並擷取兩種醇胺水溶液之特性優點,包括PZ對二氧化碳的高吸收速率及AMP、MDEA對二氧化碳的高度吸收負載;結果其最適化(高二氧化碳吸收率及低 值)之吸收液配比為PZ濃度0.30 kmol• m-3加入AMP或MDEA中。 薄膜分離程序可以大量且快速地吸收二氧化碳,吸收液之黏度及和薄膜間之關係更為影響效能最重要的因素之ㄧ。本研究之結果可做為設計薄膜接觸器吸收二氧化碳之基礎資料,更可以做為日後相關研究的參考。
This research tested the performance of CO2 absorption from simulated flue gas stream in microporous PVDF hollow fiber membrane contactor using mixed amine solutions as absorbents. The research objectives including: (1) The influence of gas and liquid flow rates on the effective gasliquid contact area; (2) Efficiency test about the effect of operational parameters on CO2 absorption rate; (3) Structure the model to correlate the mass transfer including the effects of wetting ratio and modify the correlation to predict the gas phase mass transfer; (4) Analyze the resistance of mass transfer. Experiments were conducted at various gas flow rates (200 ~ 500 ml/min), liquid flow rates (200 ~ 500 ml/min) and absorbents (AMP system and MDEA system). The fractional resistance of the membrane increases when using PZ as promoter but it is still below 25% ol the total. For maximum absorption rate with minimal wetting ratio, the recommendation concentration for PZ in AMP or MDEA is 0.3 kmol/ m-3. Gas absorption membrane process were shown to be an effective technology for absorbing CO2 from simulated flue gas streams, but the viscosity and solventmembrane relationship (wetting ratio) were critical factors that can significantly affect system performance.