請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/49220
標題: | 錯流式旋轉填充床中油水混合液吸收有機揮發物之分析 Analysis of VOCs Absorption by Oil and Water Mixture in a Cross-Flow Rotating Packed Bed |
作者: | Yi-Chun Liao 廖翊淳 |
指導教授: | 劉懷勝(Hwai-Shen Liu) |
關鍵字: | 旋轉填充床,吸收,質傳,疏水性揮發有機物,親水性揮發有機物, Rotating packed bed,Absorption,Mass transfer,Hydrophilic VOCs,Hydrophobic VOCs, |
出版年 : | 2021 |
學位: | 碩士 |
摘要: | 現今的工業排放廢氣中常會含有親水性和親油性的有機揮發性氣體(VOCs)。為了同時處理這種工業廢氣,我們實驗室先前的研究以水跟矽油在旋轉填充床(RPB)中吸收甲苯和異丙醇氣體,結果表明這是可行且有效的方法,同時也發現了加入矽油會使水對異丙醇的吸收效率下降;反之加入水會使矽油吸收甲苯的效率提升。 我們將水吸收親水性VOCs和矽油吸收親油性VOCs的質傳係數經驗迴歸式延展到油水系統,發現當把水跟矽油的物理性質視為各自獨立比視為混合的結果要更符合事實。但在此前提下,經驗迴歸式得到的KGa跟實驗得到的KGa仍有超過30%的誤差。為了校正此誤差,我們定義出 和 來代表添加第二種溶液與添加前的有效氣液接觸面積的比值,並得到 和 的經驗迴歸式。之後我們基於矽油跟水的流態性質和monte carlo方法估算出 和 。最後將水吸收親水性VOCs和矽油吸收親油性VOCs的質傳係數經驗迴歸式分別乘上 跟 ,使得KGa的估計值和實驗值的誤差大多落在30%內。 油水混合液吸收異丙醇、油水混合液吸收甲苯的質傳經驗迴歸式如下: (K_G a)/(D_G a_t^2 )=0.0186〖Re〗_G^0.389 〖Re〗_L^0.534 〖Gr〗_G^0.245 H_y^(-0.185) α_water (K_G a)/(D_G a_t^2 )=0.0231〖Re〗_G^0.315 〖Re〗_L^0.389 〖Gr〗_G^0.248 H_y^(-0.31) α_oil α_water=0.14L_o^(-1.08) L_w^0.23 φ^0.83 α_oil=2.21-1.21φ The VOCs (volatile organic compounds) emitted from industries may often include both hydrophobic and hydrophilic compounds. For the purpose of absorbing these VOCs simultaneously, we use mixture of water and silicone oil as the adsorbent to absorb isopropanol (IPA) and toluene in rotating packed bed (RPB). In our previous work, the experiments were successfully demonstrated intensified mass transfer by centrifugal force as expected. However, it was found that the absorption fraction of toluene by water/silicone oil system was higher than those of toluene by oil only for most result. In contrast, most of the absorption fraction of isopropanol by water/silicone oil system was lower than those of isopropanol by water only. This phenomeon may be attributed to coalescence of water and oil liquid drops in void of the bed or the similar effects, resulting in the change of surface area. In order to obtain the overall mass transfer coefficient (KGa) for water and oil in this mixed absorbents system numerically, we extended the correlations of KGa of isopropanol/water and toluene/silicone oil system to the dual absorbents system, it was found that the best results were obtained when physical properties of each absorbents were taken individually. This indicated that considering the two absorbents as a mixture is unnecessary. Result might imply that water and silicone oil absorb VOCs separately in the RPB. Under this premise, estimations of KGa are not satisfactory, still over 30% error. Therefore, the enhancement factors ('α' _'oil' and 'α' _'water' ) representing the change of surface area for water and silicone oil in dual absorbent system were defined and they were affected by water flow rate, oil flow rate and oil volume fraction. Then we get the empirical correlation for 'α' _'oil' and 'α' _'water' . In addition, enhancement factors were calculated by monte carlo method. The result of α was evolved and satisfactory correlations KGa were obtained successfully. The mass transfer empirical correlation for IPA-oil/water and toluene-oil/water were found to be: (K_G a)/(D_G a_t^2 )=0.0186〖Re〗_G^0.389 〖Re〗_L^0.534 〖Gr〗_G^0.245 H_y^(-0.185) α_water (K_G a)/(D_G a_t^2 )=0.0231〖Re〗_G^0.315 〖Re〗_L^0.389 〖Gr〗_G^0.248 H_y^(-0.31) α_oil α_water=0.14L_o^(-1.08) L_w^0.23 φ^0.83 α_oil=2.21-1.21φ |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/49220 |
DOI: | 10.6342/NTU202100634 |
全文授權: | 有償授權 |
顯示於系所單位: | 化學工程學系 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
U0001-0602202116170900.pdf 目前未授權公開取用 | 8.13 MB | Adobe PDF |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。