Three-component mass transfer in liquid-liquid extraction with the system glycerol-acetone-water. Part 2: Calculation and experimental investigation of three-component mass transfer in a countercurrent extraction column

1991 ◽  
Vol 14 (4) ◽  
pp. 253-263 ◽  
Author(s):  
Wolfgang Schermuly ◽  
Eckhart Blaß
2014 ◽  
Vol 92 (11) ◽  
pp. 2313-2323 ◽  
Author(s):  
Amir Bahmanyar ◽  
Nafiseh Khoobi ◽  
Mostafa Mohammad Ali Moharrer ◽  
Hossein Bahmanyar

2015 ◽  
Author(s):  
◽  
Nomakhosi Dorothy Sincuba

There are various types of separation processes used in industries, such as, distillation, liquid-liquid extraction and gas absorption. Liquid-liquid extraction (LLE) is a separation process that involves mass transfer from a liquid mixture to an immiscible extraction solvent. This process is generally used where the mixture cannot be separated by fractional distillation due to close relative volatilities of the mixture components or for heat sensitive components. LLE is rated as the second most important separation process after distillation and it is widely used in chemical engineering industries. Different types of columns are available for LLE. Reciprocating and vibrating plate extraction columns are mechanically agitated extraction columns. In this research a vibrating plate extraction column was utilised. It uses perforated plates with down-comers. The perforations provide passage for the dispersed phase, while down-comers provide passage for the continuous phase. The effectiveness of a vibrating plate extractor was previously investigated but limited research was conducted on the effect of the different tray designs and agitation levels (as the product of amplitude and frequency of vibration). These variables affect the hydrodynamics and mass transfer in the column. The determination of the optimum process parameters is important in achieving the highest separation efficiency of the vibrating extraction column. The focus of this research is to test the effect of different tray designs in order to enhance the separation process efficiency. All tests were conducted using the toluene-acetone-water system as a standard test system proposed by the European Federation for Chemical Engineering, (1985). The experiments were conducted to test the effect of mass transfer on the hydrodynamics of the system while changing the agitation levels, downcomers and hole diameters. A comparative investigation was conducted on straight segment and circular downcomers, then hole diameters analysis was performed on the effective downcomer Comparison of the effect of the tray design types on the amount of acetone extracted was utilised to select the effective tray. Tray with the circular downcomer and 3.0 mm hole diameter had high dispersed phase holdup values and with the highest percentage amount of acetone extracted (95.05%) was obtained compared to other tray designs investigated.


Konversi ◽  
2013 ◽  
Vol 2 (1) ◽  
pp. 32
Author(s):  
Agus Mirwan

Ekstraksi cair-cair dalam kolom isian merupakan proses pemisahan fasa cair yang memanfaatkan perbedaan kelarutan suatu zat. Tipe ekstraksi ini termasuk kedalam  tipe ekstraksi kolom vertikal tanpa berpengaduk (unagitated) selain kolom semprot (spray) dan kolom pelat. Operasi ekstraksi cair-cair yang baik sangat dipengaruhi oleh karakteristik perpindahan zat terlarut (solute). Karakteristik ini dapat dikuantifikasikan dengan suatu nilai yang disebut dengan koefisien perpindahan massa. Koefisien perpindahan massa ini sangat penting untuk diketahui dalam perancangan kolom ekstraksi cair-cair dan nilainya dapat dicari dengan menggunakan model-model estimasi koefisien perpindahan massa baik di fasa dispersi maupun fasa kontinyu. Penelitian ini bertujuan untuk membuktikan keberlakuan model Handloss-Baros – Garner-Foord-Tayeban (HB-GFT) pada proses ekstraksi cair-cair menggunakan prototipe kolom transparan dan jenis isian berupa bola-bola kecil dengan variasi laju alir fasa kontinyu dan fasa dispersi pada rentang tetesan bersirkulasi (Re = 10 – 200). Dari penelitian ini didapatkan bahwa jenis isian, ukuran tetesan, dan laju alir fasa kedua (dispersi dan  kontinyu) memberikan pengaruh yang cukup signifikan terhadap proses perpindahan massa yang dinyatakan dengan koefisien perpindahan massa keseluruhan (KOD). Data laju alir dan komposisi masing-masing fasa di aliran masuk dan keluar kolom dianalisis dengan menggunakan alat kromatografi gas (GC) yang ditunjukan dengan makin besar laju alir fasa dispersi (Qd), koefisien perpindahan massa keseluruhan (KOD) makin kecil. Hal ini disebabkan bahwa ukuran diameter tetesan disepanjang kolom isian dianggap sama. Dan keberlakuan model HB-GFT untuk dinamika tetesan sirkulasi internal (170<Re<200) merupakan kombinasi terbaik dalam penentuan KOD dengan standar deviasi sebesar 3,2%. Keywords: ekstraksi, kolom isian, perpindahan massa. Liquid-liquid extraction in packed column is a process of liquid phase separation in which a liquid solution (the feed) is contacted with an immiscible or nearly immiscible liquid (solvent). This type of extraction is a kind of vertical column extraction type without agitator (unagitated column) besides spray column and plate column. Good operation of liquid-liquid extraction hardly influenced by solute transfer characteristic. This characteristic can be quantification with a value so-called with mass transfer coefficient. Mass transfer coefficient is importance in order to be known in scheme of liquid-liquid extraction column and the values can be searched by using estimation models of mass transfer coefficient either in dispersion phase and also continue phase.The aim of this research is to prove model applying Handloss-Baros - Garner-Foord-Tayeban (HB-GFT) at liquid-liquid extraction process using transparent column prototype and packing type of small sphere with various of flow rate continue phase and dispersion phase at circulation drop spread (Re = 10 - 200). From this research got that packing type, droplet size, and flow rate phase (dispersion and continue) gives influence that is enough significant to mass transfer process that expressed with overall mass transfer coefficient (KOD). Flow rate and composition each phase in inlet and outlet column data are analyzed by using gas chromatography equipment (GC) that showed more and more big dispersion phase (Qd) flow rate, mass transfer coefficient (KOD) more and more small. This caused that drop diameter measure along the length of packing column assumed to be same. And model applying HB-GFT for internal circulation drop dynamics (170<Re<200) is best combination in determination of KOD with deviation standard equal to 3,2%. Keywords: extraction, packing column, mass transfer


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