Determination of diffusivities of triolein in pressurized liquids and in supercritical CO2
Determination of diffusivities of triolein in pressurized liquids and in supercritical CO2
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DOI：
10.1016/j.molliq.2022.118860
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发表时间：
2022-03-08
影响因子：
6
通讯作者：
Kong, Chang Yi
中科院分区：
文献类型：
--
作者：
Cai, Guoxiao;Katsumata, Wataru;Kong, Chang Yi
加压液体萃取和超临界流体萃取正在引起人们的关注。这些过程的精确设计和放大需要了解传输特性，即扩散系数。本研究在不同粘度的加压流体中测量了高分子量三油酸甘油酯的扩散系数D-12。通过泰勒分散法在298.15至323.15 K和1.00至12.08 MPa压力下测定乙醇、甲醇和己烷的各种加压液体中的D-12值。我们发现，泰勒色散法无法准确测量超临界CO2中的D-12数据，因为泰勒色散法得到的超临界CO2中三油酸甘油酯的响应峰拖尾严重。然而，通过使用色谱脉冲响应方法，尾矿得到了显着改善。因此，采用色谱脉冲响应法在303.15至333.15 K和压力高达31.02 MPa的条件下测量超临界CO2中的D-12值。液体中三油酸甘油酯D-12的测定量大小依次为：CO2>己烷>甲醇>乙醇。 D-12在液体乙醇中从298.15 K和10.00 MPa下的0.306 x 10(-9) m(2) s(-1)增加到超临界CO2中333.15 K和13.77 MPa下的6.323 x 10(-9) m(2) s(-1)。本研究中在CO2、己烷、甲醇和乙醇中测量的所有三油酸甘油酯的扩散率数据都可以在从液体到超临界状态的37至1179μPa·s的广泛流体粘度范围内用流体动力学方程令人满意地表示。 (C) 2022 Elsevier B.V. 保留所有权利。
Pressurized liquid extraction and supercritical fluid extraction are attracting attention. The accurate design and scale-up of these processes need the knowledge of transport property, namely, diffusion coefficients. In this study, the measurements of diffusion coefficients D-12 of triolein with a high molecular weight were carried out in pressurized fluids with different viscosities. The D-12 values in various pressurized liquids of ethanol, methanol, and hexane were determined by the Taylor dispersion method at 298.15 to 323.15 K and pressures of 1.00 to 12.08 MPa. We found that the D-12 data in supercritical CO2 cannot be accurately measured by the Taylor dispersion method because the response peaks of triolein in supercritical CO2 obtained by the Taylor dispersion method were severe tailing. However, the tailings were significantly improved by using the chromatographic impulse response method. Therefore, the D-12 values in supercritical CO2 were measured by the chromatographic impulse response method at 303.15 to 333.15 K and pressure up to 31.02 MPa. The magnitude of determined D-12 of triolein in fluids is in the order of CO2 > hexane > methanol > ethanol. The D-12 increased from 0.306 x 10(-9) m(2) s(-1) at 298.15 K and 10.00 MPa in liquid ethanol to 6.323 x 10(-9) m(2) s(-1) at 333.15 K and 13.77 MPa in supercritical CO2. All the diffusivity data of triolein measured in CO2, hexane, methanol, and ethanol in this study can be satisfactorily represented by the hydrodynamic equation over a wide range of fluid viscosity of 37 to 1179 mu Pa s from liquid to supercritical states. (C) 2022 Elsevier B.V. All rights reserved.