Improved film evaporator for mechanistic understanding of microwave-induced separation process
Xin Gao1,2, Dandan Shu1, Xingang Li1, Hong Li1()
1. School of Chemical Engineering and Technology, National Engineering Research Center of Distillation Technology, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, China 2. School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, M13 9PL, UK
Microwave-induced film evaporation separation process has been reported recently to separate the polar/nonpolar mixture. However, the efficiency of the separation is still too low for practical applications, which requires further enhancement via different strategies such as optimization design of evaporator structure. In addition the depth understanding of the separation mechanisms is great importance for better utilization of the microwave-induced separation process. To carry out these investigations, a novel microwave-induced falling film evaporation instrument was developed in this paper. The improvement of the enhancement effect of microwave-induced separation was observed based on the improved film evaporator. The systematic experiments on microwave-induced separation with different binary azeotropic mixtures (ethanol-ethyl acetate system and dimethyl carbonate (DMC)-H2O system) were conducted based on the new evaporator. For the ethanol-ethyl acetate system, microwave irradiation shifted the direction of evaporation separation at higher ethanol content in the starting liquid mixture. Moreover, for DMC-H2O system microwave-induced separation process broke through the limitations of the traditional distillation process. The results clearly demonstrated the microwave-induced evaporation separation process could be commendably applied to the separation of binary azeotrope with different dielectric properties. Effects of operating parameters are also investigated to trigger further mechanism understanding on the microwave-induced separation process.
G D Stefanidis, A N Muñoz, G S J Sturm, A Stankiewicz. A helicopter view of microwave application to chemical processes: Reactions, separations, and equipment concepts. Reviews in Chemical Engineering, 2014, 30(3): 233–259 https://doi.org/10.1515/revce-2013-0033
2
X Gao, X Li, J Zhang, J Sun, H Li. Influence of a microwave irradiation field on vapor-liquid equilibrium. Chemical Engineering Science, 2013, 90: 213–220 https://doi.org/10.1016/j.ces.2012.12.037
3
A I Stankiewicz, J A Moulin. Process intensification: Transforming chemical engineering. Chemical Engineering Progress, 2000, 96(1): 22–34
4
L Perreux, A Loupy. A tentative rationalization of microwave effects in organic synthesis according to the reaction medium, and mechanistic considerations. Tetrahedron, 2001, 57(45): 9199–9223 https://doi.org/10.1016/S0040-4020(01)00905-X
5
M Komorowska-Durka, R van Houten, G D Stefanidis. Application of microwave heating to pervaporation: A case study for separation of ethanol-water mixtures. Chemical Engineering and Processing: Process Intensification, 2014, 81: 35–40 https://doi.org/10.1016/j.cep.2014.04.009
6
C O Kappe. Controlled microwave heating in modern organic synthesis. Angewandte Chemie International Edition, 2004, 43(46): 6250–6284 https://doi.org/10.1002/anie.200400655
7
W Wang, Z Liu, J Sun, Q Ma, Y Zhang. Experimental study on the heating effects of microwave discharge caused by metals. AIChE Journal. American Institute of Chemical Engineers, 2012, 58(12): 3852–3857 https://doi.org/10.1002/aic.13766
8
F Chen, X Du, Y Zu, L Yang, F Wang. Microwave-assisted method for distillation and dual extraction in obtaining essential oil, proanthocyanidins and polysaccharides by one-pot process from Cinnamomi Cortex. Separation and Purification Technology, 2016, 164: 1–11 https://doi.org/10.1016/j.seppur.2016.03.018
9
T Constant, C Moyne, P Perré. Drying with internal heat generation: Theoretical aspects and application to microwave heating. AIChE Journal. American Institute of Chemical Engineers, 1996, 42(2): 359–368 https://doi.org/10.1002/aic.690420206
10
W Wang, G Chen. Freeze drying with dielectric-material-assisted microwave heating. AIChE Journal. American Institute of Chemical Engineers, 2007, 53(12): 3077–3088 https://doi.org/10.1002/aic.11336
11
T J Appleton, R I Colder, S W Kingman, I S Lowndes, A G Read. Microwave technology for energy-efficient processing of waste. Applied Energy, 2005, 81(1): 85–113 https://doi.org/10.1016/j.apenergy.2004.07.002
A V Salomatov, V V Salomatov. Thermal regime of slotted channel with moving incompressible liquid under microwave conditions. Journal of Engineering Thermophysics, 2017, 26(3): 359–365 https://doi.org/10.1134/S1810232817030067
14
A Man, R Shahidan. Microwave-assisted chemical reactions. Journal of Macromolecular Science, Part A. Pure and Applied Chemistry, 2007, 44(6): 651–657
15
S Chandrasekaran, S Ramanathan, T Basak. Microwave material processing—A review. AIChE Journal. American Institute of Chemical Engineers, 2012, 58(2): 330–363 https://doi.org/10.1002/aic.12766
16
E T Thostenson, T W Chou. Microwave processing: Fundamentals and applications. Composites Part a. Applied Science and Manufacturing, 1999, 30(9): 1055–1071 https://doi.org/10.1016/S1359-835X(99)00020-2
17
K Werth, P Lutze, A A Kiss, A I Stankiewicz, G D Stefanidis, A Górak. A systematic investigation of microwave-assisted reactive distillation: Influence of microwaves on separation and reaction. Chemical Engineering and Processing: Process Intensification, 2015, 93: 87–97 https://doi.org/10.1016/j.cep.2015.05.002
18
H Li, J Cui, J Liu, X Li, X Gao. Mechanism of the effects of microwave irradiation on the relative volatility of binary mixtures. AIChE Journal. American Institute of Chemical Engineers, 2017, 63(4): 1328–1337 https://doi.org/10.1002/aic.15513
19
X Gao, X Liu, X Li, J Zhang, Y Yang, H Li. Continuous microwave-assisted reactive distillation column: Pilot-scale experiments and model validation. Chemical Engineering Science, 2018, 31(186): 251–264 https://doi.org/10.1016/j.ces.2018.05.036
20
H Li, J Liu, X Li, X Gao. Microwave-induced polar/nonpolar mixture separation performance in a film evaporation process. AIChE Journal. American Institute of Chemical Engineers, 2019, 65(2): 745–754 https://doi.org/10.1002/aic.16436
21
G Link, V Ramopoulos. Simple analytical approach for industrial microwave applicator design. Chemical Engineering and Processing: Process Intensification, 2018, 125: 334–342 https://doi.org/10.1016/j.cep.2017.12.015
22
L Estel, M Poux, N Benamara, I Polaert. Continuous flow-microwave reactor: Where are we? Chemical Engineering and Processing: Process Intensification, 2017, 113: 56–64 https://doi.org/10.1016/j.cep.2016.09.022
23
C Gabriel, S Gabriel, E H Grant, B Halstead, D Mingos. Dielectric parameters relevant to microwave dielectric heating. Chemical Society Reviews, 1998, 27(3): 213–224 https://doi.org/10.1039/a827213z
24
O Ogunniran, E R Binner, A H Sklavounos, J P Robinson. Enhancing evaporative mass transfer and steam stripping using microwave heating. Chemical Engineering Science, 2017, 165: 147–153 https://doi.org/10.1016/j.ces.2017.03.003
25
X F Niu, K Du, F Xiao. Experimental study on ammonia-water falling film absorption in external magnetic fields. International Journal of Refrigeration, 2010, 33(4): 686–694 https://doi.org/10.1016/j.ijrefrig.2009.11.014
26
J Ortega, J A Pena, C De Anonso. Isobaric vapor-liquid equilibria of ethyl acetate+ ethanol mixtures at 760 ± 0.5 mmHg. Journal of Chemical & Engineering Data, 1986, 31(3): 339–342 https://doi.org/10.1021/je00045a023
27
M Chen, G Han, P Guo, Z Xiao. Solute diffusion flux under microwave enhancement. Journal of Engineering Thermophysics, 2008, 29(11): 1950–1952
28
W Won, X Feng, D Lawless. Separation of dimethyl carbonate/methanol/water mixtures by pervaporation using crosslinked chitosan membranes. Separation and Purification Technology, 2003, 31(2): 129–140 https://doi.org/10.1016/S1383-5866(02)00176-4
29
S Camy, J S Pic, E Badens, J S Condoret. Fluid phase equilibria of the reacting mixture in the dimethyl carbonate synthesis from supercritical CO2. Journal of Supercritical Fluids, 2003, 25(1): 19–32 https://doi.org/10.1016/S0896-8446(02)00087-6
30
L H Horsley. Azeotropic Data-III. Advances in Chemistry, 1973, (116): 1–628
31
G E Walrafen. Raman spectral studies of water structure. Journal of Chemical Physics, 1964, 40(11): 3249–3256 https://doi.org/10.1063/1.1724992
32
E S Kryachko. Ab initio studies of the conformations of water hexamer: Modelling the penta-coordinated hydrogen-bonded pattern in liquid water. Chemical Physics Letters, 1999, 314(3-4): 353–363 https://doi.org/10.1016/S0009-2614(99)01100-8
33
S Roy, M S Humoud, W Intrchom, S Mitra. Microwave-induced desalination via direct contact membrane distillation. ACS Sustainable Chemistry & Engineering, 2017, 6(1): 626–632 https://doi.org/10.1021/acssuschemeng.7b02950
