A multi-probe sensor for water content analysis, in liquid biofuels, by using reflection and transmission measurements in microwave frequencies range, is proposed in this letter. As preliminary step and for a better understanding, the measurements were carried out with ethanol/water mixtures, which mimic bioethanol applications, at room temperature. In order to study water/alcohol mixtures, each of them was characterized using classical techniques like open ended coaxial probe or reflection/transmission coaxial line, before being tested in multi-probe sensors. At the end, the multi-probe sensor aims to be implemented in-line production in order to perform diagnosis of water in liquid biofuels.
2. Rasool, U. and S. Hemalatha, "A review on bioenergy and biofuels: Sources and their production," Braz. J. Biol. Sci., Vol. 3, No. 5, 3-22, 2016.
3. Liu, Y., Y. Deng, and Y. Li, "Experimental investigation of gas-oil two-phase flow using electrical capacitance tomography," 2017 IEEE International Conference on Imaging Systems and Techniques (IST), 1-5, 2017.
4. Meaney, P. M., C. J. Fox, S. D. Geimer, and K. D. Paulsen, "Electrical characterization of glycerin: Water mixtures: Implications for use as a coupling medium in microwave tomography," IEEE Trans. Microw. Theory Tech., Vol. 65, No. 5, 1471-1478, 2017.
5. Middelburg, L. M., et al., "Multi-domain spectroscopy for composition measurement of water-containing bio-ethanol fuel," Fuel Process. Technol., Vol. 167, 127-135, 2017.
6. Ellison, W. J., K. Lamkaouchi, and J.-M. Moreau, "Water: A dielectric reference," J. Mol. Liq., Vol. 68, No. 2-3, 171-279, 1996.
7. Barthel, J. M. G. and R. Buchner, "High frequency permittivity and its use in the investigation of solution properties," Pure Appl. Chem., Vol. 63, No. 10, 1473-1482, 1991.
8. Sudo, S., N. Shinyashiki, Y. Kitsuki, and S. Yagihara, "Dielectric relaxation time and relaxation time distribution of alcohol-water mixtures," J. Phys. Chem. A, Vol. 106, No. 3, 458-464, 2002.
9. Petong, P., R. Pottel, and U. Kaatze, "Water-ethanol mixtures at different compositions and temperatures. A dieletric relaxation study," J. Phys. Chem. A, Vol. 104, No. 32, 7420-7428, 2000.
10. Gregory, A. P. and R. N. Clarke, "Tables of the complex permittivity of dielectric reference liquids at frequencies up to 5 GHz,", 2012.
11. Baker-Jarvis, J. R., et al., "Measuring the permittivity and permeability of lossy materials: solids, liquids, metals, and negative-index materials,", Technical Note (NIST TN)-1536, Jan. 2005.
12. Blackham, D. V. and R. D. Pollard, "An improved technique for permittivity measurements using a coaxial probe," IEEE Trans. Instrum. Meas., Vol. 46, No. 5, 1093-1099, 1997.
13. Nicolson, A. M. and G. F. Ross, "Measurement of the intrinsic properties of materials by time-domain techniques," IEEE Trans. Instrum. Meas., Vol. 19, No. 4, 377-382, Nov. 1970.
14. Ba, D. and P. Sabouroux, "Epsimu, a toolkit for permittivity and permeability measurement in microwave domain at real time of all materials: Applications to solid and semisolid materials," Microw. Opt. Technol. Lett., Vol. 52, No. 12, 2643-2648, 2010.
15. Georget, E., R. Abdeddaim, and P. Sabouroux, "A quasi-universal method to measure the electromagnetic characteristics of usual materials in the microwave range," Comptes Rendus Phys., Vol. 15, No. 5, 448-457, 2014.
16. Ajaya, B. and S. S. Kumar, "Effects of concentration and relative permittivity on the transport properties of sodium chloride in pure water and ethanol-water mixed solvent media," Res. J. Chem. Sci. ISSN, Vol. 2231, 606X, 2011.