近年各國紛紛投入海水淡化技術的開發與研究，希望能因應不斷成長的用水需求。隨著全球暖化議題的增溫與化石燃料價格的成長，低階廢熱(low grade waste heat)與再生能源的使用逐漸受到人們的重視，這使得薄膜蒸餾法(membrane distillation, MD)，一項可以利用廢熱與再生能源的淡化技術，受到了關注。本文將研究薄膜蒸餾法的其中一種，直接接觸薄膜蒸餾(direct contact membrane distillation, DCMD)搭配疏水/親水複合膜的熱質傳現象。
本研究針對單層疏水膜、疏水/親水複合膜依據不同的理論分別撰寫Fortran程式進行模擬，並與實驗室前人的實驗數據進行比較，最後調整參數以了解疊合式複合膜的可行性。依據Schofiled’s model所撰寫的模擬程式配合特定紐賽數關係式(Nusselt number correlation)其單層疏水預測結果與實驗誤差最大約18.93%，平均誤差約7.16%。疊合膜預測結果與實驗誤差最大約22.79%，平均誤差約10.25%。

In recent years, many countries have made a lot of efforts to develop sea water desalination technology for the growing demand of water. At the same time, the usage of low grade waste heat and renewable energy is paid more attention because of the global warming issues and the growing prices of fossil fuels. Therefore, the membrane distillation, which is a desalination technology used with low grade waste heat or renewable energy, is more attractive now. This thesis investigates the heat and mass transport phenomena of direct membrane distillation (DCMD), which is one of varied membrane distillation methods.
In this thesis, we develop the computer programs of Fortran to simulate the operation of DCMD within single hydrophobic membranes, or within composite membranes, and then compare the simulation results with other researchers’ work. The deviations of numerical results from experimental data for single hydrophobic membranes are below 18.93% (maximum error), and 7.16% in average. For stacked membranes, the deviations are 22.79% in maximum, and 10.25% in average.

[1] USGS. Where is Earth's water located? Available: http://ga.water.usgs.gov/edu/earthwherewater.html
[2] F. Macedonio, E. Drioli, A. A. Gusev, A. Bardow, R. Semiat, and M. Kurihara, "Efficient technologies for worldwide clean water supply," Chemical Engineering and Processing: Process Intensification, vol. 51, pp. 2-17, 2012.
[3] USGS. Earth's water distribution. Available: http://ga.water.usgs.gov/edu/waterdistribution.html
[4] IDA. IDA Desalination Yearbook. Available: http://www.desalyearbook.com/
[5] J.-B. W. Ching-Yu Wang. Analysis and Evaluation of Taiwan Water Shortage Factors and Solution Strategies. Available: http://ccsenet.org/journal/index.php/ass/article/view/7599
[6] J. Koschikowski. (2011). Water Desalination:When and Where Will it Make Sense? Available: http://ec.europa.eu/dgs/jrc/downloads/jrc_aaas2011_energy_water_koschikowski.pdf
[7] WQA. Salt water. Available: http://www.wqa.org/glossary.cfm?gl=1874
[8] WHO. (1996). Total dissolved solids in Drinking-water. Available: http://www.who.int/water_sanitation_health/dwq/chemicals/tds.pdf
[9] R. W. Baker, Membrane technology and applications, 2nd ed. Chichester ; New York: J. Wiley, 2004.
[10] T. Mezher, H. Fath, Z. Abbas, and A. Khaled, "Techno-economic assessment and environmental impacts of desalination technologies," Desalination, vol. 266, pp. 263-273, 2011.
[11] (2009). ESCWA (Economic and Social Commission for Western Asia). Available: http://www.escwa.un.org/information/publications/edit/upload/sdpd-09-4.pdf
[12] A. Cipollina, G. Micale, and L. Rizzuti, Seawater desalination : conventional and renewable energy processes. Heidelberg ; New York: Springer, 2009.
[13] B. Sauvet-Goichon, "Ashkelon desalination plant — A successful challenge," Desalination, vol. 203, pp. 75-81, 2007.
[14] T. Younos, "The Economics of Desalination," Journal of Contemporary Water Research & Education, vol. 132, pp. 39-45, 2005.
[15] B. Peñate and L. García-Rodríguez, "Current trends and future prospects in the design of seawater reverse osmosis desalination technology," Desalination, vol. 284, pp. 1-8, 2012.
[16] 臺灣電力公司. 年產銷概況. Available: http://www.taipower.com.tw/left_bar/jing_ying_ji_xiao/year_production.htm
[17] M. E. Findley, "Vaporization through Porous Membranes," Industrial & Engineering Chemistry Process Design and Development, vol. 6, pp. 226-230, 1967/04/01 1967.
[18] S. Al-Obaidani, E. Curcio, F. Macedonio, G. Di Profio, H. Al-Hinai, and E. Drioli, "Potential of membrane distillation in seawater desalination: Thermal efficiency, sensitivity study and cost estimation," Journal of Membrane Science, vol. 323, pp. 85-98, 2008.
[19] K. W. Lawson and D. R. Lloyd, "Membrane distillation," Journal of Membrane Science, vol. 124, pp. 1-25, 1997.
[20] M. S. El-Bourawi, Z. Ding, R. Ma, and M. Khayet, "A framework for better understanding membrane distillation separation process," Journal of Membrane Science, vol. 285, pp. 4-29, 2006.
[21] E. K. Summers, H. A. Arafat, and J. H. Lienhard V, "Energy efficiency comparison of single-stage membrane distillation (MD) desalination cycles in different configurations," Desalination, vol. 290, pp. 54-66, 2012.
[22] M. Khayet, T. Matsuura, and J. I. Mengual, "Porous hydrophobic/hydrophilic composite membranes: Estimation of the hydrophobic-layer thickness," Journal of Membrane Science, vol. 266, pp. 68-79, 2005.
[23] L. K. Wang, Membrane and desalination technologies. New York, NY: Humana Press, 2011.
[24] A. D. Khawaji, I. K. Kutubkhanah, and J. M. Wie, "Advances in seawater desalination technologies," Desalination, vol. 221, pp. 47-69, 2008.
[25] S. Kalogirou, Solar energy engineering : processes and systems. Burlington, MA: Elsevier/Academic Press, 2009.
[26] B. R. Bodell, "Silicone rubber vapor diffusion in saline water distillation," United States Patent 285032, 1963.
[27] A. K. Pabby, S. S. H. Rizvi, and A. M. Sastre, Handbook of membrane separations : chemical, pharmaceutical, food, and biotechnological applications. Boca Raton: CRC Press, 2009.
[28] D. Y. Cheng, "Method and apparatus for distillation," United States Patent 4265713, 1981.
[29] D. Y. Cheng and S. J. Wiersma, "Composite membrane for a membrane distillation system," United States Patent 4316772, 1982.
[30] D. Y. Cheng and S. J. Wiersma, "Composite membrane for a membrane distillation system," United States Patent 4419242, 1983.
[31] R. W. Schofield, A. G. Fane, and C. J. D. Fell, "Heat and mass transfer in membrane distillation," Journal of Membrane Science, vol. 33, pp. 299-313, 1987.
[32] R. W. Schofield, A. G. Fane, and C. J. D. Fell, "Gas and vapour transport through microporous membranes. I. Knudsen-Poiseuille transition," Journal of Membrane Science, vol. 53, pp. 159-171, 1990.
[33] R. W. Schofield, A. G. Fane, and C. J. D. Fell, "Gas and vapour transport through microporous membranes. II. Membrane distillation," Journal of Membrane Science, vol. 53, pp. 173-185, 1990.
[34] R. W. Schofield, A. G. Fane, C. J. D. Fell, and R. Macoun, "Factors affecting flux in membrane distillation," Desalination, vol. 77, pp. 279-294, 1990.
[35] M. Khayet and T. Matsuura, "Chapter 1 - Introduction to Membrane Distillation," in Membrane Distillation, ed Amsterdam: Elsevier, 2011, pp. 1-16.
[36] M. Khayet, "Membrane Distillation," in Advanced membrane technology and applications, ed Hoboken, N.J.: Wiley, 2008, pp. 297-369.
[37] M. Khayet, "Membranes and theoretical modeling of membrane distillation: A review," Advances in Colloid and Interface Science, vol. 164, pp. 56-88, 2011.
[38] N. N. Li, Advanced membrane technology and applications. Hoboken, N.J.: Wiley, 2008.
[39] M. Gryta and M. Barancewicz, "Influence of morphology of PVDF capillary membranes on the performance of direct contact membrane distillation," Journal of Membrane Science, vol. 358, pp. 158-167, 2010.
[40] M. Khayet and T. Matsuura, Membrane distillation : principles and applications. Oxford: Elsevier, 2011.
[41] S. Adnan, M. Hoang, H. Wang, and Z. Xie, "Commercial PTFE membranes for membrane distillation application: Effect of microstructure and support material," Desalination, vol. 284, pp. 297-308, 2012.
[42] S. Srisurichan, R. Jiraratananon, and A. G. Fane, "Mass transfer mechanisms and transport resistances in direct contact membrane distillation process," Journal of Membrane Science, vol. 277, pp. 186-194, 2006.
[43] K. W. Lawson and D. R. Lloyd, "Membrane distillation. II. Direct contact MD," Journal of Membrane Science, vol. 120, pp. 123-133, 1996.
[44] J. Phattaranawik and R. Jiraratananon, "Direct contact membrane distillation: effect of mass transfer on heat transfer," Journal of Membrane Science, vol. 188, pp. 137-143, 2001.
[45] C. Fernández-Pineda, M. A. Izquierdo-Gil, and M. C. Garcı́a-Payo, "Gas permeation and direct contact membrane distillation experiments and their analysis using different models," Journal of Membrane Science, vol. 198, pp. 33-49, 2002.
[46] J. Phattaranawik, R. Jiraratananon, and A. G. Fane, "Effect of pore size distribution and air flux on mass transport in direct contact membrane distillation," Journal of Membrane Science, vol. 215, pp. 75-85, 2003.
[47] V. Soni, J. Abildskov, G. Jonsson, and R. Gani, "A general model for membrane-based separation processes," Computers and Chemical Engineering, vol. 33, pp. 644-659, 2009.
[48] S. Bonyadi and T. S. Chung, "Flux enhancement in membrane distillation by fabrication of dual layer hydrophilic–hydrophobic hollow fiber membranes," Journal of Membrane Science, vol. 306, pp. 134-146, 2007.
[49] M. Qtaishat, M. Khayet, and T. Matsuura, "Guidelines for preparation of higher flux hydrophobic/hydrophilic composite membranes for membrane distillation," Journal of Membrane Science, vol. 329, pp. 193-200, 2009.
[50] N. D. Jespersen, J. E. Brady, and A. Hyslop, Chemistry : the molecular nature of matter, 6th ed. Hoboken, NJ: Wiley, 2012.
[51] R. Chang, General chemistry : the essential concepts, 5th ed. Boston: McGraw-Hill, 2008.
[52] L. Martínez and J. M. Rodríguez-Maroto, "Membrane thickness reduction effects on direct contact membrane distillation performance," Journal of Membrane Science, vol. 312, pp. 143-156, 2008.
[53] M. Qtaishat, T. Matsuura, B. Kruczek, and M. Khayet, "Heat and mass transfer analysis in direct contact membrane distillation," Desalination, vol. 219, pp. 272-292, 2008.
[54] J. Phattaranawik, R. Jiraratananon, and A. G. Fane, "Heat transport and membrane distillation coefficients in direct contact membrane distillation," Journal of Membrane Science, vol. 212, pp. 177-193, 2003.
[55] L. Martı́nez-Dı́ez and M. I. Vázquez-González, "Temperature and concentration polarization in membrane distillation of aqueous salt solutions," Journal of Membrane Science, vol. 156, pp. 265-273, 1999.
[56] M. Gryta, M. Tomaszewska, and A. W. Morawski, "Membrane distillation with laminar flow," Separation and Purification Technology, vol. 11, pp. 93-101, 1997.
[57] M. Gryta and M. Tomaszewska, "Heat transport in the membrane distillation process," Journal of Membrane Science, vol. 144, pp. 211-222, 1998.
[58] R. K. Shah and A. L. London, Laminar flow forced convection in ducts : a source book for compact heat exchanger analytical data. New York: Academic Press, 1978.
[59] A. S. Kim, "A two-interface transport model with pore-size distribution for predicting the performance of direct contact membrane distillation (DCMD)," Journal of Membrane Science, vol. 428, pp. 410-424, 2013.
[60] E. A. Mason and A. P. Malinauskas, Gas transport in porous media : the dusty-gas model. Amsterdam ; New York: Elsevier, 1983.
[61] L. Martı́nez, F. J. Florido-Dı́az, A. Hernández, and P. Prádanos, "Estimation of vapor transfer coefficient of hydrophobic porous membranes for applications in membrane distillation," Separation and Purification Technology, vol. 33, pp. 45-55, 2003.
[62] ImageJ. Available: http://imagej.nih.gov/ij/index.html
[63] 劉菊蓮, "直接接觸薄膜蒸餾之熱質傳研究," 碩士論文, 動力機械學系, 國立清華大學, 2009.
[64] 林瑋亭, "直接接觸薄膜蒸餾:水蒸氣質量流率與疏水/親水複合膜特性之關係研究," 碩士論文, 動力機械學系, 國立清華大學, 2012.