Eutectic Freeze Crystallization on Sodium Chloride Analysis of a full experimental cycle Master of Science Thesis Document number: 2461 Bruno (J.J.) Verbeek Wb1179829 29-07-2011 Eutectic Freeze Crystallization on Sodium Chloride 2 Eutectic Freeze Crystallization on Sodium Chloride Faculty: Process Equipment For obtaining the degree of Master of Science in Sustainable Process- & Energy Technology Exam committee: Prof. dr. G.J. Witkamp Dr. L Hartmann K. Yasadi Copyright © BJJ Verbeek All rights reserved 3 Eutectic Freeze Crystallization on Sodium Chloride Contents Acknowledgement ........................................................................................................................................ 6 Abstract ......................................................................................................................................................... 7 Table of figures ............................................................................................................................................. 9 Nomenclature ............................................................................................................................................. 11 1. Introduction ........................................................................................................................................ 13 1.1. Eutectic freeze crystallization ..................................................................................................... 14 1.2. Sodium chloride solutions ........................................................................................................... 16 1.3. Cooled Disk Column Crystallizer (CDCC) ..................................................................................... 18 1.4. Scraped Cooled Wall Crystallizer (SCWC) in skid ........................................................................ 20 1.5. EFRO project ............................................................................................................................... 23 1.6. Scope of the research ................................................................................................................. 24 2. Theoretical heat transfer on scraped wall .......................................................................................... 25 2.1. Overall heat transfer ................................................................................................................... 25 2.2. Heat transfer coefficient metal wall ........................................................................................... 26 2.3. Heat transfer coefficient coolant ................................................................................................ 26 2.4. Heat transfer in solution ............................................................................................................. 28 2.5. Overall heat transfer coëfficiënt ................................................................................................. 31 3. Heat transfer experiments 10L CDCC.................................................................................................. 32 3.1. Experimental procedure ............................................................................................................. 32 3.2. Results & discussion .................................................................................................................... 33 3.3. Conclusion ................................................................................................................................... 37 4. Heat transfer experiments 200L SCWC ............................................................................................... 38 4.1. Experimental procedure ............................................................................................................. 38 4.2. Results & discussion .................................................................................................................... 38 4.3. Corrosion in the 200L crystallizer ................................................................................................ 44 4.4. Conclusion ................................................................................................................................... 45 5. Continuous operation of the skid and washing of the products ........................................................ 46 5.1. Experimental procedure ............................................................................................................. 46 5.2. General results ............................................................................................................................ 48 5.3. Mass balance ............................................................................................................................... 49 4 Eutectic Freeze Crystallization on Sodium Chloride 5.4. Determination of heat losses in the crystallizer ......................................................................... 52 5.5. Ice filtration & washing ............................................................................................................... 53 5.6. Salt filtration & washing .............................................................................................................. 55 5.7. Energy balance ............................................................................................................................ 56 5.8. Conclusion ................................................................................................................................... 60 6. Optimization and up scaling................................................................................................................ 61 6.1. Refrigeration cycle ...................................................................................................................... 61 6.2. Evaporative CO2 cooling .............................................................................................................. 62 6.3. Teflon encapsulated heat exchanger .......................................................................................... 66 6.4. Filtration & washing of salt ......................................................................................................... 67 6.5. Washing & filtration of ice .......................................................................................................... 68 6.6. Energy consumption in an ideal case .......................................................................................... 71 6.7. Conclusion ................................................................................................................................... 72 7. Environmental analyses of fresh water producing methods .............................................................. 73 7.1. LCA on potable water production ............................................................................................... 73 7.2. Evaporative crystallization .......................................................................................................... 76 7.3. Conclusion ................................................................................................................................... 78 8. Conclusion ........................................................................................................................................... 79 9. Recommendations .............................................................................................................................. 81 Appendices .................................................................................................................................................. 82 A. Vapor pressure vs temperature of CO2 ........................................................................................... 82 B. ICP results of samples ..................................................................................................................... 83 C. Spreadsheet for evaporative CO2 cooling calculations ................................................................... 85 Bibliography ................................................................................................................................................ 87 5 Eutectic Freeze Crystallization on Sodium Chloride Acknowledgement The final project for obtaining a Master degree has fascinated me over the past 8 months ; it offered me a wonderful opportunity to finalize my studies in Mechanical Engineering on a subject in Process and Energy in Delft. There are a number of people whose support I would like to acknowledge. First of all I have to thank prof. dr. GJ Witkamp for giving me the opportunity to work on the subject of eutectic freezing. It was a pleasure to work in his motivating department doing interesting research on this innovative subject. Two post-doc researchers of the department kept constantly track of me and pushed me in the right direction. Jaap van Spronsen helped me especially with the experiments and it was a pleasure to work with him. He is really motivating and a passionate researcher who is always willing to help. Always curious to the outcome and having an interesting view on not only the process industry but on live in general. Furthermore, I want to thank Elif for the motivating meetings we had and her critical view on my work. When I was struggling with the equipment in the skid Hans Evers was always willing