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Aluminum Tert-Butoxide As a Rate Enhancing Meerwein-Ponndorf-Verley Reduction Catalyst Applied to the Technological Transfer from Batch to Continuous Flow

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Aluminum Tert-Butoxide As a Rate Enhancing Meerwein-Ponndorf-Verley Reduction Catalyst Applied to the Technological Transfer from Batch to Continuous Flow TWO APPROACHES TO GREEN CHEMISTRY IN INDUSTRIALLY DRIVEN PROCESSES: ALUMINUM TERT-BUTOXIDE AS A RATE ENHANCING MEERWEIN-PONNDORF-VERLEY REDUCTION CATALYST APPLIED TO THE TECHNOLOGICAL TRANSFER FROM BATCH TO CONTINUOUS FLOW AND STRUCTURAL MODIFICATIONS OF FUNCTIONALIZED TRIALKYLSILYLAMINES AS ENERGY EFFICIENT CARBON DIOXIDE CAPTURE SOLVENTS A Thesis Presented to The Academic Faculty By Kyle Flack In Partial Fulfillment Of the Requirements for the Degree Doctor of Philosophy in Chemistry Georgia Institute of Technology August 2012 TWO APPROACHES TO GREEN CHEMISTRY IN INDUSTRIALLY DRIVEN PROCESSES: ALUMINUM TERT-BUTOXIDE AS A RATE ENHANCING MEERWEIN-PONNDORF-VERLEY REDUCTION CATALYST APPLIED TO THE TECHNOLOGICAL TRANSFER FROM BATCH TO CONTINUOUS FLOW AND STRUCTURAL MODIFICATIONS OF FUNCTIONALIZED TRIALKYLSILYLAMINES AS ENERGY EFFICIENT CARBON DIOXIDE CAPTURE SOLVENTS Approved By: Dr. Charles Liotta, Co-Advisor Dr. Angelo Bongiorno School of Chemistry and Biochemistry School of Chemistry and Biochemistry Georgia Institute of Techonology Georgia Institute of Technology Dr. Charles Eckert, Co-Advisor Dr. Christopher Jones School of Chemical and Biomolecular School of Chemical and Biomolecular Engineering Engineering Georgia Institute of Techonology Georgia Institute of Technology Dr. Stefan France School of Chemistry and Biochemistry Georgia Institute of Technology Date Approved: May 25, 2012 This thesis is dedicated to David O. Halvorson, who was a loving grandfather and superb chemist iii ACKNOWLEDGMENTS I would first like to begin by thanking my advisors Dr. Charles Liotta and Dr. Charles Eckert for their unparalleled assistance and guidance through my thesis work. Dr. Liotta has helped me realized that keeping a chin-up approach to graduate school and staying positive is vital in success. Both advisors encouragement and collaborative approach to problem solving have really helped me see the importance of fundamental science and understanding and how it plays into a much larger overall picture. I would like to also thank my committee members for their support through each of the obstacles in my graduate career. Your questions and helpful insight have been important in continuing my research. I would next like to thank all of my colleagues, former and current, that have helped each of the projects move forward. Specifically, I would like to give appreciation to Dr. Pamela Pollet’s scholarly vision and answers to even the simplest questions that have led to my personal progress. Specifically, I’d also like to thank Kristen Kitagawa (Fisher) for her mentorship when I joined the group as well as her continual involvement in seeing my career progress. I’d be remiss if I didn’t thank all of the members of the Eckert-Liotta group between 2008 and 2012. I’ve had the pleasure in working with you all in some form whether it was every day in the lab or just a chat in the office. The DOE and ConocoPhillips research teams have been instrumental in the progression of this thesis work that has helped lead to interesting insights in CO2 capture. My colleagues Michael Bayless, Evan Davey, Jackson Switzer, Amy Rohan, Emily Nixon, and Will Heaner have become great friends outside of work, and I thank you for keeping my life interesting for sure! iv I’d lastly like to thank my fiancé Meghan Young for being my best friend (in Atlanta). You have kept me grounded and focused and I can’t wait for all of our adventures to come. To my family and friends in North Carolina, including the Avett Brothers, I could not have done this without your love and support! v TABLE OF CONTENTS ACKNOWLEDGEMENTS ............................................................................................... iv LIST OF TABLES ......................................................................................................... xiv LIST OF FIGURES ....................................................................................................... xvi LIST OF ABBREVIATIONS ......................................................................................... xxv SUMMARY ................................................................................................................ xxviii CHAPTER 1: INTRODUCTION ...................................................................................... 1 1.1 Green Chemistry Principles ................................................................................... 1 1.2 Alcohols and their formation through carbonyl reduction ....................................... 2 1.3 Continuous flow technology .................................................................................. 3 1.4 Carbon capture with amine based solvents ........................................................... 5 1.5 References ..........................................................................................................12 CHAPTER 2: ENHANCED MEERWEIN-PONNDORF-VERLEY (MPV) REDUCTIONS WITH Al(OtBu)3 .............................................................................................................14 2.1 Introduction ..........................................................................................................14 2.1.1 The MPV Reduction ......................................................................................14 2.1.2 The MPV reduction of (S)-CMK .....................................................................18 2.1.3 Prior work ......................................................................................................21 2.2 Results and Discussion ........................................................................................21 2.2.1 Changes in aluminum alkoxide structure .......................................................21 2.2.2 MPV reduction rates comparing Al(OiPr)3 and Al(OtBu)3 in iPrOH .................24 2.2.3 MPV Reductions in a mixed solvent system: toluene and iPrOH ...................31 2.2.4 Aggregation state of aluminum alkoxide complexes.......................................35 vi 2.2.5 Reduction rates of (S)-CMK with catalyst loading ..........................................44 2.3 Industrial advantages to using Al(OtBu)3 ..............................................................46 2.4 Conclusions .........................................................................................................47 2.5 Experimental methods .........................................................................................48 2.5.1 Experimental procedure for kinetic analysis ...................................................48 2.6 References ..........................................................................................................62 CHAPTER 3: TRANSFER OF BATCH MPV REDUCTION MODEL COMPOUNDS BENZALDEHYDE AND ACETOPHENONE TO CONTINUOUS FLOW .........................64 3.1 Introduction ..........................................................................................................64 3.2 Continuous flow equipment ..................................................................................67 3.2.1 Corning® Continuous Flow Reactor ...............................................................67 3.3 Results and Discussion ........................................................................................71 3.3.1 Initial reduction of benzaldehyde in continuous flow ......................................71 3.3.2. MPV reductions with a mixed solvent system ...............................................73 3.3.3 Experimental Method of all continuous flow experiments and analysis ..........74 3.3.4 Continuous flow reduction of benzaldehyde with two plates...........................75 3.3.5 Batch Reductions of model carbonyl compounds with toluene/iPrOH ............78 3.3.6 MPV reductions of benzaldehyde and acetophenone in continuous flow .......82 3.3.7 Comparison of batch and continuous flow methodology ................................88 3.4 Conclusions .........................................................................................................92 3.5 Experimental procedures .....................................................................................92 3.5.1 General procedure for batch reactions: ..........................................................92 vii 3.5.2 General procedure for continuous flow reactions: ..........................................93 3.5.3 Continuous flow sampling guide ....................................................................95 3.5.4. Comparisons of batch and continuous flow ...................................................96 3.6 References ..........................................................................................................99 CHAPTER 4: CO2 CAPTURE WITH TRIALKYLSILYLPROPYLAMINES ..................... 100 4.1 Introduction ........................................................................................................ 100 4.1.1 Aqueous amines for CO2 Capture ................................................................ 100 4.1.2 Ionic liquids (ILs) for CO2 capture ................................................................ 104 4.1.3 Reversible systems for CO2 capture ............................................................ 107 4.1.4 Motivation and principles behind trialkylsilylamines for CO2 capture ............ 109 4.2 Synthesis of trialkylsilylamines ........................................................................... 112 4.2.1 Hydrosilylation reaction ...............................................................................
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