hilliard dissertation(2008)

Copyright by Marcus Douglas Hilliard 2008

The Dissertation Committee for Marcus Douglas Hilliard certifies that this is the approved version of the following dissertation:

A Predictive Thermodynamic Model for an Aqueous Blend of Potassium Carbonate, Piperazine, and Monoethanolamine for Carbon Dioxide Capture from Flue Gas

Committee: ____________________________________ Gary T. Rochelle, Supervisor ____________________________________ Benny D. Freeman ____________________________________ Isaac C. Sanchez ____________________________________ R. Bruce Eldridge ____________________________________ Hallvard Fjsne Svendsen


by Marcus Douglas Hilliard, B.S.Ch.E.; M.S.E.

Dissertation Presented to the Faculty of the Graduate School of the University of Texas at Austin in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy

The University of Texas at Austin May, 2008

To my family and especially to my partner, James Shewbert for his constant love and support that always kept me going.

In modeling there is no pressure, its all partial pressure James Shewbert and Marcus Hilliard

Acknowledgements

There have been so many people who have helped me throughout the years to make me into the person that I am today. I would first like to thank my parents, Mary Elizabeth and Gregg Hannah, who have been a constant force in my life, illuminating the way while putting up with all of my shenanigans. I also want to thank my extended family and friends, Regina Sandoval, Linda Gregston, Nathanael Haddox, Frank Ramos, Jan and Doug Love, Jessica Bayless, Ken and Derenda Shewbert, Cheryl Paden, Bob Miller and Brian Jantz, Lindi Horton, Ron and Carol Barrett, Lizz and Christophe Restat, and Joy Herring. Thanks for always being there for me and nodding your head when I would tell yall what I was up to in school. I would also like to give a special than you to Pat Knight for editing my dissertation and who taught me that literature and writing could be something that was cool. I would also like to thank some very special teachers at Texas Tech University, who taught me how to become an engineer: Dr. Ted Wiesner, Dr. Robert Bethea, Dr. Jeremy Leggoe, Dr. Uzi Mann, Dr. Sindee Simon, and Dr. Karlene Hoo. Over the past six years while attending graduate school at The University of Texas at Austin, I have been very fortunate to work with so many talented and caring people. I would like to thank all of the students in Dr. Rochelles group, Jody Lester, Kay Swift, Maeve Cooney, Randy Rife, Eduardo Ibarra, Randle Martin, Kevin Haynes, Butch Cunningham, Jim Smitherman, and especially T. Stockman. I could have never done this without your support. vi

I have also been very fortunate to have been given the opportunity to travel to Norway and study at The Norwegian University of Science and Technology under the supervision of Dr. Hallvard F. Svendsen. I would like to thank him for his kindness, hospitality, encouragement, and especially the advice he gave me during my stay in Trondheim. I would also like to thank Inna Kim, Jana Poplsteinova Jakobsen, Sholeh Mamun, Eirik de Silva, Hanna Knuutila, Karl A Hoff, Synnve Hestnes, Andrew Tobiesen, Kristin Giske Lauritsen, Vishwas Dindore, and Arne Lindbrathe, for the kindness they showed and for the advice to bring extra woolen jumpers. I would also like to thank the members of my committee, who have truly been some of the best teachers I have ever had the pleasure to learn from, thank you. I would also like to thank Dr. Gary T. Rochelle for dealing with my mayhem and foolishness over the past six years. He taught me how to think as a researcher and gave me the opportunity to study at The University of Texas at Austin after some persuading, and I am truly grateful. Thank you. I would also like to thank Dr. Chau-Chyun Chen and Dr. Suphat Watanasiri from Aspen Technology. In addition, I want to thank Mark Nelson from GASMET-USA for helping me understand and optimize our FTIR analytical methods. Their support has been an integral part in this research and I am truly honored to have been able to work with them both on this project. This work was made possible in part by the Separations Research Program, Luminant Carbon Management Program, the Industrial Associates Program for CO2 Capture by Aqueous Absorption, and the Department of Energy (DE-FC26-02NT41440).

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This work was prepared with the support of the U.S. Department of Energy, under Award No. DE-FC26-02NT41440. However, any opinions, findings, conclusions, or recommendations expressed herein are those of the authors and do not necessarily reflect the views of the DOE or other sponsors.

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Publication No. __________

Marcus Douglas Hilliard, Ph.D. The University of Texas at Austin, 2008

Supervisor: Gary T. Rochelle

The Electrolyte Nonrandom Two-Liquid Activity Coefficient model in Aspen PlusTM 2006.5 was used to develop a rigorous and consistent thermodynamic representation for the base sub-component systems associated with aqueous combinations of K2CO3, KHCO3, MEA, and piperazine (PZ) in a mixed-solvent electrolyte system for the application of CO2 absorption/stripping from coal fired power plants. We developed a new vapor-liquid equilibrium apparatus to measure CO2, amine, and H2O vapor pressures at 40 and 60 oC. We found that the volatility of MEA and PZ can be approximated at 50 and 20 ppmv at 40 oC for any solvent composition studied in this work, over the CO2 partial pressure range from 0.01 to 0.1 kPa. Very few solvent compositions exhibited a greater differential capacity than 7 m MEA at 60 oC; specifically 11 m MEA, 3.5 ix

m MEA + 3.6 m PZ, 7 m MEA + 2 m PZ, 7 m MEA + 3.6 m PZ, and 5 m K+ + 7 m MEA + 3.6 m PZ. Piperazine exhibited a possible maximum differential capacity of 2.21 mole CO2/kg-H2O at a concentration of 7.3 m. At the Norwegian University of Science and Technology, Inna Kim determined the differential enthalpy of CO2 absorption for aqueous combinations of K2CO3, KHCO3, MEA, PZ, and CO2, based on a consistent experimental method developed for MEA, from 40 to 120 oC for use in this work. In addition, we developed a consistent method to measure the specific heat capacity for a number of similar solvent combinations. We found that the enthalpy of CO2 absorption increased with temperature because the apparent partial heat capacity of CO2 may be considered small. Finally, by using a differential scanning calorimeter, we determined the dissolution temperature for aqueous mixtures of unloaded piperazine, which inferred an effective operating range for solutions of concentrated piperazine, greater than 5 m PZ, over a loading range between 0.25 to 0.45 mole CO2/2mol PZ. Through unit cell x-ray diffraction, we were able to identify and characterize the presence of three solid phases (PZ6H2O, KHCO3, and K2PZ(COO)2) in aqueous mixture combinations of K2CO3, KHCO3, MEA, PZ, and CO2.

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_________________ CONTENTS Dedication Epigraph Acknowledgments Abstract Contents List of Figures List of Tables iv v vi ix xi xxi xxix

CHAPTER I General Introduction ................................................................................................1 1.1 1.2 1.3 1.4 1.5 1.6 Motivation.................................................................................................................................1 The Absorption Process .........................................................................................................2 Thermodynamic Considerations............................................................................................3 Related Research Activities.....................................................................................................5 Scope of Work..........................................................................................................................9 Outline of the dissertation ....................................................................................................11

PART I: Experimental MethodsCHAPTER II Vapor-Liquid Equilibrium Methods ...................................................................15 2.1 Introduction............................................................................................................................15 2.2 Literature Review ...................................................................................................................16 2.3 Chemicals ................................................................................................................................18 2.3.1 Experimental Design.................................................................................................18 2.3.2 Solution Preparation..................................................................................................20 2.3.3 High Temperature Apparatus (NTNU) .................................................................24 2.3.4 Low Temperature Apparatus (UT) .........................................................................29 2.3.5 Multiple Component Analysis .................................................................................32 2.3.6 Low Temperature Apparatus Benchmarking ........................................................35 2.4 Experimental Results.............................................................................................................36 ________________________________________________________________________ xi

________________________________________________________________________ 2.4.1 Pure H2O System .......................................................................................................36 2.4.2 Pure MEA System .....................................................................................................37 2.4.3 H2O-MEA-CO2 Systems ..........................................................................................39 2.4.4 H2O-PZ-CO2 Systems...............................................................................................40 2.5 Conclusions.............................................................................................................................41 CHAPTER III NMR Methods......................................................................................................43 3.1 Introduction............................................................................................................................43 3.2 Literature Review ...................................................................................................................44 3.3 Chemicals ................................................................................................................................45 3.4 Sample Preparation................................................................................................................45 3.5 Molecular Structures and Active Nuclei .............................................................................46 3.6 Spectrometer...........................................................................................................................51 3.7 Experiments with Loaded Samples .....................................................................................52 3.8 Evaluation of Spectra ............................................................................................................52 3.9 Spectra with Varying CO2 Loading .....................................................................................59 3.10 Apparent Speciation Calculation .......................................................................................63 3.11 Experimental Results...........................................................................................................64 3.12 Conclusions...........................................................................................................................68 CHAPTER IV Specific Heat Capacity Methods.........................................................................71 4.1 4.2 4.3 4.4 4.5 Introduction............................................................................................................................71 Literature Review ...................................................................................................................72 Chemicals ................................................................................................................................74 Sample Preparation................................................................................................................74 Differential Scanning Calorimeter .......................................................................................75 4.5.1 DSC Calibration.........................................................................................................77 4.6 Specific Heat Capacity Procedure........................................................................................78 4.7 Experimental Results.............................................................................................................82 4.7.1 Pure H2O System .......................................................................................................82 4.7.2 Pure MEA System .....................................................................................................84 4.7.3 H2O-MEA System .....................................................................................................85 4.8 Conclusions.............................................................................................................................87

CHAPTER V Solid-Liquid Equilibrium Methods and Solid Phase Characterization ...........89 5.1 Introduction............................................................................................................................89 5.2 Chemicals ................................................................................................................................90 5.2.1 Solution Preparation..................................................................................................91 5.3 H2O-PZ Solid Solubility........................................................................................................92 5.4 Solid Solubility Visual Observations ...................................................................................98 5.3.1 Experimental Results.................................................................................................99 ________________________________________________________________________ xii

________________________________________________________________________ 5.5 Solid Phase Characterization ..............................................................................................103 5.3.2 Unit Cell X-ray Diffraction ....................................................................................103 5.3.3 Powder X-ray Diffraction.......................................................................................112 5.6 Conclusions...........................................................................................................................115

PART II: Thermodynamic Modeling FrameworkCHAPTER VI Electrolyte Nonrandom Two-Liquid Model ..................................................119 6.1 Introduction ...........................................................................................................................119 6.2 Physical Properties ................................................................................................................120 6.2.1 Scalar Properties........................................................................................................121 6.2.2 Temperature Dependent Properties ......................................................................124 6.2.3 Aqueous Phase Chemistry .......................................................................................131 6.3 Vapor Phase Model...............................................................................................................135 6.4 Activity Coefficient Model...................................................................................................136 6.4.1 Long-Range Contribution........................................................................................139 6.4.2 Born Correction ........................................................................................................139 6.4.3 Local Contribution ...................................................................................................140 6.5 Vapor-Liquid Equilibrium Calculations.............................................................................141

PART III: Parameter Regression and Data InterpretationCHAPTER VII Pure Component Systems: MEA, PZ, and H2O..........................................145 7.1 NRTL Introduction .............................................................................................................146 7.2 Specific Heat Capacity of MEA.........................................................................................146 7.2.1 Standard Enthalpy of Vaporization ......................................................................147 7.2.2 Data Regression .......................................................................................................150 7.2.3 Full MEA Model Results ........................................................................................153 7.2.4 MEA Model Predictions.........................................................................................154 7.3 Specific Heat Capacity of PZ .............................................................................................156 7.3.1 Standard Enthalpy of Vaporization ......................................................................156 7.3.2 Solid Specific Heat Capacity...................................................................................159 7.3.3 Data Regression .......................................................................................................160 7.3.4 Full PZ Model Results ............................................................................................162 7.3.5 PZ Model Predictions .............................................................................................163 7.4 Specific Heat Capacity of H2O ..........................................................................................164 7.4.1 Standard Enthalpy of Vaporization ......................................................................165 7.4.2 Data Regression .......................................................................................................167 7.4.3 Full H2O Model Results..........................................................................................169 7.4.4 H2O Model Predictions ..........................................................................................169 7.5 NRTL Conclusions..............................................................................................................172 7.6 elecNRTL Introduction ......................................................................................................172 ________________________________________________________________________ xiii

________________________________________________________________________ 7.7 Specific Heat Capacity for a Mixture (CPMX) ................................................................173 7.8 Specific Heat Capacity of H2O ..........................................................................................174 7.9 Specific Heat Capacity of MEA.........................................................................................179 7.10 Specific Heat Capacity of PZ ...........................................................................................183 7.11 Abridged elecNRTL Predictive Correlations.................................................................186 7.12 elecNRTL Conclusions.....................................................................................................190 CHAPTER VIII Binary Systems: H2O-MEA ...........................................................................193 8.1 Introduction..........................................................................................................................193 8.2 H2O-MEA System ...............................................................................................................194 8.2.1 Total Vapor Pressure...............................................................................................196 8.2.2 Vapor-Liquid Equilibrium......................................................................................197 8.2.3 Specific Heat Capacity.............................................................................................201 8.2.4 Excess Enthalpy.......................................................................................................202 8.2.5 Freezing Point Depression.....................................................................................204 8.2.6 Dissociation Constant of Monoethanolamine.....................................................207 8.3 Data Regression....................................................................................................................210 8.3.1 Optimum Model Results ........................................................................................216 8.3.2 Chemical Equilibrium Constant ............................................................................217 8.4 Optimum Model Predictions .............................................................................................229 8.4.1 Total Vapor Pressure...............................................................................................230 8.4.2 Vapor-Liquid Equilibrium......................................................................................230 8.4.3 Specific Heat Capacity.............................................................................................235 8.4.4 Freezing Point Depression.....................................................................................238 8.4.5 Excess Enthalpy Predictions for H2O-MEA.......................................................239 8.4.6 Activity Coefficient Predictions for H2O-MEA..................................................242 8.5 Abridged elecNRTL Predictive Correlations...................................................................245 8.6 Conclusions...........................................................................................................................261 CHAPTER IX Binary Systems: H2O-PZ...................................................................................267 9.1 Introduction..........................................................................................................................267 9.2 H2O-PZ System....................................................................................................................268 9.2.1 Total Vapor Pressure...............................................................................................271 9.2.2 Vapor-Liquid Equilibrium......................................................................................272 9.2.3 Specific Heat Capacity.............................................................................................273 9.2.4 Solid Solubility..........................................................................................................275 9.2.5 Dissociation Constant of Piperazine.....................................................................277 9.3 Data Regression....................................................................................................................280 9.3.1 Optimum Model Results ........................................................................................284 9.3.2 Chemical Equilibrium Constant ............................................................................284 9.4 Optimum Model Predictions .............................................................................................293 9.4.1 Solid Solubility..........................................................................................................293 ________________________________________________________________________ xiv

________________________________________________________________________ 9.4.2 Total Vapor Pressure...............................................................................................296 9.4.3 Vapor-Liquid Equilibrium......................................................................................297 9.4.4 Specific Heat Capacity.............................................................................................302 9.4.5 Activity Coefficient Predictions for H2O-PZ......................................................303 9.5 Conclusions...........................................................................................................................307 CHAPTER X Ternary Systems: H2O-MEA-PZ .......................................................................309 10.1 Introduction........................................................................................................................309 10.2 H2O-MEA-PZ System ......................................................................................................310 10.2.1 Vapor-Liquid Equilibrium....................................................................................312 10.2.2 Specific Heat Capacity ..........................................................................................316 10.3 Data Regression .................................................................................................................319 10.3.1 Optimum Model Results ......................................................................................322 10.3.2 Vapor-Liquid Equilibrium....................................................................................323 10.4 Conclusions.........................................................................................................................328 CHAPTER XI Ternary Systems: H2O-MEA-N2O...................................................................331 11.1 Introduction........................................................................................................................331 11.2 H2O-MEA-N2O System ...................................................................................................332 11.2.1 N2O Solubility ........................................................................................................335 11.3 Data Regression .................................................................................................................339 11.3.1 Optimum Model Results ......................................................................................344 11.4 Optimum Model Predictions ...........................................................................................347 11.4.1 N2O Solubility ........................................................................................................348 11.5 Conclusions.........................................................................................................................352 CHAPTER XII Ternary Systems: H2O-K2CO3-CO2 ...............................................................353 Introduction........................................................................................................................353 H2O-K2CO3 System...........................................................................................................354 H2O-KHCO3 System ........................................................................................................355 H2O-K2CO3-CO2 System..................................................................................................355 Chemical and Vapor-liquid Equilibrium of K2CO3 ......................................................356 Data Types ..........................................................................................................................364 12.6.1 Vapor Pressure Depression..................................................................................364 12.6.2 Mean Ionic Activity Coefficient ..........................................................................365 12.6.3 Specific Heat Capacity ..........................................................................................367 12.6.4 CO2 Solubility.........................................................................................................370 12.6.5 Solid Solubility........................................................................................................372 12.7 Data Regression .................................................................................................................373 12.7.1 Optimum Model Results ......................................................................................384 12.8 Optimum Model Predictions ...........................................................................................385 ________________________________________________________________________ xv 12.1 12.2 12.3 12.4 12.5 12.6

________________________________________________________________________ 12.8.1 Vapor Pressure Depression..................................................................................386 12.8.2 Mean Ionic Activity Coefficient ..........................................................................388 12.8.3 Specific Heat Capacity ..........................................................................................389 12.8.4 CO2 Solubility.........................................................................................................394 12.8.5 Solid Solubility........................................................................................................401 12.8.6 Total Pressure Predictions for H2O-K2CO3-CO2 .............................................412 12.8.7 Enthalpy of CO2 Absorption Predictions for H2O-K2CO3-CO2 ...................414 12.8.8 Specific Heat Capacity Predictions for H2O-K2CO3-CO2 ...............................418 12.9 Conclusions.........................................................................................................................420 CHAPTER XIII Ternary Systems: H2O-MEA-CO2................................................................423 13.1 Introduction........................................................................................................................423 13.2 H2O-MEA-CO2 System ....................................................................................................424 13.3 Chemical and Vapor-liquid Equilibrium of MEA.........................................................426 13.3.1 CO2 Solubility and Amine Volatility ...................................................................431 13.3.2 Specific Heat Capacity ..........................................................................................437 13.3.3 Enthalpy of CO2 Absorption...............................................................................440 13.3.4 NMR Speciation.....................................................................................................445 13.4 Data Regression .................................................................................................................450 13.4.1 Full Model Results.................................................................................................458 13.5 Full Model Predictions......................................................................................................459 13.5.1 CO2 Solubility and Amine Volatility ...................................................................459 13.5.2 Specific Heat Capacity ..........................................................................................476 13.5.3 Enthalpy of CO2 Absorption...............................................................................484 13.5.4 NMR Speciation.....................................................................................................489 13.5.5 Carbamate Stability Constant...............................................................................502 13.6 Abridged elecNRTL Predictive Correlations.................................................................504 13.7 Conclusions.........................................................................................................................508 CHAPTER XIV Ternary Systems: H2O-PZ-CO2 ....................................................................513 14.1 Introduction........................................................................................................................513 14.2 H2O-PZ-CO2 ......................................................................................................................514 14.3 Chemical and Vapor-liquid Equilibrium of PZ.............................................................516 14.3.1 CO2 Solubility and Amine Volatility ...................................................................523 14.3.2 Specific Heat Capacity ..........................................................................................526 14.3.3 Enthalpy of CO2 Absorption...............................................................................529 14.3.4 NMR Speciation.....................................................................................................533 14.4 Data Regression .................................................................................................................538 14.4.1 Full Model Results.................................................................................................546 14.5 Full Model Predictions......................................................................................................547 14.5.1 CO2 Solubility and Amine Volatility ...................................................................547 14.5.2 Enthalpy of CO2 Absorption...............................................................................563 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________________________________________________________________________ 14.5.3 Specific Heat Capacity ..........................................................................................566 14.5.4 Liquid Phase Speciation........................................................................................577 14.5.5 Carbamate Stability Constant...............................................................................596 14.6 Solid Solubility Predictions...............................................................................................599 14.7 Conclusions.........................................................................................................................601 CHAPTER XV Ternary Systems: H2O-K2CO3-PZ-CO2.........................................................607 15.1 Introduction........................................................................................................................607 15.2 H2O-K2CO3-PZ-CO2 ........................................................................................................608 15.3 Chemical and Vapor-liquid Equilibrium of Potassium + PZ .....................................610 15.3.1 CO2 Solubility and Amine Volatility ...................................................................616 15.3.2 Specific Heat Capacity ..........................................................................................627 15.3.3 Enthalpy of CO2 Absorption...............................................................................630 15.3.4 NMR Speciation.....................................................................................................634 15.3.5 Solid Solubility........................................................................................................639 15.4 Data Regression .................................................................................................................640 15.4.1 Full Model Results.................................................................................................651 15.5 Full Model Predictions......................................................................................................652 15.5.1 CO2 Solubility and Amine Volatility ...................................................................653 15.5.2 Enthalpy of CO2 Absorption...............................................................................667 15.5.3 Specific Heat Capacity ..........................................................................................674 15.5.4 NMR Speciation.....................................................................................................683 15.5.5 Solid Solubility........................................................................................................722 15.5.6 Carbamate Stability Constant...............................................................................723 15.6 Conclusions.........................................................................................................................728

PART V: Quaternary and Quinary System PredictionsCHAPTER XVI Ternary Systems: H2O-MEA-PZ-CO2 .........................................................737 16.1 Introduction........................................................................................................................737 16.2 H2O-MEA-PZ-CO2 System .............................................................................................738 16.2.1 CO2 Solubility and Amine Volatility ...................................................................740 16.2.2 Specific Heat Capacity ..........................................................................................748 16.2.3 Enthalpy of CO2 Absorption...............................................................................751 16.2.4 NMR Speciation.....................................................................................................756 16.3 Combined Model Predictions ..........................................................................................758 16.3.1 CO2 Solubility and Amine Volatility ...................................................................759 16.3.2 Specific Heat Capacity ..........................................................................................775 16.3.3 Enthalpy of CO2 Absorption...............................................................................779 16.3.4 NMR Speciation.....................................................................................................782 16.4 Conclusions.........................................................................................................................787 ________________________________________________________________________ xvii

________________________________________________________________________ CHAPTER XVII Ternary Systems: H2O-K2CO3-MEA-CO2.................................................791 17.1 Introduction........................................................................................................................791 17.2 H2O-K2CO3-MEA-CO2 System ......................................................................................792 17.2.1 CO2 Solubility and Amine Volatility ...................................................................794 17.3 Conclusions.........................................................................................................................804 CHAPTER XVIII Ternary Systems: H2O-K2CO3-MEA-PZ-CO2 ........................................807 18.1 Introduction........................................................................................................................807 18.2 H2O-K2CO3-MEA-PZ-CO2 System ...............................................................................808 18.2.1 CO2 Solubility and Amine Volatility ...................................................................808 18.3 Combined Model Predictions ..........................................................................................827 18.4 Conclusions.........................................................................................................................842 CHAPTER XIX Overall Differential Capacity and Amine Volatility ...................................845 19.1 19.2 19.3 19.4 Introduction........................................................................................................................845 Differential Capacity..........................................................................................................846 Amine Volatility .................................................................................................................848 Conclusions.........................................................................................................................851

CHAPTER XX Summary and Recommendations ...................................................................853 ________________________________________________________________________ APPENDIX A CO2 Analysis via Titration (NTNU Method) .................................................857 APPENDIX B CO2 Analysis via Acidic Evolution (UT Method) .........................................863 APPENDIX C FT-IR Analysis Methods ...................................................................................871 APPENDIX D Tabulated VLE Data (UT)................................................................................927 APPENDIX E Tabulated VLE Data (NTNU) .........................................................................945 APPENDIX F Tabulated NMR Data (UT)...............................................................................949 APPENDIX G Tabulated Cp Data (UT) ....................................................................................953 APPENDIX H Tabulated Habs Data (NTNU).....................................................................959 ________________________________________________________________________ xviii

________________________________________________________________________ APPENDIX I Tabulated SLE Data (UT) ..................................................................................969 APPENDIX J Aspen PlusTM Input File ......................................................................................973 APPENDIX K Aspen PlusTM User Fortran Subroutine...........................................................997 APPENDIX L Regression Procedures .....................................................................................1007 APPENDIX M Nomenclature...................................................................................................1009 References .....................................................................................................................................1013 Vita...................................................................................................................................................1025

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_________________ LIST OF TABLES Table 2.3-1. VLE Experimental Design for Systems Studied in This Work............................19 Table 2.3-2. Lean Homogenous Solution Compositions for MEA+K+ (mole/kg-H2O basis) Mixtures. .......................................................................................................................21 Table 2.3-3. Lean Homogenous Solution Compositions for MEA+PZ+K+ (mole/kg-H2O basis) Mixtures. ............................................................................................................22 Table 2.3-4. Lean Homogenous Solution Compositions for PZ+K+ (mole/kg-H2O basis) Mixtures. .......................................................................................................................22 Table 2.3-5. Analysis Regions for Low, Medium, and High CO2 Concentrations..................34 Table 2.3-6. MEA Reference Spectra Required for Proper MEA Resolution.........................34 Table 2.3-7. PZ Reference Spectra Required for Proper PZ Resolution. ................................35 Table 5.5-1. Crystal Data for K2PZ(COO)2 salt.........................................................................104 Table 5.5-2. Fractional Coordinates and Equivalent Isotropic Thermal Parameters (2) for the non-hydrogen atoms for K2PZ(COO)2...........................................................107 Table 5.5-3. Bond Lengths () and Angles (o) for the Non-hydrogen Atoms for K2PZ(COO)2. .............................................................................................................107 Table 5.5-4. Bond Lengths () and Angles (o) for the Non-hydrogen Atoms for K2PZ(COO)2, Continued.........................................................................................108 Table 5.5-5. Anisotropic Thermal Parameters for the Non-hydrogen Atoms for K2PZ(COO)2..............................................................................................................108 Table 5.5-6. Fractional Coordinates and Isotropic Thermal Parameters (2) for the Hydrogen Atoms for K2PZ(COO)2. ......................................................................109 Table 5.5-7. Observed and Calculated Structure Factor Amplitudes for K2PZ(COO)2. .....109 Table 5.5-8. Observed and Calculated Structure Factor Amplitudes for K2PZ(COO)2, Continued. ..................................................................................................................110 Table 5.5-9. Pure Component Measured Intensities for KHCO3 and K2PZ(COO)2. .........112 Table 5.5-11. Relative Amounts for KHCO3 and K2PZ(COO)2 in Mixtures of Loaded Potassium + Piperazine + Monoethanolamine. ...................................................115 Table 6.2-1. Scalar Physical Properties for H2O, MEA, and PZ as given in the DIPPR database and within NRTL and elecNRTL models within Aspen PlusTM........121 Table 6.2-2. Pure Component Properties for Salt Species........................................................122 Table 6.2-3. Pure Component Properties for Molecule Solutes. .............................................122 Table 6.2-4. Pure Component Properties for Ionic Species.....................................................123 Table 6.2-5. Pure Component Properties for Ionic Species Continued. ................................123 Table 6.2-6. Pure Component Antoine Equations. ...................................................................124 Table 6.2-7. Coefficients for the Henrys Constant of CO2 in H2O (Pa/mole fraction). ....127 Table 6.2-8. Watson Heat of Vaporization Default Coefficients for H2O and MEA in the elecNRTL model [J/kmol]. ...............................................................................128 ________________________________________________________________________ xxi

________________________________________________________________________ Table 6.2-9. DIPPR Heat of Vaporization Default Coefficients for PZ in the elecNRTL model [J/kmol]. .........................................................................................................129 Table 6.2-10. Infinite Dilution Aqueous Phase Heat Capacity Default Coefficients. ..........130 Table 6.2-11. Infinite Dilution Aqueous Phase Heat Capacity Default Coefficients. ..........131 Table 7.2-1. DIPPR Heat of Vaporization Default Coefficients for MEA from 10.5 405.05 oC.....................................................................................................................148 Table 7.2-2. DIPPR Extended Antoine Vapor Pressure Default Coefficients for MEA from 10.0 365.0 oC.................................................................................................149 Table 7.2-3. Experimental data used in the regression of Heat of Vaporization Coefficients for MEA. ..............................................................................................151 Table 7.2-4. DRS Regression Output for Full MEA Model. ...................................................152 Table 7.2-5. Correlation Matrix of the Coefficient Estimates for the Full MEA Model. ....152 Table 7.2-6. Absolute Percent Relative Error for the MEA Full Model. ...............................154 Table 7.3-1. DIPPR Heat of Vaporization Default Coefficients for PZ from 106 364.85 oC..........................................................................................................157 Table 7.3-2. DIPPR Extended Antoine Vapor Pressure Default Coefficients for PZ from 106 364.85 oC................................................................................................158 Table 7.3-3. DIPPR Solid Heat Capacity Default Coefficients for PZ from 21.85 106.0 oC.........................................................................................................159 Table 7.3-4. Experimental data used in the regression of Heat of Vaporization Coefficients for PZ. ..................................................................................................161 Table 7.3-5. DRS Regression Output for Full PZ Model..........................................................161 Table 7.3-6. Correlation Matrix of the Coefficient Estimates for the Full PZ Model..........162 Table 7.3-7. Absolute Percent Relative Error for the PZ Full Model.....................................162 Table 7.4-1. DIPPR Heat of Vaporization Default Coefficients for H2O from 0.01 373.95 oC.........................................................................................................165 Table 7.4-2. DIPPR Extended Antoine Vapor Pressure Default Coefficients for H2O from 0.01 373.95 oC...............................................................................................166 Table 7.4-3. Experimental data used in the regression of Heat of Vaporization Coefficients for H2O.................................................................................................168 Table 7.4-4. DRS Regression Output for Full H2O Model. ......................................................168 Table 7.4-5. Correlation Matrix of the Coefficient Estimates for the Full H2O Model.......168 Table 7.4-6. Absolute Percent Relative Error for the H2O Full Model..................................169 Table 7.8-1. Watson Heat of Vaporization Default Coefficients for H2O in the elecNRTL model from 0.05 373.95 oC [J/kmol]...............................................175 Table 7.8-2. DRS Regression Output for 2P H2O Model for CP. ...........................................177 Table 7.9-1. Watson Heat of Vaporization Default Coefficients for MEA in the elecNRTL model from 10.5 405.05 oC [J/kmol]...............................................179 Table 7.9-2. DRS Regression Output for 2P MEA Model for CP...........................................182 Table 7.10-1. DRS Regression Output for 3P PZ Model for CP.............................................183 Table 7.11-1. DRS Regression Output for the Abridged Model Correlation for H2O. ........187 Table 7.11-2. DRS Regression Output for the Abridged Model Correlation for MEA........188 Table 7.11-3. DRS Regression Output for the Abridged Model Correlation for PZ............189 Table 8.3-1. Experimental data used in the regression of the H2O-MEA system. ...............211 ________________________________________________________________________ xxii

________________________________________________________________________ Table 8.3-2. DRS Regression Output for Full H2O-MEA System Model. ............................212 Table 8.3-3. Correlation Matrix of the Coefficient Estimates, for the Full H2O-MEA Model. .........................................................................................................................212 Table 8.3-4. DRS Regression Output for Optimum H2O-MEA Model. ...............................213 Table 8.3-5. Correlation Matrix of the Coefficient Estimates, for the Optimum H2O-MEA Model......................................................................................................214 Table 8.3-6. DRS Regression Output for H2O-MEA Submodel. ...........................................215 Table 8.3-7. Correlation Matrix of the Coefficient Estimates for the H2O-MEA Submodel....................................................................................................................216 Table 8.3-8. Absolute Percent Relative Error for the H2O-MEA Optimum Model. ...........217 Table 8.3-9. ARC Regression Output for the Infinite Dilution Activity Coefficient for Monoethanolamine. ..................................................................................................218 Table 8.3-10. Comparison between Equations 8-4 and 8-5 for the Natural Log Infinite Dilution Activity Coefficient for Monoethanolamine in Water. ........................219 Table 8.3-11. Estimates for the Chemical Equilibrium Coefficients for the H2O-MEA System.....................................................................................................222 Table 8.3-12. Standard Property Changes of Formation at 298.15 K for Molecular and Ionic Components. ............................................................................................224 Table 8.3-13. Coefficients for the Aqueous Phase Infinite Dilution Heat Capacity (J/kmolK)..................................................................................................................225 Table 8.3-14. Coefficients for the Aqueous Phase Infinite Dilution Heat Capacity (J/kmolK) of MEAH+ from 0 200 oC based on Equation 8-5......................226 Table 8.3-15. Coefficients for the Aqueous Phase Infinite Dilution Heat Capacity (J/kmolK) of MEAH+ from 0 200 oC based on Equation 8-7......................227 Table 8.5-1. Tabulated Predictions for the PMEA (kPa) from the elecNRTL Model. ............246 Table 8.5-2. ARC Regression Output for the Predictive Full PMEA Correlation....................246 Table 8.5-3. Correlation Matrix of the Coefficient Estimates, for the Full PMEA Model......247 Table 8.5-4. PMEA Backward Elimination Case Summary Results............................................248 Table 8.5-5. ARC Regression Output for the Predictive Optimum PMEA Correlation. ........249 Table 8.5-6. Correlation Matrix of the Coefficient Estimates, for the Optimum PMEA Model.................................................................................................................249 Table 8.5-7. Effective Heat of Vaporization of MEA from H2O (kJ/mol-MEA)................251 Table 8.5-8. Specific Heat Capacity Predictions (kJ/kg-K) from the elecNRTL model......252 Table 8.5-9. ARC Regression Output for the Predictive Full CPMX Correlation................253 Table 8.5-10. Correlation Matrix of the Coefficient Estimates, for the Full PMEA Model....253 Table 8.5-11. CPMX Backward Elimination Case Summary Results. ....................................254 Table 8.5-12. ARC Regression Output for the Predictive Optimum CPMX Correlation...255 Table 8.5-13. Correlation Matrix of the Coefficient Estimates, for the Optimum PMEA Model.................................................................................................................255 Table 9.3-1. Experimental data used in the regression of the H2O-PZ system.....................281 Table 9.3-2. DRS Regression Output for Full H2O-PZ System Model..................................281 Table 9.3-3. Correlation Matrix of the Coefficient Estimates for the Full H2O-PZ Model. .........................................................................................................................282 Table 9.3-4. DRS Regression Output for Optimum H2O-PZ Model.....................................283 ________________________________________________________________________ xxiii

________________________________________________________________________ Table 9.3-5. Correlation Matrix of the Coefficient Estimates for the Optimum H2O-PZ Model ..........................................................................................................................283 Table 9.3-6. Absolute Percent Relative Error for the H2O-PZ Optimum Model ................284 Table 9.3-7. Estimates for the Chemical Equilibrium Coefficients for the H2O-PZ System (mole fraction basis)..................................................................................................287 Table 9.3-8. Standard Property Changes of Formation at 298.15 K for Molecular and Ionic Components...............................................................................................................289 Table 9.3-9. Coefficients for the Aqueous Phase Infinite Dilution Heat Capacity (J/kmolK)..................................................................................................................289 Table 9.3-10. Coefficients for the Aqueous Phase Infinite Dilution Heat Capacity (J/kmolK) of PZH2+2 amd PZH+ from 0 200 oC based on Equation 9-44. ...........................................................................................................291 Table 9.3-11. Coefficients for the Aqueous Phase Infinite Dilution Heat Capacity (J/kmolK) of PZH2+2 amd PZH+ from 0 200 oC based on Equation 9-34. ...........................................................................................................291 Table 9.4-1. Chemical Equilibrium Coefficients for the Salt Precipitation of Piperazine Hexahydrate and Anhydrous Piperazine Based on Equation 9-46 (mole fraction basis)..................................................................................................294 Table 9.4-2. Comparison of PZ Volatility Based on Predictions from the elecNRTL Model and Raoults Law at 40 oC............................................................................298 Table 10.2-1. Binary Interaction Parameters for H2O-MEA and H2O-PZ Systems. ...........311 Table 10.2-2. Absolute Percent Relative Error for Experimental MEA Volatility Data......315 Table 10.2-3. Absolute Percent Relative Error for Experimental PZ Volatility Data..........316 Table 10.3-1. Experimental data used in the regression of the H2O-MEA-PZ system. ......320 Table 10.3-2. DRS Regression Output for Full H2O-MEA-PZ System Model. ...................320 Table 10.3-3. Correlation Matrix of the Coefficient Estimates for the Full H2O-MEA-PZ Model...............................................................................................321 Table 10.3-4. DRS Regression Output for the Optimum H2O-MEA-PZ Model. ...............321 Table 10.3-5. Correlation Matrix of the Coefficient Estimates for the Optimum H2O-MEA-PZ Model...............................................................................................322 Table 10.3-6. Absolute Percent Relative Error for the H2O-MEA-PZ Optimum Model...322 Table 10.3-7. Comparison of Experimental Amine Volatility in 3.5 m MEA + 1.8 m PZ to elecNRTL Combined Binary Model Predictions.............................................324 Table 10.3-8. Comparison of Experimental Amine Volatility in 3.5 m MEA + 2.0 m PZ to elecNRTL Combined Binary Model Predictions.............................................324 Table 10.3-9. Comparison of Experimental Amine Volatility in 3.5 m MEA + 3.6 m PZ to elecNRTL Combined Binary Model Predictions.............................................325 Table 10.3-10. Comparison of Experimental Amine Volatility in 7.0 m MEA + 1.8 m PZ to elecNRTL Combined Binary Model Predictions.............................................325 Table 10.3-11. Comparison of Experimental Amine Volatility in 7.0 m MEA + 2.0 m PZ to elecNRTL Combined Binary Model Predictions.............................................326 Table 10.3-12. Comparison of Experimental Amine Volatility in 7.0 m MEA + 3.6 m PZ to elecNRTL Combined Binary Model Predictions.............................................326 ________________________________________________________________________ xxiv

________________________________________________________________________ Table 10.3-13. Comparison of Predicted Amine Volatility in 7.0 m MEA + 1.8 5.0 m PZ to elecNRTL Combined Binary Model Predictions and the Deviation from Raoults Law...............................................................................................................327 Table 10.3-14. Comparison of Predicted Amine Volatility in 2.0 m PZ + 3.5 23.8 m MEA to elecNRTL Combined Binary Model Predictions and the Deviation from Raoults Law.....................................................................................................329 Table 11.2-1. Coefficients for the Henrys Constant of CO2 in H2O (Pa/mole fraction). ..333 Table 11.3-1. Aspen PlusTM Default Binary Interaction Parameters between H2O and CO2. .............................................................................................................................339 Table 11.3-2. Experimental data used in the regression of the Unreacted H2O-MEA-CO2 system. ...........................................................................................339 Table 11.3-3. DRS Regression Output for Full Unreacted H2O-MEA-CO2 System Model. .........................................................................................................................340 Table 11.3-4. Correlation Matrix of the Coefficient Estimates, for the Full Unreacted H2O-MEA-CO2 Model.............................................................................................340 Table 11.3-5. DRS Regression Output for Optimum Unreacted H2O-MEA-CO2 Model..341 Table 11.3-6. Correlation Matrix of the Coefficient Estimates, for the Optimum Unreacted H2O-MEA-CO2 Model. .......................................................................341 Table 11.3-7. DRS Regression Output for Unreacted H2O-MEA-CO2 Submodel..............343 Table 11.3-8. Correlation Matrix of the Coefficient Estimates for the Unreacted H2O-MEA-CO2 Submodel. .....................................................................................343 Table 11.3-9. Absolute Percent Relative Error for the Unreacted H2O-MEA-CO2 Optimum Model........................................................................................................344 Table 11.4-1. Comparison Between the Model of Tsai et al. (2000) to This Work based on the Percent Average Absolute Relative Deviation (AARD) Between Experimental Literature Data and Model Predictions.........................................348 Table 12.5-1. Standard State Property Values for Reactions 12-5 to 12-6 at 25 oC. .............358 Table 12.5-2. Chemical Equilibrium Coefficients for the H2O-K2CO3-CO2 System reported by Edwards et al. (1978) (mole fraction basis)......................................358 Table 12.5-3. Coefficients for the Aqueous Phase Infinite Dilution Heat Capacity (J/kmolK) of bicarbonate and carbonate from 0 200 oC based on Equation 12-24. .........................................................................................................361 Table 12.5-4. Coefficients for the Aqueous Phase Infinite Dilution Heat Capacity (J/kmolK) of bicarbonate and carbonate from 0 200 oC based on Equation 12-27. .........................................................................................................361 Table 12.6-1. Infinite Dilution Aqueous Phase Heat Capacity Default Coefficients. ..........368 Table 12.6-2. Specific Heat Capacity in Aqueous K2CO3 Mixtures from 40 to 120 oC. ......369 Table 12.6-3. Specific Heat Capacity in Aqueous KHCO3 Mixtures from 40 to 120 oC. ....369 Table 12.7-1. Default Binary Interaction Parameters for the elecNRTL Model in Aspen PlusTM. .........................................................................................................................374 Table 12.7-2. Experimental data used for regression of the H2O-K2CO3-CO2 systems......375 Table 12.7-3. DRS Regression Output for Full H2O-K2CO3-CO2 System Model................378 Table 12.7-4. Correlation Matrix of the Coefficient Estimates for the Full H2O-K2CO3-CO2 System Model.............................................................................379 ________________________________________________________________________ xxv

________________________________________________________________________ Table 12.7-5. DRS Regression Output for Optimum H2O-K2CO3-CO2 Model...................380 Table 12.7-6. Correlation Matrix of the Coefficient Estimates for the Optimum H2O-K2CO3-CO2 Model. .........................................................................................381 Table 12.7-7. DRS Regression Output for H2O-K2CO3-CO2 Submodel...............................382 Table 12.7-8. Correlation Matrix of the Coefficient Estimates for the H2O-K2CO3-CO2 Submodel....................................................................................................................383 Table 12.7-9. Absolute Percent Relative Error for the H2O-K2CO3-CO2 Optimum Model. .........................................................................................................................384 Table 12.8-1. Chemical Equilibrium Coefficients for the Salt Precipitation of K2CO32KHCO31.5H2O Based on Equation 14-27 (mole fraction basis)......402 Table 12.8-2. Enthalpy of CO2 Absorption in a Slurry of Hydrated K2CO3 and KHCO3 (kcal/mol-CO2)..........................................................................................................411 Table 13.3-1. Sources of CO2 Solubility Data.............................................................................432 Table 13.3-2. Infinite Dilution Aqueous Phase Heat Capacity Default Coefficients. ..........439 Table 13.4-1. Default Binary Interaction Parameters for the elecNRTL Model in Aspen PlusTM. .........................................................................................................................450 Table 13.4-2. Experimental data used for regression of the H2O-MEA-CO2 systems. .......451 Table 13.4-3. DRS Regression Output for Full H2O-MEA-CO2 System Model. .................452 Table 13.4-4. Correlation Matrix of the Coefficient Estimates for the Full H2O-MEACO2 System Model ....................................................................................................453 Table 13.4-5. DRS Regression Output for Optimum H2O-MEA-CO2 System Model. ......454 Table 13.4-6. Absolute Percent Relative Error for the H2O-MEA-CO2 Full Model. ..........458 Table 13.4-7. Absolute Percent Relative Error for the H2O-MEA-CO2 Full Model Speciation....................................................................................................................459 Table 13.5-1. Estimates for the Chemical Equilibrium Constant Associated with the MEA Carbamate Formation (mole fraction basis)...............................................502 Table 13.6-1. Specific Heat Capacity Predictions (kJ/kg-K) from the full model. ...............505 Table 13.6-2. ARC Regression Output for the Predictive FULL CPMX Correlation. ........505 Table 13.6-3. Correlation Matrix of the Coefficient Estimates for the Full CPMX Model. 506 Table 13.6-4. ARC Regression Output for the Predictive OPTIMUM CPMX Correlation..................................................................................................................507 Table 14.3-1. Infinite Dilution Aqueous Phase Heat Capacity Default Coefficients. ..........527 Table 14.4-1. Default Binary Interaction Parameters for the elecNRTL Model in Aspen PlusTM. .........................................................................................................................538 Table 14.4-2. Experimental data used for regression of the H2O-PZ-CO2 systems.............539 Table 14.4-3. DRS Regression Output for Full H2O-PZ-CO2 System Model. .....................540 Table 14.4-4. Correlation Matrix of the Coefficient Estimates for the Full H2O-PZ-CO2 System Model.............................................................................................................541 Table 14.4-5. DRS Regression Output for Optimum H2O-PZ-CO2 System Model............542 Table 14.4-6. Absolute Percent Relative Error for the H2O-PZ-CO2 Full Model................546 Table 14.4-7. Absolute Percent Relative Error for the H2O-PZ-CO2 Full Model Speciation....................................................................................................................547 Table 14.5-1. ARC Regression Output for Experimental Specific Heat Capacity Measurements from this work based on Equation 14-52. ..................................572 ________________________________________________________________________ xxvi

________________________________________________________________________ Table 14.5-2. Correlation Matrix of the Coefficient Estimates for the Full CPMX Model. 572 Table 14.5-3. Comparison of Average Specific Heat Capacity (kJ/kg-K) from 40 - 120 o C. ................................................................................................................................573 Table 14.5-4. Chemical Equilibrium Coefficients for the H2O-PZ-CO2 System on a Mole Fraction, Infinite Dilution in Water Basis. ..................................................596 Table 15.3-1. Selected Experimental Data Points for Acidic Evolution Loading Analysis Determined by Peak Area or Peak Height from this work.................................622 Table 15.3-2. Infinite Dilution Aqueous Phase Heat Capacity Default Coefficients. ..........629 Table 15.4-1. Default Binary Interaction Parameters for the elecNRTL Model in Aspen PlusTM. .........................................................................................................................640 Table 15.4-2. Experimental data used for regression of the H2O-K2CO3-PZ-CO2 systems. .......................................................................................................................642 Table 15.4-3. DRS Regression Output for Full H2O-K2CO3-PZ-CO2 System Model.........645 Table 15.4-4. Correlation Matrix of the Coefficient Estimates for the Full H2O-K2CO3PZ-CO2 System Model .............................................................................................646 Table 15.4-5. DRS Regression Output for Optimum H2O-K2CO3-PZ-CO2 System Model. .........................................................................................................................647 Table 15.4-6. Absolute Percent Relative Error for the H2O-K2CO3-PZ-CO2 Full Model..652 Table 15.4-7. Absolute Percent Relative Error for the H2O-K2CO3-PZ-CO2 Full Model Speciation....................................................................................................................652 Table 15.5-1. Comparison of Differential Solvent Capacity Between CO2 Partial Pressures of 0.01 and 1.0 kPa at 60 oC...................................................................660 Table 15.5-2. Comparison of Experimental Amine Volatility Evaluated at a CO2 Partial Pressure from 0.01 to 0.1 kPa at 40 oC. .................................................................667 Table 15.5-3. Comparison of Average Specific Heat Capacity (kJ/kg-K) from 40 120 o C. ................................................................................................................................676 Table 15.5-4. Apparent Partial Specific Heat Capacity of CO2 in Mixtures of Potassium Carbonate + Piperazine............................................................................................682 Table 15.5-5. Chemical Equilibrium Coefficients for the Salt Precipitation of K2PZ(COO)2 Based on Equation 15-51 (mole fraction basis)...........................722 Table 15.5-6. Chemical Equilibrium Coefficients for the H2O-K2CO3-PZ-CO2 System on a Mole Fraction, Infinite Dilution in Water Basis. .........................................724 Table 16.2-1. Binary Interaction Parameters for the H2O-MEA-PZ-CO2 system................738 Table 16.2-2. Mixed Salt/Amine Binary Interaction Parameters.............................................739 Table 16.2-3. Comparison of Differential Solvent Capacity Between a CO2 Partial Pressures of 0.01 and 1.0 kPa at 60 oC and Amine Volatility (ppmv) at 40 oC at a loading = 0.2 (mol CO2/mol MEA + 2mol PZ). ........................................747 Table 16.3-1. Absolute Percent Relative Error for the H2O-MEA-PZ-CO2 System. ..........758 Table 17.2-1. Binary Interaction Parameters for the H2O-K2CO3-MEA-CO2 system. ........792 Table 17.2-2. Mixed Salt/Amine Binary Interaction Parameters.............................................793 Table 17.2-3. Absolute Percent Relative Error for the H2O-K2CO3-MEA-CO2 System.....798 Table 18.2-1. Experimental Mixtures for the H2O-K2CO3-MEA-PZ-CO2 system. .............809 Table 18.2-2. Comparison of Differential Solvent Capacity Between CO2 Partial Pressures of 0.01 and 1.0 kPa at 60 oC...................................................................819 ________________________________________________________________________ xxvii

________________________________________________________________________ Table 18.2-3. Comparison of Experimental Amine Volatility Evaluated at a CO2 Partial Pressure from 0.01 to 0.1 kPa at 40 oC. .................................................................821 Table 18.2-4. Systematic Trends For Effects Exhibited in CO2 Solubility and Amine Volatility Due to an Increase in the Concentration of K+, MEA, or PZ..........822 Table 18.3-1. Absolute Percent Relative Error for the H2O-K2CO3-MEA-PZ-CO2 System. ........................................................................................................................827 Table 19.2-1. Differential Capacity Based on Experimental CO2 Solubility at 60 oC Between the Range of 0.01 and 1.0 kPa from this work. ....................................846 Table 19.3-1. Comparison of Experimental Amine Volatility Evaluated at a CO2 Partial Pressure from 0.01 to 0.1 kPa at 40 oC. .................................................................849

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_________________ LIST OF FIGURES Figure 1.2-1. Absorption/Stripping System for Removal of CO2 from Flue Gas using Aqueous Alkanolamine Solutions.............................................................................3 Figure 1.3-1. Thermodynamic Areas of Interest for the Absorption/Stripping Process.........4 Figure 1.5-1. Thermodynamic Sub-Component System Tree....................................................10 Figure 2.3-1. VLE Experimental Design for Loaded Solutions. ...............................................19 Figure 2.3-2. CO2 Loading Apparatus. ..........................................................................................20 Figure 2.3-3. Lean Homogenous Solution Composition Surface for MEA+K+ Mixtures....23 Figure 2.3-4. Lean Homogenous Solution Composition Surface for MEA+PZ+K+ Mixtures......................................................................................................................23 Figure 2.3-5. Lean Homogenous Solution Composition Surface for PZ+K+ Mixtures........24 Figure 2.3-6. Process Flow Diagram for High Temperature Experiments, Vapor Phase. ....25 Figure 2.3-7. Process Flow Diagram for High Temperature Experiments, Liquid Phase. ....25 Figure 2.3-8. Example CO2 Calibration Curves for 04/27/2005 - 06/17/2005.....................26 Figure 2.3-9. Process Flow Diagram for Low Temperature Experiments...............................30 Figure 2.3-10. CO2 Reference Spectrum (3.0 volume % or 30,000 ppmv) as Presented by Goff (2005). ...............................................................................................................33 Figure 2.4-1. Vapor Pressure of Water. .........................................................................................36 Figure 2.4-2. Comparison of Experimental Vapor Pressure Measurements To Predictions from DIPPR Correlations Based on the work of Kell et al. (1984). .................37 Figure 2.4-3. Vapor Pressure of MEA...........................................................................................38 Figure 2.4-4. Comparison of Experimental Vapor Pressure Measurements To Predictions from DIPPR Correlations Based on the work of Matthews et al. (1950) and Engineering Sciences Data (1979). .........................................................................38 Figure 2.4-5. CO2 Solubility Comparison in 7 m MEA at 40 and 60 oC. .................................39 Figure 2.4-6. CO2 Solubility Comparison in 2 m PZ at 40, 60, and 80 oC ...............................40 Figure 3.4-1. CO2 Loading Apparatus. ..........................................................................................46 Figure 3.5-1. Molecular structure and active nuclei of protons associated with a) MEA and MEAH+ and b) MEACOO-1. ..........................................................................47 Figure 3.5-2 Molecular structure and active nuclei of carbons associated with a) MEA and MEAH+ and b) MEACOO-1. ..........................................................................47 Figure 3.5-3 Molecular structure and active nuclei of protons associated with a) PZ and PZH+...........................................................................................................................49 Figure 3.5-4 Molecular structure and active nuclei of protons associated with PZCOOand H+PZCOO-1. ......................................................................................................49 Figure 3.5-5 Molecular structure and active nuclei of protons associated with PZ(COO-)2. 49 Figure 3.5-6 Molecular structure and active nuclei of carbons associated with PZ and PZH+...........................................................................................................................50 ________________________________________________________________________ xxix

________________________________________________________________________ Figure 3.5-7 Molecular structure and active nuclei of carbons associated with PZCOOand H+PZCOO-1. ......................................................................................................50 Figure 3.5-8 Molecular structure and active nuclei of carbons associated with PZ(COO-)2. 50 Figure 3.5-9 Molecular structure and active nuclei of carbons associated with a) HCO3-, b) CO32-, and c) CO2......................................................................................................51 Figure 3.8-1. Expanded Medium Field 1H Spectra at 27 oC for 7m MEA with 10% D2O and 1% Dioxane at Loading = 0.55. ......................................................................53 Figure 3.8-2. Expanded High Field 1H Spectra at 27 oC for 7m MEA with 10% D2O and 1% Dioxane at Loading = 0.55. ......................................................................53 Figure 3.8-3. Expanded Low Field 13C Spectra at 27 oC for 7m MEA with 10% D2O and 1% Dioxane at Loading = 0.55. ......................................................................54 Figure 3.8-4. Expanded Medium Field 13C Spectra at 27 oC for 7m MEA with 10% D2O and 1% Dioxane at Loading = 0.55. ......................................................................54 Figure 3.8-5. Expanded High Field 13C Spectra at 27 oC for 7m MEA with 10% D2O and 1% Dioxane at Loading = 0.55. ......................................................................55 Figure 3.8-6. Expanded High Field 1H Spectra at 27 oC for 2 m PZ with 10% D2O and 1% Dioxane at Loading = 0.64. ......................................................................55 Figure 3.8-7 Expanded Low Field C13 Spectra at 27 oC for 2m PZ w/ 10% D2O & 1% Dioxane at Loading = 0.64......................................................................................56 Figure 3.8-8 Expanded Low Field C13 Spectra at 27 oC for 2m PZ w/ 10% D2O & 1% Dioxane at Loading = 0.64......................................................................................56 Figure 3.8-9. Expanded Medium Field 1H Spectra at 27 oC for 7m MEA + 3.6 m PZ with 10% D2O and 1% Dioxane at Loading = 0.24............................................57 Figure 3.8-10. Expanded High Field 1H Spectra at 27 oC for 7m MEA + 3.6 m PZ with 10% D2O and 1% Dioxane at Loading = 0.24.....................................................57 Figure 3.8-11. Expanded Low Field C13 Spectra at 27 oC for 7 m MEA + 3.6 m PZ w/ 10% D2O & 1% Dioxane at Loading = 0.24. ................................................58 Figure 3.8-12. Expanded Medium Field C13 Spectra at 27 oC for 7 m MEA + 3.6 m PZ w/ 10% D2O & 1% Dioxane at Loading = 0.24. ................................................58 Figure 3.8-13. Expanded High Field C13 Spectra at 27 oC for 7 m MEA + 3.6 m PZ w/ 10% D2O & 1% Dioxane at Loading = 0.24. ................................................59 Figure 3.9-1. 1H Chemical Shifts for 7 m MEA at 27 oC with Varying CO2 Loading. ...........60 Figure 3.9-2. High Field 13C Chemical Shifts for 7 m MEA at 27 oC with Varying CO2 Loading. ......................................................................................................................60 Figure 3.9-3. Low Field 13C Chemical Shifts for 7 m MEA at 27 oC with Varying CO2 Loading. ......................................................................................................................61 Figure 3.9-4. 1H Chemical Shifts for 2 m PZ at 27 oC with Varying CO2 Loading. ...............61 Figure 3.9-5. High Field 13C Chemical Shifts for 2 m PZ at 27 oC with Varying CO2 Loading. ......................................................................................................................62 Figure 3.9-6. Low Field 13C Chemical Shifts for 2 m PZ at 27 oC with Varying CO2 Loading. ......................................................................................................................62 Figure 3.11-1. Comparison of H1 and C13 Analysis in 7 m MEA with Varying Levels of Dioxane for Use as an Internal Standard at 27 oC ...............................................65 ________________________________________________________________________ xxx

________________________________________________________________________ Figure 3.11-2. Relative Deviation of H1 and C13 Analysis in 7 m MEA with Varying Levels of Dioxane for Use as an Internal Standard at 27 oC ..........................................65 Figure 3.11-3. C13 NMR Liquid Phase Speciation for 7 m MEA at 27 oC ...............................67 Figure 3.11-4. H1 NMR Liquid Phase Speciation for 1 m PZ at 27 oC ....................................68 Figure 4.4-1. CO2 Loading Apparatus. ..........................................................................................75 Figure 4.5-1. Cross Section of a Properly Sealed Sample Pan....................................................76 Figure 4.5-2. DSC-Q100 Sample Cell ............................................................................................76 Figure 4.5-3. Typical Heat Flow Calibration Curve using ~ 5 mg of Indium. ........................78 Figure 4.6-1. Typical DSC Curves for Specific Heat Capacity Measurements. .......................79 Figure 4.6-2. Heat Capacity of Al2O3 .............................................................................................80 Figure 4.6-3. Specific Heat Capacity of 304 Stainless Steel from Dobrosavljevic and Maglic (1992). ............................................................................................................81 Figure 4.6-4. Reproducibility of the Specific Heat Capacity Experiments for H2O ...............82 Figure 4.7-1. Specific Heat Capacity of Water..............................................................................83 Figure 4.7-2. Enlargement of Figure 4.7-2 for the Specific Heat Capacity of Water..............83 Figure 4.7-3. Specific Heat Capacity of MEA. .............................................................................84 Figure 4.7-4. Specific Heat Capacity for Mixtures of H2O-MEA at 40 oC...............................85 Figure 4.7-5. Specific Heat Capacity for Mixtures of H2O-MEA at 60 oC...............................86 Figure 4.7-6. Specific Heat Capacity for Mixtures of H2O-MEA at 80 oC. . ..........................86 Figure 5.2-1. CO2 Loading Apparatus. ..........................................................................................91 Figure 5.3-1. DSC Thermal Profiles for Mixtures of 1 to 10 m PZ..........................................94 Figure 5.3-2. DSC Thermal Profiles for Mixtures of 15 to 40 m PZ........................................95 Figure 5.3-3. T-X Phase Diagram for Mixtures of H2O-PZ. .....................................................97 Figure 5.4-1. Visual Observations in Determining the Dissolution Temperature for Mixtures of 5 m K+ + 3.6 m PZ...........................................................................100 Figure 5.4-2. Visual Observations in Determining the Dissolution Temperature for Mixtures of 5 m K+ + 2.5 m PZ...........................................................................100 Figure 5.4-3. Visual Observations in Determining the Dissolution Temperature for Mixtures of 6 m K+ + 1.2 m PZ...........................................................................101 Figure 5.4-4. Visual Observations in Determining the Dissolution Temperature for Mixtures in the H2O-K2CO3-PZ-CO2 System ....................................................101 Figure 5.4-5. Scanning Electron Microscope Image of K2PZ(COO)2 salt at a Magnification of 120 m. .....................................................................................102 Figure 5.4-6. Digital Image of K2PZ(COO)2 salt. ......................................................................102 Figure 5.5-1. View of K2PZ(COO)2 showing the Atom Labeling Scheme............................111 Figure 5.5-2. Unit Cell Packing Diagram for K2PZ(COO)2 .....................................................111 Figure 5.5-3. Powder Diffraction Pattern of Pure KHCO3......................................................113 Figure 5.5-4. Powder Diffraction Pattern of Pure K2PZ(COO)2. ...........................................113 Figure 5.5-5. Calibration Curve for Determining the Relative Amounts of KHCO3 and K2PZ(COO)2 Presented in Potassium + Piperazine + Monoethanolamine Mixtures....................................................................................................................114 Figure 7.2-1. Heat of Vaporization of MEA...............................................................................148 Figure 7.2-2. Comparison of the Heat of Vaporization based on Equation 7-5 to Literature Values for MEA....................................................................................150 ________________________________________________________________________ xxxi

________________________________________________________________________ Figure 7.2-3. Comparison of Model Predictions with Experimental Data from Riddick and Bunger (1970) and Clapeyron (1834) for the Hvap of MEA from 10.50-337.23 oC. ......................................................................................................155 Figure 7.2-4. Comparison of Model Predictions with Experimental Data for the Specific Heat Capacity of MEA from 20 120 oC ............................................155 Figure 7.3-1. Heat of Vaporization of PZ...................................................................................157 Figure 7.3-2. Comparison of the Heat of Vaporization based on Equation 7-5 to Literature Values for PZ. .......................................................................................158 Figure 7.3-3. Solid Phase Specific Heat Capacity of PZ. ..........................................................160 Figure 7.3-4. Comparison of Model Predictions with Experimental Data from Clapeyron (1834) for the Heat of Vaporization of PZ from 106 301.05 oC .......................................................................................................163 Figure 7.3-5. Comparison of Model Predictions with Experimental Data for the Specific Heat Capacity of PZ from 20 200 oC.................................................164 Figure 7.4-1. Heat of Vaporization of H2O. ...............................................................................1

hilliard dissertation(2008)

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