UNIVERSITY OF CALIFORNIA, SAN DIEGO SAN DIEGO STATE UNIVERSITY Microalgae Rupture Energy and Ultrasound Biomass Processing A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Engineering Sciences (Mechanical and Aerospace Engineering) by Rory James Klinger Committee in charge: University of California, San Diego Professor Daniel Tartakovsky, Co-Chair Professor Peter Asbeck San Diego State University Professor Temesgen Garoma, Co-Chair Professor Asfaw Beyene Professor Julio Valdes 2017 Copyright Rory James Klinger, 2017 All rights reserved. SIGNATURE PAGE The Dissertation of Rory James Klinger is approved, and it is acceptable in quality and form for publication on microfilm and electronically: Co-Chair Co-Chair University of California, San Diego San Diego State University 2017 iii DEDICATION To my wife Derlin and to my parents for their kindness and support. iv EPIGRAPH “Ever tried. Ever failed. No matter. Try again. Fail again. Fail better.” - Samuel Beckett “Genius is patience.” - Isaac Newton “Keep moving forward.” - Walt Disney v TABLE OF CONTENTS SIGNATURE PAGE ................................................................................................. iii DEDICATION .......................................................................................................... iv EPIGRAPH ................................................................................................................ v TABLE OF CONTENTS .......................................................................................... vi LIST OF SYMBOLS ................................................................................................ ix LIST OF FIGURES ................................................................................................. xiii LIST OF TABLES .................................................................................................. xvi ACKNOWLEDGEMENTS ................................................................................... xviii VITA ....................................................................................................................... xx ABSTRACT OF THE DISSERTATION ............................................................... xxiv Chapter 1 - Introduction ............................................................................................. 1 1.1 MOTIVATION ..................................................................................................... 1 1.1.1 Energy Alternatives .................................................................................... 2 1.1.2 Algae Biofuels ............................................................................................ 4 1.1.3 Processing and Co-Products........................................................................ 5 1.2 PRETREATMENT OF MICROALGAE BIOMASS ........................................................ 8 1.2.1 Pretreatment Taxonomy .............................................................................. 9 1.2.2 Measures of Effectiveness ........................................................................ 12 1.2.3 Optimization ............................................................................................. 18 1.2.4 Physical and Chemical Characteristics ...................................................... 20 1.2.5 Models of Physical and Chemical Effects ................................................. 23 1.2.6 Mechanisms ............................................................................................. 24 1.3 OUTLINE AND CONTRIBUTIONS......................................................................... 25 Chapter 2 - Energy Requirements and Ultrasound Processing ................................... 28 2.1 CONSTITUTIVE MODEL OF CELL RUPTURE ........................................................ 28 2.1.1 Introduction .............................................................................................. 28 2.1.2 Conceptual Framework ............................................................................. 30 2.1.3 Model Derivation ..................................................................................... 32 2.1.4 Derivation Outline .................................................................................... 38 2.1.5 Generic Functions ..................................................................................... 40 2.1.6 Parameterization ....................................................................................... 45 vi 2.1.7 Integrals and Model Synthesis .................................................................. 50 2.1.8 Calculation ............................................................................................... 52 2.1.9 Results and Discussion ............................................................................. 54 2.1.10 Conclusions ............................................................................................ 56 2.2 ULTRASOUND SYSTEM CALORIMETRY .............................................................. 57 2.2.1 Introduction .............................................................................................. 57 2.2.2 Theory ...................................................................................................... 59 2.2.3 Experimental Approach ............................................................................ 60 2.2.4 Materials and Methods ............................................................................. 61 2.2.5 Results and Discussion ............................................................................. 63 2.2.6 Conclusions .............................................................................................. 70 2.3 ULTRASOUND PROCESSING OF CHLORELLA VULGARIS ...................................... 72 2.3.1 Introduction .............................................................................................. 72 2.3.2 Experimental Approach ............................................................................ 73 2.3.3 Materials and Methods ............................................................................. 73 2.3.4 Results and Discussion ............................................................................. 75 2.3.5 Conclusions .............................................................................................. 78 Chapter 3 - Sensitivity Analysis ............................................................................... 80 3.1 INTRODUCTION ................................................................................................ 80 3.2 SENSITIVITY ANALYSIS OF CONSTITUTIVE MODEL ............................................ 81 3.2.1 Methods ................................................................................................... 81 3.2.2 Results and Discussion ............................................................................. 83 3.2.3 Conclusions .............................................................................................. 90 3.3 CELL DIAMETER MEASUREMENT AND MONTE CARLO SIMULATIONS OF CELL STRENGTH ............................................................................................................. 92 3.3.1 Materials and Methods ............................................................................. 92 3.3.2 Results and Discussion ............................................................................. 94 3.3.3 Conclusions ............................................................................................ 101 Chapter 4 - Growth Media Selection and Power Ultrasound Processing .................. 102 4.1 INTRODUCTION .............................................................................................. 102 4.2 MATERIALS AND METHODS ............................................................................ 104 4.3 RESULTS AND DISCUSSION ............................................................................. 109 4.4 CONCLUSIONS ................................................................................................ 118 Chapter 5 - Theoretical Kinetics and Mechanism of Cell Disruption ....................... 120 5.1 INTRODUCTION .............................................................................................. 121 5.2 REACTOR MODEL .......................................................................................... 122 5.3 ELEMENTARY REACTION MODEL ................................................................... 124 vii 5.4 REACTION MECHANISM AND CRITICAL DISTANCE .......................................... 129 5.5 RATE CONSTANT MAPPING ............................................................................ 135 5.6 PREDICTION OF CAVITATION RATE ................................................................. 139 5.7 TREATMENT OF PDF INPUTS .......................................................................... 141 5.8 CONCLUSIONS ................................................................................................ 142 Chapter 6 – Conclusions ......................................................................................... 144 6.1 SUMMARY ..................................................................................................... 144 6.2 CONCLUSIONS ................................................................................................ 145 6.3 FUTURE DIRECTIONS .....................................................................................