ANAEROBIC DIGESTION OF BIOFUEL PRODUCTION RESIDUES By ZHUOLI TIAN A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2011 1 © 2011 Zhuoli Tian 2 To my parents who have always been supportive of my education 3 ACKNOWLEDGMENTS I would like to extend my deepest appreciation to my parents, Mr.Tian and Mrs. Zheng for their continuous support and encouragement towards my academic endeavors. I express my sincere gratitude to my advisor and committee chairman, Dr. Pratap Pullammanappallil, for his continual support and guidance during my time at the University of Florida. I am grateful to Dr. Lonnie O. Ingram for his support throughout this research study. I would like to thank Dr. Ben Koopman and Dr. Paul A. Chadik for serving on my committee and their inspirational lectures. I also own gratitude to Dr. Melanie Correll for her devotion and patience in helping improve my writing skills. I give thanks to Dr. Adriana Giongo and Ms. Diane Chauliac for their guidance and assistance in carrying out microbial anaysis for this research. I also would like to thank Dr. Claudia C. Geddes and Dr. Mike Mullinnix for providing necessary materials and data for this research, as well as their insightful ideas and assistances in solving analytical issues. I would like to thank the following individuals for their supports and assistances during my studies, Abhay Koppar, Cesar Moreira , Congrong Yu, Gayathri Ram Mohan, Ioannis M. Polematidis, Jaime Chavez Leon, Mandu Inyang, Patrick Dube, Samriddhi Buxy, Yuan Tian and all the friends in the Department of Agricultural and Biological Engineering. I gave my special thanks to Lushun Xiang and Ying Yao for their wholehearted supports and companies to relieve my frustration and stress. This would never have been possible without them. 4 TABLE OF CONTENTS page ACKNOWLEDGMENTS.................................................................................................. 4 LIST OF TABLES............................................................................................................ 8 LIST OF FIGURES.......................................................................................................... 9 ABSTRACT ................................................................................................................... 11 CHAPTER 1 INTRODUCTION .................................................................................................... 14 Project Focus.......................................................................................................... 14 Glycerol Byproduct from Biodiesel Production Process.......................................... 15 Residues from Bioethanol Production..................................................................... 16 Research Objectives............................................................................................... 18 Anaerobic Digestion Technique .............................................................................. 19 The Microbiology of Anaerobic Digestion ......................................................... 19 Methane Production and COD Degradation..................................................... 21 Configurations of Anaerobic Digesters ............................................................. 22 Factors Affecting Anaerobic Digestion ............................................................. 23 Methods for Investigation of Microbial Communities ........................................ 25 Current Technologies for 16S rDNA Sequencing ............................................. 25 16S rDNA Sequencing Data Analysis .............................................................. 26 2 BIOCHEMICAL METHANE POTENTIAL OF GLYCEROL BYPRODUCT FROM BIODIESEL PRODUCTION USING WASTE VEGETABLE OIL............................. 31 Summary ................................................................................................................ 31 Background............................................................................................................. 32 Material and Method ............................................................................................... 33 Feedsto ck......................................................................................................... 33 BMP Assay....................................................................................................... 34 Semi-continouous Digestion of GBP ................................................................ 35 Analys is............................................................................................................ 36 Results.................................................................................................................... 38 Characterization of the GBP............................................................................. 38 Methane Potential ............................................................................................ 38 Soluble Chemical Oxygen Demand Profiles..................................................... 42 Volatile Organic Acid Profiles ........................................................................... 43 Methane Production from Semi-continuous Digestion of GBP ......................... 43 Discuss ion........................................................................................................ 45 Closing Remarks .................................................................................................... 48 5 3 ANAEROBIC DIGESTION FOR TREATMENT OF STILLAGE FROM CELLULOSIC BIOETHANOL PRODUCTION ........................................................ 55 Summary ................................................................................................................ 55 Background............................................................................................................. 56 Materials and Methods............................................................................................ 58 Feedstock......................................................................................................... 58 Biochemcial Methane Potential Assay (BMP) .................................................. 59 Continuous Digestion of Bagasse Stillage Filtrate............................................ 60 Monitoring and Analysis ................................................................................... 62 Results.................................................................................................................... 64 Characterization of the Stillage......................................................................... 64 Methane Potential ............................................................................................ 65 Soluble COD and Volatile Organic Acids in BMP Assays ................................ 66 Continuous Digestion of Bagasse Stillage Filtrate (BF).................................... 67 Discuss ion........................................................................................................ 68 Closing Remarks .................................................................................................... 75 4 COMPARISON OF BATCH ANAEROBIC DIGESTION OF SUGARBEET TAILINGS AT MIXED AND NON-MIXED CONDITIONS ........................................ 88 Summary ................................................................................................................ 88 Background............................................................................................................. 89 Material and Method ............................................................................................... 91 Feedsto ck......................................................................................................... 91 Anaerobic Digesters ......................................................................................... 91 Experiment Description .................................................................................... 92 Temperature Monitor........................................................................................ 93 Chemical Analysis ............................................................................................ 94 Microbial Community Analysis.......................................................................... 94 Results.................................................................................................................... 96 Characterization of Substrates ......................................................................... 96 Temperature Profiles........................................................................................ 96 CH4 Production................................................................................................. 97 Profiles of sCOD Degradation Comparison...................................................... 98 Profiles of Volatile Organic Acid ....................................................................... 98 Microbial Communities Structure...................................................................... 99 Discussion ............................................................................................................ 100 Determination of Mixing Intensity ................................................................... 100 Digestion Performance Comparison..............................................................