University of Nevada, Reno DEVELOPMENT OF HOMOGENEOUS AND HETEROGENEOUS CATALYSTS FOR THE PRODUCTION OF BIODIESEL AND AVIATION FUEL A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Materials Science and Engineering by Dharshini D. Balasubramaniyan Dr. Dev Chidambaram/Dissertation Advisor August, 2016 THE GRADUATE SCHOOL We recommend that the dissertation prepared under our supervision by DHARSHINI D. BALASUBRAMANIYAN entitled Development of Homogeneous and Heterogeneous Catalysts for the Production of Biodiesel and Aviation Fuel be accepted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Dr. Dev Chidambaram, Advisor Dr. Mano Misra, Committee Member Dr. Dhanesh Chandra, Committee Member Dr. Victor Vasquez, Committee Member Dr. Glenn Miller, Graduate School Representative David Zeh, Ph. D., Dean, Graduate School August, 2016 i Abstract Biodiesel is a renewable fuel that consists of fatty acid esters synthesized from oils or fats and is non-toxic, biodegradable, and has lower carbon/sulfur emissions than petroleum- diesel. Biodiesel can be produced from waste vegetable oil, animal fats, and oil extracted from organisms such as algae or cyanobacteria. Since waste vegetable oils and algae oils are the major source for current commercial biodiesel and bio-jet fuel, they are the major feedstocks utilized in this dissertation. The focus of this research is to study biodiesel and jet fuel production using mesoporous and zeolitic heterogeneous catalysts. Heterogeneous catalysts such as KIT-51, KIT-6 and zeolite beta were prepared and tested for their catalytic ability to esterify high free fatty acid feedstocks. KIT-5 and KIT-6 mesoporous catalyst systems were found to be more efficient and recyclable for biodiesel synthesis when compared to other established mesoporous catalyst systems. Heteropoly acids, supported on KIT-5 and KIT-6, were used in single step esterification of algae oil, used cooking oil and palmitic acid. High yields, and conversions greater than 80% were observed. Slight deactivation of the catalyst was observed upon recycling. Silicotungstic acid (26 wt%) loaded KIT-6 reacted at 70 °C with an alcohol to acid volume ratio of 2 and 1.5 wt% catalyst for 3 h to yield maximum conversion. Similarly, phosphotungstic acid (26.5 wt%) loaded KIT-5 catalyzed maximum conversion of free fatty acids under identical reaction conditions maintained for 4 h. 1 KIT: Korean Institute of Technology ii Kinetics and reaction mechanism for heterogeneous esterification of used cooking oil was also established by using KIT-5 catalyst. A first order kinetic model was developed based on the experimental data obtained. Currently, most of the commercial biodiesel production facilities employ traditional alkali-catalyzed transesterification that involves high processing costs. So, a morpholine co-catalyst employed transesterification process was developed to replace the time-consuming traditional process. An improvement in the kinetics of the transesterification reaction was observed with three different feedstocks, namely corn, canola and coffee oils. The development and commercial production of sustainable alternative fuels to minimize effects of fossil fuel combustion also applies to jet fuels. Jet fuel is a highly specialized form of petroleum fuel comprised of primarily hydrocarbons such as paraffins, olefins, naphthenes, and aromatics. So finally, production of renewable jet fuels from algae oils by hydrodeoxygenation using transition metal loaded zeolite beta was investigated and is discussed in detail. This process adds hydrogen in order to remove the oxygen from the feedstock and then further cracks the remaining product to meet the specifications for bio-jet fuel. Algae oil was deoxygenized and hydrocracked at 400 °C and 400 psi, using 1 wt% catalyst to obtain a maximum mass conversion of 98%. Overall this dissertation presents a detailed insight into biodiesel production using KIT-5 and KIT-6 catalysts, jet fuel production using zeolite beta catalyst and improving reaction kinetics of traditional biodiesel production using morpholine co-catalyst. The outcomes of this research have been published in several scientific journals and presented at iii national conferences. The published articles and conference presentations are listed at the beginning of this dissertation. iv Dedicated to the memories of my beloved grandfather Thirunethiran (1941-2014) whose life will forever inspire my human experience v Acknowledgements The writing of this dissertation has been a significant academic challenge and I would like to emphasize that I would never have been able to finish my dissertation without the guidance of my advisor, committee members, timely help from friends and lab mates, and overwhelming support from my family. I am using this opportunity to express my deepest gratitude to my advisor, Dr. Dev Chidambaram, for his excellent guidance throughout my research. His wisdom, knowledge and commitment to the highest standards inspired and motivated me. I have gained a tremendous amount of knowledge while under his supervision. His guidance and continued support over the good and bad times has meant a lot to me. This work was funded, in part by, Department of Energy, under grant number DE- EE0003158. I thank Dr. Victor Vasquez, who let me improve upon my work with his advice and suggestions. I thank Dr. Mano Misra, Dr. Dhanesh Chandra and Dr. Amy Childress for agreeing to serve on my committee and for their valuable comments on my proposal which helped shape this dissertation. Special thanks go to Dr. Glenn Miller, who was willing to participate in my committee at the last moment. vi I thank Ruchi Gakhar, who was a good friend and roommate, was always encouraging, and willing to help. It would have been a very lonely home and lab without her. Many thanks to Gus Merwin, David Rodriguez, Akira Nordmeier, Zachary Karmiol, Kowsalya Rasamani, William Phillips, Thorunn Snorradottir and Dr. Satyananda K. Pilli for helping me out when I needed their assistance. I thank Dr. York Smith and Dr. Ming Chen for assisting me with characterization studies. I thank my mom and dad – Sivagami and Balasubramanian; grandparents – Thirunethiran and Sarojini; aunts – Dr. Karpagam and Shanmughapriya; and my brother – Ganesh Nethiran for they were always supporting me and encouraging me with their best wishes. Finally, I thank my besties, Deepak Subramanian, Satish Kumar and Sravanthi Yendluri, who were always there cheering me up and stood by me through the good times and bad. It is to all of these people that I owe my deepest gratitude. vii Table of Contents Chapter Page Title No. No. Abstract i Acknowledgements v Table of Figures xii List of Tables xxi List of publications xxiii 1 Introduction 1 1.1 Biofuels 1 1.1.1 Biofuel types 2 1.2 Feedstock 9 1.2.1 First generation feedstocks 9 1.2.2 Second generation feedstocks 11 1.3 Catalysts 12 1.3.1 Homogeneous catalysts 13 1.3.2 Heterogeneous catalysts 15 1.4 Biodiesel Production Process 21 1.5 Jet fuel production process 24 1.6 Objective 27 2 Materials and Methods 30 2.1 Chemicals 30 viii 2.2 Catalysts Synthesized 30 2.3 Heteropoly Acids 33 2.4 Zeolite Beta 34 2.5 Feedstock Pretreatment 37 2.6 Biofuel synthesis 38 2.6.1 Biodiesel esterification 38 2.6.2 Biodiesel traditional transesterification 38 2.6.3 Recycling 39 2.6.4 Jet Fuel Catalytic Cracking 40 2.7 Analytical Techniques 41 2.7.1 XRD (X-Ray Diffraction) 41 2.7.2 XPS (X-Ray Photoelectron Spectroscopy) 41 2.7.3 FTIR (Fourier Transform Infrared) Spectroscopy 42 2.7.4 SEM (Scanning Electron Microscope) 44 2.7.5 BET (Brunauer, Emmett and Teller) Surface Area Analysis 44 2.7.6 ICP-OES (Inductively Coupled Plasma Optical Emission 45 Spectroscopy) 2.7.7 GC–MS (Gas Chromatography Mass Spectrometry) 46 2.7.8 HPLC (High Performance Liquid Chromatography) 48 3 Results and Discussion 49 3.1 FFA analysis 49 3.2 Enhancing kinetics of biodiesel production using Morpholine 50 ix 3.2.1 Introduction 50 3.2.2 Results and Discussion 51 3.2.2.1 Glycerides and FFA profile 51 3.2.2.2 Kinetics 59 3.2.2.3 Fuel properties test 61 3.3 Conversion of high FFA feedstocks to Biodiesel Using Solid Acid 66 Supported KIT-6 3.3.1 Introduction 66 3.3.2 Results and Discussion 67 3.3.2.1 SEM characterization 67 3.3.2.2 BET analysis 68 3.3.2.3 XRD analysis 72 3.3.2.4 FTIR analysis 72 3.3.2.5 XPS analysis 72 3.3.2.6 Conversion and Yield 73 3.3.2.7 GC–MS analysis 78 3.3.2.8 Recycling studies 81 3.4 Optimization of Solid Acid Kit-5 Catalyzed Biodiesel Production, 84 Part I. A Study on Biodiesel Synthesis from Low Quality Feedstock. 3.4.1 Introduction 84 3.4.2 Results and Discussion 85 3.4.2.1 ICP-OES analysis 85 3.4.2.2 BET analysis 86 x 3.4.2.3 FTIR analysis 88 3.4.2.4 SEM analysis 89 3.4.2.5 XRD analysis 91 3.4.2.6 Leaching studies 92 3.4.2.7 Conversion and Yield 92 3.4.2.8 GC–MS analysis 94 3.4.2.9 HPLC analysis 97 3.4.2.10 Recycling studies 97 3.5 Solid Acid Catalyzed Biodiesel Production, Part II. Kinetics of KIT- 100 5 Catalyzed Esterification of Used Cooking Oil 3.5.1 Introduction 100 3.5.2 Results and Discussion 101 3.5.2.1 Determination of order of reaction 102 3.5.2.2 Effect of temperature 106 3.5.2.3 Effect of methanol to oil ratio 109 3.5.2.4 Effect of acid loading 110 3.5.2.5 Effect of catalyst quantity 112 3.5.2.6 Effect of surface area 113 3.5.2.7 Statistical analysis 115 3.5.2.8 Proposed reaction mechanism 118 3.6 Production of jet fuel range alkanes from algae oil 121 3.6.1 Introduction 121