Pedro Arcelus Thesis
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Heavy Oil Upgrading through Oxidative Cracking in Near-critical and Supercritical Water Pedro Manuel Arcelus Arrillaga Imperial College London Chemical Engineering Department Thesis submitted for the degree of Doctor of Philosophy (PhD) to Imperial College London Supervised by: Dr. Marcos Millan Agorio Prof. Klaus Hellgardt Declaration of Originality Declaration of Originality: The author declares that the contents of this work are the product of his original effort and that anything else has been appropriately referenced. Pedro Manuel Arcelus Arrillaga Copyright Declaration: The copyright of this thesis rests with the author and is made available under a Creative Commons Attribution Non-Commercial No Derivatives licence. Researchers are free to copy, distribute or transmit the thesis on the condition that they attribute it, that they do not use it for commercial purposes and that they do not alter, transform or build upon it. For any reuse or redistribution, researchers must make clear to others the licence terms of this work. Abstract Abstract The gradual decline in conventional oil production combined with an increasing world energy demand has made the production and upgrading of heavy and extra heavy oil feedstocks crucial for the future of the global energy market. Properties of heavy oil such as high viscosity and high specific gravity as well as the high percentage of asphaltenes, heteroatoms and metals cause severe problems during extraction and refining processes. As a result, traditional upgrading technologies are not suitable as a standalone method to process these feedstocks. This makes necessary the development of alternative or complementary technologies to process heavy oil feedstocks in a more efficient and environmentally friendly way. This work is aimed to study an alternative heavy oil upgrading process that takes advantage of the unique properties of water at near-critical and supercritical conditions as reaction medium to perform the oxidative cracking of heavy oil feedstocks. The process consists of three main stages including the partial oxidation, cracking of the molecule, and removal of part of the oxygen incorporated from the final product. The process was studied using phenanthrene and methyl naphthalene as heavy oil model compounds and also Maya oil vacuum residue as real feedstock. This was performed in a purposely built microbomb batch reactor and an oxidative cracking flow reactor. The effect of the main process variables and the potential reaction pathways were studied with model compounds. Then the process was tested with real feedstock and the inclusion of a zeolite based catalyst to enhance yields to light oil was considered. It was found that process conditions have an important influence in the yield and selectivity to different product fractions. Optimum conditions to maximize the production of organic soluble products were determined. It was observed that polycyclic aromatic hydrocarbons were not reactive in the absence or at low concentration of reactive oxygen species. However, oxygenated intermediates continued to react in water alone. In addition, it was observed that intermediate products were mainly oxygenated compounds and that the oxygenation proceeded preferentially through central rings. A hydrogen rich gas product was obtained. Experiments with vacuum residue showed that high yields to liquid products with low boiling point are obtained keeping low yields to coke at most conditions studied. The addition of a zeolite based catalyst showed improvement in the process, increasing the yield to light oil and reducing the average molecular weight of the product. Heteroatoms and metals present were mainly removed as coke and showed to be relatively stable. Acknowledgement Acknowledgement This thesis not only represents five years of absolute dedication, hard work and sacrifices, but the attainment of years of efforts by many professionals and friends who deserve to be acknowledged and recognized. I extend my complete gratitude to all these people that in a way or another assisted me in this quest and without whom the accomplishment of this work would have just been impossible. Throughout these years in Imperial, I have had moments of great happiness, great disappointments, moments of complete frustration and great satisfactions, which would not have meant the same if it was not for the remarkable individuals with whom I shared them. Doing a PhD in Imperial has been an amazing experience full of challenges and life lessons that have tested my character and have shaped me into the person I am today. It has also given me the opportunity to meet people from different nationalities and backgrounds from which I have not just learnt about science and engineering but have also opened my world into a whole load of different opinions, traditions and ideas enriching me not just academically but most importantly as a person. I want to take this opportunity to thank and give recognition in no particular order to the people that have helped me into the finish line and have made this dream possible. First and foremost, I want to thank my mom and sister that have been a source of inspiration every second of this great experience. They have suffered as much as I have from the distance and have remained an inexhaustible source of love and affection throughout these years. I also want to thank the rest of my family for their encouragement and support, which has been crucial throughout my life in the achievement of my goals. I would like to extend my total gratitude and give a special recognition to my supervisor and academic mentor Dr. Marcos Millan without whom the accomplishment of this thesis would have not been possible. I am indebted with Dr. Millan, whose support, advice, knowledge and kind help whenever needed, guided me to successfully finish my PhD and have opened me the doors to pursue a career in science. I also want express my gratitude to my supervisor Prof. Klaus Hellgardt from whom I have learnt a lot and whose knowledge and critical contributions have nurtured this work and have showed me the path to excel in academic research. Acknowledgement I want to specially thank Dr Khairul Rostani, Dr Elias Martinez and Mr David Flores who I consider my brothers and in the distance have lived and suffered the experience as much I have done and have remained a constant source of encouragement throughout these years. I want to thank Dr Holda Puron and Dr Manuel Piñuela who have been a family in London to me. I have no words to thank you enough. A special thanks to Dr Beatriz Fidalgo, Dr Jose Luis Pinilla, Dr Cesar Berrueco and Dr Esther Llorente for their unconditional friendship, contributions and guidance at early stages of my PhD and especially at difficult times when things got supercritical. Thank you for all the advice and also for pulling my ear every time I lost focus. I also want to thank my friends and colleagues Dr Jose Bermudez, Dr Tomas Ramirez, Dr Yatika Somrang, Mr Daniel Torres, Dr Javier Remon, Dr Matt Boot-hanford, Dr John Blamey, Ms Eneritz Fernandez, Ms Xiangyi Long, Dr Jie Yu, Dr Tomas Hills, Dr Zili Zang, Dr Mario Villanueva, Mr Marco Jano, Dr Vicky Skoulou, Dr Emilio Bejarano, Mr Jonathan Ball, Mr Aderlanio da Silva, Mr Bhavish Patel, Dr Rafizan Daud, Mr Joseph Yao and Mr Peter Clough with whom I have shared amazing times and have always been there for me. I am grateful with Susi Underwood and Anusha Sri-Pathmanathan for the support, assistance and help throughout my PhD, especially for their help to arrange and clarify details on the multiple interruption of studies occurred throughout my PhD. My gratitude to Tony Meredith, Richard Wallington, Paul Mayer, Paul Crudge, Chin Lang, Patricia Carry, Sarah Payne, Dr Severine Toson, Pim Amrit, Jesus Gomez and Ben Kistnah for their technical assistance and help in innumerable occasions throughout my PhD. I thank Dr Tatiana Klimova for her support, guidance and council since my undergraduate studies. I also want to thank my MSc students Ms Carla de Sa Martins, Mr Leonard Van Thiele and Mr Arran Marais-Gilchrist whose projects were related to this PhD thesis and who performed an outstanding work in our research group. I am very grateful with Dr Isabel Suelves and Dr Jose Luis Pinilla for giving me the opportunity to develop a short research stay in their facilities at the Institute of Carbochemistry in Zaragoza, Spain. I am thankful with Imperial College Trust who granted me economical support in two occasions to present my work in two important international conferences. Finally I want to acknowledge the economic support provided by the National Council of Science and Technology in Mexico, CONACYT for the partial funding of this PhD. 5 Acknowledgement And above all, I want to dedicate this to you who have always been at my side. Cannot thank you enough!! 6 Table of Contents Table of Contents Declaration of Originality ....................................................................................................... 2 Abstract................................................................................................................................. 3 Acknowledgement ................................................................................................................. 4 Table of Contents .................................................................................................................. 7 List of Tables .....................................................................................................................