University of Alberta Vapour Phase Cracking of Bitumen Derived Heavy Gas Oil by Weida Bu A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Chemical Engineering Department of Chemical and Materials Engineering © Weida Bu Fall 2012 Edmonton, Alberta Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission. Abstract The kinetics of vapor phase cracking of bitumen derived heavy gas oil and the quality of liquid products were investigated at temperatures of 600-700 °C . Fixed and condensed gases were analyzed by gas chromatography. The quality of liquid products was characterized using simulated distillation, elemental analysis and 13C NMR. Consistent with gas phase cracking behavior, the coke yields were negligible, below 2 %. The yields of C2-C3 olefins were 2 to 16 wt% compared with the yields of C2-C3 alkanes from 0.2 to 1.0 wt%. Hydrogen content of liquid products was lost significantly, corresponding to increase of aromatic carbon content with increase of conversion. A two-step kinetic model including fast dehydrogenation and slower cracking was proposed on the basis of chemical structure change of the reactant. The activation energy of the overall cracking reaction on reactive materials was 208 kJ/mol based on full analysis of the reactor. Acknowledgement I would like to take the chance to appreciate Dr. Gray for his responsible and meticulous supervision on my project. It is his valuable instructions and suggestions that help me to obtain important breakthroughs in the experiments. I also learned how to think and speak in a more scientific way from each discussion with him. I also want to thank Syncrude Canada and Natural Sciences and Engineering Research Council of Canada for the stable funding support. Besides, I also thank Kourosh Vafi for the systematic training on the apparatus operation and Lisa Brand for her material support on the experiments. Last but not least, I show great gratitude to my parents’ concern on my life in the last two years. Their encouragement gives me strong confidence to overcome difficulties and motivation to challenge new objectives. Table of Contents CHAPTER 1 Introduction ............................................................................................ 1 CHAPTER 2 Literature Review .................................................................................... 3 2.1 Industrial Upgrading Processes ................................................................................. 3 2.2 Novel Coking Technologies ....................................................................................... 6 2.2.1 ETX IYQ Cross Flow Coking .................................................................................. 7 2.2.2 LR-Process .......................................................................................................... 8 2.2.3 Ivanhoe Heavy to Liquid (HTL) Process .............................................................. 8 2.2.4 ART Process ...................................................................................................... 10 2.2.5 Summary .......................................................................................................... 11 2.3 Improvements on Current Fluid Coking .................................................................. 11 2.4 Industrial Petro-Chemical Processes ....................................................................... 12 2.5 Composition and Structure of Bitumen and Its Derived Heavy Gas Oil .................. 14 2.6 Mechanism for Cracking of n-alkanes ..................................................................... 21 2.7 Kinetics of Cracking of n-hexadecane as Model Compound ................................... 23 2.8 Mechanism of Cracking of Other Components of Gas Oil ...................................... 26 2.8.1 Reactions of Olefins ......................................................................................... 26 2.8.2 Reactions of Aromatics .................................................................................... 27 2.8.3 Reactions of Naphthenes ................................................................................. 27 2.8.4 Reactions of Sulfur Compounds ....................................................................... 28 2.9 Kinetics of Cracking of Gas Oil ................................................................................. 29 2.9.1 Empirical Kinetics with No Chemical Information............................................ 29 2.9.2 Empirical Lumped Kinetics with No Chemical Information.............................. 32 2.9.3 Structured Kinetics with Chemical Information ............................................... 34 2.10 Summary of Key Issues ......................................................................................... 37 CHAPTER 3 Experimental Materials and Method ...................................................... 39 3.1 Materials ................................................................................................................. 39 3.2 Reactor Apparatus and Operation .......................................................................... 41 3.2.1 Reactor Apparatus ........................................................................................... 41 3.2.1.1 Feed Introduction ..................................................................................... 42 3.2.1.2 Reaction Section ....................................................................................... 43 3.2.1.3 Product Collection ..................................................................................... 44 3.2.1.4 Data Acquisition System ........................................................................... 45 3.2.1.5 Helium Gas Flow Control........................................................................... 45 3.2.2 Reactor Feed Optimization .............................................................................. 47 3.2.3 Reactor Operation ............................................................................................ 50 3.2.3.1 Reactor Preparation .................................................................................. 50 3.2.3.2 Condenser Leak Test ................................................................................. 50 3.2.3.3 Operating Condition .................................................................................. 51 3.2.3.4 Operating Procedures ............................................................................... 52 3.3 Analysis of Reactor Samples ................................................................................... 55 3.3.1 Fixed and Condensed Gas Analysis .................................................................. 55 3.3.1.1 Gas Chromatography Apparatus ............................................................... 55 3.3.1.2 Gas Chromatography Calibration .............................................................. 56 3.3.1.3 Gas Chromatography Analysis Procedure ................................................. 57 3.3.2 Liquid Product Analysis .................................................................................... 57 3.3.2.1 Simulated Distillation ................................................................................ 57 3.3.2.1.1 Simulated Distillation Apparatus ....................................................... 57 3.3.2.1.2 Simulated Distillation Analysis Procedure ......................................... 59 3.3.2.2 Elemental Analysis .................................................................................... 60 3.3.2.2.1 Elemental Analyzer ............................................................................ 60 3.3.2.2.2 Elemental Analysis Procedure ............................................................ 61 3.3.2.3 13C NMR Analysis ....................................................................................... 62 3.3.3 Recovered Solvent Analysis ............................................................................. 62 CHAPTER 4 Results and Discussion ........................................................................... 64 4.1 Performance of the Tubular Reactor ...................................................................... 64 4.1.1 Temperature Profile ......................................................................................... 64 4.1.2 Reaction Residence Time ................................................................................. 70 4.1.3 Material Balance .............................................................................................. 76 4.2 Conversion of Heavy Gas Oil ................................................................................... 79 4.3 Yield and Distribution of Cracked Products ...........................................................