The Boduszynski Continuum: Contributions to the Understanding of the Molecular Composition of Petroleum Downloaded from pubs.acs.org by 5.189.202.134 on 09/02/18. For personal use only.
Preface Dr. Mieczyslaw M. Boduszynski (Mietek) was the recipient of the 2016 George A. Olah Award in Hydrocarbon or Petroleum Chemistry and the 2017 ENFL Distinguished Researcher Award. Dr. Boduszynski was honored for his significant contributions to the understanding of the molecular composition of petroleum and his profound influence on a generation of petroleum and fuel chemists. This book is based on the symposium titled “ENFL Distinguished Researcher Award in Honor of Mieczyslaw M. Boduszynski”, sponsored by the Energy and Fuel Division (ENFL), held at the 253rd ACS National Meeting & Exposition, April 2-6, 2017, in San Francisco. Other authors were invited to participate to complement the multiples technical areas impacted by Boduszynski’s work during his illustrious career. Dr. Boduszynski always advocated that a better understanding of petroleum molecular composition is key to predicting its properties and behavior. Such information is valuable for chemists, geologists, and chemical and petroleum engineers working in all areas of the petroleum value chain from exploration and production to refining. In a demonstration of Mietek’s influence, this book presents an in-depth account of Boduszynski’s work from the point of view of his collaborators and peers. The impacts on operations and current practices in the industry are discussed as well. This monograph covers three broad topics of Mietek’s outstanding career, Heavy Fraction and Asphaltene Characterization, The Boduszynski Continuum Model, and Distillation. Since his days as a graduate student in Poland, Mietek dedicated himself to the understanding of petroleum composition especially that of heavy ends; this means the isolation and characterization of the heaviest portions of the petroleum in a rational and consistent fashion. In Chapter 1, Dr. Michael Moir discusses the origin of the term asphaltene, the history of the science behind, and how the current state of knowledge aligns with the model of petroleum proposed by Boduszynski. In 1980, Dr. Boduszynski caused a considerable stir in his landmark conference publication “Asphaltenes, where are you?” and inspired the title of Dr. Moir’s chapter (Chapter 1) “Asphaltenes, What Art Thou?”. Next, in Chapter 2, Dr. Cesar Ovalles and coworkers present a chapter dedicated to the importance of mass balances (also called material balances) for the understanding of petroleum chemistry and to ensure the successful outcome of experimentation. During his illustrious career, Dr. Mietek Boduszynski devoted considerable time and effort to analyzing and understanding mass balances during his laboratory testing and experimentation. Following his teaching, several case studies are presented for the evaluation of asphaltene dispersants and antifoulants. ix
The primary goal is to show how mass balances were crucial to assess the validity of the new asphaltene determination method, the reliability of the data, and to evaluate the relative effectiveness of the asphaltene-dispersant and antifoulant additives. In Chapter 3, Dr. Estrella Rogel et al. present a series of correlations that link chemical composition with the solubility and thermal behavior of asphaltenes. In the late 80s and early 90s, Dr. Boduszynski used sequential elution fractionation to demonstrate that non-distillable fractions followed the same patterns as distillation cuts and that solubility could be used to perform an equivalent distillation for non-distillable materials. By using new data and some already published in the literature, Rogel and coworkers find that high hydrogen deficiencies and uneven solubility fraction distributions are the main contributors to asphaltene precipitation. Following the footsteps of Boduszynski, in Chapter 4, Dr. Ajit Pradhan et al. describes the latest developments in nuclear magnetic resonance (NMR) to characterize heavy petroleum fractions and heterogeneous catalysts. They use a combination of the extended Brown and Ladner method and surrogate molecules to monitor structural changes resulting from hydroprocessing of petroleum feeds. They also employ Diffusion Ordered Spectroscopy (DOSY) to characterize heavy petroleum fractions and asphaltenes by their size, shape, mass, and charge. Finally, they use Diffusion Ordered Spectroscopy (DOSY) and Dynamic Nuclear Polarization (DNP) to characterize heterogeneous catalysts and heavy petroleum fractions. In Chapter 5, Dr. Francisco Lopez-Linares and co-workers determine vanadium and nickel contents and distributions as a function of boiling point of vacuum gas oil by using High-Temperature Gas Chromatography coupled with Inductively Coupled Plasma Mass Spectrometry (HTGC-ICP-MS). This line of work was inspired by a late-afternoon comment from Dr. Boduszynski to Dr. Michael Moir, “Do you know what we need? We need a method to measure metal distribution versus temperature”. Dr. Moir took up the challenge, and with the help of the glass and machine shops, designed a suitable quartz torch and transfer-line. The rest is history. This brings us to the second broad topic covered in this monograph and perhaps one of the Mietek’s most significant contribution to petroleum chemistry. This topic is called “The Boduszynski Continuum Model.” In his pioneering work, Dr. Boduszynski postulated that petroleum is a continuum of compounds having a wide variety of structural and elemental compositions. The model proposed that, unlike conventional wisdom at the time, petroleum transitions from individual molecules to high molecular weight components (i.e., asphaltenes), and that the molecular composition of petroleum is a continuously variable series of molecules without abrupt transitions. His work in this area forms the basis of the current model of petroleum. He predicted that the high-boiling residue after distillation was, in fact, a continuous extension of low molecular weight components, rather than (as was then thought) high-molecular weight “polymers.” He had great difficulty in getting his ideas published, but has been overwhelmingly vindicated by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. In Chapter 6, Dr. Ryan Rodgers and co-workers review the work x
carried out at the National High Magnetic Field Laboratory in the chemical and compositional analysis of petroleum. The material discussed clearly demonstrated the validity of The Boduszynski Continuum Model from the low molecular weight compounds up to asphaltenes. Their results create a molecular-level map with the relationships between carbon number, aromaticity (DBE), heteroatom content, chemical functionality, ring number, asphaltene structures (island and archipelago), and boiling points. In Chapter 7, Lante Carbognani, from the University of Calgary, carries out a literature review on the existence of large molecular weight paraffinic compounds in petroleum streams. He finds that sample handling, diluted conditions, and high set up temperatures are mandatory for the successful characterization of such compounds. Also, he proposes a plausible locus within The Boduszynski Continuum Model for these large molecular weight paraffins within high carbon number (C90-C215 carbon atoms) and low Double Bond Equivalent (DBE
