Characterization of Oxygen-Containing Compounds in Crude Oils by Chromatographic and Mass Spectral Analysis

• Other Authors: Rowland, Steven Michael (authoraut)
• Format: Others
• Language: English; English
• Published: Florida State University
• Subjects: Chemistry
• Online Access: http://purl.flvc.org/fsu/fd/FSU_migr_etd-9673

The chemical complexity of crude oil, arguably the most complex mixture in the world, has been addressed over the past decade by ultrahigh resolution FT-ICR MS. FT-ICR MS has shown to be well suited to complex mixture analysis, and the mass accuracy and resolving power of FT-ICR MS provides the ability to assign unique chemical formulas to observed petroleum compounds. Although FT-ICR MS has proven a useful technique for petroleum characterization, the complexity of increasingly heavy crude oils challenges even the highest resolution mass spectrometers. The work presented here utilizes chromatographic separations to enhance the information derived from crude oil analysis by FT-ICR MS. Organic acids found in crude oils are known to cause corrosion, emulsions, and deposit formations during the production and refining processes. Aminopropyl silica was used to separation carboxylic acid compounds (i.e., naphthenic acids) from crude oil. This separation also fractionates acids by molecular weight and provides insight into previously undetected high molecular weight acids. Tetraprotic carboxylic acids (i.e., ARN acids) were also targeted by aminopropyl silica separation and further targeted by ammonia gas treatment. The combination of techniques provides a fast and effective measurement for the determination of ARN acids in crude oils. Oxidation of crude oils after environmental spills has been previously reported. Unprecedented oxidation of crude oil was recently observed from the Deepwater Horizon oil spill. The weathering process created tens-of-thousands of newly observed oil transformation products. Previous analysis by FT-ICR MS has catalogued these transformation products, but limited information was determined with regard to oxygen functionalities. The coupling of liquid chromatography and FT-ICR MS, as well as derivatization techniques, provided insight into crude oil oxidation products collected from the Gulf of Mexico. Asphaltenes have been referred to as the "bad actors" of petroleum because of their propensity to fall out of solution and form devastating deposits in wells and pipelines. Additives known as asphaltene inhibitors are often added to oil wells to prevent deposition. Quantitation of chemical additives is imperative to understanding their efficiency. Here LC-MS was utilized to determine the concentration of an asphaltene inhibitor additive in crude oil. === A Dissertation submitted to the Department of Chemistry and Biochemistry in partial fulfillment of the requirements for the degree of Doctor of Philosophy. === Spring Semester, 2015. === January 8, 2015. === ARN Acid, FT-ICR MS, High resolution mass spectrometry, Naphthenic acids, Petroleomics, Weathered oil === Includes bibliographical references. === Alan G. Marshall, Professor Directing Dissertation; Jeffery P. Chanton, University Representative; John G. Dorsey, Committee Member; Naresh S. Dalal, Committee Member; Ryan P. Rodgers, Committee Member.