Petroleum. Crude oils - ACS Publications - American Chemical Society

This is the thirteenth review of analytical chemistry inthe petroleum industry (1A-12A) sponsored by the Division of. Petroleum Chemistry of the Ameri...
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Petroleum J. M. FRASER Union Oil Company of California, Brea, Calif. 92521

This is the thirteenth review of analytical chemistry in the petroleum industry (IA-12A) sponsored by the Division of Petroleum Chemistry of the American Chemical Society. Its objective is to cover the most important and relevant publications appearing essentially in 1974 and 1975. Specifically, it covers the papers abstracted in Chemical Abstracts, in the American Petroleum Institute Refining Literature Abstracts, and in Analytical Abstracts (London)for the period of July 1974 through June 1976. Thus this review begins where the previous one ended and the general format of previous issues is being continued. References conform to the Chemical Abstracts "Guide for Abbreviating Periodical Titles." In addition, when a reference publication might not be readily available, the abstract journal has been appended to that for the original source. The ab-

breviations C.A., A.P.I.A., and A.A. are used to identify the abstract journals cited above. These abbreviations are followed by the volume number, the abstract number, and the year. The abstract searching was done by J. F. Hickerson, Exxon Co., U.S.A.; R. W. King, Sun Oil Company; C. A. Simpson, Mobil Research and Development Corp.; and J. M. Fraser, Union Oil Co. of California. The collected abstracts were then screened and organized by subjects. Each collection of abstracts was then additionally reviewed, screened, and organized by fourteen authors of the eleven subjects or subsections which follow. The generous assistance of the abstractors and of the authors, many of whom have contributed to previous reviews, is very much appreciated and the production of this review is due to their combined efforts.

Crude Oils

extracted with EtOH-C& were more highly branched than those extracted with CHCls (37B). Heterocompounds. Drobot and Presnova determined the amount, composition, and distribution of the main types of sulfur compounds from selected crudes of the Sikerian Platform (24B). Numanov et al. employed catalytic micro-hydrodesulfurization, followed by MS analysis to determine the structures of sulfides in two crude oils from south central Asia. Mono- and bicyclic sulfides accounted for 78-84% of the total sulfides in the samples examined (73B). Numanov and coworkers characterized other high sulfur (5.0-6.2% S) crudes from the same general area and found mercaptans and sulfides the predominant sulfur compounds in those fractions boiling below 200°, but disulfides predominated in those fractions boiling over 200' (74B).Khaitbaev et al. analyzed the sulfur compounds from petroleums of this area and confirmed the above findings, but added more detailed data (54B). Akhmedova attempted to establish a relationship between S, N, and silica gel resin content, and also between their content and depth of occurrence and specific gravity of some Azerbaidzhan crudes. However, the correlations were not close as might be hoped (3B). Orr studied changes in sulfur content and in sulfur isotope ratios with thermal maturation, using the Big Horn Basin (Wyo.) Paleozoic oils. In addition to the trends usually observed, he noted that during thermal maturation in high temperature ( >80-120') reservoirs with sulfate present, nonmicrobial sulfate reduction may take place with negligible isotopic fractionation (75B).Ho et al. determined the classes of sulfur compounds in 78 crude oils from many of the world's major fields. Oils abundant in unstable compounds, such as nonthiophenic sulfides and benzothiophenes, were classed as immature. Those containing more of the stable dibenzothiophenes were classed as mature, while a third group of intermediate distributions was termed altered (44B). Gusinskaya et al. separated the nitrogen bases from a series of Sakhalin crudes by ion-exchange and adsorption chromatography, and used IR and NMR spectroscopy to determine their general structure (38B).Brodskii and co-workers continued this study, showing that pyridine derivatives constituted 18-30% of the basic extract, quinoline derivatives 5060%, and acridine-benzoquinolines 12-20%. Most of the heteroaromatic cores were present as cata- or peri-condensed systems with one to three naphthenic rings. The majority of substituted species had one relatively long alkyl chain and several methyl or ethyl groups ( I 1 B ) . Sevast'yanova et al. determined the ratio of basic-to-total nitrogen in 29 Ukrainian crude oils, and the distribution of primary, secondary, and tertiary amines in each sample (88B).

F. C. Trusell Marathon Oil Company, Littleton, Colo.

Sampling. Sampling is often the weakest link in crude oil analysis. The Reservoir Fluids Group of the Chambre Syndicale de la Recherche et de la Production du Petrole et du Gaz Nature1 has recommended procedures for obtaining either surface or bottom-hole samples (81B). Hydrocarbons. Urazgaliev et al. determined the distribution of n-paraffins in 20' and 50' cuts of Mangyshlak petroleum boiling below 510'. They tabulated the physical property data from these fractions and proposed an explanation of the observed pour properties of the oil based on the crystallizing properties of its constituents (95B). Abidova et al. distilled Uzbekistan oils into five fractions boiling below 200' and determined the individual aronfatic hydrocarbons in them by GC. Oils from deeper strata contained substantially more aromatics than shallower oils (2B). Kasamatsu analyzed the diaromatic fractions of three lowsulfur Southeast Asia crudes and six high-sulfur Middle East crudes by GC and by IR spectroscopy, and found 2-monoalkyl naphthalenes, and naphthalenes with one methyl group on each ring were more abundant in the low-sulfur oils (52B). Zhurba et al. employed GC and MS to determine the hydrocarbon-type distributions in the 140-180' and 180-240' fractions of several eastern Ukrainian crude oils, and related their findings to the ages of the containing formations (103B). Kuklinskii and Pushkina have developed a formula for determining adamantane in crude oils based on the IR absorbtivity of a key CH group vibration, and used it in the analysis of 34 USSR crudes. They found the importance of adamantane structures falls sharply in fractions boiling above 300 'C (60B). Garmasheva analyzed the oils from the bitumen fractions of Pripyat Basin crudes. He identified tetralins, indanes, benzonaphthenes, dibenzonaphthenes, and tricyclic naphthenes, and determined the number of carbon atoms in paraffinic chains to ranges from 6 to 20 (29B). Guseva and Chernova separated asphaltenes from several samples of recent sediments by extraction with CHC13 and with EtOH-C&. The asphaltenes were studied by x-ray diffraction, and though they were in the initial stage of diagenesis, they already had aromatic structures similar to those of asphaltenes extracted from crude oils. The asphaltenes

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Fingerprinting a n d Spill Source Identification. The number of papers dealing with this topic has increased substantially since the last review, and a wide variety of analytical techniques has been brought to bear on the problem. Bentz recently reviewed the techniques used by US.agencies for oil spill identification (9B).Brown, Lynch, and co-workers have thoroughly ex lored the use of IR spectroscopy, on both fresh and weathereicrudes, for matching source to spill (12B-l4B, 68B). Kawahara and Yang applied discriminant analysis to IR data to group oils to ether (53B). Lukens characterize! spilled oils by neutron activation analysis, developing a pattern for the distribution of trace elements. He achieved unambiguous identification in the majority of cases (67B). Anbar et al. devised a technique for producing arrays of hundreds of microcones on a porous substrate for obtaining field ionization mass spectra of crude oils. The spectra, consisting primarily of unfragmented molecular ions, differentiate between samples by showing the relative abundance of the sum of the isomers at each mass (5B). Zafiriou and co-workers devised a simple GC method for matching spills to suspected sources, and tested it on samples from Portland and New York Harbor. They claim the validity of the method is only slightly affected by weathering. The rate of successful correlations was 100% if there were eight or fewer candidate oils, but dropped to 50% for 14 oils, and to 27% for 22 oils (102B). Garza and Muth used GC separation followed by dual response detection, FID for hydrocarbons and FPD for sulfur compounds, as the basis for matching s ills to sources (30B).Ilardi identified two spilled oils by G 8 of selected distillate fractions coupled with the quantitative determination of V and Ni in the distillation residue (46B). Jackson and co-workers developed a GC method for fingerprinting crude oils and condensates using only the 232-316' fraction, and demonstrated its utility on a number of Australian crudes and condensates (48B). Wilson et al. analyzed six crude oils, using a variety of analytical techniques, to evaluate the methods as means of identifying oil spill sources. They found GC, AA, and the determination of S and of N to be the most useful (99B).Lieberman artificially weathered crude oils and distillate fractions, and then analyzed the weathered and unweathered samples by GC, low- and high-volta e MS, emission and x-ray spectroscopy, and the Kjeldahl tec nique. Several of the derived indices were sufficiently unaffected by the simulated weathering to allow discrimination between like and unlike pairs of oils (66B). Green and O'Haver compared electronic differentiation of luminescence with respect to time and mechanical wavelength modulation and found the first method simpler in practice. It also gave better resolution of minor spectral features and permitted better fingerprinting of crude oils (32B).John and Soutar elucidated the influences of solvent, wavelength increment, concentration, temperature, and frequency bandpass on the spectra of oils obtained by synchronous excitation spectrofluorimetry, and concluded that this technique, when combined with conventional fluorimetry, showed promise as a tool for identifying oil spills (50B). Pattern recognition techniques have been a plied to the problems of recognizing the sources of oil spills. &ark and Jurs used them with 87 to 100%success in classifying crude oils on the basis of fingerprint gas chromatograms (16B),while Duewer et al. applied them to elemental compositions as determined by neutron activation analysis (25B). Geochemical Studies. Gubnitskii and co-workers analyzed crude oils from 93 wells, representing 11fields of the Baltic region, measuring physical properties, sulfur content, hydrocarbon type distribution, and gasoline yield. High asphaltene and resin contents of some oils were attributed to secondary loss of light hydrocarbons. The light fractions were low in aromatics, believed to be the result of water washing in the lower formations (33B). They also determined the concentrations of a few individual hydrocarbons in several samples and noted that, as the reservoir temperature increased, the ratios of n-hexane to its isomers and of cyclohexane to methylcyclopentane also increased (34B). The most thorough investigation of using the ratios of individual hydrocarbons for showing similarities between crude oils was carried out by Erdman and Morris. They coupled such measurements with determinations of the carbon isotope 232R

ANALYTICAL CHEMISTRY, VOL. 49, NO. 5, APRIL 1977

ratios of the topped crude and of its saturate, aromatic, and asphaltic fractions, the n-alkane distribution, and the oddeven preference to show wehther or not two samples have been derived from a common source (26B). Isaev and Danilov analyzed 48 petroleums from 26 deposits of the Middle Volga region and found the following trends with decreasing age of the reservoir rocks: an increase in the contents of n-paraffins, isoprenoids, Cg and C8 aromatics, and substituted cyclanes a t the expense of mono- and unsubstituted rings. The content of mono-substituted alkanes decreases (47B).Davydov et al. examined 64 samples from this region and were able to distinguish compositional changes during thermal maturation from those brought about by lateral migration and low temperature processes. The former was significant in this region only a t depths below 2000 m (2OB). Danilov and Isaev determined the distributions of n -paraffins in the ligroine-kerosene fractions of oils from 28 fields, and noted the trends observed with increasing depth (19B). Bogomolov and Chikhacheva removed the n - araffins from 26 petroleums of different compositions a n a origins by urea adduction. They used both the absolute amounts of n-paraffins and their distributions in different fractions for genetic classification of the samples (IOB). Vyshemirskii et al. measured the carbon isotope ratios of 101 petroleums and 105 bitumenoids from western Siberia and classified their findings according to geolo ic age and whether the sample had been formed where fount, or whether it had migrated into its present location, and tabulated their observations (97B).Alekseev and co-workers studied the effects of adsorption by rocks and of diffusion processes on the carbon isotope ratios and hydrocarbon com ositions of 21 Mesozoic petroleums, and attributed observes differences to changes brought about by mi ration of some of the oils through rocks Yakovets and Sibokon found they of low ermeability could gstinguish oils of sapropelic origin from those of humic origin. Oil from sapropelic sources contained more CII-CI~ n-alkanes and high molecular weight isoprenoids, while oils from humic sources contained more isoalkanes, and more pristane then phytane (IOOB). Smirnova analyzed the 100 000) from distillation residua which gave IR and ESR spectra similar to those of the asphaltenes of low- and medium-rank coals (45B). Kurokawa and Kondo distilled Khafji atmos heric residue into seven fractions, the heaviest with an en: point corresponding to 733 "C, and a residuum. Each fraction was characterized as to its n- and isoparaffin, naphthene, and aromatic

contents, and they determined that the ratio of saturates to aromatics in each fraction differed little from that of the ori inal residue (63B). !fatter-Zade et al. carried out spectropolarometric studies on Bibieibat (83B)and Ramany (84B)crude oils, and noted that optical activity, after passing through a minimum in the kerosene fractions, increased with increasing boiling point, and was higher for the saturate fractions than for the aromatics. Jackson et al. compared simulated T B P curves from GC using a 10-m capillary column with conventional T B P curves, and found the agreement to be excellent. Differences were easily explicable (49B).Levy et al. describe the modification of the injection port of a GC which facilitates the examination of tars and other viscous and/or high boiling samples (65B). API Research Project 60 has continued to be a source of new methods for analyzing the heavy ends (370-535 OC) of crude oil, and of data concerning the composition of this fraction in a world-wide series of representative crudes (22B,23B, 41B, 42B,93B, 94B). Routine Characterizations.As in previous review periods, there has been a great number of reports dealing with the routine characterization of crude oils by conventional methods. One in particular stands out for its general interest, compiling data from 94 representative crudes from around the world (35B).

Fuels, Gaseous and Liquid J. D. Beardsley The Standard Oil Co. (Ohio) Cleveland, Ohio

Natural, Refinery, and Manufactured Gases. Cardwell (19C) lists the compositions of natural gases of the United States, Canada, Indonesia, and the United Kingdom for 1972 with emphasis on helium. Routine analysis and related source data for 278 United States natural gas samples from wells and pipelines are tabulated for 1973 by Moore (76C).Analyses were made by mass spectrometer and a special helium analyzer. He (77C)also tabulates for 1974 the analyses and related source data for 352 natural gas samples from gas and oil wells and pipelines in 18 states and five foreign countries. A procedure and apparatus for the preparation of natural gas samples for C isotope determination by mass spectrometry are described by Nesmelova and Sokolov (86C).Stufkens and Bogaard (I22C) analyze natural gas by means of gas chromatography, using one, sin le, temperature-programmed column and two detectors (T8D and FID) in series. From the composition, the calorific value can be calculated without any systematic error. A comparison of calculated and measured calorific values of natural gases was made for six Algerian and North Sea natural gas samples by White, Cross, et al. (129C). The calculated values were at least as precise as those obtained by calorimetry and the average difference between the two methods was 2.87 BTU/ft3. A discussion by Lambert and Juren (63C)covers the compositions of typical U.K. natural gases, properties, and impurities; and natural gas processing including removal of hydrocarbon liquids, water, hydrogen sulfide, carbon dioxide, and nitrogen and the recovery of ethane and heavier hydrocarbons. Jones (50‘2) defines gas quality in terms of acceptable standards for internal corrosion control; i.e., H2S, CO2,Oz; and water vapor contents, temperature, and free liquid content. Methods of analysis for the corrosive agents are described. Turowska and Pruszynska (124C) determine down to approximately 1 ppm of C02 by gas chromatography. The separated constituents are passed through a column acked with firebrick covered with a nickel catalyst. At 350 O 8 the CO2 is reduced to methane. The content of COZ is calculated by comparison of peak areas for the sample and for standard mixtures of methane with COS. The theory and technique of colorimetric analysis of fuel gases for impurities such as sulfur compounds, nitrogen oxides, acetylene, phenols, hydrogen cyanide, and others, in total 20 different determinations, is reviewed by Vlckova and Kavan (127C).Afanas’ev, Denisova,

Lomovtseva, et al. ( I C ) have determined microimpurities of hydrogen sulfide in a natural gas flow by gas chromatography. The chromatographic determination of water contents of approximately 1 ppm in natural gas has been achieved by Yusfin, Okhotnikov, Rotin, et al. (134C).Water contents of 40 to 200 ppm in natural gas are determined by Davies (26C) using a modified Karl Fischer titration apparatus. The method was tested on standard water mixtures and agreed well with gravimetric, P205, and dew point procedures. The method is free from interference by light hydrocarbons and methanol. Gokhberg and Ovchinnikova (39C)make a direct chromatographic determination of moisture in natural gas mixtures. Trace amounts of tetrahydrothiophen odorant in natural gas are determined by gas chromatography by Demczak, Gawlik, and Kegel (27C). Gas chromatography is used by Kavan (55C) to determine the odorants dimethyl sulfide and tetrahydrothiophene in natural gas. The impurities of these odorants plus 14 other compounds have been studied. Knight and Verma (56C) have developed a simple low cost field test for mercaptan odorants in natural gas. A metered amount of gas is bubbled through a disposable reagent tube containing N-ethylmaleimide and the red-pink color intensity of the product is compared with a standard color chart calibrated in parts per million of mercaptan. A procedure has been developed by Skorik, Zalkin, and Konyukhov (116C) for a gas chromatographic analysis of a mixture of flue gases from high sulfur natural gas using a single apparatus. Koroleva, Moroz, Khazanov, and Baranovskii (60C) use two gas chromatographs simultaneously to analyze the combustion products from natural gas. Pro erties of liquefied natural gas are calculated by Nanjo, H a r a g , Ono, and Saito (83C).Lyle, Burghard, and Lawler (69C)have developed an instrument to measure the corrosivity of liquefied petroleum gas b means of the increase in electrical resistance of thin (500-& copper film deposited on a glass slide as tarnish products forms. The results are quantitative in contrast to the ASTM D 1838 test which gives only qualitative results. The composition of gas from the catalytic cracking of vacuum gas oil has been studied, using capillary as chromatography, by Alymova, Lulova, and Kuz’mina (46).The method is suitable for all refinery gases. Optyczne (89C)has patented an a paratus for the automatic monitoring of the presence of metfane in air. Aviation Fuels. Shelton (112C)tabulates analytical data for 104 samples of JP-4 and JP-5 military fuels and Jet A, A-1, and B commercial fuels from 15 companies. Correlation equations for calculating hydrogen content and heat of combustion on jet fuels have been evaluated by Angello (9C). Petrovic, Bogojevic, and Vitorovic (94C) contend that determining the temperature a t which 90% of the jet fuels are distilled is a better method for evaluating as compared to quality control based on determining the temperature a t the end of the distillation. The resins present in jet fuel from different USSR crudes were separated by adsorption on alumina and desorbed with methanol and acetic acid by Englin, Alekseeva, Sashevskii, et al. (28C).The varying content and composition of these resins have an important influence on the anti-wear properties and thermal stability of the fuels. Imhof and Worm (47C)have patented a device and method for determining the alcohol content of jet fuel. The alcohol is determined by a color reaction with an 8-hydroxyquinoline ester of vanadic acid (H3PO4). Gel permeation chromatography has been used by Hillman, Paul, and Cobbold (45C)to determine dilinoleic acid and acid phosphate ester in aviation fuels. Taylor (123C)has investigated the effect of trace impurity sulfur compounds on the rate of deposit formation in deoxygenated jet fuel. The results confirm that the ability of rigorous deoxygenation per se to suppress the deposit formation process depends on the type and level of the trace impurity sulfur compounds which are present in the fuel. The Coordinating Research Council (24C) reports that the use of the Alcor Inc. Mark 8A light reflectance instrument for measuring the deposits on JFTOT tubes shows promise that the Jet Fuel Thermal Oxidation Test will replace the ASTM-CRC Fuel Coker as the standard test for determining the oxidative stability of jet fuel. ANALYTICAL CHEMISTRY, VOL. 49, NO. 5, APRIL 1977

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