Anal. Chem. 1991, 63,40R-WR (W) Franklh, 1.C.; A h l y l , W. K. Anal. Chbn. Acta 1988,207,311-317. (M5) Gee, 2.; Li, P.; Dong, S.; Zhao, 2. Anal. Chkn. Acta 1990,232 (2),
367-376. (M6) schdz, F.; N M e , L.; Hsnrion, 0.; Demeschun, F. fresen/us’ 2. AMI. chsm.1989. 995 (2),189-194. (M7) Ruan, x.: Chang, H. rabnta 1989, 36 (ti),1081-1088. (Ma) Fmlng, H.: JCWnsen, E. E. B & ” h b y 1989,8 (3),205-222. (M9)VeHnsky. D. J.; Cutter, 0. A. Anal. chkn.Acta 1990,235(2),419-425. (M10)Revis, N. W.; Osborne, 1.I?.;Sedgley, D.; King, A. Analyst 1989, 114 (7),823-825. (M11) Weres, 0.;Jaounl, A.; Tsao, L. Applied Oeochemlstry 1989, 4 , 543-563. (M12) Fb, J. L.; Fujll, R. Sdl S d . Soc. Am. J . 1990. 54 (2).363-369. (M13) Chao, 1. T.; Senzdone, R. F. So// Sci. Soc. Am. J . 1989,53 (2), 385-392. (M14) chrebel. K. A.; Devis, J. A.; Ledcie, J. 0. WSCi. SOC. Am. J . 1988, 52 (2), 390-397. (M15) Shdkovk. E. R. Chsm. oed.1989, 77,47-51. (M16) Belzlle, N.; Lecomte. P.; Tessler, A. Envkon. Sci. Techno/. 1989,23 (a), 1015-1020. (M17) Abyi, S. 0.;Vanloon, 0. W. Scl. Total fnviron. 1989, 87-88 171-187. (M18)Nirel. P. M. V.; Morel, F. M. M. Water Res. 1990,24(8), 1055-1056. (Ml9) Beverldge, A.; Waller, P.; Plckerlng, W. F. Talent8 1989, 36 (5), 535-542.
(M20) Beverldge, A.; Waller, P.; Pickwing, W. F. Tabnt8 1989. 36 (12). 1217-1225. (M21) Slavek, J.; Pickering, W. F. Water, Ak, Sou pokmron 1989. 45, 63-75. (M22) Slav& J.; Waller, P.; Pickerlng, W. F. Tabnta 1990,37(4),397-408. (M23) Leventhal, J.; Taylor, C. f38ochh. Cosmoch&n. Acta 1990, 54, 2621-2625. (M24) HwKtaDlaz, M. A.; Morse. J. W. Mer. Chem. 1990, 29 (2-3), 119-144. (M25) Kong, P.; Chai, C. Chem. oed.1990, 82(1-2), 51-56. (M26) MetelSpechthm: Theory, Am&&, 8ndAppUcetkn; Kramer, J. R., Allen, H. E., Eds.; Lewis Publ.: Chelsee, MI, 1988. (M27) Trace Element SpecbrrW,: Ana&thl Methods and Robhsms; Batby, G. E., Ed.; CRC Press: Boca Raton, FL, 1989. (M28) Lund, W. fresenius. J . Ami. Chem. 1990,337(5),557-564. (M29) Mrd. F. F. pkme Gy‘sS8Theory and S S mR8-i CRC Press: Boca Raton. FL. 1989;Vols. 1 and 2. (M30)Newmen, M. C.; Dlxon, P.M.; Looney, E. E.; Pinder, J. E. Water ResOW. Bull. 1989, 25 (4),905-915. (M31) Nielson. K. K.; Rogers, V. C. Anal. Chem. 1989. 61(24),2719-2724. (M32) Haas, C. N.; Scheff, P. A. Envkon. Sci. Techno/. 1990, 24 (6). 912-919. .. - .. . (M33) Travis, C. C.; Land, M. L. Envkon. Sci. Technd. 1990, 24 (7), 961-962. (M34) Heisel, D. R. Envkon. Sci. Technol. 1990,24 (12),1766-1774.
Petroleum and Coal Tim R. McManus Marathon Oil Company, Petroleum Technology Center, Littleton, Colorado 80123
INTRODUCTION This review covers literature published between Oct 1988 and Oct 1990 and was compiled using abstracts obtained from a computer search of Chemical Abstracts. In addition to the usual subject of petroleum, this years review also covers coal and coal products. The organization of the review has been changed from the 1989 review ( A l ) in order to simplify the review process. This year the literature will be categorized as (B)coal, oil shale, (C) crude oil, shale oil, coal oil, (D) rocessed fuels, (E) lubricants, and (F)asphalts, pitches, tars, itumen. Also, far more emphasis has been laced on literature published in English. This change {as to do with concerns that much of the literature referenced in the past issue was not available to the majority of analytical chemists.
E
COAL AND OIL SHALE Jane V. Thomas
@yotMgAna&thl Labuatmk, Inc .. Laramb ,
82070
COAL Temperature- rogrammed vacuum pyrolysis together with time-resolved sol! ionization mass spectrometry identified two devolatbtion steps of coal ( B l ) ,with yields and compositions of the thermally extracted coal products bein dependent on rank, coal type, and status of weatherin ;artilcial weathering of the coal under careful1 controlled faborator y conditions indicated a rapid loss of tgermally extractable mobile phase com onents accompanied by a decrease in total pyrolysis yie1d)s. Pyrolysis-field ionization mass spectrometry of coal was used to provide information on the chemical nature of species that contain rotons detected by NMR experiments as mobile protons d 2 ) . Coupling thin-layer chromatographywith diffuse reflectance FT-IR s ectrometry was used to analyze coal extracts from three diPferent coals to provide information on the structure of coal (B3). In characterization of coal liquids by preparative-scale liquid chromatography and automated thin-layer chromatography,a ood separation of saturated aromatics and bases was achievef (B4). By using solvent extraction methods for the analysis of hydrocarbons in 29 coal Sam les from the Ruhr and Saar district (Federal Republic of Jermany), a close relationship 40 R
OOO3-2700/91/0363-48R509.50/0
between the composition of the extracts and the carbonization pro erties was revealed (B5). &e structural characteristics of asphaltenes from the liquefaction of 26 high-sulfur coals and their parent coals (B6) and the data used to help define the chemical processes involved in liquefaction were studied. In a study of the correlation of bituminous coal hydroliquefaction activation energy with fundamental coal chemical properties ( B n , direct evidence of the importance of ether cross-linking structures for the determination of hydroliquefaction reactivity was provided. Alkaline size-exclusion chromatography was used to determine the molecular wei ht distributions of lignins and lignite extracts using cross-finked dextran els, Superose columns calibrated with alkali-soluble standarcfpolymers, and low-molecular weight acidic compounds (B8). The pyrolysis process and microstructure of coke residue of thermosetting resins, h drolytic lignin, pitch, and/or tar were studied by using D T I and X-ray diffraction techniques (B9). Curie int pyrolysis/mass spedrometry in combination with factor gcriminant analysis was determined to be a fast and reliable method to characterize and classify a large colespecially when lection of coals according to their rank (ElO), used along with conventional analysis. Analytical Curie-point pyrolysis/gas chromatography was used as a tool to characterize key parameters relevant to coal reactivity (B1I ) , such as coal rank, thermo lasticity, and the addition of a catalyst. Supercritical fluitfchromato raphy on a capillary column coated with a smectic mesoxnorpficcrystalline phase exhibited a typical turnover effect for retention v9 column temperature for polycyclic aromatic hydrocarbons at lower temperatures than are found on a liauid crvstalline (methvlDolvsiloxane) -. stationary phase (B12j. Carbon-13 N M R s e a l studies of the dewlvmerized coal obtained by acidic phenolation showed that’ t h i de 01 ization reaction proceeds effectively within lignites ( l 1 3 y E i this reaction was used for conducting the or anic chemical structural studies of low rank coals. A series ofles taken from the cross section of a 3-m-diameter fossilizeCY gymnospermous log, Araucariaceae, in the Yallourn Seam of the Australian brown coals was examined b solid-state carbon-13 NMR to delineate chemical changes reyated to the combined proceases of peatification and coalification (814). The residues
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compounds within a given functional grou class, as well as for the separationof the shift ranges amonge!t various classes. The nature of hydroxyl group in cod extracts was investigated by silicon-29 NMR INEPT spectroscopy following trimethylsilylation (BI 7)and found to be largely quantitative. Isothermal pyrolysis studies were conducted on an Illinois No. 6 and a Wyodak coal at 375,400, and 425 "C (B18), and the amount of coal converted to tar, gas, and residue was determined for different reaction durations at each temperature; solid- and liquid-state carbon-13 NMR techniques were used to characterize the residue and tars produced during varying stages of pyrolysis. Solid-statecarbon-13 NMR studies of coal char structure evolution during pyrolysis showed that extensive loss of aromatic ring bridge material precedes significant change in aromatic cluster size (B19);during pyrolysis, aliphatic rich material is preferentially expelled as tar and light gases. On-line multielement analysis of coal slurries using a direct current plasma was used (B20)to develop a method for the determination of sulfur; the recovery of the signal for coal slurries was reproducible but less than 100%. The determination of major, minor, and trace elements in coal slurries was with slurry atomization direct current plasma atomic emission spectrometry (B21),with attention being paid to preparation of the coal slurries. Good precision and accuracy were reported for the direct determination of beryllium in coal slurries using graphite furnace atomic absorption spectrometry with an autosampler modified by incorporating magnetic stirring of the samples (B22). Organic geochemistry and organic petrology were used to determine the petroleum-generating potential of coal in the Ardjuna Basin of northwest Java (823). Carbon-rich solid products from a Texaco coal gasifier were analyzed by flash pyrolysis using an electrically heated grid technique (B24). Mass spectra indicated that the tars contained only relatively light alkenes, dienes, and alkylphenols. The distribution was the result of a double pyrolysis. Several review articles appeared in recent literature: 167 references in a review of the a plications of DTA and DSC to coal and oil shale evaluation 15 references in a review on high-resolution solid-state carbon-13 cross-polarization dipolar-decoupling, magic-angle spinning NMR of coals, macerals, and solid products derived from coal conversion (B26);82 references in a review on carbon-13 NMR techniques including cross-polarization and magic-angle spinnin with high-power decoupling, dipolar-dephasing sidebanf suppression at high magnetic fields, dynamic nuclear polarization, and combined rotation and multiple-pulse spectroscopy (B27). There were also reviews on solvent swelling of coals viewed as a covalently cross-linked 3-dimensional macromolecular network (B28)with 57 references, on the possibility of the characterization of coals by separation of a liquid hase in a heated centrifuge (B29) with 32 references, a n f o n the fundamental measurements of the pyrolysis rates and combustion behavior of pulverized coals (B30)with 15 references.
Tbn R. McManua Is employed at Marathon Oil Company's Pebdeum Technology Center as an Advanced Chemist in the AnatytC cal Services Department. Tim received his B.S. degree in 1980 from the University of North Texas and Is currently working toward an M.S. degree at the University of Colorado at Denver. His current function at Marathon Is as an analytical chemist swing exploration, production, refining, and marketing o p erations.
Tho" WotnlngAnalytblLaboretories, Inc..
Jlrm V.
Laramle, WY
6%);
R. J. Trodno Texam, Inc., Baacon, NY
OIL SHALE
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Jmnos R. C0up.r
of hexane extraction of a highly volatile bituminous coal, retreated under the conditions of the first stages of hydroEquefaction, were studied by solid-state, high-resolution carbon-13 NMR and FT-IR (B15).Six chlorophospholanes were evaluated as phosphorus-31 NMR tagging reagents for labile hydro en functional groups in coal materials, (R16); iodine was lemonstrated to be the best for resolving the phosphorus-31 NMR chemical shifts of a variety of model
Interest in shale oil is increasing, but not in time for many more articles to be included in the current review. Just wait until next time! Characterization of selected oil shales was the subject of several papers. Chemical and petrogra hic characterization of the Australian Tertiary Duaringa oil stale deposit (B31) was accomplished by using Rock-Eval, total organic carbon, elemental analysis, and infrared spectroscopy to investigate gross chemical features, and pyrolysis/gas chromatography to determine the yield and composition of the hydrocarbons evolved during the thermal breakdown of the isolated ker ens. Organic-carbon-rich black shales from three different Zretaceous episodes sampled during Ocean Drilling Program Leg 103 were studied by organic geochemical methods (R32): Rock-Eval analysis, carbon isotope data, and lipid biomarkers showed organic matter to contain varying proportions of marine and continental materials. The concept of functional group analysis was used for the characterization of organic functionalities in Brazilian oil shales (B33);this consisted of solid-phase functional group analysis, solid-phase functional group extraction, and solid-phasefunctional group marker incorporation. Oil shale beds from the Stellarton Basin, Nova Scotia, were characterized by using macroscopic and microscopic ANALYTICAL CHEMISTRY, VOL. 63, NO. 12, JUNE 15, 1991 49R
PETROLEUM AND COAL
fluorescence roperties of the or anic material and by Rock-Eval anefysis techniques (8348; the fluorescence pro erties of these alginite-rich oil shales are re orted. T i e chemical and physical properties of a Tipton hfember Green River Formation oil shale from Wyoming were measured and reported (B35);this shale was designated as a reference oil shale by the De artment of Energy. The yields, etmental analysis, acidity, IR spectra, UVvisible spectra, X-ray diffraction, and the pK, values of h-ic acids isolated from Jordanian oil shale by two extraction procedures were studied (B36),and earlier conclusions were confirmed that there are two t es of carboxylic rou s in addition to a phenolic group. %e alginite in the hoo8ford Shale of the Permian Basin, Texas-New Mexico, was studied by a picosecond fluorescence microscopy technique (B37); indications are that the higher peak, more mature samples have shorter component lifetimes, which may explain the lower fluorescence intensity observed with increasing rank. The decay of "Re to lm0swas used for determining de es of the Bakken Shale, a Mississip ian/Devonianc$g 8ack shale of the Williston Basin ofkorth Dakota (B38);the application of the rhenium/osmium system to black shale geochronametry is discussed, The combustion kinetics of five Australian spent oil shales were measured at temperatures from 600 to 900 OC in a fluidized bed (B39),with continuous analysis of the flue gas being used to determine the progress of the reaction. Stepwise pyrolysis/p chromatography was used in the examination of pyrolysis behavior of Colorado (USA),Condor (Australia),Timhadit (Mor"), and Maoming (China) oil shales (B40);the yield and composition of pyrol zates varied with temperature. kalysis of hydrocarbons thermally mobilized from two oil shale and three coal samples of different rank by on-line combination of thermodesorption, gas chromatography, and mass spectrometry provided information of or anic geochemical significance (B41);the method describecfproved to be of particular importance for the detedion of those volatile constituents in coals and sedimentary rocks that are not usually recovered during elaborate workup procedures because of lmes due to evaporation. Differences m the rates of change of the ratio 20S/(20S+ 20R) of the 24-ethylcholestane diastereomers in coals and shales indicate that the processin causing these changes is influenced by the nature of the roc matrix (B42), and measurement of the 20S/(20S+ 2OR) sterane diastereomer ratio provides a means for assessing the maturity of sediments and crude oils. The hydrocarbon-secretin@,planktonic green alga Botryococcus was identified in organic remains of sediments ran ing from Precambrian to Recent and is considered likely to %ea major source material for petroleum generation throu hout geologic time (B43); maturation/ thermal effects on Jginite were established by reflectance and fluorescence and compared with experimental results.
CRUDE OIL, SHALE OIL, AND COAL OIL D. L. sutton klemthon 011 Cwnpeny, Lmkton, cokredo 80180
Advances in analytical instrumentation over the past few years, particularly in the area of mass spectrometry, have provided etroleum researchers with increasingly powerful tools fore!t characterization of fossil fuels. The application of biomarkers to exploration research continues to be a growing area as does the elucidation of sulfur compounds in crudes. As always, decisions regardin what category a particular article should appear in are dificult. This section has been divided into three main subsections-crude oil, shale oil, and coal oil. While most of the articles focus on one of these three general areas, some emphasize an analytical scheme and apply it to a variety of fossil fuels. Articles of this type have been included in the crude oil subsection.
CRUDE OIL Exploration. Biomarkers. Chemical biomarkers as a tool in petroleum ex loration continues to be an area of great interest. ThougI most of the publications concentrate on specific compounds or geographic areas, the following seven articles address analytical ap roaches that can be applied to biomarker analysis in generay. Hwang discussed biomarker SOR
ANALYTICAL CHEMISTRY, VOL. 63,NO. 12, JUNE 15, 1991
anal is by using a GC-mass selective detector and compared res& to a more expensive research grade instrument ( C l ) . The ion trap detector (ITD) was also evaluated and Philip et al. illustrated the use of the ITD as a relatively inexpensive system for biomarker analysis (C2). Use of tandem mass spectrometry was addressed by other authors (C3, (74). Harriman et al. compared techniques for lectivity of the mass spectrometer when centrations of biomarkers (C5). Because is deposited in the column inlet of the GC when performing biomarker analyses, Castro et al. wrote concernin the use of retention gaps with cold on-column injection ( 6 ) . Other research examined applications of quantitative biomarker analysis (C7). Researchers compared the distributions of polycyclic alkanes in an unaltered oil and a severely biode aded oil from the K e b y i field in NW China (C8). Fan a n f k n g studied the origin of nonmarine oils in China in order to establish effective models for reconstructing paleoenvironmenta (C9). A review article addressed biomarkers in petroleum and source rocks of a terrestrial origin in China (CIO).A series of novel C&32 tetracyclic triterpanes based on the lanostane skeleton were identified for the first time in Eocene lacustrine deposita of Biyang Basin, China ( C l l ) . Crude oils and condensates from the J a anese Neogene Tertiary sedimentary basins were anal e for steroid and triterpenoid hydrocarbons by GC/MS &2). In contrast to moat GC/MS work which utilizes fragment ions, Lin et al. analyzed major hopane-type triterpanes in Arabian heavy oil by using molecular ions (C13). Biomarkers were used to predict crude oil quality (API avity) of samples from California (CI4)and North Slope A k a , the Gulf of Mexico, and the North Sea (CIS). Peters et al. studied the origin of Beatrice oil in the North Sea. They concluded that the Beatrice petroleum ori inated by mixing of bitumens from the Devonian and Midfle Jurassic source rocks at a ratio of 6040, respectively (C16). The distribution of regular ateranes, tricyclic and pentacyclic terpanes, and aromatic steroids in conjunction with other geochemical information was employed to analyze sam les from the Monterey formation, Santa Maria Basin (CI7). iiomarkers and carbon isoto es of oils in the Jurassic Smackover Trend of the Gulf Coast &des, USA, were determined in order to estimate maturities and migration distances (CIS). A series of novel methylated hytanylbenzenes were identified in sediment extracts and 01f 3 ranging in age from Miocene to Permian (C19). Various biomarkers (steranes, terpanes, and hopanes) were used to assess natural seep oils from Parsons Pond, Western Newfoundland (1220). Cassini and Gallango anal zed crude oil in reservoirs from the Oficina (Miocene) $ormation, Venezuela, and concluded that there was an accumulation of marine oil followed by a later accumulation of terrestrial oil (C21). Saturated (e.g., labdanes) and aromatic (e.g., naphthalenes, phenanthrenes) biomarkers derived from resins of the Arauceiriaceae were determined to distinguish crude oils of Eromanga Basin sediments from those of the underlyin Coo er Basin formations (Australia) (C22). Natural an8 synt\etic liquid fuels were examined b GC/MS in order to com are the different biomarkers (823). 2,2,7,8-Tetrametfyl-lI2,3,4-tetrahydronaphthalene (which is regarded as a biological marker specific for an 'osperms) was synthesized and identified in Cretaceous segments and crude oils by GC/MS (C24). Weston et al. studied biomarkers in the saturated hydrocarbon fraction of seep formations from the northern half of the East Coast basin, New Zealand (CW), while various ter ane and sterane biomarkers from the Taranaki Basin of J e w Zealand were also analyzed (C26, C27). Source correlation and maturity assessment research were conducted on sam les from the Central Adriatic Basin of Italy and Yugoslavia (8281, Brazilian mar inal basins (C29),and a Palaeogene salt formation in the resse region of France (C30). Abundance and distribution of o hyrins in selected Gulf of Suez crudes were examined ( 8 3 3 . Oil maturation and reservoir temperature were found to be the main factors controllinn vanadvhomhvrin distribution in the studied oils. Metallo hhy& 6 \len&uelan crudes were also investigated (C32, &) A paper by Brakstad and Grahl-Nielson demonstrated the use of biomarkers for identification of weathered oils (C34).
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PETROLEUM AND COAL
They studied crude oils that were weathered for 1year from the Cook and Brent formations in the same well in the Gullfaks field in the North Sea. GC/MS of sulfur heterocyclics combined with sterane and triterpane fingerprinting were utilized to examine and differentiate North Sea crudes (C35). Other. Eighteen oils from different oil producing basins in China were characterized by a variety of organic geochemical techniques including organosulfur compounds, biomarkers, and carbon isotopic composition of the aliphatic and aromatic fractions (C36). Or anic sulfur compounds present in 16 immature samples 0th oils and bitumens) re resenting different paleoenvironments were analyzed by GCffMS (C37). Schou and Myhr investigated the relative concentrations of sulfur aromatic compounds in crude oils and kerogens from the North Sea as maturity parameters (C38). Stable isotope eochemistry of crude oils and poasible source rocks from the " k i , East Coast, West Coast, and Great South Basins of New Zealand was conducted. Both carbon (C39)and sulfur (C40)isotopes were evaluated. Isotope eochemistry was em loyed to evaluate samples from the baiyanjing field in Ctina (C41),the National Petroleum Reserve of Alaska (C42),and the Taranaki Basin of New Zealand (C43).Thompson et al. reported that five groups of petroleums could be recognized in offshore Gulf of Mexico on the basis of carbon and sulfur isotope ratios, sulfur content, and the abundance of nickel and vanadium (C44).A 3-dimensional appraisal of geohistory was used to draw conclusions concerning petroleum generation in the area. Organic inclusions contained in sam les from various Chinese fields were studied and classified h45).The authors found that the t es and peculiarities of these organic inclusions are usefyindicators of oil and gas mi ration, evolution, and prospedive evaluation. Fourier-transkrm infrared (FT-IR) microspectroscopy was utilized as a rapid nondestructive technique for the analysis of petroleum fluid inclusions in natural mineral samples (C46,C47). Comparison of FT-IR spectra of inclusions with spectra of bulk oil samples from the same well or reservoir can provide constraints on the maturation and fluid flow history of the oil. Hetenyi used the 0 index, determined by Rock Eva1 pyrolysis, as a method for determinin the organic matt,or maturity in the diqenesis stage (C48).kadke published a review of the application of aromatic com ounds as maturity indicators in source rocks and crude o i i (C49).Three different oils were artificial1 matured and their hydrocarbon distributions evaluated 6 5 0 ) . The authors found that the maturity-dependent steroid ratios change in the same direction with heating in nature, but rates of change vary among specific ratios. Researchers applied sterane isomerization and steroid aromatization data to petroleum ex loration and the reconstruction of geothermal histories ($51, C52). Geochemical correlations were made between tar-sand bitumens and etroleums roduced from various formations in the Pauls Vdey area of Jklahoma (C53). The relation between molecular structure and the fluorescence spectrum of oils and rock extracts was studied, and the influence of maturation and biodegradation on the fluorescence characteristics was evaluated (C54).Organic carbon content, hydrocarbon content, visual kerogen, and vitrinite reflectance were used to evaluate source rocks from the National Petroleum Reserve in Alaska (C55). HPLC and a cluster analysis technique were used to achieve source rock correlation for crudes from different locations and depths (C56).Detailed light hydrocarbon compositional data were gathered on 29 core samples from the Ravnefeld Formation source rock of East Greenland (C57). The objectives of the study were to determine if changes in the light hydrocarbon composition reflect generation patterns or are controlled primarily by redistribution processes and to discuss possible modes by which hydrocarbon redistribution took lace. Espitalie et al. described the results of a study of ydrocarbon migration in the Paris basin (C58).Evaluation of helium concentrations in near-surface soils was used as a eochemical exploration tool for work in North Slope, Alaska C59). The technique is especially applicable to the Arctic environment because it is relatively inexpensive and environmentally nondestructive. Production and Refining. Wellington and Richardson described a process for determining the residual oil saturation in a reservoir using 14C labeled carbon dioxide (C60). A
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correlation, with engineerin accuracy, was developed for determining the density of COz/crude mixtures (C61). High- ressure PVT and viscosity measurements were conductefon North Sea crudenatural gas liquids rmxtures (C62). Kwan et al. reported on a pulse-deca technique for the measurement of heavy oil core fluid mogilities and porosity. The method was a plied to the analysis of a sand ack and preserved Cold La&e heavy oil core plugs (C63).ehemical characterization of crude recovered by using combustion techniques was described (C64,C65). Singh published a review with 43 references comparing methods of classification of crude petroleum based on physicochemical and chemical parameters (C66).He also discussed recent developments on structural parameter determination by NMR. A method for determining the fouling tendency of crudes was developed and used to predict the amount of antifouling agent needed during downstream processing (C67). Compound Characterization. The articles described in this category focus on the analysis of crude oil for a particular compound or class of compounds. Metals. Various researchers described extraction and spectrophotometric determination methods for vanadium in crude oil using mandelohydroxamic acid (C681,5-bromosalicylhydroxamic acid (C69),and quinaldohydoxamic acid (C70).The redox reaction with Nuclear Fast Red (aminoanthraquinonesulfonate acid dye) was the basis for a spectrofluorometric method for vanadium in crude (C71).Saudi Arabian crude oils were analyzed for trace metals using an inductively coupled plasma combined with a mass spectrometer (ICP/MS) (C72).Ten Mid-Eastern crudes were analyzed for V, Ni, Fe, Mg, Co, Cr, and Cu by using X-ray fluorescence (C73).Ni and V were determined in heavy crude oils by flame AA after dry ashing/acid dissolution (C74).Vanadium was found to be equally distributed between the porphyrinic and non-porphyrinic forms, while nickel was more prevalent in non-porphyrinic complexes. Flow injection flame AA was employed to determine lead in heavy oil (C75). Other. Several homologous series of monocyclic thiolanes and thianes possessing a linear framework were identified in a variety of petroleums (C76).Sinkkonen reported on a liquid chromatographic determination of planar sulfur compounds in crude (C77).A radio frequenc plasma detector was employed for the sulfur selective cap&ary GC anal is of various fossil fuels including crude and coal liquids ($8). The accuracy and sensitivity of the potentiometric determination of total sulfur in petroleum was investi ated by Farroha and Habboush (C79). Sulfides in some 8anadian crudes and fractions were examined by spectrophotometric techniques (0, C81). Williams et al. studied crudes from a Midland Basin reservoir and a Michigan Basin reservoir and found anomalous concentrations of specific alkyl aromatic and alkylcyclo araffin compounds (C82).They then performed a series of eating experiments to simulate naturally occurring reactions. The retention behavior in reversed- hase LC of all 25 dimethylphenanthrene isomers was stu8ed and a lied to the identification of these compounds in crude (833).GC-matrix isolation infrared spectrometry (GC-MI-IR) was applied to the identification of Cz na hthalene isomers. This family of compounds cannot be difgrentiated by GC-MS but can be identified by GC-MI-IR (C84). Twedimensional GC was also applied to the analysis of alkylnaphthalenes in crudes (C85). In a Western shale oil > tar sand liquids. Practical criteria for classifyin ker ens from pyrolysis were published (F122). Routinel de! lning O f er en types according to not only genetic potentid but also to %e ease with which precursors were released during pyrolysis was a step toward unifying ker en eochemistry and petroleum geochemistry. The relations 'p %etweenreactivity and structural parameters for yrolyzed and hydropyrolyzed coal asphaltenes and preaspdtenes was presented (F123). Decreased reactivity correlated well with increased C content and with increased condensation as measured by NMR.
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MISCELLANEOUS Hydrotreat' of coal li uids and heavy petroleum fractions was reported%24-F12& In the first article, a two-staged hydrotreating operation was found to be more effective than a single-staged unit as noted by increased yields of distillates, improved denitrogenation, and longer catalyst activity. In the second study, bitumen-derived coker and hydrocracker hea gas oils were hydrotreated. A good relation between t h e 3 and N contents of light oil and heavy as oil cuts versus those of the total roduct was obtained. f n the last study, Wilmington a n t Mayan crude oil residues were hydrotreated, acid-base-neutral fractionated, and characterized. In both crudes, the strong acid fractions were the most resistant while the Mayan weak acid fraction was more resistant than the Wilmington weak acid fraction. The base fractions converted to other types more easily than the acid fractions. Differential scannin calorimetry (DSC) and thermal gravimetric analysis (TGA! were used to follow 0 chemisorption of coal chars (F127). Rates of both heat release and weight increase enerally decreased with increasin rank of the oranalysis iginal c J . The simultaneous of kerogen showed that by these methods it was possible to arrive at conclusions on the ori of the source and the degree of kerogen transformation (p;" 128). From a TGA study of hydrocracked petroleum vacuum residues, linear relationshi could be established between the average molecular weig t of the oil and the temperature at which 5% mass loss took place and the Gibbs free energy (FI29). A TGDTA method for comparin the thermochemical properties of hi h-boilin fractions a n t residues of a Siberian crude was evelope (F130). This method allowed quick determination of characteristics depending on the grou compositions of the high-boiling fractions and residues. konisothermal thermoravimetry was used to compare thermal reactivities of N Eeterocompounds and aromatic hydrocarbons durin the carbonization of coal tar itch (F131). Although t i e N heterocompoundsenhancefthermal activity compared with aromatic hydrocarbons, the enhancement was not as large as previously believed, which might re uire reassessment of the influence of heteroatoms on the mec anism of carbonization. TG and DSC were used to study the hydrocracking reaction of heavy petroleum residues and products of hydrocracking (F132). Arrhenius kinetic constants of the pyrolysis reactions were obtained and correlated with the concentration of heteroatoms in the residues. Data on decompition temperatures
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63,NO. 12, JUNE 15, 1991 5 g R
PETROLEUM AND COAL
as well as variations in the specific heat and glass transition tem ratures of pitch samples were reported using TGA and DS(%echniques (F133). Viscosity and other physical properties of heavy and extraheavy crudes as well as bitumens were the subject of a .study (F134). Viscosity and density were predicted by simple correlations that require the knowledge of a single datum at a reference temperature. Hydrodynamic measurements were used to determine the size and conformation of bitumen fractions (F135).Intrinsic viscosity, molecular weights, and diffusion coefficients were generall in good agreement with other measurements;however, in t e diffusion experiments, association between constituents was believed to ex lain exand perimental differences. Vapor pressure osmometry 08’0) viscometric techniques were used to reveal the true molecular we1 t of asphaltenes and the degree of association in solvents of ifferent polarities at different temperatures (F136).The data consolidated the recognition that asphaltenes could be structurally similar to macromolecular compounds. A oneparameter correlation for bitumen viscosity was re rted,and the results indicated that an average standard &ation of
