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Experimental factors which may cause wide scatter in data include particle size and shape, and changes in the atmosphere during reaction. Habersberger (43G) also reviewed catalytic applications of thermal analysis, and described studies of catalyst preparation, deactivation, and poisoning. Kosak (61G) used differential scanning calorimetry as a screening test for noble metal hydrogenation catalysts. T h e heat of chemisorption of hydrogen was correlated with activity for hydrogenation of aromatics and nitro compounds. The same measurements gave a dependable indication of catalyst selectivity in specific cases. Sinhamahapatra and Sharma (113G) used magnetic susceptibility and isothermal gravimetry to study Co-Mo-A1203 with and without added sodium. Metallic Co was formed during reduction of catalysts containing Na in the support and this metallic cobalt accelerated the reduction of Moo3. In the absence of Na, Co inhibited molybdena reduction because of the retention of product water by Co2+. A DTA/TGA investigation of the Co-Mo-A1203 system, reported by Ratnasamy et al. (103G),also indicated that Co inhibits the formation of MOO,; and thus enhances sulfur uptake during sulfidation. The Ni-Mo-A1203 system was investigated by Irisova et al. (50G), who used thiophene conversion a t 400 "C as a measure of catalytic activity, and DTA TGA to characterize the active solid. I t was concluded that iMoO, was the phase predominantly responsible for hydrodesulfurization activity. Mulay et al. (83G) determined magnetic hysteresis curves on commercial methanation catalysts containing 43 and 67 3' % Ni on A120J heat treated at 499-700 "C. The resultant coercive force, remanence, and magnetic saturation of the catalysts were related to the properties of the nickel particles, which in turn were correlated with catalytic activity. Wentrcek and Wise (134G) varied the Mo:S ratio in a molybdenite crystal in H2/H2Sa t elevated temperatures and compared electrical conductivity measurements with the catalytic activity for olefin hydrogenation. With a crystal exhibiting initially n-type conductivity, the introduction of S2-ions eventually led to a p-type conductor. A pronounced increase in olefin hydrogenation activity accomanied the change.
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Physical Properties N. W. Lambert Union Oil Co . of California, Science and Technology Division, Brea , California
Distillation. In the analysis of the relative errors involved in attempting to measure the number of theoretical plates in a continuous distillation column, Mussche and Verhoeye (5OH) derived a general error function which enables examination of the effects of heat of vaporization, relative volatility, and internal reflux ratio. In estimating the number of theoretical trays required for a given change in composition in a continuous rectification column, the accuracy of the estimate is found to be mainly determined by the accuracy of the internal reflux ratio and the analysis of the samples. Schwanke et al. (60H) described in detail the problems encountered in the application of optimal, multivariable control theory of distillation column. Prokofeva and Molokanov (57H) presented a calculation method for determining the concentration of contaminant fractions in distillates based on the composition of the starting material, boiling points of its components, pressure during the distillation and the number of theoretical plates (N). The method was used to estimate the required N for obtaining the required purity of distillate. Douglas and Seeman ( 1 O H ) derived an approximate analytical solution for distillation columns which can be used for obtaining rapid estimate of distillation economics, for developing steady-state column control to eliminte overfractionation, and for making preliminary estimates of problem solutions. Zhukhovitskii et al. (79H) described a method for separation of mixtures based on distillation under chromatographic conditions (chromatodistillation). The mixture to be analyzed is carried by the carrier gas on to a column packed with inert material such as steel beads, the column temperature decreasing from the inlet to the outlet. In a second paper (78H), the authors used an empty copper capillary tube ( 5 m x 0.2 mm) in the
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form of a spiral (15 mm in diameter) to apply the principle described above. Green (19H) reported that the gas chromatographic method ASTM D2887 gives T B P (true boiling point) distillations for all petroleum fractions with a final boiling point 5538 "C and with a boiling range 255 "C. Ford et al. (14H) proposed two methods for the correlation of ASTM D2887 with ASTM D86 distillation data. One uses a multiple linear regression analysis and the other a series of equations relating the slopes of selected segments of the two boiling range distillation curves. Using a low resolution, or capillary, gas-liquid chromatographic technique, DeBruine and Ellison (9H)predicted Reid vapor pressure of hydrocarbon mixtures by the use of a simple linear equation which gave results within reproducibility limits in 95% of the nearly 80 samples evaluated at 5-14 psi. Almost the same Derformance was obtained in the prediction of ASTM D86 distillation data. Jackson et al. (27H) reDorted that simulated distillation of crude oils by gas Chromatography in a short capillary column coated with OV-101 results in boiling point distribution which compares well with conventional T B P curves. The column described is 10 m X 0.25 mm and is temperature programmed from 10 to 350 "C at 20 "C per min. Hickerson (25H) compared the boiling range distribution of three types of narrow boiling petroleum products when determined by ASTM D2887 (gas chromatography) and ASTM D2892 (15 theoretical plate column). On wide boiling samples, the results agree well. McTaggart ( 4 1 N ) described similar work on three crudes, two involving the use of an internal standard and the third using a miniature flash still. Gas chromatography was used by Svob et al. (70H) for simulated distillation of gasoline boiling >200 "C where the stationary nonpolar phase was squalene on Chromosorb P 6 0 / 8 0 , the column temperature was room temperature, and the cryogenic unit was not required. Montoya and Leung (48H.49H) described a multichannel chromatography data system in which up to 16 chromatographs a t different locations share a central processing computer. Mikkelsen and Green (47H) discussed user programmability in a comupter-based data system. The results of an in-depth study of the calibration and calculation procedures used for gas chromatographic distillation of gasoline are presented as an illustration of the capabilities available through user programmability. Vapor Pressure. A nomograph based on Riedel's correlation was presented by Zanker (7,5H)to predict the vapor pressure of a compound from its normal boiling temperature at 1 atmosphere, and the critical pressure and temperature. An accuracy of *5% is obtained through use of the nomagraph. An equation to predict the Reid vapor pressure of gasoline was derived by Luskin and Morris ( 3 9 H ) ,based on capillary gas chromatography data. aromatic content, and hydrocarbon activity coefficients. A comparison of calculated and determined data shows a standard deviation of 0.15 over the range 1.6-15.4 psi. Palmer (54K) described an improved computer procedure for predicting the vapor pressure of petroleum fractions, and Grabinski (2ZH) reported on the linear dependence of oil evaporation mass rates on the oil saturated vapor pressure. A method and apparatus for determining the saturated vapor pressure of jet fuel was described by Gorenkov and Belous ( 1 7 H ) , and the saturated vapor pressure of lubricating oils and lubricating oil additives was determined by Bryanskaya et al. ( 6 H ) using a chromatograph with a flame ionization detector. Rheology. In the area of rheology, Bestougeff e t al. ( 3 H ) discussed three methods for determining viscosities of bitumens: (1)Haake Rotovis (rotating viscosimeter with coaxial cylinders); ( 2 ) Kepes (cylinder and cone-plate microconsistometer); and (3) Instron (capillary forced flow viscosimeter). McLachlan ( 4 2 3 described a high pressure viscometer which is capable of measuring viscosities (lo6 P a s. The instrument consists essentially of a high pressure linear, variable, differential transformer (LVDT) which is used to detect the free fall of an unguided cylinder with a coaxial hole. The motion of the cylinder is recorded automatically by triggering the output of the LVDT, which is sensitive to changes in distance of 2 pm. Measurements on a polymethylphenylsiloxane were made a t 30 "C over the pressure range 0-350 MPa, up to viscosities of l o 6 P a s. Medani and Hasan (44H) measured the viscosities of various organic liquids a t elevated tem-
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ANALYTICAL CHEMISTRY, VOL. 51, NO. 5, APRIL 1979
peratures (253-463 K) using a rolling ball viscometer. An equation for the calibration of the viscometer was derived. And Sushilin e t al. (69H) determined viscosities and density of low molecular weight hydrocarbon systems in the gas phase at high pressures (300-1000 kg/cm3) and temperature (25-150 "C). Results are discussed as well as suitability of various emperical equations for describing them. The calculation of viscosities of light hydrocarbons based on the Enskog theory and an equation of state such as the Redlich-Kwong equation was illustrated for the first seven n-alkanes by Hernandez and Acosta (24H). A nomagram for determination of the viscosity-gravity constant of a lubricating oil from the specific gravity (0.8-1.0) and viscosity (SUSof 800-10000 a t 100 O F ) was constructed by Rao (62H). A preprint of I P 226/77, the Institute of Petroleum's standard method for calculating viscosity index from kinematic viscosities a t 40 and 100 "C, was issued (81H). Solubility, Determination of the aqueous solubility of polynuclear aromatic hydrocarbons by a novel technique based on pumping distilled water through thermostated "generator columns" was described by May et al. (43H),and Koarenman and Arefeva (32H) described an analytical method for determining the solubility of liquid hydrocarbons in water. The solubility of water in various low-dielectric solvents, including cyclohexane, carbon tetrachloride, p-xylene, benzene, chlorobenzene, and o-dichlorobenzene, was measured by Kirchnerova and Cave (35H),and a new method proposed for calculation of the dispersion component of the solubility parameter of a polar species based on a correlation with refractivity. Cohen and Regnier (7H) reported on a study of 57 hydrocarbons from which was developed a relationship based on molecular geometry and electronic characteristics which can predict the solubility of the hydrocarbon in water. King and Al-Naijar (33K) reported on the solubilities of carbon dioxide, hydrogen sulfide, and propane in some normal alkane solvents as function of temperature. The mole fraction solubilities for a solute partial pressure of 1 atm all follow straight lines, and fell with increasing temperature. In a similar paper, the same authors (34H) discussed the correlation of the solubility data a t 25 "C in terms of solubility parameters and regular solution theory. Volpicelli et al. (73H) found the extractive characteristics of tetraethylene glycol as a solvent for aromatic-paraffin separation to be superior to mono-, di-. or triethylene glycol. In order to estimate the effects of pumping steam into petroleum formations, Skripka and Boksha (65H) determined the solubility of water in individual n-alkanes and their mixtures. Bhattasali and Nanda ( 4 H ) reported that dissolved oxygen is determined in liquid petroleum naphtha by shaking a known amount of naphtha with ammonia1 CuCl in the absence of atmospheric oxygen and comparing the resulting blue color with standards. Molecular Weight and Density. Rastorguev et al. (58H) suggested an empirical equation for determining the molecular weight of petroleum products in terms of density, boiling point, and refractive index. Average deviation of the experimental data involving 270 petroleum products was 2.4-2.8%. Blagopoluchnaya and Fedorov ( 5 H ) derived an equation for calculation of the molecular weight of a petroleum fraction as a function of its specific gravity and carbon residue. Potolouskii e t al. (56H) determined the molecular weight of polymethacrylate by viscometry, osmometry, and ebullioscopy. Viscometry and ebullioscopy gave similar values (11420 and 11750 respectively). Grigor'ev et al. ( 2 0 H ) derived a generalized equation for calculating the density of petroleum products in terms of temperature. The method is reported to be especially suitable for heavy petroleum products and fractions boiling over a wide temperature range. Ll'inskaya e t al. (38H)derived an equation for calculating the density of high molecular weight naphthene-aromatic hydrocarbons of petroleum and of the organic matter of rocks as a function of refractive index. The relative error of this method was reported to be 0.7-3.7%. Singh and Teja ( 6 4 H ) reported the prediction of densities of n-alkanes from propane to n-dodecane was carried out by a modified corresponding states method, Le., the acentric factor was varied until the predicted density value coincided with the experimental value at a given temperature and pressure. Weitz and Lamphere (74H) reported that the liquid density of liquefied natural gas and liquefied petroleum gas can he determined by a capacitance method for determining dielectric constant. November (n'3H)
discussed the application of densitometers to fluid measurement. A FORTRAN subroutine for calculating the densities of liquid and vapor phases formed in "flash" vaporization was reported by Tedesco (71H). Mencke (45H)reported that the ASTM/IP petroleum measurement tables are no longer precise enough for calculating the density of the heavier (heating oil and asphalt) fractions, hut that a new calculation approach gives good correlation with measured values. Hall e t al. (22H) reported that a new program for determining the density and thermal expansion of crude oils and refined products, initiated by the Bureau of Standards and the API, will have an accuracy of better than 10 ppm. Miscellaneous. Water in petroleum was the subject of two papers: Zwierzycki (80H) discussed the applicability of dielectric loss measurement for determining water with a sensitivity of 0.1--0.2%; and Gouw (18H) described a number of the more successful methods for removal of water prior to further analysis. Color of petroleum was the subject of two papers: Shevtsov et al. (61H) compared color by two colorimeters and found that each gave reproducible results but that data obtained were not interchangeable; and Knight (36H) compared IP 17, ASTM D156 and W O M A standard color scales. Oxidative thermal stability of petroleum oils was studied by Shmiilovich and Goldenberg (63H) utilizing chemiluminescence. The increase in chemiluminescence was caused by accumulation of hydroperoxides in the oils. Hassel ( 2 3 H )discussed three thermal analytical techniques for measuring stability: pressure differential calorimetry, and dynamic and isothermal thermogravimetric analyses. The advantages of each method was discussed. Golka and Jezowska-Trzebiatowska ( I 6 H ) derived equations for the distribution of an adsorbate on an adsorbent in a column under dynamic conditions. These permitted the determination of the specific surface of the adsorbent. Affens et al. ( I H ) determined the flammability indices of vapor-air mixtures above liquid hydrocarbons a t various temperatures using a hydrogen flame ionization detector. Stein et al. (67H) used a predictive scheme for thermochemical properties of polycyclic aromatics, which is an extension of roup additivity techniques. to predict standard gas-phase [eats of formations, intrinsic entropies, and heat capacities for six-membered ring compounds. Baltov et al. ( 2 H ) used computers to determine the liquid -vapor phase equilibrium constants of some multicomponent hydrocarbon mixtures. Ultrasonic velocities at 323 K in binary liquid mixtures were used to measure the isothermal compressibility of the mixture (37H). Stupak (68H) presented equations for determining the thermal condensation and heat capacity of water-based cutting fluid emulsions containing surfactants. Thermal conductivity of petroleum products is predicted with an accuracy of 1 5 % by a method of Jamieson e t al. (28H). In a second paper on thermal conductivity, the same authors presented a survey of thermal conductivity methods to 1974 (29H). Mustafaev and Musaev (51H) reviewed existing methods of calculating heat capacity of hydrocarbns, and suggested a new formula expressed as a function of the liquid density, number of carbon atoms, and a constant dependent on the type of hydrocarbon. Zanker (77H) suggested a bipartite nomograph with a double-graduated, central specific-gravity scale, based on the Perry equations, as a means for estimating heat capacities of petroleum oils and vapors. Gawlik et al. ( 1 5 H ) described a Carberry-type differential reactor for determining specific heat of solids. Matubayasi et al. (40H) studied the effects of pressure on the interfacial tension between oil and water from pendant-drop parameters photographed in a specially constructed quartz cell. Nazarov e t al. (52H) reported on equation and nomagraph for calculating the emulsifiability of petroleum its a function of density, viscosity, surface tension, and contents of asphaltenes, paraffins, and silica gel resins. Smol'yaninova e t al. (66H) described the possibility of using calculational methods for preanalysis of the indexes of the properties of petroleum and straight-run distillates. Equations were given for the calculation of molecular weight, viscosity, and coking value. Determination of K characterization factors and the degree of their association in some mineral oils using IR spectroscopy was discussed by D'Alessio et al. (8H). Zanker (76H). presented a nomagraph for determining the equilibrium solubility of some common inorganic gases in petroleum liquids. With the nomagraph, the physical properties of the
ANALYTICAL CHEMISTRY, VOL. 51, NO 5, APRIL 1979
gases are not needed to find their solubility. T h e method assumes the applicability of the Clausius-Clapeyron equation, Henry’s law, and the perfect gas laws. Eigenson and Ivchenko (11H) gave equations for the calculation of yields, viscosities, densities, and molecular weight of distillates based on the petroleum properties. Kajikawa et al. (31H) used a displacement chromatograph and mass spectrometer to analyze distillates for hydrocarbon types. A regression analysis of the data were then made and equations for estimating smoke point, aniline point, and specific gravity were derived. Gel permeation chromatography was used by Hodgin e t al. (26H) to obtain molecular weight distribution profiles of petroleum crudes, pitches, and asphaltenes; and Melikov (46H)described a method for determining the critical Reynolds number in the flow of liquids through porous rock strata. The flammabilities of aviation kerosene, gasolines, and other liquid fuels under simulated impact conditions was studied by Ford (13H). The fuel was atomized in a jet of moving air, contacted with an ignition source, and the duration and intensity of the resulting intermittent combustion was monitored with a light-sensitive device connected to a recording system. Ferrero and Panetti ( 1 2 H ) reported on the separation of olefins from paraffins and of linear branched olefins with macroreticular ion-exchange resins in silver (ion) form. Dynamic mass measurement of natural gas liquids under flowing conditions were made and reported by Templeton (72H). Peterman et al. (55H) reported a spectroscopic method for studying the adsorption of gas in liquid films. Kaerger (30H) reported on the interpretation and correlation of zeolitic diffusibilities obtained from nuclear magnetic resonance and sorption experiments, and Romavacek (59H) described a method for determining the volatility of pitch based on the diffusion of hydrocarbon vapors emanating from a large sample a t 200 OC through a small orifice into a stream of nitrogen; the response of a flame-ionization detector to the hydrocarbon was measured.
Hydrocarbons M. P. T. Bradley Spectra - Physics, Santa Clara, California
T h e analysis of hydrocarbons in petroleum fractions continues to follow the pattern established in previous years, with gas chromatography the most used technique, although the use of liquid chromatography, particularly for aromatic compounds, continues to grow rapidly. Review. A number of review articles covering various aspects of hydrocarbon analyses have appeared recently, ranging from the chromatography of hydrocarbons by Desty (590, through a review with 212 references on the analysis of commercial C, fractions by Schoellner et al. (2161). More eneral reviews, such as the review of petroleum hydrocarbons y Sanin (2030,on modern methods of analysis by Kalmutchi (1301), the analysis and testing of hydrocarbons, catalysts, pollution control, and products by Tomii and Futami (2660, are well supported by other reviews which are more directed in nature, such as that by Vercier and Cahuzac (2750, which is focused on the views of the French Refining industry, and those by Sauerland et al. (20511, Stadelhofer et al. (2471), Altgelt and Gouw ( 6 4 , and others (1261, 7721, 2001), who focused on polynuclear aromatics in heavy fractions. Reviews of the developments in mass spectroscopy by Nishishita (1650, in liquid chromatography by Thoms and Zander (261Z), and Matsuzaki (15411, and in gas chromatography by Takeuchi and Tsuge (256n. extensively cover petroleum hydrocarbon applications. Two publications of particular note for the quantitative aspects of hydrocarbon analyses are the ASTM manual on Hydrocarbon Analysis (81),and a publication by the National Bureau of Standards on Interlaboratory comparisons for trace level petroleum hydrocarbon determinations in marine sediments (1151). Novel Methods of Analysis. In such an established field as hydrocarbon analysis, the emergence of new and novel techniques is not frequent; however, some interesting developments have occurred. Sub-part-per-trillion analyses of
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polynuclear aromatics by means of a laser induced fluorescence technique (1951),and the work of Van Gee1 and Winefordner (2741), promise increasing laser applications, whereas the concentration technique developed by Twibell and Home (2711), has the benefit of simplifying an existing analysis technique. Masini et al. (153n,reported on the use of Stark modulated microwave analysis of czs-but-2-ene in but-1-ene with high accuracy. Thuemmel et al. (2641).applied multicomponent analysis with electron and 3 radiation. Zhukhovitskii et al. (2911) developed a technique they call chromadistillation, Coetzee et al. (471),applied anodic differential pulse voltametry to the analysis of polynuclear aromatics. Templeton (26.91), reported on the application of mass measurement techniques to natural gas liquids. and Annino et al. ( I O Z ) , described a totally pneumatic gas chromatograph. New detectors, particular those designed to give selectivity and specificity were reported for gas chromatographic systems (381,671, 1311, 1831) and liquid chromatography (1821). Petroleum Origins. The iise of C2-C7 hydrocarbons as indicaters for petroleum and natural gas was reported by Leythaeuser et al. (143Z);Faber, Stahl, and Carey (781)used isotope methods, in particular, the 13C/12Cratio to determine the origins and correlate and explore the boreholes during exploration. The analysis of steranes and triterpanes in a wide range of USSR crude oils was reported by Petrov, Pusti1’nikova et al. (1751). Petrov et al. (2741), and Orcova et al. ( I 701) also examined isoprenoid hydrocarbons. Shimanskii et al. extensively examined the Cs-Clo arenes from disperse organic matter in upper Jvrassic argillite (2290. The dispersed matter and petroleum from that region was similar in nature indicating that changes in composition were due to transformation of the dispersed organic material and not subsequent secondary processes in the petroleum deposits. Group Analysis. The analysis of petroleum hydrocarbns by functional group has always been important. An extension of the Bureau of Mines procedure to heavy tar sand bitumens was reported by Haines (1031), and a modification of the original procedure to shorten the analysis time was the subject of a publication by Sawatzky et al. (2071). Other group separations were reported (371,721, 1671.234I). Schulte et al. (2710,applied similar techniques to the analysis of coke oven effluents. Chemical Methods. Chemical methods are infrequently used for hydrocarbon analysis; however, methods were reported for the direct titration of olefines in propylene carbonate (1351);the colorimetric determinate of total aromatics in refinery and petrochemical waste streams (273I),based on reaction with formaldehyde and sulfuric acid. Wyganowski (2881)applied the technique of ion pairing to titrate unsaturated hydrocarbons with permanganate in nonaqueous media, and Gabriec-Koska et al. (97T)developed a colorimetric procedure for indene in naphthalene. Spectroscopic Techniques. A wide range of spectroscopic techniques have been applied to hydrocarbon analysis ranging from Ranian spectroscopy (931, 1 I ) , to photodissociation spectroscopy (70I). The most popular techniques are infrared and UV spectroscopy. Berthold et al. (241-261) continue their work on infrared structural group analysis methods. Corbett and Scullion (510 reported a simple statistical technique for the detection of specific minor impurities by IR. Egorova (720 used infrared to follow the oxidation of hydrocarbon mixtures. Proskuryakova et al. (1841) followed the selective absorption of components when petroleum filtered through clay minerals. Hellmann ( I 100 compared polycyclic compounds produced by biological and combustion processes. Improvements to the normal infrared procedures brought about by cooling (861) and Fourier transform techniques ( 2 5 In were also reported. Ultraciolet spectroscopic techniques range from the direct determination of aromatic compounds by UV absorption (1671, 1771. 1851) to second derivatiLe techniques (2081) to fluorescence systems with ITV excitation. Several authors (1111, 2671, 2821) used fluorescence to analyze polycyclic compounds in natural sediments. Hurtubise et al. (2221) characterized the fluorescence from shale oil. Heinrich and Guesten (1091) used the technique for the analysis of air borne polycyclic aromatic hydrocarbons. A low temperature technique using matrix isolation was applied to coal-derived liquids by Stroupe et al. (2.511). Schwartz and Wasik (2200 determined several polycyclic aromatics in water.
