Korosteleva et al. (2°K) first transforming the oil into coke and then exciting it with a 20-ampere d.c. arc. Zinc, barium, and vanadium were estimated in petroleum products without preliminary ashing by Hauptman (19K),using copper electrodes. An apparatus that can be attached to any spectrograph and that permits the safe spark excitation of petroleum products and flammable liquids has been described by Buncak (SK). Crankcase oil contamination was studied by Sokolov (42K) who determined iron, lead copper, chromium, silicon, aluminum, and tin after ashing the samples and using nickel as internal standard. The analysis of diesel oil to determine metals worn away by friction from engine parts has been reported (4OK) using conventional sample handling and spectrographic techniques. To avoid sample ashing, a method has been described by Pforr et al. ( S 7 k ) for zinc and calcium in compounded motor oils in which the sample is sprayed into the spark gap by means of a rotating carbon disk. Wear metals-iron, aluminum, lead, copper, chromium, and silicon-were determined in locomotive diesel oils by Sokolov (4lK). Boron in heavy hydrocarbon mixtures has been measured by Giorgini (15K) with no previous ashing by diluting the sample in a graphite matrix. Nickel, copper, vanadium, and iron in the parts-per-billion range were determined in ashes from catalytic feedstocks by Hoggan et al. (21K),using cobalt as internal standard and a directreading spectrometer. A general computer program was developed by Tunnicliff and Wezl-Jer (48K),which calculates and reports results from the common matrix method of emission spectrographic analysis. X-Ray. A review covering problems encountered in x-ray analysis, with emphasis on applications t o mineral oil products, has been reported by Louis (29K). In this paper, x-ray tubes, crystal analyzers, collimators, and characteristics of crystals are critically discussed. Detection limits in mineral oils for elements of atomic numbers between 15 and 82, using x-ray emission analysis, have been described by Louis (SOK). For elements heavier than chlorine a detection limit below 1 ppm is possible, and between 1 and 3 ppm for sulfur and phosphorus. X-ray emission spectroscopy was applied by the same author (28K)to the determination of zinc, barium, calcium, chlorine, sulfur, and phosphorus in lubricating oils. A direct simple channel method for analyzing 0.2-10 ppm of nickel in catalytic cracking feedstocks, in about 23 minutes, with a standard deviation of 0.1 ppm and within 0.1 ppm agreement with chemical results has been reported by Gunn (17K). Calcium, barium, zinc, and lead were determined by 176 R
ANALYTICAL CHEMISTRY
Burke et al. (4K) using x-ray spectrography in lubricating oils, white oils, and gasolines. This technique uses a pellet of a suitable reference element in a conventional Phillips cup containing the sample. Catalytic cracking feedstocks have been analyzed by Rowe and Yates (S8K) using x-ray fluorescence to determine copper, iron, nickel, and vanadium; the samples are prepared by ashing with xylene sulfonic acid. A discussion on the application of x-ray fluorescence spectrometry LO the determination of barium, zinc, and calcium in lubricating oils and additives has been reported by Haycock (20K). An internal standard technique to eliminate inter-element effects is used. Miscellaneous. A procedure for ash determination in hydrocarbons that is faster than the ASTM ash analysis D482-63 has been described by Dubeau et al. ( 8 K ) . In this method the oil evaporation time is decreased from 90 to 9 minutes by using a slight vacuum. Zinc calcium, and bromine in unused lubricating oils have been selectively estimated by Fisher ( I f K ) using complexometric titration with EDTA in an alcoholic-hydrochloric acid extract of the sample. Several procedures for the complexometric determination of zinc and calcium in oils containing additives have been studied, although no satisfactory results were reported by Studeny ( 4 6 K ) . A gravimetric method by Muzychenko et al. ( S 4 K ) for the determination of carbonates in oil additives containing calcium or barium involves treating the samples with sulfuric acid and determining the liberated carbon dioxide. A chemical method for determining barium in lube oils additives concentrates has been extensively tested by several laboratories (10K). In this procedure (IP Inorganic Analysis Panel ST-G-3), which is simpler and more rapid than the I€'-110, the samples are treated with sulfuric and nitric acids and the barium is weighed as sulfate. Routine photometric analysis for the determination of zinc additives in unused lubricating oils has been carried out by Howard ( 2 2 K ) forming the zinc dithizonate complex in a carbon tetrachloride solution of the oil. A pulse polarographic determination of microgram amounts of nickel and vanadium in petroleum stocks has been reported by Gilbert ( 1 4 K ) which can be effected on a single polarogram in a short time, after chemically treating the samples. T'anadium contained in petroleum as a porphyrin complex was determined by Ishii ( 2 5 K ) using an a x . polarographic technique after extracting the vanadium with a KSCS-HTSOa solution. Simultaneous polarographic behavior of nickel, cobalt, iron, and manganese has been studied in mineral residues of crude oils and a simultaneous determination of nickel and cobalt in several Romanian
oils has been described by Serbanescu ( S 9 K ) . A review covering the subject of polarographic analysis has been wrib ten by Ishii (24K) containing 57 references. Potentiometric acid-base titration has been applied by Lyashenko et al. (S1K) to the determination of calcium salts in lubricant oil additives. Two analytical procedures have been described by Hammerich and Gonderman (18K) to analyze combustion residues from engines. In one of them, lead, barium, and silicon are gravimetrically determined after insolubilization with acids; iron, zinc manganese, molybdenum, copper, and phosphorus are spectrophotometrically determined and a potentiometric method is used for chlorine, bromine, and boron. In the other procedure by Grant (16K), silicon and aluminum are colorimetrically determined, calcium and magnesium by complexometric methods and chloride by potentiometric titration.
Catalysts Ralph 0 . Clark, Gulf Research & Development Co., Pittsburgh, Pa.
Acidity. The measurement of acid sites by the titration technique using a series of color indicators continues to be used as reported by Bertolachi (2L)and Hirschler (1SL). Spectral absorption and electron paramagnetic resonance measurements of anthracene adsorbed on silica-alumina catalysts have been employed by Karakchiev et al. (14L) to elucidate protonic and aprotonic acidities. The infrared spectrum of coordinately bonded pyridine has also been utilized by Basila et al. (1L) and by Parry (18L) to differentiate between the types of acid sites. The distribution of acid centers was reported by Strich and Becker (2OL)by potentiometric titration with potassium methoxide in a nonaqueous system. Metals. Emission spectroscopy was used by Biktirnirova and Baibazarov (SL) to determine sodium in catalysts, and copper and palladium in sediments and deposits. Townsend (2%) reported the application of a fusion-cast disk technique for analyzing catalysts by emission x-ray spectrography. A modification of the Sen titrimetric procedure for determining nickel has been reported by Danowski and Lewandowska (7L). Svajgl ( 2 f L ) devised a colorimetric and a titrimetric method for tracing vanadium in hydrogenation processes. Potentionietric titration with ceric sulfate has been employed by Giuffre and Cassani (IOL) to determine the V+2 and V+3 contents of catalysts prepared from vanadium trichloride and aluminum alkyls. And, a complexometric method for molybdenum was devised by Uvarova and Rik ( 2 4 5 ) .
Physical Properties,. The measurement of surface area of catalysts utilizing the gas chromatographic technique continues to be reported as by Chu (6L), Kuge and Yoshikawa (16L), and Liu et al. (17L) as does the x-ray diffraction technique by Keely (15L). Rapid methods using a simple calorimeter has been studied by Taylor (2%) and the Haul and Deu mbgen apparatus for surface area has been studied by Grundke and Frenzel (11L). Determination of the total metallic area of supported catalysts using chemisorption of hydrogen ar d carbon monoxide also received further attention by Germain et al. (91,). In similar type studies, Weigel et al. ( 2 t Z ) compared the BET and small-angle x-ray scattering techniques for absolute values and other information that could be derived from the data. A rapid, continuous flow method for the pore size distribution of catalysts has been described by C'ahen and Fripiat (4L). And Harris (191;) discussed the source of error in the calculation of pore size data from nitrogen isotherms. The density of porous solids by immersion in mercury in a pycnometer has been published by Cartan (5L) and a mathematical treatment was developed by Princon (19L) for coincidence corrections necessary in determining particle size distribution of catalysts using the Coulter counter. Miscellaneous. A :,tudy of the distribution of coke on catalyst beads as a function of the radiIs of the beads has been reported by Galimov et al. (8L); two different techniques for measuring the coke were evaluated
PhysicaI Pr pert ies 01
R . C. Vollmar, Standard Oil Co. of California, Richmond, Culif.
L
(,%-If) studied flow time measurements in Ostwald viscometers tilted out of the vertical; they found variations c,in be explained as a function of the geometry of the viscometer. An empirical formula developed by Bondarenko (1O.V) correlated rate of slipping of a drop of liquid along a vertical filament with the viscosity of the liquid. Results compared favorably with measur1:d data in an Ostwald viscometer. Kinoshita and Onoyama (27M) postulated that surface actk e material from solvent refined oil adsorbed onto capillary walls, resulting in rtbduced effective bore size of the tube for subsequent tests. Flow rate changed gradually with repeated measurements on the same oil. A two-way capillary viscometer measuring bulk viscosity a t shear rates from less than 0.1 to over 1,000,000 per second and pressure drop up to 1000 psi was AKGTON AND VAUGHAN
described byTzentis (65112). After Calibration with Newtonian oils it was also applied to nowNewtonian salt solutions of polyacronitrile. Lim and Johnson (SOM) made precise measurements electronically of the time required for commercially available solid steel balls to flow through a known distance in liquid samples. Seibert, Johnson, and Stross (5111.1) adapted falling ball viscometry for more rapid routine use. They found good agreement with capillary viscometry with precision largely determined by the weight range of the balls. A new constant rate of flow viscometer described by Bianchi, Patrone, and Babini (7M) permitted static measurements of dilute polymer solutions over a wide velocity gradient range even a t high temperatures and under pressure. Use of the falling cylinder for nonNewtonian fluids was evaluated by Ashare, Bird, and Lescarboura ( 4 M ) . The non-Newtonian viscosity is estimated by treating the velocity-of-fall measurements by a differentiation procedure. Billington (8M)developed a coaxial cylinder viscometer for use under oscillatory and transient conditions as well as steady-state conditions. The timedependent solutions to the shear stress us. shear rate relationships were confirmed on a series of Newtoniar, lubricatr ing oils. Ramarkrishna (46M) made measurements of absolute viscosity by three computational methods based on the rotation of a cylinder suspended in the liquid by a wire. Equations for the velocity distribution and couple when a sphere is rotated in an inelastic nonNewtonian fluid were presented by Bourne (11 M ) . He covered their application to the measurement of fluid parameters at low shear rates. Jaffe and Ruysschaert (dlJ2) described a recording rotational viscometer with glassladen Teflon cylinders; accuracy and precision are discussed both for water and benzene. An extension to power-law fluid 3f Lewis' theory for rolling ball viscometers was presented by Bryd and Turian ( 1 Z M ) . They found a correlation of the speed of the rolling ball with fluid density and with physical and geometrical parameters when applied to non-Newtonian flow. A rolling ball viscometer for use a t temperatures to 400' C under pressures to 5 kilobar was developed by Harrison and Grosser ( I S M ) . Pressure medium is compressed argon and data covers glycerol a t 75' C. Marcelin (36M) designed a microviscometer consisting of a collar centered around a conical wedge of a very small conical angle where the thickness of the oil film depends on the depth of the wedge in the collar. His data showed viscosity coefficient to vary with film
thickness. He suggested (37M) the lubricant films consist of monomolecular layers on the solid surfaces, dense stratified layers, then diffuse stratified layers separating the dense layers and the bulk liquid. The effect of the structural changes under varying lubrication conditions is discussed. A series of equations covering the relationship of pressure and viscosity were developed by Amirbekov (3M). The viscosity of oil emulsions was reported by Muratova and Korobkova (41~12) ; they used a rheoviscometer in the form of a balance. The shear stress of oil emulsions was compared with their viscosity by adding weights to a tray attached to the balance arm of the viscometer. At above 40' C, the viscosity did not depend on shear stress and the liquids were Newtonian. Porter, Klaver, and Johnson (44M) developed a recording high-shear viscometer for measurements near a million reciprocal seconds. Accurate measurements were made a t shear rates of 500 to 2 million per second within an extended temperature range of -20' to 150' C. Viscosity range varies inversely with the shear rate selected for measurement. The shear-rate range 1s greater and its upper limit higher than previously reported. ii simple flexible viscometer for testing pseudoplastic liquids a t pressures as high as 1500 psi was described by Ram and Tainir (45-11). Equations and nomographs are given for designing viscometers or for selecting operating conditions with an existing one. Freund, Csikos, and Nozes (16-11) studied anomalous flow behavior of lubricating oils and slack wax a t low temperatures. No clear-cut relationship could be obtained between instantaneous shear stress values or shear rates and the corresponding rheological conditions. 4 comparison of the (U.K.) Sational Physical Laboratory and the (C.S.) National Bureau of Standards viscosity scales reported by Daborn (Id-lI), showed results agreed with NBS values by 0% to +0.5%. A 10-year test for stability of viscosity of petroleum reference oils was carried out by Weber (56M). Samples exposed to daylight showed more viscosity increases than those kept in the dark; little effect resulted from subjecting another series of samples to temperature variations. An improved equation for converting Engler to Kinematic viscosity was reported by Martens (38-V). It is recommended particularly for Engler values below 2.5. A circular slide iule which can be used to convert viscosity units betneen Kinematic, Engler, Redwood, and Saybolt nas reported in Science Lubrication (52"). This nomogram developed by Xngleroth may also be used for determining viscosity index and SAE classifications. Nagypal (49M) reported a linear relation between the cube VOL. 39, NO. 5, APRIL 1967
177 R
