Elemental analysis of petroleum

Nadkarni, R.A., Ed., Modern Instrumental Methods of Elemental Analysis of Petroleum Products and Lubricants, ASTM, STP 1109, Philadelphia, PA, 1991. 

Elemental analysis of petroleum shows that the major constituents are carbon and hydrogen with smaller amounts of sulfur (0.1-8% w/w), nitrogen (0.1-1.0% w/w), and oxygen (0.1-3% w/w), and trace elements such as vanadium, nickel, iron, and copper present at the part per milHon (ppm) level. Of the non-hydrocarbon (heteroelements) elements, sulfur is the most abundant and often considered the most important by refiners. However, nitrogen and the trace metals also have deleterious effects on refinery catalysts and should not be discounted because of relative abundance. Process units with, for example, a capacity of 50,000 bbl/day that are in operation continuously can soon reflect the presence of the trace elements. The effect of oxygen, which also has an effect on refining catalysts, has received somewhat less study than the other heteroelements but remains equally important in refining. 

The ASTM International D02 Committee on Petroleum Products and Lubricants through its Subcommittee 3 on Elemental Analysis has played a large and crucial role in the last several decades in standardizing numerous elemental analysis methods used in the oil industry. Currently there are about 75 standard test methods under the jurisdiction of SC 3, and additionally at least 6 more are under active development and moving towards standard designations. I have no doubt that this activity will continue in the future. These standards comprise virtually ail known modem techniques for elemental analysis of petroleum products and lubricants. 

The first ASTM D02 symposium on this subject was held in New Orleans in December 1989 at which 20 papers were presented. Of these, 13 were published as a book, Modern Instrumental Methods of Elemental Analysis of Petroleum Products and Lubricants, ASTM STP 1109. The current and second quindecennial (i.e., every 15 years) was held in Tampa, Florida in December 2004. This was attended by over 120 people. Thirty papers were presented on diverse subjects from 64 authors from nine different countries Brazil, France, Germany, Italy, the Netherlands, South Africa, Switzerland, U.K., and U.S. Of these, 12 papers were from the oil industry, 15 from the instrument manufacturers, 10 from national research organizations, and 4 from the universities. 

Botto, R,L, (2002), Trace element analysis of petroleum naphthas and tars using direct injection ICP-MS, Can. ], Anal. Set Spectrosc. 47,1-13. 

Fractionation and Elemental Analysis of Crude Oils and Petroleum Cuts... 

Chaptar 2. FRACTIONATION AND ELEMENTAL ANALYSIS OF CRUDE OILS AND PETROLEUM CUTS... 

Chapter 2. FrACVONATION AND ELEMENTAL ANALYSIS OF CRUDE OlLS AND PETROLEUM CuTS... 

Although distillation and elemental analysis of the fractions provide a good evaluation of the qualities of a crude oil, they are nevertheless insufficient. Indeed, the numerous uses of petroleum demand a detailed molecular analysis. This is true for all distillation fractions, certain crude oils being valued essentially for their light fractions used in motor fuels, others because they make quality lubricating oils and still others because they make excellent base stocks for paving asphalt. 

Non-destructive elemental analysis of solid or liquid samples for major and minor constituents. Used in routine analysis of metallurgical and mineral samples. Most suited to the determination of heavy elements in light matrices (e.g. Br or Pb in petroleum). Well suited for on-stream, routine analysis. Electron beam excitation methods valuable in surface studies in combination with electron microscopy. Detection limits generally in the range 10-100 ppm. Relative precision, 5-10%. 

The analysis of petroleum for the percentages of cmbon, hydrogen, nitrogen, oxygen, and sulfm is perhaps the first method used to examine the general natme, and perform an evaluation, of a feedstock. The atomic ratios of the various elements to cmbon (i.e., H/C, N/C, 0/C, and S/C) me frequently used for indications of the overall chmacter of the feedstock. It is also of value to determine the amounts of... 

The ultimate analysis (elemental composition) of petroleum is not reported to the same extent as it is for coal (Speight, 1994). Nevertheless, there are ASTM procedures (ASTM, 1995) for the ultimate analysis of petroleum and petroleum products but many such methods may have been designed for other materials. 

The elemental composition (ultimate analysis) of petroleum, no matter what the origin of the particular petroleum, varies only slightly over very narrow limits (Chapter 1) ... 

Although the great majority of petroleum and coal-based pitch materials, as well as model compounds such as polyvinyl chloride, acenaphthylene, decacyclene and polynuclear aromatic hydrocarbons, form anisotropic graphitizable carbons, it is an almost impossible task to predict the type of optical texture of a coke from an elemental analysis of the pitch. The size, shape and reactivity of peri-condensed polynuclear aromatic molecules in the products of pyrolysis of a pitch play a more important role in determining optical texture. 

T he chapters in this book have been prepared from papers presented at a symposium on the Analysis of Petroleum for Trace Metals held at the 169th National Meeting of the American Chemical Society. The symposium reported on the Trace Metals Project carried out by five petroleum companies to develop methods for 13 elements of environmental interest (arsenic and selenium, which are not metals in the usual sense, are included). For the present purpose, the format of the papers has been changed to include detailed procedural instructions. 

Milner, O. I., Analysis of Petroleum for Trace Elements, p. 7, Pergamon,... 

The availability of high flux thermal neutron irradiation facilities and high resolution intrinsic Ge and lithium drifted germanium (Ge(Li)) or silicon (Si(Li)) detectors has made neutron activation a very attractive tool for determining trace elemental composition of petroleum and petroleum products. This analytical technique is generally referred to as instrumental neutron activation analysis (INAA) to distinguish it from neutron activation followed by radiochemical separations. INAA can be used as a multi-elemental method with high sensitivity for many trace elements (Table 3.IV), and it has been applied to various petroleum materials in recent years (45-55). In some instances as many as 30 trace elements have been identified and measured in crude oils by this technique (56, 57). 

CONTENTS 1. Basic Principles (J. W. Robinson). 2. Instrumental Requirements and Optimisation (J. E. Cantle). 3. Practical Techniques (J. E. Cantle). 4a. Water and Effluents (B. J. Farey and L A. Nelson). 4b. Marine Analysis by AAS (H. Haraguchi and K. Fuwa). 4c. Analysis of Airborne Particles in the Workplace and Ambient Atmospheres (T.J. Kneip and M. T. Kleinman). 4d. Application of AAS to the Analysis of Foodstuffs (M. Ihnat). 4e. Applications of AAS in Ferrous Metallurgy (K. Ohis and D. Sommer). 4f. The Analysis of Non-ferrous Metals by AAS (F.J. Bano). 4g. Atomic Absorption Methods in Applied Geochemistry (M. Thompson and S. J. Wood). 4h. Applications of AAS in the Petroleum Industry W. C. Campbell). 4i. Methods forthe Analysis of Glasses and Ceramics by Atomic Spectroscopy (W. M. Wise et al.). 4j. Clinical Applications of Flame Techniques (B.E. Walker). 4k. Elemental Analysis of Body Fluids and Tissues by Electrothermal Atomisation and AAS (H. T. Delves). 4I. Forensic Science (U. Dale). 4m. Fine, Industrial and Other Chemicals. Subject Index. (All chapters begin with an Introduction and end with References.)... 

X-ray fluorescence spectrometry, gas chromatography and neutron activation analysis (NAA). An older book edited by Hofstader, Milner and Runnels on Analysis of Petroleum for Trace Metals (1976), includes one chapter each on principles of trace analysis and techniques of trace analysis and others devoted to specific elements in petroleum products. Markert (1996) presents a fresh approach to sampling, sample preparation, instrumental analysis, data handling and interpretation. The Handbook on Metals in Clinical and Analytical Chemistry, edited by Seiler,... 

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