Petroleum Assay

An efficient assay is derived from a series of test data that give an accurate description of petroleum quality and allow an indication of its behavior during refining. The first step is, of course, to ensure adequate (correct) sampling by use of the prescribed protocols (ASTM D-4057). 

Thus analyses are performed to determine whether each batch of crude oil received at the refinery is suitable for refining purposes. The tests are also applied to determine whether there has been any contamination during wellhead recovery, storage, or transportation that may increase the processing difficulty (cost). The information required is generally crude oil dependent or specific to a particular refinery and is also a function of refinery operations and desired product slate. 

To obtain the necessary information, two different analytical schemes are commonly used. These are (1) an inspection assay and (2) a comprehensive assay. 

Inspection assays usually involve determination of several key bulk properties of petroleum (e.g., API gravity, sulfur content, pour point, and distillation range) as a means of determining whether major changes in characteristics have occurred since the last comprehensive assay was performed. 

For example, a more detailed inspection assay might consist of the following tests API gravity (or density or relative density), sulfur content, pour point, viscosity, salt content, water and sediment content, trace metals 

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The acid numbers will not provide the data essential to determining whether a specific petroleum or a blend with other crude oils will yield the desired product slate. Such data can only be generated when a comprehensive petroleum assay is performed and the data from several tests are taken in relation to each other. 

Component Lists IFluid Packages Cd Petroleum Assays C5 Oil Manager... 

Conditions Properties Composition Oil Gas Feed Petroleum Assay K Value User Variables Notes... 

Petroleum Assay Referenced to Stream Solids Onhi Stream... 

Petroleum Assay Refererxed to Stream Solids Or Stream... 

Petroleum Assay RefetenceiJ to Stream Solids Only Stream... 

The most common applications of petroleum assays in different areas in petroleum refining industry are the following ... 

Coupled LC-LC can separate high-boiling petroleum residues into groups of saturates, olefins, aromatics and polar compounds. However, the lack of a suitable mass-sensitive, universal detector in LC makes quantitation difficult SFC-SFC is more suitable for this purpose. Applications of multidimensional HPLC in food analysis are dominated by off-line techniques. MDHPLC has been exploited in trace component analysis (e.g. vitamin assays), in which an adequate separation for quantitation cannot be achieved on a single column [972]. LC-LC-GC-FID was used for the selective isolation of some key components among the irradiation-induced olefinic degradation products in food, e.g. dienes and trienes [946],... 

Table 5.8 gives an indication of the range of elements that may be determined. Most procedures will require an analyte concentration of 10-3 mol dm 3 or more, although with special conditions, notably potentiometric end-point detection, the sensitivity may be extended to 1(H mol dm 3. The analysis of mixtures of metal ions necessitates masking and demasking, pH adjustments and selective separation procedures. Areas of application are spread throughout the chemical field from water treatment and the analysis of refined food and petroleum products to the assay of minerals and alloys. Table 5.10 gives some selected examples. 

The flotation feed at the Valkoomesky plant contains tourmaline (18%), biotite (13%), muscovite (17%), limonite (2%) and sulphides (5%). Tin assays in the flotation feed averaged about 0.5% Sn, of which the bulk was contained in the -48 to +12 pm fractions. Flotation of tin was carried out with sea water using oxidized petroleum solution in kerosene (1 2 ratio). 

Most recently, development testwork was performed on a large perovskite deposit (Powderhom) located in the USA. An effective beneficiation process was developed, where a concentrate assaying >50% Ti02 was achieved in the pilot plant confirmation tests [7]. During this development testwork, a number of different collectors were examined at different pH values. Figure 25.5 shows the effect of the different collectors on perovsikte flotation. The most effective collector was phosphoric acid ester modified with either fatty alcohol sulphate or petroleum sulphonate. 

Asphalt chemicals, ethyleneamines application, 8 500t, 506 Asphalt emulsifier amine oxides, 2 473 fatty acid amides, 2 458 Asphalt emulsions, 10 131 Asphaltenes, in petroleum vacuum residua, 18 589-590 Asphyxiants, 21 836 Aspirating aerators, 26 165-169 compressed, 26 168-169 propeller driven, 26 168 submersible, 26 169, 170t subsurface, 26 168 Aspiratory, 11 236-237 Aspirin, 4 103-104, 104t, 701 22 17-21. See also Acetylsalicylic acid as trade name, 22 19 for cancer prevention, 2 826 Aspirin resistance, 4 104 ASP oil recovery process, 23 532-533 Assay format, competitive, 14 142 Assay limits, in Investigational New Drug Applications, 18 692 Assays, for silver, 22 650. See also... 

Litton Bionetics. 1980. Mutagenicity evaluation of M-hexane in the mouse dominant lethal assay Final report. Unpublished study by Litton Bionetics Inc., Kensington MD. Prepared for the American Petroleum Institute, Washington DC. EPA-FYI-AX-0183-0231. 

Carver, J.H., Machado, M.L. and MacGregor, J.A. (1985). Petroleum distillates suppress in vitro metabolic activation Higher (S9) required in the Salmonella/microsome mutagenicity assay. Environ. Mutagen. 7 369-380. 

Sediments of Silver Lake, which contain 6.2 % petroleum hydrocarbons, did not support PCB dechlorination in laboratory assays. 

The results from a study employing a human cell line showed that neither 5 nor 50 ppm petroleum-derived JP-5 (PD-JP5) interfered with Snyder-Theilen feline sarcoma virus (ST-FeSV)-directed transformation of human foreskin fibroblastic cells (Blakeslee et al. 1983). Higher concentrations ( 100 ppm) were cytotoxic. It was reported that marine diesel fuel failed to inhibit transformation in this assay, but data were not shown. The study authors consider this in vitro assay to be a useful predictor of carcinogenesis since several known carcinogens have been shown to suppress transformation in cells infected with the ST-FeSV virus by blocking a specific virus gene function (i.e., transformation) noncarcinogens do not inhibit virus-induced cell transformation in this test system. 

Genotoxicity. No definite conclusions can be reached from the in vitro human cell and whole animal genetic toxicology studies that have been performed with fuel oils. Data from bacterial in vitro assays are inconsistent (see Section 2.4, Genotoxic Effects). A study of the genotoxicity/mutagenicity of commercially available fuel oils and the various component petroleum streams used in their formulation would be of value. 

API. 1981. Mutagenicity evaluation of diesel fuel in the mouse dominant lethal assay. Washington, DC American Petroleum Institute. 

Blackburn GR, Deitch RA, Schreiner CA, et al. 1984. Estimation of the dermal carcinogenic activity of petroleum fractions using a modified Ames assay. Cell Biol Toxicol 1 67-80. 

Blackburn G, Deitch R, Schreiner C, et al. 1987. Testing of petroleum middle distillates in a modified Ames assay. Environmental Mutagenesis 9 15. 

Coal is our major source of fossil fuel, being about 87% of the total. Oil shale is 9%, petroleum is 2.5%, and natural gas is 1.5%. These estimates are based on the probable yield of liquid fuel. They are, at best, only very approximate (1, 9, 11). Thus, if all of the known oil-shale deposits in the United States were included, the probable yield of liquid fuel would be about 50% of the total since the 9% estimate excludes shale assaying less than 10 gallons per ton. Similarly, in estimating the probable yield of liquid fuel from coal, somewhat arbitrary assumptions must be made concerning the feasibility of mining thin seams. 

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