Oil Quality Control

This chapter will briefly review some of the new techniques proposed for crude oil quality control, and an alternative new approach will be presented. 

Assays of the crude types B and C will need frequent revisions in the crude oil assay libraries, but the nature will be different. With crude oils from group B there is a continuous need to update the crude assay in the databank, which can be platmed following two possible criteria on a fixed delta time basis or on a delta quaUty basis, which is the usual procedure. 

Crude oils Ifom group C present a more serious problem. A considerable effort in updating crude assays can be made without any improvement, due to the random quality variations. It is very difficult to define the appropriate moment to update the assay, and most of the times different qualities are ineluded in the erude oil library to represent different scenarios 

The problem is that these quality variations affect both the planning and operation processes. If planning and operation tools are not updated to reflect the ehanges in erude oil quality in the form of LP delta vectors for each crude, the model may eonverge in a solution different from the optimal, and transfer 

An increase in the quality of the received cargo does not assure a higher profitability, because LP models optimize crude mixtures according to the constraints defined, and perhaps the quality increase will be offset in operation to a specification that can not be reached with the planned yield/profit. 

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As aldehydes and some ketones have long been identified as oxidation and breakdown products of fats, their determination also has been common in soybean oil quality control. The p-anisidine value (300) measures light absorbance of aldehydes, primarily 2-alkenals, and 2,4-dienals at 350 nm. However, this measure is not entirely specific, because the color intensity developed depends not only on the concentration but also on the structure of the aldehyde. Therefore, the results are comparable only within oils of similar type and treatment (304). 

Free fatty acids are probably the most widely used characteristic of oil quality control (AOCS Ca 5a-40). Deodorized oUs, generally, have a free fatty acid level of less than 0.05%. During use for frying, there is a buildup of free fatty acids. In the initial... 

Analysis/quality control/investigation For commercially used oils, quality control tests (guidelines, see ISO 4720) generally involve determination of density, refractive index, optical rotation, and solubility. The qualitative and quantitative composition is analyzed by gas chromatography (GC). 

Polyunsaturated fatty acids in vegetable oils, particularly finolenic esters in soybean oil, are especially sensitive to oxidation. Even a slight degree of oxidation, commonly referred to as flavor reversion, results in undesirable flavors, eg, beany, grassy, painty, or fishy. Oxidation is controlled by the exclusion of metal contaminants, eg, iron and copper addition of metal inactivators such as citric acid minimum exposure to air, protection from light, and selective hydrogenation to decrease the finolenate content to ca 3% (74). Careful quality control is essential for the production of acceptable edible soybean oil products (75). 

The primary applications for spectrographic or lubricating oil are quality control, reduction of lubricating oil... 

NMR spectroscopy is one of the most widely used analytical tools for the study of molecular structure and dynamics. Spin relaxation and diffusion have been used to characterize protein dynamics [1, 2], polymer systems[3, 4], porous media [5-8], and heterogeneous fluids such as crude oils [9-12]. There has been a growing body of work to extend NMR to other areas of applications, such as material science [13] and the petroleum industry [11, 14—16]. NMR and MRI have been used extensively for research in food science and in production quality control [17-20]. For example, NMR is used to determine moisture content and solid fat fraction [20]. Multi-component analysis techniques, such as chemometrics as used by Brown et al. [21], are often employed to distinguish the components, e.g., oil and water. 

In the area of process monitoring TLC has been used for the study of the thermal decomposition of zinc di-isopropyl dithiophosphate (antiwear additive in lubricating oils) [458]. TLC analysis has been reported as a quality control tool for analysis of dispersing agents (alkylsalicylates, thioalkylphenolates), AOs (dithiophosphates, dialkyldithiophosphates) and their intermediates in lubricating oil (UV detection,... 

The original applications of NIR were in the food and agricultural industries where the routine determination of the moisture content of foodstuffs, the protein content of grain and the fat content of edible oils and meats at the 1% level and above are typical examples. The range of industries now using the technique is much wider and includes pharmaceutical, polymer, adhesives and textile companies. The first in particular are employing NIR spectrometry for the quality control of raw materials and intermediates and to check on actives and excipients in formulated products. Figure 9.26(b) demonstrates that even subtle differences between the NIR spectra of enantiomers can be detected. 

Groundnut oil, in soap making, 22 735 Ground quicklime, 75 28 production of, 75 54-56 quality control for, 75 70 uses for, 75 61-62... 

Quantitative structure-property relationships, 7 385, 386 Qaiyarah heavy oil, 18 618 QC laboratory, purpose of, 21 160. See also Quality control (QC)... 

XRF is widely used in industrial applications where a large number of elements need to be determined quantitatively. It is used for continuous quality control in the steel industry (e.g., the determination of Mn, Cr, Ni, Co, etc., in the production of stainless steels), and also for casting quality of coins in the Royal Mint (where Cu, Ni, and Zn are continuously monitored). Geological applications include whole rock analyses and clay identification. The power industry uses it as pollution control management, measuring sulfur and heavy metal concentrations in fuels (coal, oil) and ash. 

As in any scientific or engineering endeavor, the quantity and validity of input data determine the accuracy of prediction. Frequent gauging of fluid levels in monitoring wells, flow rates, and oil-water ratios, in conjunction with proper quality control, can lead to accurate estimates that support proper project performance. 

Food products Dairy products, General food additives Natural oils and fats Beverages Flavors and fragrances Fermentation reactions Blending control Composition monitoring Raw materials screening Quality control... 

M. Baranska, H. Schulz, S. Reitzenstein, et al.. Vibrational spectroscopic studies to acquire a quality control method of Eucalyptus essential oils. Biopolymers, 78, 237-248 (2005). 

The enantiomeric differentiation of linalool is useful in the quality control of essential oils and oleoresins, as it was found to provide an important indication of the authenticity of many herbs and spices. The enantiomeric composition of linalool has been determined in many essential oils, including basil, bergamot, rosemary, lavandin, lavender, balm, coriander, mace. Pelargonium, rose, Cymbopogon, lemon, mandarin, Osman-thus, davana, jasmine, Lippia alba and orange, as well as in many fruit... 

Quality control of fragrance and flavor substances as well as the products derived from them, comprises the comparison of sensory, analytical and if necessary, microbiological data with standards and specifications. To a large extent these have been established in official specification collections (Pharmacopoeias, ISO, AFNOR, Essential Oil Association). 

A prerequisite for any quality control is the definition of how the characteristics of a specific raw material, an intermediate product or a final product of a manufacturing process should be described. This means that all characteristics for every single product have to be defined in adequate standards and specifications so that the results obtained can be compared with these data. Numerous standards and specifications have been established in more or less official specification collections, for example pharmacopoeias, the aforementioned ISO or DIN standards, standards of the Essential Oil Association or the American Spice Trade Organization (ASTA). 

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