Petroleum products property measurement

Because a critical aspect of assessing the toxic effects of the release of petroleum and petroleum products is the measurement of compounds in the environment, the first approach is to understand the origin and properties of the various fractions. 

The predominant methods of measuring the properties of petroleum products are covered by approximately seven test methods used in the determination of bnlk qnantities of liquid petroleum and its products (ASTM D96, D287, D1085, D1086, D1087, D1250, D1298). 

Petroleum product physical and chemical properties such as viscosity, aromatic content and distillation profile can provide a wealth of information about product quality and performance. The information provided in this chapter can be used to help identify how specific physical and chemical property measurements can be used to identify and solve fuel problems. 

Unfortunately, the remaining technical inputs which characterize plant performance are extremely difficult to maintain and update. For whether we measure the usage of equipment and utilities, the product yields, and the product properties directly from a plant survey or whether we compute these inputs using a process simulator fitted to the plant, one fact is uncomfortably clear. The values are good only for the feed and operating concurrent Address Sun Petroleum Products Company Toledo, OH. 

The evolution of product specifications will, at times, appear sadly behind recent developments in more sophisticated analytical techniques. Certainly, the ultimate specification should be based on how well the product performs. Yet, the industry has grown comfortable with certain comparisons, and these standards are retained for easier comparison with earlier products. Thus, it is not uncommon to find petroleum products sold under an array of tests and specifications, some seemingly measuring similar properties. 

For the measurement of other petroleum products, a wide variety of tests is available. In fact, approximately three hundred and fifty tests (ASTM, 2000) are used to determine the different properties of petroleum products. Each test has its own limits of accuracy and precision that must be adhered to if the data are to be accepted. 

Density (ASTM D-1298, IP 160) is an important property of petroleum products because petroleum and especially petroleum products are usually bought and sold on that basis or, if on a volume basis, then converted to mass basis via density measurements. This property is almost synonymously termed as density, relative density, gravity, and specific gravity, all terms related to each other. Usually a hydrometer, pycnometer, or more modem digital density meter is used for the determination of density or specific gravity (ASTM 2000 Speight, 2001). 

Correlative methods have long been used as a way of dealing with the complexity of petroleum fractions. Relatively easy to measure physical properties such as density, viscosity, and refractive index (ASTM D-1218) have been correlated to hydrocarbon structure (Table 7.3) with the potential to relate refractive index data to the nature of the constituents of a petroleum product. 

Detailed analysis of residual products, such as residual fuel oil, is more complex than the analysis of lower-molecular-weight liquid products. As with other products, there are a variety of physical property measurements that are required to determine whether the residual fuel oil meets specification, but the range of molecular types present in petroleum products increases significantly with an increase in the molecular weight (i.e., an increase in the number of carbon atoms per molecule). Therefore, characterization measurements or studies cannot, and do not, focus on the identification of specific molecular structures. The focus tends to be on molecular classes (paraffins, naphthenes, aromatics, polycyclic compounds, and polar compounds). 

Test methods of interest for hydrocarbon analysis of residual fuel oil include tests that measure physical properties such as elemental analysis, density, refractive index, molecular weight, and boiling range. There may also be some emphasis on methods that are used to measure chemical composition and structural analysis, but these methods may not be as definitive as they are for other petroleum products. 

The book deals primarily with crude oils and petroleum products derived from crude oils. In addition to cleanup techniques, it covers how oil spills are measured and detected, and the properties of the oil and its long-term fate in the environment. The effects of an oil spill on the environment and the effectiveness of cleanup and control vary significantly with the type of oil spilled. The types of oil are reviewed to help the reader understand the different cleanup and control measures needed for different types of oil and environmental circumstances. A glossary of technical terms is provided at the back of the book. 

Wear Preventive Characteristics of (Four Ball Method), (b) ASTM Method D 2509-66, Measurement of Extreme-Pressure Properties of Lubricating Grease (Timken Method). (c) ASTM Method D 2596-67, Measurement of Extreme-Pressure Properties of Lubricating Grease (Four Ball MethodK ASTM Standards Book, Part 17—Petroleum Products, American Society for Testing and Materials, Philadelphia. 

Vapor and liquid phases coexist in virtually all areas of petroleum production operations, including reservoirs, wellbores, surface-production units, and gas-processing plants. Knowledge of fluid properties and phase behavior is required to calculate the fluid in place, fluid recovery by primary depletion, and fluid recovery by enhanced oil recovery techniques such as gas cycling, hydrocarbon solvent injection, and C02 displacement. Because of the complex nature of petroleum reservoir fluids and the often complicated phase behavior observed at elevated temperature and pressure conditions, the fluid properties and phase behavior historically have been measured experimentally. The complex nature of the fluids arises because of the supercritical components which are dissolved in the mixture of paraffinic, naphthenic, and... 

Three different additives (Additive 1, 2 and 3) were used in order to see their effects on Crude oil-5. The viscosity of the crude oil is decreased considerably by treatment with the additives. Measurements of the shear stress-shear rate relationships were performed at constant temperature and experimental data were fitted to the Bingham plastic model using a linear regression program. When the amount of additive was increased from 500 ppm to 1000 ppm, the pour point of the crude oil was decreased significantly (Table 3). Denis and Durand [25] determined the low temperature properties of petroleum products that had been improved either by refinery processing or by adding wax... 

Low temperature filtration (qv) is a common final refining step to remove paraffin wax in order to lower the pour point of the oil (14). As an alternative to traditional filtration aided by a propane or methyl ethyl ketone solvent, catalytic hydrodewaxing cracks the wax molecules which are then removed as lower boiling products. Finished lubricating oils are then made by blending these refined stocks to the desired viscosity, followed by introducing additives needed to provide the required performance. Table 3 Usts properties of typical commercial petroleum oils. Methods for measuring these properties are available from the ASTM (10). 

Petroleum and chemical engineers perform oil reservoir simulation to optimize the production of oil and gas. Black-oil, compositional or thermal oil reservoir models are described by sets of differential equations. The measurements consist of the pressure at the wells, water-oil ratios, gas-oil ratios etc. The objective is to estimate through history matching of the reservoir unknown reservoir properties such as porosity and permeability. 

A wide variety of liquid products are produced from petroleum, that varying from high-volatile naphtha to low-volatile lubricating oil (Guthrie, 1967 Speight, 1999). The liquid products are often characterized by a variety of techniques including measurement of physical properties and fractionation into group types (Chapter 7). 

Important properties of petroleum and its fractions are measured by standardized procedures according to the API or ASTM. A particularly distinctive property is the true boiling point (TBP) curve as a function of the volume percent distilled under standardized conditions. Figure 13.19 is the TBP curve of a whole crude on which are superimposed curves of products that can be taken off sidestreams from a main distillation column, as in Figure 19.21. As samples of the distillate are collected, their densities and other properties of interest also are measured. The figure with Example 13.14 is of such measurements. 

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