Physical properties petroleum fuels

The material in this section is divided into three parts. The first subsection deals with the general characteristics of chemical substances. The second subsection is concerned with the chemistry of petroleum it contains a brief review of the nature, composition, and chemical constituents of crude oil and natural gases. The final subsection touches upon selected topics in physical chemistry, including ideal gas behavior, the phase rule and its applications, physical properties of pure substances, ideal solution behavior in binary and multicomponent systems, standard heats of reaction, and combustion of fuels. Examples are provided to illustrate fundamental ideas and principles. Nevertheless, the reader is urged to refer to the recommended bibliography [47-52] or other standard textbooks to obtain a clearer understanding of the subject material. Topics not covered here owing to limitations of space may be readily found in appropriate technical literature. 

Chemical and Physical Properties Petroleum fuels contain paraffins, isoparaffins, naphthenes, and aromatics, plus organic sulfur, oxygen, and nitrogen compounds that were not removed by refining. Olefins are absent or negligible except when created by severe refining. Vacuum-tower distillate with a final boiling point equivalent to 730 to 840 K (850 to 1050°F) at atmospheric pressure may contain from 0.1 to... 

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. 

Information is sometimes needed about the human and environmental hazards associated with handling and shipping various petroleum products. This information can often be obtained by utilizing the physical property values and product safety data information compiled for hazardous materials. This chapter contains valuable safety and hazard information for common fuels, oils and solvents. 

Bio-oil from rapid pyrolysis is usually a dark brown, free-flowing liquid having a distinctive smoky odor. It has significantly different physical and chemical properties compared to the liquid from slow pyrolysis processes, which is more like a tar. Bio-oils are multicomponent mixtures comprised of different size molecules derived primarily from depolymerization and fragmentation reactions of the three key biomass building blocks cellulose, hemicellulose, and lignin. Therefore, the elemental composition of biooil resembles that of biomass rather than that of petroleum oils. Basic properties of biooils are shown in Table 33.7. More detail on fuel-related characteristics is provided in the literature.571... 

The physical properties for liquid fuels that interest combustion engineers most are gravity, both specific gravity and API (American Petroleum Institute) degree density flash and fire temperatures viscosity carbon residue ash water and sediment. These properties will be discussed below. 

Synthetic fuels derived from coal, shale, and tar sands are different from petroleum fuels in chemical and physical properties. Those different properties lead to substantial differences in combustion characteristics and emission. Relative to conventional oils, the synthetic fuels contain high aromatic, fuel nitrogen, and ash and trace mineral and low hydrogen, volatility, and heat of combustion and more corrosive in nature. Therefore, the combustion of synthetic fuels will generate more soot and more NOx and S02 emissions, and is more difficult to be used than that of petroleum fuels in a practical system. This is a challenge for combustion engineers to utilize synthetic fuels in full-scale equipment.19... 

The main improvement of the Ecofining technology compared to the conventional FAME biodiesel is that it allows refiners to obtain a synthetic fuel that has a similar chemical composition and similar chemical-physical properties to petroleum diesel. For this reason the product can all be easily blended with conventional refinery products. Moreover, the integrated production of the green diesel allows the refiner to... 

Dimethyl ether (DME) has been used as a fuel and propellant. It is miscible with most organic solvents and is currently under study as a fuel additive for diesel engines due to its high volatility and high cetane number. DME, like other synthetically derived fuels, can be produced from syngas, is essentially sulfur free, contains nearly zero aromatic compounds, and is considered an excellent substitute for conventional diesel and liquefied petroleum gas (LPG). DME has several physical properties similar to those of LPG. 

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 chemical composition and physical properties of the different types of oil are described in Chapter 3. The oils that are used in this book to illustrate the fate, behaviour, and cleanup of oil spills are introduced. These represent the primary oil and petroleum products used and spilled. They are gasoline, diesel fuel, a light crude oil, a heavy crude oil, an intermediate fuel oil (IFO) which is made from a heavy residual oil and diesel fuel, a residual oil, sometimes called Bunker fuel, and crude oil emulsion. 

As in the case of the miscellaneous physical properties (Table I), the range of the data, averages, specification requirements, and representative values for petroleum derived fuels are given in the table. 

The physical properties of the Shale-II fuels were similar to that of equivalent fuels derived from petroleum. The differences observed could be minimized by modest changes in refining steps. Based on these results and other Navy R and D, shale oil can be considered a promising alternative source for the production of U.S. Navy distillate fuels. 

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