Petroleum hydrocarbons chemical properties

Computes the lhcrmoOy))umic and transport properties of 7B common petroleum and chemical industry hydrocarbons. 

Paraffins are relatively inactive compared to olefins, diolefins, and aromatics. Few chemicals could be obtained from the direct reaction of paraffins with other reagents. However, these compounds are the precursors for olefins through cracking processes. The C -Cg paraffins and cycloparaffms are especially important for the production of aromatics through reforming. This section reviews some of the physical and chemical properties of C1-C4 paraffins. Long-chain paraffins normally present as mixtures with other hydrocarbon types in different petroleum fractions are discussed later in this chapter. 

Mineral Oil Hydraulic Fluids and Polyalphaolefin Hydraulic Fluids. Limited information about environmentally important physical and chemical properties is available for the mineral oil and water-in-oil emulsion hydraulic fluid products and components is presented in Tables 3-4, 3-5, and 3-7. Much of the available trade literature emphasizes properties desirable for the commercial end uses of the products as hydraulic fluids rather than the physical constants most useful in fate and transport analysis. Since the products are typically mixtures, the chief value of the trade literature is to identify specific chemical components, generally various petroleum hydrocarbons. Additional information on the properties of the various mineral oil formulations would make it easier to distinguish the toxicity and environmental effects and to trace the site contaminant s fate based on levels of distinguishing components. Improved information is especially needed on additives, some of which may be of more environmental and public health concern than the hydrocarbons that comprise the bulk of the mineral oil hydraulic fluids by weight. For the polyalphaolefin hydraulic fluids, basic physical and chemical properties related to assessing environmental fate and exposure risks are essentially unknown. Additional information for these types of hydraulic fluids is clearly needed. 

Nyer, E. K. and Skladany, G. J., 1989, Relating the Physical and Chemical Properties of Petroleum Hydrocarbons to Soil and Aquifer Remediation Ground Water Monitoring Review, Winter, pp. 54—60. 

Petroleum is typically described in terms of its physical properties (such as density and pour point) and chemical composition (such as percent composition of various petroleum hydrocarbons, asphaltenes, and sulfur). Although very complex in makeup, crude can be broken down into four basic classes of petroleum hydrocarbons. Each class is distinguished on the basis of molecular composition. In addition, properties important for characterizing the behavior of petroleum and petroleum products when spilled into waterways or onto land and/or released into the air include flash point, density (read specific gravity and/or API gravity), viscosity, emulsion formation in waterways, and adhesion to soil. 

The assessment of health effects due to exposure to the total petroleum hydrocarbons requires much more detailed information than what is provided by a single total petroleum hydrocarbon value. More detailed physical and chemical properties and analytical information on the total petroleum hydrocarbons fraction and its components are required. Indeed, a critical aspect of assessing the toxic effects of the total petroleum hydrocarbons is the measurement of the compounds, and the first task is to appreciate the origin of the various fractions (compounds) of the total petroleum hydrocarbons. Transport fractions are determined by several chemical and physical properties (i.e., solubility, vapor pressure, and propensity to bind with soil and organic particles). These properties are the basis of measures of teachability and volatility of individual hydrocarbons and transport fractions (Chapters 8, 9, and 10). 

Volatilization from mixtures of organic contaminants brings about changes in both the physical and the chemical properties of the residual liquid. We consider data on kerosene volatilization, as summarized in Yaron et al. (1998). Kerosene is an industrial petroleum product composed of more than 100 hydrocarbons, which may become a subsurface contaminant. 

Heath JS, and Koblis K. 1993. Review of chemical physical and toxicological properties of components of total petroleum hydrocarbons. Journal of Soil Contamination 2(1) 125. 

An interesting case of interproduct competition is that of the four original lacquer solvents—ethyl alcohol, butyl alcohol, ethyl acetate, and butyl acetate. These were once produced mainly by fermentation processes, but today all are also produced by synthesis from petroleum hydrocarbons. Moreover, in the past 30 years solvents have been developed from petroleum sources which are competing successfully with these materials even though the new compounds are not identical in all properties isopropyl alcohol competes with ethyl alcohol methyl isobutyl carbinol and n-propyl alcohol can replace butyl alcohol methyl ethyl ketone to a large extent supplants ethyl acetate and methyl isobutyl ketone can be substituted for butyl acetate. Thus, petroleum aliphatic chemicals have served both by displacement of source and replacement of end product to supplement and to compete with the fermentation solvents. 

The cycloalkanes also are known as naphthenes, cycloparaffins, or alicyclic hydrocarbons. In the petroleum industry, this class of hydrocarbons is known as naphthenes. Naphthenes have saturated rings. The general formula for the ring without substituents is CnH2n. This is the same as the general formula for the alkene series however, the structural configurations differ completely and, thus, the physical and chemical properties are not at all similar. 

Initially, we will be concerned with the physical properties of alkanes and how these properties can be correlated by the important concept of homology. This will be followed by a brief survey of the occurrence and uses of hydrocarbons, with special reference to the petroleum industry. Chemical reactions of alkanes then will be discussed, with special emphasis on combustion and substitution reactions. These reactions are employed to illustrate how we can predict and use energy changes — particularly AH, the heat evolved or absorbed by a reacting system, which often can be estimated from bond energies. Then we consider some of the problems involved in predicting reaction rates in the context of a specific reaction, the chlorination of methane. The example is complex, but it has the virtue that we are able to break the overall reaction into quite simple steps. 

Petroleum can be fractionated into four generic types of materials representing general chemical properties. These include saturated hydrocarbons, aromatic hydrocarbons, resins, and asphaltenes. The standard ASTM separation procedure (D2007) for isolating the asphaltenes and the other components in petroleum is based on solubility behavior and chromatography, as shown in Fig. 5. Commerically, many refineries utilize solvent separations to produce a solvent deasphalted oil which has lower impurity levels. 

UYCARB Software Systems Corporation Donna Schmidt P.O. Box 26065 Austin. IX 78755-0065 (512) 451-8634 Computes the thermodynamic and transport properties of 78 common petroleum and chemical industry hydrocarbons. 

Various catalysts used in the two processes have been described as follows zeolite, alumina, silica-alumina, FCC catalyst, reforming catalyst, and others. The most common catalysts used in the cracking of heavy hydrocarbons are acidic catalysts alumina and silica-alumina with mesopores, and also zeolite with micropores, etc. They are typically used in the commercial petroleum process. For the chemical properties of catalyst, the... 

Petroleum deposits will vary widely in chemical composition and those obtained from different localities may have entirely different physical and chemical properties. In spite of this diversity, the bulk of the chemical compounds found in petroleum are hydrocarbons. As the name implies, a hydrocarbon is a compound consisting of carbon... 

Diesel fuels are complex mixtures of hydrocarbons defined by physical and chemical properties. Petroleum diesel fuels are based on molecules with 9 to 20 carbon atoms and a boiling range between 170°C and 350°C (10). These fuels are produced by sequential chemical treatments and refining of heavy petroleum oils followed by distillation. In general, specifications for fuels are inclusive so as not to exclude compositions with similar operational characteristics. However, environmental concerns regarding toxic emissions from diesel engines have led to legislation that has forced manufacturers to modify diesel fuel chemistry (11). 

As can be appreciated, solvents possess a wide variety of chemical and physical properties. Because of this diversity there are many different health effects associated with excessive exposure to solvents. While acute renal failure has been documented following exposure to halogenated hydrocarbons [2], glycols [3] and aromatic hydrocarbons, those attributed to light petroleum hydrocarbon exposure are restricted to isolated clinical case reports [4]. More important, but less well proven, is the role of organic solvents in the development or progression of glomerulonephritis or other types of renal diseases. 

These experts collectively have knowledge of total petroleum hydrocarbons physical and chemical properties, toxicokinetics, key health end points, mechanisms of action, human and animal exposure, and quantification of risk to humans. All reviewers were selected in conformity with the conditions for peer review specified in Section 104(i)(13) of the Comprehensive Environmental Response, Compensation, and Liability Act, as amended. 

Health assessment efforts are frequently frustrated by three primary problems (1) the inability to identify and quantify the individual compounds released to the environment as a consequence of a petroleum spill (2) the lack of information characterizing the fate of the individual compounds in petroleum mixtures and (3) the lack of specific health guidance values for the majority of chemicals present in petroleum products. To define the public health implications associated with exposure to petroleum hydrocarbons, it is necessary to have a basic understanding of petroleum properties, compositions, and the physical, chemical, biological, and toxicological properties of the compounds most often identified as the key chemicals of concern. 

Noncarcinogenic Effects. These effects are assessed only if the carcinogenic indicator compounds are not detected or are below regulatory criteria. The following petroleum hydrocarbon fractions, minus the carcinogenic indicator compounds, were selected as representing compounds with similar transport properties. Toxicity values for constituents of the fraction or for a similar mixture were selected to represent the toxicity of the fraction. Aromatic and aliphatic hydrocarbons are considered separately and further subdivided on the basis of equivalent carbon number index (EC). This index is equivalent to the retention time of the compounds on a boiling point GC column (non-polar capillary column), normalized to the //-alkanes. Physical and chemical properties of hydrocarbons that are... 

Chemical and Physical Properties of Petroleum Hydrocarbons, London, Oxford University Press, 1950. 

Hydrocarbons — Organic chemical compounds composed only of the elements carbon and hydrogen. Hydrocarbons are the principal constituents of crude oils, natural gas, and refined petroleum products and include four major classes of compounds (alkanes, alkenes, naphthenes, and aromatics) each with characteristic structural arrangements of hydrogen and carbon atoms, as well as different physical and chemical properties. (See also Alkanes, Alkenes, Aromatics, Naphthenes, Olefins, Paraffin, Saturate group.)... 

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