Petroleum hydrocarbons behavior

In the lightening of petroleum hydrocarbon oil, esters of mercaptocarboxyhc acids can modify radical behavior during the distillation step (58). Thioesters of dialkanol and trialkanolamine have been found to be effective multihinctional antiwear additives for lubricants and fuels (59). Alkanolamine salts of dithiodipropionic acid [1119-62-6] are available as water-soluble extreme pressure additives in lubricants (60). 

As we increase our knowledge and hope to learn from our past errors, it becomes important that we as a professional group servicing society continue our efforts to (1) minimize and reduce the uncontrolled and accidental release of petroleum hydrocarbons and organics into the environment, (2) improve our understanding of the overall behavior of these compounds in the subsurface, and the health risks associated with their presence, and (3) continue to develop sound strategies for the recycling, remediation, and restoration of impacted soil, water, and air. 

Farmer, V. E., Jr., 1983, Behavior of Petroleum Contaminants in an Underground Environment In Proceedings of the Canadian Environment Seminar on Ground Water and Petroleum Hydrocarbons, June 26-28, Toronto, Ontario. 

Organic pollutants present in aqueous-solid phase environments and discussed in the present chapter include petroleum hydrocarbons, pesticides, phthalates, phenols, PCBs, chlorocarbons, organotin compounds, and surfactants. In order to study the chemodynamic behavior of these pollutants, it is important that (1) suitable pre-extraction and preservation treatments are implemented for the environmental samples, and (2) specific extraction and/or cleanup techniques for each organic pollutant are carried out prior to the identification and characterization steps. 

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. 

As already noted, the chemical composition of petroleum and petroleum products is complex and may change over time following release into the environment. These factors make it essential that the most appropriate analytical methods are selected from a comprehensive hst of methods and techniques that are used for the analysis of environmental samples (Dean, 1998 Miller, 2000 Budde, 2001 Sunahara et al., 2002 Nelson, 2003 Smith and Cresset, 2003). But once a method is selected, it may not be the ultimate answer to solving the problem of identification and, hence, behavior (Patnaik, 2004). There are a significant number of petroleum hydrocarbon-affected sites, and evaluation and remediation of these sites may be difficult because of the complexity of the issues (analytical, scientific, and regulatory not to mention economic) regarding water and soil affected. 

Dror I, Gerstl Z, Prost R, Yaron B (2000a) Behavior of neat and enriched volatile petroleum hydrocarbons mixture in the subsurface during leaching. Land Contam Reclam 8 341-348... 

Connell DW, Miller GJ. 1980. Petroleum hydrocarbons in aquatic ecosystems Behavior and effects of sublethal concentrations Part 1. Crit Rev Environ Control 11(1) 37-104. 

It appears that Narragansett Bay retains less than 5 % of the nutrients, less than 10 % of the Mn, and perhaps 15-30 % of the Cd that is input to the system each year. The removal of Cu (70-95 %) and Pb (80-100 %) is much more effective. Somewhere between 25-65 % of the petroleum hydrocarbons entering the Bay remain in the sediments. These estimates are in agreement with the behavior of the different materials in sediment-water flux measurements and in experiments using the large MERL mesocosms. 

In this paper we have brought together much of the information that is presently available on certain pollutants in Narragansett Bay (Rhode Island, U.S.A.) in an attempt to develop annual mass balances for carbon, nitrogen and phosphorus as well as some heavy metals (Mn, Cd, Pb, Cu) and petroleum hydrocarbons under conditions of recent input. We cannot pretend complete knowledge of the quantities or behavior of any of these substances in the Bay, but they have all been subjected to considerable study and it seemed that it would be interesting and instructive to compare the effectiveness of this one system as a trap for a variety of different materials. 

Mass-balance considerations, in particular the observed consumption of contaminants, were useful in showing the importance of biodegradation processes for limiting the mobility of petroleum hydrocarbons in groundwater systems. The mass-balance approach also contributed to our understanding of the environmental fate of chlorinated solvents in groundwater systems. In the 1980s, the observed behavior of chlorinated... 

The mixing of a synthetic surfactant and a petroleum soap can be explained in terms of surfactant mixing rules proposed by Wade et al. in 1977 (53). These rules are based on previous studies (54) of the equivalent alkane carbon number (EACN) concept, which show that hydrocarbon behavior toward surfactants is additive and weighted by mole fraction according to the formula ... 

Connell, D.W., and G.J. Miller. 1981b. Petroleum hydrocarbons in aquatic ecosystems—behavior and effects of sublethal concentrations Part 2. CRC Critical Reviews in Environmental Control 11 105-162. 

Lubricants. Petroleum lubricants continue to be the mainstay for automotive, industrial, and process lubricants. Synthetic oils are used extensively in industry and for jet engines they, of course, are made from hydrocarbons. Since the viscosity index (a measure of the viscosity behavior of a lubricant with change in temperature) of lube oil fractions from different cmdes may vary from +140 to as low as —300, additional refining steps are needed. To improve the viscosity index (VI), lube oil fractions are subjected to solvent extraction, solvent dewaxing, solvent deasphalting, and hydrogenation. Furthermore, automotive lube oils typically contain about 12—14% additives. These additives maybe oxidation inhibitors to prevent formation of gum and varnish, corrosion inhibitors, or detergent dispersants, and viscosity index improvers. The United States consumption of lubricants is shown in Table 7. 

The interfacial tension behavior between a crude oil (as opposed to pure hydrocarbon) and an aqueous surfactant phase as a function of temperature has not been extensively studied. Burkowsky and Marx T181 observed interfacial tension minima at temperatures between 50 and 80°C for crude oils with some surfactant formulations, whereas interfacial tensions for other formulations were not affected by temperature changes. Handy et al. [191 observed little or no temperature dependence (25-180°C) for interfacial tensions between California crude and aqueous petroleum sulfonate surfactants at various NaCI concentrations. In contrast, for a pure hydrocarbon or mineral oil and the same surfactant systems, an abrupt decrease in interfacial tension was observed at temperatures in excess of 120°C 1 20]. Non ionic surfactants showed sharp minima of interfacial tension for crude... 

On this basis, petroleum may have some value in the crude state but, when refined, provides fuel gas, petrochemical gas (methane, ethane, propane, and butane), fiansportation fuel (gasoline, diesel fuel, aviation fuel), solvents, lubricants, asphalt, and many other products. In addition to the hydrocarbon constituents, petroleum does contain heteroatomic (nonhydrocarbon) species, but they are in the minority compared to the number of carbon and hydrogen atoms. They do, nevertheless, impose a major influence on the behavior of petroleum and petroleum products as well as on the refining processes (Speight and Ozum, 2002). 

In very general terms, petroleum is a mixture of (1) hydrocarbon types, (2) nitrogen compounds, (3) oxygen compounds, (4) sulfur compounds, and (5) metallic constituents. Petrolenm prodncts are less well defined in terms of heteroatom compounds and are better defined in terms of the hydrocarbon types present. However, this general definition is not adequate to describe the true composition as it relates to the behavior of the petroleum, and its products, in the environment. For example, the occnrrence of amphoteric species (i.e., compounds having a mixed acid-base natnre) is not always addressed, nor is the phenomenon of molecnlar size or the occnrrence of specific functional types that can play a major role in petrolenm behavior. 

This work has demonstrated that organically bound sulfur forms can be distinguished and in some manner quantified directly in model compound mixtures, and in petroleum and coal. The use of third derivatives of the XANES spectra was the critical factor in allowing this analysis. The tentative quantitative identifications of sulfur forms appear to be consistent with the chemical behavior of the petroleum and coal samples. XANES and XPS analyses of the same samples show the same trends in relative levels of sulfide and thiophenic forms, but with significant numerical differences. This reflects the fact that use of both XPS and XANES methods for quantitative determinations of sulfur forms are in an early development stage. Work is currently in progress to resolve issues of thickness effects for XANES spectra and to define the possible interferences from pyritic sulfur in both approaches. In addition these techniques are being extended to other nonvolatile and solid hydrocarbon materials. 

---