Fractions of crude oil

Properly speaking, steam cracking is not a refining process. A key petrochemical process, it has the purpose of producing ethylene, propylene, butadiene, butenes and aromatics (BTX) mainly from light fractions of crude oil (LPG, naphthas), but also from heavy fractions hydrotreated or not (paraffinic vacuum distillates, residue from hydrocracking HOC). 

Steam reforming is, along with catalytic reforming, a process that can produce the additional hydrogen needed for upgrading and converting the heavy fractions of crude oil. 

An important industrial example of W/O emulsions arises in water-in-crude-oil emulsions that form during production. These emulsions must be broken to aid transportation and refining [43]. These suspensions have been extensively studied by Sjoblom and co-workers [10, 13, 14] and Wasan and co-workers [44]. Stabilization arises from combinations of surface-active components, asphaltenes, polymers, and particles the composition depends on the source of the crude oil. Certain copolymers can mimic the emulsion stabilizing fractions of crude oil and have been studied in terms of their pressure-area behavior [45]. 

From the produc t specifications, distillate yields are computed as follows From Fig. 13-86 and the ASTM D 86 50 percent temperatures, TBP 50 percent temperatures of the three intermediate cuts are obtained as 155, 236, and 316°C (311, 456, and 600°F) for the HN, LD, and HD respectively. The TBP cut points, corresponding volume fractions of crude oil, and flow rates of the four distillates are readily obtained by stai-ting from the specified 343°C (650°F) cut point as follows, where CP is tne cut point and T is the TBP temperature (°F) ... 

Distillation is probably Ihe most widely used separation (mass transfer) process in the chemical and allied industries. Its applications range from the rectification of alcohol, which has been practiced since antiquity, lo the fractionation of crude oil. The separation of liquid mixtures by distillation is based on differences in volatility between the components. The greater the... 

The first engines invented by Rudolf Diesel ran on groundnut oil, but because of the advent of relatively cheap oil this type of biodiesel never became commercially viable. Since about 1930 the diesel engine has been refined and fine tuned to run on the diesel fraction of crude oil, which consists mainly of saturated hydrocarbons. For this reason the modem diesel engine cannot run satisfactorily on a pure vegetable oil feedstock because of problems of high viscosity, deposit formation in the injection system and poor cold-start properties. Today, however, environmental... 

Figure 3. Content of Fractions of Crude Oil and Shale Oil by Silicon Gel Column.

Methodology Various fraction of crude oil was distilled under different condition after being sonicated by an ultrasonic processor for different intervals of time. Density of these fractions was determined by dialatometer. Viscosities of these fractions were measured using Ubbelohde viscometer and the results given as under ... 

Heavy oils and bitumens are characterized by the presence of large molecules, the asphaltenes, which among their complex molecules also present metal-containing moieties. Typical metals present in petroleum comprise various species (e.g., Ni, V, Fe, Al, Na, Ca, and Mg), which are particularly accumulated in the asphaltene fraction of crude oil [382-384],... 

Hexanc is a very volatile aliphatic hydrocarbon. It is a constituent in the paraffin fraction of crude oil and natural gas and is also used as an industrial chemical and laboratory reagent. Laboratory grade -hexane contains approximately 99% w-hexane. "Hexane" or "hexanes" is a commercial and industrial product consisting of a mixture of hydrocarbons with six carbon atoms and includes -hexane and its isomers 2-methylpentane and 3-methylpentane as well as small amounts of other hydrocarbons (Brugnone et al. 1991). Laboratory and industrial solvents such as "hexane" and petroleum ether contain -hexane from <0.1% to as much as 33% (Creaser et al. 1983). Information regarding the chemical identity of -hexane is located in Table 3-1. 

The most widely used standard is a belemnite from the Peedee Formation in South Carolina (PDB) therefore, some ratios may be expressed as negative values. Most carbon isotope ratio correlations are made on the C15+ fraction of crude oil because it is less affected by degradation processes. Valid correlations using carbon isotopes can only be conducted on the same fractions of samples. 

Wilson and Madsen [152] used the metabolic pathway for bacterial naphthalene oxidation as a guide for selecting l,2-dihydroxy-l,2-dihydronaphthalene as a unique transient intermediary metabolite whose presence in samples from a contaminated field site would indicate active in situ naphthalene biodegradation (Fig. 26). Naphthalene is a component of a variety of pollutant mixtures. It is the major constituent of coal tar [345], the pure compound was commonly used as a moth repellant and insecticide [345], and it is a predominant constituent of the fraction of crude oil used to produce diesel and jet fuels [346]. Prior studies at a coal tar-contaminated field site have focused upon contaminant transport [10,347], the presence of naphthalene catabolic genes [348, 349], and non-metabolite-based in situ contaminant biodegradation [343]. 

Naphthalene and its homologs are less acutely toxic than benzene but are more prevalent for a longer period during oil spills. The toxicity of different crude oils and refined oils depends not only on the total concentration of hydrocarbons but also the hydrocarbon composition in the water-soluble fraction (WSF) of petroleum, water solubility, concentrations of individual components, and toxicity of the components. The water-soluble fractions prepared from different oils wiU vary in these parameters. Water-soluble fractions (WSFs) of refined oils (e.g.. No. 2 fuel oil and bunker C oil) are more toxic than water-soluble fraction of crude oil to several species of fish (killifish and salmon). Compounds with either more rings or methyl substitutions are more toxic than less substituted compounds, but tend to be less water soluble and thus less plentiful in the water-soluble fraction. 

Figure 2-14 Sketch of a trickle bed reactor used for hydroprocessingjaf the residual oil fraction of crude oil into tde boiling range used for gasoline and diesel fuel.

The petroleum hydrotreating reactor is the most important example of this reactor. As discussed in Chapter 2, the hydrogenation and cracking of the heavy fraction of crude oil to produce lighter and volatile products occurs in an overall reaction... 

Carbon black includes several forms of artificially prepared carbon, such as furnace black, channel black, lamp black, and animal charcoal. It is a finely divided form of carbon consisting of particles of extremely fine size. It is obtained by partial combustion (in 50% required air) of vapors of heavy oil fraction of crude oil in a furnace or by thermal cracking of natural gas. Carbon black is used in many abrasion-resistant rubber products including tire treads and belt covers. It also is used in typewriter ribbons, printing inks, carbon paper, and paint pigments. It also can be an absorber for solar energy and UV radiation. 

A reduction in fatigue life was observed when the binder was modified by the addition of selected fractions of crude oil. The frequency distribution became bimodal with peaks at 200 x 103 and 1400 x 103 cycles. However, even these reduced fatigue lives of sulphur concrete exceed that for portland cement concretes. 

The supercritical fluid extraction of oil seeds has been investigated extensively by several authors [34,98]. Possible applications of supercritical fluids in the edible-oil industry include deacidification, deodorization, and fractionation of crude oils and chemical conversion (like hydrogenation, and enzymatic reactions). 

There are two older well-used methods for determining the carbon residue the Conradson method (ASTM D-189) and the Ramsbottom method (ASTM D-524). Both are equally applicable to the high-boiling fractions of crude oils that decompose to volatile material and coke when distilled at a pressure of 1 atm. Heavy oils and residua which contain metallic constituents (and distillation... 

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