Hydrocarbons specific gravity

Source Percentage of rubber hydrocarbon Specific gravity Percentage sulphur... 

In oil bearing formations, the presence of polar chemical functions of asphaltenes probably makes the rock wettable to hydrocarbons and limits their production. It also happens that during production, asphaltenes precipitate, blocking the tubing. The asphaltenes are partly responsible for the high viscosity and specific gravity of heavy crudes, leading to transport problems. 

The specific gravity of a pure hydrocarbon is linked to its H/C ratio, the specific gravity decreasing as the H/C ratio increases. Table 3.2 illustrates this variation for hydrocarbons having 14 carbon atoms. 

It is based on the observations that the specific gravities of hydrocarbons are related to their H/C ratios (and thus to their chemical character) and that their boiling points are linked to the number of carbon atoms in their molecules. 

Specific gravity compared with H/C ratio for pure hydrocarbons. 

As in the case of density or specific gravity, the refractive index, n, for hydrocarbons varies in relation to their chemical structures. The value of n follows the order n paraffins < n naphthenes < n aromatics and it increases with molecular weight. 

The standard specific gravity is the ratio of the density of a hydrocarbon at 15.55°C (60°F) to that of water at the same temperature. It differs from the specific gravity d] which is the ratio of the density of a hydrocarbon at 15°C to that of water at 4°C. 

It is common that a mixture of hydrocarbons whose boiling points are far enough apart petroleum cut) is characterized by a distillation curve and an average standard specific gravity. It is then necessary to calculate the standard specific gravity of each fraction composing the cut by using the relation below [4.8] ... 

Maxwell and Bonnel (1955) proposed a method to calculate the vapor pressure of pure hydrocarbons or petroleum fractions whose normal boiling point and specific gravity are known. It is iterative if the boiling point is greater than 366.5 K ... 

Distinctions between tar sands bitumens and heavy oils are based largely on differences in viscosities. The bitumen in oil sand has a specific gravity of less than 0.986 g/mL (12°API), and thus oil sands may be regarded as a source of extremely heavy cmde oil. Whereas heavy oils might be produced by the same techniques used for the lighter cmde oils, the bitumens in tar sands are too viscous for these techniques. Consequently these oil-bearing stones have to be mined and specially processed to recover contained hydrocarbon. 

Hydrocarbon Solvents. Most hydrocarbon solvents are mixtures. Few commercial hydrocarbon solvents are single compounds. Toluene is an exception. Hydrocarbon solvents are usually purchased and suppHed on specification. The most important specification properties are distillation range, solvency as expressed by aniline cloud poiat and Kauri-Butanol (KB) value, specific gravity, and dash poiat. Composition requirements such as aromatic content and benzene concentration are also important ia many appHcations. 

For undefined hydrocarbon mixtures, the liquid density may be predicted at any temperature (T) from the mean average boiling point (MeABP) and the specific gravity (sp gr) by Eq. (2-94), adopted from Ritter et al. ... 

This, the mass per unit volume, is a function of the weight of individual molecules and the way they pack. The hydrocarbons do not possess heavy atoms and therefore the mass of the molecule per unit volume is rather low. Amorphous hydrocarbon polymers generally have specific gravities of 0.86-1.05. Where large atoms are present, e.g. chlorine atoms, the mass per unit volume is higher and so PVC, a substantially amorphous polymer, has a specific gravity of about 1.4. 

The specific gravities (s.g.) of liquid chemicals vary widely, e.g. for the majority of hydrocarbon fuels s.g. <1.0 but for some natural oils and fats, chlorinated hydrocarbons, s.g. >1.0. Density is generally reduced by any increase in temperature. As a result ... 

Alkenes — Also known as olefins, and denoted as C H2 the compounds are unsaturated hydrocarbons with a single carbon-to-carbon double bond per molecule. The alkenes are very similar to the alkanes in boiling point, specific gravity, and other physical characteristics. Like alkanes, alkenes are at most only weakly polar. Alkenes are insoluble in water but quite soluble in nonpolar solvents like benzene. Because alkenes are mostly insoluble liquids that are lighter than water and flammable as well, water is not used to suppress fires involving these materials. Because of the double bond, alkenes are more reactive than alkanes. 

The aliphatic hydrocarbon heptane, CyHjg, has recently been discovered as a constituent of the oil obtained by the distillation of the resinous exudation of Pinus Sabiniana, Pinus Jeffreyi, and a few other essential oils. It is a highly volatile liquid of specific gravity 0 688 and boils at 98 to 99°. It has, probably, the lowest specific gravity of all liquids found naturally in essential oils. 

Henderson and Sutherland have prepared a hydrocarbon synthetically which is possibly a modification of terpinene. They reduced thymo-hydroquinone, thus obtaining menthane-2-5-diol, which was heated for half an hour with twice its weight of sulphate of potash under a reflux condenser, and so yielded a terpene boiling at 179°, of specific gravity about 0 840 and refractive index 1-4779. 

Its low specific gravity indicates that it is an open-chain compound, and from its easy reduction by sodium and alcohol, into dihydroaplotaxene, and by hydrogen and platinum black into normal heptadecane OjjHj,., it is evident that aplotaxene is a tetraolefinic normal chain hydrocarbon. 

The most common low-specific-gravity solids used to reduce cement slurry specific weight are bentonite, diatomaceous earth, solid hydrocarbons, expanded perlite and pozzolan. It may not be possible to reduce the cement slurry specific weight enough with the above low-specific-weight materials when very weak formations are exposed. In such cases nitrogen is used to aerate the mud column above the cement slurry to assist in further decreasing the hydrostatic pressure. 

Solid Hydrocarbons. Gilsonite (an asphaltite) and coal are used as very-low-specific-gravity solids additives. These additives do not require a great deal of water to be added to the slurry when they are used. 

The °AP1 gravity measures the density of a hydrocarbon liquid. Specific gravity (SG) is another common measurement of density. The liquid SG is the relative weight of a volume of sample to the weight of the same volume of water at 60°F (15.5°C). 

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