Hydrocarbon viscosities

Kouzel, B. (1965), How pressure affects liquid viscosity . Hydrocarbon Process. Petrol. Refiner, Vol. 44, No. 3, p. 120. 

Nemunaitis, R R., Sieve Trays Consider Viscosity, Hydrocarbon Ebocessing Nov., 235 (1971). 

A distillation operation separating a low-viscosity hydrocarbon mixture requires three shell-and-tube heat exchangers. The liquid feed is to be preheated to saturated liquid by heat recovery from another low-viscosity hydrocarbon stream. The reboiler is to be a vertical thermosyphon using steam heating. 

Comparisons of the estimated volume to the actual volume recovered prove to be the only reasonable procedure for assessing the recoverable volume considering all the variables involved. These comparisons indicate that the volume of hydrocarbon retained in the aquifer is higher than published residual saturation values. Based on experience for gasoline and low-viscosity hydrocarbons, the recoverable volumes have ranged from 20 to 60% of the pore volume in fine to medium sands. 

Tar sands Mixture of sand grains, water, and a high-viscosity hydrocarbon called bitumen, which is a member of the petroleum family. 

Metal and metal oxide catalysts with this capability were reported in the 1980s. Several of these metals occur in widely distributed petroleum samples and are among the above listed as constituents of primordial Earth planetary orbit dust. In the metallic and compounded state some have the ability to catalyze hydrogenation of carbon to kerogen like high viscosity hydrocarbons. Kerogen, a heavier petroleumlike hydrocarbon mixture occurs in tar sands and porous shales (oil shale). Thus the question of conceivable prehistoric or more recent petroleum from methane generation must be considered. 

Addition of a low viscosity hydrocarbon solvent often extracts the oil from the water the extract layer of solvent and solute separates from the water. The large amount of solvent needed to separate emulsions of water in a viscous heavy oil is uneconomic because of the dilute solution needed to obtain a continuous water phase. Addition of solvent, possibly up to an equal amount, is reasonable and is desirable to reduce the viscosity sufficiently to pump and transport the heavy oil. A cheap aliphatic solvent— e.g.9 kerosene—is preferable, but bituminous oil fractions are much more soluble in aromatic solvents, particularly at temperatures near the ambient. However, the water and solid particles are not at acceptable limits even after much dilution, especially in the presence of fine particles as in some crudes from California and Venezuela and particularly from tar sands as those in Athabasca (Alberta, Canada). 

Several techniques are employed by the industry to overcome these problems the two most commonly used methods are the application of heat and dilution with a solvent (i.e., low-viscosity hydrocarbons such as condensate, natural gasoline, and, most often, naphtha). Both methods serve to reduce the transported crude oil s viscosity dilution will also reduce the heavy-oil mixture s pour point. 

The main hazard with low volatility, low viscosity hydrocarbons such as cumene is aspiration pneumonitis, which may occur after vomiting accidentally ingested material. Cumene is irritating to the eyes and skin. Prolonged skin contact may result in... 

Another technique to increase sedimentation stability of emulsions is viscosity control of the disperse phase. It is noted in [31—32, 35] that the viscosity of the disperse phase influences the stability of o/w emulsions. The effect of the disperse phase viscosity of various nature on the mean size d of the emulsion droplets is clearly seen from Fig. 6.9. The change of the nature of high-viscosity hydrocarbon component (decane, toluene, MS-20 oil) has no substantial effect... 

Improved quality alkylates. With hydrocarbon-continuous dispersions, most of the agitation energy is transferred to the relatively low viscosity hydrocarbon phase. Transfer of reactants to the interfaces would be relatively rapid, probably significantly more rapid than those in acid-continuous dispersions. 

Hydrocarbon-continuous dispersions separate by gravity much faster than acid-continuous dispersions. The high density acid droplets sink rapidly through the rather low viscosity hydrocarbon phase. In acid-continuous dispersions, the low density droplets rise relatively slowly through the acid phase, which, in the case of sulfuric acid, has a relatively high viscosity. 

Alkylbenzenes are only mildly toxic if swallowed, however there is a danger that these low-viscosity hydrocarbon liquids will tend to break up into a foam if the patient vomits and may therefore be aspirated into the lungs - a highly hazardous situation. Ejects on the skin and mucous membranes are similar to mineral oils i.e. slightly to moderately irritating, due to their tendency to de-fat the skin. Inhalation of fumes can have a slight narcotic effect, although inhalation is unlikely at normal in-use temperatures. 

The Isodewaxing Process, commercialized in 1993 by ChevronTexaco, catalytically isomerizes n-paraffms into iso-paraffins. This decreases the wax content and increases the concentration low-viscosity hydrocarbons, both of which are desirable. Isodewaxing also removes sulfur and nitrogen, and it saturates aromatics. Products have a high viscosity index (VI), low pour point, and excellent response to additives. 

Thermal conductivity This is the ability of a material to let heat pass. Metals, water, and materials that are good conductors of electricity have a high thermal conductivity. Air, rubber, and materials that are bad conductors of electricity have a low thermal conductivity. High viscosity hydrocarbons are bad conductors of heat. 

Valentine and co-workers proposed merging the ODNP technology at 0.35 Tesla with encapsulating proteins in reverse micelles dispersed in low viscosity hydrocarbon solvents. Using these solvents rather than water greatly reduced the heating effects of microwaves. The nitroxide radicals were introduced in the reverse micelle system in three ways attached to the protein, embedded in the reverse micelle shell and free in the aqueous core. 

Insert the syringe needle through the inlet septum up to the syringe barrel and inject the sample or standard at a uniform rate of 0.2 to 1.0 pL/s. Rate of injection is dependent on such factors as viscosity, hydrocarbon type and nitrogen concentration. Each user must adopt a method whereby a consistent and uniform injection rate is ensured. 

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