Mixed Paraffinic Hydrocarbons

Intermediate liquid 8 values are obtained by mixing liquids of known solubility parameter SPS makes use of this. The 8 value of the mixture is equal to the volume-weighted sum of the individual component liquid 8 values. Thus, the mass uptake of a miscible liquid mixture by an elastomer may be very much greater than the swelling which would occur in the presence of either one of the constituent liquids alone. The mixture could of course comprise more than two liquid components, and an analogous situation would apply MERL have applied this approach for the offshore oil-production industry to allow realistic hydrocarbon model oils to be developed,basically by mixing one simple aliphatic (paraffinic) hydrocarbon, one naphthenic, and one aromatic to proportions that meet two criteria, namely, that... 

Oxyhydrochlorination A two-stage process for making gasoline from lower paraffinic hydrocarbons, especially methane. The methane, mixed with oxygen and hydrogen chloride, is passed over a supported copper chloride catalyst, yielding a mixture of chloromethanes ... 

Three broad classes of crude petroleum exist the paraffin types, the asphaltic types, and the mixed-base types. The paraffin types are composed of molecules in which the number of hydrogen atoms is always two more than twice the number of carbon atoms. The characteristic molecules in the asphaltic types are naphthenes, composed of twice as many hydrogen atoms as carbon atoms. In the mixed-base group are both paraffin hydrocarbons and naphthenes. 

One toluene production process commences with mixed hydrocarbon stocks and can be used for making both toluene and benzene, separately or simultaneously. The process is a combination of extraction and distillation. An aqueous dimethyl sulfoxide (DMSO) solution is passed countercur-rently against the mixed hydrocarbon feed. A mixture of aromatic and paraffinic hydrocarbons serves as reflux. 

Reception of a gas mix of CO and H2 from hydrocarbon raw material is a base process of chemical, oil-and-gas and metallurgical industry. In depending on use the mix of CO and H2 are called technological gas, synthesis-gas, regenerative gas. The basic row material to produce the mentioned mix are natural gas and associated petroleum gas. Hydrocarbons of these gases are oxidized with H20 or (and) C02 accordingly forming t the mix of CO and H2. The most part of natural gas and associated gas contains paraffin hydrocarbons and their reactions with water look as follows ... 

The agreement between the observed and calculated values of L is very striking, and seems to point to a definite and dominating relationship between the calorific values of the combustibles named in the table —the paraffin hydrocarbons—and their lower limits of inflammation when mixed with air. 

If the residue which remains after distillation is a waxlike solid consisting largely of paraffin hydrocarbons the crude is designated as paraffin base. If the residue is a black pitchlike solid the crude is called asphalt base, Pennsylvania crude has a paraffin base whereas California oils are for the most part asphalt base. Often a clear-cut distinction cannot be made and the crude is described as being mixed base oil. Most Mid-Continent crudes are of this tyrpe. 

It is difficult to ascertain the reasons for the magnitude of improvement in vapor-liquid predictions using the semiempirical mixing rules instead of the modified VDW one-fluid rules. The semiempirical rules probably offset the truncation error in the approximation A = Ax to some extent. It certainly is interesting that the orientation parameter yx = 8/ is independent of the set of characteristic energy parameters, cy, for the mixture. This possibly indicates for normal paraffin hydrocarbons (and perhaps similar nonpolar fluids) that contributions of molecular attraction and orientation effects are essentially independent, but that steric and size effects are dependent. 

Emulsion liquid membranes have been formulated for the removal of species without chemical carriers. These systems rely on solubility differences between permeant species. The first work performed by Li (73) dealt with the separation of a bineiry mixture of aromatic eind paraffinic hydrocarbons. The hydrocarbons were encapsulated in an aqueous liquid membrane forming an emulsion which was distributed in a hydrocarbon solvent and mixed. The aromatic hydrocarbons preferentially permeated through the aqueous liquid membrane phase due to solubility differences. Cahn and Li (7 ) describe a liquid membrane formulation for phenol removal in which sodium hydroxide is encapsulated by an organic liquid membrane. The resulting membrane phase is mixed with a continuous aqueous phase containing phenol. 

An example of this type of process of selective solute partitioning is urea based adductive crystallization. A saturated solution of urea in water at 70 °C may be mixed with a mixture of aromatic and paraffinic hydrocarbons present in a solvent at 40 °C (the Edeleanu process). Under conditions of appropriate refrigeration, lumps of urea-n-paraffin adducts appear as crystals (Findlay, 1962 Fuller, 1972). As shown in Figure 4.1.23(a), the host compound, urea, has crystallized into a form having a central tunnel open at both ends the tunnel accommodates the "guest paraffinic hydrocarbon molecule and holds it by van der Waals forces with m urea molecules forming the tunnel ... 

For desulfurization of naphtha, a more complicated process is required. Hydrodesulfurization quite often is used. About 0.5 mole of H2 is mixed with 1 mole of vaporized naphtha or 250 scf (Standard Cubic Feet) per barrel, depending upon the sulfur and olefin content. The mixture is preheated to 320 "C and passed over a cobalt-molybdenum catalyst, where the olefins are hydrogenated to paraffin hydrocarbons and the sulfur compounds are reduced to H2S. The gas then is passed over a sulfur adsorbent such as iron or zinc oxide. It may or may not be necessary to condense the naphtha, depending upon the amount of hydrogen used and the need to remove it from the naphtha. 

Pig. 6. Typical stmctures in lube oil (a) / -paraffin, (b) isoparaffin, (c) cycloparaffin, (d) aromatic hydrocarbon, and (e) mixed aUphatic and aromatic ring... 

Separation of Norma/ and Isoparaffins. The recovery of normal paraffins from mixed refinery streams was one of the first commercial appHcations of molecular sieves. Using Type 5A molecular sieve, the / -paraffins can be adsorbed and the branched and cycHc hydrocarbons rejected. During the adsorption step, the effluent contains isoparaffins. During the desorption step, the / -paraffins are recovered. Isothermal operation is typical. 

N204 also forms expl mixts with incompletely halogenated hydrocarbons, NGu, carbon disulfide, etc (Ref 33). The effect of spontaneous decompn by oxidation-reduction reactions when N204 is mixed with a number of fuels (hydrazine, gasoline, liq paraffin, etc) has resulted in its extensive use in liq propint rocket engines (Refs 12, 22, 27 35)... 

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