N -Paraffins

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. 

For paraffinic materials, the results are close to those of a TBP, the equipment being calibrated using n-paraffins. For aromatics, the differences are larger. 

The pour point is the lowest temperature at which an oil can still pour while it is cooled, without agitation, under standardized conditions. The pour point of paraffinic bases is linked to the crystallization of n-paraffins. The pour point of naphthenic bases is related to a significant viscosity increase at low temperatures. This property can be improved by additives. 

The feedstock usually comes from catalytic cracking, sometimes from steam cracking. The reaction products are Cy-Cg isoparaffins. The byproducts are the C3-C4 n-paraffins which do not react. 

Coefficients for calculation of the enthalpy of an ideal gas (equation 4.77) for n-paraffins. 

Calculational coefficients related to a change of state for n-paraffins. 

Aromatics-single ring, mono and disubstituted by n-paraffins 6 1.91 0.0418 23.5 66.1... 

Dry cleaning - Several solvents exist to replace the ozone-depleting solvents that have traditionally been used by the dry cleaning industry. Perchloroethylene has been used for more than three decades. Petroleum solvents, while flammable, can be safely used when appropriate safety precautions are taken. They include white spirit, Stoddard solvent, hydrocarbon solvents, isoparaffins, and n-paraffin. A... 

Normal paraffins in the C,o - C,5 range are recovered from petroleum fractions by adsorption-desorption using molecular sieves. Ammonia can be used to desorb the n-paraffins. By employing two beds of sieves, one on adsorption and one on desorption at all times, a continuous flow of the feed and ammonia is maintained. 

In the adsorption step, the hydrocarbon feed is vaporized in a furnace and is passed upward through the sieves which have been previously desorbed by ammonia. The n-paraffins in the feed are adsorbed by the sieve and displace the ammonia. The amount of ammonia removed depends largely on the molecular... 

Paraffin-anstrich, m. paraffin coat(ing). -bad, n. paraffin bath, -durchtrdnkung,/. impregnation with paraffin, -einbettung, /. imbedding in paraffin. 

VaseKn, n. petroleum jelly, petrolatum, (T.N.) Vaseline. -51, n. paraffin oil. 

On heating lower n-paraffins the so-called rotator phases occur a few degrees below the melting point they are either hexagonal or nearly so [78-82]. This is the earliest recognized example of a hexagonal phase and thus the best known. 

The pour point of a crude oil or product is the lowest temperature at which an oil is observed to flow under the conditions of the test. Pour point data indicates the amount of long-chain paraffins (petroleum wax) found in a crude oil. Paraffinic crudes usually have higher wax content than other crude types. Handling and transporting crude oils and heavy fuels is difficult at temperatures helow their pour points Often, chemical additives known as pour point depressants are used to improve the flow properties of the fuel. Long-chain n-paraffins ranging from 16-60 carhon atoms in particular, are responsible for near-ambient temperature precipitation. In middle distillates, less than 1% wax can be sufficient to cause solidification of the fuel. ... 

A zero value has been assumed for n-paraffins, 100 for aromatics. A low BMCI value indicates a higher paraffin concentration in a petroleum fraction. 

The IsoSiv process is an isobaric, isothermal adsorption technique used to separate n-paraffins from gas oils. The operation conditions are approximately 370°C and 100 psi. Desorption is achieved using n-pentane or n-hexane. The solvent is easily distilled from the heavier n-paraffins and then recycled. 

CHEMICALS FROM HIGH MOLECULAR WEIGHT n-PARAFFINS... 

Chlorination of n-paraffins (C10-C14) in the liquid phase produces a mixture of chloroparaffins. Selectivity to monochlorination could be increased by limiting the reaction to a low conversion and by decreasing the chlorine to hydrocarbon ratio. Substitution of secondary hydrogen predominates. The reaction may be represented as ... 

Polychlorination, on the other hand, can he carried out on the whole range of n-paraffins from C10-C30 at a temperature range of 80-120°C (using a high Cl2/paraffm ratio). The product has a chlorine content of approximately 70%. Polychloroparaffins are used as cutting oil additives, plasticizers, and retardant chemicals. 

The reliability and economics of producing high-quality n-paraffins is a critical factor in the use of n-paraffins for the production of SCR... 

Alkylation of benzene with linear monoolefms is industrially preferred. The Detal process (Figure 10-9) combines the dehydrogenation of n-paraffins and the alkylation of benzene. Monoolefms from the dehydrogenation section are introduced to a fixed-bed alkylation reactor over a heterogeneous solid catalyst. Older processes use HF catalysts in a liquid phase process at a temperature range of 40-70°C. The general alkylation reaction of benzene using alpha olefins could be represented as ... 

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