Paraffin naphthene-aromatic

H. Boer and P. van Arkel, Automatic PNA (paraffin-naphthene-aromatic) analyzer for (heavy) naphtha , Chromatographia 4 300-308 (1971). 

Facilitate pre-vulcanisation processing, increase softness, extensibility and flexibility of the vulcanised end-product. The rubber processing industry consumes large quantities of materials which have a plasticising function complex mixtures (paraffinic, naphthenic, aromatic) of mineral hydrocarbon additives, used with the large tonnage natural and synthetic hydrocarbon rubbers, are termed process oils. Because of the complexity of these products, precise chemical definition is usually not attempted. If the inclusion of an oil results in cost reduction it is functioning as an extender. The term plasticiser is commonly reserved for synthetic liquids used with the polar synthetic rubber. 

Detailed analysis of residual products, such as residual fuel oil, is more complex than the analysis of lower-molecular-weight liquid products. As with other products, there are a variety of physical property measurements that are required to determine that residnal fnel oil meets specifications. But the range of molecular types present in petrolenm prodncts increases significantly with an increase in the molecular weight (i.e., an increase in the number of carbon atoms per molecule). Therefore, characterization measurements or studies cannot, and do not, focus on the identification of specific molecular structures. The focus tends to be on molecular classes (paraffins, naphthenes, aromatics, polycyclic compounds, and polar compounds). 

The amount of benzene produced in a reformer will depend on the composition of the feed. Every crude oil has naphtha with different PNA (paraffin, naphthene, aromatics) content. In commercial naphtha trading, the PNA content is often an important specification. High naphthene and aromatic content would indicate a good reformer feed. High paraffin content would indicate a good olefin plant feed. 

Crude oils are classified chemically according to the structures of tire larger molecules in the mixture. Classification methods use combinations of the words paraffinic, naphthenic, aromatic, and asphaltic. For instance, crude oil which contains a predominance of paraffinic molecules will yield very fine lubricating oils from the gas-oil fraction and paraffin wax from the residuum. Oh the other hand, if the larger molecules are aromatic and asphaltic, the heavier fractions of the crude oil are useful for pitch, roofing compounds, paving asphalts, and other such applications. 

The chemicals in petroleum are classified as paraffins, naphthenes, aromatics, and resins-asphaltenes. We have discussed the first three classes, which are hydrocarbons. Now we turn to resins and asphaltenes. 

H. Boer, P. van Arkel and W. J. Boersma, An automatic paraffins-naphthenes-aromatics (PNA), analyzer for the under 200 °C fraction contained in a higher boiling product ,... 

Applies te paraffins, naphthenes, aromatics, alcohols, and ketones with MW <100... 

Group type (LV %) paraffins naphthenes aromatics olefins... 

Yields of pyrolysis products also depend ou the chemical composition of the naphtha feedstock. The thermal stability of hydrocarbons increases in the follov. ing order paraffins, naphthenes, aromatics. It decreases as the chain becomes longer. Thus, it is usually obser ed that the ethylene yield, as well as that of propylene, is higher if the naphtha feedstock is rich in paraffms. 

C5-400°F product gravity, API aniline point (°F) sulfur (ppm) nitrogen (ppm) low mass, LV % paraffins naphthenes aromatics... 

Methane Ethane Propane Butane C5—C9 paraffin naphthene aromatic... 

It is known that paraffins from methane to butane are gases, from C5 till Cl7 are liquids, and from Ci8 onwards are solid substances. The solid paraffins are present in all cmde oils in different amounts, often up to 5%, but in some cmde oils up to 7% or even 12% have been found. Solid fractions of cmde oils do not only contain paraffins, but indeed these solids are complicated mixtures of paraffins, naphthenes, aromatics and other compounds. It has been shown that some heavy fractions from paraffinic oils can contain up to 50% paraffins, 47% naphthenes and up to 3% aromatic compounds. It is known that the higher the boiling temperatures of the erode oil fraction, the less the amount of paraffinic compounds present in the fraction. However, paraffins are present in smaller or higher amounts in all cmde oils, cmde oil fractions and products. The kind and how the paraffins are present in oil (i.e. gas, solved or dispersed) depend on the properties of the erode oil and the chemical conditions of paraffins. 

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