Polar aromatics catalytic cracking

As is indicated in Figure 4, saturates contribute less to the vacuum gas oil (VGO) than the aromatics, but more than the polars present at percentage, rather than trace, levels. VGO itself is occasionally used as a heating oil but most commonly it is processed by catalytic cracking to produce naphtha or by extraction to yield lubricant oils. 

Saturated constituents contribute less to the vacuum gas oil than the aromatics but more than the polar constituents that are now present at percentage rather than trace levels. The vacuum gas oil itself is occasionally used as heating oil but most commonly it is processed by catalytic cracking to produce naphtha or by extraction to yield lubricating oil. Within the vacuum gas oil saturates, the distribution of paraffins, /iso-paraffins and naphthenes is highly dependent upon the petroleum source. The bulk of the vacuum gas oil saturated constituents consist of /Iso-paraffins and naphthenes. The naphthenes contain from one to more than six fused rings and have alkyl substituents. For mono- and di-aromatics, the alkyl substitution typically involves one long side chain and several short methyl and ethyl substituents. 

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