Petroleum treatment primary processes

These processes can be classified as primary or secondary processes. In this book, primary processes are used to describe processes in which crude petro-leum/products undergo only physical treatment. On the other hand, secondary processes describe processes in which petroleum/products undergo chemical transformations. 

In foregoing sections, we presented only the primary processes for petroleum treatment. It is important to note that all these processes are called primary processes because the petroleum only undergoes physical treatment. This means that chemical changes to the feed do not occur. All the processes we will describe in the sections of this chapter are referred to as secondary processes . This is intended to indicate that chemical changes of the feed occur during these treatments. 

Propane Asphalt. As noted above, cmde oils contain different quantities of residuum (Fig. 2) and, hence, asphalt. Asphalt is also a product of the propane deasphalting and fractionation process (5,6,21,22) which involves the precipitation of asphalt from a residuum stock by treatment with propane under controlled conditions. The petroleum charge stock is usually atmospheric-reduced residue from a primary distillation tower. 

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