Octane material factor

The liquids output represents a combination of transportation and utility fuels as summarized in Table III. All of the naphtha is to be reformed on site to produce a very high aromatic stock. With an exceptional octane blending value, this stream will find ready application as a gasoline component, but perhaps more important, it is also a source of substantial quantities of petrochemical raw materials as noted in Table IV. The potential yield of BTX and phenolics along with the low boiling paraffins should make such a plant an important factor in the future supply picture for these materials. 

Gasoline selectivity and octane performance are functions of not only unit cell size but also factors such as extraframework material and spatial distribution of active sites. These factors influence... 

Typical reforming catalyst are bifunctional, with a metal function (Pt, Pt-Re, Pt-Ir, etc] and an acid function (chlorided alumina). During operation, along with the desired reactions, the deposition of carbonaceous material occurs over the metal and the acid sites (1). This coke is the most important factor affecting the lifetime of the catalyst. As a consequence of this deposition, the reactor temperature must be raised to maintain the same octane number In the reformate. The partially deactivated catalyst has different selectivity than the fresh one. This suggests that the coke is deposited to a different extent on the metallic and on the acid function, and that the more demanding reactions are preferentially deactivated (2). 

All compounds that contain PO4, CO3, SO3, and SO2 are insoluble, except for those of family 1 on the periodic table and NH4. Most hydrocarbon compounds are not soluble, such as gasoline, diesel fuel, pentane, octane, etc. Compounds that are polar, such as the alcohols, ketones, aldehydes, esters, and organic acids, are soluble in water. Several factors affect the solubility of a material. One is particle size the smaller the particle, the more surface area that is exposed to the solvent therefore, more dissolving takes place over a shorter period of time. Higher temperatures usually increase the rate of dissolving. The term miscibility is often used synonymously with the term solubihty. Solubility is also related to polarity insofar as those materials that are polar are generally soluble in other polar materials. Miscibility, solubility, polarity, and mixtures will be discussed as they pertain to specific chemicals and families of chemicals in other chapters of this book. 

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