Why does blending reformate gasoline with catalytic cracking gasoline result in a uniform octane number distribution?
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The octane number of catalytic cracking gasoline decreases first and then increases, that is, as the fraction becomes heavier the octane number drops, whereas the octane number of reformed gasoline behaves in the opposite way – it decreases at first and then increases, meaning that as the fraction becomes heavier the octane number rises. When the two are combined, their octane numbers complement each other, resulting in a more uniform distribution. What are the components of the light and heavy fractions in catalytic cracking gasoline and reformed gasoline respectively, and why is there an opposite trend in their octane numbers?
The heavier the components in catalytic reforming, the higher their aromatic content, and thus the higher the octane number
Reformate gasoline has its octane number determined based on the amount of aromatics, while catalytic naphtha does not exhibit a pattern of high values at the beginning and low values at the end. This question is also incorrect; n-heptane has an octane rating of zero. The overall octane rating is not high. What truly harmonizes the mixture and raises its octane rating are methanol or ethanol, or a combination of methanol and isooctane, as well as certain mixed aromatics. Currently, for blending, catalytic cracked naphtha cannot be selected directly; it can be blended after hydrogenation, or through aromatization, or after being cut and then isomerized. A high aromatic potential in catalytic naphtha does not necessarily mean the presence of aromatics; aromatic potential refers to the amount that can be used in aromatization reactions to be converted into aromatics