What factors influence the octane number of catalytic gasoline? What are the specific influencing results?

This question is too general. There are many factors that affect the octane number of gasoline, including catalyst activity, reaction temperature, reaction pressure and raw material properties. During operation, adjust the operating conditions appropriately according to the situation. For details, please refer to the relevant chapters in the book "Fluid Catalytic Cracking".

1. The process used in the catalytic device 2. The reaction temperature

　　The octane number of gasoline is closely related to the monomer hydrocarbon composition in gasoline. The octane number of naphthenes is higher than that of straight-chain alkanes. The octane number of straight-chain alkanes is higher than that of long-chain alkanes. The octane number of isoparaffins is higher than that of normal alkanes.； For the same family of hydrocarbons, the smaller the molecular weight. The lower the boiling point, the higher the octane number. 　　The main chemical reactions that occur during the catalytic cracking reaction are cracking reaction, isomerization reaction, aromatization reaction and hydrogen transfer reaction. In terms of reaction mechanism, improving the octane number of FCC gasoline means comprehensively optimizing raw materials, catalysts, operating conditions and equipment structures. Right now: ① Cracking paraffinic hydrocarbons into olefins ； ②Cracking naphthenes into olefins or dehydroaromatization ； ③ Chain scission or dealkylation of aromatic hydrocarbons with alkyl side chains ； ④Isomerize or aromatize olefins ； ⑤ Suppress the hydrogen transfer reaction speed and avoid the re-saturation of cracked olefins, so that the reaction produces more monomer hydrocarbons such as aromatics, olefins and isomeric hydrocarbons that increase the octane number of FCC gasoline.

1. The paraffins in the raw materials will reduce the octane number of gasoline, while naphthenes and aromatic hydrocarbons can increase the octane number of gasoline; the crude gasoline in the raw materials will also reduce the octane number of the product. 2. The catalyst activity is high, and the hydrogen transfer activity is also increased accordingly. Therefore, the olefin content in the product is relatively reduced, resulting in a decrease in the gasoline octane number. 3. Shortening the reaction time can reduce secondary reactions. Olefin saturation is a secondary reaction. Therefore, shortening the contact time can produce high-quality olefin-containing gasoline and increase the octane number. 4. When the reaction temperature is constant, the greater the conversion rate, the higher the gasoline octane number. When the conversion rate is constant, the octane number of gasoline increases with the increase of reaction temperature. Because as the reaction temperature increases, the ratio of the hydrogen transfer rate and the cracking rate decreases, and the olefin content increases with the increase in temperature. 5. Increasing the agent-to-oil ratio or reducing the air velocity increases the reaction intensity and increases the cracking conversion rate. As the conversion rate increases, both RON and MON increase linearly. 6. When other operating parameters remain unchanged and the regenerated catalyst content is increased from 0.07% to 0.5%, the conversion rate decreases, but the gasoline octane number increases. For every 0.1% increase in the carbon content of the regeneration agent, the gasoline RON increases by approximately 0.5. 7. The butane content in gasoline directly affects the vapor pressure of gasoline. Both MON and RON of gasoline increase with the increase of vapor pressure, among which RON increases more significantly. Butane not only has high RON and MON itself, but also has a high blended octane number. For every 10Kpa increase in gasoline vapor pressure, RON can increase by 0.9.