In the catalytic cracking reaction unit, how is the reaction temperature controlled? What are the factors by which reaction temperature affects the device?

The reaction temperature is generally controlled by adjusting the catalyst circulation rates of the two reactors and the temperature of the reaction feed. Increasing the reaction temperature raises the reaction rate. The activation energy for the catalytic cracking reaction is approximately 41.8–125.4 kJ/mol; for every 10%-20% increase in temperature, the reaction rate increases by about 10%-20%. As the reaction temperature increases, the rate of thermal cracking reaction increases relatively rapidly. When the reaction temperature is raised to very high levels, thermal cracking reactions become increasingly important; as a result, the products exhibit characteristics of thermal cracking products, such as an increase in C1 and C2 compounds in the gases and an increased degree of unsaturation in the products. It should be noted that even at such high temperatures, the main reaction is still catalytic cracking rather than thermal cracking. As the reaction temperature increases, the reaction rate of gasoline → gas increases the most, followed by the reaction of feedstock → gasoline, while the reaction rate of feedstock → coke increases the least. Therefore, as the reaction temperature increases, if the conversion rate remains unchanged, the gasoline yield decreases, the gas yield increases, while the coke yield drops slightly. As the reaction temperature increases, the decomposition reactions (which produce olefins) and aromatization reactions increase more rapidly than the hydrogen transfer reactions; as a result, the content of olefins and aromatics in gasoline rises, and the octane rating of gasoline improves.

That’s right; we increased the reaction temperature during the operation, and as a result the volume of dry gas was particularly high during that period