Effect of reaction temperature
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Increasing the temperature of the catalytic reaction allows for an increase in the reagent-to-oil ratio as well as the preheating temperature of the feedstock. What are the differences between these two adjustments in terms of the product distribution, especially regarding the composition of dry gas, coke, and liquefied gas? Thank you!
By increasing the preheating temperature of the feedstock, in order to maintain the reaction temperature constant, it is necessary to reduce the position of the regeneration slide valve; as a result, the fuel-to-oil ratio decreases. Increasing the oil-to-agent ratio leads to an increase in active centers, intensifies the reaction, enhances the degree of conversion, and raises the yields of gases (including liquid hydrocarbons), gasoline, and coke.
Reply to 2# dugutianzuo5: Could you be more detailed? What is the extent of the change in the distribution of each product in both cases, and why does coking increase? Thank you!
An increased oil-to-agent ratio and shorter stripping time result in a large amount of raw coke.
Reply to 3# yuanweiniuniu: Does a high number of active centers lead to a high conversion rate? Large molecules are cracked into smaller ones, and polycycles are condensed into fused rings to form coke； Additionally, with a large catalyst dosage, the stripping time is reduced; less oil and gas are stripped from the catalyst, resulting in more coke
This is the essential difference between thermal cracking and catalytic cracking; you can see it by looking at the operation guidelines.
Without considering the stripping effect, how does the amount of coke formed change as the reaction temperature increases?