Why does the gasoline yield decrease as the reaction temperature increases?
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Why does the gasoline yield decrease as the reaction temperature increases?
Generally, within the normal range, as the reaction temperature increases, the yields of gasoline and diesel rise; there is a peak in these yields, with both values increasing before decreasing, and the peak for diesel occurs earlier than that for gasoline. A relatively high reverse temperature will increase gasoline yield. The higher the reaction temperature, the higher the conversion rate; however, the yields of coke and gas also increase (as the ultimate products of the reaction are gas and coke), so the yield of gasoline decreases. Conversion rate = Gas + Gasoline + Coke/Feed amount. Why isn’t it considered diesel? Because the catalytic cracking reaction was still in the experimental stage, that is, in its early phase, diesel was used as the raw material. This post was last edited by wdepei on 2009-3-21 12:15]
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 achieved conversion rate remains unchanged, the gasoline yield decreases, the gas yield increases, while the coke yield decreases
There is a limit to increasing the reaction temperature; too high a temperature will result in excessive gas and coke formation
Since it is a sequential reaction, the reaction rate of gasoline → gas increases the most, so the amount of gas increases while the amount of gasoline decreases
The catalytic reaction is a parallel-sequential reaction, with gasoline and coke as the final products. Normally, we say that a high reaction temperature corresponds to the gasoline scheme. But there are limits to this. This requires a comprehensive analysis based on the properties of the raw materials, the activity of the catalyst, etc., in order to make adjustments and achieve maximum efficiency.
For reformed gasoline, an increase in reaction temperature accelerates the reaction rate; the hydrogenation reaction becomes more intense, resulting in a decrease in yield.