When diesel is used as a reabsorbent, which component is absorbed more effectively?
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When diesel is used as a reabsorbent, which component is absorbed more effectively: C3, C4, or C5? What is the appropriate ratio between the depleted gas and diesel? I would appreciate guidance from the experts
Diesel is used as a lean absorbent oil, primarily for absorbing the absorbent oil carried away from the absorption tower, which consists of gasoline components
Diesel components are heavy, so less of them are carried away by gases; moreover, they can absorb the small amount of light gasoline components carried in the gases from the absorption tower, thereby reducing losses of liquid oil products
This post was last edited by Refiner on 2019-9-13 07:40. We operate a small catalytic cracking unit; our dry gas volume is usually around 500 standard cubic meters, and the amount of absorbent used is generally one ton……
Based on the principle of similarity and compatibility, diesel serves as an effective reabsorbent for absorbing gasoline components (C5), primarily those heavy fractions that cannot be absorbed by the absorption tower
According to the theory of similarity and compatibility, light diesel mainly absorbs gasoline carried in by the lean gas in the reabsorption tower; therefore, it is more effective at absorbing C5. As for C3 and C4, their absorption is determined primarily by the degree of desorption and the absorption efficiency of the tower. The ratio of lean air to diesel is determined according to theoretical values; for us it is around 1:4, with appropriate adjustments made through testing and sampling.
The similarity and compatibility between these substances result in good absorption by the gasoline components. The reason why diesel is used as the absorbent in the reabsorption tower is to capture the small amount of gasoline present in the dry gas; moreover, diesel is less volatile than gasoline
Our unit uses heavy diesel as the reabsorbent; how does that compare to light diesel?
From an economic perspective, the most cost-effective and optimal recovery option is cooled fractional light diesel; furthermore, it can be returned to the fractionation tower to serve as a partial reflux, thereby achieving the purpose of absorbing gasoline