If catalytic cracking is changed from a recycle operation to a single-pass conversion, how will the gasoline density change?
Thread Content
By changing catalytic cracking from a recycle operation to a single-pass conversion and raising the reaction temperature, the octane rating of gasoline increases. Does the density of gasoline increase or decrease?
As the octane rating of gasoline increases, does its density increase as well?
The density of gasoline to which reprocessed oil is not added should decrease, because reprocessed oil contains many polyyclic compounds; when added to gasoline, these compounds increase the aromatic content in gasoline, thereby raising its density. In fact, the density of catalytic gasoline is also related to the operation of the distillation tower; a lower control level for the dry point of the gasoline results in a lower density as well ； It is also somewhat related to the operation of the stabilizer tower; with a higher vapor pressure, the density should be lower as well.
I guess it’s rising, because the reaction conditions become more stringent; the aromatic content in gasoline increases, its octane rating rises, and its density increases as well.