What to do if the side-product is too heavy

Take less heat from the lower part and more from the upper part.

1. Increase reaction depth. 2. Reduce the temperature at the bottom of the main tower, thereby indirectly lowering the temperature at which the side stream is extracted

Lower the temperature of the tower bottom or reduce the side-stream extraction volume

Increase the heat extraction ratio of the top circulation, adjust the reflux ratio in the lower and middle sections, and then it is also possible to slightly reduce the distillation outlet control valve.

I think this needs to be discussed on a case-by-case basis. First of all, I am referring to the hydrogenation process; I am just a novice assistant operator, and my views are merely my own personal opinion. In a distillation tower, there is generally top reflux, kerosene extraction, diesel extraction, gasoline extraction from the bottom (not present in some units), and bottom residue oil. You mentioned that the jet fuel is relatively heavy. Well, while following the methods suggested by those above is certainly an option, there are usually quite a few side streams involved. If steam injection at the bottom of the tower is adjusted hastily, I think it could have far-reaching consequences; this is what I mean by considering the situation on a case-by-case basis. First, if the kerosene has a high density and so does the diesel, it indicates that the temperature throughout the tower is low. It is possible to reduce the steam injection at the bottom of the tower or increase the temperature there; however, I am not aware of the specific parameters for such adjustments, nor do I know by how much the temperature should be changed. Secondly, if the jet fuel has a high density, diesel is acceptable; but if steam injection at the bottom of the tower is reduced rashly, the result will be a lower density of diesel. So my suggestion to you is to reduce the draw rate from the jet fuel side line. But ensuring the return flow of aviation fuel – similarly, I think the return flow has a significant impact on the entire tower. When the side line is closed for extraction, more oil will accumulate in the kerosene collector inside the tower, or the distillation time is increased to ensure better distillation of the oil, rather than allowing it to be extracted before it has been properly distilled. I think that with such adjustments, you only end up with less jet fuel production, but it has little impact on the overall balance of the tower.

That’s wrong; if the product is heavier, it means the tower temperature is high. What I said before was incorrect, but that’s roughly the idea.

This indicates that the product is heavy; reduce the extraction amount and increase the backflow volume