Hydrocracked aviation fuel has a high dry point

Could the poster explain the distillation process? Is jet fuel extracted through a side stream or something else? There are many factors that affect the high dry point of aviation kerosene, such as changes in the properties of the feed to the tower and changes in the feed temperature ； Fluctuations in tower feed rate ； If a heating furnace is used to supply heat at the bottom of the tower, check whether the temperature at the furnace outlet is reasonable ； If there is backflow in the middle section of the tower, the amount of backflow in that section can be adjusted ； The tower pressure is low, while the top temperature of the tower is high ； If the jet fuel is drawn off via a side stream, check whether the amount drawn off is too large ； Additionally, the conversion rate in the reaction section is relatively low, with an excess of heavy components; failure to adjust the distillation process in a timely manner can also lead to this situation

Well, it’s a side-line extraction; a mid-stage reflux system for jet fuel is installed, and 0.5 Mpa(G) of steam is generated.

If nothing changes after distillation, it’s also possible to check whether there is any change in the type of oil

The dry point of a product is determined by the content of heavy components in the oil; a higher dry point indicates an increased amount of heavy components in the oil, meaning that the temperatures at the 90% point and the dry point are higher, which generally indicates a heavier composition in the oil. The dry point of the overhead product is high; it can be reduced by lowering the overhead temperature or increasing the overhead pressure. The dry point of the side-stream product is high; this can be addressed by reducing the amount of distillate from that side stream, thereby making the product lighter and lowering its dry point. It is also possible to reduce the dry point by lowering the temperature at which distillate is taken from that side stream. Additionally, the temperature or amount of distillate at one of the outlets on that side stream (or at the tower top) can be reduced, which in turn affects the temperature at which distillate is taken from that side stream and thus the product’s dry point.

Reduce the side-stream extraction volume, or lower the extraction temperature of that plate, and increase the mid-section reflux to reduce the heavy components

Operation issue. By appropriately increasing the mid-section reflux and reducing the extraction temperature of this plate, thereby reducing the amount of heavy components, the dry point of aviation fuel can be lowered.

Increase mid-stage reflux to reduce the heavy components