The crude vapor and light diesel fractions in the fractionation tower overlap; how should this be adjusted?

Increase temperature, or reduce pressure; increase backflow

Just strictly control the dry point of the crude vapor and the initial boiling point of the diesel as per your requirements~~~~~

I agree with the view from the third floor; it’s possible that you didn’t manage things properly

From my experience, it is the properties of the tray and the feed oil that determine whether there is overlap. The main operational focus is on controlling the dry point of gasoline and ensuring that the flash point of diesel meets the required standards; efforts are made to increase the distillation temperature of diesel, with limits set for the 95% cut of diesel and the dry point of gasoline.

This situation reflects an issue with the precision of distillation. The distillation accuracy is related to the number of trays, the amount of reflux, the properties of the feed material, and the structural design of the trays. If the situation described by the poster occurs frequently, it may be possible to solve the problem by increasing the number of trays and raising the reflux rate, or by checking whether the steam supply to the reaction and distillation systems is excessive.

Check whether there is a problem with the tray; for example, if salt deposition occurs, it becomes impossible to make adjustments, and the issue can only be resolved by shutting down the operation. If the equipment is in good condition, adjustments should be made at the operational level to control the dry point of gasoline and the initial boiling point of diesel

Increase the operating load of the tower and raise the temperature for reflux

It is normal for the crude steam and diesel to overlap by about 10 degrees during cutting. . . The separation and cutting of petroleum fractions is a form of separating mixtures, wherein one mixture is transformed into another mixture. . . Of course, in a properly designed and operated fractionating tower, it is quite common to encounter situations where Enneberg distillation results in an empty column, with gasoline boiling at 190 degrees and diesel having its initial boiling point at 210 degrees. . . But this does not mean there is a clear separation at its true boiling point; the mixture only has a boiling range or average boiling point. . . In terms of operational adjustments, an effective measure to increase the degree of vacuum removal in crude steam and diesel is to increase the flow rate of the steam used for diesel stripping; under unchanged other conditions, the degree of vacuum removal will increase rapidly as a result. . . In terms of design, this can only be achieved by increasing the number of distillation plates through which diesel is extracted into the gasoline section at the top of the tower. Once the objective conditions are determined, the means to increase the degree of vacuum removal involve adjusting the diesel extraction temperature, the blowing air in the side strip stripper, as well as the top temperature of the tower. One can adjust these parameters based on the characteristics of their own installation, taking into account the factors I’ve mentioned; surely they will be able to develop their own approaches over time. . . Everyone is welcome to engage in more communication here. . . :lol

We keep the bulk density at around 185. The initial distillation point of light wood is 170; it’s indeed difficult to control the product quality. Is there any good method?

It is quite normal for the crude vapor and light diesel fractions in a fractionation tower to overlap; this overlap refers to Enthalpy distillation. If overlap occurs in boiling point distillation, then it is necessary to check whether there are issues with the design of the tower trays. The dry point control for gasoline is set at a lower level; there is significant overlap in the Enneagram distillation data for the crude vapor and light diesel fractions. By increasing the temperature at which diesel is extracted, as well as by setting upper limits for the 95% diesel content and the gasoline dry point, and by increasing the amount of stripping steam used in the stripping tower, it is possible to reduce this overlap

1. Increase the top temperature of the tower, control the dry point of gasoline and aim to keep it as close to the upper limit as possible. 2. Ensure proper separation between the heavy recycle oil and diesel. 3. Control the extraction temperature and liquid level in the diesel stripping tower appropriately. 4. Slightly increase the amount of steam used for stripping in the diesel stripping tower. 5. Control the amount of reflux flow or the temperature of the fluid returning to the tower appropriately

The properties of the tray and the crude oil determine whether there is overlap. The main operational focus is on controlling the dry point of gasoline and ensuring that the flash point of diesel meets the required standards; efforts are made to increase the distillation temperature of diesel, with limits set for the 95% cut of diesel and the dry point of gasoline. :handshake

I think the solution to this problem should be to adjust the cold and hot refluxes of the side-line air lift tower. The specific adjustment methods should be outlined in the operating procedures

Some of the contents in the operating procedures are copied from other manufacturers’ documents, and they may not be suitable for one’s own equipment