We handle 800,000 tons of diesel hydroprocessing; when operating normally, the reflux tank at the top of the desulfurization tower is always full. Following technical upgrades, a line was added to send naphtha to the tank area, but the tanks there are external floating-roof tanks equipped with breather valves, which allows hydrogen sulfide to escape easily. in detail

Desulfurization tower? The top of the stripper, right? The additional naphtha line can be connected to the vent tank within the unit; after flashing, the fluid is pumped to the light dirty oil system. During startup, the tower top volume is only temporary.

The stripping column reflux tank often gets full – how should this be dealt with? ? ?

After it is started and completed. During normal production, the tanks are also full most of the time

A full reflux drum indicates an abundance of components at the top of the tower; consider the following adjustments: First, compare the component separation performance based on the design accuracy of the tower； II. Reducing the tower pressure can decrease the amount of vapor at the top of the tower ； III. Reduce the tower temperature, namely the temperature of the heat source at the bottom of the tower, the temperature at the tower inlet, or the temperature at the top of the tower; if the degree of vacuum separation is high, the heat source at the bottom of the tower can be reduced to decrease the gas-phase load ； IV. Under the observation of the pressure difference across the entire tower, if a high pressure difference is detected, the possibility of tower flooding should be considered; in such cases, reducing the heat source at the bottom of the tower can help decrease the gas-phase load. The distillation range analysis of the material in the reflux tank is used as a reference for adjustments, taking into account the fractionation degree of vacuum (the difference between the initial boiling point at the bottom of the tower and the final boiling point in the reflux tank at the top)

Increase the column pressure, reduce the amount of stripping steam, or lower the column feed temperature to decrease the amount of vapor at the top of the column.

Is the tower operated in full reflux? Is the recirculation pump insufficient? Try reducing the heat load at the bottom of the tower.

It’s full reflux; could it be that the temperature entering the tank is too low?

Based on the composition of the raw materials used in the design, check the current feeding situation

Similar problems have occurred; it’s necessary to first identify the cause of the problem and check everything step by step, with the raw materials being the first thing to consider.