Does the tower top pressure affect the reflux ratio during PROII simulation? ?
Thread Content
Does the change in tower top pressure during simulation affect the value of the reflux ratio? If the reflux ratio changes significantly with the top pressure, is there some problem? I’m just starting to work with these and don’t understand them very well yet. Thank you all!
There should be no direct relationship between the reflux ratio and the top pressure of the tower. The reflux ratio of chemical distillation columns is determined by the operation of the plant and equipment costs, while that of oil refining distillation columns is determined by heat balance.
I am performing multi-component simulations by changing the top pressure, and I find that the reflux ratio changes significantly. I’m not sure where the error lies; I would appreciate some advice……
This is relevant in such situations: if the draw rate of the top product remains essentially unchanged, and if the load on the reboiler increases, thereby increasing the gas-phase load within the column and raising the top pressure, more reflux is required, which means an increase in the reflux ratio.
Pressure has little to do with the reflux ratio, but it is closely related to the bottom temperature of the tower; generally, the higher the pressure, the higher the bottom temperature, and this is particularly evident when simulating vacuum towers. Additionally, pressure is also related to the bottom load; as for the exact relationship, conducting more simulations will help to figure it out
For the same distillation separation system, when the operating pressure increases (it depends on by how much it increases). . . ), generally this will reduce the relative volatility between the components (meaning that the number of theoretical plates will decrease); therefore, the reflux ratio needs to be increased appropriately in order to maintain the original separation accuracy. This is just a general statement; some systems may not be effective.