Issues regarding the distillation section of the hydrorefining unit
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I was transferred to work at a new plant and received training at an old plant; I encountered a problem and would like to ask for guidance from seniors and instructors. The old plant has a diesel hydrotreating unit with a capacity of 2.6 million tons per year, and it’s a similar type of facility to one we have at the new plant. Apart from the fact that our feedstock includes coker gasoline, everything else is the same – even the process flows are almost identical – yet there are significant differences in the operating parameters of the distillation section. So why is there a difference in the fractionation part?
What are the changes in the operating parameters? With the addition of coker gasoline, the gas-phase load in the distillation section increases, so it’s normal for the operating parameters to change
Mainly, the operating pressure and temperature of the distillation tower change, and I would like to know the principles behind selecting these parameters, especially the tower pressure.
I checked some information on my own, but unfortunately there isn’t much available. Here is a brief summary: Selection of the distillation column pressure – From a cost perspective, a higher pressure results in higher expenses； 2. For the physical properties of the fractionated materials, a lower operating pressure is selected for those with a high boiling point, while a higher pressure is used for those with a low boiling point ； For components with high difficulty in separation during light recombination, a lower pressure is preferable. . . . I would appreciate more guidance from experts
If coke gas is blended in, it is quite normal for the distillation system to change. Check the tower top temperature, top pressure, and reflux rate. Also, with the flash point remaining unchanged, is the bottom temperature higher than before?