Why can’t upflow reactors completely replace fixed-bed reactors?
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This post was last edited by Rist on 2016-7-22 at 16:29. The reaction cycle for hydrotreating fixed-bed residue is generally limited by the pressure drop across the reactor’s bed; it often happens that the sulfur and carbon content in the tail oil are still within acceptable levels, but operation must be stopped and the catalyst replaced due to an excessively high pressure drop across the bed. Upflow reactors have lower pressure and can accommodate more metal. Why aren’t upflow reactors widely used? Moreover, the device used is only of the upflow type in the first reactor; why not use the upflow type in the other four reactors as well?
I am also very concerned about this issue, and among the first units for residue hydrogenation we have, none use a flow-type design.