A question about the residue hydrogenation unit?
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What is the typical required purity level for fresh hydrogen in residue hydroprocessing units? I asked the design institute about this, and they said it must be 99.9%. I’m not sure whether domestic residue hydroprocessing units currently require such a high purity level for fresh hydrogen; what is the reason for this high requirement?
Theoretically, it’s 99.9%, but in practice this isn’t necessary. Our company has used reformed hydrogen to lower the reaction temperature and to remove waste hydrogen in order to maintain the proper hydrogen partial pressure. High reaction temperatures require high-purity hydrogen.
The hydrogen in our factory doesn’t seem to be this highly pure
I’m not sure if what was said upstairs refers to the residue hydroprocessing unit.
Generally, the issue of hydrogen purity is resolved by removing waste hydrogen. The waste hydrogen emitted can be sent to other hydrogenation units for reuse
The purity requirement for the hydrogen used in residue hydroprocessing is 99.9%, as specified in the design requirements. Unless it is reforming hydrogen, a purity level lower than 99.9% has no significant impact. However, if hydrogen produced by other methods does not reach 99.9% purity, other impurities will enter the system; if these impurities are carbon monoxide and carbon dioxide, it becomes problematic as methanation reactions occur, resulting in rapid heat release and a risk of temperature spikes. Furthermore, the pressure requirements for residue hydrogenation are quite high; however, this pressure refers to the hydrogen partial pressure. If the purity of hydrogen is not 99.9%, it will inevitably lead to a decrease in the hydrogen partial pressure. To maintain this partial pressure, it would be necessary to increase the total pressure, which is clearly unreasonable.