Propane dehydrogenation (PDH) has recycled hydrogen
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Why does the UOP Oleflex propane dehydrogenation process require recycled hydrogen? It is a dehydrogenation reaction – shouldn’t adding the hydrogen gas produced during this reaction to the feed stream hinder the dehydrogenation process? And it seems that this process is similar to OCP, I guess, because both are UOP processes. In the OCP process, a SHP selective hydrogenation reaction is carried out first; the resulting mixture is then heated and sent to an OCP cracking reactor where it undergoes cracking to produce crude ethylene and propylene, which are subsequently sent to the distillation unit. In contrast, the Oleflex process involves feeding the material into a depropanization tower to remove C4 compounds, while the C3 compounds are sent to four series-connected heaters and reactors for processing, after which they go through compressors, dryers, and cold separation before undergoing a SHP selective hydrogenation reaction, followed by distillation. The reactors in the OCP process are regenerated on a periodic basis, whereas those in the Oleflex process are regenerated continuously. Both processes have control systems for regeneration, but in the Oleflex process, the hydrogen gas obtained from cold separation is used as recycled hydrogen and fed back into the feed stream. Doesn’t this increase the hydrogen partial pressure, which should hinder the reaction? I’m not sure about this. . .
As a heat carrier, without a hydrogen-driven cycle, wouldn’t coke form?
He already has a catalyst regeneration system, and it’s a dehydrogenation reaction – so adding hydrogen wouldn’t that hinder the reaction?
Reformation is also a dehydrogenation process, so doesn’t it also require hydrogen as recycle hydrogen? Dehydrogenation also requires hydrogen as the reaction environment; firstly, it enhances the catalyst’s activity under hydrogen-rich reaction conditions and prevents carbon deposition ； Second, the temperature and pressure of the reaction system are controlled through a hydrogen environment ； Third, remove the components that are detrimental to the dehydrogenation reaction process from the reaction system ； Fourth, hydrogen has a low molecular weight and low viscosity, which reduces operating costs by serving as a driving force for material mass transfer.
Mm-hmm, I’ve learned it, thanks~
I would like to ask what the volume ratio of UOP cyclohexane in the feed is, thank you
Hydrogen circulation: it facilitates catalysis, reduces coking and carbon deposition, thereby increasing catalyst activity. . . . .
Many reactions are like this: hydrogen circulation in hydrogenation, a 4:1 molar ratio of chloropropene
Mm-hmm, I’ve learned it, thanks~