gas phase reactor

[elowami]

in the gas phase hydrogenation reactor, is it possible to recycling the outlet of the reactor to reduce the inlet concentration of MAP (methyl acetylene & propadiene)?!

 

[georgeverghese]

Can see the benefit of this if it is possible to increase the MA and PD concentration in the recycle stream to be higher than that in the fresh feedstream to the hydrogenation reactor. This would increase the partial pressure of these components in the reactor feed, thus enabling a higher net conversion outside the recycle loop.

To concentrate these components, it would depend on the location of this reactor in the separation section, which you havent said ( is this reactor still on the bottoms exit from the de ethaniser ?)

 

[elowami]

I do not want to increase the concentration of MAPD in the inlet stream, i want to decrease it to improve the reactor run lengths.


I searched about the reason of poor run lengths of the C3 hydrogenation reactor, and I find that for Operating safety demands that the significant exotherms experienced in MAPD hydrogenation be tightly controlled. This is commonly achieved by recycling lead bed product in liquid phase two-bed systems in order to limit the MAPD content in fresh feed.

My inquiry, is it work with gas phase system?

thank you

 

[georgeverghese]

Okay, can see the reasoning for decreasing MAPD content for plants where reactor bed intercooling is a constraint.

Although the temp rise in gas phase would be much higher than that for liquid phase for a given conversion(for obvious reasons), my simple reasoning tells me the same should be possible for gas phase, assuming you have sufficient means for intercooling and with intercooling at shorter bed depths. Would guess overall net bed depth woould be more than in liquid phase in order to enable running at lower temps to allow for bigger control response margin for temperature runaway.

 

[elowami]

Thank you for your cooperation.