7 replies to this topic

[AhmadJAQF]

In our Naphtha hydrotreating unit the reaction should be exothermic reaction but in my case the RIT is lower than reactor outlet temperture, note that the sulfur coming out from the splitter (heavy naphtha) to downstream unit is within specefication. So it will roll out the catalyst deactivation? But what does it mean if exothermic reaction becomes endothermic ?

Edited by AhmadJAQF, 16 January 2017 - 10:01 AM.

[J_Leo]

What is RIT?

​How can exothermic reaction become endothermic?

[AhmadJAQF]

Reactor inlet temperture

[pavanayi]

If Reactor Outlet Temperature is greater than Reactor Inlet Temperature, then the reaction IS exothermic. 

 

If you still have doubts, post a sketch of the system with location of the Temperature Transmitters and Quench lines properly marked?

[J_Leo]

In your post " RIT is lower than reactor outlet temperature", so it is exothermic. Sulfur meets the spec. I don't see any problems with the catalyst or reactor.

[AhmadJAQF]

I'm sorry I might mistyped the following sentence, What I meant is that the RIT is higher than the Outlet of the reactor, and sulfur for down stream units is within spec, delta P of the reactor is not in increasing trend, what I suspect is that the top layer of the catalyst is deactivated where the remaining is taking the load? does this make sense?

[Dazzler]

Hi Ahmad,

 

Perhaps there is very little reaction compared to other heat losses, and lower than original design (inlet concentration and feed flow).  You mention the downstream sulphur concentration is ok, but how is the upstream or inlet sulphur concentration?  Perhaps the feed to the hydrotreater is very low sulphur currently so there is not enough reaction to create temperature rise?

 

Keep in mind that there are often other hydrotreater reactions that could occur such as for nitrogen compounds.

 

Please let us all know what you find out.

 

Darren

[AhmadJAQF]

Thank you dazzler for your valuable comment, yes actually the up stream sulfur concentration is low and thats why the temperture is not risen, your are absloulty right