h2 unit prereformer catalyst regeneration

[skvishwa]

i am working in topsoe hydrogen plant .
the prereormer reactor is currently operating at 93% Z-90 value,and we are going to replace the catalyst soon.
has anyone any idea about regenration of prereformer catalyst?
has anyone carried out it?
any information is welcome.
regards,
santosh

 

[JBando]

Hi Santosh:

As far as I know, you can not regenerate Pre-Reformer catalyst.
You may contact catalyst vendors about the regeneration. as this catalyst is an expensive one, it will nice to regen. Just out of curiosity, what is the catalyst life you are getting, and what is the SV you are using? Is your HDS working properly?

Thanks,

Jay
jbando@ureach.com

 

[skvishwa]

we have been using prereformer for last 4 years,it is the longest running (since first start up)topsoe prereformer catalyst (iocl-india-panipat).
as regards hds we have not faced any problems with it.actually the sulphur level in the feed itself which is light naphtha from hydrocracker is very low.
santosh

 

[JBando]

I think 4 years is a good life as such. Ofcourse, depending on you GHSV ( are you in the range of 15000 Hr^-1?)
Well, one of the benefits of pre-reformer is to reduce S/C ratio (at least I would like to claim that way), besides utilizing lost energy in the convection section. I fail to understand the explanation of higher S/C. Are you running less than 2.12 S/C?

It might be that you just need to change the catalyst.

Thanks,

Jay Bando
jbando@ureach.com

 

[skvishwa]

yes, we are in that range of ghsv .the s/c ratio we operate at is 2.5-2.6.it is as per the topsoe guidelines .
how low can we operate for a feed naphtha c5-90 cut?
we have opeated the plant at 2.3 s/c for quite some time when we facing high dp problem in reformer.
could that be a problem?
but why can't we regenrate the prereformer catalyst?
we do not expect any metals in naphtha we will permanantly blck the catalyst and all the upstream treating ensures that the deactivation can be either by carbon deposition or by sintering.if sintering is the case then not much can be doen about it but for the carbon case it can be burnt off the way we do it for reformer catalyst.
santosh

 

[skvishwa]

has anyone tried to operate the h2 plant with low final boiling point of feed naphtha to elongate the run length of rpereformer when it is becoming limiting?
santosh