H2 purification Pressure Swing Adsorption

[0707]

We are just building a Rog project for hYdrogen purification, for that reason we would liKe to know from forum`s experience what are the main expectable corrosion problems related with this process unit, and how to monitorize the corrosion.

Tanks for the emphaty

Lm

 

[whylie]

Hi 0707,

Can u explain waht is ROG,the common hydrogen purification system is PSA (Pressure Swing Absorption),supplied by UOP,LINDE, SYNETIX..etc

Regards,

Whylie

 

[0707]

Our hydrogen unit PSA is being commisionated and was supllied by Lind

Regaerds

LM

 

[dimitris]

Hi everybody,
To be able to comment on any potential corrosion problems and methods to monitor them we need to know the working conditions of the unit i.e. feed and product composition, waste gas composition, temp and pressure variations on so on. We operate a UOP PSA H2 purification unit, with the add on N2 purification and repressurization step and corrosion is the last thing we worry about. All piping is CS with minimum corrosion allowances, and everything works fine for over 15 years now.
The main thing one has to worry about in such units is fatigue caused crakcs on welds, due to the continuous cycling load of the unit
Regards,
Dimitris

 

[rhysfast]

ROG stands for "Refinary Off Gas". This type of PSA feed gas normally comes for a CCR or Hydrocracker. It is mostly hydrocarbons with no light components such as CO or N2.

The only time you normally have to worry about corrosion is if there is any H2S and H2O (gas)in the feed stream. Anything less than 50 ppm is probably OK, after that you have to take it into account. Because it is easily adsorbed its vol % increases at the bottom of the vessel and the tailgas system. If there is any H2O it can also condensate in the tailgas system during blowdown. The combination of H2S and water is corrosive.