Glycol Regen PSV 1

[Renoyd]

Hello,

Has anyone sized a PSV on the glycol regen reboiler? What would be case here?

Rich glycol from the flash drum level control valve goes to the still column that opens to atmosphere with packing inside. The rich glycol going into the reboiler is heated by the directly fired firetube, and then goes to the stripping column and surge drum.

Will this be a fire, thermal, control valve failure case? Another thing is, since the still column is open to atmosphere, is a PSV necessary considering the packing inside the still column?

Thanks.

 

[MTChE]

I would hope you aren't venting to atmosphere. This is a huge new regulatory area for EPA and most glycol dehy's are required to send this gas to flare due to the B-TEX (Benzene Toluene Ethylbenzene Xylene) in the off gas.

Given that, you should size the PSV for 3 cases. 1 would be for the fire tube rupture with a failed open fuel gas regulator. 2nd would be thermal expansion. Third would be the flash tank pressure regulator failing open as it will back pressure through the line if the flare is undersized. The third case should be determining. You could consider a fire case but these glycol reboilers are generally not code vessels and cannot handle more than 5 psi.

 

[Renoyd]

Thank you MTChE for your response.
The design pressure of the reboiler is 15 Psig, and the PSV is set at 15 Psig too. Is that not normal based on your 5 psi statement?

"these glycol reboilers are generally not code vessels and cannot handle more than 5 psi" - Can this justify that the fire case is not necessary to be considered?