Mothballing of TEG dehydration unit

[Grani]

In my project we will have to isolate and mothball two TEG dehydration units (contactor & regeneration) while the up- and downstream facilities are modified. Expected duration is 6 to 9 months.
As the units are from 1982 I fear that it will be impossible to bring the units back in service, if left cold and without circulation under N2 blanket.
Hence, I am considering to isolate the units from the hydrocarbon system, establish a nitrogen blanket, keep the temperature at 30-40 deg. C and to keep the glycol pumps running at reduced rates.
Do you have any experience to share on this topic?

 

[rustbuster]

You are on the right track, a good reference is MTI publication 34, Guidelines for the Mothballing of Process Plants

 

[maddocks]

I would continue to
- check glycol pH,
- and possibly get some diesel or inhibited condensate into the separator section of the contactor.
- be prepared to do a fluid end pump service when you come back on line with operating pressure
- do periodic glycol analyses every couple of months just to watch for trends.