Methanol Injection for Dry-out of Low Temp Pumps?

[Ahmedmabrouk]

What I know that Methanol is used for decreasing Hydrate formation temperature for Hydrocarbons.

However I can not understand why it is a preferred option from Vendors of Low Temp Pumps ( Ethylene for example ) to flush the pump with Methanol before purging it with Nitrogen.

If we are capable to reach a very low Dew Point ( -60 C ) by Nitrogen only. Why I should flush by Methanol?

 

[LittleInch]

I suspect it's the hygroscopic nature so can"suck" a fair amount of water up compared to a gas.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[georgeverghese]

May also be machine safety related. In case there still are liquid water pockets in the pump casing, and the dewpoint meter is not reading correctly, this water could freeze up during pump startup - chilldown, and damage the impellers on startup. On the other hand, even if there were liquid MeOH pockets left in the pump, this should not be a problem since MeOH freeze point is much lower than -70degC.