What Happens to Methanol When It Boils

[withak36301]

I am working on an API 2000 fire relief analysis for a methanol tank. If a fire occurred outside the tank, the heat would travel through the tank wall and transfer into the liquid methane inside the tank, eventually causing the methanol to boil. I need to know if methanol vapor would vent or if the methanol would break down into CO2 and H2O and CO2 and steam would vent.

 

[Latexman]

Methanol would vent.



Good luck,
Latexman

Technically, the glass is always full - 1/2 air and 1/2 water.

 

[withak36301]

Thank you, sir!

 

[bimr]

Review these papers:

http://www.google.com/url?sa=t&rct=...d=12&cad=rja&uact=8&ved=0CFcQFjAL&url=http://

http://www.methanolfuels.org/wp-con...vIgKAH&usg=AFQjCNEMnX4SKQcFWb825SLzGGga8lLccA

http://www.csb.gov/assets/1/19/bethune_final_report.pdf

http://www.methanol.org/getattachme...icAboveGroundTankStorageMethanol-(1).pdf.aspx

 

[georgeverghese]

Methanol NBP=65degC, flash point=12degC

So the chain of events you may be alluding to is

External fire - methanol in the tank exceeds 12degC - potential for fire inside the tank leading to combustion products

To break this chain of events, the methanol tank should always be N2 blanketed to exclude O2. PSV and control vents from this tank should be safely disposed off, and should not result in HSE concerns for operators also.

Methanol is hygroscopic, and slowly oxidises to formic acid on continued exposure to air- and that is another reason to have the tank N2 blanketed.