8 replies to this topic

[farid.k]

Any one can share the experience on how to commision a methanol storage tank. Our methanol storage tank are in construction progress. Somebody asking on how to commission the tank and make sure the product will not offspec (as what happened before). Planning after finished the methanol tank construction, there will be a water jet cleaning inside the tank. After cleaning, tank will be preserved with n2 to aviod corrosion. After that then methanol will be transferred to the tank. Does the water jet and n2 preservation is good enough to prevent the product from offspect such as due to corrosion.

[ankur2061]

Hi,

 

I understand that your tank is Carbon Steel? You need to ensure that the Methanol stored does not contain any water (even trace levels) since water will over a period of time settle down and corrode the tank bottom. If you cannot ensure that, then you need to do what we had implemented in our plant i.e is to provide a corrosion resistant coating / paint for the tank. Such coatings are easily available and if properly applied will ensure corrosion protection for a long period.

 

Regards,

Ankur

[farid.k]

Yes sir..carbon steel..currently no coating inside. How about the cost for internal coating?

[ankur2061]

Farid,

 

You need to check this out locally with some of the renowned paints and coatings company such as PPG, Akzo Nobel, Kansai Paints, Asian Paints. They will tell you the right coating and the cost for coating.

 

Regards,

Ankur.

[farid.k]

In case methanol supplier can confirmed there will be no water content in methanol, doing water jetting and preserve with N2 u thing is good enough to prevent offspec especially during tank commissioning?

[DB Shah]

Dear Farid,

We operate Methanol tanks (MS) without coating. For shift tanks ( 100 MT fixed roof) the inspection frequency is once five year, but normally carried out every annual shut down. Main product tank (floating roof) is also of MS. Inspection frequency is once in ten year.

We do observe rust on inside wall of tanks.

 

As far as moisture is concerned, AA grade Methanol has 0.1 % wt limits of water content.

[breizh]

http://bsitalia.net/...1000/1391S.aspx

 

Farid,

You may consult this vendor for advice  .

Good luck

Breizh

[farid.k]

Dear sir, after empty out, do you preserve with nitrogen? What your opinion for new tank commissioning? Do we need water jetting inside or do chemical cleaning and n2 preservation prior to methanol storage?

[farid.k]

Thanks briezh for the info