Dear All

We have a spent Caustic storage tank in Our Effluent Treatment Plant. It is presently an open tank. To minimise the obnoxious vapour generated from the storage tank we are planning to cover it. We had tried FRP sheet to cover it, but during some maintenance work it caught fire. Is there any other option instead of FRP. What material do you use in your refinery?

Thanks and regards
Rabindra Patel
Mathura Refinery
Indian Oil Corporation
Mathura, India

Rabindra, I believe that you will have better results if you post your question in the refinery forum here. This is off subject for this forum. Good luck.

I am going to suggest that they move it for you.

Rabindra:

You don’t give us any specifics – except as to the results of a failed attempt to deal with a problem. You only give us generalities.

• What is the size of the tank in question?
• What is the material of construction (I have to presume carbon steel, but is it FRP?)
• What is the strength of the Caustic in the tank? Presumably it is Sodium Hydroxide.
• What is the composition of the vapors emitted from the tank and their approximate flow rate?
• In what part of your refinery (presumably this is a refinery) is the tank located?

Open tanks, as a general rule, are never permitted to exist in a refinery operation. This is an invitation to contamination, a maintenance and repair hazard, a potential environmental contamination, etc., etc., Why your operations tolerate such a situation is known to you. I strongly recommend you design and install a permanent roof on the tank – as would be expected in almost all other operations. Depending on the size, you can employ API Standard 650 (11th Edition) to design the correct carbon steel roof. See Section 5 and also refer to the sample calculations given. Also, use API 2000 to design the correct venting and relief system that you require. We also don’t know anything about the work and operations scope of the tank so we can only give generalities.