Do methanol tanks need to be covered from sun? 1

On methanol tanks you should be aware of voc emissions, methanol being a very volatile product if air goes into the tank can create explosive mixtures and put in danger the installation. For this reason methanol tanks should have a positive nitrogen blanketing pressure over the methanol liquid vapour space to avoid air in and voc emissions out.

Go to the thread bellow for a discussion on this subject


thread798-190851

luismarques

Luismarques,

I have not read the attached link yet, but I plan to read it shortly.

This tank will have closed vent system so I would not expect for air to get into the tank. Would we still need this nitrogen blanket over the methanol?

Let me go read your link and see if I can get more answers.

Thanks,
Chris

Just paint it white. You'll need a presuure relief and a pressure makeup system. If you want to do it right, add a smaller chiller system to the vent to recover methanol.

dcastro got it.

DCasto,

I am not 100% following your response. When you say we will need a pressure relief and a pressure make up system. I assume you are suggesting to keep positive pressure above the methanol in the tank? Does the gas above the methanol need to be nitrogen or can it be just compressed air? Do you have some links or more information you can send me on what you propose? I have not heard of using a chiller system at the vent, do you do this to reduce VOC or to increase safety? Or both?

Thanks,
Chris

You'll need a few ounces of positive pressure. As the tank empties (either by removal or cooling), you will need to replace that volume with something. And just the opposite, when it is being filled, you will have to remove vapors.

A mixture of methanol and air is what powers 5,000 HP dragsters, I don't think you want that mixture. Also Air has O2 and water which will rust out the tank very quickly. That leaves something like N2. In the old days we used natural gas because it has no O2, no water and a 100% mixture of it and methanol will not explode.


These are the first two on a list of VOC recovery systems. Gas stations use these systems on small scales.

Removing the methanol can be economic especilally when tank is used a lot or in etreme temperature changes. It's also good for the environment and safety.